t-cell proliferative response: Topics by Science.gov

Sample records for t-cell proliferative response

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
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.
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.
T-dependence of human B lymphocyte proliferative response to mitogens.

PubMed

Brochier, J; Samarut, C; Gueho, J P; Revillard, J P

1976-01-01

Human peripheral blood and tonsil lymphocytes were fractionated on anti-Ig-coated Sephadex columns or by centrifugation after rosetting with native sheep erythrocytes. Both methods allowed the recovery of B and T-enriched populations the purity of which was checked by fluorescein-labelled anti-Ig serum, E and EAC rosette formation, and heterologous antisera specific for B or T lymphocytes. The proliferative response of T cells to PHA, Con A, PWM, and ALS was not found different from that of unfractionated cells, whereas no response of the B cells could be observed to these mitogens providing that no contaminating T cells were present. Addition of T lymphocytes to these unresponsive B cells allowed them to respond to phytomitogens, but not to ALS. X-irradiated T cells could, to some extent, replace the diving T lymphocytes; no T-replacing factor could be found in cell-free supernatants from T cells, whether or not they had been activated by mitrogens. This model of B-T cooperation appears useful for studying the differentiation and maturation of human B lymphocytes.
Proliferative responses to canine thyroglobulin of peripheral blood mononuclear cells from hypothyroid dogs.

PubMed

Tani, Hiroyuki; Nabetani, Tomoyo; Sasai, Kazumi; Baba, Eiichiroh

2005-04-01

The immune responses of hypothyroid dogs to canine thyroglobulin (cTg) were evaluated for the proliferative ability of peripheral blood mononuclear cells (PBMC). PBMC from three hypothyroid dogs with high titers of thyroglobulin autoantibody (TgAA) and 3 clinically normal dogs were cultured with 5, 10, or 20 microg/ml of cTg for 72 hr. The proliferative responses of the cells were determined by the level of incorporated BrdU. The numbers of cells expressing Thy-1, CD4, CD8 and IgG in the PBMC were counted by the immunofluorescence method. Proliferative responses to cTg were observed in the cells from hypothyroid dogs. The number of cells expressing IgG and CD8 in the hypothyroid dogs tended to be high compared with the clinically normal dogs. The CD4+ cells in cultures from hypothyroid dogs increased depending upon the amount of cTg. There was a significant (P<0.05) positive correlation between the number of CD4+ cells and the concentration of cTg in the cultures from hypothyroid dogs. These findings suggest a possible relationship between canine hypothyroidism and cellular immunity. Loss of self tolerance to thyroid antigens in CD4+ T cells may play an important role in the development of canine hypothyroidism.
Genetic control of murine T cell proliferative responses to Mycobacterium leprae. V. Evidence for cross-reactivity between host antigens and Mycobacterium leprae

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

Harris, D.P.; Jones, A.G.; Wade, S.

1988-09-01

T cell proliferative responses to Mycobacterium leprae were measured by immunization of mice at the base of the tail with Ag and challenging lymphocytes from draining lymph nodes in culture with M. leprae. C57BL/10J and B10.BR mice were identified as low responder mice and the congenic strains B10.M, B10.Q, and B10.AKM as high responders whereas F1 (high x low) hybrid mice were found to be low responders. The cellular basis of low responsiveness did not appear to result from a defect in Ag-presenting cells or the activation of suppressor T cells by M. leprae. The influence of the environment inmore » which T cells developed on responsiveness to M. leprae was analyzed in chimeric mice prepared by irradiating F1(C57BL/10J x B10.M) mice and reconstituting with bone marrow from C57BL/10J, B10.M, or F1 donors. Six weeks later, chimeric mice were immunized with M. leprae, lymph node cells were subsequently prepared, and H-2 phenotyped and challenged in culture with M. leprae Ag. T cell proliferative responses were found to be low in all cases, similar to those observed using lymph node cells from F1 hybrid mice. These results suggested that high responder B10.M lymphocytes developing in the irradiated F1 mice became tolerized to antigenic determinants found on M. leprae. This implied cross-reactive epitopes existed between some mouse strains and M. leprae. Low responsiveness to M. leprae in low responder and F1 hybrid mice may result from tolerance to H-2-encoded Ag that show cross-reactivity with M. leprae.« less
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.
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.
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.
Impaired Upregulation of the Costimulatory Molecules, CD27 and CD28, on CD4+ T Cells from HIV Patients Receiving ART Is Associated with Poor Proliferative Responses.

PubMed

Tanaskovic, Sara; Price, Patricia; French, Martyn A; Fernandez, Sonia

2017-02-01

HIV patients beginning antiretroviral therapy (ART) with advanced immunodeficiency often retain low CD4 + T cell counts despite virological control. We examined proliferative responses and upregulation of costimulatory molecules, following anti-CD3 stimulation, in HIV patients with persistent CD4 + T cell deficiency on ART. Aviremic HIV patients with nadir CD4 + T cell counts <100 cells/μL and who had received ART for a median time of 7 (range 1-11) years were categorized into those achieving low (<350 cells/μL; n = 13) or normal (>500 cells/μL; n = 20) CD4 + T cell counts. Ten healthy controls were also recruited. CD4 + T cell proliferation (Ki67) and upregulation of costimulatory molecules (CD27 and CD28) after anti-CD3 stimulation were assessed by flow cytometry. Results were related to proportions of CD4 + T cells expressing markers of T cell senescence (CD57), activation (HLA-DR), and apoptotic potential (Fas). Expression of CD27 and/or CD28 on uncultured CD4 + T cells was similar in patients with normal CD4 + T cell counts and healthy controls, but lower in patients with low CD4 + T cell counts. Proportions of CD4 + T cells expressing CD27 and/or CD28 correlated inversely with CD4 + T cell expression of CD57, HLA-DR, and Fas. After anti-CD3 stimulation, induction of CD27 hi CD28 hi expression was independent of CD4 + T cell counts, but lower in HIV patients than in healthy controls. Induction of CD27 hi CD28 hi expression correlated with induction of Ki67 expression in total, naïve, and CD31 + naïve CD4 + T cells from patients. In HIV patients responding to ART, impaired induction of CD27 and CD28 on CD4 + T cells after stimulation with anti-CD3 is associated with poor proliferative responses as well as greater CD4 + T cell activation and immunosenescence.
Ki-67 staining for determination of rhesus macaque T cell proliferative responses ex vivo1

PubMed Central

Shedlock, Devon J.; Talbott, Kendra T.; Morrow, Matthew P.; Ferraro, Bernadette; Hokey, David A.; Muthumani, Karuppiah; Weiner, David B.

2010-01-01

The capacity for robust proliferation upon re-infection is a hallmark of adaptive immunity and the basis of vaccination. A widely used animal model for the study of human disease is the rhesus macaque (RM), where capacity for proliferation can be assessed ex vivo using carboxyfluorescein succinimidyl ester (CFSE)-based dilution assays. However, we show over the course of the standard ex vivo proliferation assay that CFSE-labeling at commonly-used dye concentrations induces significant cell death, but that this phenomenon is dose-dependent. Here we describe an alternative, semi-quantitative method for estimating T cell proliferative responses that avoids the putative biases associated with chemical modification. RM peripheral blood mononuclear cells were stimulated ex vivo with cognate peptides for five days, immunostained for intracellular Ki-67, and then analyzed by flow cytometry. We describe a gating strategy using Ki-67 and side light scatter, also a marker of blastogenesis, which correlates strongly with data from CFSE dilution. We show that this method is a valid tool for measuring RM antigen-specific cellular proliferation ex vivo and can be used as an alternative to CFSE dilution assays. PMID:20104580
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
Human immunodeficiency virus infection of helper T cell clones. Early proliferative defects despite intact antigen-specific recognition and interleukin 4 secretion.

PubMed Central

Laurence, J; Friedman, S M; Chartash, E K; Crow, M K; Posnett, D N

1989-01-01

HIV selectively inhibited the proliferative response of clonal CD4+ T lymphocytes to alloantigen while other alloantigen-dependent responses were unperturbed. Specifically, impaired blastogenesis could be dissociated from alloantigen-specific induction of the B cell activation molecule CD23, IL-4 release, and inositol lipid hydrolysis. In addition, membrane expression of pertinent T cell receptor molecules, including CD2, CD3, and T cell antigen receptor (Ti), remained intact. Using two MHC class II-specific human CD4+ helper T cell clones, the proliferative defect was shown to be an early consequence of HIV infection, occurring within 4 d of viral inoculation and preceding increases in mature virion production. It was generalizable to three distinct methods of T cell activation, all independent of antigen-presenting cells: anti-CD3 mediated cross-linking of the CD3/Ti complex; anti-CD2 and phorbol 12-myristic 13-acetate (PMA); and anti-CD28 plus PMA. These abnormalities were not mitigated by addition of exogenous IL-2, even though expression of the IL-2 receptor (CD25) was unaltered. These studies define a selective blockade in T cell function early after HIV exposure that could serve as a model for certain in vivo manifestations of AIDS. PMID:2470786
Blockade of the Programmed Death-1 Pathway Restores Sarcoidosis CD4+ T-Cell Proliferative Capacity

PubMed Central

Braun, Nicole A.; Celada, Lindsay J.; Herazo-Maya, Jose D.; Abraham, Susamma; Shaginurova, Guzel; Sevin, Carla M.; Grutters, Jan; Culver, Daniel A.; Dworski, Ryszard; Sheller, James; Massion, Pierre P.; Polosukhin, Vasiliy V.; Johnson, Joyce E.; Kaminski, Naftali; Wilkes, David S.; Oswald-Richter, Kyra A.

2014-01-01

Rationale: Effective therapeutic interventions for chronic, idiopathic lung diseases remain elusive. Normalized T-cell function is an important contributor to spontaneous resolution of pulmonary sarcoidosis. Up-regulation of inhibitor receptors, such as programmed death-1 (PD-1) and its ligand, PD-L1, are important inhibitors of T-cell function. Objectives: To determine the effects of PD-1 pathway blockade on sarcoidosis CD4+ T-cell proliferative capacity. Methods: Gene expression profiles of sarcoidosis and healthy control peripheral blood mononuclear cells were analyzed at baseline and follow-up. Flow cytometry was used to measure ex vivo expression of PD-1 and PD-L1 on systemic and bronchoalveolar lavage–derived cells of subjects with sarcoidosis and control subjects, as well as the effects of PD-1 pathway blockade on cellular proliferation after T-cell receptor stimulation. Immunohistochemistry analysis for PD-1/PD-L1 expression was conducted on sarcoidosis, malignant, and healthy control lung specimens. Measurements and Main Results: Microarray analysis demonstrates longitudinal increase in PDCD1 gene expression in sarcoidosis peripheral blood mononuclear cells. Immunohistochemistry analysis revealed increased PD-L1 expression within sarcoidosis granulomas and lung malignancy, but this was absent in healthy lungs. Increased numbers of sarcoidosis PD-1+ CD4+ T cells are present systemically, compared with healthy control subjects (P < 0.0001). Lymphocytes with reduced proliferative capacity exhibited increased proliferation with PD-1 pathway blockade. Longitudinal analysis of subjects with sarcoidosis revealed reduced PD-1+ CD4+ T cells with spontaneous clinical resolution but not with disease progression. Conclusions: Analogous to the effects in other chronic lung diseases, these findings demonstrate that the PD-1 pathway is an important contributor to sarcoidosis CD4+ T-cell proliferative capacity and clinical outcome. Blockade of the PD-1 pathway may be a
Aerobic physical training does not condition against strenuous exercise-induced changes in immune function but modulates T cell proliferative responses.

PubMed

Patiño, Pablo J; Caraballo, Domingo I; Szewczyk, Katarzyna; Quintana, Juan C; Bedoya, Lady R; Ramírez, Beatriz E; Jaramillo, Andrés

2017-09-29

Exercise-induced stress induces considerable changes in the immune system. To better understand the mechanisms related to these immune changes during acute and chronic physical stress, we studied the effects of aerobic physical training (APT) on several parameters of the immune system. Previously untrained males (18-25 years of age) were divided into a group that was subjected to 6 months of APT (n=10) and a sedentary control group (n=7). The subjects performed a cardiopulmonary exercise test (CET) at 0, 3, and 6 months of the APT program. B cell (CD19+), T cell (CD4+ and CD8+), and natural killer cell (CD56+) levels, and mitogen-induced T cell proliferation and cytokine production (interleukin-1, interleukin-4, interleukin-12, and interferon-) were evaluated before and at 30 seconds and 24 hours after the CET. There was a significant increase in CD4+ T cells and natural killer cells and a significant reduction in T cell proliferation in both groups 30 seconds after the CET at 3 and 6 months of the APT program. Of note, the trained group showed significantly lower resting T cell proliferation (before and 24 hour after the CET) than the sedentary control group at 3 and 6 months of the APT program. There were no significant differences in cytokine production after the CET between both groups at any time point of the APT program. These data show that APT does not condition against strenuous exercise induced immune changes but significantly modulates T cell proliferative responses.
Trypanosoma congolense: proliferative responses and interleukin production in lymph node cells of infected cattle.

PubMed

Lutje, V; Mertens, B; Boulangé, A; Williams, D J; Authié, E

1995-09-01

T-cell-mediated immune responses to defined antigens of Trypanosoma congolense were measured in cattle undergoing primary infection. The antigens used were the variable surface glycoprotein and two invariant antigens, a 33-kDa cysteine protease (congopain) and a recombinant form of a 69-kDa heat-shock protein. Proliferative responses were highest during the second week postinfection and were detected in cells obtained from the lymph node draining the site of infection but not in peripheral blood mononuclear cells. Production of IL-2 and IFN-gamma was measured in supernatants from antigen-stimulated lymph node cell cultures. Expression of IL-2, IL-4, and IFN-gamma mRNA was detected in antigen-stimulated lymph node cells by reverse transcription-polymerase chain amplification.
Potentiation of lymphocyte proliferative responses by nickel sulfide

NASA Technical Reports Server (NTRS)

Jaramillo, A.; Sonnenfeld, G.

1992-01-01

Crystalline nickel sulfide (NiS) induced a spleen cell proliferation that resembles a mixed lymphocyte reaction (MLR). It depended on cell-cell interaction, induced high levels of interleukin-1 (IL-1) and interleukin-2 (IL-2) and the responding cell subpopulation was composed of CD4+ T lymphocytes. Furthermore, the proliferation was inhibited in a dose-dependent manner by magnesium. Crystalline NiS also increased significantly the spleen cell proliferative response to concanavalin A (Con A) and lipopolysaccharide (LPS) with magnesium potentiating the combined effects of crystalline NiS and mitogens. Interestingly, crystalline NiS did not show any effect on the induction of IL-2 by Con A. The results described herein suggest that crystalline NiS can potentiate both antigenic (MLR) and mitogenic (Con A and LPS) proliferative responses in vitro. Crystalline NiS appears to potentiate these responses by acting in the form of ionic nickel on several intracellular targets for which magnesium ions have different noncompetitive interactions. The effects of magnesium on the potentiating action of crystalline NiS are different depending upon the type of primary stimulatory signal for proliferation (mitogenic or antigenic).
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.
HIV-Infected Children Have Elevated Levels of PD-1+ Memory CD4 T Cells With Low Proliferative Capacity and High Inflammatory Cytokine Effector Functions.

PubMed

Foldi, Julia; Kozhaya, Lina; McCarty, Bret; Mwamzuka, Mussa; Marshed, Fatma; Ilmet, Tiina; Kilberg, Max; Kravietz, Adam; Ahmed, Aabid; Borkowsky, William; Unutmaz, Derya; Khaitan, Alka

2017-09-15

During human immunodeficiency virus (HIV) disease, chronic immune activation leads to T-cell exhaustion. PD-1 identifies "exhausted" CD8 T cells with impaired HIV-specific effector functions, but its role on CD4 T cells and in HIV-infected children is poorly understood. In a Kenyan cohort of vertically HIV-infected children, we measured PD-1+ CD4 T-cell frequencies and phenotype by flow cytometry and their correlation with HIV disease progression and immune activation. Second, in vitro CD4 T-cell proliferative and cytokine responses to HIV-specific and -nonspecific stimuli were assessed with and without PD-1 blockade. HIV-infected children have increased frequencies of PD-1+ memory CD4 T cells that fail to normalize with antiretroviral treatment. These cells are comprised of central and effector memory subsets and correlate with HIV disease progression, measured by viral load, CD4 percentage, CD4:CD8 T-cell ratio, and immune activation. Last, PD-1+ CD4 T cells predict impaired proliferative potential yet preferentially secrete the Th1 and Th17 cytokines interferon-γ and interleukin 17A, and are unresponsive to in vitro PD-1 blockade. This study highlights differences in PD-1+ CD4 T-cell memory phenotype and response to blockade between HIV-infected children and adults, with implications for potential immune checkpoint therapies. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.
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.

Presence of Antigen-Experienced T Cells with Low Grade of Differentiation and Proliferative Potential in Chronic Chagas Disease Myocarditis

PubMed Central

Cabeza-Meckert, Patricia; Viotti, Rodolfo; Garelli, Fernando; Favaloro, Liliana E.; Favaloro, Roberto R.; Laguens, Rubén; Laucella, Susana A.

2014-01-01

Background The main consequence of chronic Trypanosoma cruzi infection is the development of myocarditis in approximately 20–30% of infected individuals but not until 10–20 years after the initial infection. We have previously shown that circulating interferon-γ-secreting T cells responsive to Trypanosoma cruzi antigens in chronic Chagas disease patients display a low grade of differentiation and the frequency of these T lymphocytes decreases along with the severity of heart disease. This study thought to explore the expression of inhibitory receptors, transcription factors of type 1 or regulatory T cells, and markers of T cell differentiation, immunosenescence or active cell cycle in cardiac explants from patients with advanced Chagas disease myocarditis. Methodology/Principal Findings The expression of different markers for T and B cells as well as for macrophages was evaluated by immunohistochemistry and immunofluorescence techniques in cardiac explants from patients with advanced chronic Chagas disease submitted to heart transplantation. Most infiltrating cells displayed markers of antigen-experienced T cells (CD3+, CD4+, CD8+, CD45RO+) with a low grade of differentiation (CD27+, CD57−, CD45RA−, PD-1−). A skewed T helper1/T cytotoxic 1 profile was supported by the expression of T-bet; whereas FOXP3+ cells were scarce and located only in areas of severe myocarditis. In addition, a significant proliferative capacity of CD3+ T cells, assessed by Ki67 staining, was found. Conclusions/Significance The quality of T cell responses and immunoregulatory mechanisms might determine the pattern of the cellular response and the severity of disease in chronic Trypanosoma cruzi infection. PMID:25144227
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...
Toxocara canis adult worm antigen induces proliferative response of healthy human peripheral blood mononuclear cells.

PubMed

Inuo, G; Akao, N; Kohsaka, H; Saito, I; Miyasaka, N; Fujita, K

1995-02-01

The proliferative response of human peripheral blood mononuclear cells (PBMC) from healthy donors to Toxocara canis adult worm antigens (TcA) was examined. PBMC from all donors examined (n = 7) strongly responded to TcA in a dose-dependent fashion after six days of culture, irrespective of their serological reactivity. In contrast, cord blood mononuclear cells did not react to TcA. The proliferation of PBMC in response to TcA was completely inhibited by anti-HLA-DR antibody. Purified CD4+ T cells reconstituted with autologous irradiated antigen presenting cells (APC) vigorously proliferated in response to TcA, but this was abrogated by pretreatment of APC with paraformaldehyde. Significant IL-2, IL-3, IL-4, IL-5 and IFN-gamma mRNA expression was detected in PBMC stimulated with TcA, with expression peaking at 72 h after stimulation. IL-1 beta, IL-6, IL-10 and GM-CSF mRNA expression was also upregulated, peaking at 24 h after stimulation. Taken together, these results suggest that adult T. canis-derived antigens have the ability to activate human PBMC as conventional antigens, possibly due to their cross-reactivity, which may be involved in the host defence against helminth infection.
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.
Role of redox signaling in the autonomous proliferative response of endothelial cells to hypoxia.

PubMed

Schäfer, M; Schäfer, C; Ewald, N; Piper, H M; Noll, Th

2003-05-16

Endothelial cells exhibit an autonomous proliferative response to hypoxia, independent of paracrine effectors. In cultured endothelial cells of porcine aorta, we analyzed the signaling of this response, with a focus on the roles of redox signaling and the MEK/ERK pathway. Transient hypoxia (1 hour) stimulated proliferation by 61+/-4% (n=16; P<0.05 versus control), quantified after 24 hours normoxic postincubation. Hypoxia induced an activation of ERK2 and of NAD(P)H oxidase and a burst of reactive oxygen species (ROS), determined by DCF fluorescence. To inhibit the MEK/ERK pathway, we used PD 98059 (PD, 20 micromol/L); to downregulate NAD(P)H oxidase, we applied p22phox antisense oligonucleotides; and to inhibit mitochondrial ROS generation, we used the ubiquinone derivate mitoQ (MQ, 10 micromol/L). All three inhibitions suppressed the proliferative response: PD inhibited NAD(P)H oxidase activation; p22phox antisense transfection did not inhibit ERK2 activation, but suppressed ROS production; and MQ inhibited ERK2 activation and ROS production. The autonomous proliferative response depends on the MEK/ERK pathway and redox signaling steps upstream and downstream of ERK. Located upstream is ROS generation by mitochondria, downstream is NAD(P)H oxidase.
Stress and the memory T-cell response to the Epstein-Barr virus in healthy medical students.

PubMed

Glaser, R; Pearson, G R; Bonneau, R H; Esterling, B A; Atkinson, C; Kiecolt-Glaser, J K

1993-11-01

This study investigated the memory T-cell proliferative response to several early and late Epstein-Barr virus (EBV) polypeptides. Blood samples were collected twice, 1 month before a 3-day block of examinations and again on the last day of the exam series. Ss were 25 healthy, EBV seropositive medical students. The proliferative response to 5 of the 6 EBV polypeptides significantly decreased during examinations. In addition, Ss high (above the median) in seeking support, as measured by the COPE, had lower proliferative responses to 3 EBV polypeptides (p17, p52/50, and p85), as well as higher levels of antibody to EBV virus capsid antigen. The data provide further evidence that psychological stress can modulate the cellular immune response to latent EBV.
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 ELISPOT assays measure central memory T cell (Tcm) responses in both humans and cattle. With bovine tuberculosis, vaccine-elicited long-term IFN-gamma ELISPOT responses correlate with protection. In other species, Tcm’s pose low activation threshold and a...
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
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
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.
T-kininogen induces endothelial cell proliferation.

PubMed

Pérez, Viviana; Leiva-Salcedo, Elías; Acuña-Castillo, Claudio; Aravena, Mauricio; Gómez, Christian; Sabaj, Valeria; Colombo, Alicia; Nishimura, Sumiyo; Pérez, Claudio; Walter, Robin; Sierra, Felipe

2006-03-01

Basal proliferation of endothelial cells increases with age, and this might play a role in the etiology of age-related vascular diseases, as well as angiogenesis. Serum kininogen levels increase during aging in rats and humans, and T-kininogen (T-KG) can affect proliferative homeostasis in several cell models. Both kinins and kininogens have been shown previously to be angiogenic through activation of endothelial cell proliferation, and here we show that exposure of endothelial cells to T-KG results in vigorous cell proliferation, accompanied by ERK/AKT activation. In our experiments, the proliferative response requires B1 and B2 kinin receptors, even though kinins are not released from the precursor. We hypothesize that the age-related increase in T-KG could play a significant role in the age-related dysregulation of vascular physiology and function.
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.
Micronutrient supplementation and T cell-mediated immune responses in patients with tuberculosis in Tanzania

PubMed Central

KAWAI, K.; MEYDANI, S. N.; URASSA, W.; WU, D.; MUGUSI, F. M.; SAATHOFF, E.; BOSCH, R. J.; VILLAMOR, E.; SPIEGELMAN, D.; FAWZI, W. W.

2017-01-01

SUMMARY Limited studies exist regarding whether incorporating micronutrient supplements during tuberculosis (TB) treatment may improve cell-mediated immune response. We examined the effect of micronutrient supplementation on lymphocyte proliferation response to mycobacteria or T-cell mitogens in a randomized trial conducted on 423 patients with pulmonary TB. Eligible participants were randomly assigned to receive a daily dose of micronutrients (vitamins A, B-complex, C, E, and selenium) or placebo at the time of initiation of TB treatment. We found no overall effect of micronutrient supplements on lymphocyte proliferative responses to phytohaemagglutinin or purified protein derivatives in HIV-negative and HIV-positive TB patients. Of HIV-negative TB patients, the micronutrient group tended to show higher proliferative responses to concanavalin A than the placebo group, although the clinical relevance of this finding is not readily notable. The role of nutritional intervention in this vulnerable population remains an important area of future research. PMID:24093552
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.
Beta-Amyloid Peptides Enhance the Proliferative Response of Activated CD4+CD28+ Lymphocytes from Alzheimer Disease Patients and from Healthy Elderly

PubMed Central

Jóźwik, Agnieszka; Landowski, Jerzy; Bidzan, Leszek; Fülop, Tamas; Bryl, Ewa; Witkowski, Jacek M.

2012-01-01

Alzheimer's disease (AD) is the most frequent form of dementia among elderly. Despite the vast amount of literature on non-specific immune mechanisms in AD there is still little information about the potential antigen-specific immune response in this pathology. It is known that early stages of AD include β-amyloid (Aβ)- reactive antibodies production and inflammatory response. Despite some evidence gathered proving cellular immune response background in AD pathology, the specific reactions of CD4+ and CD8+ cells remain unknown as the previous investigations yielded conflicting results. Here we investigated the CD4+CD28+ population of human peripheral blood T cells and showed that soluble β-amyloids alone were unable to stimulate these cells to proliferate significantly, resulting only in minor, probably antigen-specific, proliferative response. On the other hand, the exposure of in vitro pre-stimulated lymphocytes to soluble Aβ peptides significantly enhanced the proliferative response of these cells which had also lead to increased levels of TNF, IL-10 and IL-6. We also proved that Aβ peptide-enhanced proliferative response of CD4+CD28+ cells is autonomous and independent from disease status while being associated with the initial, ex vivo activation status of the CD4+ cells. In conclusion, we suggest that the effect of Aβ peptides on the immune system of AD patients does not depend on the specific reactivity to Aβ epitope(s), but is rather a consequence of an unspecific modulation of the cell cycle dynamics and cytokine production by T cells, occurring simultaneously in a huge proportion of Aβ peptide-exposed T lymphocytes and affecting the immune system performance. PMID:22428008
Triterpenoid Saponins from Anemone rivularis var. Flore-Minore and Their Anti-Proliferative Activity on HSC-T6 Cells.

PubMed

Wang, Xiao-Yang; Gao, Hui; Xie, Xiao-Jie; Jurhiin, Jirimubatu; Zhang, Mu-Zi-He; Zhou, Yan-Ping; Liu, Rui; Ning, Meng; Han, Jin; Tang, Hai-Feng

2018-02-23

Five previously undescribed triterpenoid saponins ( 1 - 5 ), along with eight known ones ( 6 - 13 ), were isolated from the whole plants of Anemone rivularis var. flore-minore . Their structures were clarified by extensive spectroscopic data and chemical evidence. For the first time, the lupane-type saponins ( 3 and 12 ) were reported from the Anemone genus. The anti-proliferative activity of all isolated saponins was evaluated on hepatic stellate cells (HSC-T6). Saponins 12 and 13 , which possess more monosaccharides than the others, displayed potent anti-proliferative activity, with IC 50 values of 18.21 and 15.56 μM, respectively.
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
Characterization of Effector and Memory T Cell Subsets in the Immune Response to Bovine Tuberculosis in Cattle

PubMed Central

Maggioli, Mayara F.; Palmer, Mitchell V.; Thacker, Tyler C.; Vordermeier, H. Martin; Waters, W. Ray

2015-01-01

Cultured IFN-γ ELISPOT assays are primarily a measure of central memory T cell (Tcm) responses with humans; however, this important subset of lymphocytes is poorly characterized in cattle. Vaccine-elicited cultured IFN-γ ELISPOT responses correlate with protection against bovine tuberculosis in cattle. However, whether this assay measures cattle Tcm responses or not is uncertain. The objective of the present study was to characterize the relative contribution of Tcm (CCR7+, CD62Lhi, CD45RO+), T effector memory (Tem, defined as: CCR7-, CD62Llow/int, CD45RO+), and T effector cells (CCR7-, CD62L-/low, CD45RO-), in the immune response to Mycobacterium bovis. Peripheral blood mononuclear cells (PBMC) from infected cattle were stimulated with a cocktail of M. bovis purified protein derivative, rTb10.4 and rAg85A for 13 days with periodic addition of fresh media and rIL-2. On day 13, cultured PBMC were re-stimulated with medium alone, rESAT-6:CFP10 or PPDb with fresh autologous adherent cells for antigen presentation. Cultured cells (13 days) or fresh PBMCs (ex vivo response) from the same calves were analyzed for IFN-γ production, proliferation, and CD4, CD45RO, CD62L, CD44, and CCR7 expression via flow cytometry after overnight stimulation. In response to mycobacterial antigens, ~75% of CD4+ IFN-γ+ cells in long-term cultures expressed a Tcm phenotype while less than 10% of the ex vivo response consisted of Tcm cells. Upon re-exposure to antigen, long-term cultured cells were highly proliferative, a distinctive characteristic of Tcm, and the predominant phenotype within the long-term cultures switched from Tcm to Tem. These findings suggest that proliferative responses of Tcm cells to some extent occurs simultaneously with reversion to effector phenotypes (mostly Tem). The present study characterizes Tcm cells of cattle and their participation in the response to M. bovis infection. PMID:25879774
Assessing Estrogen-Induced Proliferative Response in an Endometrial Cancer Cell Line Using a Universally Applicable Methodological Guide.

PubMed

Parkes, Christina; Kamal, Areege; Valentijn, Anthony J; Alnafakh, Rafah; Gross, Stephane R; Barraclough, Roger; Moss, Diana; Kirwan, John; Hapangama, Dharani K

2018-01-01

Translational endometrial cancer (EC) research benefits from an in vitro experimental approach using EC cell lines. We demonstrated the steps that are required to examine estrogen-induced proliferative response, a simple yet important research question pertinent to EC, and devised a pragmatic methodological workflow for using EC cell lines in experimental models. Comprehensive review of all commercially available EC cell lines was carried out, and Ishikawa cell line was selected to study the estrogen responsiveness with HEC1A, RL95-2, and MFE280 cell lines as comparators where appropriate, examining relevant differential molecular (steroid receptors) and functional (phenotype, anchorage-independent growth, hormone responsiveness, migration, invasion, and chemosensitivity) characteristics in 2-dimensional and 3-dimensional cultures in vitro using immunocytochemistry, immunofluorescence, quantitative polymerase chain reaction, and Western blotting. In vivo tumor, formation, and chemosensitivity were also assessed in a chick chorioallantoic membrane model. Short tandem repeat analysis authenticated the purchased cell lines, whereas gifted cells deviated significantly from the published profile. We demonstrate the importance of prior assessment of the suitability of each cell line for the chosen in vitro experimental technique. Prior establishment of baseline, nonenriched conditions was required to induce a proliferative response to estrogen. The chorioallantoic membrane model was a suitable in vivo multicellular animal model for EC for producing rapid and reproducible data. We have developed a methodological guide for EC researchers when using endometrial cell lines to answer important translational research questions (exemplified by estrogen-responsive cell proliferation) to facilitate robust data, while saving time and resources.
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.

Quantitative analysis of cell-free Epstein-Barr virus DNA in the plasma of patients with peripheral T-cell and NK-cell lymphomas and peripheral T-cell proliferative diseases.

PubMed

Suwiwat, Supaporn; Pradutkanchana, Jintana; Ishida, Takafumi; Mitarnun, Winyou

2007-12-01

The level of circulating EBV DNA is a prognostic marker in patients with some EBV-associated malignant diseases. To investigate the presence and nature of Epstein-Barr virus (EBV) DNA in the plasma and to evaluate the correlation of plasma concentrations of EBV DNA with the EBV genomic status in peripheral blood T-cells and neoplastic cells and with the clinical outcome of patients with peripheral T-cell and NK-cell lymphomas (PTCL) and peripheral T-cell proliferative diseases (PTPD). EBV DNA in the plasma of 45 patients and 45 controls was measured using real-time PCR. The presence of the EBV genome in the isolated peripheral blood lymphocytes (CD3+ and CD3- cells) was analysed by PCR. Detection of EBV-encoded early RNA (EBER) in corresponding tumor tissues was carried out using in situ hybridization. DNase I digestion was applied to plasma samples to detect naked EBV DNA. Cell-free EBV DNA was detected in 32/38 (84%) of PTCL patients and 5/7 (71%) of PTPD patients, but not in the controls. Patients with EBV genome in peripheral blood CD3+ cells and EBV genome (EBER) in the tumor cells, compared to those without these findings, had significantly higher plasma EBV DNA levels. The majority of circulating EBV DNA molecules was naked form. The plasma EBV DNA levels were not related to survival. The concentration of EBV DNA in the plasma was not a prognostic marker in PTCL and PTPD patients.
Screening NK-, B- and T-cell phenotype and function in patients suffering from Chronic Fatigue Syndrome.

PubMed

Curriu, Marta; Carrillo, Jorge; Massanella, Marta; Rigau, Josepa; Alegre, José; Puig, Jordi; Garcia-Quintana, Ana M; Castro-Marrero, Jesus; Negredo, Eugènia; Clotet, Bonaventura; Cabrera, Cecilia; Blanco, Julià

2013-03-20

Chronic Fatigue Syndrome (CFS) is a debilitating neuro-immune disorder of unknown etiology diagnosed by an array of clinical manifestations. Although several immunological abnormalities have been described in CFS, their heterogeneity has limited diagnostic applicability. Immunological features of CFS were screened in 22 CFS diagnosed individuals fulfilling Fukuda criteria and 30 control healthy individuals. Peripheral blood T, B and NK cell function and phenotype were analyzed by flow cytometry in both groups. CFS diagnosed individuals showed similar absolute numbers of T, B and NK cells, with minor differences in the percentage of CD4+ and CD8+ T cells. B cells showed similar subset frequencies and proliferative responses between groups. Conversely, significant differences were observed in T cell subsets. CFS individuals showed increased levels of T regulatory cells (CD25+/FOXP3+) CD4 T cells, and lower proliferative responses in vitro and in vivo. Moreover, CD8 T cells from the CFS group showed significantly lower activation and frequency of effector memory cells. No clear signs of T-cell immunosenescence were observed. NK cells from CFS individuals displayed higher expression of NKp46 and CD69 but lower expression of CD25 in all NK subsets defined. Overall, T cell and NK cell features clearly clustered CFS individuals. Our findings suggest that alterations in T-cell phenotype and proliferative response along with the specific signature of NK cell phenotype may be useful to identify CFS individuals. The striking down modulation of T cell mediated immunity may help to understand intercurrent viral infections in CFS.
Screening NK-, B- and T-cell phenotype and function in patients suffering from Chronic Fatigue Syndrome

PubMed Central

2013-01-01

Background Chronic Fatigue Syndrome (CFS) is a debilitating neuro-immune disorder of unknown etiology diagnosed by an array of clinical manifestations. Although several immunological abnormalities have been described in CFS, their heterogeneity has limited diagnostic applicability. Methods Immunological features of CFS were screened in 22 CFS diagnosed individuals fulfilling Fukuda criteria and 30 control healthy individuals. Peripheral blood T, B and NK cell function and phenotype were analyzed by flow cytometry in both groups. Results CFS diagnosed individuals showed similar absolute numbers of T, B and NK cells, with minor differences in the percentage of CD4+ and CD8+ T cells. B cells showed similar subset frequencies and proliferative responses between groups. Conversely, significant differences were observed in T cell subsets. CFS individuals showed increased levels of T regulatory cells (CD25+/FOXP3+) CD4 T cells, and lower proliferative responses in vitro and in vivo. Moreover, CD8 T cells from the CFS group showed significantly lower activation and frequency of effector memory cells. No clear signs of T-cell immunosenescence were observed. NK cells from CFS individuals displayed higher expression of NKp46 and CD69 but lower expression of CD25 in all NK subsets defined. Overall, T cell and NK cell features clearly clustered CFS individuals. Conclusions Our findings suggest that alterations in T-cell phenotype and proliferative response along with the specific signature of NK cell phenotype may be useful to identify CFS individuals. The striking down modulation of T cell mediated immunity may help to understand intercurrent viral infections in CFS. PMID:23514202
The proliferative response of cloned Peyer's patch switch T cells to syngeneic and allogeneic stimuli.

PubMed

Kawanishi, H; Ozato, K; Strober, W

1985-06-01

We previously defined a concanavalin A (Con A)-induced cloned T cell population in Peyer's patches (PP) that causes sIgM-bearing B cells to switch to sIgA-bearing B cells. In the present study we show that such IgA-specific switch T cells proliferate when exposed to syngeneic stimulator cells, i.e., the switch T cells are autoreactive. Detailed study of this phenomenon disclosed that both B cells and macrophages were capable of causing switch T cell proliferation, and in both cases, stimulation was enhanced by preactivation of the stimulator cells with lipopolysaccharide (LPS). In addition, fresh T cells can act as stimulators, but only if preactivated with Con A. Finally, it was clearly shown in blocking studies with the use of various antibodies directed at class II MHC specificities that class II MHC antigens were the stimulatory determinants. These studies suggest that IgA-specific switch T cells arise in PP as a result of autologous cell-cell interactions with activated (antigen-stimulated) B cells, macrophages, or T cells.
Nuclear calcium is required for human T cell activation

PubMed Central

Samstag, Yvonne

2016-01-01

Calcium signals in stimulated T cells are generally considered single entities that merely trigger immune responses, whereas costimulatory events specify the type of reaction. Here we show that the “T cell calcium signal” is a composite signal harboring two distinct components that antagonistically control genomic programs underlying the immune response. Using human T cells from healthy individuals, we establish nuclear calcium as a key signal in human T cell adaptogenomics that drives T cell activation and is required for signaling to cyclic adenosine monophosphate response element–binding protein and the induction of CD25, CD69, interleukin-2, and γ-interferon. In the absence of nuclear calcium signaling, cytosolic calcium activating nuclear factor of activated T cells translocation directed the genomic response toward enhanced expression of genes that negatively modulate T cell activation and are associated with a hyporesponsive state. Thus, nuclear calcium controls the T cell fate decision between a proliferative immune response and tolerance. Modulators of nuclear calcium–driven transcription may be used to develop a new type of pro-tolerance immunosuppressive therapy. PMID:27810914
Identification of helper T cell epitopes of dengue virus E-protein.

PubMed

Leclerc, C; Dériaud, E; Megret, F; Briand, J P; Van Regenmortel, M H; Deubel, V

1993-05-01

The T cell proliferative response to dengue 2 (Jamaica) E-glycoprotein (495 amino acids) was analyzed in vitro using either killed virus or E-protein fragments or synthetic peptides. Inactivated dengue virus stimulated dengue-specific lymph node (LN) CD4+T cell proliferation in BALB/c (H-2d), C3H (H-2k) and DBA/1 (H-2q) but not in C57BL/6 (H-2b) mice. Moreover, LN cells from dengue-virus primed BALB/c mice proliferated in vitro in response to three purified non-overlapping E-protein fragments expressed in E. coli as polypeptides fused to trpE (f22-205, f267-354, f366-424). To further determine T cell epitopes in the E-protein, synthetic peptides were selected using prediction algorithms for T cell epitopes. Highest proliferative responses were obtained after in vitro exposure of virus-primed LN cells to peptides p135-157, p270-298, p295-307 and p337-359. Peptide p59-78 was able to induce specific B and T cell responses in peptide-primed mice of H-2d, H-2q and H-2k haplotypes. Two peptides p59-78 corresponding to two dengue (Jamaica and Sri Lanka) isolates and differing only at position 71 cross-reacted at the B but not at the T cell level in H-2b mice. This analysis of murine T helper cell response to dengue E-protein may be of use in dengue subunit vaccine design.
PDC-E3BP is not a dominant T-cell autoantigen in primary biliary cirrhosis.

PubMed

McHugh, Anna; Robe, Amanda J; Palmer, Jeremy M; Jones, David E J

2006-05-01

Autoantibody responses reactive with the E2 and E3BP components of pyruvate dehydrogenase complex (PDC), which characterise primary biliary cirrhosis (PBC) crossreact, precluding the identification, from serological studies, of the antigen to which the principal breakdown of tolerance occurs. Although autoreactive T-cell responses to PDC-E2 have been well characterised it is, at present, unclear whether T-cell tolerance breakdown also occurs to PDC-E3BP. The aims of this study were to characterise autoreactive T-cell responses to PDC-E3BP in PBC and potential factors regulating their expression. Peripheral blood T-cell proliferative responses to purified recombinant human PDC-E2 and PDC-E3BP at a range of concentrations were characterised in PBC patients and control subjects. T-cell proliferative responses to both E2 and E3BP were absent from control subjects (median peak stimulation index (SI) to PDC-E2 1.2 [range 0.3-1.9], 0/10 positive (SI>2.32), median peak SI to PDC-E3BP 1.1 [0.7-2.1
Dysregulation of B Cell Activity During Proliferative Kidney Disease in Rainbow Trout.

PubMed

Abos, Beatriz; Estensoro, Itziar; Perdiguero, Pedro; Faber, Marc; Hu, Yehfang; Díaz Rosales, Patricia; Granja, Aitor G; Secombes, Christopher J; Holland, Jason W; Tafalla, Carolina

2018-01-01

Proliferative kidney disease (PKD) is a widespread disease caused by the endoparasite Tetracapsuloides bryosalmonae (Myxozoa: Malacosporea). Clinical disease, provoked by the proliferation of extrasporogonic parasite stages, is characterized by a chronic kidney pathology with underlying transcriptional changes indicative of altered B cell responses and dysregulated T-helper cell-like activities. Despite the relevance of PKD to European and North American salmonid aquaculture, no studies, to date, have focused on further characterizing the B cell response during the course of this disease. Thus, in this work, we have studied the behavior of diverse B cell populations in rainbow trout ( Oncorhynchus mykiss ) naturally infected with T. bryosalmonae at different stages of preclinical and clinical disease. Our results show a clear upregulation of all trout immunoglobulins (Igs) (IgM, IgD, and IgT) demonstrated by immunohistochemistry and Western blot analysis, suggesting the alteration of diverse B cell populations that coexist in the infected kidney. Substantial changes in IgM, IgD, and IgT repertoires were also identified throughout the course of the disease further pointing to the involvement of the three Igs in PKD through what appear to be independently regulated mechanisms. Thus, our results provide strong evidence of the involvement of IgD in the humoral response to a specific pathogen for the first time in teleosts. Nevertheless, it was IgT, a fish-specific Ig isotype thought to be specialized in mucosal immunity, which seemed to play a prevailing role in the kidney response to T. bryosalmonae . We found that IgT was the main Ig coating extrasporogonic parasite stages, IgT + B cells were the main B cell subset that proliferated in the kidney with increasing kidney pathology, and IgT was the Ig for which more significant changes in repertoire were detected. Hence, although our results demonstrate a profound dysregulation of different B cell subsets during PKD
Role of P-glycoprotein on CD69+CD4+ cells in the pathogenesis of proliferative lupus nephritis and non-responsiveness to immunosuppressive therapy

PubMed Central

Tsujimura, Shizuyo; Adachi, Tomoko; Saito, Kazuyoshi; Tanaka, Yoshiya

2017-01-01

Introduction P-glycoprotein (P-gp) expression on activated lymphocytes in systemic lupus erythematosus (SLE) plays a role in active efflux of intracellular drugs, resulting in drug resistance. The role of P-gp-expressing lymphocytes in the pathogenesis of SLE remains unclear. The aim of this study was to determine the importance of P-gp+CD4+ cells in organ manifestations in refractory SLE. Methods The proportion of P-gp+CD4+ cells was determined by flow cytometry in peripheral blood of patients with SLE (n=116) and healthy adults (n=10). Renal biopsy specimens were examined by immunohistochemistry for P-gp expression. Results CD69 is a marker of CD4 cell activation. The proportion of both P-gp-expressing CD4+ cells and CD69-expressing CD4+ cells in peripheral blood was higher in SLE than control. The proportion of P-gp+CD69+CD4+ cells correlated with Systemic Lupus Erythematosus Disease Activity Index and was higher in poor responders to corticosteroids. Furthermore, the proportion of P-gp+CD69+CD4+ cells was significantly higher in proliferative lupus nephritis (LN) with poor response to corticosteroids. The efficacy of immunosuppressive therapy depended on the regulation of the proportion of P-gp+CD69+CD4+ cells. Marked accumulation of P-gp+CD4+ cells in renal interstitial tissue and high proportion of peripheral P-gp+CD69+CD4+ cells were noted in patients with proliferative LN. Conclusions The results showed high proportion of P-gp+CD69+CD4+ cells in peripheral blood and their accumulation in renal tissue in patients with proliferative LN refractory to CS therapy, suggesting that P-gp expression on activated CD4+ T cells is a potentially useful marker for refractoriness to treatment and a novel target for treatment. PMID:29225917
Role of P-glycoprotein on CD69+CD4+ cells in the pathogenesis of proliferative lupus nephritis and non-responsiveness to immunosuppressive therapy.

PubMed

Tsujimura, Shizuyo; Adachi, Tomoko; Saito, Kazuyoshi; Tanaka, Yoshiya

2017-01-01

P-glycoprotein (P-gp) expression on activated lymphocytes in systemic lupus erythematosus (SLE) plays a role in active efflux of intracellular drugs, resulting in drug resistance. The role of P-gp-expressing lymphocytes in the pathogenesis of SLE remains unclear. The aim of this study was to determine the importance of P-gp + CD4 + cells in organ manifestations in refractory SLE. The proportion of P-gp + CD4 + cells was determined by flow cytometry in peripheral blood of patients with SLE (n=116) and healthy adults (n=10). Renal biopsy specimens were examined by immunohistochemistry for P-gp expression. CD69 is a marker of CD4 cell activation. The proportion of both P-gp-expressing CD4 + cells and CD69-expressing CD4 + cells in peripheral blood was higher in SLE than control. The proportion of P-gp + CD69 + CD4 + cells correlated with Systemic Lupus Erythematosus Disease Activity Index and was higher in poor responders to corticosteroids. Furthermore, the proportion of P-gp + CD69 + CD4 + cells was significantly higher in proliferative lupus nephritis (LN) with poor response to corticosteroids. The efficacy of immunosuppressive therapy depended on the regulation of the proportion of P-gp + CD69 + CD4 + cells. Marked accumulation of P-gp + CD4 + cells in renal interstitial tissue and high proportion of peripheral P-gp + CD69 + CD4 + cells were noted in patients with proliferative LN. The results showed high proportion of P-gp + CD69 + CD4 + cells in peripheral blood and their accumulation in renal tissue in patients with proliferative LN refractory to CS therapy, suggesting that P-gp expression on activated CD4 + T cells is a potentially useful marker for refractoriness to treatment and a novel target for treatment.
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.
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.
Induction of gamma delta T cells using zoledronate plus interleukin-2 in patients with metastatic cancer.

