Science.gov

Sample records for allogeneic t-cell response

  1. 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

  2. Transplantation of Tail Skin to Study Allogeneic CD4 T Cell Responses in Mice

    PubMed Central

    Rossi, Simona W.

    2014-01-01

    The study of T cell responses and their consequences during allo-antigen recognition requires a model that enables one to distinguish between donor and host T cells, to easily monitor the graft, and to adapt the system in order to answer different immunological questions. Medawar and colleagues established allogeneic tail-skin transplantation in mice in 1955. Since then, the skin transplantation model has been continuously modified and adapted to answer specific questions. The use of tail-skin renders this model easy to score for graft rejection, requires neither extensive preparation nor deep anesthesia, is applicable to animals of all genetic background, discourages ischemic necrosis, and permits chemical and biological intervention. In general, both CD4+ and CD8+ allogeneic T cells are responsible for the rejection of allografts since they recognize mismatched major histocompatibility antigens from different mouse strains. Several models have been described for activating allogeneic T cells in skin-transplanted mice. The identification of major histocompatibility complex (MHC) class I and II molecules in different mouse strains including C57BL/6 mice was an important step toward understanding and studying T cell-mediated alloresponses. In the tail-skin transplantation model described here, a three-point mutation (I-Abm12) in the antigen-presenting groove of the MHC-class II (I-Ab) molecule is sufficient to induce strong allogeneic CD4+ T cell activation in C57BL/6 mice. Skin grafts from I-Abm12 mice on C57BL/6 mice are rejected within 12-15 days, while syngeneic grafts are accepted for up to 100 days. The absence of T cells (CD3-/- and Rag2-/- mice) allows skin graft acceptance up to 100 days, which can be overcome by transferring 2 x 104 wild type or transgenic T cells. Adoptively transferred T cells proliferate and produce IFN-γ in I-Abm12-transplanted Rag2-/- mice. PMID:25147005

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

    PubMed Central

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

    2016-01-01

    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. PMID:27103745

  4. 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

    2016-07-01

    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. PMID:27103745

  5. Induction of Cytomegalovirus-Specific T Cell Responses in Healthy Volunteers and Allogeneic Stem Cell Recipients Using Vaccination With Messenger RNA–Transfected Dendritic Cells

    PubMed Central

    Van Craenenbroeck, Amaryllis H.; Smits, Evelien L.J.; Anguille, Sébastien; Van de Velde, Ann; Stein, Barbara; Braeckman, Tessa; Van Camp, Kirsten; Nijs, Griet; Ieven, Margareta; Goossens, Herman; Berneman, Zwi N.; Van Tendeloo, Viggo F.I.; Verpooten, Gert A.; Van Damme, Pierre; Cools, Nathalie

    2015-01-01

    Background Infection with human cytomegalovirus (CMV) is a significant cause of morbidity and mortality in solid organ and hematopoietic stem cell transplant (HSCT) recipients. Methods The present study explored the safety, feasibility, and immunogenicity of CMV pp65 messenger RNA–loaded autologous monocyte-derived dendritic cells (DC) as a cellular vaccine for active immunization in healthy volunteers and allogeneic HSCT recipients. Four CMV-seronegative healthy volunteers and three allogeneic HSCT recipients were included in the study. Four clinical-grade autologous monocyte-derived DC vaccines were prepared after a single leukapheresis procedure and administered intradermally at a weekly interval. Results De novo induction of CMV-specific T-cell responses was detected in three of four healthy volunteers without serious adverse events. Of the HSCT recipients, none developed CMV disease and one of two patients displayed a remarkable threefold increase in CMV pp65-specific T cells on completion of the DC vaccination trial. Conclusion In conclusion, our DC vaccination strategy induced or expanded a CMV-specific cellular response in four of six efficacy-evaluable study subjects, providing a base for its further exploration in larger cohorts. PMID:25050468

  6. Monitoring of Human Cytomegalovirus and Virus-Specific T-Cell Response in Young Patients Receiving Allogeneic Hematopoietic Stem Cell Transplantation

    PubMed Central

    Lilleri, Daniele; Gerna, Giuseppe; Zelini, Paola; Chiesa, Antonella; Rognoni, Vanina; Mastronuzzi, Angela; Giorgiani, Giovanna; Zecca, Marco; Locatelli, Franco

    2012-01-01

    In allogeneic hematopoietic stem-cell transplantation (HSCT) recipients, outcome of human cytomegalovirus (HCMV) infection results from balance between viral load/replication and pathogen-specific T-cell response. Using a cut-off of 30,000 HCMV DNA copies/ml blood for pre-emptive therapy and cut-offs of 1 and 3 virus-specific CD4+ and CD8+ T cells/µl blood for T-cell protection, we conducted in 131 young patients a prospective 3-year study aimed at verifying whether achievement of such immunological cut-offs protects from HCMV disease. In the first three months after transplantation, 55/89 (62%) HCMV-seropositive patients had infection and 36/55 (65%) were treated pre-emptively, whereas only 7/42 (17%) HCMV-seronegative patients developed infection and 3/7 (43%) were treated. After 12 months, 76 HCMV-seropositive and 9 HCMV-seronegative patients (cumulative incidence: 90% and 21%, respectively) displayed protective HCMV-specific immunity. Eighty of these 85 (95%) patients showed spontaneous control of HCMV infection without additional treatment. Five patients after reaching protective T-cell levels needed pre-emptive therapy, because they developed graft-versus-host disease (GvHD). HSCT recipients reconstituting protective levels of HCMV-specific T-cells in the absence of GvHD are no longer at risk for HCMV disease, at least within 3 years after transplantation. The decision to treat HCMV infection in young HSCT recipients may be taken by combining virological and immunological findings. PMID:22848556

  7. Murine allogeneic CD19 CAR T cells harbor potent antileukemic activity but have the potential to mediate lethal GVHD.

    PubMed

    Jacoby, Elad; Yang, Yinmeng; Qin, Haiying; Chien, Christopher D; Kochenderfer, James N; Fry, Terry J

    2016-03-10

    Acute lymphoblastic leukemia (ALL) persisting or relapsing following bone marrow transplantation (BMT) has a dismal prognosis. Success with chimeric antigen receptor (CAR) T cells offers an opportunity to treat these patients with leukemia-redirected donor-derived T cells, which may be more functional than T cells derived from patients with leukemia but have the potential to mediate graft-versus-host disease (GVHD). We, together with others, have previously demonstrated tumor-specific T-cell dysfunction in the allogeneic environment. Here, we studied CAR T-cell function following BMT using an immunocompetent murine model of minor mismatched allogeneic transplantation followed by donor-derived CD19-CAR T cells. Allogeneic donor-derived CD19-CAR T cells eliminated residual ALL with equal potency to those administered after syngeneic BMT. Surprisingly, allogeneic CAR T cells mediated lethal acute GVHD with early mortality, which is atypical for this minor mismatch model. We demonstrated that both allogeneic and syngeneic CAR T cells show initial expansion as effector T cells, with a higher peak but rapid deletion of allogeneic CAR T cells. Interestingly, CAR-mediated acute GVHD was only seen in the presence of leukemia, suggesting CAR-target interactions induced GVHD. Indeed, serum interleukin (IL)-6 was elevated only in the presence of both leukemia and CAR T cells, and IL-6 neutralization ameliorated the severity of GVHD in a delayed donor lymphocyte infusion model. Finally, allogeneic CD4(+) CAR T cells were responsible for GVHD, which correlated with their ability to produce IL-6 upon CAR stimulation. Altogether, we demonstrate that donor-derived allogeneic CAR T cells are active but have the capacity to drive GVHD. PMID:26660684

  8. Tumor immunotherapy across MHC barriers using allogeneic T-cell precursors

    PubMed Central

    Zakrzewski, Johannes L; Suh, David; Markley, John C; Smith, Odette M; King, Christopher; Goldberg, Gabrielle L; Jenq, Robert; Holland, Amanda M; Grubin, Jeremy; Cabrera-Perez, Javier; Brentjens, Renier J; Lu, Sydney X; Rizzuto, Gabrielle; Sant’Angelo, Derek B; Riviere, Isabelle; Sadelain, Michel; Heller, Glenn; Zúñiga-Pflücker, Juan Carlos; Lu, Chen; van den Brink, Marcel R M

    2009-01-01

    We present a strategy for adoptive immunotherapy using T-lineage committed lymphoid precursor cells generated by Notch1-based culture. We found that allogeneic T-cell precursors can be transferred to irradiated individuals irrespective of major histocompatibility complex (MHC) disparities and give rise to host-MHC restricted and host-tolerant functional allogeneic T cells, improving survival in irradiated recipients as well as enhancing anti-tumor responses. T-cell precursors transduced to express a chimeric receptor targeting hCD19 resulted in significant additional anti-tumor activity, demonstrating the feasibility of genetic engineering of these cells. We conclude that ex vivo generated MHC-disparate T-cell precursors from any donor can be used universally for ‘off-the-shelf’ immunotherapy, and can be further enhanced by genetic engineering for targeted immunotherapy. PMID:18376399

