Sample records for t-cell responses compared

  1. Human T cell responses to Dengue and Zika virus infection compared to Dengue/Zika coinfection.

    PubMed

    Badolato-Corrêa, Jessica; Sánchez-Arcila, Juan Camilo; Alves de Souza, Thiara Manuele; Santos Barbosa, Luciana; Conrado Guerra Nunes, Priscila; da Rocha Queiroz Lima, Monique; Gandini, Mariana; Bispo de Filippis, Ana Maria; Venâncio da Cunha, Rivaldo; Leal de Azeredo, Elzinandes; de-Oliveira-Pinto, Luzia Maria

    2018-06-01

    Zika virus (ZIKV) and dengue virus (DENV) co-circulated during latest outbreaks in Brazil, hence, it is important to evaluate the host cross-reactive immune responses to these viruses. So far, little is known about human T cell responses to ZIKV and no reports detail adaptive immune responses during DENV/ZIKV coinfection. Here, we studied T cells responses in well-characterized groups of DENV, ZIKV, or DENV/ZIKV infected patients and DENV-exposed healthy donors. We evaluated chemokine receptors expression and single/multifunctional frequencies of IFNγ, TNF, and IL2-producing T cells during these infections. Even without antigenic stimulation, it was possible to detect chemokine receptors and IFNγ, TNF, and IL2-producing T cells from all individuals by flow cytometry. Additionally, PBMCs' IFNγ response to DENV NS1 protein and to polyclonal stimuli was evaluated by ELISPOT. DENV and ZIKV infections and DENV/ZIKV coinfections similarly induced expression of CCR5, CX3CR1, and CXCR3 on CD4 and CD8 T cells. DENV/ZIKV coinfection decreased the ability of CD4 + T cells to produce IFNγ + , TNF + , TNF  +  IFNγ + , and TNF  +  IL2 + , compared to DENV and ZIKV infections. A higher magnitude of IFNγ response to DENV NS1 was found in donors with a history of dengue infection, however, a hyporesponsiveness was found in acute DENV, ZIKV, or DENV/ZIKV infected patients, even previously infected with DENV. Therefore, we emphasize the potential impact of coinfection on the immune response from human hosts, mainly in areas where DENV and ZIKV cocirculate. © 2017 The Authors. Immunity, Inflammation and Disease Published by John Wiley & Sons Ltd.

  2. Antigen specific T-cell responses against tumor antigens are controlled by regulatory T cells in patients with prostate cancer.

    PubMed

    Hadaschik, Boris; Su, Yun; Huter, Eva; Ge, Yingzi; Hohenfellner, Markus; Beckhove, Philipp

    2012-04-01

    Immunotherapy is a promising approach in an effort to control castration resistant prostate cancer. We characterized tumor antigen reactive T cells in patients with prostate cancer and analyzed the suppression of antitumor responses by regulatory T cells. Peripheral blood samples were collected from 57 patients with histologically confirmed prostate cancer, 8 patients with benign prostatic hyperplasia and 16 healthy donors. Peripheral blood mononuclear cells were isolated and antigen specific interferon-γ secretion of isolated T cells was analyzed by enzyme-linked immunospot assay. T cells were functionally characterized and T-cell responses before and after regulatory T-cell depletion were compared. As test tumor antigens, a panel of 11 long synthetic peptides derived from a total of 8 tumor antigens was used, including prostate specific antigen and prostatic acid phosphatase. In patients with prostate cancer we noted a 74.5% effector T-cell response rate compared with only 25% in patients with benign prostatic hyperplasia and 31% in healthy donors. In most patients 2 or 3 tumor antigens were recognized. Comparing various disease stages there was a clear increase in the immune response against prostate specific antigens from intermediate to high risk tumors and castration resistant disease. Regulatory T-cell depletion led to a significant boost in effector T-cell responses against prostate specific antigen and prostatic acid phosphatase. Tumor specific effector T cells were detected in most patients with prostate cancer, especially those with castration resistant prostate cancer. Since effector T-cell responses against prostate specific antigens strongly increased after regulatory T-cell depletion, our results indicate that immunotherapy efficacy could be enhanced by decreasing regulatory T cells. Copyright © 2012 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  3. Suppression of pro-inflammatory T-cell responses by human mesothelial cells.

    PubMed

    Lin, Chan-Yu; Kift-Morgan, Ann; Moser, Bernhard; Topley, Nicholas; Eberl, Matthias

    2013-07-01

    Human γδ T cells reactive to the microbial metabolite (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMB-PP) contribute to acute inflammatory responses. We have previously shown that peritoneal dialysis (PD)-associated infections with HMB-PP producing bacteria are characterized by locally elevated γδ T-cell frequencies and poorer clinical outcome compared with HMB-PP negative infections, implying that γδ T cells may be of diagnostic, prognostic and therapeutic value in acute disease. The regulation by local tissue cells of these potentially detrimental γδ T-cell responses remains to be investigated. Freshly isolated γδ or αβ T cells were cultured with primary mesothelial cells derived from omental tissue, or with mesothelial cell-conditioned medium. Stimulation of cytokine production and proliferation by peripheral T cells in response to HMB-PP or CD3/CD28 beads was assessed by flow cytometry. Resting mesothelial cells were potent suppressors of pro-inflammatory γδ T cells as well as CD4+ and CD8+ αβ T cells. The suppression of γδ T-cell responses was mediated through soluble factors released by primary mesothelial cells and could be counteracted by SB-431542, a selective inhibitor of TGF-β and activin signalling. Recombinant TGF-β1 but not activin-A mimicked the mesothelial cell-mediated suppression of γδ T-cell responses to HMB-PP. The present findings indicate an important regulatory function of mesothelial cells in the peritoneal cavity by dampening pro-inflammatory T-cell responses, which may help preserve the tissue integrity of the peritoneal membrane in the steady state and possibly during the resolution of acute inflammation.

  4. Determinants of public T cell responses.

    PubMed

    Li, Hanjie; Ye, Congting; Ji, Guoli; Han, Jiahuai

    2012-01-01

    Historically, sharing T cell receptors (TCRs) between individuals has been speculated to be impossible, considering the dramatic discrepancy between the potential enormity of the TCR repertoire and the limited number of T cells generated in each individual. However, public T cell response, in which multiple individuals share identical TCRs in responding to a same antigenic epitope, has been extensively observed in a variety of immune responses across many species. Public T cell responses enable individuals within a population to generate similar antigen-specific TCRs against certain ubiquitous pathogens, leading to favorable biological outcomes. However, the relatively concentrated feature of TCR repertoire may limit T cell response in a population to some other pathogens. It could be a great benefit for human health if public T cell responses can be manipulated. Therefore, the mechanistic insight of public TCR generation is important to know. Recently, high-throughput DNA sequencing has revolutionized the study of immune receptor repertoires, which allows a much better understanding of the factors that determine the overlap of TCR repertoire among individuals. Here, we summarize the current knowledge on public T-cell response and discuss future challenges in this field.

  5. Activation requirements and responses to TLR ligands in human CD4+ T cells: comparison of two T cell isolation techniques.

    PubMed

    Lancioni, Christina L; Thomas, Jeremy J; Rojas, Roxana E

    2009-05-15

    Direct regulation of T cell function by microbial ligands through Toll-like receptors (TLR) is an emerging area of T cell biology. Currently either immunomagnetic cell sorting (IMACS) or fluorescence-activated cell sorting (FACS), are utilized to isolate T-cell subsets for such studies. However, it is unknown to what extent differences in T cell purity between these isolation techniques influence T cell functional assays. We compared the purity, response to mitogen, activation requirements, and response to TLR ligands between human CD4(+) T cells isolated either by IMACS (IMACS-CD4(+)) or by IMACS followed by FACS (IMACS/FACS-CD4(+)). As expected, IMACS-CD4(+) were less pure than IMACS/FACS-CD4(+) (92.5%+/-1.4% versus 99.7%+/-0.2%, respectively). Consequently, IMACS-CD4(+) proliferated and produced cytokines in response to mitogen alone and had lower activation requirements compared to IMACS/FACS-CD4(+). In addition IMACS-CD4(+) but not IMACS/FACS-CD4(+) responses were upregulated by the TLR-4 ligand lipopolysaccharide (LPS). On the other hand, TLR-2 and TLR-5 engagement induced costimulation in both IMACS-CD4(+) and highly purified IMACS-/FACS-CD4(+). Altogether these results indicate that small differences in cell purity can significantly alter T cell responses to TLR ligands. This study stresses the importance of a stringent purification method when investigating the role of microbial ligands in T cell function.

  6. T-cell proliferative responses following sepsis in neonatal rats.

    PubMed

    Dallal, Ousama; Ravindranath, Thyyar M; Choudhry, Mashkoor A; Kohn, Annamarie; Muraskas, Jonathan K; Namak, Shahla Y; Alattar, Mohammad H; Sayeed, Mohammed M

    2003-01-01

    Both experimental and clinical evidence suggest a suppression of T-cell function in burn and sepsis. The objective of the present study was to evaluate splenocyte and purified T-cell proliferative response and IL-2 production in septic neonatal rats. We also examined if alterations in T-cell proliferation and IL-2 production in neonatal sepsis is due to elevation in PGE2. PGE2 is known to play a significant role in T-cell suppression during sepsis in adults. Sepsis was induced in 15-day-old neonatal Sprague-Dawley rats by implanting 0.1 cm3 of fecal pellet impregnated with Escherichia coli (50 CFU) and Bacteroides fragilis (10(3) CFU). Animals receiving fecal pellets without the bacteria were designated as sterile. A group of septic and sterile rats were treated with PGE2 synthesis inhibitors, NS398 and resveratrol. These treatments of animals allowed us to evaluate the role of PGE2 in T-cell suppression during neonatal sepsis. Splenocytes as well as purified T cells were prepared and then proliferative response and IL-2 productive capacities were measured. A significant suppression of splenocyte proliferation and IL-2 production was noticed in both sterile and septic animals compared to the T cells from unoperated control rats. In contrast, the proliferation and IL-2 production by nylon wool purified T cells in sterile rats was not significantly different from control rats, whereas, a significant suppression in Con A-mediated T-cell proliferation and IL-2 production noticed in septic rat T cells compared to the sterile and control rat T cells. Such decrease in T-cell proliferation and IL-2 production was accompanied with 20-25% deaths in neonates implanted with septic pellets. No mortality was noted in sterile-implanted neonates. Treatment of animals with COX-1 inhibitor had no effect on T-cell proliferation response in both septic and sterile groups, whereas COX-2 inhibitor abrogated the decrease in T-cell proliferative response in the septic group. The treatment

  7. Deletion of BCG Hip1 protease enhances dendritic cell and CD4 T cell responses.

    PubMed

    Bizzell, Erica; Sia, Jonathan Kevin; Quezada, Melanie; Enriquez, Ana; Georgieva, Maria; Rengarajan, Jyothi

    2018-04-01

    Dendritic cells (DCs) play a key role in the generation of CD4 T cell responses to pathogens. Mycobacterium tuberculosis (Mtb) harbors immune evasion mechanisms that impair DC responses and prevent optimal CD4 T cell immunity. The vaccine strain Mycobacterium bovis Bacille Calmette-Guérin (BCG) shares many of the immune evasion proteins utilized by Mtb, but the role of these proteins in DC and T cell responses elicited by BCG is poorly understood. We previously reported that the Mtb serine protease, Hip1, promotes sub-optimal DC responses during infection. Here, we tested the hypothesis that BCG Hip1 modulates DC functions and prevents optimal antigen-specific CD4 T cell responses that limit the immunogenicity of BCG. We generated a strain of BCG lacking hip1 (BCGΔhip1) and show that it has superior capacity to induce DC maturation and cytokine production compared with the parental BCG. Furthermore, BCGΔhip1-infected DCs were more effective at driving the production of IFN-γ and IL-17 from antigen-specific CD4 T cells in vitro. Mucosal transfer of BCGΔhip1-infected DCs into mouse lungs induced robust CD4 T cell activation in vivo and generated antigen-specific polyfunctional CD4 T cell responses in the lungs. Importantly, BCGΔhip1-infected DCs enhanced control of pulmonary bacterial burden following Mtb aerosol challenge compared with the transfer of BCG-infected DCs. These results reveal that BCG employs Hip1 to impair DC activation, leading to attenuated lung CD4 T cell responses with limited capacity to control Mtb burden after challenge. ©2017 Society for Leukocyte Biology.

  8. Postthymic maturation influences the CD8 T cell response to antigen.

    PubMed

    Makaroff, Lydia E; Hendricks, Deborah W; Niec, Rachel E; Fink, Pamela J

    2009-03-24

    Complete T cell development requires postthymic maturation, and we investigated the influence of this ontological period on the CD8 T cell response to infection by comparing responses of mature CD8 T cells with those of recent thymic emigrants (RTEs). When activated with a noninflammatory stimulus or a bacterial or viral pathogen, CD8 RTEs generated a lower proportion of cytokine-producing effector cells and long-lived memory precursors compared with their mature counterparts. Although peripheral T cell maturation is complete within several weeks after thymic egress, RTE-derived memory cells continued to express inappropriate levels of memory cell markers and display an altered pattern of cytokine production, even 8 weeks after infection. When rechallenged, RTE-derived memory cells generated secondary effector cells that were phenotypically and functionally equivalent to those generated by their mature counterparts. The defects at the effector and memory stages were not associated with differences in the expression of T cell receptor-, costimulation-, or activation-associated cell surface markers yet were associated with lower Ly6C expression levels at the effector stage. This work demonstrates that the stage of postthymic maturation influences cell fate decisions and cytokine profiles of stimulated CD8 T cells, with repercussions that are apparent long after cells have progressed from the RTE compartment.

  9. Therapeutic targeting of regulatory T cells enhances tumor-specific CD8+ T cell responses in Epstein–Barr virus associated nasopharyngeal carcinoma

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Fogg, Mark; Murphy, John R.; Lorch, Jochen

    Epstein–Barr virus (EBV) is associated with multiple malignancies including nasopharyngeal carcinoma (NPC). In nasopharynx cancer, CD8+ T cells specific for EBV Nuclear Antigen-1 (EBNA-1) and Latent Membrane Protein 2 (LMP2) are important components of anti-tumor immunity since both are consistently expressed in NPC. We have previously shown that EBNA-1-specific CD8+ T cell responses were suppressed in NPC patients compared to healthy controls. We now find that CD8+ T cell responses specific for LMP2 are also abnormal in NPC patients, and both EBNA-1- and LMP2-specific responses are suppressed by regulatory T cells (Treg). EBNA-1 and LMP2-specific CD8+ T cell responses, asmore » well as immune control of EBV-infected cells in vitro, could be restored by the depletion of Tregs and by use of a clinically approved drug targeting Tregs. Thus, in vivo modulation of Tregs may be an effective means of enhancing these anti-tumor immune responses in NPC patients. - Highlights: • Viral proteins are tumor antigens in Epstein–Barr virus associated Nasopharyngeal Carcinoma. • CD8+ T cell responses against EBV proteins EBNA-1 and LMP2 are suppressed in NPC patients. • T regulatory cells are responsible for suppressing EBV immunity in NPC patients. • Depletion of Tregs with Ontak can rescue EBV-specific CD8+ T cell responses in NPC patients. • This clinically approved drug may be effective for enhancing anti-tumor immunity in NPC patients.« less

  10. Therapeutic targeting of regulatory T cells enhances tumor-specific CD8+ T cell responses in Epstein–Barr virus associated nasopharyngeal carcinoma

    PubMed Central

    Fogg, Mark; Murphy, John R.; Lorch, Jochen; Posner, Marshall; Wang, Fred

    2013-01-01

    Epstein–Barr virus (EBV) is associated with multiple malignancies including nasopharyngeal carcinoma (NPC). In nasopharynx cancer, CD8+ T cells specific for EBV Nuclear Antigen-1 (EBNA-1) and Latent Membrane Protein 2 (LMP2) are important components of anti-tumor immunity since both are consistently expressed in NPC. We have previously shown that EBNA-1-specific CD8+ T cell responses were suppressed in NPC patients compared to healthy controls. We now find that CD8+ T cell responses specific for LMP2 are also abnormal in NPC patients, and both EBNA-1- and LMP2-specific responses are suppressed by regulatory T cells (Treg). EBNA-1 and LMP2-specific CD8+ T cell responses, as well as immune control of EBV-infected cells in vitro, could be restored by the depletion of Tregs and by use of a clinically approved drug targeting Tregs. Thus, in vivo modulation of Tregs may be an effective means of enhancing these anti-tumor immune responses in NPC patients. PMID:23601786

  11. In vitro generation of helper T cells and suppressor T cells that regulate the cytolytic T lymphocyte response to trinitrophenyl-modified syngeneic cells.

    PubMed

    Gualde, N; Weinberger, O; Ratnofsky, S; Benacerraf, B; Burakoff, S J

    1982-04-01

    Helper T cells and suppressor T cells have been generated in vitro that regulate the cytolytic T lymphocyte (CTL) response to trinitrophenyl (TNP)-modified syngeneic cells. B6D2F1 helper cells generated to TNP-modified parental (P1) cells augment the CTL response to those P1-TNP-modified antigens but not to P2-TNP-modified antigens. The generation of these helper T cells requires the presence of splenic adherent cells and these helper T cells are radioresistant. A soluble factor can be obtained from the helper T cell cultures that can also augment the CTL response. The suppressor T cells generated in culture do not demonstrate the specificity observed with the helper T cells; however, they are antigen-dependent in their induction. Whether helper or suppressor activity is obtained depends upon the length of time cells are cultured in vitro.

  12. In vitro generation of helper T cells and suppressor T cells that regulate the cytolytic T lymphocyte response to trinitrophenyl-modified syngeneic cells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gualde, N.; Weinberger, O.; Ratnofsky, S.

    1982-04-01

    Helper T cells and suppressor T cells have been generated in vitro that regulate the cytolytic T lymphocyte (CTL) response to trinitrophenyl (TNP)-modified syngeneic cells. B6D2F1 helper cells generated to TNP-modified parental (P1) cells augment the CTL response to those P1-TNP-modified antigens but not to P2-TNP-modified antigens. The generation of these helper T cells requires the presence of splenic adherent cells and these helper T cells are radioresistant. A soluble factor can be obtained from the helper T cell cultures that can also augment the CTL response. The suppressor T cells generated in culture do not demonstrate the specificity observedmore » with the helper T cells; however, they are antigen-dependent in their induction. Whether helper or suppressor activity is obtained depends upon the length of time cells are cultured in vitro.« less

  13. Mesenteric lymph node T cells but not splenic T cells maintain their proliferative response to concanavalin-A following peroral infection with Toxoplasma gondii.

    PubMed

    Neyer, L E; Kang, H; Remington, J S; Suzuki, Y

    1998-12-01

    The suppression of T cell responsiveness which occurs after infection with Toxoplasma gondii in mice has been widely studied using spleen cells. Because the natural route of infection with T. gondii is the peroral route, we examined the proliferative responses of mesenteric lymph node (MLN) cells, in addition to spleen cells, to Concanavalin-A (Con-A) in mice perorally infected with T. gondii. Proliferative responses of spleen cells were significantly suppressed seven and ten days after infection when compared with spleen cells from uninfected mice (62% and 91% reduction, respectively). In contrast, proliferative responses of MLN cells from these infected mice did not differ from those of normal MLN cells. Since IFN-gamma-induced reactive nitrogen intermediate (RNI) production has been reported to play a major role in suppression of proliferative responses in spleen cells of infected mice, we compared production of IFN-gamma and RNI by spleen and MLN cells following infection. MLN cells produced as much IFN-gamma as did spleen cells, but produced 70% less nitrite (as a measure of RNI) after Con-A stimulation. Proliferative responses of MLN cells were suppressed when co-cultured with spleen cells from infected mice, and addition of an inhibitor of RNI to these co-culture inhibited this suppression, suggesting that reduced RNI production by MLN cells contributes to their maintenance of higher proliferative responses. These results demonstrated a clear difference in activity of T cells in the MLN and spleen during the acute stage of the infection.

  14. Localization of the T-cell response to RSV infection is altered in infant mice.

    PubMed

    Eichinger, Katherine M; Kosanovich, Jessica L; Empey, Kerry M

    2018-02-01

    Respiratory syncytial virus (RSV) is a leading cause of lower respiratory tract infections worldwide, causing disproportionate morbidity and mortality in infants and children. Infants with stronger Th1 responses have less severe disease, yet little is known about the infant T-cell response within the air space. Thus, we tested the hypothesis that RSV infected infant mice would have quantitative and qualitative deficiencies in CD4 + and CD8 + T-cell populations isolated from the bronchoalveolar lavage when compared to adults and that local delivery of IFN-γ would increase airway CD4 + Tbet + and CD8 + Tbet + T-cell responses. We compared the localization of T-cell responses in RSV-infected infant and adult mice and investigated the effects of local IFN-γ administration on infant cellular immunity. Adult CD8 + CD44 HI and CD4 + CD44 HI Tbet + T-cells accumulated in the alveolar space whereas CD4 + CD44 HI Tbet + T-cells were evenly distributed between the infant lung tissue and airway and infant lungs contained higher frequencies of CD8 + T-cells. Delivery of IFN-γ to the infant airway failed to increase the accumulation of T-cells in the airspace and unexpectedly reduced CD4 + CD44 HI Tbet + T-cells. However, intranasal IFN-γ increased RSV F protein-specific CD8 + T-cells in the alveolar space. Together, these data suggest that quantitative and qualitative defects exist in the infant T-cell response to RSV but early, local IFN-γ exposure can increase the CD8 + RSV-specific T-cell response. © 2017 Wiley Periodicals, Inc.

  15. Emerging concepts in T follicular helper cell responses to malaria.

    PubMed

    Hansen, Diana S; Obeng-Adjei, Nyamekye; Ly, Ann; Ioannidis, Lisa J; Crompton, Peter D

    2017-02-01

    Antibody responses to malaria and candidate malaria vaccines are short-lived in children, leaving them susceptible to repeated malaria episodes. Because T follicular helper (T FH ) cells provide critical help to B cells to generate long-lived antibody responses, they have become the focus of recent studies of Plasmodium-infected mice and humans. The emerging data converge on common themes, namely, that malaria-induced T H1 cytokines are associated with the activation of (i) T-like memory T FH cells with impaired B cell helper function, and (ii) pre-T FH cells that acquire Th1-like features (T-bet expression, IFN-γ production), which impede their differentiation into fully functional T FH cells, thus resulting in germinal center dysfunction and suboptimal antibody responses. Deeper knowledge of T FH cells in malaria could illuminate strategies to improve vaccines through modulating T FH cell responses. This review summarizes emerging concepts in T FH cell responses to malaria. Copyright © 2016. Published by Elsevier Ltd.

  16. Ability of γδ T cells to modulate the Foxp3 T cell response is dependent on adenosine.

    PubMed

    Liang, Dongchun; Woo, Jeong-Im; Shao, Hui; Born, Willi K; O'Brien, Rebecca L; Kaplan, Henry J; Sun, Deming

    2018-01-01

    Whether γδ T cells inhibit or enhance the Foxp3 T cell response depends upon their activation status. The critical enhancing effector in the supernatant is adenosine. Activated γδ T cells express adenosine receptors at high levels, which enables them to deprive Foxp3+ T cells of adenosine, and to inhibit their expansion. Meanwhile, cell-free supernatants of γδ T cell cultures enhance Foxp3 T cell expansion. Thus, inhibition and enhancement by γδ T cells of Foxp3 T cell response are a reflection of the balance between adenosine production and absorption by γδ T cells. Non-activated γδ T cells produce adenosine but bind little, and thus enhance the Foxp3 T cell response. Activated γδ T cells express high density of adenosine receptors and have a greatly increased ability to bind adenosine. Extracellular adenosine metabolism and expression of adenosine receptor A2ARs by γδ T cells played a major role in the outcome of γδ and Foxp3 T cell interactions. A better understanding of the functional conversion of γδ T cells could lead to γδ T cell-targeted immunotherapies for related diseases.

  17. HIV-DNA priming alters T-cell responses to HIV-adenovirus vaccine even when responses to DNA are undetectable1

    PubMed Central

    De Rosa, Stephen C.; Thomas, Evan P.; Bui, John; Huang, Yunda; deCamp, Allan; Morgan, Cecilia; Kalams, Spyros; Tomaras, Georgia D.; Akondy, Rama; Ahmed, Rafi; Lau, Chuen-Yen; Graham, Barney S.; Nabel, Gary J.; McElrath, M. Juliana

    2011-01-01

    Many candidate HIV vaccines are designed to primarily elicit T-cell responses. Although repeated immunization with the same vaccine boosts antibody responses, the benefit for T-cell responses is ill-defined. We compared two immunization regimens that include the same recombinant adenoviral serotype 5 (rAd5) boost. Repeated homologous rAd5 immunization fails to increase T-cell responses, but increases gp140 antibody responses ten-fold. DNA prime, as compared with rAd5 prime, directs long-term memory CD8+ T cells toward a terminally differentiated effector memory phenotype with cytotoxic potential. Based on the kinetics of activated cells measured directly ex vivo, the DNA vaccination primes for both CD4+ and CD8+ T cells, despite the lack of detection of the latter until after the boost. These results suggest that heterologous prime-boost combinations have distinct immunological advantages over homologous prime-boosts, and suggest that the effect of DNA on subsequent boosting may not be easily detectable directly after the DNA vaccination. PMID:21844392

  18. Hepatitis C Virus Induces Regulatory T Cells by Naturally Occurring Viral Variants to Suppress T Cell Responses

    PubMed Central

    Cusick, Matthew F.; Schiller, Jennifer J.; Gill, Joan C.; Eckels, David D.

    2011-01-01

    Regulatory T cell markers are increased in chronically infected individuals with the hepatitis C virus (HCV), but to date, the induction and maintenance of Tregs in HCV infection has not been clearly defined. In this paper, we demonstrate that naturally occurring viral variants suppress T cell responses to cognate NS3358-375 in an antigen-specific manner. Of four archetypal variants, S370P induced regulatory T cell markers in comparison to NS3358-375-stimulated CD4 T cells. Further, the addition of variant-specific CD4 T cells back into a polyclonal culture in a dose-dependent manner inhibited the T cell response. These results suggest that HCV is able to induce antigen-specific regulatory T cells to suppress the antiviral T cell response in an antigen-specific manner, thus contributing to a niche within the host that could be conducive to HCV persistence. PMID:21197453

  19. Dectin-1 diversifies Aspergillus fumigatus–specific T cell responses by inhibiting T helper type 1 CD4 T cell differentiation

    PubMed Central

    Hohl, Tobias M.; Collins, Nichole; Leiner, Ingrid; Gallegos, Alena; Saijo, Shinobu; Coward, Jesse W.; Iwakura, Yoichiro

    2011-01-01

    Pulmonary infection of mice with Aspergillus fumigatus induces concurrent T helper type 1 (Th1) and Th17 responses that depend on Toll-like receptor/MyD88 and Dectin-1, respectively. However, the mechanisms balancing Th1 and Th17 CD4 T cell populations during infection remain incompletely defined. In this study, we show that Dectin-1 deficiency disproportionally increases Th1 responses and decreases Th17 differentiation after A. fumigatus infection. Dectin-1 signaling in A. fumigatus–infected wild-type mice reduces IFN-γ and IL-12p40 expression in the lung, thereby decreasing T-bet expression in responding CD4 T cells and enhancing Th17 responses. Absence of IFN-γ or IL-12p35 in infected mice or T-bet in responding CD4 T cells enhances Th17 differentiation, independent of Dectin-1 expression, in A. fumigatus–infected mice. Transient deletion of monocyte-derived dendritic cells also reduces Th1 and boosts Th17 differentiation of A. fumigatus–specific CD4 T cells. Our findings indicate that Dectin-1–mediated signals alter CD4 T cell responses to fungal infection by decreasing the production of IL-12 and IFN-γ in innate cells, thereby decreasing T-bet expression in A. fumigatus–specific CD4 T cells and enabling Th17 differentiation. PMID:21242294

  20. T cell-independent and T cell-dependent immunoglobulin G responses to polyomavirus infection are impaired in complement receptor 2-deficient mice.

    PubMed

    Szomolanyi-Tsuda, Eva; Seedhom, Mina O; Carroll, Michael C; Garcea, Robert L

    2006-08-15

    Polyomavirus (PyV) infection induces protective T cell-independent (TI) IgM and IgG antibody responses in T cell-deficient mice, but these responses are not generated by immunization with viral proteins or virus like particles. We hypothesized that innate signals contribute to the generation of isotype-switched antiviral antibody responses. We studied the role of complement receptor (CR2) engagement in TI and T cell-dependent (TD) antibody responses to PyV using CR2-deficient mice. Antiviral IgG responses were reduced by 80-40% in CR2-/- mice compared to wild type. Adoptive transfer experiments demonstrated the need for CR2 not only in TD, but also in TI IgG responses to PyV. Transfer of CR2-/- B lymphocytes to SCID mice resulted in TI antiviral IgG responses that corresponded to 10% of that seen in wild-type B cell-reconstituted mice. Thus, our studies revealed a profound dependence of TI and TD antiviral antibody responses on CR2-mediated signals in PyV-infected mice, where the viral antigen is abundant and persistent.

  1. T Cell Epitope Mapping of JC Polyoma Virus-Encoded Proteome Reveals Reduced T Cell Responses in HLA-DRB1*04:01+ Donors

    PubMed Central

    Jelčić, Ilijas; Aly, Lilian; Binder, Thomas M. C.; Jelčić, Ivan; Bofill-Mas, Sílvia; Planas, Raquel; Demina, Victoria; Eiermann, Thomas H.; Weber, Thomas; Girones, Rosina; Sospedra, Mireia

    2013-01-01

    JC polyomavirus (JCV) infection is highly prevalent and usually kept in a persistent state without clinical signs and symptoms. It is only during immunocompromise and especially impaired CD4+ T cell function in the brain, as seen in AIDS patients or natalizumab-treated multiple sclerosis patients, that JCV may cause progressive multifocal leukoencephalopathy (PML), an often life-threatening brain disease. Since CD4+ T cells likely play an important role in controlling JCV infection, we here describe the T cell response to JCV in a group of predominantly HLA-DR-heterozygotic healthy donors (HD) by using a series of overlapping 15-mer peptides spanning all JCV-encoded open reading frames. We identified immunodominant epitopes and compared T cell responses with anti-JCV VP1 antibody production and with the presence of urinary viral shedding. We observed positive JCV-specific T cell responses in 28.6% to 77.6%, humoral immune response in 42.6% to 89.4%, and urinary viral shedding in 36.4% to 45.5% of HD depending on the threshold. Four immunodominant peptides were mapped, and at least one immunogenic peptide per HLA-DRB1 allele was detected in DRB1*01+, DRB1*07+, DRB1*11+, DRB1*13+, DRB1*15+, and DRB1*03+ individuals. We show for the first time that JCV-specific T cell responses may be directed not only against JCV VP1 and large T antigen but also against all other JCV-encoded proteins. Heterozygotic DRB1*04:01+ individuals showed very low T cell responses to JCV together with normal anti-VP1 antibody levels and no urinary viral shedding, indicating a dominant-negative effect of this allele on global JCV-directed T cell responses. Our data are potentially relevant for the development of vaccines against JCV. PMID:23302880

  2. Allogeneic T cell responses are regulated by a specific miRNA-mRNA network

    PubMed Central

    Sun, Yaping; Tawara, Isao; Zhao, Meng; Qin, Zhaohui S.; Toubai, Tomomi; Mathewson, Nathan; Tamaki, Hiroya; Nieves, Evelyn; Chinnaiyan, Arul M.; Reddy, Pavan

    2013-01-01

    Donor T cells that respond to host alloantigens following allogeneic bone marrow transplantation (BMT) induce graft-versus-host (GVH) responses, but their molecular landscape is not well understood. MicroRNAs (miRNAs) regulate gene (mRNA) expression and fine-tune the molecular responses of T cells. We stimulated naive T cells with either allogeneic or nonspecific stimuli and used argonaute cross-linked immunoprecipitation (CLIP) with subsequent ChIP microarray analyses to profile miR responses and their direct mRNA targets. We identified a unique expression pattern of miRs and mRNAs following the allostimulation of T cells and a high correlation between the expression of the identified miRs and a reduction of their mRNA targets. miRs and mRNAs that were predicted to be differentially regulated in allogeneic T cells compared with nonspecifically stimulated T cells were validated in vitro. These analyses identified wings apart-like homolog (Wapal) and synaptojanin 1 (Synj1) as potential regulators of allogeneic T cell responses. The expression of these molecular targets in vivo was confirmed in MHC-mismatched experimental BMT. Targeted silencing of either Wapal or Synj1 prevented the development of GVH response, confirming a role for these regulators in allogeneic T cell responses. Thus, this genome-wide analysis of miRNA-mRNA interactions identifies previously unrecognized molecular regulators of T cell responses. PMID:24216511

  3. T cell regulation of the thymus-independent antibody response to trinitrophenylated-Brucella abortus (TNP-BA)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Tanay, A.; Strober, S.

    The authors have previously observed a reduction of the T cell-dependent primary antibody response to dinitrophenylated keyhole limpet hemocyanin, and an enhancement of the T cell-independent response to trinitrophenylated Brucella abortus (TNP-BA) in BALB/c mice after treatment with total lymphoid irradiation (TLI). To elucidate the relative contribution of T and B cells to the enhanced T cell-independent antibody responses after TLI, a syngeneic primary adoptive transfer system was utilized whereby irradiated hosts were reconstituted with unfractionated spleen cells or a combination of purified T and B cells from TLI-treated and untreated control mice. Antibody responses of purified splenic B cellsmore » from TLI-treated BALB/c mice (TLI/B) to TNP-BA were enhanced 10-fold as compared with those of unfractionated (UF) spleen cells or B cells from normal (NL) BALB/c mice (NL/UF and NL/B, respectively). Splenic T cells from normal animals (NL/T) suppressed the anti-TNP-BA response of TLI/B by more than 100-fold. NL/T neither suppressed nor enhanced the response of NL/B. On the other hand, T cells from TLI-treated mice (TLI/T) enhanced by 100-fold the anti-TNP-BA response of NL/B, but neither suppressed nor enhanced the response of TLI/B. Thus, T cells can regulate the T cell-independent antibody response to TNP-BA. However, experimental manipulation of the T and B cell populations is needed to demonstrate the regulatory functions.« less

  4. Effects of Interleukin-12 and Interleukin-15 on Measles-Specific T-Cell Responses in Vaccinated Infants

    PubMed Central

    YASUKAWA, LINDA L.; ZHANG, CATHRYN Z.; WAKIM, RIMA HANNA; RINKI, MARY; DEHOVITZ, ROSS; ARVIN, ANN M.

    2008-01-01

    Abstract Understanding the infant host response to measles vaccination is important because of their increased mortality from measles and the need to provide effective protection during the first year of life. Measles-specific T- and B-cell responses are lower in infants after measles vaccination than in adults. To define potential mechanisms, we investigated age-related differences in measles-specific T-cell proliferation, CD40-L expression, and IFN-γ production after measles immunization, and the effects of rhIL-12 and rhIL-15 on these responses. Measles-specific T-cell proliferation and mean IFN-γ release from infant PBMCs were significantly lower when compared with responses of vaccinated children and adults. Infant responses increased to ranges observed in children and adults when both rhIL-12 and rhIL-15 were added to PBMC cultures. Furthermore, a significant rise in T-cell proliferation and IFN-γ release was observed when infant PBMCs were stimulated with measles antigen in the presence of rhIL-12 and rhIL-15 compared to measles antigen alone. CD40-L expression by infant and adult T cells stimulated with measles antigen was comparable, but fewer infant CD40-L+ T cells expressed IFN-γ. These observations suggest that lower measles-specific T-cell immune responses elicited by measles vaccine in infants may be due to diminished levels of key cytokines. PMID:18419254

  5. Conventional CD4+ T cells present bacterial antigens to induce cytotoxic and memory CD8+ T cell responses.

    PubMed

    Cruz-Adalia, Aránzazu; Ramirez-Santiago, Guillermo; Osuna-Pérez, Jesús; Torres-Torresano, Mónica; Zorita, Virgina; Martínez-Riaño, Ana; Boccasavia, Viola; Borroto, Aldo; Martínez Del Hoyo, Gloria; González-Granado, José María; Alarcón, Balbino; Sánchez-Madrid, Francisco; Veiga, Esteban

    2017-11-17

    Bacterial phagocytosis and antigen cross-presentation to activate CD8 + T cells are principal functions of professional antigen presenting cells. However, conventional CD4 + T cells also capture and kill bacteria from infected dendritic cells in a process termed transphagocytosis (also known as transinfection). Here, we show that transphagocytic T cells present bacterial antigens to naive CD8 + T cells, which proliferate and become cytotoxic in response. CD4 + T-cell-mediated antigen presentation also occurs in vivo in the course of infection, and induces the generation of central memory CD8 + T cells with low PD-1 expression. Moreover, transphagocytic CD4 + T cells induce protective anti-tumour immune responses by priming CD8 + T cells, highlighting the potential of CD4 + T cells as a tool for cancer immunotherapy.

  6. Regulatory T-cell activity but not conventional HIV-specific T-cell responses are associated with protection from HIV-1 infection

    PubMed Central

    Pattacini, Laura; Baeten, Jared M.; Thomas, Katherine K.; Fluharty, Tayler R.; Murnane, Pamela M.; Donnell, Deborah; Bukusi, Elizabeth; Ronald, Allan; Mugo, Nelly; Lingappa, Jairam R.; Celum, Connie; McElrath, M. Juliana; Lund, Jennifer M.

    2015-01-01

    Objective Two distinct hypotheses have been proposed for T-cell involvement in protection from HIV-1 acquisition. First, HIV-1-specific memory T-cell responses generated upon HIV-1 exposure could mount an efficient response to HIV-1 and inhibit the establishment of an infection. Second, a lower level of immune activation could reduce the numbers of activated, HIV-1-susceptible CD4+ T-cells, thereby diminishing the likelihood of infection. Methods To test these hypotheses, we conducted a prospective study among high-risk heterosexual men and women, and tested peripheral blood samples from individuals who subsequently acquired HIV-1 during follow-up (cases) and from a subset of those who remained HIV-1 uninfected (controls). Results We found no difference in HIV-1-specific immune responses between cases and controls, but Treg frequency was higher in controls as compared to cases and was negatively associated with frequency of effector memory CD4+ T-cells. Conclusions Our findings support the hypothesis that low immune activation assists in protection from HIV-1 infection. PMID:26656786

  7. T-cell Responses in the Microenvironment of Primary Renal Cell Carcinoma-Implications for Adoptive Cell Therapy.

    PubMed

    Andersen, Rikke; Westergaard, Marie Christine Wulff; Kjeldsen, Julie Westerlin; Müller, Anja; Pedersen, Natasja Wulff; Hadrup, Sine Reker; Met, Özcan; Seliger, Barbara; Kromann-Andersen, Bjarne; Hasselager, Thomas; Donia, Marco; Svane, Inge Marie

    2018-02-01

    In vitro expansion of large numbers of highly potent tumor-reactive T cells appears a prerequisite for effective adoptive cell therapy (ACT) with autologous tumor-infiltrating lymphocytes (TIL) as shown in metastatic melanoma (MM). We therefore sought to determine whether renal cell carcinomas (RCC) are infiltrated with tumor-reactive T cells that could be efficiently employed for adoptive transfer immunotherapy. TILs and autologous tumor cell lines (TCL) were successfully generated from 22 (92%) and 17 (77%) of 24 consecutive primary RCC specimens and compared with those generated from metastatic melanoma. Immune recognition of autologous TCLs or fresh tumor digests was observed in CD8 + TILs from 82% of patients (18/22). Cytotoxicity assays confirmed the tumoricidal capacity of RCC-TILs. The overall expansion capacity of RCC-TILs was similar to MM-TILs. However, the magnitude, polyfunctionality, and ability to expand in classical expansion protocols of CD8 + T-cell responses was lower compared with MM-TILs. The RCC-TILs that did react to the tumor were functional, and antigen presentation and processing of RCC tumors was similar to MM-TILs. Direct recognition of tumors with cytokine-induced overexpression of human leukocyte antigen class II was observed from CD4 + T cells (6/12; 50%). Thus, TILs from primary RCC specimens could be isolated, expanded, and could recognize tumors. However, immune responses of expanded CD8 + RCC-TILs were typically weaker than MM-TILs and displayed a mono-/oligofunctional pattern. The ability to select, enrich, and expand tumor-reactive polyfunctional T cells may be critical in developing effective ACT with TILs for RCC. In summary, TILs isolated from primary RCC specimens could recognize tumors. However, their immune responses were weaker than MM-TILs and displayed a mono-/oligofunctional pattern. The ability to select and expand polyfunctional T cells may improve cell therapy for RCC. Cancer Immunol Res; 6(2); 222-35. ©2018 AACR

  8. Healthy human T-Cell Responses to Aspergillus fumigatus antigens.

    PubMed

    Chaudhary, Neelkamal; Staab, Janet F; Marr, Kieren A

    2010-02-17

    Aspergillus fumigatus is associated with both invasive and allergic pulmonary diseases, in different hosts. The organism is inhaled as a spore, which, if not cleared from the airway, germinates into hyphal morphotypes that are responsible for tissue invasion and resultant inflammation. Hyphae secrete multiple products that function as antigens, evoking both a protective (T(H)1-T(H)17) and destructive allergic (T(H)2) immunity. How Aspergillus allergens (Asp f proteins) participate in the development of allergic sensitization is unknown. To determine whether Asp f proteins are strictly associated with T(H)2 responses, or represent soluble hyphal products recognized by healthy hosts, human T cell responses to crude and recombinant products were characterized by ELISPOT. While responses (number of spots producing IFN-gamma, IL-4 or IL-17) to crude hyphal antigen preparations were weak, responses to recombinant Asp f proteins were higher. Recombinant allergens stimulated cells to produce IFN-gamma more so than IL-4 or IL-17. Volunteers exhibited a diverse CD4+ and CD8+ T cell antigen recognition profile, with prominent CD4 T(H)1-responses to Asp f3 (a putative peroxismal membrane protein), Asp f9/16 (cell wall glucanase), Asp f11 (cyclophilin type peptidyl-prolyl isomerase) and Asp f22 (enolase). Strong IFN-gamma responses were reproduced in most subjects tested over 6 month intervals. Products secreted after conidial germination into hyphae are differentially recognized by protective T cells in healthy, non-atopic individuals. Defining the specificity of the human T cell repertoire, and identifying factors that govern early responses may allow for development of novel diagnostics and therapeutics for both invasive and allergic Aspergillus diseases.

  9. Regional Variation in the Correlation of Antibody and T-Cell Responses to Trypanosoma cruzi

    PubMed Central

    Martin, Diana L.; Marks, Morgan; Galdos-Cardenas, Gerson; Gilman, Robert H.; Goodhew, Brook; Ferrufino, Lisbeth; Halperin, Anthony; Sanchez, Gerardo; Verastegui, Manuela; Escalante, Patricia; Naquira, Cesar; Levy, Michael Z.; Bern, Caryn

    2014-01-01

    Chagas disease, caused by the protozoan parasite Trypanosoma cruzi, is a major cause of morbidity and mortality in Central and South America. Geographic variations in the sensitivity of serologic diagnostic assays to T. cruzi may reflect differences in T. cruzi exposure. We measured parasite-specific T-cell responses among seropositive individuals in two populations from South America with widely varying antibody titers against T. cruzi. Antibody titers among seropositive individuals were significantly lower in Arequipa, Peru compared with Santa Cruz, Bolivia. Similarly, the proportion of seropositive individuals with positive T-cell responses was lower in Peru than Bolivia, resulting in overall lower frequencies of interferon-γ (IFNγ)-secreting cells from Peruvian samples. However, the magnitude of the IFNγ response was similar among the IFNγ responders in both locations. These data indicate that immunological discrepancies based on geographic region are reflected in T-cell responses as well as antibody responses. PMID:24710614

  10. Innate T cell responses in human gut.

    PubMed

    Meresse, Bertrand; Cerf-Bensussan, Nadine

    2009-06-01

    One arm of the gut-associated immune system is represented by a vast collection of T lymphocytes which participate in the subtle interplay between innate and adaptive immune mechanisms and maintain homeostasis at the main body external surface. Mounting data are providing exciting new insight into the innate-like mechanisms which enable intestinal T cells to rapidly sense local conditions and which broaden the spectrum of their functions and regulation at this strategic location. Herein we discuss how innate-like T cell recognition by unconventional T cell subsets and expression of innate NK receptors might modulate immune T cell responses in the human normal or diseased intestine.

  11. Plasmid DNA vaccination using skin electroporation promotes poly-functional CD4 T-cell responses.

    PubMed

    Bråve, Andreas; Nyström, Sanna; Roos, Anna-Karin; Applequist, Steven E

    2011-03-01

    Plasmid DNA vaccination using skin electroporation (EP) is a promising method able to elicit robust humoral and CD8(+) T-cell immune responses while limiting invasiveness of delivery. However, there is still only limited data available on the induction of CD4(+) T-cell immunity using this method. Here, we compare the ability of homologous prime/boost DNA vaccinations by skin EP and intramuscular (i.m.) injection to elicit immune responses by cytokine enzyme-linked immunosorbent spot (ELISPOT) assay, as well as study the complexity of CD4(+) T-cell responses to the human immunodeficiency virus antigen Gag, using multiparamater flow cytometry. We find that DNA vaccinations by skin EP and i.m. injection are capable of eliciting both single- and poly-functional vaccine-specific CD4(+) T cells. However, although DNA delivered by skin EP was administered at a five-fold lower dose it elicited significant increases in the magnitude of multiple-cytokine producers compared with i.m. immunization suggesting that the skin EP could provide greater poly-functional T-cell help, a feature associated with successful immune defense against infectious agents.

  12. Comparative Expression Profiling of Distinct T Cell Subsets Undergoing Oxidative Stress

    PubMed Central

    Lichtenfels, Rudolf; Mougiakakos, Dimitrios; Johansson, C. Christian; Dressler, Sven P.; Recktenwald, Christian V.; Kiessling, Rolf; Seliger, Barbara

    2012-01-01

    The clinical outcome of adoptive T cell transfer-based immunotherapies is often limited due to different escape mechanisms established by tumors in order to evade the hosts' immune system. The establishment of an immunosuppressive micromilieu by tumor cells along with distinct subsets of tumor-infiltrating lymphocytes is often associated with oxidative stress that can affect antigen-specific memory/effector cytotoxic T cells thereby substantially reducing their frequency and functional activation. Therefore, protection of tumor-reactive cytotoxic T lymphocytes from oxidative stress may enhance the anti-tumor-directed immune response. In order to better define the key pathways/proteins involved in the response to oxidative stress a comparative 2-DE-based proteome analysis of naïve CD45RA+ and their memory/effector CD45RO+ T cell counterparts in the presence and absence of low dose hydrogen peroxide (H2O2) was performed in this pilot study. Based on the profiling data of these T cell subpopulations under the various conditions, a series of differentially expressed spots were defined, members thereof identified by mass spectrometry and subsequently classified according to their cellular function and localization. Representative targets responding to oxidative stress including proteins involved in signaling pathways, in regulating the cellular redox status as well as in shaping/maintaining the structural cell integrity were independently verified at the transcript and protein level under the same conditions in both T cell subsets. In conclusion the resulting profiling data describe complex, oxidative stress-induced, but not strictly concordant changes within the respective expression profiles of CD45RA+ and CD45RO+ T cells. Some of the differentially expressed genes/proteins might be further exploited as potential targets toward modulating the redox capacity of the distinct lymphocyte subsets thereby providing the basis for further studies aiming at rendering them

  13. CD4+ T-Cell-Independent Secondary Immune Responses to Pneumocystis Pneumonia

    PubMed Central

    de la Rua, Nicholas M.; Samuelson, Derrick R.; Charles, Tysheena P.; Welsh, David A.; Shellito, Judd E.

    2016-01-01

    Pneumocystis pneumonia is a major cause of morbidity and mortality among immunocompromised patients, especially in the context of HIV/AIDS. In the murine model of Pneumocystis pneumonia, CD4+ T-cells are required for clearance of a primary infection of Pneumocystis, but not the memory recall response. We hypothesized that the memory recall response in the absence of CD4+ T-cells is mediated by a robust memory humoral response, CD8+ T-cells, and IgG-mediated phagocytosis by alveolar macrophages. To investigate the role of CD8+ T-cells and alveolar macrophages in the immune memory response to Pneumocystis, mice previously challenged with Pneumocystis were depleted of CD8+ T-cells or alveolar macrophages prior to re-infection. Mice depleted of CD4+ T-cells prior to secondary challenge cleared Pneumocystis infection within 48 h identical to immunocompetent mice during a secondary memory recall response. However, loss of CD8+ T-cells or macrophages prior to the memory recall response significantly impaired Pneumocystis clearance. Specifically, mice depleted of CD8+ T-cells or alveolar macrophages had significantly higher fungal burden in the lungs. Furthermore, loss of alveolar macrophages significantly skewed the lung CD8+ T-cell response toward a terminally differentiated effector memory population and increased the percentage of IFN-γ+ CD8+ T-cells. Finally, Pneumocystis-infected animals produced significantly more bone marrow plasma cells and Pneumocystis-specific IgG significantly increased macrophage-mediated killing of Pneumocystis in vitro. These data suggest that secondary immune memory responses to Pneumocystis are mediated, in part, by CD8+ T-cells, alveolar macrophages, and the production of Pneumocystis-specific IgG. PMID:27242785

  14. Response of γδ T cells to plant-derived tannins

    PubMed Central

    Holderness, Jeff; Hedges, Jodi F.; Daughenbaugh, Katie; Kimmel, Emily; Graff, Jill; Freedman, Brett; Jutila, Mark A.

    2008-01-01

    Many pharmaceutical drugs are isolated from plants used in traditional medicines. Through screening plant extracts, both traditional medicines and compound libraries, new pharmaceutical drugs continue to be identified. Currently, two plant-derived agonists for γδ T cells are described. These plant-derived agonists impart innate effector functions upon distinct γδ T cell subsets. Plant tannins represent one class of γδ T cell agonist and preferentially activate the mucosal population. Mucosal γδ T cells function to modulate tissue immune responses and induce epithelium repair. Select tannins, isolated from apple peel, rapidly induce immune gene transcription in γδ T cells, leading to cytokine production and increased responsiveness to secondary signals. Activity of these tannin preparations tracks to the procyanidin fraction, with the procyanidin trimer (C1) having the most robust activity defined to date. The response to the procyanidins is evolutionarily conserved in that responses are seen with human, bovine, and murine γδ T cells. Procyanidin-induced responses described in this review likely account for the expansion of mucosal γδ T cells seen in mice and rats fed soluble extracts of tannins. Procyanidins may represent a novel approach for treatment of tissue damage, chronic infection, and autoimmune therpies. PMID:19166386

  15. CD8+ memory T-cell inflation renders compromised CD4+ T-cell-dependent CD8+ T-cell immunity via naïve T-cell anergy.

    PubMed

    Xu, Aizhang; Freywald, Andrew; Xie, Yufeng; Li, Zejun; Xiang, Jim

    2017-01-01

    Whether inflation of CD8 + memory T (mT) cells, which is often derived from repeated prime-boost vaccinations or chronic viral infections in the elderly, would affect late CD8 + T-cell immunity is a long-standing paradox. We have previously established an animal model with mT-cell inflation by transferring ConA-stimulated monoclonal CD8 + T cells derived from Ova-specific T-cell-receptor transgenic OTI mice into irradiation-induced lymphopenic B6 mice. In this study, we also established another two animal models with mT-cell inflation by transferring, 1) ConA-stimulated monoclonal CD8 + T cells derived from lymphocytic choriomeningitis virus glycoprotein-specific T-cell-receptor transgenic P14 mice, and 2) ConA-stimulated polyclonal CD8 + T cells derived from B6.1 mice into B6 mice with irradiation-induced lymphopenia. We vaccinated these mice with recombinant Ova-expressing Listeria monocytogenes and Ova-pulsed dendritic cells, which stimulated CD4 + T cell-independent and CD4 + T-cell-dependent CD8 + T-cell responses, respectively, and assessed Ova-specific CD8 + T-cell responses by flow cytometry. We found that Ova-specific CD8 + T-cell responses derived from the latter but not the former vaccination were significantly reduced in mice with CD8 + mT-cell inflation compared to wild-type B6 mice. We determined that naïve CD8 + T cells purified from splenocytes of mice with mT-cell inflation had defects in cell proliferation upon stimulation in vitro and in vivo and upregulated T-cell anergy-associated Itch and GRAIL molecules. Taken together, our data reveal that CD8 + mT-cell inflation renders compromised CD4 + T-cell-dependent CD8 + T-cell immunity via naïve T-cell anergy, and thus show promise for the design of efficient vaccines for elderly patients with CD8 + mT-cell inflation.

  16. Contribution of herpesvirus specific CD8 T cells to anti-viral T cell response in humans.

    PubMed

    Sandalova, Elena; Laccabue, Diletta; Boni, Carolina; Tan, Anthony T; Fink, Katja; Ooi, Eng Eong; Chua, Robert; Shafaeddin Schreve, Bahar; Ferrari, Carlo; Bertoletti, Antonio

    2010-08-19

    Herpesviruses infect most humans. Their infections can be associated with pathological conditions and significant changes in T cell repertoire but evidences of symbiotic effects of herpesvirus latency have never been demonstrated. We tested the hypothesis that HCMV and EBV-specific CD8 T cells contribute to the heterologous anti-viral immune response. Volume of activated/proliferating virus-specific and total CD8 T cells was evaluated in 50 patients with acute viral infections: 20 with HBV, 12 with Dengue, 12 with Influenza, 3 with Adenovirus infection and 3 with fevers of unknown etiology. Virus-specific (EBV, HCMV, Influenza) pentamer+ and total CD8 T cells were analyzed for activation (CD38/HLA-DR), proliferation (Ki-67/Bcl-2(low)) and cytokine production. We observed that all acute viral infections trigger an expansion of activated/proliferating CD8 T cells, which differs in size depending on the infection but is invariably inflated by CD8 T cells specific for persistent herpesviruses (HCMV/EBV). CD8 T cells specific for other non-related non persistent viral infection (i.e. Influenza) were not activated. IL-15, which is produced during acute viral infections, is the likely contributing mechanism driving the selective activation of herpesvirus specific CD8 T cells. In addition we were able to show that herpesvirus specific CD8 T cells displayed an increased ability to produce the anti-viral cytokine interferon-gamma during the acute phase of heterologous viral infection. Taken together, these data demonstrated that activated herpesvirus specific CD8 T cells inflate the activated/proliferating CD8 T cells population present during acute viral infections in human and can contribute to the heterologous anti-viral T cell response.

  17. Identification of novel gammadelta T-cell subsets following bacterial infection in the absence of Vgamma1+ T cells: homeostatic control of gammadelta T-cell responses to pathogen infection by Vgamma1+ T cells.

    PubMed

    Newton, Darren J; Andrew, Elizabeth M; Dalton, Jane E; Mears, Rainy; Carding, Simon R

    2006-02-01

    Although gammadelta T cells are a common feature of many pathogen-induced immune responses, the factors that influence, promote, or regulate the response of individual gammadelta T-cell subsets to infection is unknown. Here we show that in the absence of Vgamma1+ T cells, novel subsets of gammadelta T cells, expressing T-cell receptor (TCR)-Vgamma chains that normally define TCRgammadelta+ dendritic epidermal T cells (DETCs) (Vgamma5+), intestinal intraepithelial lymphocytes (iIELs) (Vgamma7+), and lymphocytes associated with the vaginal epithelia (Vgamma6+), are recruited to the spleen in response to bacterial infection in TCR-Vgamma1-/- mice. By comparison of phenotype and structure of TCR-Vgamma chains and/or -Vdelta chains expressed by these novel subsets with those of their epithelium-associated counterparts, the Vgamma6+ T cells elicited in infected Vgamma1-/- mice were shown to be identical to those found in the reproductive tract, from where they are presumably recruited in the absence of Vgamma1+ T cells. By contrast, Vgamma5+ and Vgamma7+ T cells found in infected Vgamma1-/- mice were distinct from Vgamma5+ DETCs and Vgamma7+ iIELs. Functional analyses of the novel gammadelta T-cell subsets identified for infected Vgamma1-/- mice showed that whereas the Vgamma5+ and Vgamma7+ subsets may compensate for the absence of Vgamma1+ T cells by producing similar cytokines, they do not possess cytocidal activity and they cannot replace the macrophage homeostasis function of Vgamma1+ T cells. Collectively, these findings identify novel subsets of gammadelta T cells, the recruitment and activity of which is under the control of Vgamma1+ T cells.

  18. Protective CD8 Memory T Cell Responses to Mouse Melanoma Are Generated in the Absence of CD4 T Cell Help

    PubMed Central

    Steinberg, Shannon M.; Zhang, Peisheng; Turk, Mary Jo

    2011-01-01

    Background We have previously demonstrated that temporary depletion of CD4 T cells in mice with progressive B16 melanoma, followed by surgical tumor excision, induces protective memory CD8 T cell responses to melanoma/melanocyte antigens. We also showed that persistence of these CD8 T cells is supported, in an antigen-dependent fashion, by concurrent autoimmune melanocyte destruction. Herein we explore the requirement of CD4 T cell help in priming and maintaining this protective CD8 T cell response to melanoma. Methodology and Principal Findings To induce melanoma/melanocyte antigen-specific CD8 T cells, B16 tumor bearing mice were depleted of regulatory T cells (Treg) by either temporary, or long-term continuous treatment with anti-CD4 (mAb clone GK1.5). Total depletion of CD4 T cells led to significant priming of IFN-γ-producing CD8 T cell responses to TRP-2 and gp100. Surprisingly, treatment with anti-CD25 (mAb clone PC61), to specifically deplete Treg cells while leaving help intact, was ineffective at priming CD8 T cells. Thirty to sixty days after primary tumors were surgically excised, mice completely lacking CD4 T cell help developed autoimmune vitiligo, and maintained antigen-specific memory CD8 T cell responses that were highly effective at producing cytokines (IFN-γ, TNF-α, and IL-2). Mice lacking total CD4 T cell help also mounted protection against re-challenge with B16 melanoma sixty days after primary tumor excision. Conclusions and Significance This work establishes that CD4 T cell help is dispensable for the generation of protective memory T cell responses to melanoma. Our findings support further use of CD4 T cell depletion therapy for inducing long-lived immunity to cancer. PMID:22046294

  19. T-Cell Artificial Focal Triggering Tools: Linking Surface Interactions with Cell Response

    PubMed Central

    Carpentier, Benoît; Pierobon, Paolo; Hivroz, Claire; Henry, Nelly

    2009-01-01

    T-cell activation is a key event in the immune system, involving the interaction of several receptor ligand pairs in a complex intercellular contact that forms between T-cell and antigen-presenting cells. Molecular components implicated in contact formation have been identified, but the mechanism of activation and the link between molecular interactions and cell response remain poorly understood due to the complexity and dynamics exhibited by whole cell-cell conjugates. Here we demonstrate that simplified model colloids grafted so as to target appropriate cell receptors can be efficiently used to explore the relationship of receptor engagement to the T-cell response. Using immortalized Jurkat T cells, we monitored both binding and activation events, as seen by changes in the intracellular calcium concentration. Our experimental strategy used flow cytometry analysis to follow the short time scale cell response in populations of thousands of cells. We targeted both T-cell receptor CD3 (TCR/CD3) and leukocyte-function-associated antigen (LFA-1) alone or in combination. We showed that specific engagement of TCR/CD3 with a single particle induced a transient calcium signal, confirming previous results and validating our approach. By decreasing anti-CD3 particle density, we showed that contact nucleation was the most crucial and determining step in the cell-particle interaction under dynamic conditions, due to shear stress produced by hydrodynamic flow. Introduction of LFA-1 adhesion molecule ligands at the surface of the particle overcame this limitation and elucidated the low TCR/CD3 ligand density regime. Despite their simplicity, model colloids induced relevant biological responses which consistently echoed whole cell behavior. We thus concluded that this biophysical approach provides useful tools for investigating initial events in T-cell activation, and should enable the design of intelligent artificial systems for adoptive immunotherapy. PMID:19274104

  20. First-in-human response of BCL-2 inhibitor venetoclax in T-cell prolymphocytic leukemia.

    PubMed

    Boidol, Bernd; Kornauth, Christoph; van der Kouwe, Emiel; Prutsch, Nicole; Kazianka, Lukas; Gültekin, Sinan; Hoermann, Gregor; Mayerhoefer, Marius E; Hopfinger, Georg; Hauswirth, Alexander; Panny, Michael; Aretin, Marie-Bernadette; Hilgarth, Bernadette; Sperr, Wolfgang R; Valent, Peter; Simonitsch-Klupp, Ingrid; Moriggl, Richard; Merkel, Olaf; Kenner, Lukas; Jäger, Ulrich; Kubicek, Stefan; Staber, Philipp B

    2017-12-07

    T-cell prolymphocytic leukemia (T-PLL) is a rare and aggressive T-lymphoid malignancy usually refractory to current treatment strategies and associated with short overall survival. By applying next-generation functional testing of primary patient-derived lymphoma cells using a library of 106 US Food and Drug Administration (FDA)-approved anticancer drugs or compounds currently in clinical development, we set out to identify novel effective treatments for T-PLL patients. We found that the B-cell lymphoma 2 (BCL-2) inhibitor venetoclax (ABT-199) demonstrated the strongest T-PLL-specific response when comparing individual ex vivo drug response in 86 patients with refractory hematologic malignancies. Mechanistically, responses to venetoclax correlated with protein expression of BCL-2 but not with expression of the BCL-2 family members myeloid cell leukemia 1 (MCL-1) and BCL-XL in lymphoma cells. BCL-2 expression was inversely correlated with the expression of MCL-1. Based on the ex vivo responses, venetoclax treatment was commenced in 2 late-stage refractory T-PLL patients resulting in clinical responses. Our findings demonstrate first evidence of single-agent activity of venetoclax both ex vivo and in humans, offering a novel agent in T-PLL. © 2017 by The American Society of Hematology.

  1. Programmed cell death 1 inhibits inflammatory helper T-cell development through controlling the innate immune response

    PubMed Central

    Rui, Yuxiang; Honjo, Tasuku; Chikuma, Shunsuke

    2013-01-01

    Programmed cell death 1 (PD-1) is an inhibitory coreceptor on immune cells and is essential for self-tolerance because mice genetically lacking PD-1 (PD-1−/−) develop spontaneous autoimmune diseases. PD-1−/− mice are also susceptible to severe experimental autoimmune encephalomyelitis (EAE), characterized by a massive production of effector/memory T cells against myelin autoantigen, the mechanism of which is not fully understood. We found that an increased primary response of PD-1−/− mice to heat-killed mycobacteria (HKMTB), an adjuvant for EAE, contributed to the enhanced production of T-helper 17 (Th17) cells. Splenocytes from HKMTB-immunized, lymphocyte-deficient PD-1−/− recombination activating gene (RAG)2−/− mice were found to drive antigen-specific Th17 cell differentiation more efficiently than splenocytes from HKMTB-immunized PD-1+/+ RAG2−/− mice. This result suggested PD-1’s involvement in the regulation of innate immune responses. Mice reconstituted with PD-1−/− RAG2−/− bone marrow and PD-1+/+ CD4+ T cells developed more severe EAE compared with the ones reconstituted with PD-1+/+ RAG2−/− bone marrow and PD-1+/+ CD4+ T cells. We found that upon recognition of HKMTB, CD11b+ macrophages from PD-1−/− mice produced very high levels of IL-6, which helped promote naive CD4+ T-cell differentiation into IL-17–producing cells. We propose a model in which PD-1 negatively regulates antimycobacterial responses by suppressing innate immune cells, which in turn prevents autoreactive T-cell priming and differentiation to inflammatory effector T cells. PMID:24043779

  2. Detailed analysis of Epstein–Barr virus-specific CD4+ and CD8+ T cell responses during infectious mononucleosis

    PubMed Central

    Scherrenburg, J; Piriou, E R W A N; Nanlohy, N M; van Baarle, D

    2008-01-01

    We studied simultaneously Epstein–Barr virus (EBV)-specific CD4+ and CD8+ T cell responses during and after infectious mononucleosis (IM), using a previously described 12-day stimulation protocol with EBNA1 or BZLF1 peptide pools. Effector function of EBV-specific T cells was determined after restimulation by measuring intracellular interferon-γ production. During IM, BZLF1-specifc CD4+ T cell responses were dominant compared with CD8+ T cell responses. EBNA1-specific CD4+ and CD8+ T cell responses were low and remained similar for 6 months. However, 6 months after IM, BZLF1-specific CD4+ T cell responses had declined, but CD8+ T cell responses had increased. At diagnosis, EBV-specific CD8+ T cells as studied by human leucocyte antigen class I tetramer staining comprised a tetramerbrightCD8bright population consisting mainly of CD27+ memory T cells and a tetramerdimCD8dim population consisting primarily of CD27- effector T cells. The remaining EBV-specific CD8+ T cell population 6 months after the diagnosis of IM consisted mainly of tetramerbrightCD8bright CD27+ T cells, suggesting preferential preservation of memory T cells after contraction of the EBV-specific T cell pool. PMID:18549439

  3. CD4 and CD8 T-Cell Responses to Mycobacterial Antigens in African Children

    PubMed Central

    Tena-Coki, Nontobeko G.; Scriba, Thomas J.; Peteni, Nomathemba; Eley, Brian; Wilkinson, Robert J.; Andersen, Peter; Hanekom, Willem A.; Kampmann, Beate

    2010-01-01

    Rationale: The current tuberculosis (TB) vaccine, bacille Calmette-Guérin (BCG), does not provide adequate protection against TB disease in children. Furthermore, more efficacious TB vaccines are needed for children with immunodeficiencies such as HIV infection, who are at highest risk of disease. Objectives: To characterize mycobacteria-specific T cells in children who might benefit from vaccination against TB, focusing on responses to antigens contained in novel TB vaccines. Methods: Whole blood was collected from three groups of BCG-vaccinated children: HIV-seronegative children receiving TB treatment (n = 30), HIV-infected children (n = 30), and HIV-unexposed healthy children (n = 30). Blood was stimulated with Ag85B and TB10.4, or purified protein derivative, and T-cell cytokine production by CD4 and CD8 was determined by flow cytometry. The memory phenotype of antigen-specific CD4 and CD8 T cells was also determined. Measurements and Main Results: Mycobacteria-specific CD4 and CD8 T-cell responses were detectable in all three groups of children. Children receiving TB treatment had significantly higher frequencies of antigen-specific CD4 T cells compared with HIV-infected children (P = 0.0176). No significant differences in magnitude, function, or phenotype of specific T cells were observed in HIV-infected children compared with healthy control subjects. CD4 T cells expressing IFN-γ, IL-2, or both expressed a CD45RA−CCR7−CD27+/− effector memory phenotype. Mycobacteria-specific CD8 T cells expressed mostly IFN-γ in all groups of children; these cells expressed CD45RA−CCR7−CD27+/− or CD45RA+CCR7−CD27+/− effector memory phenotypes. Conclusions: Mycobacteria-specific T-cell responses could be demonstrated in all groups of children, suggesting that the responses could be boosted by new TB vaccines currently in clinical trials. PMID:20224065

  4. β-cell specific T-lymphocyte response has a distinct inflammatory phenotype in children with Type 1 diabetes compared with adults.

    PubMed

    Arif, S; Gibson, V B; Nguyen, V; Bingley, P J; Todd, J A; Guy, C; Dunger, D B; Dayan, C M; Powrie, J; Lorenc, A; Peakman, M

    2017-03-01

    To examine the hypothesis that the quality, magnitude and breadth of helper T-lymphocyte responses to β cells differ in Type 1 diabetes according to diagnosis in childhood or adulthood. We studied helper T-lymphocyte reactivity against β-cell autoantigens by measuring production of the pro-inflammatory cytokine interferon-γ and the anti-inflammatory cytokine interleukin-10, using enzyme-linked immunospot assays in 61 people with Type 1 diabetes (within 3 months of diagnosis, positive for HLA DRB1*0301 and/or *0401), of whom 33 were children/adolescents, and a further 91 were unaffected siblings. Interferon-γ responses were significantly more frequent in children with Type 1 diabetes compared with adults (85 vs 61%; P = 0.04). Insulin and proinsulin peptides were preferentially targeted in children (P = 0.0001 and P = 0.04, respectively) and the breadth of the interferon-γ response was also greater, with 70% of children having an interferon-γ response to three or more peptides compared with 14% of adults (P < 0.0001). Islet β-cell antigen-specific interleukin-10 responses were similar in children and adults in terms of frequency, breadth and magnitude, with the exception of responses to glutamic acid decarboxylase 65, which were significantly less frequent in adults. At diagnosis of Type 1 diabetes, pro-inflammatory autoreactivity is significantly more prevalent, focuses on a wider range of targets, and is more focused on insulin/proinsulin in children than adults. We interpret this as indicating a more aggressive immunological response in the younger age group that is especially characterized by loss of tolerance to proinsulin. These findings highlight the existence of age-related heterogeneity in Type 1 diabetes pathogenesis that could have relevance to the development of immune-based therapies. © 2016 Diabetes UK.

  5. Expanded breadth of the T-cell response to mosaic HIV-1 envelope DNA vaccination

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Korber, Bette; Fischer, William; Wallstrom, Timothy

    2009-01-01

    An effective AIDS vaccine must control highly diverse circulating strains of HIV-1. Among HIV -I gene products, the envelope (Env) protein contains variable as well as conserved regions. In this report, an informatic approach to the design of T-cell vaccines directed to HIV -I Env M group global sequences was tested. Synthetic Env antigens were designed to express mosaics that maximize the inclusion of common potential Tcell epitope (PTE) 9-mers and minimize the inclusion of rare epitopes likely to elicit strain-specific responses. DNA vaccines were evaluated using intracellular cytokine staining (ICS) in inbred mice with a standardized panel of highlymore » conserved 15-mer PTE peptides. I, 2 and 3 mosaic sets were developed that increased theoretical epitope coverage. The breadth and magnitude ofT-cell immunity stimulated by these vaccines were compared to natural strain Env's; additional comparisons were performed on mutant Env's, including gpl60 or gpl45 with or without V regions and gp41 deletions. Among them, the 2 or 3 mosaic Env sets elicited the optimal CD4 and CD8 responses. These responses were most evident in CD8 T cells; the 3 mosaic set elicited responses to an average of 8 peptide pools compared to 2 pools for a set of3 natural Env's. Synthetic mosaic HIV -I antigens can therefore induce T-cell responses with expanded breadth and may facilitate the development of effective T -cell-based HIV -1 vaccines.« less

  6. Targeting of non-dominant antigens as a vaccine strategy to broaden T-cell responses during chronic viral infection.

    PubMed

    Holst, Peter J; Jensen, Benjamin A H; Ragonnaud, Emeline; Thomsen, Allan R; Christensen, Jan P

    2015-01-01

    In this study, we compared adenoviral vaccine vectors with the capacity to induce equally potent immune responses against non-dominant and immunodominant epitopes of murine lymphocytic choriomeningitis virus (LCMV). Our results demonstrate that vaccination targeting non-dominant epitopes facilitates potent virus-induced T-cell responses against immunodominant epitopes during subsequent challenge with highly invasive virus. In contrast, when an immunodominant epitope was included in the vaccine, the T-cell response associated with viral challenge remained focussed on that epitope. Early after challenge with live virus, the CD8+ T cells specific for vaccine-encoded epitopes, displayed a phenotype typically associated with prolonged/persistent antigenic stimulation marked by high levels of KLRG-1, as compared to T cells reacting to epitopes not included in the vaccine. Notably, this association was lost over time in T cells specific for the dominant T cell epitopes, and these cells were fully capable of expanding in response to a new viral challenge. Overall, our data suggests a potential for broadening of the antiviral CD8+ T-cell response by selecting non-dominant antigens to be targeted by vaccination. In addition, our findings suggest that prior adenoviral vaccination is not likely to negatively impact the long-term and protective immune response induced and maintained by a vaccine-attenuated chronic viral infection.

  7. Reduced response to Epstein–Barr virus antigens by T-cells in systemic lupus erythematosus patients

    PubMed Central

    Draborg, Anette Holck; Jacobsen, Søren; Westergaard, Marie; Mortensen, Shila; Larsen, Janni Lisander; Houen, Gunnar; Duus, Karen

    2014-01-01

    Objective Epstein–Barr virus (EBV) has for long been associated with systemic lupus erythematosus (SLE). In this study, we investigated the levels of latent and lytic antigen EBV-specific T-cells and antibodies in SLE patients. Methods T cells were analyzed by flow cytometry and antibodies were analyzed by enzyme-linked immunosorbent assay. Results SLE patients showed a significantly reduced number of activated (CD69) T-cells upon ex vivo stimulation with EBV nuclear antigen (EBNA) 1 or EBV early antigen diffuse (EBV-EA/D) in whole blood samples compared with healthy controls. Also, a reduced number of T-cells from SLE patients were found to produce interferon-γ upon stimulation with these antigens. Importantly, responses to a superantigen were normal in SLE patients. Compared with healthy controls, SLE patients had fewer EBV-specific T-cells but higher titres of antibodies against EBV. Furthermore, an inverse correlation was revealed between the number of lytic antigen EBV-specific T-cells and disease activity of the SLE patients, with high-activity SLE patients having fewer T-cells than low-activity SLE patients. Conclusions These results indicate a limited or a defective EBV-specific T-cell response in SLE patients, which may suggest poor control of EBV infection in SLE with an immune reaction shift towards a humoral response in an attempt to control viral reactivation. A role for decreased control of EBV as a contributing agent in the development or exacerbation of SLE is proposed. PMID:25396062

  8. T cell epitope immunotherapy ameliorates allergic responses in a murine model of shrimp allergy.

    PubMed

    Wai, C Y Y; Leung, N Y H; Leung, P S C; Chu, K H

    2016-03-01

    Shellfish allergy is one of the most common food hypersensitivities worldwide but allergen-specific immunotherapy for shellfish allergy is not yet available. We believe that T cell peptide-based immunotherapy holds the potential for modulating allergic responses without IgE cross-linking. We sought to identify the immunodominant T cell epitopes of tropomyosin, the major shrimp allergen of Metapenaeus ensis (Met e 1), and to evaluate their therapeutic effects in a Balb/c mouse model of Met e 1 hypersensitivity. T cell epitopes of Met e 1 were first identified based on the proliferation and cytokine responses of splenocytes isolated from Met e 1-sensitized Balb/c mice upon stimulation by 18 synthetic peptides that span the full-length Met e 1. The immunodominant T cell peptides identified were then fed orally to Met e 1-sensitized Balb/c mice twice a week for four weeks. Allergic responses, serological antibody levels, intestinal histology and systemic and local cytokine profiles were compared between the treated and the untreated groups. Six major Met e 1 T cell epitopes were identified. Mice treated with the T cell epitope peptide mixture demonstrated an amelioration of systemic allergic symptoms and a significant reduction in Th2-associated antibody and cytokine responses. These benefits were accompanied by a shift to a balanced Th1/Th2 response, induction of IgG2a antibodies possessing in vitro and in vivo blocking activities and the induction of regulatory T cell responses. T cell epitope-based oral immunotherapy is effective in reducing allergic responses towards shrimp tropomyosin. This is a novel strategy for clinical management of shellfish allergy and is a model for mechanistic studies of oral immunotherapy. © 2015 John Wiley & Sons Ltd.

  9. Age-related T cell responses to allergens in childhood.

    PubMed

    Smart, J M; Suphioglu, C; Kemp, A S

    2003-03-01

    T cell priming, as determined by allergen-induced proliferative responses, is believed to occur principally in early childhood in both atopic and non-atopic infants under the influence of multiple factors including environmental allergen exposure. It is considered that T cell priming with expansion of Th2 cells is a crucial factor in the development of atopic disease. To examine T cell priming to commonly encountered allergens in childhood in relation to age. In a cross-sectional study T cell proliferation in relation to age was examined for three common allergens, ovalbumin (OVA), house dust mite (HDM) and rye grass pollen (RYE), in atopic and non-atopic children. The effect of age on Th1 (IFN-gamma) and Th2 (IL-5 and IL-13) cytokine production in response to these allergens was investigated to examine the possibility of immune deviation with time. A significant increase in T cell proliferation with age was observed with RYE among atopic children only. However, the same was not observed with the two other allergens studied (i.e. OVA and HDM). In addition, RYE-induced (but not HDM or OVA) cytokine production showed an increased Th2 deviation with age as reflected in the increasing IL-5/IFN-gamma and IL-13/IFN-gamma ratios only among the atopic subjects with rye grass pollen sensitivity. These findings suggest that grass pollen sensitivity in childhood is accompanied by a progressive accumulation of allergen-primed T cells and progressive deviation of the allergen-induced cytokine response towards a Th2 response in atopic subjects throughout childhood.

  10. The CD3-Zeta Chimeric Antigen Receptor Overcomes TCR Hypo-Responsiveness of Human Terminal Late-Stage T Cells

    PubMed Central

    Awerkiew, Sabine; Schmidt, Annette; Hombach, Andreas A.; Pfister, Herbert; Abken, Hinrich

    2012-01-01

    Adoptive therapy of malignant diseases with tumor-specific cytotoxic T cells showed remarkable efficacy in recent trials. Repetitive T cell receptor (TCR) engagement of target antigen, however, inevitably ends up in hypo-responsive cells with terminally differentiated KLRG-1+ CD57+ CD7− phenotype limiting their therapeutic efficacy. We here revealed that hypo-responsiveness of CMV-specific late-stage CD8+ T cells is due to reduced TCR synapse formation compared to younger cells. Membrane anchoring of TCR components contributes to T cell hypo-responsiveness since dislocation of galectin-3 from the synapse by swainsonine restored both TCR synapse formation and T cell response. Transgenic expression of a CD3-zeta signaling chimeric antigen receptor (CAR) recovered hypo-responsive T cells to full effector functions indicating that the defect is restricted to TCR membrane components while synapse formation of the transgenic CAR was not blocked. CAR engineered late-stage T cells released cytokines and mediated redirected cytotoxicity as efficiently as younger effector T cells. Our data provide a rationale for TCR independent, CAR mediated activation in the adoptive cell therapy to avoid hypo-responsiveness of late-stage T cells upon repetitive antigen encounter. PMID:22292024

  11. Adjuvant-enhanced CD4 T Cell Responses are Critical to Durable Vaccine Immunity.

    PubMed

    Martins, Karen A O; Cooper, Christopher L; Stronsky, Sabrina M; Norris, Sarah L W; Kwilas, Steven A; Steffens, Jesse T; Benko, Jacqueline G; van Tongeren, Sean A; Bavari, Sina

    2016-01-01

    Protein-based vaccines offer a safer alternative to live-attenuated or inactivated vaccines but have limited immunogenicity. The identification of adjuvants that augment immunogenicity, specifically in a manner that is durable and antigen-specific, is therefore critical for advanced development. In this study, we use the filovirus virus-like particle (VLP) as a model protein-based vaccine in order to evaluate the impact of four candidate vaccine adjuvants on enhancing long term protection from Ebola virus challenge. Adjuvants tested include poly-ICLC (Hiltonol), MPLA, CpG 2395, and alhydrogel. We compared and contrasted antibody responses, neutralizing antibody responses, effector T cell responses, and T follicular helper (Tfh) cell frequencies with each adjuvant's impact on durable protection. We demonstrate that in this system, the most effective adjuvant elicits a Th1-skewed antibody response and strong CD4 T cell responses, including an increase in Tfh frequency. Using immune-deficient animals and adoptive transfer of serum and cells from vaccinated animals into naïve animals, we further demonstrate that serum and CD4 T cells play a critical role in conferring protection within effective vaccination regimens. These studies inform on the requirements of long term immune protection, which can potentially be used to guide screening of clinical-grade adjuvants for vaccine clinical development.

  12. HIV infection-induced transcriptional program in renal tubular epithelial cells activates a CXCR2-driven CD4+ T-cell chemotactic response.

    PubMed

    Chen, Ping; Yi, Zhengzi; Zhang, Weijia; Klotman, Mary E; Chen, Benjamin K

    2016-07-31

    Viral replication and interstitial inflammation play important roles in the pathogenesis of HIV-associated nephropathy. Cell-cell interactions between renal tubule epithelial cells (RTECs) and HIV-infected T cells can trigger efficient virus internalization and viral gene expression by RTEC. To understand how HIV replication initiates HIV-associated nephropathy, we studied the cellular response of RTECs to HIV, examining the transcriptional profiles of primary RTECs exposed to cell-free HIV or HIV-infected T cells. HIV-induced gene expression in hRTECs was examined in vitro by Illumina RNA deep sequencing and revealed an innate response to HIV, which was subclassified by gene ontology biological process terms. Chemokine responses were examined by CD4 T-cell chemotaxis assays. As compared with cell-free virus infection, exposure to HIV-infected T cells elicited a stronger upregulation of inflammatory and immune response genes. A major category of upregulated genes are chemokine/cytokine families involved in inflammation and immune response, including inflammatory cytokines CCL20, IL6 and IL8-related chemokines: IL8, CXCL1, CXCL2, CXCL3, CXCL5 and CXCL6. Supernatants from virus-exposed RTECs contained strong chemoattractant activity on primary CD4 T cells, which was potently blocked by a CXCR2 antagonist that antagonizes IL8-related chemokines. We observed a preferential migration of CXCR2-expressing, central memory CD4 T cells in response to HIV infection of RTECs. Interactions between primary RTECs and HIV-infected T cells result in potent induction of inflammatory response genes and release of cytokines/chemokines from RTECs that can attract additional T cells. Activation of these genes reflects an innate response to HIV by nonimmune cells.

  13. Preserved immune functionality and high CMV-specific T-cell responses in HIV-infected individuals with poor CD4+ T-cell immune recovery.

    PubMed

    Gómez-Mora, Elisabet; García, Elisabet; Urrea, Victor; Massanella, Marta; Puig, Jordi; Negredo, Eugenia; Clotet, Bonaventura; Blanco, Julià; Cabrera, Cecilia

    2017-09-15

    Poor CD4 + T-cell recovery after cART has been associated with skewed T-cell maturation, inflammation and immunosenescence; however, T-cell functionality in those individuals has not been fully characterized. In the present study, we assessed T-cell function by assessing cytokine production after polyclonal, CMV and HIV stimulations of T-cells from ART-suppressed HIV-infected individuals with CD4 + T-cell counts >350 cells/μL (immunoconcordants) or <350 cells/μL (immunodiscordants). A group of HIV-uninfected individuals were also included as controls. Since CMV co-infection significantly affected T-cell maturation and polyfunctionality, only CMV + individuals were analyzed. Despite their reduced and skewed CD4 + T-cell compartment, immunodiscordant individuals showed preserved polyclonal and HIV-specific responses. However, CMV response in immunodiscordant participants was significantly different from immunoconcordant or HIV-seronegative individuals. In immunodiscordant subjects, the magnitude of IFN-γ + CD8 + and IL-2 + CD4 + T-cells in response to CMV was higher and differently associated with the CD4 + T-cell maturation profile., showing an increased frequency of naïve, central memory and EMRA CMV-specific CD4 + T-cells. In conclusion, CD4 + and CD8 + T-cell polyfunctionality was not reduced in immunodiscordant individuals, although heightened CMV-specific immune responses, likely related to subclinical CMV reactivations, may be contributing to the skewed T-cell maturation and the higher risk of clinical progression observed in those individuals.

  14. Understanding delayed T-cell priming, lung recruitment, and airway luminal T-cell responses in host defense against pulmonary tuberculosis.

    PubMed

    Shaler, Christopher R; Horvath, Carly; Lai, Rocky; Xing, Zhou

    2012-01-01

    Mycobacterium tuberculosis (M.tb), the causative bacterium of pulmonary tuberculosis (TB), is a serious global health concern. Central to M.tb effective immune avoidance is its ability to modulate the early innate inflammatory response and prevent the establishment of adaptive T-cell immunity for nearly three weeks. When compared with other intracellular bacterial lung pathogens, such as Legionella pneumophila, or even closely related mycobacterial species such as M. smegmatis, this delay is astonishing. Customarily, the alveolar macrophage (AM) acts as a sentinel, detecting and alerting surrounding cells to the presence of an invader. However, in the case of M.tb, this may be impaired, thus delaying the recruitment of antigen-presenting cells (APCs) to the lung. Upon uptake by APC populations, M.tb is able to subvert and delay the processing of antigen, MHC class II loading, and the priming of effector T cell populations. This delay ultimately results in the deferred recruitment of effector T cells to not only the lung interstitium but also the airway lumen. Therefore, it is of upmost importance to dissect the mechanisms that contribute to the delayed onset of immune responses following M.tb infection. Such knowledge will help design the most effective vaccination strategies against pulmonary TB.

  15. Detecting Antigen-Specific T Cell Responses: From Bulk Populations to Single Cells.

    PubMed

    Phetsouphanh, Chansavath; Zaunders, John James; Kelleher, Anthony Dominic

    2015-08-12

    A new generation of sensitive T cell-based assays facilitates the direct quantitation and characterization of antigen-specific T cell responses. Single-cell analyses have focused on measuring the quality and breadth of a response. Accumulating data from these studies demonstrate that there is considerable, previously-unrecognized, heterogeneity. Standard assays, such as the ICS, are often insufficient for characterization of rare subsets of cells. Enhanced flow cytometry with imaging capabilities enables the determination of cell morphology, as well as the spatial localization of the protein molecules within a single cell. Advances in both microfluidics and digital PCR have improved the efficiency of single-cell sorting and allowed multiplexed gene detection at the single-cell level. Delving further into the transcriptome of single-cells using RNA-seq is likely to reveal the fine-specificity of cellular events such as alternative splicing (i.e., splice variants) and allele-specific expression, and will also define the roles of new genes. Finally, detailed analysis of clonally related antigen-specific T cells using single-cell TCR RNA-seq will provide information on pathways of differentiation of memory T cells. With these state of the art technologies the transcriptomics and genomics of Ag-specific T cells can be more definitively elucidated.

  16. Detecting Antigen-Specific T Cell Responses: From Bulk Populations to Single Cells

    PubMed Central

    Phetsouphanh, Chansavath; Zaunders, John James; Kelleher, Anthony Dominic

    2015-01-01

    A new generation of sensitive T cell-based assays facilitates the direct quantitation and characterization of antigen-specific T cell responses. Single-cell analyses have focused on measuring the quality and breadth of a response. Accumulating data from these studies demonstrate that there is considerable, previously-unrecognized, heterogeneity. Standard assays, such as the ICS, are often insufficient for characterization of rare subsets of cells. Enhanced flow cytometry with imaging capabilities enables the determination of cell morphology, as well as the spatial localization of the protein molecules within a single cell. Advances in both microfluidics and digital PCR have improved the efficiency of single-cell sorting and allowed multiplexed gene detection at the single-cell level. Delving further into the transcriptome of single-cells using RNA-seq is likely to reveal the fine-specificity of cellular events such as alternative splicing (i.e., splice variants) and allele-specific expression, and will also define the roles of new genes. Finally, detailed analysis of clonally related antigen-specific T cells using single-cell TCR RNA-seq will provide information on pathways of differentiation of memory T cells. With these state of the art technologies the transcriptomics and genomics of Ag-specific T cells can be more definitively elucidated. PMID:26274954

  17. An Enhanced ELISPOT Assay for Sensitive Detection of Antigen-Specific T Cell Responses to Borrelia burgdorferi

    PubMed Central

    Jin, Chenggang; Roen, Diana R.; Lehmann, Paul V.; Kellermann, Gottfried H.

    2013-01-01

    Lyme Borreliosis is an infectious disease caused by the spirochete Borrelia burgdorferi that is transmitted through the bite of infected ticks. Both B cell-mediated humoral immunity and T cell immunity develop during natural Borrelia infection. However, compared with humoral immunity, the T cell response to Borrelia infection has not been well elucidated. In this study, a novel T cell-based assay was developed and validated for the sensitive detection of antigen-specific T cell response to B. burgdorferi. Using interferon-γ as a biomarker, we developed a new enzyme-linked immunospot method (iSpot LymeTM) to detect Borrelia antigen-specific effector/memory T cells that were activated in vivo by exposing them to recombinant Borrelia antigens ex vivo. To test this new method as a potential laboratory diagnostic tool, we performed a clinical study with a cohort of Borrelia positive patients and healthy controls. We demonstrated that the iSpot Lyme assay has a significantly higher specificity and sensitivity compared with the Western Blot assay that is currently used as a diagnostic measure. A comprehensive evaluation of the T cell response to Borrelia infection should, therefore, provide new insights into the pathogenesis, diagnosis, treatment and monitoring of Lyme disease. PMID:24709800

  18. Natural killer cells regulate T cell immune responses in primary biliary cirrhosis.

    PubMed

    Shimoda, Shinji; Hisamoto, Satomi; Harada, Kenichi; Iwasaka, Sho; Chong, Yong; Nakamura, Minoru; Bekki, Yuki; Yoshizumi, Tomoharu; Shirabe, Ken; Ikegami, Toru; Maehara, Yoshihiko; He, Xiao-Song; Gershwin, M Eric; Akashi, Koichi

    2015-12-01

    The hallmark of primary biliary cirrhosis (PBC) is the presence of autoreactive T- and B-cell responses that target biliary epithelial cells (BECs). Biliary cell cytotoxicity is dependent upon initiation of innate immune responses followed by chronic adaptive, as well as bystander, mechanisms. Critical to these mechanisms are interactions between natural killer (NK) cells and BECs. We have taken advantage of the ability to isolate relatively pure viable preparations of liver-derived NK cells, BECs, and endothelial cells, and studied interactions between NK cells and BECs and focused on the mechanisms that activate autoreactive T cells, their dependence on interferon (IFN)-γ, and expression of BEC major histocompatibility complex (MHC) class I and II molecules. Here we show that at a high NK/BEC ratio, NK cells are cytotoxic for autologous BECs, but are not dependent on autoantigen, yet still activate autoreactive CD4(+) T cells in the presence of antigen presenting cells. In contrast, at a low NK/BEC ratio, BECs are not lysed, but IFN-γ production is induced, which facilitates expression of MHC class I and II molecules on BEC and protects them from lysis upon subsequent exposure to autoreactive NK cells. Furthermore, IFN-γ secreted from NK cells after exposure to autologous BECs is essential for this protective function and enables autoreactive CD4(+) T cells to become cytopathic. NK cell-mediated innate immune responses are likely critical at the initial stage of PBC, but also facilitate and maintain the chronic cytopathic effect of autoantigen-specific T cells, essential for progression of disease. © 2015 by the American Association for the Study of Liver Diseases.

  19. Induction and function of virus-specific CD4+ T cell responses

    PubMed Central

    Whitmire, Jason K.

    2010-01-01

    CD4+ T cells -- often referred to as T-helper cells -- play a central role in immune defense and pathogenesis. Virus infections and vaccines stimulate and expand populations of antigen-specific CD4+ T cells in mice and in man. These virus-specific CD4+ T cells are extremely important in antiviral protection: deficiencies in CD4+ T cells are associated with virus reactivation, generalized susceptibility to opportunistic infections, and poor vaccine efficacy. As described below, CD4+ T cells influence effector and memory CD8+ T cell responses, humoral immunity, and the antimicrobial activity of macrophages and are involved in recruiting cells to sites of infection. This review summarizes a few key points about the dynamics of the CD4+ T cell response to virus infection, the positive role of pro-inflammatory cytokines in the differentiation of virus-specific CD4+ T cells, and new areas of investigation to improve vaccines against virus infection. PMID:21236461

  20. Invariant NKT Cells Regulate the CD8 T Cell Response during Theiler's Virus Infection

    PubMed Central

    Mars, Lennart T.; Mas, Magali; Beaudoin, Lucie; Bauer, Jan; Leite-de-Moraes, Maria; Lehuen, Agnès; Bureau, Jean-Francois; Liblau, Roland S.

    2014-01-01

    Invariant NKT cells are innate lymphocytes with a broad tissue distribution. Here we demonstrate that iNKT cells reside in the central nervous system (CNS) in the absence of inflammation. Their presence in the CNS dramatically augments following inoculation of C57Bl/6 mice with the neurotropic Theiler's murine encephalomyelitis virus (TMEV). At the peak of inflammation the cellular infiltrate comprises 45 000 iNKT cells for 1 250 CD8 T cells specific for the immunodominant TMEV epitope. To study the interaction between these two T cell subsets, we infected both iNKT cell deficient Jα18-/- mice and iNKT cell enriched Vα14 transgenic mice with TMEV. The CD8 T cell response readily cleared TMEV infection in the iNKT cell deficient mice. However, in the iNKT cell enriched mice TMEV infection persisted and was associated with significant mortality. This was caused by the inhibition of the CD8 T cell response in the cervical lymph nodes and spleen after T cell priming. Taken together we demonstrate that iNKT cells reside in the CNS in the absence of inflammation and that their enrichment is associated with the inhibition of the anti-viral CD8 T cell response and an augmented mortality during acute encephalomyelitis. PMID:24498175

  1. T-cell help permits memory CD8(+) T-cell inflation during cytomegalovirus latency.

    PubMed

    Walton, Senta M; Torti, Nicole; Mandaric, Sanja; Oxenius, Annette

    2011-08-01

    CD4(+) T cells are implied to sustain CD8(+) T-cell responses during persistent infections. As CD4(+) T cells are often themselves antiviral effectors, they might shape CD8(+) T-cell responses via help or via controlling antigen load. We used persistent murine CMV (MCMV) infection to dissect the impact of CD4(+) T cells on virus-specific CD8(+) T cells, distinguishing between increased viral load in the absence of CD4(+) T cells and CD4(+) T-cell-mediated helper mechanisms. Absence of T-helper cells was associated with sustained lytic MCMV replication and led to a slow and gradual reduction of the size and function of the MCMV-specific CD8(+) T-cell pool. However, when virus replication was controlled in the absence of CD4(+) T cells, CD8(+) T-cell function was comparably impaired, but in addition CD8(+) T-cell inflation, a hallmark of CMV infection, was completely abolished. Thus, CD8(+) T-cell inflation during latent CMV infection is strongly dependent on CD4(+) T-cell helper functions, which can partially be compensated by ongoing lytic viral replication in the absence of CD4(+) T cells. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Acid sphingomyelinase mediates human CD4+ T-cell signaling: potential roles in T-cell responses and diseases

    PubMed Central

    Bai, Aiping; Guo, Yuan

    2017-01-01

    Acid sphingomyelinase (ASM) is a lipid hydrolase. By generating ceramide, ASM had been reported to have an important role in regulating immune cell functions inclusive of macrophages, NK cells, and CD8+ T cells, whereas the role of ASM bioactivity in regulation of human CD4+ T-cell functions remained uncertain. Recent studies have provided novel findings in this field. Upon stimulation of CD3 and/or CD28, ASM-dependent ceramide signaling mediates intracellular downstream signal cascades of CD3 and CD28, and regulates CD4+ T-cell activation and proliferation. Meanwhile, CD39 and CD161 have direct interactions with ASM, which mediates downstream signals inclusive of STAT3 and mTOR and thus defines human Th17 cells. Intriguingly, ASM mediates Th1 responses, but negatively regulates Treg functions. In this review, we summarized the pivotal roles of ASM in regulation of human CD4+ T-cell activation and responses. ASM/sphingolipid signaling may be a novel target for the therapy of human autoimmune diseases. PMID:28749465

  3. Deficient EBV-specific B- and T-cell response in patients with chronic fatigue syndrome.

    PubMed

    Loebel, Madlen; Strohschein, Kristin; Giannini, Carolin; Koelsch, Uwe; Bauer, Sandra; Doebis, Cornelia; Thomas, Sybill; Unterwalder, Nadine; von Baehr, Volker; Reinke, Petra; Knops, Michael; Hanitsch, Leif G; Meisel, Christian; Volk, Hans-Dieter; Scheibenbogen, Carmen

    2014-01-01

    Epstein-Barr virus (EBV) has long been discussed as a possible cause or trigger of Chronic Fatigue Syndrome (CFS). In a subset of patients the disease starts with infectious mononucleosis and both enhanced and diminished EBV-specific antibody titers have been reported. In this study, we comprehensively analyzed the EBV-specific memory B- and T-cell response in patients with CFS. While we observed no difference in viral capsid antigen (VCA)-IgG antibodies, EBV nuclear antigen (EBNA)-IgG titers were low or absent in 10% of CFS patients. Remarkably, when analyzing the EBV-specific memory B-cell reservoir in vitro a diminished or absent number of EBNA-1- and VCA-antibody secreting cells was found in up to 76% of patients. Moreover, the ex vivo EBV-induced secretion of TNF-α and IFN-γ was significantly lower in patients. Multicolor flow cytometry revealed that the frequencies of EBNA-1-specific triple TNF-α/IFN-γ/IL-2 producing CD4(+) and CD8(+) T-cell subsets were significantly diminished whereas no difference could be detected for HCMV-specific T-cell responses. When comparing EBV load in blood immune cells, we found more frequently EBER-DNA but not BZLF-1 RNA in CFS patients compared to healthy controls suggesting more frequent latent replication. Taken together, our findings give evidence for a deficient EBV-specific B- and T-cell memory response in CFS patients and suggest an impaired ability to control early steps of EBV reactivation. In addition the diminished EBV response might be suitable to develop diagnostic marker in CFS.

  4. Role of T cells in the B-cell response: glutaraldehyde-fixed T-helper hybridoma cells synergize with the lymphokine IL-4 to induce B-cell activation and proliferation.

    PubMed

    Kubota, E; McKenzie, D T; Dutton, R W; Swain, S L

    1991-01-01

    Antigen-unselected helper T-cell hybridomas (Th) which activate normal resting B cells to RNA synthesis and proliferation in the presence of concanavalin A (Con A) have been developed. The response is completely Th cell dependent, and not restricted by the haplotype of the B-cell major histocompatibility complex (MHC). Culture supernatants from the Con A-stimulated Th hybridomas contain interleukin-4 (IL-4) and IL-2, but undetectable level of IL-5. The supernatant alone, however, does not induce B-cell activation or proliferation. Although the Con A-mediated Th cell-dependent B-cell response occurs in an MHC-unrestricted manner, the response of resting B cells can be blocked by monoclonal Ia antibody specific for the surface class II molecules of the responding B cell. The response is also blocked by monoclonal antibody to L3T4. Significant activation and proliferation of resting B cells can also be triggered by glutaraldehyde-fixed Th hybridomas and Con A when exogenous IL-4 is added. The stimulation with fixed Th hybridomas plus IL-4 can be inhibited by monoclonal anti-L3T4 or anti-Ia. These results suggest that maximal B-cell activation requires a direct helper T cell-B cell interaction which depends on availability of Ia on the B cell and L3T4 on the T cell, even when Con A overcomes the requirement for MHC-restricted T-cell recognition. We suggest that this signal, in conjunction with T-cell produced lymphokine IL-4, is responsible for the activation and subsequent proliferation of the B cells which occurs following interaction with T cells.

  5. Dendritic cell internalization of α-galactosylceramide from CD8 T cells induces potent antitumor CD8 T-cell responses.

    PubMed

    Choi, Dong Hoon; Kim, Kwang Soon; Yang, Se Hwan; Chung, Doo Hyun; Song, Boyeong; Sprent, Jonathan; Cho, Jae Ho; Sung, Young Chul

    2011-12-15

    Dendritic cells (DC) present α-galactosylceramide (αGalCer) to invariant T-cell receptor-expressing natural killer T cells (iNKT) activating these cells to secrete a variety of cytokines, which in turn results in DC maturation and activation of other cell types, including NK cells, B cells, and conventional T cells. In this study, we showed that αGalCer-pulsing of antigen-activated CD8 T cells before adoptive transfer to tumor-bearing mice caused a marked increase in donor T-cell proliferation, precursor frequency, and cytotoxic lymphocyte activity. This effect was interleukin (IL)-2 dependent and involved both natural killer T cells (NKT) and DCs, as mice lacking IL-2, NKTs, and DCs lacked any enhanced response to adoptively transferred αGalCer-loaded CD8 T cells. iNKT activation was mediated by transfer of αGalCer from the cell membrane of the donor CD8 T cells onto the αGalCer receptor CD1d which is present on host DCs. αGalCer transfer was increased by prior activation of the donor CD8 T cells and required AP-2-mediated endocytosis by host DCs. In addition, host iNKT cell activation led to strong IL-2 synthesis, thereby increasing expansion and differentiation of donor CD8 T cells. Transfer of these cells led to improved therapeutic efficacy against established solid tumors in mice. Thus, our findings illustrate how αGalCer loading of CD8 T cells after antigen activation in vitro may leverage the therapeutic potential of adoptive T-cell therapies.