PubMed

Nagamine, Ichiro; Yamaguchi, Yoshiyuki; Ohara, Masahiro; Ikeda, Takuhiro; Okada, Morihito

2009-03-01

A loss of human leukocyte antigen (HLA) expression in clinical tumors is one of their escape mechanisms from immune attack by HLA-restricted effector cells. In this study, the induction of HLA-unrestricted effector cells, gamma delta T cells, using zoledronate (ZOL) and interleukin (IL)-2 in vitro was investigated in patients with metastatic cancer. Peripheral blood mononuclear cells (PBMCs) from 10 cancer patients (8 colorectal and 2 esophageal) with multiple metastases and ascites lymphocytes from 3 cancer patients (1 gastric and 2 colorectal) were stimulated with varied concentrations of ZOL plus 100 U/ml IL-2 for 48 hr followed by culturing with IL-2 alone for 12 days. Lymphocyte proliferative responses were determined using 3H-TdR uptakes and interferon (IFN)-gamma production was evaluated using enzyme-linked immunosorbent assay. Surface phenotyping was performed using flow cytometry. Cytotoxic activity of effector cells was determined using 51Cr-releasing assay. It was found that proliferative responses of PBMCs were significantly stimulated with ZOL plus IL-2 when compared with IL-2 alone, showing 200 to 500-fold expansions for 2 weeks, although ZOL alone induced no response. The optimal concentration of ZOL was 1-5 microM. Ascites lymphocytes could also be stimulated with ZOL plus IL-2. The proliferative responses were remarkable in patients whose PBMCs could produce high levels of IFN-gamma during an initial 48-hr stimulation using ZOL plus IL-2. Removal of an adherent cell fraction before the induction augmented the proliferative responses in patients who otherwise had low-grade proliferative responses. Generated cells comprising approximately 90 or 20% in PBMCs from healthy donors or cancer patients, respectively, expressed gamma delta-type T-cell receptor. Gamma delta T cells showed high cytotoxic activity against CD166-positive TE12 and TE13 cancer cells but not against CD166-negative MKN45 cells. The cytotoxic activity against TE13 cells was augmented
Genetic control of T cell responsiveness to the Friend murine leukemia virus envelope antigen. Identification of class II loci of the H-2 as immune response genes

PubMed Central

1988-01-01

T cells primed specifically for the envelope glycoprotein of Friend murine leukemia helper virus (F-MuLV) were prepared by immunizing mice with a recombinant vaccinia virus that expressed the entire env gene of F-MuLV. Significant proliferative responses of F-MuLV envelope- specific, H-2a/b T cells were observed when the T cells were stimulated with antigen-pulsed peritoneal exudate cells (PEC) having the b allele at the K, A beta, A alpha, and E beta loci of the H-2. On the other hand, PEC having only the kappa allele at these loci did not induce the envelope-specific T cell proliferation, even when the PEC had the b allele at the E alpha, S, or D loci. F-MuLV envelope-specific proliferation of H-2a/b T cells under the stimulation of antigen- pulsed, H-2a/b PEC was specifically blocked with anti-I-Ab and anti-I- Ek mAbs but not with anti-Kb, anti-Kk, or anti-I-Ak mAbs. Moreover, (B10.MBR x A/WySn)F1 mice that have the b allele only at the K locus but not in I-A subregion were nonresponders to the envelope glycoprotein, and the bm12 mutation at the A beta locus completely abolished the T cell responsiveness to this antigen. These results indicate that proliferative T cells recognize a limited number of epitopes on F-MuLV envelope protein in the context of I-Ab, hybrid I- Ak/b, and/or hybrid I-Ek/b class II MHC molecules but fail to recognize the same envelope protein in the context of I-Ak or I-Ek molecules. This influence of the H-2I region on T cell recognition of the envelope glycoprotein appeared to control in vivo induction of protective immunity against Friend virus complex after immunization with the vaccinia-F-MuLV env vaccine. Thus, these results provide, for the first time, direct evidence for Ir gene-controlled responder/nonresponder phenotypes influencing the immune response to a pathogenic virus of mice. PMID:3141552
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.
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
Human Atopic Dermatitis Skin-derived T Cells can Induce a Reaction in Mouse Keratinocytes in vivo.

PubMed

Martel, B C; Blom, L; Dyring-Andersen, B; Skov, L; Thestrup-Pedersen, K; Skov, S; Skak, K; Poulsen, L K

2015-08-01

In atopic dermatitis (AD), the inflammatory response between skin-infiltrating T cells and keratinocytes is fundamental to the development of chronic lesional eczema. The aim of this study was to investigate whether skin-derived T cells from AD patients could induce an inflammatory response in mice through keratinocyte activation and consequently cause the development of eczematous lesions. Punch biopsies of the lesional skin from AD patients were used to establish skin-derived T cell cultures, which were transferred to NOD.Cg-Prkd(scid) Il2rg(tm1Sug) /JicTac (NOG) mice. We found that the subcutaneous injection of the human AD skin-derived T cells resulted in the migration of the human T cells from subcutis to the papillary dermis followed by the development of erythema and oedema in the mouse skin. Furthermore, the human T cells induced a transient proliferative response in the mouse keratinocytes shown as increased numbers of Ki-67(+) keratinocytes and increased epidermal thickness. Out of six established AD skin-derived T cell cultures, two were superior at inducing a skin reaction in the mice, and these cultures were found to contain >10% CCR10(+) T cells compared to <2% for the other cultures. In comparison, blood-derived in vitro-differentiated Th2 cells only induced a weak response in a few of the mice. Thus, we conclude that human AD skin-derived T cells can induce a reaction in the mouse skin through the induction of a proliferative response in the mouse keratinocytes. © 2015 The Foundation for the Scandinavian Journal of Immunology.
T cell function in tuatara (Sphenodon punctatus).

PubMed

Burnham, D Kim; Keall, Susan N; Nelson, Nicola J; Daugherty, Charles H

2005-05-01

Tuatara are the sole survivors of an entire order of reptiles that thrived during the age of the dinosaurs. Therefore, knowledge of their physiology is critical to understanding the phylogeny of reptiles. Previous studies of the immune system of the tuatara did not assess T cell function. We analyzed T cell function among six captive tuatara by assessing concanavalin A (Con A), phytohemagglutinin (PHA) and mixed lymphocyte reaction (MLR) induced T cell proliferation. Peripheral blood mononuclear cells from six out of six and four out of four tuatara tested exhibited significant proliferative responses to Con A and PHA, respectively, as measured by an MTT reduction assay. A lower level of proliferation was detected in an MLR. However, Con A activated lymphocytes were not cytotoxic for a xenogeneic murine mastocytoma cell line (P815).
Different Regions of the Malaria Merozoite Surface Protein 1 of Plasmodium chabaudi Elicit Distinct T-Cell and Antibody Isotype Responses

PubMed Central

Quin, Stuart J.; Langhorne, Jean

2001-01-01

In this study we have investigated the antibody and CD4 T-cell responses to the well-characterized malaria vaccine candidate MSP-1 during the course of a primary Plasmodium chabaudi chabaudi (AS) infection. Specific antibody responses can be detected within the first week of infection, and CD4 T cells can be detected after 3 weeks of infection. The magnitude of the CD4 T-cell response elicited during a primary infection depended upon the region of MSP-1. In general, the highest precursor frequencies were obtained when a recombinant MSP-1 fragment corresponding to amino acids 900 to 1507 was used as the antigen in vitro. By contrast, proliferative and cytokine responses against amino acids 1508 to 1766 containing the C-terminal 21-kDa region of the molecule were low. The characteristic interleukin 4 (IL-4) switch that occurs in the CD4 T-cell population after an acute blood stage P. c. chabaudi infection was only consistently observed in the response to the amino acid 900 to 1507 MSP1 fragment. A lower frequency of IL-4-producing cells was seen in response to other regions. Although the magnitudes of the immunoglobulin G antibody responses to the different regions of MSP-1 were similar, the isotype composition of each response was distinct, and there was no obvious relationship with the type of T helper cells generated. Interestingly, a relatively high antibody response to the C-terminal region of MSP-1 was observed, suggesting that T-cell epitopes outside of this region may provide the necessary cognate help for specific antibody production. PMID:11254580
Inhibition of phosphoantigen-mediated gammadelta T-cell proliferation by CD4+ CD25+ FoxP3+ regulatory T cells.

PubMed

Kunzmann, Volker; Kimmel, Brigitte; Herrmann, Thomas; Einsele, Hermann; Wilhelm, Martin

2009-02-01

Tumour growth promotes the expansion of CD4(+) CD25(+) FoxP3(+) regulatory T cells (Tregs) which suppress various arms of immune responses and might therefore contribute to tumour immunosurveillance. In this study, we found an inverse correlation between circulating Treg frequencies and phosphoantigen-induced gammadelta T-cell proliferation in cancer patients, which prompted us to address the role of Tregs in controlling the gammadelta T-cell arm of innate immune responses. In vitro, human Treg-peripheral blood mononuclear cell (PBMC) co-cultures strongly inhibited phosphoantigen-induced proliferation of gammadelta T cells and depletion of Tregs restored the impaired phosphoantigen-induced gammadelta T-cell proliferation of cancer patients. Tregs did not suppress other effector functions of gammadelta T cells such as cytokine production or cytotoxicity. Our experiments indicate that Tregs do not mediate their suppressive activity via a cell-cell contact-dependent mechanism, but rather secrete a soluble non-proteinaceous factor, which is independent of known soluble factors interacting with amino acid depletion (e.g. arginase-diminished arginine and indolamine 2,3-dioxygenase-diminished tryptophan) or nitric oxide (NO) production. However, the proliferative activity of alphabeta T cells was not affected by this cell-cell contact-independent suppressive activity induced by Tregs. In conclusion, these findings indicate a potential new mechanism by which Tregs can specifically suppress gammadelta T cells and highlight the strategy of combining Treg inhibition with subsequent gammadelta T-cell activation to enhance gammadelta T cell-mediated immunotherapy.

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.
Immunomodulation by memantine in therapy of Alzheimer's disease is mediated through inhibition of Kv1.3 channels and T cell responsiveness

PubMed Central

Lowinus, Theresa; Bose, Tanima; Busse, Stefan; Busse, Mandy; Reinhold, Dirk; Schraven, Burkhart; Bommhardt, Ursula H.H.

2016-01-01

Memantine is approved for the treatment of advanced Alzheimer's disease (AD) and reduces glutamate-mediated neuronal excitotoxicity by antagonism of N-methyl-D-aspartate receptors. In the pathophysiology of AD immune responses deviate and infectious side effects are observed during memantine therapy. However, the particular effects of memantine on human T lymphocytes are unresolved. Here, we provide evidence that memantine blocks Kv1.3 potassium channels, inhibits CD3-antibody- and alloantigen-induced proliferation and suppresses chemokine-induced migration of peripheral blood T cells of healthy donors. Concurrent with the in vitro data, CD4+ T cells from AD patients receiving therapeutic doses of memantine show a transient decline of Kv1.3 channel activity and a long-lasting reduced proliferative response to alloantigens in mixed lymphocyte reactions. Furthermore, memantine treatment provokes a profound depletion of peripheral blood memory CD45RO+ CD4+ T cells. Thus, standard doses of memantine profoundly reduce T cell responses in treated patients through blockade of Kv1.3 channels. This may normalize deviant immunopathology in AD and contribute to the beneficial effects of memantine, but may also account for the enhanced infection rate. PMID:27462773
Immunomodulation by memantine in therapy of Alzheimer's disease is mediated through inhibition of Kv1.3 channels and T cell responsiveness.

PubMed

Lowinus, Theresa; Bose, Tanima; Busse, Stefan; Busse, Mandy; Reinhold, Dirk; Schraven, Burkhart; Bommhardt, Ursula H H

2016-08-16

Memantine is approved for the treatment of advanced Alzheimer´s disease (AD) and reduces glutamate-mediated neuronal excitotoxicity by antagonism of N-methyl-D-aspartate receptors. In the pathophysiology of AD immune responses deviate and infectious side effects are observed during memantine therapy. However, the particular effects of memantine on human T lymphocytes are unresolved. Here, we provide evidence that memantine blocks Kv1.3 potassium channels, inhibits CD3-antibody- and alloantigen-induced proliferation and suppresses chemokine-induced migration of peripheral blood T cells of healthy donors. Concurrent with the in vitro data, CD4+ T cells from AD patients receiving therapeutic doses of memantine show a transient decline of Kv1.3 channel activity and a long-lasting reduced proliferative response to alloantigens in mixed lymphocyte reactions. Furthermore, memantine treatment provokes a profound depletion of peripheral blood memory CD45RO+ CD4+ T cells. Thus, standard doses of memantine profoundly reduce T cell responses in treated patients through blockade of Kv1.3 channels. This may normalize deviant immunopathology in AD and contribute to the beneficial effects of memantine, but may also account for the enhanced infection rate.
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.
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
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.
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
The mechanism of retrovirus suppression of human T cell proliferation in vitro.

PubMed

Copelan, E A; Rinehart, J J; Lewis, M; Mathes, L; Olsen, R; Sagone, A

1983-10-01

Immunosuppression is commonly associated with retrovirus-induced animal tumors. Studies in the murine and feline retrovirus systems suggest that the 15,000-dalton envelope protein (p15E) of the virion may contribute to immunosuppression by interfering with normal lymphocyte function. We examined the effect of inactivated feline leukemia virus (UV-FeLV) and p15E derived from this virus on concanavalin A (Con A) driven human T cell proliferation. Virus and p15E markedly suppressed mononuclear cell proliferative response to Con A. Suppression was not due to inhibition of monocyte accessory cell function, or interleukin 1 (IL 1) secretion. In fact, the presence of monocytes partially protected T cells from UV-FeLV suppression. UV-FeLV, however, suppressed T cell secretion of and response to interleukin 2 (IL 2). We conclude that UV-FeLV and derived p15E inhibit T cell proliferation by direct inhibition of T cell function. These findings, extended to the in vivo situations, suggest that retrovirus-associated suppression of the immune response involves the induction of T cell but not monocyte dysfunction.
Involvement of Semaphorin (Sema4D) in T-Dependent Activation of B Cells.

PubMed

Kuklina, Е М; Nekrasova, I V; Valieva, Yu V

2017-08-01

The involvement of endogenous semaphorin (Sema4D) into the key stage of T-dependent differentiation of B cells, formation of plasmoblasts, was demonstrated in vitro in T/B cell co-culture under conditions of polyclonal activation of T cells. The effect of semaphorin was not associated with activation of high-affinity Sema4D receptor plexin B1, but involves lowaffinity receptor CD72. These data indicate that Sema4D-dependent signal regulates not only the initial stage of B-cell activation, proliferative response to the antigen, but also further differentiation of B cells into plasma cells.
Pleural mesothelial cells promote expansion of IL-17-producing CD8+ T cells in tuberculous pleural effusion.

PubMed

Li, X; Zhou, Q; Yang, W B; Xiong, X Z; Du, R H; Zhang, J C

2013-05-01

IL-17-producing CD8(+) T lymphocytes (Tc17 cells) have recently been detected in many cancers and autoimmune diseases. However, the possible implication of Tc17 cells in tuberculous pleural effusion remains unclarified. In this study, distribution and phenotypic features of Tc17 cells in both tuberculous pleural effusion (TPE) and peripheral blood from patients with tuberculosis were determined. The effects of proinflammatory cytokines and local accessory cells (pleural mesothelial cells) on Tc17 cell expansion were also explored. We found that TPE contained more Tc17 cells than the blood. Compared with IFN-γ-producing CD8(+) T cells, Tc17 cells displayed higher expression of chemokine receptors (CCRs) and lower expression of cytotoxic molecules. In particularly, Tc17 cells in TPE exhibited high expression levels of CCR6, which could migrate in response to CCL20. Furthermore, IL-1β, IL-6, IL-23, or their various combinations could promote Tc17 cell expansion from CD8(+) T cells, whereas the proliferative response of Tc17 cells to above cytokines was lower than that of Th17 cells. Pleural mesothelial cells (PMCs) were able to stimulate Tc17 cell expansion via cell contact in an IL-1β/IL-6/IL-23 independent fashion. Thus this study demonstrates that Tc17 cells marks a subset of non-cytotoxic, CCR6(+) CD8(+) T lymphocytes with low proliferative capacity. The overrepresentation of Tc17 cells in TPE may be due to Tc17 cell expansion stimulated by pleural proinflammatory cytokines and to recruitment of Tc17 cells from peripheral blood. Additionally, PMCs may promote the production of IL-17 by CD8(+) T cells at sites of TPE via cell-cell interactions.
Tolerogenic effect of mesenchymal stromal cells on gliadin-specific T lymphocytes in celiac disease.

PubMed

Ciccocioppo, Rachele; Camarca, Alessandra; Cangemi, Giuseppina Cristina; Radano, Giorgia; Vitale, Serena; Betti, Elena; Ferrari, Davide; Visai, Livia; Strada, Elena; Badulli, Carla; Locatelli, Franco; Klersy, Catherine; Gianfrani, Carmen; Corazza, Gino Roberto

2014-08-01

Celiac disease is caused by a dysregulated immune response toward dietary gluten, whose only treatment is a lifelong gluten-free diet. We investigated the effects of mesenchymal stromal cells (MSCs) on gliadin-specific T cells, which are known to induce intestinal lesions, in view of a possible use as new therapy. Bone marrow-derived MSCs and gliadin-specific T-cell lines were obtained from allogeneic donors and mucosal specimens of celiac patients, respectively. The immunosuppressant effect of MSCs was evaluated in terms of proliferative response and interferon (IFN)-γ production upon gliadin stimulation of long-term T-cell lines; the immunomodulant effect was assessed in terms of apoptotic rate, immunophenotype and cytokine profile of short-term T-cell lines generated in the presence of MSCs. Different MSC:T-cell ratios were applied, and statistics were performed as appropriate. MSCs inhibited both proliferative response and IFN-γ production of long-term T-cell lines in a dose-dependent manner while limiting the expansion of short-term T-cell lines by increasing the apoptotic rate. Moreover, a reduction of the CD4(+) population and expansion of the regulatory FoxP3+ subset were found in T-cell lines cultured with MSCs, in which a significant decrease of interleukin (IL)-21, IFN-γ and IL-10 paralleled by an upregulation of transforming growth factor-β1, IL-6 and IL-8 were observed. Finally, an increase of the indoleamine 2,3-dioxygenase activity was found, possibly playing a key role in mediating these effects. MSCs exert potent immunomodulant effects on gliadin-specific T cells, which may be exploited for future therapeutic application in celiac disease. Copyright © 2014 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.
Capsaicin Displays Anti-Proliferative Activity against Human Small Cell Lung Cancer in Cell Culture and Nude Mice Models via the E2F Pathway

PubMed Central

Hardman, W. Elaine; Luo, Haitao; Chen, Yi C.; Carpenter, A. Betts; Lau, Jamie K.; Dasgupta, Piyali

2010-01-01

Background Small cell lung cancer (SCLC) is characterized by rapid progression and low survival rates. Therefore, novel therapeutic agents are urgently needed for this disease. Capsaicin, the active ingredient of chilli peppers, displays anti-proliferative activity in prostate and epidermoid cancer in vitro. However, the anti-proliferative activity of capsaicin has not been studied in human SCLCs. The present manuscript fills this void of knowledge and explores the anti-proliferative effect of capsaicin in SCLC in vitro and in vivo. Methodology/Principal Findings BrdU assays and PCNA ELISAs showed that capsaicin displays robust anti-proliferative activity in four human SCLC cell lines. Furthermore, capsaicin potently suppressed the growth of H69 human SCLC tumors in vivo as ascertained by CAM assays and nude mice models. The second part of our study attempted to provide insight into molecular mechanisms underlying the anti-proliferative activity of capsaicin. We found that the anti-proliferative activity of capsaicin is correlated with a decrease in the expression of E2F-responsive proliferative genes like cyclin E, thymidylate synthase, cdc25A and cdc6, both at mRNA and protein levels. The transcription factor E2F4 mediated the anti-proliferative activity of capsaicin. Ablation of E2F4 levels by siRNA methodology suppressed capsaicin-induced G1 arrest. ChIP assays demonstrated that capsaicin caused the recruitment of E2F4 and p130 on E2F-responsive proliferative promoters, thereby inhibiting cell proliferation. Conclusions/Significance Our findings suggest that the anti-proliferative effects of capsaicin could be useful in the therapy of human SCLCs. PMID:20421925
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
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.
Breast cancer cell-associated endopeptidase EC 24.11 modulates proliferative response to bombesin.

PubMed

Burns, D M; Walker, B; Gray, J; Nelson, J

1999-01-01

We have investigated the production, growth and inactivation of gastrin-releasing peptide (GRP)-like peptides in human breast cancer cell lines. Radioimmunoassay detected GRP-like immunoreactivity (GRP-LI) in T47D breast cancer cells but not in the conditioned medium, indicating rapid clearance. No GRP-LI was found in the ZR-75-1 or MDA-MB-436 cells or their conditioned medium. High-performance liquid chromatography (HPLC) analysis of the GRP-LI in the T47D cells revealed a major peak, which co-eluted with GRP(18-27), and a minor more hydrophilic peak. In vitro stimulation of T47D cell growth by bombesin (BN) was enhanced to 138% of control levels (bombesin alone) by the addition of the selective endopeptidase EC 3.4.24.11 inhibitor phosphoramidon (0.1 ng ml(-1)). Fluorogenic analysis using whole cells confirmed low levels of this phosphoramidon-sensitive enzyme on the T47D cells. This enzyme, previously unreported in human breast cancer cells, significantly modulates both T47D growth and its response to BN-induced growth.
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.
PD-1 ligand expression by human colonic myofibroblasts/fibroblasts regulates CD4+ T-cell activity.

PubMed

Pinchuk, Irina V; Saada, Jamal I; Beswick, Ellen J; Boya, Gushyalatha; Qiu, Sumin M; Mifflin, Randy C; Raju, Gottumukkala S; Reyes, Victor E; Powell, Don W

2008-10-01

A prominent role for inhibitory molecules PD-L1 and PD-L2 in peripheral tolerance has been proposed. However, the phenotype and function of PD-L-expressing cells in human gut remains unclear. Recent studies suggest that colonic myofibroblasts (CMFs) and fibroblasts are important in the switch from acute inflammation to adaptive immunity. In the normal human colon, CMFs represent a distinct population of major histocompatibility complex class II(+) cells involved in the regulation of mucosal CD4(+) T-cell responses. PD-L1 and PD-L2 expression on human CMFs was determined using Western blot, fluorescence-activated cell sorter analysis and confocal microscopy. Lymphoproliferation assays and cytokine enzyme-linked immunosorbent assays were used to evaluate the role of B7 costimulators expressed by CMFs with regard to the regulation of preactivated T-helper cell responses. We demonstrate here the expression of PD-L1/2 molecules by normal human CMF and fibroblasts in situ and in culture. Both molecules support suppressive functions of CMFs in the regulation of activated CD4(+) T-helper cell proliferative responses; blocking this interaction reverses the suppressive effect of CMFs on T-cell proliferation and leads to increased production of the major T-cell growth factor, interleukin (IL)-2. PD-L1/2-mediated CMF suppressive functions are mainly due to the inhibition of IL-2 production, because supplementation of the coculture media with exogenous IL-2 led to partial recovery of activated T-cell proliferation. Our data suggest that stromal myofibroblasts and fibroblasts may limit T-helper cell proliferative activity in the gut and, thus, might play a prominent role in mucosal intestinal tolerance.
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
Simian immunodeficiency virus infection induces severe loss of intestinal central memory T cells which impairs CD4+ T-cell restoration during antiretroviral therapy.

PubMed

Verhoeven, D; Sankaran, S; Dandekar, S

2007-08-01

Simian immunodeficiency virus (SIV) infection leads to severe loss of intestinal CD4(+) T cells and, as compared to peripheral blood, restoration of these cells is slow during antiretroviral therapy (ART). Mechanisms for this delay have not been examined in context of which specific CD4(+) memory subsets or lost and fail to regenerate during ART. Fifteen rhesus macaques were infected with SIV, five of which received ART (FTC/PMPA) for 30 weeks. Viral loads were measured by real-time PCR. Flow cytometric analysis determined changes in T-cell subsets and their proliferative state. Changes in proliferative CD4(+) memory subsets during infection accelerated their depletion. This reduced the central memory CD4(+) T-cell pool and contributed to slow CD4(+) T-cell restoration during ART. There was a lack of restoration of the CD4(+) central memory and effector memory T-cell subsets in gut-associated lymphoid tissue during ART, which may contribute to the altered intestinal T-cell homeostasis in SIV infection.
Local and Systemic CD4+ T Cell Exhaustion Reverses with Clinical Resolution of Pulmonary Sarcoidosis

PubMed Central

Hawkins, Charlene; Shaginurova, Guzel; Shelton, D. Auriel; Herazo-Maya, Jose D.; Oswald-Richter, Kyra A.; Young, Anjuli; Celada, Lindsay J.; Kaminski, Naftali; Sevin, Carla

2017-01-01

Investigation of the Th1 immune response in sarcoidosis CD4+ T cells has revealed reduced proliferative capacity and cytokine expression upon TCR stimulation. In other disease models, such cellular dysfunction has been associated with a step-wise, progressive loss of T cell function that results from chronic antigenic stimulation. T cell exhaustion is defined by decreased cytokine production upon TCR activation, decreased proliferation, increased expression of inhibitory cell surface receptors, and increased susceptibility to apoptosis. We characterized sarcoidosis CD4+ T cell immune function in systemic and local environments among subjects undergoing disease progression compared to those experiencing disease resolution. Spontaneous and TCR-stimulated Th1 cytokine expression and proliferation assays were performed in 53 sarcoidosis subjects and 30 healthy controls. PD-1 expression and apoptosis were assessed by flow cytometry. Compared to healthy controls, sarcoidosis CD4+ T cells demonstrated reductions in Th1 cytokine expression, proliferative capacity (p < 0.05), enhanced apoptosis (p < 0.01), and increased PD-1 expression (p < 0.001). BAL-derived CD4+ T cells also demonstrated multiple facets of T cell exhaustion (p < 0.05). Reversal of CD4+ T cell exhaustion was observed in subjects undergoing spontaneous resolution (p < 0.05). Sarcoidosis CD4+ T cells exhibit loss of cellular function during progressive disease that follows the archetype of T cell exhaustion. PMID:29234685

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
Mitomycin C-treated or irradiated concanavalin A-activated T cells augment the activation of cytotoxic T cells in vivo.

PubMed

Moyers, C; Pottmeyer-Gerber, C; Gerber, M; Buszello, H; Dröge, W

1984-10-01

The activation of cytotoxic T lymphocytes (CTL) in vivo after immunization of normal or cyclophosphamide-treated mice with allogeneic cells was strongly augmented by the administration of mitomycin C-treated or irradiated concanavalin A-activated spleen cells (Con A-spl). This effect of the Con A-spl was abrogated by treatment with Anti-Thy 1 antibody plus complement, and was therefore presumably mediated by activated "helper" T cells. (The term "helper" cell is only operationally defined in this context and indicates that the augmenting irradiation resistant T cells are obviously not CTL precursor cells). These observations indicated (i) that even the cytotoxic response against allogeneic stimulator cells suffers in vivo from insufficient "helper" T cell activity, and (ii) that the injection of Con A-spl may serve as a simple procedure to apply this "helper" activity in vivo. This procedure was at least as effective as the repeated injection of interleukin 2 (IL-2)-containing cell supernatants with up to four 30-unit doses of IL-2 per mouse. IL-2-containing cell supernatants were found to mediate similar effects only if injected into the footpads but not intravenously. This was in line with the reported observation that IL-2 has an extremely short half-life in vivo. The injection of Con A-spl was also found to augment the proliferative response in the regional lymph nodes.
Breast cancer cell-associated endopeptidase EC 24.11 modulates proliferative response to bombesin

PubMed Central

Burns, D M; Walker, B; Gray, J; Nelson, J

1999-01-01

We have investigated the production, growth and inactivation of gastrin-releasing peptide (GRP)-like peptides in human breast cancer cell lines. Radioimmunoassay detected GRP-like immunoreactivity (GRP-LI) in T47D breast cancer cells but not in the conditioned medium, indicating rapid clearance. No GRP-LI was found in the ZR-75-1 or MDA-MB-436 cells or their conditioned medium. High-performance liquid chromatography (HPLC) analysis of the GRP-LI in the T47D cells revealed a major peak, which co-eluted with GRP18–27, and a minor more hydrophilic peak. In vitro stimulation of T47D cell growth by bombesin (BN) was enhanced to 138% of control levels (bombesin alone) by the addition of the selective endopeptidase EC 3.4.24.11 inhibitor phosphoramidon (0.1 ng ml−;1). Fluorogenic analysis using whole cells confirmed low levels of this phosphoramidon-sensitive enzyme on the T47D cells. This enzyme, previously unreported in human breast cancer cells, significantly modulates both T47D growth and its response to BN-induced growth. © 1999 Cancer Research Campaign PMID:9888460
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.
Functional and molecular alterations in T Cells induced by CCL5.

PubMed

Cridge, T J; Horowitz, K M; Marinucci, M N; Rose, K M; Wells, M; Werner, M T; Kurt, Robert A

2006-01-01

To delineate whether, and the extent to which, CCL5 could impact T cell function we examined cytokine production and proliferative ability following CCL5 treatment in vitro. We report a decreased ability of splenic T cells to produce IFN-? and TNF-a as well as proliferate in response to crosslinking with antibody to CD3 after 72, but not 24 hours of CCL5 exposure. To identify a mechanism by which CCL5 modulated T cell function, we examined T cell receptor translocation and lipid raft clustering. After exposure to CCL5, T cells were less efficient at translocating the TCR and clustering lipid rafts. Since TCR translocation and lipid raft clustering are required for creation of an immunological synapse, these data suggest that extended exposure to CCL5 may impact T cell effector function by modulating the ability to create a functional immunological synapse.
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
The state of T cells before cryopreservation: Effects on post-thaw proliferation and function.

PubMed

Luo, Ying; Wang, Peng; Liu, Hui; Zhu, Zhengyan; Li, Chenglong; Gao, Yingtang

2017-12-01

We aim to assess the effect of the state of T cells before cryopreservation on the post-thaw proliferative capacity, phenotype and functional response. Peripheral blood mononuclear cells (PBMCs) were isolated from a hepatocellular carcinoma (HCC) patient, and the T cells were frozen during cell culture according to our experimental design. After a period of re-culture, the proliferative capacity of the cryopreserved cells, the expression of T cell surface markers and the secretion of IFN-γ and IL-10 were assayed. There was >90% cell viability after thaw in every group. Lymphocytes cryopreserved at day 4, 8 or 12 during the cell culture were allowed to recover for 24 h, whereas lymphocytes cryopreserved while freshly isolated were allowed to recover for 72 h. After the period of re-culture, cryopreservation at day 4, 8 or 12 during T cell culture was not found to alter the T cell subpopulation. The proportions of NKT and Treg cells were unchanged when cells were cryopreserved at day 12 during T cell culture. IFN-γ secretion was not impacted by cryopreservation, and IL-10 secretion was significantly decreased when cells were cryopreserved at day 8 or 12 during T cell culture. The state of T cells before cryopreservation has effects on the post-thaw proliferation capacity, the phenotype and the secretion of IFN-γ and IL-10. Cryopreservation of lymphocytes at day 8 or 12 during the cell culture may be the best choice for T cell immunotherapy. Copyright © 2017 Elsevier Inc. All rights reserved.
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.
Functional Analysis of Dendritic Cells Generated from T-iPSCs from CD4+ T Cell Clones of Sjögren's Syndrome.

PubMed

Iizuka-Koga, Mana; Asashima, Hiromitsu; Ando, Miki; Lai, Chen-Yi; Mochizuki, Shinji; Nakanishi, Mahito; Nishimura, Toshinobu; Tsuboi, Hiroto; Hirota, Tomoya; Takahashi, Hiroyuki; Matsumoto, Isao; Otsu, Makoto; Sumida, Takayuki

2017-05-09

Although it is important to clarify the pathogenic functions of T cells in human samples, their examination is often limited due to difficulty in obtaining sufficient numbers of dendritic cells (DCs), used as antigen-presenting cells, especially in autoimmune diseases. We describe the generation of DCs from induced pluripotent stem cells derived from T cells (T-iPSCs). We reprogrammed CD4+ T cell clones from a patient with Sjögren's syndrome (SS) into iPSCs, which were differentiated into DCs (T-iPS-DCs). T-iPS-DCs had dendritic cell-like morphology, and expressed CD11c, HLA-DR, CD80, CD86, and also BDCA-3. Compared with monocyte-derived DCs, the capacity for antigen processing was similar, and T-iPS-DCs induced the proliferative response of autoreactive CD4+ T cells. Moreover, we could evaluate T cell functions of the patient with SS. In conclusion, we obtained adequate numbers of DCs from T-iPSCs, which could be used to characterize pathogenic T cells in autoimmune diseases such as SS. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.
T cell activation responses are differentially regulated during clinorotation and in spaceflight

NASA Technical Reports Server (NTRS)

Hashemi, B. B.; Penkala, J. E.; Vens, C.; Huls, H.; Cubbage, M.; Sams, C. F.

1999-01-01

Studies of T lymphocyte activation with mitogenic lectins during spaceflight have shown a dramatic inhibition of activation as measured by DNA synthesis at 72 h, but the mechanism of this inhibition is unknown. We have investigated the progression of cellular events during the first 24 h of activation using both spaceflight microgravity culture and a ground-based model system that relies on the low shear culture environment of a rotating clinostat (clinorotation). Stimulation of human peripheral blood mononuclear cells (PBMCs) with soluble anti-CD3 (Leu4) in clinorotation and in microgravity culture shows a dramatic reduction in surface expression of the receptor for IL-2 (CD25) and CD69. An absence of bulk RNA synthesis in clinorotation indicates that stimulation with soluble Leu4 does not induce transition of T cells from G0 to the G1 stage of the cell cycle. However, internalization of the TCR by T cells and normal levels of IL-1 synthesis by monocytes indicate that intercellular interactions that are required for activation occur during clinorotation. Complementation of TCR-mediated signaling by phorbol ester restores the ability of PBMCs to express CD25 in clinorotation, indicating that a PKC-associated pathway may be compromised under these conditions. Bypassing the TCR by direct activation of intracellular pathways with a combination of phorbol ester and calcium ionophore in clinorotation resulted in full expression of CD25; however, only partial expression of CD25 occurred in microgravity culture. Though stimulation of purified T cells with Bead-Leu4 in microgravity culture resulted in the engagement and internalization of the TCR, the cells still failed to express CD25. When T cells were stimulated with Bead-Leu4 in microgravity culture, they were able to partially express CD69, a receptor that is constitutively stored in intracellular pools and can be expressed in the absence of new gene expression. Our results suggest that the inhibition of T cell
Gammadelta T lymphocytes from cystic fibrosis patients and healthy donors are high TNF-alpha and IFN-gamma-producers in response to Pseudomonas aeruginosa.

PubMed

Raga, Salvador; Julià, M Rosa; Crespí, Catalina; Figuerola, Joan; Martínez, Natalia; Milà, Joan; Matamoros, Núria

2003-01-01

Gammadelta T cells have an important immunoregulatory and effector function through cytokine release. They are involved in the responses to Gram-negative bacterium and in protection of lung epithelium integrity. On the other hand, they have been implicated in airway inflammation. The aim of the present work was to study intracytoplasmic IL-2, IL-4, IFN-gamma and TNF-alpha production by gammadelta and alphabeta T lymphocytes from cystic fibrosis patients and healthy donors in response to Pseudomonas aeruginosa (PA). Flow cytometric detection was performed after peripheral blood mononuclear cells (PBMC) culture with a cytosolic extract from PA and restimulation with phorbol ester plus ionomycine. Proliferative responses, activation markers and receptor usage of gammadelta T cells were also evaluated. The highest production of cytokine was of TNF-alpha and IFN-gamma, gammadelta being better producers than alphabeta. No differences were found between patients and controls. The Vgamma9delta2 subset of gammadelta T cells was preferentially expanded. CD25 and CD45RO expression by the alphabeta T subset and PBMC proliferative response to PA were defective in cystic fibrosis lymphocytes. Our results support the hypothesis that gammadelta T lymphocytes play an important role in the immune response to PA and in the chronic inflammatory lung reaction in cystic fibrosis patients. They do not confirm the involvement of a supressed Th1 cytokine response in the pathogenesis of this disease.
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.
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 Â© 2012 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.
Desmoglein 3-specific T regulatory 1 cells consist of two subpopulations with differential expression of the transcription factor Foxp3

PubMed Central

Veldman, Christian; Pahl, Andreas; Hertl, Michael

2009-01-01

Pemphigus vulgaris (PV) is an autoimmune bullous skin disorder associated with autoantibodies against desmoglein (Dsg) 3. An imbalance of type 1 regulatory T (Tr1) cells and T helper type 2 (Th2) cells specific for Dsg3 may be critical for the loss of tolerance against Dsg3 in PV. Within the population of Dsg3-responsive, interleukin (IL)-10-secreting Tr1 cell clones, two major subpopulations were identified and sorted by fluorescence-activated cell sorting (FACS) based on their size and granularity. Upon in vitro culture, the larger subpopulation differentiated back into the two former subpopulations of the Tr1 cell clones, while the smaller subpopulation died within 2 weeks. The smaller subpopulation of the Tr1 cell clones was characterized by the expression of Foxp3, the secretion of IL-10, transforming growth factor (TGF)-β and IL-5 upon stimulation with Dsg3, a proliferative response to IL-2 but not to Dsg3 or mitogenic stimuli, and an inhibitory effect on the proliferative response of Dsg3-responsive Th clones in a Dsg3-specific manner. In contrast, the larger subpopulation showed a Th-like phenotype, lacking Foxp3, cytotoxic T-lymphocyte antigen 4 (CTLA4) and glucocorticoid-induced tumour necrosis factor receptor (GITR) expression and IL-2 secretion, and did not mount a proliferative response to Dsg3 and mitogenic stimuli. The two Tr1 subpopulations showed expression of identical T-cell receptor (TCR) Vβ chains which varied among the PV patients studied. Upon inhibition of Foxp3, the smaller Tr1 subpopulation developed a proliferate response to Dsg3 and mitogenic stimuli, no longer suppressed Dsg3-specific Th cells, lost expression of GITR and CTLA4 and secreted IL-2. Thus, our observations suggest a distinct relationship between Dsg3-specific Tr1 and Th-like cells which may be critical for the continuous generation and survival of Dsg3-specific Tr1 cells. PMID:18800988
Circulating natural killer T cells in patients with asthma.

PubMed

Ikegami, Yasuhiko; Yokoyama, Akihito; Haruta, Yoshinori; Hiyama, Keiko; Kohno, Nobuoki

2004-01-01

Recent studies suggest that therapies targeted at depletion or limiting of natural killer (NK) T cells may be a possible strategy for the treatment of asthma. In the present study, we measured the number of circulating V alpha24+ NKT cells in 32 asthmatic patients and compared these patients with 29 nonatopic healthy controls. We investigated the relationships between NKT cell number and clinical variables such as the number of eosinophils, the circulating level of IgE, and the severity of asthma. In addition, we also investigated the ability of NKT cells to proliferate in response to alpha-galactosyl ceramide (alpha-GalCer) in vitro. The V alpha24+ NKT cell counts of asthmatic patients were significantly lower than those of healthy controls. There were no significant differences observed in asthmatic patients among the subgroups in terms of atopic status and severity. There was no significant correlation between the number of NKT cells and clinical variables. The proliferative response to alpha-GalCer of the patients and controls was not significantly different, indicating no intrinsic proliferative defect of NKT cells in asthma. These results suggest that the number of circulating NKT cells was already decreased in patients with asthma. Further study, such as the evaluation of lung NKT cells, will be needed to determine the role of NKT cells in patients with asthma.
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.
[Systemic EBV+ T-cell lymphoproliferative disease of childhood].

PubMed

Lemaire, Anne-Sophie; Daussay, Dorothée; Bouchindhomme, Brigitte; Grardel, Nathalie; Botte, Astrid; Copin, Marie-Christine

2014-08-01

Systemic EBV+ T-cell lymphoproliferative disease of childhood is a recent entity described in the 2008 World Health Organisation tumours of haematopoietic system and lymphoid tissues as a clonal T-cell EBV+ systemic proliferation. It occurs after acute or chronic active EBV infection. We report the case of a caucasian, immunocompetent 12-year-old girl, with no particular history, who presented with hemophagocytic lymphohistiocytosis in the aftermath of an infectious mononucleosis. Main symptoms were multiple organ failure, hepatosplenomegaly and pancytopenia. Histopathology of peripheral lymph node and bone marrow revealed a T-cell, CD8+, EBV+ lymphoproliferation. An elevated viral load was detected in blood by PCR. The patient died within 3 weeks. Since most of the cases have been reported in Asia and South America, few cases still have been described in Europe. Unlike B-cell lymphoproliferation in immunocompromised individuals, T-cell EBV+ lymphoproliferation occurs in immunocompetent patients and seems to be the consequence of a proliferative disorder of EBV-infected T-cells, attributed to a cytotoxic T-cell response deficiency. These T-cell proliferations are more frequently immunoreactive for CD8 than CD4. A key feature of the diagnosis might be EBV viral load. Copyright © 2014 Elsevier Masson SAS. All rights reserved.
ESR1 Mutations Affect Anti-proliferative Responses to Tamoxifen through Enhanced Cross-Talk with IGF Signaling

PubMed Central

Gelsomino, Luca; Gu, Guowei; Rechoum, Yassine; Beyer, Amanda R; Pejerrey, Sasha M; Tsimelzon, Anna; Wang, Tao; Huffman, Kenneth; Ludlow, Andrew; Ando’, Sebastiano; Fuqua, Suzanne AW

2017-01-01

It is now generally accepted that estrogen receptor (ESR1) mutations occur frequently in metastatic breast cancers, however we do not yet know how to best treat these patients. We have modeled the three most frequent hormone binding ESR1 (HBD-ESR1) mutations (Y537N, Y537S, and D538G) using stable lentiviral transduction in human breast cancer cell lines. Effects on growth were examined in response to hormonal and targeted agents, and mutation-specific changes were studied using microarray and western blot analysis. We determined that the HBD-ESR1 mutations alter anti-proliferative effects to tamoxifen (Tam), due to cell-intrinsic changes in activation of the insulin-like growth factor receptor (IGF1R) signaling pathway and levels of PIK3R1/PIK3R3. The selective estrogen receptor degrader, fulvestrant, significantly reduced the anchorage-independent growth of ESR1 mutant-expressing cells, while combination treatments with the mTOR inhibitor everolimus, or an inhibitor blocking IGF1R and the insulin receptor significantly enhanced anti-proliferative responses. Using digital drop (dd) PCR we identified mutations at high frequencies ranging from 12% for Y537N, 5% for Y537S, and 2% for D538G in archived primary breast tumors from women treated with adjuvant mono-tamoxifen therapy. The HBD-ESR1 mutations were not associated with recurrence-free or overall survival in response in this patient cohort, and suggest that knowledge of other cell-intrinsic factors in combination with ESR1 mutation status will be needed determine anti-proliferative responses to Tam. PMID:27178332
Real-time tracking of cell cycle progression during CD8+ effector and memory T-cell differentiation

PubMed Central

Kinjyo, Ichiko; Qin, Jim; Tan, Sioh-Yang; Wellard, Cameron J.; Mrass, Paulus; Ritchie, William; Doi, Atsushi; Cavanagh, Lois L.; Tomura, Michio; Sakaue-Sawano, Asako; Kanagawa, Osami; Miyawaki, Atsushi; Hodgkin, Philip D.; Weninger, Wolfgang

2015-01-01

The precise pathways of memory T-cell differentiation are incompletely understood. Here we exploit transgenic mice expressing fluorescent cell cycle indicators to longitudinally track the division dynamics of individual CD8+ T cells. During influenza virus infection in vivo, naive T cells enter a CD62Lintermediate state of fast proliferation, which continues for at least nine generations. At the peak of the anti-viral immune response, a subpopulation of these cells markedly reduces their cycling speed and acquires a CD62Lhi central memory cell phenotype. Construction of T-cell family division trees in vitro reveals two patterns of proliferation dynamics. While cells initially divide rapidly with moderate stochastic variations of cycling times after each generation, a slow-cycling subpopulation displaying a CD62Lhi memory phenotype appears after eight divisions. Phenotype and cell cycle duration are inherited by the progeny of slow cyclers. We propose that memory precursors cell-intrinsically modulate their proliferative activity to diversify differentiation pathways. PMID:25709008
Real-time tracking of cell cycle progression during CD8+ effector and memory T-cell differentiation.

PubMed

Kinjyo, Ichiko; Qin, Jim; Tan, Sioh-Yang; Wellard, Cameron J; Mrass, Paulus; Ritchie, William; Doi, Atsushi; Cavanagh, Lois L; Tomura, Michio; Sakaue-Sawano, Asako; Kanagawa, Osami; Miyawaki, Atsushi; Hodgkin, Philip D; Weninger, Wolfgang

2015-02-24

The precise pathways of memory T-cell differentiation are incompletely understood. Here we exploit transgenic mice expressing fluorescent cell cycle indicators to longitudinally track the division dynamics of individual CD8(+) T cells. During influenza virus infection in vivo, naive T cells enter a CD62L(intermediate) state of fast proliferation, which continues for at least nine generations. At the peak of the anti-viral immune response, a subpopulation of these cells markedly reduces their cycling speed and acquires a CD62L(hi) central memory cell phenotype. Construction of T-cell family division trees in vitro reveals two patterns of proliferation dynamics. While cells initially divide rapidly with moderate stochastic variations of cycling times after each generation, a slow-cycling subpopulation displaying a CD62L(hi) memory phenotype appears after eight divisions. Phenotype and cell cycle duration are inherited by the progeny of slow cyclers. We propose that memory precursors cell-intrinsically modulate their proliferative activity to diversify differentiation pathways.