  9. Regulatory T Cells in Allogeneic Stem Cell Transplantation

    PubMed Central

    Nagler, Arnon

    2013-01-01

    Growing evidence suggests that cellular adoptive immunotherapy is becoming an attractive though challenging approach in regulating tumor immunity and alloresponses in clinical transplantation. Naturally arising CD4+CD25+Foxp3+ regulatory T cells (Treg) have emerged as a key component in this regard. Over the last decade, a large body of evidence from preclinical models has demonstrated their crucial role in auto- and tumor immunity and has opened the door to their “first-in-man” clinical application. Initial studies in clinical allogeneic stem cell transplantation are very encouraging and may pave the way for other applications. Further improvements in Treg ex vivo or in vivo expansion technologies will simplify their global clinical application. In this review, we discuss the current knowledge of Treg biology and their potential for cell-based immunotherapy in allogeneic stem cell transplantation. PMID:23737813

  10. High proportions of regulatory T cells in PBSC grafts predict improved survival after allogeneic haematopoietic SCT

    PubMed Central

    Danby, R D; Zhang, W; Medd, P; Littlewood, T J; Peniket, A; Rocha, V; Roberts, D J

    2016-01-01

    Regulatory T cells (Tregs) modulate immune responses and improve survival in murine transplant models. However, whether the Treg content of allogeneic cell grafts influences the outcome in human haematopoietic stem cell (HSC) transplantation is not well established. In a prospective study of 94 adult allogeneic PBSC transplants (60% unrelated; 85% reduced intensity conditioning), the median Treg (CD3+CD4+CD25+FOXP3+CD127dim/−) dose transplanted was 4.7 × 106/kg, with Tregs accounting for a median of 2.96% of CD4+ T cells. Patients transplanted with grafts containing a Treg/CD4+ T-cell ratio above the median had a 3-year overall survival of 75%, compared with 49% in those receiving grafts with a Treg/CD4+ T-cell ratio below the median (P=0.02), with a 3-year non-relapse mortality of 13% and 35%, respectively (P=0.02). In multivariate analysis, a high graft Treg/CD4+ T-cell ratio was an independent predictor of lower non-relapse mortality (hazard ratio (HR), 0.30; P=0.02), improved overall survival (HR, 0.45; P=0.03) and improved sustained neutrophil (HR, 0.52; P=0.002), platelet (HR, 0.51; P<0.001) and lymphocyte (HR, 0.54; P=0.009) recovery. These data support the hypothesis that the proportion of Tregs in allogeneic HSC grafts influences clinical outcome and suggest that Treg therapies could improve allogeneic HSC transplantation. PMID:26389831

  11. Adaptive Natural Killer Cell and Killer Cell Immunoglobulin-Like Receptor-Expressing T Cell Responses are Induced by Cytomegalovirus and Are Associated with Protection against Cytomegalovirus Reactivation after Allogeneic Donor Hematopoietic Cell Transplantation.

    PubMed

    Davis, Zachary B; Cooley, Sarah A; Cichocki, Frank; Felices, Martin; Wangen, Rose; Luo, Xianghua; DeFor, Todd E; Bryceson, Yenan T; Diamond, Don J; Brunstein, Claudio; Blazar, Bruce R; Wagner, John E; Weisdorf, Daniel J; Horowitz, Amir; Guethlein, Lisbeth A; Parham, Peter; Verneris, Michael R; Miller, Jeffrey S

    2015-09-01

    Cytomegalovirus (CMV) reactivates in >30% of CMV-seropositive patients after allogeneic hematopoietic cell transplantation (HCT). Previously, we reported an increase of natural killer (NK) cells expressing NKG2C, CD57, and inhibitory killer cell immunoglobulin-like receptors (KIRs) in response to CMV reactivation after HCT. These NK cells persist after the resolution of infection and display "adaptive" or memory properties. Despite these findings, the differential impact of persistent/inactive versus reactivated CMV on NK versus T cell maturation after HCT from different graft sources has not been defined. We compared the phenotype of NK and T cells from 292 recipients of allogeneic sibling (n = 118) or umbilical cord blood (UCB; n = 174) grafts based on recipient pretransplantation CMV serostatus and post-HCT CMV reactivation. This cohort was utilized to evaluate CMV-dependent increases in KIR-expressing NK cells exhibiting an adaptive phenotype (NKG2C(+)CD57(+)). Compared with CMV-seronegative recipients, those who reactivated CMV had the highest adaptive cell frequencies, whereas intermediate frequencies were observed in CMV-seropositive recipients harboring persistent/nonreplicating CMV. The same effect was observed in T cells and CD56(+) T cells. These adaptive lymphocyte subsets were increased in CMV-seropositive recipients of sibling but not UCB grafts and were correlated with lower rates of CMV reactivation (sibling 33% versus UCB 51%; P < .01). These data suggest that persistent/nonreplicating recipient CMV induces rapid production of adaptive NK and T cells from mature cells from sibling but not UCB grafts. These adaptive lymphocytes are associated with protection from CMV reactivation. PMID:26055301

  12. Allogeneic IgG combined with dendritic cell stimuli induces anti-tumor T cell immunity

    PubMed Central

    Carmi, Yaron; Spitzer, Matthew H.; Linde, Ian L.; Burt, Bryan M; Prestwood, Tyler R.; Perlman, Nikola; Davidson, Matthew G.; Kenkel, Justin A.; Segal, Ehud; Pusapati, Ganesh V.; Bhattacharya, Nupur; Engleman, Edgar G.

    2015-01-01

    While cancers grow in their hosts and evade host immunity through immunoediting and immunosuppression1–5, tumors are rarely transmissible between individuals. Much like transplanted allogeneic organs, allogeneic tumors are reliably rejected by host T cells, even when the tumor and host share the same major histocompatibility complex (MHC) alleles, the most potent determinants of transplant rejection6–10. How such tumor-eradicating immunity is initiated remains unknown, though elucidating this process could provide a roadmap for inducing similar responses against naturally arising tumors. We found that allogeneic tumor rejection is initiated by naturally occurring tumor-binding IgG antibodies, which enable dendritic cells (DC) to internalize tumor antigens and subsequently activate tumor-reactive T cells. We exploited this mechanism to successfully treat autologous and autochthonous tumors. Either systemic administration of DC loaded with allogeneic IgG (alloIgG)-coated tumor cells or intratumoral injection of alloIgG in combination with DC stimuli induced potent T cell mediated anti-tumor immune responses, resulting in tumor eradication in mouse models of melanoma, pancreas, lung and breast cancer. Moreover, this strategy led to eradication of distant tumors and metastases, as well as the injected primary tumors. To assess the clinical relevance of these findings, we studied antibodies and cells from patients with lung cancer. T cells from these patients responded vigorously to autologous tumor antigens after culture with alloIgG-loaded DC, recapitulating our findings in mice. These results reveal that tumor-binding alloIgG can induce powerful anti-tumor immunity that can be exploited for cancer immunotherapy. PMID:25924063

  13. Origin and Biology of the Allogeneic Response

    PubMed Central

    Lakkis, Fadi G.; Lechler, Robert I.

    2013-01-01

    The recognition by the immune system of nonself determinants on cells, tissues, or organs transplanted between genetically disparate members of the same species can lead to a potent allogeneic response that is responsible for rejection. We review here fundamental concepts that underlie the origins and biology of allorecognition in the mammalian immune system. We examine why and how T cells are alloreactive and discuss emerging evidence of allorecognition by innate immune cells. The nature of T cells (naïve vs. memory) and the alloantigen presentation pathways (direct, indirect, and semidirect) that initiate the allogeneic response are outlined. PMID:23906882

  14. Abundant cytomegalovirus (CMV) reactive clonotypes in the CD8(+) T cell receptor alpha repertoire following allogeneic transplantation.

    PubMed

    Link, C S; Eugster, A; Heidenreich, F; Rücker-Braun, E; Schmiedgen, M; Oelschlägel, U; Kühn, D; Dietz, S; Fuchs, Y; Dahl, A; Domingues, A M J; Klesse, C; Schmitz, M; Ehninger, G; Bornhäuser, M; Schetelig, J; Bonifacio, E

    2016-06-01

    Allogeneic stem cell transplantation is potentially curative, but associated with post-transplantation complications, including cytomegalovirus (CMV) infections. An effective immune response requires T cells recognizing CMV epitopes via their T cell receptors (TCRs). Little is known about the TCR repertoire, in particular the TCR-α repertoire and its clinical relevance in patients following stem cell transplantation. Using next-generation sequencing we examined the TCR-α repertoire of CD8(+) T cells and CMV-specific CD8(+) T cells in four patients. Additionally, we performed single-cell TCR-αβ sequencing of CMV-specific CD8(+) T cells. The TCR-α composition of human leucocyte antigen (HLA)-A*0201 CMVpp65- and CMVIE -specific T cells was oligoclonal and defined by few dominant clonotypes. Frequencies of single clonotypes reached up to 11% of all CD8(+) T cells and half of the total CD8(+) T cell repertoire was dominated by few CMV-reactive clonotypes. Some TCR-α clonotypes were shared between patients. Gene expression of the circulating CMV-specific CD8(+) T cells was consistent with chronically activated effector memory T cells. The CD8(+) T cell response to CMV reactivation resulted in an expansion of a few TCR-α clonotypes to dominate the CD8(+) repertoires. These results warrant further larger studies to define the ability of oligoclonally expanded T cell clones to achieve an effective anti-viral T cell response in this setting. PMID:26800118

  15. Susceptibility of neonatal T cells and adult thymocytes to peripheral tolerance to allogeneic stimuli

    PubMed Central

    do Canto, Fábio B; Lima, Celso; Teixeira, Ivan A; Bellio, Maria; Nóbrega, Alberto; Fucs, Rita