  6. Defective B cell response to T-dependent immunization in lupus-prone mice

    PubMed Central

    Niu, Haitao; Sobel, Eric S.; Morel, Laurence

    2009-01-01

    Lupus anti-nuclear Abs show the characteristics of Ag-driven T cell-dependent (TD) humoral responses. If autoAgs elicit the same response as exogenous Ags, lupus should enhance humoral responses to immunization. Blunted responses to various immunizations have, however, been reported in a significant portion of lupus patients. In this study, we show that lupus-prone B6.Sle1.Sle2.Sle3 (B6.TC) mice produce significantly less Ab in response to TD immunization than congenic controls, while producing significantly more total Ig. This blunted Ab response to TD Ag could be reconstituted with B6.TC B and CD4+ T cells. Multiple defects were found in the B6.TC response to NP-KLH as compared to total Ig, including a smaller percentage of B cells participating to the NP-response, a reduced entry into germinal centers, and highly defective production of NP-specific long-lived plasma cells in the bone marrow. B6.TC plasma cells expressed reduced levels of FcγRIIb, which suggests that reduced apoptosis in resident plasma cells prevents the establishment of newly-formed NP-specific plasma cells in bone marrow niches. Overall, these results show that lupus-prone mice responded differently to auto- and exogenous antigens and suggest that low FcγRIIb, hypergammaglobulinemia and high autoantibody production would be predictive of a poor response to immunization in lupus patients. PMID:18924209

  7. Impact of regulated secretion on anti-parasitic CD8 T cell responses

    PubMed Central

    Grover, Harshita Satija; Chu, H. Hamlet; Kelly, Felice D.; Yang, Soo Jung; Reese, Michael L.; Blanchard, Nicolas; Gonzalez, Federico; Chan, Shiao Wei; Boothroyd, John C.; Shastri, Nilabh; Robey, Ellen A.

    2014-01-01

    Summary CD8 T cells play a key role in defense against the intracellular parasite Toxoplasma but why certain CD8 responses are more potent than others is not well understood. Here, we describe a parasite antigen ROP5 that elicits a modest CD8 T cell response in genetically susceptible mice. ROP5 is secreted via parasite organelles termed rhoptries that are injected directly into host cells during invasion, whereas the protective, dense granule antigen, GRA6, is constitutively secreted into the parasitophorous vacuole. Transgenic parasites in which the ROP5 antigenic epitope was targeted for secretion through dense granules led to enhanced CD8 T cell responses, whereas targeting the GRA6 epitope to rhoptries led to reduced CD8 responses. CD8 T cell responses to the dense granule-targeted ROP5 epitope resulted in reduced parasite load in the brain. These data suggest that the mode of secretion impacts the efficacy of parasite-specific CD8 T cell responses. PMID:24857659

  8. Peptide-loaded Langerhans cells, despite increased IL15 secretion and T cell activation in vitro, elicit anti-tumor T cell responses comparable to peptide-loaded monocyte-derived dendritic cells in vivo

    PubMed Central

    Romano, Emanuela; Rossi, Marco; Ratzinger, Gudrun; de Cos, Maria-Angeles; Chung, David J.; Panageas, Katherine S.; Wolchok, Jedd D.; Houghton, Alan N.; Chapman, Paul B.; Heller, Glenn; Yuan, Jianda; Young, James W.

    2013-01-01

    Purpose We compared the efficacy of human Langerhans cells (LCs) as tumor immunogens in vivo with monocyte-derived DCs (moDCs) and investigated how IL15 supports optimal DC-stimulated antitumor immunity. Experimental Design AJCC stage III/IV melanoma patients participated in this first clinical trial comparing melanoma peptide-pulsed LC with moDC vaccines (NCT00700167,www.ClinicalTrials.gov). Correlative studies evaluated mechanisms mediating IL15 support of DC-stimulated antitumor immunity. Results Both DC vaccines were safe and immunogenic for melanoma antigens. LC-based vaccines stimulated significantly greater tyrosinase-HLA-A*0201 tetramer reactivity than did moDC-based vaccines. The two DC subtypes were otherwise statistically comparable, in contrast to extensive prior data in vitro demonstrating LC superiority. LCs synthesize much more IL15 than moDCs and stimulate significantly more antigen-specific lymphocytes with a cytolytic IFN-gamma profile even without exogenous IL15. When supplemented by low dose IL15, instead of IL2, moDCs stimulate 5-6 logs more tumor antigen-specific effector memory T-cells (TEMRA) over 3-4 weeks in vitro. IL2 and IL15 can be synergistic in moDC stimulation of cytolytic T-cells. IL15 promotes T-cell expression of the antiapoptotic bcl-2 and inhibits candidate regulatory T-cell (Treg) expansion after DC stimulation, countering two effects of IL2 that do not foster tumor immunity. Conclusions MoDC-based vaccines will require exogenous IL15 to achieve clinical efficacy. Alternatively, LCs can couple the endogenous production of IL15 with potent T-cell stimulatory activity. Optimization of full length tumor antigen expression for processing into multiple immunogenic peptides for presentation by both class I and II MHC therefore merits emphasis to support more effective antitumor immunity stimulated by LCs. PMID:21355077

  9. Preserving HIV-specific T cell responses: does timing of antiretroviral therapy help?

    PubMed

    Macatangay, Bernard J C; Rinaldo, Charles R

    2015-01-01

    HIV-specific T cell responses are likely to have an important role in HIV cure strategies that aim for long-lasting viral control without antiretroviral therapy (ART). An important issue in enhancing virus-specific T cell responses is whether timing of ART can influence their magnitude and breadth. Early ART is associated with lower T cell activation, preservation of T cell numbers, smaller DNA and RNA reservoir size, and, in a single study (VISCONTI), control of plasma viremia after treatment interruption. The prevention of T cell destruction by early ART is associated with relatively low anti-HIV CD8⁺ T cell responses but stronger CD4⁺ T helper function. The relatively lower CD8⁺T cell response, which is presumably due to rapid lowering of HIV antigen burden after early ART, appears sufficient to control residual viral replication as well as viral rebound upon treatment interruption. Available evidence of starting ART during acute or early HIV infection has shown benefit in both virologic and immunologic parameters despite the lower HIV-specific CD8⁺ T cell responses observed. Encouraging as this is, more extensive data are necessary to evaluate its role in combination with immunotherapeutic and latency activation strategies that are being assessed in various HIV cure-related studies.

  10. Cytokines and the Inception of CD8 T Cell Responses

    PubMed Central

    Cox, Maureen A.; Harrington, Laurie E.; Zajac, Allan J.

    2011-01-01

    The activation and differentiation of CD8 T cells is a necessary first step that endows these cells with the phenotypic and functional properties required for the control of intracellular pathogens. The induction of the CD8 T cell responses typically results in the development of a massive overall population of effector cells, comprised of both highly functional but short-lived terminally differentiated cells, as well as a smaller subset of precursors that are predisposed to survive and transition into the memory T cell pool. In this article we discuss how inflammatory cytokines and IL-2 bias the initial response towards short-lived effector generation and also highlight the potential counterbalancing role of IL-21. PMID:21371940

  11. CD4+ T-cell responses to foot-and-mouth disease virus in vaccinated cattle.

    PubMed

    Carr, B Veronica; Lefevre, Eric A; Windsor, Miriam A; Inghese, Cristina; Gubbins, Simon; Prentice, Helen; Juleff, Nicholas D; Charleston, Bryan

    2013-01-01

    We have performed a series of studies to investigate the role of CD4(+) T-cells in the immune response to foot-and-mouth disease virus (FMDV) post-vaccination. Virus neutralizing antibody titres (VNT) in cattle vaccinated with killed FMD commercial vaccine were significantly reduced and class switching delayed as a consequence of rigorous in vivo CD4(+) T-cell depletion. Further studies were performed to examine whether the magnitude of T-cell proliferative responses correlated with the antibody responses. FMD vaccination was found to induce T-cell proliferative responses, with CD4(+) T-cells responding specifically to the FMDV antigen. In addition, gamma interferon (IFN-γ) was detected in the supernatant of FMDV antigen-stimulated PBMC and purified CD4(+) T-cells from vaccinated cattle. Similarly, intracellular IFN-γ could be detected specifically in purified CD4(+) T-cells after restimulation. It was not possible to correlate in vitro proliferative responses or IFN-γ production of PBMC with VNT, probably as a consequence of the induction of T-independent and T-dependent antibody responses and antigen non-specific T-cell responses. However, our studies demonstrate the importance of stimulating CD4(+) T-cell responses for the induction of optimum antibody responses to FMD-killed vaccines.

  12. The Role of B Cells for in Vivo T Cell Responses to a Friend Virus-Induced Leukemia

    NASA Astrophysics Data System (ADS)

    Schultz, Kirk R.; Klarnet, Jay P.; Gieni, Randall S.; Hayglass, Kent T.; Greenberg, Philip D.

    1990-08-01

    B cells can function as antigen-presenting cells and accessory cells for T cell responses. This study evaluated the role of B cells in the induction of protective T cell immunity to a Friend murine leukemia virus (F-MuLV)-induced leukemia (FBL). B cell-deficient mice exhibited significantly reduced tumor-specific CD4^+ helper and CD8^+ cytotoxic T cell responses after priming with FBL or a recombinant vaccinia virus containing F-MuLV antigens. Moreover, these mice had diminished T cell responses to the vaccinia viral antigens. Tumor-primed T cells transferred into B cell-deficient mice effectively eradicated disseminated FBL. Thus, B cells appear necessary for efficient priming but not expression of tumor and viral T cell immunity.

  13. Immunoregulatory mechanisms in Chagas disease: modulation of apoptosis in T-cell mediated immune responses.

    PubMed

    Chaves, Ana Thereza; de Assis Silva Gomes Estanislau, Juliana; Fiuza, Jacqueline Araújo; Carvalho, Andréa Teixeira; Ferreira, Karine Silvestre; Fares, Rafaelle Christine Gomes; Guimarães, Pedro Henrique Gazzinelli; de Souza Fagundes, Elaine Maria; Morato, Maria José; Fujiwara, Ricardo Toshio; da Costa Rocha, Manoel Otávio; Correa-Oliveira, Rodrigo

    2016-04-30

    Chronic Chagas disease presents different clinical manifestations ranging from asymptomatic (namely indeterminate) to severe cardiac and/or digestive. Previous results have shown that the immune response plays an important role, although no all mechanisms are understood. Immunoregulatory mechanisms such as apoptosis are important for the control of Chagas disease, possibly affecting the morbidity in chronic clinical forms. Apoptosis has been suggested to be an important mechanism of cellular response during T. cruzi infection. We aimed to further understand the putative role of apoptosis in Chagas disease and its relation to the clinical forms of the disease. Apoptosis of lymphocytes, under antigenic stimuli (soluble T. cruzi antigens - TcAg) where compared to that of non-stimulated cells. Apoptosis was evaluated using the expression of annexin and caspase 3(+) by T cells and the percentage of cells positive evaluated by flow cytometry. In addition activation and T cell markers were used for the identification of TCD4(+) and TCD8(+) subpopulations. The presence of intracellular and plasma cytokines were also evaluated. Analysis of the activation status of the peripheral blood cells showed that patients with Chagas disease presented higher levels of activation determined by the expression of activation markers, after TcAg stimulation. PCR array were used to evaluate the contribution of this mechanism in specific cell populations from patients with different clinical forms of human Chagas disease. Our results showed a reduced proliferative response associated a high expression of T CD4(+)CD62L(-) cells in CARD patients when compared with IND group and NI individuals. We also observed that both groups of patients presented a significant increase of CD4(+) and CD8(+) T cell subsets in undergoing apoptosis after in vitro stimulation with T. cruzi antigens. In CARD patients, both CD4(+) and CD8(+) T cells expressing TNF-α were highly susceptible to undergo apoptosis

  14. CD4/CD8/Dendritic cell complexes in the spleen: CD8+ T cells can directly bind CD4+ T cells and modulate their response

    PubMed Central

    Barinov, Aleksandr; Galgano, Alessia; Krenn, Gerald; Tanchot, Corinne; Vasseur, Florence

    2017-01-01

    CD4+ T cell help to CD8+ T cell responses requires that CD4+ and CD8+ T cells interact with the same antigen presenting dendritic cell (Ag+DC), but it remains controversial whether helper signals are delivered indirectly through a licensed DC and/or involve direct CD4+/CD8+ T cell contacts and/or the formation of ternary complexes. We here describe the first in vivo imaging of the intact spleen, aiming to evaluate the first interactions between antigen-specific CD4+, CD8+ T cells and Ag+DCs. We show that in contrast to CD4+ T cells which form transient contacts with Ag+DC, CD8+ T cells form immediate stable contacts and activate the Ag+DC, acquire fragments of the DC membranes by trogocytosis, leading to their acquisition of some of the DC properties. They express MHC class II, and become able to present the specific Marilyn peptide to naïve Marilyn CD4+ T cells, inducing their extensive division. In vivo, these CD8+ T cells form direct stable contacts with motile naïve CD4+ T cells, recruiting them to Ag+DC binding and to the formation of ternary complexes, where CD4+ and CD8+ T cells interact with the DC and with one another. The presence of CD8+ T cells during in vivo immune responses leads to the early activation and up-regulation of multiple functions by CD4+ T lymphocytes. Thus, while CD4+ T cell help is important to CD8+ T cell responses, CD8+ T cells can interact directly with naïve CD4+ T cells impacting their recruitment and differentiation. PMID:28686740

  15. Lysophosphatidic acid receptor-5 negatively regulates cellular responses in mouse fibroblast 3T3 cells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dong, Yan; Hirane, Miku; Araki, Mutsumi

    2014-04-04

    Highlights: • LPA{sub 5} inhibits the cell growth and motile activities of 3T3 cells. • LPA{sub 5} suppresses the cell motile activities stimulated by hydrogen peroxide in 3T3 cells. • Enhancement of LPA{sub 5} on the cell motile activities inhibited by LPA{sub 1} in 3T3 cells. • The expression and activation of Mmp-9 were inhibited by LPA{sub 5} in 3T3 cells. • LPA signaling via LPA{sub 5} acts as a negative regulator of cellular responses in 3T3 cells. - Abstract: Lysophosphatidic acid (LPA) signaling via G protein-coupled LPA receptors (LPA{sub 1}–LPA{sub 6}) mediates a variety of biological functions, including cellmore » migration. Recently, we have reported that LPA{sub 1} inhibited the cell motile activities of mouse fibroblast 3T3 cells. In the present study, to evaluate a role of LPA{sub 5} in cellular responses, Lpar5 knockdown (3T3-L5) cells were generated from 3T3 cells. In cell proliferation assays, LPA markedly stimulated the cell proliferation activities of 3T3-L5 cells, compared with control cells. In cell motility assays with Cell Culture Inserts, the cell motile activities of 3T3-L5 cells were significantly higher than those of control cells. The activity levels of matrix metalloproteinases (MMPs) were measured by gelatin zymography. 3T3-L5 cells stimulated the activation of Mmp-2, correlating with the expression levels of Mmp-2 gene. Moreover, to assess the co-effects of LPA{sub 1} and LPA{sub 5} on cell motile activities, Lpar5 knockdown (3T3a1-L5) cells were also established from Lpar1 over-expressing (3T3a1) cells. 3T3a1-L5 cells increased the cell motile activities of 3T3a1 cells, while the cell motile activities of 3T3a1 cells were significantly lower than those of control cells. These results suggest that LPA{sub 5} may act as a negative regulator of cellular responses in mouse fibroblast 3T3 cells, similar to the case for LPA{sub 1}.« less

  16. Neutral Polymer Micelle Carriers with pH-Responsive, Endosome-Releasing Activity Modulate Antigen Trafficking to Enhance CD8 T-Cell Responses

    PubMed Central

    Keller, Salka; Wilson, John T; Patilea, Gabriela I; Kern, Hanna B; Convertine, Anthony J; Stayton, Patrick S

    2014-01-01

    Synthetic subunit vaccines need to induce CD8+ cytotoxic T-cell (CTL) responses for effective vaccination against intracellular pathogens. Most subunit vaccines primarily generate humoral immune responses, with a weaker than desired CD8+ cytotoxic T-cell response. Here, a neutral, pH-responsive polymer micelle carrier that alters intracellular antigen trafficking was shown to enhance CD8+ T-cell responses with a correlated increase in cytosolic delivery and a decrease in exocytosis. Polymer diblock carriers consisted of a N-(2-hydroxypropyl) methacrylamide corona block with pendant pyridyl disulfide groups for reversible conjugation of thiolated ovalbumin, and a tercopolymer ampholytic core-forming block composed of propylacrylic acid (PAA), dimethylaminoethyl methacrylate (DMAEMA), and butyl methacrylate (BMA). The diblock copolymers self-assembled into 25–30 nm diameter micellar nanoparticles. Conjugation of ovalbumin to the micelles significantly enhanced antigen cross-presentation in vitro relative to free ovalbumin, an unconjugated physical mixture of ovalbumin and polymer, and a non pH-responsive micelle-ovalbumin control. Mechanistic studies in a murine dendritic cell line (DC2.4) demonstrated micelle-mediated enhancements in intracellular antigen retention and cytosolic antigen accumulation. Approximately 90% of initially internalized ovalbumin-conjugated micelles were retained in cells after 1.5 h, compared to only ~40% for controls. Furthermore, cells dosed with conjugates displayed 67-fold higher cytosolic antigen levels relative to soluble ovalbumin 4 h post uptake. Subcutaneous immunization of mice with ovalbumin-polymer conjugates significantly enhanced antigen-specific CD8+ T cell responses (0.4 % IFN-γ+ of CD8+) compared to immunization with soluble protein, ovalbumin and polymer mixture, and the control micelle without endosome-releasing activity. Additionally, pH-responsive carrier facilitated antigen delivery to antigen presenting cells in the

  17. Neutral polymer micelle carriers with pH-responsive, endosome-releasing activity modulate antigen trafficking to enhance CD8(+) T cell responses.

    PubMed

    Keller, Salka; Wilson, John T; Patilea, Gabriela I; Kern, Hanna B; Convertine, Anthony J; Stayton, Patrick S

    2014-10-10

    Synthetic subunit vaccines need to induce CD8(+) cytotoxic T cell (CTL) responses for effective vaccination against intracellular pathogens. Most subunit vaccines primarily generate humoral immune responses, with a weaker than desired CD8(+) cytotoxic T cell response. Here, a neutral, pH-responsive polymer micelle carrier that alters intracellular antigen trafficking was shown to enhance CD8(+) T cell responses with a correlated increase in cytosolic delivery and a decrease in exocytosis. Polymer diblock carriers consisted of a N-(2-hydroxypropyl) methacrylamide corona block with pendent pyridyl disulfide groups for reversible conjugation of thiolated ovalbumin, and a tercopolymer ampholytic core-forming block composed of propylacrylic acid (PAA), dimethylaminoethyl methacrylate (DMAEMA), and butyl methacrylate (BMA). The diblock copolymers self-assembled into 25-30nm diameter micellar nanoparticles. Conjugation of ovalbumin to the micelles significantly enhanced antigen cross-presentation in vitro relative to free ovalbumin, an unconjugated physical mixture of ovalbumin and polymer, and a non-pH-responsive micelle-ovalbumin control. Mechanistic studies in a murine dendritic cell line (DC 2.4) demonstrated micelle-mediated enhancements in intracellular antigen retention and cytosolic antigen accumulation. Approximately 90% of initially internalized ovalbumin-conjugated micelles were retained in cells after 1.5h, compared to only ~40% for controls. Furthermore, cells dosed with conjugates displayed 67-fold higher cytosolic antigen levels relative to soluble ovalbumin 4h post uptake. Subcutaneous immunization of mice with ovalbumin-polymer conjugates significantly enhanced antigen-specific CD8(+) T cell responses (0.4% IFN-γ(+) of CD8(+)) compared to immunization with soluble protein, ovalbumin and polymer mixture, and the control micelle without endosome-releasing activity. Additionally, pH-responsive carrier facilitated antigen delivery to antigen presenting cells

  18. Dissecting the T Cell Response: Proliferation Assays vs. Cytokine Signatures by ELISPOT

    PubMed Central

    Anthony, Donald D.; Milkovich, Kimberly A.; Zhang, Wenji; Rodriguez, Benigno; Yonkers, Nicole L.; Tary-Lehmann, Magdalena; Lehmann, Paul V.

    2012-01-01

    Chronic allograft rejection is in part mediated by host T cells that recognize allogeneic antigens on transplanted tissue. One factor that determines the outcome of a T cell response is clonal size, while another is the effector quality. Studies of alloimmune predictors of transplant graft survival have most commonly focused on only one measure of the alloimmune response. Because differing qualities and frequencies of the allospecific T cell response may provide distinctly different information we analyzed the relationship between frequency of soluble antigen and allo-antigen specific memory IFN-γ secreting CD4 and CD8 T cells, their ability to secrete IL-2, and their proliferative capacity, while accounting for cognate and bystander proliferation. The results show proliferative responses primarily reflect on IL-2 production by antigen-specific T cells, and that proliferating cells in such assays entail a considerable fraction of bystander cells. On the other hand, proliferation (and IL-2 production) did not reflect on the frequency of IFN-γ producing memory cells, a finding particularly accentuated in the CD8 T cell compartment. These data provide rationale for considering both frequency and effector function of pre-transplant T cell reactivity when analyzing immune predictors of graft rejection. PMID:24710419

  19. B cells as accessory cells in a Con A response of a T cell clone.

    PubMed

    Takeuchi, M; Kakiuchi, T; Taira, S; Nariuchi, H

    1987-12-01

    Accessory cell (AC) function of B cells was examined in Con A response of a cloned T cell line, 22-9D, which is Thy 1+,L3T4+,Lyt2-,H-2KbDb+ and I-Ab-.22-9D cells produced IL 2 in the presence of Con A without participation of AC. For the initiation of a proliferative response to Con A, the addition of spleen cells or spleen adherent cells was required. B cells as AC were unable to induce the proliferative response. In the presence of culture supernatant of spleen cells stimulated with Con A (CAS), 22-9D cells showed proliferative response to Con A with B cell AC. The response was inhibited by a relevant monoclonal anti-I-A antibody. Although irradiated spleen cells as AC induced IL 2 receptor expression of 22-9D cells in the presence of Con A, B cells were shown to require the addition of unknown factor(s) in CAS, which was suggested to be different from IL 1, IL 2, IL 3, or IFN-gamma, for the induction of the receptor expression on 22-9D cells.

  20. The primary immune response to Vaccinia virus vaccination includes cells with a distinct cytotoxic effector CD4 T-cell phenotype.

    PubMed

    Munier, C Mee Ling; van Bockel, David; Bailey, Michelle; Ip, Susanna; Xu, Yin; Alcantara, Sheilajen; Liu, Sue Min; Denyer, Gareth; Kaplan, Warren; Suzuki, Kazuo; Croft, Nathan; Purcell, Anthony; Tscharke, David; Cooper, David A; Kent, Stephen J; Zaunders, John J; Kelleher, Anthony D

    2016-10-17

    Smallpox was eradicated by a global program of inoculation with Vaccinia virus (VV). Robust VV-specific CD4 T-cell responses during primary infection are likely essential to controlling VV replication. Although there is increasing interest in cytolytic CD4 T-cells across many viral infections, the importance of these cells during acute VV infection is unclear. We undertook a detailed functional and genetic characterization of CD4 T-cells during acute VV-infection of humans. VV-specific T-cells were identified by up-regulation of activation markers directly ex vivo and through cytokine and co-stimulatory molecule expression. At day-13-post primary inoculation with VV, CD38highCD45RO+ CD4 T-cells were purified by cell sorting, RNA isolated and analysed by microarray. Differential expression of up-regulated genes in activated CD4 T-cells was confirmed at the mRNA and protein levels. We compared analyses of VV-specific CD4 T-cells to studies on 12 subjects with primary HIV infection (PHI). VV-specific T-cells lines were established from PBMCs collected post vaccination and checked for cytotoxicity potential. A median 11.9% CD4 T-cells were CD38highCD45RO+ at day-13 post-VV inoculation, compared to 3.0% prior and 10.4% during PHI. Activated CD4 T-cells had an up-regulation of genes related to cytolytic function, including granzymes K and A, perforin, granulysin, TIA-1, and Rab27a. No difference was seen between CD4 T-cell expression of perforin or TIA-1 to VV and PHI, however granzyme k was more dominant in the VV response. At 25:1 effector to target ratio, two VV-specific T-cell lines exhibited 62% and 30% cytotoxicity respectively and CD107a degranulation. We show for the first time that CD4 CTL are prominent in the early response to VV. Understanding the role of CD4 CTL in the generation of an effective anti-viral memory may help develop more effective vaccines for diseases such as HIV. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

  1. Generation of TCR-Expressing Innate Lymphoid-like Helper Cells that Induce Cytotoxic T Cell-Mediated Anti-leukemic Cell Response.

    PubMed

    Ueda, Norihiro; Uemura, Yasushi; Zhang, Rong; Kitayama, Shuichi; Iriguchi, Shoichi; Kawai, Yohei; Yasui, Yutaka; Tatsumi, Minako; Ueda, Tatsuki; Liu, Tian-Yi; Mizoro, Yasutaka; Okada, Chihiro; Watanabe, Akira; Nakanishi, Mahito; Senju, Satoru; Nishimura, Yasuharu; Kuzushima, Kiyotaka; Kiyoi, Hitoshi; Naoe, Tomoki; Kaneko, Shin

    2018-06-05

    CD4 + T helper (Th) cell activation is essential for inducing cytotoxic T lymphocyte (CTL) responses against malignancy. We reprogrammed a Th clone specific for chronic myelogenous leukemia (CML)-derived b3a2 peptide to pluripotency and re-differentiated the cells into original TCR-expressing T-lineage cells (iPS-T cells) with gene expression patterns resembling those of group 1 innate lymphoid cells. CD4 gene transduction into iPS-T cells enhanced b3a2 peptide-specific responses via b3a2 peptide-specific TCR. iPS-T cells upregulated CD40 ligand (CD40L) expression in response to interleukin-2 and interleukin-15. In the presence of Wilms tumor 1 (WT1) peptide, antigen-specific dendritic cells (DCs) conditioned by CD4-modified CD40L high iPS-T cells stimulated WT1-specific CTL priming, which eliminated WT1 peptide-expressing CML cells in vitro and in vivo. Thus, CD4 modification of CD40L high iPS-T cells generates innate lymphoid helper-like cells inducing bcr-abl-specific TCR signaling that mediates effectiveanti-leukemic CTL responses via DC maturation, showing potential for adjuvant immunotherapy against leukemia. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

  2. Transcutaneous immunization with a novel imiquimod nanoemulsion induces superior T cell responses and virus protection.

    PubMed

    Lopez, Pamela Aranda; Denny, Mark; Hartmann, Ann-Kathrin; Alflen, Astrid; Probst, Hans Christian; von Stebut, Esther; Tenzer, Stefan; Schild, Hansjörg; Stassen, Michael; Langguth, Peter; Radsak, Markus P

    2017-09-01

    Transcutaneous immunization (TCI) is a novel vaccination strategy utilizing the skin associated lymphatic tissue to induce immune responses. TCI using a cytotoxic T lymphocyte (CTL) epitope and the Toll-like receptor 7 (TLR7) agonist imiquimod mounts strong CTL responses by activation and maturation of skin-derived dendritic cells (DCs) and their migration to lymph nodes. However, TCI based on the commercial formulation Aldara only induces transient CTL responses that needs further improvement for the induction of durable therapeutic immune responses. Therefore we aimed to develop a novel imiquimod solid nanoemulsion (IMI-Sol) for TCI with superior vaccination properties suited to induce high quality T cell responses for enhanced protection against infections. TCI was performed by applying a MHC class I or II restricted epitope along with IMI-Sol or Aldara (each containing 5% Imiquimod) on the shaved dorsum of C57BL/6, IL-1R, Myd88, Tlr7 or Ccr7 deficient mice. T cell responses as well as DC migration upon TCI were subsequently analyzed by flow cytometry. To determine in vivo efficacy of TCI induced immune responses, CTL responses and frequency of peptide specific T cells were evaluated on day 8 or 35 post vaccination and protection in a lymphocytic choriomeningitis virus (LCMV) infection model was assessed. TCI with the imiquimod formulation IMI-Sol displayed equal skin penetration of imiquimod compared to Aldara, but elicited superior CD8 + as well as CD4 + T cell responses. The induction of T-cell responses induced by IMI-Sol TCI was dependent on the TLR7/MyD88 pathway and independent of IL-1R. IMI-Sol TCI activated skin-derived DCs in skin-draining lymph nodes more efficiently compared to Aldara leading to enhanced protection in a LCMV infection model. Our data demonstrate that IMI-Sol TCI can overcome current limitations of previous imiquimod based TCI approaches opening new perspectives for transcutaneous vaccination strategies and allowing the use of this

  3. Role of gamma-delta T cells in host response against Staphylococcus aureus-induced pneumonia

    PubMed Central

    2012-01-01

    Background Staphylococcus aureus is the major cause of hospital-acquired and community-acquired pneumonia. Host defense to S.aureus infection is largely mediated by the innate immune system. γδ T cells play an important role in innate immunity to many infectious diseases. However, less is known about the role of these cells during S.aureus-induced pneumonia. In this study, we examined the response and the role of γδ T cells to pulmonary S.aureus infection. Results Mice infected with S. aureus intranasally showed rapid γδ T cells accumulation in the lung. Deficiency of γδ T cells led to attenuated bacterial clearance and less tissue damage in lung compared with WT mice. Moreover, TCR-δ−/− mice exhibited impaired neutrophil recruitment and reduced cytokine production at the site of infection. The γδ T cells in response to pulmonary S. aureus infection mainly secreted IL-17 and γδ T cells deficiency reduced IL-17 production, which might regulate the production of neutrophil-inducing cytokine/chemokine in the S. aureus-infected lungs. Conclusions Accumulation of γδ T cells in the lungs to S. aureus infection is beneficial for bacteria clearance and also contributes to the tissue damage. These cells were the primary source of IL-17, which might influence the recruitment of neutrophils at the early stage of infection. PMID:22776294

  4. LAG-3 Confers a Competitive Disadvantage upon Antiviral CD8+ T Cell Responses.

    PubMed

    Cook, Kevin D; Whitmire, Jason K

    2016-07-01

    Ongoing clinical trials are evaluating the benefits of systemic blockade of lymphocyte activation gene-3 (LAG-3) signals to improve immunity to tumors. Those studies are founded on the well-established inhibitory role of LAG-3 in regulating CD8(+) T cells during chronic virus infection and antitumor responses. However, the T cell response in LAG-3-deficient mice is similar in size and function to that in wild type animals, suggesting LAG-3 has nuanced immune-regulatory functions. We performed a series of adoptive transfer experiments in mice to better understand the T cell-intrinsic functions of LAG-3 in the regulation of CD8(+) T cell responses. Our results indicate that LAG-3 expression by CD8(+) T cells inhibits their competitive fitness and results in a slightly reduced rate of cell division in comparison with LAG-3-deficient cells. This cell-intrinsic effect of LAG-3 was consistent across both acute and chronic virus infections. These data show that LAG-3 directly modulates the size of the T cell response and support the use of LAG-3 blockade regimens to enhance CD8(+) T cell responses. Copyright © 2016 by The American Association of Immunologists, Inc.

  5. Anti-bacterial antibody and T cell responses in bronchiectasis are differentially associated with lung colonization and disease.

    PubMed

    Jaat, Fathia G; Hasan, Sajidah F; Perry, Audrey; Cookson, Sharon; Murali, Santosh; Perry, John D; Lanyon, Clare V; De Soyza, Anthony; Todryk, Stephen M

    2018-05-30

    As a way to determine markers of infection or disease informing disease management, and to reveal disease-associated immune mechanisms, this study sought to measure antibody and T cell responses against key lung pathogens and to relate these to patients' microbial colonization status, exacerbation history and lung function, in Bronchiectasis (BR) and Chronic Obstructive Pulmonary Disease (COPD). One hundred nineteen patients with stable BR, 58 with COPD and 28 healthy volunteers were recruited and spirometry was performed. Bacterial lysates were used to measure specific antibody responses by ELISA and T cells by ELIspot. Cytokine secretion by lysate-stimulated T cells was measured by multiplex cytokine assay whilst activation phenotype was measured by flow cytometry. Typical colonization profiles were observed in BR and COPD, dominated by P.aeruginosa, H.influenzae, S.pneumoniae and M.catarrhalis. Colonization frequency was greater in BR, showing association with increased antibody responses against P.aeruginosa compared to COPD and HV, and with sensitivity of 73% and specificity of 95%. Interferon-gamma T cell responses against P.aeruginosa and S.pneumoniae were reduced in BR and COPD, whilst reactive T cells in BR had similar markers of homing and senescence compared to healthy volunteers. Exacerbation frequency in BR was associated with increased antibodies against P. aeruginosa, M.catarrhalis and S.maltophilia. T cell responses against H.influenzae showed positive correlation with FEV 1 % (r = 0.201, p = 0.033) and negative correlation with Bronchiectasis Severity Index (r = - 0.287, p = 0.0035). Our findings suggest a difference in antibody and T cell immunity in BR, with antibody being a marker of exposure and disease in BR for P.aeruginosa, M.catarrhalis and H.influenzae, and T cells a marker of reduced disease for H.influenzae.

  6. Dynamics of the cytotoxic T cell response to a model of acute viral infection.

    PubMed

    DeWitt, William S; Emerson, Ryan O; Lindau, Paul; Vignali, Marissa; Snyder, Thomas M; Desmarais, Cindy; Sanders, Catherine; Utsugi, Heidi; Warren, Edus H; McElrath, Juliana; Makar, Karen W; Wald, Anna; Robins, Harlan S

    2015-04-01

    previous work by reporting the identity of activated effector T cell clones that expand in response to the YFV 2 weeks postvaccination (as defined by their unique T cell receptor gene sequence) and by tracking clones that enter the memory compartment 3 months postvaccination. This is the first study to use high-throughput sequencing of immune cells to characterize the breadth of the antiviral effector cell response and to determine the contribution of unique virus-induced clones to the long-lived memory T cell repertoire. Thus, this study establishes a benchmark against which future vaccines can be compared to predict their efficacy. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  7. Dynamics of the Cytotoxic T Cell Response to a Model of Acute Viral Infection

    PubMed Central

    DeWitt, William S.; Emerson, Ryan O.; Lindau, Paul; Vignali, Marissa; Snyder, Thomas M.; Desmarais, Cindy; Sanders, Catherine; Utsugi, Heidi; Warren, Edus H.; McElrath, Juliana; Makar, Karen W.; Wald, Anna

    2015-01-01

    extend this previous work by reporting the identity of activated effector T cell clones that expand in response to the YFV 2 weeks postvaccination (as defined by their unique T cell receptor gene sequence) and by tracking clones that enter the memory compartment 3 months postvaccination. This is the first study to use high-throughput sequencing of immune cells to characterize the breadth of the antiviral effector cell response and to determine the contribution of unique virus-induced clones to the long-lived memory T cell repertoire. Thus, this study establishes a benchmark against which future vaccines can be compared to predict their efficacy. PMID:25653453

  8. T cell responses in senior patients with community-acquired pneumonia related to disease severity.

    PubMed

    Bian, Lu-Qin; Bi, Ying; Zhou, Shao-Wei; Chen, Zi-Dan; Wen, Jun; Shi, Jin; Mao, Ling; Wang, Ling

    2017-12-01

    Senior individuals older than 65 years of age are at a disproportionally higher risk of developing pneumonia. Impaired capacity to defend against airway infections may be one of the reasons. It is generally believed that weaker regulatory T cell responses may be beneficial to host defense against pathogens. In senior patients with community-acquired bacterial pneumonia, we investigated the frequencies and functions of regulatory T cells. Interestingly, we found that compared to age- and sex-matched healthy controls, senior pneumonia patients presented lower frequencies of Foxp3-expressing and Helios-expressing CD4 + T cells. The quantity of Foxp3 and Helios being expressed, measured by their mRNA transcription levels, was also lower in CD4 + T cells from pneumonia patients. Furthermore, following TCR and TGF-β stimulation, pneumonia patients presented impaired capacity to upregulate Foxp3 and Helios. Functional analyses revealed that CD4 + T cells from pneumonia patients secreted lower amounts of IL-10 and TGF-β, two cytokines critical to regulatory T cell-mediated suppression. Also, the expression of granzyme B and perforin, which were cytolytic molecules potentially utilized by regulatory T cells to mediate the elimination of antigen-presenting cells and effector T cells, were reduced in CD4 + CD25 + T cells from senior pneumonia patients. In addition, the CD4 + CD25 + T cells from senior pneumonia patients presented reduced capacity to suppress effector CD4 + and CD8 + T cell proliferation. Moreover, the value of pneumonia severity index was inversely correlated with several parameters of regulatory T cell function. Together, our results demonstrated that senior pneumonia patients presented a counterintuitive impairment in regulatory T cell responses that was associated with worse prognosis. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Lack of Original Antigenic Sin in Recall CD8+ T Cell Responses

    PubMed Central

    Zehn, Dietmar; Turner, Michael J.; Lefrançois, Leo; Bevan, Michael J.

    2010-01-01

    In the real world, mice and men are not immunologically naive, having been exposed to numerous antigenic challenges. Prior infections sometimes negatively impact the response to a subsequent infection. This can occur in serial infections with pathogens sharing cross-reactive Ags. At the T cell level it has been proposed that preformed memory T cells, which cross-react with low avidity to epitopes presented in subsequent infections, dampen the response of high-avidity T cells. We investigated this with a series of related MHC class-I restricted Ags expressed by bacterial and viral pathogens. In all cases, we find that high-avidity CD8+ T cell precursors, either naive or memory, massively expand in secondary cross-reactive infections to dominate the response over low-avidity memory T cells. This holds true even when >10% of the CD8+ T cell compartment consists of memory T cells that cross-react weakly with the rechallenge ligand. Occasionally, memory cells generated by low-avidity stimulation in a primary infection recognize a cross-reactive epitope with high avidity and contribute positively to the response to a second infection. Taken together, our data show that the phenomenon of original antigenic sin does not occur in all heterologous infections. PMID:20439913

  10. Dynamics of T cell, antigen-presenting cell, and pathogen interactions during recall responses in the lymph node.

    PubMed

    Chtanova, Tatyana; Han, Seong-Ji; Schaeffer, Marie; van Dooren, Giel G; Herzmark, Paul; Striepen, Boris; Robey, Ellen A

    2009-08-21

    Memory T cells circulate through lymph nodes where they are poised to respond rapidly upon re-exposure to a pathogen; however, the dynamics of memory T cell, antigen-presenting cell, and pathogen interactions during recall responses are largely unknown. We used a mouse model of infection with the intracellular protozoan parasite, Toxoplasma gondii, in conjunction with two-photon microscopy, to address this question. After challenge, memory T cells migrated more rapidly than naive T cells, relocalized toward the subcapsular sinus (SCS) near invaded macrophages, and engaged in prolonged interactions with infected cells. Parasite invasion of T cells occurred by direct transfer of the parasite from the target cell into the T cell and corresponded to an antigen-specific increase in the rate of T cell invasion. Our results provide insight into cellular interactions during recall responses and suggest a mechanism of pathogen subversion of the immune response.

  11. Parasite Fate and Involvement of Infected Cells in the Induction of CD4+ and CD8+ T Cell Responses to Toxoplasma gondii

    PubMed Central

    Dupont, Christopher D.; Christian, David A.; Selleck, Elizabeth M.; Pepper, Marion; Leney-Greene, Michael; Harms Pritchard, Gretchen; Koshy, Anita A.; Wagage, Sagie; Reuter, Morgan A.; Sibley, L. David; Betts, Michael R.; Hunter, Christopher A.

    2014-01-01

    During infection with the intracellular parasite Toxoplasma gondii, the presentation of parasite-derived antigens to CD4+ and CD8+ T cells is essential for long-term resistance to this pathogen. Fundamental questions remain regarding the roles of phagocytosis and active invasion in the events that lead to the processing and presentation of parasite antigens. To understand the most proximal events in this process, an attenuated non-replicating strain of T. gondii (the cpsII strain) was combined with a cytometry-based approach to distinguish active invasion from phagocytic uptake. In vivo studies revealed that T. gondii disproportionately infected dendritic cells and macrophages, and that infected dendritic cells and macrophages displayed an activated phenotype characterized by enhanced levels of CD86 compared to cells that had phagocytosed the parasite, thus suggesting a role for these cells in priming naïve T cells. Indeed, dendritic cells were required for optimal CD4+ and CD8+ T cell responses, and the phagocytosis of heat-killed or invasion-blocked parasites was not sufficient to induce T cell responses. Rather, the selective transfer of cpsII-infected dendritic cells or macrophages (but not those that had phagocytosed the parasite) to naïve mice potently induced CD4+ and CD8+ T cell responses, and conferred protection against challenge with virulent T. gondii. Collectively, these results point toward a critical role for actively infected host cells in initiating T. gondii-specific CD4+ and CD8+ T cell responses. PMID:24722202

  12. T-cell-mediated immune response to respiratory coronaviruses

    PubMed Central

    Channappanavar, Rudragouda; Zhao, Jincun; Perlman, Stanley

    2014-01-01

    Emerging respiratory coronaviruses such as the Severe Acute Respiratory Syndrome coronavirus (SARS-CoV) and Middle East Respiratory Syndrome coronavirus (MERS-CoV) pose potential biological threats to humans. SARS and MERS are manifested as severe atypical pneumonia associated with high morbidity and mortality in humans. The majority of studies carried out in SARS-CoV-infected humans and animals attribute a dysregulated/exuberant innate response as a leading contributor to SARS-CoV-mediated pathology. A decade after the 2002–2003 SARS epidemic, we do not have any approved preventive or therapeutic agents available in case of re-emergence of SARS-CoV or other related viruses. A strong neutralizing antibody response generated against the spike (S) glycoprotein of SARS-CoV is completely protective in the susceptible host. However, neutralizing antibody titers and the memory B cell response are short-lived in SARS-recovered patients and the antibody will target primary homologous strain. Interestingly, the acute phase of SARS in humans is associated with a severe reduction in the number of T cells in the blood. Surprisingly, only a limited number of studies have explored the role of the T cell-mediated adaptive immune response in respiratory coronavirus pathogenesis. In this review, we discuss the role of anti-virus CD4 and CD8 T cells during respiratory coronavirus infections with a special emphasis on emerging coronaviruses. PMID:24845462

  13. Peripheral self-reactivity regulates antigen-specific CD8 T-cell responses and cell division under physiological conditions.

    PubMed

    Swee, Lee Kim; Tan, Zhen Wei; Sanecka, Anna; Yoshida, Nagisa; Patel, Harshil; Grotenbreg, Gijsbert; Frickel, Eva-Maria; Ploegh, Hidde L

    2016-11-01

    T-cell identity is established by the expression of a clonotypic T-cell receptor (TCR), generated by somatic rearrangement of TCRα and β genes. The properties of the TCR determine both the degree of self-reactivity and the repertoire of antigens that can be recognized. For CD8 T cells, the relationship between TCR identity-hence reactivity to self-and effector function(s) remains to be fully understood and has rarely been explored outside of the H-2 b haplotype. We measured the affinity of three structurally distinct CD8 T-cell-derived TCRs that recognize the identical H-2 L d -restricted epitope, derived from the Rop7 protein of Toxoplasma gondii We used CD8 T cells obtained from mice generated by somatic cell nuclear transfer as the closest approximation of primary T cells with physiological TCR rearrangements and TCR expression levels. First, we demonstrate the common occurrence of secondary rearrangements in endogenously rearranged loci. Furthermore, we characterized and compared the response of Rop7-specific CD8 T-cell clones upon Toxoplasma gondii infection as well as effector function and TCR signalling upon antigenic stimulation in vitro Antigen-independent TCR cross-linking in vitro uncovered profound intrinsic differences in the effector functions between T-cell clones. Finally, by assessing the degree of self-reactivity and comparing the transcriptomes of naive Rop7 CD8 T cells, we show that lower self-reactivity correlates with lower effector capacity, whereas higher self-reactivity is associated with enhanced effector function as well as cell cycle entry under physiological conditions. Altogether, our data show that potential effector functions and basal proliferation of CD8 T cells are set by self-reactivity thresholds. © 2016 The Authors.

  14. Loss of the ex vivo but not the reinducible CD8+ T-cell response to Tax in human T-cell leukemia virus type 1-infected patients with adult T-cell leukemia/lymphoma.

    PubMed

    Arnulf, B; Thorel, M; Poirot, Y; Tamouza, R; Boulanger, E; Jaccard, A; Oksenhendler, E; Hermine, O; Pique, C

    2004-01-01

    Human T-cell leukemia virus type 1 (HTLV-1) causes adult T-cell leukemia/lymphoma (ATLL) and HTLV-1-associated myelopathy (HAM). In asymptomatic carriers and HAM patients, HTLV-1 infection leads to a vigorous cytotoxic T-cell (CTL) response mainly directed to the regulatory Tax protein. In contrast, initial studies showed that anti-HTLV-1 CTL activities were not reproductively detected in ATLL patients, neither ex vivo, nor after in vitro restimulation. To better understand this discrepancy, we explored the anti-HTLV-1 CD8+ T-cell response of eight ATLL patients by using in vitro restimulated or freshly isolated CD8+ T cells. In all the ATLL patients, we found that mitogenic activation allowed the induction of CD8+ T cells able to lyse autologous HTLV-1-infected cells and/or to produce IFNgamma in response to Tax peptides. In contrast, only a minority of the patients possessed CD8+ cells able to respond ex vivo to the same epitopes. These findings indicate that although a restimulatable anti-HTLV-1 CTL activity persists during ATLL, the specific ex vivo response is not constantly maintained. This provides definitive evidence that the CD8+ T-cell response to HTLV-1 is affected by ATLL development and reveals that a major defect concerns the generation and/or the functionality of CD8+ effectors.

  15. Human Memory CD4+ T Cell Immune Responses against Giardia lamblia

    PubMed Central

    Sørnes, Steinar; Peirasmaki, Dimitra; Svärd, Staffan; Langeland, Nina

    2015-01-01

    The intestinal protozoan parasite Giardia lamblia may cause severe prolonged diarrheal disease or pass unnoticed as an asymptomatic infection. T cells seem to play an important role in the immune response to Giardia infection, and memory responses may last years. Recently, TH17 responses have been found in three animal studies of Giardia infection. The aim of this study was to characterize the human CD4+ T cell responses to Giardia. Peripheral blood mononuclear cells (PBMCs) were obtained from 21 returning travelers with recent or ongoing giardiasis and 12 low-risk healthy controls and stimulated in vitro with Giardia lamblia proteins. Production of tumor necrosis factor alpha (TNF-α), gamma interferon, interleukin-17A (IL-17A), IL-10, and IL-4 was measured in CD4+ effector memory (EM) T cells after 24 h by flow cytometry. After 6 days of culture, activation and proliferation were measured by flow cytometry, while an array of inflammatory cytokine levels in supernatants were measured with multiplex assays. We found the number of IL-17A-producing CD4+ EM T cells, as well as that of cells simultaneously producing both IL-17A and TNF-α, to be significantly elevated in the Giardia-exposed individuals after 24 h of antigen stimulation. In supernatants of PBMCs stimulated with Giardia antigens for 6 days, we found inflammation-associated cytokines, including 1L-17A, as well as CD4+ T cell activation and proliferation, to be significantly elevated in the Giardia-exposed individuals. We conclude that symptomatic Giardia infection in humans induces a CD4+ EM T cell response of which IL-17A production seems to be an important component. PMID:26376930

  16. Circulating cytotoxic T cells and natural killer cells as potential predictors for antidepressant response in melancholic depression. Restoration of T regulatory cell populations after antidepressant therapy.

    PubMed

    Grosse, Laura; Carvalho, Livia A; Birkenhager, Tom K; Hoogendijk, Witte J; Kushner, Steven A; Drexhage, Hemmo A; Bergink, Veerle

    2016-05-01

    There is a substantial unmet need for biomarkers to predict treatment response in major depressive disorder (MDD). Evidence has converged on activation of the inflammatory response system as a fundamental mechanism underlying MDD. By investigating circulating leukocyte subsets quantified by fluorescence-activated cell sorting (FACS) analysis before treatment, we aim to predict antidepressant response. Forty medication-free inpatients with melancholic, non-psychotic depression before treatment with either venlafaxine or imipramine and 40 age- and gender-matched healthy controls were included. Leukocyte subsets were quantified by FACS analysis using frozen peripheral blood mononuclear cells (PBMC) collected prior to and after 7 weeks of treatment with either venlafaxine (375 mg/day) or imipramine (blood level 200-300 ng/ml). Response was defined as at least 50 % reduction of the baseline Hamilton Rating Scale for Depression (HAM-D) score. Prior to treatment, MDD patients showed reduced percentages of CD4(+)CD25(high)Foxp3(+) T regulatory (Treg) cells when compared with controls (1.5 ± 0.6 vs. 1.8 ± 0.6, p = .037). After treatment, robust rises in Treg cells were observed in patients (1.8 ± 0.7, p < .001), yet Treg cells were not predictors of the clinical outcome of treatment. Antidepressant non-responders showed increased CD8(+) cytotoxic T cell percentages (24.0 ± 8.6 vs. 15.9 ± 5.9, p = .004) and decreased natural killer (NK) cell percentages (14.0 ± 6.9 vs. 21.4 ± 11.9, p = .020) compared with responders before treatment. Both lymphocyte levels were not significantly modulated by treatment. In melancholic MDD, FACS analysis of circulating leukocyte subpopulations might help to discriminate between patients with high or low responsiveness to antidepressant treatment.

  17. CD83 Antibody Inhibits Human B Cell Responses to Antigen as well as Dendritic Cell-Mediated CD4 T Cell Responses.

    PubMed

    Wong, Kuan Y; Baron, Rebecca; Seldon, Therese A; Jones, Martina L; Rice, Alison M; Munster, David J

    2018-05-15

    Anti-CD83 Ab capable of Ab-dependent cellular cytotoxicity can deplete activated CD83 + human dendritic cells, thereby inhibiting CD4 T cell-mediated acute graft-versus-host disease. As CD83 is also expressed on the surface of activated B lymphocytes, we hypothesized that anti-CD83 would also inhibit B cell responses to stimulation. We found that anti-CD83 inhibited total IgM and IgG production in vitro by allostimulated human PBMC. Also, Ag-specific Ab responses to immunization of SCID mice xenografted with human PBMC were inhibited by anti-CD83 treatment. This inhibition occurred without depletion of all human B cells because anti-CD83 lysed activated CD83 + B cells by Ab-dependent cellular cytotoxicity and spared resting (CD83 - ) B cells. In cultured human PBMC, anti-CD83 inhibited tetanus toxoid-stimulated B cell proliferation and concomitant dendritic cell-mediated CD4 T cell proliferation and expression of IFN-γ and IL-17A, with minimal losses of B cells (<20%). In contrast, the anti-CD20 mAb rituximab depleted >80% of B cells but had no effect on CD4 T cell proliferation and cytokine expression. By virtue of the ability of anti-CD83 to selectively deplete activated, but not resting, B cells and dendritic cells, with the latter reducing CD4 T cell responses, anti-CD83 may be clinically useful in autoimmunity and transplantation. Advantages might include inhibited expansion of autoantigen- or alloantigen-specific B cells and CD4 T cells, thus preventing further production of pathogenic Abs and inflammatory cytokines while preserving protective memory and regulatory cells. Copyright © 2018 by The American Association of Immunologists, Inc.

  18. Genetic ablation or pharmacological blockade of dipeptidyl peptidase IV does not impact T cell-dependent immune responses

    PubMed Central

    Vora, Kalpit A; Porter, Gene; Peng, Roche; Cui, Yan; Pryor, Kellyann; Eiermann, George; Zaller, Dennis M

    2009-01-01

    Background Current literature suggests that dipeptidyl peptidase IV (DPP-IV; CD26) plays an essential role in T-dependent immune responses, a role that could have important clinical consequences. To rigorously define the role of DPP-IV in the immune system, we evaluated genetic and pharmacological inhibition of the enzyme on T-dependent immune responses in vivo. Results The DPP-IV null animals mounted robust primary and secondary antibody responses to the T dependent antigens, 4-hydroxy-3-nitrophenylacetyl-ovalbumin (NP-Ova) and 4-hydroxy-3-nitrophenylacetyl-chicken gamma globulin (NP-CGG), which were comparable to wild type mice. Serum levels of antigen specific IgM, IgG1, IgG2a, IgG2b and IgG3 were similar between the two groups of animals. DPP-IV null animals mounted an efficient germinal center reaction by day 10 after antigen stimulation that was comparable to wild type mice. Moreover, the antibodies produced by DPP-IV null animals after repeated antigenic challenge were affinity matured. Similar observations were made using wild type animals treated with a highly selective DPP-IV inhibitor during the entire course of the experiments. T cell recall responses to ovalbumin and MOG peptide, evaluated by measuring proliferation and IL-2 release from cells isolated from draining lymph nodes, were equivalent in DPP-IV null and wild type animals. Furthermore, mice treated with DPP-IV inhibitor had intact T-cell recall responses to MOG peptide. In addition, female DPP-IV null and wild type mice treated with DPP-IV inhibitor exhibited normal and robust in vivo cytotoxic T cell responses after challenge with cells expressing the male H-Y minor histocompatibility antigen. Conclusion These data indicate Selective inhibition of DPP-IV does not impair T dependent immune responses to antigenic challenge. PMID:19358731

  19. Helper T Cell Responses to Respiratory Viruses in the Lung: Development, Virus Suppression, and Pathogenesis.

    PubMed

    Miyauchi, Kosuke

    The lung is an important line of defense that is exposed to respiratory infectious pathogens, including viruses. Lung epithelial cells and/or alveolar macrophages are initially targeted by respiratory viruses. Once respiratory viruses invade the cells of the lung, innate immunity is activated to inhibit viral replication. Innate immune signaling also activates virus-specific adaptive immune responses. The helper T cells play pivotal roles in the humoral and cellular adaptive immune responses. Helper T cells are categorized into several distinct subsets (e.g., T H 1, T H 2, T FH , T H 17, and Treg), differentiated by their corresponding signature cytokine production profiles. Helper T cells migrate into the airways and the lung after respiratory virus infections. The behavior of the helper T cells differs with each respiratory virus-in some cases, the response is beneficial; in other cases, it is harmful. Here, the general mechanisms underlying helper T cell responses to viral infections are summarized, and functions and reactions of the helper T cells against some respiratory viral infections are discussed. In influenza virus infections, T H 1 cells, which regulate the cytotoxic T lymphocytes and IgG2 responses, are efficiently activated. T FH cells required for highly specific and memory humoral responses are also activated on influenza infections. In infections with respiratory syncytial virus and rhinovirus, T H 2 cells develop in the lung and contribute to pathogenesis. In many cases, Treg cells inhibit excessive virus-specific T cell responses that can contribute to viral pathogenicity.

  20. Interleukin-10 from CD4+ follicular regulatory T cells promotes the germinal center response.

    PubMed

    Laidlaw, Brian J; Lu, Yisi; Amezquita, Robert A; Weinstein, Jason S; Vander Heiden, Jason A; Gupta, Namita T; Kleinstein, Steven H; Kaech, Susan M; Craft, Joe

    2017-10-20

    CD4 + follicular regulatory T (T fr ) cells suppress B cell responses through modulation of follicular helper T (T fh ) cells and germinal center (GC) development. We found that T fr cells can also promote the GC response through provision of interleukin-10 (IL-10) after acute infection with lymphocytic choriomeningitis virus (LCMV). Sensing of IL-10 by B cells was necessary for optimal development of the GC response. GC B cells formed in the absence of T reg cell-derived IL-10 displayed an altered dark zone state and decreased expression of the transcription factor Forkhead box protein 1 (FOXO1). IL-10 promoted nuclear translocation of FOXO1 in activated B cells. These data indicate that T fr cells play a multifaceted role in the fine-tuning of the GC response and identify IL-10 as an important mediator by which T fr cells support the GC reaction. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  1. Differential CD4+ versus CD8+ T-cell responses elicited by different poxvirus-based human immunodeficiency virus type 1 vaccine candidates provide comparable efficacies in primates.

    PubMed

    Mooij, Petra; Balla-Jhagjhoorsingh, Sunita S; Koopman, Gerrit; Beenhakker, Niels; van Haaften, Patricia; Baak, Ilona; Nieuwenhuis, Ivonne G; Kondova, Ivanela; Wagner, Ralf; Wolf, Hans; Gómez, Carmen E; Nájera, José L; Jiménez, Victoria; Esteban, Mariano; Heeney, Jonathan L

    2008-03-01

    Poxvirus vectors have proven to be highly effective for boosting immune responses in diverse vaccine settings. Recent reports reveal marked differences in the gene expression of human dendritic cells infected with two leading poxvirus-based human immunodeficiency virus (HIV) vaccine candidates, New York vaccinia virus (NYVAC) and modified vaccinia virus Ankara (MVA). To understand how complex genomic changes in these two vaccine vectors translate into antigen-specific systemic immune responses, we undertook a head-to-head vaccine immunogenicity and efficacy study in the pathogenic HIV type 1 (HIV-1) model of AIDS in Indian rhesus macaques. Differences in the immune responses in outbred animals were not distinguished by enzyme-linked immunospot assays, but differences were distinguished by multiparameter fluorescence-activated cell sorter analysis, revealing a difference between the number of animals with both CD4(+) and CD8(+) T-cell responses to vaccine inserts (MVA) and those that elicit a dominant CD4(+) T-cell response (NYVAC). Remarkably, vector-induced differences in CD4(+)/CD8(+) T-cell immune responses persisted for more than a year after challenge and even accompanied antigenic modulation throughout the control of chronic infection. Importantly, strong preexposure HIV-1/simian immunodeficiency virus-specific CD4(+) T-cell responses did not prove deleterious with respect to accelerated disease progression. In contrast, in this setting, animals with strong vaccine-induced polyfunctional CD4(+) T-cell responses showed efficacies similar to those with stronger CD8(+) T-cell responses.

  2. Human influenza viruses and CD8(+) T cell responses.

    PubMed

    Grant, Emma J; Quiñones-Parra, Sergio M; Clemens, E Bridie; Kedzierska, Katherine

    2016-02-01

    Influenza A viruses (IAVs) cause significant morbidity and mortality worldwide, despite new strain-specific vaccines being available annually. As IAV-specific CD8(+) T cells promote viral control in the absence of neutralizing antibodies, and can mediate cross-reactive immunity toward distinct IAVs to drive rapid recovery from both mild and severe influenza disease, there is great interest in developing a universal T cell vaccine. However, despite detailed studies in mouse models of influenza virus infection, there is still a paucity of data on human epitope-specific CD8(+) T cell responses to IAVs. This review focuses on our current understanding of human CD8(+) T cell immunity against distinct IAVs and discusses the possibility of achieving a CD8(+) T cell mediated-vaccine that protects against multiple, distinct IAV strains across diverse human populations. We also review the importance of CD8(+) T cell immunity in individuals highly susceptible to severe influenza infection, including those hospitalised with influenza, the elderly and Indigenous populations. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Positive and negative regulation of T cell responses by fibroblastic reticular cells within paracortical regions of lymph nodes

    PubMed Central

    Siegert, Stefanie; Luther, Sanjiv A.

    2012-01-01

    Fibroblastic reticular cells (FRC) form the structural backbone of the T cell rich zones in secondary lymphoid organs (SLO), but also actively influence the adaptive immune response. They provide a guidance path for immigrating T lymphocytes and dendritic cells (DC) and are the main local source of the cytokines CCL19, CCL21, and IL-7, all of which are thought to positively regulate T cell homeostasis and T cell interactions with DC. Recently, FRC in lymph nodes (LN) were also described to negatively regulate T cell responses in two distinct ways. During homeostasis they express and present a range of peripheral tissue antigens, thereby participating in peripheral tolerance induction of self-reactive CD8+ T cells. During acute inflammation T cells responding to foreign antigens presented on DC very quickly release pro-inflammatory cytokines such as interferon γ. These cytokines are sensed by FRC which transiently produce nitric oxide (NO) gas dampening the proliferation of neighboring T cells in a non-cognate fashion. In summary, we propose a model in which FRC engage in a bidirectional crosstalk with both DC and T cells to increase the efficiency of the T cell response. However, during an acute response, FRC limit excessive expansion and inflammatory activity of antigen-specific T cells. This negative feedback loop may help to maintain tissue integrity and function during rapid organ growth. PMID:22973278

  4. LAG-3 confers a competitive disadvantage upon antiviral CD8+ T cell responses1

    PubMed Central

    Cook, Kevin D.; Whitmire, Jason K.

    2016-01-01

    Ongoing clinical trials are evaluating the benefits of systemic blockade of lymphocyte activation gene-3 (LAG-3) signals to improve immunity to tumors. Those studies are founded on the well-established inhibitory role of LAG-3 in regulating CD8+ T cells during chronic virus infection and anti-tumor responses. However, the T cell response in LAG-3 deficient mice is similar in size and function to that in wild type animals, suggesting LAG-3 has nuanced immune-regulatory functions. We performed a series of adoptive transfer experiments in mice to better understand the T cell-intrinsic functions of LAG-3 in the regulation of CD8+ T cell responses. Our results indicate that LAG-3 expression by CD8+ T cells inhibits their competitive fitness and results in a slightly reduced rate of cell division in comparison to LAG-3 deficient cells. This cell-intrinsic effect of LAG-3 was consistent across both acute and chronic virus infections. These data show that LAG-3 directly modulates the size of the T cell response and support the use of LAG-3 blockade regimens to enhance CD8+ T cell responses. PMID:27206765

  5. Brain Ischemia Induces Diversified Neuroantigen-Specific T-Cell Responses That Exacerbate Brain Injury.

    PubMed

    Jin, Wei-Na; Gonzales, Rayna; Feng, Yan; Wood, Kristofer; Chai, Zhi; Dong, Jing-Fei; La Cava, Antonio; Shi, Fu-Dong; Liu, Qiang

    2018-06-01

    Autoimmune responses can occur when antigens from the central nervous system are presented to lymphocytes in the periphery or central nervous system in several neurological diseases. However, whether autoimmune responses emerge after brain ischemia and their impact on clinical outcomes remains controversial. We hypothesized that brain ischemia facilitates the genesis of autoimmunity and aggravates ischemic brain injury. Using a mouse strain that harbors a transgenic T-cell receptor to a central nervous system antigen, MOG 35-55 (myelin oligodendrocyte glycoprotein) epitope (2D2), we determined the anatomic location and involvement of antigen-presenting cells in the development of T-cell reactivity after brain ischemia and how T-cell reactivity impacts stroke outcome. Transient middle cerebral artery occlusion and photothrombotic stroke models were used in this study. We also quantified the presence and status of T cells from brain slices of ischemic patients. By coupling transfer of labeled MOG 35-55 -specific (2D2) T cells with tetramer tracking, we show an expansion in reactivity of 2D2 T cells to MOG 91-108 and MOG 103-125 in transient middle cerebral artery occlusion and photothrombotic stroke models. This reactivity and T-cell activation first occur locally in the brain after ischemia. Also, microglia act as antigen-presenting cells that effectively present MOG antigens, and depletion of microglia ablates expansion of 2D2 reactive T cells. Notably, the adoptive transfer of neuroantigen-experienced 2D2 T cells exacerbates Th1/Th17 responses and brain injury. Finally, T-cell activation and MOG-specific T cells are present in the brain of patients with ischemic stroke. Our findings suggest that brain ischemia activates and diversifies T-cell responses locally, which exacerbates ischemic brain injury. © 2018 The Authors.

  6. L-Asparaginase II Produced by Salmonella Typhimurium Inhibits T Cell Responses and Mediates Virulence

    PubMed Central

    Kullas, Amy L.; McClelland, Michael; Yang, Hee-Jeong; Tam, Jason W.; Torres, AnnMarie; Porwollik, Steffen; Mena, Patricio; McPhee, Joseph B.; Bogomolnaya, Lydia; Andrews-Polymenis, Helene; van der Velden, Adrianus W.M.

    2013-01-01

    SUMMARY Salmonella enterica serovar Typhimurium avoids clearance by the host immune system by suppressing T cell responses; however, the mechanisms that mediate this immunosuppression remain unknown. We show that S. Typhimurium inhibit T cell responses by producing L-Asparaginase II, which catalyzes the hydrolysis of L-asparagine to aspartic acid and ammonia. L-Asparaginase II is necessary and sufficient to suppress T cell blastogenesis, cytokine production, and proliferation and to downmodulate expression of the T cell receptor. Furthermore, S. Typhimurium-induced inhibition of T cells in vitro is prevented upon addition of L-asparagine. S. Typhimurium lacking the L-Asparaginase II gene (STM3106) are unable to inhibit T cell responses and exhibit attenuated virulence in vivo. L-Asparaginases are used to treat acute lymphoblastic leukemia through mechanisms that likely involve amino acid starvation of leukemic cells, and these findings indicate that pathogens similarly use L-asparagine deprivation to limit T cell responses. PMID:23245323

  7. Naive T-cell receptor transgenic T cells help memory B cells produce antibody

    PubMed Central

    Duffy, Darragh; Yang, Chun-Ping; Heath, Andrew; Garside, Paul; Bell, Eric B

    2006-01-01

    Injection of the same antigen following primary immunization induces a classic secondary response characterized by a large quantity of high-affinity antibody of an immunoglobulin G class produced more rapidly than in the initial response – the products of memory B cells are qualitatively distinct from that of the original naive B lymphocytes. Very little is known of the help provided by the CD4 T cells that stimulate memory B cells. Using antigen-specific T-cell receptor transgenic CD4 T cells (DO11.10) as a source of help, we found that naive transgenic T cells stimulated memory B cells almost as well (in terms of quantity and speed) as transgenic T cells that had been recently primed. There was a direct correlation between serum antibody levels and the number of naive transgenic T cells transferred. Using T cells from transgenic interleukin-2-deficient mice we showed that interleukin-2 was not required for a secondary response, although it was necessary for a primary response. The results suggested that the signals delivered by CD4 T cells and required by memory B cells for their activation were common to both antigen-primed and naive CD4 T cells. PMID:17067314

  8. Pathogen-Specific T Cell Polyfunctionality Is a Correlate of T Cell Efficacy and Immune Protection

    PubMed Central

    Boyd, Anders; Almeida, Jorge R.; Darrah, Patricia A.; Sauce, Delphine; Seder, Robert A.; Appay, Victor; Gorochov, Guy; Larsen, Martin

    2015-01-01

    Introduction Understanding the factors that delineate the efficacy of T cell responses towards pathogens is crucial for our ability to develop potent therapies against infectious diseases. Multidimensional evaluation of T cell functionality at the single-cell level enables exhaustive analysis of combinatorial functional properties, hence polyfunctionality. We have recently invented an algorithm that quantifies polyfunctionality, the Polyfunctionality Index (Larsen et al. PLoS One 2012). Here we demonstrate that quantitative assessment of T cell polyfunctionality correlates with T cell efficacy measured as the capacity to kill target cells in vitro and control infection in vivo. Methods We employed the polyfunctionality index on two datasets selected for their unique ability to evaluate the polyfunctional imprint on T cell efficacy. 1) HIV-specific CD8+ T cells and 2) Leishmania major-specific CD4+ T cells were analysed for their capacity to secrete multiple effector molecules, kill target cells and control infection. Briefly, employing the Polyfunctionality Index algorithm we determined the parameter estimates resulting in optimal correlation between T cell polyfunctionality and T cell efficacy. Results T cell polyfunctionality is correlated with T cell efficacy measured as 1) target killing (r=0.807, P<0.0001) and 2) lesion size upon challenge with Leishmania major (r=-0.50, P=0.004). Contrary to an approach relying on the Polyfunctionality Index algorithm, quantitative evaluation of T cell polyfunctionality traditionally ignores the gradual contribution of more or less polyfunctional T cells. Indeed, comparing both approaches we show that optimal description of T cell efficacy is obtained when gradually integrating all levels of polyfunctionality in accordance with the Polyfunctionality Index. Conclusions Our study presents a generalizable methodology to objectively evaluate the impact of polyfunctionality on T cell efficacy. We show that T cell polyfunctionality

  9. Superior induction of T cell responses to conserved HIV-1 regions by electroporated alphavirus replicon DNA compared to that with conventional plasmid DNA vaccine.

    PubMed

    Knudsen, Maria L; Mbewe-Mvula, Alice; Rosario, Maximillian; Johansson, Daniel X; Kakoulidou, Maria; Bridgeman, Anne; Reyes-Sandoval, Arturo; Nicosia, Alfredo; Ljungberg, Karl; Hanke, Tomás; Liljeström, Peter

    2012-04-01

    Vaccination using "naked" DNA is a highly attractive strategy for induction of pathogen-specific immune responses; however, it has been only weakly immunogenic in humans. Previously, we constructed DNA-launched Semliki Forest virus replicons (DREP), which stimulate pattern recognition receptors and induce augmented immune responses. Also, in vivo electroporation was shown to enhance immune responses induced by conventional DNA vaccines. Here, we combine these two approaches and show that in vivo electroporation increases CD8(+) T cell responses induced by DREP and consequently decreases the DNA dose required to induce a response. The vaccines used in this study encode the multiclade HIV-1 T cell immunogen HIVconsv, which is currently being evaluated in clinical trials. Using intradermal delivery followed by electroporation, the DREP.HIVconsv DNA dose could be reduced to as low as 3.2 ng to elicit frequencies of HIV-1-specific CD8(+) T cells comparable to those induced by 1 μg of a conventional pTH.HIVconsv DNA vaccine, representing a 625-fold molar reduction in dose. Responses induced by both DREP.HIVconsv and pTH.HIVconsv were further increased by heterologous vaccine boosts employing modified vaccinia virus Ankara MVA.HIVconsv and attenuated chimpanzee adenovirus ChAdV63.HIVconsv. Using the same HIVconsv vaccines, the mouse observations were supported by an at least 20-fold-lower dose of DNA vaccine in rhesus macaques. These data point toward a strategy for overcoming the low immunogenicity of DNA vaccines in humans and strongly support further development of the DREP vaccine platform for clinical evaluation.

  10. Understanding the T cell immune response in SARS coronavirus infection

    PubMed Central

    Janice Oh, Hsueh-Ling; Ken-En Gan, Samuel; Bertoletti, Antonio; Tan, Yee-Joo

    2012-01-01

    The severe acute respiratory syndrome (SARS) epidemic started in late 2002 and swiftly spread across 5 continents with a mortality rate of around 10%. Although the epidemic was eventually controlled through the implementation of strict quarantine measures, there continues a need to investigate the SARS coronavirus (SARS-CoV) and develop interventions should it re-emerge. Numerous studies have shown that neutralizing antibodies against the virus can be found in patients infected with SARS-CoV within days upon the onset of illness and lasting up to several months. In contrast, there is little data on the kinetics of T cell responses during SARS-CoV infection and little is known about their role in the recovery process. However, recent studies in mice suggest the importance of T cells in viral clearance during SARS-CoV infection. Moreover, a growing number of studies have investigated the memory T cell responses in recovered SARS patients. This review covers the available literature on the emerging importance of T cell responses in SARS-CoV infection, particularly on the mapping of cytotoxic T lymphocyte (CTL) epitopes, longevity, polyfunctionality and human leukocyte antigen (HLA) association as well as their potential implications on treatment and vaccine development. PMID:26038429

  11. Understanding the T cell immune response in SARS coronavirus infection.

    PubMed

    Janice Oh, Hsueh-Ling; Ken-En Gan, Samuel; Bertoletti, Antonio; Tan, Yee-Joo

    2012-09-01

    The severe acute respiratory syndrome (SARS) epidemic started in late 2002 and swiftly spread across 5 continents with a mortality rate of around 10%. Although the epidemic was eventually controlled through the implementation of strict quarantine measures, there continues a need to investigate the SARS coronavirus (SARS-CoV) and develop interventions should it re-emerge. Numerous studies have shown that neutralizing antibodies against the virus can be found in patients infected with SARS-CoV within days upon the onset of illness and lasting up to several months. In contrast, there is little data on the kinetics of T cell responses during SARS-CoV infection and little is known about their role in the recovery process. However, recent studies in mice suggest the importance of T cells in viral clearance during SARS-CoV infection. Moreover, a growing number of studies have investigated the memory T cell responses in recovered SARS patients. This review covers the available literature on the emerging importance of T cell responses in SARS-CoV infection, particularly on the mapping of cytotoxic T lymphocyte (CTL) epitopes, longevity, polyfunctionality and human leukocyte antigen (HLA) association as well as their potential implications on treatment and vaccine development.

  12. Constitutive CD40L Expression on B Cells Prematurely Terminates Germinal Center Response and Leads to Augmented Plasma Cell Production in T Cell Areas

    PubMed Central

    Bolduc, Anna; Long, Eugene; Stapler, Dale; Cascalho, Marilia; Tsubata, Takeshi; Koni, Pandelakis A.; Shimoda, Michiko

    2013-01-01

    CD40/CD40L engagement is essential to T cell-dependent B cell proliferation and differentiation. However, the precise role of CD40 signaling through cognate T–B interaction in the generation of germinal center and memory B cells is still incompletely understood. To address this issue, a B cell-specific CD40L transgene (CD40LBTg) was introduced into mice with B cell-restricted MHC class II deficiency. Using this mouse model, we show that constitutive CD40L expression on B cells alone could not induce germinal center differentiation of MHC class II-deficient B cells after immunization with T cell-dependent Ag. Thus, some other MHC class II-dependent T cell-derived signals are essential for the generation of germinal center B cells in response to T cell-dependent Ag. In fact, CD40LBTg mice generated a complex Ag-specific IgG1 response, which was greatly enhanced in early, but reduced in late, primary response compared with control mice. We also found that the frequency of Ag-specific germinal center B cells in CD40LBTg mice was abruptly reduced 1 wk after immunization. As a result, the numbers of Ag-specific IgG1 long-lived plasma cells and memory B cells were reduced. By histology, large numbers of Ag-specific plasma cells were found in T cell areas adjacent to Ag-specific germinal centers of CD40LBTg mice, temporarily during the second week of primary response. These results indicate that CD40L expression on B cells prematurely terminated their ongoing germinal center response and produced plasma cells. Our results support the notion that CD40 signaling is an active termination signal for germinal center reaction. PMID:20505142

  13. T cell-derived Lymphotoxin is Essential for anti-HSV-1 Humoral Immune Response.

    PubMed

    Yang, Kaiting; Liang, Yong; Sun, Zhichen; Xue, Diyuan; Xu, Hairong; Zhu, Mingzhao; Fu, Yang-Xin; Peng, Hua

    2018-05-09

    B cell-derived lymphotoxin (LT) is required for the development of follicular dendritic cell clusters for the formation of primary and secondary lymphoid follicles, but the role of T cell-derived LT in antibody response has not been well demonstrated. We observed that lymphotoxin-β-receptor (LTβR) signaling is essential for optimal humoral immune response and protection against an acute HSV-1 infection. Blocking the LTβR pathway caused poor maintenance of germinal center B (GC-B) cells and follicular helper T (Tfh) cells. Using bone marrow chimeric mice and adoptive transplantation, we determined that T cell-derived LT played an indispensable role in the humoral immune response to HSV-1. Up-regulation of IFNγ by the LTβR-Ig blockade impairs the sustainability of Tfh-like cells, thus leading to an impaired humoral immune response. Our findings have identified a novel role of T cell-derived LT in the humoral immune response against HSV-1 infection. IMPORTANCE Immunocompromised people are susceptible for HSV-1 infection and lethal recurrence, which could be inhibited by anti-HSV-1 humoral immune response in the host. This study sought to explore the role of T cell-derived LT in the anti-HSV-1 humoral immune response using LT-LTβR signaling deficient mice and the LTβR-Ig blockade. The data indicate that the T cell-derived LT may play an essential role in sustaining Tfh-like cells and ensure Tfh-like cells' migration into primary or secondary follicles for further maturation. This study provides insights for vaccine development against infectious diseases. Copyright © 2018 American Society for Microbiology.

  14. T cell cytokine responses to stimulation with Ureaplasma parvum in pregnancy.

    PubMed

    Friedland, Yael D; Lee-Pullen, Tracey F; Nathan, Elizabeth A; Watts, Rory; Keelan, Jeffrey A; Payne, Matthew S; Ireland, Demelza J

    2016-08-01

    Ureaplasma spp. are a common vaginal microorganism causally linked to inflammation-driven preterm birth (PTB). The nature of the immune response to Ureaplasma spp. may influence PTB risk. This study sought to define maternal T cell cytokine responses to in vitro stimulation with Ureaplasma parvum serovar 3 (UpSV3) in vaginally colonised (UP+) and non-colonised (UP-) pregnant women. Whole blood flow cytometry demonstrated an increase (p=0.027) in the baseline frequency of IFNγ-positive CD3(+)CD4(-)(CD8(+)) T cells in UP+ women. UpSV3 stimulation resulted in a significant and specific increase (p=0.001) in the frequency of IFNγ-positive CD3(+)CD4(-)(CD8(+)) T cells, regardless of vaginal colonisation status. UpSV3 stimulation also increased the frequency of IFNγ-positive CD3(+)CD4(+) T cells, particularly in the UP+ group (p=0.003). This is the first published study to examine T cell responses to Ureaplasma spp. Future appropriately-powered studies are needed to assess whether insufficient priming or a loss of tolerance to Ureaplasma spp. is occurring in UP+ women at risk of PTB. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  15. Aberrant T-cell function in vitro and impaired T-cell dependent antibody response in vivo in vitamin A-deficient rats.

    PubMed Central

    Wiedermann, U; Hanson, L A; Kahu, H; Dahlgren, U I

    1993-01-01

    We have previously reported that vitamin A deficiency resulted in a reduced IgA antibody response to cholera toxin (CT) after per-oral immunization. In the present investigation we have studied the in vivo and in vitro immune response in vitamin A-deficient rats to two parenterally applied antigens, beta-lactoglobulin (beta-LG) and picrylsulphonic acid (TNP)-Ficoll. The serum IgG and IgM antibody responses to the T-cell dependent antigen beta-LG were significantly lower in the vitamin A-deficient rats than in the pair-fed control rats. No such differences were seen with the IgG and IgM responses to the T-cell independent antigen TNP-Ficoll. However, the biliary IgA and the serum IgE antibodies against both antigens were decreased in the vitamin A-deficient rats. In vitro lymphocyte stimulation with concanavalin A (Con A) or beta-LG gave higher T-cell proliferation rates in the vitamin A-deficient than in the control rats. Interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) levels in supernatants from Con A-stimulated mesenteric lymph node cells were also higher in the vitamin A-deficient rats, while IL-6 levels were decreased, which is consistent with an up-regulated Th1 activity. Proliferation studies on purified accessory cells and T cells from the deficient and the control rats, mixed in different combinations, showed that the T cells, but not the accessory cells, were disturbed in the vitamin A-deficient rats. Despite the increased T-cell activity in vitro the vitamin A-deficient rats had a lower delayed-type hypersensitivity (DTH) reaction than the pair-fed control rats. In conclusion, the increased IL-2 and IFN-gamma levels may reflect an up-regulation of Th1 cell function, while the decreased IgA, IgE and IL-6 levels indicate a suppression of Th2 cells. The disturbed T-lymphocyte function is manifested in vivo as a decreased DTH reaction and suppressed antibody production, the latter possibly due to a lack of B-cell switching and proliferation factors in

  16. Age-associated Epstein–Barr virus-specific T cell responses in seropositive healthy adults

    PubMed Central

    Cárdenas Sierra, D; Vélez Colmenares, G; Orfao de Matos, A; Fiorentino Gómez, S; Quijano Gómez, S M

    2014-01-01

    Epstein–Barr virus (EBV) is present in 95% of the world's adult population. The immune response participates in immune vigilance and persistent infection control, and this condition is maintained by both a good quality (functionality) and quantity of specific T cells throughout life. In the present study, we evaluated EBV-specific CD4+ and CD8+ T lymphocyte responses in seropositive healthy individuals younger and older than 50 years of age. The assessment comprised the frequency, phenotype, functionality and clonotypic distribution of T lymphocytes. We found that in both age groups a similar EBV-specific T cell response was found, with overlapping numbers of tumour necrosis factor (TNF)-α+ T lymphocytes (CD4+ and CD8+) within the memory and effector cell compartments, in addition to monofunctional and multi-functional T cells producing interleukin (IL)-2 and/or interferon (IFN)-γ. However, individuals aged more than 50 years showed significantly higher frequencies of IL-2-producing CD4+ T lymphocytes in association with greater production of soluble IFN-γ, TNF-α and IL-6 than subjects younger than 50 years. A polyclonal T cell receptor (TCR)-variable beta region (Vβ) repertoire exists in both age groups under basal conditions and in response to EBV; the major TCR families found in TNF-α+/CD4+ T lymphocytes were Vβ1, Vβ2, Vβ17 and Vβ22 in both age groups, and the major TCR family in TNF-α+/CD8+ T cells was Vβ13·1 for individuals younger than 50 years and Vβ9 for individuals aged more than 50 years. Our findings suggest that the EBV-specific T cell response (using a polyclonal stimulation model) is distributed throughout several T cell differentiation compartments in an age-independent manner and includes both monofunctional and multi-functional T lymphocytes. PMID:24666437

  17. Tim-3 directly enhances CD8 T cell responses to acute Listeria monocytogenes infection

    PubMed Central

    Gorman, Jacob V.; Starbeck-Miller, Gabriel; Pham, Nhat-Long L.; Traver, Geri L.; Rothman, Paul B.; Harty, John T.; Colgan, John D.

    2014-01-01

    Tim-3 is a surface molecule expressed throughout the immune system that can mediate both stimulatory and inhibitory effects. Previous studies have provided evidence that Tim-3 functions to enforce CD8 T cell exhaustion, a dysfunctional state associated with chronic stimulation. In contrast, the role of Tim-3 in the regulation of CD8 T cell responses to acute and transient stimulation remains undefined. To address this knowledge gap, we examined how Tim-3 affects CD8 T cell responses to acute Listeria monocytogenes (LM) infection. Analysis of wild-type (WT) mice infected with LM revealed that Tim-3 was transiently expressed by activated CD8 T cells and was associated primarily with acquisition of an effector phenotype. Comparison of responses to LM by WT and Tim-3 KO mice showed that the absence of Tim-3 significantly reduced the magnitudes of both primary and secondary CD8 T cell responses, which correlated with decreased IFN-γ production and degranulation by Tim-3 KO cells stimulated with peptide antigen ex vivo. To address the T cell-intrinsic role of Tim-3, we analyzed responses to LM infection by WT and Tim-3 KO TCR-transgenic CD8 T cells following adoptive transfer into a shared WT host. In this setting, the accumulation of CD8 T cells and the generation of cytokine-producing cells were significantly reduced by the lack of Tim-3, demonstrating that this molecule has a direct effect on CD8 T cell function. Combined, our results suggest that Tim-3 can mediate a stimulatory effect on CD8 T cell responses to an acute infection. PMID:24567532

  18. Transcriptomic analysis of mouse EL4 T cells upon T cell activation and in response to protein synthesis inhibition via cycloheximide treatment.

    PubMed

    Lim, Pek Siew; Hardy, Kristine; Peng, Kaiman; Shannon, Frances M

    2016-03-01

    T cell activation involves the recognition of a foreign antigen complexed to the major histocompatibility complex on the antigen presenting T cell to the T cell receptor. This leads to activation of signaling pathways, which ultimately leads to induction of key cytokine genes responsible for eradication of foreign antigens. We used the mouse EL4 T cell as a model system to study genes that are induced as a result of T cell activation using phorbol myristate acetate (PMA) and calcium ionomycin (I) as stimuli. We were also interested to examine the importance of new protein synthesis in regulating the expression of genes involved in T cell activation. Thus we have pre-treated mouse EL4 T cells with cycloheximide, a protein synthesis inhibitor, and left the cells unstimulated or stimulated with PMA/I for 4 h. We performed microarray expression profiling of these cells to correlate the gene expression with chromatin state of T cells upon T cell activation [1]. Here, we detail further information and analysis of the microarray data, which shows that T cell activation leads to differential expression of genes and inducible genes can be further classified as primary and secondary response genes based on their protein synthesis dependency. The data is available in the Gene Expression Omnibus under accession number GSE13278.

  19. NK T Cells Contribute to Expansion of CD8+ T Cells and Amplification of Antiviral Immune Responses to Respiratory Syncytial Virus

    PubMed Central

    Johnson, Teresa R.; Hong, Seokmann; Van Kaer, Luc; Koezuka, Yasuhiko; Graham, Barney S.

    2002-01-01

    CD1d-deficient mice have normal numbers of T lymphocytes and natural killer cells but lack Vα14+ natural killer T cells. Respiratory syncytial virus (RSV) immunopathogenesis was evaluated in 129×C57BL/6, C57BL/6, and BALB/c CD1d−/− mice. CD8+ T lymphocytes were reduced in CD1d−/− mice of all strains, as shown by cell surface staining and major histocompatibility complex class I tetramer analysis, and resulted in strain-specific alterations in illness, viral clearance, and gamma interferon (IFN-γ) production. Transient activation of NK T cells in CD1d+/+ mice by α-GalCer resulted in reduced illness and delayed viral clearance. These data suggest that early IFN-γ production and efficient induction of CD8+-T-cell responses during primary RSV infection require CD1d-dependent events. We also tested the ability of α-GalCer as an adjuvant to modulate the type 2 immune responses induced by RSV glycoprotein G or formalin-inactivated RSV immunization. However, immunized CD1-deficient or α-GalCer-treated wild-type mice did not exhibit diminished disease following RSV challenge. Rather, some disease parameters, including cytokine production, eosinophilia, and viral clearance, were increased. These findings indicate that CD1d-dependent NK T cells play a role in expansion of CD8+ T cells and amplification of antiviral responses to RSV. PMID:11932395

  20. The T Cell Response to Staphylococcus aureus

    PubMed Central

    Bröker, Barbara M.; Mrochen, Daniel; Péton, Vincent

    2016-01-01

    Staphylococcus aureus (S. aureus) is a dangerous pathogen and a leading cause of both nosocomial and community acquired bacterial infection worldwide. However, on the other hand, we are all exposed to this bacterium, often within the first hours of life, and usually manage to establish equilibrium and coexist with it. What does the adaptive immune system contribute toward lifelong control of S. aureus? Will it become possible to raise or enhance protective immune memory by vaccination? While in the past the S. aureus-specific antibody response has dominated this discussion, the research community is now coming to appreciate the role that the cellular arm of adaptive immunity, the T cells, plays. There are numerous T cell subsets, each with differing functions, which together have the ability to orchestrate the immune response to S. aureus and hence to tip the balance between protection and pathology. This review summarizes the state of the art in this dynamic field of research. PMID:26999219

  1. Oral Vaccination with Lipid-Formulated BCG Induces a Long-lived, Multifunctional CD4+ T Cell Memory Immune Response

    PubMed Central

    Ancelet, Lindsay R.; Aldwell, Frank E.; Rich, Fenella J.; Kirman, Joanna R.

    2012-01-01

    Oral delivery of BCG in a lipid formulation (Liporale™-BCG) targets delivery of viable bacilli to the mesenteric lymph nodes and confers protection against an aerosol Mycobacterium tuberculosis challenge. The magnitude, quality and duration of the effector and memory immune response induced by Liporale™-BCG vaccination is unknown. Therefore, we compared the effector and memory CD4+ T cell response in the spleen and lungs of mice vaccinated with Liporale™-BCG to the response induced by subcutaneous BCG vaccination. Liporale™-BCG vaccination induced a long-lived CD4+ T cell response, evident by the detection of effector CD4+ T cells in the lungs and a significant increase in the number of Ag85B tetramer-specific CD4+ T cells in the spleen up to 30 weeks post vaccination. Moreover, following polyclonal stimulation, Liporale™-BCG vaccination, but not s.c. BCG vaccination, induced a significant increase in both the percentage of CD4+ T cells in the lungs capable of producing IFNγ and the number of multifunctional CD4+ T cells in the lungs at 30 weeks post vaccination. These results demonstrate that orally delivered Liporale™-BCG vaccine induces a long-lived multifunctional immune response, and could therefore represent a practical and effective means of delivering novel BCG-based TB vaccines. PMID:23049885

  2. CD4 T-helper cell cytokine phenotypes and antibody response following tetanus toxoid booster immunization

    USDA-ARS?s Scientific Manuscript database

    Routine methods for enumerating antigen-specific T-helper cells may not identify low-frequency phenotypes such as Th2 cells. We compared methods of evaluating such responses to identify tetanus toxoid- (TT) specific Th1, Th2, Th17 and IL10+ cells. Eight healthy subjects were given a TT booster vacci...

  3. Vaccine of engineered tumor cells secreting stromal cell-derived factor-1 induces T-cell dependent antitumor responses.

    PubMed

    Shi, Meiqing; Hao, Siguo; Su, Liping; Zhang, Xueshu; Yuan, Jinying; Guo, Xuling; Zheng, Changyu; Xiang, Jim

    2005-08-01

    The CXC chemokine SDF-1 has been characterized as a T-cell chemoattractant both in vitro and in vivo. To determine whether SDF-1 expression within tumors can influence tumor growth, we transfected an expression vector pCI-SDF-1 for SDF-1 into J558 myeloma cells and tested their ability to form tumors in BALB/c. Production of biologically active SDF-1 (1.2 ng/mL) was detected in the culture supernatants of cells transfected with the expression vector pCI-SDF-1. J558 cells gave rise to a 100% tumor incidence, whereas SDF-1-expressing J558/SDF-1 tumors invariably regressed in BALB/c mice and became infiltrated with CD4(+) and CD8(+) T cells. Regression of the J558/SDF-1 tumors was dependent on both CD4(+) and CD8(+) T-cells. Our data also indicate that TIT cells containing both CD4(+) and CD8(+) T-cells within J558/SDF-1 tumors express the SDF-1 receptor CXCR4, and that SDF-1 specifically chemoattracts these cells in vitro. Furthermore, immunization of mice with engineered J558/SDF-1 cells elicited the most potent protective immunity against 0.5 x 10(6) cells J558 tumor challenge in vivo, compared to immunization with the J558 alone, and this antitumor immunity mediated by J558/SDF-1 tumor cell vaccination in vivo appeared to be dependent on CD8(+) CTL. Thus, SDF-1 has natural adjuvant activities that may augment antitumor responses through their effects on T-cells and thereby could be important in gene transfer immunotherapies for some cancers.

  4. Direct Measurement of T Cell Receptor Affinity and Sequence from Naïve Anti-Viral T Cells

    PubMed Central

    Zhang, Shuqi; Parker, Patricia; Ma, Keyue; He, Chenfeng; Shi, Qian; Cui, Zhonghao; Williams, Chad; Wendel, Ben S.; Meriwether, Amanda; Salazar, Mary A.; Jiang, Ning

    2016-01-01

    T cells recognize and kill a myriad of pathogen-infected or cancer cells using a diverse set of T cell receptors (TCR). The affinity of TCR to cognate antigen is of high interest in adoptive T cell transfer immunotherapy and antigen-specific T cell repertoire immune profiling because it is widely known to correlate with downstream T cell responses. Here, we introduce the in situ TCR affinity and sequence test (iTAST) for simultaneous measurement of TCR affinity and sequence from single primary CD8+ T cells in human blood. We demonstrate that the repertoire of primary antigen-specific T cells from pathogen inexperienced individuals has a surprisingly broad affinity range of 1000-fold composed of diverse TCR sequences. Within this range, samples from older individuals contained a reduced frequency of high affinity T cells compared to young individuals, demonstrating an age-related effect of T cell attrition that could cause holes in the repertoire. iTAST should enable the rapid selection of high affinity TCRs ex vivo for adoptive immunotherapy and measurement of T cell response for immune monitoring applications. PMID:27252176

  5. Secondary allergic T cell responses are regulated by dendritic cell-derived thrombospondin-1 in the setting of allergic eye disease

    PubMed Central

    Smith, R. E.; Reyes, N. J.; Khandelwal, P.; Schlereth, S. L.; Lee, H. S.; Masli, S.; Saban, D. R.

    2016-01-01

    Allergic eye disease, as in most forms of atopy, ranges in severity among individuals from immediate hypersensitivity to a severe and debilitating chronic disease. Dendritic cells play a key role in stimulating pathogenic T cells in allergen re-exposure, or secondary responses. However, molecular cues by dendritic cells underpinning allergic T cell response levels and the impact that this control has on consequent severity of allergic disease are poorly understood. Here, we show that a deficiency in thrombospondin-1, a matricellular protein known to affect immune function, has subsequent effects on downstream T cell responses during allergy, as revealed in an established mouse model of allergic eye disease. More specifically, we demonstrate that a thrombospondin-1 deficiency specific to dendritic cells leads to heightened secondary T cell responses and consequent clinical disease. Interestingly, whereas thrombospondin-1-deficient dendritic cells augmented activity of allergen-primed T cells, this increase was not recapitulated with naïve T cells in vitro. The role of dendritic cell-derived thrombospondin-1 in regulating secondary allergic T cell responses was confirmed in vivo, as local transfer of thrombospondin-1-sufficient dendritic cells to the ocular mucosa of thrombospondin-1 null hosts prevented the development of augmented secondary T cell responses and heightened allergic eye disease clinical responses. Finally, we demonstrate that topical instillation of thrombospondin-1-derived peptide reduces T cell activity and clinical progression of allergic eye disease. Taken together, this study reveals an important modulatory role of dendritic cell-derived thrombospondin-1 on secondary allergic T cell responses and suggests the possible dysregulation of dendritic cell-derived thrombospondin-1 expression as a factor in allergic eye disease severity. PMID:26856994

  6. T-cell Responses to HSV-1 in Persons Who Have Survived Childhood Herpes Simplex Encephalitis.

    PubMed

    Ott, Mariliis; Jing, Lichen; Lorenzo, Lazaro; Casanova, Jean-Laurent; Zhang, Shen-Ying; Koelle, David M

    2017-08-01

    Herpes simplex encephalitis (HSE) after primary herpes simplex virus (HSV)-1 infection can occur in children due to inborn errors of cell-intrinsic immunity in the central nervous system. Paradoxically, symptomatic mucocutaneous HSV-1 recurrences are rare survivors of childhood HSE. T-cell-acquired immunity is thought to be involved in control of recurrent mucocutaneous HSV infection. We thus tested HSV-1-specific immunity in HSE survivors. We obtained serum and peripheral blood mononuclear cells (PBMCs) from participants a median of 13.5 years after HSE. HSV-1 and HSV-2 IgG was detected by type-specific immunoblot. PBMCs from subjects passing quality control criteria were tested using enzyme-linked immunospot assay for CD4 interferon-γ responses with an HSV-1 lysate and for CD8 responses using pooled synthetic HSV-1 peptide CD8 T-cell epitopes. Healthy adult PBMCs were used to standardize assays and as comparators. All participants were HSV-1 seropositive. Most (23/24) HSE survivors had human leukocyte antigen class I types matching the human leukocyte antigen restriction of the pooled peptides. We detected HSV-specific CD8 T-cell responses in 14 of 24 (58%) HSE survivors and in 9 of 9 healthy HSV-1 seropositive adults. HSV-specific CD4 T-cell responses were present in all 5 HSE subjects tested and in 8 of 9 healthy adults. Response magnitudes were overlapping between subject groups. The defects in cell-intrinsic immunity leading to failure to control primary central nervous system HSV-1 infection do not preclude the acquisition of specific immunity or the control of recurrent mucocutaneous HSV infections. The rarity and lack of severe or recurrent mucocutaneous HSV infection in survivors of childhood HSE corresponds with intact adaptive T-cell immunity.

  7. Altered Memory T-Cell Responses to Bacillus Calmette-Guerin and Tetanus Toxoid Vaccination and Altered Cytokine Responses to Polyclonal Stimulation in HIV-Exposed Uninfected Kenyan Infants.

    PubMed

    Garcia-Knight, Miguel A; Nduati, Eunice; Hassan, Amin S; Gambo, Faith; Odera, Dennis; Etyang, Timothy J; Hajj, Nassim J; Berkley, James Alexander; Urban, Britta C; Rowland-Jones, Sarah L

    2015-01-01

    Implementation of successful prevention of mother-to-child transmission of HIV strategies has resulted in an increased population of HIV-exposed uninfected (HEU) infants. HEU infants have higher rates of morbidity and mortality than HIV-unexposed (HU) infants. Numerous factors may contribute to poor health in HEU infants including immunological alterations. The present study assessed T-cell phenotype and function in HEU infants with a focus on memory Th1 responses to vaccination. We compared cross-sectionally selected parameters at 3 and 12 months of age in HIV-exposed (n = 42) and HU (n = 28) Kenyan infants. We measured ex vivo activated and bulk memory CD4 and CD8 T-cells and regulatory T-cells by flow cytometry. In addition, we measured the magnitude, quality and memory phenotype of antigen-specific T-cell responses to Bacillus Calmette-Guerin and Tetanus Toxoid vaccine antigens, and the magnitude and quality of the T cell response following polyclonal stimulation with staphylococcal enterotoxin B. Finally, the influence of maternal disease markers on the immunological parameters measured was assessed in HEU infants. Few perturbations were detected in ex vivo T-cell subsets, though amongst HEU infants maternal HIV viral load positively correlated with CD8 T cell immune activation at 12 months. Conversely, we observed age-dependent differences in the magnitude and polyfunctionality of IL-2 and TNF-α responses to vaccine antigens particularly in Th1 cells. These changes mirrored those seen following polyclonal stimulation, where at 3 months, cytokine responses were higher in HEU infants compared to HU infants, and at 12 months, HEU infant cytokine responses were consistently lower than those seen in HU infants. Finally, reduced effector memory Th1 responses to vaccine antigens were observed in HEU infants at 3 and 12 months and higher central memory Th1 responses to M. tuberculosis antigens were observed at 3 months only. Long-term monitoring of vaccine efficacy

  8. Candida albicans morphology and dendritic cell subsets determine T helper cell differentiation

    PubMed Central

    Gerami-Nejad, Maryam; Kumamoto, Yosuke; Mohammed, Javed A.; Jarrett, Elizabeth; Drummond, Rebecca A.; Zurawski, Sandra M.; Zurawski, Gerard; Berman, Judith; Iwasaki, Akiko; Brown, Gordon D.; Kaplan, Daniel H.

    2015-01-01

    Summary Candida albicans is a dimorphic fungus responsible for chronic mucocutaneous and systemic infections. Mucocutaneous immunity to C. albicans requires T helper-17 (Th17) cell differentiation that is thought to depend on recognition of filamentous C. albicans. Systemic immunity is considered T cell independent. Using a murine skin infection model, we compared T helper cell responses to yeast and filamentous C. albicans, We found that only yeast induced Th17 cell responses through a mechanism that required Dectin-1 mediated expression of interleukin-6 (IL-6) by Langerhans cells. Filamentous forms induced Th1 without Th17 cell responses due to the absence of Dectin-1 ligation. Notably, Th17 cell responses provided protection against cutaneous infection while Th1 cell responses provided protection against systemic infection. Thus, C. albicans morphology drives distinct T helper cell responses that provide tissue specific protection. These findings provide insight into compartmentalization of Th responses, C. albicans pathogenesis and have critical implications for vaccine strategies. PMID:25680275

  9. Fish T cells: recent advances through genomics

    USGS Publications Warehouse

    Laing, Kerry J.; Hansen, John D.