T-helper cell receptors from long-term survivors after telomerase cancer vaccination for use in adoptive cell therapy.

PubMed

Kyte, Jon Amund; Gaudernack, Gustav; Faane, Anne; Lislerud, Kari; Inderberg, Else Marit; Brunsvig, Paal; Aamdal, Steinar; Kvalheim, Gunnar; Wälchli, Sébastien; Pule, Martin

2016-01-01

We herein report retargeting of T-helper (Th) cells against the universal cancer antigen telomerase for use in adoptive cell therapy. The redirected Th cells may counter tumor tolerance, transform the inflammatory milieu, and induce epitope spreading and cancer senescence. We have previously conducted a series of trials evaluating vaccination with telomerase peptides. From long-term survivors, we isolated >100 CD4 + Th-cell clones recognizing telomerase epitopes. The clones were characterized with regard to HLA restriction, functional avidity, fine specificity, proliferative capacity, cytokine profile, and recognition of naturally processed epitopes. DP4 is the most prevalent HLA molecule worldwide. Two DP4-restricted T-cell clones with different functional avidity, C13 and D71, were selected for molecular T-cell receptor (TCR) cloning. Both clones showed a high proliferative capacity, recognition of naturally processed telomerase epitopes, and a polyfunctional and Th1-weighted cytokine profile. TCR C13 and D71 were cloned into the retroviral vector MP71 together with the compact and GMP-applicable marker/suicide gene RQR8. Both TCRs were expressed well in recipient T cells after PBMC transduction. The transduced T cells co-expressed RQR8 and acquired the desired telomerase specificity, with a polyfunctional response including production of TNFa, IFNγ, and CD107a. Interestingly, the DP4-restricted TCRs were expressed and functional both in CD4 + and CD8 + T cells. The findings demonstrate that the cloned TCRs confer recipient T cells with the desired hTERT-specificity and functionality. We hypothesize that adoptive therapy with Th cells may offer a powerful novel approach for overcoming tumor tolerance and synergize with other forms of immunotherapy.
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
Zoledronic Acid-Induced Expansion of γδ T Cells from Early-Stage Breast Cancer Patients: Effect of IL-18 on Helper NK Cells

PubMed Central

Sugie, Tomoharu; Murata-Hirai, Kaoru; Iwasaki, Masashi; Morita, Craig T.; Li, Wen; Okamura, Haruki; Minato, Nagahiro; Toi, Masakazu; Tanaka, Yoshimasa

2013-01-01

Human γδ T cells display potent cytotoxicity against various tumor cells pretreated with zoledronic acid (Zol). Zol has shown benefits when added to adjuvant endocrine therapy for patients with early-stage breast cancer or to standard chemotherapy for patients with multiple myeloma. Although γδ T cells may contribute to this additive effect, the responsiveness of γδ T cells from early-stage breast cancer patients has not been fully investigated. In this study, we determined the number, frequency, and responsiveness of Vγ2Vδ2 T cells from early- and late-stage breast cancer patients and examined the effect of IL-18 on their ex vivo expansion. The responsiveness of Vγ2Vδ2 T cells from patients with low frequencies of Vγ2Vδ2 T cells was significantly diminished. IL-18, however, enhanced ex vivo proliferative responses of Vγ2Vδ2 T cells and helper NK cells from patients with either low or high frequencies of Vγ2Vδ2 T cells. Treatment of breast cancer patients with Zol alone decreased the number of Vγ2Vδ2 T cells and reduced their ex vivo responsiveness. These results demonstrate that Zol can elicit immunological responses by γδ T cells from early-stage breast cancer patients but that frequent in vivo treatment reduces Vγ2Vδ2 T cell numbers and their responsiveness to stimulation. PMID:23151944
Non-specific factor enhancement of human in vitro antigen-dependent antibody synthesis: role of B cell activation and T cell help.

PubMed Central

Brenner, M K; North, M E; Chadda, H R; Farrant, J

1984-01-01

Lectin-free supernatants obtained from PWM-stimulated lymphocytes, enable B cells to proliferate and secrete immunoglobulin. Both functions are augmented by the addition of irradiated T cells. In the presence of antigen, these supernatants also enhance specific anti-tetanus toxoid antibody production. The components of the supernatant responsible for these activities have a molecular weight between 30,000 and 60,000, and have the characteristics of non-specific factors: they are genetically unrestricted, and do not bind to either antigen or anti-DR affinity columns. There is no evidence that the partial T dependency of these factors is an indication that their target is a T cell. Instead, T cells appear necessary to move the B cell into a state of activation in which it becomes responsive to the factor. Alternative activation signals such as Staph. A. Cowan can substitute for T cell help in the proliferative response, but not for immunoglobulin or antibody synthesis. The implications of these results for the approaches used to detect and classify B cell growth factors are discussed. PMID:6608488
DNA damage signaling regulates age-dependent proliferative capacity of quiescent inner ear supporting cells

PubMed Central

Laos, Maarja; Anttonen, Tommi; Kirjavainen, Anna; Hällström, Taija af; Laiho, Marikki; Pirvola, Ulla

2014-01-01

Supporting cells (SCs) of the cochlear (auditory) and vestibular (balance) organs hold promise as a platform for therapeutic regeneration of the sensory hair cells. Prior data have shown proliferative restrictions of adult SCs forced to re-enter the cell cycle. By comparing juvenile and adult SCs in explant cultures, we have here studied how proliferative restrictions are linked with DNA damage signaling. Cyclin D1 overexpression, used to stimulate cell cycle re-entry, triggered higher proliferative activity of juvenile SCs. Phosphorylated form of histone H2AX (γH2AX) and p53 binding protein 1 (53BP1) were induced in a foci-like pattern in SCs of both ages as an indication of DNA double-strand break formation and activated DNA damage response. Compared to juvenile SCs, γH2AX and the repair protein Rad51 were resolved with slower kinetics in adult SCs, accompanied by increased apoptosis. Consistent with the in vitro data, in a Rb mutant mouse model in vivo, cell cycle re-entry of SCs was associated with γH2AX foci induction. In contrast to cell cycle reactivation, pharmacological stimulation of SC-to-hair-cell transdifferentiation in vitro did not trigger γH2AX. Thus, DNA damage and its prolonged resolution are critical barriers in the efforts to stimulate proliferation of the adult inner ear SCs. PMID:25063730
Limited CD4+ T cell proliferation leads to preservation of CD4+ T cell counts in SIV-infected sooty mangabeys.

PubMed

Chan, Ming Liang; Petravic, Janka; Ortiz, Alexandra M; Engram, Jessica; Paiardini, Mirko; Cromer, Deborah; Silvestri, Guido; Davenport, Miles P

2010-12-22

Human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) infections result in chronic virus replication and progressive depletion of CD4+ T cells, leading to immunodeficiency and death. In contrast, 'natural hosts' of SIV experience persistent infection with high virus replication but no severe CD4+ T cell depletion, and remain AIDS-free. One important difference between pathogenic and non-pathogenic infections is the level of activation and proliferation of CD4+ T cells. We analysed the relationship between CD4+ T cell number and proliferation in HIV, pathogenic SIV in macaques, and non-pathogenic SIV in sooty mangabeys (SMs) and mandrills. We found that CD4+ T cell proliferation was negatively correlated with CD4+ T cell number, suggesting that animals respond to the loss of CD4+ T cells by increasing the proliferation of remaining cells. However, the level of proliferation seen in pathogenic infections (SIV in rhesus macaques and HIV) was much greater than in non-pathogenic infections (SMs and mandrills). We then used a modelling approach to understand how the host proliferative response to CD4+ T cell depletion may impact the outcome of infection. This modelling demonstrates that the rapid proliferation of CD4+ T cells in humans and macaques associated with low CD4+ T cell levels can act to 'fuel the fire' of infection by providing more proliferating cells for infection. Natural host species, on the other hand, have limited proliferation of CD4+ T cells at low CD4+ T cell levels, which allows them to restrict the number of proliferating cells susceptible to infection.
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
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.
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
Presence of natural killer-cell clones with variable proliferative capacity in chronic active Epstein-Barr virus infection.

PubMed

Nagata, H; Numata, T; Konno, A; Mikata, I; Kurasawa, K; Hara, S; Nishimura, M; Yamamoto, K; Shimizu, N

2001-10-01

Chronic active Epstein-Barr virus infection (CAEBV) is a syndrome that takes diverse clinical courses and is often associated with lymphoproliferative disorders of T/natural killer (NK)-cell lineage. We describe a patient with CAEBV associated with persistent pharyngeal ulcer, and with subsequent nasal T/NK-cell lymphoma in her neck lymph nodes and nasopharynx. Immunophenotyping of lymphoid cells showed that the lineage of Epstein-Barr virus (EBV)-positive cells in the patient was of NK-cell origin. By means of high-dose recombinant interleukin-2, we established an EBV-positive cell line of NK-cell lineage from her peripheral blood. Southern blot analysis for the number of terminal repeat sequences of EBV detected three NK-cell clones in the patient's lymph node. One of these clones was identical to the established cell line but was not observed in the pharyngeal ulcer, while the other two clones were present in the pharyngeal ulcer. These results suggest that the patient had expansion of the three NK-cell clones, one of which had proliferative capacity in vitro and was involved in the formation of the lymphoma. Moreover, the results suggest that the proliferative capacity of EBV-positive cells can be variable even in a single patient, and this variability may explain the clinical diversity in CAEBV.
Inhibition of anti-CD3 monoclonal antibody-induced T-cell proliferation and interleukin-2 secretion by physiologic combinations of dexamethasone and prostaglandin E2.

PubMed

Elliott, L; Brooks, W; Roszman, T

1993-12-01

1. The purpose of these studies was to characterize further previous observations from our laboratory indicating that physiologic concentrations of dexamethasone (DEX) and prostaglandin E2 (PGE2) added together result in synergistic inhibition of the proliferative response of T cells stimulated via the T-cell receptor CD3 signaling complex (TCR/CD3). 2. Various physiologic concentrations of DEX and PGE2 were added to T cells stimulated with immobilized anti-CD3 monoclonal antibody (mAb) and cultured at optimal and suboptimal cell densities. The results demonstrate that the proliferative response of anti-CD3 mAb-stimulated T cells cultured at a suboptimal cell density is more suppressed than that of T cells cultured at optimal concentrations. 3. The proliferative response of CD4+ T cells to immobilized anti-CD3 mAb was also determined in the presence of PGE2 and DEX. The data indicate that the CD4+ subset of T cells is more sensitive to the synergistic antiproliferative effects of DEX and PGE2 compared to whole T-cell populations. 4. Various concentrations of DEX and/or PGE2 were added to T cells stimulated with anti-CD3 mAb and the secretion of interleukin-2 (IL-2) was determined. The results demonstrate that concentrations of DEX and PGE2 which individually do not significantly suppress IL-2 synthesis act together to inhibit the synthesis of IL-2 synergistically. 5. The addition of an exogenous source of recombinant IL-2 (rIL-2) to T cells stimulated in the presence of DEX and PGE2 completely reversed the synergistic antiproliferative effect of these two compounds. This reversal was even more pronounced with T cells cultured at a suboptimal cell density. Additionally, PGE2 and DEX did not affect expression of the IL-2 receptor (IL-2R), as measured by upregulation of the alpha chain, on anti-CD3 mAb stimulated T cells. 6. Collectively these data indicate that physiologic concentrations of PGE2 and DEX, which alone have no effect on anti-CD3 mAb-induced T-cell
[Activity of non-specific T-suppressors regulating the proliferation of B- and T-lymphocytes in patients with fibroadenomatosis, breast cancer and stomach cancer].

PubMed

Grinevich, Iu A; Drannik, G N; Nikol'skiĭ, I S; Kalinina, N A; Litvishchenko, E I

1984-01-01

A decrease in proliferative rate of blood-circulating lymphocytes in response to LPS and PHA was registered in patients with fibroadenomatosis and cancer of the breast and stomach cancer. The said cells preincubated with Concanavalin A showed a weak inhibitory action on B-cells. The inhibition of T-cell proliferation by lymphocytes either remained unchanged or became less apparent in stage II breast cancer and slightly increased in stage III gastric cancer. Since no correlation was established between proliferative levels of T- and B-lymphocytes, two separate subpopulations of non-specific lymphocytes (T-T and T-B) were suggested.
Low-dose controlled release of mTOR inhibitors maintains T cell plasticity and promotes central memory T cells.

PubMed

Gammon, Joshua M; Gosselin, Emily A; Tostanoski, Lisa H; Chiu, Yu-Chieh; Zeng, Xiangbin; Zeng, Qin; Jewell, Christopher M

2017-10-10

An important goal for improving vaccine and immunotherapy technologies is the ability to provide further control over the specific phenotypes of T cells arising from these agents. Along these lines, frequent administration of rapamycin (Rapa), a small molecule inhibitor of the mammalian target of rapamycin (mTOR), exhibits a striking ability to polarize T cells toward central memory phenotypes (T CM ), or to suppress immune function, depending on the concentrations and other signals present during administration. T CM exhibit greater plasticity and proliferative capacity than effector memory T cells (T EFF ) and, therefore, polarizing vaccine-induced T cells toward T CM is an intriguing strategy to enhance T cell expansion and function against pathogens or tumors. Here we combined biodegradable microparticles encapsulating Rapa (Rapa MPs) with vaccines composed of soluble peptide antigens and molecular adjuvants to test if this approach allows polarization of differentiating T cells toward T CM . We show Rapa MPs modulate DC function, enhancing secretion of inflammatory cytokines at very low doses, and suppressing function at high doses. While Rapa MP treatment reduced - but did not stop - T cell proliferation in both CD4 + and CD8 + transgenic T cell co-cultures, the expanding CD8 + T cells differentiated to higher frequencies of T CM at low doses of MP Rapa MPs. Lastly, we show in mice that local delivery of Rapa MPs to lymph nodes during vaccination either suppresses or enhances T cell function in response to melanoma antigens, depending on the dose of drug in the depots. In particular, at low Rapa MP doses, vaccines increased antigen-specific T CM , resulting in enhanced T cell expansion measured during subsequent booster injections over at least 100days. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.
Programmed Death-1 Inhibition of Phosphatidylinositol 3-Kinase/AKT/Mechanistic Target of Rapamycin Signaling Impairs Sarcoidosis CD4+ T Cell Proliferation.

PubMed

Celada, Lindsay J; Rotsinger, Joseph E; Young, Anjuli; Shaginurova, Guzel; Shelton, Debresha; Hawkins, Charlene; Drake, Wonder P

2017-01-01

Patients with progressive sarcoidosis exhibit increased expression of programmed death-1 (PD-1) receptor on their CD4 + T cells. Up-regulation of this marker of T cell exhaustion is associated with a reduction in the proliferative response to T cell receptor (TCR) stimulation, a defect that is reversed by PD-1 pathway blockade. Genome-wide association studies and microarray analyses have correlated signaling downstream from the TCR with sarcoidosis disease severity, but the mechanism is not yet known. Reduced phosphatidylinositol 3-kinase (PI3K)/AKT expression inhibits proliferation by inhibiting cell cycle progression. To test the hypothesis that PD-1 expression attenuates TCR-dependent activation of PI3K/AKT activity in progressive systemic sarcoidosis, we analyzed PI3K/AKT/mechanistic target of rapamycin (mTOR) expression at baseline and after PD-1 pathway blockade in CD4 + T cells isolated from patients with sarcoidosis and healthy control subjects. We confirmed an increased percentage of PD-1 + CD4 + T cells and reduced proliferative capacity in patients with sarcoidosis compared with healthy control subjects (P < 0.001). There was a negative correlation with PD-1 expression and proliferative capacity (r = -0.70, P < 0.001). Expression of key mediators of cell cycle progression, including PI3K and AKT, were significantly decreased. Gene and protein expression levels reverted to healthy control levels after PD-1 pathway blockade. Reduction in sarcoidosis CD4 + T cell proliferative capacity is secondary to altered expression of key mediators of cell cycle progression, including the PI3K/AKT/mTOR pathway, via PD-1 up-regulation. This supports the concept that PD-1 up-regulation drives the immunologic deficits associated with sarcoidosis severity by inducing signaling aberrancies in key mediators of cell cycle progression.
Programmed Death-1 Inhibition of Phosphatidylinositol 3-Kinase/AKT/Mechanistic Target of Rapamycin Signaling Impairs Sarcoidosis CD4+ T Cell Proliferation

PubMed Central

Celada, Lindsay J.; Rotsinger, Joseph E.; Young, Anjuli; Shaginurova, Guzel; Shelton, Debresha; Hawkins, Charlene

2017-01-01

Patients with progressive sarcoidosis exhibit increased expression of programmed death-1 (PD-1) receptor on their CD4+ T cells. Up-regulation of this marker of T cell exhaustion is associated with a reduction in the proliferative response to T cell receptor (TCR) stimulation, a defect that is reversed by PD-1 pathway blockade. Genome-wide association studies and microarray analyses have correlated signaling downstream from the TCR with sarcoidosis disease severity, but the mechanism is not yet known. Reduced phosphatidylinositol 3-kinase (PI3K)/AKT expression inhibits proliferation by inhibiting cell cycle progression. To test the hypothesis that PD-1 expression attenuates TCR-dependent activation of PI3K/AKT activity in progressive systemic sarcoidosis, we analyzed PI3K/AKT/mechanistic target of rapamycin (mTOR) expression at baseline and after PD-1 pathway blockade in CD4+ T cells isolated from patients with sarcoidosis and healthy control subjects. We confirmed an increased percentage of PD-1+ CD4+ T cells and reduced proliferative capacity in patients with sarcoidosis compared with healthy control subjects (P < 0.001). There was a negative correlation with PD-1 expression and proliferative capacity (r = −0.70, P < 0.001). Expression of key mediators of cell cycle progression, including PI3K and AKT, were significantly decreased. Gene and protein expression levels reverted to healthy control levels after PD-1 pathway blockade. Reduction in sarcoidosis CD4+ T cell proliferative capacity is secondary to altered expression of key mediators of cell cycle progression, including the PI3K/AKT/mTOR pathway, via PD-1 up-regulation. This supports the concept that PD-1 up-regulation drives the immunologic deficits associated with sarcoidosis severity by inducing signaling aberrancies in key mediators of cell cycle progression. PMID:27564547
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
Ex vivo immunosuppressive effects of mesenchymal stem cells on Crohn's disease mucosal T cells are largely dependent on indoleamine 2,3-dioxygenase activity and cell-cell contact.

PubMed

Ciccocioppo, Rachele; Cangemi, Giuseppina C; Kruzliak, Peter; Gallia, Alessandra; Betti, Elena; Badulli, Carla; Martinetti, Miryam; Cervio, Marila; Pecci, Alessandro; Bozzi, Valeria; Dionigi, Paolo; Visai, Livia; Gurrado, Antonella; Alvisi, Costanza; Picone, Cristina; Monti, Manuela; Bernardo, Maria E; Gobbi, Paolo; Corazza, Gino R

2015-07-24

Crohn's disease (CD) is a disabling chronic enteropathy sustained by a harmful T-cell response toward antigens of the gut microbiota in genetically susceptible subjects. Growing evidence highlights the safety and possible efficacy of mesenchymal stem cells (MSCs) as a new therapeutic tool for this condition. Therefore, we aimed to investigate the effects of bone marrow-derived MSCs on pathogenic T cells with a view to clinical application. T-cell lines from both inflamed and non-inflamed colonic mucosal specimens of CD patients and from healthy mucosa of control subjects were grown with the antigen muramyl-dipeptide in the absence or presence of donors' MSCs. The MSC effects were evaluated in terms of T-cell viability, apoptotic rate, proliferative response, immunophenotype, and cytokine profile. The role of the indoleamine 2,3-dioxygenase (IDO) was established by adding a specific inhibitor, the 1-methyl-DL-tryptophan, and by using MSCs transfected with the small interfering RNA (siRNA) targeting IDO. The relevance of cell-cell contact was evaluated by applying transwell membranes. A significant reduction in both cell viability and proliferative response to muramyl-dipeptide, with simultaneous increase in the apoptotic rate, was found in T cells from both inflamed and non-inflamed CD mucosa when co-cultured with MSCs and was reverted by inhibiting IDO activity and expression. A reduction of the activated CD4(+)CD25(+) subset and increase of the CD3(+)CD69(+) population were also observed when T-cell lines from CD mucosa were co-cultured with MSCs. In parallel, an inhibitory effect was evident on the expression of the pro-inflammatory cytokines tumor necrosis factor-α, interferon-γ, interleukin-17A and -21, whereas that of the transforming growth factor-β and interleukin-6 were increased, and production of the tolerogenic molecule soluble HLA-G was high. These latter effects were almost completely eliminated by blocking the IDO, whose activity was upregulated in
Suppressor cell hyperactivity relative to allogeneic lymphocyte proliferation as a manifestation of defective T-T-cell interactions in systemic lupus erythematosus

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

Stenina, M.A.; Potapova, A.A.; Biryukov, A.V.

1987-01-01

The authors study the state of immunoregulatory process in patients with systemic lupus erythematosus at the T-T-cell interaction level and seek to test the possibility of the pharmacological modulation of this process. The proliferative activity of mononuclear lymphocytes, extracted from the blood of ten lupus patients, was assessed by measuring the incorporation of tritiated thymidine into cultures stimulated by phytohemagglutinin, concanavalin, and theophylline. The comparative effects of each of these agents on the immunoregulatory and proliferative activity of the lymphocytes are reported.
A hypoallergenic variant of the major birch pollen allergen shows distinct characteristics in antigen processing and T-cell activation.

PubMed

Kitzmüller, C; Wallner, M; Deifl, S; Mutschlechner, S; Walterskirchen, C; Zlabinger, G J; Ferreira, F; Bohle, B

2012-11-01

BM4 is a novel genetically engineered variant of the major birch pollen allergen Bet v 1 that lacks the typical Bet v 1-like fold and displays negligible IgE-binding but strong T cell-activating capacity. The aim of this study was to elucidate possible differences between BM4 and Bet v 1 in internalization, antigen processing, and presentation. Proliferative responses to BM4 and Bet v 1 of peripheral blood mononuclear cells and Bet v 1-specific T-cell clones were compared. Fluorescently labeled BM4 and Bet v 1 were used to study surface binding, endocytosis, and intracellular degradation by monocyte-derived DC (mdDC). Both proteins were digested by endolysosomal extracts of mdDC. BM4- and Bet v 1-pulsed mdDC were employed to assess the kinetics of activation of Bet v 1-specific T-cell clones and the polarization of naïve T cells. BM4 displayed a significantly stronger T cell-activating capacity than Bet v 1. Furthermore, BM4 showed increased surface binding and internalization as well as faster endolysosomal degradation compared with Bet v 1. BM4-pulsed mdDC induced enhanced proliferative responses at earlier time-points in Bet v 1-specific T-cell clones and promoted less IL-5 production in T cells than Bet v 1-pulsed mdDC. The loss of the Bet v 1-fold changes the protein's interaction with the human immune system at the level of antigen-presenting cells resulting in altered T-cell responses. By combining low IgE-binding with strong and modulating T cell-activating capacity, BM4 represents a highly interesting candidate for specific immunotherapy of birch pollen allergy. © 2012 John Wiley & Sons A/S.
Fc receptors for mouse IgG1 on human monocytes: polymorphism and role in antibody-induced T cell proliferation.

PubMed

Tax, W J; Hermes, F F; Willems, R W; Capel, P J; Koene, R A

1984-09-01

In previous studies, it was shown that there is polymorphism in the mitogenic effect of mouse IgG1 monoclonal antibodies against the T3 antigen of human T cells. This polymorphism implies that IgG1 anti-T3 antibodies are not mitogenic for T cells from 30% of healthy individuals. The present results demonstrate that this polymorphism is caused by polymorphism of an Fc receptor for mouse IgG1, present on human monocytes. The Fc receptor for murine IgG1 could be detected by a newly developed rosetting assay on monocytes from all individuals responsive to the mitogenic effect of IgG1 anti-T3 antibodies. This Fc receptor was not detectable on monocytes from those individuals exhibiting no mitogenic responses to IgG1 anti-T3 monoclonal antibodies. Cross-linking of T3 antigens appears to be essential for antibody-induced mitosis of T cells, because mononuclear cells that did not proliferate in response to WT 31 (an IgG1 antibody against T3 antigen) showed a proliferative response to Sepharose beads coated with WT 31. The Fc receptor--if functionally present--may be involved in the cross-linking of T3 antigens through anti-T3 antibodies. Further evidence for the involvement of this Fc receptor in antibody-induced T cell proliferation was provided by inhibition studies. Immune complexes containing IgG1 antibodies were able to inhibit the proliferative response to IgG1 anti-T3 antibodies. This inhibition by immune complexes appears to be mediated through the monocyte Fc receptor for mouse IgG1. These findings are important for the interpretation of previously described inhibitory effects of anti-T cell monoclonal antibodies on T cell proliferation, and show that such inhibitory effects may be monocyte-mediated (via immune complexes) rather than caused by a direct involvement of the respective T cell antigens in T cell mitosis. The Fc receptor for mouse IgG1 plays a role in antibody-induced T cell proliferation. Its polymorphism may have important implications for the

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.
Differential effects of arsenic on intracellular free calcium levels and the proliferative response of murine mitogen-stimulated lymphocytes.

PubMed

Goytia-Acevedo, Raquel C; Cebrian, Mariano E; Calderon-Aranda, Emma S

2003-08-01

This study examined the effects of sodium arsenite treatment on free [Ca(2+)]i and cell death in mitogen-activated murine lymphocytes. The main findings of this study were that simultaneous sodium arsenite treatment inhibited PHA- but not Con A-induced T cell proliferation, induced a higher increase in free [Ca(2+)]i and an early increase in the proportion of dead cells in PHA than in Con A activated cells. Sodium arsenite pre-treatment reduced both PHA- and Con A-induced T-cell proliferation. Phorbol myristate ester (PMA) did not prevent the inhibitory effects of both sodium arsenite treatments, suggesting that sodium arsenite did not significantly decreased PKC activation or that its effects occurred on events parallel to PKC activation. Both PHA and Con A increased free [Ca(2+)]i after stimulation, yet the effect was more pronounced in mitogen-activated cells simultaneously treated with sodium arsenite and particularly in those activated with PHA. The increase in free [Ca(2+)]i was in agreement with the early cell death induced by sodium arsenite in PHA-activated cells, a finding consistent with the inhibitory effects on PHA-induced proliferation. Sodium arsenite-induced cell death occurred faster in PHA-activated cells. Further studies are needed to ascertain the relationships between the effects of sodium arsenite on free [Ca(2+)]i levels and the type of cell death induced by sodium arsenite and their relevance for the proliferative response of T cells.
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.
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
Limited CD4+ T cell proliferation leads to preservation of CD4+ T cell counts in SIV-infected sooty mangabeys

PubMed Central

Chan, Ming Liang; Petravic, Janka; Ortiz, Alexandra M.; Engram, Jessica; Paiardini, Mirko; Cromer, Deborah; Silvestri, Guido; Davenport, Miles P.

2010-01-01

Human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) infections result in chronic virus replication and progressive depletion of CD4+ T cells, leading to immunodeficiency and death. In contrast, ‘natural hosts’ of SIV experience persistent infection with high virus replication but no severe CD4+ T cell depletion, and remain AIDS-free. One important difference between pathogenic and non-pathogenic infections is the level of activation and proliferation of CD4+ T cells. We analysed the relationship between CD4+ T cell number and proliferation in HIV, pathogenic SIV in macaques, and non-pathogenic SIV in sooty mangabeys (SMs) and mandrills. We found that CD4+ T cell proliferation was negatively correlated with CD4+ T cell number, suggesting that animals respond to the loss of CD4+ T cells by increasing the proliferation of remaining cells. However, the level of proliferation seen in pathogenic infections (SIV in rhesus macaques and HIV) was much greater than in non-pathogenic infections (SMs and mandrills). We then used a modelling approach to understand how the host proliferative response to CD4+ T cell depletion may impact the outcome of infection. This modelling demonstrates that the rapid proliferation of CD4+ T cells in humans and macaques associated with low CD4+ T cell levels can act to ‘fuel the fire’ of infection by providing more proliferating cells for infection. Natural host species, on the other hand, have limited proliferation of CD4+ T cells at low CD4+ T cell levels, which allows them to restrict the number of proliferating cells susceptible to infection. PMID:20591864
A T-cell-dependent humoral immune response is preserved during the administration of the nerve agent pre-treatment pyridostigmine bromide in a murine model.

PubMed

Griffiths, Gareth D; Telford, Gary; Hooi, Doreen S W; Cook, David L; Wilkinson, Lucy J; Green, Christopher A; Pritchard, David I

2005-03-01

Immune regulation, either via the autonomic nervous system or by a proposed "non-neuronal" cholinergic system, suggests that the immune system may be susceptible to perturbation by compounds affecting cholinergic function. Here, the current UK and US nerve agent pre-treatment, pyridostigmine bromide (PB) and the related anti-acetylcholinesterase (AChE) compounds physostigmine (PHY) and BW284c51 were tested for their ability to affect mouse splenocyte function in vitro. In addition, PB, at a dose equivalent to that received during pre-treatment for nerve agent poisoning, was tested for its effect on a T-cell-dependent humoral response to antigen in vivo in the mouse. None of the anti-AChEs tested affected concanavalin A (Con A)-, anti-CD3- or lipopolysaccharide LPS-driven splenocyte proliferation, in vitro, at concentrations expected to give effective nerve agent pre-treatment. However, higher concentrations (>100 microM) particularly of PHY caused some inhibition of the proliferative responses. In vivo, PB or saline was administered via 28-day mini-osmotic pumps to give a 25-40% inhibition of whole blood AChE in the PB-treated animals. During PB or saline administration, primary and secondary doses (i.p.) of sheep red blood cells (SRBC) were given and the humoral response determined by monitoring anti-SRBC IgM and IgG levels. Splenocytes isolated from the experimental animals were also examined for their proliferative and cytokine responses to stimulation. No remarkable effects of PB were seen during the period of AChE inhibition on the humoral immune response. However, a modest elevation in IL-2 and IFN(gamma) in Con A-stimulated lymphocytes was seen in PB-treated animals following pump removal. Overall these data suggest that, in vivo, the SRBC stimulated T-cell-dependent immune response is unaffected by the administration of PB at pre-treatment doses.
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
Effects of burn with and without Escherichia coli infection in rats on intestinal vs. splenic T-cell responses.

PubMed

Ravindranath, T; Al-Ghoul, W; Namak, S; Fazal, N; Durazo-Arvizu, R; Choudhry, M; Sayeed, M M

2001-12-01

To evaluate the effect of burn injury with and without an Escherichia coliseptic complication on T-cell proliferation, interleukin-2 production, and Ca(2+) signaling responses in intestinal Peyer's patch and splenic T cells. Prospective, randomized, sham-controlled animal study. University medical center research laboratory. Adult male Sprague-Dawley rats. Rats were subjected to a 30% total body surface area, full skin thickness burn. Infection in rats was induced via intraperitoneal inoculation of E. coli, 10(9) colony forming units/kg, with or without a prior burn. Rat Peyer's patch and splenic T lymphocytes were isolated by using a nylon wool cell purification protocol. T-cell proliferation, interleukin-2 production, and Ca(2+) signaling responses were measured after stimulation of cells with the mitogen, concanavalin A. T-cell proliferation was determined by measuring incorporation of (3)H-thymidine into T-cell cultures. Interleukin-2 production by T-cell cultures was measured by using enzyme-linked immunosorbent assay. Intracellular T-cell Ca2(+ )concentration, [Ca(2+)](i), was measured by the use of Ca(2+)-specific fluorescent label, fura-2, and its fluorometric quantification. [Ca(2+)](i) was also evaluated by the use of digital video imaging of fura-2 loaded individual T cells. T-cell proliferation and interleukin-2 production were suppressed substantially in both Peyer's patch and splenic T cells 3 days after either the initial burn alone or burn followed by the E. coli inoculation at 24 hrs after the initial burn. There seemed to be no demonstrable additive effects of E. coli infection on the effects produced by burn injury alone. The T-cell proliferation and interleukin-2 production suppressions with burn or burn-plus-infection insults were correlated with attenuated Ca(2+) signaling. E. coli infection alone suppressed T-cell proliferation in Peyer's patch but not in splenic T cells at 2 days postbacterial inoculation; E. coli infection had no effect on
Slc3a2 Mediates Branched-Chain Amino-Acid-Dependent Maintenance of Regulatory T Cells.

PubMed

Ikeda, Kayo; Kinoshita, Makoto; Kayama, Hisako; Nagamori, Shushi; Kongpracha, Pornparn; Umemoto, Eiji; Okumura, Ryu; Kurakawa, Takashi; Murakami, Mari; Mikami, Norihisa; Shintani, Yasunori; Ueno, Satoko; Andou, Ayatoshi; Ito, Morihiro; Tsumura, Hideki; Yasutomo, Koji; Ozono, Keiichi; Takashima, Seiji; Sakaguchi, Shimon; Kanai, Yoshikatsu; Takeda, Kiyoshi

2017-11-14

Foxp3 + regulatory T (Treg) cells, which suppress immune responses, are highly proliferative in vivo. However, it remains unclear how the active replication of Treg cells is maintained in vivo. Here, we show that branched-chain amino acids (BCAAs), including isoleucine, are required for maintenance of the proliferative state of Treg cells via the amino acid transporter Slc3a2-dependent metabolic reprogramming. Mice fed BCAA-reduced diets showed decreased numbers of Foxp3 + Treg cells with defective in vivo proliferative capacity. Mice lacking Slc3a2 specifically in Foxp3 + Treg cells showed impaired in vivo replication and decreased numbers of Treg cells. Slc3a2-deficient Treg cells showed impaired isoleucine-induced activation of the mTORC1 pathway and an altered metabolic state. Slc3a2 mutant mice did not show an isoleucine-induced increase of Treg cells in vivo and exhibited multi-organ inflammation. Taken together, these findings demonstrate that BCAA controls Treg cell maintenance via Slc3a2-dependent metabolic regulation. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.
Regulatory function of cytomegalovirus-specific CD4{sup +}CD27{sup -}CD28{sup -} T cells

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

Tovar-Salazar, Adriana; Patterson-Bartlett, Julie; Jesser, Renee

2010-03-15

CMV infection is characterized by high of frequencies of CD27{sup -}CD28{sup -} T cells. Here we demonstrate that CMV-specific CD4{sup +}CD27{sup -}CD28{sup -} cells are regulatory T cells (T{sub R}). CD4{sup +}CD27{sup -}CD28{sup -} cells sorted from CMV-stimulated PBMC of CMV-seropositive donors inhibited de novo CMV-specific proliferation of autologous PBMC in a dose-dependent fashion. Compared with the entire CMV-stimulated CD4{sup +} T-cell population, higher proportions of CD4{sup +}CD27{sup -}CD28{sup -} T{sub R} expressed FoxP3, TGFbeta, granzyme B, perforin, GITR and PD-1, lower proportions expressed CD127 and PD1-L and similar proportions expressed CD25, CTLA4, Fas-L and GITR-L. CMV-CD4{sup +}CD27{sup -}CD28{sup -}more » T{sub R} expanded in response to IL-2, but not to CMV antigenic restimulation. The anti-proliferative effect of CMV-CD4{sup +}CD27{sup -}CD28{sup -} T{sub R} significantly decreased after granzyme B or TGFbeta inhibition. The CMV-CD4{sup +}CD27{sup -}CD28{sup -} T{sub R} of HIV-infected and uninfected donors had similar phenotypes and anti-proliferative potency, but HIV-infected individuals had higher proportions of CMV-CD4{sup +}CD27{sup -}CD28{sup -} T{sub R}. The CMV-CD4{sup +}CD27{sup -}CD28{sup -} T{sub R} may contribute to the downregulation of CMV-specific and nonspecific immune responses of CMV-infected individuals.« less
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.
CD8+CD28- T cells: certainties and uncertainties of a prevalent human T-cell subset.

PubMed

Arosa, Fernando A

2002-02-01

Human peripheral blood CD8+ T cells comprise cells that are in different states of differentiation and under the control of complex homeostatic processes. In a number of situations ranging from chronic inflammatory conditions and infectious diseases to ageing, immunodeficiency, iron overload and heavy alcohol intake, major phenotypic changes, usually associated with an increase in CD8+ T cells lacking CD28 expression, take place. CD8+CD28- T cells are characterized by a low proliferative capacity to conventional stimulation in vitro and by morphological and functional features of activated/memory T cells. Although the nature of the signals that give origin to this T-cell subset is uncertain, growing evidence argues for the existence of an interplay between epithelial cells, molecules with the MHC-class I fold and CD8+ T cells. The possibility that the generation of CD8+CD28- T cells is the combination of TCR/CD3zeta- and regulatory factor-mediated signals as a result of the sensing of modifications of the internal environment is discussed.
Opioid maintenance therapy restores CD4+ T cell function by normalizing CD4+CD25(high) regulatory T cell frequencies in heroin user.

PubMed

Riss, Gina-Lucia; Chang, Dae-In; Wevers, Carolin; Westendorf, Astrid M; Buer, Jan; Scherbaum, Norbert; Hansen, Wiebke

2012-08-01

There is an increasing body of evidence that heroin addiction is associated with severe alterations in immune function, which might contribute to an increased risk to contract infectious diseases like hepatitis B and C or HIV. However, the impact of heroin consumption on the CD4(+) T cell compartment is not well understood. Therefore, we analyzed the frequency and functional phenotype of CD4(+) T cells as well as immune-suppressive CD4(+)CD25(high) regulatory T cells (Tregs) isolated from the peripheral blood of opiate addicts currently abusing heroin (n=27) in comparison to healthy controls (n=25) and opiate addicts currently in opioid maintenance treatment (OMT; n=27). Interestingly, we detected a significant increase in the percentage of CD4(+)CD25(high) Tregs in the peripheral blood of heroin addicted patients in contrast to patients in OMT. The proliferative response of CD4(+) T cells upon stimulation with anti-CD3 and anti-CD28 antibodies was significantly decreased in heroin users, but could be restored by depletion of CD25(high) regulatory T cells from CD4(+) T cells to similar values as observed from healthy controls and patients in OMT. These results suggest that impaired immune responses observed in heroin users are related to the expansion of CD4(+)CD25(high) Tregs and more importantly, can be restored by OMT. Copyright © 2012 Elsevier Inc. All rights reserved.
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
SIRT1 deacetylase is overexpressed in human melanoma and its small molecule inhibition imparts anti-proliferative response via p53 activation.

PubMed

Wilking, Melissa J; Singh, Chandra; Nihal, Minakshi; Zhong, Weixiong; Ahmad, Nihal

2014-12-01

Melanoma causes more deaths than any other skin cancer, and its incidence in the US continues to rise. Current medical therapies are insufficient to control this deadly neoplasm, necessitating the development of new target-based approaches. The objective of this study was to determine the role and functional significance of the class III histone deacetylase SIRT1 in melanoma. We have found that SIRT1 is overexpressed in clinical human melanoma tissues and human melanoma cell lines (Sk-Mel-2, WM35, G361, A375, and Hs294T) compared to normal skin and normal melanocytes, respectively. In addition, treatment of melanoma cell lines A375, Hs294T, and G361 with Tenovin-1, a small molecule SIRT1 inhibitor, resulted in a significant decrease in cell growth and cell viability. Further, Tenovin-1 treatment also resulted in a marked decrease in the clonogenic survival of melanoma cells. Further experiments showed that the anti-proliferative response of Tenovin-1 was accompanied by an increase in the protein as well as activity of the tumor suppressor p53. This increase in p53 activity was substantiated by an increase in the protein level of its downstream target p21. Overall, these data suggest that small molecule inhibition of SIRT1 causes anti-proliferative effects in melanoma cells. SIRT1 appears to be acting through the activity of the tumor suppressor p53, which is not mutated in the majority of melanomas. However, future detailed studies are needed to further explore the role and mechanism of SIRT1 in melanoma development and progression and its usefulness in melanoma treatment.
Ta1, a novel 105 KD human T cell activation antigen defined by a monoclonal antibody.

PubMed

Fox, D A; Hussey, R E; Fitzgerald, K A; Acuto, O; Poole, C; Palley, L; Daley, J F; Schlossman, S F; Reinherz, E L

1984-09-01

By using a murine monoclonal antibody produced against an IL 2-dependent human T cell line, we defined a T lineage-specific molecule, termed Ta1, that is expressed strongly on activated T lymphocytes of both the T4 and T8 subsets, as well as on T cell lines and clones, but only weakly on a fraction of resting T cells. SDS-PAGE analysis of immunoprecipitates from 125I-labeled, activated T cells demonstrates a single major band of apparent m.w. 105 KD under both reducing and nonreducing conditions. Unlike anti-IL 2 receptor antibodies, anti-Ta1 does not inhibit T cell proliferative responses to mitogen, antigen, or IL 2-containing medium. Moreover, anti-Ta1 has no effect on T cell-mediated cytotoxicity. Ta1 appears to be a novel human T cell-specific activation antigen that may serve as a useful marker of T cell activation in human disease.
Cell-mediated immune response and Th/Th cytokine profile of B-T constructs of F1 and V antigen of Yersinia pestis.

PubMed

Gupta, G; Khan, A A; Rao, D N

2010-03-01

Yersinia pestis, a Gram-negative bacterium, is the etiological agent of pneumonic and bubonic plague and still active in various regions of the world. Because plague is highly infectious and can readily spread by aerosolization, it poses a bioterrorism threat. The effective induction of mucosal as well as systemic immunity is an important attribute of an improved vaccine for plague. An alternative approach described here is the use of protective epitopes derived from immunodominant antigens (F1 and V) of Yersinia pestis. As T-cell immunity is also a major contributor of protection, microencapsulated B-T constructs of F1 and V antigen were used to immunize outbred and inbred mice through intranasal route, and lympho-proliferative response and cytokine profile of both Th(1) and Th(2) arms were measured in spleen, lamina propria and Peyer's patches. Three B-T constructs of F1 antigen and seven of V antigen showed significantly high T-cell response in terms of inducing systemic as well as mucosal response when compared to constituent peptides. These ten conjugates showed Th(1) cytokine profile whereas rest of the conjugates showed mixed Th(1)/Th(2) response. Four conjugates of V antigen showed high level of IL-10 production. In present study, microencapsulated B-T constructs after intranasal immunization generated systemic as well as mucosal immune response in all three sites, which offers an alternative approach for plague vaccine.
Aqueous exposure to Aroclor 1254 modulates the mitogenic response of Atlantic salmon anterior kidney T-cells: indications of short- and long-term immunomodulation.

PubMed

Iwanowicz, Luke R; Lerner, Darren T; Blazer, Vicki S; McCormick, Stephen D

2005-05-15

Polychlorinated biphenyls (PCBs) exist as persistent organic pollutants in numerous river systems in the United States. Unfortunately, some of these rivers are sites of active Atlantic salmon restoration programs, and polychlorinated biphenyls have been implicated as ancillary factors contributing to failed salmon restoration. Here, we investigate the immediate and chronic effects of intermediate duration aqueous PCB exposure (1 or 10 microgL-1 Aroclor 1254) on the mitogen-stimulated lymphoproliferative response of Atlantic salmon anterior kidney leukocytes (AKLs). A short-term study was designed to examine immunomodulation in Atlantic salmon smolts immediately following 21 days of aqueous exposure, while a long-term study evaluated chronic impacts in the mitogen response in parr 15 months post-exposure as larvae. The proliferative response of AKLs to the mitogens concanavalin A (CON A), phytohemaglutinnin-P (PHA-P), pokeweed mitogen (PWM), and lipopolysaccharide were used as an indice of immunomodulation. The proliferative response to the T-cell mitogens CON A and PHA-P was significantly increased in the 10 microgL-1 group (n=10; P=0.043 and 0.002, respectively) immediately following exposure of smolts. Additionally, The PHA-P response was significantly increased in the 1 microgL-1 exposure group (n=10, P=0.036). In fish treated as larvae and tested 15 months later, the PHA-P sensitive populations exhibited elevated proliferation in the 1 and 10 microgL-1 groups (n=12, P<0.04) relative to the vehicle control while the PWM response was significantly increased (n=12, P=0.036) only in the 10 microgL-1 treated groups. These results demonstrate an immunomodulatory effect of PCBs on T-cell mitogen sensitive populations of lymphocytes in Atlantic salmon as well as long-term immunomodulation in PHA-P and PWM sensitive populations.
Aqueous exposure to Aroclor 1254 modulates the mitogenic response of Atlantic salmon anterior kidney T-cells: Indications of short- and long-term immunomodulation

USGS Publications Warehouse

Iwanowicz, L.R.; Lerner, D.T.; Blazer, V.S.; McCormick, S.D.