    2008-01-01

    We studied the tolerization of neonatal thymocytes (NT), neonatal splenocytes (NS) and adult thymocytes (AT), transferred to syngeneic nude (nu/nu) hosts previously injected with semi-allogeneic splenocytes, without any supportive immunosuppressive treatment. This protocol allows the study of peripheral tolerance in the absence of the thymus. BALB/c neonatal T cells and ATs were able to expand in syngeneic BALB/c nu/nu mice and functionally reconstituted an allogeneic response, rejecting (BALB/c × B6.Ba) F1 splenocytes transferred 3–4 weeks after injection of BALB/c cells. However, if (BALB/c × B6.Ba) F1 cells were injected into BALB/c nude hosts 30 days before transfer of NT, NS or AT cells, the F1 population was preserved and specific tolerance to B6 allografts was established. Furthermore, transfer to lymphopenic F1 nu/nu showed that tolerance could be established only for neonatal populations, showing that unique properties of neonatal T cells allow their tolerization in both lymphopenic and non-lymphopenic conditions, in the absence of suppressive immunotherapy. These results bring empirical support to the possibility of T-cell engraftment in immunodeficient patients showing partial identity with donor major histocompatibility complex (MHC) genes; the manipulation of immunological maturity of donor T cells may be the key for successful reconstitution of immunocompetence without induction of graft-versus-host disease. PMID:18462348

  16. Cytomegalovirus-infected human endothelial cells can stimulate allogeneic CD4+ memory T cells by releasing antigenic exosomes1

    PubMed Central

    Walker, Jason D.; Maier, Cheryl L.; Pober, Jordan S.

    2008-01-01

    Human CMV infection is controlled by T cell-mediated immunity and in immunosuppressed transplant patients it is associated with acute allograft rejection as well as chronic allograft vasculopathy. CMV infects endothelial cells (EC) and it is thought that CMV-specific host immune responses to infected allograft EC contribute to rejection. In vitro, CD4+ T cells from CMV-positive donors (but not CMV-negative donors) are readily activated by CMV-infected allogeneic EC, although it is unclear how allogeneic CMV-infected EC activate self-class II MHC-restricted memory CD4+ T cells. In this study we confirm that purified CD4+ T cells from CMV+ donors are activated by allogeneic CMV-infected EC, but find that the response is dependent upon co-purified APC expressing class II MHC that are autologous to the T cells. The transfer of CMV antigens from infected EC to APC can be mediated by EC-derived exosome-like particles. These results provide a mechanism by which CMV can exacerbate allograft rejection, and suggest a novel function of EC-derived exosomes that could contribute in a more general manner to immune surveillance. PMID:19155503

  17. T cell responses to cytomegalovirus.

    PubMed

    Klenerman, Paul; Oxenius, Annette

    2016-06-01

    Human cytomegalovirus (HCMV) establishes a latent infection that generally remains asymptomatic in immune-competent hosts for decades but can cause serious illness in immune-compromised individuals. The long-term control of CMV requires considerable effort from the host immune system and has a lasting impact on the profile of the immune system. One hallmark of CMV infection is the maintenance of large populations of CMV-specific memory CD8(+) T cells - a phenomenon termed memory inflation - and emerging data suggest that memory inflation is associated with impaired immunity in the elderly. In this Review, we discuss the molecular triggers that promote memory inflation, the idea that memory inflation could be considered a natural pathway of T cell maturation that could be harnessed in vaccination, and the broader implications of CMV infection and the T cell responses it elicits. PMID:27108521

  18. T-cell Depleted Allogeneic Hematopoietic Cell Transplants As A Platform For Adoptive Therapy With Leukemia Selective Or Virus-Specific T-cells

    PubMed Central

    O'Reilly, Richard J.; Koehne, Gunther; Hasan, Aisha N; Doubrovina, Ekaterina; Prockop, Susan

    2016-01-01

    Allogeneic hematopoietic cell transplants adequately depleted of T-cells can reduce or prevent acute and chronic GVHD in both HLA matched and haplotype disparate hosts, without post-transplant prophylaxis with immunosuppressive drugs. Recent trials indicate that high doses of CD34+ progenitors from G-CSF mobilized peripheral blood leukocytes isolated and T-cell depleted by immunoadsorption to paramagnetic beads, when administered after myeloablative conditioning with TBI and chemotherapy or chemotherapy alone can secure consistent engraftment and abrogate GVHD in patients with acute leukemia without incurring an increased risk of a recurrent leukemia. Early clinical trials also indicate that high doses of in vitro generated leukemia reactive donor T-cells can be adoptively transferred and can induce remissions of leukemia relapse without GVHD. Similarly, virus-specific T-cells generated from the transplant donor or an HLA partially matched third party, have induced remissions of Rituxan-refractory EBV lymphomas and can clear CMV disease or viremia persisting despite antiviral therapy in a high proportion of cases. Analyses of treatment responses and failures illustrate both the advantages and limitations of donor or banked, third party derived T-cells, but underscore the potential of adoptive T-cell therapy in the absence of ongoing immunosuppression. PMID:26039207

  19. A Multidrug-resistant Engineered CAR T Cell for Allogeneic Combination Immunotherapy

    PubMed Central

    Valton, Julien; Guyot, Valérie; Marechal, Alan; Filhol, Jean-Marie; Juillerat, Alexandre; Duclert, Aymeric; Duchateau, Philippe; Poirot, Laurent

    2015-01-01

    The adoptive transfer of chimeric antigen receptor (CAR) T cell represents a highly promising strategy to fight against multiple cancers. The clinical outcome of such therapies is intimately linked to the ability of effector cells to engraft, proliferate, and specifically kill tumor cells within patients. When allogeneic CAR T-cell infusion is considered, host versus graft and graft versus host reactions must be avoided to prevent rejection of adoptively transferred cells, host tissue damages and to elicit significant antitumoral outcome. This work proposes to address these three requirements through the development of multidrug-resistant T cell receptor αβ-deficient CAR T cells. We demonstrate that these engineered T cells displayed efficient antitumor activity and proliferated in the presence of purine and pyrimidine nucleoside analogues, currently used in clinic as preconditioning lymphodepleting regimens. The absence of TCRαβ at their cell surface along with their purine nucleotide analogues-resistance properties could prevent their alloreactivity and enable them to resist to lymphodepleting regimens that may be required to avoid their ablation via HvG reaction. By providing a basic framework to develop a universal T cell compatible with allogeneic adoptive transfer, this work is laying the foundation stone of the large-scale utilization of CAR T-cell immunotherapies. PMID:26061646

  20. Activity of host-derived T cells which differentiate in nude mice grafted with co-isogenic or allogeneic thymuses.

    PubMed

    Kindred, B; Loor, F

    1974-05-01

    If nude mice are grafted with a neonatal thymus, host type precursor cells develop within the graft thymus and after about 6 wk the T-cell population of the thymus, spleen, and lymph nodes is of host type. However, immunological responsiveness produced in nude mice in this manner is incomplete: (a) the ability to react to T-cell mitogens in vitro is greater than in untreated nudes but lower than in normal mice; (b) the response to T-cell dependent antigens is less than normal; and (c) the rejection of skin grafts is slower than in normal animals. Whether host precursor cells which differentiate in an allogeneic thymus are able to reject skin grafts from thymus donor strain appears to depend on the strain combination used. PMID:4596513

  1. Dynamics of T cell responses after stroke.

    PubMed

    Gill, Dipender; Veltkamp, Roland

    2016-02-01

    T cells are integral to the pathophysiology of stroke. The initial inflammatory cascade leads to T cell migration, which results in deleterious and protective effects mediated through CD4(+), CD(8)+, γδ T cells and regulatory T cells, respectively. Cytokines are central to the T cell responses, with key roles established for TNF-α, IFN-γ, IL-17, IL-21 and IL-10. Through communication with the systemic immune system via neural and hormonal pathways, there is also transient immunosuppression after severe strokes. With time, the inflammatory process eventually transforms to one more conducive of repair and recovery, though some evidence also suggests ongoing chronic inflammation. The role of antigen-specific T cell responses requires further investigation. As our understanding develops, there is increasing scope to modulate the T cell response after stroke. PMID:26452204

  2. Phase I Trial of Adoptive Cell Transfer with Mixed-Profile Type-I/Type-II Allogeneic T Cells for Metastatic Breast Cancer

    PubMed Central

    Hardy, Nancy M.; Mossoba, Miriam E.; Steinberg, Seth M.; Fellowes, Vicki; Yan, Xiao-Yi; Hakim, Frances T.; Babb, Rebecca R.; Avila, Daniele; Gea-Banacloche, Juan; Sportès, Claude; Levine, Bruce L.; June, Carl H.; Khuu, Hahn M.; Carpenter, Ashley E.; Krumlauf, Michael C.; Dwyer, Andrew J.; Gress, Ronald E.; Fowler, Daniel H.; Bishop, Michael R.