    2011-01-01

    This brief review is intended to provide a concise overview of the current literature concerning T cells, advances in identifying distinct T cell functional subsets, and in distinguishing effector cells from memory cells. We compare and contrast a wealth of recent progress made in T cell immunology of teleost, elasmobranch, and agnathan fish, to knowledge derived from mammalian T cell studies. From genome studies, fish clearly have most components associated with T cell function and we can speculate on the presence of putative T cell subsets, and the ability to detect their differentiation to form memory cells. Some recombinant proteins for T cell associated cytokines and antibodies for T cell surface receptors have been generated that will facilitate studying the functional roles of teleost T cells during immune responses. Although there is still a long way to go, major advances have occurred in recent years for investigating T cell responses, thus phenotypic and functional characterization is on the near horizon.

  10. Comparative analysis of activation induced marker (AIM) assays for sensitive identification of antigen-specific CD4 T cells

    PubMed Central

    Cirelli, Kimberly M.; Dan, Jennifer M.; Morou, Antigoni; Daigneault, Audrey; Brassard, Nathalie; Silvestri, Guido; Routy, Jean-Pierre; Havenar-Daughton, Colin; Crotty, Shane

    2017-01-01

    The identification and study of antigen-specific CD4 T cells, both in peripheral blood and in tissues, is key for a broad range of immunological research, including vaccine responses and infectious diseases. Detection of these cells is hampered by both their rarity and their heterogeneity, in particular with regards to cytokine secretion profiles. These factors prevent the identification of the total pool of antigen-specific CD4 T cells by classical methods. We have developed assays for the highly sensitive detection of such cells by measuring the upregulation of surface activation induced markers (AIM). Here, we compare two such assays based on concurrent expression of CD69 plus CD40L (CD154) or expression of OX40 plus CD25, and we develop additional AIM assays based on OX40 plus PD-L1 or 4-1BB. We compare the relative sensitivity of these assays for detection of vaccine and natural infection-induced CD4 T cell responses and show that these assays identify distinct, but overlapping populations of antigen-specific CD4 T cells, a subpopulation of which can also be detected on the basis of cytokine synthesis. Bystander activation had minimal effect on AIM markers. However, some T regulatory cells upregulate CD25 upon antigen stimulation. We therefore validated AIM assays designed to exclude most T regulatory cells, for both human and non-human primate (NHP, Macaca mulatta) studies. Overall, through head-to-head comparisons and methodological improvements, we show that AIM assays represent a sensitive and valuable method for the detection of antigen-specific CD4 T cells. PMID:29065175

  11. Comparative analysis of activation induced marker (AIM) assays for sensitive identification of antigen-specific CD4 T cells.

    PubMed

    Reiss, Samantha; Baxter, Amy E; Cirelli, Kimberly M; Dan, Jennifer M; Morou, Antigoni; Daigneault, Audrey; Brassard, Nathalie; Silvestri, Guido; Routy, Jean-Pierre; Havenar-Daughton, Colin; Crotty, Shane; Kaufmann, Daniel E

    2017-01-01

    The identification and study of antigen-specific CD4 T cells, both in peripheral blood and in tissues, is key for a broad range of immunological research, including vaccine responses and infectious diseases. Detection of these cells is hampered by both their rarity and their heterogeneity, in particular with regards to cytokine secretion profiles. These factors prevent the identification of the total pool of antigen-specific CD4 T cells by classical methods. We have developed assays for the highly sensitive detection of such cells by measuring the upregulation of surface activation induced markers (AIM). Here, we compare two such assays based on concurrent expression of CD69 plus CD40L (CD154) or expression of OX40 plus CD25, and we develop additional AIM assays based on OX40 plus PD-L1 or 4-1BB. We compare the relative sensitivity of these assays for detection of vaccine and natural infection-induced CD4 T cell responses and show that these assays identify distinct, but overlapping populations of antigen-specific CD4 T cells, a subpopulation of which can also be detected on the basis of cytokine synthesis. Bystander activation had minimal effect on AIM markers. However, some T regulatory cells upregulate CD25 upon antigen stimulation. We therefore validated AIM assays designed to exclude most T regulatory cells, for both human and non-human primate (NHP, Macaca mulatta) studies. Overall, through head-to-head comparisons and methodological improvements, we show that AIM assays represent a sensitive and valuable method for the detection of antigen-specific CD4 T cells.

  12. IL-1 Receptor Signaling on Graft Parenchymal Cells Regulates Memory and De Novo Donor-Reactive CD8 T Cell Responses to Cardiac Allografts.

    PubMed

    Iida, Shoichi; Tsuda, Hidetoshi; Tanaka, Toshiaki; Kish, Danielle D; Abe, Toyofumi; Su, Charles A; Abe, Ryo; Tanabe, Kazunari; Valujskikh, Anna; Baldwin, William M; Fairchild, Robert L

    2016-03-15

    Reperfusion of organ allografts induces a potent inflammatory response that directs rapid memory T cell, neutrophil, and macrophage graft infiltration and their activation to express functions mediating graft tissue injury. The role of cardiac allograft IL-1 receptor (IL-1R) signaling in this early inflammation and the downstream primary alloimmune response was investigated. When compared with complete MHC-mismatched wild-type cardiac allografts, IL-1R(-/-) allografts had marked decreases in endogenous memory CD8 T cell and neutrophil infiltration and expression of proinflammatory mediators at early times after transplant, whereas endogenous memory CD4 T cell and macrophage infiltration was not decreased. IL-1R(-/-) allograft recipients also had marked decreases in de novo donor-reactive CD8, but not CD4, T cell development to IFN-γ-producing cells. CD8 T cell-mediated rejection of IL-1R(-/-) cardiac allografts took 3 wk longer than wild-type allografts. Cardiac allografts from reciprocal bone marrow reconstituted IL-1R(-/-)/wild-type chimeric donors indicated that IL-1R signaling on graft nonhematopoietic-derived, but not bone marrow-derived, cells is required for the potent donor-reactive memory and primary CD8 T cell alloimmune responses observed in response to wild-type allografts. These studies implicate IL-1R-mediated signals by allograft parenchymal cells in generating the stimuli-provoking development and elicitation of optimal alloimmune responses to the grafts. Copyright © 2016 by The American Association of Immunologists, Inc.

  13. Vaccine Targeting of Subdominant CD8+ T Cell Epitopes Increases the Breadth of the T Cell Response upon Viral Challenge, but May Impair Immediate Virus Control.

    PubMed

    Steffensen, Maria A; Pedersen, Louise H; Jahn, Marie L; Nielsen, Karen N; Christensen, Jan P; Thomsen, Allan R

    2016-03-15

    As a result of the difficulties in making efficient vaccines against genetically unstable viruses such as HIV, it has been suggested that future vaccines should preferentially target subdominant epitopes, the idea being that this should allow a greater breadth of the induced T cell response and, hence, a greater efficiency in controlling escape variants. However, to our knowledge the evidence supporting this concept is limited at best. To improve upon this, we used the murine lymphocytic choriomeningitis virus model and adenoviral vectors to compare a vaccine expressing unmodified Ag to a vaccine expressing the same Ag without its immunodominant epitope. We found that removal of the dominant epitope allowed the induction of CD8(+) T cell responses targeting at least two otherwise subdominant epitopes. Importantly, the overall magnitude of the induced T cell responses was similar, allowing us to directly compare the efficiency of these vaccines. Doing this, we observed that mice vaccinated with the vaccine expressing unmodified Ag more efficiently controlled an acute viral challenge. In the course of a more chronic viral infection, mice vaccinated using the vaccine targeting subdominant epitopes caught up with the conventionally vaccinated mice, and analysis of the breadth of the CD8(+) T cell response revealed that this was notably greater in the former mice. However, under the conditions of our studies, we never saw any functional advantage of this. This may represent a limitation of our model, but clearly our findings underscore the importance of carefully weighing the pros and cons of changes in epitope targeting before any implementation. Copyright © 2016 by The American Association of Immunologists, Inc.

  14. Depressed primary in vitro antibody response in untreated systemic lupus erythematosus. T helper cell defect and lack of defective suppressor cell function.

    PubMed Central

    Delfraissy, J F; Segond, P; Galanaud, P; Wallon, C; Massias, P; Dormont, J

    1980-01-01

    The in vitro antibody response of peripheral blood lymphocytes (PBL) from 19 patients with untreated systemic lupus erythematosus (SLE) was compared with that of 20 control patients and 44 normal subjects. Trinitrophenyl polyacrylamide beads (TNP-PAA) were used to induce IgM anti-TNP plaque-forming cells. SLE patients displayed a markedly depressed, and in most instances virtually absent, response. This was not due to an unusual kinetics of the response; nor could it be induced by preincubation of SLE patients' PBL. In co-cultures of SLE patients and normal PBL, the former, with few exceptions, did not exert a suppressive effect. In four patients the anti-TNP response of either unfractionated or T-depleted SLE PBL could be restored by T cells from a normal individual. Conversely in three of these patients, SLE T cells could not support the response of normal B cells, suggesting a T helper cell defect in SLE PBL. Concanavalin A (Con A)-induced suppressor cells of the antibody response could be assayed by two approaches: (a) in responder SLE patients, by the direct addition of Con A to TNP-PAA-stimulated cultures; (b) in seven patients by transfer of Con A-activated cells to the responding culture of a normal allogeneic donor. In both cases SLE PBL were able to exert a suppressive effect to the same extent as normal PBL. PMID:6447163

  15. Nucleoside-modified mRNA vaccines induce potent T follicular helper and germinal center B cell responses.

    PubMed

    Pardi, Norbert; Hogan, Michael J; Naradikian, Martin S; Parkhouse, Kaela; Cain, Derek W; Jones, Letitia; Moody, M Anthony; Verkerke, Hans P; Myles, Arpita; Willis, Elinor; LaBranche, Celia C; Montefiori, David C; Lobby, Jenna L; Saunders, Kevin O; Liao, Hua-Xin; Korber, Bette T; Sutherland, Laura L; Scearce, Richard M; Hraber, Peter T; Tombácz, István; Muramatsu, Hiromi; Ni, Houping; Balikov, Daniel A; Li, Charles; Mui, Barbara L; Tam, Ying K; Krammer, Florian; Karikó, Katalin; Polacino, Patricia; Eisenlohr, Laurence C; Madden, Thomas D; Hope, Michael J; Lewis, Mark G; Lee, Kelly K; Hu, Shiu-Lok; Hensley, Scott E; Cancro, Michael P; Haynes, Barton F; Weissman, Drew

    2018-06-04

    T follicular helper (Tfh) cells are required to develop germinal center (GC) responses and drive immunoglobulin class switch, affinity maturation, and long-term B cell memory. In this study, we characterize a recently developed vaccine platform, nucleoside-modified, purified mRNA encapsulated in lipid nanoparticles (mRNA-LNPs), that induces high levels of Tfh and GC B cells. Intradermal vaccination with nucleoside-modified mRNA-LNPs encoding various viral surface antigens elicited polyfunctional, antigen-specific, CD4 + T cell responses and potent neutralizing antibody responses in mice and nonhuman primates. Importantly, the strong antigen-specific Tfh cell response and high numbers of GC B cells and plasma cells were associated with long-lived and high-affinity neutralizing antibodies and durable protection. Comparative studies demonstrated that nucleoside-modified mRNA-LNP vaccines outperformed adjuvanted protein and inactivated virus vaccines and pathogen infection. The incorporation of noninflammatory, modified nucleosides in the mRNA is required for the production of large amounts of antigen and for robust immune responses. © 2018 Pardi et al.

  16. Secondary allergic T cell responses are regulated by dendritic cell-derived thrombospondin-1 in the setting of allergic eye disease.

    PubMed

    Smith, R E; Reyes, N J; Khandelwal, P; Schlereth, S L; Lee, H S; Masli, S; Saban, D R

    2016-08-01

    Allergic eye disease, as in most forms of atopy, ranges in severity among individuals from immediate hypersensitivity to a severe and debilitating chronic disease. Dendritic cells play a key role in stimulating pathogenic T cells in allergen re-exposure, or secondary responses. However, molecular cues by dendritic cells underpinning allergic T cell response levels and the impact that this control has on consequent severity of allergic disease are poorly understood. Here, we show that a deficiency in thrombospondin-1, a matricellular protein known to affect immune function, has subsequent effects on downstream T cell responses during allergy, as revealed in an established mouse model of allergic eye disease. More specifically, we demonstrate that a thrombospondin-1 deficiency specific to dendritic cells leads to heightened secondary T cell responses and consequent clinical disease. Interestingly, whereas thrombospondin-1-deficient dendritic cells augmented activity of allergen-primed T cells, this increase was not recapitulated with naïve T cells in vitro. The role of dendritic cell-derived thrombospondin-1 in regulating secondary allergic T cell responses was confirmed in vivo, as local transfer of thrombospondin-1-sufficient dendritic cells to the ocular mucosa of thrombospondin-1 null hosts prevented the development of augmented secondary T cell responses and heightened allergic eye disease clinical responses. Finally, we demonstrate that topical instillation of thrombospondin-1-derived peptide reduces T cell activity and clinical progression of allergic eye disease. Taken together, this study reveals an important modulatory role of dendritic cell-derived thrombospondin-1 on secondary allergic T cell responses and suggests the possible dysregulation of dendritic cell-derived thrombospondin-1 expression as a factor in allergic eye disease severity. © Society for Leukocyte Biology.

  17. T cell Bim levels reflect responses to anti–PD-1 cancer therapy

    PubMed Central

    Dronca, Roxana S.; Liu, Xin; Harrington, Susan M.; Chen, Lingling; Cao, Siyu; Kottschade, Lisa A.; McWilliams, Robert R.; Block, Matthew S.; Nevala, Wendy K.; Thompson, Michael A.; Mansfield, Aaron S.; Park, Sean S.; Markovic, Svetomir N.

    2016-01-01

    Immune checkpoint therapy with PD-1 blockade has emerged as an effective therapy for many advanced cancers; however, only a small fraction of patients achieve durable responses. To date, there is no validated blood-based means of predicting the response to PD-1 blockade. We report that Bim is a downstream signaling molecule of the PD-1 pathway, and its detection in T cells is significantly associated with expression of PD-1 and effector T cell markers. High levels of Bim in circulating tumor-reactive (PD-1+CD11ahiCD8+) T cells were prognostic of poor survival in patients with metastatic melanoma who did not receive anti–PD-1 therapy and were also predictive of clinical benefit in patients with metastatic melanoma who were treated with anti–PD-1 therapy. Moreover, this circulating tumor-reactive T cell population significantly decreased after successful anti–PD-1 therapy. Our study supports a crucial role of Bim in both T cell activation and apoptosis as regulated by PD-1 and PD-L1 interactions in effector CD8+ T cells. Measurement of Bim levels in circulating T cells of patients with cancer may provide a less invasive strategy to predict and monitor responses to anti–PD-1 therapy, although future prospective analyses are needed to validate its utility. PMID:27182556

  18. Two separate defects affecting true naive or virtual memory T cell precursors combine to reduce naive T cell responses with aging.

    PubMed

    Renkema, Kristin R; Li, Gang; Wu, Angela; Smithey, Megan J; Nikolich-Žugich, Janko

    2014-01-01

    Naive T cell responses are eroded with aging. We and others have recently shown that unimmunized old mice lose ≥ 70% of Ag-specific CD8 T cell precursors and that many of the remaining precursors acquire a virtual (central) memory (VM; CD44(hi)CD62L(hi)) phenotype. In this study, we demonstrate that unimmunized TCR transgenic (TCRTg) mice also undergo massive VM conversion with age, exhibiting rapid effector function upon both TCR and cytokine triggering. Age-related VM conversion in TCRTg mice directly depended on replacement of the original TCRTg specificity by endogenous TCRα rearrangements, indicating that TCR signals must be critical in VM conversion. Importantly, we found that VM conversion had adverse functional effects in both old wild-type and old TCRTg mice; that is, old VM, but not old true naive, T cells exhibited blunted TCR-mediated, but not IL-15-mediated, proliferation. This selective proliferative senescence correlated with increased apoptosis in old VM cells in response to peptide, but decreased apoptosis in response to homeostatic cytokines IL-7 and IL-15. Our results identify TCR as the key factor in differential maintenance and function of Ag-specific precursors in unimmunized mice with aging, and they demonstrate that two separate age-related defects--drastic reduction in true naive T cell precursors and impaired proliferative capacity of their VM cousins--combine to reduce naive T cell responses with aging.

  19. HIV infection impairs Th1 and Th17 Mycobacterium tuberculosis-specific T cell responses

    PubMed Central

    Murray, Lyle W; Satti, Iman; Meyerowitz, Jodi; Jones, Matthew; Willberg, Christian B; Ussher, James E; Goedhals, Dominique; Hurst, Jacob; Phillips, Rodney E; McShane, Helen

    2018-01-01

    Background HIV-infected individuals have a higher risk of developing active tuberculosis than HIV-uninfected individuals, but the mechanisms underpinning this are unclear. We hypothesized that depletion of specific components of Mycobacterium tuberculosis (M.tb)-specific CD4+ and CD8+ T cell responses contributed to this increased risk. Methods M.tb-specific T cell responses in 147 HIV-infected and 44 HIV-uninfected control subjects in a TB-endemic setting in Bloemfontein, South Africa were evaluated. Using a whole-blood flow cytometry assay, we measured expression of IFNγ, TNFα, IL-2 and IL-17 in CD4+ and CD8+ T cells in response to M.tb antigens (PPD, ESAT-6/CFP-10 (EC) and DosR regulon-encoded α-crystallin (Rv2031c)). Results Fewer HIV-infected individuals had detectable CD4+ and CD8+ T cell responses to PPD and Rv2031c than HIV-uninfected subjects. M.tb-specific T cells showed distinct patterns of cytokine expression comprising both Th1 (CD4 and CD8) and Th17 (CD4) cytokines, the latter at highest frequency for Rv2031c. Th17 antigen-specific responses to all antigens tested were specifically impaired in HIV-infected individuals. Conclusions HIV-associated impairment of CD4+ and CD8+ M.tb-specific T cell responses is antigen-specific, particularly impacting responses to PPD and Rv2031c. Preferential depletion of Th17 cytokine-expressing CD4+ T cells suggests this T cell subset may be key to TB susceptibility in HIV-infected individuals. PMID:29546381

  20. Identification of vaccinia virus epitope-specific HLA-A*0201-restricted T cells and comparative analysis of smallpox vaccines

    PubMed Central

    Drexler, Ingo; Staib, Caroline; Kastenmüller, Wolfgang; Stevanović, Stefan; Schmidt, Burkhard; Lemonnier, François A.; Rammensee, Hans-Georg; Busch, Dirk H.; Bernhard, Helga; Erfle, Volker; Sutter, Gerd

    2003-01-01

    Despite worldwide eradication of naturally occurring variola virus, smallpox remains a potential threat to both civilian and military populations. New, safe smallpox vaccines are being developed, and there is an urgent need for methods to evaluate vaccine efficacy after immunization. Here we report the identification of an immunodominant HLA-A*0201-restricted epitope that is recognized by cytotoxic CD8+ T cells and conserved among Orthopoxvirus species including variola virus. This finding has permitted analysis and monitoring of epitope-specific T cell responses after immunization and demonstration of the identified T cell specificity in an A*0201-positive human donor. Vaccination of transgenic mice allowed us to compare the immunogenicity of several vaccinia viruses including highly attenuated, replication-deficient modified vaccinia virus Ankara (MVA). MVA vaccines elicited levels of CD8+ T cell responses that were comparable to those induced by the replication-competent vaccinia virus strains. Finally, we demonstrate that MVA vaccination is fully protective against a lethal respiratory challenge with virulent vaccinia virus strain Western Reserve. Our data provide a basis to rationally estimate immunogenicity of safe, second-generation poxvirus vaccines and suggest that MVA may be a suitable candidate. PMID:12518065

  1. The comparative profile of lymphoid cells and the T and B cell spectratype of germ-free piglets infected with viruses SIV, PRRSV or PCV2

    USDA-ARS?s Scientific Manuscript database

    Parallel studies on the cellular aspects of the immune response of germ-free isolator piglets experimentally infected with SIV, PRRSV or PSV2 were compared with special emphasis on the response of alphabeta T, gammadelta T, B and NK cells. PRRSV infection caused an extraordinary local increase in ly...

  2. Immune-responsiveness of CD4+ T cells during Streptococcus suis serotype 2 infection

    PubMed Central

    Lecours, Marie-Pier; Letendre, Corinne; Clarke, Damian; Lemire, Paul; Galbas, Tristan; Benoit-Biancamano, Marie-Odile; Thibodeau, Jacques; Gottschalk, Marcelo; Segura, Mariela

    2016-01-01

    The pathogenesis of Streptococcus suis infection, a major swine and human pathogen, is only partially understood and knowledge on the host adaptive immune response is critically scarce. Yet, S. suis virulence factors, particularly its capsular polysaccharide (CPS), enable this bacterium to modulate dendritic cell (DC) functions and potentially impair the immune response. This study aimed to evaluate modulation of T cell activation during S. suis infection and the role of DCs in this response. S. suis-stimulated total mouse splenocytes readily produced TNF-α, IL-6, IFN-γ, CCL3, CXCL9, and IL-10. Ex vivo and in vivo analyses revealed the involvement of CD4+ T cells and a Th1 response. Nevertheless, during S. suis infection, levels of the Th1-derived cytokines TNF-α and IFN-γ were very low. A transient splenic depletion of CD4+ T cells and a poor memory response were also observed. Moreover, CD4+ T cells secreted IL-10 and failed to up-regulate optimal levels of CD40L and CD69 in coculture with DCs. The CPS hampered release of several T cell-derived cytokines in vitro. Finally, a correlation was established between severe clinical signs of S. suis disease and impaired antibody responses. Altogether, these results suggest S. suis interferes with the adaptive immune response. PMID:27905502

  3. Multiplexed Nanoplasmonic Temporal Profiling of T-Cell Response under Immunomodulatory Agent Exposure

    PubMed Central

    2016-01-01

    Immunomodulatory drugs—agents regulating the immune response—are commonly used for treating immune system disorders and minimizing graft versus host disease in persons receiving organ transplants. At the cellular level, immunosuppressant drugs are used to inhibit pro-inflammatory or tissue-damaging responses of cells. However, few studies have so far precisely characterized the cellular-level effect of immunomodulatory treatment. The primary challenge arises due to the rapid and transient nature of T-cell immune responses to such treatment. T-cell responses involve a highly interactive network of different types of cytokines, which makes precise monitoring of drug-modulated T-cell response difficult. Here, we present a nanoplasmonic biosensing approach to quantitatively characterize cytokine secretion behaviors of T cells with a fine time-resolution (every 10 min) that are altered by an immunosuppressive drug used in the treatment of T-cell-mediated diseases. With a microfluidic platform integrating antibody-conjugated gold nanorod (AuNR) arrays, the technique enables simultaneous multi-time-point measurements of pro-inflammatory (IL-2, IFN-γ, and TNF-α) and anti-inflammatory (IL-10) cytokines secreted by T cells. The integrated nanoplasmonic biosensors achieve precise measurements with low operating sample volume (1 μL), short assay time (∼30 min), heightened sensitivity (∼20–30 pg/mL), and negligible sensor crosstalk. Data obtained from the multicytokine secretion profiles with high practicality resulting from all of these sensing capabilities provide a comprehensive picture of the time-varying cellular functional state during pharmacologic immunosuppression. The capability to monitor cellular functional response demonstrated in this study has great potential to ultimately permit personalized immunomodulatory treatment. PMID:27478873

  4. PD-L1 limits the mucosal CD8+ T cell response to Chlamydia trachomatis

    PubMed Central

    Fankhauser, Sarah C.; Starnbach, Michael N.

    2014-01-01

    Chlamydia trachomatis infection is the most common bacterial sexually transmitted disease in the United States. Repeated infections with C. trachomatis lead to serious sequelae such as infertility. It is unclear why the adaptive immune system, specifically the CD8+ T cell response, is unable to protect against subsequent C. trachomatis infections. In this article we characterize the mucosal CD8+ T cell response to C. trachomatis in the murine genital tract. We demonstrate that the immunoinhibitory ligand, PD-L1, contributes to the defective CD8+ T cell response. Deletion or inhibition of PD-L1 restores the CD8+ T cell response and enhances C. trachomatis clearance. PMID:24353266

  5. Dynamics of the CD8 T-cell response following yellow fever virus 17D immunization

    PubMed Central

    Co, Mary Dawn T; Kilpatrick, Elizabeth D; Rothman, Alan L

    2009-01-01

    Management of yellow fever is focused on the prevention of illness by the use of the yellow fever virus (YFV) 17D vaccine. The role of neutralizing antibodies in protection is generally accepted with YFV-specific T cells likely contributing to the control of viral replication. We studied CD8+ T-cell responses to four defined human leucocyte antigen-B35-restricted epitopes in YFV vaccine recipients as a model of the kinetics of cytotoxic T-lymphocyte responses to an acute human viral infection. Multiple features of these epitope-specific responses were analysed after vaccination including magnitude, cytokine production, phenotype and T-cell receptor repertoire. Peak peptide-specific interferon-γ (IFN-γ) responses of almost 1% of CD8+ T cells were seen as early as 2 weeks post-vaccination; however, dominant responses varied between donors. Peptide-specific responses were still detectable at 54 months post-vaccination. Tetramer-positive cells, at high frequencies, were detected as early as 7–9 days, before detectable IFN-γ-producing cells, suggesting a defect in the functional capacity of some antigen-specific cells early post-vaccination. The predominant memory phenotype of the tetramer-positive population was a differentiated effector (CD45RA+ CCR7− CD62L−) phenotype. The T-cell receptor Vβ analysis revealed a diverse oligoclonal repertoire in tetramer-positive T-cell populations in two individuals. These characteristics of the YFV-specific T-cell response could contribute to vaccine effectiveness. PMID:19740333

  6. Dynamics of the CD8 T-cell response following yellow fever virus 17D immunization.

    PubMed

    Co, Mary Dawn T; Kilpatrick, Elizabeth D; Rothman, Alan L

    2009-09-01

    Management of yellow fever is focused on the prevention of illness by the use of the yellow fever virus (YFV) 17D vaccine. The role of neutralizing antibodies in protection is generally accepted with YFV-specific T cells likely contributing to the control of viral replication. We studied CD8(+) T-cell responses to four defined human leucocyte antigen-B35-restricted epitopes in YFV vaccine recipients as a model of the kinetics of cytotoxic T-lymphocyte responses to an acute human viral infection. Multiple features of these epitope-specific responses were analysed after vaccination including magnitude, cytokine production, phenotype and T-cell receptor repertoire. Peak peptide-specific interferon-gamma (IFN-gamma) responses of almost 1% of CD8(+) T cells were seen as early as 2 weeks post-vaccination; however, dominant responses varied between donors. Peptide-specific responses were still detectable at 54 months post-vaccination. Tetramer-positive cells, at high frequencies, were detected as early as 7-9 days, before detectable IFN-gamma-producing cells, suggesting a defect in the functional capacity of some antigen-specific cells early post-vaccination. The predominant memory phenotype of the tetramer-positive population was a differentiated effector (CD45RA(+) CCR7(-) CD62L(-)) phenotype. The T-cell receptor Vbeta analysis revealed a diverse oligoclonal repertoire in tetramer-positive T-cell populations in two individuals. These characteristics of the YFV-specific T-cell response could contribute to vaccine effectiveness.

  7. A Case of Human Lassa Virus Infection With Robust Acute T-Cell Activation and Long-Term Virus-Specific T-Cell Responses.

    PubMed

    McElroy, Anita K; Akondy, Rama S; Harmon, Jessica R; Ellebedy, Ali H; Cannon, Deborah; Klena, John D; Sidney, John; Sette, Alessandro; Mehta, Aneesh K; Kraft, Colleen S; Lyon, Marshall G; Varkey, Jay B; Ribner, Bruce S; Nichol, Stuart T; Spiropoulou, Christina F

    2017-06-15

    A nurse who acquired Lassa virus infection in Togo in the spring of 2016 was repatriated to the United States for care at Emory University Hospital. Serial sampling from this patient permitted the characterization of several aspects of the innate and cellular immune responses to Lassa virus. Although most of the immune responses correlated with the kinetics of viremia resolution, the CD8 T-cell response was of surprisingly high magnitude and prolonged duration, implying prolonged presentation of viral antigens. Indeed, long after viremia resolution, there was persistent viral RNA detected in the semen of the patient, accompanied by epididymitis, suggesting the male reproductive tract as 1 site of antigen persistence. Consistent with the magnitude of acute T-cell responses, the patient ultimately developed long-term, polyfunctional memory T-cell responses to Lassa virus. Published by Oxford University Press for the Infectious Diseases Society of America 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  8. T inflammatory memory CD8 T cells participate to antiviral response and generate secondary memory cells with an advantage in XCL1 production.

    PubMed

    Jubin, Virginie; Ventre, Erwan; Leverrier, Yann; Djebali, Sophia; Mayol, Katia; Tomkowiak, Martine; Mafille, Julien; Teixeira, Marie; Teoh, Denise Y-L; Lina, Bruno; Walzer, Thierry; Arpin, Christophe; Marvel, Jacqueline

    2012-06-01

    Besides the classically described subsets of memory CD8 T cells generated under infectious conditions, are T inflammatory memory cells generated under sterile priming conditions, such as sensitization to allergens. Although not fully differentiated as pathogen-induced memory cells, they display memory properties that distinguish them from naive CD8 T cells. Given these memory cells are generated in an antigen-specific context that is devoid of pathogen-derived danger signals and CD4 T cell help, we herein questioned whether they maintained their activation and differentiation potential, could be recruited in an immune response directed against a pathogen expressing their cognate antigen and further differentiate in fully competent secondary memory cells. We show that T inflammatory memory cells can indeed take part to the immune response triggered by a viral infection, differentiate into secondary effectors and further generate typical central memory CD8 T cells and effector memory CD8 T cells. Furthermore, the secondary memory cells they generate display a functional advantage over primary memory cells in their capacity to produce TNF-α and the XCL1 chemokine. These results suggest that cross-reactive stimulations and differentiation of cells directed against allergens or self into fully competent pathogen-induced memory cells might have incidences in inflammatory immuno-pathologies.

  9. Dendritic Cells Program Non-Immunogenic Prostate-Specific T Cell Responses Beginning at Early Stages of Prostate Tumorigenesis

    PubMed Central

    Mihalyo, Marianne A.; Hagymasi, Adam T.; Slaiby, Aaron M.; Nevius, Erin E.; Adler, Adam J.

    2010-01-01

    BACKGROUND Prostate cancer promotes the development of T cell tolerance towards prostatic antigens, potentially limiting the efficacy of prostate cancer vaccines targeting these antigens. Here, we sought to determine the stage of disease progression when T cell tolerance develops, as well as the role of steady state dendritic cells (DC) and CD4+CD25+ T regulatory cells (Tregs) in programming tolerance. METHODS The response of naïve HA-specific CD4+ T cells were analyzed following adoptive transfer into Pro-HA × TRAMP transgenic mice harboring variably-staged HA-expressing prostate tumors on two genetic backgrounds that display different patterns and kinetics of tumorigenesis. The role of DC and Tregs in programming HA-specific CD4 cell responses were assessed via depletion. RESULTS HA-specific CD4 cells underwent non-immunogenic responses at all stages of tumorigenesis in both genetic backgrounds. These responses were completely dependent on DC, but not appreciably influenced by Tregs. CONCLUSIONS These results suggest that tolerogenicity is an early and general property of prostate tumors. PMID:17221844

  10. Single-cell profiling of peanut-responsive T cells in patients with peanut allergy reveals heterogeneous effector TH2 subsets.

    PubMed

    Chiang, David; Chen, Xintong; Jones, Stacie M; Wood, Robert A; Sicherer, Scott H; Burks, A Wesley; Leung, Donald Y M; Agashe, Charuta; Grishin, Alexander; Dawson, Peter; Davidson, Wendy F; Newman, Leah; Sebra, Robert; Merad, Miriam; Sampson, Hugh A; Losic, Bojan; Berin, M Cecilia

    2018-06-01

    The contribution of phenotypic variation of peanut-specific T cells to clinical allergy or tolerance to peanut is not well understood. Our objective was to comprehensively phenotype peanut-specific T cells in the peripheral blood of subjects with and without peanut allergy (PA). We obtained samples from patients with PA, including a cohort undergoing baseline peanut challenges for an immunotherapy trial (Consortium of Food Allergy Research [CoFAR] 6). Subjects were confirmed as having PA, or if they passed a 1-g peanut challenge, they were termed high-threshold subjects. Healthy control (HC) subjects were also recruited. Peanut-responsive T cells were identified based on CD154 expression after 6 to 18 hours of stimulation with peanut extract. Cells were analyzed by using flow cytometry and single-cell RNA sequencing. Patients with PA had tissue- and follicle-homing peanut-responsive CD4 + T cells with a heterogeneous pattern of T H 2 differentiation, whereas control subjects had undetectable T-cell responses to peanut. The PA group had a delayed and IL-2-dependent upregulation of CD154 on cells expressing regulatory T (Treg) cell markers, which was absent in HC or high-threshold subjects. Depletion of Treg cells enhanced cytokine production in HC subjects and patients with PA in vitro, but cytokines associated with highly differentiated T H 2 cells were more resistant to Treg cell suppression in patients with PA. Analysis of gene expression by means of single-cell RNA sequencing identified T cells with highly correlated expression of IL4, IL5, IL9, IL13, and the IL-25 receptor IL17RB. These results demonstrate the presence of highly differentiated T H 2 cells producing T H 2-associated cytokines with functions beyond IgE class-switching in patients with PA. A multifunctional T H 2 response was more evident than a Treg cell deficit among peanut-responsive T cells. Copyright © 2018 American Academy of Allergy, Asthma & Immunology. All rights reserved.

  11. T cells which proliferate in response to concanavalin A include cells which proliferate in mixed leucocyte reactions.

    PubMed

    Watanabe, T; Fathman, C G; Coutinho, A

    1977-09-01

    Selection in long-term culture of alloreactive T cells, by successive in vitro restimulation with semi-allogeneic cells, results in primed responder cell populations which maintain full proliferative reactivity to allogeneic cells as well as to the T cell mitogens concanavalin A (Con A) and phytohemagglutinin (PHA) but are depleted of cells which can effect target cell destruction in either a specific or nonspecific manner. Con A-induced T cell blasts (selected by velocity sedimentation) can revert to small resting lymphocytes in the presence of inert "filler" cells. Con A blasts which have reverted, readily proliferate in response to Con A or allogeneic stimulator cells but are largely depleted of effector killer cells and PHA-responsive cells.

  12. Hunger-promoting hypothalamic neurons modulate effector and regulatory T-cell responses

    PubMed Central

    Matarese, Giuseppe; Procaccini, Claudio; Menale, Ciro; Kim, Jae Geun; Kim, Jung Dae; Diano, Sabrina; Diano, Nadia; De Rosa, Veronica; Dietrich, Marcelo O.; Horvath, Tamas L.

    2013-01-01

    Whole-body energy metabolism is regulated by the hypothalamus and has an impact on diverse tissue functions. Here we show that selective knockdown of Sirtuin 1 Sirt1 in hypothalamic Agouti-related peptide-expressing neurons, which renders these cells less responsive to cues of low energy availability, significantly promotes CD4+ T-cell activation by increasing production of T helper 1 and 17 proinflammatory cytokines via mediation of the sympathetic nervous system. These phenomena were associated with an impaired thymic generation of forkhead box P3 (FoxP3+) naturally occurring regulatory T cells and their reduced suppressive capacity in the periphery, which resulted in increased delayed-type hypersensitivity responses and autoimmune disease susceptibility in mice. These observations unmask a previously unsuspected role of hypothalamic feeding circuits in the regulation of adaptive immune response. PMID:23530205

  13. Clonal analysis of T-cell responses to herpes simplex virus: isolation, characterization and antiviral properties of an antigen-specific helper T-cell clone.

    PubMed Central

    Leung, K N; Nash, A A; Sia, D Y; Wildy, P

    1984-01-01

    A herpes simplex virus (HSV)-specific long-term T-cell clone has been established from the draining lymph node cells of BALB/c mice; the cells required repeated in vitro restimulation with UV-irradiated virus. The established T-cell clone expresses the Thy-1 and Lyt-1+2,3- surface antigens. For optimal proliferation of the cloned cells, both the presence of specific antigen and an exogenous source of T-cell growth factor are required. The proliferative response of the cloned T cells was found to be virus-specific but it did not distinguish between HSV-1 and HSV-2. Adoptive cell transfer of the cloned T cells helped primed B cells to produce anti-herpes antibodies: the response was antigen-specific and cell dose-dependent. The clone failed to produce a significant DTH reaction in vivo, but did produce high levels of macrophage-activating factor. Furthermore, the T-cell clone could protect from HSV infection, as measured by a reduction in local virus growth, and by enhanced survival following the challenge of mice with a lethal dose of virus. The mechanism(s) whereby this clone protects in vivo is discussed. PMID:6209206

  14. Clonal analysis of T-cell responses to herpes simplex virus: isolation, characterization and antiviral properties of an antigen-specific helper T-cell clone.

    PubMed

    Leung, K N; Nash, A A; Sia, D Y; Wildy, P

    1984-12-01

    A herpes simplex virus (HSV)-specific long-term T-cell clone has been established from the draining lymph node cells of BALB/c mice; the cells required repeated in vitro restimulation with UV-irradiated virus. The established T-cell clone expresses the Thy-1 and Lyt-1+2,3- surface antigens. For optimal proliferation of the cloned cells, both the presence of specific antigen and an exogenous source of T-cell growth factor are required. The proliferative response of the cloned T cells was found to be virus-specific but it did not distinguish between HSV-1 and HSV-2. Adoptive cell transfer of the cloned T cells helped primed B cells to produce anti-herpes antibodies: the response was antigen-specific and cell dose-dependent. The clone failed to produce a significant DTH reaction in vivo, but did produce high levels of macrophage-activating factor. Furthermore, the T-cell clone could protect from HSV infection, as measured by a reduction in local virus growth, and by enhanced survival following the challenge of mice with a lethal dose of virus. The mechanism(s) whereby this clone protects in vivo is discussed.

  15. Radiation Therapy Induces Macrophages to Suppress T-Cell Responses Against Pancreatic Tumors in Mice.

    PubMed

    Seifert, Lena; Werba, Gregor; Tiwari, Shaun; Giao Ly, Nancy Ngoc; Nguy, Susanna; Alothman, Sara; Alqunaibit, Dalia; Avanzi, Antonina; Daley, Donnele; Barilla, Rocky; Tippens, Daniel; Torres-Hernandez, Alejandro; Hundeyin, Mautin; Mani, Vishnu R; Hajdu, Cristina; Pellicciotta, Ilenia; Oh, Philmo; Du, Kevin; Miller, George

    2016-06-01

    The role of radiation therapy in the treatment of patients with pancreatic ductal adenocarcinoma (PDA) is controversial. Randomized controlled trials investigating the efficacy of radiation therapy in patients with locally advanced unresectable PDA have reported mixed results, with effects ranging from modest benefit to worse outcomes compared with control therapies. We investigated whether radiation causes inflammatory cells to acquire an immune-suppressive phenotype that limits the therapeutic effects of radiation on invasive PDAs and accelerates progression of preinvasive foci. We investigated the effects of radiation therapy in p48(Cre);LSL-Kras(G12D) (KC) and p48(Cre);LSLKras(G12D);LSL-Trp53(R172H) (KPC) mice, as well as in C57BL/6 mice with orthotopic tumors grown from FC1242 cells derived from KPC mice. Some mice were given neutralizing antibodies against macrophage colony-stimulating factor 1 (CSF1 or MCSF) or F4/80. Pancreata were exposed to doses of radiation ranging from 2 to 12 Gy and analyzed by flow cytometry. Pancreata of KC mice exposed to radiation had a higher frequency of advanced pancreatic intraepithelial lesions and more foci of invasive cancer than pancreata of unexposed mice (controls); radiation reduced survival time by more than 6 months. A greater proportion of macrophages from radiation treated invasive and preinvasive pancreatic tumors had an immune-suppressive, M2-like phenotype compared with control mice. Pancreata from mice exposed to radiation had fewer CD8(+) T cells than controls, and greater numbers of CD4(+) T cells of T-helper 2 and T-regulatory cell phenotypes. Adoptive transfer of T cells from irradiated PDA to tumors of control mice accelerated tumor growth. Radiation induced production of MCSF by PDA cells. A neutralizing antibody against MCSF prevented radiation from altering the phenotype of macrophages in tumors, increasing the anti-tumor T-cell response and slowing tumor growth. Radiation treatment causes macrophages

  16. Persistence of memory B-cell and T-cell responses to the quadrivalent HPV vaccine in HIV-infected children.

    PubMed

    Weinberg, Adriana; Huang, Sharon; Moscicki, Anna-Barbara; Saah, Afred; Levin, Myron J

    2018-04-24

    To determine the magnitude and persistence of quadrivalent human papillomavirus (HPV)16 and HPV18 B-cell and T-cell memory after three or four doses of quadrivalent HPV vaccine (QHPV) in HIV-infected children. Seventy-four HIV-infected children immunized with four doses and 23 with three doses of QHPV had HPV16 and HPV18 IgG B-cell and IFNγ and IL2 T-cell ELISPOT performed at 2, 3.5 and 4-5 years after the last dose. HPV16 and HPV18 T-cell responses were similar in both treatment groups, with higher responses to HPV16 vs. HPV18. These HPV T-cell responses correlated with HIV disease characteristics at the study visits. Global T-cell function declined over time as measured by nonspecific mitogenic stimulation. B-cell memory was similar across treatment groups and HPV genotypes. There was a decline in HPV-specific B-cell memory over time that reached statistical significance for HPV16 in the four-dose group. B-cell and T-cell memory did not significantly differ after either three or four doses of QHPV in HIV-infected children. The clinical consequences of decreasing global T-cell function and HPV B-cell memory over time in HIV-infected children requires further investigation.

  17. HIV-1 Antibody Neutralization Breadth Is Associated with Enhanced HIV-Specific CD4+ T Cell Responses

    PubMed Central

    Soghoian, Damien Z.; Lindqvist, Madelene; Ghebremichael, Musie; Donaghey, Faith; Carrington, Mary; Seaman, Michael S.; Kaufmann, Daniel E.; Walker, Bruce D.

    2015-01-01

    ABSTRACT Antigen-specific CD4+ T helper cell responses have long been recognized to be a critical component of effective vaccine immunity. CD4+ T cells are necessary to generate and maintain humoral immune responses by providing help to antigen-specific B cells for the production of antibodies. In HIV infection, CD4+ T cells are thought to be necessary for the induction of Env-specific broadly neutralizing antibodies. However, few studies have investigated the role of HIV-specific CD4+ T cells in association with HIV neutralizing antibody activity in vaccination or natural infection settings. Here, we conducted a comprehensive analysis of HIV-specific CD4+ T cell responses in a cohort of 34 untreated HIV-infected controllers matched for viral load, with and without neutralizing antibody breadth to a panel of viral strains. Our results show that the breadth and magnitude of Gag-specific CD4+ T cell responses were significantly higher in individuals with neutralizing antibodies than in those without neutralizing antibodies. The breadth of Gag-specific CD4+ T cell responses was positively correlated with the breadth of neutralizing antibody activity. Furthermore, the breadth and magnitude of gp41-specific, but not gp120-specific, CD4+ T cell responses were significantly elevated in individuals with neutralizing antibodies. Together, these data suggest that robust Gag-specific CD4+ T cells and, to a lesser extent, gp41-specific CD4+ T cells may provide important intermolecular help to Env-specific B cells that promote the generation or maintenance of Env-specific neutralizing antibodies. IMPORTANCE One of the earliest discoveries related to CD4+ T cell function was their provision of help to B cells in the development of antibody responses. Yet little is known about the role of CD4+ T helper responses in the setting of HIV infection, and no studies to date have evaluated the impact of HIV-specific CD4+ T cells on the generation of antibodies that can neutralize

  18. CD4 T-helper cell cytokine phenotypes and antibody response following tetanus toxoid booster immunization.

    PubMed

    Livingston, Kimberly A; Jiang, Xiaowen; Stephensen, Charles B

    2013-04-30

    Routine methods for enumerating antigen-specific T-helper cells may not identify low-frequency phenotypes such as Th2 cells. We compared methods of evaluating such responses to identify tetanus toxoid- (TT) specific Th1, Th2, Th17 and IL10(+) cells. Eight healthy subjects were given a TT booster vaccination. Blood was drawn before, 3, 7, 14, and 28days after vaccination and peripheral blood mononuclear cells (PBMC) were cultured for 7days with TT, negative control (diluent), and a positive control (Staphylococcus enterotoxin B [SEB]). Activation markers (CD25 and CD69) were measured after 44h (n=8), cytokines in supernatant after 3 and 7days, and intracellular cytokine staining (ICS) of proliferated cells (identified by dye dilution) after 7days (n=6). Vaccination increased TT-specific expression of CD25 and CD69 on CD3(+)CD4(+) lymphocytes, and TT-specific proliferation at 7, 14 and 28days post vaccination. Vaccination induced TT-specific Th1 (IFN-γ, TNF-α, and IL-2) Th2 (IL-13, IL-5, and IL-4), Th17 (IL-17A) and IL-10(+) cells as measured by ICS. TT-specific Th1 cells were the most abundant (12-15% of all TT-specific CD4(+) T-cells) while IL10(+) (1.8%) Th17 (1.1%) and Th2 cells (0.2-0.6%) were less abundant. TT-specific cytokine concentrations in PBMC supernatants followed the same pattern where a TT-specific IL-9 response was also seen. In conclusion, TT booster vaccination induced a broad T-helper cell response. This method of evaluating cytokine phenotypes may be useful in examining the impact of nutrition and environmental conditions on the plasticity of T-helper cell memory responses. Published by Elsevier B.V.

  19. T Cell Responses: Naive to Memory and Everything in Between

    ERIC Educational Resources Information Center

    Pennock, Nathan D.; White, Jason T.; Cross, Eric W.; Cheney, Elizabeth E.; Tamburini, Beth A.; Kedl, Ross M.

    2013-01-01

    The authors describe the actions that take place in T cells because of their amazing capacity to proliferate and adopt functional roles aimed at clearing a host of an infectious agent. There is a drastic decline in the T cell population once the primary response is over and the infection is terminated. What remains afterward is a population of T…

  20. Intrinsic and extrinsic contributors to defective CD8+ T cell responses with aging.

    PubMed

    Jergović, Mladen; Smithey, Megan J; Nikolich-Žugich, Janko

    2018-05-01

    Aging has a profound effect on the immune system, and both innate and adaptive arms of the immune system show functional decline with age. In response to infection with intracellular microorganisms, old animals mobilize decreased numbers of antigen-specific CD8+ T cells with reduced production of effector molecules and impaired cytolytic activity. However, the CD8+ T cell-intrinsic contribution to, and molecular mechanisms behind, these defects remain unclear. In this review we will discuss the mechanistic contributions of age related changes in the CD8+ T cell pool and the relative roles of intrinsic functional defects in aged CD8+ T cells vs. defects in the aged environment initiating the CD8+ T cell response. Copyright © 2018 Elsevier Inc. All rights reserved.

  1. Neurofascin and Compact Myelin Antigen-Specific T Cell Response Pattern in Chronic Inflammatory Demyelinating Polyneuropathy Subtypes.

    PubMed

    Diederich, Jan-Markus; Staudt, Maximilian; Meisel, Christian; Hahn, Katrin; Meinl, Edgar; Meisel, Andreas; Klehmet, Juliane

    2018-01-01

    The objective of this study is to investigate whether chronic inflammatory demyelinating polyneuropathy (CIDP) and its subtypes differ in their type 1 T-helper (TH1) cell response against nodal/paranodal neurofascin (NF186, NF155) as well as myelin protein zero (P0 180-199) and myelin basic protein (MBP 82-100). Interferon-gamma (IFN-γ) enzyme-linked immunospot assay was used to detect antigen-specific T cell responses in 48 patients suffering typical CIDP ( n  = 18), distal acquired demyelinating polyneuropathy ( n  = 8), multifocal acquired demyelinating sensory and motor polyneuropathy (MADSAM; n  = 9), and sensory CIDP ( n  = 13) compared to other non-immune polyneuropathy (ON; n  = 19) and healthy controls ( n  = 9). Compared to controls, MADSAM and sensory CIDP patients showed broadest IFN-γ T cell responses to all four antigens. Positive IFN-γ responses against two or more antigens were highly predictive for CIDP (positive predictive value = 0.95) and were found in 77% of CIDP patients. Patients with limited antigen-specific response were females, more severely affected with neuropathic pain and proximal paresis. The area under the receiver operating characteristics curve (AUC) of NF186 in MADSAM was 0.94 [95% confidential interval (CI) 0.82-1.00] compared to ON. For sensory CIDP, AUC of P0 180-199 was 0.94 (95% CI 0.86-1.00) and for MBP 82-100 0.95 (95% CI 0.88-1.00) compared to ON. Cell-mediated immune responses to (para)nodal and myelin-derived antigens are common in CIDP. TH1 response against NF186 may be used as a biomarker for MADSAM and TH1 responses against P0 180-199 and MBP 82-100 as biomarkers for sensory CIDP. Larger multicenter studies study are warranted in order to establish these immunological markers as a diagnostic tools.

  2. Tetanus Toxoid carrier protein induced T-helper cell responses upon vaccination of middle-aged adults.

    PubMed

    van der Heiden, Marieke; Duizendstra, Aafke; Berbers, Guy A M; Boots, Annemieke M H; Buisman, Anne-Marie

    2017-10-09

    Vaccines frequently induce suboptimal immune responses in the elderly, due to immunological ageing. Timely vaccination may be a strategy to overcome this problem, which classifies middle-aged adults asan interesting target group for future vaccine interventions. However, the immunological fitness of the middle-aged population is ill-defined. It is currently unknown whether effective T-cell help towards B-cells is initiated by conjugate-carrier vaccines at middle-age. We characterized systemic Tetanus Toxoid (TT) specific T-helper cell responses in the circulation of middle-aged adults (50-65years of age, n=31) having received the MenACWY-TT vaccination. Blood samples were taken pre- as well as 7days, 28days, and 1year post-vaccination. TT-specific T-cell responses were determined by IFNγ Elispot and by the secretion of IFNγ, IL13, IL10, IL17, and IL21 in cell culture supernatants. Circulating CD4+CXCR5+ICOS+IL21+ cells were analyzed by flow cytometry, and meningococcal and TT-specific IgG responses by bead-based immunoassays. The correlation between the T-cell help and humoral responses was evaluated. Vaccination with a TT-carrier protein induced a mixed TT-specific Th1 (IFNγ), Th2 (IL13, IL10), and Th17 (IL17) response in most participants. Additionally, circulating CD4+CXCR5+ICOS+IL21+ cells were significantly increased 7days post-vaccination. Pre-vaccination TT-specific cytokine production and post-vaccination Th2 responses correlated positively with the increase of CD4+CXCR5+ICOS+IL21+ cells. No correlation between T-cell help and antibody responses was found. The characteristics of the T-cell response upon a TT-carrier vaccination suggests effective T-cell help towards B-cells in response to meningococcal polysaccharides, although the absence of a correlation with the antibody responses warrants further clarification. However, the robust T-helper cell response in middle-aged adults, decades after previous TT vaccinations, strengthens the classification of

  3. ESAT-6 Targeting to DEC205+ Antigen Presenting Cells Induces Specific-T Cell Responses against ESAT-6 and Reduces Pulmonary Infection with Virulent Mycobacterium tuberculosis.

    PubMed

    Silva-Sánchez, Aarón; Meza-Pérez, Selene; Flores-Langarica, Adriana; Donis-Maturano, Luis; Estrada-García, Iris; Calderón-Amador, Juana; Hernández-Pando, Rogelio; Idoyaga, Juliana; Steinman, Ralph M; Flores-Romo, Leopoldo

    2015-01-01

    Airways infection with Mycobacterium tuberculosis (Mtb) is contained mostly by T cell responses, however, Mtb has developed evasion mechanisms which affect antigen presenting cell (APC) maturation/recruitment delaying the onset of Ag-specific T cell responses. Hypothetically, bypassing the natural infection routes by delivering antigens directly to APCs may overcome the pathogen's naturally evolved evasion mechanisms, thus facilitating the induction of protective immune responses. We generated a murine monoclonal fusion antibody (α-DEC-ESAT) to deliver Early Secretory Antigen Target (ESAT)-6 directly to DEC205+ APCs and to assess its in vivo effects on protection associated responses (IFN-γ production, in vivo CTL killing, and pulmonary mycobacterial load). Treatment with α-DEC-ESAT alone induced ESAT-6-specific IFN-γ producing CD4+ T cells and prime-boost immunization prior to Mtb infection resulted in early influx (d14 post-infection) and increased IFN-γ+ production by specific T cells in the lungs, compared to scarce IFN-γ production in control mice. In vivo CTL killing was quantified in relevant tissues upon transferring target cells loaded with mycobacterial antigens. During infection, α-DEC-ESAT-treated mice showed increased target cell killing in the lungs, where histology revealed cellular infiltrate and considerably reduced bacterial burden. Targeting the mycobacterial antigen ESAT-6 to DEC205+ APCs before infection expands specific T cell clones responsible for early T cell responses (IFN-γ production and CTL activity) and substantially reduces lung bacterial burden. Delivering mycobacterial antigens directly to APCs provides a unique approach to study in vivo the role of APCs and specific T cell responses to assess their potential anti-mycobacterial functions.

  4. ESAT-6 Targeting to DEC205+ Antigen Presenting Cells Induces Specific-T Cell Responses against ESAT-6 and Reduces Pulmonary Infection with Virulent Mycobacterium tuberculosis

    PubMed Central

    Silva-Sánchez, Aarón; Meza-Pérez, Selene; Flores-Langarica, Adriana; Donis-Maturano, Luis; Estrada-García, Iris; Calderón-Amador, Juana; Hernández-Pando, Rogelio; Idoyaga, Juliana; Flores-Romo, Leopoldo

    2015-01-01

    Airways infection with Mycobacterium tuberculosis (Mtb) is contained mostly by T cell responses, however, Mtb has developed evasion mechanisms which affect antigen presenting cell (APC) maturation/recruitment delaying the onset of Ag-specific T cell responses. Hypothetically, bypassing the natural infection routes by delivering antigens directly to APCs may overcome the pathogen’s naturally evolved evasion mechanisms, thus facilitating the induction of protective immune responses. We generated a murine monoclonal fusion antibody (α-DEC-ESAT) to deliver Early Secretory Antigen Target (ESAT)-6 directly to DEC205+ APCs and to assess its in vivo effects on protection associated responses (IFN-γ production, in vivo CTL killing, and pulmonary mycobacterial load). Treatment with α-DEC-ESAT alone induced ESAT-6-specific IFN-γ producing CD4+ T cells and prime-boost immunization prior to Mtb infection resulted in early influx (d14 post-infection) and increased IFN-γ+ production by specific T cells in the lungs, compared to scarce IFN-γ production in control mice. In vivo CTL killing was quantified in relevant tissues upon transferring target cells loaded with mycobacterial antigens. During infection, α-DEC-ESAT-treated mice showed increased target cell killing in the lungs, where histology revealed cellular infiltrate and considerably reduced bacterial burden. Targeting the mycobacterial antigen ESAT-6 to DEC205+ APCs before infection expands specific T cell clones responsible for early T cell responses (IFN-γ production and CTL activity) and substantially reduces lung bacterial burden. Delivering mycobacterial antigens directly to APCs provides a unique approach to study in vivo the role of APCs and specific T cell responses to assess their potential anti-mycobacterial functions. PMID:25915045

  5. Distinct T cell interactions with HLA class II tetramers characterize a spectrum of TCR affinities in the human antigen-specific T cell response.

    PubMed

    Reichstetter, S; Ettinger, R A; Liu, A W; Gebe, J A; Nepom, G T; Kwok, W W

    2000-12-15

    The polyclonal nature of T cells expanding in an ongoing immune response results in a range of disparate affinities and activation potential. Recently developed human class II tetramers provide a means to analyze this diversity by direct characterization of the trimolecular TCR-peptide-MHC interaction in live cells. Two HSV-2 VP16(369-379)-specific, DQA1*0102/DQB1*0602 (DQ0602)-restricted T cell clones were compared by means of T cell proliferation assay and HLA-DQ0602 tetramer staining. These two clones were obtained from the same subject, but show different TCR gene usage. Clone 48 was 10-fold more sensitive to VP16(369-379) peptide stimulation than clone 5 as assayed by proliferation assays, correlating with differences in MHC tetramer binding. Clone 48 gave positive staining with the DQ0602/VP16(369-379) tetramer at either 23 or 37 degrees C. Weak staining was also observed at 4 degrees C. Clone 5 showed weaker staining compared with clone 48 at 37 degrees C, and no staining was observed at 23 degrees C or on ice. Receptor internalization was not required for positive staining. Competitive binding indicates that the cell surface TCR of clone 48 has higher affinity for the DQ0602/VP16(369-379) complex than clone 5. The higher binding affinity of clone 48 for the peptide-MHC complex also correlates with a slower dissociation rate compared with clone 5.

  6. The CD8 T Cell Response to Respiratory Virus Infections.

    PubMed

    Schmidt, Megan E; Varga, Steven M

    2018-01-01

    Humans are highly susceptible to infection with respiratory viruses including respiratory syncytial virus (RSV), influenza virus, human metapneumovirus, rhinovirus, coronavirus, and parainfluenza virus. While some viruses simply cause symptoms of the common cold, many respiratory viruses induce severe bronchiolitis, pneumonia, and even death following infection. Despite the immense clinical burden, the majority of the most common pulmonary viruses lack long-lasting efficacious vaccines. Nearly all current vaccination strategies are designed to elicit broadly neutralizing antibodies, which prevent severe disease following a subsequent infection. However, the mucosal antibody response to many respiratory viruses is not long-lasting and declines with age. CD8 T cells are critical for mediating clearance following many acute viral infections in the lung. In addition, memory CD8 T cells are capable of providing protection against secondary infections. Therefore, the combined induction of virus-specific CD8 T cells and antibodies may provide optimal protective immunity. Herein, we review the current literature on CD8 T cell responses induced by respiratory virus infections. Additionally, we explore how this knowledge could be utilized in the development of future vaccines against respiratory viruses, with a special emphasis on RSV vaccination.

  7. HMBPP-deficient Listeria mutant immunization alters pulmonary/systemic responses, effector functions, and memory polarization of Vγ2Vδ2 T cells

    PubMed Central

    Frencher, James T.; Shen, Hongbo; Yan, Lin; Wilson, Jessica O.; Freitag, Nancy E.; Rizzo, Alicia N.; Chen, Crystal Y.; Chen, Zheng W.

    2014-01-01

    Whereas infection or immunization of humans/primates with microbes coproducing HMBPP/IPP can remarkably activate Vγ2Vδ2 T cells, in vivo studies have not been done to dissect HMBPP- and IPP-driven expansion, pulmonary trafficking, effector functions, and memory polarization of Vγ2Vδ2 T cells. We define these phosphoantigen-host interplays by comparative immunizations of macaques with the HMBPP/IPP-coproducing Listeria ΔactA prfA* and HMBPP-deficient Listeria ΔactAΔgcpE prfA* mutant. The HMBPP-deficient ΔgcpE mutant shows lower ability to expand Vγ2Vδ2 T cells in vitro than the parental HMBPP-producing strain but displays comparably attenuated infectivity or immunogenicity. Respiratory immunization of macaques with the HMBPP-deficient mutant elicits lower pulmonary and systemic responses of Vγ2Vδ2 T cells compared with the HMBPP-producing vaccine strain. Interestingly, HMBPP-deficient mutant reimmunization or boosting elicits enhanced responses of Vγ2Vδ2 T cells, but the magnitude is lower than that by HMBPP-producing listeria. HMBPP-deficient listeria differentiated fewer Vγ2Vδ2 T effector cells capable of coproducing IFN-γ and TNF-α and inhibiting intracellular listeria than HMBPP-producing listeria. Furthermore, HMBPP deficiency in listerial immunization influences memory polarization of Vγ2Vδ2 T cells. Thus, both HMBPP and IPP production in listerial immunization or infection elicit systemic/pulmonary responses and differentiation of Vγ2Vδ2 T cells, but a role for HMBPP is more dominant. Findings may help devise immune intervention. PMID:25114162

  8. Cannabidiol (CBD) Induces Functional Tregs in Response to Low-Level T Cell Activation

    PubMed Central

    Dhital, Saphala; Stokes, John V.; Park, Nogi; Seo, Keun-Seok; Kaplan, Barbara L.F.

    2016-01-01

    Many effects of the non-psychoactive cannabinoid, cannabidiol (CBD), have been described in immune responses induced by strong immunological stimuli. It has also been shown that CBD enhances IL-2 production in response to low-level T cell stimulation. Since IL-2, in combination with TGF-β1, are critical for Treg induction, we hypothesized that CBD would induce CD4+CD25+FOXP3+ Tregs in response to low-level stimulation. Low-level T cell stimulation conditions were established based on minimal CD25 expression in CD4+ cells using suboptimal PMA/Io (4 nM/0.05 μM, S/o), ultrasuboptimal PMA/Io (1 nM/0.0125 μM, Us/o) or soluble anti-CD3/28 (400-800 ng each, s3/28). CBD increased CD25+FOXP3+ cells from CD4+, CD4+CD25+, and CD4+CD25− T cells, as well as in CD4+ T cells derived from FOXP3-GFP mice. Most importantly, the Us/o + CBD-induced CD4+CD25+ Tregs robustly suppressed responder T cell proliferation, demonstrating that the mechanism by which CBD is immunosuppressive under low-level T cell stimulation involves induction of functional Tregs. PMID:27865421

  9. Cannabidiol (CBD) induces functional Tregs in response to low-level T cell activation.

    PubMed

    Dhital, Saphala; Stokes, John V; Park, Nogi; Seo, Keun Seok; Kaplan, Barbara L F

    2017-02-01

    Many effects of the non-psychoactive cannabinoid, cannabidiol (CBD), have been described in immune responses induced by strong immunological stimuli. It has also been shown that CBD enhances IL-2 production in response to low-level T cell stimulation. Since IL-2, in combination with TGF-β1, are critical for Treg induction, we hypothesized that CBD would induce CD4 + CD25 + FOXP3 + Tregs in response to low-level stimulation. Low-level T cell stimulation conditions were established based on minimal CD25 expression in CD4 + cells using suboptimal PMA/Io (4nM/0.05μM, S/o), ultrasuboptimal PMA/Io (1nM/0.0125μM, Us/o) or soluble anti-CD3/28 (400-800ng each, s3/28). CBD increased CD25 + FOXP3 + cells from CD4 + , CD4 + CD25 + , and CD4 + CD25 - T cells, as well as in CD4 + T cells derived from FOXP3-GFP mice. Most importantly, the Us/o+CBD-induced CD4 + CD25 + Tregs robustly suppressed responder T cell proliferation, demonstrating that the mechanism by which CBD is immunosuppressive under low-level T cell stimulation involves induction of functional Tregs. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Pathogen-Sensing and Regulatory T Cells: Integrated Regulators of Immune Responses

    PubMed Central

    Grossman, Zvi; Paul, William E.

    2014-01-01

    We present the concept that pathogen-sensing and Tregs mutually regulate immune responses to conventional and tumor antigens through countervailing effects on dendritic cells. Normally, conventional CD4 T cells recognizing their cognate antigen-presented by a dendritic cell will respond only if the dendritic cell also receives a signal through its pathogen-sensing/ danger / adjuvant recognition systems (the pathogen-sensing triad). However, if Tregs capable of interacting with the same DC are absent, dendritic cells are competent to present antigens, both foreign and self, even without the stimulation provided by the pathogen-sensing triad. Tregs recognizing an antigen presented by the DC that is also presenting antigen to a conventional CD4 T cell will prevent such responses but a signal delivered by a member of the pathogen-sensing traid will overcome the Tregs’inhibitory action and will allow responses to go forward. These considerations take on special meaning for responses to “weak antigens” such as many of the antigens displayed by spontaneous human tumors. PMID:24894087

  11. Isolation and preservation of peripheral blood mononuclear cells for analysis of islet antigen-reactive T cell responses: position statement of the T-Cell Workshop Committee of the Immunology of Diabetes Society.

    PubMed

    Mallone, R; Mannering, S I; Brooks-Worrell, B M; Durinovic-Belló, I; Cilio, C M; Wong, F S; Schloot, N C

    2011-01-01

    Autoimmune T cell responses directed against insulin-producing β cells are central to the pathogenesis of type 1 diabetes (T1D). Detection of such responses is therefore critical to provide novel biomarkers for T1D 'immune staging' and to understand the mechanisms underlying the disease. While different T cell assays are being developed for these purposes, it is important to optimize and standardize methods for processing human blood samples for these assays. To this end, we review data relevant to critical parameters in peripheral blood mononuclear cell (PBMC) isolation, (cryo)preservation, distribution and usage for detecting antigen-specific T cell responses. Based on these data, we propose recommendations on processing blood samples for T cell assays and identify gaps in knowledge that need to be addressed. These recommendations may be relevant not only for the analysis of T cell responses in autoimmune disease, but also in cancer and infectious disease, particularly in the context of clinical trials. © 2010 The Authors. Clinical and Experimental Immunology © 2010 British Society for Immunology.

  12. CD8+ T-cell responses rapidly select for antigen-negative tumor cells in the prostate.

    PubMed

    Bak, S Peter; Barnkob, Mike Stein; Wittrup, K Dane; Chen, Jianzhu

    2013-12-01

    Stimulation of patients' immune systems for the treatment of solid tumors is an emerging therapeutic paradigm. The use of enriched autologous T cells for adoptive cell therapy or vaccination with antigen-loaded dendritic cells have shown clinical efficacy in melanoma and prostate cancer, respectively. However, the long-term effects of immune responses on selection and outgrowth of antigen-negative tumor cells in specific tumor types must be determined to understand and achieve long-term therapeutic effects. In this study, we have investigated the expression of a tumor-specific antigen in situ after treatment with tumor-specific CD8(+) T cells in an autochthonous mouse model of prostate cancer. After T-cell treatment, aggregates of dead antigen-positive tumor cells were concentrated in the lumen of the prostate gland and were eventually eliminated from the prostate tissue. Despite the elimination of antigen-positive tumor cells, prostate tumor continued to grow in T-cell-treated mice. Interestingly, the remaining tumor cells were antigen negative and downregulated MHC class I expression. These results show that CD8(+) T cells are effective in eliminating antigen-bearing prostate tumor cells but they also can select for the outgrowth of antigen-negative tumor cells. These findings provide insights into the requirements for an effective cancer immunotherapy within the prostate that not only induces potent immune responses but also avoids selection and outgrowth of antigen-negative tumor cells. ©2013 AACR.

  13. Conditional deletion of SLP-76 in mature T cells abrogates peripheral immune responses.

    PubMed

    Wu, Gregory F; Corbo, Evann; Schmidt, Michelle; Smith-Garvin, Jennifer E; Riese, Matthew J; Jordan, Martha S; Laufer, Terri M; Brown, Eric J; Maltzman, Jonathan S

    2011-07-01

    The adaptor protein Src homology 2 domain-containing leukocyte-specific protein of 76 kDa (SLP-76) is central to the organization of intracellular signaling downstream of the T-cell receptor (TCR). Evaluation of its role in mature, primary T cells has been hampered by developmental defects that occur in the absence of WT SLP-76 protein in thymocytes. Here, we show that following tamoxifen-regulated conditional deletion of SLP-76, mature, antigen-inexperienced T cells maintain normal TCR surface expression but fail to transduce TCR-generated signals. Conditionally deficient T cells fail to proliferate in response to antigenic stimulation or a lymphopenic environment. Mice with induced deletion of SLP-76 are resistant to induction of the CD4+ T-cell-mediated autoimmune disease experimental autoimmune encephalomyelitis. Altogether, our findings demonstrate the critical role of SLP-76-mediated signaling in initiating T-cell-directed immune responses both in vitro and in vivo and highlight the ability to analyze signaling processes in mature T cells in the absence of developmental defects. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Mitochondrial cyclophilin D regulates T cell metabolic responses and disease tolerance to tuberculosis.

    PubMed

    Tzelepis, Fanny; Blagih, Julianna; Khan, Nargis; Gillard, Joshua; Mendonca, Laura; Roy, Dominic G; Ma, Eric H; Joubert, Philippe; Jones, Russell G; Divangahi, Maziar

    2018-05-11

    Mycobacterium tuberculosis ( Mtb ) is one of the most ancient human pathogens, yet the exact mechanism(s) of host defense against Mtb remains unclear. Although one-third of the world's population is chronically infected with Mtb , only 5 to 10% develop active disease. This indicates that, in addition to resistance mechanisms that control bacterial burden, the host has also evolved strategies to tolerate the presence of Mtb to limit disease severity. We identify mitochondrial cyclophilin D (CypD) as a critical checkpoint of T cell metabolism that controls the expansion of activated T cells. Although loss of CypD function in T cells led to enhanced Mtb antigen-specific T cell responses, this increased T cell response had no impact on bacterial burden. Rather, mice containing CypD-deficient T cells exhibited substantially compromised disease tolerance and succumbed to Mtb infection. This study establishes a mechanistic link between T cell-mediated immunity and disease tolerance during Mtb infection. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  15. Plasmacytoid Dendritic Cells Require Direct Infection To Sustain the Pulmonary Influenza A Virus-Specific CD8 T Cell Response

    PubMed Central

    Hemann, Emily A.; Sjaastad, Louisa E.; Langlois, Ryan A.

    2015-01-01

    ABSTRACT Following influenza A virus (IAV) infection, development of a robust IAV-specific CD8 T cell response is required for clearance of primary infection and enhances memory protection. Following IAV infection, plasmacytoid dendritic cells (pDC) or CD8α+ DC regulate pulmonary effector CD8 T cell responses within the lung. Without this DC-T cell interaction, insufficient effector CD8 T cells are maintained in the lungs, leading to enhanced morbidity and mortality. Previous studies have demonstrated that pDC are capable of classical presentation or cross-presentation of IAV antigens and could potentially regulate IAV-specific CD8 T cell responses through either mechanism. Our results demonstrate that pDC from the lungs of donor mice infected with an IAV that is not able to replicate in hematopoietic cells (142t-IAV), unlike donor pDC isolated from the lungs of control infected mice, are not able to rescue the host IAV-specific CD8 T cell response from apoptosis. This indicates that pDC must utilize the direct presentation pathway for this rescue. This inability of pDC from 142t-IAV donors to rescue the IAV-specific CD8 T cell response is not due to differences in the overall ability of 142t-IAV to replicate within the lungs or generate defective viral genomes or to differences in levels of costimulatory molecules required for this interaction. We further demonstrate that bypassing the antigen presentation pathway by coating the 142t-IAV pDC with IAV peptide epitopes restores their ability to rescue the IAV-specific CD8 T cell response. IMPORTANCE IAV continues to be a global health burden, infecting 5 to 20% of the global population annually. Continued investigation into the mechanisms that mediate protective immune responses against IAV is important to improving current vaccination and antiviral strategies antagonistic toward IAV. Our findings presented herein demonstrate a key requirement for pDC promotion of effector CD8 T cell survival: that rather than

  16. Plasmacytoid Dendritic Cells Require Direct Infection To Sustain the Pulmonary Influenza A Virus-Specific CD8 T Cell Response.

    PubMed

    Hemann, Emily A; Sjaastad, Louisa E; Langlois, Ryan A; Legge, Kevin L

    2015-12-30

    Following influenza A virus (IAV) infection, development of a robust IAV-specific CD8 T cell response is required for clearance of primary infection and enhances memory protection. Following IAV infection, plasmacytoid dendritic cells (pDC) or CD8α(+) DC regulate pulmonary effector CD8 T cell responses within the lung. Without this DC-T cell interaction, insufficient effector CD8 T cells are maintained in the lungs, leading to enhanced morbidity and mortality. Previous studies have demonstrated that pDC are capable of classical presentation or cross-presentation of IAV antigens and could potentially regulate IAV-specific CD8 T cell responses through either mechanism. Our results demonstrate that pDC from the lungs of donor mice infected with an IAV that is not able to replicate in hematopoietic cells (142t-IAV), unlike donor pDC isolated from the lungs of control infected mice, are not able to rescue the host IAV-specific CD8 T cell response from apoptosis. This indicates that pDC must utilize the direct presentation pathway for this rescue. This inability of pDC from 142t-IAV donors to rescue the IAV-specific CD8 T cell response is not due to differences in the overall ability of 142t-IAV to replicate within the lungs or generate defective viral genomes or to differences in levels of costimulatory molecules required for this interaction. We further demonstrate that bypassing the antigen presentation pathway by coating the 142t-IAV pDC with IAV peptide epitopes restores their ability to rescue the IAV-specific CD8 T cell response. IAV continues to be a global health burden, infecting 5 to 20% of the global population annually. Continued investigation into the mechanisms that mediate protective immune responses against IAV is important to improving current vaccination and antiviral strategies antagonistic toward IAV. Our findings presented herein demonstrate a key requirement for pDC promotion of effector CD8 T cell survival: that rather than utilizing cross

  17. Intestinal T cell responses to cereal proteins in celiac disease.

    PubMed

    Kilmartin, C; Wieser, H; Abuzakouk, M; Kelly, J; Jackson, J; Feighery, C

    2006-01-01

    Celiac disease is caused by sensitivity to wheat gluten in genetically susceptible individuals. The etiological role of the other wheat-related cereals, barley, rye, and oats, is still debated. In order to investigate this issue further, in this study we examined the immune response of celiac mucosal T cell lines to fractions from all four cereals. Cell stimulation was assessed by measuring proliferation (employing (3)H-thymidine incorporation) or cytokine (IL-2, IFN-gamma) production. All five T cell lines demonstrated immunoreactivity to protein fractions from the four related cereals. In some cell lines, reactivity to wheat, barley, and rye was only evident when these cereal fractions had been pretreated with tissue transglutaminase. This study confirms the similar T cell antigenic reactivity of these four related cereals and has implications for their exclusion in the gluten-free diet. However, despite oats stimulation of T cell lines, this cereal does not activate a mucosal lesion in most celiac patients.

  18. Distinct CD4+-T-cell responses to live and heat-inactivated Aspergillus fumigatus conidia.

    PubMed

    Rivera, Amariliz; Van Epps, Heather L; Hohl, Tobias M; Rizzuto, Gabrielle; Pamer, Eric G

    2005-11-01

    Aspergillus fumigatus is an important fungal pathogen that causes invasive pulmonary disease in immunocompromised hosts. Respiratory exposure to A. fumigatus spores also causes allergic bronchopulmonary aspergillosis, a Th2 CD4+-T-cell-mediated disease that accompanies asthma. The microbial factors that influence the differentiation of A. fumigatus-specific CD4+ T lymphocytes into Th1 versus Th2 cells remain incompletely defined. We therefore examined CD4+-T-cell responses of immunologically intact mice to intratracheal challenge with live or heat-inactivated A. fumigatus spores. Live but not heat-inactivated fungal spores resulted in recruitment of gamma interferon (IFN-gamma)-producing, fungus-specific CD4+ T cells to lung airways, achieving A. fumigatus-specific frequencies exceeding 5% of total CD4+ T cells. While heat-inactivated spores did not induce detectable levels of IFN-gamma-producing, A. fumigatus-specific CD4+ T cells in the airways, they did prime CD4+ T-cell responses in draining lymph nodes that produced greater amounts of interleukin 4 (IL-4) and IL-13 than T cells responding to live conidia. While immunization with live fungal spores induced antibody responses, we found a marked decrease in isotype-switched, A. fumigatus-specific antibodies in sera of mice following immunization with heat-inactivated spores. Our studies demonstrate that robust Th1 T-cell and humoral responses are restricted to challenge with fungal spores that have the potential to germinate and cause invasive infection. How the adaptive immune system distinguishes between metabolically active and inactive fungal spores remains an important question.

  19. Trypanosoma cruzi Subverts Host Cell Sialylation and May Compromise Antigen-specific CD8+ T Cell Responses*

    PubMed Central

    Freire-de-Lima, Leonardo; Alisson-Silva, Frederico; Carvalho, Sebastião T.; Takiya, Christina M.; Rodrigues, Maurício M.; DosReis, George A.; Mendonça-Previato, Lucia; Previato, José O.; Todeschini, Adriane R.

    2010-01-01

    Upon activation, cytotoxic CD8+ T lymphocytes are desialylated exposing β-galactose residues in a physiological change that enhances their effector activity and that can be monitored on the basis of increased binding of the lectin peanut agglutinin. Herein, we investigated the impact of sialylation mediated by trans-sialidase, a specific and unique Trypanosoma transglycosylase for sialic acid, on CD8+ T cell response of mice infected with T. cruzi. Our data demonstrate that T. cruzi uses its trans-sialidase enzyme to resialylate the CD8+ T cell surface, thereby dampening antigen-specific CD8+ T cell response that might favor its own persistence in the mammalian host. Binding of the monoclonal antibody S7, which recognizes sialic acid-containing epitopes on the 115-kDa isoform of CD43, was augmented on CD8+ T cells from ST3Gal-I-deficient infected mice, indicating that CD43 is one sialic acid acceptor for trans-sialidase activity on the CD8+ T cell surface. The cytotoxic activity of antigen-experienced CD8+ T cells against the immunodominant trans-sialidase synthetic peptide IYNVGQVSI was decreased following active trans-sialidase- mediated resialylation in vitro and in vivo. Inhibition of the parasite's native trans-sialidase activity during infection strongly decreased CD8+ T cell sialylation, reverting it to the glycosylation status expected in the absence of parasite manipulation increasing mouse survival. Taken together, these results demonstrate, for the first time, that T. cruzi subverts sialylation to attenuate CD8+ T cell interactions with peptide-major histocompatibility complex class I complexes. CD8+ T cell resialylation may represent a sophisticated strategy to ensure lifetime host parasitism. PMID:20106975

  20. Robust interferon-α and IL-12 responses by dendritic cells are related to efficient CD4+ T-cell recovery in HIV patients on ART.

    PubMed

    Tan, Dino Bee Aik; Yong, Yean Kong; Lim, Andrew; Tan, Hong Yien; Kamarulzaman, Adeeba; French, Martyn; Price, Patricia

    2011-05-01

    Amongst HIV patients with successful virological responses to antiretroviral therapy (ART), poor CD4(+) T-cell recovery is associated with low nadir CD4(+) T-cell counts and persistent immune activation. These factors might be influenced by dendritic cell (DC) function. Interferon-α-producing plasmacytoid DC and IL-12-producing myeloid DC were quantified by flow cytometry after stimulation with agonists to TLR7/8 (CL075) or TLR9 (CpG-ODN). These were compared between patients who achieved CD4(+) T-cell counts above or below 200 cells/μL after 6 months on ART (High vs. Low groups). High Group patients had more DC producing interferon-α or IL-12 at Weeks 6 and 12 on ART than Low Group patients. The frequencies of cytokine-producing DC at Week 12 were directly correlated with CD4(+) T-cell counts at baseline and at Week 12. Patients with good recovery of CD4(+) T-cells had robust TLR-mediated interferon-α responses by plasmacytoid DC and IL-12 responses by myeloid DC during early ART (1-3 months). Copyright © 2011 Elsevier Inc. All rights reserved.

  1. Hit parade for adoptive cell transfer therapy: the best T cells for superior clinical responses.

    PubMed

    Speiser, Daniel E

    2013-04-01

    Adoptive cell transfer (ACT) of T cells has great clinical potential, but the numerous variables of this therapy make choices difficult. A new study takes advantage of a novel technology for characterizing the T-cell responses of patients. If applied systematically, this approach may identify biomedical correlates of protection, thereby supporting treatment optimization. ©2013 AACR.

  2. Decreased diacylglycerol metabolism enhances ERK activation and augments CD8+ T cell functional responses.

    PubMed

    Riese, Matthew J; Grewal, Jashanpreet; Das, Jayajit; Zou, Tao; Patil, Vineet; Chakraborty, Arup K; Koretzky, Gary A

    2011-02-18

    Modulation of T cell receptor signal transduction in CD8(+) T cells represents a novel strategy toward enhancing the immune response to tumor. Recently, levels of guanine exchange factors, RasGRP and SOS, within T cells have been shown to represent a key determinant in the regulation of the analog to the digital activation threshold of Ras. One important for regulating activation levels of RasGRP is diacylglycerol (DAG), and its levels are influenced by diacylglycerol kinase-ζ (DGKζ), which metabolizes DAG into phosphatidic acid, terminating DAG-mediated Ras signaling. We sought to determine whether DGKζ-deficient CD8(+) T cells demonstrated enhanced in vitro responses in a manner predicted by the current model of Ras activation and to evaluate whether targeting this threshold confers enhanced CD8(+) T cell responsiveness to tumor. We observed that DGKζ-deficient CD8(+) T cells conform to most predictions of the current model of how RasGRP levels influence Ras activation. But our results differ in that the EC(50) value of stimulation is not altered for any T cell receptor stimulus, a finding that suggests a further degree of complexity to how DGKζ deficiency affects signals important for Ras and ERK activation. Additionally, we found that DGKζ-deficient CD8(+) T cells demonstrate enhanced responsiveness in a subcutaneous lymphoma model, implicating the analog to a digital conversion threshold as a novel target for potential therapeutic manipulation.

  3. Analysis of T Cell Responses during Active Varicella-Zoster Virus Reactivation in Human Ganglia

    PubMed Central

    Steain, Megan; Sutherland, Jeremy P.; Rodriguez, Michael; Cunningham, Anthony L.; Slobedman, Barry

    2014-01-01

    ABSTRACT Varicella-zoster virus (VZV) is responsible for both varicella (chickenpox) and herpes zoster (shingles). During varicella, the virus establishes latency within the sensory ganglia and can reactivate to cause herpes zoster, but the immune responses that occur in ganglia during herpes zoster have not previously been defined. We examined ganglia obtained from individuals who, at the time of death, had active herpes zoster. Ganglia innervating the site of the cutaneous herpes zoster rash showed evidence of necrosis, secondary to vasculitis, or localized hemorrhage. Despite this, there was limited evidence of VZV antigen expression, although a large inflammatory infiltrate was observed. Characterization of the infiltrating T cells showed a large number of infiltrating CD4+ T cells and cytolytic CD8+ T cells. Many of the infiltrating T cells were closely associated with neurons within the reactivated ganglia, yet there was little evidence of T cell-induced neuronal apoptosis. Notably, an upregulation in the expression of major histocompatibility complex class I (MHC-I) and MHC-II molecules was observed on satellite glial cells, implying these cells play an active role in directing the immune response during herpes zoster. This is the first detailed characterization of the interaction between T cells and neuronal cells within ganglia obtained from patients suffering herpes zoster at the time of death and provides evidence that CD4+ and cytolytic CD8+ T cell responses play an important role in controlling VZV replication in ganglia during active herpes zoster. IMPORTANCE VZV is responsible for both varicella (chickenpox) and herpes zoster (shingles). During varicella, the virus establishes a life-long dormant infection within the sensory ganglia and can reawaken to cause herpes zoster, but the immune responses that occur in ganglia during herpes zoster have not previously been defined. We examined ganglia obtained from individuals who, at the time of death, had

  4. Split T Cell Tolerance against a Self/Tumor Antigen: Spontaneous CD4+ but Not CD8+ T Cell Responses against p53 in Cancer Patients and Healthy Donors

    PubMed Central

    Tsuji, Takemasa; Matsuzaki, Junko; Ritter, Erika; Miliotto, Anthony; Ritter, Gerd; Odunsi, Kunle; Old, Lloyd J.; Gnjatic, Sacha

    2011-01-01

    Analyses of NY-ESO-1-specific spontaneous immune responses in cancer patients revealed that antibody and both CD4+ and CD8+ T cell responses were induced together in cancer patients. To explore whether such integrated immune responses are also spontaneously induced for other tumor antigens, we have evaluated antibody and T cell responses against self/tumor antigen p53 in ovarian cancer patients and healthy individuals. We found that 21% (64/298) of ovarian cancer patients but no healthy donors showed specific IgG responses against wild-type p53 protein. While none of 12 patients with high titer p53 antibody showed spontaneous p53-specific CD8+ T cell responses following a single in vitro sensitization, significant p53-specific IFN-γ producing CD4+ T cells were detected in 6 patients. Surprisingly, similar levels of p53-specific CD4+ T cells but not CD8+ T cells were also detected in 5/10 seronegative cancer patients and 9/12 healthy donors. Importantly, p53-specific CD4+ T cells in healthy donors originated from a CD45RA− antigen-experienced T cell population and recognized naturally processed wild-type p53 protein. These results raise the possibility that p53-specific CD4+ T cells reflect abnormalities in p53 occurring in normal individuals and that they may play a role in processes of immunosurveillance or immunoregulation of p53-related neoplastic events. PMID:21858191

  5. Regulation of oxidative stress responses by ataxia-telangiectasia mutated is required for T cell proliferation.

    PubMed

    Bagley, Jessamyn; Singh, Gyanesh; Iacomini, John

    2007-04-15

    Mutations in the gene encoding ataxia-telangiectasia (A-T) mutated (Atm) cause the disease A-T, characterized by immunodeficiency, the molecular basis of which is not known. Following stimulation through the TCR, Atm-deficient T cells and normal T cells in which Atm is inhibited undergo apoptosis rather than proliferation. Apoptosis is prevented by scavenging reactive oxygen species (ROS) during activation. Atm therefore plays a critical role in T cell proliferation by regulating responses to ROS generated following T cell activation. The inability of Atm-deficient T cells to control responses to ROS is therefore the molecular basis of immunodeficiency associated with A-T.

  6. Interleukin (IL)-1 Receptor Signaling on Graft Parenchymal Cells Regulates Memory and De Novo Donor-Reactive CD8 T Cell Responses to Cardiac Allografts1

    PubMed Central

    Iida, Shoichi; Tsuda, Hidetoshi; Tanaka, Toshiaki; Kish, Danielle D.; Abe, Toyofumi; Su, Charles A.; Abe, Ryo; Tanabe, Kazunari; Valujskikh, Anna; Baldwin, William M.; Fairchild, Robert L.

    2016-01-01

    Reperfusion of organ allografts induces a potent inflammatory response that directs rapid memory T cell, neutrophil and macrophage graft infiltration and their activation to express functions mediating graft tissue injury. The role of cardiac allograft IL-1 receptor signaling in this early inflammation and the downstream primary alloimmune response was investigated. When compared to complete MHC-mismatched wild type cardiac allografts, IL-1R−/− allografts had marked decreases in endogenous memory CD8 T cell and neutrophil infiltration and expression of proinflammatory mediators at early times after transplant whereas endogenous memory CD4 T cell and macrophage infiltration was not decreased. IL-1R−/− allograft recipients also had marked decreases in de novo donor-reactive CD8, but not CD4, T cell development to IFN-γ-producing cells. CD8 T cell-mediated rejection of IL-1R−/− cardiac allografts took 3 weeks longer than wild type allografts. Cardiac allografts from reciprocal bone marrow reconstituted IL-1R−/−/wild type chimeric donors indicated that IL-1R signaling on graft non-hematopoietic-derived, but not bone marrow-derived, cells is required for the potent donor-reactive memory and primary CD8 T cell alloimmune responses observed in response to wild type allografts. These studies implicate IL-1R-mediated signals by allograft parenchymal cells in generating the stimuli provoking development and elicitation of optimal alloimmune responses to the grafts. PMID:26856697

  7. Administration of HPV DNA vaccine via electroporation elicits the strongest CD8+ T cell immune responses compared to intramuscular injection and intradermal gene gun delivery

    PubMed Central

    Best, Simon R.; Peng, Shiwen; Juang, Chi-Mou; Hung, Chien-Fu; Hannaman, Drew; Saunders, John R.; Wu, T.-C.; Pai, Sara I.

    2009-01-01

    DNA vaccines are an attractive approach to eliciting antigen-specific immunity. Intracellular targeting of tumor antigens through its linkage to immunostimulatory molecules such as calreticulin (CRT) can improve antigen processing and presentation through the MHC Class I pathway and increase cytotoxic CD8+ T cell production. However, even with these enhancements, the efficacy of such immunotherapeutic strategies is dependent on the identification of an effective route and method of DNA administration. Electroporation and gene gun-mediated particle delivery are leading methods of DNA vaccine delivery that can generate protective and therapeutic levels of immune responses in experimental models. In this study, we perform a head-to-head comparison of three methods of vaccination – conventional intramuscular injection, electroporation mediated intramuscular delivery, and epidermal gene gun-mediated particle delivery - in the ability to generate antigen specific cytotoxic CD8+ T cell responses as well as anti-tumor immune responses against an HPV-16 E7 expressing tumor cell line using the pNGVL4a-CRT/E7(detox) DNA vaccine. Vaccination via electroporation generated the highest number of E7-specific cytotoxic CD8+ T cells, which correlated to improved outcomes in the treatment of growing tumors. In addition, we demonstrate that electroporation results in significantly higher levels of circulating protein compared to gene gun or intramuscular vaccination, which likely enhances calreticulin’s role as a local tumor anti-angiogenesis agent. We conclude that electroporation is a promising method for delivery of HPV DNA vaccines and should be considered for DNA vaccine delivery in human clinical trials. PMID:19622402

  8. A novel subset of helper T cells promotes immune responses by secreting GM-CSF

    PubMed Central

    Zhang, J; Roberts, A I; Liu, C; Ren, G; Xu, G; Zhang, L; Devadas, S; Shi, Yufang

    2013-01-01

    Helper T cells are crucial for maintaining proper immune responses. Yet, they have an undefined relationship with one of the most potent immune stimulatory cytokines, granulocyte macrophage-colony-stimulating factor (GM-CSF). By depleting major cytokines during the differentiation of CD4+ T cells in vitro, we derived cells that were found to produce large amounts of GM-CSF, but little of the cytokines produced by other helper T subsets. By their secretion of GM-CSF, this novel subset of helper T cells (which we have termed ThGM cells) promoted the production of cytokines by other T-cell subtypes, including type 1 helper T cell (Th1), type 2 helper T cell (Th2), type 1 cytotoxic T cell (Tc1), type 2 cytotoxic T cell (Tc2), and naive T cells, as evidenced by the fact that antibody neutralization of GM-CSF abolished this effect. ThGM cells were found to be highly prone to activation-induced cell death (AICD). Inhibitors of TRAIL or granzymes could not block AICD in ThGM cells, whereas inhibition of FasL/Fas interaction partially rescued ThGM cells from AICD. Thus, ThGM cells are a novel subpopulation of T helper cells that produce abundant GM-CSF, exhibit exquisite susceptibility to apoptosis, and therefore play a pivotal role in the regulation of the early stages of immune responses. PMID:24076588

  9. Antigen presenting cells (APCs) from thermally injured and/or septic rats modulate CD4+ T cell responses of naive rat.

    PubMed

    Fazal, Nadeem; Raziuddin, Syed; Khan, Mehdi; Al-Ghoul, Walid M

    2006-01-01

    Regulation of immune response is marked by complex interactions among the cells that recognize and present antigens. Antigen presenting cells (APCs), the antigen presenting cell component of the innate immune response plays an important role in effector CD4+ T cell response. Thermal injury and/or superimposed sepsis in rats' leads to suppressed CD4+ T cell functions. We investigated modulations of CD4+ T cell function by APCs (purified non-T cells) from thermally injured and/or septic rats. Rats were subjected to 30% total body surface area scald burn or exposed to 37 degrees C water (Sham burn) and sepsis was induced by cecal-ligation and puncture (CLP) method. At day 3 post-injury animals were sacrificed and CD4+ T cells and APCs from mesenteric lymph nodes (MLN) were obtained using magnetic microbead isolation procedure. APCs from injured rats were co-cultured with sham rat MLN CD4+ T cells and proliferative responses (thymidine incorporation), phenotypic changes (Flow cytometry), IL-2 production (ELISA) and CTLA-4 mRNA (RT-PCR) were determined in naive rat CD4+ T cells. The data indicate that APCs from thermally injured and/or septic rats when co-cultured with CD4+ T cells suppressed CD4+ T cell effector functions. This lack of CD4+ T cell activation was accompanied with altered co-stimulatory molecules, i.e., CD28 and/or CTLA-4 (CD152). In conclusion, our studies indicated that defective APCs from thermally injured and/or septic rats modulate CD4+ T cell functions via changes in co-stimulatory molecules expressed on naive CD4+ T cells. This altered APC: CD4+ T cell interaction leads to suppressed CD4+ T cell activation of healthy animals.

  10. Blockade of LAG3 enhances responses of tumor-infiltrating T cells in mismatch repair-proficient liver metastases of colorectal cancer

    PubMed Central

    Noordam, Lisanne; Sprengers, Dave; Boor, Patrick P. C.; Mancham, Shanta; Menon, Anand G.; Lange, Johan F.; Burger, Pim J. W. A.; Brandt, Alexandra; Galjart, Boris; Kwekkeboom, Jaap; Bruno, Marco J.

    2018-01-01

    ABSTRACT Purpose: Liver metastasis develops in >50% of patients with colorectal cancer (CRC), and is a leading cause of CRC-related mortality. We aimed to identify which inhibitory immune checkpoint pathways can be targeted to enhance functionality of intra-tumoral T-cells in mismatch repair-proficient liver metastases of colorectal cancer (LM-CRC). Methodology: Intra-tumoral expression of multiple inhibitory molecules was compared among mismatch repair-proficient LM-CRC, peritoneal metastases of colorectal cancer (PM-CRC) and primary CRC. Expression of inhibitory molecules was also analyzed on leukocytes isolated from paired resected metastatic liver tumors, tumor-free liver tissues, and blood of patients with mismatch repair-proficient LM-CRC. The effects of blocking inhibitory pathways on tumor-infiltrating T-cell responses were studied in ex vivo functional assays. Results: Mismatch repair-proficient LM-CRC showed higher expression of inhibitory receptors on intra-tumoral T-cells and contained higher proportions of CD8+ T-cells, dendritic cells and monocytes than mismatch repair-proficient primary CRC and/or PM-CRC. Inhibitory receptors LAG3, PD-1, TIM3 and CTLA4 were higher expressed on CD8+ T-cells, CD4+ T-helper and/or regulatory T-cells in LM-CRC tumors compared with tumor-free liver and blood. Antibody blockade of LAG3 or PD-L1 increased proliferation and effector cytokine production of intra-tumoral T-cells isolated from LM-CRC in response to both polyclonal and autologous tumor-specific stimulations. Higher LAG3 expression on intra-tumoral CD8+ T-cells associated with longer progression-free survival of LM-CRC patients. Conclusion: Mismatch repair-proficient LM-CRC may be more sensitive to immune checkpoint inhibitors than mismatch repair-proficient primary CRC. Blocking LAG3 enhances tumor-infiltrating T-cell responses of mismatch repair-proficient LM-CRC, and therefore may be a new promising immunotherapeutic target for LM-CRC.

  11. Memory CD8+ T Cells Protect Dendritic Cells from CTL Killing1

    PubMed Central

    Watchmaker, Payal B.; Urban, Julie A.; Berk, Erik; Nakamura, Yutaro; Mailliard, Robbie B.; Watkins, Simon C.; van Ham, S. Marieke; Kalinski, Pawel

    2010-01-01

    CD8+ T cells have been shown to be capable of either suppressing or promoting immune responses. To reconcile these contrasting regulatory functions, we compared the ability of human effector and memory CD8+ T cells to regulate survival and functions of dendritic cells (DC). We report that, in sharp contrast to the effector cells (CTLs) that kill DCs in a granzyme B- and perforin-dependent mechanism, memory CD8+ T cells enhance the ability of DCs to produce IL-12 and to induce functional Th1 and CTL responses in naive CD4+ and CD8+ T cell populations. Moreover, memory CD8+ T cells that release the DC-activating factor TNF-α before the release of cytotoxic granules induce DC expression of an endogenous granzyme B inhibitor PI-9 and protect DCs from CTL killing with similar efficacy as CD4+ Th cells. The currently identified DC-protective function of memory CD8+ T cells helps to explain the phenomenon of CD8+ T cell memory, reduced dependence of recall responses on CD4+ T cell help, and the importance of delayed administration of booster doses of vaccines for the optimal outcome of immunization. PMID:18322193

  12. Prolonged Intake of Dietary Lipids Alters Membrane Structure and T Cell Responses in LDLr-/- Mice.

    PubMed

    Pollock, Abigail H; Tedla, Nicodemus; Hancock, Sarah E; Cornely, Rhea; Mitchell, Todd W; Yang, Zhengmin; Kockx, Maaike; Parton, Robert G; Rossy, Jérémie; Gaus, Katharina

    2016-05-15

    Although it is recognized that lipids and membrane organization in T cells affect signaling and T cell activation, to what extent dietary lipids alter T cell responsiveness in the absence of obesity and inflammation is not known. In this study, we fed low-density lipoprotein receptor knockout mice a Western high-fat diet for 1 or 9 wk and examined T cell responses in vivo along with T cell lipid composition, membrane order, and activation ex vivo. Our data showed that high levels of circulating lipids for a prolonged period elevated CD4(+) and CD8(+) T cell proliferation and resulted in an increased proportion of CD4(+) central-memory T cells within the draining lymph nodes following induction of contact hypersensitivity. In addition, the 9-wk Western high-fat diet elevated the total phospholipid content and monounsaturated fatty acid level, but decreased saturated phosphatidylcholine and sphingomyelin within the T cells. The altered lipid composition in the circulation, and of T cells, was also reflected by enhanced membrane order at the activation site of ex vivo activated T cells that corresponded to increased IL-2 mRNA levels. In conclusion, dietary lipids can modulate T cell lipid composition and responses in lipoprotein receptor knockout mice even in the absence of excess weight gain and a proinflammatory environment. Copyright © 2016 by The American Association of Immunologists, Inc.

  13. Dynamic gene expression response to altered gravity in human T cells.

    PubMed

    Thiel, Cora S; Hauschild, Swantje; Huge, Andreas; Tauber, Svantje; Lauber, Beatrice A; Polzer, Jennifer; Paulsen, Katrin; Lier, Hartwin; Engelmann, Frank; Schmitz, Burkhard; Schütte, Andreas; Layer, Liliana E; Ullrich, Oliver

    2017-07-12

    We investigated the dynamics of immediate and initial gene expression response to different gravitational environments in human Jurkat T lymphocytic cells and compared expression profiles to identify potential gravity-regulated genes and adaptation processes. We used the Affymetrix GeneChip® Human Transcriptome Array 2.0 containing 44,699 protein coding genes and 22,829 non-protein coding genes and performed the experiments during a parabolic flight and a suborbital ballistic rocket mission to cross-validate gravity-regulated gene expression through independent research platforms and different sets of control experiments to exclude other factors than alteration of gravity. We found that gene expression in human T cells rapidly responded to altered gravity in the time frame of 20 s and 5 min. The initial response to microgravity involved mostly regulatory RNAs. We identified three gravity-regulated genes which could be cross-validated in both completely independent experiment missions: ATP6V1A/D, a vacuolar H + -ATPase (V-ATPase) responsible for acidification during bone resorption, IGHD3-3/IGHD3-10, diversity genes of the immunoglobulin heavy-chain locus participating in V(D)J recombination, and LINC00837, a long intergenic non-protein coding RNA. Due to the extensive and rapid alteration of gene expression associated with regulatory RNAs, we conclude that human cells are equipped with a robust and efficient adaptation potential when challenged with altered gravitational environments.

  14. Potent Cell-Intrinsic Immune Responses in Dendritic Cells Facilitate HIV-1-Specific T Cell Immunity in HIV-1 Elite Controllers.