2005-01-01

Polychlorinated biphenyls (PCBs) exist as persistent organic pollutants in numerous river systems in the United States. Unfortunately, some of these rivers are sites of active Atlantic salmon restoration programs, and polychlorinated biphenyls have been implicated as ancillary factors contributing to failed salmon restoration. Here, we investigate the immediate and chronic effects of intermediate duration aqueous PCB exposure (1 or 10 ??g L-1 Aroclor 1254) on the mitogen-stimulated lymphoproliferative response of Atlantic salmon anterior kidney leukocytes (AKLs). A short-term study was designed to examine immunomodulation in Atlantic salmon smolts immediately following 21 days of aqueous exposure, while a long-term study evaluated chronic impacts in the mitogen response in parr 15 months post-exposure as larvae. The proliferative response of AKLs to the mitogens concanavalin A (CON A), phytohemaglutinnin-P (PHA-P), pokeweed mitogen (PWM), and lipopolysaccharide were used as an indice of immunomodulation. The proliferative response to the T-cell mitogens CON A and PHA-P was significantly increased in the 10 ??g L-1 group (n = 10; P = 0.043 and 0.002, respectively) immediately following exposure of smolts. Additionally, The PHA-P response was significantly increased in the 1 ??g L-1 exposure group (n = 10, P = 0.036). In fish treated as larvae and tested 15 months later, the PHA-P sensitive populations exhibited elevated proliferation in the 1 and 10 ??g L-1 groups (n = 12, P < 0.04) relative to the vehicle control while the PWM response was significantly increased (n = 12, P = 0.036) only in the 10 ??g L-1 treated groups. These results demonstrate an immunomodulatory effect of PCBs on T-cell mitogen sensitive populations of lymphocytes in Atlantic salmon as well as long-term immunomodulation in PHA-P and PWM sensitive populations. ?? 2005 Elsevier B.V. All rights reserved.
COMPARISON OF PROLIFERATIVE CAPACITY OF GENETICALLY-ENGINEERED PIG AND HUMAN CORNEAL ENDOTHELIAL CELLS

PubMed Central

Fujita, Minoru; Mehra, Ruhina; Lee, Seung Eun; Roh, Danny S.; Long, Cassandra; Funderburgh, James L.; Ayares, David L.; Cooper, David K. C.; Hara, Hidetaka

2013-01-01

Purpose The possibility of providing cultured corneal endothelial cells (CECs) for clinical transplantation has gained much attention. However, the worldwide need for human (h) donor corneas far exceeds supply. The pig (p) might provide an alternative source. The aim of this study was to compare the proliferative capacity of CECs from wild-type (WT) pigs, genetically-engineered (GE) pigs, and humans. Methods The following CECs were cultured – hCECs from donors (i) ≤36 years (young), (ii) ≥49 years (old), and WT pCECs from (iii) neonatal (<5 days), (iv) young (<2 months), and (v) old (>20 months) pigs, and CECs from young (vi) GE pigs (GTKO/CD46 and GTKO/CD46/CD55). Proliferative capacity of CECs was assessed by direct cell counting over 15 days of culture and by BrdU assay. Cell viability during culture was assessed by annexin V staining. The MTT assay assessed cell metabolic activity. Results There was significantly lower proliferative capacity of old CECs than of young CECs (p<0.01) in both pigs and humans. There was no significant difference in proliferative capacity/metabolic activity between young pCECs and young hCECs. However, there was a significantly higher percentage of cell death in hCECs compared to pCECs during culture (p<0.01). Young GE pCECs showed similar proliferative capacity/cell viability/metabolic activity to young WT pCECs. Conclusions Because of the greater availability of young pigs and the excellent proliferative capacity of cultured GE pCECs, GE pigs could provide a source of CECs for clinical transplantation. PMID:23258190

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.
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.
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
ESR1 mutations affect anti-proliferative responses to tamoxifen through enhanced cross-talk with IGF signaling.

PubMed

Gelsomino, Luca; Gu, Guowei; Rechoum, Yassine; Beyer, Amanda R; Pejerrey, Sasha M; Tsimelzon, Anna; Wang, Tao; Huffman, Kenneth; Ludlow, Andrew; Andò, Sebastiano; Fuqua, Suzanne A W

2016-06-01

The purpose of this study was to address the role of ESR1 hormone-binding mutations in breast cancer. Soft agar anchorage-independent growth assay, Western blot, ERE reporter transactivation assay, proximity ligation assay (PLA), coimmunoprecipitation assay, silencing assay, digital droplet PCR (ddPCR), Kaplan-Meier analysis, and statistical analysis. It is now generally accepted that estrogen receptor (ESR1) mutations occur frequently in metastatic breast cancers; however, we do not yet know how to best treat these patients. We have modeled the three most frequent hormone-binding ESR1 (HBD-ESR1) mutations (Y537N, Y537S, and D538G) using stable lentiviral transduction in human breast cancer cell lines. Effects on growth were examined in response to hormonal and targeted agents, and mutation-specific changes were studied using microarray and Western blot analysis. We determined that the HBD-ESR1 mutations alter anti-proliferative effects to tamoxifen (Tam), due to cell-intrinsic changes in activation of the insulin-like growth factor receptor (IGF1R) signaling pathway and levels of PIK3R1/PIK3R3. The selective estrogen receptor degrader, fulvestrant, significantly reduced the anchorage-independent growth of ESR1 mutant-expressing cells, while combination treatments with the mTOR inhibitor everolimus, or an inhibitor blocking IGF1R, and the insulin receptor significantly enhanced anti-proliferative responses. Using digital drop (dd) PCR, we identified mutations at high frequencies ranging from 12 % for Y537N, 5 % for Y537S, and 2 % for D538G in archived primary breast tumors from women treated with adjuvant mono-tamoxifen therapy. The HBD-ESR1 mutations were not associated with recurrence-free or overall survival in response in this patient cohort and suggest that knowledge of other cell-intrinsic factors in combination with ESR1 mutation status will be needed determine anti-proliferative responses to Tam.
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.
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
A Lipid Based Antigen Delivery System Efficiently Facilitates MHC Class-I Antigen Presentation in Dendritic Cells to Stimulate CD8+ T Cells

NASA Astrophysics Data System (ADS)

Maji, Mithun; Mazumder, Saumyabrata; Bhattacharya, Souparno; Choudhury, Somsubhra Thakur; Sabur, Abdus; Shadab, Md.; Bhattacharya, Pradyot; Ali, Nahid

2016-06-01

The most effective strategy for protection against intracellular infections such as Leishmania is vaccination with live parasites. Use of recombinant proteins avoids the risks associated with live vaccines. However, due to low immunogenicity, they fail to trigger T cell responses particularly of CD8+ cells requisite for persistent immunity. Previously we showed the importance of protein entrapment in cationic liposomes and MPL as adjuvant for elicitation of CD4+ and CD8+ T cell responses for long-term protection. In this study we investigated the role of cationic liposomes on maturation and antigen presentation capacity of dendritic cells (DCs). We observed that cationic liposomes were taken up very efficiently by DCs and transported to different cellular sites. DCs activated with liposomal rgp63 led to efficient presentation of antigen to specific CD4+ and CD8+ T cells. Furthermore, lymphoid CD8+ T cells from liposomal rgp63 immunized mice demonstrated better proliferative ability when co-cultured ex vivo with stimulated DCs. Addition of MPL to vaccine enhanced the antigen presentation by DCs and induced more efficient antigen specific CD8+ T cell responses when compared to free and liposomal antigen. These liposomal formulations presented to CD8+ T cells through TAP-dependent MHC-I pathway offer new possibilities for a safe subunit vaccine.
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
The pyrimidin analogue cyclopentenyl cytosine induces alloantigen-specific non-responsiveness of human T lymphocytes

PubMed Central

Nikolaeva, N; Bemelman, F J; Yong, S-L; Verschuur, A; van Lier, R A W; ten Berge, I J M

2008-01-01

Cyclopentenyl cytosine (CPEC) has been shown to induce apoptosis in human T lymphoblastic cell lines and T cells from leukaemia patients. In this study we have addressed the question of whether CPEC is able to decrease proliferation and effector functions of human alloresponsive T lymphocytes and induce T cell anergy. The proliferative capacity of human peripheral blood mononuclear cells in response to allogeneic stimulation was measured by 5,6-carboxy-succinimidyl-diacetate-fluorescein-ester staining. Flow cytometric analysis was performed using surface CD4, CD8, CD25, CD103 and intracellular perforin, granzyme A, granzyme B, caspase-3 and forkhead box P3 (FoxP3) markers. The in vivo immunosuppressive capacity was tested in a murine skin graft model. Addition of CPEC at a concentration of 20 nM strongly decreased the expansion and cytotoxicity of alloreactive T cells. Specific restimulation in the absence of CPEC showed that the cells became anergic. The drug induced caspase-dependent apoptosis of alloreactive T lymphocytes. Finally, CPEC increased the percentage of CD25high FoxP3+ CD4+ and CD103+ CD8+ T cells, and potentiated the effect of rapamycin in increasing the numbers of alloreactive regulatory T cells. Treatment with CPEC of CBA/CA mice transplanted with B10/Br skin grafts significantly prolonged graft survival. We conclude that CPEC inhibits proliferation and cytotoxicity of human alloreactive T cells and induces alloantigen non-responsiveness in vitro. PMID:18062797
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
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.
Cytokine-mediated induction of endothelial adhesion molecule and histocompatibility leukocyte antigen expression by cytomegalovirus-activated T cells.

PubMed Central

Waldman, W. J.; Knight, D. A.

1996-01-01

Cytomegalovirus (CMV) has been associated with allograft rejection and transplantation-associated arteriosclerosis. CMV infects endothelium, the interface between allograft tissue and the host immune system; however, mechanisms by which such interaction might exacerbate the rejection process remain unresolved. Here we test the hypothesis that host immune activity, triggered by CMV-infected graft endothelial cells (ECs), can result in the production of cytokines capable of enhancing the alloimmunogenicity of nearby uninfected endothelia. To model these phenomena in vitro, confluent monolayers of ECs derived from human umbilical vein or adult gonadal vein were incubated 5 days beneath trans-well culture inserts containing CMV-seropositive or CMV-seronegative donor-derived CD3+ or CD4+ T cells alone or in combination with CMV-infected or uninfected allogeneic ECs. The extent of T cell proliferation was determined by [3H]thymidine labeling of trans-well contents after transfer to microtiter plates. Endothelial responses to soluble factors elaborated by CMV-activated T cells were determined by immunohistochemical staining and immunofluorescence flow cytometric analysis of underlying EC monolayers. Results of experiments with CMV-seropositive donor-derived CD4+ T cells demonstrated enhancement of ICAM-1 and histocompatibility leukocyte antigen class I, as well as induction of histocompatibility leukocyte antigen DR on ECs incubated beneath T cell/EC/CMV trans-well co-cultures. Total (CD3+) T cells co-cultured with EC/CMV induced VCAM-1 as well. Furthermore, [3H]thymidine incorporation by these T cells indicated a strong proliferative response. Endothelial responses to T cells alone or in combination with uninfected ECs were minimal, and T cells cultured under these conditions showed little proliferative activity. Similarly, little or no endothelial responses were apparent in monolayers beneath trans-wells containing T cells isolated from CMV-seronegative individuals
T-cell antigenic sites involved in myasthenia gravis: correlations with antibody titre and disease severity.

PubMed

Berrih-Aknin, S; Cohen-Kaminsky, S; Lepage, V; Neumann, D; Bach, J F; Fuchs, S

1991-02-01

We have evaluated the ability of eight synthetic peptides corresponding to selected regions of the alpha-subunit from human (H) or Torpedo (T) acetylcholine receptor (AChR) to stimulate proliferative responses of peripheral blood lymphocytes (PBL) and thymic cells from patients with Myasthenia Gravis (MG) in comparison to healthy controls. Using PBL, two of the peptides were most reactive: in the 40 myasthenic patients tested, peptide 169-181 (H) induced significant proliferative responses in 10 patients and peptide 351-368 (H) in five, while there was no response in any of the 34 healthy controls tested. Interestingly, clear associations between proliferation to peptides and clinical data were observed. Indeed, among responding patients, all presented thymic hyperplasia and most showed a high anti-AChR Ab titre and/or a severe form of the disease. In addition, responses to AChR cytoplasmic sequences were observed only in severely affected patients. Correlation with HLA-DR haplotype, sought in a subgroup of patients, indicated that response to 169-181 (H) is associated with HLA-DR5 in the patients presenting a high anti-AChR antibody titre. Using thymic lymphocytes, few responses were obtained with the human peptides, suggesting that the frequency of autoreactive cells is lower than in the blood. Similar to PBL, responses to peptides were observed only with lymphocytes isolated from hyperplastic thymuses. The correlations observed between responses to peptides and clinical parameters underline the pathophysiological relevance of our data and indicate that pathogenic and nonpathogenic T-cell antigenic sites involved in the anti-AChR response could be identified by this approach.
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.
[Effect of low-intensity electromagnetic fields of industrial frequency on the ultrastructure and proliferative activity of rat's thymus cells].

PubMed

Zhitkevich, T I; Bokut', T B; Netukova, N I

2001-01-01

Effects of two types of low-intensity electromagnetic fields (EMF) of industrial frequency (50 Hz) on the fine structure and proliferative activity of thymic cells in white rats were studied. It was found that a weak EMF with a prevailing electrical component (380-480 V/m, 120-140 nT1) did not affect the DNA synthesis intensity. An EMF with a stronger magnetic induction (10-15 V/m, 800-1500 nT1) diminished the glucose-6-phosphate dehydrogenase activity and proliferative processes in cultured stimulated lymphocytes. Electron microscopic investigation of the thymus after both types of exposure revealed an accumulation of lymphocytes with pyknotic nuclei and electron-dense cytoplasm, as well as hypoplasia of the vascular endothelium. At the same time, EMF with a prevailing magnetic component produced a more marked negative effect on the ultrastructure of thymic cells, which indicated a lowered secretory activity of epitheliocytes.
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.
In Vitro Priming of Naı̈ve T-cells with p-Phenylenediamine and Bandrowski's Base.

PubMed

Gibson, Andrew; Kim, Seung-Hyun; Faulkner, Lee; Evely, Jane; Pirmohamed, Munir; Park, Kevin B; Naisbitt, Dean J

2015-10-19

p-Phenylenediamine (PPD) is a component of hair dye formulations that is associated with T-cell mediated allergic contact dermatitis. Antigen-specific T-cells from allergic contact dermatitis patients are activated with either PPD or the oxidation product, Bandrowski's base. In nonallergic individuals, T-cells that are activated by Bandrowski's base, but not by PPD, are readily detectable. The aim of the current study was to use an in vitro T-cell priming assay to assess the activation of memory and naı̈ve T-cells from healthy donors with PPD and Bandrowski's base, and to compare these responses to those observed from allergic patients. Both PPD and Bandrowski's base-responsive clones were generated from allergic patients. The majority of Bandrowski's base-responsive clones were CD4+ and displayed a lack of PPD reactivity. In contrast, CD4+ and CD8+ clones displaying PPD reactivity were detected. Approximately 25% of these displayed low levels of reactivity to Bandrowski's base. Clones from the allergic patients secreted a range of cytokines including IFN-γ, Il-13, and Il-22. In healthy donors, Bandrowski's base-specific T-cell proliferative responses and cytokine secretion were detected with both naı̈ve and memory T-cells. T-cell clones generated from the Bandrowski's base-responsive cultures responded to Bandrowski's base but not PPD. PPD-specific naı̈ve and memory T-cell responses were not detected from healthy donors. These data show that Bandrowski's base stimulates pre-existing memory T-cells isolated from healthy donors and primes naı̈ve T-cells when the chemical is bound to autologous dendritic cells. Priming naı̈ve T-cells against PPD failed, suggesting an important individual susceptibility factor is missing from the in vitro T-cell priming assay.
Human mesenchymal stem cells target adhesion molecules and receptors involved in T cell extravasation.

PubMed

Benvenuto, Federica; Voci, Adriana; Carminati, Enrico; Gualandi, Francesca; Mancardi, Gianluigi; Uccelli, Antonio; Vergani, Laura

2015-12-10

Systemic delivery of bone marrow-derived mesenchymal stem cells (MSC) seems to be of benefit in the treatment of multiple sclerosis (MS), an autoimmune disease of the central nervous system (CNS) sustained by migration of T cells across the brain blood barrier (BBB) and subsequent induction of inflammatory lesions into CNS. MSC have been found to modulate several effector functions of T cells. In this study, we investigated the effects of MSC on adhesion molecules and receptors on T cell surface that sustain their transendothelial migration. We used different co-culture methods combined with real-time PCR and flow cytometry to evaluate the expression both at the mRNA and at the plasma-membrane level of α4 integrin, β2 integrin, ICAM-1 and CXCR3. In parallel, we assessed if MSC are able to modulate expression of adhesion molecules on the endothelial cells that interact with T cells during their transendothelial migration. Our in vitro analyses revealed that MSC: (i) inhibit proliferation and activation of both peripheral blood mononuclear cells (PBMC) and CD3(+)-selected lymphocytes through the release of soluble factors; (ii) exert suppressive effects on those surface molecules highly expressed by activated lymphocytes and involved in transendothelial migration; (iii) inhibit CXCL10-driven chemotaxis of CD3(+) cells; (iv) down-regulated expression of adhesion molecules on endothelial cells. Taken together, these data demonstrate that the immunosuppressive effect of MSC does not exclusively depends on their anti-proliferative activity on T cells, but also on the impairment of leukocyte migratory potential through the inhibition of the adhesion molecules and receptors that are responsible for T cell trafficking across BBB. This could suggest a new mechanism through which MSC modulate T cell responses.
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
Anti-proliferative and mutagenic activities of aqueous and methanol extracts of leaves from Pereskia bleo (Kunth) DC (Cactaceae).

PubMed

Er, Hui Meng; Cheng, En-Hsiang; Radhakrishnan, Ammu Kutty

2007-09-25

The anti-proliferative effects of the aqueous and methanol extracts of leaves of Pereskia bleo (Kunth) DC (Cactaceae) against a mouse mammary cancer cell line (4T1) and a normal mouse fibroblast cell line (NIH/3T3) were evaluated under an optimal (in culture medium containing 10% foetal bovine serum (FBS)) and a sub-optimal (in culture medium containing 0.5% FBS) conditions. Under the optimal condition, the aqueous extract showed a significant (p<0.05) anti-proliferative effect at 200 microg/mL and 300 microg/mL in 4T1 cells and 300 microg/mL in NIH/3T3 cells, whereas the methanol extract did not show any notable anti-proliferative effect in these cell lines, at any of the concentrations tested. Under the sub-optimal condition, the aqueous extract showed a significant (p<0.05) anti-proliferative effect at 200 microg/mL and 300 microg/mL in NIH/3T3 cells, whilst the methanol extract showed a significant (p<0.05) anti-proliferative effect at 200 microg/mL and 300 microg/mL in both cell lines. An upward trend of apoptosis was observed in both 4T1 and NIH/3T3 cells treated with increasing concentrations of the aqueous extract. The level of apoptosis observed at all the concentrations of the aqueous extract tested was consistently higher than necrosis. There was a significant (p<0.05) increase in the level of necrosis observed in the 4T1 cells treated with 300 microg/mL of the methanol extract. Generally, the level of necrosis was noted to be higher than that of apoptosis in the methanol extract-treated cells. The mutagenicity assay performed showed that in the absence of S-9 liver metabolic activation, the extract was not mutagenic up to the concentration of 165 microg/mL . However, in the presence of S-9 liver metabolic activation, the aqueous extract was mutagenic at all the concentrations tested. This study shows that both the aqueous and methanol extracts of the leaves from Pereskia bleo (Kunth) DC (Cactaceae) do not have appreciable anti-proliferative effect on

Split T-cell tolerance in herpes simplex virus-infected mice and its implication for anti-viral immunity.

PubMed Central

Nash, A A; Ashford, N P

1982-01-01

Mice simultaneously injected intravenously and subcutaneously with herpes simplex virus fail to adoptively transfer delayed hypersensitivity (DH) to syngeneic recipients. The transferred lymph node cells also failed to rapidly eliminate infectious herpes from the pinna, despite the presence of cytotoxic T cells in the transferred suspension. Both primary and secondary cytotoxic cell responses in the draining lymph node were unaffected by the inhibition of DH. The lymph nodes from DH tolerized mice also contain lymphocytes capable of undergoing a proliferative response in vitro to herpes antigens. In addition, a neutralizing antibody response with IgG antibodies against herpes are also present in DH tolerized mice. These data suggest a form of split T-cell tolerance in which only DH responses are directly compromised. The implication of these findings for the pathogenesis of herpes simplex virus is discussed. PMID:6279490
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
Functional classification of memory CD8(+) T cells by CX3CR1 expression.

PubMed

Böttcher, Jan P; Beyer, Marc; Meissner, Felix; Abdullah, Zeinab; Sander, Jil; Höchst, Bastian; Eickhoff, Sarah; Rieckmann, Jan C; Russo, Caroline; Bauer, Tanja; Flecken, Tobias; Giesen, Dominik; Engel, Daniel; Jung, Steffen; Busch, Dirk H; Protzer, Ulrike; Thimme, Robert; Mann, Matthias; Kurts, Christian; Schultze, Joachim L; Kastenmüller, Wolfgang; Knolle, Percy A

2015-09-25

Localization of memory CD8(+) T cells to lymphoid or peripheral tissues is believed to correlate with proliferative capacity or effector function. Here we demonstrate that the fractalkine-receptor/CX3CR1 distinguishes memory CD8(+) T cells with cytotoxic effector function from those with proliferative capacity, independent of tissue-homing properties. CX3CR1-based transcriptome and proteome-profiling defines a core signature of memory CD8(+) T cells with effector function. We find CD62L(hi)CX3CR1(+) memory T cells that reside within lymph nodes. This population shows distinct migration patterns and positioning in proximity to pathogen entry sites. Virus-specific CX3CR1(+) memory CD8(+) T cells are scarce during chronic infection in humans and mice but increase when infection is controlled spontaneously or by therapeutic intervention. This CX3CR1-based functional classification will help to resolve the principles of protective CD8(+) T-cell memory.
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.
Pupillary responses in non-proliferative diabetic retinopathy.

PubMed

Park, Jason C; Chen, Yi-Fan; Blair, Norman P; Chau, Felix Y; Lim, Jennifer I; Leiderman, Yannek I; Shahidi, Mahnaz; McAnany, J Jason

2017-03-23

The goal of this study was to determine the extent of rod-, cone-, and melanopsin-mediated pupillary light reflex (PLR) abnormalities in diabetic patients who have non-proliferative diabetic retinopathy (NPDR). Fifty diabetic subjects who have different stages of NPDR and 25 age-equivalent, non-diabetic controls participated. PLRs were measured in response to full-field, brief-flash stimuli under conditions that target the rod, cone, and intrinsically-photosensitive (melanopsin) retinal ganglion cell pathways. Pupil responses were compared among the subjects groups using age-corrected linear mixed models. Compared to control, the mean baseline pupil diameters were significantly smaller for all patient groups in the dark (all p < 0.001) and for the moderate-severe NPDR group in the light (p = 0.003). Pairwise comparisons indicated: (1) the mean melanopsin-mediated PLR was significantly reduced in the mild and moderate-severe groups (both p < 0.001); (2) the mean cone-mediated PLR was reduced significantly in the moderate-severe group (p = 0.008); (3) no significant differences in the mean rod-mediated responses. The data indicate abnormalities in NPDR patients under conditions that separately assess pupil function driven by different photoreceptor classes. The results provide evidence for compromised neural function in these patients and provide a promising approach for quantifying their neural abnormalities.
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
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.
Proliferative capability of parietal and zymogen cells.

PubMed Central

Chen, K Y; Withers, H R

1975-01-01

Six to eight week old male mice of C3Hf/Bu strain were killed and studied at various times from 30 minutes to 30 days after tritiated thymidine (3H-TdR) injection. Labelling of parietal and zymogen cells was observed in autoradiographic histological specimens. There were 590 +/- 22 gastric glands per circumference at the body of the stomach. Parietal cells were counted as 16-2 (14-0-18-4) per gland or 9600 per circumference. There were 11-4 (9-4-13-7) zymogen cells per gland or 6700 per circumference. Two labelled immature parietal cells per circumference were seen 30 minutes after 3H-TdR injection, equivalent to a ratio of 1:5000; more mature labelled parietal cells were seen at later times up to 30 days. There was evidence for proliferation during maturation and downward migration of cells toward the body and the lower part of the gastric gland. Our data support earlier evidence that immature parietal cells constantly supply mature parietal cells through migration from a proliferative zone. Whether the parietal cells are derived from the same stem cell compartment as surface epithelium cells is unclear at the present time. An average of 2-6 zymogen cells per circumference, or 1:2500, was found to be labelled. While most zymogen cells were not proliferating, cells entered the proliferating cycle at random. Based on the findings reported in this paper and the radiation responses of both parietal and zymogen cells, it is postulated that they form part of a slow renewal system. Images Fig. 1 (cont.) Fig. 1 (cont.) Fig. 1 (cont.) Fig. 1 Fig. 2 (cont.) Fig. 2 (cont.) Fig. 2 PMID:1213947
Generation and application of human induced-stem cell memory T (iTSCM ) cells for adoptive immunotherapy.

PubMed

Kondo, Taisuke; Imura, Yuuki; Chikuma, Shunsuke; Hibino, Sana; Omata-Mise, Setsuko; Ando, Makoto; Akanuma, Takashi; Iizuka, Mana; Sakai, Ryota; Morita, Rimpei; Yoshimura, Akihiko

2018-05-23

Adoptive T cell therapy is an effective strategy for cancer immunotherapy. However, infused T cells frequently become functionally exhausted, and consequently offer a poor prognosis after transplantation into patients. Adoptive transfer of tumor antigen-specific stem cell memory T (T SCM ) cells is expected to overcome this shortcoming since T SCM cells are close to naïve T cells, but are also highly proliferative, long-lived, and produce a large number of effector T cells in response to antigen stimulation. We previously reported that activated effector T cells can be converted into T SCM -like cells (iT SCM ) by co-culturing with OP9 cells expressing Notch ligand, Delta-like 1 (OP9-hDLL1). Here we show the methodological parameters of human CD8 + iT SCM cell generation and their application to adoptive cancer immunotherapy. Regardless of the stimulation by anti-CD3/CD28 antibodies or by antigen-presenting cells, human iT SCM cells were more efficiently induced from central memory type T cells than from effector memory T cells. During the induction phase by co-culture with OP9-hDLL1 cells, IL-7 and IL-15 (but not IL-2 or IL-21) could efficiently generate iT SCM cells. Epstein Barr (EB) virus-specific iT SCM cells showed much stronger antitumor potentials than conventionally activated T cells did in humanized EB virus transformed-tumor model mice. Thus, adoptive T cell therapy with iT SCM offers a promising therapeutic strategy for cancer immunotherapy. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
The Transcription Factor T-Bet Is Regulated by MicroRNA-155 in Murine Anti-Viral CD8+ T Cells via SHIP-1.

PubMed

Hope, Jennifer L; Stairiker, Christopher J; Spantidea, Panagiota I; Gracias, Donald T; Carey, Alison J; Fike, Adam J; van Meurs, Marjan; Brouwers-Haspels, Inge; Rijsbergen, Laurine C; Fraietta, Joseph A; Mueller, Yvonne M; Klop, Rosemarieke C; Stelekati, Erietta; Wherry, E John; Erkeland, Stefan J; Katsikis, Peter D

2017-01-01

We report here that the expression of the transcription factor T-bet, which is known to be required for effector cytotoxic CD8 + T lymphocytes (CTL) generation and effector memory cell formation, is regulated in CTL by microRNA-155 (miR-155). Importantly, we show that the proliferative effect of miR-155 on CD8 + T cells is mediated by T-bet. T-bet levels in CTL were controlled in vivo by miR-155 via SH2 (Src homology 2)-containing inositol phosphatase-1 (SHIP-1), a known direct target of miR-155, and SHIP-1 directly downregulated T-bet. Our studies reveal an important and unexpected signaling axis between miR-155, T-bet, and SHIP-1 in in vivo CTL responses and suggest an important signaling module that regulates effector CTL immunity.
Effects of vitamin K3 and K5 on proliferation, cytokine production, and regulatory T cell-frequency in human peripheral-blood mononuclear cells.

PubMed

Hatanaka, Hiroshige; Ishizawa, Hitomi; Nakamura, Yurie; Tadokoro, Hiroko; Tanaka, Sachiko; Onda, Kenji; Sugiyama, Kentaro; Hirano, Toshihiko

2014-03-18

The effects of vitamin K (VK) derivatives VK3 and VK5 on human immune cells have not been extensively investigated. We examined the effects of VK3 and VK5 on proliferation, apoptosis, cytokine production, and CD4+CD25+Foxp3+ regulatory T (Treg) cell-frequency in human peripheral blood mononuclear cells (PBMCs) activated by T cell mitogen in vitro. Anti-proliferative effects of VK3 and VK5 on T-cell mitogen activated PBMCs were assessed by WST assay procedures. Apoptotic cells were determined as Annexin V positive/propidium iodide (PI) negative cells. Cytokine concentrations in the supernatant of the culture medium were measured with bead-array procedures followed by analysis with flow cytometry. The CD4+CD25+Foxp3+Treg cells in mitogen-activated PBMCs were stained with fluorescence-labeled specific antibodies followed by flow cytometry. VK3 and VK5 suppressed the mitogen-activated proliferation of PBMCs significantly at 10-100μM (p<0.05). The data also suggest that VK3 and VK5 promote apoptosis in the mitogen-activated T cells. VK3 and VK5 significantly inhibited the production of tumor necrosis factor (TNF) α, interleukin (IL)-4, -6, and -10 from the activated PBMCs at 10-100μM (p<0.05). In contrast, VK3 and VK5 significantly increased Treg cell-frequency in the activated PBMCs at concentrations more than 10μM (p<0.001). Our data suggest that VK3 and VK5 attenuate T cell mediated immunity by inhibiting the proliferative response and inducing apoptosis in activated T cells. Copyright © 2014 Elsevier Inc. All rights reserved.
In vitro stimulation of rabbit T lymphocytes by cells expressing herpes simplex antigens.

PubMed

Kapoor, A K; Ling, N R; Nash, A A; Bachan, A; Wildy, P

1982-04-01

Lymphocyte stimulation responses to herpes antigens were studied using virus-infected X-irradiated cells. Rabbits were immunized with herpes simplex virus type 1 (strain HFEM) grown in RK 13 cells. For in vitro stimulation assay BHK21 cells were X-irradiated (15 000 rad) and infected with a high m.o.i. of a temperature-sensitive (ts) mutant (N102) of HFEM strain at the non-permissive temperature (38.5 degrees C) of virus. Virus antigens were expressed on the infected cells and there was no leakage of infectious virus into the medium at 38.5 degrees C. T lymphocytes from rabbits immunized with herpes simplex virus were specifically activated by herpesvirus-infected X-irradiated cells; lymph node cells from rabbits immunized with RK13 cells and from non-immune rabbits showed no proliferative response.
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
Environmental modulation of autoimmune arthritis involves the spontaneous microbial induction of T cell responses to regulatory determinants within heat shock protein 65.

PubMed

Moudgil, K D; Kim, E; Yun, O J; Chi, H H; Brahn, E; Sercarz, E E

2001-03-15

Both genetic and environmental factors are believed to be involved in the induction of autoimmune diseases. Adjuvant arthritis (AA) is inducible in susceptible rat strains by injection of Mycobacterium tuberculosis, and arthritic rats raise T cell responses to the 65-kDa mycobacterial heat-shock protein (Bhsp65). We observed that Fischer 344 (F344) rats raised in a barrier facility (BF-F344) are susceptible to AA, whereas F344 rats maintained in a conventional facility (CV-F344) show significantly reduced incidence and severity of AA, despite responding well to the arthritogenic determinant within Bhsp65. The acquisition of protection from AA can be circumvented if rats are maintained on neomycin/acidified water. Strikingly, naive unimmunized CV-F344 rats but not BF-F344 rats raised T cell responses to Bhsp65 C-terminal determinants (BCTD) (we have previously shown that BCTD are involved in regulation of acute AA in the Lewis rat); however, T cells of naive CV-F344 and BF-F344 gave a comparable level of proliferative response to a mitogen, but no response at all to an irrelevant Ag. Furthermore, adoptive transfer into naive BF-F344 rats of splenic cells of naive CV-F344 rats (restimulated with BCTD in vitro) before induction of AA resulted in a considerably reduced severity of AA. These results suggest that spontaneous (inadvertent) priming of BCTD-reactive T cells, owing to determinant mimicry between Bhsp65 and its homologues in microbial agents in the conventional environment, is involved in modulating the severity of AA in CV-F344 rats. These results have important implications in broadening understanding of the host-microbe interaction in human autoimmune diseases.
Inhibition of T cell-mediated functions by MVM(i), a parvovirus closely related to minute virus of mice.

PubMed

Engers, H D; Louis, J A; Zubler, R H; Hirt, B

1981-12-01

A purified preparation of MVM(i), a murine parvovirus closely related to minute virus of mice (MVM), was found to inhibit various functions mediated by murine T cells in vitro. Addition of MVM(i) virus to secondary allogeneic mixed leukocyte cultures resulted in the inhibition of both lymphocyte proliferation (3H-thymidine incorporation) and the generation of cytolytic T lymphocyte activity but not interferon production. MVM(i) virus also inhibited the growth and cytolytic activity of several cloned, long-term Lyt-2+ cytolytic T cell lines. Furthermore, the antigen-induced proliferative responses of parasite- (Leishmania) specific Lyt-1+ T cells in vitro was abrogated by the addition of MVM(i) virus to the culture. Finally, the suppression of an in vitro antibody response to SRBC by MVM(i) virus was the result of the inhibition of T helper cells required for the B cell response. These suppressive effects were specific for MVM(i); parallel studies in which the prototype MVM parvovirus was used showed no significant inhibition in the various systems tested.
Immunization of Cattle by Infection with Cowdria ruminantium Elicits T Lymphocytes That Recognize Autologous, Infected Endothelial Cells and Monocytes†

PubMed Central

Mwangi, Duncan M.; Mahan, Suman M.; Nyanjui, John K.; Taracha, Evans L. N.; McKeever, Declan J.

1998-01-01

Peripheral blood mononuclear cells (PBMC) from immune cattle proliferate in the presence of autologous Cowdria ruminantium-infected endothelial cells and monocytes. Endothelial cells required treatment with T-cell growth factors to induce class II major histocompatibility complex expression prior to infection and use as stimulators. Proliferative responses to both infected autologous endothelial cells and monocytes were characterized by expansion of a mixture of CD4+, CD8+, and γδ T cells. However, γδ T cells dominated following several restimulations. Reverse transcription-PCR analysis of cytokine expression by C. ruminantium-specific T-cell lines and immune PBMC revealed weak interleukin-2 (IL-2), IL-4, and gamma interferon (IFN-γ) transcripts at 3 to 24 h after stimulation. Strong expression of IFN-γ, tumor necrosis factor alpha (TNF-α), TNF-β, and IL-2 receptor α-chain mRNA was detected in T-cell lines 48 h after antigen stimulation. Supernatants from these T-cell cultures contained IFN-γ protein. Our findings suggest that in immune cattle a C. ruminantium-specific T-cell response is induced and that infected endothelial cells and monocytes may present C. ruminantium antigens to specific T lymphocytes in vivo during infection and thereby play a role in induction of protective immune responses to the pathogen. PMID:9573061
FoxP3+ CD25+ CD8+ T-Cell Induction during Primary Simian Immunodeficiency Virus Infection in Cynomolgus Macaques Correlates with Low CD4+ T-Cell Activation and High Viral Load▿

PubMed Central

Karlsson, Ingrid; Malleret, Benoît; Brochard, Patricia; Delache, Benoît; Calvo, Julien; Le Grand, Roger; Vaslin, Bruno

2007-01-01

The early immune response fails to prevent the establishment of chronic human immunodeficiency virus (HIV) infection but may influence viremia during primary infection, thereby possibly affecting long-term disease progression. CD25+ FoxP3+ regulatory T cells may contribute to HIV/simian immunodeficiency virus (SIV) pathogenesis by suppressing efficient antiviral responses during primary infection, favoring high levels of viral replication and the establishment of chronic infection. In contrast, they may decrease immune activation during chronic infection. CD4+ regulatory T cells have been studied in the most detail, but CD8+ CD25+ FoxP3+ T cells also have regulatory properties. We monitored the dynamics of CD25+ FoxP3+ T cells during primary and chronic SIVmac251 infection in cynomolgus macaques. The number of peripheral CD4+ CD25+ FoxP3+ T cells paralleled that of memory CD4+ T cells, with a rapid decline during primary infection followed by a rebound to levels just below baseline and gradual depletion during the course of infection. No change in the proportion of CD25+ FoxP3+ T cells was observed in peripheral lymph nodes. A small number of CD4+ CD25+ FoxP3+ T cells at set point was associated with a high plasma viral load. In contrast, peripheral CD8+ CD25+ FoxP3+ T cells were induced a few days after peak plasma viral load during primary infection. The number of these cells was positively correlated with viral load and negatively correlated with CD4+ T-cell activation, SIV antigen-specific proliferative responses during primary infection, and plasma viral load at set point, with large numbers of CD8+ CD25+ FoxP3+ T cells being indicative of a poor prognosis. PMID:17898053
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.
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.
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

Increased B7-H1 expression on dendritic cells correlates with programmed death 1 expression on T cells in simian immunodeficiency virus-infected macaques and may contribute to T cell dysfunction and disease progression.

PubMed

Xu, Huanbin; Wang, Xiaolei; Pahar, Bapi; Moroney-Rasmussen, Terri; Alvarez, Xavier; Lackner, Andrew A; Veazey, Ronald S

2010-12-15

Suppression of dendritic cell (DC) function in HIV-1 infection is thought to contribute to inhibition of immune responses and disease progression, but the mechanism of this suppression remains undetermined. Using the rhesus macaque model, we show B7-H1 (programmed death [PD]-L1) is expressed on lymphoid and mucosal DCs (both myeloid DCs and plasmacytoid DCs), and its expression significantly increases after SIV infection. Meanwhile, its receptor, PD-1, is upregulated on T cells in both peripheral and mucosal tissues and maintained at high levels on SIV-specific CD8(+) T cell clones in chronic infection. However, both B7-H1 and PD-1 expression in SIV controllers was similar to that of controls. Expression of B7-H1 on both peripheral myeloid DCs and plasmacytoid DCs positively correlated with levels of PD-1 on circulating CD4(+) and CD8(+) T cells, viremia, and declining peripheral CD4(+) T cell levels in SIV-infected macaques. Importantly, blocking DC B7-H1 interaction with PD-1(+) T cells could restore SIV-specific CD4(+) and CD8(+) T cell function as evidenced by increased cytokine secretion and proliferative capacity. Combined, the results indicate that interaction of B7-H1-PD-1 between APCs and T cells correlates with impairment of CD4(+) Th cells and CTL responses in vivo, and all are associated with disease progression in SIV infection. Blockade of this pathway may have therapeutic implications for HIV-infected patients.
Suboptimal T-cell receptor signaling compromises protein translation, ribosome biogenesis, and proliferation of mouse CD8 T cells.

PubMed

Tan, Thomas C J; Knight, John; Sbarrato, Thomas; Dudek, Kate; Willis, Anne E; Zamoyska, Rose

2017-07-25

Global transcriptomic and proteomic analyses of T cells have been rich sources of unbiased data for understanding T-cell activation. Lack of full concordance of these datasets has illustrated that important facets of T-cell activation are controlled at the level of translation. We undertook translatome analysis of CD8 T-cell activation, combining polysome profiling and microarray analysis. We revealed that altering T-cell receptor stimulation influenced recruitment of mRNAs to heavy polysomes and translation of subsets of genes. A major pathway that was compromised, when TCR signaling was suboptimal, was linked to ribosome biogenesis, a rate-limiting factor in both cell growth and proliferation. Defective TCR signaling affected transcription and processing of ribosomal RNA precursors, as well as the translation of specific ribosomal proteins and translation factors. Mechanistically, IL-2 production was compromised in weakly stimulated T cells, affecting the abundance of Myc protein, a known regulator of ribosome biogenesis. Consequently, weakly activated T cells showed impaired production of ribosomes and a failure to maintain proliferative capacity after stimulation. We demonstrate that primary T cells respond to various environmental cues by regulating ribosome biogenesis and mRNA translation at multiple levels to sustain proliferation and differentiation.
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
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.
Infection of human T lymphotropic virus-I-specific immune T cell clones by human T lymphotropic virus-I.

PubMed Central

Mitsuya, H; Jarrett, R F; Cossman, J; Cohen, O J; Kao, C S; Guo, H G; Reitz, M S; Broder, S

1986-01-01

Human T lymphotropic virus-I (HTLV-I)-specific T cell lines were established and cloned. K5, an OKT8+ clone bearing multiple proviral integration sites, retained its HTLV-I-specific cytotoxicity and a normal dependence on interleukin 2 (IL-2), indicating that there is a finite number of transforming integration sites. R2, an OKT4+ HTLV-I-infected clone, initially mounted a proliferative response to HTLV-I; but then its IL-2-independent proliferation increased and the antigen specificity was lost. All HTLV-I-infected clones tested including K7, another OKT8+ transformed cytotoxic clone that had lost its reactivity, expressed comparable levels of T cell receptor beta-chain (TCR-beta) messenger (m)RNA. Although clones K5 and K7 had different functional properties, they had the same rearrangement of the TCR-beta gene, suggesting that they had the same clonal origin. These data indicate that HTLV-I-specific T cells retain their immune reactivity for variable periods of time following infection, but then usually lose it; in some cases, however, no alteration in function can be detected. The data also suggest that different consequences can take place in the same clone depending on the pattern of retroviral infection. Images PMID:2877011
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
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.
Radiosensitization by PARP Inhibition in DNA Repair Proficient and Deficient Tumor Cells: Proliferative Recovery in Senescent Cells

PubMed Central

Alotaibi, Moureq; Sharma, Khushboo; Saleh, Tareq; Povirk, Lawrence F.; Hendrickson, Eric A.; Gewirtz, David A.

2016-01-01

Radiotherapy continues to be a primary modality in the treatment of cancer. DNA damage induced by radiation can promote apoptosis as well as both autophagy and senescence, where autophagy and senescence can theoretically function to prolong tumor survival. A primary aim of this work was to investigate the hypothesis that autophagy and/or senescence could be permissive for DNA repair, thereby facilitating tumor cell recovery from radiation-induced growth arrest and/or cell death. In addition, studies were designed to elucidate the involvement of autophagy and senescence in radiation sensitization by PARP inhibitors and the re-emergence of a proliferating tumor cell population. In the context of this work, the relationship between radiation-induced autophagy and senescence was also determined. Studies were performed using DNA repair proficient HCT116 colon carcinoma cells and a repair deficient Ligase IV (−/−) isogenic cell line. Irradiation promoted a parallel induction of autophagy and senescence that was strongly correlated with the extent of persistent H2AX phosphorylation in both cell lines; however inhibition of autophagy failed to suppress senescence, indicating that the two responses were dissociable. Irradiation resulted in a transient arrest in the HCT116 cells while arrest was prolonged in the Ligase IV (−/−) cells; however, both cell lines ultimately recovered proliferative function, which may reflect maintenance of DNA repair capacity. The PARP inhibitors (Olaparib) and (Niraparib) increased the extent of persistent DNA damage induced by radiation as well as the extent of both autophagy and senescence; neither cell line underwent significant apoptosis by radiation alone or in the presence of the PARP inhibitors. Inhibition of autophagy failed to attenuate radiation sensitization, indicating that autophagy was not involved in the action of the PARP inhibitors. As with radiation alone, despite sensitization by PARP inhibition, proliferative
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
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
Memory T cell proliferative responses and IFN-γ productivity sustain long-lasting efficacy of a Cap-based PCV2 vaccine upon PCV2 natural infection and associated disease.

PubMed

Ferrari, Luca; Borghetti, Paolo; De Angelis, Elena; Martelli, Paolo

2014-04-16

Porcine circovirus type 2 (PCV2) vaccination represents an important measure to cope with PCV2 infection; however, data regarding the modulation of the immune cell compartment are still limited, especially under field conditions. This study is aimed at investigating the features of the cellular immune response in conventional piglets induced by vaccination using a capsid (Cap) protein-based PCV2 vaccine compared to unvaccinated animals when exposed to PCV2 natural infection. Immune reactivity was evaluated by quantifying peripheral cell subsets involved in the anti-viral response and characterizing the interferon-gamma (IFN-γ) secreting cell (SC) responsiveness both in vivo and upon in vitro whole PCV2 recall. The vaccination triggered an early and intense IFN-γ secreting cell response and induced the activation of peripheral lymphocytes. The early increase of IFN-γ SC frequencies resulted in a remarkable and transient tendency to increased IFN-γ productivity in vaccinated pigs. In vaccinated animals, soon before the onset of infection occurred 15-16 weeks post-vaccination, the recalled PCV2-specific immune response was characterized by moderate PCV2-specific IFN-γ secreting cell frequencies and augmented productivity together with reactive CD4+CD8+ memory T cells. Conversely, upon infection, unvaccinated animals showed very high frequencies of IFN-γ secreting cells and a tendency to lower productivity, which paralleled with effector CD4-CD8+ cytotoxic cell responsiveness. The study shows that PCV2 vaccination induces a long-lasting immunity sustained by memory T cells and IFN-γ secreting cells that potentially played a role in preventing the onset of infection; the extent and duration of this reactivity can be an important feature for evaluating the protective immunity induced by vaccination.
Memory T cell proliferative responses and IFN-γ productivity sustain long-lasting efficacy of a Cap-based PCV2 vaccine upon PCV2 natural infection and associated disease

PubMed Central

2014-01-01

Porcine circovirus type 2 (PCV2) vaccination represents an important measure to cope with PCV2 infection; however, data regarding the modulation of the immune cell compartment are still limited, especially under field conditions. This study is aimed at investigating the features of the cellular immune response in conventional piglets induced by vaccination using a capsid (Cap) protein-based PCV2 vaccine compared to unvaccinated animals when exposed to PCV2 natural infection. Immune reactivity was evaluated by quantifying peripheral cell subsets involved in the anti-viral response and characterizing the interferon-gamma (IFN-γ) secreting cell (SC) responsiveness both in vivo and upon in vitro whole PCV2 recall. The vaccination triggered an early and intense IFN-γ secreting cell response and induced the activation of peripheral lymphocytes. The early increase of IFN-γ SC frequencies resulted in a remarkable and transient tendency to increased IFN-γ productivity in vaccinated pigs. In vaccinated animals, soon before the onset of infection occurred 15-16 weeks post-vaccination, the recalled PCV2-specific immune response was characterized by moderate PCV2-specific IFN-γ secreting cell frequencies and augmented productivity together with reactive CD4+CD8+ memory T cells. Conversely, upon infection, unvaccinated animals showed very high frequencies of IFN-γ secreting cells and a tendency to lower productivity, which paralleled with effector CD4–CD8+ cytotoxic cell responsiveness. The study shows that PCV2 vaccination induces a long-lasting immunity sustained by memory T cells and IFN-γ secreting cells that potentially played a role in preventing the onset of infection; the extent and duration of this reactivity can be an important feature for evaluating the protective immunity induced by vaccination. PMID:24735253
Phenotypic and Functional Alterations in Circulating Memory CD8 T Cells with Time after Primary Infection.