    2011-01-01

    PURPOSE Metastatic breast cancer (MBC) response to allogeneic lymphocytes requires donor T-cell engraftment and is limited by graft-versus-host disease (GVHD). In mice, Type-II-polarized T cells promote engraftment and modulate GVHD whereas Type-I-polarized T cells mediate more potent graft-versus-tumor (GVT) effects. This Phase-I translational study evaluated adoptive transfer of ex-vivo-costimulated Type-I/Type-II (T1/T2) donor T cells with T-cell-depleted (TCD) allogeneic stem-cell transplantation (AlloSCT) for MBC. EXPERIMENTAL DESIGN Patients had received anthracycline, taxane and antibody therapies, been treated for metastatic disease and an HLA-identical-sibling donor. Donor lymphocytes were costimulated ex vivo with anti-CD3/anti-CD28 antibody-coated magnetic beads in IL-2/IL-4-supplemented media. Patients received reduced-intensity conditioning, donor stem cells and T1/T2 cells, and monitoring for toxicity, engraftment, GVHD and tumor response; results were compared with historical controls, identically treated except for T1/T2-product infusions. RESULTS Mixed Type-I/Type-II CD4+-T cells predominated in T1/T2 products. Nine patients received T1/T2 cells at Dose-Level 1 (5×106 cells/kg). T-cell donor chimerism reached 100% by a median of 28 days. Seven (78%) developed acute GVHD. At Day +28, five patients had partial responses (56%) and none had MBC progression; thereafter, two patients had continued responses. Donor-T-cell engraftment and tumor responses appeared faster than in historical controls, but GVHD rates were similar and responders progressed early, often following treatment of acute GVHD. CONCLUSION Allogeneic T1/T2 cells were safely infused with TCD-AlloSCT, appeared to promote donor engraftment, and may have contributed to transient early tumor responses. PMID:21948234

  3. Donor CD4 T Cell Diversity Determines Virus Reactivation in Patients After HLA-Matched Allogeneic Stem Cell Transplantation

    PubMed Central

    Ritter, J; Seitz, V; Balzer, H; Gary, R; Lenze, D; Moi, S; Pasemann, S; Seegebarth, A; Wurdack, M; Hennig, S; Gerbitz, A; Hummel, M

    2015-01-01

    Delayed reconstitution of the T cell compartment in recipients of allogeneic stem cell grafts is associated with an increase of reactivation of latent viruses. Thereby, the transplanted T cell repertoire appears to be one of the factors that affect T cell reconstitution. Therefore, we studied the T cell receptor beta (TCRβ) gene rearrangements of flow cytometry–sorted CD4+ and CD8+ T cells from the peripheral blood of 23 allogeneic donors before G-CSF administration and on the day of apheresis. For this purpose, TCRβ rearrangements were amplified by multiplex PCR followed by high-throughput amplicon sequencing. Overall, CD4+ T cells displayed a significantly higher TCRβ diversity compared to CD8+ T cells irrespective of G-CSF administration. In line, no significant impact of G-CSF treatment on the TCR Vβ repertoire usage was found. However, correlation of the donor T cell repertoire with clinical outcomes of the recipient revealed that a higher CD4+ TCRβ diversity after G-CSF treatment is associated with lower reactivation of cytomegalovirus and Epstein–Barr virus. By contrast, no protecting correlation was observed for CD8+ T cells. In essence, our deep TCRβ analysis identifies the importance of the CD4+ T cell compartment for the control of latent viruses after allogeneic stem cell transplantation. PMID:25873100

  4. T cell responses in dengue viral infections.

    PubMed

    Malavige, Gathsaurie Neelika; Ogg, Graham S

    2013-12-01

    Dengue viral infections are the commonest mosquito borne viral infection in the world, affecting more than 100 countries and 390 million individuals annually. Currently, there are no effective antiviral drugs or an effective vaccine to prevent infection. A main hurdle in developing a safe and effective vaccine has been our poor understanding of the complex nature of the protective immune response in acute dengue infection and the presence of four dengue virus (DV) serotypes that are highly homologous. The role of DV specific T cells in the pathogenesis of severe clinical disease in not clear. It has been speculated that highly cross reactive T cells for the previous infecting heterologous DV serotype, which produce pro-inflammatory cytokines, contribute to disease pathogenesis. These cross reactive T cells are believed to be suboptimal in clearing the infection with the current DV-serotype. However, other studies have shown that cross-reactive DV-specific T cells are absent or present in very low frequency during acute infection, appearing only during the convalescent period in the majority of patients. Furthermore, significant apoptosis of T cells occurs in severe acute clinical disease. Overall therefore, it is unclear what role T cells play in contributing to disease pathogenesis during acute dengue infection. Existing data have been complicated by cross-reactivity in T cells assays. These findings can now be re-evaluated in the light of novel technologies to identify serotype-specific T cell responses. PMID:24220605

  5. [18F]FHBG PET/CT Imaging of CD34-TK75 Transduced Donor T Cells in Relapsed Allogeneic Stem Cell Transplant Patients: Safety and Feasibility

    PubMed Central

    Eissenberg, Linda G; Rettig, Michael P; Ritchey, Julie K; Prior, Julie L; Schwarz, Sally W; Frye, Jennifer; White, Brian S; Fulton, Robert S; Ghobadi, Armin; Cooper, Matthew L; Couriel, Daniel R; Seegulam, Muhammad Esa; Piwnica-Worms, David; Dehdashti, Farrokh; Cornetta, Kenneth; DiPersio, John F

    2015-01-01

    Described herein is a first-in-man attempt to both genetically modify T cells with an imagable suicide gene and track these transduced donor T cells in allogeneic stem cell transplantation recipients using noninvasive positron emission tomography/computerized tomography (PET/CT) imaging. A suicide gene encoding a human CD34-Herpes Simplex Virus-1-thymidine kinase (CD34-TK75) fusion enabled enrichment of retrovirally transduced T cells (TdT), control of graft-versus-host disease and imaging of TdT migration and expansion in vivo in mice and man. Analysis confirmed that CD34-TK75-enriched TdT contained no replication competent γ-retrovirus, were sensitive to ganciclovir, and displayed characteristic retroviral insertion sites (by targeted sequencing). Affinity-purified CD34-TK75+-selected donor T cells (1.0–13 × 105)/kg were infused into eight patients who relapsed after allogeneic stem cell transplantation. Six patients also were administered 9-[4-(18F)fluoro-3-hydroxymethyl-butyl]guanine ([18F]FHBG) to specifically track the genetically modified donor T cells by PET/CT at several time points after infusion. All patients were assessed for graft-versus-host disease, response to ganciclovir, circulating TdT cells (using both quantitative polymerase chain reaction and [18F]FHBG PET/CT imaging), TdT cell clonal expansion, and immune response to the TdT. This phase 1 trial demonstrated that genetically modified T cells and [18F]FHBG can be safely infused in patients with relapsed hematologic malignancies after allogeneic stem cell transplantation. PMID:25807290

  6. [(18)F]FHBG PET/CT Imaging of CD34-TK75 Transduced Donor T Cells in Relapsed Allogeneic Stem Cell Transplant Patients: Safety and Feasibility.

    PubMed

    Eissenberg, Linda G; Rettig, Michael P; Ritchey, Julie K; Prior, Julie L; Schwarz, Sally W; Frye, Jennifer; White, Brian S; Fulton, Robert S; Ghobadi, Armin; Cooper, Matthew L; Couriel, Daniel R; Seegulam, Muhammad Esa; Piwnica-Worms, David; Dehdashti, Farrokh; Cornetta, Kenneth; DiPersio, John F

    2015-06-01

    Described herein is a first-in-man attempt to both genetically modify T cells with an imagable suicide gene and track these transduced donor T cells in allogeneic stem cell transplantation recipients using noninvasive positron emission tomography/computerized tomography (PET/CT) imaging. A suicide gene encoding a human CD34-Herpes Simplex Virus-1-thymidine kinase (CD34-TK75) fusion enabled enrichment of retrovirally transduced T cells (TdT), control of graft-versus-host disease and imaging of TdT migration and expansion in vivo in mice and man. Analysis confirmed that CD34-TK75-enriched TdT contained no replication competent γ-retrovirus, were sensitive to ganciclovir, and displayed characteristic retroviral insertion sites (by targeted sequencing). Affinity-purified CD34-TK75(+)-selected donor T cells (1.0-13 × 10(5))/kg were infused into eight patients who relapsed after allogeneic stem cell transplantation. Six patients also were administered 9-[4-((18)F)fluoro-3-hydroxymethyl-butyl]guanine ([(18)F]FHBG) to specifically track the genetically modified donor T cells by PET/CT at several time points after infusion. All patients were assessed for graft-versus-host disease, response to ganciclovir, circulating TdT cells (using both quantitative polymerase chain reaction and [(18)F]FHBG PET/CT imaging), TdT cell clonal expansion, and immune response to the TdT. This phase 1 trial demonstrated that genetically modified T cells and [(18)F]FHBG can be safely infused in patients with relapsed hematologic malignancies after allogeneic stem cell transplantation. PMID:25807290

  7. Programming of donor T cells using allogeneic δ-like ligand 4-positive dendritic cells to reduce GVHD in mice.

    PubMed

    Mochizuki, Kazuhiro; Meng, Lijun; Mochizuki, Izumi; Tong, Qing; He, Shan; Liu, Yongnian; Purushe, Janaki; Fung, Henry; Zaidi, M Raza; Zhang, Yanyun; Reshef, Ran; Blazar, Bruce R; Yagita, Hideo; Mineishi, Shin; Zhang, Yi