    PubMed

    Martin-Gayo, Enrique; Buzon, Maria Jose; Ouyang, Zhengyu; Hickman, Taylor; Cronin, Jacqueline; Pimenova, Dina; Walker, Bruce D; Lichterfeld, Mathias; Yu, Xu G

    2015-06-01

    The majority of HIV-1 elite controllers (EC) restrict HIV-1 replication through highly functional HIV-1-specific T cell responses, but mechanisms supporting the evolution of effective HIV-1-specific T cell immunity in these patients remain undefined. Cytosolic immune recognition of HIV-1 in conventional dendritic cells (cDC) can facilitate priming and expansion of HIV-1-specific T cells; however, HIV-1 seems to be able to avoid intracellular immune recognition in cDCs in most infected individuals. Here, we show that exposure of cDCs from EC to HIV-1 leads to a rapid and sustained production of type I interferons and upregulation of several interferon-stimulated effector genes. Emergence of these cell-intrinsic immune responses was associated with a reduced induction of SAMHD1 and LEDGF/p75, and an accumulation of viral reverse transcripts, but inhibited by pharmacological blockade of viral reverse transcription or siRNA-mediated silencing of the cytosolic DNA sensor cGAS. Importantly, improved cell-intrinsic immune recognition of HIV-1 in cDCs from elite controllers translated into stronger abilities to stimulate and expand HIV-1-specific CD8 T cell responses. These data suggest an important role of cell-intrinsic type I interferon secretion in dendritic cells for the induction of effective HIV-1-specific CD8 T cells, and may be helpful for eliciting functional T cell immunity against HIV-1 for preventative or therapeutic clinical purposes.

  15. Skin-Resident T Cells Drive Dermal Dendritic Cell Migration in Response to Tissue Self-Antigen.

    PubMed

    Ali, Niwa; Zirak, Bahar; Truong, Hong-An; Maurano, Megan M; Gratz, Iris K; Abbas, Abul K; Rosenblum, Michael D

    2018-05-01

    Migratory dendritic cell (DC) subsets deliver tissue Ags to draining lymph nodes (DLNs) to either initiate or inhibit T cell-mediated immune responses. The signals mediating DC migration in response to tissue self-antigen are largely unknown. Using a mouse model of inducible skin-specific self-antigen expression, we demonstrate that CD103 + dermal DCs (DDCs) rapidly migrate from skin to skin DLN (SDLNs) within the first 48 h after Ag expression. This window of time was characterized by the preferential activation of tissue-resident Ag-specific effector T cells (Teffs), with no concurrent activation of Ag-specific Teffs in SDLNs. Using genetic deletion and adoptive transfer approaches, we show that activation of skin-resident Teffs is required to drive CD103 + DDC migration in response to tissue self-antigen and this Batf3-dependent DC population is necessary to mount a fulminant autoimmune response in skin. Conversely, activation of Ag-specific Teffs in SDLNs played no role in DDC migration. Our studies reveal a crucial role for skin-resident T cell-derived signals, originating at the site of self-antigen expression, to drive DDC migration during the elicitation phase of an autoimmune response. Copyright © 2018 by The American Association of Immunologists, Inc.

  16. TNFRSF14 aberrations in follicular lymphoma increase clinically significant allogeneic T-cell responses.

    PubMed

    Kotsiou, Eleni; Okosun, Jessica; Besley, Caroline; Iqbal, Sameena; Matthews, Janet; Fitzgibbon, Jude; Gribben, John G; Davies, Jeffrey K

    2016-07-07

    Donor T-cell immune responses can eradicate lymphomas after allogeneic hematopoietic stem cell transplantation (AHSCT), but can also damage healthy tissues resulting in harmful graft-versus-host disease (GVHD). Next-generation sequencing has recently identified many new genetic lesions in follicular lymphoma (FL). One such gene, tumor necrosis factor receptor superfamily 14 (TNFRSF14), abnormal in 40% of FL patients, encodes the herpes virus entry mediator (HVEM) which limits T-cell activation via ligation of the B- and T-lymphocyte attenuator. As lymphoma B cells can act as antigen-presenting cells, we hypothesized that TNFRSF14 aberrations that reduce HVEM expression could alter the capacity of FL B cells to stimulate allogeneic T-cell responses and impact the outcome of AHSCT. In an in vitro model of alloreactivity, human lymphoma B cells with TNFRSF14 aberrations had reduced HVEM expression and greater alloantigen-presenting capacity than wild-type lymphoma B cells. The increased immune-stimulatory capacity of lymphoma B cells with TNFRSF14 aberrations had clinical relevance, associating with higher incidence of acute GVHD in patients undergoing AHSCT. FL patients with TNFRSF14 aberrations may benefit from more aggressive immunosuppression to reduce harmful GVHD after transplantation. Importantly, this study is the first to demonstrate the impact of an acquired genetic lesion on the capacity of tumor cells to stimulate allogeneic T-cell immune responses which may have wider consequences for adoptive immunotherapy strategies. © 2016 by The American Society of Hematology.

  17. TACI is required for efficient plasma cell differentiation in response to T-independent type 2 antigens.

    PubMed

    Mantchev, George T; Cortesão, Catarina S; Rebrovich, Michelle; Cascalho, Marilia; Bram, Richard J

    2007-08-15

    The control of systemic infection by encapsulated microorganisms requires T-independent type II (TI-2) Ab responses to bacterial polysaccharides. To understand how such responses evolve, we explored the function of transmembrane activator calcium modulator and cyclophilin ligand interactor (TACI), a member of the TNFR family, required for TI-2 Ab production. Quasimonoclonal (QM) mice produce robust TI-2 responses to 4-hydroxy-3-nitrophenylacetate (NP)-Ficoll, owing to the high precursor frequency of NP-specific B cells in the marginal zone of the spleen. QM mice that lack TACI produce decreased numbers of IgM (2-fold) and IgG (1.6-fold) NP-specific ASCs, compared with TACI-positive QM mice in response to immunization with NP-Ficoll. Our studies indicate that TACI acts at a remote time from activation because TACI is not necessary for activation and proliferation of B cells both in vitro and in vivo. Instead, TACI-deficient QM B cells remained in the cell cycle longer than TACI-proficient QM cells and had impaired plasma cell differentiation in response to NP-Ficoll. We conclude that TACI has dual B cell-autonomous functions, inhibiting prolonged B cell proliferation and stimulating plasma cell differentiation, thus resolving the longstanding paradox that TACI may have both B cell-inhibitory and -stimulatory functions. By promoting plasma cell differentiation earlier during clonal expansion, TACI may decrease the chances of autoantibody production by somatic hypermutation of Ig genes in response to T-independent Ags.

  18. Mitochondrial respiration controls lysosomal function during inflammatory T cell responses

    PubMed Central

    Baixauli, Francesc; Acín-Pérez, Rebeca; Villarroya-Beltrí, Carolina; Mazzeo, Carla; Nuñez-Andrade, Norman; Gabandé-Rodriguez, Enrique; Dolores Ledesma, Maria; Blázquez, Alberto; Martin, Miguel Angel; Falcón-Pérez, Juan Manuel; Redondo, Juan Miguel; Enríquez, Jose Antonio; Mittelbrunn, Maria

    2016-01-01

    Summary The endolysosomal system is critical for the maintenance of cellular homeostasis. However, how endolysosomal compartment is regulated by mitochondrial function is largely unknown. We have generated a mouse model with defective mitochondrial function in CD4+ T lymphocytes by genetic deletion of the mitochondrial transcription factor A (Tfam). Mitochondrial respiration-deficiency impairs lysosome function, promotes p62 and sphingomyelin accumulation and disrupts endolysosomal trafficking pathways and autophagy, thus linking a primary mitochondrial dysfunction to a lysosomal storage disorder. The impaired lysosome function in Tfam-deficient cells subverts T cell differentiation toward pro-inflammatory subsets and exacerbates the in vivo inflammatory response. Restoration of NAD+ levels improves lysosome function and corrects the inflammatory defects in Tfam-deficient T cells. Our results uncover a mechanism by which mitochondria regulate lysosome function to preserve T cell differentiation and effector functions, and identify novel strategies for intervention in mitochondrial-related diseases. PMID:26299452

  19. A tuberculosis vaccine based on phosphoantigens and fusion proteins induces distinct gammadelta and alphabeta T cell responses in primates.

    PubMed

    Cendron, Delphine; Ingoure, Sophie; Martino, Angelo; Casetti, Rita; Horand, Françoise; Romagné, François; Sicard, Hélène; Fournié, Jean-Jacques; Poccia, Fabrizio

    2007-02-01

    Phosphoantigens are mycobacterial non-peptide antigens that might enhance the immunogenicity of current subunit candidate vaccines for tuberculosis. However, their testing requires monkeys, the only animal models suitable for gammadelta T cell responses to mycobacteria. Thus here, the immunogenicity of 6-kDa early secretory antigenic target-mycolyl transferase complex antigen 85B (ESAT-6-Ag85B) (H-1 hybrid) fusion protein associated or not to a synthetic phosphoantigen was compared by a prime-boost regimen of two groups of eight cynomolgus. Although phosphoantigen activated immediately a strong release of systemic Th1 cytokines (IL-2, IL-6, IFN-gamma, TNF-alpha), it further anergized blood gammadelta T lymphocytes selectively. By contrast, the hybrid H-1 induced only memory alphabeta T cell responses, regardless of phosphoantigen. These latter essentially comprised cytotoxic T lymphocytes specific for Ag85B (on average + 430 cells/million PBMC) and few IFN-gamma-secreting cells (+ 40 cells/million PBMC, equally specific for ESAT-6 and for Ag85B). Hence, in macaques, a prime-boost with the H-1/phosphoantigen subunit combination induces two waves of immune responses, successively by gammadelta T and alphabeta T lymphocytes.

  20. HIV-TB coinfection impairs CD8(+) T-cell differentiation and function while dehydroepiandrosterone improves cytotoxic antitubercular immune responses.

    PubMed

    Suarez, Guadalupe V; Angerami, Matías T; Vecchione, María B; Laufer, Natalia; Turk, Gabriela; Ruiz, Maria J; Mesch, Viviana; Fabre, Bibiana; Maidana, Patricia; Ameri, Diego; Cahn, Pedro; Sued, Omar; Salomón, Horacio; Bottasso, Oscar A; Quiroga, María F

    2015-09-01

    Tuberculosis (TB) is the leading cause of death among HIV-positive patients. The decreasing frequencies of terminal effector (TTE ) CD8(+) T cells may increase reactivation risk in persons latently infected with Mycobacterium tuberculosis (Mtb). We have previously shown that dehydroepiandrosterone (DHEA) increases the protective antitubercular immune responses in HIV-TB patients. Here, we aimed to study Mtb-specific cytotoxicity, IFN-γ secretion, memory status of CD8(+) T cells, and their modulation by DHEA during HIV-TB coinfection. CD8(+) T cells from HIV-TB patients showed a more differentiated phenotype with diminished naïve and higher effector memory and TTE T-cell frequencies compared to healthy donors both in total and Mtb-specific CD8(+) T cells. Notably, CD8(+) T cells from HIV-TB patients displayed higher Terminal Effector (TTE ) CD45RA(dim) proportions with lower CD45RA expression levels, suggesting a not fully differentiated phenotype. Also, PD-1 expression levels on CD8(+) T cells from HIV-TB patients increased although restricted to the CD27(+) population. Interestingly, DHEA plasma levels positively correlated with TTE in CD8(+) T cells and in vitro DHEA treatment enhanced Mtb-specific cytotoxic responses and terminal differentiation in CD8(+) T cells from HIV-TB patients. Our data suggest that HIV-TB coinfection promotes a deficient CD8(+) T-cell differentiation, whereas DHEA may contribute to improving antitubercular immunity by enhancing CD8(+) T-cell functions during HIV-TB coinfection. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Long-lived CD8+ T cell responses following Crimean-Congo haemorrhagic fever virus infection

    PubMed Central

    Goedhals, Dominique; Paweska, Janusz T.

    2017-01-01

    Crimean-Congo haemorrhagic fever virus (CCHFV) is a member of the Orthonairovirus genus of the Nairoviridae family and is associated with haemorrhagic fever in humans. Although T lymphocyte responses are known to play a role in protection from and clearance of viral infections, specific T cell epitopes have yet to be identified for CCHFV following infection. A panel of overlapping peptides covering the CCHFV nucleoprotein and the structural glycoproteins, GN and GC, were screened by ELISpot assay to detect interferon gamma (IFN-γ) production in vitro by peripheral blood mononuclear cells from eleven survivors with previous laboratory confirmed CCHFV infection. Reactive peptides were located predominantly on the nucleoprotein, with only one survivor reacting to two peptides from the glycoprotein GC. No single epitope was immunodominant, however all but one survivor showed reactivity to at least one T cell epitope. The responses were present at high frequency and detectable several years after the acute infection despite the absence of continued antigenic stimulation. T cell depletion studies confirmed that IFN-γ production as detected using the ELISpot assay was mediated chiefly by CD8+ T cells. This is the first description of CD8+ T cell epitopic regions for CCHFV and provides confirmation of long-lived T cell responses in survivors of CCHFV infection. PMID:29261651

  2. CD4 T Cell Responses in Latent and Chronic Viral Infections

    PubMed Central

    Walton, Senta; Mandaric, Sanja; Oxenius, Annette

    2013-01-01

    The spectrum of tasks which is fulfilled by CD4 T cells in the setting of viral infections is large, ranging from support of CD8 T cells and humoral immunity to exertion of direct antiviral effector functions. While our knowledge about the differentiation pathways, plasticity, and memory of CD4 T cell responses upon acute infections or immunizations has significantly increased during the past years, much less is still known about CD4 T cell differentiation and their beneficial or pathological functions during persistent viral infections. In this review we summarize current knowledge about the differentiation, direct or indirect antiviral effector functions, and the regulation of virus-specific CD4 T cells in the setting of persistent latent or active chronic viral infections with a particular emphasis on herpes virus infections for the former and chronic lymphocytic choriomeningitis virus infection for the latter. PMID:23717308

  3. Elevated and cross‐responsive CD1a‐reactive T cells in bee and wasp venom allergic individuals

    PubMed Central

    Subramaniam, Sumithra; Aslam, Aamir; Misbah, Siraj A.; Salio, Mariolina; Cerundolo, Vincenzo; Moody, D Branch

    2015-01-01

    The role of CD1a‐reactive T cells in human allergic disease is unknown. We have previously shown that circulating CD1a‐reactive T cells recognize neolipid antigens generated by bee and wasp venom phospholipase, and here tested the hypothesis that venom‐responsive CD1a‐reactive T cells associate with venom allergy. Circulating T cells from bee and wasp venom allergic individuals, before and during immunotherapy, were exposed to CD1a‐transfected K562 cells in the presence of wasp or bee venom. T‐cell response was evaluated based on IFNγ, GM‐CSF, and IL‐13 cytokine production. Venom allergic individuals showed significantly higher frequencies of IFN‐γ, GM‐CSF, and IL‐13 producing CD1a‐reactive T cells responsive to venom and venom‐derived phospholipase than healthy individuals. Venom‐responsive CD1a‐reactive T cells were cross‐responsive between wasp and bee suggesting shared pathways of allergenicity. Frequencies of CD1a‐reactive T cells were initially induced during subcutaneous immunotherapy, peaking by weeks 5, but then reduced despite escalation of antigen dose. Our current understanding of venom allergy and immunotherapy is largely based on peptide and protein‐specific T cell and antibody responses. Here, we show that lipid antigens and CD1a‐reactive T cells associate with the allergic response. These data have implications for mechanisms of allergy and approaches to immunotherapy. PMID:26518614

  4. Myeloid-derived suppressor cells regulate T cell and B cell responses during autoimmune disease.

    PubMed

    Crook, Kristen R; Jin, Mengyao; Weeks, Michael F; Rampersad, Rishi R; Baldi, Robert M; Glekas, Amy S; Shen, Yajuan; Esserman, Denise A; Little, Paul; Schwartz, Todd A; Liu, Peng

    2015-03-01

    MDSCs are a heterogeneous group of myeloid cells that suppress T cell activity in cancer and autoimmune disease. The effect of MDSCs on B cell function is not clear. Using the CIA model of autoimmune disease, we found an increase in M-MDSCs in the periphery of WT mice with CIA compared with naïve mice. These MDSCs were absent from the periphery of CCR2(-/-) mice that developed exacerbated disease. M-MDSCs, isolated from immunized mice, inhibited autologous CD4(+) T cell proliferation. The M-MDSC-mediated suppression of T cell proliferation was NO and IFN-γ dependent but IL-17 independent. Furthermore, we demonstrated for the first time that M-MDSCs from CIA mice also inhibited autologous B cell proliferation and antibody production. The suppression of B cells by M-MDSCs was dependent on the production of NO and PGE2 and required cell-cell contact. Administration of M-MDSCs rescued CCR2(-/-) mice from the exacerbated CIA phenotype and ameliorated disease in WT mice. Furthermore, adoptive transfer of M-MDSCs reduced autoantibody production by CCR2(-/-) and WT mice. In summary, M-MDSCs inhibit T cell and B cell function in CIA and may serve as a therapeutic approach in the treatment of autoimmune arthritis. © Society for Leukocyte Biology.

  5. Redirecting the Immune Response: Role of Adoptive T Cell Therapy

    PubMed Central

    Dardalhon, Valérie; Michelini, Rodrigo Hess; Loisel-Meyer, Severine

    2010-01-01

    Abstract Adoptive T cell therapy is aimed at overcoming constraints of the endogenous immune response. In patients with malignancies, this approach is based on the possibility of administering sufficient numbers of tumor-reactive lymphocytes under conditions in which they will promote a therapeutic response. Although this strategy is potentially applicable to a vast number of malignancies, its efficacy, to date, has been limited. This is likely related to several factors including an insufficient persistence and reactivation of infused cells, insufficient tumor infiltration, and the presence of an immunosuppressive environment. Here, we review the importance of pretransplantation host conditioning and posttransplantation strategies that have been shown to contribute to the therapeutic efficacy of infused T lymphocytes. PMID:20201627

  6. Maternal allergic disease does not affect the phenotype of T and B cells or the immune response to allergens in neonates.

    PubMed

    Rindsjö, E; Joerink, M; Johansson, C; Bremme, K; Malmström, V; Scheynius, A

    2010-07-01

    It is hypothesized that the in utero environment in allergic mothers can affect the neonatal immune responses. The aim of this study was to analyse the effect of maternal allergic disease on cord blood mononuclear cell (CBMC) phenotype and proliferative responses upon allergen stimulation. Peripheral blood mononuclear cells (PBMC) from 12 allergic and 14 nonallergic mothers and CBMC from their children were analysed. In the mothers, we determined cell proliferation, production of IL-4 and expression of FOXP3 in response to allergen stimulation. In the children, we evaluated cell proliferation and FOXP3 expression following allergen stimulation. Furthermore, expression of different homing markers on T cells and regulatory T cells and maturity of the T cells and B cell subsets were evaluated directly ex vivo. The timothy- and birch-allergic mothers responded with increased proliferation and/or IL-4 production towards timothy and birch extract, respectively, when compared to nonallergic mothers. This could not be explained by impairment of FOXP3(+) regulatory T cells in the allergic mothers. CBMC proliferation and FOXP3 expression in response to allergens were not affected by the allergic status of the mother. Also, phenotype of T cells, FOXP3(+) regulatory T cells and B cells was not affected by the allergic status of the mother. Our results suggest that maternal allergic disease has no effect on the neonatal response to allergens or the phenotype of neonatal lymphocytes. The factors studied here could, however, still affect later development of allergy.

  7. Listeria Monocytogenes: A Model Pathogen Continues to Refine Our Knowledge of the CD8 T Cell Response.

    PubMed

    Qiu, Zhijuan; Khairallah, Camille; Sheridan, Brian S

    2018-06-16

    Listeria monocytogenes ( Lm ) infection induces robust CD8 T cell responses, which play a critical role in resolving Lm during primary infection and provide protective immunity to re-infections. Comprehensive studies have been conducted to delineate the CD8 T cell response after Lm infection. In this review, the generation of the CD8 T cell response to Lm infection will be discussed. The role of dendritic cell subsets in acquiring and presenting Lm antigens to CD8 T cells and the events that occur during T cell priming and activation will be addressed. CD8 T cell expansion, differentiation and contraction as well as the signals that regulate these processes during Lm infection will be explored. Finally, the formation of memory CD8 T cell subsets in the circulation and in the intestine will be analyzed. Recently, the study of CD8 T cell responses to Lm infection has begun to shift focus from the intravenous infection model to a natural oral infection model as the humanized mouse and murinized Lm have become readily available. Recent findings in the generation of CD8 T cell responses to oral infection using murinized Lm will be explored throughout the review. Finally, CD8 T cell-mediated protective immunity against Lm infection and the use of Lm as a vaccine vector for cancer immunotherapy will be highlighted. Overall, this review will provide detailed knowledge on the biology of CD8 T cell responses after Lm infection that may shed light on improving rational vaccine design.

  8. Sequential Dysfunction and Progressive Depletion of Candida albicans-Specific CD4 T Cell Response in HIV-1 Infection

    PubMed Central

    Liu, Fengliang; Fan, Xiuzhen; Auclair, Sarah; Ferguson, Monique; Sun, Jiaren; Soong, Lynn; Hou, Wei; Redfield, Robert R.; Birx, Deborah L.; Ratto-Kim, Silvia; Robb, Merlin L.; Kim, Jerome H.; Michael, Nelson L.; Hu, Haitao

    2016-01-01

    Loss of immune control over opportunistic infections can occur at different stages of HIV-1 (HIV) disease, among which mucosal candidiasis caused by the fungal pathogen Candida albicans (C. albicans) is one of the early and common manifestations in HIV-infected human subjects. The underlying immunological basis is not well defined. We have previously shown that compared to cytomegalovirus (CMV)-specific CD4 cells, C. albicans-specific CD4 T cells are highly permissive to HIV in vitro. Here, based on an antiretroviral treatment (ART) naïve HIV infection cohort (RV21), we investigated longitudinally the impact of HIV on C. albicans- and CMV-specific CD4 T-cell immunity in vivo. We found a sequential dysfunction and preferential depletion for C. albicans-specific CD4 T cell response during progressive HIV infection. Compared to Th1 (IFN-γ, MIP-1β) functional subsets, the Th17 functional subsets (IL-17, IL-22) of C. albicans-specific CD4 T cells were more permissive to HIV in vitro and impaired earlier in HIV-infected subjects. Infection history analysis showed that C. albicans-specific CD4 T cells were more susceptible to HIV in vivo, harboring modestly but significantly higher levels of HIV DNA, than CMV-specific CD4 T cells. Longitudinal analysis of HIV-infected individuals with ongoing CD4 depletion demonstrated that C. albicans-specific CD4 T-cell response was preferentially and progressively depleted. Taken together, these data suggest a potential mechanism for earlier loss of immune control over mucosal candidiasis in HIV-infected patients and provide new insights into pathogen-specific immune failure in AIDS pathogenesis. PMID:27280548

  9. CD22 Promotes B-1b Cell Responses to T Cell-Independent Type 2 Antigens.

    PubMed

    Haas, Karen M; Johnson, Kristen L; Phipps, James P; Do, Cardinal

    2018-03-01

    CD22 (Siglec-2) is a critical regulator of B cell activation and survival. CD22 -/- mice generate significantly impaired Ab responses to T cell-independent type 2 (TI-2) Ags, including haptenated Ficoll and pneumococcal polysaccharides, Ags that elicit poor T cell help and activate BCR signaling via multivalent epitope crosslinking. This has been proposed to be due to impaired marginal zone (MZ) B cell development/maintenance in CD22 -/- mice. However, mice expressing a mutant form of CD22 unable to bind sialic acid ligands generated normal TI-2 Ab responses, despite significantly reduced MZ B cells. Moreover, mice treated with CD22 ligand-binding blocking mAbs, which deplete MZ B cells, had little effect on TI-2 Ab responses. We therefore investigated the effects of CD22 deficiency on B-1b cells, an innate-like B cell population that plays a key role in TI-2 Ab responses. B-1b cells from CD22 -/- mice had impaired BCR-induced proliferation and significantly increased intracellular Ca 2+ concentration responses following BCR crosslinking. Ag-specific B-1b cell expansion and plasmablast differentiation following TI-2 Ag immunization was significantly impaired in CD22 -/- mice, consistent with reduced TI-2 Ab responses. We generated CD22 -/- mice with reduced CD19 levels (CD22 -/- CD19 +/- ) to test the hypothesis that augmented B-1b cell BCR signaling in CD22 -/- mice contributes to impaired TI-2 Ab responses. BCR-induced proliferation and intracellular Ca 2+ concentration responses were normalized in CD22 -/- CD19 +/- B-1b cells. Consistent with this, TI-2 Ag-specific B-1b cell expansion, plasmablast differentiation, survival, and Ab responses were rescued in CD22 -/- CD19 +/- mice. Thus, CD22 plays a critical role in regulating TI-2 Ab responses through regulating B-1b cell signaling thresholds. Copyright © 2018 by The American Association of Immunologists, Inc.

  10. Spontaneous T-cell responses against the immune check point programmed-death-ligand 1 (PD-L1) in patients with chronic myeloproliferative neoplasms correlate with disease stage and clinical response.

    PubMed

    Holmström, Morten Orebo; Riley, Caroline Hasselbalch; Skov, Vibe; Svane, Inge Marie; Hasselbalch, Hans Carl; Andersen, Mads Hald

    2018-01-01

    The Chronic Myeloproliferative Neoplasms (MPN) are cancers characterized by hyperinflammation and immune deregulation. Concurrently, the expression of the immune check point programmed death ligand 1 (PD-L1) is induced by inflammation. In this study we report on the occurrence of spontaneous T cell responses against a PD-L1 derived epitope in patients with MPN. We show that 71% of patients display a significant immune response against PD-L1, and patients with advanced MPN have significantly fewer and weaker PD-L1 specific immune responses compared to patients with non-advanced MPN. The PD-L1 specific T cell responses are CD4 + T cell responses, and by gene expression analysis we show that expression of PD-L1 is enhanced in patients with MPN. This could imply that the tumor specific immune response in MPN could be enhanced by vaccination with PD-L1 derived epitopes by boosting the anti-regulatory immune response hereby allowing tumor specific T cell to exert anti-tumor immunity.

  11. High Frequency, Sustained T Cell Responses to PARV4 Suggest Viral Persistence In Vivo

    PubMed Central

    Simmons, Ruth; Sharp, Colin; Sims, Stuart; Kloverpris, Henrik; Goulder, Philip; Simmonds, Peter; Bowness, Paul; Klenerman, Paul

    2011-01-01

    Background. Parvovirus 4 (PARV4) is a recently identified human virus that has been found in livers of patients infected with hepatitis C virus (HCV) and in bone marrow of individuals infected with human immunodeficiency virus (HIV). T cells are important in controlling viruses but may also contribute to disease pathogenesis. The interaction of PARV4 with the cellular immune system has not been described. Consequently, we investigated whether T cell responses to PARV4 could be detected in individuals exposed to blood-borne viruses. Methods. Interferon γ (IFN-γ) enzyme-linked immunospot assay, intracellular cytokine staining, and a tetrameric HLA-A*0201–peptide complex were used to define the lymphocyte populations responding to PARV4 NS peptides in 88 HCV-positive and 13 HIV-positive individuals. Antibody responses were tested using a recently developed PARV4 enzyme-linked immunosorbent assay. Results. High-frequency T cell responses against multiple PARV4 NS peptides and antibodies were observed in 26% of individuals. Typical responses to the NS pools were >1000 spot-forming units per million peripheral blood mononuclear cells. Conclusions. PARV4 infection is common in individuals exposed to blood-borne viruses and elicits strong T cell responses, a feature typically associated with persistent, contained infections such as cytomegalovirus. Persistence of PARV4 viral antigen in tissue in HCV-positive and HIV-positive individuals and/or the associated activated antiviral T cell response may contribute to disease pathogenesis. PMID:21502079

  12. Comparison of cytotoxic T lymphocyte responses against pancreatic cancer induced by dendritic cells transfected with total tumor RNA and fusion hybrided with tumor cell

    PubMed Central

    Chen, Jiang; Li, Hong-Yu; Wang, Di; Shao, Xiao-Dong

    2015-01-01

    Pancreatic cancer (PC) is a deadly human malignancy. Dendritic cell (DC)-based immunotherapy with whole tumor antigens demonstrates potential efficiency in cancer treatment. Tumor RNA and tumor fusion hybrid cells are sources of whole tumor antigens for preparing DC tumor vaccines. However, the efficacy of these sources in eliciting immune responses against PC has not yet to be directly compared. In the present study, patient-derived PC cells and DCs were fused (DC–tumor hybrids) and primary cultured PC cell-derived total RNA was electroporated into autologous DCs (DC–tumor RNA). The antitumor immune responses induced by DC–tumor hybrids and DC–tumor RNA were compared directly. The results showed that both RNA and hybrid methodologies could induce tumor-specific cytotoxic T lymphocyte (CTL) responses, but pulsing DCs with total tumor RNA could induce a higher frequency of activated CTLs and T-helper cells than fusing DCs with autologous tumor cells. In addition, DC–tumor RNA triggered stronger autologous tumor cell lysis than DC–tumor hybrids. It could be concluded that DCs pulsed with whole tumor RNA are superior to those fused with tumor cells in priming anti-PC CTL responses. Electroporation with total tumor RNA may be more suitable for DC-based PC vaccination. PMID:25736302

  13. Conditional deletion of SLP-76 in mature T cells abrogates peripheral immune responses1

    PubMed Central

    Wu, Gregory F.; Corbo, Evann; Schmidt, Michelle; Smith-Garvin, Jennifer E.; Riese, Matthew J.; Jordan, Martha S.; Laufer, Terri M.; Brown, Eric J.; Maltzman, Jonathan S.

    2011-01-01

    SUMMARY The adaptor protein Src homology 2 domain-containing leukocyte-specific protein of 76 kDa (SLP-76) is central to the organization of intracellular signaling downstream of the T cell receptor (TCR). Evaluation of its role in mature, primary T cells has been hampered by developmental defects that occur in the absence of wild-type SLP-76 protein in thymocytes. Following tamoxifen-regulated conditional deletion of SLP-76, mature, antigen-inexperienced T cells maintain normal TCR surface expression but fail to transduce TCR generated signals. Conditionally deficient T cells fail to proliferate in response to antigenic stimulation or a lymphopenic environment. Mice with induced deletion of SLP-76 are resistant to induction of the CD4+ T cell mediated autoimmune disease experimental autoimmune encephalomyelitis. Our findings demonstrate the critical role of SLP-76-mediated signaling in initiating T cell-directed immune responses both in vitro and in vivo and highlight the ability to analyze signaling processes in mature T cells in the absence of developmental defects. PMID:21469089

  14. Transmitted virus fitness and host T cell responses collectively define divergent infection outcomes in two HIV-1 recipients

    DOE PAGES

    Yue, Ling; Pfafferott, Katja J.; Baalwa, Joshua; ...

    2015-01-08

    Control of virus replication in HIV-1 infection is critical to delaying disease progression. While cellular immune responses are a key determinant of control, relatively little is known about the contribution of the infecting virus to this process. To gain insight into this interplay between virus and host in viral control, we conducted a detailed analysis of two heterosexual HIV-1 subtype A transmission pairs in which female recipients sharing three HLA class I alleles exhibited contrasting clinical outcomes: R880F controlled virus replication while R463F experienced high viral loads and rapid disease progression. Near full-length single genome amplification defined the infecting transmitted/foundermore » (T/F) virus proteome and subsequent sequence evolution over the first year of infection for both acutely infected recipients. T/F virus replicative capacities were compared in vitro, while the development of the earliest cellular immune response was defined using autologous virus sequence-based peptides. The R880F T/F virus replicated significantly slower in vitro than that transmitted to R463F. While neutralizing antibody responses were similar in both subjects, during acute infection R880F mounted a broad T cell response, the most dominant components of which targeted epitopes from which escape was limited. In contrast, the primary HIV-specific T cell response in R463F was focused on just two epitopes, one of which rapidly escaped. This comprehensive study highlights both the importance of the contribution of the lower replication capacity of the transmitted/founder virus and an associated induction of a broad primary HIV-specific T cell response, which was not undermined by rapid epitope escape, to long-term viral control in HIV-1 infection. It underscores the importance of the earliest CD8 T cell response targeting regions of the virus proteome that cannot mutate without a high fitness cost, further emphasizing the need for vaccines that elicit a breadth of

  15. Transmitted virus fitness and host T cell responses collectively define divergent infection outcomes in two HIV-1 recipients

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yue, Ling; Pfafferott, Katja J.; Baalwa, Joshua

    Control of virus replication in HIV-1 infection is critical to delaying disease progression. While cellular immune responses are a key determinant of control, relatively little is known about the contribution of the infecting virus to this process. To gain insight into this interplay between virus and host in viral control, we conducted a detailed analysis of two heterosexual HIV-1 subtype A transmission pairs in which female recipients sharing three HLA class I alleles exhibited contrasting clinical outcomes: R880F controlled virus replication while R463F experienced high viral loads and rapid disease progression. Near full-length single genome amplification defined the infecting transmitted/foundermore » (T/F) virus proteome and subsequent sequence evolution over the first year of infection for both acutely infected recipients. T/F virus replicative capacities were compared in vitro, while the development of the earliest cellular immune response was defined using autologous virus sequence-based peptides. The R880F T/F virus replicated significantly slower in vitro than that transmitted to R463F. While neutralizing antibody responses were similar in both subjects, during acute infection R880F mounted a broad T cell response, the most dominant components of which targeted epitopes from which escape was limited. In contrast, the primary HIV-specific T cell response in R463F was focused on just two epitopes, one of which rapidly escaped. This comprehensive study highlights both the importance of the contribution of the lower replication capacity of the transmitted/founder virus and an associated induction of a broad primary HIV-specific T cell response, which was not undermined by rapid epitope escape, to long-term viral control in HIV-1 infection. It underscores the importance of the earliest CD8 T cell response targeting regions of the virus proteome that cannot mutate without a high fitness cost, further emphasizing the need for vaccines that elicit a breadth of

  16. Differential Responsiveness of Innate-like IL-17- and IFN-γ-Producing γδ T Cells to Homeostatic Cytokines.

    PubMed

    Corpuz, Theresa M; Stolp, Jessica; Kim, Hee-Ok; Pinget, Gabriela V; Gray, Daniel H D; Cho, Jae-Ho; Sprent, Jonathan; Webster, Kylie E

    2016-01-15

    γδ T cells respond to molecules upregulated following infection or cellular stress using both TCR and non-TCR molecules. The importance of innate signals versus TCR ligation varies greatly. Both innate-like IL-17-producing γδ T (γδT-17) and IFN-γ-producing γδ T (γδT-IFNγ) subsets tune the sensitivity of their TCR following thymic development, allowing robust responses to inflammatory cytokines in the periphery. The remaining conventional γδ T cells retain high TCR responsiveness. We determined homeostatic mechanisms that govern these various subsets in the peripheral lymphoid tissues. We found that, although innate-like γδT-17 and γδT-IFNγ cells share elements of thymic development, they diverge when it comes to homeostasis. Both exhibit acute sensitivity to cytokines compared with conventional γδ T cells, but they do not monopolize the same cytokine. γδT-17 cells rely exclusively on IL-7 for turnover and survival, aligning them with NKT17 cells; IL-7 ligation triggers proliferation, as well as promotes survival, upregulating Bcl-2 and Bcl-xL. γδT-IFNγ cells instead depend heavily on IL-15. They display traits analogous to memory CD8(+) T cells and upregulate Bcl-xL and Mcl-1 upon cytokine stimulation. The conventional γδ T cells display low sensitivity to cytokine-alone stimulation and favor IL-7 for their turnover, characteristics reminiscent of naive αβ T cells, suggesting that they may also require tonic TCR signaling for population maintenance. These survival constraints suggest that γδ T cell subsets do not directly compete with each other for cytokines, but instead fall into resource niches with other functionally similar lymphocytes. Copyright © 2016 by The American Association of Immunologists, Inc.

  17. The Control of the Specificity of CD4 T Cell Responses: Thresholds, Breakpoints, and Ceilings

    PubMed Central

    Sant, Andrea J.; Chaves, Francisco A.; Leddon, Scott A.; Tung, Jacqueline

    2013-01-01

    It has been known for over 25 years that CD4 T cell responses are restricted to a finite number of peptide epitopes within pathogens or protein vaccines. These selected peptide epitopes are termed “immunodominant.” Other peptides within the antigen that can bind to host MHC molecules and recruit CD4 T cells as single peptides are termed “cryptic” because they fail to induce responses when expressed in complex proteins or when in competition with other peptides during the immune response. In the last decade, our laboratory has evaluated the mechanisms that underlie the preferential specificity of CD4 T cells and have discovered that both intracellular events within antigen presenting cells, particular selective DM editing, and intercellular regulatory pathways, involving IFN-γ, indoleamine 2,3-dioxygenase, and regulatory T cells, play a role in selecting the final peptide specificity of CD4 T cells. In this review, we summarize our findings, discuss the implications of this work on responses to pathogens and vaccines and speculate on the logic of these regulatory events. PMID:24167504

  18. The CD8 T-cell response during tolerance induction in liver transplantation

    PubMed Central

    Wong, Yik Chun; McCaughan, Geoffrey W; Bowen, David G; Bertolino, Patrick

    2016-01-01

    Both experimental and clinical studies have shown that the liver possesses unique tolerogenic properties. Liver allografts can be spontaneously accepted across complete major histocompatibility mismatch in some animal models. In addition, some liver transplant patients can be successfully withdrawn from immunosuppressive medications, developing ‘operational tolerance'. Multiple mechanisms have been shown to be involved in inducing and maintaining alloimmune tolerance associated with liver transplantation. Here, we focus on CD8 T-cell tolerance in this setting. We first discuss how alloreactive cytotoxic T-cell responses are generated against allografts, before reviewing how the liver parenchyma, donor passenger leucocytes and the host immune system function together to attenuate alloreactive CD8 T-cell responses to promote the long-term survival of liver transplants. PMID:27867515

  19. The biological and practical significance of antigenic variability in protective T cell responses against Theileria parva.

    PubMed

    Morrison, W I

    2007-08-19

    The evolution of antigenically distinct pathogen strains that fail to cross-protect is well documented for pathogens controlled primarily by humoral immune responses. Unlike antibodies, which recognise native proteins, protective T cells can potentially recognise epitopes in a variety of proteins that are not necessarily displayed on the pathogen surface. Moreover, individual hosts of different MHC genotypes generally respond to different sets of epitopes. It is therefore less easy to envisage how strain restricted immunity can arise for pathogens controlled by T cell responses, particularly in antigenically complex parasites. Nevertheless, strain restricted immunity is clearly a feature of a number of parasitic infections, where immunity is known to be mediated by T cell responses. One such parasite is Theileria parva which induces potent CD8 T cell responses that play an important role in immunity. CD8 T cells specific for parasitized lymphoblasts exhibit strain specificity, which appears to correlate with the ability of parasite strains to cross-protect. Studies using recently identified T. parva antigens recognised by CD8 T cells have shown that the strain restricted nature of immunity is a consequence of the CD8 T cell response in individual animals being focused on a limited number of dominant polymorphic antigenic determinants. Responses in animals of different MHC genotypes are often directed to different parasite antigens, indicating that, at the host population level, a larger number of parasite proteins can serve as targets for the protective T cell response. Nevertheless, the finding that parasite strains show overlapping antigenic profiles, probably as a consequence of sexual recombination, suggests that induction of responses to an extended but limited set of antigens in individual animals may overcome the strain restricted nature of immunity.

  20. Impact of Chronic Viral Infection on T-Cell Dependent Humoral Immune Response.

    PubMed

    Rodriguez, Stéphane; Roussel, Mikaël; Tarte, Karin; Amé-Thomas, Patricia

    2017-01-01

    During the last decades, considerable efforts have been done to decipher mechanisms supported by microorganisms or viruses involved in the development, differentiation, and function of immune cells. Pathogens and their associated secretome as well as the continuous inflammation observed in chronic infection are shaping both innate and adaptive immunity. Secondary lymphoid organs are functional structures ensuring the mounting of adaptive immune response against microorganisms and viruses. Inside these organs, germinal centers (GCs) are the specialized sites where mature B-cell differentiation occurs leading to the release of high-affinity immunoglobulin (Ig)-secreting cells. Different steps are critical to complete B-cell differentiation process, including proliferation, somatic hypermutations in Ig variable genes, affinity-based selection, and class switch recombination. All these steps require intense interactions with cognate CD4 + helper T cells belonging to follicular helper lineage. Interestingly, pathogens can disturb this subtle machinery affecting the classical adaptive immune response. In this review, we describe how viruses could act directly on GC B cells, either through B-cell infection or by their contribution to B-cell cancer development and maintenance. In addition, we depict the indirect impact of viruses on B-cell response through infection of GC T cells and stromal cells, leading to immune response modulation.

  1. Tailored immune responses: novel effector helper T cell subsets in protective immunity.

    PubMed

    Kara, Ervin E; Comerford, Iain; Fenix, Kevin A; Bastow, Cameron R; Gregor, Carly E; McKenzie, Duncan R; McColl, Shaun R

    2014-02-01

    Differentiation of naïve CD4⁺ cells into functionally distinct effector helper T cell subsets, characterised by distinct "cytokine signatures," is a cardinal strategy employed by the mammalian immune system to efficiently deal with the rapidly evolving array of pathogenic microorganisms encountered by the host. Since the T(H)1/T(H)2 paradigm was first described by Mosmann and Coffman, research in the field of helper T cell biology has grown exponentially with seven functionally unique subsets having now been described. In this review, recent insights into the molecular mechanisms that govern differentiation and function of effector helper T cell subsets will be discussed in the context of microbial infections, with a focus on how these different helper T cell subsets orchestrate immune responses tailored to combat the nature of the pathogenic threat encountered.

  2. Gene Deletions in Mycobacterium bovis BCG Stimulate Increased CD8+ T Cell Responses

    PubMed Central

    Panas, Michael W.; Sixsmith, Jaimie D.; White, KeriAnn; Korioth-Schmitz, Birgit; Shields, Shana T.; Moy, Brian T.; Lee, Sunhee; Schmitz, Joern E.; Jacobs, William R.; Porcelli, Steven A.; Haynes, Barton F.; Letvin, Norman L.

    2014-01-01

    Mycobacteria, the etiological agents of tuberculosis and leprosy, have coevolved with mammals for millions of years and have numerous ways of suppressing their host's immune response. It has been suggested that mycobacteria may contain genes that reduce the host's ability to elicit CD8+ T cell responses. We screened 3,290 mutant Mycobacterium bovis bacillus Calmette Guerin (BCG) strains to identify genes that decrease major histocompatibility complex (MHC) class I presentation of mycobacterium-encoded epitope peptides. Through our analysis, we identified 16 mutant BCG strains that generated increased transgene product-specific CD8+ T cell responses. The genes disrupted in these mutant strains had disparate predicted functions. Reconstruction of strains via targeted deletion of genes identified in the screen recapitulated the enhanced immunogenicity phenotype of the original mutant strains. When we introduced the simian immunodeficiency virus (SIV) gag gene into several of these novel BCG strains, we observed enhanced SIV Gag-specific CD8+ T cell responses in vivo. This study demonstrates that mycobacteria carry numerous genes that act to dampen CD8+ T cell responses and suggests that genetic modification of these genes may generate a novel group of recombinant BCG strains capable of serving as more effective and immunogenic vaccine vectors. PMID:25287928

  3. Gene deletions in Mycobacterium bovis BCG stimulate increased CD8+ T cell responses.

    PubMed

    Panas, Michael W; Sixsmith, Jaimie D; White, KeriAnn; Korioth-Schmitz, Birgit; Shields, Shana T; Moy, Brian T; Lee, Sunhee; Schmitz, Joern E; Jacobs, William R; Porcelli, Steven A; Haynes, Barton F; Letvin, Norman L; Gillard, Geoffrey O

    2014-12-01

    Mycobacteria, the etiological agents of tuberculosis and leprosy, have coevolved with mammals for millions of years and have numerous ways of suppressing their host's immune response. It has been suggested that mycobacteria may contain genes that reduce the host's ability to elicit CD8(+) T cell responses. We screened 3,290 mutant Mycobacterium bovis bacillus Calmette Guerin (BCG) strains to identify genes that decrease major histocompatibility complex (MHC) class I presentation of mycobacterium-encoded epitope peptides. Through our analysis, we identified 16 mutant BCG strains that generated increased transgene product-specific CD8(+) T cell responses. The genes disrupted in these mutant strains had disparate predicted functions. Reconstruction of strains via targeted deletion of genes identified in the screen recapitulated the enhanced immunogenicity phenotype of the original mutant strains. When we introduced the simian immunodeficiency virus (SIV) gag gene into several of these novel BCG strains, we observed enhanced SIV Gag-specific CD8(+) T cell responses in vivo. This study demonstrates that mycobacteria carry numerous genes that act to dampen CD8(+) T cell responses and suggests that genetic modification of these genes may generate a novel group of recombinant BCG strains capable of serving as more effective and immunogenic vaccine vectors. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  4. Cyclic citrullinated MBP87-99 peptide stimulates T cell responses: Implications in triggering disease.

    PubMed

    Apostolopoulos, Vasso; Deraos, George; Matsoukas, Minos-Timotheos; Day, Stephanie; Stojanovska, Lily; Tselios, Theodore; Androutsou, Maria-Eleni; Matsoukas, John

    2017-01-15

    Amino acid mutations to agonist peptide epitopes of myelin proteins have been used to modulate immune responses and experimental autoimmune encephalomyelitis (EAE, animal model of multiple sclerosis). Such amino acid alteration are termed, altered peptide ligands (APL). We have shown that the agonist myelin basic protein (MBP) 87-99 epitope (MBP 87-99 ) with crucial T cell receptor (TCR) substitutions at positions 91 and 96 (K 91 ,P 96 (TCR contact residues) to R 91 ,A 96 ; [R 91 ,A 96 ]MBP 87-99 ) results in altered T cell responses and inhibits EAE symptoms. In this study, the role of citrullination of arginines in [R 91 ,A 96 ]MBP 87-99 peptide analog was determined using in vivo experiments in combination with computational studies. The immunogenicity of linear [Cit 91 ,A 96 ,Cit 97 ]MBP 87-99 and its cyclic analog - cyclo(87-99)[Cit 91 ,A 96 ,Cit 97 ]MBP 87-99 when conjugated to the carrier mannan (polysaccharide) were studied in SJL/J mice. It was found that mannosylated cyclo(87-99)[Cit 91 ,A 96 ,Cit 97 ]MBP 87-99 peptide induced strong T cell proliferative responses and IFN-gamma cytokine secretion compared with the linear one. Moreover, the interaction of linear and cyclic peptide analogs with the major histocompatibility complex (MHC II, H2-IA s ) and TCR was analyzed using molecular dynamics simulations at the receptor level, in order to gain a better understanding of the molecular recognition mechanisms that underly the different immunological profiles of citrullinated peptides compared to its agonist native counterpart MBP 87-99 epitope. The results demonstrate that the citrullination of arginine in combination with the backbone conformation of mutated linear and cyclic analogs are significant elements for the immune response triggering the induction of pro-inflammatory cytokines. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Increased peripheral blood CD4+ T cell responses to deamidated but not to native gliadin in children with coeliac disease

    PubMed Central

    Lammi, A; Arikoski, P; Vaarala, O; Kinnunen, T; Ilonen, J

    2012-01-01

    T cell recognition of gliadin from dietary gluten is essential for the pathogenesis of coeliac disease (CD). The aim of the present study was to analyse whether gliadin-specific T cells are detectable in the circulation of children with newly diagnosed coeliac disease by using a sensitive carboxfluorescein diacetate succinimidyl ester (CFSE) dilution method. Peripheral blood CD4+ T cell responses were analysed in 20 children at diagnosis of CD and compared to those in 64 healthy control children carrying the CD-associated human leucocyte antigen (HLA)-DQ2 or -DQ8 alleles. Deamidated gliadin (gTG)-specific T cells were detectable in the peripheral blood of more than half the children with CD (11 of 20, 55%) compared to 15 of 64 (23·4%) of the control children (P = 0·008). Proliferative responses to gTG were also significantly stronger in children with CD than in controls (P = 0·01). In contrast, T cells specific to native gliadin were detectable at comparable frequencies in children with CD (two of 19, 10·5%) and controls (13 of 64, 20·3%). gTG-specific T cells had a memory phenotype more often than those specific to native gliadin in children with CD (P = 0·02), whereas controls had similar percentages of memory cells in both stimulations. Finally, gTG-specific CD4+ T cells had a higher expression of the gut-homing molecule β7 integrin than those specific to the control antigen tetanus toxoid. Collectively, our current results demonstrate that the frequency of circulating memory CD4+ T cells specific to gTG but not native gliadin is increased in children with newly diagnosed CD. PMID:22471282

  6. Increased peripheral blood CD4+ T cell responses to deamidated but not to native gliadin in children with coeliac disease.

    PubMed

    Lammi, A; Arikoski, P; Vaarala, O; Kinnunen, T; Ilonen, J

    2012-05-01

    T cell recognition of gliadin from dietary gluten is essential for the pathogenesis of coeliac disease (CD). The aim of the present study was to analyse whether gliadin-specific T cells are detectable in the circulation of children with newly diagnosed coeliac disease by using a sensitive carboxfluorescein diacetate succinimidyl ester (CFSE) dilution method. Peripheral blood CD4(+) T cell responses were analysed in 20 children at diagnosis of CD and compared to those in 64 healthy control children carrying the CD-associated human leucocyte antigen (HLA)-DQ2 or -DQ8 alleles. Deamidated gliadin (gTG)-specific T cells were detectable in the peripheral blood of more than half the children with CD (11 of 20, 55%) compared to 15 of 64 (23.4%) of the control children (P = 0.008). Proliferative responses to gTG were also significantly stronger in children with CD than in controls (P = 0.01). In contrast, T cells specific to native gliadin were detectable at comparable frequencies in children with CD (two of 19, 10.5%) and controls (13 of 64, 20.3%). gTG-specific T cells had a memory phenotype more often than those specific to native gliadin in children with CD (P = 0.02), whereas controls had similar percentages of memory cells in both stimulations. Finally, gTG-specific CD4(+) T cells had a higher expression of the gut-homing molecule β7 integrin than those specific to the control antigen tetanus toxoid. Collectively, our current results demonstrate that the frequency of circulating memory CD4(+) T cells specific to gTG but not native gliadin is increased in children with newly diagnosed CD. © 2012 The Authors;Clinical and Experimental Immunology © 2012 British Society for Immunology.

  7. Cytomegalovirus-Specific CD8+ T-Cells With Different T-Cell Receptor Affinities Segregate T-Cell Phenotypes and Correlate With Chronic Graft-Versus-Host Disease in Patients Post-Hematopoietic Stem Cell Transplantation

    PubMed Central

    Poiret, Thomas; Axelsson-Robertson, Rebecca; Remberger, Mats; Luo, Xiao-Hua; Rao, Martin; Nagchowdhury, Anurupa; Von Landenberg, Anna; Ernberg, Ingemar; Ringden, Olle; Maeurer, Markus

    2018-01-01

    Virus-specific T-cell responses are crucial to control cytomegalovirus (CMV) infections/reactivation in immunocompromised individuals. Adoptive cellular therapy with CMV-specific T-cells has become a viable treatment option. High-affinity anti-viral cellular immune responses are associated with improved long-term immune protection against CMV infection. To date, the characterization of high-affinity T-cell responses against CMV has not been achieved in blood from patients after allogeneic hematopoietic stem cell transplantation (HSCT). Therefore, the purpose of this study was to describe and analyze the phenotype and clinical impact of different CMV-specific CD8+ cytotoxic T-lymphocytes (CMV-CTL) classes based on their T-cell receptor (TCR) affinity. T-cells isolated from 23 patients during the first year following HSCT were tested for the expression of memory markers, programmed cell death 1 (PD-1), as well as TCR affinity, using three different HLA-A*02:01 CMVNLVPMVATV-Pp65 tetramers (wild-type, a245v and q226a mutants). High-affinity CMV-CTL defined by q226a tetramer binding, exhibited a higher frequency in CD8+ T-cells in the first month post-HSCT and exhibited an effector memory phenotype associated with strong PD-1 expression as compared to the medium- and low-affinity CMV-CTLs. High-affinity CMV-CTL was found at higher proportion in patients with chronic graft-versus-host disease (p < 0.001). This study provides a first insight into the detailed TCR affinities of CMV-CTL. This may be useful in order to improve current immunotherapy protocols using isolation of viral-specific T-cell populations based on their TCR affinity. PMID:29692783

  8. Scavenger receptor WC1 contributes to the γδ T cell response to Leptospira.

    PubMed

    Wang, Fei; Herzig, Carolyn T A; Chen, Chuang; Hsu, Haoting; Baldwin, Cynthia L; Telfer, Janice C

    2011-03-01

    WC1 molecules are exclusively expressed on the surface of γδ T cells. They belong to the scavenger receptor cysteine-rich (SRCR) superfamily and are encoded by a multi-gene family. WC1 molecules have been grouped on the basis of antibody reactivity. The expression of WC1 molecules from these serologically defined groups is correlated with differences in γδ T cell responses. The expression of receptors within the WC1.1 group correlates with the capacity of γδ T cells to respond to Leptospira antigen. In this study, we used RNA interference to directly investigate the role of WC1 expression in the response to Leptospira borgpetersenii. We found that when three out of thirteen WC1 gene products were downregulated by RNA interference, γδ T cell proliferation and IFN-γ production in response to Leptospira antigen was significantly reduced. Our data demonstrate that specific receptors in the WC1 family directly participate in Leptospira recognition and/or activation of γδ T cells. Copyright © 2010 Elsevier Ltd. All rights reserved.

  9. A High Frequency of HIV-Specific Circulating Follicular Helper T Cells Is Associated with Preserved Memory B Cell Responses in HIV Controllers.

    PubMed

    Claireaux, M; Galperin, M; Benati, D; Nouël, A; Mukhopadhyay, M; Klingler, J; de Truchis, P; Zucman, D; Hendou, S; Boufassa, F; Moog, C; Lambotte, O; Chakrabarti, L A

    2018-05-08

    Follicular helper T cells (Tfh) play an essential role in the affinity maturation of the antibody response by providing help to B cells. To determine whether this CD4 + T cell subset may contribute to the spontaneous control of HIV infection, we analyzed the phenotype and function of circulating Tfh (cTfh) in patients from the ANRS CO21 CODEX cohort who naturally controlled HIV-1 replication to undetectable levels and compared them to treated patients with similarly low viral loads. HIV-specific cTfh (Tet + ), detected by Gag-major histocompatibility complex class II (MHC-II) tetramer labeling in the CD45RA - CXCR5 + CD4 + T cell population, proved more frequent in the controller group ( P = 0.002). The frequency of PD-1 expression in Tet + cTfh was increased in both groups (median, >75%) compared to total cTfh (<30%), but the intensity of PD-1 expression per cell remained higher in the treated patient group ( P = 0.02), pointing to the persistence of abnormal immune activation in treated patients. The function of cTfh, analyzed by the capacity to promote IgG secretion in cocultures with autologous memory B cells, did not show major differences between groups in terms of total IgG production but proved significantly more efficient in the controller group when measuring HIV-specific IgG production. The frequency of Tet + cTfh correlated with HIV-specific IgG production ( R = 0.71 for Gag-specific and R = 0.79 for Env-specific IgG, respectively). Taken together, our findings indicate that key cTfh-B cell interactions are preserved in controlled HIV infection, resulting in potent memory B cell responses that may play an underappreciated role in HIV control. IMPORTANCE The rare patients who spontaneously control HIV replication in the absence of therapy provide a unique model to identify determinants of an effective anti-HIV immune response. HIV controllers show signs of particularly efficient antiviral T cell responses, while their humoral response was until recently

  10. Human leucocyte antigen class I-redirected anti-tumour CD4+ T cells require a higher T cell receptor binding affinity for optimal activity than CD8+ T cells.

    PubMed

    Tan, M P; Dolton, G M; Gerry, A B; Brewer, J E; Bennett, A D; Pumphrey, N J; Jakobsen, B K; Sewell, A K

    2017-01-01

    CD4 + T helper cells are a valuable component of the immune response towards cancer. Unfortunately, natural tumour-specific CD4 + T cells occur in low frequency, express relatively low-affinity T cell receptors (TCRs) and show poor reactivity towards cognate antigen. In addition, the lack of human leucocyte antigen (HLA) class II expression on most cancers dictates that these cells are often unable to respond to tumour cells directly. These deficiencies can be overcome by transducing primary CD4 + T cells with tumour-specific HLA class I-restricted TCRs prior to adoptive transfer. The lack of help from the co-receptor CD8 glycoprotein in CD4 + cells might result in these cells requiring a different optimal TCR binding affinity. Here we compared primary CD4 + and CD8 + T cells expressing wild-type and a range of affinity-enhanced TCRs specific for the HLA A*0201-restricted NY-ESO-1- and gp100 tumour antigens. Our major findings are: (i) redirected primary CD4 + T cells expressing TCRs of sufficiently high affinity exhibit a wide range of effector functions, including cytotoxicity, in response to cognate peptide; and (ii) optimal TCR binding affinity is higher in CD4 + T cells than CD8 + T cells. These results indicate that the CD4 + T cell component of current adoptive therapies using TCRs optimized for CD8 + T cells is below par and that there is room for substantial improvement. © 2016 The Authors. Clinical & Experimental Immunology published by John Wiley & Sons Ltd on behalf of British Society for Immunology.

  11. Effector and memory T cell subsets in the response to bovine tuberculosis

    USDA-ARS?s Scientific Manuscript database

    Long-term (i.e., 14 days) cultured IFN-gamma ELISPOT assays of peripheral blood mononuclear cells (PBMC) are used to access T cell central memory (Tcm) responses in both cattle and humans. With bovine tuberculosis, vaccine-elicited long-term IFN-gamma ELISPOT response correlates with protection; how...

  12. Functional characterization of CD4 and CD8 T cell responses among human papillomavirus infected patients with ano-genital warts.

    PubMed

    Singh, Manjula; Thakral, Deepshi; Rishi, Narayan; Kar, Hemanta Kumar; Mitra, Dipendra Kumar

    2017-06-01

    Ano-genital warts are considered one of the commonest and highly infectious sexually transmitted infections. These warts are primarily caused by the human papillomavirus (HPV) of the family Papillomaviridae , genus alpha - papillomavirus , species 10 and types 6 and 11. However the high recurrence rate of warts is a matter of serious concern to the patients and a challenge for the treating physician. The conventional treatment options are targeted only to the local site of warts. There is no systemic treatment modality as there is limited understanding of the disease immune-pathogenesis. The role of cell-mediated immunity in combating HPV infection is not clearly defined. Hence the present study is aimed at investigating the CD4 + T helper (Th1 and Th2) and CD8 + T cell responses among wart patients. In this study, we compared HPV6 and HPV11 antigen-specific T cell responses among venereal wart patients relative to healthy controls. Significant decrease in percent frequencies of IFN-γ producing CD4 + and CD8 + T cells were observed in HPV infected wart patients. On the other hand, the frequency of CD4 + T cells expressing IL-4 was significantly increased in these patients as compared to healthy controls. The observed functional skewing of HPV specific T cells from Th1 to Th2 response in patients indicated suppressed immunity against the HPV. Moreover, decrease in CD8 T cell function correlated with poor wart clearance. Our findings open future avenues for exploring potential immunomodulation strategies as an adjunct to standard treatment for better management of these patients and prevention of recurrence.

  13. Human CD4+ T-cell response to hepatitis delta virus: identification of multiple epitopes and characterization of T-helper cytokine profiles.

    PubMed Central

    Nisini, R; Paroli, M; Accapezzato, D; Bonino, F; Rosina, F; Santantonio, T; Sallusto, F; Amoroso, A; Houghton, M; Barnaba, V

    1997-01-01

    The T-cell-mediated immune response plays a crucial role in defense against hepatotropic viruses as well as in the pathogenesis of viral chronic hepatitides. However, very little is known about the role of specific T cells during hepatitis delta virus (HDV) infection in humans. In this study, the T-cell response to HDV in chronic hepatitis B virus (HBV) carriers with HDV superinfection was investigated at different levels. Analysis of peripheral blood mononuclear cell (PBMC) proliferation in response to a recombinant form of large hepatitis delta antigen (HDAg) revealed that 8 of 30 patients studied (27%) specifically responded to HDAg. By employing synthetic peptides spanning the entire HDAg sequence, we found that T-cell recognition was directed against different antigenic determinants, with patient-to-patient variation in the pattern of response to peptides. Interestingly, all responders had signs of inactive HDV-induced disease, while none of the patients with active disease and none of the control subjects showed any significant proliferation. More accurate information about the specific T-cell response was obtained at the clonal level. A panel of HDAg-specific CD4+ T-cell clones from three HDV-infected individuals and fine-specificity analysis revealed that the clones tested individually recognized four epitopes corresponding to amino acids (aa) 26 to 41, 50 to 65, 66 to 81, or 106 to 121 of HDAg sequence. The study of human leukocyte antigen (HLA) restriction revealed that peptides 50 to 65 and 106 to 121 were presented to specific T cells in association with multiple class II molecules. In addition, peptide 26 to 41 was efficiently generated after processing of HDAg through the endogenous processing pathway. Cytokine secretion analysis showed that all the CD4+ T-cell clones assayed were able to produce high levels of gamma interferon (IFN-gamma), belonging either to T helper-1 (Th1) or Th0 subsets and that some of them were cytotoxic in a specific assay

  14. Optimization of interferon gamma ELISPOT assay to detect human cytomegalovirus specific T-cell responses in solid organ transplants.

    PubMed

    Abate, Davide; Saldan, Alda; Forner, Gabriella; Tinto, Daniel; Bianchin, Alice; Palù, Giorgio

    2014-02-01

    Assessing the CMV specific CMI in transplant subjects represents a promising strategy to determine the risk of infection on individual basis. In this study 61 adult CMV IgG seropositive solid organ transplant recipients were examined in order to improve the efficacy of CMI detection. For this purpose, pair-wise comparisons were conducted comparing positive control stimuli PWM and PMA/iono and CMV stimuli, pp65 peptide pool and whole CMV particle. Rosette pre-depletion of blood was also investigated for detecting CD4+ or CD8+ T-cell responses using the IFN-g ELISPOT assay. In the time-points 30-180 days after transplantation, PMA/iono produced statistically significant higher responses compared to PWM, probably because PMA/iono activation pathway is independent from the effect of immunosuppressive drugs. The data showed that 11% of transplant patients displayed very low or undetectable responses to pp65 peptide pool antigen while having sustained high responses to whole CMV particle. In addition, in all the subjects analyzed, CMI responses to CMV particle produced a statistically significant higher number of spots compared to pp65 peptide pool antigen. Rosette pre-depletion of whole blood proved to be effective in detecting CD4+ or CD8+ T-cell responses similarly to flow cytometry. Taken together, the following recommendations are suggested to optimize the CMV-ELISPOT for transplantation settings: (1) use PMA/iono as positive control; (2) whole virus particle should be used to avoid peptide-related false negative responses; (3) a rosette pre-depletion step may be useful to detect CD4+ or CD8+ T-cell responses. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Relevance of studying T cell responses in SIV-infected rhesus macaques

    PubMed Central

    Valentine, Laura E.; Watkins, David I.

    2010-01-01

    HIV infection, once established, is never cleared. Rare individuals do, however, control viral replication to low levels. These successful immune responses are primarily linked to certain class I MHC alleles (MHC-I). Because of this association, many AIDS vaccines in development are designed to generate virus-specific CD8+ T cells. The Merck STEP phase 2b efficacy trial of one such vaccine was recently halted, and declared a failure. Thus, basic questions regarding what constitutes an effective T cell response and how such responses could be elicited by vaccination remain open. The best animal model available to explore such issues is simian immunodeficiency virus infection of rhesus macaques, which serves as the primary proving ground for AIDS vaccines. PMID:18964016

  16. Naive T cells are dispensable for memory CD4+ T cell homeostasis in progressive simian immunodeficiency virus infection.

    PubMed

    Okoye, Afam A; Rohankhedkar, Mukta; Abana, Chike; Pattenn, Audrie; Reyes, Matthew; Pexton, Christopher; Lum, Richard; Sylwester, Andrew; Planer, Shannon L; Legasse, Alfred; Park, Byung S; Piatak, Michael; Lifson, Jeffrey D; Axthelm, Michael K; Picker, Louis J

    2012-04-09

    The development of AIDS in chronic HIV/simian immunodeficiency virus (SIV) infection has been closely linked to progressive failure of CD4(+) memory T cell (T(M)) homeostasis. CD4(+) naive T cells (T(N)) also decline in these infections, but their contribution to disease progression is less clear. We assessed the role of CD4(+) T(N) in SIV pathogenesis using rhesus macaques (RMs) selectively and permanently depleted of CD4(+) T(N) before SIV infection. CD4(+) T(N)-depleted and CD4(+) T(N)-repleted RMs were created by subjecting juvenile RMs to thymectomy versus sham surgery, respectively, followed by total CD4(+) T cell depletion and recovery from this depletion. Although thymectomized and sham-treated RMs manifested comparable CD4(+) T(M) recovery, only sham-treated RMs reconstituted CD4(+) T(N). CD4(+) T(N)-depleted RMs responded to SIVmac239 infection with markedly attenuated SIV-specific CD4(+) T cell responses, delayed SIVenv-specific Ab responses, and reduced SIV-specific CD8(+) T cell responses. However, CD4(+) T(N)-depleted and -repleted groups showed similar levels of SIV replication. Moreover, CD4(+) T(N) deficiency had no significant effect on CD4(+) T(M) homeostasis (either on or off anti-retroviral therapy) or disease progression. These data demonstrate that the CD4(+) T(N) compartment is dispensable for CD4(+) T(M) homeostasis in progressive SIV infection, and they confirm that CD4(+) T(M) comprise a homeostatically independent compartment that is intrinsically capable of self-renewal.

  17. Zoster Vaccination Increases the Breadth of CD4+ T Cells Responsive to Varicella Zoster Virus

    PubMed Central

    Laing, Kerry J.; Russell, Ronnie M.; Dong, Lichun; Schmid, D. Scott; Stern, Michael; Magaret, Amalia; Haas, Jürgen G.; Johnston, Christine; Wald, Anna; Koelle, David M.

    2015-01-01

    Background. The live, attenuated varicella vaccine strain (vOka) is the only licensed therapeutic vaccine. Boost of varicella zoster virus (VZV)–specific cellular immunity is a likely mechanism of action. We examined memory CD4+ T-cell responses to each VZV protein at baseline and after zoster vaccination. Methods. Serial blood samples were collected from 12 subjects vaccinated with Zostavax and immunogenicity confirmed by ex vivo VZV-specific T-cell and antibody assays. CD4+ T-cell lines enriched for VZV specificity were generated and probed for proliferative responses to every VZV protein and selected peptide sets. Results. Zoster vaccination increased the median magnitude (2.3-fold) and breadth (4.2-fold) of VZV-specific CD4+ T cells one month post-vaccination. Both measures declined by 6 months. The most prevalent responses at baseline included VZV open reading frames (ORFs) 68, 4, 37, and 63. After vaccination, responses to ORFs 40, 67, 9, 59, 12, 62, and 18 were also prevalent. The immunogenicity of ORF9 and ORF18 were confirmed using peptides, defining a large number of discrete CD4 T-cell epitopes. Conclusions. The breadth and magnitude of the VZV-specific CD4+ T-cell response increase after zoster vaccination. In addition to glycoprotein E (ORF68), we identified antigenic ORFs that may be useful components of subunit vaccines. PMID:25784732

  18. T-Cell-Specific Loss of the PI-3-Kinase p110α Catalytic Subunit Results in Enhanced Cytokine Production and Antitumor Response

    PubMed Central

    Aragoneses-Fenoll, Laura; Ojeda, Gloria; Montes-Casado, María; Acosta-Ampudia, Yeny; Dianzani, Umberto; Portolés, Pilar; Rojo, José M.

    2018-01-01

    Class IA phosphatidylinositol 3-kinase (PI3K) catalytic subunits p110α and p110δ are targets in cancer therapy expressed at high levels in T lymphocytes. The role of p110δ PI3K in normal or pathological immune responses is well established, yet the importance of p110α subunits in T cell-dependent immune responses is not clear. To address this problem, mice with p110α conditionally deleted in CD4+ and CD8+ T lymphocytes (p110α−/−ΔT) were used. p110α−/−ΔT mice show normal development of T cell subsets, but slightly reduced numbers of CD4+ T cells in the spleen. “In vitro,” TCR/CD3 plus CD28 activation of naive CD4+ and CD8+ p110α−/−ΔT T cells showed enhanced effector function, particularly IFN-γ secretion, T-bet induction, and Akt, Erk, or P38 activation. Tfh derived from p110α−/−ΔT cells also have enhanced responses when compared to normal mice, and IL-2 expanded p110α−/−ΔT CD8+ T cells had enhanced levels of LAMP-1 and Granzyme B. By contrast, the expansion of p110α−/−ΔT iTreg cells was diminished. Also, p110α−/−ΔT mice had enhanced anti-keyhole limpet hemocyanin (KLH) IFN-γ, or IL-4 responses and IgG1 and IgG2b anti-KLH antibodies, using CFA or Alum as adjuvant, respectively. When compared to WT mice, p110α−/−ΔT mice inoculated with B16.F10 melanoma showed delayed tumor progression. The percentage of CD8+ T lymphocytes was higher and the percentage of Treg cells lower in the spleen of tumor-bearing p110α−/−ΔT mice. Also, IFN-γ production in tumor antigen-activated spleen cells was enhanced. Thus, PI3K p110α plays a significant role in antigen activation and differentiation of CD4+ and CD8+ T lymphocytes modulating antitumor immunity. PMID:29535720

  19. Immunotherapeutic strategies targeting Natural killer T cell responses in cancer

    PubMed Central

    Shissler, Susannah C.; Bollino, Dominique R.; Tiper, Irina V.; Bates, Joshua; Derakhshandeh, Roshanak; Webb, Tonya J.

    2017-01-01

    Natural killer T (NKT) cells are a unique subset of lymphocytes that bridge the innate and adaptive immune system. NKT cells possess a classic αβ T-cell receptor (TCR) that is able to recognize self and foreign glycolipid antigens presented by the nonclassical class I major histocompatibility complex (MHC) molecule, CD1d. Type I NKT cells (referred to as invariant NKT cells) express a semi-invariant Vα14Jα18 TCR in mice and Vα24Jα18 TCR in humans. Type II NKT cells are CD1d-restricted T cells that express a more diverse set of TCR α chains. The two types of NKT cells often exert opposing effects especially in tumor immunity, where Type II cells generally suppress tumor immunity while Type I NKT cells can enhance antitumor immune responses. In this review, we focus on the role of NKT cells in cancer. We discuss their effector and suppressive functions, as well as describe preclinical and clinical studies utilizing therapeutic strategies focused on harnessing their potent anti-tumor effector functions, and conclude with a discussion on potential next steps for the utilization of NKT cell targeted therapies for the treatment of cancer. PMID:27393665

  20. Bim is required for T-cell allogeneic responses and graft-versus-host disease in vivo

    PubMed Central

    Yu, Yu; Yu, Jing; Iclozan, Cristina; Kaosaard, Kane; Anasetti, Claudio; Yu, Xue-Zhong

    2012-01-01

    Bim, a BH3-only Bcl-2-family protein, is essential for T-cell negative selection in the thymus as well as for the death of activated T cells in the periphery. The role of Bim has been extensively studied in T-cell responses to self-antigens and viral infections. Recent findings on Bim in autoimmunity triggered our interest in investigating whether Bim may play a role in another disease with inflammatory symptoms as graft-versus-host disease (GVHD). Here we report that Bim is required for optimal T-cell responses to alloantigens in vivo and for the development of GVHD. Using murine models of allogeneic bone marrow transplantation (BMT), we found that donor T cells deficient for Bim are impaired in the induction of GVHD primarily due to a significant defect in T cell activation and expansion in vivo. Upon TCR engagement, Bim-/- T cells exhibited selective defects in CD69 expression and phosphorylation of PLCγ1. Our studies uncover a novel aspect of Bim function in T-cell activation with important implications in understanding the mechanisms of T-cell activation and tolerance under allogeneic transplantation. PMID:22432091

  1. T cell resistance to activation by dendritic cells requires long-term culture in simulated microgravity

    NASA Astrophysics Data System (ADS)

    Bradley, Jillian H.; Stein, Rachel; Randolph, Brad; Molina, Emily; Arnold, Jennifer P.; Gregg, Randal K.

    2017-11-01

    Immune impairment mediated by microgravity threatens the success of space exploration requiring long-duration spaceflight. The cells of most concern, T lymphocytes, coordinate the host response against microbial and cancerous challenges leading to elimination and long-term protection. T cells are activated upon recognition of specific microbial peptides bound on the surface of antigen presenting cells, such as dendritic cells (DC). Subsequently, this engagement results in T cell proliferation and differentiation into effector T cells driven by autocrine interleukin-2 (IL-2) and other cytokines. Finally, the effector T cells acquire the weaponry needed to destroy microbial invaders and tumors. Studies conducted on T cells during spaceflight, or using Earth-based culture systems, have shown reduced production of cytokines, proliferation and effector functions as compared to controls. This may account for the cases of viral reactivation events and opportunistic infections associated with astronauts of numerous missions. This work has largely been based upon the outcome of T cell activation by stimulatory factors that target select T cell signaling pathways rather than the complex, signaling events related to the natural process of antigen presentation by DC. This study tested the response of an ovalbumin peptide-specific T cell line, OT-II TCH, to activation by DC when the T cells were cultured 24-120 h in a simulated microgravity (SMG) environment generated by a rotary cell culture system. Following 72 h culture of T cells in SMG (SMG-T) or control static (Static-T) conditions, IL-2 production by the T cells was reduced in SMG-T cells compared to Static-T cells upon stimulation by phorbol 12-myristate 13-acetate (PMA) and ionomycin. However, when the SMG-T cells were stimulated with DC and peptide, IL-2 was significantly increased compared to Static-T cells. Such enhanced IL-2 production by SMG-T cells peaked at 72 h SMG culture time and decreased thereafter. When

  2. Long term protection after immunization with P. berghei sporozoites correlates with sustained IFNγ responses of hepatic CD8+ memory T cells.

    PubMed

    Nganou-Makamdop, Krystelle; van Gemert, Geert-Jan; Arens, Theo; Hermsen, Cornelus C; Sauerwein, Robert W

    2012-01-01

    Protection against P. berghei malaria can successfully be induced in mice by immunization with both radiation attenuated sporozoites (RAS) arresting early during liver stage development, or sporozoites combined with chloroquine chemoprophylaxis (CPS), resulting in complete intra-hepatic parasite development before killing of blood-stages by chloroquine takes place. We assessed the longevity of protective cellular immune responses by RAS and CPS P. berghei immunization of C57BL/6j mice. Strong effector and memory (T(EM)) CD8+ T cell responses were induced predominantly in the liver of both RAS and CPS immunized mice while CD4+ T cells with memory phenotype remained at base line levels. Compared to unprotected naïve mice, we found high sporozoite-specific IFNγ ex vivo responses that associated with induced levels of in vivo CD8+ T(EM) cells in the liver but not spleen. Long term evaluation over a period of 9 months showed a decline of malaria-specific IFNγ responses in RAS and CPS mice that significantly correlated with loss of protection (r(2) = 0.60, p<0.0001). The reducing IFNγ response by hepatic memory CD8+ T cells could be boosted by re-exposure to wild-type sporozoites. Our data show that sustainable protection against malaria associates with distinct intra-hepatic immune responses characterized by strong IFNγ producing CD8+ memory T cells.

  3. Cellular cooperation in lymphocyte activation. III. B-cell helper effect in the enhancement of T-cell response.

    PubMed

    Kasahara, T; Kin, K; Itoh, Y; Kawai, T; Kano, Y; Shioiri-Nakano, K

    1979-01-01

    T and B cells were purified from human tonsil and peripheral blood by the removal of phagocytic cells, followed by filtration through a nylon fiber column (NC) and E-rosette formation. Purified T and B cells contained less than 1% of other cell types. The responses of T cells to concanavalin A (Con A) and soluble protein A were greatly enhanced in the presence of autologous B cells. Participation of B cells in T-cell enhancement was confirmed by the following observations: (a) purified B copulation, which was separated further from adherent B cells, retained its enhancing activity. (b) Another adherent cell-free B-cell preparation, which was purified from the NC-passed fraction, and (c) no T lymphoid but some B lymphoid cell lines, elicited strong T-cell enhancement. It was also found that the enhancing capacity of B cells required no metabolic activity, but rather an intact cell form and direct cell-to-cell contact with responding cells. The stimulatory determinants on B cells were resistant to trypsin and neuraminidase treatment. In this paper a hypothesis will be presented that at least two signals are prerequisite for the effective activation of T cells.

  4. Yellow fever vaccination elicits broad functional CD4+ T cell responses that recognize structural and nonstructural proteins.

    PubMed

    James, Eddie A; LaFond, Rebecca E; Gates, Theresa J; Mai, Duy T; Malhotra, Uma; Kwok, William W

    2013-12-01

    Yellow fever virus (YFV) can induce acute, life-threatening disease that is a significant health burden in areas where yellow fever is endemic, but it is preventable through vaccination. The live attenuated 17D YFV strain induces responses characterized by neutralizing antibodies and strong T cell responses. This vaccine provides an excellent model for studying human immunity. While several studies have characterized YFV-specific antibody and CD8(+) T cell responses, less is known about YFV-specific CD4(+) T cells. Here we characterize the epitope specificity, functional attributes, and dynamics of YFV-specific T cell responses in vaccinated subjects by investigating peripheral blood mononuclear cells by using HLA-DR tetramers. A total of 112 epitopes restricted by seven common HLA-DRB1 alleles were identified. Epitopes were present within all YFV proteins, but the capsid, envelope, NS2a, and NS3 proteins had the highest epitope density. Antibody blocking demonstrated that the majority of YFV-specific T cells were HLA-DR restricted. Therefore, CD4(+) T cell responses could be effectively characterized with HLA-DR tetramers. Ex vivo tetramer analysis revealed that YFV-specific T cells persisted at frequencies ranging from 0 to 100 cells per million that are detectable years after vaccination. Longitudinal analysis indicated that YFV-specific CD4(+) T cells reached peak frequencies, often exceeding 250 cells per million, approximately 2 weeks after vaccination. As frequencies subsequently declined, YFV-specific cells regained CCR7 expression, indicating a shift from effector to central memory. Cells were typically CXCR3 positive, suggesting Th1 polarization, and produced gamma interferon and other cytokines after reactivation in vitro. Therefore, YFV elicits robust early effector CD4(+) T cell responses that contract, forming a detectable memory population.

  5. Yellow Fever Vaccination Elicits Broad Functional CD4+ T Cell Responses That Recognize Structural and Nonstructural Proteins

    PubMed Central

    James, Eddie A.; LaFond, Rebecca E.; Gates, Theresa J.; Mai, Duy T.; Malhotra, Uma

    2013-01-01

    Yellow fever virus (YFV) can induce acute, life-threatening disease that is a significant health burden in areas where yellow fever is endemic, but it is preventable through vaccination. The live attenuated 17D YFV strain induces responses characterized by neutralizing antibodies and strong T cell responses. This vaccine provides an excellent model for studying human immunity. While several studies have characterized YFV-specific antibody and CD8+ T cell responses, less is known about YFV-specific CD4+ T cells. Here we characterize the epitope specificity, functional attributes, and dynamics of YFV-specific T cell responses in vaccinated subjects by investigating peripheral blood mononuclear cells by using HLA-DR tetramers. A total of 112 epitopes restricted by seven common HLA-DRB1 alleles were identified. Epitopes were present within all YFV proteins, but the capsid, envelope, NS2a, and NS3 proteins had the highest epitope density. Antibody blocking demonstrated that the majority of YFV-specific T cells were HLA-DR restricted. Therefore, CD4+ T cell responses could be effectively characterized with HLA-DR tetramers. Ex vivo tetramer analysis revealed that YFV-specific T cells persisted at frequencies ranging from 0 to 100 cells per million that are detectable years after vaccination. Longitudinal analysis indicated that YFV-specific CD4+ T cells reached peak frequencies, often exceeding 250 cells per million, approximately 2 weeks after vaccination. As frequencies subsequently declined, YFV-specific cells regained CCR7 expression, indicating a shift from effector to central memory. Cells were typically CXCR3 positive, suggesting Th1 polarization, and produced gamma interferon and other cytokines after reactivation in vitro. Therefore, YFV elicits robust early effector CD4+ T cell responses that contract, forming a detectable memory population. PMID:24049183

  6. Role of B7 costimulatory molecules in immune responses and T-helper cell differentiation in response to recombinant HagB from Porphyromonas gingivalis.

    PubMed

    Zhang, Ping; Martin, Michael; Yang, Qiu-Bo; Michalek, Suzanne M; Katz, Jannet

    2004-02-01

    In addition to antigen-specific signals mediated through the T-cell receptor, T cells also require antigen nonspecific costimulation for activation. The B7 family of molecules on antigen-presenting cells, which include B7-1 (CD80) and B7-2 (CD86), play important roles in providing costimulatory signals required for development of antigen-specific immune responses. Hemagglutinin B (HagB) is a nonfimbrial adhesin of the periodontopathic microorganism Porphyromonas gingivalis and is thought to be involved in the attachment of the bacterium to host tissues. However, the immune mechanisms involved in responses to HagB and their roles in pathogenesis have yet to be elucidated. Therefore, the purpose of this study was to determine the role of B7 costimulatory molecules on T-helper-cell differentiation for the induction of immune responses to HagB. Mice deficient in either or both of the costimulatory molecules B7-1 and B7-2 were used to explore their role in immune responses to HagB after subcutaneous immunization. B7-1(-/-) mice had levels of immunoglobulin G (IgG) anti-HagB antibody activity in serum similar to those of wild-type mice, whereas lower serum IgG anti-HagB antibody responses were seen in B7-2(-/-) mice. Moreover, significantly lower numbers of IgG antibody-secreting cells and lower levels of CD4(+)-T-cell proliferation were observed in B7-2(-/-) mice compared to wild-type mice. No serum IgG response to HagB was detected in B7-1/B7-2(-/-) mice. Analysis of the subclass of the serum IgG responses and the cytokines induced in response to HagB revealed that B7-2(-/-) mice had significantly lower IgG1 and higher IgG2a anti-HagB antibody responses compared to wild-type mice. The B7-2(-/-) mice also had significantly reduced levels of interleukin-4 (IL-4) and IL-5 and enhanced level of gamma interferon. Furthermore, assessment of B7-1 and B7-2 expression on B cells and macrophages derived from wild-type BALB/c mice after in vitro stimulation with HagB revealed a

  7. In vitro responses to avian influenza H5 by human CD4 T-cells*

    PubMed Central

    Cusick, Matthew F; Wang, Shuping; Eckels, David D

    2009-01-01

    To address the question of whether human T-cells are capable of recognizing novel isolates of influenza virus, in vitro responses to recombinant antigens and synthetic peptides derived from the sequences of H1, H3, and H5 were examined in a cohort of 64 individuals selected from a healthy blood donor population. Humans respond in vitro to H1 and H3 following exposure through natural infection and vaccination. Responses to H5 were well correlated with those to H1 or H3 and thus a significant repertoire of H5-responsive T-cells is present in many individuals; clear non-responders to H1, H3, and H5, however, do exist. Differences were observed in the cytokine responses to H1, H3, and H5; whereas both IL-2 and IFN-γ production characteristic of memory responses were observed for H1 and H3, H5-specific responses elicited primarily IL-2 and little or no IFN-γ consistent with a naïve T cell phenotype. Responses to all influenza HA were restricted by HLA-DR molecules. To address the structural basis for T-cell recognition of H1 and H5, overlapping synthetic peptides were used to identify epitopes and to determine whether recognition of H5 was limited to homologous sequences in H1, the most closely related HA phylogenetically. Although responses were generally correlated, no complete structural overlap was observed. These results suggest that helper T cell cross reactivity between different influenza strains may impart cross-protection to H5N1 strain of influenza. PMID:19841175

  8. HBV-specific and global T-cell dysfunction in chronic hepatitis B

    PubMed Central

    Park, Jang-June; Wong, David K.; Wahed, Abdus S.; Lee, William M.; Feld, Jordan J.; Terrault, Norah; Khalili, Mandana; Sterling, Richard K.; Kowdley, Kris V.; Bzowej, Natalie; Lau, Daryl T.; Kim, W. Ray; Smith, Coleman; Carithers, Robert L.; Torrey, Keith W.; Keith, James W.; Levine, Danielle L.; Traum, Daniel; Ho, Suzanne; Valiga, Mary E.; Johnson, Geoffrey S.; Doo, Edward; Lok, Anna S. F.; Chang, Kyong-Mi

    2015-01-01

    Background & Aims T cells play a critical role in in viral infection. We examined whether T-cell effector and regulatory responses can define clinical stages of chronic hepatitis B (CHB). Methods We enrolled 200 adults with CHB who participated in the NIH-supported Hepatitis B Research Network from 2011 through 2013 and 20 uninfected individuals (controls). Peripheral blood lymphocytes from these subjects were analyzed for T-cell responses (proliferation and production of interferon-γ and interleukin-10) to overlapping hepatitis B virus (HBV) peptides (preS, S, preC, core, and reverse transcriptase), influenza matrix peptides, and lipopolysaccharide. T-cell expression of regulatory markers FOXP3, programmed death-1 (PD1), and cytotoxic T lymphocyte-associated antigen-4 (CTLA4) was examined by flow cytometry. Immune measures were compared with clinical parameters, including physician-defined immune-active, immune-tolerant, or inactive CHB phenotypes, in a blinded fashion. Results Compared to controls, patients with CHB had weak T-cell proliferative, interferon-γ, and interleukin-10 responses to HBV, with increased frequency of circulating FOXP3+CD127− regulatory T cells and CD4+ T-cell expression of PD1 and CTLA4. T-cell measures did not clearly distinguish between clinical CHB phenotypes, although the HBV core-specific T-cell response was weaker in HBeAg+ than HBeAg− patients (% responders: 3% vs 23%, P=.00008). Although in vitro blockade of PD1 or CTLA4 increased T-cell responses to HBV, the effect was weaker in HBeAg+ than HBeAg− patients. Furthermore, T-cell responses to influenza and lipopolysaccharide were weaker in CHB patients than controls. Conclusion HBV persists with virus-specific and global T-cell dysfunction mediated by multiple regulatory mechanisms including circulating HBeAg, but without distinct T-cell–based immune signatures for clinical phenotypes. These findings suggest additional T-cell independent or regulatory mechanisms of CHB

  9. The polyomavirus BK large T-antigen-derived peptide elicits an HLA-DR promiscuous and polyfunctional CD4+ T-cell response.

    PubMed

    Ramaswami, Bala; Popescu, Iulia; Macedo, Camila; Luo, Chunqing; Shapiro, Ron; Metes, Diana; Chalasani, Geetha; Randhawa, Parmjeet S

    2011-05-01

    BK virus (BKV) nephropathy and hemorrhagic cystitis are increasingly recognized causes of disease in renal and hematopoietic stem cell transplant recipients, respectively. Functional characterization of the immune response to BKV is important for clinical diagnosis, prognosis, and vaccine design. A peptide mix (PepMix) and overlapping (OPP) or random (RPP) peptide pools derived from BKV large T antigen (LTA) were used to restimulate 14-day-expanded peripheral blood mononuclear cells (PBMC) from 27 healthy control subjects in gamma interferon (IFN-γ)-specific enzyme-linked immunospot (ELISPOT) assays. A T-cell response to LTA PepMix was detected in 15/27 subjects. A response was frequently observed with peptides derived from the helicase domain (9/15 subjects), while the DNA binding and host range domains were immunologically inert (0/15 subjects). For all nine subjects who responded to LTA peptide pools, the immune response could be explained largely by a 15-mer peptide designated P313. P313-specific CD4(+) T-cell clones demonstrated (i) stringent LTA peptide specificity; (ii) promiscuous recognition in the context of HLA-DR alleles; (iii) cross recognition of homologous peptides from the polyomavirus simian virus 40 (SV40); (iv) an effector memory phenotype, CD107a expression, and intracellular production of IFN-γ and tumor necrosis factor alpha (TNF-α); (v) cytotoxic activity in a chromium release assay; and (vi) the ability to directly present cognate antigen to autologous T cells. In conclusion, T-cell-mediated immunity to BKV in healthy subjects is associated with a polyfunctional population of CD4(+) T cells with dual T-helper and T-cytotoxic properties. HLA class II promiscuity in antigen presentation makes the targeted LTA peptide sequence a suitable candidate for inclusion in immunotherapy protocols.

  10. Enhancement of antigen-specific CD4 + and CD8 + T cell responses using a self-assembled biologic nanolipoprotein particle vaccine

    DOE PAGES

    Weilhammer, Dina; Dunkle, Alexis D.; Blanchette, Craig D.; ...

    2017-02-14

    To address the need for vaccine platforms that induce robust cell-mediated immunity, we investigated the potential of utilizing self-assembling biologic nanolipoprotein particles (NLPs) as an antigen and adjuvant delivery system to induce antigen-specific murine T cell responses. Here, we utilized OT-I and OT-II TCR-transgenic mice to investigate the effects of NLP-mediated delivery of the model antigen ovalbumin (OVA) on T cell activation. Delivery of OVA with the TLR4 agonist monophosphoryl lipid A (MPLA) in the context of NLPs significantly enhanced the activation of both CD4 + and CD8 + T cells in vitro compared to co-administration of free OVA andmore » MPLA. Upon intranasal immunization of mice harboring TCR-transgenic cells, NLPs enhanced the adjuvant effects of MPLA and the in vivo delivery of OVA, leading to significantly increased expansion of CD4 + and CD8 + T cells in lung-draining lymph nodes. Therefore, NLPs are a promising vaccine platform for inducing T cell responses following intranasal administration.« less

  11. Enhancement of antigen-specific CD4 + and CD8 + T cell responses using a self-assembled biologic nanolipoprotein particle vaccine

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Weilhammer, Dina; Dunkle, Alexis D.; Blanchette, Craig D.

    To address the need for vaccine platforms that induce robust cell-mediated immunity, we investigated the potential of utilizing self-assembling biologic nanolipoprotein particles (NLPs) as an antigen and adjuvant delivery system to induce antigen-specific murine T cell responses. Here, we utilized OT-I and OT-II TCR-transgenic mice to investigate the effects of NLP-mediated delivery of the model antigen ovalbumin (OVA) on T cell activation. Delivery of OVA with the TLR4 agonist monophosphoryl lipid A (MPLA) in the context of NLPs significantly enhanced the activation of both CD4 + and CD8 + T cells in vitro compared to co-administration of free OVA andmore » MPLA. Upon intranasal immunization of mice harboring TCR-transgenic cells, NLPs enhanced the adjuvant effects of MPLA and the in vivo delivery of OVA, leading to significantly increased expansion of CD4 + and CD8 + T cells in lung-draining lymph nodes. Therefore, NLPs are a promising vaccine platform for inducing T cell responses following intranasal administration.« less

  12. Memory T-cell immune response in healthy young adults vaccinated with live attenuated influenza A (H5N2) vaccine.

    PubMed

    Chirkova, T V; Naykhin, A N; Petukhova, G D; Korenkov, D A; Donina, S A; Mironov, A N; Rudenko, L G

    2011-10-01

    Cellular immune responses of both CD4 and CD8 memory/effector T cells were evaluated in healthy young adults who received two doses of live attenuated influenza A (H5N2) vaccine. The vaccine was developed by reassortment of nonpathogenic avian A/Duck/Potsdam/1402-6/68 (H5N2) and cold-adapted A/Leningrad/134/17/57 (H2N2) viruses. T-cell responses were measured by standard methods of intracellular cytokine staining of gamma interferon (IFN-γ)-producing cells and a novel T-cell recognition of antigen-presenting cells by protein capture (TRAP) assay based on the trogocytosis phenomenon, namely, plasma membrane exchange between interacting immune cells. TRAP enables the detection of activated trogocytosis-positive T cells after virus stimulation. We showed that two doses of live attenuated influenza A (H5N2) vaccine promoted both CD4 and CD8 T-memory-cell responses in peripheral blood of healthy young subjects in the clinical study. Significant differences in geometric mean titers (GMTs) of influenza A (H5N2)-specific IFN-γ(+) cells were observed at day 42 following the second vaccination, while peak levels of trogocytosis(+) T cells were detected earlier, on the 21st day after the second vaccination. The inverse correlation of baseline levels compared to postvaccine fold changes in GMTs of influenza-specific CD4 and CD8 T cells demonstrated that baseline levels of these specific cells could be considered a predictive factor of vaccine immunogenicity.

  13. Genetically-modified pig mesenchymal stromal cells: xenoantigenicity and effect on human T-cell xenoresponses.

    PubMed

    Ezzelarab, Mohamed; Ezzelarab, Corin; Wilhite, Tyler; Kumar, Goutham; Hara, Hidetaka; Ayares, David; Cooper, David K C

    2011-01-01

    Mesenchymal stromal cells (MSC) are being investigated as immunomodulatory therapy in the field of transplantation, particularly islet transplantation. While MSC can regenerate across species barriers, the immunoregulatory influence of genetically modified pig MSC (pMSC) on the human and non-human primate T-cell responses has not been studied. Mesenchymal stromal cells from wild-type (WT), α1,3-galactosyltransferase gene knockout (GTKO) and GTKO pigs transgenic for the human complement-regulatory protein CD46 (GTKO/CD46) were isolated and tested for differentiation. Antibody binding and T-cell responses to WT and GTKO pMSC in comparison with GTKO pig aortic endothelial cells (pAEC) were investigated. The expression of swine leukocyte antigen (SLA) class II (SLA II) was tested. Costimulatory molecules CD80 and CD86 mRNA levels were measured. Human T-cell proliferation and the production of pro-inflammatory cytokines in response to GTKO and GTKO/CD46 pMSC in comparison with human MSC (hMSC) were evaluated. α1,3-galactosyltransferase gene knockout and GTKO/CD46 pMSC isolation and differentiation were achieved in vitro. Binding of human antibodies and T-cell responses were lower to GTKO than those to WT pMSC. Human and baboon (naïve and sensitized) antibody binding were significantly lower to GTKO pMSC than to GTKO pAEC. Before activation, <1% of GTKO pMSC expressed SLA II, compared with 2.5% of GTKO pAEC. After pig interferon-gamma (pIFN-γ) activation, 99% of GTKO pAEC upregulated SLA II expression, compared with 49% of GTKO pMSC. Only 3% of GTKO pMSC expressed CD80 compared with 80% of GTKO pAEC without activation. After pIFN-γ activation, GTKO pAEC upregulated CD86 mRNA level stronger than GTKO pMSC. The human CD4(+) T-cell response to GTKO pMSC was significantly weaker than that to GTKO pAEC, even after pIFN-γ activation. More than 99% of GTKO/CD46 pMSC expressed hCD46. Human peripheral blood mononuclear cells and CD4(+) T-cell responses to GTKO and GTKO/CD46

  14. CD4+ T-cell engagement by both wild-type and variant HCV peptides modulates the conversion of viral clearing helper T cells to Tregs

    PubMed Central

    Cusick, Matthew F; Libbey, Jane E; Cox Gill, Joan; Fujinami, Robert S; Eckels, David D

    2013-01-01

    Aim To determine whether modulation of T-cell responses by naturally occurring viral variants caused an increase in numbers of Tregs in HCV-infected patients. Patients, materials & methods Human peripheral blood mononuclear cells, having proliferative responses to a wild-type HCV-specific CD4+ T-cell epitope, were used to quantify, via proliferative assays, flow cytometry and class II tetramers, the effects of naturally occurring viral variants arising in the immunodominant epitope. Results In combination, the wild-type and variant peptides led to enhanced suppression of an anti-HCV T-cell response. The variant had a lower avidity for the wild-type-specific CD4+ T cell. Variant-stimulated CD4+ T cells had increased Foxp3, compared with wild-type-stimulated cells. Conclusion A stable viral variant from a chronic HCV subject was able to induce Tregs in multiple individuals that responded to the wild-type HCV-specific CD4+ T-cell epitope. PMID:24421862

  15. Activated leucocyte cell adhesion molecule (ALCAM/CD166) regulates T cell responses in a murine model of food allergy.

    PubMed

    Kim, Y S; Kim, M N; Lee, K E; Hong, J Y; Oh, M S; Kim, S Y; Kim, K W; Sohn, M H

    2018-05-01

    Food allergy is a major public health problem. Studies have shown that long-term interactions between activated leucocyte cell adhesion molecule (ALCAM/CD166) on the surface of antigen-presenting cells, and CD6, a co-stimulatory molecule, influence immune responses. However, there are currently no studies on the functions of ALCAM in food allergy. Therefore, we aimed to identify the functions of ALCAM in ovalbumin (OVA)-induced food allergy using ALCAM-deficient mice. Wild-type (WT) and ALCAM-deficient (ALCAM -/- ) mice were sensitized intraperitoneally and with orally fed OVA. The mice were killed, and parameters related to food allergy and T helper type 2 (Th2) immune responses were analysed. ALCAM serum levels increased and mRNA expression decreased in OVA-challenged WT mice. Serum immunoglobulin (Ig)E levels, Th2 cytokine mRNA and histological injuries were higher in OVA-challenged WT mice than in control mice, and these were attenuated in ALCAM -/- mice. T cell proliferation of total cells, CD3 + CD4 + T cells and activated T cells in immune tissues were diminished in OVA-challenged ALCAM -/- mice. Proliferation of co-cultured T cells and dendritic cells (DCs) was decreased by the anti-CD6 antibody. In addition, WT mice sensitized by adoptive transfer of OVA-pulsed ALCAM -/- BM-derived DCs showed reduced immune responses. Lastly, serum ALCAM levels were higher in children with food allergy than in control subjects. In this study, serum levels of ALCAM were elevated in food allergy-induced WT mice and children with food allergy. Moreover, immune responses and T cell activation were attenuated in OVA-challenged ALCAM -/- mice. These results indicate that ALCAM regulates food allergy by affecting T cell activation. © 2018 British Society for Immunology.

  16. Inducible nitric oxide synthase in T cells regulates T cell death and immune memory

    PubMed Central

    Vig, Monika; Srivastava, Smita; Kandpal, Usha; Sade, Hadassah; Lewis, Virginia; Sarin, Apurva; George, Anna; Bal, Vineeta; Durdik, Jeannine M.; Rath, Satyajit

    2004-01-01

    The progeny of T lymphocytes responding to immunization mostly die rapidly, leaving a few long-lived survivors functioning as immune memory. Thus, control of this choice of death versus survival is critical for immune memory. There are indications that reactive radicals may be involved in this death pathway. We now show that, in mice lacking inducible nitric oxide synthase (iNOS), higher frequencies of both CD4 and CD8 memory T cells persist in response to immunization, even when iNOS+/+ APCs are used for immunization. Postactivation T cell death by neglect is reduced in iNOS–/– T cells, and levels of the antiapoptotic proteins Bcl-2 and Bcl-xL are increased. Inhibitors of the iNOS-peroxynitrite pathway also enhance memory responses and block postactivation death by neglect in both mouse and human T cells. However, early primary immune responses are not enhanced, which suggests that altered survival, rather than enhanced activation, is responsible for the persistent immunity observed. Thus, in primary immune responses, iNOS in activated T cells autocrinely controls their susceptibility to death by neglect to determine the level of persisting CD4 and CD8 T cell memory, and modulation of this pathway can enhance the persistence of immune memory in response to vaccination. PMID:15199408

  17. Natural Killer Dendritic Cells Enhance Immune Responses Elicited by α -Galactosylceramide-Stimulated Natural Killer T Cells.