PubMed

Martin, Matthew D; Kim, Marie T; Shan, Qiang; Sompallae, Ramakrishna; Xue, Hai-Hui; Harty, John T; Badovinac, Vladimir P

2015-10-01

Memory CD8 T cells confer increased protection to immune hosts upon secondary viral, bacterial, and parasitic infections. The level of protection provided depends on the numbers, quality (functional ability), and location of memory CD8 T cells present at the time of infection. While primary memory CD8 T cells can be maintained for the life of the host, the full extent of phenotypic and functional changes that occur over time after initial antigen encounter remains poorly characterized. Here we show that critical properties of circulating primary memory CD8 T cells, including location, phenotype, cytokine production, maintenance, secondary proliferation, secondary memory generation potential, and mitochondrial function change with time after infection. Interestingly, phenotypic and functional alterations in the memory population are not due solely to shifts in the ratio of effector (CD62Llo) and central memory (CD62Lhi) cells, but also occur within defined CD62Lhi memory CD8 T cell subsets. CD62Lhi memory cells retain the ability to efficiently produce cytokines with time after infection. However, while it is was not formally tested whether changes in CD62Lhi memory CD8 T cells over time occur in a cell intrinsic manner or are due to selective death and/or survival, the gene expression profiles of CD62Lhi memory CD8 T cells change, phenotypic heterogeneity decreases, and mitochondrial function and proliferative capacity in either a lymphopenic environment or in response to antigen re-encounter increase with time. Importantly, and in accordance with their enhanced proliferative and metabolic capabilities, protection provided against chronic LCMV clone-13 infection increases over time for both circulating memory CD8 T cell populations and for CD62Lhi memory cells. Taken together, the data in this study reveal that memory CD8 T cells continue to change with time after infection and suggest that the outcome of vaccination strategies designed to elicit protective memory
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
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.
Interplay of macrophages and T cells in the lung vasculature.

PubMed

Gerasimovskaya, Evgenia; Kratzer, Adelheid; Sidiakova, Asya; Salys, Jonas; Zamora, Martin; Taraseviciene-Stewart, Laimute

2012-05-15

In severe pulmonary arterial hypertension (PAH), vascular lesions are composed of phenotypically altered vascular and inflammatory cells that form clusters or tumorlets. Because macrophages are found in increased numbers in intravascular and perivascular space in human PAH, here we address the question whether macrophages play a role in pulmonary vascular remodeling and whether accumulation of macrophages in the lung vasculature could be compromised by the immune system. We used the mouse macrophage cell line RAW 264.7 because these cells are resistant to apoptosis, have high proliferative capacity, and resemble cells in the plexiform lesions that tend to pile up instead of maintaining a monolayer. Cells were characterized by immunocytochemistry with cell surface markers (Lycopersicon Esculentum Lectin, CD117, CD133, FVIII, CD31, VEGFR-2, and S100). Activated, but not quiescent, T cells were able to suppress RAW 264.7 cell proliferative and migration activity in vitro. The carboxyfluorescein diacetate-labeled RAW 264.7 cells were injected into the naïve Sprague Dawley (SD) rat and athymic nude rat. Twelve days later, cells were found in the lung vasculature of athymic nude rats that lack functional T cells, contributing to vascular remodeling. No labeled RAW 264.7 cells were detected in the lungs of immune-competent SD rats. Our data demonstrate that T cells can inhibit in vitro migration and in vivo accumulation of macrophage-like cells.
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.
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.
Retinol induces morphological alterations and proliferative focus formation through free radical-mediated activation of multiple signaling pathways.

PubMed

Gelain, Daniel Pens; Pasquali, Matheus Augusto de Bittencourt; Caregnato, Fernanda Freitas; Castro, Mauro Antonio Alves; Moreira, José Claudio Fonseca

2012-04-01

Toxicity of retinol (vitamin A) has been previously associated with apoptosis and/or cell malignant transformation. Thus, we investigated the pathways involved in the induction of proliferation, deformation and proliferative focus formation by retinol in cultured Sertoli cells of rats. Sertoli cells were isolated from immature rats and cultured. The cells were subjected to a 24-h treatment with different concentrations of retinol. Parameters of oxidative stress and cytotoxicity were analyzed. The effects of the p38 inhibitor SB203580 (10 μmol/L), the JNK inhibitor SP600125 (10 μmol/L), the Akt inhibitor LY294002 (10 μmol/L), the ERK inhibitor U0126 (10 μmol/L) the pan-PKC inhibitor Gö6983 (10 μmol/L) and the PKA inhibitor H89 (1 μmol/L) on morphological and proliferative/transformation-associated modifications were studied. Retinol (7 and 14 μmol/L) significantly increases the reactive species production in Sertoli cells. Inhibition of p38, JNK, ERK1/2, Akt, and PKA suppressed retinol-induced [(3)H]dT incorporation into the cells, while PKC inhibition had no effect. ERK1/2 and p38 inhibition also blocked retinol-induced proliferative focus formation in the cells, while Akt and JNK inhibition partially decreased focus formation. ERK1/2 and p38 inhibition hindered transformation-associated deformation in retinol-treated cells, while other treatments had no effect. Our results suggest that activation of multiple kinases is responsible for morphological and proliferative changes associated to malignancy development in Sertoli cells by retinol at the concentrations higher than physiological level.
Differences In Early T-Cell Signaling In Cultures Grown In a Rotating Clinostat vs. Static Controls

NASA Technical Reports Server (NTRS)

Alexamder. M.; Nelman-Gonzales, M.; Penkala, J.; Sams, C.

1999-01-01

Altered gravity has previously been demonstrated to be a stress that can influence components of the immune system. Specifically, T-cell activation has been shown to be affected by changes in gravity, exhibiting a decrease in proliferative response to in vitro stimulation in microgravity. Subsequent ground based studies utilizing a rotating clinostat to model some of the effects of microgravity have been consistent with earlier flight based experiments. These ground and flight experiments have examined T-cell activation by measuring various responses including production of cytokines, DNA synthesis and the production of various cell surface activation markers. These indicators of T-cell activation were measured anywhere from 4 to 72 hours after stimulation. Prior to the work described here, the initial signaling events in T-cell activation had not been directly examined. The goal of this project was to determine how the process of early signal transduction was affected by growth in a rotating clinostat. Here we directly show a defect in signaling from TCR to MAPK in purified peripheral T-cells activated in the clinostat by OKT3/antiCD28 coated microbeads as compared to static controls.

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.
Acquisition of Pneumococci Specific Effector and Regulatory Cd4+ T Cells Localising within Human Upper Respiratory-Tract Mucosal Lymphoid Tissue

PubMed Central

Pido-Lopez, Jeffrey; Kwok, William W.; Mitchell, Timothy J.; Heyderman, Robert S.; Williams, Neil A.

2011-01-01

The upper respiratory tract mucosa is the location for commensal Streptococcus (S.) pneumoniae colonization and therefore represents a major site of contact between host and bacteria. The CD4+ T cell response to pneumococcus is increasingly recognised as an important mediator of immunity that protects against invasive disease, with data suggesting a critical role for Th17 cells in mucosal clearance. By assessing CD4 T cell proliferative responses we demonstrate age-related sequestration of Th1 and Th17 CD4+ T cells reactive to pneumococcal protein antigens within mucosal lymphoid tissue. CD25hi T cell depletion and utilisation of pneumococcal specific MHCII tetramers revealed the presence of antigen specific Tregs that utilised CTLA-4 and PDL-1 surface molecules to suppress these responses. The balance between mucosal effector and regulatory CD4+ T cell immunity is likely to be critical to pneumococcal commensalism and the prevention of unwanted pathology associated with carriage. However, if dysregulated, such responses may render the host more susceptible to invasive pneumococcal infection and adversely affect the successful implementation of both polysaccharide-conjugate and novel protein-based pneumococcal vaccines. PMID:22144893
The effect of burn injury on CD8+ and CD4+ T cells in an irradiation model of homeostatic proliferation.

PubMed

Buchanan, Ian B; Maile, Robert; Frelinger, Jeffrey A; Fair, Jeffrey H; Meyer, Anthony A; Cairns, Bruce A

2006-11-01

Homeostatic proliferation of T cells has recently been shown to be an important mechanism in the host response to infection. However, its role in the T cell response to burn injury is unknown. In this study, we examine the effect of burn injury on CD4+ and CD8+ T cell homeostatic proliferation after irradiation. Wild-type C57BL/6 female mice were irradiated with six grays ionizing radiation and 48 hours later, syngeneic whole splenocytes or purified CD4+ or CD8+ T cells labeled with carboxy-fluorescein diacetate, succinimidyl ester were adoptively transferred. Two days later, mice underwent a 20% burn injury, followed by splenocyte harvest 3 and 10 days after injury. Burn mice demonstrate increased splenic cellularity and CD8+ T cell proliferation after adoptive transfer of either purified CD8+ cells or whole spleen populations compared with unburned (sham) mice. In contrast, CD4+ T cell proliferation after burn injury is unchanged after adoptive transfer of whole spleen cells and drastically decreased after adoptive transfer of a purified CD4+ population compared with sham mice. Ten days after burn injury CD8+ T cells continue to demonstrate greater proliferation than CD4+ T cells. CD8+ T cells are more robust than CD4+ T cells in their proliferative response after burn injury. In addition, CD8+ T cell proliferation appears less reliant on other immune cells than purified CD4+ T cell proliferation. These data reiterate the importance of CD8+ T cells in the initial immune response to burn injury.
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.
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.
Multipotent Adult Progenitor Cells Suppress T Cell Activation in In Vivo Models of Homeostatic Proliferation in a Prostaglandin E2-Dependent Manner

PubMed Central

Carty, Fiona; Corbett, Jennifer M.; Cunha, João Paulo M. C. M.; Reading, James L.; Tree, Timothy I. M.; Ting, Anthony E.; Stubblefield, Samantha R.; English, Karen

2018-01-01

Lymphodepletion strategies are used in the setting of transplantation (including bone marrow, hematopoietic cell, and solid organ) to create space or to prevent allograft rejection and graft versus host disease. Following lymphodepletion, there is an excess of IL-7 available, and T cells that escape depletion respond to this cytokine undergoing accelerated proliferation. Moreover, this environment promotes the skew of T cells to a Th1 pro-inflammatory phenotype. Existing immunosuppressive regimens fail to control this homeostatic proliferative (HP) response, and thus the development of strategies to successfully control HP while sparing T cell reconstitution (providing a functioning immune system) represents a significant unmet need in patients requiring lymphodepletion. Multipotent adult progenitor cells (MAPC®) have the capacity to control T cell proliferation and Th1 cytokine production. Herein, this study shows that MAPC cells suppressed anti-thymocyte globulin-induced cytokine production but spared T cell reconstitution in a pre-clinical model of lymphodepletion. Importantly, MAPC cells administered intraperitoneally were efficacious in suppressing interferon-γ production and in promoting the expansion of regulatory T cells in the lymph nodes. MAPC cells administered intraperitoneally accumulated in the omentum but were not present in the spleen suggesting a role for soluble factors. MAPC cells suppressed lymphopenia-induced cytokine production in a prostaglandin E2-dependent manner. This study suggests that MAPC cell therapy may be useful as a novel strategy to target lymphopenia-induced pathogenic T cell responses in lymphodepleted patients. PMID:29740426
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
CCR4+T cell recruitment to the skin in mycosis fungoides: potential contributions by thymic stromal lymphopoietin and interleukin-16.

PubMed

Tuzova, Marina; Richmond, Jillian; Wolpowitz, Deon; Curiel-Lewandrowski, Clara; Chaney, Keri; Kupper, Thomas; Cruikshank, William

2015-02-01

Mycosis fungoides (MF) is characterized by skin accumulation of CCR4+CCR7- effector memory T cells; however the mechanism for their recruitment is not clearly identified. Thymic Stromal Lymphopoietin (TSLP) is a keratinocyte-derived cytokine that triggers Th2 immunity and is associated with T cell recruitment to the skin in atopic dermatitis. Interleukin-16 (IL-16) is a chemoattractant and growth factor for CD4+T cells. We hypothesized that TSLP and IL-16 could contribute to recruitment of malignant T cells in MF. We found elevated TSLP and IL-16 in very early stage patients' plasma and skin biopsies, prior to elevation in CCL22. Both TSLP and IL-16 induced migratory responses of CCR4+TSLPR+CD4+CCR7-CD31+cells, characteristic of malignant T cells in the skin. Co-stimulation also resulted in significant proliferative responses. We conclude that TSLP and IL-16, expressed at early stages of disease, function to recruit malignant T cells to the skin and contribute to their enhanced proliferation.
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
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.
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.
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
Plumbagin exerts an immunosuppressive effect on human T-cell acute lymphoblastic leukemia MOLT-4 cells

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

Bae, Kyoung Jun; Lee, Yura; Kim, Soon Ae

2016-04-22

Of the hematological disorders typified by poor prognoses and survival rates, T-cell acute lymphoblastic leukemia (T-ALL) is one of the most commonly diagnosed. Despite the development of new therapeutic agents, the treatment options for this cancer remain limited. In this manuscript, we investigated the anti-proliferative effects of plumbagin, mediated by the activation of mitogen-activated protein kinase (MAPK) pathways, and inhibition of NF-κB signaling; the human T-ALL MOLT-4 cell line was used as our experimental system. Plumbagin is a natural, plant derived compound, which exerts an anti-proliferative activity against many types of human cancer. Our experiments confirm that plumbagin induces a caspase-dependentmore » apoptosis of MOLT-4 cells, with no significant cytotoxicity seen for normal peripheral blood mononuclear cells (PBMCs). Plumbagin also inhibited LPS-induced phosphorylation of p65, and the transcription of NF-κB target genes. Our results now show that plumbagin is a potent inhibitor of the NF-κB signaling pathway, and suppressor of T-ALL cell proliferation. - Highlights: • Plumbagin induces caspase-dependent apoptosis in T-ALL MOLT-4 cells. • Plumbagin activates phosphorylation of stress-activated protein kinase (SAPK) JNK and p38. • Plumbagin inhibits LPS-mediated NF-κB signaling cascade. • Plumbagin inhibits LPS-mediated transcriptional activity of pro-inflammatory cytokines.« less
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
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
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.
Improving T Cell Expansion with a Soft Touch

PubMed Central

Lambert, Lester H.; Goebrecht, Geraldine K.E.; De Leo, Sarah E.; O’Connor, Roddy S.; Nunez-Cruz, Selene; Li, Tai-De; Yuan, Jinglun; Milone, Michael C.; Kam, Lance C.

2017-01-01

Protein-coated microbeads provide a consistent approach for activating and expanding populations of T cells for immunotherapy, but don’t fully capture the properties of antigen presenting cells. In this report, we enhance T cell expansion by replacing the conventional, rigid bead with a mechanically soft elastomer. Polydimethylsiloxane (PDMS) was prepared in a microbead format and modified with activating antibodies to CD3 and CD28. Three different formulations of PDMS provided an extended proliferative phase in both CD4+-only and mixed CD4+/CD8+ T cell preparations. CD8+ T cells retained cytotoxic function, as measured by a set of biomarkers (perforin production, LAMP2 mobilization, and IFN-γ secretion) and an in vivo assay of targeted cell killing. Notably, PDMS beads presented a nanoscale polymer structure and higher rigidity than associated with conventional bulk material. These data suggest T cells respond to this higher rigidity, indicating an unexpected effect of curing conditions. Together, these studies demonstrate that adopting mechanobiology ideas into the bead platform can provide new tools for T cell-based immunotherapy. PMID:28122453
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.
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.
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

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
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
Antigen targeting to antigen-presenting cells enhances presentation to class II-restricted T lymphocytes.

PubMed Central

Scardino, A; Paroli, M; De Petrillo, G; Michel, M L; Barnaba, V

1994-01-01

Receptor-mediated uptake increases by several orders of magnitude the efficiency of APC to internalize Ag, and is stringently required for the Ag-presenting function of T lymphocytes due to their inability to take up Ag non-specifically. We have previously reported that hepatitis B envelope antigen (HBenvAg) can be internalized by T cells via transferrin receptor (TfR). To evaluate if Ag targeting to receptors expressed on APC could be an effective tool for promoting Ag uptake and presentation, we tested the capacity of activated T cells not expressing TfR to induce HBenvAg-specific T-cell responses when pulsed with a hybrid particle containing HBenvAg coupled to gp120 of human immunodeficiency virus (HIV), exploiting the ability of gp120 to bind to CD4 receptor. We found that CD4+/TfR- T cells pulsed either with the hybrid particle or peptide (S193-207) but not with S, L Ag, a recombinant form of HBenvAg, induced a specific proliferative response of a T-cell clone recognizing peptide (S193-207) of HBenvAg. The finding that the addition of anti-CD4 monoclonal antibody (mAb) before the pulsing of CD4+/TfR- T cells with the hybrid particle drastically blocked the specific T-cell response, together with the finding that CD8+/TfR- T cells were unable to serve as APC even if pulsed with this molecule, demonstrated that CD4 receptor was crucial for the HBenvAg internalization. On the other hand, HBenvAg presentation by CD4+/TfR+ T cells pulsed with the hybrid particle was inhibited only when both anti-CD4 and anti-TfR were added before the pulsing. These results suggest that Ag targeting to APC receptors may be usefully exploited to improve Ag-presentation efficiency in potential immunotherapeutic approaches. PMID:7907575
CD8+ T Cell-Mediated Immunity during Trypanosoma cruzi Infection: A Path for Vaccine Development?

PubMed Central

dos Santos Virgilio, Fernando; Pontes, Camila; Dominguez, Mariana Ribeiro; Ersching, Jonatan; Rodrigues, Mauricio Martins; Vasconcelos, José Ronnie

2014-01-01

MHC-restricted CD8+ T cells are important during infection with the intracellular protozoan parasite Trypanosoma cruzi, the causative agent of Chagas disease. Experimental studies performed in the past 25 years have elucidated a number of features related to the immune response mediated by these T cells, which are important for establishing the parasite/host equilibrium leading to chronic infection. CD8+ T cells are specific for highly immunodominant antigens expressed by members of the trans-sialidase family. After infection, their activation is delayed, and the cells display a high proliferative activity associated with high apoptotic rates. Although they participate in parasite control and elimination, they are unable to clear the infection due to their low fitness, allowing the parasite to establish the chronic phase when these cells then play an active role in the induction of heart immunopathology. Vaccination with a number of subunit recombinant vaccines aimed at eliciting specific CD8+ T cells can reverse this path, thereby generating a productive immune response that will lead to the control of infection, reduction of symptoms, and reduction of disease transmission. Due to these attributes, activation of CD8+ T lymphocytes may constitute a path for the development of a veterinarian or human vaccine. PMID:25104879
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.
Regulation of gene expression in autoimmune disease loci and the genetic basis of proliferation in CD4+ effector memory T cells.

PubMed

Hu, Xinli; Kim, Hyun; Raj, Towfique; Brennan, Patrick J; Trynka, Gosia; Teslovich, Nikola; Slowikowski, Kamil; Chen, Wei-Min; Onengut, Suna; Baecher-Allan, Clare; De Jager, Philip L; Rich, Stephen S; Stranger, Barbara E; Brenner, Michael B; Raychaudhuri, Soumya

2014-06-01

Genome-wide association studies (GWAS) and subsequent dense-genotyping of associated loci identified over a hundred single-nucleotide polymorphism (SNP) variants associated with the risk of rheumatoid arthritis (RA), type 1 diabetes (T1D), and celiac disease (CeD). Immunological and genetic studies suggest a role for CD4-positive effector memory T (CD+ TEM) cells in the pathogenesis of these diseases. To elucidate mechanisms of autoimmune disease alleles, we investigated molecular phenotypes in CD4+ effector memory T cells potentially affected by these variants. In a cohort of genotyped healthy individuals, we isolated high purity CD4+ TEM cells from peripheral blood, then assayed relative abundance, proliferation upon T cell receptor (TCR) stimulation, and the transcription of 215 genes within disease loci before and after stimulation. We identified 46 genes regulated by cis-acting expression quantitative trait loci (eQTL), the majority of which we detected in stimulated cells. Eleven of the 46 genes with eQTLs were previously undetected in peripheral blood mononuclear cells. Of 96 risk alleles of RA, T1D, and/or CeD in densely genotyped loci, eleven overlapped cis-eQTLs, of which five alleles completely explained the respective signals. A non-coding variant, rs389862A, increased proliferative response (p=4.75 × 10-8). In addition, baseline expression of seventeen genes in resting cells reliably predicted proliferative response after TCR stimulation. Strikingly, however, there was no evidence that risk alleles modulated CD4+ TEM abundance or proliferation. Our study underscores the power of examining molecular phenotypes in relevant cells and conditions for understanding pathogenic mechanisms of disease variants.
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
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
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
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
Single blood transfusion induces the production of donor-specific alloantibodies and regulatory T cells mainly in the spleen

PubMed Central

Kitazawa, Yusuke; Sawanobori, Yasushi; Ueno, Takamasa; Ueha, Satoshi; Matsushima, Kouji; Matsuno, Kenjiro

2018-01-01

Abstract Donor-specific blood transfusion is known to induce alloresponses and lead to immunosuppression. We examined their underlying mechanisms by employing fully allogeneic rat combinations. Transfused recipients efficiently produced alloantibodies of the IgM and IgG subclasses directed against donor class I MHC. The recipients exhibited active expansion of CD4+ T cells and CD4+FOXP3+ regulatory T cells (Treg cells), followed by CD45R+ B cells and IgM+ or IgG subclass+ antibody-forming cells mainly in the spleen. From 1.5 days, the resident MHCII+CD103+ dendritic cells (DCs) in the splenic T-cell area, periarterial lymphocyte sheath, formed clusters with recipient BrdU+ or 5-ethynyl-2′-deoxyuridine+ cells, from which the proliferative response of CD4+ T cells originated peaking at 3–4 days. Transfusion-induced antibodies had donor passenger cell-depleting activity in vitro and in vivo and could suppress acute GvH disease caused by donor T cells. Furthermore, Treg cells significantly suppressed mixed leukocyte reactions in a donor-specific manner. In conclusion, single blood transfusion efficiently induced a helper T-cell-dependent anti-donor class I MHC antibody-forming cell response with immunoglobulin class switching, and a donor-specific Treg cell response mainly in the spleen, probably by way of the indirect allorecognition via resident DCs. These antibodies and Treg cells may be involved, at least partly, in the donor-specific transfusion-induced suppression of allograft rejection. PMID:29361165
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.
Early Increases in Superantigen-Specific Foxp3+ Regulatory T Cells during Mouse Mammary Tumor Virus Infection▿ †

PubMed Central

Cabrera, Gabriel; Burzyn, Dalia; Mundiñano, Juliana; Courreges, M. Cecilia; Camicia, Gabriela; Lorenzo, Daniela; Costa, Héctor; Ross, Susan R.; Nepomnaschy, Irene; Piazzon, Isabel

2008-01-01

Mouse mammary tumor virus (MMTV) is a milk-borne betaretrovirus that has developed strategies to exploit and subvert the host immune system. Here, we show in a natural model of MMTV infection that the virus causes early and progressive increases in superantigen (SAg)-specific Foxp3+ regulatory T cells (Treg) in Peyer's patches (PP). These increases were shown to be dependent on the presence of dendritic cells. CD4+ CD25+ T cells from the PP of infected mice preferentially suppress the proliferative response of T cells to SAg-expressing antigen-presenting cells ex vivo. We investigated the influence of the depletion of CD25+ cells at different stages of the infection. When CD25+ cells were depleted before MMTV infection, an increase in the number of PP SAg-cognate Foxp3− T cells was found at day 6 of infection. Since the SAg response is associated with viral amplification, the possibility exists that Treg cells attenuate the increase in viral load at the beginning of the infection. In contrast, depletion of CD25+ cells once the initial SAg response has developed caused a lower viral load, suggesting that at later stages Treg cells may favor viral persistence. Thus, our results indicated that Treg cells play an important and complex role during MMTV infection. PMID:18495774
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.
CD4+ T-cell clones obtained from cattle chronically infected with Fasciola hepatica and specific for adult worm antigen express both unrestricted and Th2 cytokine profiles.

PubMed Central

Brown, W C; Davis, W C; Dobbelaere, D A; Rice-Ficht, A C

1994-01-01

The well-established importance of helper T (Th)-cell subsets in immunity and immunoregulation of many experimental helminth infections prompted a detailed study of the cellular immune response against Fasciola hepatica in the natural bovine host. T-cell lines established from two cattle infected with F. hepatica were characterized for the expression of T-cell surface markers and proliferative responses against F. hepatica adult worm antigen. Parasite-specific T-cell lines contained a mixture of CD4+, CD8+, and gamma/delta T-cell-receptor-bearing T cells. However, cell lines containing either fewer than 10% CD8+ T cells or depleted of gamma/delta T cells proliferated vigorously against F. hepatica antigen, indicating that these T-cell subsets are not required for proliferative responses in vitro. Seventeen F. hepatica-specific CD4+ Th-cell clones were examined for cytokine expression following concanavalin A stimulation. Biological assays to measure interleukin-2 (IL-2) or IL-4, gamma interferon (IFN-gamma), and tumor necrosis factor and Northern (RNA) blot analysis to verify the expression of IL-2, IL-4, and IFN-gamma revealed that the Th-cell clones expressed a spectrum of cytokine profiles. Several Th-cell clones were identified as Th2 cells by the strong expression of IL-4 but little or no IL-2 or IFN-gamma mRNA. The majority of Th-cell clones were classified as Th0 cells by the expression of either all three cytokines or combinations of IL-2 and IL-4 or IL-4 and IFN-gamma. No Th1-cell clones were obtained. All of the Th-cell clones expressed a typical memory cell surface phenotype, characterized as CD45Rlow, and all expressed the lymph node homing receptor (L selectin). These results are the first to describe cytokine responses of F. hepatica-specific T cells obtained from infected cattle and extend our previous analysis of Th0 and Th1 cells from cattle immune to Babesia bovis (W. C. Brown, V. M. Woods, D. A. E. Dobbelaere, and K. S. Logan, Infect. Immun. 61
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
Increased telomere length and proliferative potential in peripheral blood mononuclear cells of adults of different ages stimulated with concanavalin A

PubMed Central

2013-01-01

Background Recently, a direct correlation with telomere length, proliferative potential and telomerase activity has been found in the process of aging in peripheral blood cells. The objective of the study was to evaluate telomere length and proliferative potential in peripheral blood mononuclear cells (PBMCs) after stimulation with Concanavalin A (ConA) of young adults compared with older adults. Methods Blood samples were obtained from 20 healthy young males (20–25 years old) (group Y) and 20 males (60–65 years old) (group O). We compared PBMC proliferation before and after stimulation with ConA. DNA was isolated from cells separated before and after culture with ConA for telomeric measurement by real-time polymerase chain reaction. Results In vitro stimulation of PBMCs from young subjects induced an increase of telomere length as well as a higher replicative capacity of cell proliferation. Samples from older adults showed higher loss of telomeric DNA (p = 0.03) and higher levels of senescent (≤6.2 kb) telomeric DNA (p = 0.02) and displayed a marked decrease of proliferation capacity. Viability cell counts and CFSE tracking in 72-h-old cell cultures indicated that group O PBMCs (CD8+ and CD4+ T cells) underwent fewer mitotic cycles and had shorter telomeres than group Y (p = 0.04). Conclusions Our findings confirm that telomere length in older-age adults is shorter than in younger subjects. After stimulation with ConA, cells are not restored to the previous telomere length and undergo replicative senescence. This is in sharp contrast to the response observed in young adults after ConA stimulation where cells increase in telomere length and replicative capacity. The mechanisms involved in this phenomenon are not yet clear and merit further investigation. PMID:24063536
Premature cell senescence and T cell receptor-independent activation of CD8T cells in Juvenile Idiopathic Arthritis*

PubMed Central

Dvergsten, Jeffrey A.; Mueller, Robert G.; Griffin, Patricia; Abedin, Sameem; Pishko, Allyson; Michel, Joshua J.; Rosenkranz, Margalit E.; Reed, Ann M.; Kietz, Daniel A.; Vallejo, Abbe N.

2013-01-01

Objectives CD8T cells lacking CD28 were originally reported by Wedderburn and colleagues as a characteristic feature of JIA, but the relevance of these unusual cells to JIA remains to be elucidated. Because of recent evidence that CD28 loss is typical of terminally differentiated lymphocytes, we examined for functional subsets of CD8T cells in JIA. Methods Following informed consent/assent, blood and/or waste synovial fluid were collected from children with definite diagnosis of JIA (n = 98). De-identified blood (n = 33) and cord blood (n = 13) samples from healthy donors were also collected. CD8T and CD4T cells were screened for novel receptors, and where indicated, bioassays were performed to determine functional relevance of the identified receptor. Results Patients had a naïve T cell compartment with shortened telomeres, and their entire T cell pool had reduced proliferative capacity. They had an over abundance of CD31+CD28null CD8T cells, which was a significant feature of oligoarticular JIA (n = 62) compared to polyarticular JIA (n = 36). CD31+CD28null CD8T cells had limited mitotic capacity, and expressed high levels of the senescence antigens γH2Ax and/or p16. Ligation of CD31, independent of the TCR, sufficiently induced tyrosine phosphorylation, vesicle exocytosis, and production of IFN-γ and IL-10. Conclusion These data provide the first evidence for cell senescence, represented by CD31+CD28null CD8T cells, in the pathophysiology of JIA. Activation of these unusual cells in a TCR-independent manner suggests they are maladaptive, and could be potential targets for immunotherapy. PMID:23686519
Dramatic increase in naive T cell turnover is linked to loss of naive T cells from old primates.

PubMed

Cicin-Sain, Luka; Messaoudi, Ilhem; Park, Byung; Currier, Noreen; Planer, Shannon; Fischer, Miranda; Tackitt, Shane; Nikolich-Zugich, Dragana; Legasse, Alfred; Axthelm, Michael K; Picker, Louis J; Mori, Motomi; Nikolich-Zugich, Janko

2007-12-11

The loss of naïve T cells is a hallmark of immune aging. Although thymic involution is a primary driver of this naïve T cell loss, less is known about the contribution of other mechanisms to the depletion of naïve T cells in aging primates. We examined the role of homeostatic cycling and proliferative expansion in different T cell subsets of aging rhesus macaques (RM). BrdU incorporation and the expression of the G(1)-M marker Ki-67 were elevated in peripheral naïve CD4 and even more markedly in the naïve CD8 T cells of old, but not young adult, RM. Proliferating naïve cells did not accumulate in old animals. Rather, the relative size of the naïve CD8 T cell compartment correlated inversely to its proliferation rate. Likewise, T cell receptor diversity decreased in individuals with elevated naïve CD8 T cell proliferation. This apparent contradiction was explained by a significant increase in turnover concomitant with the naïve pool loss. The turnover increased exponentially when the naïve CD8 T cell pool decreased below 4% of total blood CD8 cells. These results link the shrinking naïve T cell pool with a dramatic increase in homeostatic turnover, which has the potential to exacerbate the progressive exhaustion of the naïve pool and constrict the T cell repertoire. Thus, homeostatic T cell proliferation exhibits temporal antagonistic pleiotropy, being beneficial to T cell maintenance in adulthood but detrimental to the long-term T cell maintenance in aging individuals.
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

Antigen-specific, CD4+CD25+ regulatory T cell clones induced in Peyer's patches.

PubMed

Tsuji, Noriko M; Mizumachi, Koko; Kurisaki, Jun-Ichi

2003-04-01

Since intestine is exposed to numerous exogenous antigens such as food and commensal bacteria, the organ bears efficient mechanisms for establishment of tolerance and induction of regulatory T cells (T(reg)). Intestinal and inducible T(reg) include T(r)1-like and T(h)3 cells whose major effector molecules are IL-10 and transforming growth factor (TGF)-beta. These antigen-specific T(reg) are expected to become clinical targets to modify the inflammatory immune response associated with allergy, autoimmune diseases and transplantation. In the present study, we characterized the antigen-specific T(reg) induced in the intestine by orally administering high-dose beta-lactoglobulin (BLG) to BALB/c mice. Seven days after feeding, only Peyer's patch (PP) cells among different organs exerted significant suppressive effect on antibody production upon in vitro BLG stimulation. This suppressive effect was also prominent in six BLG-specific CD4(+) T cell clones (OPP1-6) established from PP from mice orally administered with high doses of BLG and was partially reversed by antibodies to TGF-beta. Intravenous transfer of OPP2 efficiently suppressed BLG-specific IgG1 production in serum following immunization, indicating the role of such T(reg) in the systemic tolerance after oral administration of antigen (oral tolerance). OPP clones secrete TGF-beta, IFN-gamma and low levels of IL-10, a cytokine pattern similar to that secreted by anergic T cells. OPP clones bear a CD4(+)CD25(+) phenotype and show significantly lower proliferative response compared to T(h)0 clones. This lower response is recovered by the addition of IL-2. Thus, antigen-specific CD4(+)CD25(+) T(reg), which have characteristics of anergic cells and actively suppress antibody production are induced in PP upon oral administration of protein antigen.
Content of endoplasmic reticulum and Golgi complex membranes positively correlates with the proliferative status of brain cells.

PubMed

Silvestre, David C; Maccioni, Hugo J F; Caputto, Beatriz L

2009-03-01

Although the molecular and cellular basis of particular events that lead to the biogenesis of membranes in eukaryotic cells has been described in detail, understanding of the intrinsic complexity of the pleiotropic response by which a cell adjusts the overall activity of its endomembrane system to accomplish these requirements is limited. Here we carried out an immunocytochemical and biochemical examination of the content and quality of the endoplasmic reticulum (ER) and Golgi apparatus membranes in two in vivo situations characterized by a phase of active cell proliferation followed by a phase of declination in proliferation (rat brain tissue at early and late developmental stages) or by permanent active proliferation (gliomas and their most malignant manifestation, glioblastomas multiforme). It was found that, in highly proliferative phases of brain development (early embryo brain cells), the content of ER and Golgi apparatus membranes, measured as total lipid phosphorous content, is higher than in adult brain cells. In addition, the concentration of protein markers of ER and Golgi is also higher in early embryo brain cells and in human glioblastoma multiforme cells than in adult rat brain or in nonpathological human brain cells. Results suggest that the amount of endomembranes and the concentration of constituent functional proteins diminish as cells decline in their proliferative activity.
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
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
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
Distinct susceptibility of HIV vaccine vector-induced CD4 T cells to HIV infection

PubMed Central

Niu, Qingli; Hou, Wei; Churchyard, Gavin; Nitayaphan, Sorachai; Pitisuthithum, Punnee; Rerks-Ngarm, Supachai; Franchini, Genoveffa

2018-01-01

The concerns raised from adenovirus 5 (Ad5)-based HIV vaccine clinical trials, where excess HIV infections were observed in some vaccine recipients, have highlighted the importance of understanding host responses to vaccine vectors and the HIV susceptibility of vector-specific CD4 T cells in HIV vaccination. Our recent study reported that human Ad5-specific CD4 T cells induced by Ad5 vaccination (RV156A trial) are susceptible to HIV. Here we further investigated the HIV susceptibility of vector-specific CD4 T cells induced by ALVAC, a canarypox viral vector tested in the Thai trial RV144, as compared to Ad5 vector-specific CD4 T cells in the HVTN204 trial. We showed that while Ad5 vector-specific CD4 T cells were readily susceptible to HIV, ALVAC-specific CD4 T cells in RV144 PBMC were substantially less susceptible to both R5 and X4 HIV in vitro. The lower HIV susceptibility of ALVAC-specific CD4 T cells was associated with the reduced surface expression of HIV entry co-receptors CCR5 and CXCR4 on these cells. Phenotypic analyses identified that ALVAC-specific CD4 T cells displayed a strong Th1 phenotype, producing higher levels of IFN-γ and CCL4 (MIP-1β) but little IL-17. Of interest, ALVAC and Ad5 vectors induced distinct profiles of vector-specific CD8 vs. CD4 T-cell proliferative responses in PBMC, with ALVAC preferentially inducing CD8 T-cell proliferation, while Ad5 vector induced CD4 T-cell proliferation. Depletion of ALVAC-, but not Ad5-, induced CD8 T cells in PBMC led to a modest increase in HIV infection of vector-specific CD4 T cells, suggesting a role of ALVAC-specific CD8 T cells in protecting ALVAC-specific CD4 T cells from HIV. Taken together, our data provide strong evidence for distinct HIV susceptibility of CD4 T cells induced by different vaccine vectors and highlight the importance of better evaluating anti-vector responses in HIV vaccination. PMID:29474461
Conformation-dependent recognition of a protein by T-lymphocytes: apomyoglobin-specific T-cell clone recognizes conformational changes between apomyoglobin and myoglobin

NASA Technical Reports Server (NTRS)

Cohly, H. H.; Morrison, D. R.; Atassi, M. Z.

1988-01-01

A T-cell clone specific to apomyoglobin was generated. It was prepared from a T-cell culture obtained by in vitro driving of lymph node cells with apomyoglobin from SJL mice that have been primed in vivo with apomyoglobin. In proliferative assays, the T-cell clone responded to apomyoglobin but did not recognize native myoglobin or any of the synthetic peptides corresponding to the six T sites of myoglobin. The demonstration that a T-cell clone can be isolated, whose specificity is directed entirely to apomyoglobin and not to its counterpart myoglobin, with an identical amino acid composition, indicates the importance of the three-dimensional structure in the presentation of the protein to T cells.
Rapid down-regulation of γc on T cells in early SIV infection correlates with impairment of T-cell function.

PubMed

Xu, Huanbin; Wang, Xiaolei; Pahar, Bapi; Alvarez, Xavier; Rasmussen, Kelsi K; Lackner, Andrew A; Veazey, Ronald S

2012-06-01

The common γ(c) subunit molecule is shared among all γ(c) cytokines and clearly involved in T-cell function, but its role in HIV infection and immunity is not well understood. Here, we examined expression and function of γ(c) on T cells during SIV infection in Rhesus macaques. Surface γ(c) distribution was differentially expressed on CD4(+) and CD8(+) T cells, and CD4(+) naive/memory cell populations in various lymphoid tissues of normal macaques. However, surface γ(c) expression was rapidly and significantly down-regulated on T cells in acute infection with pathogenic SIV, compared to infection with a less virulent SHIV or controls and did not recover on CD8(+) T cells in the chronic stage. Moreover, the peripheral and CD4(+)T cell loss was inversely correlated with γ(c)(+) CD8(+) T cells in individual tissues. γ(c)(+) T cells were mainly functional as evidenced by higher cytokine secretion and proliferative capacity. Further in vitro experiments found that surface γ(c) expression could be down-regulated following high level of IL-7 treatment by both internalization and shedding. Down-regulation of γ(c) during early HIV/SIV infection may inhibit T-cell function, particularly of CD8(+) T cells, and, may be linked with immune failure and loss of viral containment.
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
Establishment of proliferative tetraploid cells from telomerase-immortalized normal human fibroblasts.

PubMed

Ohshima, Susumu; Seyama, Atsushi

2016-06-01

Aneuploidy is observed in the majority of human cancers and is considered to be causally related to carcinogenesis. Although malignant aneuploid cells are suggested to develop from polyploid cells formed in precancerous lesions, the mechanisms of this process remain elusive. This is partly because no experimental model is available where nontransformed polyploid human cells propagate in vitro. We previously showed that proliferative tetraploid cells can be established from normal human fibroblasts by treatment with the spindle poison demecolcine (DC). However, the limited lifespan of these cells hampered detailed analysis of a link between chromosomal instability and the oncogenic transformation of polyploid cells. Here, we report the establishment of proliferative tetraploid cells from the telomerase-immortalized normal human fibroblast cell line TIG-1. Treatment of immortalized diploid cells with DC for 4 days resulted in proliferation of cells with tetraploid DNA content and near-tetraploid/tetraploid chromosome counts. Established tetraploid cells had functional TP53 despite growing at almost the same rate as diploid cells. The frequency of clonal and sporadic chromosome aberrations in tetraploid cells was higher than in diploid cells and in one experiment, gradually increased with repeated subculture. This study suggests that tetraploid cells established from telomerase-immortalized normal human fibroblasts can be a valuable model for studying chromosomal instability and the oncogenic potential of polyploid cells. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.
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
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.
Capacity of Lung Stroma to Educate Dendritic Cells Inhibiting Mycobacteria-Specific T-Cell Response Depends upon Genetic Susceptibility to Tuberculosis

PubMed Central

Majorov, Konstantin B.; Logunova, Nadezhda N.; Apt, Alexander S.

2013-01-01

The balance between activation and inhibition of local immune responses in affected tissues during prolonged chronic infections is important for host protection. There is ample evidence that regulatory, tolerogenic dendritic cells (DC) are developed and present in tissues and inhibit overwhelming inflammatory reactions. Also, it was firmly established that stromal microenvironment of many organs is able to induce development of immature regulatory DC (DCreg), an essential element of a general immune regulatory network. However, direct experimental data demonstrating inhibition of immune responses by stroma-instructed immature DCreg in infectious models are scarce, and virtually nothing is known about functioning of this axis of immunity during tuberculosis (TB) infection. In this study, we demonstrate that lung stromal cells are capable of supporting the development in culture of immature CD11b+CD11clowCD103- DCreg from lineage-negative (lin-) bone marrow precursors. DCreg developed on lung stroma isolated from mice of genetically TB-hyper-susceptible I/St and relatively resistant B6 inbred strains inhibited proliferative response of mycobacteria-specific CD4+ T-cell lines a dose-dependent manner. Importantly, the inhibitory activity of B6 DCreg was substantially higher than that of I/St Dcreg. Moreover, when the donors of stromal cells were chronically infected with virulent mycobacteria, the capacity to instruct inhibitory DCreg was retained in B6, but further diminished in I/St stromal cells. DCreg-provided suppression was mediated by a few soluble mediators, including PGE2, NO and IL-10. The content of CD4+Foxp3+ Treg cells in the mediastinal, lung-draining lymph nodes at the advanced stages of chronic infection did not change in I/St, but increased 2-fold in B6 mice, and lung pathology was much more pronounced in the former mice. Taken together, these data provide genetic evidence that the capacity to maintain populations of regulatory cells during M
Capacity of lung stroma to educate dendritic cells inhibiting mycobacteria-specific T-cell response depends upon genetic susceptibility to tuberculosis.

PubMed

Kapina, Marina A; Rubakova, Elvira I; Majorov, Konstantin B; Logunova, Nadezhda N; Apt, Alexander S

2013-01-01

The balance between activation and inhibition of local immune responses in affected tissues during prolonged chronic infections is important for host protection. There is ample evidence that regulatory, tolerogenic dendritic cells (DC) are developed and present in tissues and inhibit overwhelming inflammatory reactions. Also, it was firmly established that stromal microenvironment of many organs is able to induce development of immature regulatory DC (DCreg), an essential element of a general immune regulatory network. However, direct experimental data demonstrating inhibition of immune responses by stroma-instructed immature DCreg in infectious models are scarce, and virtually nothing is known about functioning of this axis of immunity during tuberculosis (TB) infection. In this study, we demonstrate that lung stromal cells are capable of supporting the development in culture of immature CD11b(+)CD11c(low)CD103(-) DCreg from lineage-negative (lin(-)) bone marrow precursors. DCreg developed on lung stroma isolated from mice of genetically TB-hyper-susceptible I/St and relatively resistant B6 inbred strains inhibited proliferative response of mycobacteria-specific CD4(+) T-cell lines a dose-dependent manner. Importantly, the inhibitory activity of B6 DCreg was substantially higher than that of I/St Dcreg. Moreover, when the donors of stromal cells were chronically infected with virulent mycobacteria, the capacity to instruct inhibitory DCreg was retained in B6, but further diminished in I/St stromal cells. DCreg-provided suppression was mediated by a few soluble mediators, including PGE2, NO and IL-10. The content of CD4(+)Foxp3(+) Treg cells in the mediastinal, lung-draining lymph nodes at the advanced stages of chronic infection did not change in I/St, but increased 2-fold in B6 mice, and lung pathology was much more pronounced in the former mice. Taken together, these data provide genetic evidence that the capacity to maintain populations of regulatory cells
Effector cell signature in peripheral blood following nasal allergen challenge in grass pollen allergic individuals.

PubMed

Shamji, M H; Bellido, V; Scadding, G W; Layhadi, J A; Cheung, D K M; Calderon, M A; Asare, A; Gao, Z; Turka, L A; Tchao, N; Togias, A; Phippard, D; Durham, S R

2015-02-01

Several studies have demonstrated the time course of inflammatory mediators in nasal fluids following nasal allergen challenge (NAC), whereas the effects of NAC on cells in the periphery are unknown. We examined the time course of effector cell markers (for basophils, dendritic cells and T cells) in peripheral blood after nasal grass pollen allergen challenge. Twelve participants with seasonal allergic rhinitis underwent a control (diluent) challenge followed by NAC after an interval of 14 days. Nasal symptoms and peak nasal inspiratory flow (PNIF) were recorded along with peripheral basophil, T-cell and dendritic cell responses (flow cytometry), T-cell proliferative responses (thymidine incorporation), and cytokine expression (FluoroSpot assay). Robust increases in nasal symptoms and decreases in PNIF were observed during the early (0-1 h) response and modest significant changes during the late (1-24 h) response. Sequential peaks in peripheral blood basophil activation markers were observed (CD107a at 3 h, CD63 at 6 h, and CD203c(bright) at 24 h). T effector/memory cells (CD4(+) CD25(lo) ) were increased at 6 h and accompanied by increases in CD80(+) and CD86(+) plasmacytoid dendritic cells (pDCs). Ex vivo grass antigen-driven T-cell proliferative responses and the frequency of IL-4(+) CD4(+) T cells were significantly increased at 6 h after NAC when compared to the control day. Basophil, T-cell, and dendritic cell activation increased the frequency of allergen-driven IL-4(+) CD4(+) T cells, and T-cell proliferative responses are detectable in the periphery after NAC. These data confirm systemic cellular activation following a local nasal provocation. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
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.
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
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.
An Ahemolytic Pneumolysin of Streptococcus Pneumoniae Manipulates Human Innate and CD4+ T-Cell Responses and Reduces Resistance to Colonization in Mice in a Serotype-Independent Manner

PubMed Central

Khan, M. Nadeem; Coleman, John Robert; Vernatter, Joshua; Varshney, Avanish Kumar; Dufaud, Chad; Pirofski, Liise-anne

2014-01-01

Background. Some Streptococcus pneumoniae serotypes express an ahemolytic pneumolysin (PLYa). Serotypes that commonly express PLYa, including serotype 8 (ST8) and ST1, are often associated with a low prevalence during colonization but a higher propensity to cause invasive disease. We sought to study the host response to ST8 PLYa in a homologous and heterologous capsular background. Methods. We genetically exchanged the PLYa of ST8 strain 6308 with the hemolytic PLY (PLYh) of ST3 A66.1 and vice versa and determined the impact of the exchange on nasopharyngeal colonization in mice. Then, to compare the response of human cells to PLYa-expressing and PLYh-expressing strains, we infected human peripheral blood mononuclear cells (PBMCs) with PLY-switched strains and assessed dendritic cell and CD4+ T-cell responses by intracellular cytokine staining. Result. Mice colonized with PLYa-expressing strains had significantly higher colonization densities than those colonized with PLYh-expressing strains, irrespective of capsular background. Compared with infection of PBMCs with PLYh-expressing strains, infection with PLYa-expressing strains induced diminished innate (dendritic cell cytokines, costimulatory receptor, and apoptotic) and adaptive (CD4+ T-cell proliferative and memory interleukin 17A) responses. Conclusion. Our findings demonstrate that PLYa has the potential to manipulate host immunity irrespective of capsule type. PLY exchange between STs expressing PLYa and PLYh could lead to unexpected colonization or invasion phenotypes. PMID:25001458
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

Antibody response is required for protection from Theiler's virus-induced encephalitis in C57BL/6 mice in the absence of CD8{sup +} T cells

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

Kang, B.-S.; Palma, Joann P.; Lyman, Michael A.