    2016-06-23

    Alloreactive T cells play a critical role in eliminating hematopoietic malignant cells but are also the mediators of graft-versus-host disease (GVHD), a major complication that subverts the success of allogeneic hematopoietic stem cell transplantation (HSCT). However, induction of alloreactive T cells does not necessarily lead to GVHD. Here we report the development of a cellular programming approach to render alloreactive T cells incapable of causing severe GVHD in both major histocompatibility complex (MHC)-mismatched and MHC-identical but minor histocompatibility antigen-mismatched mouse models. We established a novel platform that produced δ-like ligand 4-positive dendritic cells (Dll4(hi)DCs) from murine bone marrow using Flt3 ligand and Toll-like receptor agonists. Upon allogeneic Dll4(hi)DC stimulation, CD4(+) naïve T cells underwent effector differentiation and produced high levels of interferon γ (IFN-γ) and interleukin-17 in vitro, depending on Dll4 activation of Notch signaling. Following transfer, allogeneic Dll4(hi)DC-induced T cells were unable to mediate severe GVHD but preserved antileukemic activity, significantly improving the survival of leukemic mice undergoing allogeneic HSCT. This effect of Dll4(hi)DC-induced T cells was associated with their impaired expansion in GVHD target tissues. IFN-γ was important for Dll4(hi)DC programming to reduce GVHD toxicities of alloreactive T cells. Absence of T-cell IFN-γ led to improved survival and expansion of Dll4(hi)DC-induced CD4(+) T cells in transplant recipients and caused lethal GVHD. Our findings demonstrate that Dll4(hi)DC programming can overcome GVHD toxicity of donor T cells and produce leukemia-reactive T cells for effective immunotherapy. PMID:27143255

  8. Novel mode of action of the calcium antagonist mibefradil (Ro 40-5967): potent immunosuppression by inhibition of T-cell infiltration through allogeneic endothelium.

    PubMed Central

    Blaheta, R A; Hailer, N P; Brude, N; Wittig, B; Oppermann, E; Leckel, K; Harder, S; Scholz, M; Weber, S; Encke, A; Markus, B H

    1998-01-01

    Cyclosporin A reduces the mitotic activity of allosensitized lymphocytes, but fails to limit emigration of these cells into the donor organ. However, the modulation of both lymphocyte proliferation and infiltration are desirable characteristics of immunosuppressive therapy. The calcium-channel blocker, verapamil, has recently been shown to effectively prevent the transmigration of CD4+ and CD8+ T cells through allogeneic endothelium. Mibefradil (Ro 40-5967) represents a new generation of calcium antagonists with high potency and long-term activity. To evaluate the immunosuppressive potential of this drug, the influence of mibefradil on lymphocyte adhesion to, horizontal locomotion along, and penetration through allogeneic endothelium (HUVEC) was performed. When lymphocytes were prestimulated for 24 hr with mibefradil, adhesion and penetration were dose-dependently reduced. The adhesion ID50 values were 3.4 microM (CD4+ T cells) versus 9.2 microM (CD8+ T cells) and 2.1 microM (CD4+ T cells) versus 3.9 microM (CD8+ T cells) with regard to penetration. Mibefradil also effectively blocked horizontal locomotion. Specific down-regulation of T-cell binding to the P-selection receptor (ID50: CD4+ T cells, 0.8 microM: CD8+ T cells, 1.2 microM) and to the intracellular adhesion molecule-1 (ICAM-1) receptor (ID50: CD4+ T cells, 1.9 microM; CD8+ T cells, 1.5 microM) by mibefradil seems to be responsible for the decreased adhesion and penetration rates. Reduction of intracellular F-actin in T lymphocytes could diminish cell locomotion. In conclusion, the potent suppressive properties of mibefradil support its use as a co-medication in cyclosporin A-based immunosuppressive therapy. PMID:9741343

  9. Effects of T cell depletion in radiation bone marrow chimeras. III. Characterization of allogeneic bone marrow cell populations that increase allogeneic chimerism independently of graft-vs-host disease in mixed marrow recipients

    SciTech Connect

    Sykes, M.; Chester, C.H.; Sundt, T.M.; Romick, M.L.; Hoyles, K.A.; Sachs, D.H. )

    1989-12-01

    The opposing problems of graft-vs-host disease vs failure of alloengraftment severely limit the success of allogeneic bone marrow transplantation as a therapeutic modality. We have recently used a murine bone marrow transplantation model involving reconstitution of lethally irradiated mice with mixtures of allogeneic and syngeneic marrow to demonstrate that an allogeneic bone marrow subpopulation, removed by T cell depletion with rabbit anti-mouse brain serum and complement (RAMB/C), is capable of increasing levels of allogeneic chimerism. This effect was observed in an F1 into parent genetic combination lacking the potential for graft-vs-host disease, and radiation protection studies suggested that it was not due to depletion of stem cells by RAMB/C. We have now attempted to characterize the cell population responsible for increasing allogeneic chimerism in this model. The results indicate that neither mature T cells nor NK cells are responsible for this activity. However, an assay involving mixed marrow reconstitution in an Ly-5 congenic strain combination was found to be more sensitive to small degrees of stem cell depletion than radiation protection assays using three-fold titrations of bone marrow cells. Using this assay, we were able to detect some degree of stem cell depletion by treatment with RAMB/C, but not with anti-T cell mAb. Nevertheless, if the effects of alloresistance observed in this model are considered, the degree of stem cell depletion detected by such mixing studies in insufficient to account for the effects of RAMB/C depletion on levels of allogeneic chimerism, suggesting that another cell population with this property remains to be identified.

  10. Stereotaxic administrations of allogeneic human Vγ9Vδ2 T cells efficiently control the development of human glioblastoma brain tumors.

    PubMed

    Jarry, Ulrich; Chauvin, Cynthia; Joalland, Noémie; Léger, Alexandra; Minault, Sandrine; Robard, Myriam; Bonneville, Marc; Oliver, Lisa; Vallette, François M; Vié, Henri; Pecqueur, Claire; Scotet, Emmanuel

    2016-06-01

    Glioblastoma multiforme (GBM) represents the most frequent and deadliest primary brain tumor. Aggressive treatment still fails to eliminate deep brain infiltrative and highly resistant tumor cells. Human Vγ9Vδ2 T cells, the major peripheral blood γδ T cell subset, react against a wide array of tumor cells and represent attractive immune effector T cells for the design of antitumor therapies. This study aims at providing a preclinical rationale for immunotherapies in GBM based on stereotaxic administration of allogeneic human Vγ9Vδ2 T cells. The feasibility and the antitumor efficacy of stereotaxic Vγ9Vδ2 T cell injections have been investigated in orthotopic GBM mice model using selected heterogeneous and invasive primary human GBM cells. Allogeneic human Vγ9Vδ2 T cells survive and patrol for several days within the brain parenchyma following adoptive transfer and can successfully eliminate infiltrative GBM primary cells. These striking observations pave the way for optimized stereotaxic antitumor immunotherapies targeting human allogeneic Vγ9Vδ2 T cells in GBM patients. PMID:27471644

  11. Quantitative characterization of T-cell repertoire in allogeneic hematopoietic stem cell transplant recipients.

    PubMed

    Yew, P Y; Alachkar, H; Yamaguchi, R; Kiyotani, K; Fang, H; Yap, K L; Liu, H T; Wickrema, A; Artz, A; van Besien, K; Imoto, S; Miyano, S; Bishop, M R; Stock, W; Nakamura, Y

    2015-09-01

    Allogeneic hematopoietic stem cell transplantation (HSCT) is one of curative treatment options for patients with hematologic malignancies. Although GVHD mediated by the donor's T lymphocytes remains the most challenging toxicity of allo-HSCT, graft-versus-leukemia (GVL) effect targeting leukemic cells, has an important role in affecting the overall outcome of patients with AML. Here we comprehensively characterized the TCR repertoire in patients who underwent matched donor or haplo-cord HSCT using next-generation sequencing approach. Our study defines the functional kinetics of each TCRA and TCRB clone, and changes in T-cell diversity (with identification of CDR3 sequences) and the extent of clonal expansion of certain T-cells. Using this approach, our study demonstrates that higher percentage of cord-blood cells at 30 days after transplant was correlated with higher diversity of TCR repertoire, implicating the role of cord-chimerism in enhancing immune recovery. Importantly, we found that GVHD and relapse, exclusive of each other, were correlated with lower TCR repertoire diversity and expansion of certain T-cell clones. Our results highlight novel insights into the balance between GVHD and GVL effect, suggesting that higher diversity early after transplant possibly implies lower risks of both GVHD and relapse following the HSCT transplantation. PMID:26052909

  12. Quantitative characterization of T-cell repertoire in allogeneic hematopoietic stem cell transplant recipients

    PubMed Central

    Yew, P Y; Alachkar, H; Yamaguchi, R; Kiyotani, K; Fang, H; Yap, K L; Liu, H T; Wickrema, A; Artz, A; van Besien, K; Imoto, S; Miyano, S; Bishop, M R; Stock, W; Nakamura, Y

    2015-01-01

    Allogeneic hematopoietic stem cell transplantation (HSCT) is one of curative treatment options for patients with hematologic malignancies. Although GVHD mediated by the donor's T lymphocytes remains the most challenging toxicity of allo-HSCT, graft-versus-leukemia (GVL) effect targeting leukemic cells, has an important role in affecting the overall outcome of patients with AML. Here we comprehensively characterized the TCR repertoire in patients who underwent matched donor or haplo-cord HSCT using next-generation sequencing approach. Our study defines the functional kinetics of each TCRA and TCRB clone, and changes in T-cell diversity (with identification of CDR3 sequences) and the extent of clonal expansion of certain T-cells. Using this approach, our study demonstrates that higher percentage of cord-blood cells at 30 days after transplant was correlated with higher diversity of TCR repertoire, implicating the role of cord-chimerism in enhancing immune recovery. Importantly, we found that GVHD and relapse, exclusive of each other, were correlated with lower TCR repertoire diversity and expansion of certain T-cell clones. Our results highlight novel insights into the balance between GVHD and GVL effect, suggesting that higher diversity early after transplant possibly implies lower risks of both GVHD and relapse following the HSCT transplantation. PMID:26052909