    PubMed

    Lee, Sung Won; Park, Hyun Jung; Kim, Nayoung; Hong, Seokmann

    2013-01-01

    Natural killer dendritic cells (NKDCs) possess potent anti-tumor activity, but the cellular effect of NKDC interactions with other innate immune cells is unclear. In this study, we demonstrate that the interaction of NKDCs and natural killer T (NKT) cells is required for the anti-tumor immune responses that are elicited by α -galactosylceramide ( α -GC) in mice. The rapid and strong expression of interferon- γ by NKDCs after α -GC stimulation was dependent on NKT cells. Various NK and DC molecular markers and cytotoxic molecules were up-regulated following α -GC administration. This up-regulation could improve NKDC presentation of tumor antigens and increase cytotoxicity against tumor cells. NKDCs were required for the stimulation of DCs, NK cells, and NKT cells. The strong anti-tumor immune responses elicited by α -GC may be due to the down-regulation of regulatory T cells. Furthermore, the depletion of NKDCs dampened the tumor clearance mediated by α -GC-stimulated NKT cells in vivo. Taken together, these results indicate that complex interactions of innate immune cells might be required to achieve optimal anti-tumor immune responses during the early stages of tumorigenesis.

  18. Development of memory CD8+ T cells and their recall responses during blood-stage infection with Plasmodium berghei ANKA.

    PubMed

    Miyakoda, Mana; Kimura, Daisuke; Honma, Kiri; Kimura, Kazumi; Yuda, Masao; Yui, Katsuyuki

    2012-11-01

    Conditions required for establishing protective immune memory vary depending on the infecting microbe. Although the memory immune response against malaria infection is generally thought to be relatively slow to develop and can be lost rapidly, experimental evidence is insufficient. In this report, we investigated the generation, maintenance, and recall responses of Ag-specific memory CD8(+) T cells using Plasmodium berghei ANKA expressing OVA (PbA-OVA) as a model system. Mice were transferred with OVA-specific CD8(+) T (OT-I) cells and infected with PbA-OVA or control Listeria monocytogenes expressing OVA (LM-OVA). Central memory type OT-I cells were maintained for >2 mo postinfection and recovery from PbA-OVA. Memory OT-I cells produced IFN-γ as well as TNF-α upon activation and were protective against challenge with a tumor expressing OVA, indicating that functional memory CD8(+) T cells can be generated and maintained postinfection with P. berghei ANKA. Cotransfer of memory OT-I cells with naive OT-I cells to mice followed by infection with PbA-OVA or LM-OVA revealed that clonal expansion of memory OT-I cells was limited during PbA-OVA infection compared with expansion of naive OT-I cells, whereas it was more rapid during LM-OVA infection. The expression of inhibitory receptors programmed cell death-1 and LAG-3 was higher in memory-derived OT-I cells than naive-derived OT-I cells during infection with PbA-OVA. These results suggest that memory CD8(+) T cells can be established postinfection with P. berghei ANKA, but their recall responses during reinfection are more profoundly inhibited than responses of naive CD8(+) T cells.

  19. Trypanosoma congolense: tissue distribution of long-term T- and B-cell responses in cattle.

    PubMed

    Lutje, V; Taylor, K A; Boulangé, A; Authié, E

    1995-11-01

    Memory T- and B-cell responses to trypanosome antigens were measured in peripheral blood mononuclear cells, spleen and lymph node cells obtained from four trypanotolerant N'Dama cattle which had been exposed to six experimental infections with Trypanosoma congolense. These cattle were treated with trypanocidal drugs following each infection and had remained aparasitemic for 3 years prior to this study. The antigens used were whole trypanosome lysate, variable surface glycoprotein, a 33-kDa cysteine protease (congopain) and a 70-kDa heat-shock protein. As parameters of T-cell-mediated immunity, we measured T-cell proliferation and IFN-gamma production. Lymph node cells, spleen cells and peripheral blood mononuclear cells all proliferated to a mitogenic stimulus (concanavalin A) but only lymph node cells responded to trypanosome antigens. Similarly, IFN-gamma was produced by both lymph node and spleen cells stimulated with concanavalin A but only by lymph node cells stimulated with variable surface glycoprotein and whole trypanosome lysate. T. congolense-specific antibodies were detected in sera and in supernatants of cultured lymph node and spleen cells after in vitro stimulation with lipopolysaccharide and recombinant bovine interleukin-2. In conclusion, we have demonstrated that memory T- and B-cell responses are detectable in various lymphoid organs in cattle 3 years following infection and treatment with T. congolense.

  20. Barcoding T Cell Calcium Response Diversity with Methods for Automated and Accurate Analysis of Cell Signals (MAAACS)

    PubMed Central

    Sergé, Arnauld; Bernard, Anne-Marie; Phélipot, Marie-Claire; Bertaux, Nicolas; Fallet, Mathieu; Grenot, Pierre; Marguet, Didier; He, Hai-Tao; Hamon, Yannick

    2013-01-01

    We introduce a series of experimental procedures enabling sensitive calcium monitoring in T cell populations by confocal video-microscopy. Tracking and post-acquisition analysis was performed using Methods for Automated and Accurate Analysis of Cell Signals (MAAACS), a fully customized program that associates a high throughput tracking algorithm, an intuitive reconnection routine and a statistical platform to provide, at a glance, the calcium barcode of a population of individual T-cells. Combined with a sensitive calcium probe, this method allowed us to unravel the heterogeneity in shape and intensity of the calcium response in T cell populations and especially in naive T cells, which display intracellular calcium oscillations upon stimulation by antigen presenting cells. PMID:24086124

  1. Early Gag Immunodominance of the HIV-Specific T-Cell Response during Acute/Early Infection Is Associated with Higher CD8+ T-Cell Antiviral Activity and Correlates with Preservation of the CD4+ T-Cell Compartment

    PubMed Central

    Ghiglione, Yanina; Falivene, Juliana; Socias, María Eugenia; Laufer, Natalia; Coloccini, Romina Soledad; Rodriguez, Ana María; Ruiz, María Julia; Pando, María Ángeles; Giavedoni, Luis David; Cahn, Pedro; Sued, Omar; Salomon, Horacio; Gherardi, María Magdalena

    2013-01-01

    The important role of the CD8+ T-cell response on HIV control is well established. Moreover, the acute phase of infection represents a proper scenario to delineate the antiviral cellular functions that best correlate with control. Here, multiple functional aspects (specificity, ex vivo viral inhibitory activity [VIA] and polyfunctionality) of the HIV-specific CD8+ T-cell subset arising early after infection, and their association with disease progression markers, were examined. Blood samples from 44 subjects recruited within 6 months from infection (primary HIV infection [PHI] group), 16 chronically infected subjects, 11 elite controllers (EC), and 10 healthy donors were obtained. Results indicated that, although Nef dominated the anti-HIV response during acute/early infection, a higher proportion of early anti-Gag T cells correlated with delayed progression. Polyfunctional HIV-specific CD8+ T cells were detected at early time points but did not associate with virus control. Conversely, higher CD4+ T-cell set points were observed in PHI subjects with higher HIV-specific CD8+ T-cell VIA at baseline. Importantly, VIA levels correlated with the magnitude of the anti-Gag cellular response. The advantage of Gag-specific cells may result from their enhanced ability to mediate lysis of infected cells (evidenced by a higher capacity to degranulate and to mediate VIA) and to simultaneously produce IFN-γ. Finally, Gag immunodominance was associated with elevated plasma levels of interleukin 2 (IL-2) and macrophage inflammatory protein 1β (MIP-1β). All together, this study underscores the importance of CD8+ T-cell specificity in the improved control of disease progression, which was related to the capacity of Gag-specific cells to mediate both lytic and nonlytic antiviral mechanisms at early time points postinfection. PMID:23616666

  2. Protein kinase CK2 enables regulatory T cells to suppress excessive TH2 responses in vivo.

    PubMed

    Ulges, Alexander; Klein, Matthias; Reuter, Sebastian; Gerlitzki, Bastian; Hoffmann, Markus; Grebe, Nadine; Staudt, Valérie; Stergiou, Natascha; Bohn, Toszka; Brühl, Till-Julius; Muth, Sabine; Yurugi, Hajime; Rajalingam, Krishnaraj; Bellinghausen, Iris; Tuettenberg, Andrea; Hahn, Susanne; Reißig, Sonja; Haben, Irma; Zipp, Frauke; Waisman, Ari; Probst, Hans-Christian; Beilhack, Andreas; Buchou, Thierry; Filhol-Cochet, Odile; Boldyreff, Brigitte; Breloer, Minka; Jonuleit, Helmut; Schild, Hansjörg; Schmitt, Edgar; Bopp, Tobias

    2015-03-01

    The quality of the adaptive immune response depends on the differentiation of distinct CD4(+) helper T cell subsets, and the magnitude of an immune response is controlled by CD4(+)Foxp3(+) regulatory T cells (Treg cells). However, how a tissue- and cell type-specific suppressor program of Treg cells is mechanistically orchestrated has remained largely unexplored. Through the use of Treg cell-specific gene targeting, we found that the suppression of allergic immune responses in the lungs mediated by T helper type 2 (TH2) cells was dependent on the activity of the protein kinase CK2. Genetic ablation of the β-subunit of CK2 specifically in Treg cells resulted in the proliferation of a hitherto-unexplored ILT3(+) Treg cell subpopulation that was unable to control the maturation of IRF4(+)PD-L2(+) dendritic cells required for the development of TH2 responses in vivo.

  3. Reduced T cell response to beta-lactoglobulin by conjugation with acidic oligosaccharides.

    PubMed

    Yoshida, Tadashi; Sasahara, Yoshimasa; Miyakawa, Shunpei; Hattori, Makoto

    2005-08-24

    We have previously reported that the conjugation of beta-lactoglobulin (beta-LG) with alginic acid oligosaccharide (ALGO) and phosphoryl oligosaccharides reduced the immunogenicity of beta-LG. In addition, those conjugates showed higher thermal stability and improved emulsifying properties than those of native beta-LG. We examine in this study the effect of conjugation on the T cell response. Our results demonstrate that the T cell response was reduced when mice were immunized with the conjugates. The findings obtained from an experiment using overlapping synthetic peptides show that novel epitopes were not generated by conjugation. One of the mechanisms for the reduced T cell response to the conjugates was found to be the reduced susceptibility of the conjugates to processing enzymes for antigen presentation. We further clarify that the beta-LG-ALGO conjugate modulated the immune response to Th1 dominance. We consider that this property of the beta-LG-ALGO conjugate would be effective for preventing food allergy as well as by its reduced immunogenicity. Our observations indicate that the method used in this study could be applied to various protein allergens to achieve reduced allergenicity with multiple improvements in their properties.

  4. Comparative Analysis of the Magnitude, Quality, Phenotype and Protective Capacity of SIV Gag-Specific CD8+ T Cells Following Human-, Simian- and Chimpanzee-Derived Recombinant Adenoviral Vector Immunisation

    PubMed Central

    Quinn, Kylie M.; Costa, Andreia Da; Yamamoto, Ayako; Berry, Dana; Lindsay, Ross W.B.; Darrah, Patricia A.; Wang, Lingshu; Cheng, Cheng; Kong, Wing-Pui; Gall, Jason G.D.; Nicosia, Alfredo; Folgori, Antonella; Colloca, Stefano; Cortese, Riccardo; Gostick, Emma; Price, David A.; Gomez, Carmen E.; Esteban, Mariano; Wyatt, Linda S.; Moss, Bernard; Morgan, Cecilia; Roederer, Mario; Bailer, Robert T.; Nabel, Gary J.; Koup, Richard A.; Seder, Robert A.

    2013-01-01

    Recombinant adenoviral vectors (rAds) are the most potent recombinant vaccines for eliciting CD8+ T cell-mediated immunity in humans; however, prior exposure from natural adenoviral infection can decrease such responses. Here we show low seroreactivity in humans against simian- (sAd11, sAd16), or chimpanzee-derived (chAd3, chAd63) compared to human-derived (rAd5, rAd28, rAd35) vectors across multiple geographic regions. We then compared the magnitude, quality, phenotype and protective capacity of CD8+ T cell responses in mice vaccinated with rAds encoding SIV Gag. Using a dose range (1 × 107 to 109 PU), we defined a hierarchy among rAd vectors based on the magnitude and protective capacity of CD8+ T cell responses, from most to least as: rAd5 and chAd3, rAd28 and sAd11, chAd63, sAd16, and rAd35. Selection of rAd vector or dose could modulate the proportion and/or frequency of IFNγ+TNFα+IL-2+ and KLRG1+CD127- CD8+ T cells, but strikingly ~30–80% of memory CD8+ T cells co-expressed CD127 and KLRG1. To further optimise CD8+ T cell responses, we assessed rAds as part of prime-boost regimens. Mice primed with rAds and boosted with NYVAC generated Gag-specific responses that approached ~60% of total CD8+ T cells at peak. Alternatively, priming with DNA or rAd28 and boosting with rAd5 or chAd3 induced robust and equivalent CD8+ T cell responses compared to prime or boost alone. Collectively, these data provide the immunologic basis for using specific rAd vectors alone or as part of prime-boost regimens to induce CD8+ T cells for rapid effector function or robust long-term memory, respectively. PMID:23390298

  5. γ/δ T cell subsets in human aging using the classical α/β T cell model.

    PubMed

    Vasudev, Anusha; Ying, Crystal Tan Tze; Ayyadhury, Shamini; Puan, Kia Joo; Andiappan, Anand Kumar; Nyunt, Ma Shwe Zin; Shadan, Nurhidaya Binte; Mustafa, Seri; Low, Ivy; Rotzschke, Olaf; Fulop, Tamas; Ng, Tze Pin; Larbi, Anis

    2014-10-01

    Aging is associated with an increased susceptibility to infections and diseases. It has also been associated with reduced functionality and altered distribution of immune cells, especially T cells. Whereas classical α/β T cells, especially CD8(+) T cells, were shown to be highly susceptible to aging, the effects of viral persistent stimulations on the fate of γ/δ T cells are much less documented. Healthy, elderly individuals of Chinese ethnical background were recruited under the aegis of SLAS-II. In this observational study, γ/δ T cell populations were characterized by flow cytometry and compared with the α/β CD4(+) and CD8(+) T cells in elderly and young controls. In our study, we identified a reduced frequency of γ/δ T cells but not α/β T cells with aging. The classical markers of α/β T cell aging, including CD28, CD27, and CD57, did not prove significant for γ/δ T cells. The extreme range of expression of these markers in γ/δ T cells was responsible for the lack of relationship between γ/δ T cell subsets, CD4/CD8 ratio, and anti-CMV titers that was significant for α/β T cells and, especially, CD8(+) T cells. Although markers of aging for γ/δ T cells are not clearly identified, our data collectively suggest that the presence of CD27 γ/δ T cells is associated with markers of α/β T cell aging. © 2014 Society for Leukocyte Biology.

  6. Treatment with cyclophosphamide supported by various dendritic cell-based vaccines induces diversification in CD4+ T cell response against MC38 colon carcinoma

    PubMed Central

    WOJAS-TUREK, JUSTYNA; SZCZYGIEŁ, AGNIESZKA; KICIELIŃSKA, JAGODA; ROSSOWSKA, JOANNA; PIASECKI, EGBERT; PAJTASZ-PIASECKA, ELŻBIETA

    2016-01-01

    The present study shows that an application of cyclophosphamide (CY) supported by dendritic cell (DC)-based vaccines affected differentiation of the activity of CD4+ T cell subpopulations accompanied by an alteration in CD8+ cell number. Vaccines were composed of bone marrow-derived DCs activated with tumor cell lysate (BM-DC/TAgTNF-α) and/or genetically modified DCs of JAWS II line (JAWS II/ Neo or JAWS II/IL-2 cells). Compared to untreated or CY-treated mice, the combined treatment of MC38 colon carcinoma-bearing mice resulted in significant tumor growth inhibition associated with an increase in influx of CD4+ and CD8+ T cells into tumor tissue. Whereas, the division of these cell population in spleen was not observed. Depending on the nature of DC-based vaccines and number of their applications, both tumor infiltrating cells and spleen cells were able to produce various amount of IFN-γ, IL-4 and IL-10 after mitogenic ex vivo stimulation. The administration of CY followed by BM-DC/TAgTNF-α and genetically modified JAWS II cells, increased the percentage of CD4+T-bet+ and CD4+GATA3+ cells and decreased the percentage of CD4+RORγt+ and CD4+FoxP3+ lymphocytes. However, the most intensive response against tumor was noted after the ternary treatment with CY + BM-DC/TAgTNF-α + JAWS II/IL-2 cells. Thus, the administration of various DC-based vaccines was responsible for generation of the diversified antitumor response. These findings demonstrate that the determination of the size of particular CD4+ T cell subpopulations may become a prognostic factor and be the basis for future development of anticancer therapy. PMID:26648160

  7. Immune responses induced by T-cell vaccination in patients with rheumatoid arthritis

    PubMed Central

    Ivanova, Irina; Seledtsova, Galina; Mamaev, Sergey; Shishkov, Alexey; Seledtsov, Viktor

    2014-01-01

    Patients with rheumatoid arthritis (RA) were treated with a cellular vaccine, which consisted of autologous collagen-reactive T-cells. This study showed that antigen-specific proliferative activity of the peripheral blood mononuclear cells was significantly downregulated after T-cell vaccination in RA patients. T-cell vaccination resulted in a statistically significant decrease in plasma IFNγ levels and a concomitant increase in IL-4 levels in treated patients. Accordingly, following T-cell vaccination the number of IFNγ-producing CD4+ and CD8+ T-cells was decreased by 1.6–1.8-fold, which was paralleled by 1.7-fold increases in IL-4-producing CD4+ T-cells. In addition, the present study showed 5–7-fold increase in the CD8+CD45RO+CD62L– effector memory T-cells and central memory T-cells (both CD4+ CD45RO+CD62L+ T-cells and CD8+CD45RO+CD62L+ T-cells) in RA patients, as compared with healthy individuals. We observed significant reduction in CD4+ and CD8+ central memory T-cells, as well as reduction in CD8+ effector memory T-cells in vaccinated patients in the course of the treatment. We also demonstrated that CD4+CD25+FoxP3+ regulatory T-cell levels were significantly up-regulated in the peripheral blood of RA patients following T-cell vaccination. However, CD4+CD25-FoxP3+ Т-cell levels did not significantly change during the entire T-cell vaccination course. In conclusion, the T-cell immunotherapy regimen used resulted in the clinical improvement, which was achieved in 87% patients. PMID:24633313

  8. T-cell responses in oiled guillemots and swans in a rehabilitation setting.

    PubMed

    Troisi, Gera M

    2013-07-01

    Aquatic birds are commonly affected by oil spills. Despite rehabilitation efforts, the majority of rehabilitated common guillemots (Uria aalge) do not survive, whereas mute swans (Cygnus olor) tend to have higher postrelease survival. Polyaromatic hydrocarbons (PAHs) present in crude oil and diesel are immunotoxic in birds affecting cell-mediated responses to immunogens. Because it is a target of PAH toxicity, T-lymphocyte response to controlled mitogen administration (phytohemagglutinnin test) was investigated in a scoping study as a potentially useful minimally invasive in vivo test of cell-mediated immunity. The test was performed on 69 mute swans and 31 common guillemots stranded on the Norfolk and Lincolnshire coastline and inland waterways in England (UK) either due to injury or to contamination with crude or diesel oil. T-lymphocyte response was significantly decreased in swans with greater oil scores. T-lymphocyte responses were also decreased in guillemots, but this finding was not statistically significant.

  9. Identification of HLA-A2–restricted CD8+ Cytotoxic T Cell Responses in Primary Biliary Cirrhosis

    PubMed Central

    Kita, Hiroto; Lian, Zhe-Xiong; Van de Water, Judy; He, Xiao-Song; Matsumura, Shuji; Kaplan, Marshall; Luketic, Velimir; Coppel, Ross L.; Ansari, Aftab A.; Gershwin, M. Eric

    2002-01-01

    Primary biliary cirrhosis (PBC) is characterized by an intense biliary inflammatory CD4+ and CD8+ T cell response. Very limited information on autoantigen-specific cytotoxic T lymphocyte (CTL) responses is available compared with autoreactive CD4+ T cell responses. Using peripheral blood mononuclear cells (PBMCs) from PBC, we identified an HLA-A2–restricted CTL epitope of the E2 component of pyruvate dehydrogenase (PDC-E2), the immunodominant mitochondrial autoantigen. This peptide, amino acids 159–167 of PDC-E2, induces specific MHC class I–restricted CD8+ CTL lines from 10/12 HLA-A2+ PBC patients, but not controls, after in vitro stimulation with antigen-pulsed dendritic cells (DCs). PDC-E2–specific CTLs could also be generated by pulsing DCs with full-length recombinant PDC-E2 protein. Furthermore, using soluble PDC-E2 complexed with either PDC-E2–specific human monoclonal antibody or affinity-purified autoantibodies against PDC-E2, the generation of PDC-E2–specific CTLs, occurred at 100-fold and 10-fold less concentration, respectively, compared with soluble antigen alone. Collectively, these data demonstrate that autoantibody, helper, and CTL epitopes all contain a shared peptide sequence. The finding that autoantigen–immune complexes can not only cross-present but also that presentation of the autoantigen is of a higher relative efficiency, for the first time defines a unique role for autoantibodies in the pathogenesis of an autoimmune disease. PMID:11781370

  10. Mycophenolate mofetil prevents the delayed T cell response after pilocarpine-induced status epilepticus in mice

    PubMed Central

    Engelmann, Robby; Sellmann, Tina; Köhling, Rüdiger; Müller-Hilke, Brigitte

    2017-01-01

    Growing clinical and laboratory evidence corroborates a role for the immune system in the pathophysiology of epilepsy. In order to delineate the immune response following pilocarpine-induced status epilepticus (SE) in the mouse, we monitored the kinetics of leukocyte presence in the hippocampus over the period of four weeks. SE was induced following a ramping protocol of pilocarpine injection into 4–5 weeks old C57BL/6 mice. Brains were removed at days 1–4, 14 or 28 after SE, and the hippocampi were analyzed via flow cytometry, via quantitative reverse transcriptase PCR (qRT-PCR) and via immunohistochemistry. Epileptogenesis was confirmed by Timm staining of mossy fiber sprouting in the inner molecular layer of the dentate gyrus. The flow cytometry data revealed a biphasic immune response following pilocarpine-induced SE with a transient increase in activated CD11b+ and F4/80+ macrophages within the first four days replaced by an increase in CD3+ T-lymphocytes around day 28. This delayed T cell response was confirmed via qRT-PCR and via immunohistochemistry. In addition, qRT-PCR data could show that the delayed T cell response was associated with an increased CD8/CD4 ratio indicating a cytotoxic T cell response after SE. Intriguingly, early intervention with mycophenolate mofetil administration on days 0–3 after SE prevented this delayed T cell response. These results show an orchestrated immunological sequela and provide evidence that the delayed T cell response is sensitive to early immunomodulatory intervention. PMID:29182639

  11. Influenza-specific T cells from older people are enriched in the late effector subset and their presence inversely correlates with vaccine response.

    PubMed

    Wagar, Lisa E; Gentleman, Beth; Pircher, Hanspeter; McElhaney, Janet E; Watts, Tania H

    2011-01-01

    T cells specific for persistent pathogens accumulate with age and express markers of immune senescence. In contrast, much less is known about the state of T cell memory for acutely infecting pathogens. Here we examined T cell responses to influenza in human peripheral blood mononuclear cells from older (>64) and younger (<40) donors using whole virus restimulation with influenza A (A/PR8/34) ex vivo. Although most donors had pre-existing influenza reactive T cells as measured by IFNγ production, older donors had smaller populations of influenza-responsive T cells than young controls and had lost a significant proportion of their CD45RA-negative functional memory population. Despite this apparent dysfunction in a proportion of the older T cells, both old and young donors' T cells from 2008 could respond to A/California/07/2009 ex vivo. For HLA-A2+ donors, MHC tetramer staining showed that a higher proportion of influenza-specific memory CD8 T cells from the 65+ group co-express the markers killer cell lectin-like receptor G1 (KLRG1) and CD57 compared to their younger counterparts. These markers have previously been associated with a late differentiation state or immune senescence. Thus, memory CD8 T cells to an acutely infecting pathogen show signs of advanced differentiation and functional deterioration with age. There was a significant negative correlation between the frequency of KLRG1(+)CD57(+) influenza M1-specific CD8 T cells pre-vaccination and the ability to make antibodies in response to vaccination with seasonal trivalent inactivated vaccine, whereas no such trend was observed when the total CD8(+)KLRG1(+)CD57(+) population was analyzed. These results suggest that the state of the influenza-specific memory CD8 T cells may be a predictive indicator of a vaccine responsive healthy immune system in old age.

  12. OX62+OX6+OX35+ rat dendritic cells are unable to prime CD4+ T cells for an effective immune response following acute burn injury.

    PubMed

    Fazal, Nadeem

    2013-01-01

    Co-stimulatory molecules expressed on Dendritic Cells (DCs) function to coordinate an efficient immune response by T cells in the peripheral lymph nodes. We hypothesized that CD4+ T cell-mediated immune suppression following burn injury may be related to dysfunctional DCs residing in gut associated lymphoid tissues (GALT), such as Mesenteric Lymph Nodes (MLN). Therefore, we studied co-stimulatory molecules expressed on burn rat MLN DCs as an index of functional DCs that would mount an effective normal CD4+ T cell immune response. In a rat model of 30% Total Body Surface Area (TBSA) scald burn, OX62+OX6+OX35+ DCs and CD4+ T cells were isolated from MLN of day 3 post-burn and sham control rats. DCs were tested for their expression of co-stimulatory molecules, and prime CD4+ T cell (DC:CD4+T cell co-culture assays) to determine an effector immune response such as CD4+ T cell proliferation. The surface receptor expressions of MLN DCs co-stimulatory molecules, i.e., MHC-II, CD40, CD80 (B7-1), and CD86 (B7-2) were determined by Flow cytometry (quantitatively) and confocal microscopy (qualitatively). Tritiated thymidine and CFDA-SE determined CD4+ T cell proliferation following co-incubation with DCs. Cytokine milieu of MLN (IL-12 and IL-10) was assessed by mRNA determination by RT-PCR. The results showed down-regulated expressions of co-stimulatory markers (CD80, CD86, CD40 and MHC-II) of MLN DCs obtained from burn-injured rats, as well as lack of ability of these burn-induced DCs to stimulate CD4+ T cell proliferation in co-culture assays, as compared to the sham rats. Moreover, anti-CD40 stimulation of affected burn MLN DCs did not reverse this alteration. Furthermore, a marked up-regulation of mRNA IL-10 and down-regulation of mRNA IL-12 in burn MLN as compared to sham animals was also observed. To surmise, the data indicated that dysfunctional OX62+OX6+OX35+ rat MLN DCs may contribute to CD4+ T-cell-mediated immune suppression observed following acute burn injury.

  13. OX62+OX6+OX35+ rat dendritic cells are unable to prime CD4+ T cells for an effective immune response following acute burn injury☆

    PubMed Central

    Fazal, Nadeem

    2013-01-01

    Co-stimulatory molecules expressed on Dendritic Cells (DCs) function to coordinate an efficient immune response by T cells in the peripheral lymph nodes. We hypothesized that CD4+ T cell-mediated immune suppression following burn injury may be related to dysfunctional DCs residing in gut associated lymphoid tissues (GALT), such as Mesenteric Lymph Nodes (MLN). Therefore, we studied co-stimulatory molecules expressed on burn rat MLN DCs as an index of functional DCs that would mount an effective normal CD4+ T cell immune response. In a rat model of 30% Total Body Surface Area (TBSA) scald burn, OX62+OX6+OX35+ DCs and CD4+ T cells were isolated from MLN of day 3 post-burn and sham control rats. DCs were tested for their expression of co-stimulatory molecules, and prime CD4+ T cell (DC:CD4+T cell co-culture assays) to determine an effector immune response such as CD4+ T cell proliferation. The surface receptor expressions of MLN DCs co-stimulatory molecules, i.e., MHC-II, CD40, CD80 (B7-1), and CD86 (B7-2) were determined by Flow cytometry (quantitatively) and confocal microscopy (qualitatively). Tritiated thymidine and CFDA-SE determined CD4+ T cell proliferation following co-incubation with DCs. Cytokine milieu of MLN (IL-12 and IL-10) was assessed by mRNA determination by RT-PCR. The results showed down-regulated expressions of co-stimulatory markers (CD80, CD86, CD40 and MHC-II) of MLN DCs obtained from burn-injured rats, as well as lack of ability of these burn-induced DCs to stimulate CD4+ T cell proliferation in co-culture assays, as compared to the sham rats. Moreover, anti-CD40 stimulation of affected burn MLN DCs did not reverse this alteration. Furthermore, a marked up-regulation of mRNA IL-10 and down-regulation of mRNA IL-12 in burn MLN as compared to sham animals was also observed. To surmise, the data indicated that dysfunctional OX62+OX6+OX35+ rat MLN DCs may contribute to CD4+ T-cell-mediated immune suppression observed following acute burn injury

  14. Similar Responses of Intestinal T Cells From Untreated Children and Adults With Celiac Disease to Deamidated Gluten Epitopes.

    PubMed

    Ráki, Melinda; Dahal-Koirala, Shiva; Yu, Hao; Korponay-Szabó, Ilma R; Gyimesi, Judit; Castillejo, Gemma; Jahnsen, Jørgen; Qiao, Shuo-Wang; Sollid, Ludvig M

    2017-09-01

    Celiac disease is a chronic small intestinal inflammatory disorder mediated by an immune response to gluten peptides in genetically susceptible individuals. Celiac disease is often diagnosed in early childhood, but some patients receive a diagnosis late in life. It is uncertain whether pediatric celiac disease is distinct from adult celiac disease. It has been proposed that gluten-reactive T cells in children recognize deamidated and native gluten epitopes, whereas T cells from adults only recognize deamidated gluten peptides. We studied the repertoire of gluten epitopes recognized by T cells from children and adults. We examined T-cell responses against gluten by generating T-cell lines and T-cell clones from intestinal biopsies of adults and children and tested proliferative response to various gluten peptides. We analyzed T cells from 14 children (2-5 years old) at high risk for celiac disease who were followed for celiac disease development. We also analyzed T cells from 6 adults (26-55 years old) with untreated celiac disease. All children and adults were positive for HLA-DQ2.5. Biopsies were incubated with gluten digested with chymotrypsin (modified or unmodified by the enzyme transglutaminase 2) or the peptic-tryptic digest of gliadin (in native and deamidated forms) before T-cell collection. Levels of T-cell responses were higher to deamidated gluten than to native gluten in children and adults. T cells from children and adults each reacted to multiple gluten epitopes. Several T-cell clones were cross-reactive, especially clones that recognized epitopes from γ-and ω-gliadin. About half of the generated T-cell clones from children and adults reacted to unknown epitopes. T-cell responses to different gluten peptides appear to be similar between adults and children at the time of diagnosis of celiac disease. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

  15. Initial viral load determines the magnitude of the human CD8 T cell response to yellow fever vaccination.

    PubMed

    Akondy, Rama S; Johnson, Philip L F; Nakaya, Helder I; Edupuganti, Srilatha; Mulligan, Mark J; Lawson, Benton; Miller, Joseph D; Pulendran, Bali; Antia, Rustom; Ahmed, Rafi

    2015-03-10

    CD8 T cells are a potent tool for eliminating intracellular pathogens and tumor cells. Thus, eliciting robust CD8 T-cell immunity is the basis for many vaccines under development. However, the relationship between antigen load and the magnitude of the CD8 T-cell response is not well-described in a human immune response. Here we address this issue by quantifying viral load and the CD8 T-cell response in a cohort of 80 individuals immunized with the live attenuated yellow fever vaccine (YFV-17D) by sampling peripheral blood at days 0, 1, 2, 3, 5, 7, 9, 11, 14, 30, and 90. When the virus load was below a threshold (peak virus load < 225 genomes per mL, or integrated virus load < 400 genome days per mL), the magnitude of the CD8 T-cell response correlated strongly with the virus load (R(2) ∼ 0.63). As the virus load increased above this threshold, the magnitude of the CD8 T-cell responses saturated. Recent advances in CD8 T-cell-based vaccines have focused on replication-incompetent or single-cycle vectors. However, these approaches deliver relatively limited amounts of antigen after immunization. Our results highlight the requirement that T-cell-based vaccines should deliver sufficient antigen during the initial period of the immune response to elicit a large number of CD8 T cells that may be needed for protection.

  16. T cell resistance to activation by dendritic cells requires long-term culture in simulated microgravity.

    PubMed

    Bradley, Jillian H; Stein, Rachel; Randolph, Brad; Molina, Emily; Arnold, Jennifer P; Gregg, Randal K

    2017-11-01

    Immune impairment mediated by microgravity threatens the success of space exploration requiring long-duration spaceflight. The cells of most concern, T lymphocytes, coordinate the host response against microbial and cancerous challenges leading to elimination and long-term protection. T cells are activated upon recognition of specific microbial peptides bound on the surface of antigen presenting cells, such as dendritic cells (DC). Subsequently, this engagement results in T cell proliferation and differentiation into effector T cells driven by autocrine interleukin-2 (IL-2) and other cytokines. Finally, the effector T cells acquire the weaponry needed to destroy microbial invaders and tumors. Studies conducted on T cells during spaceflight, or using Earth-based culture systems, have shown reduced production of cytokines, proliferation and effector functions as compared to controls. This may account for the cases of viral reactivation events and opportunistic infections associated with astronauts of numerous missions. This work has largely been based upon the outcome of T cell activation by stimulatory factors that target select T cell signaling pathways rather than the complex, signaling events related to the natural process of antigen presentation by DC. This study tested the response of an ovalbumin peptide-specific T cell line, OT-II TCH, to activation by DC when the T cells were cultured 24-120 h in a simulated microgravity (SMG) environment generated by a rotary cell culture system. Following 72 h culture of T cells in SMG (SMG-T) or control static (Static-T) conditions, IL-2 production by the T cells was reduced in SMG-T cells compared to Static-T cells upon stimulation by phorbol 12-myristate 13-acetate (PMA) and ionomycin. However, when the SMG-T cells were stimulated with DC and peptide, IL-2 was significantly increased compared to Static-T cells. Such enhanced IL-2 production by SMG-T cells peaked at 72 h SMG culture time and decreased thereafter

  17. Targeting Inflammatory T Helper Cells via Retinoic Acid-Related Orphan Receptor Gamma t Is Ineffective to Prevent Allo-Response-Driven Colitis.

    PubMed

    Buchele, Vera; Abendroth, Benjamin; Büttner-Herold, Maike; Vogler, Tina; Rothamer, Johanna; Ghimire, Sakhila; Ullrich, Evelyn; Holler, Ernst; Neurath, Markus F; Hildner, Kai

    2018-01-01

    Intestinal graft-versus-host disease (GvHD) is a life-threatening, inflammatory donor T cell-mediated complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT). In the light of the reported efficacy of interleukin-23 (IL-23)-blockade to mitigate syngeneic intestinal inflammation in inflammatory bowel disease patients, targeting IL-23 and thereby interleukin-17a (IL-17a) producing T helper (Th17) cells as the T cell subset assumed to be mostly regulated by IL-23, has emerged as a putatively general concept to harness immune-mediated mucosal inflammation irrespective of the underlying trigger. However, the role of Th17 cells during allo-response driven colitis remains ambiguous due to a series of studies with inconclusive results. Interestingly, we recently identified granulocyte-macrophage colony-stimulating factor (GM-CSF + ) T cells to be promoted by interleukin-7 (IL-7) signaling and controlled by the activating protein-1 transcription factor family member basic leucine zipper transcription factor ATF-like (BATF) as critical mediators of intestinal GvHD in mice. Given the dual role of BATF, the contribution of IL-23-mediated signaling within donor T cells and bona fide Th17 cells remains to be delineated from the regulation of GM-CSF + T cells in the absence of BATF. Here, we found in a complete MHC class I-mismatched model that genetic inactivation of the IL-23 receptor (IL-23R) or the transcription factor retinoic acid-related orphan receptor gamma t (RORγt) within donor T cells similarly ablated Th17 cell formation in vivo but preserved the T cells' ability to induce intestinal GvHD in a compared to wild-type controls indistinguishable manner. Importantly, RORγt-independent manifestation of intestinal GvHD was completely dependent on BATF-regulated GM-CSF + T cells as BATF/RORγt double-deficient T cells failed to induce colitis and the antibody-mediated blockage of IL-7/IL-7R interaction and GM-CSF significantly diminished signs

  18. Filarial infection modulates the immune response to Mycobacterium tuberculosis through expansion of CD4+ IL-4 memory T cells

    PubMed Central

    Chatterjee, Soumya; Clark, Carolyn E.; Lugli, Enrico; Roederer, Mario; Nutman, Thomas B.

    2015-01-01

    Exaggerated CD4+T helper 2-specific cytokine producing memory T cell responses developing concomitantly with a T helper1 response might have a detrimental role in immunity to infection caused by Mycobacterium tuberculosis (Mtb). To assess the dynamics of antigen (Ag)-specific memory T cell compartments in the context of filarial infection we used multiparameter flow cytometry on PBMCs from 25 microfilaremic filarial -infected (Inf) and 14 filarial-uninfected (Uninf) subjects following stimulation with filarial (BmA) or with the Mycobacterium tuberculosis (Mtb)-specific Ag CFP10. Our data demonstrated that the Inf group not only had a marked increase in BmA-specific CD4+IL-4+ cells (Median net frequency compared to baseline (Fo)=0.09% vs. 0.01%, p=0.038) but also to CFP10 (Fo =0.16% vs. 0.007%, p=0.04) and Staphylococcal Enterotoxin B (SEB) (Fo =0.49% vs. 0.26%, p=0.04). The Inf subjects showed a BmA-specific expansion of CD4+CD45RO+IL-4+ producing central memory (TCM, CD45RO+CCR7+CD27+) (Fo =1.1% vs. 0.5%, p=0.04) as well as effector memory (TEM CD45RO+CCR7-CD27-) (Fo =1.5% vs. 0.2%, p=0.03) with a similar but non-significant response to CFP10. In addition, there was expansion of CD4+ IL-4+ CD45RA+ CCR7+CD27+ (naïve-like) in Inf individuals compared to Uninf subjects. Among Inf subjects with definitive latent tuberculosis , there were no differences in frequencies of IL-4 producing cells within any of the memory compartments compared to the Uninf group. Our data suggest that filarial infection induces antigen-specific, exaggerated IL-4 responses in distinct T cell memory compartments to Mtb-specific antigens, which are attenuated in subjects who are able to mount a delayed type hypersensitivity reaction to Mtb. PMID:25667413

  19. CD4+ T cells defined by their Vβ T cell receptor expression are associated with immunoregulatory profiles and lesion size in human leishmaniasis

    PubMed Central

    Keesen, T S L; Antonelli, L R V; Faria, D R; Guimarães, L H; Bacellar, O; Carvalho, E M; Dutra, W O; Gollob, K J

    2011-01-01

    Leishmaniasis is caused by infection with the protozoan parasite, Leishmania, that parasitizes human cells, and the cellular immune response is essential for controlling infection. In order to measure the host T cell response to Leishmania infection, we have measured the expansion, activation state and functional potential of specific T cells as identified by their T cell receptor Vβ region expression. In a group of cutaneous leishmaniasis (CL) patients, we evaluated these characteristics in nine different T cell subpopulations as identified by their Vβ region expression, before and after specific Leishmania antigen stimulation. Our results show: (1) an increase in CD4+ T cells expressing Vβ 5·2 and Vβ 24 in CL compared to controls; (2) a Leishmania antigen-induced increase in CD4+ T cells expressing Vβ 5·2, 11, 12 and 17; (3) a profile of previous activation of CD4+ Vβ 5·2-, 11- and 24-positive T cells, with higher expression of CD45RO, HLA-DR, interferon-γ, tumour necrosis factor-α and interleukin-10 compared to other Vβ-expressing subpopulations; (4) a positive correlation between higher frequencies of CD4+Vβ5·2+ T cells and larger lesions; and (5) biased homing of CD4+ T cells expressing Vβ 5·2 to the lesion site. Given that CL disease involves a level of pathology (ulcerated lesions) and is often followed by long-lived protection and cure, the identification of specific subpopulations active in this form of disease could allow for the discovery of immunodominant Leishmania antigens important for triggering efficient host responses against the parasite, or identify cell populations most involved in pathology. PMID:21726211

  20. Single-cell quantification of IL-2 response by effector and regulatory T cells reveals critical plasticity in immune response

    PubMed Central

    Feinerman, Ofer; Jentsch, Garrit; Tkach, Karen E; Coward, Jesse W; Hathorn, Matthew M; Sneddon, Michael W; Emonet, Thierry; Smith, Kendall A; Altan-Bonnet, Grégoire

    2010-01-01

    Understanding how the immune system decides between tolerance and activation by antigens requires addressing cytokine regulation as a highly dynamic process. We quantified the dynamics of interleukin-2 (IL-2) signaling in a population of T cells during an immune response by combining in silico modeling and single-cell measurements in vitro. We demonstrate that IL-2 receptor expression levels vary widely among T cells creating a large variability in the ability of the individual cells to consume, produce and participate in IL-2 signaling within the population. Our model reveals that at the population level, these heterogeneous cells are engaged in a tug-of-war for IL-2 between regulatory (Treg) and effector (Teff) T cells, whereby access to IL-2 can either increase the survival of Teff cells or the suppressive capacity of Treg cells. This tug-of-war is the mechanism enforcing, at the systems level, a core function of Treg cells, namely the specific suppression of survival signals for weakly activated Teff cells but not for strongly activated cells. Our integrated model yields quantitative, experimentally validated predictions for the manipulation of Treg suppression. PMID:21119631

  1. NKp46+ Innate Lymphoid Cells Dampen Vaginal CD8 T Cell Responses following Local Immunization with a Cholera Toxin-Based Vaccine

    PubMed Central

    Luci, Carmelo; Bekri, Selma; Bihl, Franck; Pini, Jonathan; Bourdely, Pierre; Nouhen, Kelly; Malgogne, Angélique; Walzer, Thierry; Braud, Véronique M.; Anjuère, Fabienne

    2015-01-01

    Innate and adaptive immune cells work in concert to generate efficient protection at mucosal surface. Vaginal mucosa is an epithelial tissue that contains innate and adaptive immune effector cells. Our previous studies demonstrated that vaginal administration of Cholera toxin -based vaccines generate antigen-specific CD8 T cells through the stimulation of local dendritic cells (DC). Innate lymphoid cells (ILC) are a group of lymphocytes localized in epithelial tissues that have important immune functions against pathogens and in tissue homeostasis. Their contribution to vaccine-induced mucosal T cell responses is an important issue for the design of protective vaccines. We report here that the vaginal mucosa contains a heterogeneous population of NKp46+ ILC that includes conventional NK cells and ILC1-like cells. We show that vaginal NKp46+ ILC dampen vaccine-induced CD8 T cell responses generated after local immunization. Indeed, in vivo depletion of NKp46+ ILC with anti-NK1.1 antibody or NKG2D blockade increases the magnitude of vaginal OVA-specific CD8 T cells. Furthermore, such treatments also increase the number of DC in the vagina. NKG2D ligands being expressed by vaginal DC but not by CD8 T cells, these results support that NKp46+ ILC limit mucosal CD8 T cell responses indirectly through the NKG2D-dependent elimination of vaginal DC. Our data reveal an unappreciated role of NKp46+ ILC in the regulation of mucosal CD8 T cell responses. PMID:26630176

  2. Specific CD8+ T Cell Responses Correlate with Control of Simian Immunodeficiency Virus Replication in Mauritian Cynomolgus Macaques

    PubMed Central

    Budde, Melisa L.; Greene, Justin M.; Chin, Emily N.; Ericsen, Adam J.; Scarlotta, Matthew; Cain, Brian T.; Pham, Ngoc H.; Becker, Ericka A.; Harris, Max; Weinfurter, Jason T.; O'Connor, Shelby L.; Piatak, Michael; Lifson, Jeffrey D.; Gostick, Emma; Price, David A.; Friedrich, Thomas C.

    2012-01-01

    Specific major histocompatibility complex (MHC) class I alleles are associated with an increased frequency of spontaneous control of human and simian immunodeficiency viruses (HIV and SIV). The mechanism of control is thought to involve MHC class I-restricted CD8+ T cells, but it is not clear whether particular CD8+ T cell responses or a broad repertoire of epitope-specific CD8+ T cell populations (termed T cell breadth) are principally responsible for mediating immunologic control. To test the hypothesis that heterozygous macaques control SIV replication as a function of superior T cell breadth, we infected MHC-homozygous and MHC-heterozygous cynomolgus macaques with the pathogenic virus SIVmac239. As measured by a gamma interferon enzyme-linked immunosorbent spot assay (IFN-γ ELISPOT) using blood, T cell breadth did not differ significantly between homozygotes and heterozygotes. Surprisingly, macaques that controlled SIV replication, regardless of their MHC zygosity, shared durable T cell responses against similar regions of Nef. While the limited genetic variability in these animals prevents us from making generalizations about the importance of Nef-specific T cell responses in controlling HIV, these results suggest that the T cell-mediated control of virus replication that we observed is more likely the consequence of targeting specificity rather than T cell breadth. PMID:22573864

  3. Long noncoding RNA derived from CD244 signaling epigenetically controls CD8+ T-cell immune responses in tuberculosis infection

    PubMed Central

    Wang, Yang; Zhong, Huiling; Xie, Xiaodan; Chen, Crystal Y.; Huang, Dan; Shen, Ling; Zhang, Hui; Chen, Zheng W.; Zeng, Gucheng

    2015-01-01

    Molecular mechanisms for T-cell immune responses modulated by T cell-inhibitory molecules during tuberculosis (TB) infection remain unclear. Here, we show that active human TB infection up-regulates CD244 and CD244 signaling-associated molecules in CD8+ T cells and that blockade of CD244 signaling enhances production of IFN-γ and TNF-α. CD244 expression/signaling in TB correlates with high levels of a long noncoding RNA (lncRNA)-BC050410 [named as lncRNA-AS-GSTT1(1-72) or lncRNA-CD244] in the CD244+CD8+ T-cell subpopulation. CD244 signaling drives lncRNA-CD244 expression via sustaining a permissive chromatin state in the lncRNA-CD244 locus. By recruiting polycomb protein enhancer of zeste homolog 2 (EZH2) to infg/tnfa promoters, lncRNA-CD244 mediates H3K27 trimethylation at infg/tnfa loci toward repressive chromatin states and inhibits IFN-γ/TNF-α expression in CD8+ T cells. Such inhibition can be reversed by knock down of lncRNA-CD244. Interestingly, adoptive transfer of lncRNA-CD244–depressed CD8+ T cells to Mycobacterium tuberculosis (MTB)-infected mice reduced MTB infection and TB pathology compared with lncRNA-CD244–expressed controls. Thus, this work uncovers previously unidentified mechanisms in which T cell-inhibitory signaling and lncRNAs regulate T-cell responses and host defense against TB infection. PMID:26150504

  4. Physiological numbers of CD4+ T cells generate weak recall responses following influenza virus challenge.

    PubMed

    Thomas, Paul G; Brown, Scott A; Morris, Melissa Y; Yue, Wen; So, Jenny; Reynolds, Cory; Webby, Richard J; Doherty, Peter C

    2010-02-15

    Naive and recall CD4(+) T cell responses were probed with recombinant influenza A viruses incorporating the OVA OT-II peptide. The extent of OT-II-specific CD4(+) T cell expansion was greater following primary exposure, with secondary challenge achieving no significant increase in numbers, despite higher precursor frequencies. Adoptive transfer experiments with OT-II TCR-transgenic T cells established that the predominant memory set is CD62L(hi), whereas the CD62L(lo) precursors make little contribution to the recall response. Unlike the situation described by other investigators, in which the transfer of very large numbers of in vitro-activated CD4 effectors can modify the disease process, providing CD62L(hi) or CD62L(lo) OT-II-specific T cells at physiological levels neither enhanced virus clearance nor altered clinical progression. Some confounding effects of the transgenic model were observed, with decreasing primary expansion efficiency correlating with greater numbers of transferred cells. This was associated with increased levels of mRNA for the proapoptotic molecule Bim in cells recovered following high-dose transfer. However, even with very low numbers of transferred cells, memory T cells did not expand significantly following secondary challenge. A similar result was recorded in mice primed and boosted to respond to an endogenous IA(b)-restricted epitope derived from the influenza virus hemagglutinin glycoprotein. Depletion of CD8(+) T cells during secondary challenge generated an increased accumulation of OT-II-specific T cells but only at the site of infection. Taken together, significant expansion was not a feature of these secondary influenza-specific CD4 T cell responses and the recall of memory did not enhance recovery.

  5. The function of the chemokine receptor CXCR6 in the T cell response of mice against Listeria monocytogenes.

    PubMed

    Heesch, Kira; Raczkowski, Friederike; Schumacher, Valéa; Hünemörder, Stefanie; Panzer, Ulf; Mittrücker, Hans-Willi

    2014-01-01

    The chemokine receptor CXCR6 is expressed on different T cell subsets and up-regulated following T cell activation. CXCR6 has been implicated in the localization of cells to the liver due to the constitutive expression of its ligand CXCL16 on liver sinusoidal endothelial cells. Here, we analyzed the role of CXCR6 in CD8+ T cell responses to infection of mice with Listeria monocytogenes. CD8+ T cells responding to listerial antigens acquired high expression levels of CXCR6. However, deficiency of mice in CXCR6 did not impair control of the L. monocytogenes infection. CXCR6-deficient mice were able to generate listeria-specific CD4+ and CD8+ T cell responses and showed accumulation of T cells in the infected liver. In transfer assays, we detected reduced accumulation of listeria-specific CXCR6-deficient CD8+ T cells in the liver at early time points post infection. Though, CXCR6 was dispensable at later time points of the CD8+ T cell response. When transferred CD8+ T cells were followed for extended time periods, we observed a decline in CXCR6-deficient CD8+ T cells. The manifestation of this cell loss depended on the tissue analyzed. In conclusion, our results demonstrate that CXCR6 is not required for the formation of a T cell response to L. monocytogenes and for the accumulation of T cells in the infected liver but CXCR6 appears to influence long-term survival and tissue distribution of activated cells.

  6. The Function of the Chemokine Receptor CXCR6 in the T Cell Response of Mice against Listeria monocytogenes

    PubMed Central

    Heesch, Kira; Raczkowski, Friederike; Schumacher, Valéa; Hünemörder, Stefanie; Panzer, Ulf; Mittrücker, Hans-Willi

    2014-01-01

    The chemokine receptor CXCR6 is expressed on different T cell subsets and up-regulated following T cell activation. CXCR6 has been implicated in the localization of cells to the liver due to the constitutive expression of its ligand CXCL16 on liver sinusoidal endothelial cells. Here, we analyzed the role of CXCR6 in CD8+ T cell responses to infection of mice with Listeria monocytogenes. CD8+ T cells responding to listerial antigens acquired high expression levels of CXCR6. However, deficiency of mice in CXCR6 did not impair control of the L. monocytogenes infection. CXCR6-deficient mice were able to generate listeria-specific CD4+ and CD8+ T cell responses and showed accumulation of T cells in the infected liver. In transfer assays, we detected reduced accumulation of listeria-specific CXCR6-deficient CD8+ T cells in the liver at early time points post infection. Though, CXCR6 was dispensable at later time points of the CD8+ T cell response. When transferred CD8+ T cells were followed for extended time periods, we observed a decline in CXCR6-deficient CD8+ T cells. The manifestation of this cell loss depended on the tissue analyzed. In conclusion, our results demonstrate that CXCR6 is not required for the formation of a T cell response to L. monocytogenes and for the accumulation of T cells in the infected liver but CXCR6 appears to influence long-term survival and tissue distribution of activated cells. PMID:24832098

  7. Comparative proteomics of exosomes secreted by tumoral Jurkat T cells and normal human T cell blasts unravels a potential tumorigenic role for valosin-containing protein.

    PubMed

    Bosque, Alberto; Dietz, Lisa; Gallego-Lleyda, Ana; Sanclemente, Manuel; Iturralde, María; Naval, Javier; Alava, María Angeles; Martínez-Lostao, Luis; Thierse, Hermann-Josef; Anel, Alberto

    2016-05-17

    We have previously characterized that FasL and Apo2L/TRAIL are stored in their bioactive form inside human T cell blasts in intraluminal vesicles present in multivesicular bodies. These vesicles are rapidly released to the supernatant in the form of exosomes upon re-activation of T cells. In this study we have compared for the first time proteomics of exosomes produced by normal human T cell blasts with those produced by tumoral Jurkat cells, with the objective of identify proteins associated with tumoral exosomes that could have a previously unrecognized role in malignancy. We have identified 359 and 418 proteins in exosomes from T cell blasts and Jurkat cells, respectively. Interestingly, only 145 (around a 40%) are common. The major proteins in both cases are actin and tubulin isoforms and the common interaction nodes correspond to these cytoskeleton and related proteins, as well as to ribosomal and mRNA granule proteins. We detected 14 membrane proteins that were especially enriched in exosomes from Jurkat cells as compared with T cell blasts. The most abundant of these proteins was valosin-containing protein (VCP), a membrane ATPase involved in ER homeostasis and ubiquitination. In this work, we also show that leukemic cells are more sensitive to cell death induced by the VCP inhibitor DBeQ than normal T cells. Furthermore, VCP inhibition prevents functional exosome secretion only in Jurkat cells, but not in T cell blasts. These results suggest VCP targeting as a new selective pathway to exploit in cancer treatment to prevent tumoral exosome secretion.

  8. Trichomonas vaginalis α-Actinin 2 Modulates Host Immune Responses by Inducing Tolerogenic Dendritic Cells via IL-10 Production from Regulatory T Cells.

    PubMed

    Lee, Hye-Yeon; Kim, Juri; Ryu, Jae-Sook; Park, Soon-Jung

    2017-08-01

    Trichomonas vaginalis is a pathogen that triggers severe immune responses in hosts. T. vaginalis α-actinin 2, Tvα-actinin 2, has been used to diagnose trichomoniasis. This study was undertaken to examine the role of Tvα-actinin 2 as an antigenic molecule to induce immune responses from humans. Western blot analysis using anti-Tvα-actinin 2 antibodies indicated its presence in the secreted proteins of T. vaginalis. ELISA was employed to measure cytokine production by vaginal epithelial cells, prostate cells, mouse dendritic cells (DCs), or T cells stimulated with T. vaginalis or Tvα-actinin 2 protein. Both T. vaginalis and rTvα-actinin 2 induced cytokine production from epithelial cell lines, including IL-10. Moreover, CD4+CD25- regulatory T cells (Treg cells) incubated with rTvα-actinin 2-treated DCs produced high levels of IL-10. These data indicate that Tvα-actinin 2 modulates immune responses via IL-10 production by Treg cells.

  9. The type of adjuvant strongly influences the T-cell response during nanoparticle-based immunization

    PubMed Central

    Knuschke, Torben; Epple, Matthias; Westendorf, Astrid M

    2014-01-01

    Potent vaccines require the ability to effectively induce immune responses. Especially for the control of infectious diseases with intracellular pathogens, like viruses or bacteria, potent T-cell responses are indispensable. Several delivery systems such as nanoparticles have been considered to boost the immunogenicity of pathogen derived peptides or subunits for the induction of potent T-cell responses. Since they can be further functionalized with immunostimulants, like Toll-like receptor (TLR) agonists, they improve the response by enhanced activation of the innate immune system. Currently, TLR agonists like unmethylated CpG oligonucleotides and the synthetic dsRNA derivate polyriboinosinic acid-polyribocytidylic acid (poly[I:C]) are widely used as vaccine adjuvants. CpG and poly(I:C) trigger different TLRs and therefore show differential signal transduction. Recently, we established biodegradable calcium phosphate (CaP) nanoparticles as potent T cell inducing vaccination vehicles. In this commentary we discuss the role of CpG and poly(I:C) for the effective induction of virus-specific T cells during immunization with CaP nanoparticles. The presented results underline the importance of the right formulation of vaccines for specific immunization purpose. PMID:23982325

  10. Polyfunctional response by ImmTAC (IMCgp100) redirected CD8+ and CD4+ T cells.

    PubMed

    Boudousquie, Caroline; Bossi, Giovanna; Hurst, Jacob M; Rygiel, Karolina A; Jakobsen, Bent K; Hassan, Namir J

    2017-11-01

    The success of immune system-based cancer therapies depends on a broad immune response engaging a range of effector cells and mechanisms. Immune mobilizing monoclonal T cell receptors (TCRs) against cancer (ImmTAC™ molecules: fusion proteins consisting of a soluble, affinity enhanced TCR and an anti-CD3 scFv antibody) were previously shown to redirect CD8 + and CD4 + T cells against tumours. Here we present evidence that IMCgp100 (ImmTAC recognizing a peptide derived from the melanoma-specific protein, gp100, presented by HLA-A*0201) efficiently redirects and activates effector and memory cells from both CD8 + and CD4 + repertoires. Using isolated subpopulations of T cells, we find that both terminally differentiated and effector memory CD8 + T cells redirected by IMCgp100 are potent killers of melanoma cells. Furthermore, CD4 + effector memory T cells elicit potent cytotoxic activity leading to melanoma cell killing upon redirection by IMCgp100. The majority of T cell subsets belonging to both the CD8 + and CD4 + repertoires secrete key pro-inflammatory cytokines (tumour necrosis factor-α, interferon-γ, interleukin-6) and chemokines (macrophage inflammatory protein-1α-β, interferon-γ-inducible protein-10, monocyte chemoattractant protein-1). At an individual cell level, IMCgp100-redirected T cells display a polyfunctional phenotype, which is a hallmark of a potent anti-cancer response. This study demonstrates that IMCgp100 induces broad immune responses that extend beyond the induction of CD8 + T cell-mediated cytotoxicity. These findings are of particular importance because IMCgp100 is currently undergoing clinical trials as a single agent or in combination with check point inhibitors for patients with malignant melanoma. © 2017 The Authors. Immunology Published by John Wiley & Sons Ltd.

  11. T-Cell-Mediated Immune Responses in Patients with Cutaneous or Mucosal Leishmaniasis: Long-Term Evaluation after Therapy

    PubMed Central

    Da-Cruz, Alda Maria; Bittar, Rita; Mattos, Marise; Oliveira-Neto, Manuel P.; Nogueira, Ricardo; Pinho-Ribeiro, Vanessa; Azeredo-Coutinho, Rilza Beatriz; Coutinho, Sergio G.

    2002-01-01

    T-cell immune responses in patients with cutaneous leishmaniasis (CL) and mucosal leishmaniasis (ML) were studied during the active disease, at the end of therapy, and 1 to 17 years posttherapy (long-term follow-up). Lymphocyte proliferative responses, phenotypic characterization of CD4+ and CD8+ Leishmania-reactive T cells, and cytokine production were assayed. Patients with active ML and CL showed higher proportions of CD4+ than CD8+ T cells. In CL, the healing process was associated with a decrease of CD4+ and an increase of CD8+, leading to similar CD4+ and CD8+ proportions. This pattern was only seen in ML after long-term therapy. Long-term follow-up of patients with CL showed a positive CD4+/CD8+ ratio as observed during the active disease, although the percentages of these T cell subsets were significantly lower. Patients with CL did not show significant differences between gamma interferon (IFN-γ) and interleukin-5 (IL-5) production during the period of study. Patients with active ML presented higher IFN-γ and IL-5 levels compared to patients with active CL. IL-4 was only detected during active disease. Patients long term after cure from ML showed increasing production of IFN-γ, significant decrease of IL-5, and no IL-4 production. Two apparently beneficial immunological parameters were detected in tegumentary leishmaniasis: (i) decreasing proportions of CD4+ Leishmania-reactive T cells in the absence of IL-4 production associated with cure of CL and ML and (ii) decreasing levels of IL-5 long after cure, better detected in patients with ML. The observed T-cell responses maintained for a long period in healed patients could be relevant for immunoprotection against reinfection and used as a parameter for determining the prognosis of patients and selecting future vaccine preparations. PMID:11874860

  12. Compartmentalization of immune responses in human tuberculosis: few CD8+ effector T cells but elevated levels of FoxP3+ regulatory t cells in the granulomatous lesions.

    PubMed

    Rahman, Sayma; Gudetta, Berhanu; Fink, Joshua; Granath, Anna; Ashenafi, Senait; Aseffa, Abraham; Derbew, Milliard; Svensson, Mattias; Andersson, Jan; Brighenti, Susanna Grundström

    2009-06-01

    Immune responses were assessed at the single-cell level in lymph nodes from children with tuberculous lymphadenitis. Tuberculosis infection was associated with tissue remodeling of lymph nodes as well as altered cellular composition. Granulomas were significantly enriched with CD68+ macrophages expressing the M. tuberculosis complex-specific protein antigen MPT64 and inducible nitric oxide synthase. There was a significant increase in CD8+ cytolytic T cells surrounding the granuloma; however, CD8+ T cells expressed low levels of the cytolytic and antimicrobial effector molecules perforin and granulysin in the granulomatous lesions. Quantitative real-time mRNA analysis revealed that interferon-gamma, tumor necrosis factor-alpha, and interleukin-17 were not up-regulated in infected lymph nodes, but there was a significant induction of both transforming growth factor-beta and interleukin-13. In addition, granulomas contained an increased number of CD4+FoxP3+ T cells co-expressing the immunoregulatory cytotoxic T-lymphocyte antigen-4 and glucocorticoid-induced tumor necrosis factor receptor molecules. Low numbers of CD8+ T cells in the lesions correlated with high levels of transforming growth factor-beta and FoxP3+ regulatory T cells, suggesting active immunosuppression at the local infection site. Compartmentalization and skewing of the immune response toward a regulatory phenotype may result in an uncoordinated effector T-cell response that reduces granule-mediated killing of M. tuberculosis-infected cells and subsequent disease control.

  13. Targeting Peripheral-Derived Regulatory T Cells as a Means of Enhancing Immune Responses Directed against Prostate Cancer

    DTIC Science & Technology

    2017-08-01

    Award Number: W81XWH-15-1-0328 TITLE: Targeting Peripheral-Derived Regulatory T Cells as a Means of Enhancing Immune Responses Directed against...1 August 2016 - 31 July 2017 4. TITLE AND SUBTITLE Targeting Peripheral-Derived Regulatory T Cells as a Means of Enhancing Immune Responses Directed...discovered that a subset of regulatory T cells (Tregs), termed peripheral-derived Tregs (pTregs), impair immune responses directed against tumor

  14. Natural killer T cells are required for the development of a superantigen-driven T helper type 2 immune response in mice

    PubMed Central

    Nomizo, Auro; Postol, Edilberto; de Alencar, Raquel; Cardillo, Fabíola; Mengel, José

    2005-01-01

    We show, here, that one single injection or weekly injections of staphylococcal enterotoxin B (SEB), starting in 1-day-old newborn mice, induced a powerful immune response with a T helper type 2 (Th2) pattern, as judged by the isotype and cytokine profile, with the production of large amounts of SEB-specific immunoglobulin G1 (IgG1), detectable levels of SEB-specific IgE and increased production of interleukin-4 by spleen cells. These protocols also induced an increase in the levels of total IgE in the serum. Memory of SEB was transferred to secondary recipients by using total spleen cells from primed animals. The secondary humoral response in transferred mice was diminished if spleen cells from SEB-treated mice were previously depleted of CD3+ or Vβ8+ T cells or NK1.1+ cells. In vivo depletion of NK1.1+ cells in adult mice resulted in a marked reduction in the SEB-specific antibody response in both the primary and secondary immune responses. Additionally, purified NK1.1+ T cells were able to perform SEB-specific helper B-cell actions in vitro and in vivo. These results suggest that NK1.1+ T cells are required for the full development of humoral immunological memory, whilst making neonatal tolerance to SEB unachievable. PMID:16162272

  15. Foxp3+ regulatory T cells impede the priming of protective CD8+ T cells

    PubMed Central

    Ertelt, James M.; Rowe, Jared H.; Mysz, Margaret A.; Singh, Charanjeet; Roychowdhury, Monika; Aguilera, Marijo N.; Way, Sing Sing

    2011-01-01

    T cell activation is controlled by incompletely defined opposing stimulation and suppression signals that together sustain the balance between optimal host defense against infection and peripheral tolerance. Herein, we explored the impacts of Foxp3+ regulatory T cell (Treg) suppression in priming antigen-specific T cell activation under non-infection and infection conditions. We find the transient ablation of Foxp3+ Tregs unleashes the robust expansion and activation of peptide stimulated CD8+ T cells that provide protection against Listeria monocytogenes (Lm) infection in an antigen-specific fashion. By contrast, Treg-ablation had non-significant impacts on the CD8+ T cell response primed by infection with recombinant Lm. Similarly, non-recombinant Lm administered with peptide stimulated the expansion and activation of CD8+ T cells that paralleled the response primed by Treg-ablation. Interestingly, these adjuvant properties of Lm did not require CD8+ T cell stimulation by IL-12 produced in response to infection, but instead were associated with sharp reductions in Foxp3+ Treg suppressive potency. Therefore, Foxp3+ Tregs impose critical barriers that when overcome naturally during infection or artificially with ablation allows the priming of protective antigen-specific CD8+ T cells. PMID:21810602

  16. iNKT cell cytotoxic responses control T-lymphoma growth in vitro and in vivo

    PubMed Central

    Bassiri, Hamid; Das, Rupali; Guan, Peng; Barrett, David M.; Brennan, Patrick J.; Banerjee, Pinaki P.; Wiener, Susan J.; Orange, Jordan S.; Brenner, Michael B.; Grupp, Stephan A.; Nichols, Kim E.

    2013-01-01

    Invariant natural killer T (iNKT) cells comprise a lineage of CD1d-restricted glycolipid-reactive T lymphocytes with important roles in host immunity to cancer. iNKT cells indirectly participate in antitumor responses by inducing dendritic cell maturation and producing cytokines that promote tumor clearance by CD8+ T and NK cells. Although iNKT cells thereby act as potent cellular adjuvants, it is less clear whether they directly control the growth of tumors. To gain insights into the direct contribution of iNKT cells to tumor immune surveillance, we developed in vitro and in vivo systems to selectively examine the antitumor activity of iNKT cells in the absence of other cytolytic effectors. Using the EL4 T-lymphoma cell line as a model, we find that iNKT cells exert robust and specific lysis of tumor cells in vitro in a manner that is differentially-induced by iNKT cell agonists of varying TCR affinities, such as OCH, α-galactosyl ceramide and PBS44. In vitro blockade of CD1d-mediated lipid antigen presentation, disruption of T cell receptor (TCR) signaling, or loss of perforin expression significantly reduce iNKT cell killing. Consistent with these findings, iNKT cell reconstitution of T, B, and NK cell-deficient mice slows EL4 growth in vivo via TCR-CD1d and perforin-dependent mechanisms. Together, these observations establish that iNKT cells are sufficient to control the growth of T-lymphoma in vitro and in vivo. They also suggest that the induction of iNKT cell cytotoxic responses in situ might serve as a more effective strategy to prevent and/or treat CD1d+ cancers, such as T-lymphoma. PMID:24563871

  17. Influence of adenovirus and MVA vaccines on the breadth and hierarchy of T cell responses.

    PubMed

    Rollier, Christine S; Hill, Adrian V S; Reyes-Sandoval, Arturo

    2016-08-31

    Viral-vectored vaccines are in clinical development for several infectious diseases where T-cell responses can mediate protection, and responses to sub-dominant epitopes is needed. Little is known about the influence of MVA or adenoviral vectors on the hierarchy of the dominant and sub-dominant T-cell epitopes. We investigated this aspect in mice using a malaria immunogen. Our results demonstrate that the T-cell hierarchy is influenced by the timing of analysis, rather than by the vector after a single immunization, with hierarchy changing over time. Repeated homologous immunization reduced the breadth of responses, while heterologous prime-boost induced the strongest response to the dominant epitope, albeit with only modest response to the sub-dominant epitopes. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  18. CD28 T-cell costimulatory molecule expression in pemphigus vulgaris.

    PubMed

    Alecu, M; Ursaciuc, C; Surcel, M; Coman, G; Ciotaru, D; Dobre, M

    2009-03-01

    CD28 superfamily of immune costimulatory molecules could play an important role in autotolerance control. CD28 costimulation seems to be necessary for regulatory T cell (Treg) activation and successive suppressive activities involved in autoimmunity protection. This study investigates CD28 expression, especially inducible costimulator fraction, on T lymphocytes in pemphigus vulgaris (PV) patients. CD28 expression on T lymphocytes was assessed in 16 PV patients during acute attack. All patients and 10 healthy control subjects were tested for lymphocyte populations, T-cell subpopulations (T-CD4+, T-CD8+), Treg and CD28 expression on T-cell subpopulations. T, B and natural killer cells average values in PV patients were close to the control group values. Compared with control group, PV values showed lower Treg (2.2% compared with 4.7%), slightly decreased CD4+ CD28+ T cells (91% compared with 95%), higher CD4+ CD28- T cells (9% compared with 5%), decreased CD8+ CD28+ T cells (57% and 73%, respectively) and significantly enhanced CD8+ CD28- T cells (43% compared with 27%). These data suggest that Treg-mediated suppressor T-cell effects could be diminished in PV, together with an abnormal or ineffective subsequent helper T-cell suppression. CD28 high expression on helper T cells and low expression on suppressor T cells are arguments for a potential CD28 role in PV autoimmune response mechanism.

  19. Memory T cells and vaccines.

    PubMed

    Esser, Mark T; Marchese, Rocio D; Kierstead, Lisa S; Tussey, Lynda G; Wang, Fubao; Chirmule, Narendra; Washabaugh, Michael W

    2003-01-17

    T lymphocytes play a central role in the generation of a protective immune response in many microbial infections. After immunization, dendritic cells take up microbial antigens and traffic to draining lymph nodes where they present processed antigens to naïve T cells. These naïve T cells are stimulated to proliferate and differentiate into effector and memory T cells. Activated, effector and memory T cells provide B cell help in the lymph nodes and traffic to sites of infection where they secrete anti-microbial cytokines and kill infected cells. At least two types of memory cells have been defined in humans based on their functional and migratory properties. T central-memory (T(CM)) cells are found predominantly in lymphoid organs and can not be immediately activated, whereas T effector-memory (T(EM)) cells are found predominantly in peripheral tissue and sites of inflammation and exhibit rapid effector function. Most currently licensed vaccines induce antibody responses capable of mediating long-term protection against lytic viruses such as influenza and small pox. In contrast, vaccines against chronic pathogens that require cell-mediated immune responses to control, such as malaria, Mycobacterium tuberculosis (TB), human immunodeficiency virus (HIV) and hepatitis C virus (HCV), are currently not available or are ineffective. Understanding the mechanisms by which long-lived cellular immune responses are generated following vaccination should facilitate the development of safe and effective vaccines against these emerging diseases. Here, we review the current literature with respect to memory T cells and their implications to vaccine development.

  20. Ki-67 expression reveals strong, transient influenza specific CD4 T cell responses after adult vaccination.

    PubMed

    Li, Xi; Miao, Hongyu; Henn, Alicia; Topham, David J; Wu, Hulin; Zand, Martin S; Mosmann, Tim R

    2012-06-29

    Although previous studies have found minimal changes in CD4 T cell responses after vaccination of adults with trivalent inactivated influenza vaccine, daily sampling and monitoring of the proliferation marker Ki-67 have now been used to reveal that a substantial fraction of influenza-specific CD4 T cells respond to vaccination. At 4-6 days after vaccination, there is a sharp rise in the numbers of Ki-67-expressing PBMC that produce IFNγ, IL-2 and/or TNFα in vitro in response to influenza vaccine or peptide. Ki-67(+) cell numbers then decline rapidly, and 10 days after vaccination, both Ki-67(+) and overall influenza-specific cell numbers are similar to pre-vaccination levels. These results provide a tool for assessing the quality and quantity of CD4 T cell responses to different influenza vaccines, and raise the possibility that the anti-influenza T cell memory response may be qualitatively altered by vaccination, even if the overall memory cell numbers do not change significantly. Copyright © 2012. Published by Elsevier Ltd.

  1. iNKT cell cytotoxic responses control T-lymphoma growth in vitro and in vivo .

    PubMed

    Bassiri, Hamid; Das, Rupali; Guan, Peng; Barrett, David M; Brennan, Patrick J; Banerjee, Pinaki P; Wiener, Susan J; Orange, Jordan S; Brenner, Michael B; Grupp, Stephan A; Nichols, Kim E

    2014-01-01

    Invariant natural killer T (iNKT) cells comprise a lineage of CD1d-restricted glycolipid-reactive T lymphocytes with important roles in host immunity to cancer. iNKT cells indirectly participate in antitumor responses by inducing dendritic cell maturation and producing cytokines that promote tumor clearance by CD8+ T and NK cells. Although iNKT cells thereby act as potent cellular adjuvants, it is less clear whether they directly control the growth of tumors. To gain insights into the direct contribution of iNKT cells to tumor immune surveillance, we developed in vitro and in vivo systems to selectively examine the antitumor activity of iNKT cells in the absence of other cytolytic effectors. Using the EL4 T-lymphoma cell line as a model, we found that iNKT cells exert robust and specific lysis of tumor cells in vitro in a manner that is differentially induced by iNKT cell agonists of varying T-cell receptor (TCR) affinities, such as OCH, α-galactosyl ceramide, and PBS44. In vitro blockade of CD1d-mediated lipid antigen presentation, disruption of TCR signaling, or loss of perforin expression significantly reduce iNKT cell killing. Consistent with these findings, iNKT cell reconstitution of T, B, and NK cell–deficient mice slows EL4 growth in vivo via TCR-CD1d and perforin-dependent mechanisms. Together, these observations establish that iNKT cells are sufficient to control the growth of T lymphoma in vitro and in vivo. They also suggest that the induction of iNKT cell cytotoxic responses in situ might serve as a more effective strategy to prevent and/or treat CD1d+ cancers, such as T lymphoma. ©2013 AACR.

  2. Evidence for clonal selection of gamma/delta T cells in response to a human pathogen

    PubMed Central

    1991-01-01

    T cells bearing gamma/delta antigen receptors comprise a resident population of intraepithelial lymphocytes in organs such as skin, gut, and lungs, where they are strategically located to contribute to the initial defense against infection. An important unsolved question about antigen-driven gamma/delta T cell responses regards the breadth of their T cell receptor (TCR) repertoire, since many specific epithelial compartments in mice display limited diversity. We have examined the diversity of TCR delta gene expression among human gamma/delta T cells from skin lesions induced by intradermal challenge with Mycobacterium leprae. We show that the vast majority of gamma/delta cells from M. leprae lesions use either V delta 1-J delta 1 or V delta 2-J delta 1 gene rearrangements and, within a given region of the lesion, display limited junctional diversity. This contrasts markedly with the extensive diversity of gamma/delta T cells from peripheral blood of these same individuals, as well as skin from normal donors. These results indicate that the gamma/delta response to M. leprae involves the selection of a limited number of clones from among a diverse repertoire, probably in response to specific mycobacterial and/or host antigens. PMID:1651977

  3. Cytomegalovirus-Responsive CD8+ T Cells Expand After Solid Organ Transplantation in the Absence of CMV Disease.

    PubMed

    Higdon, L E; Trofe-Clark, J; Liu, S; Margulies, K B; Sahoo, M K; Blumberg, E; Pinsky, B A; Maltzman, J S

    2017-08-01

    Cytomegalovirus (CMV) is a major cause of morbidity and mortality in solid organ transplant recipients. Approximately 60% of adults are CMV seropositive, indicating previous exposure. Following resolution of the primary infection, CMV remains in a latent state. Reactivation is controlled by memory T cells in healthy individuals; transplant recipients have reduced memory T cell function due to chronic immunosuppressive therapies. In this study, CD8 + T cell responses to CMV polypeptides immediate-early-1 and pp65 were analyzed in 16 CMV-seropositive kidney and heart transplant recipients longitudinally pretransplantation and posttransplantation. All patients received standard of care maintenance immunosuppression, antiviral prophylaxis, and CMV viral load monitoring, with approximately half receiving T cell-depleting induction therapy. The frequency of CMV-responsive CD8 + T cells, defined by the production of effector molecules in response to CMV peptides, increased during the course of 1 year posttransplantation. The increase commenced after the completion of antiviral prophylaxis, and these T cells tended to be terminally differentiated effector cells. Based on this small cohort, these data suggest that even in the absence of disease, antigenic exposure may continually shape the CMV-responsive T cell population posttransplantation. © 2017 The American Society of Transplantation and the American Society of Transplant Surgeons.

  4. Role of T Cell TGF-β Signaling in Intestinal Cytokine Responses and Helminthic Immune Modulation

    PubMed Central

    Ince, M. Nedim; Elliott, David E.; Setiawan, Tommy; Metwali, Ahmed; Blum, Arthur; Chen, Hung-lin; Urban, Joseph F.; Flavell, Richard A.; Weinstock, Joel V.

    2010-01-01

    Colonization with helminthic parasites induces mucosal regulatory cytokines, like IL-10 or TGF-β that are important in suppressing colitis. Helminths induce mucosal T cell IL-10 secretion and regulate lamina propria mononuclear cell Th1 cytokine generation in an IL-10 dependent manner in wild-type mice. Helminths also stimulate mucosal TGF-β release. As TGF-β exerts major regulatory effects on T lymphocytes, we investigated the role of T lymphocyte TGF-β signaling in helminthic modulation of intestinal immunity. T cell TGF-β signaling is interrupted in TGF-βRII DN mice by T cell-specific over-expression of a dominant negative TGF-β receptor II. We studied lamina propria mononuclear cell responses in wild-type and TGF-βRII DN mice that were uninfected or colonized with the nematode, Heligmosomoides polygyrus. Our results indicate an essential role of T cell TGF-β signaling in limiting mucosal Th1 and Th2 responses. Furthermore, we demonstrate that helminthic induction of intestinal T cell IL-10 secretion requires intact T cell TGF-β signaling pathway. Helminths fail to curtail robust, dysregulated intestinal Th1 cytokine production and chronic colitis in TGF-βRII DN mice. Thus, T cell TGF-β signaling is essential for helminthic stimulation of mucosal IL-10 production, helminthic modulation of intestinal interferon-γ generation and H. polygyrus-mediated suppression of chronic colitis. PMID:19544487

  5. Strong and frequent T-cell responses to the minor allergen Phl p 12 in Spanish patients IgE-sensitized to Profilins.

    PubMed

    Lund, G; Brand, S; Ramos, T; Jimeno, L; Boissy, P; Vega, F; Arina, M; Christensen, L H; Hoof, I; Meno, K H; Barber, D; Blanco, C; Würtzen, P A; Andersen, P S

    2018-05-01

    Profilins are dominant pan-allergens known to cause cross-sensitization, leading to clinical symptoms such as pollen-food syndrome. This study aimed to determine the T-cell response to Phl p 12 in profilin-sensitized patients, by measuring the prevalence, strength and cross-reactivity to clinically relevant profilins. The release of Phl p allergens from pollen was determined by mass spectrometry and immunochemistry. T-cell responses, epitope mapping and cross-reactivity to profilins (Phl p 12, Ole e 2, Bet v 2 and Mal d 4) were measured in vitro using PBMCs from 26 Spanish grass-allergic donors IgE-sensitized to profilin. Cross-reactivity was addressed in vivo using 2 different mouse strains (BALB/c and C3H). Phl p 12 and Phl p 1 are released from pollen simultaneously and in similar amounts. Both T-cell response frequency (17/26 donors) and strength were comparable between Phl p 12 and Phl p 1. T-cell cross-reactivity to other profilins correlated with overall sequence homology, and 2 immunodominant epitope regions of Phl p 12 were identified. Data from mice immunized with Phl p 12 showed that cross-reactivity to Bet v 2 was mediated by conserved epitopes and further influenced by additional genetic factors, likely to be MHC II. The strength, prevalence and cross-reactivity of T-cell responses towards Phl p 12 are comparable to the major allergen Phl p 1, which supports the hypothesis that T cells to Phl p 12 can play an important role in development of allergic symptoms, such as those associated with pollen-food syndrome. © 2017 EAACI and John Wiley and Sons A/S. Published by John Wiley and Sons Ltd.

  6. Central Memory CD4+ T Cells Are Responsible for the Recombinant Bacillus Calmette-Guérin ΔureC::hly Vaccine's Superior Protection Against Tuberculosis

    PubMed Central

    Vogelzang, Alexis; Perdomo, Carolina; Zedler, Ulrike; Kuhlmann, Stefanie; Hurwitz, Robert; Gengenbacher, Martin; Kaufmann, Stefan H. E.

    2014-01-01

    Bacillus Calmette-Guérin (BCG) has been used for vaccination against tuberculosis for nearly a century. Here, we analyze immunity induced by a live tuberculosis vaccine candidate, recombinant BCG ΔureC::hly vaccine (rBCG), with proven preclinical and clinical safety and immunogenicity. We pursue in-depth analysis of the endogenous mycobacteria-specific CD4+ T-cell population, comparing the more efficacious rBCG with canonical BCG to determine which T-cell memory responses are prerequisites for superior protection against tuberculosis. rBCG induced higher numbers and proportions of antigen-specific memory CD4+ T cells than BCG, with a CXCR5+CCR7+ phenotype and low expression of the effector transcription factors T-bet and Bcl-6. We found that the superior protection of rBCG, compared with BCG, correlated with higher proportions and numbers of these central memory T cells and of T follicular helper cells associated with specific antibody responses. Adoptive transfer of mycobacteria-specific central memory T cells validated their critical role in protection against pulmonary tuberculosis. PMID:24943726

  7. Characterization of CD4 and CD8 T Cell Responses in MuSK Myasthenia Gravis

    PubMed Central

    Yi, JS; Guidon, A; Sparks, S; Osborne, R; Juel, VC; Massey, JM; Sanders, DB; Weinhold, KJ; Guptill, JT

    2014-01-01

    Muscle specific tyrosine kinase myasthenia gravis (MuSK MG) is a form of autoimmune MG that predominantly affects women and has unique clinical features, including prominent bulbar weakness, muscle atrophy, and excellent response to therapeutic plasma exchange. Patients with MuSK MG have predominantly IgG4 autoantibodies directed against MuSK on the postsynaptic muscle membrane. Lymphocyte functionality has not been reported in this condition. The goal of this study was to characterize T-cell responses in patients with MuSK MG. Intracellular production of IFN-gamma, TNF-alpha, IL-2, IL-17, and IL-21 by CD4+ and CD8+ T-cells was measured by polychromatic flow cytometry in peripheral blood samples from 11 Musk MG patients and 10 healthy controls. Only one MuSK MG patient was not receiving immunosuppressive therapy. Regulatory T-cells (Treg) were also included in our analysis to determine if changes in T cell function were due to altered Treg frequencies. CD8+ T-cells from MuSK MG patients had higher frequencies of polyfunctional responses than controls, and CD4+ T-cells had higher IL-2, TNF-alpha, and IL-17. MuSK MG patients had a higher percentage of CD4+ T-cells producing combinations of IFN-gamma/IL-2/TNF-gamma, TNF-alpha/IL-2, and IFN-gamma/TNF-alpha. Interestingly, Treg numbers and CD39 expression were not different from control values. MuSK MG patients had increased frequencies of Th1 and Th17 cytokines and were primed for polyfunctional proinflammatory responses that cannot be explained by a defect in Treg function or number. PMID:24378287

  8. Metabolic mysteries of the inflammatory response: T cell polarization and plasticity.

    PubMed

    Fracchia, Kelley M; Walsh, Craig M

    2015-01-01

    While simultaneously maintaining homeostasis and reducing further harm to the host, the immune system is equipped to eliminate both tumors and pathogenic microorganisms. Bifurcated into cell-mediated and humoral immunity, the adaptive immune system requires a series of complex and coordinated signals to drive the proliferation and differentiation of appropriate subsets. These include signals that modulate cellular metabolism. When first published in the 1920s, "the Warburg effect" was used to describe a phenomenon in which most cancer cells relied on aerobic glycolysis to meet their biosynthetic demands. Despite the early observations of Warburg and his colleagues, targeting cancer cell metabolism for therapeutic purposes still remains theoretical. Notably, many T cells exhibit the same Warburg metabolism as cancer cells and the therapeutic benefit of targeting their metabolic pathways has since been reexamined. Emerging evidence suggests that specific metabolic alterations associated with T cells may be ancillary to their subset differentiation and influential in their inflammatory response. Thus, T cell lymphocyte activation leads to skewing in metabolic plasticity, and issue that will be the subject of this review.

  9. T-Cell Therapy Using Interleukin-21-Primed Cytotoxic T-Cell Lymphocytes Combined With Cytotoxic T-Cell Lymphocyte Antigen-4 Blockade Results in Long-Term Cell Persistence and Durable Tumor Regression.

    PubMed

    Chapuis, Aude G; Roberts, Ilana M; Thompson, John A; Margolin, Kim A; Bhatia, Shailender; Lee, Sylvia M; Sloan, Heather L; Lai, Ivy P; Farrar, Erik A; Wagener, Felecia; Shibuya, Kendall C; Cao, Jianhong; Wolchok, Jedd D; Greenberg, Philip D; Yee, Cassian

    2016-11-01

    Purpose Peripheral blood-derived antigen-specific cytotoxic T cells (CTLs) provide a readily available source of effector cells that can be administered with minimal toxicity in an outpatient setting. In metastatic melanoma, this approach results in measurable albeit modest clinical responses in patients resistant to conventional therapy. We reasoned that concurrent cytotoxic T-cell lymphocyte antigen-4 (CTLA-4) checkpoint blockade might enhance the antitumor activity of adoptively transferred CTLs. Patients and Methods Autologous MART1-specific CTLs were generated by priming with peptide-pulsed dendritic cells in the presence of interleukin-21 and enriched by peptide-major histocompatibility complex multimer-guided cell sorting. This expeditiously yielded polyclonal CTL lines uniformly expressing markers associated with an enhanced survival potential. In this first-in-human strategy, 10 patients with stage IV melanoma received the MART1-specific CTLs followed by a standard course of anti-CTLA-4 (ipilimumab). Results The toxicity profile of the combined treatment was comparable to that of ipilimumab monotherapy. Evaluation of best responses at 12 weeks yielded two continuous complete remissions, one partial response (PR) using RECIST criteria (two PRs using immune-related response criteria), and three instances of stable disease. Infused CTLs persisted with frequencies up to 2.9% of CD8 + T cells for as long as the patients were monitored (up to 40 weeks). In patients who experienced complete remissions, PRs, or stable disease, the persisting CTLs acquired phenotypic and functional characteristics of long-lived memory cells. Moreover, these patients also developed responses to nontargeted tumor antigens (epitope spreading). Conclusion We demonstrate that combining antigen-specific CTLs with CTLA-4 blockade is safe and produces durable clinical responses, likely reflecting both enhanced activity of transferred cells and improved recruitment of new responses

  10. γδ T Cells Regulate the Early Inflammatory Response to Bordetella pertussis Infection in the Murine Respiratory Tract

    PubMed Central

    Zachariadis, O.; Cassidy, J. P.; Brady, J.; Mahon, B. P.

    2006-01-01

    The role of γδ T cells in the regulation of pulmonary inflammation following Bordetella pertussis infection was investigated. Using a well-characterized murine aerosol challenge model, inflammatory events in mice with targeted disruption of the T-cell receptor δ-chain gene (γδ TCR−/− mice) were compared with those in wild-type animals. Early following challenge with B. pertussis, γδ TCR−/− mice exhibited greater pulmonary inflammation, as measured by intra-alveolar albumin leakage and lesion histomorphometry, yet had lower contemporaneous bacterial lung loads. The larger numbers of neutrophils and macrophages and the greater concentration of the neutrophil marker myeloperoxidase in bronchoalveolar lavage fluid from γδ TCR−/− mice at this time suggested that differences in lung injury were mediated through increased leukocyte trafficking into infected alveoli. Furthermore, flow cytometric analysis found the pattern of recruitment of natural killer (NK) and NK receptor+ T cells into airspaces differed between the two mouse types over the same time period. Taken together, these findings suggest a regulatory influence for γδ T cells over the early pulmonary inflammatory response to bacterial infection. The absence of γδ T cells also influenced the subsequent adaptive immune response to specific bacterial components, as evidenced by a shift from a Th1 to a Th2 type response against the B. pertussis virulence factor filamentous hemagglutinin in γδ TCR−/− mice. The findings are relevant to the study of conditions such as neonatal B. pertussis infection and acute respiratory distress syndrome where γδ T cell dysfunction has been implicated in the inflammatory process. PMID:16495558

  11. Correlation between thyroidal and peripheral blood total T cells, CD8+ T cells, and CD8+ T- regulatory cells and T-cell reactivity to calsequestrin and collagen XIII in patients with Graves' ophthalmopathy.

    PubMed

    Al-Ansari, Farah; Lahooti, Hooshang; Stokes, Leanne; Edirimanne, Senarath; Wall, Jack

    2018-05-22

    Purpose/aim of the study: Graves' ophthalmopathy (GO) is closely related to the thyroid autoimmune disorder Graves' disease. Previous studies have suggested roles for thyroidal CD8 +  T cells and autoimmunity against calsequestrin-1 (CASQ)-1 in the link between thyroidal and orbital autoimmune reactions in GO. A role for autoimmunity against CollXIII has also been suggested. In this study, we aimed to investigate correlations between some thyroidal and peripheral blood T-cell subsets and thyroidal T-cell reactivity against CASQ1 and CollXIII in patients with GO. Fresh thyroid tissues were processed by enzyme digestion and density gradient to isolate mononuclear cells (MNCs). Peripheral blood MNCs were also isolated using density gradient. Flow-cytometric analysis was used to identify the various T-cell subsets. T -cell reactivity to CASQ1 and CollXIII was measured by a 5-day culture of the MNCs and BrdU uptake method. We found a positive correlation between thyroidal CD8 +  T cells and CD8 +  T-regulatory (T-reg) cells in patients with GO. Thyroidal T cells from two out of the three patients with GO tested (66.7%) showed a positive response to CASQ1, while thyroidal T cells from none of the six Graves' Disease patients without ophthalmopathy (GD) tested showed a positive response to this antigen. Thyroidal T cells from these patient groups however, showed no significant differences in their response to CollXIII. Our observations provide further evidence for a possible role of thyroidal CD8 +  T cells, CD8 +  T-reg cells and the autoantigen CASQ1 in the link between thyroidal and orbital autoimmune reactions of GO.

  12. A Numerically Subdominant CD8 T Cell Response to Matrix Protein of Respiratory Syncytial Virus Controls Infection with Limited Immunopathology

    PubMed Central

    Liu, Jie; Haddad, Elias K.; Marceau, Joshua; Morabito, Kaitlyn M.; Rao, Srinivas S.; Filali-Mouhim, Ali; Sekaly, Rafick-Pierre; Graham, Barney S.

    2016-01-01

    CD8 T cells are involved in pathogen clearance and infection-induced pathology in respiratory syncytial virus (RSV) infection. Studying bulk responses masks the contribution of individual CD8 T cell subsets to protective immunity and immunopathology. In particular, the roles of subdominant responses that are potentially beneficial to the host are rarely appreciated when the focus is on magnitude instead of quality of response. Here, by evaluating CD8 T cell responses in CB6F1 hybrid mice, in which multiple epitopes are recognized, we found that a numerically subdominant CD8 T cell response against DbM187 epitope of the virus matrix protein expressed high avidity TCR and enhanced signaling pathways associated with CD8 T cell effector functions. Each DbM187 T effector cell lysed more infected targets on a per cell basis than the numerically dominant KdM282 T cells, and controlled virus replication more efficiently with less pulmonary inflammation and illness than the previously well-characterized KdM282 T cell response. Our data suggest that the clinical outcome of viral infections is determined by the integrated functional properties of a variety of responding CD8 T cells, and that the highest magnitude response may not necessarily be the best in terms of benefit to the host. Understanding how to induce highly efficient and functional T cells would inform strategies for designing vaccines intended to provide T cell-mediated immunity. PMID:26943673

  13. ArtinM Mediates Murine T Cell Activation and Induces Cell Death in Jurkat Human Leukemic T Cells

    PubMed Central

    Oliveira-Brito, Patrícia Kellen Martins; Gonçalves, Thiago Eleutério; Vendruscolo, Patrícia Edivânia; Roque-Barreira, Maria Cristina

    2017-01-01

    The recognition of cell surface glycans by lectins may be critical for the innate and adaptive immune responses. ArtinM, a d-mannose-binding lectin from Artocarpus heterophyllus, activates antigen-presenting cells by recognizing TLR2 N-glycans and induces Th1 immunity. We recently demonstrated that ArtinM stimulated CD4+ T cells to produce proinflammatory cytokines. Here, we further studied the effects of ArtinM on adaptive immune cells. We showed that ArtinM activates murine CD4+ and CD8+ T cells, augmenting their positivity for CD25, CD69, and CD95 and showed higher interleukin (IL)-2 and interferon (IFN)-γ production. The CD4+ T cells exhibited increased T-bet expression in response to ArtinM, and IL-2 production by CD4+ and CD8+ T cells depended on the recognition of CD3εγ-chain glycans by ArtinM. The ArtinM effect on aberrantly-glycosylated neoplastic lymphocytes was studied in Jurkat T cells, in which ArtinM induced IL-2, IFN-γ, and IL-1β production, but decreased cell viability and growth. A higher frequency of AnnexinV- and propidium iodide-stained cells demonstrated the induction of Jurkat T cells apoptosis by ArtinM, and this apoptotic response was reduced by caspases and protein tyrosine kinase inhibitors. The ArtinM effects on murine T cells corroborated with the immunomodulatory property of lectin, whereas the promotion of Jurkat T cells apoptosis may reflect a potential applicability of ArtinM in novel strategies for treating lymphocytic leukemia. PMID:28665310

  14. T Cell Dynamic Activation and Functional Analysis in Nanoliter Droplet Microarray.

    PubMed

    Sarkar, Saheli; Motwani, Vinny; Sabhachandani, Pooja; Cohen, Noa; Konry, Tania

    2015-06-01

    Characterization of the heterogeneity in immune reactions requires assessing dynamic single cell responses as well as interactions between the various immune cell subsets. Maturation and activation of effector cells is regulated by cell contact-dependent and soluble factor-mediated paracrine signalling. Currently there are few methods available that allow dynamic investigation of both processes simultaneously without physically constraining non-adherent cells and eliminating crosstalk from neighboring cell pairs. We describe here a microfluidic droplet microarray platform that permits rapid functional analysis of single cell responses and co-encapsulation of heterotypic cell pairs, thereby allowing us to evaluate the dynamic activation state of primary T cells. The microfluidic droplet platform enables generation and docking of monodisperse nanoliter volume (0.523 nl) droplets, with the capacity of monitoring a thousand droplets per experiment. Single human T cells were encapsulated in droplets and stimulated on-chip with the calcium ionophore ionomycin. T cells were also co-encapsulated with dendritic cells activated by ovalbumin peptide, followed by dynamic calcium signal monitoring. Ionomycin-stimulated cells depicted fluctuation in calcium signalling compared to control. Both cell populations demonstrated marked heterogeneity in responses. Calcium signalling was observed in T cells immediately following contact with DCs, suggesting an early activation signal. T cells further showed non-contact mediated increase in calcium level, although this response was delayed compared to contact-mediated signals. Our results suggest that this nanoliter droplet array-based microfluidic platform is a promising technique for assessment of heterogeneity in various types of cellular responses, detection of early/delayed signalling events and live cell phenotyping of immune cells.

  15. Suppression of unprimed T and B cells in antibody responses by irradiation-resistant and plastic-adherent suppressor cells in Toxoplasma gondii-infected mice

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Suzuki, Y.; Kobayashi, A.

    1983-04-01

    In the acute phase of Toxoplasma infection, the function of both helper T and B cells was suppressed in primary antibody responses to dinitrophenol (DNP)-conjugated protein antigens. During the course of infection, the suppressive effect on T cells seems to continue longer than that on B cells, since suppression in responses to sheep erythrocytes, a T-dependent antigen, persisted longer than those to DNP-Ficoll, a T-independent antigen. Plastic-adherent cells from the spleens of Toxoplasma-infected and X-irradiated (400 rads) mice had strong suppressor activity in primary anti-sheep erythrocyte antibody responses of normal mouse spleen cells in vitro. These data suggest that themore » activation of irradiation-resistant and plastic-adherent suppressor cells causes the suppression of both T and B cells in Toxoplasma-infected mice.« less

  16. Human Infant Memory B Cell and CD4+ T Cell Responses to HibMenCY-TT Glyco-Conjugate Vaccine

    PubMed Central

    Fuery, Angela; Richmond, Peter C.; Currie, Andrew J.

    2015-01-01

    Carrier-specific T cell and polysaccharide-specific B cell memory responses are not well characterised in infants following glyco-conjugate vaccination. We aimed to determine if the number of Meningococcal (Men) C- and Y- specific memory B cells and; number and quality of Tetanus Toxoid (TT) carrier-specific memory CD4+ T cells are associated with polysaccharide-specific IgG post HibMenCY-TT vaccination. Healthy infants received HibMenCY-TT vaccine at 2, 4 and 6 months with a booster at 12 months. Peripheral blood mononuclear cells were isolated and polysaccharide-specific memory B cells enumerated using ELISpot. TT-specific memory CD4+ T cells were detected and phenotyped based on CD154 expression and intracellular TNF-α, IL-2 and IFN-γ expression following stimulation. Functional polysaccharide-specific IgG titres were measured using the serum bactericidal activity (SBA) assay. Polysaccharide-specific Men C- but not Men Y- specific memory B cell frequencies pre-boost (12 months) were significantly associated with post-boost (13 months) SBA titres. Regression analysis showed no association between memory B cell frequencies post-priming (at 6 or 7 months) and SBA at 12 months or 13 months. TT-specific CD4+ T cells were detected at frequencies between 0.001 and 0.112 as a percentage of CD3+ T cells, but their numbers were not associated with SBA titres. There were significant negative associations between SBA titres at M13 and cytokine expression at M7 and M12. Conclusion: Induction of persistent polysaccharide-specific memory B cells prior to boosting is an important determinant of secondary IgG responses in infants. However, polysaccharide-specific functional IgG responses appear to be independent of the number and quality of circulating carrier-specific CD4+ T cells after priming. PMID:26191794

  17. The Yin and Yang aspects of IL-27 in induction of cancer-specific T-cell responses and immunotherapy.

    PubMed

    Li, Ming-Song; Liu, Zhenzhen; Liu, Jin-Qing; Zhu, Xiaotong; Liu, Zhihao; Bai, Xue-Feng

    2015-01-01

    Accumulating evidences from animal studies have indicated that both endogenous and exogenous IL-27, an IL-12 family of cytokine, can increase antitumor T-cell activities and inhibit tumor growth. IL-27 can modulate Treg responses, and program effector T cells into a unique T-effector stem cell (TSEC) phenotype, which enhances T-cell survival in the tumor microenvironment. However, animal studies also suggest that IL-27 induces molecular pathways such as IL-10, PD-L1 and CD39, which may downregulate tumor-specific T-cell responses. In this review paper, we will discuss the Yin and Yang aspects of IL-27 in the induction of tumor-specific T-cell responses, and the potential impacts of these functions of IL-27 in the design of cancer immunotherapy.