2005-09-15

Intracerebral infection of susceptible mice with Theiler's murine encephalomyelitis virus (TMEV) induces immune-mediated demyelinating disease and this system serves as a relevant infectious model for human multiple sclerosis. It was previously shown that {beta}{sub 2}M-deficient C57BL/6 mice lacking functional CD8{sup +} T cells display increased viral persistence and enhanced susceptibility to TMEV-induced demyelination, and yet the majority of mice are free of clinical signs. To understand the mechanisms involved in this general resistance of C57BL/6 mice in the absence of CTL responses, mice ({mu}MT) deficient in the B-cell compartment lacking membrane IgM molecules were treated with anti-CD8 antibody and thenmore » infected with TMEV. Although little difference in the proliferative responses of peripheral T cells to UV-inactivated TMEV and the resistance to demyelinating disease was observed between virus-infected {mu}MT and control B6 mice, the levels of CD4{sup +} T cells were higher in the CNS of {mu}MT mice. However, after treatment with anti-CD8 antibody, 100% of the mice displayed clinical gray matter disease and prolonged viral persistence in {mu}MT mice, while only 10% of B6 mice showed clinical symptoms and very low viral persistence. Transfusion of sera from TMEV-infected B6 mice into anti-CD8 antibody-treated {mu}MT mice partially restored resistance to virus-induced encephalitis. These results indicate that the early anti-viral antibody response is also important in the protection from TMEV-induced encephalitis particularly in the absence of CD8{sup +} T cells.« less
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.
Immunosuppressive myeloid cells induced by chemotherapy attenuate antitumor CD4+ T-cell responses through the PD-1-PD-L1 axis.

PubMed

Ding, Zhi-Chun; Lu, Xiaoyun; Yu, Miao; Lemos, Henrique; Huang, Lei; Chandler, Phillip; Liu, Kebin; Walters, Matthew; Krasinski, Antoni; Mack, Matthias; Blazar, Bruce R; Mellor, Andrew L; Munn, David H; Zhou, Gang

2014-07-01

In recent years, immune-based therapies have become an increasingly attractive treatment option for patients with cancer. Cancer immunotherapy is often used in combination with conventional chemotherapy for synergistic effects. The alkylating agent cyclophosphamide (CTX) has been included in various chemoimmunotherapy regimens because of its well-known immunostimulatory effects. Paradoxically, cyclophosphamide can also induce suppressor cells that inhibit immune responses. However, the identity and biologic relevance of these suppressor cells are poorly defined. Here we report that cyclophosphamide treatment drives the expansion of inflammatory monocytic myeloid cells (CD11b(+)Ly6C(hi)CCR2(hi)) that possess immunosuppressive activities. In mice with advanced lymphoma, adoptive transfer (AT) of tumor-specific CD4(+) T cells following cyclophosphamide treatment (CTX+CD4 AT) provoked a robust initial antitumor immune response, but also resulted in enhanced expansion of monocytic myeloid cells. These therapy-induced monocytes inhibited long-term tumor control and allowed subsequent relapse by mediating functional tolerization of antitumor CD4(+) effector cells through the PD-1-PD-L1 axis. PD-1/PD-L1 blockade after CTX+CD4 AT therapy led to persistence of CD4(+) effector cells and durable antitumor effects. Depleting proliferative monocytes by administering low-dose gemcitabine effectively prevented tumor recurrence after CTX+CD4 AT therapy. Similarly, targeting inflammatory monocytes by disrupting the CCR2 signaling pathway markedly potentiated the efficacy of cyclophosphamide-based therapy. Besides cyclophosphamide, we found that melphalan and doxorubicin can also induce monocytic myeloid suppressor cells. These findings reveal a counter-regulation mechanism elicited by certain chemotherapeutic agents and highlight the importance of overcoming this barrier to prevent late tumor relapse after chemoimmunotherapy. ©2014 American Association for Cancer Research.
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
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
UVB radiation and human monocyte accessory function: Differential effects on pre-mitotic events in T-cell activation

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

Krutmann, J.K.; Kammer, G.M.; Toossi, Z.

Purified T lymphocytes fail to proliferate in response to antigenic and mitogenic stimuli when cultured in the presence of accessory cells that have been exposed in vitro to sublethal doses of UVB radiation. Because proliferation represents a final stage in the T-cell activation process, the present study was conducted to determine whether T cells were able to progress through any of the pre-mitotic stages when UVB-irradiated monocytes were used as model accessory cells. In these experiments, monoclonal anti-CD3 antibodies were employed as the mitogenic stimulus. Culture of T cells with UVB-irradiated monocytes did allow the T cells to undergo anmore » increase in intracellular free calcium, which is one of the first steps in the activation sequence. The T cells expressed interleukin-2 receptors, although at a reduced level. However, T cells failed to produce interleukin-2 above background levels when they were placed in culture with monocytes exposed to UVB doses as low as 50 J/m2. Incubation of T cells with UVB-irradiated monocytes did not affect the subsequent capacity of T cells to proliferate, since they developed a normal proliferative response in secondary culture when restimulated with anti-CD3 antibodies and unirradiated monocytes. These studies indicate that T lymphocytes become partially activated when cultured with UVB-irradiated monocytes and mitogenic anti-CD3 monoclonal antibodies. In addition, they suggest that interleukin-2 production is the T-cell activation step most sensitive to inhibition when UVB-irradiated monocytes are employed as accessory cells.« less
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.
Heme oxygenase is not involved in the anti-proliferative effects of statins on pancreatic cancer cells.

PubMed

Vanova, K; Boukalova, S; Gbelcova, H; Muchova, L; Neuzil, J; Gurlich, R; Ruml, T; Vitek, L

2016-05-12

Pancreatic cancer is recognized as one of the most fatal tumors due to its aggressiveness and resistance to therapy. Statins were previously shown to inhibit the proliferation of cancer cells via various signaling pathways. In healthy tissues, statins activate the heme oxygenase pathway, nevertheless the role of heme oxygenase in pancreatic cancer is still controversial. The aim of this study was to evaluate, whether anti-proliferative effects of statins in pancreatic cancer cells are mediated via the heme oxygenase pathway. In vitro effects of various statins and hemin, a heme oxygenase inducer, on cell proliferation were evaluated in PA-TU-8902, MiaPaCa-2 and BxPC-3 human pancreatic cancer cell lines. The effect of statins on heme oxygenase activity was assessed and heme oxygenase-silenced cells were used for pancreatic cancer cell proliferation studies. Cell death rate and reactive oxygen species production were measured in PA-TU-8902 cells, followed by evaluation of the effect of cerivastatin on GFP-K-Ras trafficking and expression of markers of invasiveness, osteopontin (SPP1) and SOX2. While simvastatin and cerivastatin displayed major anti-proliferative properties in all cell lines tested, pravastatin did not affect the cell growth at all. Strong anti-proliferative effect was observed also for hemin. Co-treatment of cerivastatin and hemin increased anti-proliferative potential of these agents, via increased production of reactive oxygen species and cell death compared to individual treatment. Heme oxygenase silencing did not prevent pancreatic cancer cells from the tumor-suppressive effect of cerivastatin or hemin. Cerivastatin, but not pravastatin, protected Ras protein from trafficking to the cell membrane and significantly reduced expressions of SPP1 (p < 0.05) and SOX2 (p < 0.01). Anti-proliferative effects of statins and hemin on human pancreatic cancer cell lines do not seem to be related to the heme oxygenase pathway. While hemin triggers
Proliferative lifespan is conserved after nuclear transfer.

PubMed

Clark, A John; Ferrier, Patricia; Aslam, Samena; Burl, Sarah; Denning, Chris; Wylie, Diana; Ross, Arlene; de Sousa, Paul; Wilmut, Ian; Cui, Wei

2003-06-01

Cultured primary cells exhibit a finite proliferative lifespan, termed the Hayflick limit. Cloning by nuclear transfer can reverse this cellular ageing process and can be accomplished with cultured cells nearing senescence. Here we describe nuclear transfer experiments in which donor cell lines at different ages and with different proliferative capacities were used to clone foetuses and animals from which new primary cell lines were generated. The rederived lines had the same proliferative capacity and rate of telomere shortening as the donor cell lines, suggesting that these are innate, genetically determined, properties that are conserved by nuclear transfer.
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
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…
Clinical methods of cryopreservation for donor lymphocyte infusions vary in their ability to preserve functional T-cell subpopulations.

PubMed

Worsham, D Nicole; Reems, Jo-Anna; Szczepiorkowski, Zbigniew M; McKenna, David H; Leemhuis, Thomas; Mathew, Aby J; Cancelas, Jose A

2017-06-01

Cryopreserved donor lymphocyte infusion (DLI) products are manufactured and administered to treat relapse after allogeneic hematopoietic stem cell transplantation. Reported clinical responses to DLIs vary broadly, even within the same group of patients. While there is an implicit recognition of the fact that different manufacturing protocols may have specific effects on different cell types, cryopreservation protocols are frequently derived from our experience in the cryopreservation of stem cell products and do not account for the heterogeneous functional nature of DLI T-cell populations. Here, we report the results of a prospective, multicenter trial on the effect of four different cryopreservation solutions that were used to freeze DLIs compared to control DLIs that were refrigerated overnight. Cryopreserved postthawed and refrigerated specimens were analyzed side by side for their T-cell subpopulation content and viability, as well as T-cell proliferation, cytokine secretion, and cytotoxic activities. This study indicates that "homemade" 10% dimethyl sulfoxide (DMSO) results in reduced viability of different CD4+ T-cell populations, including T-helper, T-cytotoxic, and T-regulatory populations, and a decrease in their proliferative and cytotoxic response to immunologically relevant stimuli, while the use of solutions containing 5% DMSO with intracellular-like cryoprotectant stabilizers maintains T-cell function at levels similar to refrigerated control samples. This study has important implications in determining the best cryoprotectant solution for specific clinical applications in allogeneic immunotherapy. © 2017 AABB.
A possible mechanism of NK cell-lineage granular lymphocyte proliferative disorder (NK-GLPD) in a patient with chronic active Epstein-Barr virus infection (CAEBV) and severe hypersensitivity to mosquito bites (SHMB).

PubMed

Ohshima, Shiro; Ishii, Masaru; Asada, Hideo; Tatekawa, Toyoshi; Yamaguchi, Norihiko; Kobayashi, Hideyuki; Ishii, Taeko; Mima, Toru; Kawase, Ichiro; Saeki, Yukihiko

2002-08-01

We report the case of a young female patient with chronic active Epstein-Barr virus infection (CAEBV) and severe hypersensitivity to mosquito bites (SHMB). She showed a marked increase of NK cell population in peripheral blood. The NK cell population was suggested to be infected with EBV, and to be oligoclonal by Southern blotting using an EBV genome terminal-repeat probe. The NK cells aberrantly expressed CD25, a high affinity receptor for IL-2, and showed an augmented in vitro proliferative response to IL-2. Moreover, they also showed enhanced expression of both Fas-ligand and Bcl-2, and resistance to in vitro Fas-induced apoptotic cell death (Fas-ACD). Taken together, these observations suggested that both the augmentation of proliferative response to IL-2 and the decrease in Fas-ACD may cause NK cell lineage granular lymphocyte proliferative disorder (NK-GLPD) in patients with CAEBV and SHMB.
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.
Cell output, cell cycle duration and neuronal specification: a model of integrated mechanisms of the neocortical proliferative process

NASA Technical Reports Server (NTRS)

Caviness, V. S. Jr; Goto, T.; Tarui, T.; Takahashi, T.; Bhide, P. G.; Nowakowski, R. S.

2003-01-01

The neurons of the neocortex are generated over a 6 day neuronogenetic interval that comprises 11 cell cycles. During these 11 cell cycles, the length of cell cycle increases and the proportion of cells that exits (Q) versus re-enters (P) the cell cycle changes systematically. At the same time, the fate of the neurons produced at each of the 11 cell cycles appears to be specified at least in terms of their laminar destination. As a first step towards determining the causal interrelationships of the proliferative process with the process of laminar specification, we present a two-pronged approach. This consists of (i) a mathematical model that integrates the output of the proliferative process with the laminar fate of the output and predicts the effects of induced changes in Q and P during the neuronogenetic interval on the developing and mature cortex and (ii) an experimental system that allows the manipulation of Q and P in vivo. Here we show that the predictions of the model and the results of the experiments agree. The results indicate that events affecting the output of the proliferative population affect both the number of neurons produced and their specification with regard to their laminar fate.
The anti-proliferative effect of cation channel blockers in T lymphocytes depends on the strength of mitogenic stimulation.

PubMed

Petho, Zoltan; Balajthy, Andras; Bartok, Adam; Bene, Krisztian; Somodi, Sandor; Szilagyi, Orsolya; Rajnavolgyi, Eva; Panyi, Gyorgy; Varga, Zoltan

2016-03-01

Ion channels are crucially important for the activation and proliferation of T lymphocytes, and thus, for the function of the immune system. Previous studies on the effects of channel blockers on T cell proliferation reported variable effectiveness due to differing experimental systems. Therefore our aim was to investigate how the strength of the mitogenic stimulation influences the efficiency of cation channel blockers in inhibiting activation, cytokine secretion and proliferation of T cells under standardized conditions. Human peripheral blood lymphocytes were activated via monoclonal antibodies targeting the TCR-CD3 complex and the co-stimulator CD28. We applied the blockers of Kv1.3 (Anuroctoxin), KCa3.1 (TRAM-34) and CRAC (2-Apb) channels of T cells either alone or in combination with rapamycin, the inhibitor of the mammalian target of rapamycin (mTOR). Five days after the stimulation ELISA and flow cytometric measurements were performed to determine IL-10 and IFN-γ secretion, cellular viability and proliferation. Our results showed that ion channel blockers and rapamycin inhibit IL-10 and IFN-γ secretion and cell division in a dose-dependent manner. Simultaneous application of the blockers for each channel along with rapamycin was the most effective, indicating synergy among the various activation pathways. Upon increasing the extent of mitogenic stimulation the anti-proliferative effect of the ion channel blockers diminished. This phenomenon may be important in understanding the fine-tuning of T cell activation. Copyright © 2016 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.
Recognition of prostate-specific antigenic peptide determinants by human CD4 and CD8 T cells.

PubMed

Corman, J M; Sercarz, E E; Nanda, N K

1998-11-01

It is now becoming accepted that one is not tolerant to all the determinants of self proteins: the T cell repertoire directed to some sequences in self proteins is intact and can be activated. When a self protein is exclusively expressed by tumour cells, the T cell repertoire directed to the particular self antigen can potentially be activated to attack the tumour: this would amount to induction of a beneficial autoimmune response. Prostate cancer offers a unique opportunity for activation of a tumour-specific immune response owing to the exclusive synthesis of prostate-specific antigen (PSA) and prostate-specific membrane antigen (PSM) by prostatic tissue and prostate tumour cells. In this study we examine the CD4 and CD8 T cell repertoires specific for peptides of PSA and PSM in normal human male individuals, using short-term, peptide antigen-driven CD4 and CD8 T cell lines. We show that short-term, CD4 T cell lines derived from six HLA-DR4 individuals showed strong proliferative responses to six of 10 tested peptides of PSA, selected as to contain a DR4 binding motif. Short-term, CD8 T cell lines from three HLA-A1 individuals showed specific cytolytic activity for autologous targets loaded with five of five tested peptides of PSA and PSM, selected to possess an HLA-A1 binding motif. One of the peptides chosen is termed a 'dual-motif' peptide, as it encodes determinants for both CD4 and CD8 T cells. These results, indicating the existence of CD4 and CD8 T cells against determinants of the self proteins, PSA and PSM, in healthy male individuals reveal the potential of the T cell repertoire from the typical prostate cancer patient to eradicate prostate tumours upon being appropriately activated.
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
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
Proliferative human cell sources applied as biocomponent in bioartificial livers: a review.

PubMed

Nibourg, Geert A A; Chamuleau, Robert A F M; van Gulik, Thomas M; Hoekstra, Ruurdtje

2012-07-01

Bioartificial livers (BALs) are urgently needed to bridge severe liver failure patients to liver transplantation or liver regeneration. When based on primary hepatocytes, their efficacy has been shown in animal experiments and their safety was confirmed in clinical trials. However, a proliferative human cell source with therapeutic functionality is needed to secure availability and move BAL application forward. This review compares the performance of BALs based on proliferative human biocomponents and primary hepatocytes. This review evaluates relevant studies identified by searching the MEDLINE database until July 2011 and some of our own unpublished data. All the discussed hepatocyte-like biocomponents show deficiencies in their hepatic functionality compared with primary hepatocytes, particularly functions occurring late in liver development. Nonetheless, the HepaRG, HepG2-GS-CYP3A4, and mesenchymal stem cells show efficacy in a statistically well-powered animal model of acute liver failure, when applied in a BAL device. Various methods to gain higher functionality of BALs, including genetic modification, the usage of combinatory cell sources, and improvement of culture methods, have scarcely been applied, but may further pave the path for BAL application. Clinical implementation of a BAL based on a human proliferative biocomponent is still several years away.

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.
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.
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
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.
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
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.
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.
Role of T Cells in Malnutrition and Obesity

PubMed Central

Gerriets, Valerie A.; MacIver, Nancie J.

2014-01-01

Nutritional status is critically important for immune cell function. While obesity is characterized by inflammation that promotes metabolic syndrome including cardiovascular disease and insulin resistance, malnutrition can result in immune cell defects and increased risk of mortality from infectious diseases. T cells play an important role in the immune adaptation to both obesity and malnutrition. T cells in obesity have been shown to have an early and critical role in inducing inflammation, accompanying the accumulation of inflammatory macrophages in obese adipose tissue, which are known to promote insulin resistance. How T cells are recruited to adipose tissue and activated in obesity is a topic of considerable interest. Conversely, T cell number is decreased in malnourished individuals, and T cells in the setting of malnutrition have decreased effector function and proliferative capacity. The adipokine leptin, which is secreted in proportion to adipocyte mass, may have a key role in mediating adipocyte-T cell interactions in both obesity and malnutrition, and has been shown to promote effector T cell function and metabolism while inhibiting regulatory T cell proliferation. Additionally, key molecular signals are involved in T cell metabolic adaptation during nutrient stress; among them, the metabolic regulator AMP kinase and the mammalian target of rapamycin have critical roles in regulating T cell number, function, and metabolism. In summary, understanding how T cell number and function are altered in obesity and malnutrition will lead to better understanding of and treatment for diseases where nutritional status determines clinical outcome. PMID:25157251
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.
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.
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
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
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.
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.
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
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.
Rapid down-regulation of γc on T cells in early SIV infection correlates with impairment of T-cell function

PubMed Central

Xu, Huanbin; Wang, Xiaolei; Pahar, Bapi; Alvarez, Xavier; Rasmussen, Kelsi K.; Lackner, Andrew A.; Veazey, Ronald S.

2012-01-01

The common γc subunit molecule is shared among all γc cytokines and clearly involved in T-cell function, but its role in HIV infection and immunity is not well understood. Here, we examined expression and function of γc on T cells during SIV infection in Rhesus macaques. Surface γc distribution was differentially expressed on CD4+ and CD8+ T cells, and CD4+ naive/memory cell populations in various lymphoid tissues of normal macaques. However, surface γc expression was rapidly and significantly down-regulated on T cells in acute infection with pathogenic SIV, compared to infection with a less virulent SHIV or controls and did not recover on CD8+ T cells in the chronic stage. Moreover, the peripheral and CD4+T cell loss was inversely correlated with γc+ CD8+ T cells in individual tissues. γc+ T cells were mainly functional as evidenced by higher cytokine secretion and proliferative capacity. Further in vitro experiments found that surface γc expression could be down-regulated following high level of IL-7 treatment by both internalization and shedding. Down-regulation of γc during early HIV/SIV infection may inhibit T-cell function, particularly of CD8+ T cells, and, may be linked with immune failure and loss of viral containment.—Xu, H., Wang, X., Pahar, B., Alvarez, X., Rasmussen, K. K., Lackner, A. A., Veazey, R. S. Rapid down-regulation of γc on T cells in early SIV infection correlates with impairment of T-cell function. PMID:22375017
Persistence of collagen type II-specific T-cell clones in the synovial membrane of a patient with rheumatoid arthritis

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

Londei, M.; Savill, C.M.; Verhoef, A.

Rheumatoid arthritis is an autoimmune disease characterized by T-cell infiltration of the synovium of joints. Analysis of the phenotype and antigen specificity of the infiltrating cells may thus provide insight into the pathogenesis of rheumatoid arthritis. T cells were cloned with interleukin 2, a procedure that selects for in vivo-activated cells. All clones had the CD4 CDW29 phenotype. Their antigen specificity was tested by using a panel of candidate joint autoantigens. Four of 17 reacted against autologous blood mononuclear cells. Two clones proliferated in response to collagen type II. After 21 months, another set of clones was derived from synovialmore » tissue of the same joint. One of eight clones tested showed a strong proliferative response against collagen type II. The uncloned synovial T cells of a third operation from another joint also responded to collagen type II. The persistence of collagen type II-specific T cells in active rheumatoid joints over a period of 3 years suggests that collagen type II could be one of the autoantigens involved in perpetuating the inflammatory process in rheumatoid arthritis.« less
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.
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.

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
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
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.
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
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
Increased numbers of preexisting memory CD8 T cells and decreased T-bet expression can restrain terminal differentiation of secondary effector and memory CD8 T cells.

PubMed

Joshi, Nikhil S; Cui, Weiguo; Dominguez, Claudia X; Chen, Jonathan H; Hand, Timothy W; Kaech, Susan M

2011-10-15

Memory CD8 T cells acquire effector memory cell properties after reinfection and may reach terminally differentiated, senescent states ("Hayflick limit") after multiple infections. The signals controlling this process are not well understood, but we found that the degree of secondary effector and memory CD8 T cell differentiation was intimately linked to the amount of T-bet expressed upon reactivation and preexisting memory CD8 T cell number (i.e., primary memory CD8 T cell precursor frequency) present during secondary infection. Compared with naive cells, memory CD8 T cells were predisposed toward terminal effector (TE) cell differentiation because they could immediately respond to IL-12 and induce T-bet, even in the absence of Ag. TE cell formation after secondary (2°) or tertiary infections was dependent on increased T-bet expression because T-bet(+/-) cells were resistant to these phenotypic changes. Larger numbers of preexisting memory CD8 T cells limited the duration of 2° infection and the amount of IL-12 produced, and consequently, this reduced T-bet expression and the proportion of 2° TE CD8 T cells that formed. Together, these data show that over repeated infections, memory CD8 T cell quality and proliferative fitness is not strictly determined by the number of serial encounters with Ag or cell divisions, but is a function of the CD8 T cell differentiation state, which is genetically controlled in a T-bet-dependent manner. This differentiation state can be modulated by preexisting memory CD8 T cell number and the intensity of inflammation during reinfection. These results have important implications for vaccinations involving prime-boost strategies.
Allergoid-specific T-cell reaction as a measure of the immunological response to specific immunotherapy (SIT) with a Th1-adjuvanted allergy vaccine.

PubMed

von Baehr, V; Hermes, A; von Baehr, R; Scherf, H P; Volk, H D; Fischer von Weikersthal-Drachenberg, K J; Woroniecki, S

2005-01-01

Specific immunotherapy (SIT) is believed to modulate CD4+ T-helper cells. In order to improve safety, SIT vaccines are often formulated with allergoids (chemically modified allergens). Interaction between T-cells and allergoids is necessary to influence cellular cytokine expression. There have been few reports on identification the early cellular effects of SIT. Patients allergic to grass and/or mugwort pollen (n= 21) were treated with a 4-shot allergy vaccine (Pollinex Quattro) containing appropriate allergoids (grass/rye and/or mugwort) adsorbed to L-tyrosine plus a Th1 adjuvant, monophosphoryl lipid A (MPL). Fourteen grass-allergic patients served as untreated controls. Using the peripheral blood mononuclear cells of these patients, an optimized lymphocyte transformation test (LTT) was employed to monitor the in vitro proliferative response of T-cells to an allergoid challenge (solubilised Pollinex Quattro) before the first and last injection and then 2 and 20 weeks after the final injection. Control challenges utilised preparations of a similar pollen vaccine without the adjuvant MPL and a tree pollen vaccine with and without MPL. The LTT showed increased LTT stimulation indices (SI) in 17/20 SIT patients when the solublised vaccine preparation was used as a challenge before the last injection and 2 weeks after, in comparison to pre-treatment levels. Twenty weeks after therapy, the SI decreased to baseline level. A vaccine challenge without MPL gave lower SI levels. A challenge of a clinically inappropriate tree allergoid vaccine gave no response, and a nontreated group also showed no response. Following a short-course SIT adjuvated with MPL, challenges of allergoids were shown to activate allergen-specific T cells in vitro. There was an additional stimulating effect when the challenge was in combination with MPL. There were no non-specific effects of MPL, shown by the tree allergoid/MPL control. The timing of the response was closely correlated to the
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.
CD8+ T cells induce complete regression of advanced ovarian cancers by an interleukin (IL)-2/IL-15 dependent mechanism.

PubMed

Yang, Taimei; Wall, Erika M; Milne, Katy; Theiss, Patty; Watson, Peter; Nelson, Brad H

2007-12-01

In vitro studies suggest that ovarian cancer evades immune rejection by fostering an immunosuppressive environment within the peritoneum; however, the functional responses of ovarian cancer-specific T cells have not been directly investigated in vivo. Therefore, we developed a new murine model to enable tracking of tumor-specific CD8(+) T-cell responses to advanced ovarian tumors. The ovarian tumor cell line ID8 was transfected to stably express an epitope-tagged version of HER-2/neu (designated Neu(OT-I/OT-II)). After i.p. injection into C57BL/6 mice, ID8 cells expressing Neu(OT-I/OT-II) gave rise to disseminated serous adenocarcinomas with extensive ascites. CD8(+) T cells expressing a transgenic T-cell receptor specific for the OT-I epitope of Neu(OT-I/OT-II) were adoptively transferred into tumor-bearing mice, and functional responses were monitored. Cytokine signaling requirements were evaluated by comparing the responses of wild-type donor T cells with those with genetic deletion of the interleukin (IL)-2/IL-15 receptor beta subunit (CD122) or the IL-2 receptor alpha subunit (CD25). On adoptive transfer into tumor-bearing hosts, wild-type OT-I T cells underwent a striking proliferative response, reaching peak densities of approximately 40% and approximately 90% of CD8(+) T cells in peripheral blood and ascites, respectively. OT-I cells infiltrated and destroyed tumor tissue, and ascites completely resolved within 10 days. By contrast, CD122(-/-) OT-I cells and CD25(-/-) OT-I cells proliferated in blood but failed to accumulate in ascites or tumor tissue or induce tumor regression. Contrary to expectation, advanced ovarian cancers can support extraordinary CD8(+) T-cell proliferation and antitumor activity through an IL-2/IL-15-dependent mechanism.
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.
Effects of peptides on proliferative activity of retinal and pigmented epithelial cells.

PubMed

Khavinson, V Kh; Zemchikhina, V N; Trofimova, S V; Malinin, V V

2003-06-01

We studied the effects of Retinalamin (polypeptide preparation isolated from the retina) and a synthetic peptide Epithalon (Ala-Glu-Asp-Gly) on proliferative activity of retinal and pigmented epithelial cells. Experiments showed that Retinalamin and Epithalon (in certain concentrations) tissue-specifically stimulated proliferation of retinal and pigmented epithelial cell in culture.
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.
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.
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.
SDF-1 is both necessary and sufficient to promote proliferative retinopathy

PubMed Central

Butler, Jason M.; Guthrie, Steven M.; Koc, Mehmet; Afzal, Aqeela; Caballero, Sergio; Brooks, H. Logan; Mames, Robert N.; Segal, Mark S.; Grant, Maria B.; Scott, Edward W.

2005-01-01

Diabetic retinopathy is the leading cause of blindness in working-age adults. It is caused by oxygen starvation in the retina inducing aberrant formation of blood vessels that destroy retinal architecture. In humans, vitreal stromal cell–derived factor–1 (SDF-1) concentration increases as proliferative diabetic retinopathy progresses. Treatment of patients with triamcinolone decreases SDF-1 levels in the vitreous, with marked disease improvement. SDF-1 induces human retinal endothelial cells to increase expression of VCAM-1, a receptor for very late antigen–4 found on many hematopoietic progenitors, and reduce tight cellular junctions by reducing occludin expression. Both changes would serve to recruit hematopoietic and endothelial progenitor cells along an SDF-1 gradient. We have shown, using a murine model of proliferative adult retinopathy, that the majority of new vessels formed in response to oxygen starvation originate from hematopoietic stem cell–derived endothelial progenitor cells. We now show that the levels of SDF-1 found in patients with proliferative retinopathy induce retinopathy in our murine model. Intravitreal injection of blocking antibodies to SDF-1 prevented retinal neovascularization in our murine model, even in the presence of exogenous VEGF. Together, these data demonstrate that SDF-1 plays a major role in proliferative retinopathy and may be an ideal target for the prevention of proliferative retinopathy. PMID:15630447
High frequency of cytolytic 21-Hydroxylase specific CD8+ T cells in autoimmune Addison’s disease patients1

PubMed Central

Dawoodji, Amina; Chen, Ji-Li; Shepherd, Dawn; Dalin, Frida; Tarlton, Andrea; Alimohammadi, Mohammad; Penna-Martinez, Marissa; Meyer, Gesine; Mitchell, Anna L; Gan, Earn H; Bratland, Eirik; Bensing, Sophie; Husebye, Eystein; Pearce, Simon H.; Badenhoop, Klaus; Kämpe, Olle; Cerundolo, Vincenzo

2016-01-01

The mechanisms behind the destruction of the adrenal glands in autoimmune Addison’s disease remain unclear. Autoantibodies against steroid 21-hydroxylase, an intracellular key enzyme of the adrenal cortex, are found in over 90% of patients, but these autoantibodies are not thought to mediate the disease. Here we demonstrate highly frequent 21-hydroxylase specific T cells detectable in 20 patients with Addison’s disease. Using overlapping 18aa peptides spanning the full length of 21-hydroxylase, we identified immunodominant CD8+ and CD4+ T cell responses in a large proportion of Addison’s patients both ex-vivo and after in-vitro culture of peripheral blood lymphocytes up to 20 years after diagnosis. In a large proportion of patients, CD8+ 21-hydroxylase specific T cells and CD4+ 21-hydroxylase specific T cells were very abundant and detectable in ex-vivo assays. HLA class-I tetramer-guided isolation of 21-hydroxylase specific CD8+ T cells showed their ability to lyse 21-hydroxylase positive target cells, consistent with a potential mechanism for disease pathogenesis. These data indicate strong cytotoxic T lymphocyte responses to 21-hydroxylase often occur in-vivo, and that reactive cytotoxic T lymphocytes have substantial proliferative and cytolytic potential. These results have implications for earlier diagnosis of adrenal failure and ultimately a potential target for therapeutic intervention and induction of immunity against adrenal cortex cancer. PMID:25063864
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
Lymphocyte proliferative responses of goats vaccinated with Brucella melitensis 16M or a delta purE201 strain.

PubMed Central

Olsen, S C; Cheville, N F; Stevens, M G; Houng, H H; Drazek, E S; Hadfield, T L; Warren, R L; Hoover, D L

1997-01-01

The response to a Brucella melitensis purEK deletion mutant, delta purE201 (referred to as strain 201), was compared with the response to its parental strain, 16M, in juvenile goats. Proliferative responses to gamma-irradiated bacteria were detected earlier in strain 201-infected goats. Lymphocytes from strain 16M- or 201-infected goats proliferated in response to one-dimensional polyacrylamide gel electrophoresis-separated proteins of similar mass isolated from strain 16M or Brucella abortus RB51. Data from this study suggest that some antigens stimulating cell-mediated responses are conserved among Brucella species, as 201- and 16M-infected goats recognized similar proteins expressed by RB51 and 16M. PMID:9199478
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.
A synthetic cryptochrome inhibitor induces anti-proliferative effects and increases chemosensitivity in human breast cancer cells

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

Chun, Sung Kook; Department of Biological Sciences, Seoul National University, Seoul, 151-747; Department of Brain & Cognitive Sciences, Seoul National University, Seoul, 151-747

Disruption of circadian rhythm is a major cause of breast cancer in humans. Cryptochrome (CRY), a circadian transcription factor, is a risk factor for initiation of breast cancer, and it is differentially expressed between normal and breast cancer tissues. Here, we evaluated the anti-proliferative and pro-apoptotic activity of KS15, a recently discovered small-molecule inhibitor of CRY, in human breast cancer cells. First, we investigated whether KS15 treatment could promote E-box-mediated transcription by inhibiting the activity of CRY in MCF-7 human breast cancer cells. Protein and mRNA levels of regulators of cell cycle and apoptosis, as well as core clock genes,more » were differentially modulated in response to KS15. Next, we investigated whether KS15 could inhibit proliferation and increase sensitivity to anti-tumor drugs in MCF-7 cells. We found that KS15 decreased the speed of cell growth and increased the chemosensitivity of MCF-7 cells to doxorubicin and tamoxifen, but had no effect on MCF-10A cells. These findings suggested that pharmacological inhibition of CRY by KS15 exerts an anti-proliferative effect and increases sensitivity to anti-tumor drugs in a specific type of breast cancer. - Highlights: • Cryptochrome inhibitor (KS15) has anti-tumor activity to human breast cancer cells. • KS15 induces differential changes in cell cycle regulators and pro-apoptotic genes. • KS15 inhibits MCF-7 cell growth and enhances susceptibility to anti-tumor drugs.« less

Effect of thermal processing on T cell reactivity of shellfish allergens - Discordance with IgE reactivity.

PubMed

Abramovitch, Jodie B; Lopata, Andreas L; O'Hehir, Robyn E; Rolland, Jennifer M

2017-01-01

Crustacean allergy is a major cause of food-induced anaphylaxis. We showed previously that heating increases IgE reactivity of crustacean allergens. Here we investigate the effects of thermal processing of crustacean extracts on cellular immune reactivity. Raw and cooked black tiger prawn, banana prawn, mud crab and blue swimmer crab extracts were prepared and IgE reactivity assessed by ELISA. Mass spectrometry revealed a mix of several allergens in the raw mud crab extract but predominant heat-stable tropomyosin in the cooked extract. PBMC from crustacean-allergic and non-atopic control subjects were cultured with the crab and prawn extracts and proliferation of lymphocyte subsets was analysed by CFSE labelling and flow cytometry. Effector responses were assessed by intracellular IL-4 and IFN-γ, and regulatory T (CD4+CD25+CD127loFoxp3+) cell proportions in cultures were also compared by flow cytometry. For each crustacean species, the cooked extract had greater IgE reactivity than the raw (mud crab p<0.05, other species p<0.01). In contrast, there was a trend for lower PBMC proliferative responses to cooked compared with raw extracts. In crustacean-stimulated PBMC cultures, dividing CD4+ and CD56+ lymphocytes showed higher IL-4+/IFN-γ+ ratios for crustacean-allergic subjects than for non-atopics (p<0.01), but there was no significant difference between raw and cooked extracts. The percentage IL-4+ of dividing CD4+ cells correlated with total and allergen-specific IgE levels (prawns p<0.01, crabs p<0.05). Regulatory T cell proportions were lower in cultures stimulated with cooked compared with raw extracts (mud crab p<0.001, banana prawn p<0.05). In conclusion, cooking did not substantially alter overall T cell proliferative or cytokine reactivity of crustacean extracts, but decreased induction of Tregs. In contrast, IgE reactivity of cooked extracts was increased markedly. These novel findings have important implications for improved diagnostics, managing
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

A detailed characterization of the dynamics and breadth of the immune response to an acute viral infection, as well as the determinants of recruitment to immunological memory, can greatly contribute to our basic understanding of the mechanics of the human immune system and can ultimately guide the design of effective vaccines. In addition to neutralizing antibodies, T cells have been shown to be critical for the effective resolution of acute viral infections. We report the first in-depth analysis of the dynamics of the CD8(+) T cell repertoire at the level of individual T cell clonal lineages upon vaccination of human volunteers with a single dose of YF-17D. This live attenuated yellow fever virus vaccine yields sterile, long-term immunity and has been previously used as a model to understand the immune response to a controlled acute viral infection. We identified and enumerated unique CD8(+) T cell clones specifically induced by this vaccine through a combined experimental and statistical approach that included high-throughput sequencing of the CDR3 variable region of the T cell receptor β-chain and an algorithm that detected significantly expanded T cell clones. This allowed us to establish that (i) on average, ∼ 2,000 CD8(+) T cell clones were induced by YF-17D, (ii) 5 to 6% of the responding clones were recruited to long-term memory 3 months postvaccination, (iii) the most highly expanded effector clones were preferentially recruited to the memory compartment, and (iv) a fraction of the YF-17D-induced clones could be identified from peripheral blood lymphocytes solely by measuring clonal expansion. The exhaustive investigation of pathogen-induced effector T cells is essential to accurately quantify the dynamics of the human immune response. The yellow fever vaccine (YFV) has been broadly used as a model to understand how a controlled, self-resolving acute viral infection induces an effective and long-term protective immune response. Here, we extend this
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

ABSTRACT A detailed characterization of the dynamics and breadth of the immune response to an acute viral infection, as well as the determinants of recruitment to immunological memory, can greatly contribute to our basic understanding of the mechanics of the human immune system and can ultimately guide the design of effective vaccines. In addition to neutralizing antibodies, T cells have been shown to be critical for the effective resolution of acute viral infections. We report the first in-depth analysis of the dynamics of the CD8+ T cell repertoire at the level of individual T cell clonal lineages upon vaccination of human volunteers with a single dose of YF-17D. This live attenuated yellow fever virus vaccine yields sterile, long-term immunity and has been previously used as a model to understand the immune response to a controlled acute viral infection. We identified and enumerated unique CD8+ T cell clones specifically induced by this vaccine through a combined experimental and statistical approach that included high-throughput sequencing of the CDR3 variable region of the T cell receptor β-chain and an algorithm that detected significantly expanded T cell clones. This allowed us to establish that (i) on average, ∼2,000 CD8+ T cell clones were induced by YF-17D, (ii) 5 to 6% of the responding clones were recruited to long-term memory 3 months postvaccination, (iii) the most highly expanded effector clones were preferentially recruited to the memory compartment, and (iv) a fraction of the YF-17D-induced clones could be identified from peripheral blood lymphocytes solely by measuring clonal expansion. IMPORTANCE The exhaustive investigation of pathogen-induced effector T cells is essential to accurately quantify the dynamics of the human immune response. The yellow fever vaccine (YFV) has been broadly used as a model to understand how a controlled, self-resolving acute viral infection induces an effective and long-term protective immune response. Here, we
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
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
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
Stimulation of interleukin-13 expression by human T-cell leukemia virus type 1 oncoprotein Tax via a dually active promoter element responsive to NF-kappaB and NFAT.

PubMed

Silbermann, Katrin; Schneider, Grit; Grassmann, Ralph

2008-11-01

The human T-cell leukemia virus type 1 (HTLV-1) Tax oncoprotein transforms human lymphocytes and is critical for the pathogenesis of HTLV-1-induced adult T-cell leukaemia. In HTLV-transformed cells, Tax upregulates interleukin (IL)-13, a cytokine with proliferative and anti-apoptotic functions that is linked to leukaemogenesis. Tax-stimulated IL-13 is thought to result in autocrine stimulation of HTLV-infected cells and thus may be relevant to their growth. The causal transactivation of the IL-13 promoter by Tax is predominantly dependent on a nuclear factor of activated T cells (NFAT)-binding P element. Here, it was shown that the isolated IL-13 Tax-responsive element (IL13TaxRE) was sufficient to mediate IL-13 transactivation by Tax and NFAT1. However, cyclosporin A, a specific NFAT inhibitor, revealed that Tax transactivation of IL13TaxRE or wild-type IL-13 promoter was independent of NFAT and that NFAT did not contribute to IL-13 upregulation in HTLV-transformed cells. By contrast, Tax stimulation was repressible by an efficient nuclear factor (NF)-kappaB inhibitor (IkBaDN), indicating the requirement for NF-kappaB. The capacity of NF-kappaB to stimulate IL13TaxRE was demonstrated by a strong response to NF-kappaB in reporter assays and by direct binding of NF-kappaB to IL13TaxRE. Thus, IL13TaxRE in the IL-13 promoter represents a dually active promoter element responsive to NF-kappaB and NFAT. Together, these results indicate that Tax causes IL-13 upregulation in HTLV-1-infected cells via NF-kappaB.
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
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
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
Isolation of Chlorogenic Acid from Soil Borne Fungi Screlotium rolfsii, their Reversal of Multidrug Resistance and Anti-proliferative in Mouse Lymphoma Cells.

PubMed

Ahmad, Bashir; Rizwan, Muhammad; Rauf, Abdur; Raza, Muslim; Bashir, Shumaila; Molnar, Joseph; Csonka, Akos; Szabo, Diana; Mubarak, Mohammad S; Noor, Mah; Siddiqui, Bina S

2017-01-01

Fungi performing a wide range of function in soil by secreting low molecular weight compound known as secondary metabolites. S. rolfsii is a soil borne phytopathogenic fungi was used for the production of bioactive compounds. The present study belongs to evaluate the anticancer potentials of a secondary metabolites isolated from S. rolfsii, their multidrug resistance (MDR), and molecular docking study. (1S,3R,4R,5R,E)-3-(3-(3,4-Dihydroxyphenyl)acryloyloxy)-1,4,5 trihydroxycyclohexanecarboxylic acid (1), or best known as chlorogenic acid, was isolated from the ethyl acetate fraction of crude secondary metabolites produced by the soil borne Fungus Screlotium rolfsii. Structure of chlorogenic acid (1) was confirmed by means of FT-IR, 1H NMR, 13C NMR, and mass spectrometry as well as by melting point. Effect of compound 1 on the reversion of multidrug resistant (MDR) mediated by Pglycoprotein (P-gp) against cancer cells was evaluated with a rhodamine-123 exclusion screening test on human mdr1 gene transfected mouse gene transfected L5178 and L5178Y mouse T-cell lymphoma. Compound 1 was also evaluated for Anti-proliferative effect on the L5178 mouse Tcell lymphoma cell line. Results from the present investigation revealed that compound 1 exhibits excellent MDR reversing effect in a dose-dependent manner against mouse T-lymphoma cell line. Compound 1 also showed anti-proliferative effect on L5178Y mouse T-lymphoma cell line. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.
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.
Merkel cell polyomavirus small T antigen initiates Merkel cell carcinoma-like tumor development in mice

PubMed Central

Verhaegen, Monique E.; Mangelberger, Doris; Harms, Paul W.; Eberl, Markus; Wilbert, Dawn M.; Meireles, Julia; Bichakjian, Christopher K.; Saunders, Thomas L.; Wong, Sunny Y.; Dlugosz, Andrzej A.

2017-01-01

Merkel cell carcinoma (MCC) tumor cells express several markers detected in normal Merkel cells, a non-proliferative population of neuroendocrine cells which arise from epidermis. MCCs frequently contain Merkel cell polyomavirus (MCPyV) DNA and express viral transforming antigens, sT and tLT, but the role of these putative oncogenes in MCC development, and this tumor’s cell of origin, are unknown. Using a panel of pre-term transgenic mice, we show that epidermis-targeted co-expression of sT and the cell fate determinant atonal bHLH transcription factor 1 (Atoh1) leads to development of widespread cellular aggregates with histology and marker expression mimicking that of human intraepidermal MCC. The MCC-like tumor phenotype was dependent on the FBXW7-binding domain of sT, but not the sT-PP2A binding domain. Co-expression of MCPyV tLT did not appreciably alter the phenotype driven by either sT or sT combined with Atoh1. MCPyV sT, when co-expressed with Atoh1, is thus sufficient to initiate development of epidermis-derived MCC-like tumors in mice. PMID:28512245
Inhibition of lymphocyte proliferative responses to Helicobacter pylori by plastic adherent cells.

PubMed

Uyub, A M; Anuar, A K

2001-03-01

A study was carried out on 49 H. pylori-positive and 11 H. pylori-negative patients to determine the reactivity of peripheral blood lymphocytes (PBL) to phytohemagglutinin (PHA) and acid glycine extract (AGE) of H. pylori, and to identify cells responsible for imunosuppression. Based on response to PHA stimulation, cell-mediated immunity of all patients were competent. In some patients, however, response to AGE of H. pylori was suppressed by plastic adherent cells. This study provided evidence of the presence of plastic adherent suppressor cells which suppressed PBL response to AGE of H. pylori but not to PHA suggesting that immunosuppression is antigen specific. There is also an indication that immunosuppression may be species-specific as PBL devoid of plastic adherent cells only responded to stimulation by AGE of H. pylori but not that to AGE of C. jejuni.
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.
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.
Deconvoluting Post-Transplant Immunity: Cell Subset-Specific Mapping Reveals Pathways for Activation and Expansion of Memory T, Monocytes and B Cells

PubMed Central

Grigoryev, Yevgeniy A.; Kurian, Sunil M.; Avnur, Zafi; Borie, Dominic; Deng, Jun; Campbell, Daniel; Sung, Joanna; Nikolcheva, Tania; Quinn, Anthony; Schulman, Howard; Peng, Stanford L.; Schaffer, Randolph; Fisher, Jonathan; Mondala, Tony; Head, Steven; Flechner, Stuart M.; Kantor, Aaron B.; Marsh, Christopher; Salomon, Daniel R.