  13. A stochastic T cell response criterion

    PubMed Central

    Currie, James; Castro, Mario; Lythe, Grant; Palmer, Ed; Molina-París, Carmen

    2012-01-01

    The adaptive immune system relies on different cell types to provide fast and coordinated responses, characterized by recognition of pathogenic challenge, extensive cellular proliferation and differentiation, as well as death. T cells are a subset of the adaptive immune cellular pool that recognize immunogenic peptides expressed on the surface of antigen-presenting cells by means of specialized receptors on their membrane. T cell receptor binding to ligand determines T cell responses at different times and locations during the life of a T cell. Current experimental evidence provides support to the following: (i) sufficiently long receptor–ligand engagements are required to initiate the T cell signalling cascade that results in productive signal transduction and (ii) counting devices are at work in T cells to allow signal accumulation, decoding and translation into biological responses. In the light of these results, we explore, with mathematical models, the timescales associated with T cell responses. We consider two different criteria: a stochastic one (the mean time it takes to have had N receptor–ligand complexes bound for at least a dwell time, τ, each) and one based on equilibrium (the time to reach a threshold number N of receptor–ligand complexes). We have applied mathematical models to previous experiments in the context of thymic negative selection and to recent two-dimensional experiments. Our results indicate that the stochastic criterion provides support to the thymic affinity threshold hypothesis, whereas the equilibrium one does not, and agrees with the ligand hierarchy experimentally established for thymic negative selection. PMID:22745227

  14. Unbalanced recovery of regulatory and effector T cells after allogeneic stem cell transplantation contributes to chronic GVHD

    PubMed Central

    Alho, Ana C.; Kim, Haesook T.; Chammas, Marie J.; Reynolds, Carol G.; Matos, Tiago R.; Forcade, Edouard; Whangbo, Jennifer; Nikiforow, Sarah; Cutler, Corey S.; Koreth, John; Ho, Vincent T.; Armand, Philippe; Antin, Joseph H.; Alyea, Edwin P.; Lacerda, Joao F.; Soiffer, Robert J.

    2016-01-01

    The development and maintenance of immune tolerance after allogeneic hematopoietic stem cell transplantation (HSCT) requires the balanced reconstitution of donor-derived CD4 regulatory T cells (CD4Tregs) as well as effector CD4 (conventional CD4 T cells [CD4Tcons]) and CD8 T cells. To characterize the complex mechanisms that lead to unbalanced recovery of these distinct T-cell populations, we studied 107 adult patients who received T-replete stem cell grafts after reduced-intensity conditioning. Immune reconstitution of CD4Treg, CD4Tcon, and CD8 T cells was monitored for a 2-year period. CD3 T-cell counts gradually recovered to normal levels during this period but CD8 T cells recovered more rapidly than either CD4Tregs or CD4Tcons. Reconstituting CD4Tregs and CD4Tcons were predominantly central memory (CM) and effector memory (EM) cells and CD8 T cells were predominantly terminal EM cells. Thymic generation of naive CD4Tcon and CD8 T cells was maintained but thymic production of CD4Tregs was markedly decreased with little recovery during the 2-year study. T-cell proliferation was skewed in favor of CM and EM CD4Tcon and CD8 T cells, especially 6 to 12 months after HSCT. Intracellular expression of BCL2 was increased in CD4Tcon and CD8 T cells in the first 3 to 6 months after HSCT. Early recovery of naive and CM fractions within each T-cell population 3 months after transplant was also strongly correlated with the subsequent development of chronic graft-versus-host disease (GVHD). These dynamic imbalances favor the production, expansion, and persistence of effector T cells over CD4Tregs and were associated with the development of chronic GVHD. PMID:26670634

  15. Modeling T cell responses to antigenic challenge

    PubMed Central

    Wodarz, Dominik

    2014-01-01

    T cell responses are a crucial part of the adaptive immune system in the fight against infections. This article discusses the use of mathematical models for understanding the dynamics of cytotoxic T lymphocyte (CTL) responses against viral infections. Complementing experimental research, mathematical models have been very useful for exploring new hypotheses, interpreting experimental data, and for defining what needs to be measured to improve understanding. This review will start with minimally parameterized models of CTL responses, which have generated some valuable insights into basic dynamics and correlates of control. Subsequently, more biological complexity is incorporated into this modeling framework, examining different mechanisms of CTL expansion, different effector activities, and the influence of T cell help. Models and results are discussed in the context of data from specific infections. PMID:25269610

  16. Regulation of the T cell response.

    PubMed

    Romagnani, S

    2006-11-01

    The T cell branch of the immune system can respond to a virtually infinite variety of exogenous antigens, thus including the possibility of self-antigen recognition and dangerous autoimmune reactions. Therefore, regulatory mechanisms operate both during ontogeny within the thymus and after birth in the periphery. The control of self-reactive T cells occurs through a process of negative selection that results in apoptosis of T cells showing high affinity for self-peptides expressed at the thymic level by means of promiscuous gene expression. Self-reactive T cells escaped to negative selection are controlled in the periphery by other regulatory mechanisms, the most important being natural Foxp3+ T regulatory (Treg) cells. Regulation is also required to control excessive effector T cell responses against exogenous antigens, when they become dangerous for the body. Three types of effector T cells have been recognized: T helper 1 (Th1) cells, which are protective against intracellular bacteria; Th2 cells, which play some role in the protection against nematodes, but are responsible for allergic reactions; Th17 cells, which are probably effective in the protection against extracellular bacteria, but also play a role in the amplification of autoimmune disorders. Abnormal or excessive Th effector responses are regulated by different mechanisms. Redirection or immune deviation of Th1- or Th2-dominated responses is provided by cytokines [interferon-gamma (IFN-gamma) vs. interleukin-4 (IL-4)] produced by the same cell types and by the CXCR3-binding chemokines CXCL4 and CXCL10. Moreover, both Th1 and Th2 responses can be suppressed by adaptive Treg cells through contact-dependent mechanisms and/or the production of IL-10 and transforming growth factor-beta (TGF-beta). Finally, TGF-beta1 can promote the development of both Th17 effector and adaptive Treg cells, while the contemporaneous production of IL-6 contributes to the development of Th17 cells, but inhibits Treg cells

  17. 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

  18. T-cell response to allergens.

    PubMed

    Ozdemir, Cevdet; Akdis, Mübeccel; Akdis, Cezmi A

    2010-01-01

    Anaphylaxis is a life-threatening IgE-dependent type 1 hypersensitivity reaction in which multiple organ systems are involved. The existence of allergen exposure and specific IgE are the major contributors to this systemic reaction. The decision of the immune system to respond to allergens is highly dependent on factors including the type and load of allergen, behavior and type of antigen-presenting cells, innate immune response stimulating substances in the same micromilieu, the tissue of exposure, interactions between T and B lymphocytes, costimulators, and genetic propensity known as atopy. Antigen-presenting cells introduce processed allergens to T-helper lymphocytes, where a decision of developing different types of T-cell immunity is given under the influence of several cytokines, chemokines, costimulatory signals and regulatory T cells. Among Th2-type cytokines, interleukin (IL)-4 and IL-13 are responsible for class switching in B cells, which results in production of allergen-specific IgE antibodies that bind to specific receptors on mast cells and basophils. After re-exposure to the sensitized allergen, this phase is followed by activation of IgE Fc receptors on mast cells and basophils resulting in biogenic mediator releases responsible for the symptoms and signs of anaphylaxis. Since the discovery of regulatory T cells, the concepts of immune regulation have substantially changed during the last decade. Peripheral T-cell tolerance is a key immunologic mechanism in healthy immune response to self antigens and non-infectious non-self antigens. Both naturally occurring CD4+CD25+ regulatory T (Treg) cells and inducible populations of allergen-specific, IL-10-secreting Treg type 1 cells inhibit allergen-specific effector cells and have been shown to play a central role in the maintenance of peripheral homeostasis and the establishment of controlled immune responses. On the other hand, Th17 cells are characterized by their IL-17 (or IL-17A), IL-17F, IL-6

  19. Dose-Dependent Changes in Influenza Virus-Infected Dendritic Cells Result in Increased Allogeneic T-Cell Proliferation at Low, but Not High, Doses of Virus

    PubMed Central

    Oh, SangKon; McCaffery, J. Michael; Eichelberger, Maryna C.