  18. Human Neutrophil Clearance of Bacterial Pathogens Triggers Anti-Microbial γδ T Cell Responses in Early Infection

    PubMed Central

    Roberts, Gareth W.; Heuston, Sinéad; Brown, Amanda C.; Chess, James A.; Toleman, Mark A.; Gahan, Cormac G. M.; Hill, Colin; Parish, Tanya; Williams, John D.; Davies, Simon J.; Johnson, David W.; Topley, Nicholas; Moser, Bernhard; Eberl, Matthias

    2011-01-01

    Human blood Vγ9/Vδ2 T cells, monocytes and neutrophils share a responsiveness toward inflammatory chemokines and are rapidly recruited to sites of infection. Studying their interaction in vitro and relating these findings to in vivo observations in patients may therefore provide crucial insight into inflammatory events. Our present data demonstrate that Vγ9/Vδ2 T cells provide potent survival signals resulting in neutrophil activation and the release of the neutrophil chemoattractant CXCL8 (IL-8). In turn, Vγ9/Vδ2 T cells readily respond to neutrophils harboring phagocytosed bacteria, as evidenced by expression of CD69, interferon (IFN)-γ and tumor necrosis factor (TNF)-α. This response is dependent on the ability of these bacteria to produce the microbial metabolite (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMB-PP), requires cell-cell contact of Vγ9/Vδ2 T cells with accessory monocytes through lymphocyte function-associated antigen-1 (LFA-1), and results in a TNF-α dependent proliferation of Vγ9/Vδ2 T cells. The antibiotic fosmidomycin, which targets the HMB-PP biosynthesis pathway, not only has a direct antibacterial effect on most HMB-PP producing bacteria but also possesses rapid anti-inflammatory properties by inhibiting γδ T cell responses in vitro. Patients with acute peritoneal-dialysis (PD)-associated bacterial peritonitis – characterized by an excessive influx of neutrophils and monocytes into the peritoneal cavity – show a selective activation of local Vγ9/Vδ2 T cells by HMB-PP producing but not by HMB-PP deficient bacterial pathogens. The γδ T cell-driven perpetuation of inflammatory responses during acute peritonitis is associated with elevated peritoneal levels of γδ T cells and TNF-α and detrimental clinical outcomes in infections caused by HMB-PP positive microorganisms. Taken together, our findings indicate a direct link between invading pathogens, neutrophils, monocytes and microbe-responsive γδ T cells in early

  19. Elastin receptor (S-gal) occupancy by elastin peptides modulates T-cell response during murine emphysema.

    PubMed

    Meghraoui-Kheddar, Aïda; Pierre, Alexandre; Sellami, Mehdi; Audonnet, Sandra; Lemaire, Flora; Le Naour, Richard

    2017-09-01

    Chronic obstructive pulmonary disease and emphysema are associated with increased elastin peptides (EP) production because of excessive breakdown of lung connective tissue. We recently reported that exposure of mice to EP elicited hallmark features of emphysema. EP effects are largely mediated through a receptor complex that includes the elastin-binding protein spliced-galactosidase (S-gal). In previous studies, we established a correlation between cytokine production and S-gal protein expression in EP-treated immune cells. In this study, we investigated the S-gal-dependent EP effects on T-helper (Th) and T-cytotoxic (Tc) responses during murine EP-triggered pulmonary inflammation. C57BL/6J mice were endotracheally instilled with the valine-glycine-valine-alanine-proline-glycine (VGVAPG) elastin peptide, and, 21 days after treatment, local and systemic T-lymphocyte phenotypes were analyzed at cytokine and transcription factor expression levels by multicolor flow cytometry. Exposure of mice to the VGVAPG peptide resulted in a significant increase in the proportion of the CD4 + and CD8 + T cells expressing the cytokines IFN-γ or IL-17a and the transcription factors T-box expressed in T cells or retinoic acid-related orphan receptor-γt (RORγt) without effects on IL-4 and Gata-binding protein 3 to DNA sequence [A/T]GATA[A/G] expression. These effects were maximized when each T-cell subpopulation was challenged ex vivo with EP, and they were inhibited in vivo when an analogous peptide antagonizing the EP/S-gal interactions was instilled together with the VGVAPG peptide. This study demonstrates that, during murine emphysema, EP-S-gal interactions contribute to a Th-1 and Th-17 proinflammatory T-cell response combined with a Tc-1 response. Our study also highlights the S-gal receptor as a putative pharmacological target to modulate such an immune response. Copyright © 2017 the American Physiological Society.

  20. Inhibition of T Helper Cell Type 2 Cell Differentiation and Immunoglobulin E Response by Ligand-Activated Vα14 Natural Killer T Cells

    PubMed Central

    Cui, Junqing; Watanabe, Naohiro; Kawano, Tetsu; Yamashita, Masakatsu; Kamata, Tohru; Shimizu, Chiori; Kimura, Motoko; Shimizu, Eiko; Koike, Jyunzo; Koseki, Haruhiko; Tanaka, Yujiro; Taniguchi, Masaru; Nakayama, Toshinori

    1999-01-01

    Murine Vα14 natural killer T (NKT) cells are thought to play a crucial role in various immune responses, including infectious, allergic, and autoimmune diseases. Because Vα14 NKT cells produce large amounts of both interleukin (IL)-4 and interferon (IFN)-γ upon in vivo stimulation with a specific ligand, α-galactosylceramide (α-GalCer), or after treatment with anti-CD3 antibody, a regulatory role on helper T (Th) cell differentiation has been proposed for these cells. However, the identity of the cytokine produced by Vα14 NKT cells that play a dominant role on the Th cell differentiation still remains controversial. Here, we demonstrate by using Vα14 NKT-deficient mice that Vα14 NKT cells are dispensable for the induction of antigen-specific immunoglobulin (Ig)E responses induced by ovalbumin immunization or Nippostrongylus brasiliensis infection. However, upon in vivo activation with α-GalCer, Vα14 NKT cells are found to suppress antigen-specific IgE production. The suppression appeared to be IgE specific, and was not detected in either Vα14 NKT– or IFN-γ–deficient mice. Consistent with these results, we also found that ligand-activated Vα14 NKT cells inhibited Th2 cell differentiation in an in vitro induction culture system. Thus, it is likely that activated Vα14 NKT cells exert a potent inhibitory effect on Th2 cell differentiation and subsequent IgE production by producing a large amount of IFN-γ. In marked contrast, our studies have revealed that IL-4 produced by Vα14 NKT cells has only a minor effect on Th2 cell differentiation. PMID:10499917

  1. RTS,S/AS01E Malaria Vaccine Induces Memory and Polyfunctional T Cell Responses in a Pediatric African Phase III Trial.

    PubMed

    Moncunill, Gemma; De Rosa, Stephen C; Ayestaran, Aintzane; Nhabomba, Augusto J; Mpina, Maximillian; Cohen, Kristen W; Jairoce, Chenjerai; Rutishauser, Tobias; Campo, Joseph J; Harezlak, Jaroslaw; Sanz, Héctor; Díez-Padrisa, Núria; Williams, Nana Aba; Morris, Daryl; Aponte, John J; Valim, Clarissa; Daubenberger, Claudia; Dobaño, Carlota; McElrath, M Juliana

    2017-01-01

    Comprehensive assessment of cellular responses to the RTS,S/AS01E vaccine is needed to understand potential correlates and ultimately mechanisms of protection against malaria disease. Cellular responses recognizing the RTS,S/AS01E-containing circumsporozoite protein (CSP) and Hepatitis B surface antigen (HBsAg) were assessed before and 1 month after primary vaccination by intracellular cytokine staining and 16-color flow cytometry in 105 RTS,S/AS01-vaccinated and 74 rabies-vaccinated participants (controls) in a pediatric phase III trial in Africa. RTS,S/AS01E-vaccinated children had significantly higher frequencies of CSP- and HBsAg-specific CD4 + T cells producing IL-2, TNF-α, and CD40L and HBsAg-specific CD4 + T producing IFN-γ and IL-17 than baseline and the control group. Vaccine-induced responses were identified in both central and effector memory (EM) compartments. EM CD4 + T cells expressing IL-4 and IL-21 were detected recognizing both vaccine antigens. Consistently higher response rates to both antigens in RTS,S/AS01E-vaccinated than comparator-vaccinated children were observed. RTS,S/AS01E induced polyfunctional CSP- and HBsAg-specific CD4 + T cells, with a greater degree of polyfunctionality in HBsAg responses. In conclusion, RTS,S/AS01E vaccine induces T cells of higher functional heterogeneity and polyfunctionality than previously characterized. Responses detected in memory CD4 + T cell compartments may provide correlates of RTS,S/AS01-induced immunity and duration of protection in future correlates of immunity studies.

  2. CD4+ T cells are important mediators of oxidative stress that cause hypertension in response to placental ischemia.

    PubMed

    Wallace, Kedra; Cornelius, Denise C; Scott, Jeremy; Heath, Judith; Moseley, Janae; Chatman, Krystal; LaMarca, Babbette

    2014-11-01

    Preeclampsia is associated with oxidative stress, which is suspected to play a role in hypertension, placental ischemia, and fetal demise associated with the disease. Various cellular sources of oxidative stress, such as neutrophils, monocytes, and CD4(+) T cells have been suggested as culprits in the pathophysiology of preeclampsia. The objective of this study was to examine a role of circulating and placental CD4(+) T cells in oxidative stress in response to placental ischemia during pregnancy. CD4(+) T cells and oxidative stress were measured in preeclamptic and normal pregnant women, placental ischemic and normal pregnant rats, and normal pregnant recipient rats of placental ischemic CD4(+) T cells. Women with preeclampsia had significantly increased circulating (P=0.02) and placental CD4(+) T cells (P=0.0001); lymphocyte secretion of myeloperoxidase (P=0.004); and placental reactive oxygen species (P=0.0004) when compared with normal pregnant women. CD4(+) T cells from placental ischemic rats cause many facets of preeclampsia when injected into normal pregnant recipient rats on gestational day 13. On gestational day 19, blood pressure increased in normal pregnant recipients of placental ischemic CD4(+) T cells (P=0.002) compared with that in normal pregnant rats. Similar to preeclamptic patients, CD4(+) T cells from placental ischemic rats secreted significantly more myeloperoxidase (P=0.003) and induced oxidative stress in cultured vascular cells (P=0.003) than normal pregnant rat CD4(+)Tcells. Apocynin, a nicotinamide adenine dinucleotide phosphate inhibitor, attenuated hypertension and all oxidative stress markers in placental ischemic and normal pregnant recipient rats of placental ischemic CD4(+)Tcells (P=0.05). These data demonstrate an important role for CD4(+) T cells in mediating another factor, oxidative stress, to cause hypertension during preeclampsia. © 2014 American Heart Association, Inc.

  3. Curtailed T-cell activation curbs effector differentiation and generates CD8+ T cells with a naturally-occurring memory stem cell phenotype.

    PubMed

    Zanon, Veronica; Pilipow, Karolina; Scamardella, Eloise; De Paoli, Federica; De Simone, Gabriele; Price, David A; Martinez Usatorre, Amaia; Romero, Pedro; Mavilio, Domenico; Roberto, Alessandra; Lugli, Enrico

    2017-09-01

    Human T memory stem (T SCM ) cells with superior persistence capacity and effector functions are emerging as important players in the maintenance of long-lived T-cell memory and are thus considered an attractive population to be used in adoptive transfer-based immunotherapy of cancer. However, the molecular signals regulating their generation remain poorly defined. Here we show that curtailed T-cell receptor stimulation curbs human effector CD8 + T-cell differentiation and allows the generation of CD45RO - CD45RA + CCR7 + CD27 + CD95 + -phenotype cells from highly purified naïve T-cell precursors, resembling naturally-occurring human T SCM . These cells proliferate extensively in vitro and in vivo, express low amounts of effector-associated genes and transcription factors and undergo considerable self-renewal in response to IL-15 while retaining effector differentiation potential. Such a phenotype is associated with a lower number of mitochondria compared to highly-activated effector T cells committed to terminal differentiation. These results shed light on the molecular signals that are required to generate long-lived memory T cells with potential application in adoptive cell transfer immunotherapy. © 2017 The Authors. European Journal of Immunology published by WILEY-VCH Verlag GmbH & Co.KGaA, Weinheim.

  4. Ex vivo detection of adenovirus specific CD4{sup +} T-cell responses to HLA-DR-epitopes of the Hexon protein show a contracted specificity of T{sub HELPER} cells following stem cell transplantation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Serangeli, Celine; Bicanic, Oliver; Scheible, Michael H.

    2010-02-20

    Human adenovirus (HAdV) is a cause of significant morbidity and mortality in immunocompromised patients, especially after stem cell transplantation (SCT). Viral clearance has been attributed to CD4{sup +} T-cell responses against the Hexon-protein, but the frequency of specific T{sub HELPER} cells is extremely low or not detectable ex vivo and preference for different CD4{sup +} T-cell epitopes is variable among individuals. We therefore analyzed 44 healthy donors and 6 SCT-recipients for Hexon-specific CD4{sup +}-responses ex vivo, to identify epitopes which would be broadly applicable. We selected 19 candidate epitopes with predicted restriction to HLA-DR1/DR3/DR4/DR7; 16 were located within the highlymore » conserved regions, indicating cross-reactivity of T cells among HAdV-subspecies. Ten epitopes induced CD4{sup +}-proliferation in >50% of individuals, confirmed by intracellular IFN-gamma detection. Three SCT recipients who recovered from an infection with HAdV displayed reactivity towards only a single hexon epitope, whereas healthy individuals were responsive to two to eight epitopes (median 3). The ex vivo detection of Hexon-specific CD4{sup +} T-cells, without any long-term culture in vitro, enables the detection and generation of HAdV-specific CD4{sup +} T cells for adoptive T-cell transfer against HAdV-infection post SCT.« less

  5. Functional diversity of human vaginal APC subsets in directing T cell responses

    PubMed Central

    Duluc, Dorothée; Gannevat, Julien; Anguiano, Esperanza; Zurawski, Sandra; Carley, Michael; Boreham, Muriel; Stecher, Jack; Dullaers, Melissa; Banchereau, Jacques; Oh, SangKon

    2012-01-01

    Human vaginal mucosa is the major entry site of sexually transmitted pathogens and thus has long been attractive as a site for mounting mucosal immunity. It is also known as a tolerogenic microenvironment. Here, we demonstrate that immune responses in the vagina are orchestrated by the functional diversity of four major antigen-presenting cell (APC) subsets. Langerhans cells (LCs) and CD14− lamina propria (LP)-DCs polarize CD4+ and CD8+ T cells toward Th2, whereas CD14+ LP-DCs and macrophages polarize CD4+ T cells toward Th1. Both LCs and CD14− LP-DCs are potent inducers of Th22. Due to their functional specialties and the different expression levels of pattern-recognition receptors on the APC subsets, microbial products do not bias them to elicit common types of immune responses (Th1 or Th2). To evoke desired types of adaptive immune responses in the human vagina, antigens may need to be targeted to proper APC subsets with right adjuvants. PMID:23131784

  6. Adult T-Cell Leukemia/Lymphoma

    MedlinePlus

    ... Adult T-Cell Leukemia/Lymphoma Adult T-Cell Leukemia/Lymphoma Adult T-cell A type of white ... immune responses by destroying harmful substances or cells. leukemia Disease generally characterized by the overproduction of abnormal ...

  7. Timing and magnitude of type I interferon responses by distinct sensors impact CD8 T cell exhaustion and chronic viral infection

    PubMed Central

    Wang, Yaming; Swiecki, Melissa; Cella, Marina; Alber, Gottfried; Schreiber, Robert D; Gilfillan, Susan; Colonna, Marco

    2013-01-01

    Summary Type I Interferons (IFN-I) promote antiviral CD8+T cell responses, but the contribution of different IFN-I sources and signaling pathways are ill-defined. While plasmacytoid dendritic cells (pDCs) produce IFN-I upon TLR stimulation, IFN-I are induced in most cells by helicases like MDA5. Using acute and chronic lymphocytic choriomeningitis virus (LCMV) infection models, we determined that pDCs transiently produce IFN-I that minimally impacts CD8+T cell responses and viral persistence. Rather, MDA5 is the key sensor that induces IFN-I required for CD8+T cell responses. In the absence of MDA5, CD8+T cell responses to acute infection rely on CD4+T cell help, and loss of both CD4+T cells and MDA5 results in CD8+T cell exhaustion and persistent infection. Chronic LCMV infection rapidly attenuates IFN-I responses, but early administration of exogenous IFN-I rescues CD8+T cells, promoting viral clearance. Thus, effective antiviral CD8+T cell responses depend on the timing and magnitude of IFN-I responses. PMID:22704623

  8. Cerebral regulatory T cells restrain microglia/macrophage-mediated inflammatory responses via IL-10

    PubMed Central

    Xie, Luokun; Choudhury, Gourav Roy; Winters, Ali; Yang, Shao-Hua; Jin, Kunlin

    2014-01-01

    Forkhead box P3 (Foxp3)+ regulatory T (Treg) cells maintain the immune tolerance and prevent inflammatory responses in the periphery. However, the presence of Treg cells in the central nervous system under steady state has not been studied. Here, for the first time, we show a substantial TCRαβ+CD4+Foxp3+ T-cell population (cerebral Treg cells) in the normal rat cerebrum, constituting more than 15% of the cerebral CD4+ T-cell compartment. Cerebral Treg cells showed an activated/memory phenotype and expressed many Treg-cell signature genes at higher levels than peripheral Treg cells. Consistent with their activated/memory phenotype, cerebral Treg cells robustly restrained the LPS-induced inflammatory responses of brain microglia/macrophages, suggesting a role in maintaining the cerebral homeostasis by inhibiting the neuroinflammation. In addition, brain astrocytes were the helper cells that sustained Foxp3 expression in Treg cells through IL-2/STAT5 signaling, showing that the interaction between astrocytes and Treg cells contributes to the maintenance of Treg-cell identity in the brain. Taken together, our work represents the first study to characterize the phenotypic and functional features of Treg cells in the normal rat cerebrum. Our data have provided a novel insight for the contribution of Treg cells to the immunosurveillance and immunomodulation in the cerebrum under steady state. PMID:25329858

  9. Mast cells enhance T cell activation: Importance of mast cell-derived TNF

    NASA Astrophysics Data System (ADS)

    Nakae, Susumu; Suto, Hajime; Kakurai, Maki; Sedgwick, Jonathon D.; Tsai, Mindy; Galli, Stephen J.

    2005-05-01

    Mast cells are not only important effector cells in immediate hypersensitivity reactions and immune responses to pathogens but also can contribute to T cell-mediated disorders. However, the mechanisms by which mast cells might influence T cells in such settings are not fully understood. We find that mast cells can enhance proliferation and cytokine production in multiple T cell subsets. Mast cell-dependent enhancement of T cell activation can be promoted by FcRI-dependent mast cell activation, TNF production by both mast cells and T cells, and mast cell-T cell contact. However, at high concentrations of cells, mast cells can promote T cell activation independent of IgE or TNF. Finally, mast cells also can promote T cell activation by means of soluble factors. These findings identify multiple mechanisms by which mast cells can influence T cell proliferation and cytokine production. allergy | asthma | autoimmunity | cytokines | immune response

  10. T-Cell Therapy Using Interleukin-21–Primed Cytotoxic T-Cell Lymphocytes Combined With Cytotoxic T-Cell Lymphocyte Antigen-4 Blockade Results in Long-Term Cell Persistence and Durable Tumor Regression

    PubMed Central

    Chapuis, Aude G.; Roberts, Ilana M.; Thompson, John A.; Margolin, Kim A.; Bhatia, Shailender; Lee, Sylvia M.; Sloan, Heather L.; Lai, Ivy P.; Farrar, Erik A.; Wagener, Felecia; Shibuya, Kendall C.; Cao, Jianhong; Wolchok, Jedd D.; Greenberg, Philip D.

    2016-01-01

    Purpose Peripheral blood–derived antigen-specific cytotoxic T cells (CTLs) provide a readily available source of effector cells that can be administered with minimal toxicity in an outpatient setting. In metastatic melanoma, this approach results in measurable albeit modest clinical responses in patients resistant to conventional therapy. We reasoned that concurrent cytotoxic T-cell lymphocyte antigen-4 (CTLA-4) checkpoint blockade might enhance the antitumor activity of adoptively transferred CTLs. Patients and Methods Autologous MART1-specific CTLs were generated by priming with peptide-pulsed dendritic cells in the presence of interleukin-21 and enriched by peptide-major histocompatibility complex multimer-guided cell sorting. This expeditiously yielded polyclonal CTL lines uniformly expressing markers associated with an enhanced survival potential. In this first-in-human strategy, 10 patients with stage IV melanoma received the MART1-specific CTLs followed by a standard course of anti–CTLA-4 (ipilimumab). Results The toxicity profile of the combined treatment was comparable to that of ipilimumab monotherapy. Evaluation of best responses at 12 weeks yielded two continuous complete remissions, one partial response (PR) using RECIST criteria (two PRs using immune-related response criteria), and three instances of stable disease. Infused CTLs persisted with frequencies up to 2.9% of CD8+ T cells for as long as the patients were monitored (up to 40 weeks). In patients who experienced complete remissions, PRs, or stable disease, the persisting CTLs acquired phenotypic and functional characteristics of long-lived memory cells. Moreover, these patients also developed responses to nontargeted tumor antigens (epitope spreading). Conclusion We demonstrate that combining antigen-specific CTLs with CTLA-4 blockade is safe and produces durable clinical responses, likely reflecting both enhanced activity of transferred cells and improved recruitment of new responses

  11. Distinct T helper cell dependence of memory B-cell proliferation versus plasma cell differentiation.

    PubMed

    Zabel, Franziska; Fettelschoss, Antonia; Vogel, Monique; Johansen, Pål; Kündig, Thomas M; Bachmann, Martin F

    2017-03-01

    Several memory B-cell subclasses with distinct functions have been described, of which the most effective is the class-switched (CS) memory B-cell population. We have previously shown, using virus-like particles (VLPs), that the proliferative potential of these CS memory B cells is limited and they fail to re-enter germinal centres (GCs). However, VLP-specific memory B cells quickly differentiated into secondary plasma cells (PCs) with the virtue of elevated antibody production compared with primary PCs. Whereas the induction of VLP + memory B cells was strongly dependent on T helper cells, we were wondering whether re-stimulation of VLP + memory B cells and their differentiation into secondary PCs would also require T helper cells. Global absence of T helper cells led to strongly impaired memory B cell proliferation and PC differentiation. In contrast, lack of interleukin-21 receptor-dependent follicular T helper cells or CD40 ligand signalling strongly affected proliferation of memory B cells, but differentiation into mature secondary PCs exhibiting increased antibody production was essentially normal. This contrasts with primary B-cell responses, where a strong dependence on CD40 ligand but limited importance of interleukin-21 receptor was seen. Hence, T helper cell dependence differs between primary and secondary B-cell responses as well as between memory B-cell proliferation and PC differentiation. © 2016 John Wiley & Sons Ltd.

  12. [Regulatory T cells].

    PubMed

    Marinić, Igor; Gagro, Alenka; Rabatić, Sabina

    2006-12-01

    Regulatory T-cells are a subset of T cells that have beene extensively studied in modern immunology. They are important for the maintenance of peripheral tolerance, and have an important role in various clinical conditions such as allergy, autoimmune disorders, tumors, infections, and in transplant medicine. Basically, this population has a suppressive effect on the neighboring immune cells, thus contributing to the local modulation and control of immune response. There are two main populations of regulatory T cells - natural regulatory T cells, which form a distinct cellular lineage, develop in thymus and perform their modulatory action through direct intercellular contact, along with the secreted cytokines; and inducible regulatory T cells, which develop in the periphery after contact with the antigen that is presented on the antigen presenting cell, and their primary mode of action is through the interleukin 10 (IL-10) and transforming growth factor beta (TGF-alpha) cytokines. Natural regulatory T cells are activated through T cell receptor after contact with specific antigen and inhibit proliferation of other T cells in an antigen independent manner. One of the major difficulties in the research of regulatory T cells is the lack of specific molecular markers that would identify these cells. Natural regulatory T cells constitutively express surface molecule CD25, but many other surface and intracellular molecules (HLA-DR, CD122, CD45RO, CD62, CTLA-4, GITR, PD-1, Notch, FOXP3, etc.) are being investigated for further phenotypic characterization of these cells. Because regulatory T cells have an important role in establishing peripheral tolerance, their importance is manifested in a number of clinical conditions. In the IPEX syndrome (immunodysregulation, polyendocrinopathy and enteropathy, X-linked), which is caused by mutation in Foxp3 gene that influences the development and function of regulatory T cells, patients develop severe autoimmune reactions that

  13. Viral Infection of Tumors Overcomes Resistance to PD-1-immunotherapy by Broadening Neoantigenome-directed T-cell Responses

    PubMed Central

    Woller, Norman; Gürlevik, Engin; Fleischmann-Mundt, Bettina; Schumacher, Anja; Knocke, Sarah; Kloos, Arnold M; Saborowski, Michael; Geffers, Robert; Manns, Michael P; Wirth, Thomas C; Kubicka, Stefan; Kühnel, Florian

    2015-01-01

    There is evidence that viral oncolysis is synergistic with immune checkpoint inhibition in cancer therapy but the underlying mechanisms are unclear. Here, we investigated whether local viral infection of malignant tumors is capable of overcoming systemic resistance to PD-1-immunotherapy by modulating the spectrum of tumor-directed CD8 T-cells. To focus on neoantigen-specific CD8 T-cell responses, we performed transcriptomic sequencing of PD-1-resistant CMT64 lung adenocarcinoma cells followed by algorithm-based neoepitope prediction. Investigations on neoepitope-specific T-cell responses in tumor-bearing mice demonstrated that PD-1 immunotherapy was insufficient whereas viral oncolysis elicited cytotoxic T-cell responses to a conserved panel of neoepitopes. After combined treatment, we observed that PD-1-blockade did not affect the magnitude of oncolysis-mediated antitumoral immune responses but a broader spectrum of T-cell responses including additional neoepitopes was observed. Oncolysis of the primary tumor significantly abrogated systemic resistance to PD-1-immunotherapy leading to improved elimination of disseminated lung tumors. Our observations were confirmed in a transgenic murine model of liver cancer where viral oncolysis strongly induced PD-L1 expression in primary liver tumors and lung metastasis. Furthermore, we demonstrated that combined treatment completely inhibited dissemination in a CD8 T-cell-dependent manner. Therefore, our results strongly recommend further evaluation of virotherapy and concomitant PD-1 immunotherapy in clinical studies. PMID:26112079

  14. Viral Infection of Tumors Overcomes Resistance to PD-1-immunotherapy by Broadening Neoantigenome-directed T-cell Responses.

    PubMed

    Woller, Norman; Gürlevik, Engin; Fleischmann-Mundt, Bettina; Schumacher, Anja; Knocke, Sarah; Kloos, Arnold M; Saborowski, Michael; Geffers, Robert; Manns, Michael P; Wirth, Thomas C; Kubicka, Stefan; Kühnel, Florian

    2015-10-01

    There is evidence that viral oncolysis is synergistic with immune checkpoint inhibition in cancer therapy but the underlying mechanisms are unclear. Here, we investigated whether local viral infection of malignant tumors is capable of overcoming systemic resistance to PD-1-immunotherapy by modulating the spectrum of tumor-directed CD8 T-cells. To focus on neoantigen-specific CD8 T-cell responses, we performed transcriptomic sequencing of PD-1-resistant CMT64 lung adenocarcinoma cells followed by algorithm-based neoepitope prediction. Investigations on neoepitope-specific T-cell responses in tumor-bearing mice demonstrated that PD-1 immunotherapy was insufficient whereas viral oncolysis elicited cytotoxic T-cell responses to a conserved panel of neoepitopes. After combined treatment, we observed that PD-1-blockade did not affect the magnitude of oncolysis-mediated antitumoral immune responses but a broader spectrum of T-cell responses including additional neoepitopes was observed. Oncolysis of the primary tumor significantly abrogated systemic resistance to PD-1-immunotherapy leading to improved elimination of disseminated lung tumors. Our observations were confirmed in a transgenic murine model of liver cancer where viral oncolysis strongly induced PD-L1 expression in primary liver tumors and lung metastasis. Furthermore, we demonstrated that combined treatment completely inhibited dissemination in a CD8 T-cell-dependent manner. Therefore, our results strongly recommend further evaluation of virotherapy and concomitant PD-1 immunotherapy in clinical studies.

  15. The Subcellular Location of Ovalbumin in Plasmodium berghei Blood Stages Influences the Magnitude of T-Cell Responses

    PubMed Central

    Lin, Jing-Wen; Shaw, Tovah N.; Annoura, Takeshi; Fougère, Aurélie; Bouchier, Pascale; Chevalley-Maurel, Séverine; Kroeze, Hans; Franke-Fayard, Blandine; Janse, Chris J.; Couper, Kevin N.

    2014-01-01

    Model antigens are frequently introduced into pathogens to study determinants that influence T-cell responses to infections. To address whether an antigen's subcellular location influences the nature and magnitude of antigen-specific T-cell responses, we generated Plasmodium berghei parasites expressing the model antigen ovalbumin (OVA) either in the parasite cytoplasm or on the parasitophorous vacuole membrane (PVM). For cytosolic expression, OVA alone or conjugated to mCherry was expressed from a strong constitutive promoter (OVAhsp70 or OVA::mCherryhsp70); for PVM expression, OVA was fused to HEP17/EXP1 (OVA::Hep17hep17). Unexpectedly, OVA expression in OVAhsp70 parasites was very low, but when OVA was fused to mCherry (OVA::mCherryhsp70), it was highly expressed. OVA expression in OVA::Hep17hep17 parasites was strong but significantly less than that in OVA::mCherryhsp70 parasites. These transgenic parasites were used to examine the effects of antigen subcellular location and expression level on the development of T-cell responses during blood-stage infections. While all OVA-expressing parasites induced activation and proliferation of OVA-specific CD8+ T cells (OT-I) and CD4+ T cells (OT-II), the level of activation varied: OVA::Hep17hep17 parasites induced significantly stronger splenic and intracerebral OT-I and OT-II responses than those of OVA::mCherryhsp70 parasites, but OVA::mCherryhsp70 parasites promoted stronger OT-I and OT-II responses than those of OVAhsp70 parasites. Despite lower OVA expression levels, OVA::Hep17hep17 parasites induced stronger T-cell responses than those of OVA::mCherryhsp70 parasites. These results indicate that unconjugated cytosolic OVA is not stably expressed in Plasmodium parasites and, importantly, that its cellular location and expression level influence both the induction and magnitude of parasite-specific T-cell responses. These parasites represent useful tools for studying the development and function of antigen

  16. Endogenous antigen processing drives the primary CD4+ T cell response to influenza

    PubMed Central

    Miller, Michael A.; Ganesan, Asha Purnima V.; Luckashenak, Nancy; Mendonca, Mark; Eisenlohr, Laurence C.

    2015-01-01

    By convention, CD4+ T lymphocytes recognize foreign and self peptides derived from internalized antigens in combination with MHC class II molecules. Alternative pathways of epitope production have been identified but their contributions to host defense have not been established. We show here in a mouse infection model that the CD4+ T cell response to influenza, critical for durable protection from the virus, is driven principally by unconventional processing of antigen synthesized within the infected antigen-presenting cell, not by classical processing of endocytosed virions or material from infected cells. Investigation of the cellular components involved, including the H2-M molecular chaperone, the proteasome, and gamma-interferon inducible lysosomal thiol reductase revealed considerable heterogeneity in the generation of individual epitopes, an arrangement that ensures peptide diversity and broad CD4+ T cell engagement. These results could fundamentally revise strategies for rational vaccine design and may lead to key insights into the induction of autoimmune and anti-tumor responses. PMID:26413780

  17. Expression of Master Regulators of T-cell, Helper T-cell and Follicular Helper T-cell Differentiation in Angioimmunoblastic T-cell Lymphoma.

    PubMed

    Matsumoto, Yosuke; Nagoshi, Hisao; Yoshida, Mihoko; Kato, Seiichi; Kuroda, Junya; Shimura, Kazuho; Kaneko, Hiroto; Horiike, Shigeo; Nakamura, Shigeo; Taniwaki, Masafumi

    2017-11-01

    Objective It has been postulated that the normal counterpart of angioimmunoblastic T-cell lymphoma (AITL) is the follicular helper T-cell (TFH). Recent immunological studies have identified several transcription factors responsible for T-cell differentiation. The master regulators associated with T-cell, helper T-cell (Th), and TFH differentiation are reportedly BCL11B, Th-POK, and BCL6, respectively. We explored the postulated normal counterpart of AITL with respect to the expression of the master regulators of T-cell differentiation. Methods We performed an immunohistochemical analysis in 15 AITL patients to determine the expression of the master regulators and several surface markers associated with T-cell differentiation. Results BCL11B was detected in 10 patients (67%), and the surface marker of T-cells (CD3) was detected in all patients. Only 2 patients (13%) expressed the marker of naïve T-cells (CD45RA), but all patients expressed the marker of effector T-cells (CD45RO). Nine patients expressed Th-POK (60%), and 7 (47%) expressed a set of surface antigens of Th (CD4-positive and CD8-negative). In addition, BCL6 and the surface markers of TFH (CXCL13, PD-1, and SAP) were detected in 11 (73%), 8 (53%), 14 (93%), and all patients, respectively. Th-POK-positive/BCL6-negative patients showed a significantly shorter overall survival (OS) than the other patients (median OS: 33.0 months vs. 74.0 months, p=0.020; log-rank test). Conclusion Many of the AITL patients analyzed in this study expressed the master regulators of T-cell differentiation. The clarification of the diagnostic significance and pathophysiology based on the expression of these master regulators in AITL is expected in the future.

  18. Intranasal delivery of recombinant parvovirus-like particles elicits cytotoxic T-cell and neutralizing antibody responses.

    PubMed

    Sedlik, C; Dridi, A; Deriaud, E; Saron, M F; Rueda, P; Sarraseca, J; Casal, J I; Leclerc, C

    1999-04-01

    We previously demonstrated that chimeric porcine parvovirus-like particles (PPV:VLP) carrying heterologous epitopes, when injected intraperitoneally into mice without adjuvant, activate strong CD4(+) and CD8(+) T-cell responses specific for the foreign epitopes. In the present study, we investigated the immunogenicity of PPV:VLP carrying a CD8(+) T-cell epitope from the lymphocytic choriomeningitis virus (LCMV) administered by mucosal routes. Mice immunized intranasally with recombinant PPV:VLP, in the absence of adjuvant, developed high levels of PPV-specific immunoglobulin G (IgG) and/or IgA in their serum, as well as in mucosal sites such as the bronchoalveolar and intestinal fluids. Antibodies in sera from mice immunized parenterally or intranasally with PPV:VLP were strongly neutralizing in vitro. Intranasal immunization with PPV:VLP carrying the LCMV CD8(+) T-cell epitope also elicited a strong peptide-specific cytotoxic-T-cell (CTL) response. In contrast, mice orally immunized with recombinant PPV:VLP did not develop any antibody or CTL responses. We also showed that mice primed with PPV:VLP are still able to develop strong CTL responses after subsequent immunization with chimeric PPV:VLP carrying a foreign CD8(+) T-cell epitope. These results highlight the attractive potential of PPV:VLP as a safe, nonreplicating antigen carrier to stimulate systemic and mucosal immunity after nasal administration.

  19. Intranasal Delivery of Recombinant Parvovirus-Like Particles Elicits Cytotoxic T-Cell and Neutralizing Antibody Responses

    PubMed Central

    Sedlik, C.; Dridi, A.; Deriaud, E.; Saron, M. F.; Rueda, P.; Sarraseca, J.; Casal, J. I.; Leclerc, C.

    1999-01-01

    We previously demonstrated that chimeric porcine parvovirus-like particles (PPV:VLP) carrying heterologous epitopes, when injected intraperitoneally into mice without adjuvant, activate strong CD4+ and CD8+ T-cell responses specific for the foreign epitopes. In the present study, we investigated the immunogenicity of PPV:VLP carrying a CD8+ T-cell epitope from the lymphocytic choriomeningitis virus (LCMV) administered by mucosal routes. Mice immunized intranasally with recombinant PPV:VLP, in the absence of adjuvant, developed high levels of PPV-specific immunoglobulin G (IgG) and/or IgA in their serum, as well as in mucosal sites such as the bronchoalveolar and intestinal fluids. Antibodies in sera from mice immunized parenterally or intranasally with PPV:VLP were strongly neutralizing in vitro. Intranasal immunization with PPV:VLP carrying the LCMV CD8+ T-cell epitope also elicited a strong peptide-specific cytotoxic-T-cell (CTL) response. In contrast, mice orally immunized with recombinant PPV:VLP did not develop any antibody or CTL responses. We also showed that mice primed with PPV:VLP are still able to develop strong CTL responses after subsequent immunization with chimeric PPV:VLP carrying a foreign CD8+ T-cell epitope. These results highlight the attractive potential of PPV:VLP as a safe, nonreplicating antigen carrier to stimulate systemic and mucosal immunity after nasal administration. PMID:10074120

  20. Regulatory T cells in the actinic cheilitis.

    PubMed

    Gasparoto, Thaís Helena; de Souza Malaspina, Tatiana Salles; Damante, José Humberto; de Mello, Edgard Franco; Ikoma, Maura Rosane Valério; Garlet, Gustavo Pompermaier; Costa, Maria Renata Sales Nogueira; Cavassani, Karen Angélica; da Silva, João Santana; Campanelli, Ana Paula

    2014-11-01

    Actinic cheilitis (AC) is an oral potentially malignant lesion which is the counterpart of actinic keratosis of the skin and has potential to develop into squamous cell carcinoma. Regulatory T cells (Tregs) have a critical role in modulating the antitumor immune responses. The presence of regulatory T cells in potentially malignant lesions has not been described. We chose investigate the involvement of regulatory T cells in potentially malignant lesions. The frequency, phenotype, and activity of CD4+CD25+ T cells isolated from blood and lesion of AC patients were analyzed by flow cytometry. Cytokines were quantified by ELISA. Data were compared with samples from healthy subjects. The frequency and suppressor activity of circulating CD4+CD25+ T cells was similar in AC patients and control subjects. However, the frequencies of IL-10-positive Tregs were higher in AC patients, and these cells inhibited interferon-gamma (IFN-γ) and increased interleukin (IL)-10 productions in co-cultures. Furthermore, CD4+CD25+ T cells accumulate in AC lesions. Lesions-derived regulatory T cells suppressed lymphocyte proliferation and pro-inflammatory cytokine production. Moreover, high levels of IL-10 and transforming growth factor-β (TGF-β), and low IFN-γ were detected in the potentially malignant lesions. Therefore, our data show that Tregs accumulate in AC lesions, and these cells could be suppressing immune responses in a potentially malignant microenvironment. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  1. BTLA interaction with HVEM expressed on CD8(+) T cells promotes survival and memory generation in response to a bacterial infection.

    PubMed

    Steinberg, Marcos W; Huang, Yujun; Wang-Zhu, Yiran; Ware, Carl F; Cheroutre, Hilde; Kronenberg, Mitchell

    2013-01-01

    The B and T lymphocyte attenuator (BTLA) is an Ig super family member that binds to the herpes virus entry mediator (HVEM), a TNF receptor super family (TNFRSF) member. Engagement of BTLA by HVEM triggers inhibitory signals, although recent evidence indicates that BTLA also may act as an activating ligand for HVEM. In this study, we reveal a novel role for the BTLA-HVEM pathway in promoting the survival of activated CD8(+) T cells in the response to an oral microbial infection. Our data show that both BTLA- and HVEM-deficient mice infected with Listeria monocytogenes had significantly reduced numbers of primary effector and memory CD8(+) T cells, despite normal proliferation and expansion compared to controls. In addition, blockade of the BTLA-HVEM interaction early in the response led to significantly reduced numbers of antigen-specific CD8(+) T cells. HVEM expression on the CD8(+) T cells as well as BTLA expression on a cell type other than CD8(+) T lymphocytes, was required. Collectively, our data demonstrate that the function of the BTLA-HVEM pathway is not limited to inhibitory signaling in T lymphocytes, and instead, that BTLA can provide crucial, HVEM-dependent signals that promote survival of antigen activated CD8(+) T cell during bacterial infection.

  2. Strategy for eliciting antigen-specific CD8+ T cell-mediated immune response against a cryptic CTL epitope of merkel cell polyomavirus large T antigen

    PubMed Central

    2012-01-01

    Background Merkel cell carcinoma (MCC) is a relatively new addition to the expanding category of oncovirus-induced cancers. Although still comparably rare, the number of cases has risen dramatically in recent years. Further complicating this trend is that MCC is an extremely aggressive neoplasm with poor patient prognosis and limited treatment options for advanced disease. The causative agent of MCC has been identified as the merkel cell polyomavirus (MCPyV). The MCPyV-encoded large T (LT) antigen is an oncoprotein that is theorized to be essential for virus-mediated tumorigenesis and is therefore, an excellent MCC antigen for the generation of antitumor immune responses. As a foreign antigen, the LT oncoprotein avoids the obstacle of immune tolerance, which normally impedes the development of antitumor immunity. Ergo, it is an excellent target for anti-MCC immunotherapy. Since tumor-specific CD8+ T cells lead to better prognosis for MCC and numerous other cancers, we have generated a DNA vaccine that is capable of eliciting LT-specific CD8+ T cells. The DNA vaccine (pcDNA3-CRT/LT) encodes the LT antigen linked to a damage-associated molecular pattern, calreticulin (CRT), as it has been demonstrated that the linkage of CRT to antigens promotes the induction of antigen-specific CD8+ T cells. Results The present study shows that DNA vaccine-induced generation of LT-specific CD8+ T cells is augmented by linking CRT to the LT antigen. This is relevant since the therapeutic effects of the pcDNA3-CRT/LT DNA vaccine is mediated by LT-specific CD8+ T cells. Mice vaccinated with the DNA vaccine produced demonstrably more LT-specific CD8+ T cells. The DNA vaccine was also able to confer LT-specific CD8+ T cell-mediated protective and therapeutic effects to prolong the survival of mice with LT-expressing tumors. In the interest of determining the LT epitope which most MCC-specific CD8+ T cells recognize, we identified the amino acid sequence of the immunodominant LT epitope

  3. Dysregulated luminal bacterial antigen-specific T-cell responses and antigen-presenting cell function in HLA-B27 transgenic rats with chronic colitis

    PubMed Central

    Qian, Bi-Feng; Tonkonogy, Susan L; Hoentjen, Frank; Dieleman, Levinus A; Sartor, R Balfour

    2005-01-01

    HLA-B27/β2 microglobulin transgenic (TG) rats spontaneously develop T-cell-mediated colitis when colonized with normal commensal bacteria, but remain disease-free under germ-free conditions. We investigated regulation of in vitro T-cell responses to enteric bacterial components. Bacterial lysates prepared from the caecal contents of specific pathogen-free (SPF) rats stimulated interferon-γ (IFN-γ) production by TG but not non-TG mesenteric lymph node (MLN) cells. In contrast, essentially equivalent amounts of interleukin-10 (IL-10) were produced by TG and non-TG cells. However, when cells from MLNs of non-TG rats were cocultured with TG MLN cells, no suppression of IFN-γ production was noted. Both non-TG and TG antigen-presenting cells (APC) pulsed with caecal bacterial lysate were able to induce IFN-γ production by TG CD4+ cells, although non-TG APC were more efficient than TG APC. Interestingly, the addition of exogenous IL-10 inhibited non-TG APC but not TG APC stimulation of IFN-γ production by cocultured TG CD4+ lymphocytes. Conversely, in the presence of exogenous IFN-γ, production of IL-10 was significantly lower in the supernatants of TG compared to non-TG APC cultures. We conclude that commensal luminal bacterial components induce exaggerated in vitro IFN-γ responses in HLA-B27 TG T cells, which may in turn inhibit the production of regulatory molecules, such as IL-10. Alterations in the production of IFN-γ, and in responses to this cytokine, as well as possible resistance of TG cells to suppressive regulation could together contribute to the development of chronic colitis in TG rats. PMID:16108823

  4. B-Cell and T-Cell Immune Responses to Experimental Helicobacter pylori Infection in Humans

    PubMed Central

    Nurgalieva, Zhannat Z.; Conner, Margaret E.; Opekun, Antone R.; Zheng, Carl Q.; Elliott, Susan N.; Ernst, Peter B.; Osato, Michael; Estes, Mary K.; Graham, David Y.

    2005-01-01

    The acute antibody and T-cell immune response to Helicobacter pylori infection in humans has not been studied systematically. Serum from H. pylori-naive volunteers challenged with H. pylori and cured after 4 or 12 weeks was tested by enzyme-linked immunosorbent assays for anti-H. pylori-specific immunoglobulin M (IgM) and IgA established using bacterial lysates from homologous (the infecting strain) and heterologous H. pylori. Proteins recognized by IgM antibody were identified by mass spectrometry of immunoreactive bands separated by two-dimensional gel electrophoresis. Mucosal T-cell subsets (CD4, CD8, CD3, and CD30 cells) were assessed by immunohistochemistry. All 18 infected volunteers developed H. pylori-specific IgM responses to both homologous or heterologous H. pylori antigens. H. pylori antigens reacted with IgM antibody at 4 weeks postinfection. IgM Western blotting showed immunoreactivity of postinfection serum samples to multiple H. pylori proteins with molecular weights ranging between 9,000 (9K) to 150K with homologous strains but only a 70K band using heterologous antigens. Two-dimensional electrophoresis demonstrated that production of H. pylori-specific IgM antibodies was elicited by H. pylori flagellins A and B, urease B, ABC transporter binding protein, heat shock protein 70 (DnaK), and alkyl hydroperoxide reductase. Mucosal CD3, CD4, and CD8 T-cell numbers increased following infection. IgM antibody responses were detected to a range of homologous H. pylori antigens 2 to 4 weeks postchallenge. The majority of H. pylori proteins were those involved in motility and colonization and may represent targets for vaccine development. PMID:15845507

  5. Characterization of CD8+ T-cell response in acute and resolved hepatitis A virus infection.

    PubMed

    Schulte, I; Hitziger, T; Giugliano, S; Timm, J; Gold, H; Heinemann, F M; Khudyakov, Y; Strasser, M; König, C; Castermans, E; Mok, J Y; van Esch, W J E; Bertoletti, A; Schumacher, T N; Roggendorf, M

    2011-02-01

    In contrast to the infection with other hepatotropic viruses, hepatitis A virus (HAV) always causes acute self-limited hepatitis, although the role for virus-specific CD8 T cells in viral containment is unclear. Herein, we analyzed the T cell response in patients with acute hepatitis by utilizing a set of overlapping peptides and predicted HLA-A2 binders from the polyprotein. A set of 11 predicted peptides from the HAV polyprotein, identified as potential binders, were synthesized. Peripheral blood mononuclear cells (PBMCs) from patients were tested for IFNγ secretion after stimulation with these peptides and ex vivo with HLA-A2 tetramers. Phenotyping was carried out by staining with the activation marker CD38 and the memory marker CD127. Eight out of 11 predicted HLA-A2 binders showed a high binding affinity and five of them were recognized by CD8+ T cells from patients with hepatitis A. There were significant differences in the magnitude of the responses to these five peptides. One was reproducibly immunodominant and the only one detectable ex vivo by tetramer staining of CD8+ T cells. These cells have an activated phenotype (CD38hi CD127lo) during acute infection. Three additional epitopes were identified in HLA-A2 negative patients, most likely representing epitopes restricted by other HLA-class I-alleles (HLA-A11, B35, B40). Patients with acute hepatitis A have a strong multi-specific T cell response detected by ICS. With the tetramer carrying the dominant HLA-A2 epitope, HAV-specific and activated CD8+ T cells could be detected ex vivo. This first description of the HAV specific CTL-epitopes will allow future studies on strength, breadth, and kinetics of the T-cell response in hepatitis A. Copyright © 2010 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

  6. Antibody-Independent Control of γ-Herpesvirus Latency via B Cell Induction of Anti-Viral T Cell Responses

    PubMed Central

    McClellan, Kelly B; Gangappa, Shivaprakash; Speck, Samuel H; Virgin, Herbert W.

    2006-01-01

    B cells can use antibody-dependent mechanisms to control latent viral infections. It is unknown whether this represents the sole function of B cells during chronic viral infection. We report here that hen egg lysozyme (HEL)-specific B cells can contribute to the control of murine γ-herpesvirus 68 (γHV68) latency without producing anti-viral antibody. HEL-specific B cells normalized defects in T cell numbers and proliferation observed in B cell−/− mice during the early phase of γHV68 latency. HEL-specific B cells also reversed defects in CD8 and CD4 T cell cytokine production observed in B cell−/− mice, generating CD8 and CD4 T cells necessary for control of latency. Furthermore, HEL-specific B cells were able to present virally encoded antigen to CD8 T cells. Therefore, B cells have antibody independent functions, including antigen presentation, that are important for control of γ-herpesvirus latency. Exploitation of this property of B cells may allow enhanced vaccine responses to chronic virus infection. PMID:16789842

  7. The compartmentalized inflammatory response in the multiple sclerosis brain is composed of tissue-resident CD8+ T lymphocytes and B cells.

    PubMed

    Machado-Santos, Joana; Saji, Etsuji; Tröscher, Anna R; Paunovic, Manuela; Liblau, Roland; Gabriely, Galina; Bien, Christian G; Bauer, Jan; Lassmann, Hans

    2018-06-04

    Multiple sclerosis is an inflammatory demyelinating disease in which active demyelination and neurodegeneration are associated with lymphocyte infiltrates in the brain. However, so far little is known regarding the phenotype and function of these infiltrating lymphocyte populations. In this study, we performed an in-depth phenotypic characterization of T and B cell infiltrates in a large set of multiple sclerosis cases with different disease and lesion stages and compared the findings with those seen in inflammatory, non-inflammatory and normal human controls. In multiple sclerosis lesions, we found a dominance of CD8+ T cells and a prominent contribution of CD20+ B cells in all disease courses and lesion stages, including acute multiple sclerosis cases with very short disease duration, while CD4+ T cells were sparse. A dominance of CD8+ T cells was also seen in other inflammatory controls, such as Rasmussen's encephalitis and viral encephalitis, but the contribution of B cells in these diseases was modest. Phenotypic analysis of the CD8+ T cells suggested that part of the infiltrating cells in active lesions proliferate, show an activated cytotoxic phenotype and are in part destroyed by apoptosis. Further characterization of the remaining cells suggest that CD8+ T cells acquire features of tissue-resident memory cells, which may be focally reactivated in active lesions of acute, relapsing and progressive multiple sclerosis, while B cells, at least in part, gradually transform into plasma cells. The loss of surface molecules involved in the egress of leucocytes from inflamed tissue, such as S1P1 or CCR7, and the upregulation of CD103 expression may be responsible for the compartmentalization of the inflammatory response in established lesions. Similar phenotypic changes of tissue-infiltrating CD8+ T cells were also seen in Rasmussen's encephalitis. Our data underline the potential importance of CD8+ T lymphocytes and B cells in the inflammatory response in

  8. Adoptive immunotherapy with allodepleted donor T-cells improves immune reconstitution after haploidentical stem cell transplantation

    PubMed Central

    Amrolia, Persis J.; Muccioli-Casadei, Giada; Huls, Helen; Adams, Stuart; Durett, April; Gee, Adrian; Yvon, Eric; Weiss, Heidi; Cobbold, Mark; Gaspar, H. Bobby; Rooney, Cliona; Kuehnle, Ingrid; Ghetie, Victor; Schindler, John; Krance, Robert; Heslop, Helen E.; Veys, Paul; Vitetta, Ellen; Brenner, Malcolm K.

    2006-01-01

    Poor T lymphocyte reconstitution limits the use of haploidentical stem cell transplantation (SCT) because it results in a high mortality from viral infections. One approach to overcome this problem is to infuse donor T cells from which alloreactive lymphocytes have been selectively depleted, but the immunologic benefit of this approach is unknown. We have used an anti-CD25 immunotoxin to deplete alloreactive lymphocytes and have compared immune reconstitution after allodepleted donor T cells were infused at 2 dose levels into recipients of T-cell–depleted haploidentical SCT. Eight patients were treated at 104 cells/kg/dose, and 8 patients received 105 cells/kg/dose. Patients receiving 105 cells/kg/dose showed significantly improved T-cell recovery at 3, 4, and 5 months after SCT compared with those receiving 104 cells/kg/dose (P < .05). Accelerated T-cell recovery occurred as a result of expansion of the effector memory (CD45RA–CCR-7-) population (P < .05), suggesting that protective T-cell responses are likely to be long lived. T-cell–receptor signal joint excision circles (TRECs) were not detected in reconstituting T cells in dose-level 2 patients, indicating they are likely to be derived from the infused allodepleted cells. Spectratyping of the T cells at 4 months demonstrated a polyclonal Vβ repertoire. Using tetramer and enzyme-linked immunospot (ELISPOT) assays, we have observed cytomegalovirus (CMV)– and Epstein-Barr virus (EBV)–specific responses in 4 of 6 evaluable patients at dose level 2 as early as 2 to 4 months after transplantation, whereas such responses were not observed until 6 to 12 months in dose-level 1 patients. The incidence of significant acute (2 of 16) and chronic graft-versus-host disease (GVHD; 2 of 15) was low. These data demonstrate that allodepleted donor T cells can be safely used to improve T-cell recovery after haploidentical SCT and may broaden the applicability of this approach. PMID:16741253

  9. Selective T-cell depletion targeting CD45RA reduces viremia and enhances early T-cell recovery compared with CD3-targeted T-cell depletion.

    PubMed

    Triplett, Brandon M; Muller, Brad; Kang, Guolian; Li, Ying; Cross, Shane J; Moen, Joseph; Cunningham, Lea; Janssen, William; Mamcarz, Ewelina; Shook, David R; Srinivasan, Ashok; Choi, John; Hayden, Randall T; Leung, Wing

    2018-02-01

    T-cell depletion (TCD) effectively reduces severe graft-versus-host disease in recipients of HLA-mismatched allografts. However, TCD is associated with delayed immune recovery and increased infections. We hypothesized that specific depletion of CD45RA+ naive T cells, rather than broad depletion of CD3+ T cells, can preserve memory-immunity in the allografts and confer protection against important viral infections in the early post-transplant period. Sixty-seven patients who received TCD haploidentical donor transplantation for hematologic malignancy on 3 consecutive trials were analyzed. Patients receiving CD45RA-depleted donor grafts had 2000-fold more donor T cells infused, significantly higher T-cell counts at Day +30 post transplant (550/μL vs 10/μL; P < .001), and higher T-cell diversity by Vbeta spectratyping at Day +100 (P < .001). Importantly, these recipients experienced a significant reduction in both the incidence (P = .002) and duration (P = .02) of any viremia (cytomegalovirus, Epstein-Barr virus, or adenovirus) in the first 6 months post transplant. Specifically, recipients of CD3-depleted grafts were more likely to experience adenovirus viremia (27% vs 4%, P = .02). CD45RA-depletion provided a large number of donor memory T cells to the recipients and was associated with enhanced early T-cell recovery and protection against viremia. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  10. Helminth-induced regulatory T cells and suppression of allergic responses.

    PubMed

    Logan, Jayden; Navarro, Severine; Loukas, Alex; Giacomin, Paul

    2018-05-28

    Infection with helminths has been associated with lower rates of asthma and other allergic diseases. This has been attributed, in part, to the ability of helminths to induce regulatory T cells that suppress inappropriate immune responses to allergens. Recent compelling evidence suggests that helminths may promote regulatory T cell expansion or effector functions through either direct (secretion of excretory/secretory molecules) or indirect mechanisms (regulation of the microbiome). This review will discuss key findings from human immunoepidemiological observations, studies using animal models of disease, and clinical trials with live worm infections, discussing the therapeutic potential for worms and their secreted products for treating allergic inflammation. Crown Copyright © 2018. Published by Elsevier Ltd. All rights reserved.

  11. Timing and magnitude of type I interferon responses by distinct sensors impact CD8 T cell exhaustion and chronic viral infection.

    PubMed

    Wang, Yaming; Swiecki, Melissa; Cella, Marina; Alber, Gottfried; Schreiber, Robert D; Gilfillan, Susan; Colonna, Marco

    2012-06-14

    Type I interferon (IFN-I) promotes antiviral CD8(+)T cell responses, but the contribution of different IFN-I sources and signaling pathways are ill defined. While plasmacytoid dendritic cells (pDCs) produce IFN-I upon TLR stimulation, IFN-I is induced in most cells by helicases like MDA5. Using acute and chronic lymphocytic choriomeningitis virus (LCMV) infection models, we determined that pDCs transiently produce IFN-I that minimally impacts CD8(+)T cell responses and viral persistence. Rather, MDA5 is the key sensor that induces IFN-I required for CD8(+)T cell responses. In the absence of MDA5, CD8(+)T cell responses to acute infection rely on CD4(+)T cell help, and loss of both CD4(+)T cells and MDA5 results in CD8(+)T cell exhaustion and persistent infection. Chronic LCMV infection rapidly attenuates IFN-I responses, but early administration of exogenous IFN-I rescues CD8(+)T cells, promoting viral clearance. Thus, effective antiviral CD8(+)T cell responses depend on the timing and magnitude of IFN-I production. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. Somatic mutations and affinity maturation are impaired by excessive numbers of T follicular helper cells and restored by Treg cells or memory T cells.

    PubMed

    Preite, Silvia; Baumjohann, Dirk; Foglierini, Mathilde; Basso, Camilla; Ronchi, Francesca; Fernandez Rodriguez, Blanca M; Corti, Davide; Lanzavecchia, Antonio; Sallusto, Federica

    2015-11-01

    We previously reported that Cd3e-deficient mice adoptively transferred with CD4(+) T cells generate high numbers of T follicular helper (Tfh) cells, which go on to induce a strong B-cell and germinal center (GC) reaction. Here, we show that in this system, GC B cells display an altered distribution between the dark and light zones, and express low levels of activation-induced cytidine deaminase. Furthermore, GC B cells from Cd3e(-/-) mice accumulate fewer somatic mutations as compared with GC B cells from wild-type mice, and exhibit impaired affinity maturation and reduced differentiation into long-lived plasma cells. Reconstitution of Cd3e(-/-) mice with regulatory T (Treg) cells restored Tfh-cell numbers, GC B-cell numbers and B-cell distribution within dark and light zones, and the rate of antibody somatic mutations. Tfh-cell numbers and GC B-cell numbers and dynamics were also restored by pre-reconstitution of Cd3e(-/-) mice with Cxcr5(-/-) Treg cells or non-regulatory, memory CD4(+) T cells. Taken together, these findings underline the importance of a quantitatively regulated Tfh-cell response for an efficient and long-lasting serological response. © 2015 The Authors. European Journal of Immunology published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Significant IFNγ responses of CD8+ T cells in CMV-seropositive individuals with autoimmune arthritis.

    PubMed

    Almanzar, Giovanni; Schmalzing, Marc; Trippen, Raimund; Höfner, Kerstin; Weißbrich, Benedikt; Geissinger, Eva; Meyer, Thomas; Liese, Johannes; Tony, Hans-Peter; Prelog, Martina

    2016-04-01

    Latent Cytomegalovirus (CMV) infection accelerates immunosenescence in elderly with reactivations reported in Rheumatoid Arthritis (RA) and abnormal responses towards CMV in Juvenile Idiopathic Arthritis (JIA). Considering the signs of premature T-cell immunosenescence in arthritis patients, the known effect of CMV latency on speeding up many of these signs in an age-dependent manner and the role of CMV on IFNγ-mediated inflammation in healthy elderly and RA, we hypothesized that latent CMV infection accelerates TCR repertoire restriction, loss of CD28, peripheral T-cell proliferation and aberrant IFNγ responses in arthritis patients. Unspecific and CMVpp65-specific IFNγ responses were investigated in peripheral CD8+ T-cells in RA or JIA patients and healthy, age-matched controls. Despite higher prevalence and concentrations of IgG-anti-CMV, arthritis patients showed lower unspecific IFNγ production, lower CD69-mediated activation and lower CD8+ T-cell proliferation. CMV-seropositive RA patients showed higher intracellular IFNγ production and increased proportions of CD28-CD8+ T-cells after specific CMVpp65 long-term stimulation which was not altered by in vitro blockade of TNFα or IL-6. A skewed TCR repertoire towards oligoclonality and less polyclonality was found in JIA. CMVpp65-specific IFNγ production with expansion of CD28-CD8+ T-cells suggests an efficient control of latent CMV regardless of immunosuppressive therapy or in vitro blockade of TNFα or IL-6 in CMV-seropositive arthritis patients. Increased IgG-anti-CMV antibody concentrations and increased proportions of intracellular IFNγ-producing CMVpp65-specific CD8+ T-cells in long-term cultures propose a possibly role of endogenous CMV reactivations boosting antibody levels and a higher possibly CMV-driven IFNγ-mediated inflammatory potential of CD8+ T-cells in arthritis patients. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Antigen localization controls T cell-mediated tumor immunity.

    PubMed

    Zeelenberg, Ingrid S; van Maren, Wendy W C; Boissonnas, Alexandre; Van Hout-Kuijer, Maaike A; Den Brok, Martijn H M G M; Wagenaars, Jori A L; van der Schaaf, Alie; Jansen, Eric J R; Amigorena, Sebastian; Théry, Clotilde; Figdor, Carl G; Adema, Gosse J

    2011-08-01

    Effective antitumor immunotherapy requires the identification of suitable target Ags. Interestingly, many of the tumor Ags used in clinical trials are present in preparations of secreted tumor vesicles (exosomes). In this study, we compared T cell responses elicited by murine MCA101 fibrosarcoma tumors expressing a model Ag at different localizations within the tumor cell in association with secreted vesicles (exosomes), as a nonsecreted cell-associated protein, or as secreted soluble protein. Remarkably, we demonstrated that only the tumor-secreting vesicle-bound Ag elicited a strong Ag-specific CD8(+) T cell response, CD4(+) T cell help, Ag-specific Abs, and a decrease in the percentage of immunosuppressive regulatory T cells in the tumor. Moreover, in a therapeutic tumor model of cryoablation, only in tumors secreting vesicle-bound Ag could Ag-specific CD8(+) T cells still be detected up to 16 d after therapy. We concluded that the localization of an Ag within the tumor codetermines whether a robust immunostimulatory response is elicited. In vivo, vesicle-bound Ag clearly skews toward a more immunogenic phenotype, whereas soluble or cell-associated Ag expression cannot prevent or even delay outgrowth and results in tumor tolerance. This may explain why particular immunotherapies based on these vesicle-bound tumor Ags are potentially successful. Therefore, we conclude that this study may have significant implications in the discovery of new tumor Ags suitable for immunotherapy and that their location should be taken into account to ensure a strong antitumor immune response.

  15. Functional Heterogeneity in the CD4+ T Cell Response to Murine γ-Herpesvirus 68

    PubMed Central

    Hu, Zhuting; Blackman, Marcia A.; Kaye, Kenneth M.; Usherwood, Edward J.

    2015-01-01

    CD4+ T cells are critical for the control of virus infections, T cell memory and immune surveillance. Here we studied the differentiation and function of murine γ-herpesvirus 68 (MHV-68)-specific CD4+ T cells using gp150-specific TCR transgenic mice. This allowed a more detailed study of the characteristics of the CD4+ T cell response than previously available approaches for this virus. Most gp150-specific CD4+ T cells expressed T-bet and produced IFN-γ, indicating MHV-68 infection triggered differentiation of CD4+ T cells largely into the Th1 subset, whereas some became TFH and Foxp3+ regulatory T cells. These CD4+ T cells were protective against MHV-68 infection, in the absence of CD8+ T cells and B cells, and protection depended on IFN-γ secretion. Marked heterogeneity was observed in the CD4+ T cells, based on Ly6C expression. Ly6C expression positively correlated with IFN-γ, TNF-α and granzyme B production, T-bet and KLRG1 expression, proliferation and CD4+ T cell-mediated cytotoxicity. Ly6C expression inversely correlated with survival, CCR7 expression and secondary expansion potential. Ly6C+ and Ly6C− gp150-specific CD4+ T cells were able to interconvert in a bidirectional manner upon secondary antigen exposure in vivo. These results indicate that Ly6C expression is closely associated with antiviral activity in effector CD4+ T cells, but inversely correlated with memory potential. Interconversion between Ly6C+ and Ly6C− cells may maintain a balance between the two antigen-specific CD4+ T cell populations during MHV-68 infection. These findings have significant implications for Ly6C as a surface marker to distinguish functionally distinct CD4+ T cells during persistent virus infection. PMID:25662997

  16. Temporal dynamics of the primary human T cell response to yellow fever virus 17D as it matures from an effector- to a memory-type response.

    PubMed

    Blom, Kim; Braun, Monika; Ivarsson, Martin A; Gonzalez, Veronica D; Falconer, Karolin; Moll, Markus; Ljunggren, Hans-Gustaf; Michaëlsson, Jakob; Sandberg, Johan K

    2013-03-01

    The live attenuated yellow fever virus (YFV) 17D vaccine provides a good model to study immune responses to an acute viral infection in humans. We studied the temporal dynamics, composition, and character of the primary human T cell response to YFV. The acute YFV-specific effector CD8 T cell response was broad and complex; it was composed of dominant responses that persisted into the memory population, as well as of transient subdominant responses that were not detected at the memory stage. Furthermore, HLA-A2- and HLA-B7-restricted YFV epitope-specific effector cells predominantly displayed a CD45RA(-)CCR7(-)PD-1(+)CD27(high) phenotype, which transitioned into a CD45RA(+)CCR7(-)PD-1(-)CD27(low) memory population phenotype. The functional profile of the YFV-specific CD8 T cell response changed in composition as it matured from an effector- to a memory-type response, and it tended to become less polyfunctional during the course of this transition. Interestingly, activation of CD4 T cells, as well as FOXP3(+) T regulatory cells, in response to YFV vaccination preceded the kinetics of the CD8 T cell response. The present results contribute to our understanding of how immunodominance patterns develop, as well as the phenotypic and functional characteristics of the primary human T cell response to a viral infection as it evolves and matures into memory.

  17. Potentiating the antitumour response of CD8+ T cells by modulating cholesterol metabolism

    PubMed Central

    Yang, Wei; Bai, Yibing; Xiong, Ying; Zhang, Jin; Chen, Shuokai; Zheng, Xiaojun; Meng, Xiangbo; Li, Lunyi; Wang, Jing; Xu, Chenguang; Yan, Chengsong; Wang, Lijuan; Chang, Catharine C. Y.; Chang, Ta-Yuan; Zhang, Ti; Zhou, Penghui; Song, Bao-Liang; Liu, Wanli; Sun, Shao-cong; Liu, Xiaolong; Li, Bo-liang; Xu, Chenqi

    2016-01-01

    CD8+ T cells have a central role in antitumour immunity, but their activity is suppressed in the tumour microenvironment1–4. Reactivating the cytotoxicity of CD8+ T cells is of great clinical interest in cancer immunotherapy. Here we report a new mechanism by which the antitumour response of mouse CD8+ T cells can be potentiated by modulating cholesterol metabolism. Inhibiting cholesterol esterification in T cells by genetic ablation or pharmacological inhibition of ACAT1, a key cholesterol esterification enzyme5, led to potentiated effector function and enhanced proliferation of CD8+ but not CD4+ T cells. This is due to the increase in the plasma membrane cholesterol level of CD8+ T cells, which causes enhanced T-cell receptor clustering and signalling as well as more efficient formation of the immunological synapse. ACAT1-deficient CD8+ T cells were better than wild-type CD8+ T cells at controlling melanoma growth and metastasis in mice. We used the ACAT inhibitor avasimibe, which was previously tested in clinical trials for treating atherosclerosis and showed a good human safety profile6,7, to treat melanoma in mice and observed a good antitumour effect. A combined therapy of avasimibe plus an anti-PD-1 antibody showed better efficacy than monotherapies in controlling tumour progression. ACAT1, an established target for atherosclerosis, is therefore also a potential target for cancer immunotherapy. PMID:26982734

  18. Tolerogenic dendritic cells inhibit antiphospholipid syndrome derived effector/memory CD4⁺ T cell response to β2GPI.

    PubMed

    Torres-Aguilar, Honorio; Blank, Miri; Kivity, Shaye; Misgav, Mudi; Luboshitz, Jacob; Pierangeli, Silvia S; Shoenfeld, Yehuda

    2012-01-01

    The importance of β(2)-glycoprotein I (β(2)GPI)-specific CD4(+) T cells in the development of pathogenic processes in patients with antiphospholipid syndrome (APS) and APS mouse models is well established. Therefore, our objective is to manipulate the β2GPI specific CD4(+) T cells using tolerogenic dendritic cells (tDCs) to induce tolerance. We aim to evaluate the capability of tDCs to induce antigen-specific tolerance in effector/memory T cells from patients with APS and to elucidate the involved mechanism. DCs and tDCs were produced from patients with APS peripheral-blood-monocytes, using specific cytokines. β(2)GPI-specific tolerance induction was investigated by coculturing control DC (cDC) or tDC, β(2)GPI-loaded, with autologous effector/memory T cells, evaluating the proliferative response, phenotype, cytokines secretion, viability and regulatory T cells. Human monocyte-derived DCs treated with interleukin (IL)-10 and transforming growth factor β-1 (10/TGF-DC) induced β(2)GPI-specific-unresponsiveness in effector/memory CD4(+) T cells (46.5% ± 26.0 less proliferation) in 16 of 20 analysed patients with APS, without affecting the proliferative response to an unrelated candidin. In five analysed patients, 10/TGF-DC-stimulated T cells acquired an IL-2(low)interferon γ(low)IL-10(high) cytokine profile, with just a propensity to express higher numbers of Foxp3(+)CTLA-4(+) cells, but with an evident suppressive ability. In four of 10 analysed patients, 10/TGF-DC-stimulated T cell hyporesponsiveness could not be reverted and showed higher percentages of late apoptosis, p<0.02. The inherent tolerance induction resistance of activated T cells present during the development of autoimmune diseases has delayed the application of tDC as an alternative therapy. This study highlights the 10/TGF-DC feasibility to induce antigen-specific unresponsiveness in autoreactive T cells generated in patients with APS by inducing apoptosis or T cells with regulatory abilities.

  19. Development of a luciferase based viral inhibition assay to evaluate vaccine induced CD8 T-cell responses

    PubMed Central

    Naarding, Marloes A.; Fernandez-Fernandez, Natalia; Kappes, John C.; Hayes, Peter; Ahmed, Tina; Icyuz, Mert; Edmonds, Tara G.; Bergin, Philip; Anzala, Omu; Hanke, Tomas; Clark, Lorna; Cox, Josephine H.; Cormier, Emmanuel; Ochsenbauer, Christina; Gilmour, Jill

    2014-01-01

    Emergence of SIV and HIV specific CD8 T cells has been shown to correlate with control of in vivo replication. Poor correlation between IFN-γ ELISPOT responses and in vivo control of the virus has triggered the development of more relevant assays to assess functional HIV-1 specific CD8 T-cell responses for the evaluation and prioritization of new HIV-1 vaccine candidates. We previously established a viral inhibition assay (VIA) that measures the ability of vaccine-induced CD8 T-cell responses to inhibit viral replication in autologous CD4 T cells. In this assay, viral replication is determined by measuring p24 in the culture supernatant. Here we describe the development of a novel VIA, referred to as IMC LucR VIA that exploits replication-competent HIV-1 infectious molecular clones (IMCs) in which the complete proviral genome is strain-specific and which express the Renilla luciferase (LucR) gene to determine viral growth and inhibition. The introduction of the luciferase readout does provide significant improvement of the read out time. In addition to switching to the LucR read out, changes made to the overall protocol resulted in the miniaturization of the assay from a 48 to a 96-well plate format, which preserved sample and allowed for the introduction of replicates. The overall assay time was reduced from 13 to 8 days. The assay has a high degree of specificity, and the previously observed non-specific background inhibition in cells from HIV-1 negative volunteers has been reduced dramatically. Importantly, we observed an increase in positive responses, indicating an improvement in sensitivity compared to the original VIA. Currently, only a limited number of “whole-genome” IMC-LucR viruses are available and our efforts will focus on expanding the panel to better evaluate anti-viral breadth. Overall, we believe the IMC LucR VIA provides a platform to assess functional CD8 T-cell responses in large-scale clinical trial testing, which will enhance the ability

  20. Upregulation of bacterial-specific Th1 and Th17 responses that are enriched in CXCR5+CD4+ T cells in non-small cell lung cancer.

    PubMed

    Ma, Qin-Yun; Huang, Da-Yu; Zhang, Hui-Jun; Wang, Shaohua; Chen, Xiao-Feng

    2017-11-01

    The microbial community in the mucosal surfaces is involved in the development of human cancers, including gastric cancer and colorectal cancer. The respiratory tract in the lung also hosts a distinctive microbial community, but the correlation between this community and lung cancer is largely unknown. Here, we examined the Th1 and Th17 responses toward several bacterial antigens, in CD4 + T cells sourced from the peripheral blood (PB), the lung cancer (LC) tissue, and the gastrointestinal (GI) tract of non-small cell lung cancer (NSCLC) patients. Compared to healthy controls, the NSCLC patients presented significantly higher frequencies of Th1 and Th17 cells reacting to Streptococcus salivarius and S. agalactiae, in the PB, LC, and GI tract. Further investigation showed that the upregulation in anti-bacteria response was likely antigen-specific for two reasons. Firstly, the frequencies of Th1 and Th17 cells reacting to Escherichia coli, a typical GI bacterium, were not upregulated in the PB and the LC of NSCLC patients. Secondly, the S. salivarius and S. agalactiae responses could be partially blocked by Tü39, a MHC class II blocking antibody, suggesting that antigen-specific interaction between CD4 + T cells and antigen-presenting cells was required. We also found that S. salivarius and S. agalactiae could potently activate the monocytes to secrete higher levels of interleukin (IL)-6, IL-12, and tumor necrosis factor, which were Th1- and Th17-skewing cytokines. Interestingly, whereas CXCR5 + CD4 + T cells represented <20% of total CD4 + T cells, they represented 17%-82% of bacteria-specific Th1 or Th17 cells. Together, these data demonstrated that NSCLC patients presented a significant upregulation of bacterial-specific Th1 and Th17 responses that were enriched in CXCR5 + CD4 + T cells. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Adoptive cell therapy for lymphoma with CD4 T cells depleted of CD137-expressing regulatory T cells.

    PubMed

    Goldstein, Matthew J; Kohrt, Holbrook E; Houot, Roch; Varghese, Bindu; Lin, Jack T; Swanson, Erica; Levy, Ronald

    2012-03-01

    Adoptive immunotherapy with antitumor T cells is a promising novel approach for the treatment of cancer. However, T-cell therapy may be limited by the cotransfer of regulatory T cells (T(reg)). Here, we explored this hypothesis by using 2 cell surface markers, CD44 and CD137, to isolate antitumor CD4 T cells while excluding T(regs). In a murine model of B-cell lymphoma, only CD137(neg)CD44(hi) CD4 T cells infiltrated tumor sites and provided protection. Conversely, the population of CD137(pos)CD44hi CD4 T cells consisted primarily of activated T(regs). Notably, this CD137(pos) T(reg) population persisted following adoptive transfer and maintained expression of FoxP3 as well as CD137. Moreover, in vitro these CD137(pos) cells suppressed the proliferation of effector cells in a contact-dependent manner, and in vivo adding the CD137(pos)CD44(hi) CD4 cells to CD137(neg)CD44(hi) CD4 cells suppressed the antitumor immune response. Thus, CD137 expression on CD4 T cells defined a population of activated T(regs) that greatly limited antitumor immune responses. Consistent with observations in the murine model, human lymphoma biopsies also contained a population of CD137(pos) CD4 T cells that were predominantly CD25(pos)FoxP3(pos) T(regs). In conclusion, our findings identify 2 surface markers that can be used to facilitate the enrichment of antitumor CD4 T cells while depleting an inhibitory T(reg) population.

  2. Effect of lipoxygenase metabolites of arachidonic acid on proliferation of human T cells and T cell subsets.

    PubMed

    Gualde, N; Atluru, D; Goodwin, J S

    1985-02-01

    The lipoxygenase products LTB4 and 15 HPETE have been reported to stimulate T suppressor cell function and also to inhibit [3H]thymidine incorporation into mitogen-stimulated T cells. This present report documents that although these compounds do indeed inhibit [3H]thymidine incorporation into unfractionated T cells, they significantly enhance [3H]thymidine incorporation into T cell preparation enriched for cells bearing the cytotoxic suppressor cell phenotype identified by the OKT8 monoclonal antibody. The mitogen response of T cells enriched for OKT4+ helper-inducer cells is inhibited in manner similar to the response of unfractionated T cells. Thus, LTB4 and 15 HPETE stimulate both the function and the proliferation of the cytotoxic-suppressor T cell subset.

  3. Qualitative features of the HIV-specific CD8+ T-cell response associated with immunologic control.

    PubMed

    Hersperger, Adam R; Migueles, Stephen A; Betts, Michael R; Connors, Mark

    2011-05-01

    Over the past 2 years, a clearer picture has emerged regarding the properties of HIV-specific CD8+ T cells associated with immunologic control of HIV replication. These properties represent a potential mechanism by which rare patients might control HIV replication in the absence of antiretroviral therapy. This review addresses the background and recent findings that have lead to our current understanding of these mechanism(s). Patients with immunologic control of HIV are not distinguished by targeted specificities, or greater numbers or breadth of their HIV-specific CD8+ T-cell response. For this reason, recent work has focused greater attention on qualitative features of this response. The qualitative features most closely associated with immunologic control of HIV are related to the granule-exocytosis-mediated elimination of HIV-infected CD4 T cells. The ability of HIV-specific CD8+ T cells to increase their contents of proteins known to mediate cytotoxicity, such as granzyme B and perforin, appears to be a critical means by which HIV-specific cytotoxic capacity is regulated. Investigation from multiple groups has now focused upon HIV-specific CD8+ T-cell granule-exocytosis-mediated cytotoxicity as a correlate of immunologic control of HIV. In the near future, a more detailed understanding of the qualities associated with immunologic control may provide critical insights regarding the necessary features of a response that should be stimulated by immunotherapies or T-cell-based vaccines.

  4. Sequential activation of CD8+ T cells in the draining lymph nodes in response to pulmonary virus infection.

    PubMed

    Yoon, Heesik; Legge, Kevin L; Sung, Sun-sang J; Braciale, Thomas J

    2007-07-01

    We have used a TCR-transgenic CD8+ T cell adoptive transfer model to examine the tempo of T cell activation and proliferation in the draining lymph nodes (DLN) in response to respiratory virus infection. The T cell response in the DLN differed for mice infected with different type A influenza strains with the onset of T cell activation/proliferation to the A/JAPAN virus infection preceding the A/PR8 response by 12-24 h. This difference in T cell activation/proliferation correlated with the tempo of accelerated respiratory DC (RDC) migration from the infected lungs to the DLN in response to influenza virus infection, with the migrant RDC responding to the A/JAPAN infection exhibiting a more rapid accumulation in the lymph nodes (i.e., peak migration for A/JAPAN at 18 h, A/PR8 at 24-36 h). Furthermore, in vivo administration of blocking anti-CD62L Ab at various time points before/after infection revealed that the virus-specific CD8+ T cells entered the DLN and activated in a sequential "conveyor belt"-like fashion. These results indicate that the tempo of CD8+ T cell activation/proliferation after viral infection is dependent on the tempo of RDC migration to the DLN and that T cell activation occurs in an ordered sequential fashion.

  5. Supernatural T cells: genetic modification of T cells for cancer therapy.

    PubMed

    Kershaw, Michael H; Teng, Michele W L; Smyth, Mark J; Darcy, Phillip K

    2005-12-01

    Immunotherapy is receiving much attention as a means of treating cancer, but complete, durable responses remain rare for most malignancies. The natural immune system seems to have limitations and deficiencies that might affect its ability to control malignant disease. An alternative to relying on endogenous components in the immune repertoire is to generate lymphocytes with abilities that are greater than those of natural T cells, through genetic modification to produce 'supernatural' T cells. This Review describes how such T cells can circumvent many of the barriers that are inherent in the tumour microenvironment while optimizing T-cell specificity, activation, homing and antitumour function.

  6. Endogenous antigen tunes the responsiveness of naive B cells but not T cells

    PubMed Central

    Zikherman, Julie; Parameswaran, Ramya; Weiss, Arthur

    2012-01-01

    In humans up to 75% of newly generated B cells and about 30% of mature B cells exhibit some degree of autoreactivity1. Yet, how B cells establish and maintain tolerance in the face of autoantigen exposure during and after development is not certain. Studies of model BCR transgenic systems have highlighted the critical role played by functional unresponsiveness or ‘anergy’2,3. Unlike T cells, evidence suggests that receptor editing and anergy, rather than deletion, account for much of B cell tolerance4,5. However, it remains unclear whether the mature diverse B cell repertoire of mice contains anergic autoreactive B cells, and if so, whether antigen was encountered during or after their development. By taking advantage of a reporter mouse in which B cell antigen receptor (BCR) signaling rapidly and robustly induces GFP expression under the control of the Nur77 regulatory region, antigen-dependent and – independent BCR signaling events in vivo during B cell maturation were visualized. Here we show that B cells encounter antigen during development in the spleen, and that this antigen exposure in turn tunes the responsiveness of BCR signaling in B cells at least partly by down-modulating expression of surface IgM but not IgD BCRs, and by modifying basal calcium levels. By contrast, no analogous process occurs in naive mature T cells. Our data demonstrate not only that autoreactive B cells persist in the mature repertoire, but that functional unresponsiveness or ‘anergy’ exists in the mature B cell repertoire along a continuum, a fact that has long been suspected, but never yet shown. These results have important implications for understanding how tolerance in T and B cells is differently imposed, and how these processes might go awry in disease. PMID:22902503

  7. Effector and memory T cell subsets in the response to bovine tuberculosis

    USDA-ARS?s Scientific Manuscript database

    Long-term (i.e., 14d) cultured IFN-gamma ELISPOT assays of PBMC are used as a correlate of T cell central memory (Tcm) responses in cattle and humans. With bovine tuberculosis, vaccine-elicited Tcm responses correlate with protection against experimental Mycobacterium bovis infection. The objective ...

  8. Mycobacterium leprae-Infected Macrophages Preferentially Primed Regulatory T Cell Responses and Was Associated with Lepromatous Leprosy.

    PubMed

    Yang, Degang; Shui, Tiejun; Miranda, Jake W; Gilson, Danny J; Song, Zhengyu; Chen, Jia; Shi, Chao; Zhu, Jianyu; Yang, Jun; Jing, Zhichun

    2016-01-01

    The persistence of Mycobacterium leprae (M. leprae) infection is largely dependent on the types of host immune responses being induced. Macrophage, a crucial modulator of innate and adaptive immune responses, could be directly infected by M. leprae. We therefore postulated that M. leprae-infected macrophages might have altered immune functions. Here, we treated monocyte-derived macrophages with live or killed M. leprae, and examined their activation status and antigen presentation. We found that macrophages treated with live M. leprae showed committed M2-like function, with decreased interleukin 1 beta (IL-1beta), IL-6, tumor necrosis factor alpha (TNF-alpha) and MHC class II molecule expression and elevated IL-10 and CD163 expression. When incubating with naive T cells, macrophages treated with live M. leprae preferentially primed regulatory T (Treg) cell responses with elevated FoxP3 and IL-10 expression, while interferon gamma (IFN-gamma) expression and CD8+ T cell cytotoxicity were reduced. Chromium release assay also found that live M. leprae-treated macrophages were more resistant to CD8+ T cell-mediated cytotoxicity than sonicated M. leprae-treated monocytes. Ex vivo studies showed that the phenotype and function of monocytes and macrophages had clear differences between L-lep and T-lep patients, consistent with the in vitro findings. Together, our data demonstrate that M. leprae could utilize infected macrophages by two mechanisms: firstly, M. leprae-infected macrophages preferentially primed Treg but not Th1 or cytotoxic T cell responses; secondly, M. leprae-infected macrophages were more effective at evading CD8+ T cell-mediated cytotoxicity.

  9. CD4+ T Cells Reactive to Enteric Bacterial Antigens in Spontaneously Colitic C3H/HeJBir Mice: Increased T Helper Cell Type 1 Response and Ability to Transfer Disease

    PubMed Central

    Cong, Yingzi; Brandwein, Steven L.; McCabe, Robert P.; Lazenby, A.; Birkenmeier, Edward H.; Sundberg, John P.; Elson, Charles O.

    1998-01-01

    C3H/HeJBir mice are a new substrain that spontaneously develop colitis early in life. This study was done to determine the T cell reactivity of C3H/HeJBir mice to candidate antigens that might be involved in their disease. C3H/HeJBir CD4+ T cells were strongly reactive to antigens of the enteric bacterial flora, but not to epithelial or food antigens. The stimulatory material in the enteric bacteria was trypsin sensitive and restricted by class II major histocompatibility complex molecules, but did not have the properties of a superantigen. The precursor frequency of interleuken (IL)-2–producing, bacterial-reactive CD4+ T cells in colitic mice was 1 out of 2,000 compared to 1 out of 20,000–25,000 in noncolitic control mice. These T cells produced predominately IL-2 and interferon γ, consistent with a T helper type 1 cell response and were present at 3–4 wk, the age of onset of the colitis. Adoptive transfer of bacterial-antigen–activated CD4+ T cells from colitic C3H/HeJBir but not from control C3H/HeJ mice into C3H/HeSnJ scid/scid recipients induced colitis. These data represent a direct demonstration that T cells reactive with conventional antigens of the enteric bacterial flora can mediate chronic inflammatory bowel disease. PMID:9500788

  10. Galectin-3 Shapes Antitumor Immune Responses by Suppressing CD8+ T Cells via LAG-3 and Inhibiting Expansion of Plasmacytoid Dendritic Cells.

    PubMed

    Kouo, Theodore; Huang, Lanqing; Pucsek, Alexandra B; Cao, Minwei; Solt, Sara; Armstrong, Todd; Jaffee, Elizabeth

    2015-04-01

    Galectin-3 is a 31-kDa lectin that modulates T-cell responses through several mechanisms, including apoptosis, T-cell receptor (TCR) cross-linking, and TCR downregulation. We found that patients with pancreatic ductal adenocarcinoma (PDA) who responded to a granulocyte-macrophage colony-stimulating factor-secreting allogeneic PDA vaccine developed neutralizing antibodies to galectin-3 after immunization. We show that galectin-3 binds activated antigen-committed CD8(+) T cells only in the tumor microenvironment. Galectin-3-deficient mice exhibit improved CD8(+) T-cell effector function and increased expression of several inflammatory genes. Galectin-3 binds to LAG-3, and LAG-3 expression is necessary for galectin-3-mediated suppression of CD8(+) T cells in vitro. Lastly, galectin-3-deficient mice have elevated levels of circulating plasmacytoid dendritic cells, which are superior to conventional dendritic cells in activating CD8(+) T cells. Thus, inhibiting galectin-3 in conjunction with CD8(+) T-cell-directed immunotherapies should enhance the tumor-specific immune response. ©2015 American Association for Cancer Research.

  11. Estradiol Enhances CD4+ T-Cell Anti-Viral Immunity by Priming Vaginal DCs to Induce Th17 Responses via an IL-1-Dependent Pathway

    PubMed Central

    Anipindi, Varun C.; Dizzell, Sara E.; Nguyen, Philip V.; Shaler, Christopher R.; Chu, Derek K.; Jiménez-Saiz, Rodrigo; Liang, Hong; Swift, Stephanie; Nazli, Aisha; Kafka, Jessica K.; Bramson, Jonathan; Xing, Zhou; Jordana, Manel; Wan, Yonghong; Snider, Denis P.; Stampfli, Martin R.; Kaushic, Charu

    2016-01-01

    Clinical and experimental studies have shown that estradiol (E2) confers protection against HIV and other sexually transmitted infections. Here, we investigated the underlying mechanism. Better protection in E2-treated mice, immunized against genital HSV-2, coincided with earlier recruitment and higher proportions of Th1 and Th17 effector cells in the vagina post-challenge, compared to placebo-treated controls. Vaginal APCs isolated from E2-treated mice induced 10-fold higher Th17 and Th1 responses, compared to APCs from progesterone-treated, placebo-treated, and estradiol-receptor knockout mice in APC-T cell co-cultures. CD11c+ DCs in the vagina were the predominant APC population responsible for priming these Th17 responses, and a potent source of IL-6 and IL-1β, important factors for Th17 differentiation. Th17 responses were abrogated in APC-T cell co-cultures containing IL-1β KO, but not IL-6 KO vaginal DCs, showing that IL-1β is a critical factor for Th17 induction in the genital tract. E2 treatment in vivo directly induced high expression of IL-1β in vaginal DCs, and addition of IL-1β restored Th17 induction by IL-1β KO APCs in co-cultures. Finally, we examined the role of IL-17 in anti-HSV-2 memory T cell responses. IL-17 KO mice were more susceptible to intravaginal HSV-2 challenge, compared to WT controls, and vaginal DCs from these mice were defective at priming efficient Th1 responses in vitro, indicating that IL-17 is important for the generation of efficient anti-viral memory responses. We conclude that the genital mucosa has a unique microenvironment whereby E2 enhances CD4+ T cell anti-viral immunity by priming vaginal DCs to induce Th17 responses through an IL-1-dependent pathway. PMID:27148737

  12. [The role of regulatory T cells in the modulation of anti-tumor immune response].

    PubMed

    Radosavljević, Gordana D; Jovanović, Ivan P; Kanjevac, Tatjana V; Arsenijević, Nebojsa N

    2013-01-01

    Regulatory T cells (Treg) represent a subset of CD4+T cells whose function is to suppress immune responses. Treg lymphocytes can be divided into two subsets: natural nTreg lymphocytes that are developed in the thymus and inducible iTreg lymphocytes, which originate from conventional T lymphocytes on the periphery.The majority of Treg lymphocytes express high levels of interleukin-2 (IL-2) receptor a chain (CD25) and transcription factor FoxP3 (critical for the development and suppressor activity of iTreg lymphocytes). Cancer cells can modulate anti-tumor immune response indirectly, through the activation of Treg lymphocytes. It has been shown that the loss of regulatory function by depletion of tumor-induced Treg lymphocytes may enhance effectors response, resulting in tumor rejection, while the increased number of Treg lymphocytes effectively prevents tumor destruction. nTreg lymphocytes express increasingly CTLA-4 and membrane-bound TGF-beta, which inhibits cytokine production and responses of effectors lymphocytes.iTreg lymphocytes secrete immunosuppressive cytokines such as ILreg-10 and TGF-beta.Treg lymphocytes represent one of important obstruction in anti-tumor immunity.

  13. Characterization of guinea pig T cell responses elicited after EP-assisted delivery of DNA vaccines to the skin

    PubMed Central

    Schultheis, Katherine; Schaefer, Hubert; Yung, Bryan S.; Oh, Janet; Muthumani, Karuppiah; Humeau, Laurent; Broderick, Kate E.

    2016-01-01

    The skin is an ideal target tissue for vaccine delivery for a number of reasons. It is highly accessible, and most importantly, enriched in professional antigen presenting cells. Possessing strong similarities to human skin physiology and displaying a defined epidermis, the guinea pig is an appropriate model to study epidermal delivery of vaccine. However, whilst we have characterized the humoral responses in the guinea pig associated with skin vaccine protocols we have yet to investigate the T cell responses. In response to this inadequacy, we developed an IFN-γ ELISpot assay to characterize the cellular immune response in the peripheral blood of guinea pigs. Using a nucleoprotein (NP) influenza pDNA vaccination regimen, we characterized host T cell responses. After delivery of the DNA vaccine to the guinea pig epidermis we detected robust and rapid T cell responses. The levels of IFN-γ spot-forming units averaged approximately 5000 per million cells after two immunizations. These responses were broad in that multiple regions across the NP antigen elicited a T cell response. Interestingly, we identified a number of NP immunodominant T cell epitopes to be conserved across an outbred guinea pig population, a phenomenon which was also observed after immunization with a RSV DNA vaccine. We believe this data enhances our understanding of the cellular immune response elicited to a vaccine in guinea pigs, and globally, will advance the use of this model for vaccine development, especially those targeting skin as a delivery site. PMID:27894716

  14. Memory T cell responses targeting the SARS coronavirus persist up to 11 years post-infection.

    PubMed

    Ng, Oi-Wing; Chia, Adeline; Tan, Anthony T; Jadi, Ramesh S; Leong, Hoe Nam; Bertoletti, Antonio; Tan, Yee-Joo

    2016-04-12

    Severe acute respiratory syndrome (SARS) is a highly contagious infectious disease which first emerged in late 2002, caused by a then novel human coronavirus, SARS coronavirus (SARS-CoV). The virus is believed to have originated from bats and transmitted to human through intermediate animals such as civet cats. The re-emergence of SARS-CoV remains a valid concern due to the continual persistence of zoonotic SARS-CoVs and SARS-like CoVs (SL-CoVs) in bat reservoirs. In this study, the screening for the presence of SARS-specific T cells in a cohort of three SARS-recovered individuals at 9 and 11 years post-infection was carried out, and all memory T cell responses detected target the SARS-CoV structural proteins. Two CD8(+) T cell responses targeting the SARS-CoV membrane (M) and nucleocapsid (N) proteins were characterized by determining their HLA restriction and minimal T cell epitope regions. Furthermore, these responses were found to persist up to 11 years post-infection. An absence of cross-reactivity of these CD8(+) T cell responses against the newly-emerged Middle East respiratory syndrome coronavirus (MERS-CoV) was also demonstrated. The knowledge of the persistence of SARS-specific celullar immunity targeting the viral structural proteins in SARS-recovered individuals is important in the design and development of SARS vaccines, which are currently unavailable. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. B and T lymphocyte attenuator mediates inhibition of tumor-reactive CD8+ T cells in patients after allogeneic stem cell transplantation.

    PubMed

    Hobo, Willemijn; Norde, Wieger J; Schaap, Nicolaas; Fredrix, Hanny; Maas, Frans; Schellens, Karen; Falkenburg, J H Frederik; Korman, Alan J; Olive, Daniel; van der Voort, Robbert; Dolstra, Harry

    2012-07-01

    Allogeneic stem cell transplantation (allo-SCT) can cure hematological malignancies by inducing alloreactive T cell responses targeting minor histocompatibility antigens (MiHA) expressed on malignant cells. Despite induction of robust MiHA-specific T cell responses and long-term persistence of alloreactive memory T cells specific for the tumor, often these T cells fail to respond efficiently to tumor relapse. Previously, we demonstrated the involvement of the coinhibitory receptor programmed death-1 (PD-1) in suppressing MiHA-specific CD8(+) T cell immunity. In this study, we investigated whether B and T lymphocyte attenuator (BTLA) plays a similar role in functional impairment of MiHA-specific T cells after allo-SCT. In addition to PD-1, we observed higher BTLA expression on MiHA-specific CD8(+) T cells compared with that of the total population of CD8(+) effector-memory T cells. In addition, BTLA's ligand, herpes virus entry mediator (HVEM), was found constitutively expressed by myeloid leukemia, B cell lymphoma, and multiple myeloma cells. Interference with the BTLA-HVEM pathway, using a BTLA blocking Ab, augmented proliferation of BTLA(+)PD-1(+) MiHA-specific CD8(+) T cells by HVEM-expressing dendritic cells. Notably, we demonstrated that blocking of BTLA or PD-1 enhanced ex vivo proliferation of MiHA-specific CD8(+) T cells in respectively 7 and 9 of 11 allo-SCT patients. Notably, in 3 of 11 patients, the effect of BTLA blockade was more prominent than that of PD-1 blockade. Furthermore, these expanded MiHA-specific CD8(+) T cells competently produced effector cytokines and degranulated upon Ag reencounter. Together, these results demonstrate that BTLA-HVEM interactions impair MiHA-specific T cell functionality, providing a rationale for interfering with BTLA signaling in post-stem cell transplantation therapies.

  16. Granulocytic myeloid-derived suppressor cells from human cord blood modulate T-helper cell response towards an anti-inflammatory phenotype.

    PubMed

    Köstlin, Natascha; Vogelmann, Margit; Spring, Bärbel; Schwarz, Julian; Feucht, Judith; Härtel, Christoph; Orlikowsky, Thorsten W; Poets, Christian F; Gille, Christian

    2017-09-01

    Infections are a leading cause of perinatal morbidity and mortality. The outstandingly high susceptibility to infections early in life is mainly attributable to the compromised state of the neonatal immune system. One important difference to the adult immune system is a bias towards T helper type 2 (Th2) responses in newborns. However, mechanisms regulating neonatal T-cell responses are incompletely understood. Granulocytic myeloid-derived suppressor cells (GR-MDSC) are myeloid cells with a granulocytic phenotype that suppress various functions of other immune cells and accumulate under physiological conditions during pregnancy in maternal and fetal blood. Although it has been hypothesized that GR-MDSC accumulation during fetal life could be important for the maintenance of maternal-fetal tolerance, the influence of GR-MDSC on the immunological phenotype of neonates is still unclear. Here, we investigated the impact of GR-MDSC isolated from cord blood (CB-MDSC) on the polarization of Th cells. We demonstrate that CB-MDSC inhibit Th1 responses and induced Th2 responses and regulatory T (Treg) cells. Th1 inhibition was cell-contact dependent and occurred independent of other cell types, while Th2 induction was mediated independently of cell contact through expression of ArgI and reactive oxygen species by CB-MDSC and partially needed the presence of monocytes. Treg cell induction by CB-MDSC also occurred cell-contact independently but was partially mediated through inducible nitric oxide synthase. These results point towards a role of MDSC in regulating neonatal immune responses. Targeting MDSC function in neonates could be a therapeutic opportunity to improve neonatal host defence. © 2017 John Wiley & Sons Ltd.

  17. Antigen expression level threshold tunes the fate of CD8 T cells during primary hepatic immune responses.

    PubMed

    Tay, Szun Szun; Wong, Yik Chun; McDonald, David M; Wood, Nicole A W; Roediger, Ben; Sierro, Frederic; Mcguffog, Claire; Alexander, Ian E; Bishop, G Alex; Gamble, Jennifer R; Weninger, Wolfgang; McCaughan, Geoffrey W; Bertolino, Patrick; Bowen, David G

    2014-06-24

    CD8 T-cell responses to liver-expressed antigens range from deletional tolerance to full effector differentiation resulting in overt hepatotoxicity. The reasons for these heterogeneous outcomes are not well understood. To identify factors that govern the fate of CD8 T cells activated by hepatocyte-expressed antigen, we exploited recombinant adenoassociated viral vectors that enabled us to vary potential parameters determining these outcomes in vivo. Our findings reveal a threshold of antigen expression within the liver as the dominant factor determining T-cell fate, irrespective of T-cell receptor affinity or antigen cross-presentation. Thus, when a low percentage of hepatocytes expressed cognate antigen, high-affinity T cells developed and maintained effector function, whereas, at a high percentage, they became functionally exhausted and silenced. Exhaustion was not irreversibly determined by initial activation, but was maintained by high intrahepatic antigen load during the early phase of the response; cytolytic function was restored when T cells primed under high antigen load conditions were transferred into an environment of low-level antigen expression. Our study reveals a hierarchy of factors dictating the fate of CD8 T cells during hepatic immune responses, and provides an explanation for the different immune outcomes observed in a variety of immune-mediated liver pathologic conditions.