2010-01-01

A major challenge for the field of transplantation is the lack of understanding of genomic and molecular drivers of early post-transplant immunity. The early immune response creates a complex milieu that determines the course of ensuing immune events and the ultimate outcome of the transplant. The objective of the current study was to mechanistically deconvolute the early immune response by purifying and profiling the constituent cell subsets of the peripheral blood. We employed genome-wide profiling of whole blood and purified CD4, CD8, B cells and monocytes in tandem with high-throughput laser-scanning cytometry in 10 kidney transplants sampled serially pre-transplant, 1, 2, 4, 8 and 12 weeks. Cytometry confirmed early cell subset depletion by antibody induction and immunosuppression. Multiple markers revealed the activation and proliferative expansion of CD45RO+CD62L− effector memory CD4/CD8 T cells as well as progressive activation of monocytes and B cells. Next, we mechanistically deconvoluted early post-transplant immunity by serial monitoring of whole blood using DNA microarrays. Parallel analysis of cell subset-specific gene expression revealed a unique spectrum of time-dependent changes and functional pathways. Gene expression profiling results were validated with 157 different probesets matching all 65 antigens detected by cytometry. Thus, serial blood cell monitoring reflects the profound changes in blood cell composition and immune activation early post-transplant. Each cell subset reveals distinct pathways and functional programs. These changes illuminate a complex, early phase of immunity and inflammation that includes activation and proliferative expansion of the memory effector and regulatory cells that may determine the phenotype and outcome of the kidney transplant. PMID:20976225
Deconvoluting post-transplant immunity: cell subset-specific mapping reveals pathways for activation and expansion of memory T, monocytes and B cells.

PubMed

Grigoryev, Yevgeniy A; Kurian, Sunil M; Avnur, Zafi; Borie, Dominic; Deng, Jun; Campbell, Daniel; Sung, Joanna; Nikolcheva, Tania; Quinn, Anthony; Schulman, Howard; Peng, Stanford L; Schaffer, Randolph; Fisher, Jonathan; Mondala, Tony; Head, Steven; Flechner, Stuart M; Kantor, Aaron B; Marsh, Christopher; Salomon, Daniel R

2010-10-14

A major challenge for the field of transplantation is the lack of understanding of genomic and molecular drivers of early post-transplant immunity. The early immune response creates a complex milieu that determines the course of ensuing immune events and the ultimate outcome of the transplant. The objective of the current study was to mechanistically deconvolute the early immune response by purifying and profiling the constituent cell subsets of the peripheral blood. We employed genome-wide profiling of whole blood and purified CD4, CD8, B cells and monocytes in tandem with high-throughput laser-scanning cytometry in 10 kidney transplants sampled serially pre-transplant, 1, 2, 4, 8 and 12 weeks. Cytometry confirmed early cell subset depletion by antibody induction and immunosuppression. Multiple markers revealed the activation and proliferative expansion of CD45RO(+)CD62L(-) effector memory CD4/CD8 T cells as well as progressive activation of monocytes and B cells. Next, we mechanistically deconvoluted early post-transplant immunity by serial monitoring of whole blood using DNA microarrays. Parallel analysis of cell subset-specific gene expression revealed a unique spectrum of time-dependent changes and functional pathways. Gene expression profiling results were validated with 157 different probesets matching all 65 antigens detected by cytometry. Thus, serial blood cell monitoring reflects the profound changes in blood cell composition and immune activation early post-transplant. Each cell subset reveals distinct pathways and functional programs. These changes illuminate a complex, early phase of immunity and inflammation that includes activation and proliferative expansion of the memory effector and regulatory cells that may determine the phenotype and outcome of the kidney transplant.
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
PGE2 suppresses intestinal T cell function in thermal injury: a cause of enhanced bacterial translocation.

PubMed

Choudhry, M A; Fazal, N; Namak, S Y; Haque, F; Ravindranath, T; Sayeed, M M

2001-09-01

Increased gut bacterial translocation in burn and trauma patients has been demonstrated in a number of previous studies, however, the mechanism for such an increased gut bacterial translocation in injured patients remains poorly understood. Utilizing a rat model of burn injury, in the present study we examined the role of intestinal immune defense by analyzing the T cell functions. We investigated if intestinal T cells dysfunction contributes to bacterial translocation after burn injury. Also our study determined if burn-mediated alterations in intestinal T cell functions are related to enhanced release of PGE2. Finally, we examined whether or not burn-related alterations in intestinal T cell function are due to inappropriate activation of signaling molecule P59fyn, which is required for T cell activation and proliferation. The results presented here showed an increase in gut bacterial accumulation in mesenteric lymph nodes after thermal injury. This was accompanied by a decrease in the intestinal T cell proliferative responses. Furthermore, the treatments of burn-injured animals with PGE2 synthesis blocker (indomethacin or NS398) prevented both the decrease in intestinal T cell proliferation and enhanced bacterial translocation. Finally, our data suggested that the inhibition of intestinal T cell proliferation could result via PGE2-mediated down-regulation of the T cell activation-signaling molecule P59fyn. These findings support a role of T cell-mediated immune defense against bacterial translocation in burn injury.

T Cells Encountering Myeloid Cells Programmed for Amino Acid-dependent Immunosuppression Use Rictor/mTORC2 Protein for Proliferative Checkpoint Decisions*

PubMed Central

Van de Velde, Lee-Ann; Subramanian, Chitra; Smith, Amber M.; Barron, Luke; Qualls, Joseph E.; Neale, Geoffrey; Alfonso-Pecchio, Adolfo; Jackowski, Suzanne; Rock, Charles O.; Wynn, Thomas A.; Murray, Peter J.

2017-01-01

Modulation of T cell proliferation and function by immunoregulatory myeloid cells are an essential means of preventing self-reactivity and restoring tissue homeostasis. Consumption of amino acids such as arginine and tryptophan by immunoregulatory macrophages is one pathway that suppresses local T cell proliferation. Using a reduced complexity in vitro macrophage-T cell co-culture system, we show that macrophage arginase-1 is the only factor required by M2 macrophages to block T cells in G1, and this effect is mediated by l-arginine elimination rather than metabolite generation. Tracking how T cells adjust their metabolism when deprived of arginine revealed the significance of macrophage-mediated arginine deprivation to T cells. We found mTORC1 activity was unaffected in the initial G1 block. After 2 days of arginine deprivation, mTORC1 activity declined paralleling a selective down-regulation of SREBP target gene expression, whereas mRNAs involved in glycolysis, gluconeogenesis, and T cell activation were unaffected. Cell cycle arrest was reversible at any point by exogenous arginine, suggesting starved T cells remain poised awaiting nutrients. Arginine deprivation-induced cell cycle arrest was mediated in part by Rictor/mTORC2, providing evidence that this nutrient recognition pathway is a central component of how T cells measure environmental arginine. PMID:27903651
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
Peanut-specific type 1 regulatory T cells induced in vitro from allergic subjects are functionally impaired.

PubMed

Pellerin, Laurence; Jenks, Jennifer Anne; Chinthrajah, Sharon; Dominguez, Tina; Block, Whitney; Zhou, Xiaoying; Noshirvan, Arram; Gregori, Silvia; Roncarolo, Maria Grazia; Nadeau, Kari Christine; Bacchetta, Rosa

2018-01-01

Peanut allergy (PA) is a life-threatening condition that lacks regulator-approved treatment. Regulatory T type 1 (T R 1) cells are potent suppressors of immune responses and can be induced in vivo upon repeated antigen exposure or in vitro by using tolerogenic dendritic cells. Whether oral immunotherapy (OIT) leads to antigen-specific T R 1 cell induction has not been established. We sought to determine whether peanut-specific T R 1 cells can be generated in vitro from peripheral blood of patients with PA at baseline or during OIT and whether they are functional compared with peanut-specific T R 1 cells induced from healthy control (HC) subjects. Tolerogenic dendritic cells were differentiated in the presence of IL-10 from PBMCs of patients with PA and HC subjects pulsed with the main peanut allergens of Arachis hypogaea, Ara h 1 and 2, and used as antigen-presenting cells for autologous CD4 + T cells (CD4 + T cells coincubated with tolerogenic dendritic cells pulsed with the main peanut allergens [pea-T10 cells]). Pea-T10 cells were characterized by the presence of CD49b + lymphocyte-activation gene 3 (LAG3) + T R 1 cells, antigen-specific proliferative responses, and cytokine production. CD49b + LAG3 + T R 1 cells were induced in pea-T10 cells at comparable percentages from HC subjects and patients with PA. Despite their antigen specificity, pea-T10 cells of patients with PA with or without OIT, as compared with those of HC subjects, were not anergic and had high T H 2 cytokine production upon peanut-specific restimulation. Peanut-specific T R 1 cells can be induced from HC subjects and patients with PA, but those from patients with PA are functionally defective independent of OIT. The unfavorable T R 1/T H 2 ratio is discussed as a possible cause of PA T R 1 cell impairment. Copyright © 2017 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.
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
Regional control of Drosophila gut stem cell proliferation: EGF establishes GSSC proliferative set point & controls emergence from quiescence.

PubMed

Strand, Marie; Micchelli, Craig A

2013-01-01

Adult stem cells vary widely in their rates of proliferation. Some stem cells are constitutively active, while others divide only in response to injury. The mechanism controlling this differential proliferative set point is not well understood. The anterior-posterior (A/P) axis of the adult Drosophila midgut has a segmental organization, displaying physiological compartmentalization and region-specific epithelia. These distinct midgut regions are maintained by defined stem cell populations with unique division schedules, providing an excellent experimental model with which to investigate this question. Here, we focus on the quiescent gastric stem cells (GSSCs) of the acidic copper cell region (CCR), which exhibit the greatest period of latency between divisions of all characterized gut stem cells, to define the molecular basis of differential stem cell activity. Our molecular genetic analysis demonstrates that the mitogenic EGF signaling pathway is a limiting factor controlling GSSC proliferation. We find that under baseline conditions, when GSSCs are largely quiescent, the lowest levels of EGF ligands in the midgut are found in the CCR. However, acute epithelial injury by enteric pathogens leads to an increase in EGF ligand expression in the CCR and rapid expansion of the GSSC lineage. Thus, the unique proliferative set points for gut stem cells residing in physiologically distinct compartments are governed by regional control of niche signals along the A/P axis.
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
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
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.
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.
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.
Dramatic increase in naïve T cell turnover is linked to loss of naïve T cells from old primates

PubMed Central

Čičin-Šain, Luka; Messaoudi, Ilhem; Park, Byung; Currier, Noreen; Planer, Shannon; Fischer, Miranda; Tackitt, Shane; Nikolich-Žugich, Dragana; Legasse, Alfred; Axthelm, Michael K.; Picker, Louis J.; Mori, Motomi; Nikolich-Žugich, Janko

2007-01-01

The loss of naïve T cells is a hallmark of immune aging. Although thymic involution is a primary driver of this naïve T cell loss, less is known about the contribution of other mechanisms to the depletion of naïve T cells in aging primates. We examined the role of homeostatic cycling and proliferative expansion in different T cell subsets of aging rhesus macaques (RM). BrdU incorporation and the expression of the G1-M marker Ki-67 were elevated in peripheral naïve CD4 and even more markedly in the naïve CD8 T cells of old, but not young adult, RM. Proliferating naïve cells did not accumulate in old animals. Rather, the relative size of the naïve CD8 T cell compartment correlated inversely to its proliferation rate. Likewise, T cell receptor diversity decreased in individuals with elevated naïve CD8 T cell proliferation. This apparent contradiction was explained by a significant increase in turnover concomitant with the naïve pool loss. The turnover increased exponentially when the naïve CD8 T cell pool decreased below 4% of total blood CD8 cells. These results link the shrinking naïve T cell pool with a dramatic increase in homeostatic turnover, which has the potential to exacerbate the progressive exhaustion of the naïve pool and constrict the T cell repertoire. Thus, homeostatic T cell proliferation exhibits temporal antagonistic pleiotropy, being beneficial to T cell maintenance in adulthood but detrimental to the long-term T cell maintenance in aging individuals. PMID:18056811
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
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
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.
T Cells Encountering Myeloid Cells Programmed for Amino Acid-dependent Immunosuppression Use Rictor/mTORC2 Protein for Proliferative Checkpoint Decisions.

PubMed

Van de Velde, Lee-Ann; Subramanian, Chitra; Smith, Amber M; Barron, Luke; Qualls, Joseph E; Neale, Geoffrey; Alfonso-Pecchio, Adolfo; Jackowski, Suzanne; Rock, Charles O; Wynn, Thomas A; Murray, Peter J

2017-01-06

Modulation of T cell proliferation and function by immunoregulatory myeloid cells are an essential means of preventing self-reactivity and restoring tissue homeostasis. Consumption of amino acids such as arginine and tryptophan by immunoregulatory macrophages is one pathway that suppresses local T cell proliferation. Using a reduced complexity in vitro macrophage-T cell co-culture system, we show that macrophage arginase-1 is the only factor required by M2 macrophages to block T cells in G 1 , and this effect is mediated by l-arginine elimination rather than metabolite generation. Tracking how T cells adjust their metabolism when deprived of arginine revealed the significance of macrophage-mediated arginine deprivation to T cells. We found mTORC1 activity was unaffected in the initial G 1 block. After 2 days of arginine deprivation, mTORC1 activity declined paralleling a selective down-regulation of SREBP target gene expression, whereas mRNAs involved in glycolysis, gluconeogenesis, and T cell activation were unaffected. Cell cycle arrest was reversible at any point by exogenous arginine, suggesting starved T cells remain poised awaiting nutrients. Arginine deprivation-induced cell cycle arrest was mediated in part by Rictor/mTORC2, providing evidence that this nutrient recognition pathway is a central component of how T cells measure environmental arginine. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.
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
Enhanced clonal burst size corrects an otherwise defective memory response by CD8+ recent thymic emigrants

PubMed Central

Deets, Katherine A.; Berkley, Amy M.; Bergsbaken, Tessa; Fink, Pamela J.

2016-01-01

The youngest peripheral T cells (recent thymic emigrants or RTEs) are functionally distinct from naïve T cells that have completed post-thymic maturation. We now assess the RTE memory response, and find that RTEs produced less granzyme B than their mature counterparts during infection, but proliferated more and therefore generated equivalent target killing in vivo. After infection, RTE numbers contracted less dramatically than those of mature T cells, but RTEs were delayed in their transition to central memory, displaying impaired expression of CD62L, IL-2, Eomesodermin, and CXCR4, which resulted in impaired bone marrow localization. RTE-derived and mature memory cells expanded equivalently during rechallenge, indicating the robust proliferative capacity of RTEs was maintained independently of central memory phenotype. Thus, the diminished effector function and delayed central memory differentiation of RTE-derived memory cells are counterbalanced by their increased proliferative capacity, driving the efficacy of the RTE response to that of mature T cells. PMID:26873989
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.
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.
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.

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...
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
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
Detection of invariant natural killer T cells in ejaculates from infertile patients with chronic inflammation of genital tract.

PubMed

Duan, Yong-Gang; Chen, Shujian; Haidl, Gerhard; Allam, Jean-Pierre

2017-08-01

Chronic inflammation of genital tract is thought to play a major role in male fertility disorder. Natural killer (NK) T cells are a heterogeneous group of T cells that share properties of both T cells and NK cells which display immunoregulatory properties. However, little is known regarding the presence and function of NK T cells in ejaculates from patients with chronic inflammation of genital tract. Invariant NK T (iNK T) cells were detected by invariant (Vα24-JαQ) TCR chain in ejaculates from patients suffering from chronic inflammation of genital tract (CIGT) using flow cytometry and immunofluorescence of double staining (n=40). Inflammatory cytokines interleukin (IL)-6, IL-17, and IFN-γ were detected in cell-free seminal plasma using an enzyme-linked immunosorbent assay (ELISA). The correlation between the percentage of iNK T cells and spermatozoa count, motility, vitality, seminal IL-6, IL-17, and IFN-γ was investigated. Significant percentages of iNK T cells above 10% were detected in 50% (CIGT-NKT + group). A negative correlation was detected between the percentage of iNK T cells and spermatozoa count (r=-.5957, P=.0056), motility (r=-.6163, P=.0038), and vitality (r=-.8032, P=.0019) in CIGT-NKT + group (n=20). Interestingly, a significant correlation of iNK T cells to seminal IL-6 (r=.7083, P=.0005), IFN-γ (r=.9578, P<.0001) was detected whereas lack of correlation between iNK T cells and IL-17 (r=-.1557, P=.5122) in CIGT-NKT + group. The proliferative response of iNK T cells could accompany an inflammatory response to spermatozoa and consequently influence sperm quality through secretion of IFN-γ but not IL-17 under chronic inflammatory condition. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Secretion of cytokines in breast cancer cells: the molecular mechanism of procathepsin D proliferative effects.

PubMed

Fusek, Martin; Vetvickova, Jana; Vetvicka, Vaclav

2007-03-01

Procathepsin D (pCD) is a major secreted protein in estrogen receptor-positive (ER+) breast cancer cell lines. Several independent studies have documented pronounced mitogenic effect of secreted pCD on cancer tissue-derived cell lines, including those from breast, lung, and prostate cancer. It has also been shown that the proliferative effect of pCD involves both autocrine and paracrine modes of action. Recent studies have suggested that pCD could act as a key paracrine communicator between cancer and stromal cells. We have shown earlier that the proliferative activity of pCD depends on the activation peptide sequence of pCD. The present study casts light on the mechanism by which pCD influences the proliferation of cancer cells expressing the ER. Results described in the current paper clearly show that pCD initiates secretion of cytokines interleukin-4 (IL-4), IL-8, IL-10, IL-13, macrophage inflammatory protein-1beta and (MIP-1beta) from such tumor cells. Secreted cytokines take part in the proliferation of the cancer cells, as proven by selective inhibition using antibodies. In addition, expression of cytokine receptors on tested cell lines corresponded to the effects of individual cytokines. An analogous pattern was also observed for fibroblasts, which, under physiologic conditions, are the cells in closest contact with the tumor tissue and play a role in tumor growth and invasion. Our observations were further supported by coculture experiments that are in agreement. Although very similar in response to addition of pCD, the invasive ER- cells do not secrete cytokines. Together with previous in vivo results, these data point to pCD as one of key molecules for therapeutic attack in breast cancer.
GARP-TGF-β complexes negatively regulate regulatory T cell development and maintenance of peripheral CD4+ T cells in vivo.

PubMed

Zhou, Angela X; Kozhaya, Lina; Fujii, Hodaka; Unutmaz, Derya

2013-05-15

The role of surface-bound TGF-β on regulatory T cells (Tregs) and the mechanisms that mediate its functions are not well defined. We recently identified a cell-surface molecule called Glycoprotein A Repetitions Predominant (GARP), which is expressed specifically on activated Tregs and was found to bind latent TGF-β and mediate a portion of Treg suppressive activity in vitro. In this article, we address the role of GARP in regulating Treg and conventional T cell development and immune suppression in vivo using a transgenic mouse expressing GARP on all T cells. We found that, despite forced expression of GARP on all T cells, stimulation through the TCR was required for efficient localization of GARP to the cell surface. In addition, IL-2 signals enhanced GARP cell surface expression specifically on Tregs. GARP-transgenic CD4(+) T cells and Tregs, especially those expressing higher levels of GARP, were significantly reduced in the periphery. Mature Tregs, but not conventional CD4(+) T cells, were also reduced in the thymus. CD4(+) T cell reduction was more pronounced within the effector/memory subset, especially as the mouse aged. In addition, GARP-overexpressing CD4(+) T cells stimulated through the TCR displayed reduced proliferative capacity, which was restored by inhibiting TGF-β signaling. Furthermore, inhibiting TGF-β signals greatly enhanced surface expression of GARP on Tregs and blocked the induction of Foxp3 in activated CD4(+) T cells overexpressing GARP. These findings suggest a role for GARP in natural and induced Treg development through activation of bound latent TGF-β and signaling, which negatively regulates GARP expression on Tregs.
High frequency of cytolytic 21-hydroxylase-specific CD8+ T cells in autoimmune Addison's disease patients.

PubMed

Dawoodji, Amina; Chen, Ji-Li; Shepherd, Dawn; Dalin, Frida; Tarlton, Andrea; Alimohammadi, Mohammad; Penna-Martinez, Marissa; Meyer, Gesine; Mitchell, Anna L; Gan, Earn H; Bratland, Eirik; Bensing, Sophie; Husebye, Eystein S; Pearce, Simon H; Badenhoop, Klaus; Kämpe, Olle; Cerundolo, Vincenzo

2014-09-01

The mechanisms behind destruction of the adrenal glands in autoimmune Addison's disease remain unclear. Autoantibodies against steroid 21-hydroxylase, an intracellular key enzyme of the adrenal cortex, are found in >90% of patients, but these autoantibodies are not thought to mediate the disease. In this article, we demonstrate highly frequent 21-hydroxylase-specific T cells detectable in 20 patients with Addison's disease. Using overlapping 18-aa peptides spanning the full length of 21-hydroxylase, we identified immunodominant CD8(+) and CD4(+) T cell responses in a large proportion of Addison's patients both ex vivo and after in vitro culture of PBLs ≤20 y after diagnosis. In a large proportion of patients, CD8(+) and CD4(+) 21-hydroxylase-specific T cells were very abundant and detectable in ex vivo assays. HLA class I tetramer-guided isolation of 21-hydroxylase-specific CD8(+) T cells showed their ability to lyse 21-hydroxylase-positive target cells, consistent with a potential mechanism for disease pathogenesis. These data indicate that strong CTL responses to 21-hydroxylase often occur in vivo, and that reactive CTLs have substantial proliferative and cytolytic potential. These results have implications for earlier diagnosis of adrenal failure and ultimately a potential target for therapeutic intervention and induction of immunity against adrenal cortex cancer. Copyright © 2014 by The American Association of Immunologists, Inc.
Cellular basis for neonatally induced T-suppressor activity. Primary B cell maturation is blocked by suppressor-helper interactions restricted by loci on chromosome 12

PubMed Central

1985-01-01

The cellular mechanism and genetic restriction of neonatally induced HA- specific suppressor T (Ts) cells have been examined. The in vivo effect of these Ts cells on antibody production, primary B cell proliferation, B cell surface marker changes, and helper T (Th) cell priming during primary responses to HA have been determined. The results indicate that, although antigen-induced B cell proliferative responses and surface marker changes occur in the presence of Ts cells, differentiation to Ig secretion, and long-lived memory B cell production are prevented. Further, antigen-specific Th cell priming is completely ablated by Ts cells, suggesting that Ts act by preventing the delivery of Th signals required for both the later stages of primary B cell maturation, and the formation of memory B cell populations. Finally, in vivo cell mixing experiments using congenic mice indicate that this Ts-Th interaction is restricted by loci on mouse chromosome 12. PMID:2580040
Selective anti-proliferative activities of Carica papaya leaf juice extracts against prostate cancer.

PubMed

Pandey, Saurabh; Walpole, Carina; Cabot, Peter J; Shaw, Paul N; Batra, Jyotsna; Hewavitharana, Amitha K

2017-05-01

Prostate cancer (PCa) is the leading cause of cancer related deaths in men. Carica papaya is a popular tropical plant that has been traditionally used for its nutritional and medicinal properties. We investigated the anti-proliferative responses of papaya leaf juice (LJP) and its various extracts ("biological"- in vitro digested, "physical"- size exclusion, and "chemical"-solvent extraction) on a range of cell lines representing benign hyperplasia, tumorigenic and normal cells of prostate origin. Time course analysis (by 24h, 48h and 72h) of LJP (1-0.1mg/mL) before and after in vitro digestion, and of molecular weight based fractions of LJP showed anti-proliferative responses. The medium polarity fraction of LJP (0.03-0.003mg/mL) after 72h exposure showed potent growth inhibitory (IC 50 =0.02-0.07mg/mL) and cytotoxic activities on all prostate cells, with the exception of the normal (RWPE-1 and WPMY-1) cells. Flow cytometry analysis showed S phase cell cycle arrest and apoptosis as a possible mechanism for these activities. Medium polar fraction of LJP also inhibited migration and adhesion of metastatic PC-3 cells. This is the first report suggesting selective anti-proliferative and anti-metastatic attributes of LJP extract against prostatic diseases, including PCa. Copyright © 2017 Elsevier Masson SAS. All rights reserved.
Elucidation of proliferative capability of mononuclear tetraploid cells, emerging spontaneously from diploid cells, using image cytometry and fluorescence in situ hybridization.

PubMed

Ito, Hideaki; Oga, Atsunori; Furuya, Tomoko; Ikemoto, Kenzo; Amakawa, Genta; Chochi, Yasuyo; Kawauchi, Shigeto; Sasaki, Kohsuke

2013-06-01

Proliferation of tetraploid cells (TCs) emerging from diploid cells is considered to be a critical event toward tumourigenesis, or cancer progression. Recently, several studies have reported that binuclear TCs emerging from normal cells are capable of mitosis, however, it has not been confirmed directly whether mononuclear TCs emerging from normal cells could proliferate, even cancer cells. The aim of this study is to detect mononuclear TCs in vitro, spontaneously emerging from diploid cells and to elucidate their proliferative capability directly. For this purpose, we have developed a novel method. In this study, two completely disomic cell lines were used, TIG-7, a fibroblast cell line and CAL-51, a breast cancer cell line. Cells were cultured on microscope slides and their DNA content was determined using an image cytometer. On the same slides, chromosome numbers were scored using centromere fluorescence in situ hybridization (FISH). For evaluating proliferative capability of TCs, bromodeoxyuridine (BrdUrd) incorporation and colony-forming ability were examined. Using our method, spontaneous emergence of mononuclear TCs was detected in both TIG-7 and CAL-51. Colonies of TIG-7 TCs were not observed, but were observed of CAL-51 TCs. Our method enables detection of mononuclear TCs and elucidation of their proliferative capability, directly; this evidence reveals that mononuclear TIG-7 TCs do not proliferate but that mononuclear CAL-51 TCs are able to. © 2013 Blackwell Publishing Ltd.
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.
Impact of T-cell-specific Smad4 deficiency on the development of autoimmune diabetes in NOD mice

PubMed Central

Kim, Donghee; Lee, Song Mi; Jun, Hee-Sook

2017-01-01

Type 1 diabetes results from autoimmune-mediated pancreatic beta-cell destruction and transforming growth factor-beta (TGF-β) is known to play a preventive role in type 1 diabetes in non-obese diabetic (NOD) mice. In this study, we investigated the role of Smad4, a key molecule for Smad-dependent TGF-β signaling, in T cells of NOD mice in the pathogenesis of autoimmune diabetes. We generated T-cell-specific Smad4 knockout (Smad4 tKO) NOD mice and assessed the pathological and immunological changes. Smad4 tKO showed earlier onset and increased incidence of diabetes than wild type (WT) NOD mice. Pathological features such as insulitis, anti-glutamic acid decarboxylase auto-antibody levels and serum IFN-γ levels were significantly increased in Smad4 tKO compared with WT NOD mice. Proportion and number of activated/memory CD4+ T cell were significantly increased in pancreatic lymph nodes of Smad4 tKO compared with WT NOD mice. However, the proportion and function of regulatory T cells was not different. Effector CD4+ T cells from Smad4 tKO were more resistant to suppression by regulatory T cells than effector cells from WT NOD mice. The proliferative potential of effector T cells from Smad4 tKO was significantly elevated compared with WT NOD mice, and activation of sterol regulatory element binding protein-1c (SREBP-1c) in T cells of Smad4 tKO NOD mice was correlated with this proliferative activity. We conclude that Smad4 deletion in T cells of NOD mice accelerated the development of autoimmune diabetes and increased the incidence of the disease by dysregulation of T cell activation at least in part via SREBP-1c activation. PMID:27686408
Impact of T-cell-specific Smad4 deficiency on the development of autoimmune diabetes in NOD mice.

PubMed

Kim, Donghee; Lee, Song Mi; Jun, Hee-Sook

2017-03-01

Type 1 diabetes results from autoimmune-mediated pancreatic beta-cell destruction and transforming growth factor-beta (TGF-β) is known to play a preventive role in type 1 diabetes in non-obese diabetic (NOD) mice. In this study, we investigated the role of Smad4, a key molecule for Smad-dependent TGF-β signaling, in T cells of NOD mice in the pathogenesis of autoimmune diabetes. We generated T-cell-specific Smad4 knockout (Smad4 tKO) NOD mice and assessed the pathological and immunological changes. Smad4 tKO showed earlier onset and increased incidence of diabetes than wild type (WT) NOD mice. Pathological features such as insulitis, anti-glutamic acid decarboxylase auto-antibody levels and serum IFN-γ levels were significantly increased in Smad4 tKO compared with WT NOD mice. Proportion and number of activated/memory CD4 + T cell were significantly increased in pancreatic lymph nodes of Smad4 tKO compared with WT NOD mice. However, the proportion and function of regulatory T cells was not different. Effector CD4 + T cells from Smad4 tKO were more resistant to suppression by regulatory T cells than effector cells from WT NOD mice. The proliferative potential of effector T cells from Smad4 tKO was significantly elevated compared with WT NOD mice, and activation of sterol regulatory element binding protein-1c (SREBP-1c) in T cells of Smad4 tKO NOD mice was correlated with this proliferative activity. We conclude that Smad4 deletion in T cells of NOD mice accelerated the development of autoimmune diabetes and increased the incidence of the disease by dysregulation of T cell activation at least in part via SREBP-1c activation.
A peroxisome proliferator-activated receptor ligand MCC-555 imparts anti-proliferative response in pancreatic cancer cells by PPARgamma-independent up-regulation of KLF4

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

Min, Kyung-Won; Zhang, Xiaobo; College of Animal Science and Technology, Northwest A and F University, Yangling, Shaanxi, 712100

2012-09-01

MCC-555 is a novel PPARα/γ dual ligand of the thiazolidinedione class and was recently developed as an anti-diabetic drug with unique properties. MCC-555 also has anti-proliferative activity through growth inhibition and apoptosis induction in several cancer cell types. Our group has shown that MCC-555 targets several proteins in colorectal tumorigenesis including nonsteroidal anti-inflammatory drug (NSAID)-activated gene (NAG-1) which plays an important role in chemoprevention responsible for chemopreventive compounds. NAG-1 is a member of the TGF-β superfamily and is involved in tumor progression and development; however, NAG-1's roles in pancreatic cancer have not been studied. In this report, we found thatmore » MCC-555 alters not only NAG-1 expression, but also p21 and cyclin D1 expression. NAG-1 and p21 expression was not blocked by PPARγ-specific antagonist GW9662, suggesting that MCC-555-induced NAG-1 and p21 expression is independent of PPARγ activation. However, decreasing cyclin D1 by MCC-555 seems to be affected by PPARγ activation. Further, we found that the GC box located in the NAG-1 promoter play an important role in NAG-1 transactivation by MCC-555. Subsequently, we screened several transcription factors that may bind to the GC box region in the NAG-1 promoter and found that KLF4 potentially binds to this region. Expression of KLF4 precedes NAG-1 and p21 expression in the presence of MCC-555, whereas blocking KLF4 expression using specific KLF4 siRNA showed that both NAG-1 and p21 expression by MCC-555 was blocked. In conclusion, MCC-555's actions on anti-proliferation involve both PPARγ-dependent and -independent pathways, thereby enhancing anti-tumorigenesis in pancreatic cancer cells. -- Highlights: ► PPARα/γ ligand MCC-555 exhibits anti-proliferative activity in pancreatic cancer cells. ► MCC-555 affects KLF4 expression following by NAG-1 and p21 expression in a PPARγ independent manner. ► MCC-555 also affects cyclin D1 down
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
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
Canine corneal epithelial cells possess a sustained proliferative capacity and generate a spontaneously derived cell line.

PubMed

Morita, Maresuke; Fujita, Naoki; Abe, Momoko; Hayashimoto, Koji; Nakagawa, Takayuki; Nishimura, Ryohei; Tsuzuki, Keiko

2018-06-01

We have previously reported characteristics of canine corneal epithelial cells in vitro and found that canine corneal epithelial cells could maintain their proliferative capacity even after continuous culture without the use of feeder cells and growth promoting additives. The objective of this study was to elucidate proliferative characteristics of canine corneal epithelial cells independent of feeder cells and growth promoting additives, with the aim of developing a spontaneously derived corneal epithelial cell line. Canine and rabbit corneal epithelial cells were harvested from the limbus and cultured with, or without, feeder cells and growth promoting additives, and both were passaged continuously until growth arrest. Canine corneal epithelial cells could proliferate independently, and could be passaged more times than rabbit cells. A canine corneal epithelial cell line, cCEpi, which could be passaged more than 100 times without using feeder cells and growth promoting additives, was established. cCEpi cells maintained a cell morphology close to the primary culture and expressed p63, cytokeratin 15 (K15), and K3. Although changes in colony morphology, shortening of the population doubling time and a heteroploid karyotype were observed, cCEpi was not tumorigenic. Stratified cell sheets cultured from cCEpi were morphologically and immunohistologically similar to sheets cultivated from early passage cells. In conclusion, canine corneal epithelial cells can proliferate independent of feeder cells and growth promoting additives. cCEpi maintains properties similar to normal corneal epithelial cells and could be a useful source for studies in cellular biology and for developing novel therapies. Copyright © 2018 Elsevier Ltd. All rights reserved.
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.
Increased numbers of pre-existing memory CD8 T cells and decreased T-bet expression can restrain terminal differentiation of secondary effector and memory CD8 T cells1

PubMed Central

Joshi, Nikhil S.; Cui, Weiguo; Dominguez, Claudia; Chen, Jonathan H.; Hand, Timothy W.; Kaech, Susan M.

2011-01-01

Memory CD8 T cells acquire TEM properties following reinfection, and may reach terminally differentiated, senescent states (“Hayflick limit”) after multiple infections. The signals controlling this process are not well understood, but we found that the degree of 2o effector and memory CD8 T cell differentiation was intimately linked to the amount of T-bet expressed upon reactivation and pre-existing memory CD8 T cell number (i.e., 1o memory CD8 T cell precursor frequency) present during secondary infection. Compared to naïve cells, memory CD8 T cells were predisposed towards terminal effector (TE) cell differentiation because they could immediately respond to IL-12 and induce T-bet, even in the absence of antigen. TE cell formation following 2o or 3o infections was dependent on increased T-bet expression because T-bet+/− cells were resistant to these phenotypic changes. Larger numbers of pre-existing memory CD8 T cells limited the duration of 2o infection and the amount of IL-12 produced, and consequently, this reduced T-bet expression and the proportion of 2o TE CD8 T cells that formed. Together, these data show that, over repeated infections, memory CD8 T cell quality and proliferative fitness is not strictly determined by the number of serial encounters with antigen or cell divisions, but is a function of the CD8 T cell differentiation state, which is genetically controlled in a T-bet-dependent manner. This differentiation state can be modulated by pre-existing memory CD8 T cell number and the intensity of inflammation during reinfection. These results have important implications for vaccinations involving prime-boost strategies. PMID:21930973
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.

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
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
Stable, Nonviral Expression of Mutated Tumor Neoantigen-specific T-cell Receptors Using the Sleeping Beauty Transposon/Transposase System

PubMed Central

Deniger, Drew C; Pasetto, Anna; Tran, Eric; Parkhurst, Maria R; Cohen, Cyrille J; Robbins, Paul F; Cooper, Laurence JN; Rosenberg, Steven A

2016-01-01

Neoantigens unique to each patient's tumor can be recognized by autologous T cells through their T-cell receptor (TCR) but the low frequency and/or terminal differentiation of mutation-specific T cells in tumors can limit their utility as adoptive T-cell therapies. Transfer of TCR genes into younger T cells from peripheral blood with a high proliferative potential could obviate this problem. We generated a rapid, cost-effective strategy to genetically engineer cancer patient T cells with TCRs using the clinical Sleeping Beauty transposon/transposase system. Patient-specific TCRs reactive against HLA-A*0201-restriced neoantigens AHNAKS2580F or ERBB2H473Y or the HLA-DQB*0601-restricted neoantigen ERBB2IPE805G were assembled with murine constant chains and cloned into Sleeping Beauty transposons. Patient peripheral blood lymphocytes were coelectroporated with SB11 transposase and Sleeping Beauty transposon, and transposed T cells were enriched by sorting on murine TCRβ (mTCRβ) expression. Rapid expansion of mTCRβ+ T cells with irradiated allogeneic peripheral blood lymphocytes feeders, OKT3, interleukin-2 (IL-2), IL-15, and IL-21 resulted in a preponderance of effector (CD27−CD45RA−) and less-differentiated (CD27+CD45RA+) T cells. Transposed T cells specifically mounted a polyfunctional response against cognate mutated neoantigens and tumor cell lines. Thus, Sleeping Beauty transposition of mutation-specific TCRs can facilitate the use of personalized T-cell therapy targeting unique neoantigens. PMID:26945006
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.
Role of latent membrane protein 1 in chronic active Epstein–Barr virus infection-derived T/NK-cell proliferation

PubMed Central

Ito, Takuto; Kawazu, Hidetaka; Murata, Takayuki; Iwata, Seiko; Arakawa, Saki; Sato, Yoshitaka; Kuzushima, Kiyotaka; Goshima, Fumi; Kimura, Hiroshi

2014-01-01

Epstein–Barr virus (EBV) predominantly infects B cells and causes B-cell lymphomas, such as Burkitt lymphoma and Hodgkin lymphoma. However, it also infects other types of cells, including T and natural killer (NK) cells, and causes disorders, such as chronic active EBV infection (CAEBV) and T/NK-cell lymphoma. The CAEBV is a lymphoproliferative disease with poor prognosis, where EBV-positive T or NK cells grow rapidly, although the molecular mechanisms that cause the cell expansion still remain to be elucidated. EBV-encoded latent membrane protein 1 (LMP1) is an oncogene that can transform some cell types, such as B cells and mouse fibroblasts, and thus may stimulate cell proliferation in CAEBV. Here, we examined the effect of LMP1 on EBV-negative cells using the cells conditionally expressing LMP1, and on CAEBV-derived EBV-positive cells by inhibiting the function of LMP1 using a dominant negative form of LMP1. We demonstrated that LMP1 was responsible for the increased cell proliferation in the cell lines derived from CAEBV, while LMP1 did not give any proliferative advantage to the EBV-negative cell line. PMID:24799376
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.
Cutting Edge: Enhanced Clonal Burst Size Corrects an Otherwise Defective Memory Response by CD8+ Recent Thymic Emigrants.

PubMed

Deets, Katherine A; Berkley, Amy M; Bergsbaken, Tessa; Fink, Pamela J

2016-03-15

The youngest peripheral T cells (recent thymic emigrants [RTEs]) are functionally distinct from naive T cells that have completed postthymic maturation. We assessed the RTE memory response and found that RTEs produced less granzyme B than their mature counterparts during infection but proliferated more and, therefore, generated equivalent target killing in vivo. Postinfection, RTE numbers contracted less dramatically than those of mature T cells, but RTEs were delayed in their transition to central memory, displaying impaired expression of CD62L, IL-2, Eomesodermin, and CXCR4, which resulted in impaired bone marrow localization. RTE-derived and mature memory cells expanded equivalently during rechallenge, indicating that the robust proliferative capacity of RTEs was maintained independently of central memory phenotype. Thus, the diminished effector function and delayed central memory differentiation of RTE-derived memory cells are counterbalanced by their increased proliferative capacity, driving the efficacy of the RTE response to that of mature T cells. Copyright © 2016 by The American Association of Immunologists, Inc.
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
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.
Cytological Study of Breast Carcinoma Before and After Oncotherapy with Special Reference to Morphometry and Proliferative Activity.

PubMed

Koley, Sananda; Chakrabarti, Srabani; Pathak, Swapan; Manna, Asim Kumar; Basu, Siddhartha

2015-12-01

Our study was done to assess the cytological changes due to oncotherapy in breast carcinoma especially on morphometry and proliferative activity. Cytological aspirates were collected from a total of 32 cases of invasive ductal carcinoma both before and after oncotherapy. Morphometry was done on the stained cytological smears to assess the different morphological parameters of cell dimension by using the ocular morphometer and the software AutoCAD 2007. Staining was done with Ki-67 and proliferating cell nuclear antigen (PCNA) as proliferative markers. Different morphological parameters were compared before and after oncotherapy by unpaired Student's t test. Statistically significant differences were found in morphometric parameters, e.g., mean nuclear diameter, mean nuclear area, mean cell diameter, and mean cell area, and in the expression of proliferative markers (Ki-67 and PCNA). Statistical analysis was done by obtaining p values. There are statistically significant differences between morphological parameter of breast carcinoma cells before and after oncotherapy.
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.
The apoptotic and anti-proliferative activity of Origanum majorana extracts on human leukemic cell line.

PubMed

Abdel-Massih, Roula M; Fares, Rida; Bazzi, Samer; El-Chami, Nisrine; Baydoun, Elias

2010-08-01

Scientists are constantly searching for phytochemicals and compounds with anti-cancer and antioxidant activity. In this study, the anti-proliferative activity of plant extracts from Origanum majorana (marjoram) was tested on human lymphoblastic leukemia cell line Jurkat. Cytotoxicity was examined using non-radioactive cytotoxicity assay and the IC(50) was calculated. At non-cytotoxic concentrations, the viability of cells decreased with increase of concentration of plant extract. The anti-proliferative effect was also found to be dose-dependent. Analysis via flow cytometry shows that marjoram extracts stimulated apoptosis. Induction of apoptosis was caused by an up-regulation of p53 protein levels and down-regulation of Bcl-2alpha. Marjoram exhibited a strong scavenging activity (SC(50)=0.03mg dry weight). The conclusions from this study suggest that marjoram extracts exhibit anti-proliferative effect and high antioxidant activity. For that it merits further investigation as a potential therapeutic agent. Copyright (c) 2010 Elsevier Ltd. All rights reserved.
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.
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
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
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
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.
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.
T-cell receptor BV gene usage in colorectal carcinoma patients immunised with recombinant Ep-CAM protein or anti-idiotypic antibody.

PubMed

Mosolits, Szilvia; Markovic, Katja; Fagerberg, Jan; Frödin, Jan-Erik; Rezvany, Mohammad-Reza; Kiaii, Shahryar; Mellstedt, Håkan; Jeddi-Tehrani, Mahmood

2005-06-01

The tumour-associated antigen, Ep-CAM, is over-expressed in colorectal carcinoma (CRC). In the present study, a recombinant Ep-CAM protein or a human anti-idiotypic antibody (anti-Id) mimicking Ep-CAM, either alone or in combination, was used for vaccination of CRC patients (n=9). GM-CSF was given as an adjuvant cytokine. A cellular immune response was assessed by measuring anti-Ep-CAM lymphoproliferation, IFN-gamma production (ELISPOT) and by analysing the TCR BV gene usage within the CD4+ and CD8+ T-cell subsets followed by CDR3 fragment analysis. A proliferative and/or IFN-gamma T-cell response was induced against the Ep-CAM protein in eight out of nine patients, and against Ep-CAM-derived peptides in nine out of nine patients. Analysis of the TCR BV gene usage showed a significantly higher usage of BV12 family in CD4+ T cells of patients both before and after immunisation than in those of healthy control donors (p<0.05). In the CD8+ T-cell subset, a significant (p<0.05) increase in the BV19 usage was noted in patients after immunisation. In individual patients, a number of TCR BV gene families in both CD4+ and CD8+ T cells were over-expressed mainly in post-immunisation samples. Analysis of the CDR3 length polymorphism revealed a higher degree of clonality in post-immunisation samples than in pre-immunisation samples. In vitro stimulation with Ep-CAM protein confirmed the expansion of anti-Ep-CAM T-cell clones. The results indicate that immunisation with the Ep-CAM protein and/or anti-Id entails the induction of an anti-Ep-CAM T-cell response in CRC patients, and suggest that BV19+ CD8+ T cells might be involved in a vaccine-induced immune response.
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.

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
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
Red blood cells promote survival and cell cycle progression of human peripheral blood T cells independently of CD58/LFA-3 and heme compounds.

PubMed

Fonseca, Ana Mafalda; Pereira, Carlos Filipe; Porto, Graça; Arosa, Fernando A

2003-07-01

Red blood cells (RBC) are known to modulate T cell proliferation and function possibly through downregulation of oxidative stress. By examining parameters of activation, division, and cell death in vitro, we show evidence that the increase in survival afforded by RBC is due to the maintenance of the proliferative capacity of the activated T cells. We also show that the CD3+CD8+ T cell subset was preferentially expanded and rescued from apoptosis both in bulk peripheral blood lymphocyte cultures and with highly purified CD8+ T cells. The ability of RBC to induce survival of dividing T cells was not affected by blocking the CD58/CD2 interaction. Moreover, addition of hemoglobin, heme or protoporphyrin IX to cultures of activated T cells did not reproduce the effect of intact RBC. Considering that RBC circulate throughout the body, they could play a biological role in the modulation of T cell differentiation and survival in places of active cell division. Neither CD58 nor the heme compounds studied seem to play a direct relevant role in the modulation of T cell survival.
Functional heterogeneity of human effector CD8+ T cells.

PubMed

Takata, Hiroshi; Naruto, Takuya; Takiguchi, Masafumi

2012-02-09

Effector CD8(+) T cells are believed to be terminally differentiated cells having cytotoxic activity and the ability to produce effector cytokines such as INF-γ and TNF-α. We investigated the difference between CXCR1(+) and CXCR1(-) subsets of human effector CD27(-)CD28(-)CD8(+) T cells. The subsets expressed cytolytic molecules similarly and exerted substantial cytolytic activity, whereas only the CXCR1(-) subset had IL-2 productivity and self-proliferative activity and was more resistant to cell death than the CXCR1(+) subset. These differences were explained by the specific up-regulation of CAMK4, SPRY2, and IL-7R in the CXCR1(-) subset and that of pro-apoptotic death-associated protein kinase 1 (DAPK1) in the CXCR1(+) subset. The IL-2 producers were more frequently found in the IL-7R(+) subset of the CXCR1(-) effector CD8(+) T cells than in the IL-7R(-) subset. IL-7/IL-7R signaling promoted cell survival only in the CXCR1(-) subset. The present study has highlighted a novel subset of effector CD8(+) T cells producing IL-2 and suggests the importance of this subset in the homeostasis of effector CD8(+) T cells.
Development of novobiocin analogues that manifest anti-proliferative activity against several cancer cell lines.