    2000-01-01

    During the acute phase of infection with influenza A virus, the degree of lymphopenia correlates with severity of disease. Factors that contribute to T-cell activation during influenza virus infection may contribute to this observation. Since the immune response is initiated when dendritic cells (DC) interact with T cells, we have established an in vitro system to examine the effects of influenza virus infection on DC function. Our results show that allogeneic T-cell proliferation was dependent on the dose of A/PR/8/34 used to infect DC, with enhanced responses at low, but not high, multiplicities of infection. The lack of enhancement at high virus doses was not primarily due to the increased rate of DC apoptosis, but required viral replication and neuraminidase (NA) activity. Clusters that formed between DC or between DC and T cells were also dependent on the viral dose. This change in cellular interaction may oppose T-cell proliferation in response to DC infected with high doses of PR8, since the increased contact between DC resulted in the exclusion of T cells. The enhanced alloreactive T-cell response was restored by neutralization of transforming growth factor β1 (TGF-β1). It is likely that NA present on viral particles released from DC infected with high doses of PR8 activates TGF-β1. Future studies will determine the mechanism by which TGF-β1 modifies the in vitro T-cell response and address the contribution of this cytokine to the lymphopenia observed in severe disease. PMID:10823850

  20. Functionally Active HIV-Specific T Cells that Target Gag and Nef Can Be Expanded from Virus-Naïve Donors and Target a Range of Viral Epitopes: Implications for a Cure Strategy after Allogeneic Hematopoietic Stem Cell Transplantation.

    PubMed

    Patel, Shabnum; Lam, Sharon; Cruz, Conrad Russell; Wright, Kaylor; Cochran, Christina; Ambinder, Richard F; Bollard, Catherine M

    2016-03-01

    Allogeneic hematopoietic stem cell transplantation (HSCT) can potentially cure human immunodeficiency virus (HIV) by eliminating infected recipient cells, particularly in the context of technologies that may confer HIV resistance to these stem cells. But, to date, the Berlin patient remains the only case of HIV cure despite multiple attempts to eradicate infection with HSCT. One approach to improve this is to administer virus-specific T cells, a strategy that has proven success in preventing other infections after transplantation. Although we have reported that broadly HIV-specific T cells can be expanded from HIV+ patients, allogeneic transplantations only contain virus-naïve T cells. Modifying this approach for the allogeneic setting requires a robust, reproducible platform that can expand HIV-specific cells from the naïve pool. Hence, we hypothesized that HIV-specific T cells could be primed ex vivo from seronegative individuals to effectively target HIV. Here, we show that ex vivo-primed and expanded HIV-specific T cells released IFNγ in response to HIV antigens and that these cells have enhanced ability to suppress replication in vitro. This is the first demonstration of ex vivo priming and expansion of functional, multi-HIV antigen-specific T cells from HIV-negative donors, which has implications for use of allogeneic HSCT as a functional HIV cure. PMID:26721209

  1. Engraftment of allogeneic bone marrow following administration of anti-T cell monoclonal antibodies and low-dose irradiation

    SciTech Connect

    Sharabi, Y.; Sachs, D.H.

    1989-02-01

    A nonlethal conditioning regimen involving administration of mAb in vivo, low-dose WBI and 700 rads of thymic irradiation, permits engraftment of T cell-depleted allogeneic BM. Engraftment of class I + II disparate allogeneic BM after conditioning with this regimen required depletion of both L3T4 and Lyt2 host T cell subsets in vivo. Treatment with a combination of specific mAbs to each subset (GK1.5 plus 2.43) was more effective than treatment with an anti-Thy1 mAb (30-H12). The low incidence of engraftment after 30-H12 treatment is probably due to reduced efficiency of 30-H12 in depletion of host alloreactive cell populations rather than an effect of this mAb on a particular population of donor cells that are important for engraftment.

  2. De novo alloreactive memory CD8+ T cells develop following allogeneic challenge when CNI immunosuppression is delayed.

    PubMed

    Hart-Matyas, M; Gareau, A J; Hirsch, G M; Lee, T D G

    2015-01-01

    Allospecific memory T cells are a recognized threat to the maintenance of solid-organ transplants. Limited information exists regarding the development of alloreactive memory T cells when post-transplant immunosuppression is present. The clinical practice of delaying calcineurin inhibitor (CNI) initiation post-transplant may permit the development of a de novo allospecific memory population. We investigated the development of de novo allospecific memory CD8+ T cells following the introduction of CNI immunosuppression in a murine model using allogeneic cell priming. Recipient mice alloprimed with splenocytes from fully mismatched donors received cyclosporine (CyA), initiated at 0, 2, 6, or 10days post-prime. Splenocytes from recipients were analyzed by flow cytometry or enzyme-linked immunosorbent assay for evidence of memory cell formation. Memory and effector CD8+ T cell development was prevented when CyA was initiated at 0day or 2days post-prime (p<0.001), but not 6days post-prime. Following a boost challenge, these memory CD8+ T cells were capable of producing a similarly sized population of secondary effectors as recipients not treated with CyA (p>0.05). Delaying CyA up to 6days or later post-prime permits the development of functional de novo allospecific memory CD8+ T cells. The development of this potentially detrimental T cell population in patients could be prevented by starting CNI immunosuppression early post-transplant. PMID:25315500

  3. Spinal fluid lymphocytes responsive to autologous and allogeneic cells in multiple sclerosis and control individuals.

    PubMed Central

    Birnbaum, G; Kotilinek, L; Schwartz, M; Sternad, M

    1984-01-01

    Spinal fluid lymphocytes from multiple sclerosis (MS) patients and controls were stimulated with either autologous non-T cells or with allogeneic non-T cells followed by stimulation with autologous non-T lymphocytes. Cells responding to these stimuli were cloned and their proliferative responses to autologous and allogeneic MS and normal non-T cells were measured. Large numbers of clones with specific patterns of reaction to both autologous and allogeneic cells were obtained from lymphocytes in MS cerebrospinal fluid (CSF), but only occasionally from cells in control CSF. Patterns of responses among clones from a particular CSF were similar and often identical, which suggested that cells in MS CSF were relatively restricted in their specificities. Surface antigen phenotyping of the clones showed them to be predominantly OKT4+, with 13% OKT8+ and 11% OKT4+8+. Peripheral T cells that were stimulated and cultured in parallel with CSF cells were different in that they usually did not give rise to as many clones nor were their patterns of response similar. Many CSF clones were heteroclitic, that is they responded to particular allogeneic cells but not autologous cells. Lymphocytes in MS CSF thus appear to represent a selected population of cells with a high frequency of responsiveness to autologous and allogeneic antigens. Such responses may be evidence for immune regulation within the central nervous system or could represent responses to altered-self antigens. PMID:6237121

  4. Facilitation of allogeneic bone marrow transplantation by a T cell-specific immunotoxin containing daunomycin

    SciTech Connect

    Xie, S.S.; Inazawa, M.; Sinha, N.; Sawada, S.; Vergidis, R.; Diener, E.

    1987-12-01

    Daunomycin coupled via an acid-sensitive spacer to monoclonal Thy-1.2-specific antibody was used to purge T lymphocytes from a 1:1 mixture of murine C57BL/6J bone marrow and spleen cells prior to engraftment in fully allogeneic, irradiated BALB/c recipients. Treatment of bone marrow with the immunotoxin at a concentration used for purging had no effect on the viability of committed hematopoietic progenitor or multipotent stem cells. All of the recipients of purged bone marrow were at least 80% chimeric for donor peripheral blood cells and none developed graft-versus-host disease. Out of 50 chimeras, 49 were still alive more than 200 days posttransplantation. The chimeras were shown to be tolerant to donor tissue as tested by mixed lymphocyte reactivity, cell-mediated cytotoxicity, and skin grafting. The same tests revealed full immunocompetence of chimeras to third-party alloantigens. In vivo IgM and IgG antibody responses to sheep red blood cells were similar in magnitude in allogeneically and syngeneically reconstituted mice.

  5. Prostaglandin E2 Production and T Cell Function in Mouse Adenovirus Type 1 Infection following Allogeneic Bone Marrow Transplantation

    PubMed Central

    McCarthy, Mary K.; Procario, Megan C.; Wilke, Carol A.; Moore, Bethany B.; Weinberg, Jason B.

    2015-01-01

    Adenovirus infections are important complications of bone marrow transplantation (BMT). We demonstrate delayed clearance of mouse adenovirus type 1 (MAV-1) from lungs of mice following allogeneic BMT. Virus-induced prostaglandin E2 (PGE2) production was greater in BMT mice than in untransplanted controls, but BMT using PGE2-deficient donors or recipients failed to improve viral clearance, and treatment of untransplanted mice with the PGE2 analog misoprostol did not affect virus clearance. Lymphocyte recruitment to the lungs was not significantly affected by BMT. Intracellular cytokine staining of lung lymphocytes demonstrated impaired production of INF-γ and granzyme B by cells from BMT mice, and production of IFN-γ, IL-2, IL-4, and IL-17 following ex vivo stimulation was impaired in lymphocytes obtained from lungs of BMT mice. Viral clearance was not delayed in untransplanted INF-γ-deficient mice, suggesting that delayed viral clearance in BMT mice was not a direct consequence of impaired IFN-γ production. However, lung viral loads were higher in untransplanted CD8-deficient mice than in controls, suggesting that delayed MAV-1 clearance in BMT mice is due to defective CD8 T cell function. We did not detect significant induction of IFN-β expression in lungs of BMT mice or untransplanted controls, and viral clearance was not delayed in untransplanted type I IFN-unresponsive mice. We conclude that PGE2 overproduction in BMT mice is not directly responsible for delayed viral clearance. PGE2-independent effects on CD8 T cell function likely contribute to the inability of BMT mice to clear MAV-1 from the lungs. PMID:26407316

  6. The in vitro generation of multi-tumor antigen-specific cytotoxic T cell clones: Candidates for leukemia adoptive immunotherapy following allogeneic stem cell transplantation.