  18. Oncolytic HSV virotherapy in murine sarcomas differentially triggers an antitumor T-cell response in the absence of virus permissivity

    PubMed Central

    Leddon, Jennifer L; Chen, Chun-Yu; Currier, Mark A; Wang, Pin-Yi; Jung, Francesca A; Denton, Nicholas L; Cripe, Kevin M; Haworth, Kellie B; Arnold, Michael A; Gross, Amy C; Eubank, Timothy D; Goins, William F; Glorioso, Joseph C; Cohen, Justus B; Grandi, Paola; Hildeman, David A; Cripe, Timothy P

    2015-01-01

    Multiple studies have indicated that in addition to direct oncolysis, virotherapy promotes an antitumor cytotoxic T cell response important for efficacy. To study this phenomenon further, we tested three syngeneic murine sarcoma models that displayed varied degrees of permissiveness to oncolytic herpes simplex virus replication and cytotoxicity in vitro, with the most permissive being comparable to some human sarcoma tumor lines. The in vivo antitumor effect ranged from no or modest response to complete tumor regression and protection from tumor rechallenge. The in vitro permissiveness to viral oncolysis was not predictive of the in vivo antitumor effect, as all three tumors showed intact interferon signaling and minimal permissiveness to virus in vivo. Tumor shrinkage was T-cell mediated with a tumor-specific antigen response required for maximal antitumor activity. Further analysis of the innate and adaptive immune microenvironment revealed potential correlates of susceptibility and resistance, including favorable and unfavorable cytokine profiles, differential composition of intratumoral myeloid cells, and baseline differences in tumor cell immunogenicity and tumor-infiltrating T-cell subsets. It is likely that a more complete understanding of the interplay between the immunologic immune microenvironment and virus infection will be necessary to fully leverage the antitumor effects of this therapeutic platform. PMID:27119100

  19. Responses of human birch pollen allergen-reactive T cells to chemically modified allergens (allergoids).

    PubMed

    Dormann, D; Ebner, C; Jarman, E R; Montermann, E; Kraft, D; Reske-Kunz, A B

    1998-11-01

    Allergoids are widely used in specific immunotherapy for the treatment of IgE-mediated allergic diseases. The aim of this study was to analyse whether a modification of birch pollen allergens with formaldehyde affects the availability of T-cell epitopes. Efficient modification of the allergens was verified by determining IgE and IgG binding activity using ELISA inhibition tests. T-cell responses to birch pollen allergoids were analysed in polyclonal systems, using peripheral blood mononuclear cells (PBMC) of five birch pollen-allergic individuals, as well as birch pollen extract-reactive T-cell lines (TCL), established from the peripheral blood of 14 birch pollen-allergic donors. To determine whether the modification of natural (n)Bet v 1 with formaldehyde or maleic anhydride results in epitope-specific changes in T-cell reactivities, 22 Bet v 1-specific T-cell clones (TCC), established from nine additional birch pollen-allergic individuals, were tested for their reactivity with these products. The majority of PBMC and TCL showed a reduced response to the birch pollen extract allergoid. Bet v 1-specific TCC could be divided into allergoid-reactive and -non-reactive TCC. No simple correlation between possible modification sites of formaldehyde in the respective T-cell epitopes and the stimulatory potential of the allergoid was observed. Mechanisms of suppression or of anergy induction were excluded as an explanation for the non-reactivity of representative TCC. All TCC could be stimulated by maleylated and unmodified nBet v 1 to a similar extent. These results demonstrate differences in the availability of T-cell epitopes between allergoids and unmodified allergens, which are most likely due to structural changes within the allergen molecule.

  20. Prolonged survival of dendritic cell-vaccinated melanoma patients correlates with tumor-specific delayed type IV hypersensitivity response and reduction of tumor growth factor beta-expressing T cells.

    PubMed

    López, Mercedes N; Pereda, Cristian; Segal, Gabriela; Muñoz, Leonel; Aguilera, Raquel; González, Fermín E; Escobar, Alejandro; Ginesta, Alexandra; Reyes, Diego; González, Rodrigo; Mendoza-Naranjo, Ariadna; Larrondo, Milton; Compán, Alvaro; Ferrada, Carlos; Salazar-Onfray, Flavio

    2009-02-20

    The aim of this work was to assess immunologic response, disease progression, and post-treatment survival of melanoma patients vaccinated with autologous dendritic cells (DCs) pulsed with a novel allogeneic cell lysate (TRIMEL) derived from three melanoma cell lines. Forty-three stage IV and seven stage III patients were vaccinated four times with TRIMEL/DC vaccine. Specific delayed type IV hypersensitivity (DTH) reaction, ex vivo cytokine production, and regulatory T-cell populations were determined. Overall survival and disease progression rates were analyzed using Kaplan-Meier curves and compared with historical records. The overall survival for stage IV patients was 15 months. More than 60% of patients showed DTH-positive reaction against the TRIMEL. Stage IV/DTH-positive patients displayed a median survival of 33 months compared with 11 months observed for DTH-negative patients (P = .0014). All stage III treated patients were DTH positive and remained alive and tumor free for a median follow-up period of 48 months (range, 33 to 64 months). DTH-positive patients showed a marked reduction in the proportion of CD4+ transforming growth factor (TGF) beta+ regulatory T cells compared to DTH-negative patients (1.54% v 5.78%; P < .0001). Our findings strongly suggest that TRIMEL-pulsed DCs provide a standardized and widely applicable source of melanoma antigens, very effective in evoking antimelanoma immune response. To our knowledge, this is the first report describing a correlation between vaccine-induced reduction of CD4+TGFbeta+ regulatory T cells and in vivo antimelanoma immune response associated to improved patient survival and disease stability.

  1. Broadening CD4+ and CD8+ T Cell Responses against Hepatitis C Virus by Vaccination with NS3 Overlapping Peptide Panels in Cross-Priming Liposomes

    PubMed Central

    Filskov, Jonathan; Mikkelsen, Marianne; Hansen, Paul R.; Christensen, Jan P.; Thomsen, Allan R.; Andersen, Peter; Agger, Else Marie

    2017-01-01

    ABSTRACT Despite the introduction of effective drugs to treat patients with chronic hepatitis C virus (HCV) infection, a vaccine would be the only means to substantially reduce the worldwide disease burden. An incomplete understanding of how HCV interacts with its human host and evades immune surveillance has hampered vaccine development. It is generally accepted that in infected individuals, a narrow repertoire of exhausted T cells is a hallmark of persistent infection, whereas broad, vigorous CD4+ and CD8+ T cell responses are associated with control of acute hepatitis C. We employed a vaccine approach based on a mixture of peptides (pepmix) spanning the entire sequence of HCV nonstructural protein 3 (NS3) in cross-priming cationic liposomes (CAF09) to facilitate a versatile presentation of all possible T cell epitopes, regardless of the HLA background of the vaccine recipient. Here, we demonstrate that vaccination of mice with NS3 pepmix broadens the repertoire of epitope-specific T cells compared to the corresponding recombinant protein (rNS3). Moreover, vaccination with rNS3 induced only CD4+ T cells, whereas the NS3 pepmix induced a far more vigorous CD4+ T cell response and was as potent a CD8+ T cell inducer as an adenovirus-vectored vaccine expressing NS3. Importantly, the cellular responses are dominated by multifunctional T cells, such as gamma interferon-positive (IFN-γ+) tumor necrosis factor alpha-positive (TNF-α+) coproducers, and displayed cytotoxic capacity in mice. In conclusion, we present a novel vaccine approach against HCV, inducing a broadened T cell response targeting both immunodominant and potential subdominant epitopes, which may be key elements to counter T cell exhaustion and prevent chronicity. IMPORTANCE With at least 700,000 annual deaths, development of a vaccine against hepatitis C virus (HCV) has high priority, but the tremendous ability of the virus to dodge the human immune system poses great challenges. Furthermore, many

  2. Nasopharyngeal infection by Streptococcus pyogenes requires superantigen-responsive Vβ-specific T cells

    PubMed Central

    Zeppa, Joseph J.; Kasper, Katherine J.; Mohorovic, Ivor; Mazzuca, Delfina M.

    2017-01-01

    The globally prominent pathogen Streptococcus pyogenes secretes potent immunomodulatory proteins known as superantigens (SAgs), which engage lateral surfaces of major histocompatibility class II molecules and T-cell receptor (TCR) β-chain variable domains (Vβs). These interactions result in the activation of numerous Vβ-specific T cells, which is the defining activity of a SAg. Although streptococcal SAgs are known virulence factors in scarlet fever and toxic shock syndrome, mechanisms by how SAgs contribute to the life cycle of S. pyogenes remain poorly understood. Herein, we demonstrate that passive immunization against the Vβ8-targeting SAg streptococcal pyrogenic exotoxin A (SpeA), or active immunization with either wild-type or a nonfunctional SpeA mutant, protects mice from nasopharyngeal infection; however, only passive immunization, or vaccination with inactive SpeA, resulted in high-titer SpeA-specific antibodies in vivo. Mice vaccinated with wild-type SpeA rendered Vβ8+ T cells poorly responsive, which prevented infection. This phenotype was reproduced with staphylococcal enterotoxin B, a heterologous SAg that also targets Vβ8+ T cells, and rendered mice resistant to infection. Furthermore, antibody-mediated depletion of T cells prevented nasopharyngeal infection by S. pyogenes, but not by Streptococcus pneumoniae, a bacterium that does not produce SAgs. Remarkably, these observations suggest that S. pyogenes uses SAgs to manipulate Vβ-specific T cells to establish nasopharyngeal infection. PMID:28794279

  3. Single-cell multiplexed cytokine profiling of CD19 CAR-T cells reveals a diverse landscape of polyfunctional antigen-specific response.

    PubMed

    Xue, Qiong; Bettini, Emily; Paczkowski, Patrick; Ng, Colin; Kaiser, Alaina; McConnell, Timothy; Kodrasi, Olja; Quigley, Máire F; Heath, James; Fan, Rong; Mackay, Sean; Dudley, Mark E; Kassim, Sadik H; Zhou, Jing

    2017-11-21

    It remains challenging to characterize the functional attributes of chimeric antigen receptor (CAR)-engineered T cell product targeting CD19 related to potency and immunotoxicity ex vivo, despite promising in vivo efficacy in patients with B cell malignancies. We employed a single-cell, 16-plex cytokine microfluidics device and new analysis techniques to evaluate the functional profile of CD19 CAR-T cells upon antigen-specific stimulation. CAR-T cells were manufactured from human PBMCs transfected with the lentivirus encoding the CD19-BB-z transgene and expanded with anti-CD3/anti-CD28 coated beads. The enriched CAR-T cells were stimulated with anti-CAR or control IgG beads, stained with anti-CD4 RPE and anti-CD8 Alexa Fluor 647 antibodies, and incubated for 16 h in a single-cell barcode chip (SCBC). Each SCBC contains ~12,000 microchambers, covered with a glass slide that was pre-patterned with a complete copy of a 16-plex antibody array. Protein secretions from single CAR-T cells were captured and subsequently analyzed using proprietary software and new visualization methods. We demonstrate a new method for single-cell profiling of CD19 CAR-T pre-infusion products prepared from 4 healthy donors. CAR-T single cells exhibited a marked heterogeneity of cytokine secretions and polyfunctional (2+ cytokine) subsets specific to anti-CAR bead stimulation. The breadth of responses includes anti-tumor effector (Granzyme B, IFN-γ, MIP-1α, TNF-α), stimulatory (GM-CSF, IL-2, IL-8), regulatory (IL-4, IL-13, IL-22), and inflammatory (IL-6, IL-17A) functions. Furthermore, we developed two new bioinformatics tools for more effective polyfunctional subset visualization and comparison between donors. Single-cell, multiplexed, proteomic profiling of CD19 CAR-T product reveals a diverse landscape of immune effector response of CD19 CAR-T cells to antigen-specific challenge, providing a new platform for capturing CAR-T product data for correlative analysis. Additionally, such high

  4. Narrowing the Gap: Preserving Repertoire Diversity Despite Clonal Selection during the CD4 T Cell Response.

    PubMed

    Merkenschlager, Julia; Kassiotis, George

    2015-01-01

    T cell immunity relies on the generation and maintenance of a diverse repertoire of T cell antigen receptors (TCRs). The strength of signaling emanating from the TCR dictates the fate of T cells during development, as well as during the immune response. Whereas development of new T cells in the thymus increases the available TCR repertoire, clonal selection during the immune response narrows TCR diversity through the outgrowth of clonotypes with the fittest TCR. To ensure maintenance of TCR diversity in the antigen-selected repertoire, specific mechanisms can be envisaged that facilitate the participation of T cell clonotypes with less than best fit TCRs. Here, we summarize the evidence for the existence of such mechanisms that can prevent the loss of diversity. A number of T cell-autonomous or extrinsic factors can reverse clonotypic hierarchies set by TCR affinity for given antigen. Although not yet complete, understanding of these factors and their mechanism of action will be critical in interventional attempts to mold the antigen-selected TCR repertoire.

  5. Perfluorooctanoic Acid Exposure Suppresses T-independent Antibody Responses

    EPA Science Inventory

    Exposure to  3.75mg/kg of perfluoroocatnoic acid (PFOA) for 15d suppresses T-dependent antibody responses (TDAR), suggesting that T helper cells and/or B cells/plasma cells may be impacted. This study evaluated effects of PFOA exposure on the T cell-independent antibody response...

  6. Adaptive NK cell and KIR-expressing T cell responses are induced by CMV and are associated with protection against CMV reactivation after allogeneic donor hematopoietic cell transplantation1

    PubMed Central

    Davis, Zachary B.; Cooley, Sarah A.; Cichocki, Frank; Felices, Martin; Wangen, Rose; Luo, Xianghua; DeFor, Todd E.; Bryceson, Yenan T.; Diamond, Don J.; Brunstein, Claudio; Blazar, Bruce R.; Wagner, John E.; Weisdorf, Daniel J.; Horowitz, Amir; Guethlein, Lisbeth A.; Parham, Peter; Verneris, Michael R.; Miller, Jeffrey S.

    2015-01-01

    Cytomegalovirus (CMV) reactivates in >30% of CMV seropositive patients after allogeneic hematopoietic cell transplantation (HCT). Previously, we reported an increase of NK cells expressing NKG2C, CD57 and inhibitory killer-cell immunoglobulin-like receptors (KIRs) in response to CMV reactivation post-HCT. These NK cells persist after the resolution of infection and display ‘adaptive’ or memory properties. Despite these findings, the differential impact of persistent/inactive vs. reactivated CMV on NK vs. T cell maturation following HCT from different graft sources has not been defined. We compared the phenotype of NK and T cells from 292 recipients of allogeneic sibling (n = 118) or umbilical cord blood (UCB; n = 174) grafts based on recipient pre-transplant CMV serostatus and post-HCT CMV reactivation. This cohort was utilized to evaluate CMV-dependent increases in KIR-expressing NK cells exhibiting an ‘adaptive’ phenotype (NKG2C+CD57+). Compared to CMV seronegative recipients, those who reactivated CMV (React+) had the highest adaptive cell frequencies, while intermediate frequencies were observed in CMV seropositive recipients harboring persistent/non-replicating CMV. The same effect was observed in T cells and CD56+ T cells. These adaptive lymphocyte subsets were increased in CMV seropositive recipients of sibling, but not UCB grafts, and correlated with lower rates of CMV reactivation (sibling 33% vs. UCB 51%; p<0.01). These data suggest that persistent/non-replicating recipient CMV induces rapid production of adaptive NK and T cells from mature cells from sibling, but not UCB grafts. These adaptive lymphocytes are associated with protection from CMV reactivation. PMID:26055301

  7. Childhood tuberculosis is associated with decreased abundance of T cell gene transcripts and impaired T cell function.

    PubMed

    Hemingway, Cheryl; Berk, Maurice; Anderson, Suzanne T; Wright, Victoria J; Hamilton, Shea; Eleftherohorinou, Hariklia; Kaforou, Myrsini; Goldgof, Greg M; Hickman, Katy; Kampmann, Beate; Schoeman, Johan; Eley, Brian; Beatty, David; Pienaar, Sandra; Nicol, Mark P; Griffiths, Michael J; Waddell, Simon J; Newton, Sandra M; Coin, Lachlan J; Relman, David A; Montana, Giovanni; Levin, Michael

    2017-01-01

    The WHO estimates around a million children contract tuberculosis (TB) annually with over 80 000 deaths from dissemination of infection outside of the lungs. The insidious onset and association with skin test anergy suggests failure of the immune system to both recognise and respond to infection. To understand the immune mechanisms, we studied genome-wide whole blood RNA expression in children with TB meningitis (TBM). Findings were validated in a second cohort of children with TBM and pulmonary TB (PTB), and functional T-cell responses studied in a third cohort of children with TBM, other extrapulmonary TB (EPTB) and PTB. The predominant RNA transcriptional response in children with TBM was decreased abundance of multiple genes, with 140/204 (68%) of all differentially regulated genes showing reduced abundance compared to healthy controls. Findings were validated in a second cohort with concordance of the direction of differential expression in both TBM (r2 = 0.78 p = 2x10-16) and PTB patients (r2 = 0.71 p = 2x10-16) when compared to a second group of healthy controls. Although the direction of expression of these significant genes was similar in the PTB patients, the magnitude of differential transcript abundance was less in PTB than in TBM. The majority of genes were involved in activation of leucocytes (p = 2.67E-11) and T-cell receptor signalling (p = 6.56E-07). Less abundant gene expression in immune cells was associated with a functional defect in T-cell proliferation that recovered after full TB treatment (p<0.0003). Multiple genes involved in T-cell activation show decreased abundance in children with acute TB, who also have impaired functional T-cell responses. Our data suggest that childhood TB is associated with an acquired immune defect, potentially resulting in failure to contain the pathogen. Elucidation of the mechanism causing the immune paresis may identify new treatment and prevention strategies.

  8. Age-Related Decline in Primary CD8+ T Cell Responses Is Associated with the Development of Senescence in Virtual Memory CD8+ T Cells.

    PubMed

    Quinn, Kylie M; Fox, Annette; Harland, Kim L; Russ, Brendan E; Li, Jasmine; Nguyen, Thi H O; Loh, Liyen; Olshanksy, Moshe; Naeem, Haroon; Tsyganov, Kirill; Wiede, Florian; Webster, Rosela; Blyth, Chantelle; Sng, Xavier Y X; Tiganis, Tony; Powell, David; Doherty, Peter C; Turner, Stephen J; Kedzierska, Katherine; La Gruta, Nicole L

    2018-06-19

    Age-associated decreases in primary CD8 + T cell responses occur, in part, due to direct effects on naive CD8 + T cells to reduce intrinsic functionality, but the precise nature of this defect remains undefined. Aging also causes accumulation of antigen-naive but semi-differentiated "virtual memory" (T VM ) cells, but their contribution to age-related functional decline is unclear. Here, we show that T VM cells are poorly proliferative in aged mice and humans, despite being highly proliferative in young individuals, while conventional naive T cells (T N cells) retain proliferative capacity in both aged mice and humans. Adoptive transfer experiments in mice illustrated that naive CD8 T cells can acquire a proliferative defect imposed by the aged environment but age-related proliferative dysfunction could not be rescued by a young environment. Molecular analyses demonstrate that aged T VM cells exhibit a profile consistent with senescence, marking an observation of senescence in an antigenically naive T cell population. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

  9. Evidence for the involvement of lung-specific γδ T cell subsets in local responses to Streptococcus pneumoniae infection

    PubMed Central

    Kirby, Alun C; Newton, Darren J; Carding, Simon R; Kaye, Paul M

    2007-01-01

    Although γδ T cells are involved in the response to many pathogens, the dynamics and heterogeneity of the local γδ T cell response remains poorly defined. We recently identified γδ T cells as regulators of macrophages and dendritic cells during the resolution of Streptococcus pneumoniae-mediated lung inflammation. Here, using PCR, spectratype analysis and flow cytometry, we show that multiple γδ T cell subsets, including those bearing Vγ1, Vγ4 and Vγ6 TCR, increase in number in the lungs of infected mice, but not in associated lymphoid tissue. These γδ T cells displayed signs of activation, as defined by CD69 and CD25 expression. In vivo BrdU incorporation suggested that local expansion, rather than recruitment, was the principal mechanism underlying this increase in γδ T cells. This conclusion was supported by the finding that pulmonary γδ T cells, but not αβ T cells, isolated from mice that had resolved infection exhibited lung-homing capacity in both naive and infected recipients. Together, these data provide novel insights into the origins of the heterogeneous γδ T cell response that accompanies lung infection, and the first evidence that inflammation-associated γδ T cells may exhibit distinct tissue-homing potential. PMID:18022862

  10. Characterization of the CD8{sup +} T cell responses directed against respiratory syncytial virus during primary and secondary infection in C57BL/6 mice

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lukens, Michael V.; Claassen, Erwin A.W.; Graaff, Patricia M.A. de

    2006-08-15

    The BALB/c mouse model for human respiratory syncytial virus infection has contributed significantly to our understanding of the relative role for CD4{sup +} and CD8{sup +} T cells to immune protection and pathogenic immune responses. To enable comparison of RSV-specific T cell responses in different mouse strains and allow dissection of immune mechanisms by using transgenic and knockout mice that are mostly available on a C57BL/6 background, we characterized the specificity, level and functional capabilities of CD8{sup +} T cells during primary and secondary responses in lung parenchyma, airways and spleens of C57BL/6 mice. During the primary response, epitopes weremore » recognized originating from the matrix, fusion, nucleo- and attachment proteins, whereas the secondary response focused predominantly on the matrix epitope. C57BL/6 mice are less permissive for hRSV infection than BALB/c mice, yet we found CD8{sup +} T cell responses in the lungs and bronchoalveolar lavage, comparable to the responses described for BALB/c mice.« less

  11. Bovine central memory T cells are highly proliferative in response to bovine tuberculosis infection

    USDA-ARS?s Scientific Manuscript database

    Long-term (i.e., 14 days) cultured IFN-gamma responses of peripheral blood mononuclear cells are used as a correlate of T cell central memory (Tcm) responses in both humans and cattle. With bovine tuberculosis, vaccine-elicited long-term IFN-gamma ELISPOT assays are a correlate of protection. Recent...

  12. Evaluation of accessory cell heterogeneity. I. Differential accessory cell requirement for T helper cell activation and for T-B cooperation.

    PubMed

    Ramila, G; Studer, S; Kennedy, M; Sklenar, I; Erb, P

    1985-01-01

    Several Ia+ tumor cell lines and peritoneal exudate macrophages were tested as accessory cells (AC) for the activation of antigen-specific T cells and for T-B cooperation. The macrophages and all the Ia+ tumor lines tested induced the release of lymphokines from T cells in a major histocompatibility complex (MHC)-restricted fashion and reconstituted the antibody responses of AC-depleted spleen cells or of purified T and B cells. However, only the normal macrophages but none of the tumor lines induced carrier-specific T helper (Th) cells which help B cells for specific antihapten antibody responses by linked recognition. For T-B cooperation accessory cells were also required, but in contrast to Th cell activation any type of Ia+ AC (e.g. macrophage or tumor line) was effective. Strong MHC-restriction between the lymphocytes and the AC was seen if antigen-pulsed AC were added into the AC-depleted T-B cooperation cultures. If the AC and antigen were concomitantly added to the AC-depleted T-B cultures, MHC-restriction was less obvious. Concanavalin A supernatant reconstituted the response of AC-depleted T-B cultures provided antigen-specific Th cells and the hapten-carrier conjugate were present. If, however, tumor line-activated T cells were added instead of macrophage-induced Th cells, no cooperation with B cells took place even in the presence of Con A supernatant. The results obtained demonstrate a differential AC requirement for the induction of Th cells depending on the differentiation stage of the Th cells.

  13. Naive T cells are dispensable for memory CD4+ T cell homeostasis in progressive simian immunodeficiency virus infection

    PubMed Central

    Okoye, Afam A.; Rohankhedkar, Mukta; Abana, Chike; Pattenn, Audrie; Reyes, Matthew; Pexton, Christopher; Lum, Richard; Sylwester, Andrew; Planer, Shannon L.; Legasse, Alfred; Park, Byung S.; Piatak, Michael; Lifson, Jeffrey D.; Axthelm, Michael K.

    2012-01-01

    The development of AIDS in chronic HIV/simian immunodeficiency virus (SIV) infection has been closely linked to progressive failure of CD4+ memory T cell (TM) homeostasis. CD4+ naive T cells (TN) also decline in these infections, but their contribution to disease progression is less clear. We assessed the role of CD4+ TN in SIV pathogenesis using rhesus macaques (RMs) selectively and permanently depleted of CD4+ TN before SIV infection. CD4+ TN-depleted and CD4+ TN-repleted RMs were created by subjecting juvenile RMs to thymectomy versus sham surgery, respectively, followed by total CD4+ T cell depletion and recovery from this depletion. Although thymectomized and sham-treated RMs manifested comparable CD4+ TM recovery, only sham-treated RMs reconstituted CD4+ TN. CD4+ TN-depleted RMs responded to SIVmac239 infection with markedly attenuated SIV-specific CD4+ T cell responses, delayed SIVenv-specific Ab responses, and reduced SIV-specific CD8+ T cell responses. However, CD4+ TN-depleted and -repleted groups showed similar levels of SIV replication. Moreover, CD4+ TN deficiency had no significant effect on CD4+ TM homeostasis (either on or off anti-retroviral therapy) or disease progression. These data demonstrate that the CD4+ TN compartment is dispensable for CD4+ TM homeostasis in progressive SIV infection, and they confirm that CD4+ TM comprise a homeostatically independent compartment that is intrinsically capable of self-renewal. PMID:22451717

  14. Increased T cell proliferative responses to islet antigens identify clinical responders to anti-CD20 monoclonal antibody (rituximab) therapy in type 1 diabetes.

    PubMed

    Herold, Kevan C; Pescovitz, Mark D; McGee, Paula; Krause-Steinrauf, Heidi; Spain, Lisa M; Bourcier, Kasia; Asare, Adam; Liu, Zhugong; Lachin, John M; Dosch, H Michael

    2011-08-15

    Type 1 diabetes mellitus is believed to be due to the autoimmune destruction of β-cells by T lymphocytes, but a single course of rituximab, a monoclonal anti-CD20 B lymphocyte Ab, can attenuate C-peptide loss over the first year of disease. The effects of B cell depletion on disease-associated T cell responses have not been studied. We compare changes in lymphocyte subsets, T cell proliferative responses to disease-associated target Ags, and C-peptide levels of participants who did (responders) or did not (nonresponders) show signs of β-cell preservation 1 y after rituximab therapy in a placebo-controlled TrialNet trial. Rituximab decreased B lymphocyte levels after four weekly doses of mAb. T cell proliferative responses to diabetes-associated Ags were present at baseline in 75% of anti-CD20- and 82% of placebo-treated subjects and were not different over time. However, in rituximab-treated subjects with significant C-peptide preservation at 6 mo (58%), the proliferative responses to diabetes-associated total (p = 0.032), islet-specific (p = 0.048), and neuronal autoantigens (p = 0.005) increased over the 12-mo observation period. This relationship was not seen in placebo-treated patients. We conclude that in patients with type 1 diabetes mellitus, anti-B cell mAb causes increased proliferative responses to diabetes Ags and attenuated β-cell loss. The way in which these responses affect the disease course remains unknown.

  15. Blockade of PD-1/B7-H1 Interaction Restores Effector CD8+ T Cell Responses in a Hepatitis C Virus Core Murine Model1

    PubMed Central

    Lukens, John R.; Cruise, Michael W.; Lassen, Matthew G.; Hahn, Young S.

    2010-01-01

    The impaired function of CD8+ T cells is characteristic of hepatitis C virus (HCV) persistent infection. HCV core protein has been reported to inhibit CD8+ T cell responses. To determine the mechanism of the HCV core in suppressing Ag-specific CD8+ T cell responses, we generated a transgenic mouse, core(+) mice, where the expression of core protein is directed to the liver using the albumin promoter. Using a recombinant adenovirus to deliver Ag, we demonstrated that core(+) mice failed to clear adenovirus-LacZ (Ad-LacZ) infection in the liver. The effector function of LacZ-specific CD8+ T cells was particularly impaired in the livers of core(+) mice, with suppression of IFN-γ, TNF-α, and granzyme B production by CD8+ T cells. In addition, the impaired CD8+ T cell responses in core(+) mice were accompanied by the enhanced expression of the inhibitory receptor programmed death-1 (PD-1) by LacZ-specific CD8+ T cells and its ligand B7-H1 on liver dendritic cells following Ad-LacZ infection. Importantly, blockade of the PD-1/B7-H1 inhibitory pathway (using a B7-H1 blocking antibody) in core(+) mice enhanced effector function of CD8+ T cells and cleared Ad-LacZ-infection as compared with that in mice treated with control Ab. This suggests that the regulation of the PD-1/B7-H1 inhibitory pathway is crucial for HCV core-mediated impaired T cell responses and viral persistence in the liver. This also suggests that manipulation of the PD-1/B7-H1 pathway may be a potential immunotherapy to enhance effector T cell responses during persistent HCV infection. PMID:18354211

  16. HLA Class I Binding 9mer Peptides from Influenza A Virus Induce CD4+ T Cell Responses

    PubMed Central

    Wang, Mingjun; Larsen, Mette V.; Nielsen, Morten; Harndahl, Mikkel; Justesen, Sune; Dziegiel, Morten H.; Buus, Søren; Tang, Sheila T.; Lund, Ole; Claesson, Mogens H.

    2010-01-01

    Background Identification of human leukocyte antigen class I (HLA-I) restricted cytotoxic T cell (CTL) epitopes from influenza virus is of importance for the development of new effective peptide-based vaccines. Methodology/Principal Findings In the present work, bioinformatics was used to predict 9mer peptides derived from available influenza A viral proteins with binding affinity for at least one of the 12 HLA-I supertypes. The predicted peptides were then selected in a way that ensured maximal coverage of the available influenza A strains. One hundred and thirty one peptides were synthesized and their binding affinities for the HLA-I supertypes were measured in a biochemical assay. Influenza-specific T cell responses towards the peptides were quantified using IFNγ ELISPOT assays with peripheral blood mononuclear cells (PBMC) from adult healthy HLA-I typed donors as responder cells. Of the 131 peptides, 21 were found to induce T cell responses in 19 donors. In the ELISPOT assay, five peptides induced responses that could be totally blocked by the pan-specific anti-HLA-I antibody W6/32, whereas 15 peptides induced responses that could be completely blocked in the presence of the pan-specific anti-HLA class II (HLA-II) antibody IVA12. Blocking of HLA-II subtype reactivity revealed that 8 and 6 peptide responses were blocked by anti-HLA-DR and -DP antibodies, respectively. Peptide reactivity of PBMC depleted of CD4+ or CD8+ T cells prior to the ELISPOT culture revealed that effectors are either CD4+ (the majority of reactivities) or CD8+ T cells, never a mixture of these subsets. Three of the peptides, recognized by CD4+ T cells showed binding to recombinant DRA1*0101/DRB1*0401 or DRA1*0101/DRB5*0101 molecules in a recently developed biochemical assay. Conclusions/Significance HLA-I binding 9mer influenza virus-derived peptides induce in many cases CD4+ T cell responses restricted by HLA-II molecules. PMID:20479886

  17. Early postnatal exposure to cigarette smoke impairs the antigen-specific T-cell responses in the spleen.

    PubMed

    Singh, Shashi P; Razani-Boroujerdi, Seddigheh; Pena-Philippides, Juan C; Langley, Raymond J; Mishra, Neerad C; Sopori, Mohan L

    2006-12-15

    Annually, approximately two million babies are exposed to cigarette smoke in utero and postnatally through cigarette smoking of their mothers. Exposure to mainstream cigarette smoke is known to impair both innate and adaptive immunities, and it has been hypothesized that the effects of in utero exposure to cigarette smoke on children's health might primarily stem from the adverse effects of cigarette smoke on the immune system. To simulate the environment that babies from smoking mothers encounter, we examined the effects of prenatal mainstream and postnatal sidestream cigarette smoke on spleen cell responses. Results show that postnatal exposure of newborn Balb/c mouse pups to sidestream cigarette smoke through the first 6 weeks of life strongly suppresses the antibody response of spleen cells to the T-cell-dependent antigen, sheep red blood cells. The reduction in the antibody response seen within 6 weeks of postnatal smoke exposure is much quicker than the published data on the time 25 weeks) required to establish reproducible immunosuppression in adult rats and mice. Moreover, the immunosuppression is not associated with significant changes in T-cell numbers or subset distribution. While the postnatal exposure to cigarette smoke did not affect the mitogenic response of T and B cells, the exposure inhibited the T cell receptor-mediated rise in the intracellular calcium concentration. These results suggest that the early postnatal period is highly sensitive to the immunosuppressive effects of environmental tobacco smoke, and the effects are causally associated with impaired antigen-mediated signaling in T cells.

  18. MIF: a down-regulator of early T cell-dependent IFN-γ responses in Plasmodium chabaudi adami (DK) infected mice

    PubMed Central

    Tshikudi Malu, Diane; Bélanger, Benoit; Desautels, François; Kelendji, Karine; Dalko, Esther; Sanchez-Dardon, Jaime; Leng, Lin; Bucala, Richard; Satoskar, Abhay; Scorza, Tatiana

    2012-01-01

    Neutralization of macrophage migration inhibitory factor (MIF) increases anti-tumor cytotoxic T cell responses in vivo and IFN-γ responses in vitro, suggesting a plausible regulatory role for MIF in T cell activation. Considering that IFN-γ production by CD4+ T cells is pivotal to resolve murine malaria and that secretion of MIF is induced by Plasmodium chabaudi adami parasites, we investigated the effect of MIF deficiency on the infection with this pathogen. Infections with P.c. adami DK parasites were more efficiently controlled in MIF-neutralized and MIF-deficient (KO) BALB/c mice. The reduction in parasitemia was associated with reduced production of IL-4 by non-T/non-B cells throughout patent infection. At day 4 post-infection, higher numbers of activated CD4+ cells were measured in MIF KO mice, which secreted more IFN-γ, less IL-4 and less IL-10 than CD4+ T cells from WT mice. Enhanced IFN-γ and decreased IL-4 responses also were measured in MIF KO CD4+ T cells stimulated with or without IL-12 and anti-IL-4 blocking antibody to induce Th1 polarization. However, MIF KO CD4+ T cells efficiently acquired a Th2 phenotype when stimulated in the presence of IL-4 and anti-IL-12 antibody, indicating normal responsiveness to IL-4/STAT6 signaling. These results suggest that by promoting IL-4 responses in cells other than T/B cells during early P.c. adami infection, MIF decreases IFN-γ secretion in CD4+ T cells and in addition, has the intrinsic ability to render CD4+ T cells less capable of acquiring a robust Th1 phenotype when stimulated in the presence of IL-12. PMID:21518974

  19. Depletion of Regulatory T Cells Augments a Vaccine-Induced T Effector Cell Response against the Liver-Stage of Malaria but Fails to Increase Memory

    PubMed Central

    Espinoza Mora, Maria del Rosario; Steeg, Christiane; Tartz, Susanne; Heussler, Volker; Sparwasser, Tim; Link, Andreas; Fleischer, Bernhard; Jacobs, Thomas

    2014-01-01

    Regulatory T cells (Treg) have been shown to restrict vaccine-induced T cell responses in different experimental models. In these studies CD4+CD25+ Treg were depleted using monoclonal antibodies against CD25, which might also interfere with CD25 on non-regulatory T cell populations and would have no effect on Foxp3+CD25− Treg. To obtain more insights in the specific function of Treg during vaccination we used mice that are transgenic for a bacterial artificial chromosome expressing a diphtheria toxin (DT) receptor-eGFP fusion protein under the control of the foxp3 gene locus (depletion of regulatory T cell mice; DEREG). As an experimental vaccine-carrier recombinant Bordetella adenylate cyclase toxoid fused with a MHC-class I-restricted epitope of the circumsporozoite protein (ACT-CSP) of Plasmodium berghei (Pb) was used. ACT-CSP was shown by us previously to introduce the CD8+ epitope of Pb-CSP into the MHC class I presentation pathway of professional antigen-presenting cells (APC). Using this system we demonstrate here that the number of CSP-specific T cells increases when Treg are depleted during prime but also during boost immunization. Importantly, despite this increase of T effector cells no difference in the number of antigen-specific memory cells was observed. PMID:25115805

  20. HLA-DR4-associated T and B cell responses to specific determinants on the IA-2 autoantigen in type 1 diabetes.

    PubMed

    McLaughlin, Kerry A; Gulati, Kavita; Richardson, Carolyn C; Morgan, Diana; Bodansky, H Jonathan; Feltbower, Richard G; Christie, Michael R

    2014-11-01

    Autoantibodies to IA-2 in type 1 diabetes are associated with HLA-DR4, suggesting influences of HLA-DR4-restricted T cells on IA-2-specific B cell responses. The aim of this study was to investigate possible T-B cell collaboration by determining whether autoantibodies to IA-2 epitopes are associated with T cell responses to IA-2 peptides presented by DR4. T cells secreting the cytokines IFN-γ and IL-10 in response to seven peptides known to elicit T cell responses in type 1 diabetes were quantified by cytokine ELISPOT in HLA-typed patients characterized for Abs to IA-2 epitopes. T cell responses were detected to all peptides tested, but only IL-10 responses to 841-860 and 853-872 peptides were associated with DR4. Phenotyping by RT-PCR of FACS-sorted CD45RO(hi) T cells secreting IL-10 in response to these two peptides indicated that these expressed GATA-3 or T-bet, but not FOXP3, consistent with these being Th2 or Th1 memory T cells rather than of regulatory phenotype. T cell responses to the same two peptides were also associated with specific Abs: those to 841-860 peptide with Abs to juxtamembrane epitopes, which appear early in prediabetes, and those to peptide 853-872 with Abs to an epitope located in the 831-862 central region of the IA-2 tyrosine phosphatase domain. Abs to juxtamembrane and central region constructs were both DR4 associated. This study identifies a region of focus for B and T cell responses to IA-2 in HLA-DR4 diabetic patients that may explain HLA associations of IA-2 autoantibodies, and this region may provide a target for future immune intervention to prevent disease. Copyright © 2014 by The American Association of Immunologists, Inc.

  1. Mycobacterium leprae-Infected Macrophages Preferentially Primed Regulatory T Cell Responses and Was Associated with Lepromatous Leprosy

    PubMed Central

    Miranda, Jake W.; Gilson, Danny J.; Song, Zhengyu; Chen, Jia; Shi, Chao; Zhu, Jianyu; Yang, Jun; Jing, Zhichun

    2016-01-01

    Background The persistence of Mycobacterium leprae (M. leprae) infection is largely dependent on the types of host immune responses being induced. Macrophage, a crucial modulator of innate and adaptive immune responses, could be directly infected by M. leprae. We therefore postulated that M. leprae-infected macrophages might have altered immune functions. Methodology/Principal Findings Here, we treated monocyte-derived macrophages with live or killed M. leprae, and examined their activation status and antigen presentation. We found that macrophages treated with live M. leprae showed committed M2-like function, with decreased interleukin 1 beta (IL-1beta), IL-6, tumor necrosis factor alpha (TNF-alpha) and MHC class II molecule expression and elevated IL-10 and CD163 expression. When incubating with naive T cells, macrophages treated with live M. leprae preferentially primed regulatory T (Treg) cell responses with elevated FoxP3 and IL-10 expression, while interferon gamma (IFN-gamma) expression and CD8+ T cell cytotoxicity were reduced. Chromium release assay also found that live M. leprae-treated macrophages were more resistant to CD8+ T cell-mediated cytotoxicity than sonicated M. leprae-treated monocytes. Ex vivo studies showed that the phenotype and function of monocytes and macrophages had clear differences between L-lep and T-lep patients, consistent with the in vitro findings. Conclusions/Significance Together, our data demonstrate that M. leprae could utilize infected macrophages by two mechanisms: firstly, M. leprae-infected macrophages preferentially primed Treg but not Th1 or cytotoxic T cell responses; secondly, M. leprae-infected macrophages were more effective at evading CD8+ T cell-mediated cytotoxicity. PMID:26751388

  2. Characterization of guinea pig T cell responses elicited after EP-assisted delivery of DNA vaccines to the skin.

    PubMed

    Schultheis, Katherine; Schaefer, Hubert; Yung, Bryan S; Oh, Janet; Muthumani, Karuppiah; Humeau, Laurent; Broderick, Kate E; Smith, Trevor R F

    2017-01-03

    The skin is an ideal target tissue for vaccine delivery for a number of reasons. It is highly accessible, and most importantly, enriched in professional antigen presenting cells. Possessing strong similarities to human skin physiology and displaying a defined epidermis, the guinea pig is an appropriate model to study epidermal delivery of vaccine. However, whilst we have characterized the humoral responses in the guinea pig associated with skin vaccine protocols we have yet to investigate the T cell responses. In response to this inadequacy, we developed an IFN-γ ELISpot assay to characterize the cellular immune response in the peripheral blood of guinea pigs. Using a nucleoprotein (NP) influenza pDNA vaccination regimen, we characterized host T cell responses. After delivery of the DNA vaccine to the guinea pig epidermis we detected robust and rapid T cell responses. The levels of IFN-γ spot-forming units averaged approximately 5000 per million cells after two immunizations. These responses were broad in that multiple regions across the NP antigen elicited a T cell response. Interestingly, we identified a number of NP immunodominant T cell epitopes to be conserved across an outbred guinea pig population, a phenomenon which was also observed after immunization with a RSV DNA vaccine. We believe this data enhances our understanding of the cellular immune response elicited to a vaccine in guinea pigs, and globally, will advance the use of this model for vaccine development, especially those targeting skin as a delivery site. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  3. PKC-Theta is a Novel SC35 Splicing Factor Regulator in Response to T Cell Activation.

    PubMed

    McCuaig, Robert Duncan; Dunn, Jennifer; Li, Jasmine; Masch, Antonia; Knaute, Tobias; Schutkowski, Mike; Zerweck, Johannes; Rao, Sudha

    2015-01-01

    Alternative splicing of nuclear pre-mRNA is essential for generating protein diversity and regulating gene expression. While many immunologically relevant genes undergo alternative splicing, the role of regulated splicing in T cell immune responses is largely unexplored, and the signaling pathways and splicing factors that regulate alternative splicing in T cells are poorly defined. Here, we show using a combination of Jurkat T cells, human primary T cells, and ex vivo naïve and effector virus-specific T cells isolated after influenza A virus infection that SC35 phosphorylation is induced in response to stimulatory signals. We show that SC35 colocalizes with RNA polymerase II in activated T cells and spatially overlaps with H3K27ac and H3K4me3, which mark transcriptionally active genes. Interestingly, SC35 remains coupled to the active histone marks in the absence of continuing stimulatory signals. We show for the first time that nuclear PKC-θ co-exists with SC35 in the context of the chromatin template and is a key regulator of SC35 in T cells, directly phosphorylating SC35 peptide residues at RNA recognition motif and RS domains. Collectively, our findings suggest that nuclear PKC-θ is a novel regulator of the key splicing factor SC35 in T cells.

  4. A Lower Baseline CD4/CD8 T-Cell Ratio Is Independently Associated with Immunodiscordant Response to Antiretroviral Therapy in HIV-Infected Subjects

    PubMed Central

    Rosado-Sánchez, I.; Herrero-Fernández, I.; Álvarez-Ríos, A. I.; Genebat, M.; Abad-Carrillo, M. A.; Ruiz-Mateos, E.; Pulido, F.; González-García, J.; Montero, M.; Bernal-Morell, E.; Vidal, F.; Leal, M.

    2017-01-01

    ABSTRACT We explored if baseline CD4/CD8 T-cell ratio is associated with immunodiscordant response to antiretroviral therapy in HIV-infected subjects. Comparing immunodiscordant and immunoconcordant subjects matched by pretreatment CD4 counts, we observed a lower pretreatment CD4/CD8 T-cell ratio in immunodiscordant subjects. Furthermore, pretreatment CD4/CD8 T-cell ratio, but not CD4 counts, correlated with the main immunological alterations observed in immunodiscordants, including increased regulatory T-cell (Treg) frequency and T-cell turnover-related markers. Then, in a larger cohort, only baseline CD4/CD8 T-cell ratio was independently associated with immunodiscordance, after adjusting by the viral CXCR4-tropic HIV variants. Our results suggest that the CD4/CD8 T-cell ratio could be an accurate biomarker of the subjacent immunological damage triggering immunodiscordance. PMID:28559274

  5. Characterization of Diabetogenic CD8+ T Cells

    PubMed Central

    Garyu, Justin W.; Uduman, Mohamed; Stewart, Alex; Rui, Jinxiu; Deng, Songyan; Shenson, Jared; Staron, Matt M.; Kleinstein, Steven H.

    2016-01-01

    Type 1 diabetes mellitus is caused by the killing of insulin-producing β cells by CD8+T cells. The disease progression, which is chronic, does not follow a course like responses to conventional antigens such as viruses, but accelerates as glucose tolerance deteriorates. To identify the unique features of the autoimmune effectors that may explain this behavior, we analyzed diabetogenic CD8+ T cells that recognize a peptide from the diabetes antigen IGRP (NRP-V7-reactive) in prediabetic NOD mice and compared them to others that shared their phenotype (CD44+CD62LloPD-1+CXCR3+) but negative for diabetes antigen tetramers and to LCMV (lymphocytic choriomeningitis)-reactive CD8+ T cells. There was an increase in the frequency of the NRP-V7-reactive cells coinciding with the time of glucose intolerance. The T cells persisted in hyperglycemic NOD mice maintained with an insulin pellet despite destruction of β cells. We compared gene expression in the three groups of cells compared with the other two subsets of cells, and the NRP-V7-reactive cells exhibited gene expression of memory precursor effector cells. They had reduced cellular proliferation and were less dependent on oxidative phosphorylation. When prediabetic NOD mice were treated with 2-deoxyglucose to block aerobic glycolysis, there was a reduction in the diabetes antigen versus other cells of similar phenotype and loss of lymphoid cells infiltrating the islets. In addition, treatment of NOD mice with 2-deoxyglucose resulted in improved β cell granularity. These findings identify a link between metabolic disturbances and autoreactive T cells that promotes development of autoimmune diabetes. PMID:26994137

  6. Reduced generation of lung tissue–resident memory T cells during infancy

    PubMed Central

    Zens, Kyra D.; Chen, Jun Kui; Wu, Felix L.; Cvetkovski, Filip

    2017-01-01

    Infants suffer disproportionately from respiratory infections and generate reduced vaccine responses compared with adults, although the underlying mechanisms remain unclear. In adult mice, lung-localized, tissue-resident memory T cells (TRMs) mediate optimal protection to respiratory pathogens, and we hypothesized that reduced protection in infancy could be due to impaired establishment of lung TRM. Using an infant mouse model, we demonstrate generation of lung-homing, virus-specific T effectors after influenza infection or live-attenuated vaccination, similar to adults. However, infection during infancy generated markedly fewer lung TRMs, and heterosubtypic protection was reduced compared with adults. Impaired TRM establishment was infant–T cell intrinsic, and infant effectors displayed distinct transcriptional profiles enriched for T-bet–regulated genes. Notably, mouse and human infant T cells exhibited increased T-bet expression after activation, and reduction of T-bet levels in infant mice enhanced lung TRM establishment. Our findings reveal that infant T cells are intrinsically programmed for short-term responses, and targeting key regulators could promote long-term, tissue-targeted protection at this critical life stage. PMID:28855242

  7. Tumor exosomes block dendritic cells maturation to decrease the T cell immune response.

    PubMed

    Ning, Yongling; Shen, Kai; Wu, Qiyong; Sun, Xiao; Bai, Yu; Xie, Yewen; Pan, Jie; Qi, Chunjian

    2018-07-01

    Tumors can induce the generation and accumulation of immunosuppression in a tumor microenvironment, contributing to the tumor's escape from immunological surveillance. Although tumor antigen-pulsed dendritic cell can improve anti-tumor immune responses, tumor associated regulatory dendritic cells are involved in the induction of immune tolerance. The current study sought to investigate whether exosomes produced by tumor cells had any effect on DCs in immune suppression. In this study, we examined the effect of tumor exosomes on DCs and found that exosomes from LLC Lewis lung carcinoma or 4T1 breast cancer cell blocked the differentiation of myeloid precursor cells into CD11c + DCs and induced cell apoptosis. Tumor exosome treatment inhibited the maturation and migration of DCs and promoted the immune suppression of DCs. The treatment of tumor exosomes drastically decreased CD4 + IFN-γ + Th1 differentiation but increased the rates of regulatory T (Treg) cells. The immunosuppressive ability of tumor exosome-treated DCs were partially restored with PD-L1 blockage. These data suggested that PD-L1 played a role in tumor exosome-induced DC-associated immune suppression. Copyright © 2018 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.

  8. Idiotypic properties of the murine anti-arsonate antibody response: B- and T-cell influences.

    PubMed

    Conger, J D; Lewis, G K; Goodman, J W

    1985-10-01

    In a previous report characterizing the arsonate (ABA)-specific plaque-forming cell (PFC) responses of A/J mice induced by ABA-KLH, two interesting characteristics of the idiotypic (Id) profile were noted: (1) an apparent Id selectivity in the isotype switch since the earliest appearing IgG PFC in the primary response were significantly more "cross-reactive Id" (CRI)-dominant than the IgM PFC population, and, (2) a temporal waning of CRI dominance with time among IgG PFC, from 75-100% CRI+ PFC to about 25-45% CRI+ PFC in secondary responses. Experiments were performed to determine whether these effects are largely attributable to T or to B cells. Mice were immunized with a T-independent (TI) form of ABA (ABA-Brucella abortus) and apparent Id selectivity was observed; the earliest IgG PFC averaged 75% CRI+ while IgM PFC were only 39% CRI+. Due to the TI nature of the Ag, this provides suggestive, but not conclusive, evidence that the Id asymmetry in the isotype switch may be attributable to the direct interaction of Ag with B cells. Other studies addressed the temporal shift in CRI dominance. First, it was found that preexposure of mice to either KLH or to ABA (on an irrelevant carrier) resulted in diminished CRI dominance in subsequent "primary" responses to ABA-KLH. Secondly, adoptive transfer experiments with B and T cells from virgin mice (Bv, Tv) or ABA-KLH-primed mice (Bp, Tp) showed that recipients of Bv + Tp or Bp + Tv generated anti-ABA PFC responses with intermediate CRI levels. The Tv cells had some preferential tendency to activate CRI+ clones in the Bp population. The results demonstrate that CRI levels are jointly determined by the immune status of both B and T cells. A simple model is offered which accounts for early Id dominance and its gradual decline and has as its central postulate the assumption that CRI+ B cells in the virgin ABA-specific repertoire have an affinity advantage over CRI- clones.

  9. Enhanced CD8+ cytolytic T cell responses in the peripheral circulation of patients with sarcoidosis and non-Löfgren's disease.

    PubMed

    Parasa, Venkata Ramanarao; Forsslund, Helena; Enger, Tobias; Lorenz, Daniel; Kullberg, Susanna; Eklund, Anders; Sköld, Magnus; Wahlström, Jan; Grunewald, Johan; Brighenti, Susanna

    2018-05-01

    The role of CD4 + T cells in the immunopathogenesis of pulmonary sarcoidosis is well-established, while less is known about the phenotype and function of CD8 + cytolytic T cells (CTLs). CD8 + CTLs were explored in peripheral blood and bronchoalveolar lavage (BAL) samples obtained from up to 25 patients with sarcoidosis and 25 healthy controls. The proportion of CTLs was assessed by the expression of cytolytic effector molecules perforin, granzyme B and granulysin in CD8 + T cells, using flow cytometry. Cytolytic function in blood lymphocytes was assessed using a standard 51 Cr-release assay. Patients with Löfgren´s syndrome (LS) and an acute disease onset, were compared to non-LS patients with an insidious onset. Higher proportions of peripheral CD8 + CTLs expressing perforin and granzyme B were observed in sarcoidosis compared to healthy controls. Blood CTLs from non-LS patients had significantly higher expression of perforin, granzyme B and granulysin compared to matched BAL, while LS patients maintained lower levels of effector molecules in both compartments. Mitogen-stimulated peripheral lymphocytes from sarcoidosis patients, particularly from the non-LS group, showed a higher target cell lysis compared to controls. These results demonstrated enhanced peripheral CD8 + CTL responses in sarcoidosis, especially in non-LS patients who have an increased risk of chronic disease. Further comprehensive clinical studies are warranted to increase our understanding of CD8 + CTL responses in sarcoidosis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Comparable polyfunctionality of ectromelia virus- and vaccinia virus-specific murine T cells despite markedly different in vivo replication and pathogenicity.

    PubMed

    Hersperger, Adam R; Siciliano, Nicholas A; Eisenlohr, Laurence C

    2012-07-01

    Vaccinia virus (VACV) stimulates long-term immunity against highly pathogenic orthopoxvirus infection of humans (smallpox) and mice (mousepox [ectromelia virus {ECTV}]) despite the lack of a natural host-pathogen relationship with either of these species. Previous research revealed that VACV is able to induce polyfunctional CD8(+) T-cell responses after immunization of humans. However, the degree to which the functional profile of T cells induced by VACV is similar to that generated during natural poxvirus infection remains unknown. In this study, we monitored virus-specific T-cell responses following the dermal infection of C57BL/6 mice with ECTV or VACV. Using polychromatic flow cytometry, we measured levels of degranulation, cytokine expression (gamma interferon [IFN-γ], tumor necrosis factor alpha [TNF-α], and interleukin-2 [IL-2]), and the cytolytic mediator granzyme B. We observed that the functional capacities of T cells induced by VACV and ECTV were of a similar quality in spite of the markedly different replication abilities and pathogenic outcomes of these viruses. In general, a significant fraction (≥50%) of all T-cell responses were positive for at least three functions both during acute infection and into the memory phase. In vivo killing assays revealed that CD8(+) T cells specific for both viruses were equally cytolytic (∼80% target cell lysis after 4 h), consistent with the similar levels of granzyme B and degranulation detected among these cells. Collectively, these data provide a mechanism to explain the ability of VACV to induce protective T-cell responses against pathogenic poxviruses in their natural hosts and provide further support for the use of VACV as a vaccine platform able to induce polyfunctional T cells.

  11. Prophylactic and therapeutic vaccination with carrier-bound Bet v 1 peptides lacking allergen-specific T cell epitopes reduces Bet v 1-specific T cell responses via blocking antibodies in a murine model for birch pollen allergy.

    PubMed

    Linhart, B; Narayanan, M; Focke-Tejkl, M; Wrba, F; Vrtala, S; Valenta, R

    2014-02-01

    Vaccines consisting of allergen-derived peptides lacking IgE reactivity and allergen-specific T cell epitopes bound to allergen-unrelated carrier molecules have been suggested as candidates for allergen-specific immunotherapy. To study whether prophylactic and therapeutic vaccination with carrier-bound peptides from the major birch pollen allergen Bet v 1 lacking allergen-specific T cell epitopes has influence on Bet v 1-specific T cell responses. Three Bet v 1-derived peptides, devoid of Bet v 1-specific T cell epitopes, were coupled to KLH and adsorbed to aluminium hydroxide to obtain a Bet v 1-specific allergy vaccine. Groups of BALB/c mice were immunized with the peptide vaccine before or after sensitization to Bet v 1. Bet v 1- and peptide-specific antibody responses were analysed by ELISA. T cell and cytokine responses to Bet v 1, KLH, and the peptides were studied in proliferation assays. The effects of peptide-specific and allergen-specific antibodies on T cell responses and allergic lung inflammation were studied using specific antibodies. Prophylactic and therapeutic vaccination with carrier-bound Bet v 1 peptides induced a Bet v 1-specific IgG antibody response without priming/boosting of Bet v 1-specific T cells. Prophylactic and therapeutic vaccination of mice with the peptide vaccine induced Bet v 1-specific antibodies which suppressed Bet v 1-specific T cell responses and allergic lung inflammation. Vaccination with carrier-bound allergen-derived peptides lacking allergen-specific T cell epitopes induces allergen-specific IgG antibodies which suppress allergen-specific T cell responses and allergic lung inflammation. © 2013 John Wiley & Sons Ltd.

  12. Protein structure shapes immunodominance in the CD4 T cell response to yellow fever vaccination.

    PubMed

    Koblischke, Maximilian; Mackroth, Maria S; Schwaiger, Julia; Fae, Ingrid; Fischer, Gottfried; Stiasny, Karin; Heinz, Franz X; Aberle, Judith H

    2017-08-21

    The live attenuated yellow fever (YF) vaccine is a highly effective human vaccine and induces long-term protective neutralizing antibodies directed against the viral envelope protein E. The generation of such antibodies requires the help of CD4 T cells which recognize peptides derived from proteins in virus particles internalized and processed by E-specific B cells. The CD4 T helper cell response is restricted to few immunodominant epitopes, but the mechanisms of their selection are largely unknown. Here, we report that CD4 T cell responses elicited by the YF-17D vaccine are focused to hotspots of two helices of the viral capsid protein and to exposed strands and loops of E. We found that the locations of immunodominant epitopes within three-dimensional protein structures exhibit a high degree of overlap between YF virus and the structurally homologous flavivirus tick-borne encephalitis virus, although amino acid sequence identity of the epitope regions is only 15-45%. The restriction of epitopes to exposed E protein surfaces and their strikingly similar positioning within proteins of distantly related flaviviruses are consistent with a strong influence of protein structure that shapes CD4 T cell responses and provide leads for a rational design of immunogens for vaccination.

  13. T cell subtypes and reciprocal inflammatory mediator expression differentiate P. falciparum memory recall responses in asymptomatic and symptomatic malaria patients in southeastern Haiti

    PubMed Central

    Campo, Joseph J.; Cicéron, Micheline; Raccurt, Christian P.; Beau De Rochars, Valery E. M.

    2017-01-01

    Asymptomatic Plasmodium falciparum infection is responsible for maintaining malarial disease within human populations in low transmission countries such as Haiti. Investigating differential host immune responses to the parasite as a potential underlying mechanism could help provide insight into this highly complex phenomenon and possibly identify asymptomatic individuals. We performed a cross-sectional analysis of individuals who were diagnosed with malaria in Sud-Est, Haiti by comparing the cellular and humoral responses of both symptomatic and asymptomatic subjects. Plasma samples were analyzed with a P. falciparum protein microarray, which demonstrated serologic reactivity to 3,877 P. falciparum proteins of known serologic reactivity; however, no antigen-antibody reactions delineating asymptomatics from symptomatics were identified. In contrast, differences in cellular responses were observed. Flow cytometric analysis of patient peripheral blood mononuclear cells co-cultured with P. falciparum infected erythrocytes demonstrated a statistically significant increase in the proportion of T regulatory cells (CD4+ CD25+ CD127-), and increases in unique populations of both NKT-like cells (CD3+ CD8+ CD56+) and CD8mid T cells in asymptomatics compared to symptomatics. Also, CD38+/HLA-DR+ expression on γδ T cells, CD8mid (CD56-) T cells, and CD8mid CD56+ NKT-like cells decreased upon exposure to infected erythrocytes in both groups. Cytometric bead analysis of the co-culture supernatants demonstrated an upregulation of monocyte-activating chemokines/cytokines in asymptomatics, while immunomodulatory soluble factors were elevated in symptomatics. Principal component analysis of these expression values revealed a distinct clustering of individual responses within their respective phenotypic groups. This is the first comprehensive investigation of immune responses to P. falciparum in Haiti, and describes unique cell-mediated immune repertoires that delineate individuals

  14. T cell subtypes and reciprocal inflammatory mediator expression differentiate P. falciparum memory recall responses in asymptomatic and symptomatic malaria patients in southeastern Haiti.

    PubMed

    Lehmann, Jason S; Campo, Joseph J; Cicéron, Micheline; Raccurt, Christian P; Boncy, Jacques; Beau De Rochars, Valery E M; Cannella, Anthony P

    2017-01-01

    Asymptomatic Plasmodium falciparum infection is responsible for maintaining malarial disease within human populations in low transmission countries such as Haiti. Investigating differential host immune responses to the parasite as a potential underlying mechanism could help provide insight into this highly complex phenomenon and possibly identify asymptomatic individuals. We performed a cross-sectional analysis of individuals who were diagnosed with malaria in Sud-Est, Haiti by comparing the cellular and humoral responses of both symptomatic and asymptomatic subjects. Plasma samples were analyzed with a P. falciparum protein microarray, which demonstrated serologic reactivity to 3,877 P. falciparum proteins of known serologic reactivity; however, no antigen-antibody reactions delineating asymptomatics from symptomatics were identified. In contrast, differences in cellular responses were observed. Flow cytometric analysis of patient peripheral blood mononuclear cells co-cultured with P. falciparum infected erythrocytes demonstrated a statistically significant increase in the proportion of T regulatory cells (CD4+ CD25+ CD127-), and increases in unique populations of both NKT-like cells (CD3+ CD8+ CD56+) and CD8mid T cells in asymptomatics compared to symptomatics. Also, CD38+/HLA-DR+ expression on γδ T cells, CD8mid (CD56-) T cells, and CD8mid CD56+ NKT-like cells decreased upon exposure to infected erythrocytes in both groups. Cytometric bead analysis of the co-culture supernatants demonstrated an upregulation of monocyte-activating chemokines/cytokines in asymptomatics, while immunomodulatory soluble factors were elevated in symptomatics. Principal component analysis of these expression values revealed a distinct clustering of individual responses within their respective phenotypic groups. This is the first comprehensive investigation of immune responses to P. falciparum in Haiti, and describes unique cell-mediated immune repertoires that delineate individuals

  15. Persistence of T-cell immune response induced by two acellular pertussis vaccines in children five years after primary vaccination.

    PubMed

    Palazzo, Raffaella; Carollo, Maria; Bianco, Manuela; Fedele, Giorgio; Schiavoni, Ilaria; Pandolfi, Elisabetta; Villani, Alberto; Tozzi, Alberto E; Mascart, Françoise; Ausiello, Clara M

    2016-01-01

    The resurgence of pertussis suggests the need for greater efforts to understand the long-lasting protective responses induced by vaccination. In this paper we dissect the persistence of T memory responses induced by primary vaccination with two different acellular pertussis (aP) vaccines, hexavalent Hexavac® vaccine (Hexavac) (Sanofi Pasteur MSD) and Infanrix hexa® (Infanrix) (Glaxo-SmithKline Biologicals). We evaluated magnitude and duration of T-cell responses to pertussis toxin (PT) by measuring T-cell proliferation, cytokines (IL-2 and IFNγ) production and memory subsets in two groups of children 5 years after primary vaccination. Some of the enrolled children received only primary vaccination, while others had the pre-school boost dose. Positive T-cell responses to PT were detected in 36% of children. Percentage of responsive children, T-cell proliferation and CD4IL-2+ cells were significantly higher in the children primed with Hexavac than in those who received Infanrix vaccine. No major effects of the boost on PT-specific proliferation were observed. Overall, our data documented a persistence of T-cell memory against PT in a minor fraction of children 5 years after primary vaccination. The different responses induced by Hexavac and Infanrix vaccine could rely on differences in PT inactivation process or excipients/adjuvants formulations.

  16. Involvement of CD8+ T cell-mediated immune responses in LcrV DNA vaccine induced protection against lethal Yersinia pestis challenge.

    PubMed

    Wang, Shixia; Goguen, Jon D; Li, Fusheng; Lu, Shan

    2011-09-09

    Yersinia pestis (Y. pestis) is the causative pathogen of plague, a highly fatal disease for which an effective vaccine, especially against mucosal transmission, is still not available. Like many bacterial infections, antigen-specific antibody responses have been traditionally considered critical, if not solely responsible, for vaccine-induced protection against Y. pestis. Studies in recent years have suggested the importance of T cell immune responses against Y. pestis infection but information is still limited about the details of Y. pestis antigen-specific T cell immune responses. In current report, studies are conducted to identify the presence of CD8+ T cell epitopes in LcrV protein, the leading antigen of plague vaccine development. Furthermore, depletion of CD8+ T cells in LcrV DNA vaccinated Balb/C mice led to reduced protection against lethal intranasal challenge of Y. pestis. These findings establish that an LcrV DNA vaccine is able to elicit CD8+ T cell immune responses against specific epitopes of this key plague antigen and that a CD8+ T cell immune response is involved in LcrV DNA vaccine-elicited protection. Future studies in plague vaccine development will need to examine if the presence of detectable T cell immune responses, in particular CD8+ T-cell immune responses, will enhance the protection against Y. pestis in higher animal species or humans. Copyright © 2010 Elsevier Ltd. All rights reserved.

  17. Predicting the response to CTLA-4 blockade by longitudinal noninvasive monitoring of CD8 T cells

    PubMed Central

    Whang, Katherine A.; LeGall, Camille; Cragnolini, Juan J.; Bierie, Brian; Gostissa, Monica; Grotenbreg, Gijsbert M.; Bhan, Atul; Weinberg, Robert A.

    2017-01-01

    Immunotherapy using checkpoint-blocking antibodies against targets such as CTLA-4 and PD-1 can cure melanoma and non–small cell lung cancer in a subset of patients. The presence of CD8 T cells in the tumor correlates with improved survival. We show that immuno–positron emission tomography (immuno-PET) can visualize tumors by detecting infiltrating lymphocytes and, through longitudinal observation of individual animals, distinguish responding tumors from those that do not respond to therapy. We used 89Zr-labeled PEGylated single-domain antibody fragments (VHHs) specific for CD8 to track the presence of intratumoral CD8+ T cells in the immunotherapy-susceptible B16 melanoma model in response to checkpoint blockade. A 89Zr-labeled PEGylated anti-CD8 VHH detected thymus and secondary lymphoid structures as well as intratumoral CD8 T cells. Animals that responded to CTLA-4 therapy showed a homogeneous distribution of the anti-CD8 PET signal throughout the tumor, whereas more heterogeneous infiltration of CD8 T cells correlated with faster tumor growth and worse responses. To support the validity of these observations, we used two different transplantable breast cancer models, yielding results that conformed with predictions based on the antimelanoma response. It may thus be possible to use immuno-PET and monitor antitumor immune responses as a prognostic tool to predict patient responses to checkpoint therapies. PMID:28666979

  18. The yellow fever virus vaccine induces a broad and polyfunctional human memory CD8+ T cell response.

    PubMed

    Akondy, Rama S; Monson, Nathan D; Miller, Joseph D; Edupuganti, Srilatha; Teuwen, Dirk; Wu, Hong; Quyyumi, Farah; Garg, Seema; Altman, John D; Del Rio, Carlos; Keyserling, Harry L; Ploss, Alexander; Rice, Charles M; Orenstein, Walter A; Mulligan, Mark J; Ahmed, Rafi

    2009-12-15

    The live yellow fever vaccine (YF-17D) offers a unique opportunity to study memory CD8(+) T cell differentiation in humans following an acute viral infection. We have performed a comprehensive analysis of the virus-specific CD8(+) T cell response using overlapping peptides spanning the entire viral genome. Our results showed that the YF-17D vaccine induces a broad CD8(+) T cell response targeting several epitopes within each viral protein. We identified a dominant HLA-A2-restricted epitope in the NS4B protein and used tetramers specific for this epitope to track the CD8(+) T cell response over a 2 year period. This longitudinal analysis showed the following. 1) Memory CD8(+) T cells appear to pass through an effector phase and then gradually down-regulate expression of activation markers and effector molecules. 2) This effector phase was characterized by down-regulation of CD127, Bcl-2, CCR7, and CD45RA and was followed by a substantial contraction resulting in a pool of memory T cells that re-expressed CD127, Bcl-2, and CD45RA. 3) These memory cells were polyfunctional in terms of degranulation and production of the cytokines IFN-gamma, TNF-alpha, IL-2, and MIP-1beta. 4) The YF-17D-specific memory CD8(+) T cells had a phenotype (CCR7(-)CD45RA(+)) that is typically associated with terminally differentiated cells with limited proliferative capacity (T(EMRA)). However, these cells exhibited robust proliferative potential showing that expression of CD45RA may not always associate with terminal differentiation and, in fact, may be an indicator of highly functional memory CD8(+) T cells generated after acute viral infections.

  19. Severe Malaria Infections Impair Germinal Center Responses by Inhibiting T Follicular Helper Cell Differentiation.

    PubMed

    Ryg-Cornejo, Victoria; Ioannidis, Lisa Julia; Ly, Ann; Chiu, Chris Yu; Tellier, Julie; Hill, Danika Lea; Preston, Simon Peter; Pellegrini, Marc; Yu, Di; Nutt, Stephen Laurence; Kallies, Axel; Hansen, Diana Silvia

    2016-01-05

    Naturally acquired immunity to malaria develops only after years of repeated exposure to Plasmodium parasites. Despite the key role antibodies play in protection, the cellular processes underlying the slow acquisition of immunity remain unknown. Using mouse models, we show that severe malaria infection inhibits the establishment of germinal centers (GCs) in the spleen. We demonstrate that infection induces high frequencies of T follicular helper (Tfh) cell precursors but results in impaired Tfh cell differentiation. Despite high expression of Bcl-6 and IL-21, precursor Tfh cells induced during infection displayed low levels of PD-1 and CXCR5 and co-expressed Th1-associated molecules such as T-bet and CXCR3. Blockade of the inflammatory cytokines TNF and IFN-γ or T-bet deletion restored Tfh cell differentiation and GC responses to infection. Thus, this study demonstrates that the same pro-inflammatory mediators that drive severe malaria pathology have detrimental effects on the induction of protective B cell responses. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  20. The Respiratory Environment Diverts the Development of Antiviral Memory CD8 T Cells.

    PubMed

    Shane, Hillary L; Reagin, Katie L; Klonowski, Kimberly D

    2018-06-01

    Our understanding of memory CD8 + T cells has been largely derived from acute, systemic infection models. However, memory CD8 + T cells generated from mucosal infection exhibit unique properties and, following respiratory infection, are not maintained in the lung long term. To better understand how infection route modifies memory differentiation, we compared murine CD8 + T cell responses to a vesicular stomatitis virus (VSV) challenge generated intranasally (i.n.) or i.v. The i.n. infection resulted in greater peak expansion of VSV-specific CD8 + T cells. However, this numerical advantage was rapidly lost during the contraction phase of the immune response, resulting in memory CD8 + T cell numerical deficiencies when compared with i.v. infection. Interestingly, the antiviral CD8 + T cells generated in response to i.n. VSV exhibited a biased and sustained proportion of early effector cells (CD127 lo KLRG1 lo ) akin to the developmental program favored after i.n. influenza infection, suggesting that respiratory infection broadly favors an incomplete memory differentiation program. Correspondingly, i.n. VSV infection resulted in lower CD122 expression and eomesodermin levels by VSV-specific CD8 + T cells, further indicative of an inferior transition to bona fide memory. These results may be due to distinct (CD103 + CD11b + ) dendritic cell subsets in the i.n. versus i.v. T cell priming environments, which express molecules that regulate T cell signaling and the balance between tolerance and immunity. Therefore, we propose that distinct immunization routes modulate both the quality and quantity of antiviral effector and memory CD8 + T cells in response to an identical pathogen and should be considered in CD8 + T cell-based vaccine design. Copyright © 2018 by The American Association of Immunologists, Inc.

  1. Lytic and Latent Antigens of the Human Gammaherpesviruses Kaposi's Sarcoma-Associated Herpesvirus and Epstein-Barr Virus Induce T-Cell Responses with Similar Functional Properties and Memory Phenotypes▿

    PubMed Central

    Bihl, Florian; Narayan, Murli; Chisholm, John V.; Henry, Leah M.; Suscovich, Todd J.; Brown, Elizabeth E.; Welzel, Tania M.; Kaufmann, Daniel E.; Zaman, Tauheed M.; Dollard, Sheila; Martin, Jeff N.; Wang, Fred; Scadden, David T.; Kaye, Kenneth M.; Brander, Christian

    2007-01-01

    The cellular immunity against Kaposi's sarcoma-associated herpesvirus (KSHV) is poorly characterized and has not been compared to T-cell responses against other human herpesviruses. Here, novel and dominant targets of KSHV-specific cellular immunity are identified and compared to T cells specific for lytic and latent antigens in a second human gammaherpesvirus, Epstein-Barr virus. The data identify a novel HLA-B57- and HLA-B58-restricted epitope in the Orf57 protein and show consistently close parallels in immune phenotypes and functional response patterns between cells targeting lytic or latent KSHV- and EBV-encoded antigens, suggesting common mechanisms in the induction of these responses. PMID:17329344

  2. Lytic and latent antigens of the human gammaherpesviruses Kaposi's sarcoma-associated herpesvirus and Epstein-Barr virus induce T-cell responses with similar functional properties and memory phenotypes.

    PubMed

    Bihl, Florian; Narayan, Murli; Chisholm, John V; Henry, Leah M; Suscovich, Todd J; Brown, Elizabeth E; Welzel, Tania M; Kaufmann, Daniel E; Zaman, Tauheed M; Dollard, Sheila; Martin, Jeff N; Wang, Fred; Scadden, David T; Kaye, Kenneth M; Brander, Christian

    2007-05-01

    The cellular immunity against Kaposi's sarcoma-associated herpesvirus (KSHV) is poorly characterized and has not been compared to T-cell responses against other human herpesviruses. Here, novel and dominant targets of KSHV-specific cellular immunity are identified and compared to T cells specific for lytic and latent antigens in a second human gammaherpesvirus, Epstein-Barr virus. The data identify a novel HLA-B57- and HLA-B58-restricted epitope in the Orf57 protein and show consistently close parallels in immune phenotypes and functional response patterns between cells targeting lytic or latent KSHV- and EBV-encoded antigens, suggesting common mechanisms in the induction of these responses.

  3. REGULATION OF THE T-CELL RESPONSE BY CD39

    PubMed Central

    Takenaka, Maisa C.; Robson, Simon; Quintana, Francisco J.

    2016-01-01

    The ectonucleoside triphosphate diphosphohydrolase 1 (ENTPD1, or CD39) catalyzes the phosphohydrolysis of extracellular adenosine triphosphate (eATP) and diphosphate (eADP) released under conditions of inflammatory stress and cell injury. CD39 generates adenosine monophosphate (AMP), which is in turn used by the ecto-5’-nucleotidase CD73 to synthesize adenosine. These ectonucleotidases have major impacts on the dynamic equilibrium of pro-inflammatory eATP and ADP nucleotides vs. immunosuppressive adenosine nucleosides. Indeed, CD39 plays a dominant role in the purinergic regulation of inflammation and the immune response because its expression is influenced by genetic and environmental factors. Here, we review the specific role of CD39 in the kinetic regulation of cellular immune responses in the evolution of disease. We focus on the effects of CD39 on T cells and explore potential clinical applications in autoimmunity, chronic infections and cancer. PMID:27236363

  4. The role of accessory cells in polyclonal T cell activation. I. Both induction of interleukin 2 production and of interleukin 2 responsiveness by concanavalin A are accessory cell dependent.

    PubMed

    Hünig, T; Loos, M; Schimpl, A

    1983-01-01

    Recent studies from other laboratories have shown that concanavalin A (Con A) acts at two separate steps in polyclonal T cell activation: interleukin 2 (IL2) production, and induction of responsiveness to IL2. Using a combination of techniques for the depletion of accessory cells from lymph node T cells, we have investigated which of these steps, if not both, is responsible for the known requirement for accessory cells in the Con A response. It was found that with increasing T cell purification, first the ability is lost to produce sufficient levels of endogenous IL2, whereas induction of IL2 responsiveness can still take place. Further removal of accessory cells however yields a population of resting T cells that cannot be induced by Con A to become IL2-reactive. It was concluded that both IL2 production and induction of reactivity to IL2 are accessory cell-dependent events.

  5. Maturation of monocyte derived dendritic cells with OK432 boosts IL-12p70 secretion and conveys strong T-cell responses

    PubMed Central

    2011-01-01

    Background Design of tumour specific immunotherapies using the patients' own dendritic cells (DC) is a fast advancing scientific field. The functional qualities of the DC generated in vitro are critical, and today's gold standard for maturation is a cytokine cocktail consisting of IL-1β, IL-6, TNF-α and PGE2 generating cells lacking IL-12p70 production. OK432 is an immunotherapeutic agent derived from killed Streptococcus pyogenes that has been used clinically to treat malignant and benign neoplasms for decades. Methods In this study, we analysed the effects of OK432 on DC maturation, DC migration, cytokine and chemokine secretion as well as T-cell stimulatory capacity, and compared it to the cytokine cocktail alone and combinations of OK432 with the cytokine cocktail. Results OK432 induced a marked up-regulation of CD40 on the cell surface as well as a strong inflammatory response from the DC with significantly more secretion of 19 different cytokines and chemokines compared to the cytokine cocktail. Interestingly, secretion of IL-15 and IL-12p70 was detected at high concentrations after maturation of DC with OK432. However, the OK432 treated DC did not migrate as well as DC treated with cytokine cocktail in a transwell migration assay. During allogeneic T-cell stimulation OK432 treated DC induced proliferation of over 50 percent of CD4 and 30 percent of CD8 T-cells for more than two cell divisions, whereas cytokine cocktail treated DC induced proliferation of 12 and 11 percent of CD4 and CD8 T-cells, respectively. Conclusions The clinically approved compound OK432 has interesting properties that warrants its use in DC immunotherapy and should be considered as a potential immunomodulating agent in cancer immunotherapy. PMID:21208424

  6. Induction of micronuclei and apoptosis in natural killer cells compared to T lymphocytes after gamma-irradiation.

    PubMed

    Louagie, H; Philippé, J; Vral, A; Cornelissen, M; Thierens, H; De Ridder, L

    1998-02-01

    To investigate the chromosomal damage caused by gamma-irradiation in T lymphocytes and natural killer (NK) cells and compare this with apoptosis induction in both lymphocyte subsets. Apoptosis induction by gamma-irradiation in T lymphocytes and NK cells was quantified using the annexin V flow cytometric assay. The cytokinesis-block micronucleus (MN) assay was used to evaluate the induced cytogenetic damage. For the MN assays on NK cells, gamma-irradiated peripheral blood mononuclear cells were cultured and stimulated with interleukin 15 (IL-15). Afterwards the NK cells (characterized by the CD3-/CD56+ phenotype) were separated with the FACSort flow cytometer and the number of MN in the sorted binuclear cells was scored. Doses of 1 and 2 Gy gamma-irradiation were applied. Higher numbers of MN in NK cells were found compared with the MN yield in T lymphocytes. In contrast, NK cells were less than T lymphocytes prone to apoptosis after gamma-irradiation. The results support the view that cytogenetic damage and apoptosis after gamma-irradiation are not necessarily correlated.

  7. Promiscuous survivin peptide induces robust CD4+ T-cell responses in the majority of vaccinated cancer patients.

    PubMed

    Widenmeyer, Melanie; Griesemann, Heinrich; Stevanović, Stefan; Feyerabend, Susan; Klein, Reinhild; Attig, Sebastian; Hennenlotter, Jörg; Wernet, Dorothee; Kuprash, Dmitri V; Sazykin, Alexei Y; Pascolo, Steve; Stenzl, Arnulf; Gouttefangeas, Cécile; Rammensee, Hans-Georg

    2012-07-01

    CD4(+) T cells have been shown to be crucial for the induction and maintenance of cytotoxic T cell responses and to be also capable of mediating direct tumor rejection. Therefore, the anticancer therapeutic efficacy of peptide-based vaccines may be improved by addition of HLA class II epitopes to stimulate T helper cells. Survivin is an apoptosis inhibiting protein frequently overexpressed in tumors. Here we describe the first immunological evaluation of a survivin-derived CD4(+) T cell epitope in a multipeptide immunotherapy trial for prostate carcinoma patients. The survivin peptide is promiscuously presented by several human HLA-DRB1 molecules and, most importantly, is naturally processed by dendritic cells. In vaccinated patients, it was able to induce frequent, robust and multifunctional CD4(+) T cell responses, as monitored by IFN-γ ELISPOT and intracellular cytokine staining. Thus, this HLA-DR restricted epitope is broadly immunogenic and should be valuable for stimulating T helper cells in patients suffering from a wide range of tumors. Copyright © 2011 UICC.

  8. Chitin recognition via chitotriosidase promotes pathologic type-2 helper T cell responses to cryptococcal infection.

    PubMed

    Wiesner, Darin L; Specht, Charles A; Lee, Chrono K; Smith, Kyle D; Mukaremera, Liliane; Lee, S Thera; Lee, Chun G; Elias, Jack A; Nielsen, Judith N; Boulware, David R; Bohjanen, Paul R; Jenkins, Marc K; Levitz, Stuart M; Nielsen, Kirsten

    2015-03-01

    Pulmonary mycoses are often associated with type-2 helper T (Th2) cell responses. However, mechanisms of Th2 cell accumulation are multifactorial and incompletely known. To investigate Th2 cell responses to pulmonary fungal infection, we developed a peptide-MHCII tetramer to track antigen-specific CD4+ T cells produced in response to infection with the fungal pathogen Cryptococcus neoformans. We noted massive accruement of pathologic cryptococcal antigen-specific Th2 cells in the lungs following infection that was coordinated by lung-resident CD11b+ IRF4-dependent conventional dendritic cells. Other researchers have demonstrated that this dendritic cell subset is also capable of priming protective Th17 cell responses to another pulmonary fungal infection, Aspergillus fumigatus. Thus, higher order detection of specific features of fungal infection by these dendritic cells must direct Th2 cell lineage commitment. Since chitin-containing parasites commonly elicit Th2 responses, we hypothesized that recognition of fungal chitin is an important determinant of Th2 cell-mediated mycosis. Using C. neoformans mutants or purified chitin, we found that chitin abundance impacted Th2 cell accumulation and disease. Importantly, we determined Th2 cell induction depended on cleavage of chitin via the mammalian chitinase, chitotriosidase, an enzyme that was also prevalent in humans experiencing overt cryptococcosis. The data presented herein offers a new perspective on fungal disease susceptibility, whereby chitin recognition via chitotriosidase leads to the initiation of harmful Th2 cell differentiation by CD11b+ conventional dendritic cells in response to pulmonary fungal infection.

  9. Chitin Recognition via Chitotriosidase Promotes Pathologic Type-2 Helper T Cell Responses to Cryptococcal Infection

    PubMed Central

    Wiesner, Darin L.; Specht, Charles A.; Lee, Chrono K.; Smith, Kyle D.; Mukaremera, Liliane; Lee, S. Thera; Lee, Chun G.; Elias, Jack A.; Nielsen, Judith N.; Boulware, David R.; Bohjanen, Paul R.; Jenkins, Marc K.; Levitz, Stuart M.; Nielsen, Kirsten

    2015-01-01

    Pulmonary mycoses are often associated with type-2 helper T (Th2) cell responses. However, mechanisms of Th2 cell accumulation are multifactorial and incompletely known. To investigate Th2 cell responses to pulmonary fungal infection, we developed a peptide-MHCII tetramer to track antigen-specific CD4+ T cells produced in response to infection with the fungal pathogen Cryptococcus neoformans. We noted massive accruement of pathologic cryptococcal antigen-specific Th2 cells in the lungs following infection that was coordinated by lung-resident CD11b+ IRF4-dependent conventional dendritic cells. Other researchers have demonstrated that this dendritic cell subset is also capable of priming protective Th17 cell responses to another pulmonary fungal infection, Aspergillus fumigatus. Thus, higher order detection of specific features of fungal infection by these dendritic cells must direct Th2 cell lineage commitment. Since chitin-containing parasites commonly elicit Th2 responses, we hypothesized that recognition of fungal chitin is an important determinant of Th2 cell-mediated mycosis. Using C. neoformans mutants or purified chitin, we found that chitin abundance impacted Th2 cell accumulation and disease. Importantly, we determined Th2 cell induction depended on cleavage of chitin via the mammalian chitinase, chitotriosidase, an enzyme that was also prevalent in humans experiencing overt cryptococcosis. The data presented herein offers a new perspective on fungal disease susceptibility, whereby chitin recognition via chitotriosidase leads to the initiation of harmful Th2 cell differentiation by CD11b+ conventional dendritic cells in response to pulmonary fungal infection. PMID:25764512

  10. Polyfunctional CD4 T cells in the response to bovine tuberculosis

    USDA-ARS?s Scientific Manuscript database

    Polyfunctional CD4 T cells simultaneously produce interferon-gamma (IFN-gamma), interleukin-2 (IL-2) and tumor necrosis factor-alpha (TNF-alpha) and play relevant roles in several chronic infections, including human TB and HIV. However, the assessment of this response in bovine infections was not fe...

  11. The signaling symphony: T cell receptor tunes cytokine-mediated T cell differentiation

    PubMed Central

    Huang, Weishan; August, Avery

    2015-01-01

    T cell development, differentiation, and maintenance are orchestrated by 2 key signaling axes: the antigen-specific TCR and cytokine-mediated signals. The TCR signals the recognition of self- and foreign antigens to control T cell homeostasis for immune tolerance and immunity, which is regulated by a variety of cytokines to determine T cell subset homeostasis and differentiation. TCR signaling can synergize with or antagonize cytokine-mediated signaling to fine tune T cell fate; however, the latter is less investigated. Murine models with attenuated TCR signaling strength have revealed that TCR signaling can function as regulatory feedback machinery for T cell homeostasis and differentiation in differential cytokine milieus, such as IL-2-mediated Treg development; IL-7-mediated, naïve CD8+ T cell homeostasis; and IL-4-induced innate memory CD8+ T cell development. In this review, we discuss the symphonic cross-talk between TCR and cytokine-mediated responses that differentially control T cell behavior, with a focus on the negative tuning by TCR activation on the cytokine effects. PMID:25525115

  12. Targeting LAG-3 and PD-1 to Enhance T Cell Activation by Antigen-Presenting Cells

    PubMed Central

    Lichtenegger, Felix S.; Rothe, Maurine; Schnorfeil, Frauke M.; Deiser, Katrin; Krupka, Christina; Augsberger, Christian; Schlüter, Miriam; Neitz, Julia; Subklewe, Marion

    2018-01-01

    Immune checkpoint inhibition has been shown to successfully reactivate endogenous T cell responses directed against tumor-associated antigens, resulting in significantly prolonged overall survival in patients with various tumor entities. For malignancies with low endogenous immune responses, this approach has not shown a clear clinical benefit so far. Therapeutic vaccination, particularly dendritic cell (DC) vaccination, is a strategy to induce T cell responses. Interaction of DCs and T cells is dependent on receptor–ligand interactions of various immune checkpoints. In this study, we analyzed the influence of blocking antibodies targeting programmed cell death protein 1 (PD-1), HVEM, CD244, TIM-3, and lymphocyte activation gene 3 (LAG-3) on the proliferation and cytokine secretion of T cells after stimulation with autologous TLR-matured DCs. In this context, we found that LAG-3 blockade resulted in superior T cell activation compared to inhibition of other pathways, including PD-1/PD-L1. This result was consistent across different methods to measure T cell stimulation (proliferation, IFN-γ secretion), various stimulatory antigens (viral and bacterial peptide pool, specific viral antigen, specific tumor antigen), and seen for both CD4+ and CD8+ T cells. Only under conditions with a weak antigenic stimulus, particularly when combining antigen presentation by peripheral blood mononuclear cells with low concentrations of peptides, we observed the highest T cell stimulation with dual blockade of LAG-3 and PD-1 blockade. We conclude that priming of novel immune responses can be strongly enhanced by blockade of LAG-3 or dual blockade of LAG-3 and PD-1, depending on the strength of the antigenic stimulus. PMID:29535740

  13. Targeting LAG-3 and PD-1 to Enhance T Cell Activation by Antigen-Presenting Cells.

    PubMed

    Lichtenegger, Felix S; Rothe, Maurine; Schnorfeil, Frauke M; Deiser, Katrin; Krupka, Christina; Augsberger, Christian; Schlüter, Miriam; Neitz, Julia; Subklewe, Marion

    2018-01-01

    Immune checkpoint inhibition has been shown to successfully reactivate endogenous T cell responses directed against tumor-associated antigens, resulting in significantly prolonged overall survival in patients with various tumor entities. For malignancies with low endogenous immune responses, this approach has not shown a clear clinical benefit so far. Therapeutic vaccination, particularly dendritic cell (DC) vaccination, is a strategy to induce T cell responses. Interaction of DCs and T cells is dependent on receptor-ligand interactions of various immune checkpoints. In this study, we analyzed the influence of blocking antibodies targeting programmed cell death protein 1 (PD-1), HVEM, CD244, TIM-3, and lymphocyte activation gene 3 (LAG-3) on the proliferation and cytokine secretion of T cells after stimulation with autologous TLR-matured DCs. In this context, we found that LAG-3 blockade resulted in superior T cell activation compared to inhibition of other pathways, including PD-1/PD-L1. This result was consistent across different methods to measure T cell stimulation (proliferation, IFN-γ secretion), various stimulatory antigens (viral and bacterial peptide pool, specific viral antigen, specific tumor antigen), and seen for both CD4 + and CD8 + T cells. Only under conditions with a weak antigenic stimulus, particularly when combining antigen presentation by peripheral blood mononuclear cells with low concentrations of peptides, we observed the highest T cell stimulation with dual blockade of LAG-3 and PD-1 blockade. We conclude that priming of novel immune responses can be strongly enhanced by blockade of LAG-3 or dual blockade of LAG-3 and PD-1, depending on the strength of the antigenic stimulus.

  14. Armc5 deletion causes developmental defects and compromises T-cell immune responses

    PubMed Central

    Hu, Yan; Lao, Linjiang; Mao, Jianning; Jin, Wei; Luo, Hongyu; Charpentier, Tania; Qi, Shijie; Peng, Junzheng; Hu, Bing; Marcinkiewicz, Mieczyslaw Martin; Lamarre, Alain; Wu, Jiangping

    2017-01-01

    Armadillo repeat containing 5 (ARMC5) is a cytosolic protein with no enzymatic activities. Little is known about its function and mechanisms of action, except that gene mutations are associated with risks of primary macronodular adrenal gland hyperplasia. Here we map Armc5 expression by in situ hybridization, and generate Armc5 knockout mice, which are small in body size. Armc5 knockout mice have compromised T-cell proliferation and differentiation into Th1 and Th17 cells, increased T-cell apoptosis, reduced severity of experimental autoimmune encephalitis, and defective immune responses to lymphocytic choriomeningitis virus infection. These mice also develop adrenal gland hyperplasia in old age. Yeast 2-hybrid assays identify 16 ARMC5-binding partners. Together these data indicate that ARMC5 is crucial in fetal development, T-cell function and adrenal gland growth homeostasis, and that the functions of ARMC5 probably depend on interaction with multiple signalling pathways. PMID:28169274

  15. Strategy for monitoring T cell responses to NY-ESO-1 in patients with any HLA class I allele

    PubMed Central

    Gnjatic, Sacha; Nagata, Yasuhiro; Jäger, Elke; Stockert, Elisabeth; Shankara, Srinivas; Roberts, Bruce L.; Mazzara, Gail P.; Lee, Sang Yull; Dunbar, P. Rod; Dupont, Bo; Cerundolo, Vincenzo; Ritter, Gerd; Chen, Yao-Tseng; Knuth, Alexander; Old, Lloyd J.

    2000-01-01

    NY-ESO-1 elicits frequent antibody responses in cancer patients, accompanied by strong CD8+ T cell responses against HLA-A2-restricted epitopes. To broaden the range of cancer patients who can be assessed for immunity to NY-ESO-1, a general method was devised to detect T cell reactivity independent of prior characterization of epitopes. A recombinant adenoviral vector encoding the full cDNA sequence of NY-ESO-1 was used to transduce CD8-depleted peripheral blood lymphocytes as antigen-presenting cells. These modified antigen-presenting cells were then used to restimulate memory effector cells against NY-ESO-1 from the peripheral blood of cancer patients. Specific CD8+ T cells thus sensitized were assayed on autologous B cell targets infected with a recombinant vaccinia virus encoding NY-ESO-1. Strong polyclonal responses were observed against NY-ESO-1 in antibody-positive patients, regardless of their HLA profile. Because the vectors do not cross-react immunologically, only responses to NY-ESO-1 were detected. The approach described here allows monitoring of CD8+ T cell responses to NY-ESO-1 in the context of various HLA alleles and has led to the definition of NY-ESO-1 peptides presented by HLA-Cw3 and HLA-Cw6 molecules. PMID:11005863

  16. T regulatory cells in contact hypersensitivity.

    PubMed

    Cavani, Andrea

    2008-08-01

    The review summarizes the recent investigations focused on T regulatory cells in hapten diseases. Multiple mechanisms ensure tolerance to small chemicals penetrating the skin. Among these, specific T regulatory cells play a major role in controlling harmful immune responses to environmental antigens. Most of the T regulatory cells involved in this process belongs to the CD4 subset and suppress hapten-specific immune response through the release of IL-10 and through direct interaction with effector T cells, blocking their function. Methods for in-vitro and in-vivo expansion of specific T regulatory cells may represent an innovative approach for the cure of contact hypersensitivity.

  17. A modified anthrax toxin-based enzyme-linked immunospot assay reveals robust T cell responses in symptomatic and asymptomatic Ebola virus exposed individuals.

    PubMed

    Herrera, Bobby Brooke; Hamel, Donald J; Oshun, Philip; Akinsola, Rolake; Akanmu, Alani S; Chang, Charlotte A; Eromon, Philomena; Folarin, Onikepe; Adeyemi, Kayode T; Happi, Christian T; Lu, Yichen; Ogunsola, Folasade; Kanki, Phyllis J

    2018-05-01

    Ebola virus (EBOV) caused more than 11,000 deaths during the 2013-2016 epidemic in West Africa without approved vaccines or immunotherapeutics. Despite its high lethality in some individuals, EBOV infection can produce little to no symptoms in others. A better understanding of the immune responses in individuals who experienced minimally symptomatic and asymptomatic infection could aid the development of more effective vaccines and antivirals against EBOV and related filoviruses. Between August and November 2017, blood samples were collected from 19 study participants in Lagos, Nigeria, including 3 Ebola virus disease (EVD) survivors, 10 individuals with documented close contact with symptomatic EVD patients, and 6 control healthcare workers for a cross-sectional serosurvey and T cell analysis. The Lagos samples, as well as archived serum collected from healthy individuals living in surrounding areas of the 1976 Democratic Republic of Congo (DRC) epidemic, were tested for EBOV IgG using commercial enzyme-linked immunosorbent assays (ELISAs) and Western blots. We detected antibodies in 3 out of 3 Lagos survivors and identified 2 seropositive individuals not known to have ever been infected. Of the DRC samples tested, we detected antibodies in 9 out of 71 (12.7%). To characterize the T cell responses in the Lagos samples, we developed an anthrax toxin-based enzyme-linked immunospot (ELISPOT) assay. The seropositive asymptomatic individuals had T cell responses against EBOV nucleoprotein, matrix protein, and glycoprotein 1 that were stronger in magnitude compared to the survivors. Our data provide further evidence of EBOV exposure in individuals without EVD-like illness and, for the first time, demonstrate that these individuals have T cell responses that are stronger in magnitude compared to severe cases. These findings suggest that T cell immunity may protect against severe EVD, which has important implications for vaccine development.

  18. T cell-intrinsic factors contribute to the differential ability of CD8+ T cells to rapidly secrete IFN-γ in the absence of antigen.

    PubMed

    Bou Ghanem, Elsa N; Nelson, Christina C; D'Orazio, Sarah E F

    2011-02-01

    A subset of CD44(hi)CD8(+) T cells isolated from C57BL/6/J (B6) mice, but not BALB/c/By/J (BALB/c) mice, rapidly secrete IFN-γ within 16 h of infection with Listeria monocytogenes. This Ag-independent response requires the presence of both IL-12 and IL-18. Previous studies showed that dendritic cells from B6 mice produced more Th1-type cytokines such as IL-12 than did those from BALB/c mice in response to L. monocytogenes infection. In this report, we demonstrate that the microenvironment in L. monocytogenes-infected BALB/c mice is sufficient to induce responsive B6 CD8(+) T cells to rapidly secrete IFN-γ. Furthermore, BALB/c CD8(+) T cells did not rapidly secrete IFN-γ even when they were exposed to high concentrations of IL-12 plus IL-18 in vitro. In the presence of IL-12 and IL-18, B6 CD44(hi)CD8(+) T cells upregulated expression of the receptor subunits for these cytokines more rapidly than did BALB/c T cells. In comparing particular subsets of memory phenotype CD8(+) T cells, we found that virtual memory cells, rather than true Ag-experienced cells, had the greatest level of impairment in BALB/c mice. These data suggest that the degree of cytokine-driven bystander activation of CD8(+) T cells that occurs during infection depends on both APCs and T cell-intrinsic properties that can vary among mouse strains.

  19. Cluster Intradermal DNA Vaccination Rapidly Induces E7-specific CD8+ T Cell Immune Responses Leading to Therapeutic Antitumor Effects

    PubMed Central

    Peng, Shiwen; Trimble, Cornelia; Alvarez, Ronald D.; Huh, Warner K.; Lin, Zhenhua; Monie, Archana; Hung, Chien-Fu; Wu, T.-C.

    2010-01-01

    Intradermal administration of DNA vaccines via a gene gun represents a feasible strategy to deliver DNA directly into the professional antigen-presenting cells (APCs) in the skin. This helps to facilitate the enhancement of DNA vaccine potency via strategies that modify the properties of APCs. We have previously demonstrated that DNA vaccines encoding human papillomavirus type 16 (HPV-16) E7 antigen linked to calreticulin (CRT) are capable of enhancing the E7-specific CD8+ T cell immune responses and antitumor effects against E7-expressing tumors. It has also been shown that cluster (short-interval) DNA vaccination regimen generates potent immune responses in a minimal timeframe. Thus, in the current study we hypothesize that the cluster intradermal CRT/E7 DNA vaccination will generate significant antigen-specific CD8+ T cell infiltrates in E7-expressing tumors in tumor-bearing mice, leading to an increase in apoptotic tumor cell death. We found that cluster intradermal CRT/E7 DNA vaccination is capable of rapidly generating a significant number of E7-specific CD8+ T cells, resulting in significant therapeutic antitumor effects in vaccinated mice. We also observed that cluster intradermal CRT/E7 DNA vaccination in the presence of tumor generates significantly higher E7-specific CD8+ T cell immune responses in the systemic circulation as well as in the tumors. In addition, this vaccination regimen also led to significantly lower levels of CD4+Foxp3+ T regulatory cells and myeloid suppressor cells compared to vaccination with CRT DNA in peripheral blood and in tumor infiltrating lymphocytes, resulting in an increase in apoptotic tumor cell death. Thus, our study has significant potential for future clinical translation. PMID:18401437

  20. Transmitted/Founder Viruses Rapidly Escape from CD8+ T Cell Responses in Acute Hepatitis C Virus Infection.

    PubMed

    Bull, Rowena A; Leung, Preston; Gaudieri, Silvana; Deshpande, Pooja; Cameron, Barbara; Walker, Melanie; Chopra, Abha; Lloyd, Andrew R; Luciani, Fabio

    2015-05-01

    The interaction between hepatitis C virus (HCV) and cellular immune responses during very early infection is critical for disease outcome. To date, the impact of antigen-specific cellular immune responses on the evolution of the viral population establishing infection and on potential escape has not been studied. Understanding these early host-virus dynamics is important for the development of a preventative vaccine. Three subjects who were followed longitudinally from the detection of viremia preseroconversion until disease outcome were analyzed. The evolution of transmitted/founder (T/F) viruses was undertaken using deep sequencing. CD8(+) T cell responses were measured via enzyme-linked immunosorbent spot (ELISpot) assay using HLA class I-restricted T/F epitopes. T/F viruses were rapidly extinguished in all subjects associated with either viral clearance (n = 1) or replacement with viral variants leading to establishment of chronic infection (n = 2). CD8(+) T cell responses against 11 T/F epitopes were detectable by 33 to 44 days postinfection, and 5 of these epitopes had not previously been reported. These responses declined rapidly in those who became chronically infected and were maintained in the subject who cleared infection. Higher-magnitude CD8(+) T cell responses were associated with rapid development of immune escape variants at a rate of up to 0.1 per day. Rapid escape from CD8(+) T cell responses has been quantified for the first time in the early phase of primary HCV infection. These rapid escape dynamics were associated with higher-magnitude CD8(+) T cell responses. These findings raise questions regarding optimal selection of immunogens for HCV vaccine development and suggest that detailed analysis of individual epitopes may be required. A major limitation in our detailed understanding of the role of immune response in HCV clearance has been the lack of data on very early primary infection when the transmitted viral variants successfully establish

  1. Vaccination Expands Antigen-Specific CD4+ Memory T Cells and Mobilizes Bystander Central Memory T Cells

    PubMed Central

    Li Causi, Eleonora; Parikh, Suraj C.; Chudley, Lindsey; Layfield, David M.; Ottensmeier, Christian H.; Stevenson, Freda K.; Di Genova, Gianfranco

    2015-01-01

    CD4+ T helper memory (Thmem) cells influence both natural and vaccine-boosted immunity, but mechanisms for their maintenance remain unclear. Pro-survival signals from the common gamma-chain cytokines, in particular IL-7, appear important. Previously we showed in healthy volunteers that a booster vaccination with tetanus toxoid (TT) expanded peripheral blood TT-specific Thmem cells as expected, but was accompanied by parallel increase of Thmem cells specific for two unrelated and non cross-reactive common recall antigens. Here, in a new cohort of healthy human subjects, we compare blood vaccine-specific and bystander Thmem cells in terms of differentiation stage, function, activation and proliferative status. Both responses peaked 1 week post-vaccination. Vaccine-specific cytokine-producing Thmem cells were predominantly effector memory, whereas bystander cells were mainly of central memory phenotype. Importantly, TT-specific Thmem cells were activated (CD38High HLA-DR+), cycling or recently divided (Ki-67+), and apparently vulnerable to death (IL-7RαLow and Bcl-2 Low). In contrast, bystander Thmem cells were resting (CD38Low HLA-DR- Ki-67-) with high expression of IL-7Rα and Bcl-2. These findings allow a clear distinction between vaccine-specific and bystander Thmem cells, suggesting the latter do not derive from recent proliferation but from cells mobilized from as yet undefined reservoirs. Furthermore, they reveal the interdependent dynamics of specific and bystander T-cell responses which will inform assessments of responses to vaccines. PMID:26332995

  2. Characterisation of the clinical and activated T cell response to repeat delayed-type hypersensitivity skin challenges in human subjects, with KLH and PPD, as a potential model to test T cell-targeted therapies.