PubMed

Burlison, Joseph A; Avila, Christopher; Vielhauer, George; Lubbers, Donna J; Holzbeierlein, Jeffrey; Blagg, Brian S J

2008-03-21

Recent studies have shown that the DNA gyrase inhibitor, novobiocin, binds to a previously unrecognized ATP-binding site located at the C-terminus of Hsp90 and induces degradation of Hsp90-dependent client proteins at approximately 700 microM. As a result of these studies, several analogues of the coumarin family of antibiotics have been reported and shown to exhibit increased Hsp90 inhibitory activity; however, the monomeric species lacked the ability to manifest anti-proliferative activity against cancer cell lines at concentrations tested. In an effort to develop more efficacious compounds that produce growth inhibitory activity against cancer cell lines, structure-activity relationships were investigated surrounding the prenylated benzamide side chain of the natural product. Results obtained from these studies have produced the first novobiocin analogues that manifest anti-proliferative activity against several cancer cell lines.
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
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
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.
Regulation of T Cell Differentiation and Alloimmunity by the Cyclin-Dependent Kinase Inhibitor p18ink4c

PubMed Central

Rowell, Emily A.; Wang, Liqing; Chunder, Neelanjana; Hancock, Wayne W.; Wells, Andrew D.

2014-01-01

Cellular proliferation in response to mitogenic stimuli is negatively regulated by the Cip/Kip and the Ink4 families of cyclin-dependent kinase (CDK) inhibitors. Several of these proteins are elevated in anergic T cells, suggesting a potential role in the induction or maintenance of tolerance. Our previous studies showed that p27kip1 is required for the induction of T cell anergy and transplantation tolerance by costimulatory blockade, but a role for Ink4 proteins in these processes has not been established. Here we show that CD4+ T cells from mice genetically deficient for p18ink4c divide more rapidly than wild-type cells in response to antigenic, costimulatory and growth factor signals. However, this gain of proliferative function was accompanied by a moderate increase in the rate of cell death, and was accompanied by an overall defect in the generation of alloreactive IFNγ-producing effector cells. Consistent with this, p18ink4c-deficient T cells were unable to induce graft-vs-host disease in vivo, and p18ink4c deficiency cooperated with costimulatory blockade to significantly increase the survival of fully mismatched allografts in a cardiac transplantation model. While both p18ink4c and p27kip1 act to restrict T cell proliferation, p18ink4c exerts an opposite effect from p27kip1 on alloimmunity and organ transplant rejection, most likely by sustaining T cell survival and the development of effector function. Our studies point to additional important links between the cell cycle machinery and the processes of T cell differentiation, survival and tolerance. PMID:24614758
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
[Enhanced lymphocyte proliferation in the presence of epidermal cells of HIV-infected patients in vitro].

PubMed

Kappus, R P; Berger, S; Thomas, C A; Ottmann, O G; Ganser, A; Stille, W; Shah, P M

1992-07-01

Clinical observations show that the HIV infection is often associated with affections of the skin. In order to examine the involvement of the epidermal immune system in the HIV infection, we determined accessory cell function of epidermal cells from HIV-1-infected patients. For this we measured the proliferative response of enriched CD(4+)-T-lymphocytes from HIV-infected patients and noninfected controls to stimulation with anti-CD3 and IL-2 in the presence of epidermal cells; the enhancement of the response is dependent on the presence of functionally intact accessory cells. The capacity of epidermal cells to increase the anti-CD3-stimulated T-cell proliferative response was significantly enhanced in HIV patients (CDC III/IVA) as compared with noninfected donors. It is discussed, whether the increased activity of epidermal cells from HIV-infected patients may be responsible for several of the dermal lesions in the course of an HIV infection as due to an enhanced production and release of epidermal cell-derived cytokines.
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
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
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.
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.
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
Functional characterization of a regulatory human T-cell subpopulation increasing during autologous MLR.

PubMed Central

Cosulich, M E; Risso, A; Canonica, G W; Bargellesi, A

1986-01-01

The present study was undertaken to investigate the heterogeneity of helper T cells in humans using two different monoclonal antibodies: 5/9 and MLR4. The former identifies 15-20% of resting T lymphocytes from peripheral blood and corresponds to an anti-helper/inducer T cell. The second antibody, MLR4, recognizes 5% of total T lymphocytes and partially overlaps with the 5/9+ T cells. In order to investigate functional differences within the 5/9+ cells, we separated two different subsets (5/9+ MLR+ and 5/9+ MLR4-) by a rosetting technique. Although both subsets provide help for Ig synthesis in a PWM-stimulated culture, only the 5/9+ MLR4- fraction gave a proliferative response in both autologous and allogeneic MLR and to soluble protein antigens. The effect of radiation on the ability of the two subsets to provide help for Ig synthesis showed that the 5/9+ MLR4+ subset is highly radiation-sensitive, while 5/9+ MLR- is relatively radiation-resistant. In a further series of experiments, 5/9+ MLR4+ cells isolated after activation in an autologous MLR but not by Con A, were no longer able to induce T-cell differentiation but now showed a strong suppressor effect. The 5/9+ MLR4- subset separated from the same cultures did not display any suppressor function. These data demonstrate in fresh PBL the existence of a radiation-sensitive regulatory subset exerting a helper activity, and which acquires suppressor activity after activation in autologous MLR. PMID:2936679
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.
Suppression of antitumour protective cytotoxic T lymphocyte responses to a human papillomavirus 16 E7 DNA vaccine by coinjection of interleukin-12 complementary DNA: involvement of nitric oxide in immune suppression

PubMed Central

Sin, Jeong-Im

2009-01-01

Interleukin-12 (IL-12) has been shown to enhance cellular immunity in vitro and in vivo. The beneficial roles of IL-12 as a DNA vaccine adjuvant have been commonly observed. Here the impact of IL-12 complementary DNA (cDNA) as an adjuvant for a human papillomavirus (HPV) type 16 E7 DNA vaccine is investigated in a mouse tumour model. Coinjection of E7 DNA vaccine with IL-12 cDNA completely suppressed antigen-specific cytotoxic T-lymphocyte (CTL) responses, leading to a complete loss of antitumour protection from a tumour cell challenge. In addition, antigen-specific antibody and T helper cell proliferative responses were also suppressed by IL-12 cDNA coinjection. This inhibition was observed over different IL-12 cDNA doses. Furthermore, separate leg injections of IL-12 and E7 cDNAs suppressed antigen-specific CTL and tumour protective responses, but not antibody and T helper cell proliferative responses, suggesting different pathways for suppression of these two separate responses. Further knockout animal studies demonstrated that interferon-γ and nitric oxide are not directly associated with suppression of antigen-specific antibody responses by IL-12 cDNA coinjection. However, nitric oxide was found to be involved in suppression of antigen-specific CTL and tumour protective responses by IL-12 cDNA coinjection. These data suggest that coinjection of IL-12 cDNA results in suppression of E7-specific CTL responses through nitric oxide, leading to a loss of antitumour resistance in this DNA vaccine model. This study further shows that the adjuvant effect of IL-12 is dependent on the antigen types tested. PMID:19740332
Suppression of antitumour protective cytotoxic T lymphocyte responses to a human papillomavirus 16 E7 DNA vaccine by coinjection of interleukin-12 complementary DNA: involvement of nitric oxide in immune suppression.

PubMed

Sin, Jeong-Im

2009-09-01

Interleukin-12 (IL-12) has been shown to enhance cellular immunity in vitro and in vivo. The beneficial roles of IL-12 as a DNA vaccine adjuvant have been commonly observed. Here the impact of IL-12 complementary DNA (cDNA) as an adjuvant for a human papillomavirus (HPV) type 16 E7 DNA vaccine is investigated in a mouse tumour model. Coinjection of E7 DNA vaccine with IL-12 cDNA completely suppressed antigen-specific cytotoxic T-lymphocyte (CTL) responses, leading to a complete loss of antitumour protection from a tumour cell challenge. In addition, antigen-specific antibody and T helper cell proliferative responses were also suppressed by IL-12 cDNA coinjection. This inhibition was observed over different IL-12 cDNA doses. Furthermore, separate leg injections of IL-12 and E7 cDNAs suppressed antigen-specific CTL and tumour protective responses, but not antibody and T helper cell proliferative responses, suggesting different pathways for suppression of these two separate responses. Further knockout animal studies demonstrated that interferon-gamma and nitric oxide are not directly associated with suppression of antigen-specific antibody responses by IL-12 cDNA coinjection. However, nitric oxide was found to be involved in suppression of antigen-specific CTL and tumour protective responses by IL-12 cDNA coinjection. These data suggest that coinjection of IL-12 cDNA results in suppression of E7-specific CTL responses through nitric oxide, leading to a loss of antitumour resistance in this DNA vaccine model. This study further shows that the adjuvant effect of IL-12 is dependent on the antigen types tested.

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
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.
Recombinant adenovirus-p21 attenuates proliferative responses associated with excessive scarring.

PubMed

Gu, Danling; Atencio, Isabella; Kang, David W; Looper, L David; Ahmed, C M I; Levy, Alina; Maneval, Dan; Zepeda, Monica L

2005-01-01

Excessive cutaneous scarring is an important clinical disorder resulting in adverse tissue growth and function as well as undesirable cosmetic appearance. p21WAF-1/Cip-1 is a cyclin-dependent kinase inhibitor that blocks cell cycle progression and inhibits cell proliferation. We used a recombinant adenovirus containing the human p21WAF-1/Cip-1 cDNA (rAd-p21) to evaluate proliferative responses in skin models. In vitro dose-response studies using primary human dermal fibroblasts resulted in a dose-dependent expression of p21WAF-1/Cip-1 protein and a 3- to 80-fold reduction in cell proliferation as measured by 5-bromodeoxyuridine incorporation. Further, rAd-p21 reduced type I procollagen production when compared to control virus. A rat polyvinyl alcohol sponge model was used to determine rAd-p21 effects on granulation tissue formation in vivo. Sponges pretreated with a granulation tissue stimulator, rAd-PDGF-B and subsequently rAd-p21 on a second injection, showed a p21WAF-1/Cip-1 specific dose-dependent decrease in percent granulation fill as the rAd-p21 dose increased (p < 0.001). Immunohistochemistry identified human p21WAF-1/Cip-1 expression in sponges treated with rAd-p21 5 days postinjection. Additionally, 5-bromodeoxyuridine and Ki67 staining in sponges treated with rAd-p21 showed a significant decrease in proliferation when compared to rAd-platelet-derived growth factor-B alone or vehicle control groups (p < 0.01). These data support the utility of p21WAF-1/Cip-1 in targeting hyperproliferative disorders of the skin.
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.
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
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.
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
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
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
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.
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.
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.
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.
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
Changes in the Proliferative Program Limit Astrocyte Homeostasis in the Aged Post-Traumatic Murine Cerebral Cortex.

PubMed

Heimann, Gábor; Canhos, Luisa L; Frik, Jesica; Jäger, Gabriele; Lepko, Tjasa; Ninkovic, Jovica; Götz, Magdalena; Sirko, Swetlana

2017-08-01

Aging leads to adverse outcomes after traumatic brain injury. The mechanisms underlying these defects, however, are not yet clear. In this study, we found that astrocytes in the aged post-traumatic cerebral cortex develop a significantly reduced proliferative response, resulting in reduced astrocyte numbers in the penumbra. Moreover, experiments of reactive astrocytes in vitro reveal that their diminished proliferation is due to an age-related switch in the division mode with reduced cell-cycle re-entry rather than changes in cell-cycle length. Notably, reactive astrocytes in vivo and in vitro become refractory to stimuli increasing their proliferation during aging, such as Sonic hedgehog signaling. These data demonstrate for the first time that age-dependent, most likely intrinsic changes in the proliferative program of reactive astrocytes result in their severely hampered proliferative response to traumatic injury thereby affecting astrocyte homeostasis. © The Author 2017. Published by Oxford University Press.
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.
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
Mesenchymal stem cells alleviate TNBS-induced colitis by modulating inflammatory and autoimmune responses

PubMed Central

Chen, Qian-Qian; Yan, Li; Wang, Chang-Zheng; Wang, Wei-Hua; Shi, Hui; Su, Bin-Bin; Zeng, Qing-Huan; Du, Hai-Tao; Wan, Jun

2013-01-01

AIM: To investigate the potential therapeutic effects of mesenchymal stem cells (MSCs) in inflammatory bowel disease (IBD), we transplanted MSCs into an experimental model of IBD. METHODS: A rectal enema of trinitrobenzene sulfonic acid (TNBS) (100 mg/kg body weight) was administered to female BALB/c mice. Bone marrow mesenchymal stem cells (BMSCs) were derived from male green fluorescent protein (GFP) transgenic mice and were transplanted intravenously into the experimental animals after disease onset. Clinical activity scores and histological changes were evaluated. GFP and Sex determining region Y gene (SRY) expression were used for cell tracking. Ki67 positive cells and Lgr5-expressing cells were determined to measure proliferative activity. Inflammatory response was determined by measuring the levels of different inflammatory mediators in the colon and serum. The inflammatory cytokines included tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), interleukin-2 (IL-2), IL-6, IL-17, IL-4, IL-10, and transforming growth factor (TGF-β). Master regulators of Th1 cells (T-box expressed in T cells, T-bet), Th17 cells (retinoid related orphan receptor gamma(t), RORγt), Th2 cells (GATA family of transcription factors 3, GATA3) and regulatory T cells (forkhead box P3, Foxp3) were also determined. RESULTS: Systemic infusion of GFP-BMSCs ameliorated the clinical and histopathologic severity of colitis, including body weight loss, diarrhea and inflammation, and increased survival (P < 0.05). The cell tracking study showed that MSCs homed to the injured colon. MSCs promoted proliferation of intestinal epithelial cells and differentiation of intestinal stem cells (P < 0.01). This therapeutic effect was mainly mediated by down-regulation of both Th1-Th17-driven autoimmune and inflammatory responses (IL-2, TNF-α, IFN-γ, T-bet; IL-6, IL-17, RORγt), and by up-regulation of Th2 activities (IL-4, IL-10, GATA-3) (P < 0.05). MSCs also induced activated CD4+CD25+Foxp3
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
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.

Chemical Constituents from Cimicifuga dahurica and Their Anti-Proliferative Effects on MCF-7 Breast Cancer Cells.

PubMed

Huyen, Chu Thi Thanh; Luyen, Bui Thi Thuy; Khan, Ghulam Jilany; Oanh, Ha Van; Hung, Ta Manh; Li, Hui-Jun; Li, Ping

2018-05-04

This study was designed to search for novel anti-cancer compounds from natural plants. The 70% ethanolic extract from the rizhomes of Cimicifuga dahurica (Turcz.) Maxim. (Ranunculaceae) was found to possess significant in vitro anti-proliferative effects on MCF-7 breast cancer cells. A phytochemical investigation using assay-guided fractionation of the ethanolic extract of C. dahurica resulted in the isolation of one new phenolic amide glycoside 3 , two new lignan glycosides 4 and 7 , one new 9,19-cycloartane triterpenoid glycoside 6 , and thirteen known constituents 1 , 2 , 5 , and 8 ⁻ 17 . The structures of 3 , 4 , 6 , and 7 were established using contemporary NMR methods and from their HRESIMS data. The anti-proliferative effects of isolated compounds were evaluated using the BrdU-proliferation kit. Five among the 17 isolated compounds showed significant anti-proliferative effects ( p ≤ 0.05), wherein compound 7 showed the most significant anti-proliferative and cell cycle arresting effect ( p ≤ 0.05) which followed a dose dependent manner. Western blot protein expression analysis showed a down expression of c-Myc and cyclin D1 which further elucidated the anti-proliferation mechanism of compound 7 while apoptotic effects were found in association with Bcl-2 family protein expression variations. Conclusively this study reports the isolation and identification of 17 compounds from C. dahurica , including four novel molecules, in addition to the fact that compound 7 possesses significant anti-proliferative and apoptotic effects in vitro that may require further exploration.
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.
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
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
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
Lung Inflammation, Injury, and Proliferative Response after Repetitive Particulate Hexavalent Chromium Exposure

PubMed Central

Beaver, Laura M.; Stemmy, Erik J.; Schwartz, Arnold M.; Damsker, Jesse M.; Constant, Stephanie L.; Ceryak, Susan M.; Patierno, Steven R.

2009-01-01

Background Chronic inflammation is implicated in the development of several human cancers, including lung cancer. Certain particulate hexavalent chromium [Cr(VI)] compounds are well-documented human respiratory carcinogens that release genotoxic soluble chromate and are associated with fibrosis, fibrosarcomas, adenocarcinomas, and squamous cell carcinomas of the lung. Despite this, little is known about the pathologic injury and immune responses after repetitive exposure to particulate chromates. Objectives In this study we investigated the lung injury, inflammation, proliferation, and survival signaling responses after repetitive exposure to particulate chromate. Methods BALB/c mice were repetitively treated with particulate basic zinc chromate or saline using an intranasal exposure regimen. We assessed lungs for Cr(VI)-induced changes by bronchoalveolar lavage, histologic examination, and immunohistochemistry. Results Single exposure to Cr(VI) resulted in inflammation of lung tissue that persists for up to 21 days. Repetitive Cr(VI) exposure induced a neutrophilic inflammatory airway response 24 hr after each treatment. Neutrophils were subsequently replaced by increasing numbers of macrophages by 5 days after treatment. Repetitive Cr(VI) exposure induced chronic peribronchial inflammation with alveolar and interstitial pneumonitis dominated by lymphocytes and macrophages. Moreover, chronic toxic mucosal injury was observed and accompanied by increased airway pro-matrix metalloprotease-9. Injury and inflammation correlated with airways becoming immunoreactive for phosphorylation of the survival signaling protein Akt and the proliferation marker Ki-67. We observed a reactive proliferative response in epithelial cells lining airways of chromate-exposed animals. Conclusions These data illustrate that repetitive exposure to particulate chromate induces chronic injury and an inflammatory microenvironment that may promote Cr(VI) carcinogenesis. PMID:20049209
N-terminal tyrosine phosphorylation of caveolin-2 negates anti-proliferative effect of transforming growth factor beta in endothelial cells

PubMed Central

Abel, Britain; Willoughby, Cara; Jang, Sungchan; Cooper, Laura; Xie, Leike; Vo-Ransdell, Chi; Sowa, Grzegorz

2012-01-01

Here we show that tyrosine phosphorylation of caveolin-2 (Cav-2) negatively regulates the anti-proliferative function of transforming growth factor beta (TGF-beta) in endothelial cells. In contrast to wild-type-Cav-2, retroviral re-expression of Y19/27F-Cav-2 in Cav-2 knockout endothelial cells did not affect anti-proliferative effect of TGF-beta compared to empty vector. Conversely, although less effective than wild-type, re-expression of S23/36A-Cav-2 reduced the effect of TGF-beta compared to empty vector. This differential effect of tyrosine and serine phosphorylation mutants of Cav-2 correlated with TGF-beta-induced Smad3 phosphorylation and transcriptional activation of plasminogen activator inhibitor-1. Thus tyrosine-phosphorylated Cav-2 counteracts anti-proliferative effect of TGF-beta in endothelial cells. PMID:22819829
Tenascin-C in the extracellular matrix promotes the selection of highly proliferative and tubulogenesis-defective endothelial cells

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

Alves, Tercia Rodrigues; Universidade Federal do Rio de Janeiro; Carvalho da Fonseca, Anna Carolina

2011-09-10

The extracellular matrix (ECM) contains important cues for tissue homeostasis and morphogenesis. The matricellular protein tenascin-C (TN-C) is overexpressed in remodeling tissues and cancer. In the present work, we studied the effect of different ECM-which exhibited a significant diversity in their TN-C content-in endothelial survival, proliferation and tubulogenic differentiation: autologous (endothelial) ECM devoid of TN-C, but bearing large amounts of FN; fibroblast ECM, bearing both high TN-C and FN contents; and finally, glioma-derived matrices, usually poor in FN, but very rich in TN-C. HUVECs initially adhered to the immobilized matrix produced by U373 MG glioma cells, but significantly detached andmore » died by anoikis (50 to 80%) after 24 h, as compared with cells incubated with endothelial and fibroblast matrices. Surviving endothelial cells (20 to 50%) became up to 6-fold more proliferative and formed 74-97% less tube-like structures in vitro than cells grown on non-tumoral matrices. An antibody against the EGF-like repeats of tenascin-C (TN-C) partially rescued cells from the tubulogenic defect, indicating that this molecule is responsible for the selection of highly proliferative and tubulogenic defective endothelial cells. Interestingly, by using defined substrata, in conditions that mimic glioma and normal cell ECM composition, we observed that fibronectin (FN) modulates the TN-C-induced selection of endothelial cells. Our data show that TN-C is able to modulate endothelial branching morphogenesis in vitro and, since it is prevalent in matrices of injured and tumor tissues, also suggest a role for this protein in vascular morphogenesis, in these physiological contexts.« less
Submolecular recognition of the C-terminal domain of the heavy chain of botulinum neurotoxin type A by T cells from toxin-treated cervical dystonia patients.

PubMed

Oshima, Minako; Deitiker, Philip; Jankovic, Joseph; Aoki, K Roger; Atassi, M Zouhair

2016-04-01

We determined the T-cell proliferative responses of the peripheral blood lymphocytes (PBL) from 25 botulinum neurotoxin (BoNT)-treated patients to 31 overlapping synthetic peptides encompassing the C-terminal half (residues 855-1296) of BoNT/A heavy chain. Responses of PBL to HC peptides varied among patients. Samples from 14 patients treated solely with BoNT/A recognized 2-13 (average 6.4) peptides/sample at Z>3.0 level. Six peptide regions representing residues 855-873, 1023-1041, 1051-1069, 1093-1111, 1135-1153 and 1247-1265 were frequently recognized by 36-57% of these PBLs. Influence of treatment parameters on T-cell recognition of the peptides was also investigated. Copyright © 2015 Elsevier GmbH. All rights reserved.
Effective antigen presentation to helper T cells by human eosinophils.

PubMed

Farhan, Ruhaifah K; Vickers, Mark A; Ghaemmaghami, Amir M; Hall, Andrew M; Barker, Robert N; Walsh, Garry M

2016-12-01

Although eosinophils are inflammatory cells, there is increasing attention on their immunomodulatory roles. For example, murine eosinophils can present antigen to CD4 + T helper (Th) cells, but it remains unclear whether human eosinophils also have this ability. This study determined whether human eosinophils present a range of antigens, including allergens, to activate Th cells, and characterized their expression of MHC class II and co-stimulatory molecules required for effective presentation. Human peripheral blood eosinophils purified from non-allergic donors were pulsed with the antigens house dust mite extract (HDM), Timothy Grass extract (TG) or Mycobacterium tuberculosis purified protein derivative (PPD), before co-culture with autologous CD4 + Th cells. Proliferative and cytokine responses were measured, with eosinophil expression of HLA-DR/DP/DQ and the co-stimulatory molecules CD40, CD80 and CD86 determined by flow cytometry. Eosinophils pulsed with HDM, TG or PPD drove Th cell proliferation, with the response strength dependent on antigen concentration. The cytokine responses varied with donor and antigen, and were not biased towards any particular Th subset, often including combinations of pro- and anti-inflammatory cytokines. Eosinophils up-regulated surface expression of HLA-DR/DP/DQ, CD80, CD86 and CD40 in culture, increases that were sustained over 5 days when incubated with antigens, including HDM, or the major allergens it contains, Der p I or Der p II. Human eosinophils can, therefore, act as effective antigen-presenting cells to stimulate varied Th cell responses against a panel of antigens including HDM, TG or PPD, an ability that may help to determine the development of allergic disease. © 2016 John Wiley & Sons Ltd.
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
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
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
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
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.
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
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.
Anti-proliferative activities on HeLa cancer cell line of Thai medicinal plant recipes selected from MANOSROI II database.

PubMed

Manosroi, Jiradej; Boonpisuttinant, Korawinwich; Manosroi, Worapaka; Manosroi, Aranya

2012-07-13

The Thai/Lanna medicinal plant recipe database "MANOSROI II" contained the medicinal plant recipes of all regions in Thailand for the treatment of various diseases including anti-cancer medicinal plant recipes. To investigate anti-proliferative activity on HeLa cell lines of medicinal plant recipes selected from the Thai/Lanna medicinal plant recipe database "MANOSROI II". The forty aqueous extracts of Thai/Lanna medicinal plant recipes selected from the Thai/Lanna medicinal plant recipe database "MANOSROI II" were investigated for anti-proliferative activity on HeLa cell line by SRB assay. The apoptosis induction by caspase-3 activity and MMP-2 inhibition activity by zymography on HeLa cell line of the three selected aqueous extracts, which gave the highest anti-proliferative activity were determined. Phytochemicals and anti-oxidative activities including free radical scavenging activity, inhibition of lipid peroxidation and metal chelating inhibition activities were also investigated. Sixty percentages of the medicinal plant recipes selected from "MANOSROI II" database showed anti-proliferative activity on HeLa cell line. The recipes of N031(Albizia chinensis (Osbeck) Merr, Cassia fistula L., and Dargea volubilis Benth.ex Hook. etc.), N039 (Nymphoides indica L., Peltophorum pterocarpum (DC.), and Polyalthia debilis Finet et Gagnep etc.) and N040 (Nymphoides indica L. Kuntze, Sida rhombifolia L., and Xylinbaria minutiflora Pierre. etc.) gave higher anti-proliferative activity than the standard anti-cancer drug, cisplatin of 1.25, 1.29 and 30.18 times, respectively. The positive relationship between the anti-proliferative activity and the MMP-2 inhibition activity and metal chelating inhibition activity was observed, but no relationship between the anti-proliferative activity and apoptosis induction, free radical scavenging activity and lipid peroxidation inhibition activity. Phytochemicals found in these extracts were alkaloids, flavonoids, tannins and xanthones
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
Effect of L-arginine supplementation on immune responsiveness in patients with sickle cell disease.

PubMed

Scavella, Arnette; Leiva, Lily; Monjure, Hanh; Zea, Arnold H; Gardner, Renee V

2010-08-01

L-arginine (L-Arg) is deficient in sickle cell disease (SSD) during vasoocclusion. We investigated possible causal relationship between L-Arg deficiency and immune dysfunction in SSD in steady-state. Fifteen patients with SSD in steady-state and 13 controls were studied. Plasma L-Arg levels were measured using liquid chromatography. T cell subsets and CD3zeta (CD3zeta) chain expression were analyzed using flow cytometry. Lymphocyte proliferative response to phytohemagglutinin (PHA) and production of IL-6 and interferon-gamma (IFN-gamma) were evaluated with and without L-Arg. SSD patients had significantly lower L-Arg levels than controls. CD3 and CD19 cell populations were comparable for both groups, but SSD patients had above normal numbers of natural killer cells (P = 0.06). Patients and controls exhibited significantly increased lymphocyte blastogenesis to PHA after introduction of L-Arg to cultures; response of patients was significantly greater than values for control individuals. Proliferative response to candida in SSD patients was significantly lower than in controls; L-Arg supplementation did not increase this response. L-Arg had no effect on blastogenic response to PPD and candida albicans. No effect was likewise seen in production of IL-6 and IFN-gamma after addition of L-Arg. CD3zeta chain expression increased after addition of L-Arg in both groups; differences were insignificant. L-Arg levels in steady-state SSD are significantly lower than in controls. L-Arg supplementation enhanced lymphocyte blastogenesis to PHA for both controls and patients, but not in response to antigen. There were no significant differences in CD3zeta chain expression although upregulation of expression occurred after L-Arg supplementation for both groups. (c) 2010 Wiley-Liss, Inc.

Changes in T and B blood lymphocytes after splenectomy.

PubMed Central

Millard, R E; Banerjee, D K

1979-01-01

The blood lymphocytes of 37 splenectomised patients were analysed by means of T and B lymphocyte surface markers. Sixteen patients had had a splenectomy for non-haematological and 21 for haematological reasons. The results show that 15 had normal numbers of T and B cells; decreased T cells were found in two patients, raised B cells in seven, raised T and B cells in eight, and raised T cells in five patients. Increased numbers of 'null' cells were observed in some patients, especially in those with raised B cells. Follow-up studies indicate that raised levels of T and B cells can be established by one to three months post-splenectomy and may persist, although in some patients the cells fall to normal levels. The lymphocyte proliferative response to phytohaemagglutinin and Concanavalin A in vitro was normal in eight out of nine patients with raised T cells and was depressed in one patient, possibly due to an intrinsic cell defect. PMID:316436
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
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
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 ...
T-cell antigenic determinants within hepatitis C virus nonstructural protein 3 and cytokine production profiles in hepatitis C.

PubMed

Pan, C-H; Yang, P-M; Hwang, L-H; Kao, Shing-F; Chen, P-J; Chiang, B-L; Chen, D-S

2002-07-01

The aim of this study was to further investigate the role of T-helper cells in hepatitis C virus (HCV) infection, focusing on the T-cell antigenic determinants and cytokine profiles of nonstructural 3 (NS3) protein-stimulated peripheral blood mononuclear cells (PBMCs) of HCV patients. A total of 12 recombinant proteins of theNS3 region were purified and used to test T-cell proliferative response and antigenic determinants of HCV-seropositive patients. In addition, cytokines produced by antigen stimulated PBMCs were measured. Our data showed that PBMCs from 55.7% (34/61) of HCV patients proliferated to at least one antigen, but PBMCs of HCV seronegative patients did not. In addition, PBMCs from about 82.0% (32/39) HCV-seropositive patients produced significant amounts of cytokines (10 pg/mL). Interestingly, PBMCs from 66% of patients produced TH2-related cytokines such as interleukin (IL)-4 and IL-5. In mappingexperiments, the data showed multiple T-cell antigenic determinants. Our data demonstrated that NS3 antigen-stimulated PBMCs of HCV patients recognized multiple T-cell antigenic determinants and produced significant amounts of TH0 or TH2-related cytokines, which might play a critical role in the chronicity of HCV infection.
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
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.
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
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.
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
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
[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
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
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.
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
Proliferative responses in the local lymph node assay associated with concomitant exposure to 1,4-phenylenediamine and methyldibromo glutaronitrile: evidence for synergy?

PubMed

Jowsey, Ian R; Basketter, David A; Irwin, Anita

2008-08-01

A key consideration when undertaking risk assessments should be the potential for synergy between contact allergens. Previously, this concept has only been investigated during elicitation in contact allergic individuals. To determine whether there exists evidence for synergy between contact allergens during the induction phase of skin sensitization using the mouse local lymph node assay (LLNA) as a model system. Proliferative responses in draining lymph nodes were assessed with increasing concentrations of 1,4-phenylenediamine (PPD), methyldibromo glutaronitrile (MDBGN), and a combination of PPD and MDBGN. Data from each of two independent experiments show that lymph node cell proliferation associated with combined exposure to PPD and MDBGN was, in general, only modestly increased relative to that predicted from a simple summation of their individual responses. Although the increase in response is very modest, it does imply a relationship between this combination of sensitizers that may not be simply additive in terms of their ability to stimulate proliferative responses in draining lymph nodes. The reproducibility of this observation should be confirmed in future studies with additional pairs of contact allergens to ascertain whether or not this represents evidence of synergy.
Role of latent membrane protein 1 in chronic active Epstein-Barr virus infection-derived T/NK-cell proliferation.

PubMed

Ito, Takuto; Kawazu, Hidetaka; Murata, Takayuki; Iwata, Seiko; Arakawa, Saki; Sato, Yoshitaka; Kuzushima, Kiyotaka; Goshima, Fumi; Kimura, Hiroshi

2014-08-01

Epstein-Barr virus (EBV) predominantly infects B cells and causes B-cell lymphomas, such as Burkitt lymphoma and Hodgkin lymphoma. However, it also infects other types of cells, including T and natural killer (NK) cells, and causes disorders, such as chronic active EBV infection (CAEBV) and T/NK-cell lymphoma. The CAEBV is a lymphoproliferative disease with poor prognosis, where EBV-positive T or NK cells grow rapidly, although the molecular mechanisms that cause the cell expansion still remain to be elucidated. EBV-encoded latent membrane protein 1 (LMP1) is an oncogene that can transform some cell types, such as B cells and mouse fibroblasts, and thus may stimulate cell proliferation in CAEBV. Here, we examined the effect of LMP1 on EBV-negative cells using the cells conditionally expressing LMP1, and on CAEBV-derived EBV-positive cells by inhibiting the function of LMP1 using a dominant negative form of LMP1. We demonstrated that LMP1 was responsible for the increased cell proliferation in the cell lines derived from CAEBV, while LMP1 did not give any proliferative advantage to the EBV-negative cell line. © 2014 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.
Relationship between DNA ploidy and proliferative cell nuclear antigen index in canine hemangiopericytoma.

PubMed

Kang, Seong-Kwi; Park, Nam-Yong; Cho, Ho-Sung; Shin, Sung-Shik; Kang, Mun-Il; Kim, Sang-Ki; Hyun, Changbaig; Park, In-Chul; Kim, Jong-Tack; Jeong, Cheol; Park, Sung-Hee; Park, Su-Jin; Jeong, Jae-Ho; Kim, You-Jung; Ochiai, Kenji; Umemura, Takashi; Cho, Kyoung-Oh

2006-03-01

The mitotic index is reported to be correlated with recurrence, mean patient survival, and metastasis of canine hemangiopericytoma (CHP). However, to the authors' knowledge, studies investigating the parameters that can predict recurrence or metastasis of CHP with low mitotic index have not been done. To evaluate growth kinetics of CHP with low mitotic index, a retrospective analysis of the proliferative activity by antiproliferative cell nuclear antigen monoclonal antibody and DNA contents by flow cytometry (FCM) was performed with 21 formalin-fixed and paraffin-embedded CHP samples. Of the 21 tumors evaluated by FCM, 6 (26.6%) were aneuploid tumors, and 15 (71.4%) were diploid tumors. There was significant correlation between the PCNA index and ploidy pattern. The diploid group had 39.1 +/- 9.2 PCNA index, whereas the aneuploid group's proliferative cell nuclear antigen (PCNA) index was 63.1 +/- 8.2. The diploid group had mean mitotic index value of 1.140 +/- 0.855, and the aneuploid group had a mean value of 1.067 +/- 0.767. From these results, the CHP samples with low mitotic index were classified into either the aneuploid group with higher PCNA index or the diploid group with lower PCNA index, suggesting that DNA ploidy and proliferative activity may give an indication about malignancy of CHPs with a low mitotic index.
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
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.

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.
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.
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
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
Insufficient interleukin-2 production from splenic CD4+ T cells causes impaired cell proliferation and early apoptosis in SAMP1, a strain of senescence-accelerated mouse

PubMed Central

Nishimura, Yasumitsu; Hosokawa, Tomohide; Hosono, Masamichi; Baba, Mitsuo; Hosokawa, Masanori

2002-01-01

We examined the proliferative and cytokine-producing activities of CD4+ T cells from young mice of the senescence-accelerated mouse strain SAMP1, which had shown markedly low T-dependent antibody-producing responses. When splenic T cells were cultured with concanavalin A (Con A), the percentage of CD4+ cells decreased earlier in SAMP1 than in C3H/He mice. At 40 hr of culture, the percentage of BrdU-labelled proliferating CD4+ cells increased strongly in C3H/He, but only slightly in SAMP1. When purified CD4+ T cells were cultured with Con A, the percentage of 5-bromo-2′-deoxyuridine (BrdU)-labelled cells peaked at around 48 hr of culture in both strains, but decreased significantly at 64 hr in SAMP1. The production of interleukin (IL)-2 but not IL-4 or interferon-γ (IFN-γ) was significantly lower in SAMP1 than in C3H/He at 48 hr of culture. IL-2 production was also markedly low in SAMP1, even under the stimulation of anti-CD3 with anti-CD28 antibodies. The frequency of cells producing IL-2 was significantly lower in SAMP1 than in C3H/He at 6–24 hr of culture with Con A. The percentage of annexin-positive and propidium iodide (PI)-negative apoptotic cells was significantly higher in SAMP1 than in C3H/He at 96 hr of culture. Exogenous IL-2 prevented the decrease in BrdU-labelled cells and the increase in apoptotic cells in the SAMP1 cell culture. These results indicate that SAMP1 CD4+ T cells cannot produce IL-2 at levels sufficient to support cell proliferation and survival. This may account for the weak T-dependent antibody response in SAMP1 mice. PMID:12383198
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.
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
Role for granulocyte colony-stimulating factor in the generation of human T regulatory type 1 cells.

PubMed

Rutella, Sergio; Pierelli, Luca; Bonanno, Giuseppina; Sica, Simona; Ameglio, Franco; Capoluongo, Ettore; Mariotti, Andrea; Scambia, Giovanni; d'Onofrio, Giuseppe; Leone, Giuseppe

2002-10-01

Granulocyte colony-stimulating factor (G-CSF) may affect T-cell homeostasis by multiple mechanisms, inducing polarization of cytokine secretion, inhibition of T-cell proliferation, and enhancement of T-cell apoptosis. We analyzed the production of interleukin-10 (IL-10) and transforming growth factor-beta1 (TGF-beta1) by T cells from healthy volunteer donors treated with recombinant human G-CSF. Highly purified CD4(+) T cells obtained before and after G-CSF administration (pre-G and post-G, respectively) were activated using the allogeneic mixed leukocyte reaction. Post-G CD4(+) T cells produced high levels of IL-10 but undetectable levels of IL-2 and IL-4, whereas the level of TGF-beta1 release was comparable to that of pre-G CD4(+) T cells. Notably, post-G CD4(+) T cells proliferated poorly in response to alloantigens and to recall antigens and suppressed the proliferation of autologous CD4(+) T cells in a cell contact-independent and an antigen-nonspecific manner. TGF-beta1 and IL-10 were not dispensable for post-G CD4(+) T cells to mediate suppression, as shown by neutralization studies. Compared with pre-G CD4(+) T cells, alloantigen-activated post-G CD4(+) T cells preferentially expressed markers associated with memory T cells, in conjunction with reduced levels of CD28 and CD62L. Collectively, these data demonstrate that CD4(+) T cells exposed to G-CSF in vivo acquire the properties of T regulatory (Tr) cells once triggered in vitro through the T-cell receptor, including a peculiar cytokine production profile (IL-10(++)TGF-beta1(+)IL-2(low/-)IL-4(low/-)), an intrinsic low proliferative capacity, and a contact-independent suppression of antigen-driven proliferation. Tr cells generated ex vivo after exposure to G-CSF might be clinically relevant for transplantation medicine and for the treatment of human immune-mediated diseases.
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.
Stochastic cellular automata model of neurosphere growth: Roles of proliferative potential, contact inhibition, cell death, and phagocytosis.

PubMed

Sipahi, Rifat; Zupanc, Günther K H

2018-05-14

Neural stem and progenitor cells isolated from the central nervous system form, under specific culture conditions, clonal cell clusters known as neurospheres. The neurosphere assay has proven to be a powerful in vitro system to study the behavior of such cells and the development of their progeny. However, the theory of neurosphere growth has remained poorly understood. To overcome this limitation, we have, in the present paper, developed a cellular automata model, with which we examined the effects of proliferative potential, contact inhibition, cell death, and clearance of dead cells on growth rate, final size, and composition of neurospheres. Simulations based on this model indicated that the proliferative potential of the founder cell and its progenitors has a major influence on neurosphere size. On the other hand, contact inhibition of proliferation limits the final size, and reduces the growth rate, of neurospheres. The effect of this inhibition is particularly dramatic when a stem cell becomes encapsulated by differentiated or other non-proliferating cells, thereby suppressing any further mitotic division - despite the existing proliferative potential of the stem cell. Conversely, clearance of dead cells through phagocytosis is predicted to accelerate growth by reducing contact inhibition. A surprising prediction derived from our model is that cell death, while resulting in a decrease in growth rate and final size of neurospheres, increases the degree of differentiation of neurosphere cells. It is likely that the cellular automata model developed as part of the present investigation is applicable to the study of tissue growth in a wide range of systems. Copyright © 2018 Elsevier Ltd. All rights reserved.
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
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.
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.
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.
Preparing clinical grade Ag-specific T cells for adoptive immunotherapy trials

PubMed Central

DiGiusto, DL; Cooper, LJN

2007-01-01

The production of clinical-grade T cells for adoptive immunotherapy has evolved from the ex vivo numerical expansion of tumor-infiltrating lymphocytes to sophisticated bioengineering processes often requiring cell selection, genetic modification and other extensive tissue culture manipulations, to produce desired cells with improved therapeutic potential. Advancements in understanding the biology of lymphocyte signaling, activation, homing and sustained in vivo proliferative potential have redefined the strategies used to produce T cells suitable for clinical investigation. When combined with new technical methods in cell processing and culturing, the therapeutic potential of T cells manufactured in academic centers has improved dramatically. Paralleling these technical achievements in cell manufacturing is the development of broadly applied regulatory standards that define the requirements for the clinical implementation of cell products with ever-increasing complexity. In concert with academic facilities operating in compliance with current good manufacturing practice, the prescribing physician can now infuse T cells with a highly selected or endowed phenotype that has been uniformly manufactured according to standard operating procedures and that meets federal guidelines for quality of investigational cell products. In this review we address salient issues related to the technical, immunologic, practical and regulatory aspects of manufacturing these advanced T-cell products for clinical use. PMID:17943498
Adult systemic Epstein-Barr virus-positive T-cell lymphoproliferative disease: A case report.

PubMed

Wang, Youping; Liu, Xinyue; Chen, Yan

2015-09-01

Systemic Epstein-Barr virus (EBV)-positive T-cell lymphoproliferative disease (EBV + T-LPD) occurs mainly in Asia and South America and is extremely rare in adults. The disease is characterized by a clonal proliferation of EBV-infected T cells with a cytotoxic immunophenotype and is associated with a poor clinical outcome and can be life-threatening. The majority of the patients have evidence of systemic disease, often with lymph node, liver and spleen involvement. The present study describes a case of adult systemic EBV + T-LPD with high fever, systemic lymphadenopathy, hepatosplenomegaly, nose-pharynx neoplasm, pancytopenia, EB virus infection and proliferative bone marrow, with the aim of improving the understanding of the condition.
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
A Convenient and Efficient Method to Enrich and Maintain Highly Proliferative Human Fetal Liver Stem Cells

PubMed Central

Guo, Xuan; Wang, Shu; Dou, Ya-ling; Guo, Xiang-fei; Chen, Zhao-li; Wang, Xin-wei; Shen, Zhi-qiang; Qiu, Zhi-gang

2015-01-01

Abstract Pluripotent human hepatic stem cells have broad research and clinical applications, which are, however, restricted by both limited resources and technical difficulties with respect to isolation of stem cells from the adult or fetal liver. In this study, we developed a convenient and efficient method involving a two-step in situ collagenase perfusion, gravity sedimentation, and Percoll density gradient centrifugation to enrich and maintain highly proliferative human fetal liver stem cells (hFLSCs). Using this method, the isolated hFLSCs entered into the exponential growth phase within 10 days and maintained sufficient proliferative activity to permit subculture for at least 20 passages without differentiation. Immunocytochemistry, immunofluorescence, and flow cytometry results showed that these cells expressed stem cell markers, such as c-kit, CD44, epithelial cell adhesion molecule (EpCAM), oval cell marker-6 (OV-6), epithelial marker cytokeratin 18 (CK18), biliary ductal marker CK19, and alpha-fetoprotein (AFP). Gene expression analysis showed that these cells had stable mRNA expression of c-Kit, EpCAM, neural cell adhesion molecule (NCAM), CK19, CK18, AFP, and claudin 3 (CLDN-3) throughout each passage while maintaining low levels of ALB, but with complete absence of cytochrome P450 3A4 (C3A4), phosphoenolpyruvate carboxykinase (PEPCK), telomeric repeat binding factor (TRF), and connexin 26 (CX26) expression. When grown in appropriate medium, these isolated liver stem cells could differentiate into hepatocytes, cholangiocytes, osteoblasts, adipocytes, or endothelial cells. Thus, we have demonstrated a more economical and efficient method to isolate hFLSCs than magnetic-activated cell sorting (MACS). This novel approach may provide an excellent tool to isolate highly proliferative hFLSCs for tissue engineering and regenerative therapies. PMID:25556695
A Convenient and Efficient Method to Enrich and Maintain Highly Proliferative Human Fetal Liver Stem Cells.

PubMed

Guo, Xuan; Wang, Shu; Dou, Ya-ling; Guo, Xiang-fei; Chen, Zhao-li; Wang, Xin-wei; Shen, Zhi-qiang; Qiu, Zhi-gang; Jin, Min; Li, Jun-wen

2015-06-01

Pluripotent human hepatic stem cells have broad research and clinical applications, which are, however, restricted by both limited resources and technical difficulties with respect to isolation of stem cells from the adult or fetal liver. In this study, we developed a convenient and efficient method involving a two-step in situ collagenase perfusion, gravity sedimentation, and Percoll density gradient centrifugation to enrich and maintain highly proliferative human fetal liver stem cells (hFLSCs). Using this method, the isolated hFLSCs entered into the exponential growth phase within 10 days and maintained sufficient proliferative activity to permit subculture for at least 20 passages without differentiation. Immunocytochemistry, immunofluorescence, and flow cytometry results showed that these cells expressed stem cell markers, such as c-kit, CD44, epithelial cell adhesion molecule (EpCAM), oval cell marker-6 (OV-6), epithelial marker cytokeratin 18 (CK18), biliary ductal marker CK19, and alpha-fetoprotein (AFP). Gene expression analysis showed that these cells had stable mRNA expression of c-Kit, EpCAM, neural cell adhesion molecule (NCAM), CK19, CK18, AFP, and claudin 3 (CLDN-3) throughout each passage while maintaining low levels of ALB, but with complete absence of cytochrome P450 3A4 (C3A4), phosphoenolpyruvate carboxykinase (PEPCK), telomeric repeat binding factor (TRF), and connexin 26 (CX26) expression. When grown in appropriate medium, these isolated liver stem cells could differentiate into hepatocytes, cholangiocytes, osteoblasts, adipocytes, or endothelial cells. Thus, we have demonstrated a more economical and efficient method to isolate hFLSCs than magnetic-activated cell sorting (MACS). This novel approach may provide an excellent tool to isolate highly proliferative hFLSCs for tissue engineering and regenerative therapies.
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.

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