    PubMed

    Belson, Alexandra; Schmidt, Tim; Fernando, Disala; Hardes, Kelly; Scott, Nicola; Brett, Sara; Clark, Deborah; Oliveira, João Joaquim; Davis, Bill; McHugh, Simon; Stone, John

    2016-05-01

    To characterise the delayed-type hypersensitivity (DTH) skin reaction to repeated challenges of keyhole limpet hemocyanin (KLH) and tuberculin purified protein derivative (PPD) in healthy volunteers, as a potential model to test T cell-targeted investigational agents. Forty-nine subjects received either KLH, PPD, or PBS repeat skin challenges, and clinical assessments including induration, erythema and Laser Doppler Imaging. Skin biopsies or suction blisters were taken after challenge to investigate the cellular infiltrate of the challenge site, the T cell activation status, as determined by LAG-3 expression, and, specifically for the blister, the concentrations of inflammatory cytokines. Point estimates, estimates of variation and corresponding 95% confidence intervals were constructed for each type of challenge and timepoint. The DTH response could be measured at 48 and 120 h post-KLH and PPD challenge with induration, erythema and Laser Doppler Imaging, with 48 h post-challenge demonstrating the peak of the response. PPD was well tolerated in subjects after multiple challenges, however, a significant number of KLH-treated subjects demonstrated an injection site reaction 6-7 days following the SC injection. PPD demonstrated a boost effect on the second challenge as measured by increased induration, where as this was not noted consistently for KLH. Compared to unchallenged and PBS control-injected skin, increased T cell numbers were detected in the challenge site by both the skin suction blister and biopsy technique, at either time point following KLH or PPD challenge. Use of the T cell activation marker LAG-3 demonstrated the activated phenotype of these cells. In skin blisters, higher numbers of LAG-3+ T cells were detected at 48 h post-challenge, whereas in the biopsies, similar numbers of LAG-3+ cells were observed at both 48 and 120 h. Analysis of blister T cell subpopulations revealed some differences in phenotypes between the time points and between the CD4

  3. Just-in-time vaccines: Biomineralized calcium phosphate core-immunogen shell nanoparticles induce long-lasting CD8+ T cell responses in mice

    PubMed Central

    Zhou, Weibin; Moguche, Albanus; Chiu, David; Murali-Krishna, Kaja; Baneyx, François

    2014-01-01

    Distributed and on-demand vaccine production could be game-changing for infectious disease treatment in the developing world by providing new therapeutic opportunities and breaking the refrigeration “cold chain”. Here, we show that a fusion protein between a calcium phosphate binding domain and the model antigen ovalbumin can mineralize a biocompatible adjuvant in a single step. The resulting 50 nm calcium phosphate core-immunogen shell particles are comparable to soluble protein in inducing ovalbumin-specific antibody response and class switch recombination in mice. However, single dose vaccination with nanoparticles leads to higher expansion of ovalbumin-specific CD8+ T cells upon challenge with an influenza virus bearing the ovalbumin-derived SIINFEKL peptide, and these cells produce high levels of IFN-γ. Furthermore, mice exhibit a robust antigen-specific CD8+ T cell recall response when challenged with virus 8 months post-immunization. These results underscore the promise of immunogen-controlled adjuvant mineralization for just-in-time manufacturing of effective T cell vaccines. PMID:24275478

  4. Differential effects of immunosuppressive drugs on T-cell motility.

    PubMed

    Datta, A; David, R; Glennie, S; Scott, D; Cernuda-Morollon, E; Lechler, R I; Ridley, A J; Marelli-Berg, F M

    2006-12-01

    The best-characterized mechanism of the action of immunosuppressive drugs is to prevent T-cell clonal expansion, thus containing the magnitude of the ensuing immune response. As T-cell recruitment to the inflammatory site is another key step in the development of T-cell-mediated inflammation, we analyzed and compared the effects of two commonly used immunosuppressants, cyclosporin A (CsA) and the rapamycin-related compound SDZ-RAD, on the motility of human CD4+ T cells. We show that CsA, but not SDZ-RAD, inhibits T-cell transendothelial migration in vitro. CsA selectively impaired chemokine-induced T-cell chemotaxis while integrin-mediated migration was unaffected. The inhibition of T-cell chemotaxis correlated with reduced AKT/PKB but not ERK activation following exposure to the chemokine CXCL-12/SDF-1. In addition, CsA, but not SDZ-RAD, prevents some T-cell receptor-mediated effects on T-cell motility. Finally, we show that CsA, but not SDZ-RAD inhibits tissue infiltration by T cells in vivo. Our data suggest a prominent antiinflammatory role for CsA in T-cell-mediated tissue damage, by inhibiting T-cell trafficking into tissues in addition to containing clonal expansion.

  5. Abacavir induced T cell reactivity from drug naïve individuals shares features of allo-immune responses.

    PubMed

    Adam, Jacqueline; Wuillemin, Natascha; Watkins, Stephan; Jamin, Heidi; Eriksson, Klara K; Villiger, Peter; Fontana, Stefano; Pichler, Werner J; Yerly, Daniel

    2014-01-01

    Abacavir hypersensitivity is a severe hypersensitivity reaction which occurs exclusively in carriers of the HLA-B*57∶01 allele. In vitro culture of PBMC with abacavir results in the outgrowth of abacavir-reacting CD8+ T cells, which release IFNγ and are cytotoxic. How this immune response is induced and what is recognized by these T cells is still a matter of debate. We analyzed the conditions required to develop an abacavir-dependent T cell response in vitro. The abacavir reactivity was independent of co-stimulatory signals, as neither DC maturation nor release of inflammatory cytokines were observed upon abacavir exposure. Abacavir induced T cells arose in the absence of professional APC and stemmed from naïve and memory compartments. These features are reminiscent of allo-reactivity. Screening for allo-reactivity revealed that about 5% of generated T cell clones (n = 136) from three donors were allo-reactive exclusively to the related HLA-B*58∶01. The addition of peptides which can bind to the HLA-B*57∶01-abacavir complex and to HLA-B*58∶01 during the induction phase increased the proportion of HLA-B*58∶01 allo-reactive T cell clones from 5% to 42%. In conclusion, abacavir can alter the HLA-B*57∶01-peptide complex in a way that mimics an allo-allele ('altered self-allele') and create the potential for robust T cell responses.

  6. Abacavir Induced T Cell Reactivity from Drug Naïve Individuals Shares Features of Allo-Immune Responses

    PubMed Central

    Adam, Jacqueline; Wuillemin, Natascha; Watkins, Stephan; Jamin, Heidi; Eriksson, Klara K.; Villiger, Peter; Fontana, Stefano; Pichler, Werner J.; Yerly, Daniel

    2014-01-01

    Abacavir hypersensitivity is a severe hypersensitivity reaction which occurs exclusively in carriers of the HLA-B*57∶01 allele. In vitro culture of PBMC with abacavir results in the outgrowth of abacavir-reacting CD8+ T cells, which release IFNγ and are cytotoxic. How this immune response is induced and what is recognized by these T cells is still a matter of debate. We analyzed the conditions required to develop an abacavir-dependent T cell response in vitro. The abacavir reactivity was independent of co-stimulatory signals, as neither DC maturation nor release of inflammatory cytokines were observed upon abacavir exposure. Abacavir induced T cells arose in the absence of professional APC and stemmed from naïve and memory compartments. These features are reminiscent of allo-reactivity. Screening for allo-reactivity revealed that about 5% of generated T cell clones (n = 136) from three donors were allo-reactive exclusively to the related HLA-B*58∶01. The addition of peptides which can bind to the HLA-B*57∶01-abacavir complex and to HLA-B*58∶01 during the induction phase increased the proportion of HLA-B*58∶01 allo-reactive T cell clones from 5% to 42%. In conclusion, abacavir can alter the HLA-B*57∶01-peptide complex in a way that mimics an allo-allele (‘altered self-allele’) and create the potential for robust T cell responses. PMID:24751900

  7. Phenotypic and functional characterization of T cells from patients with myasthenia gravis.

    PubMed Central

    Mokhtarian, F; Pino, M; Ofosu-Appiah, W; Grob, D

    1990-01-01

    A study of cell surface phenotypes of PBL of myasthenia gravis (MG) patients showed that their T cells had a significantly higher percentage of 4B4+ T cells (the helper/inducer subset) than age- and sex-matched controls. The PBL of MG patients proliferated significantly higher than those of normal subjects (NS) in response to the purified alpha chain of the acetylcholine receptor (AChR). Anti-AChR antibody was present in sera of 88% of MG and none of the NS. The PBL B cells from MG only, when cultured with autologous T cells and stimulated with either pokeweed mitogen (69%), or AChR-alpha chain (38%), secreted antibody to AChR-alpha chain, whereas T and B cells alone secreted no antibody. T cells from PBL of MG patients were more readily cloned than T cells of NS, by limiting dilution, in the presence of recombinant IL-2 and in the absence of AChR-alpha chain. About 50% of T cell clones from MG patients, compared to none from NS, proliferated to AChR-alpha chain. This response was HLA-DR restricted. MG T cell clones did not display significant cytotoxic activity, as compared to control T cell clones. Our results indicate that in MG, 4B4+ regulatory T cells play their role in the pathogenesis of MG, not by cytotoxicity, but more likely by their ability to stimulate specific antibody production by B cells. Images PMID:1979338

  8. Peptide-MHC Class I Tetramers Can Fail To Detect Relevant Functional T Cell Clonotypes and Underestimate Antigen-Reactive T Cell Populations.

    PubMed

    Rius, Cristina; Attaf, Meriem; Tungatt, Katie; Bianchi, Valentina; Legut, Mateusz; Bovay, Amandine; Donia, Marco; Thor Straten, Per; Peakman, Mark; Svane, Inge Marie; Ott, Sascha; Connor, Tom; Szomolay, Barbara; Dolton, Garry; Sewell, Andrew K

    2018-04-01

    Peptide-MHC (pMHC) multimers, usually used as streptavidin-based tetramers, have transformed the study of Ag-specific T cells by allowing direct detection, phenotyping, and enumeration within polyclonal T cell populations. These reagents are now a standard part of the immunology toolkit and have been used in many thousands of published studies. Unfortunately, the TCR-affinity threshold required for staining with standard pMHC multimer protocols is higher than that required for efficient T cell activation. This discrepancy makes it possible for pMHC multimer staining to miss fully functional T cells, especially where low-affinity TCRs predominate, such as in MHC class II-restricted responses or those directed against self-antigens. Several recent, somewhat alarming, reports indicate that pMHC staining might fail to detect the majority of functional T cells and have prompted suggestions that T cell immunology has become biased toward the type of cells amenable to detection with multimeric pMHC. We use several viral- and tumor-specific pMHC reagents to compare populations of human T cells stained by standard pMHC protocols and optimized protocols that we have developed. Our results confirm that optimized protocols recover greater populations of T cells that include fully functional T cell clonotypes that cannot be stained by regular pMHC-staining protocols. These results highlight the importance of using optimized procedures that include the use of protein kinase inhibitor and Ab cross-linking during staining to maximize the recovery of Ag-specific T cells and serve to further highlight that many previous quantifications of T cell responses with pMHC reagents are likely to have considerably underestimated the size of the relevant populations. Copyright © 2018 The Authors.

  9. TRAV7-2*02 Expressing CD8+ T Cells Are Responsible for Palladium Allergy

    PubMed Central

    Takeda, Yuri; Suto, Yoshiko; Ito, Koyu; Hashimoto, Wataru; Nishiya, Tadashi; Ueda, Kyosuke; Narushima, Takayuki; Takahashi, Tetsu; Ogasawara, Kouetsu

    2017-01-01

    While metallic biomaterials have led to an improvement in the quality of life, metal allergies, especially to palladium (Pd), has caused a recent increase in allergic patients. Metal allergy is known to be a T cell-mediated delayed-type hypersensitivity (DTH); however, the pathogenic T cell subsets and the specific T cell receptor (TCR) have not been identified. Therefore, we attempted to identify the pathogenic T cells responsible for Pd allergy. We found that activating CD8+ T cells significantly increased and that the TRAV (TCRα variable) 7-2*02 chain skewed in Pd allergic mice. Furthermore, adoptive transfer experiments revealed that in vitro-cultured Pd-stimulated antigen presenting cells (APCs) function as memory APCs with recipient mice developing Pd allergy and that the frequency of TRAV7-2*02 increases the same as conventional Pd allergic mice. In contrast, neither proliferation of CD8+ T cells nor increasing of TRAV7-2*02 was observed in major histocompatibility complex I (MHC I)-deficient Pd-APCs transferred to mice. Taken together, we revealed that TRAV7-2*02-expressing CD8+ T cells are the pathogenic T cells for the development of Pd allergy. We also identified the CDR3 consensus motif of pathogenic TCRs as CAAXSGSWQLIF in TRAV7-2*02/TRAJ (TCRα junction)22*01 positive cells. These results suggest that the specific TCRs represent novel targets for the development of diagnostics and treatments for metal allergy. PMID:28561797

  10. The level of PPD-specific IFN-gamma-producing CD4+ T cells in the blood predicts the in vivo response to PPD.

    PubMed

    Martins, Marcia Valéria B S; Lima, Mônica Cristina B S; Duppre, Nadia C; Matos, Haroldo J; Spencer, John S; Brennan, Patrick J; Sarno, Euzenir N; Fonseca, Leila; Pereira, Geraldo M B; Pessolani, Maria Cristina V

    2007-05-01

    There are no reliable means for detecting subclinical mycobacterial infections. The recent sequencing of several mycobacterial genomes has now afforded new opportunities for the development of pathogen-specific diagnostic tests, critical in the context of leprosy and tuberculosis control. In the present study, we applied a multi-parametric flow cytometric analysis that allowed the investigation of T-cell functions in order to define immunological markers that measure previous exposure to mycobacteria. We compared the in vivo response to PPD, the gold standard skin test reagent for measuring previous exposure to Mycobacterium tuberculosis, with in vitro parameters of leukocyte activation in five PPD positive and five PPD negative healthy volunteers. PPD-stimulated peripheral leukocytes expressing CD4, CD69, cutaneous lymphocyte-associated antigen (CLA) and intracellular IFN-gamma were enumerated in whole blood and compared with the size of in vivo PPD-induced induration and IFN-gamma production levels as measured by ELISA in supernatants of PPD-stimulated peripheral blood mononuclear cells. The reactivity to the tuberculin skin test (TST) was associated with markedly increased frequencies of PPD-responsive activated (CD69+) and IFN-gamma-producing CD4+T cells. Detection of PPD-specific IFN-gamma producing leukocytes was restricted to CD4+T cells and a subset of these cells was shown to express the skin homing molecule CLA. Multiple linear regression modeling of responses to PPD showed the highest association between skin test indurations and frequencies of PPD-responsive IFN-gamma-producing CD4+CD69+ T cells. Our data show that the in vitro enumeration of antigen-specific IFN-gamma-producing CD4+ T cells can provide an alternative to the in vivo tuberculin test for the detection of latent Mycobacterium tuberculosis infection. Moreover, the measurement of these immunological parameters can be useful for the screening of new specific antigens defined by the genome

  11. T Cell Epitope Regions of the P. falciparum MSP1-33 Critically Influence Immune Responses and In Vitro Efficacy of MSP1-42 Vaccines

    PubMed Central

    Pusic, Kae M.; Hashimoto, Caryn N.; Lehrer, Axel; Aniya, Charmaine; Clements, David E.; Hui, George S.

    2011-01-01

    The C-terminal 42 kDa fragments of the P. falciparum Merozoite Surface Protein 1, MSP1-42 is a leading malaria vaccine candidate. MSP1-33, the N-terminal processed fragment of MSP1-42, is rich in T cell epitopes and it is hypothesized that they enhance antibody response toward MSP1-19. Here, we gave in vivo evidence that T cell epitope regions of MSP1-33 provide functional help in inducing anti-MSP1-19 antibodies. Eleven truncated MSP1-33 segments were expressed in tandem with MSP1-19, and immunogenicity was evaluated in Swiss Webster mice and New Zealand White rabbits. Analyses of anti-MSP1-19 antibody responses revealed striking differences in these segments' helper function despite that they all possess T cell epitopes. Only a few fragments induced a generalized response (100%) in outbred mice. These were comparable to or surpassed the responses observed with the full length MSP1-42. In rabbits, only a subset of truncated antigens induced potent parasite growth inhibitory antibodies. Notably, two constructs were more efficacious than MSP1-42, with one containing only conserved T cell epitopes. Moreover, another T cell epitope region induced high titers of non-inhibitory antibodies and they interfered with the inhibitory activities of anti-MSP1-42 antibodies. In mice, this region also induced a skewed TH2 cellular response. This is the first demonstration that T cell epitope regions of MSP1-33 positively or negatively influenced antibody responses. Differential recognition of these regions by humans may play critical roles in vaccine induced and/or natural immunity to MSP1-42. This study provides the rational basis to re-engineer more efficacious MSP1-42 vaccines by selective inclusion and exclusion of MSP1-33 specific T cell epitopes. PMID:21931852

  12. Persistence of mucosal T-cell responses to herpes simplex virus type 2 in the female genital tract.

    PubMed

    Posavad, C M; Zhao, L; Mueller, D E; Stevens, C E; Huang, M L; Wald, A; Corey, L

    2015-01-01

    Relatively little is known about the human T-cell response to herpes simplex virus type 2 (HSV-2) in the female genital tract, a major site of heterosexual HSV-2 acquisition, transmission, and reactivation. In order to understand the role of local mucosal immunity in HSV-2 infection, T-cell lines were expanded from serial cervical cytobrush samples from 30 HSV-2-infected women and examined for reactivity to HSV-2. Approximately 3% of the CD3+ T cells isolated from the cervix were HSV-2 specific and of these, a median of 91.3% were CD4+, whereas a median of 3.9% were CD8+. HSV-2-specific CD4+ T cells expanded from the cervix were not only more frequent than CD8+ T cells but also exhibited greater breadth in terms of antigenic reactivity. T cells directed at the same HSV-2 protein were often detected in serial cervical cytobrush samples and in blood. Thus, broad and persistent mucosal T-cell responses to HSV-2 were detected in the female genital tract of HSV-2+ women suggesting that these cells are resident at the site of HSV-2 infection. Understanding the role of these T cells at this biologically relevant site will be central to the elucidation of adaptive immune mechanisms involved in controlling HSV-2 disease.

  13. [T-lymphocytes--do they control rheumatic immune responses?].

    PubMed

    Wagner, U; Schulze-Koops, H

    2005-09-01

    T cells, in particular CD4(+) T cells, have been implicated in mediating many aspects of rheumatoid inflammation. In rheumatoid arthritis (RA), CD4(+) T cells display various functional abnormalities in the synovium as well as in the peripheral circulation. Current evidence suggests, however, that the role of CD4(+) T cells in the development of rheumatoid inflammation exceeds that of activated pro-inflammatory effector T cells that drive the chronic autoimmune response. Subsets of CD4(+) T cells with regulatory capacity, such as CD25(+) Tregs, have been identified in mice and man, and recent observations suggest that in RA, the function of these regulatory T cells is severely impaired. Thus, in RA, defective regulatory immune mechanisms might allow the breakdown of peripheral tolerance, following which the detrimental CD4(+) T-cell-driven immune response evolves and proceeds to chronic inflammation. Here, we review the functional abnormalities and the contribution of different T-cell subsets to rheumatoid inflammation.

  14. Hemin controls T cell polarization in sickle cell alloimmunization.

    PubMed

    Zhong, Hui; Bao, Weili; Friedman, David; Yazdanbakhsh, Karina

    2014-07-01

    Patients with sickle cell disease (SCD) often require transfusions to treat and prevent worsening anemia and other SCD complications. However, transfusions can trigger alloimmunization against transfused RBCs with serious clinical sequelae. Risk factors for alloimmunization in SCD remain poorly understood. We recently reported altered regulatory T cell (Treg) and Th responses with higher circulating Th1 (IFN-γ(+)) cytokines in chronically transfused SCD patients with alloantibodies as compared with those without alloantibodies. Because monocytes play a critical role in polarization of T cell subsets and participate in clearance of transfused RBCs, we tested the hypothesis that in response to the RBC breakdown product hemin, monocyte control of T cell polarization will differ between alloimmunized and non-alloimmunized SCD patients. Exogenous hemin induced Treg polarization in purified T cell/monocyte cocultures from healthy volunteers through the monocyte anti-inflammatory heme-degrading enzyme heme oxygenase-1. Importantly, hemin primarily through its effect on CD16+ monocytes induced an anti-inflammatory (higher Treg/lower Th1) polarization state in the non-alloimmunized SCD group, whereas it had little effect in the alloimmunized group. Non-alloimmunized SCD CD16+ monocytes expressed higher basal levels of heme oxygenase-1. Furthermore, IL-12, which contributed to a proinflammatory polarization state (low Treg/high Th1) in SCD, was dampened in hemin-treated stimulated monocytes from non-alloimmunized SCD patients, but not in the alloimmunized group. These data suggest that unlike alloimmunized patients, non-alloimmunized SCD CD16+ monocytes in response to transfused RBC breakdown products promote an anti-inflammatory state that is less conducive to alloimmunization. Copyright © 2014 by The American Association of Immunologists, Inc.

  15. Unique and Common Features of Innate-Like Human Vδ2+ γδT Cells and Mucosal-Associated Invariant T Cells.

    PubMed

    Provine, Nicholas M; Binder, Benedikt; FitzPatrick, Michael E B; Schuch, Anita; Garner, Lucy C; Williamson, Kate D; van Wilgenburg, Bonnie; Thimme, Robert; Klenerman, Paul; Hofmann, Maike

    2018-01-01

    Mucosal-associated invariant T (MAIT) cells are innate-like T cells abundant in humans that can be activated in a TCR-independent manner by inflammatory and antiviral cytokines. In humans, the capacity for TCR-independent activation is functionally linked to a transcriptional program that can be identified by the expression of the C-type lectin receptor, CD161. In addition to MAIT cells, it has been demonstrated that a subset of γδT cells expresses CD161 and can be activated by TCR-independent cytokine stimulation. In this study, we sought to clarify the nature of cytokine-responsive human γδT cells. We could link CD161 expression on Vδ2 + versus Vδ1 + γδT cells to the observation that Vδ2 + γδT cells, but not Vδ1 + γδT cells, robustly produced IFN-γ upon stimulation with a variety of cytokine combinations. Interestingly, both CD161 + and CD161 - Vδ2 + γδT cells responded to these stimuli, with increased functionality within the CD161 + subset. This innate-like responsiveness corresponded to high expression of PLZF and IL-18Rα, analogous to MAIT cells. Vδ2 + γδT cells in human duodenum and liver maintained a CD161 + IL-18Rα + phenotype and produced IFN-γ in response to IL-12 and IL-18 stimulation. In contrast to MAIT cells, we could not detect IL-17A production but observed higher steady-state expression of Granzyme B by Vδ2 + γδT cells. Finally, we investigated the frequency and functionality of γδT cells in the context of chronic hepatitis C virus infection, as MAIT cells are reduced in frequency in this disease. By contrast, Vδ2 + γδT cells were maintained in frequency and displayed unimpaired IFN-γ production in response to cytokine stimulation. In sum, human Vδ2 + γδT cells are a functionally distinct population of cytokine-responsive innate-like T cells that is abundant in blood and tissues with similarities to human MAIT cells.

  16. Downmodulation of the Inflammatory Response to Bacterial Infection by γδ T Cells Cytotoxic for Activated Macrophages

    PubMed Central

    Egan, Paul J.; Carding, Simon R.

    2000-01-01

    Although γδ T cells are involved in the regulation of inflammation after infection, their precise function is not known. Intraperitoneal infection of T cell receptor (TCR)-δ−/− mice with the intracellular bacterium Listeria monocytogenes resulted in the development of necrotic foci in the livers. In contrast, the peritoneal cavities of infected TCR-δ−/− mice contained an accumulation of low density activated macrophages and a reduced percentage of macrophages undergoing apoptosis. γδ T cell hybridomas derived from mice infected with Listeria were preferentially stimulated by low density macrophages from peritoneal exudates of infected mice. Furthermore, primary splenic γδ T cells isolated from Listeria-infected mice were cytotoxic for low density macrophages in vitro, and cytotoxicity was inhibited in the presence of antibodies to the γδ TCR. These results demonstrate a novel interaction between γδ T cells and activated macrophages in which γδ T cells are stimulated by terminally differentiated macrophages to acquire cytotoxic activity and which, in turn, induce macrophage cell death. This interaction suggests that γδ T cells regulate the inflammatory response to infection with intracellular pathogens by eliminating activated macrophages at the termination of the response. PMID:10859339

  17. Contact hypersensitivity: the mechanism of immune responses and T cell balance.

    PubMed

    Watanabe, Hideaki; Unger, Mark; Tuvel, Brandon; Wang, Binghe; Sauder, Daniel N

    2002-04-01

    The skin is the largest organ in the human body. It acts not only as an important structural barrier against injury but also as a peripheral arm of the immune system. Elucidating the characteristics of this latter function has taken on renewed importance in recent years. Exposure to chemicals in everyday life has increased exponentially over the past decades. This has been accompanied by an increased incidence of contact hypersensitivity (CHS), a dendritic cell-dependent, T cell-derived, cytokine-mediated skin inflammation. Cytokines derived from Langerhans cells (i.e., interleukin-12 [IL-12]) and from T cell (i.e., interferon-gamma [IFN-gamma], IL-4, and IL-10) play a pivotal role in the induction and initiation of CHS. Developments in immunology and molecular biology have improved our understanding of the molecular mechanisms underlying this immune response. However, the conflicting opinions that continue to characterize discussions of CHS supply clear testimony that our knowledge is as yet incomplete.

  18. Antiviral therapy during primary simian immunodeficiency virus infection fails to prevent acute loss of CD4+ T cells in gut mucosa but enhances their rapid restoration through central memory T cells.

    PubMed

    Verhoeven, David; Sankaran, Sumathi; Silvey, Melanie; Dandekar, Satya

    2008-04-01

    Gut-associated lymphoid tissue (GALT) is an early target of human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) and a site for severe CD4+ T-cell depletion. Although antiretroviral therapy (ART) is effective in suppressing HIV replication and restoring CD4+ T cells in peripheral blood, restoration in GALT is delayed. The role of restored CD4+ T-cell help in GALT during ART and its impact on antiviral CD8+ T-cell responses have not been investigated. Using the SIV model, we investigated gut CD4+ T-cell restoration in infected macaques, initiating ART during either the primary stage (1 week postinfection), prior to acute CD4+ cell loss (PSI), or during the chronic stage at 10 weeks postinfection (CSI). ART led to viral suppression in GALT and peripheral blood mononuclear cells of PSI and CSI animals at comparable levels. CSI animals had incomplete CD4+ T-cell restoration in GALT. In PSI animals, ART did not prevent acute CD4+ T-cell loss by 2 weeks postinfection in GALT but supported rapid and complete CD4+ T-cell restoration thereafter. This correlated with an accumulation of central memory CD4+ T cells and better suppression of inflammation. Restoration of CD4+ T cells in GALT correlated with qualitative changes in SIV gag-specific CD8+ T-cell responses, with a dominance of interleukin-2-producing responses in PSI animals, while both CSI macaques and untreated SIV-infected controls were dominated by gamma interferon responses. Thus, central memory CD4+ T-cell levels and qualitative antiviral CD8+ T-cell responses, independent of viral suppression, were the immune correlates of gut mucosal immune restoration during ART.

  19. Inability to induce consistent T-cell responses recognizing conserved regions within HIIV-1 antigens: a potential mechanism for lack of vaccine efficacy in the step study

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Korber, Bette; Szinger, James

    2009-01-01

    T cell based vaccines are based upon the induction of CD8+ T cell memory responses that would be effective in inhibiting infection and subsequent replication of an infecting HIV-1 strain, a process that requires a high probability of matching the epitope induced by vaccination with the infecting viral strain. We compared the frequency and specificity of the CTL epitopes elicited by the replication defective AdS gag/pol/nef vaccine used in the STEP trial with the likelihood of encountering those epitopes among recently sequenced Clade B isolates of HIV-1. On average vaccination elicited only one epitope per gene. Importantly, the highly conservedmore » epitopes in gag, pol, and nef (> 80% of strains in the current collection of the Los Alamos database [www.hiv.lanl.gov]) were rarely elicited by vaccination. Moreover there was a statistically significant skewing of the T cell response to relative variable epitopes of each gene; only 20% of persons possessed > 3 T cell responses to epitopes likely to be found in circulating strains in the CladeB populations in which the Step trial was conducted. This inability to elicit T cell responses likely to be found in circulating viral strains is a likely factor in the lack of efficacy of the vaccine utilized in the STEP trial. Modeling of the epitope specific responses elicited by vaccination, we project that a median of 8-10 CD8+ T cell epitopes are required to provide >80% likelihood of eliciting at least 3 CD8+ T cell epitopes that would be found on a circulating population of viruses. Development of vaccine regimens which elicit either a greater breadth of responses or elicit responses to conserved regions of the HIV-1 genome are needed to fully evaluate the concept of whether induction of T cell immunity can alter HIV-1 in vivo.« less

  20. NK Cells and Their Ability to Modulate T Cells during Virus Infections

    PubMed Central

    Cook, Kevin D.; Waggoner, Stephen N.; Whitmire, Jason K.

    2014-01-01

    Natural killer (NK) cells are important in protection against virus infections, and many viruses have evolved mechanisms to thwart NK cell activity. NK cells respond to inflammatory signals at an early stage of virus infection, resulting in proliferation, cytokine production, and cytolytic activity that can reduce virus loads. Moreover, the rapid kinetics of the NK cell response enables NK cells to influence other populations of innate immune cells, affect the inflammatory milieu, and guide adaptive immune responses to infection. Early NK cell interactions with other leukocytes can have long-lasting effects on the number and quality of memory T cells, as well as impact the exhaustion of T cells during chronic infections. The ability of NK cells to modulate T cell responses can be mediated through direct T-NK interactions, cytokine production, or indirectly through dendritic cells and other cell types. Herein, we summarize our current understanding of how NK cells interact with T cells, dendritic cells, B cells, and other cell types involved in adaptive immune responses to virus infection. We outline several mechanisms by which NK cells enhance or suppress adaptive immune response and long-lived immunological memory. PMID:25404045

  1. Broadly targeted CD8 + T cell responses restricted by major histocompatibility complex E

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hansen, Scott G.; Wu, Helen L.; Burwits, Benjamin J.

    Major histocompatibility complex (MHC)-E is a highly conserved, ubiquitously expressed, nonclassical, MHC-Ib molecule with limited polymorphism primarily involved in regulation of NK cell reactivity via interaction with NKG2/CD94 receptors. We found that vaccination of rhesus macaques with Rh157.5/.4 gene-deleted rhesus Cytomegalovirus (RhCMV) vectors uniquely diverts MHC-E function to presentation of highly diverse peptide epitopes to CD8α/β + T cells, approximately 4 distinct epitopes per 100 amino acids, in all tested protein antigens. Computational structural analysis revealed that a relatively stable, open binding groove in MHC-E attains broad peptide binding specificity by imposing a similar backbone configuration on bound peptides withmore » few restrictions based on amino acid side chains. Since MHC-E is up-regulated on cells infected with HIV/SIV and other persistent viruses to evade NK cell activity, MHC-E-restricted CD8 + T cell responses have the potential to exploit pathogen immune evasion adaptations, a capability that might endow these unconventional responses with superior efficacy.« less

  2. Broadly targeted CD8 + T cell responses restricted by major histocompatibility complex E

    DOE PAGES

    Hansen, Scott G.; Wu, Helen L.; Burwits, Benjamin J.; ...

    2016-02-12

    Major histocompatibility complex (MHC)-E is a highly conserved, ubiquitously expressed, nonclassical, MHC-Ib molecule with limited polymorphism primarily involved in regulation of NK cell reactivity via interaction with NKG2/CD94 receptors. We found that vaccination of rhesus macaques with Rh157.5/.4 gene-deleted rhesus Cytomegalovirus (RhCMV) vectors uniquely diverts MHC-E function to presentation of highly diverse peptide epitopes to CD8α/β + T cells, approximately 4 distinct epitopes per 100 amino acids, in all tested protein antigens. Computational structural analysis revealed that a relatively stable, open binding groove in MHC-E attains broad peptide binding specificity by imposing a similar backbone configuration on bound peptides withmore » few restrictions based on amino acid side chains. Since MHC-E is up-regulated on cells infected with HIV/SIV and other persistent viruses to evade NK cell activity, MHC-E-restricted CD8 + T cell responses have the potential to exploit pathogen immune evasion adaptations, a capability that might endow these unconventional responses with superior efficacy.« less

  3. c-Maf controls immune responses by regulating disease-specific gene networks and repressing IL-2 in CD4+ T cells.

    PubMed

    Gabryšová, Leona; Alvarez-Martinez, Marisol; Luisier, Raphaëlle; Cox, Luke S; Sodenkamp, Jan; Hosking, Caroline; Pérez-Mazliah, Damián; Whicher, Charlotte; Kannan, Yashaswini; Potempa, Krzysztof; Wu, Xuemei; Bhaw, Leena; Wende, Hagen; Sieweke, Michael H; Elgar, Greg; Wilson, Mark; Briscoe, James; Metzis, Vicki; Langhorne, Jean; Luscombe, Nicholas M; O'Garra, Anne

    2018-05-01

    The transcription factor c-Maf induces the anti-inflammatory cytokine IL-10 in CD4 + T cells in vitro. However, the global effects of c-Maf on diverse immune responses in vivo are unknown. Here we found that c-Maf regulated IL-10 production in CD4 + T cells in disease models involving the T H 1 subset of helper T cells (malaria), T H 2 cells (allergy) and T H 17 cells (autoimmunity) in vivo. Although mice with c-Maf deficiency targeted to T cells showed greater pathology in T H 1 and T H 2 responses, T H 17 cell-mediated pathology was reduced in this context, with an accompanying decrease in T H 17 cells and increase in Foxp3 + regulatory T cells. Bivariate genomic footprinting elucidated the c-Maf transcription-factor network, including enhanced activity of NFAT; this led to the identification and validation of c-Maf as a negative regulator of IL-2. The decreased expression of the gene encoding the transcription factor RORγt (Rorc) that resulted from c-Maf deficiency was dependent on IL-2, which explained the in vivo observations. Thus, c-Maf is a positive and negative regulator of the expression of cytokine-encoding genes, with context-specific effects that allow each immune response to occur in a controlled yet effective manner.

  4. T helper type 2-polarized invariant natural killer T cells reduce disease severity in acute intra-abdominal sepsis

    PubMed Central

    Anantha, R V; Mazzuca, D M; Xu, S X; Porcelli, S A; Fraser, D D; Martin, C M; Welch, I; Mele, T; Haeryfar, S M M; McCormick, J K

    2014-01-01

    Sepsis is characterized by a severe systemic inflammatory response to infection that is associated with high morbidity and mortality despite optimal care. Invariant natural killer T (iNK T) cells are potent regulatory lymphocytes that can produce pro- and/or anti-inflammatory cytokines, thus shaping the course and nature of immune responses; however, little is known about their role in sepsis. We demonstrate here that patients with sepsis/severe sepsis have significantly elevated proportions of iNK T cells in their peripheral blood (as a percentage of their circulating T cells) compared to non-septic patients. We therefore investigated the role of iNK T cells in a mouse model of intra-abdominal sepsis (IAS). Our data show that iNK T cells are pathogenic in IAS, and that T helper type 2 (Th2) polarization of iNK T cells using the synthetic glycolipid OCH significantly reduces mortality from IAS. This reduction in mortality is associated with the systemic elevation of the anti-inflammatory cytokine interleukin (IL)-13 and reduction of several proinflammatory cytokines within the spleen, notably interleukin (IL)-17. Finally, we show that treatment of sepsis with OCH in mice is accompanied by significantly reduced apoptosis of splenic T and B lymphocytes and macrophages, but not natural killer cells. We propose that modulation of iNK T cell responses towards a Th2 phenotype may be an effective therapeutic strategy in early sepsis. PMID:24965554

  5. T-cell Responses in Individuals Infected with Zika Virus and in Those Vaccinated Against Dengue Virus.

    PubMed

    Paquin-Proulx, Dominic; Leal, Fabio E; Terrassani Silveira, Cassia G; Maestri, Alvino; Brockmeyer, Claudia; Kitchen, Shannon M; Cabido, Vinicius D; Kallas, Esper G; Nixon, Douglas F

    2017-01-01

    The outbreak of Zika virus (ZIKV) infection in Brazil has raised concerns that infection during pregnancy could cause microcephaly and other severe neurodevelopmental malformations in the fetus. The mechanisms by which ZIKV causes fetal abnormalities are largely unknown. The importance of pre-infection with dengue virus (DENV), or other flaviviruses endemic to Brazil, remains to be investigated. It has been reported that antibodies directed against DENV can increase ZIKV infectivity by antibody dependent enhancement (ADE), suggesting that a history of prior DENV infection might worsen the outcome of ZIKV infection. We used bioinformatics tools to design 18 peptides from the ZIKV envelope containing predicted HLA-I T-cell epitopes and investigated T-cell cross-reactivity between ZIKV-infected individuals and DENV-vaccinated subjects by IFNγ ELISPOT. Three peptides induced IFNγ production in both ZIKV-infected subjects and in DENV-vaccinated individuals. Flow cytometry indicated that 1 ZIKV peptide induced a CD4+ T-cell response in DENV-vaccinated subjects. We demonstrated that vaccination against DENV induced a T-cell response against ZIKV and identified one such CD4+ T-cell epitope. The ZIKV-reactive CD4+ T cells induced by DENV vaccination and identified in this study could contribute to the appearance of cross-reactive antibodies mediating ADE.

  6. Adoptive cell therapy with CD4+ T helper 1 cells and CD8+ cytotoxic T cells enhances complete rejection of an established tumour, leading to generation of endogenous memory responses to non-targeted tumour epitopes.

    PubMed

    Li, Kunyu; Donaldson, Braeden; Young, Vivienne; Ward, Vernon; Jackson, Christopher; Baird, Margaret; Young, Sarah

    2017-10-01

    The results of adoptive T-cell therapies (ACTs) are very encouraging and show clinical evidence that ACT can provide a cure for patients with metastatic disease. However, various response rates and long-term cancer remission have been observed in different ACT trials. The types of T cells, prior treatment with chemotherapy and co-administration of other immune-target therapies have been found to influence the efficacy of ACT. In this study, we investigate the ability of ACT using CD4 + T helper 1 (Th1) cells and CD8 + cytotoxic T lymphocytes (CTLs) to reject the growth of established B16-ovalbumin (OVA) melanoma. CD8 + CTLs were found to be the main effector T cells that mediated tumour regression. However, low tumour-free survival rates were observed in ACT with CD8 + CTLs only. Co-transferring CD4 + Th1 cells and CD8 + CTLs has been observed to induce a synergistic antitumour response, resulting in complete regression in 80% of the tumour-bearing mice. We also examined a prior Dacarbazine (DTIC) and after virus-like particle (VLP)-OVA vaccine treatment to enhance ACT, but no therapeutic benefit was observed during primary B16-OVA tumour growth. Nevertheless, the ACT-mediated antitumour response was able to generate memory responses to both B16-OVA and B16-gp33 tumours. VLP-OVA vaccination following ACT enhances the memory responses to tumours that express a heterogenic population of both B16-OVA and B16-gp33 cells; however, it abolished the memory response to tumours consisting of only gp33-expressing cells. These findings provide important information for designing therapeutic treatments for patients with metastatic disease and cancer relapse to achieve durable cancer remission.

  7. Adoptive cell therapy with CD4+ T helper 1 cells and CD8+ cytotoxic T cells enhances complete rejection of an established tumour, leading to generation of endogenous memory responses to non-targeted tumour epitopes

    PubMed Central

    Li, Kunyu; Donaldson, Braeden; Young, Vivienne; Ward, Vernon; Jackson, Christopher; Baird, Margaret; Young, Sarah

    2017-01-01

    The results of adoptive T-cell therapies (ACTs) are very encouraging and show clinical evidence that ACT can provide a cure for patients with metastatic disease. However, various response rates and long-term cancer remission have been observed in different ACT trials. The types of T cells, prior treatment with chemotherapy and co-administration of other immune-target therapies have been found to influence the efficacy of ACT. In this study, we investigate the ability of ACT using CD4+ T helper 1 (Th1) cells and CD8+ cytotoxic T lymphocytes (CTLs) to reject the growth of established B16-ovalbumin (OVA) melanoma. CD8+ CTLs were found to be the main effector T cells that mediated tumour regression. However, low tumour-free survival rates were observed in ACT with CD8+ CTLs only. Co-transferring CD4+ Th1 cells and CD8+ CTLs has been observed to induce a synergistic antitumour response, resulting in complete regression in 80% of the tumour-bearing mice. We also examined a prior Dacarbazine (DTIC) and after virus-like particle (VLP)-OVA vaccine treatment to enhance ACT, but no therapeutic benefit was observed during primary B16-OVA tumour growth. Nevertheless, the ACT-mediated antitumour response was able to generate memory responses to both B16-OVA and B16-gp33 tumours. VLP-OVA vaccination following ACT enhances the memory responses to tumours that express a heterogenic population of both B16-OVA and B16-gp33 cells; however, it abolished the memory response to tumours consisting of only gp33-expressing cells. These findings provide important information for designing therapeutic treatments for patients with metastatic disease and cancer relapse to achieve durable cancer remission. PMID:29114389

  8. Rapid selection of escape mutants by the first CD8 T cell responses in acute HIV-1 infection

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Korber, Bette Tina Marie

    2008-01-01

    The recent failure of a vaccine that primes T cell responses to control primary HIV-1 infection has raised doubts about the role of CD8+ T cells in early HIV-1 infection. We studied four patients who were identified shortly after HIV-1 infection and before seroconversion. In each patient there was very rapid selection of multiple HIV-1 escape mutants in the transmitted virus by CD8 T cells, including examples of complete fixation of non-synonymous substitutions within 2 weeks. Sequencing by single genome amplification suggested that the high rate of virus replication in acute infection gave a selective advantage to virus molecules thatmore » contained simultaneous and gained sequential T cell escape mutations. These observations show that whilst early HIV-1 specific CD8 T cells can act against virus, rapid escape means that these T cell responses are unlikely to benefit the patient and may in part explain why current HIV-1 T cell vaccines may not be protective.« less

  9. Effect of Chronic Oxidative Stress on Neuroinflammatory Response Mediated by CD4+T Cells in Neurodegenerative Diseases

    PubMed Central

    Solleiro-Villavicencio, Helena; Rivas-Arancibia, Selva

    2018-01-01

    In a state of oxidative stress, there is an increase of reactive species, which induce an altered intracellular signaling, leading to dysregulation of the inflammatory response. The inability of the antioxidant defense systems to modulate the proinflammatory response is key to the onset and progression of neurodegenerative diseases. The aim of this work is to review the effect of the state of oxidative stress on the loss of regulation of the inflammatory response on the microglia and astrocytes, the induction of different CD4+T cell populations in neuroinflammation, as well as its role in some neurodegenerative diseases. For this purpose, an intentional search of original articles, short communications, and reviews, was carried out in the following databases: PubMed, Scopus, and Google Scholar. The articles reviewed included the period from 1997 to 2017. With the evidence obtained, we conclude that the loss of redox balance induces alterations in the differentiation and number of CD4+T cell subpopulations, leading to an increase in Th1 and Th17 response. This contributes to the development of neuroinflammation as well as loss of the regulation of the inflammatory response in neurodegenerative diseases such as Alzheimer's (AD), Parkinson's (PD), and Multiple Sclerosis (MS). In contrast, regulatory T cells (Tregs) and Th2 modulate the inflammatory response of effect of T cells, microglia, and astrocytes. In this respect, it has been found that the mobilization of T cells with anti-inflammatory characteristics toward damaged regions of the CNS can provide neuroprotection and become a therapeutic strategy to control inflammatory processes in neurodegeneration. PMID:29755324

  10. Effect of Chronic Oxidative Stress on Neuroinflammatory Response Mediated by CD4+T Cells in Neurodegenerative Diseases.

    PubMed

    Solleiro-Villavicencio, Helena; Rivas-Arancibia, Selva

    2018-01-01

    In a state of oxidative stress, there is an increase of reactive species, which induce an altered intracellular signaling, leading to dysregulation of the inflammatory response. The inability of the antioxidant defense systems to modulate the proinflammatory response is key to the onset and progression of neurodegenerative diseases. The aim of this work is to review the effect of the state of oxidative stress on the loss of regulation of the inflammatory response on the microglia and astrocytes, the induction of different CD4 + T cell populations in neuroinflammation, as well as its role in some neurodegenerative diseases. For this purpose, an intentional search of original articles, short communications, and reviews, was carried out in the following databases: PubMed, Scopus, and Google Scholar. The articles reviewed included the period from 1997 to 2017. With the evidence obtained, we conclude that the loss of redox balance induces alterations in the differentiation and number of CD4 + T cell subpopulations, leading to an increase in Th1 and Th17 response. This contributes to the development of neuroinflammation as well as loss of the regulation of the inflammatory response in neurodegenerative diseases such as Alzheimer's (AD), Parkinson's (PD), and Multiple Sclerosis (MS). In contrast, regulatory T cells (Tregs) and Th2 modulate the inflammatory response of effect of T cells, microglia, and astrocytes. In this respect, it has been found that the mobilization of T cells with anti-inflammatory characteristics toward damaged regions of the CNS can provide neuroprotection and become a therapeutic strategy to control inflammatory processes in neurodegeneration.

  11. APRIL modulates B and T cell immunity

    PubMed Central

    Stein, Jens V.; López-Fraga, Marta; Elustondo, Fernando A.; Carvalho-Pinto, Carla E.; Rodríguez, Dolores; Gómez-Caro, Ruth; de Jong, Joan; Martínez-A, Carlos; Medema, Jan Paul; Hahne, Michael

    2002-01-01

    The TNF-like ligands APRIL and BLyS are close relatives and share the capacity to bind the receptors TACI and BCMA. BLyS has been shown to play an important role in B cell homeostasis and autoimmunity, but the biological role of APRIL remains less well defined. Analysis of T cells revealed an activation-dependent increase in APRIL mRNA expression. We therefore generated mice expressing APRIL as a transgene in T cells. These mice appeared normal and showed no signs of B cell hyperplasia. Transgenic T cells revealed a greatly enhanced survival in vitro as well as enhanced survival of staphylococcal enterotoxin B–reactive CD4+ T cells in vivo, which both directly correlate with elevated Bcl-2 levels. Analysis of humoral responses to T cell–dependent antigens in the transgenic mice indicated that APRIL affects only IgM but not IgG responses. In contrast, T cell–independent type 2 (TI-2) humoral response was enhanced in APRIL transgenic mice. As TACI was previously reported to be indispensable for TI-2 antibody formation, these results suggest a role for APRIL/TACI interactions in the generation of this response. Taken together, our data indicate that APRIL is involved in the induction and/or maintenance of T and B cell responses. PMID:12070306

  12. Complementarity-Determining Region 3 Size Spectratypes of T Cell Receptor β Chains in CD8+ T Cells following Antiviral Treatment of Chronic Hepatitis B▿

    PubMed Central

    Ma, Shi-Wu; Li, Yong-Yin; Zhang, Guang-Wen; Huang, Xuan; Sun, Jian; Li, Chris; Abbott, William G. H.; Hou, Jin-Lin

    2011-01-01

    An increased CD8+ T cell response to hepatitis B virus (HBV) peptides occurs between 12 and 24 weeks after starting antiviral therapy for chronic hepatitis B. It is not known whether these cells have antiviral function. The aim of this study was to determine whether clonal expansions of CD8+ T cells at these time points predict the virological response to therapy. Peripheral blood CD8+ T cells were obtained from 20 patients treated with lamivudine or telbivudine for chronic hepatitis B at baseline, 12 weeks, and 24 weeks. The CDR3 spectratype of each T cell receptor (TCR) β chain variable region (Vβ) gene family was analyzed, and the changes in the numbers of Vβ families with clonal expansions were compared in subjects with (n = 12) and without (n = 8) a virological response (52 week HBV DNA < 300 copies/ml). The number of CD8+ TCR Vβ families with clonal expansions at 12 weeks relative to baseline (median [10th to 90th percentile], +2.5 [0 to +7] versus +1 [0 to +2], P = 0.03) and at 24 weeks relative to 12 weeks (+1 [0 to +2] versus −1 [−3 to +4], P = 0.006) was higher in subjects with a virological response versus subjects without a virological response, as were interleukin-2 (IL-2) but not IL-21 mRNA levels in peripheral blood mononuclear cells. The duration of new expansions at 12 weeks was higher (P < 0.0001) in responders. Increased numbers of CD8+ T cell expansions after antiviral therapy are associated with a virological response to treatment. These CD8+ T cells are a potential target for a therapeutic vaccine for chronic hepatitis B. PMID:21098256

  13. Functional analysis of T cells expressing Ia antigens. I. Demonstration of helper T-cell heterogeneity.

    PubMed

    Swierkosz, J E; Marrack, P; Kappler, J W

    1979-12-01

    We have examined the expression of I-region antigens on functional subpopulations of murine T cells. A.TH anti-A.TL (anti-Ik, Sk, Gk) alloantiserum was raised by immunization of recipients with concanavalin A (Con A) stimulated thymic and peripheral T-cell blasts. In contrast to similar antisera made by conventional methods, the anti-Ia blast serum was highly cytotoxic for purified T lymphocytes. Moreover, it reacted in a specific fashion with T cells having particular functions. Treatment of keyhole limpet hemocyanin (KLH)-primed B10.A (H-2 alpha) T cells with this antiserum plus complement resulted in the elimination of helper activity for B-cell responses to trinitrophenyl-KLH. Inhibition was shown to be a result of the selective killing of one type of helper T cell whose activity could be replaced by a factor(s) found in the supernate of Con A-activated spleen cells. A second type of helper cell required for responses to protein-bound antigens appeared to be Ia-. By absorption and analysis on H-2 recombinants, at least two specificities were detectable on helper T cells; one mapping in the I-A subregion and a second in a region(s) to the right of I-J. In addition, the helper T cell(s) involved in the generation of alloreactive cytotoxic lymphocytes was shown to be Ia+, whereas cytotoxic effector cells and their precursors were Ia- with this antiserum. These results provide strong evidence for the selective expression of I-region determinants on T-cell subsets and suggest that T-cell-associated Ia antigens may play an important role in T-lymphocyte function.

  14. Potential contribution of a novel Tax epitope-specific CD4+ T cells to graft-versus-Tax effect in adult T cell leukemia patients after allogeneic hematopoietic stem cell transplantation.

    PubMed

    Tamai, Yotaro; Hasegawa, Atsuhiko; Takamori, Ayako; Sasada, Amane; Tanosaki, Ryuji; Choi, Ilseung; Utsunomiya, Atae; Maeda, Yasuhiro; Yamano, Yoshihisa; Eto, Tetsuya; Koh, Ki-Ryang; Nakamae, Hirohisa; Suehiro, Youko; Kato, Koji; Takemoto, Shigeki; Okamura, Jun; Uike, Naokuni; Kannagi, Mari

    2013-04-15

    Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an effective treatment for adult T cell leukemia/lymphoma (ATL) caused by human T cell leukemia virus type 1 (HTLV-1). We previously reported that Tax-specific CD8(+) cytotoxic T lymphocyte (CTL) contributed to graft-versus-ATL effects in ATL patients after allo-HSCT. However, the role of HTLV-1-specific CD4(+) T cells in the effects remains unclear. In this study, we showed that Tax-specific CD4(+) as well as CD8(+) T cell responses were induced in some ATL patients following allo-HSCT. To further analyze HTLV-1-specific CD4(+) T cell responses, we identified a novel HLA-DRB1*0101-restricted epitope, Tax155-167, recognized by HTLV-1-specific CD4(+) Th1-like cells, a major population of HTLV-1-specific CD4(+) T cell line, which was established from an ATL patient at 180 d after allo-HSCT from an unrelated seronegative donor by in vitro stimulation with HTLV-1-infected cells from the same patient. Costimulation of PBMCs with both the identified epitope (Tax155-167) and known CTL epitope peptides markedly enhanced the expansion of Tax-specific CD8(+) T cells in PBMCs compared with stimulation with CTL epitope peptide alone in all three HLA-DRB1*0101(+) patients post-allo-HSCT tested. In addition, direct detection using newly generated HLA-DRB1*0101/Tax155-167 tetramers revealed that Tax155-167-specific CD4(+) T cells were present in all HTLV-1-infected individuals tested, regardless of HSCT. These results suggest that Tax155-167 may be the dominant epitope recognized by HTLV-1-specific CD4(+) T cells in HLA-DRB1*0101(+)-infected individuals and that Tax-specific CD4(+) T cells may augment the graft-versus-Tax effects via efficient induction of Tax-specific CD8(+) T cell responses.

  15. Comprehensive Approach for Identifying the T Cell Subset Origin of CD3 and CD28 Antibody-Activated Chimeric Antigen Receptor-Modified T Cells.

    PubMed

    Schmueck-Henneresse, Michael; Omer, Bilal; Shum, Thomas; Tashiro, Haruko; Mamonkin, Maksim; Lapteva, Natalia; Sharma, Sandhya; Rollins, Lisa; Dotti, Gianpietro; Reinke, Petra; Volk, Hans-Dieter; Rooney, Cliona M

    2017-07-01

    The outcome of therapy with chimeric Ag receptor (CAR)-modified T cells is strongly influenced by the subset origin of the infused T cells. However, because polyclonally activated T cells acquire a largely CD45RO + CCR7 - effector memory phenotype after expansion, regardless of subset origin, it is impossible to know which subsets contribute to the final T cell product. To determine the contribution of naive T cell, memory stem T cell, central memory T cell, effector memory T cell, and terminally differentiated effector T cell populations to the CD3 and CD28-activated CAR-modified T cells that we use for therapy, we followed the fate and function of individually sorted CAR-modified T cell subsets after activation with CD3 and CD28 Abs (CD3/28), transduction and culture alone, or after reconstitution into the relevant subset-depleted population. We show that all subsets are sensitive to CAR transduction, and each developed a distinct T cell functional profile during culture. Naive-derived T cells showed the greatest rate of proliferation but had more limited effector functions and reduced killing compared with memory-derived populations. When cultured in the presence of memory T cells, naive-derived T cells show increased differentiation, reduced effector cytokine production, and a reduced reproliferative response to CAR stimulation. CD3/28-activated T cells expanded in IL-7 and IL-15 produced greater expansion of memory stem T cells and central memory T cell-derived T cells compared with IL-2. Our strategy provides a powerful tool to elucidate the characteristics of CAR-modified T cells, regardless of the protocol used for expansion, reveals the functional properties of each expanded T cell subset, and paves the way for a more detailed evaluation of the effects of manufacturing changes on the subset contribution to in vitro-expanded T cells. Copyright © 2017 by The American Association of Immunologists, Inc.

  16. Intestinal Epithelial Cells Modulate Antigen-Presenting Cell Responses to Bacterial DNA

    PubMed Central

    Campeau, J. L.; Salim, S. Y.; Albert, E. J.; Hotte, N.

    2012-01-01

    Intestinal epithelial cells and antigen-presenting cells orchestrate mucosal innate immunity. This study investigated the role of bacterial DNA in modulating epithelial and bone marrow-derived antigen-presenting cells (BM-APCs) and subsequent T-lymphocyte responses. Murine MODE-K epithelial cells and BM-APCs were treated with DNA from either Bifidobacterium breve or Salmonella enterica serovar Dublin directly and under coculture conditions with CD4+ T cells. Apical stimulation of MODE-K cells with S. Dublin DNA enhanced secretion of cytokines from underlying BM-APCs and induced interleukin-17 (IL-17) and gamma interferon (IFN-γ) secretion from CD4+ T cells. Bacterial DNA isolated from either strain induced maturation and increased cytokine secretion from BM-APCs. Conditioned medium from S. Dublin-treated MODE-K cells elicited an increase in cytokine secretion similar to that seen for S. Dublin DNA. Treatment of conditioned medium from MODE-K cells with RNase and protease prevented the S. Dublin-induced increased cytokine secretion. Oral feeding of mice with B. breve DNA resulted in enhanced levels of colonic IL-10 and transforming growth factor β (TGFβ) compared with what was seen for mice treated with S. Dublin DNA. In contrast, feeding mice with S. Dublin DNA increased levels of colonic IL-17 and IL-12p70. T cells from S. Dublin DNA-treated mice secreted high levels of IL-12 and IFN-γ compared to controls and B. breve DNA-treated mice. These results demonstrate that intestinal epithelial cells are able to modulate subsequent antigen-presenting and T-cell responses to bacterial DNA with pathogenic but not commensal bacterial DNA inducing effector CD4+ T lymphocytes. PMID:22615241

  17. CD8+ T Cells Provide an Immunologic Signature of Tuberculosis in Young Children

    PubMed Central

    Nyendak, Melissa; Kiguli, Sarah; Zalwango, Sarah; Mori, Tomi; Mayanja-Kizza, Harriet; Balyejusa, Stephen; Null, Megan; Baseke, Joy; Mulindwa, Deo; Byrd, Laura; Swarbrick, Gwendolyn; Scott, Christine; Johnson, Denise F.; Malone, LaShaunda; Mudido-Musoke, Philipa; Boom, W. Henry; Lewinsohn, David M.; Lewinsohn, Deborah A.

    2012-01-01

    Rationale: The immunologic events surrounding primary Mycobacterium tuberculosis infection and development of tuberculosis remain controversial. Young children who develop tuberculosis do so quickly after first exposure, thus permitting study of immune response to primary infection and disease. We hypothesized that M. tuberculosis–specific CD8+ T cells are generated in response to high bacillary loads occurring during tuberculosis. Objectives: To determine if M. tuberculosis–specific T cells are generated among healthy children exposed to M. tuberculosis and children with tuberculosis. Methods: Enzyme-linked immunosorbent spot assays were used to measure IFN-γ production in response to M. tuberculosis–specific proteins ESAT-6/CFP-10 by peripheral blood mononuclear cells and CD8+ T cells isolated from Ugandan children hospitalized with tuberculosis (n = 96) or healthy tuberculosis contacts (n = 62). Measurements and Main Results: The proportion of positive CD8+ T-cell assays and magnitude of CD8+ T-cell responses were significantly greater among young (<5 yr) tuberculosis cases compared with young contacts (P = 0.02, Fisher exact test, P = 0.01, Wilcoxon rank-sum, respectively). M. tuberculosis–specific T-cell responses measured in peripheral blood mononuclear cells were equivalent between groups. Conclusions: Among young children, M. tuberculosis–specific CD8+ T cells develop in response to high bacillary loads, as occurs during tuberculosis, and are unlikely to be found after M. tuberculosis exposure. T-cell responses measured in peripheral blood mononuclear cells are generated after M. tuberculosis exposure alone, and thus cannot distinguish exposure from disease. In young children, IFN-γ–producing M. tuberculosis–specific CD8+ T cells provide an immunologic signature of primary M. tuberculosis infection resulting in disease. PMID:22071329

  18. Interlesional diversity of T cell receptors in melanoma with immune checkpoints enriched in tissue-resident memory T cells

    PubMed Central

    Boddupalli, Chandra Sekhar; Bar, Noffar; Kadaveru, Krishna; Krauthammer, Michael; Pornputtapong, Natopol; Ariyan, Stephan; Narayan, Deepak; Kluger, Harriet; Deng, Yanhong; Verma, Rakesh; Das, Rituparna; Bacchiocchi, Antonella; Halaban, Ruth; Sznol, Mario; Dhodapkar, Madhav V.; Dhodapkar, Kavita M.

    2016-01-01

    Heterogeneity of tumor cells and their microenvironment can affect outcome in cancer. Blockade of immune checkpoints (ICPs) expressed only on a subset of immune cells leads to durable responses in advanced melanoma. Tissue-resident memory T (TRM) cells have recently emerged as a distinct subset of memory T cells in nonlymphoid tissues. Here, we show that functional properties and expression of ICPs within tumor-infiltrating lymphocytes (TILs) differ from those of blood T cells. TILs secrete less IL-2, IFN-γ, and TNF-α compared with circulating counterparts, and expression of VEGF correlated with reduced TIL infiltration. Within tumors, ICPs are particularly enriched within T cells with phenotype and genomic features of TRM cells and the CD16+ subset of myeloid cells. Concurrent T cell receptor (TCR) and tumor exome sequencing of individual metastases in the same patient revealed that interlesional diversity of TCRs exceeded differences in mutation/neoantigen load in tumor cells. These findings suggest that the TRM subset of TILs may be the major target of ICP blockade and illustrate interlesional diversity of tissue-resident TCRs within individual metastases, which did not equilibrate between metastases and may differentially affect the outcome of immune therapy at each site. PMID:28018970

  19. Expression of NK cell receptors on decidual T cells in human pregnancy.

    PubMed

    Tilburgs, Tamara; van der Mast, Barbara J; Nagtzaam, Nicole M A; Roelen, Dave L; Scherjon, Sicco A; Claas, Frans H J

    2009-06-01

    Specific receptors enable NK cells to discriminate between cells with normal expression of MHC class I and cells that have low or absent expression of MHC class I molecules. In addition to NK cells, these receptors can be expressed on T cell subsets, mainly on CD8+ T cells but also on gammadeltaTCR+ T cells and CD4+ T cells. Although the function of NK cell receptor expression on T cells is not completely understood, various studies have shown that they are involved in down regulation of T cell receptor (TCR)-mediated activation and influence effector functions, like cytotoxicity and cytokine production. The aim of this study was to analyze expression of NK cell receptors on peripheral blood and decidual T cells during human pregnancy using flow cytometry. We demonstrate that a proportion of decidual T cells express HLA-C specific killer immunoglobulin-like receptors (KIRs). Furthermore, a small proportion of decidual T cells express the HLA-E specific CD94-NKG2A inhibitory and CD94-NKG2C activating receptors. Decidual KIR+ and CD94-NKG2+ T cells mainly display a CD3+CD4-CD8- phenotype. However, decidual tissue also contains higher percentages of KIR and CD94-NKG2 expressing CD4+ and CD8+ T cells compared to peripheral blood. So far, the functional capacities of decidual T cells expressing the NK cell receptors are unknown but NK cell receptor expression on decidual T cells may provide an alternative means by which decidual T cells distinguish self (maternal) cells from allogeneic fetal cells, and act to modulate the decidual immune response.

  20. Compound heterozygosity for Pten and SHIP augments T-dependent humoral immune responses and cytokine production by CD4+ T cells

    PubMed Central

    Moody, J L; Jirik, F R

    2004-01-01

    Tight regulation of the phosphatidylinositiol 3-kinase (PI3K) pathway is essential not only for normal immune system development and responsiveness, but also in the prevention of immunopathology. Indeed, unchecked activation of the PI3K pathway in T cells induces lymphoproliferation and systemic autoimmunity. Evaluating the importance of threshold levels of two key PI3K pathway phosphoinositol phosphatases, we previously reported that mice heterozygous for both Pten and SHIP develop a more rapid progression of a lymphoproliferative autoimmune syndrome than do Pten+\\− mice. Investigating the basis for this difference, we now describe a quantitative and qualitative difference in the antibody responses of C57BL\\6 Pten+\\− SHIP+\\− mice upon challenge with a T-dependent antigen. Suspecting that this phenotypic difference might be the result, at least in part, of a T-helper cell defect, an in vitro analysis of anti-CD3/interleukin (IL)-2-expanded CD4+ T cells was performed. After stimulation with anti-CD3, cells from mice heterozygous for both Pten and SHIP exhibited a striking increase in IL-4 secretion (> 10-fold), without a corresponding increase in T helper 2 (Th2) cell numbers being evident by intracellular staining for this cytokine. Modest increases were also seen for both IL-13 and IFN-γ. Perhaps in keeping with this abnormal in vitro cytokine profile, IgG1 serum levels were significantly elevated in young C57BL\\6 Pten+\\− SHIP+\\− mice. Thus, the relative levels of Pten and SHIP appear to be key variables in CD4+ T-cell function, primarily via their ability to regulate IL-4 production. PMID:15196208

  1. T cells' immunological synapses induce polarization of brain astrocytes in vivo and in vitro: a novel astrocyte response mechanism to cellular injury.

    PubMed

    Barcia, Carlos; Sanderson, Nicholas S R; Barrett, Robert J; Wawrowsky, Kolja; Kroeger, Kurt M; Puntel, Mariana; Liu, Chunyan; Castro, Maria G; Lowenstein, Pedro R

    2008-08-20

    Astrocytes usually respond to trauma, stroke, or neurodegeneration by undergoing cellular hypertrophy, yet, their response to a specific immune attack by T cells is poorly understood. Effector T cells establish specific contacts with target cells, known as immunological synapses, during clearance of virally infected cells from the brain. Immunological synapses mediate intercellular communication between T cells and target cells, both in vitro and in vivo. How target virally infected astrocytes respond to the formation of immunological synapses established by effector T cells is unknown. Herein we demonstrate that, as a consequence of T cell attack, infected astrocytes undergo dramatic morphological changes. From normally multipolar cells, they become unipolar, extending a major protrusion towards the immunological synapse formed by the effector T cells, and withdrawing most of their finer processes. Thus, target astrocytes become polarized towards the contacting T cells. The MTOC, the organizer of cell polarity, is localized to the base of the protrusion, and Golgi stacks are distributed throughout the protrusion, reaching distally towards the immunological synapse. Thus, rather than causing astrocyte hypertrophy, antiviral T cells cause a major structural reorganization of target virally infected astrocytes. Astrocyte polarization, as opposed to hypertrophy, in response to T cell attack may be due to T cells providing a very focused attack, and thus, astrocytes responding in a polarized manner. A similar polarization of Golgi stacks towards contacting T cells was also detected using an in vitro allogeneic model. Thus, different T cells are able to induce polarization of target astrocytes. Polarization of target astrocytes in response to immunological synapses may play an important role in regulating the outcome of the response of astrocytes to attacking effector T cells, whether during antiviral (e.g. infected during HIV, HTLV-1, HSV-1 or LCMV infection), anti

  2. Gamma delta T cell responses associated with the development of tuberculosis in health care workers.

    PubMed

    Ordway, Diane J; Pinto, Luisa; Costa, Leonor; Martins, Marta; Leandro, Clara; Viveiros, Miguel; Amaral, Leonard; Arroz, Maria J; Ventura, Fernando A; Dockrell, Hazel M

    2005-03-01

    This study evaluated T cell immune responses to purified protein derivative (PPD) and Mycobacterium tuberculosis (Mtb) in health care workers who remained free of active tuberculosis (HCWs w/o TB), health care workers who went on to develop active TB (HCWs w/TB), non-health care workers who were TB free (Non-HCWs) and tuberculosis patients presenting with minimal (Min TB) or advanced (Adv TB) disease. Peripheral blood mononuclear cells (PBMC) were stimulated with Mtb and PPD and the expression of T cell activation markers CD25+ and HLA-DR+, intracellular IL-4 and IFN-gamma production and cytotoxic responses were evaluated. PBMC from HCWs who developed TB showed decreased percentages of cells expressing CD8+CD25+ in comparison to HCWs who remained healthy. HCWs who developed TB showed increased gammadelta TCR+ cell cytotoxicity and decreased CD3+gammadelta TCR- cell cytotoxicity in comparison to HCWs who remained healthy. PBMC from TB patients with advanced disease showed decreased percentages of CD25+CD4+ and CD25+CD8+ T cells that were associated with increased IL-4 production in CD8+ and gammadelta TCR+ phenotypes, in comparison with TB patients presenting minimal disease. TB patients with advanced disease showed increased gammadelta TCR+ cytotoxicity and reduced CD3+gammadelta TCR- cell cytotoxicity. Our results suggest that HCWs who developed TB show an early compensatory mechanism involving an increase in lytic responses of gammadelta TCR+ cells which did not prevent TB.

  3. Synergism of Cytotoxic T Lymphocyte–Associated Antigen 4 Blockade and Depletion of Cd25+ Regulatory T Cells in Antitumor Therapy Reveals Alternative Pathways for Suppression of Autoreactive Cytotoxic T Lymphocyte Responses

    PubMed Central

    Sutmuller, Roger P.M.; van Duivenvoorde, Leonie M.; van Elsas, Andrea; Schumacher, Ton N.M.; Wildenberg, Manon E.; Allison, James P.; Toes, Rene E.M.; Offringa, Rienk; Melief, Cornelis J.M.

    2001-01-01

    Therapeutic efficacy of a tumor cell–based vaccine against experimental B16 melanoma requires the disruption of either of two immunoregulatory mechanisms that control autoreactive T cell responses: the cytotoxic T lymphocyte–associated antigen (CTLA)-4 pathway or the CD25+ regulatory T (Treg) cells. Combination of CTLA-4 blockade and depletion of CD25+ Treg cells results in maximal tumor rejection. Efficacy of the antitumor therapy correlates with the extent of autoimmune skin depigmentation as well as with the frequency of tyrosinase-related protein 2180–188–specific CTLs detected in the periphery. Furthermore, tumor rejection is dependent on the CD8+ T cell subset. Our data demonstrate that the CTL response against melanoma antigens is an important component of the therapeutic antitumor response and that the reactivity of these CTLs can be augmented through interference with immunoregulatory mechanisms. The synergism in the effects of CTLA-4 blockade and depletion of CD25+ Treg cells indicates that CD25+ Treg cells and CTLA-4 signaling represent two alternative pathways for suppression of autoreactive T cell immunity. Simultaneous intervention with both regulatory mechanisms is therefore a promising concept for the induction of therapeutic antitumor immunity. PMID:11560997

  4. Prior Dengue virus exposure shapes T cell immunity to Zika virus in humans.

    PubMed

    Grifoni, Alba; Pham, John; Sidney, John; O'Rourke, Patrick H; Paul, Sinu; Peters, Bjoern; Martini, Sheridan R; de Silva, Aruna D; Ricciardi, Michael J; Magnani, Diogo M; Silveira, Cassia G T; Maestri, Alvino; Costa, Priscilla R; de-Oliveira-Pinto, Luzia Maria; de Azeredo, Elzinandes Leal; Damasco, Paulo Vieira; Phillips, Elizabeth; Mallal, Simon; de Silva, Aravinda M; Collins, Matthew; Durbin, Anna; Diehl, Sean A; Cerpas, Cristhiam; Balmaseda, Angel; Kuan, Guillermina; Coloma, Josefina; Harris, Eva; Crowe, James E; Stone, Mars; Norris, Phillip J; Busch, Michael; Vivanco-Cid, Hector; Cox, Josephine; Graham, Barney S; Ledgerwood, Julie E; Turtle, Lance; Solomon, Tom; Kallas, Esper G; Watkins, David I; Weiskopf, Daniela; Sette, Alessandro

    2017-10-04

    While progress has been made in characterizing humoral immunity to Zika virus (ZIKV) in humans, little is known regarding the corresponding T cell responses to ZIKV. Here we investigate the kinetics and viral epitopes targeted by T cells responding to ZIKV and address the critical question of whether pre-existing dengue virus (DENV) T cell immunity modulates these responses. We find that memory T cell responses elicited by prior infection with DENV or vaccination with Tetravalent Dengue Attenuated Vaccines (TDLAV) recognize ZIKV-derived peptides. This cross-reactivity is explained by the sequence similarity of the two viruses, as the ZIKV peptides recognized by DENV-elicited memory T cells are identical or highly conserved in DENV and ZIKV. DENV exposure prior to ZIKV infection also influences the timing and magnitude of the T cell response. ZIKV-reactive T cells in the acute phase of infection are detected earlier and in greater magnitude in DENV-immune patients. Conversely, the frequency of ZIKV-reactive T cells continues to rise in the convalescent phase in DENV-naive donors, but declines in DENV pre-exposed donors, compatible with more efficient control of ZIKV replication and/or clearance of ZIKV antigen. The quality of responses is also influenced by previous DENV exposure, and ZIKV-specific CD8 T cells form DENV pre-exposed donors selectively up-regulated granzyme B and PD1, as compared to DENV-naïve donors. Finally, we discovered that ZIKV structural proteins (E, prM and C) are major targets of both the CD4 and CD8 T cell responses, whereas DENV T cell epitopes are found primarily in nonstructural proteins. IMPORTANCE The issue of potential ZIKV and DENV cross-reactivity and how pre-existing DENV T cell immunity modulates ZIKA T cell responses is of great relevance as the two viruses often co-circulate and ZIKA virus has been spreading in geographical regions where DENV is endemic or hyper-endemic. Our data show that memory T cell responses elicited by

  5. How much of virus-specific CD8 T cell reactivity is detected with a peptide pool when compared to individual peptides?

    PubMed

    Zhang, Wenji; Moldovan, Ioana; Targoni, Oleg S; Subbramanian, Ramu A; Lehmann, Paul V

    2012-10-29

    Immune monitoring of T cell responses increasingly relies on the use of peptide pools. Peptides, when restricted by the same HLA allele, and presented from within the same peptide pool, can compete for HLA binding sites. What impact such competition has on functional T cell stimulation, however, is not clear. Using a model peptide pool that is comprised of 32 well-defined viral epitopes from Cytomegalovirus, Epstein-Barr virus, and Influenza viruses (CEF peptide pool), we assessed peptide competition in PBMC from 42 human subjects. The magnitude of the peptide pool-elicited CD8 T cell responses was a mean 79% and a median 77% of the sum of the CD8 T cell responses elicited by the individual peptides. Therefore, while the effect of peptide competition was evident, it was of a relatively minor magnitude. By studying the dose-response curves for individual CEF peptides, we show that several of these peptides are present in the CEF-pool at concentrations that are orders of magnitude in excess of what is needed for the activation threshold of the CD8 T cells. The presence of such T cells with very high functional avidity for the viral antigens can explain why the effect of peptide competition is relatively minor within the CEF-pool.

  6. An inducible transgenic mouse breast cancer model for the analysis of tumor antigen specific CD8+ T-cell responses

    PubMed Central

    Bruns, Michael; Wanger, Jara; Utermöhlen, Olaf; Deppert, Wolfgang

    2015-01-01

    In Simian virus 40 (SV40) transgenic BALB/c WAP-T mice tumor development and progression is driven by SV40 tumor antigens encoded by inducible transgenes. WAP-T mice constitute a well characterized mouse model for breast cancer with strong similarities to the corresponding human disease. BALB/c mice mount only a weak cellular immune response against SV40 T-antigen (T-Ag). For studying tumor antigen specific CD8+ T-cell responses against transgene expressing cells, we created WAP-TNP mice, in which the transgene additionally codes for the NP118–126-epitope contained within the nucleoprotein of lymphocytic choriomeningitis virus (LCMV), the immune-dominant T-cell epitope in BALB/c mice. We then investigated in WAP-TNP mice the immune responses against SV40 tumor antigens and the NP-epitope within the chimeric T-Ag/NP protein (T-AgNP). Analysis of the immune-reactivity against T-Ag in WAP-T and of T-AgNP in WAP-TNP mice revealed that, in contrast to wild type (wt) BALB/c mice, WAP-T and WAP-TNP mice were non-reactive against T-Ag. However, like wtBALB/c mice, WAP-T as well as WAP-TNP mice were highly reactive against the immune-dominant LCMV NP-epitope, thereby allowing the analysis of NP-epitope specific cellular immune responses in WAP-TNP mice. LCMV infection of WAP-TNP mice induced a strong, LCMV NP-epitope specific CD8+ T-cell response, which was able to specifically eliminate T-AgNP expressing mammary epithelial cells both prior to tumor formation (i.e. in cells of lactating mammary glands), as well as in invasive tumors. Elimination of tumor cells, however, was only transient, even after repeated LCMV infections. Further studies showed that already non-infected WAP-TNP tumor mice contained LCMV NP-epitope specific CD8+ T-cells, albeit with strongly reduced, though measurable activity. Functional impairment of these ‘endogenous’ NP-epitope specific T-cells seems to be caused by expression of the programmed death-1 protein (PD1), as anti-PD1 treatment of

  7. An IFNG SNP with an estrogen-like response element selectively enhances promoter expression in peripheral but not lamina propria T cells.

    PubMed

    Gonsky, R; Deem, R L; Bream, J H; Young, H A; Targan, S R

    2006-07-01

    This study examines mucosa-specific regulatory pathways involved in modulation of interferon-gamma (IFN-gamma) in lamina propria T cells. Previous studies identified mucosa-specific CD2 cis-elements within the -204 to -108 bp IFNG promoter. Within this region, a single-site nucleotide polymorphism, -179G/T, imparts tumor necrosis factor-alpha stimulation of IFNG in peripheral blood lymphocytes, and is linked with accelerated AIDS progression. We discovered a putative estrogen response element (ERE) introduced by the -179T, which displays selective activation in peripheral blood mononuclear cells (PBMC) vs lamina propria mononuclear cells (LPMC). Transfection of PBMC with constructs containing the -179G or -179T site revealed CD2-mediated enhancement of the -179T compared to -179G allele, although, in LPMC, a similar level of expression was detected. Electrophoretic mobility shift assay (EMSA) analysis demonstrated CD2-mediated nucleoprotein binding to the -179T but not the -179G in PBMC. In LPMC, binding is constitutive to both -179G and -179T regions. Sequence and EMSA analysis suggests that the -179T allele creates an ERE-like binding site capable of binding recombinant estrogen receptor. Estrogen response element transactivation is enhanced by CD2 signaling, but inhibited by estrogen in PBMC but not in LPMC, although expression of estrogen receptor was similar. This is the first report to describe a potential molecular mechanism responsible for selectively controlling IFN-gamma production in LPMC.

  8. Memory T cells in organ transplantation: progress and challenges

    PubMed Central

    Espinosa, Jaclyn R.; Samy, Kannan P.; Kirk, Allan D.

    2017-01-01

    Antigen-experienced T cells, also known as memory T cells, are functionally and phenotypically distinct from naive T cells. Their enhanced expression of adhesion molecules and reduced requirement for co-stimulation enables them to mount potent and rapid recall responses to subsequent antigen encounters. Memory T cells generated in response to prior antigen exposures can cross-react with other nonidentical, but similar, antigens. This heterologous cross-reactivity not only enhances protective immune responses, but also engenders de novo alloimmunity. This latter characteristic is increasingly recognized as a potential barrier to allograft acceptance that is worthy of immunotherapeutic intervention, and several approaches have been investigated. Calcineurin inhibition effectively controls memory T-cell responses to allografts, but this benefit comes at the expense of increased infectious morbidity. Lymphocyte depletion eliminates allospecific T cells but spares memory T cells to some extent, such that patients do not completely lose protective immunity. Co-stimulation blockade is associated with reduced adverse-effect profiles and improved graft function relative to calcineurin inhibition, but lacks efficacy in controlling memory T-cell responses. Targeting the adhesion molecules that are upregulated on memory T cells might offer additional means to control co-stimulation-blockade-resistant memory T-cell responses. PMID:26923209

  9. Exogenous C3 protein enhances the adaptive immune response to polymicrobial sepsis through down-regulation of regulatory T cells.

    PubMed

    Yuan, Yujie; Ren, Jianan; Cao, Shougen; Zhang, Weiwei; Li, Jieshou

    2012-01-01

    The role of complement system in bridging innate and adaptive immunity has been confirmed in various invasive pathogens. It is still obscure how complement proteins promote T cell-mediated immune response during sepsis. The aim of this study is to investigate the role of exogenous C3 protein in the T-cell responses to sepsis. Sepsis was induced by colon ascendens stent peritonitis (CASP) in wild-type C57BL/6 mice, sham-operated mice for control. Human purified C3 protein (HuC3, 1 mg) was intraperitoneally injected at 6 h post-surgery, with 200 μl phosphate-buffered saline as control. The levels of C3 and cytokines, the expression of FOXP3 and NF-κB, and the percentages of CD4(+) T-cell subsets were compared among the groups at given time points. The polymicrobial sepsis produced considerable release of TNF-α and IL-10, and caused complement C3 exhaustion. Exogenous C3 administration markedly improved the 48 h survival rate, as compared with nontreatment (40% vs. 5%, P<0.01). The expression of FOXP3 protein was increased during sepsis, but can be suppressed by HuC3 administration. A single injection of HuC3 postponed the decline of differentiated Th1 cells, and depressed the activation of Th2/Th17 cells. Besides, the Th1-Th2 shift in late stage of sepsis can be controlled under C3 supplementation. The suppression of NF-κB pathway might be related to the appearance of immunocompromise. The study confirmed the important role of exogenous C3 in up-regulation of adaptive immune response to sepsis. The complement pathway would be a pivotal target for severe sepsis management. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. Enteropathy-associated T-cell lymphoma--a clinicopathologic and array comparative genomic hybridization study.

    PubMed

    Ko, Young Hyeh; Karnan, Sivasundaram; Kim, Kyeong Mee; Park, Cheol Keun; Kang, Eun Suk; Kim, Young Ho; Kang, Won Ki; Kim, Seok Jin; Kim, Won Seog; Lee, Woo Yong; Chun, Ho Kyung; Seto, Masao

    2010-09-01

    According to the new World Health Organization classification system, there are 2 types of enteropathy-associated T-cell lymphoma. Type 1 is associated with celiac disease and accounts for the majority of cases in Western countries, whereas type 2 is not associated with celiac disease. To characterize enteropathy-associated T-cell lymphoma types in Korea, we carried out clinicopathologic and immunophenotypic analyses of 8 Koreans with enteropathy-associated T-cell lymphoma and investigated genomic profile using array comparative genomic hybridization. The tumors involved the small intestine in 5 patients and the colorectum in 3 patients. Two patients carried an HLA DQB10302 allele that corresponds to HLA DQ8. None of the patients had gluten-sensitive malabsorption syndrome. Intraepithelial lymphocytosis was observed in all patients. The sizes of the tumor cells were small or small-to-medium in 7 cases and medium-to-large in 1 case. The immunophenotypes of the tumor cells were CD4-CD8+CD56+ in 4 cases, CD4-CD8+CD56- in 1 case, CD4-CD8-CD56+ in 2 cases, and CD4-CD8-CD56- in 1 case. Array comparative genomic hybridization analysis showed that chromosome 9q33-q34.1 gain was present in 4 (80%) of the 5 cases examined. Other recurrent genomic alterations were gain of 6p21.1-21.31 (3/5, 60%), gain of 19q (2/5), and the loss of 3p12.1-p12.2 (2/5) and 3q26.31 (2/5). These results suggest that the most prevalent type of enteropathy-associated T-cell lymphoma in this geographic region is type 2, and the genetic changes associated with it are similar to those in Western countries. Copyright 2010 Elsevier Inc. All rights reserved.

  11. The suppression of mitogen responses associated with resistance to experimental autoimmune encephalomyelitis requires adherent and T cells.

    PubMed

    Lyman, W D; Brosnan, C F; Kadish, A S; Raine, C S

    1984-05-01

    Resistance to experimental autoimmune encephalomyelitis (EAE) in Hartley guinea pigs has previously been reported to be associated with disease-specific antigen-induced suppression of mitogen responses in vitro. The present studies were initiated to investigate the requirement for different cell populations in this suppression. Intact and adherent-cell-depleted cultures of spleen cells from experimental and control animals were incubated with myelin basic protein (MBP), the major antigen of EAE, with the T-cell mitogen concanavalin A (Con A) alone or with Con A in the presence of MBP. In agreement with previous studies, MBP-induced suppression of the Con A response was observed only in cultures derived from resistant animals. In addition, it was observed that this suppression was abrogated by depletion of adherent cells. When cells from resistant and susceptible animals were mixed, suppression occurred only in the presence of nonadherent cells from resistant guinea pigs. Adherent cells from either resistant or susceptible animals functioned equally well. Cultures of purified E-rosette-forming cells (E+) from resistant animals (i.e., T cells) showed no suppression. Similarly, cells from these same animals which were depleted of E+ cells (i.e., non-T cells) did not demonstrate suppression in vitro. Upon reconstitution of spleen cell populations from resistant guinea pigs by mixing E+ and E- cells, suppression was restored. These experiments show that this model of suppression in vitro requires adherent cells as well as T cells and suggests that antigen-induced suppression of mitogen responses is dependent upon a cell-mediated immunologic mechanism.

  12. Immune response of T cells during herpes simplex virus type 1 (HSV-1) infection.

    PubMed

    Zhang, Jie; Liu, Huan; Wei, Bin

    Herpes simplex virus type 1 (HSV-1), a neurotropic member of the alphaherpes virus family, is among the most prevalent and successful human pathogens. HSV-1 can cause serious diseases at every stage of life including fatal disseminated disease in newborns, cold sores, eye disease, and fatal encephalitis in adults. HSV-1 infection can trigger rapid immune responses, and efficient inhibition and clearance of HSV-1 infection rely on both the innate and adaptive immune responses of the host. Multiple strategies have been used to restrict host innate immune responses by HSV-1 to facilitate its infection in host cells. The adaptive immunity of the host plays an important role in inhibiting HSV-1 infections. The activation and regulation of T cells are the important aspects of the adaptive immunity. They play a crucial role in host-mediated immunity and are important for clearing HSV-1. In this review, we examine the findings on T cell immune responses during HSV-1 infection, which hold promise in the design of new vaccine candidates for HSV-1.

  13. Immune response of T cells during herpes simplex virus type 1 (HSV-1) infection*

    PubMed Central

    Zhang, Jie; Liu, Huan; Wei, Bin

    2017-01-01

    Herpes simplex virus type 1 (HSV-1), a neurotropic member of the alphaherpes virus family, is among the most prevalent and successful human pathogens. HSV-1 can cause serious diseases at every stage of life including fatal disseminated disease in newborns, cold sores, eye disease, and fatal encephalitis in adults. HSV-1 infection can trigger rapid immune responses, and efficient inhibition and clearance of HSV-1 infection rely on both the innate and adaptive immune responses of the host. Multiple strategies have been used to restrict host innate immune responses by HSV-1 to facilitate its infection in host cells. The adaptive immunity of the host plays an important role in inhibiting HSV-1 infections. The activation and regulation of T cells are the important aspects of the adaptive immunity. They play a crucial role in host-mediated immunity and are important for clearing HSV-1. In this review, we examine the findings on T cell immune responses during HSV-1 infection, which hold promise in the design of new vaccine candidates for HSV-1. PMID:28378566

  14. γδ T cells recognize a microbial encoded B cell antigen to initiate a rapid antigen specific Interleukin 17 response

    PubMed Central

    Zeng, Xun; Wei, Yu-ling; Huang, Jun; Newell, Evan W.; Yu, Hongxiang; Kidd, Brian A.; Kuhns, Michael S.; Waters, Ray W.; Davis, Mark M.; Weaver, Casey T.; Chien, Yueh-hsiu

    2012-01-01

    Summary γδ T cells contribute uniquely to host immune defense. However, how they function remains an enigma. Although it is unclear what most γδ T cells recognize, common dogma asserts that they recognize self-antigens. While they are the major initial Interleukin-17 (IL-17) producers in infections, it is unclear what is required to trigger these cells to act. Here, we report that a noted B cell antigen, the algae protein-phycoerythrin (PE) is an antigen for murine and human γδ T cells. PE also stained specific bovine γδ T cells. Employing this specificity, we demonstrated that antigen recognition, but not extensive clonal expansion, was required to activate naïve γδ T cells to make IL-17. In this activated state, γδ T cells gained the ability to respond to cytokine signals that perpetuated the IL-17 production. These results underscore the adaptability of lymphocyte antigen receptors and suggest a previously unrecognized antigen-driven rapid response in protective immunity prior to the maturation of classical adaptive immunity. PMID:22960222

  15. Antibody response against Betaferon® in immune tolerant mice: involvement of marginal zone B-cells and CD4+ T-cells and apparent lack of immunological memory.

    PubMed

    Sauerborn, Melody; van Beers, Miranda M C; Jiskoot, Wim; Kijanka, Grzegorz M; Boon, Louis; Schellekens, Huub; Brinks, Vera

    2013-01-01

    The immunological processes underlying immunogenicity of recombinant human therapeutics are poorly understood. Using an immune tolerant mouse model we previously demonstrated that aggregates are a major trigger of the antidrug antibody (ADA) response against recombinant human interferon beta (rhIFNβ) products including Betaferon®, and that immunological memory seems to be lacking after a rechallenge with non-aggregated rhIFNβ. The apparent absence of immunological memory indicates a CD4+ T-cell independent (Tind) immune response underlying ADA formation against Betaferon®. This hypothesis was tested. Using the immune tolerant mouse model we first validated that rechallenge with highly aggregated rhIFNβ (Betaferon®) does not lead to a subsequent fast increase in ADA titers, suggesting a lack of immunological memory. Next we assessed whether Betaferon® could act as Tind antigen by inactivation of marginal zone (MZ) B-cells during treatment. MZ B-cells are major effector cells involved in a Tind immune response. In a following experiment we depleted the mice from CD4+ T-cells to test their involvement in the ADA response against Betaferon®. Inactivation of MZ B-cells at the start of Betaferon® treatment drastically lowered ADA levels, suggesting a Tind immune response. However, persistent depletion of CD4+ T-cells before and during Betaferon® treatment abolished the ADA response in almost all mice. The immune response against rhIFNβ in immune tolerant mice is neither a T-cell independent nor a classical T-cell dependent immune response. Further studies are needed to confirm absence of immunological memory (cells).

  16. Potent CD4+ T-cell epitope P30 enhances HER2/neu-engineered dendritic cell-induced immunity against Tg1-1 breast cancer in transgenic FVBneuN mice by enhanced CD4+ T-cell-stimulated CTL responses.

    PubMed

    Xie, Y; Chen, Y; Ahmed, K A; Li, W; Ahmed, S; Sami, A; Chibbar, R; Tang, X; Tao, M; Xu, J; Xiang, J

    2013-10-01

    One of the major obstacles in human epidermal growth factor receptor (HER)-2/neu-specific trastuzumab immunotherapy of HER2/neu-positive breast cancer is the development of trastuzumab resistance, warranting the search for other therapeutic strategies. Although dendritic cell (DC) vaccines have been extensively applied in clinical trials for cancer treatment, the vaccination efficacy is still limited, mostly because DC vaccines are not sufficient to break tumor-associated antigen-specific self-immune tolerance in cancer patients. P30 (FNNFTVSFWLRVPKVSASHLE) derived from tetanus toxin is a universally potent CD4(+) T helper epitope capable of enhancing CD8(+) cytotoxic T-lymphocyte (CTL) responses. In this study, we constructed two recombinant adenoviral vectors (AdVs), AdVOVA-P30 and AdVHER2/neu-P30, expressing ovalbumin (OVA)-P30 and HER2/neu-P30. In order to enhance DC vaccine efficacy, we transfected mouse bone marrow (BM)-derived DCs with AdVOVA-P30 and AdVHER2/neu-P30 to generate engineered DCOVA-P30 and DCHER2/neu-P30 vaccines, respectively. We, then, compared CD4(+) and CD8(+) T-cell responses and antitumor immunity derived from DCOVA-P30 and DCHER2/neu-P30 vaccination in wild-type C57BL/6 and transgenic FVBneuN mice, respectively. We demonstrate that engineered DCOVA-P30 vaccine stimulates more efficient CD4(+) and CD8(+) T-cell responses than DCOVA in C57BL/6 mice. Interestingly, the increased DCOVA-P30-induced CTL responses are mainly contributed by enhanced CD4(+) T-cell-stimulated CTL proliferation. We show that DCOVA-P30 vaccine also stimulates more efficient therapeutic immunity against OVA-expressing BL6-10OVA melanoma than DCOVA in C57BL/6 mice. In addition, we demonstrate that DCHER2/neu-P30 vaccine stimulates more efficient CD4(+) and CD8(+) T-cell responses and protective immunity against HER2/neu-expressing Tg1-1 breast cancer than DCHER2/neu in transgenic FVBneuN mice with HER2/neu-specific self-immune tolerance. Therefore, the engineered DCHER

  17. Detection of novel cancer-testis antigen-specific T-cell responses in TIL, regional lymph nodes, and PBL in patients with esophageal squamous cell carcinoma.

    PubMed

    Mizukami, Yoshiki; Kono, Koji; Daigo, Yataro; Takano, Atsushi; Tsunoda, Takuya; Kawaguchi, Yoshihiko; Nakamura, Yusuke; Fujii, Hideki

    2008-07-01

    We recently identified three HLA-A2402-restricted epitope peptides derived from cancer-testis antigens (CTA), TTK protein kinase (TTK), lymphocyte antigen 6 complex locus K (LY6K), and insulin-like growth factor (IGF)-II mRNA binding protein 3 (IMP-3) for the development of immunotherapies against esophageal squamous cell carcinoma (ESCC). In order to evaluate their immunotherapeutic potential in ESCC patients, we estimated by ELISPOT assay the TTK-, LY6K-, or IMP-3-specific T-cell immune responses in tumor-infiltrating lymphocytes (TIL), regional lymph node lymphocytes (RLNL), and peripheral blood lymphocytes (PBL) expanded from 20HLA-A2402 (+) ESCC patients, and correlated their immune activity with the expression levels of TTK, LY6K, and IMP-3, and MHC class I in the tumors. Induction of TTK-antigen specific T-cell response in TIL to the peptide-pulsed target cells was detected in 14 out of 20 (70%) cases, while LY6K or IMP-3 specific T-cell activity was observed in 11 of 20 (55%) or in eight of 20 (40%) cases, respectively. Furthermore, T-cell activity in RLNL and PBL was detectable in the similar proportion of the 20 ESCC patients. Interestingly, CTA-specific T-cell immune response was found in 13 of 14 (93%) TIL obtained from ESCC tumors with strong MHC class I expression, while it could be observed only in two of six (33%) TIL from ESCC tumors with weak MHC class I expression. These results strongly suggest the pre-existence of specific T-cell responses to HLA-A24-restricted epitope peptides from TTK, LY6K, and IMP-3 in ESCC patients. Monitoring antigen-specific T-cell responses, as well as the expression levels of MHC class I and epitope CTA in tumors, should be a selection index for application of cancer vaccine therapies to the patients who are likely to show good immune response.

  18. Myristoylation increases the CD8+T-cell response to a GFP prototype antigen delivered by modified vaccinia virus Ankara.

    PubMed

    Marr, Lisa; Lülf, Anna-Theresa; Freudenstein, Astrid; Sutter, Gerd; Volz, Asisa

    2016-04-01

    Activation of CD8(+)T-cells is an essential part of immune responses elicited by recombinant modified vaccinia virus Ankara (MVA). Strategies to enhance T-cell responses to antigens may be particularly necessary for broadly protective immunization against influenza A virus infections or for candidate vaccines targeting chronic infections and cancer. Here, we tested recombinant MVAs that targeted a model antigen, GFP, to different localizations in infected cells. In vitro characterization demonstrated that GFP accumulated in the nucleus (MVA-nls-GFP), associated with cellular membranes (MVA-myr-GFP) or was equally distributed throughout the cell (MVA-GFP). On vaccination, we found significantly higher levels of GFP-specific CD8(+)T-cells in MVA-myr-GFP-vaccinated BALB/c mice than in those immunized with MVA-GFP or MVA-nls-GFP. Thus, myristoyl modification may be a useful strategy to enhance CD8(+)T-cell responses to MVA-delivered target antigens.

  19. Myeloid-derived suppressor cells in murine retrovirus-induced AIDS inhibit T- and B-cell responses in vitro that are used to define the immunodeficiency.

    PubMed

    Green, Kathy A; Cook, W James; Green, William R

    2013-02-01

    Myeloid-derived suppressor cells (MDSCs) have been characterized in several disease settings, especially in many tumor systems. Compared to their involvement in tumor microenvironments, however, MDSCs have been less well studied in their responses to infectious disease processes, in particular to retroviruses that induce immunodeficiency. Here, we demonstrate for the first time the development of a highly immunosuppressive MDSC population that is dependent on infection by the LP-BM5 retrovirus, which causes murine acquired immunodeficiency. These MDSCs express a cell surface marker signature (CD11b(+) Gr-1(+) Ly6C(+)) characteristic of monocyte-type MDSCs. Such MDSCs profoundly inhibit immune responsiveness by a cell dose- and substantially inducible nitric oxide synthase (iNOS)-dependent mechanism that is independent of arginase activity, PD-1-PD-L1 expression, and interleukin 10 (IL-10) production. These MDSCs display levels of immunosuppressive function in parallel with the extent of disease in LP-BM5-infected wild-type (w.t.) versus knockout mouse strains that are differentially susceptible to pathogenesis. These MDSCs suppressed not only T-cell but also B-cell responses, which are an understudied target for MDSC inhibition. The MDSC immunosuppression of B-cell responses was confirmed by the use of purified B responder cells, multiple B-cell stimuli, and independent assays measuring B-cell expansion. Retroviral load measurements indicated that the suppressive Ly6G(low/±) Ly6C(+) CD11b(+)-enriched MDSC subset was positive for LP-BM5, albeit at a significantly lower level than that of nonfractionated splenocytes from LP-BM5-infected mice. These results, including the strong direct MDSC inhibition of B-cell responsiveness, are novel for murine retrovirus-induced immunosuppression and, as this broadly suppressive function mirrors that of the LP-BM5-induced disease syndrome, support a possible pathogenic effector role for these retrovirus-induced MDSCs.

  20. Blocking of PDL-1 interaction enhances primary and secondary CD8 T cell response to herpes simplex virus-1 infection.

    PubMed

    Channappanavar, Rudragouda; Twardy, Brandon S; Suvas, Susmit

    2012-01-01

    The blocking of programmed death ligand-1 (PDL-1) has been shown to enhance virus-specific CD8 T cell function during chronic viral infections. Though, how PDL-1 blocking at the time of priming affects the quality of CD8 T cell response to acute infections is not well understood and remains controversial. This report demonstrates that the magnitude of the primary and secondary CD8 T cell responses to herpes simplex virus-1 (HSV-1) infection is subject to control by PDL-1. Our results showed that after footpad HSV-1 infection, PD-1 expression increases on immunodominant SSIEFARL peptide specific CD8 T cells. Additionally, post-infection, the level of PDL-1 expression also increases on CD11c+ dendritic cells. Intraperitoneal administration of anti-PDL-1 monoclonal antibody given one day prior to and three days after cutaneous HSV-1 infection, resulted in a marked increase in effector and memory CD8 T cell response to SSIEFARL peptide. This was shown by measuring the quantity and quality of SSIEFARL-specific CD8 T cells by making use of ex-vivo assays that determine antigen specific CD8 T cell function, such as intracellular cytokine assay, degranulation assay to measure cytotoxicity and viral clearance. Our results are discussed in terms of the beneficial effects of blocking PDL-1 interactions, while giving prophylactic vaccines, to generate a more effective CD8 T cell response to viral infection.