    PubMed

    Mohamed, Yehia S; Bashawri, Layla A; Vatte, Chittibabu; Abu-Rish, Eman Y; Cyrus, Cyril; Khalaf, Wafaa S; Browning, Michael J

    2016-09-01

    Adoptive T-cell immunotherapy is a promising approach to manage and maintain relapse-free survival of leukemia patients, especially following allogeneic stem cell transplantation. Post-transplant adoptive immunotherapy using cytotoxic T lymphocytes (CTLs) of the donor origin provide graft-versus-tumor effects, with or without graft-versus-host disease. Myeloid leukemias express immunogenic leukemia associated antigens (LAAs); such as WT-1, PRAME, MAGE, h-TERT and others, most of them are able to induce specific T cell responses whenever associated with the proper co-stimulation. We investigated the ability of a LAA-expressing hybridoma cell line to induce CTL clones in PBMCs of HLA-matched healthy donors in vitro. The CTL clones were induced by repetitive co-culture with LAAs-expressing, HLA-A*0201(+) hybrid cell line, generated by fusion of leukemia blasts to human immortalized APC (EBV-sensitized B-lymphoblastoid cell line; HMy2). The induced cytotoxic T cell clones were phenotypically and functionally characterized by pentamer analysis, IFN-γ release ELISPOT and cellular cytotoxicity assays. All T cell lines showed robust peptide recognition and functional activity when sensitized with HLA-A*0201-restricted WT-1235-243, hTERT615-624 or PRAME100-108 peptides-pulsed T2 cells, in addition to partially HLA-matched leukemia blasts. This study demonstrates the feasibility of developing multi-tumor antigen-specific T cell lines in allogeneic PBMCs in vitro, using LAA-expressing tumor/HMy2 hybrid cell line model, for potential use in leukemia adoptive immunotherapy in partially matched donor-recipient setting. PMID:27490939

  7. In Vivo Interleukin-13-Primed Macrophages Contribute to Reduced Alloantigen-Specific T Cell Activation and Prolong Immunological Survival of Allogeneic Mesenchymal Stem Cell Implants.

    PubMed

    Hoornaert, Chloé J; Luyckx, Evi; Reekmans, Kristien; Dhainaut, Maxime; Guglielmetti, Caroline; Le Blon, Debbie; Dooley, Dearbhaile; Fransen, Erik; Daans, Jasmijn; Verbeeck, Louca; Quarta, Alessandra; De Vocht, Nathalie; Lemmens, Evi; Goossens, Herman; Van der Linden, Annemie; Roobrouck, Valerie D; Verfaillie, Catherine; Hendrix, Sven; Moser, Muriel; Berneman, Zwi N; Ponsaerts, Peter

    2016-07-01

    Transplantation of mesenchymal stem cells (MSCs) into injured or diseased tissue-for the in situ delivery of a wide variety of MSC-secreted therapeutic proteins-is an emerging approach for the modulation of the clinical course of several diseases and traumata. From an emergency point-of-view, allogeneic MSCs have numerous advantages over patient-specific autologous MSCs since "off-the-shelf" cell preparations could be readily available for instant therapeutic intervention following acute injury. Although we confirmed the in vitro immunomodulatory capacity of allogeneic MSCs on antigen-presenting cells with standard coculture experiments, allogeneic MSC grafts were irrevocably rejected by the host's immune system upon either intramuscular or intracerebral transplantation. In an attempt to modulate MSC allograft rejection in vivo, we transduced MSCs with an interleukin-13 (IL13)-expressing lentiviral vector. Our data clearly indicate that prolonged survival of IL13-expressing allogeneic MSC grafts in muscle tissue coincided with the induction of an alternatively activated macrophage phenotype in vivo and a reduced number of alloantigen-reactive IFNγ- and/or IL2-producing CD8(+) T cells compared to nonmodified allografts. Similarly, intracerebral IL13-expressing MSC allografts also exhibited prolonged survival and induction of an alternatively activated macrophage phenotype, although a peripheral T cell component was absent. In summary, this study demonstrates that both innate and adaptive immune responses are effectively modulated in vivo by locally secreted IL13, ultimately resulting in prolonged MSC allograft survival in both muscle and brain tissue. Stem Cells 2016;34:1971-1984. PMID:26992046

  8. Polyfunctional T cells accumulate in large human cytomegalovirus-specific T cell responses.

    PubMed

    Lachmann, Raskit; Bajwa, Martha; Vita, Serena; Smith, Helen; Cheek, Elizabeth; Akbar, Arne; Kern, Florian

    2012-01-01

    Large cytomegalovirus (CMV)-specific CD8 T-cell responses are observed in both young and, somewhat more often, old people. Frequent CMV reactivation is thought to exhaust these cells and render them dysfunctional so that larger numbers of them are needed to control CMV. Expansions of CMV-specific CD4 T cells are also seen but are less well studied. In this study, we examined the T-cell response to the dominant CMV pp65 and IE-1 antigens in healthy CMV-infected people across a wide age range (20 to 84 years) by using multicolor flow cytometry. CMV-specific T cells were characterized by the activation markers CD40 ligand (CD40L), interleukin-2 (IL-2), tumor necrosis factor alpha (TNF-α), and gamma interferon (IFN-γ) and the memory markers CD27 and CD45RA. The proportions of effector memory T cells increased in large responses, as did the proportions of polyfunctional CD8 (IFN-γ(+) IL-2(+/-) TNF-α(+)) and CD4 (CD40L(+/-) IFN-γ(+) IL-2(+) TNF-α(+)) T-cell subsets, while the proportion of naïve T cells decreased. The bigger the CD4 or CD8 T-cell response to pp65, the larger was the proportion of T cells with an advanced memory phenotype in the entire (including non-CMV-specific) T-cell compartment. In addition, the number of activation markers per cell correlated with the degree of T-cell receptor downregulation, suggesting increased antigen sensitivity in polyfunctional cells. In summary, our findings show that polyfunctional CMV-specific T cells were not superseded by dysfunctional cells, even in very large responses. At the same time, however, the memory subset composition of the entire T-cell compartment correlated with the size of the T-cell response to CMV pp65, confirming a strong effect of CMV infection on the immune systems of some, but not all, infected people. PMID:22072753

  9. Chronic Tumor Necrosis Factor Alters T Cell Responses by Attenuating T Cell Receptor Signaling

    PubMed Central

    Cope, Andrew P.; Liblau, Roland S.; Yang, Xiao-Dong; Congia, Mauro; Laudanna, Carlo; Schreiber, Robert D.; Probert, Lesley; Kollias, George; McDevitt, Hugh O.

    1997-01-01

    Repeated injections of adult mice with recombinant murine TNF prolong the survival of NZB/W F1 mice, and suppress type I insulin-dependent diabetes mellitus (IDDM) in nonobese diabetic (NOD) mice. To determine whether repeated TNF injections suppress T cell function in adult mice, we studied the responses of influenza hemagglutinin-specific T cells derived from T cell receptor (HNT-TCR) transgenic mice. Treatment of adult mice with murine TNF for 3 wk suppressed a broad range of T cell responses, including proliferation and cytokine production. Furthermore, T cell responses of HNT-TCR transgenic mice also expressing the human TNF-globin transgene were markedly reduced compared to HNT-TCR single transgenic littermates, indicating that sustained p55 TNF-R signaling is sufficient to suppress T cell function in vivo. Using a model of chronic TNF exposure in vitro, we demonstrate that (a) chronic TNF effects are dose and time dependent, (b) TNF suppresses the responses of both Th1 and Th2 T helper subsets, (c) the suppressive effects of endogenous TNF produced in T cell cultures could be reversed with neutralizing monoclonal antibodies to TNF, and (d) prolonged TNF exposure attenuates T cell receptor signaling. The finding that anti-TNF treatment in vivo enhances T cell proliferative responses and cytokine production provides evidence for a novel regulatory effect of TNF on T cells in healthy laboratory mice. These effects are more pronounced in chronic inflammatory disease. In addition, our data provide a mechanism through which prolonged TNF exposure suppresses disease in animal models of autoimmunity. PMID:9151895

  10. Regulatory T Cells in Radiotherapeutic Responses

    PubMed Central

    Schaue, Dörthe; Xie, Michael W.; Ratikan, Josephine A.; McBride, William H.

    2012-01-01

    Radiation therapy (RT) can extend its influence in cancer therapy beyond what can be attributed to in-field cytotoxicity by modulating the immune system. While complex, these systemic effects can help tip the therapeutic balance in favor of treatment success or failure. Engagement of the immune system is generally through recognition of damage-associated molecules expressed or released as a result of tumor and normal tissue radiation damage. This system has evolved to discriminate pathological from physiological forms of cell death by signaling “danger.” The multiple mechanisms that can be evoked include a shift toward a pro-inflammatory, pro-oxidant microenvironment that can promote maturation of dendritic cells and, in cancer treatment, the development of effector T cell responses to tumor-associated antigens. Control over these processes is exerted by regulatory T cells (Tregs), suppressor macrophages, and immunosuppressive cytokines that act in consort to maintain tolerance to self, limit tissue damage, and re-establish tissue homeostasis. Unfortunately, by the time RT for cancer is initiated the tumor-host relationship has already been sculpted in favor of tumor growth and against immune-mediated mechanisms for tumor regression. Reversing this situation is a major challenge. However, recent data show that removal of Tregs can tip the balance in favor of the generation of radiation-induced anti-tumor immunity. The clinical challenge is to do so without excessive depletion that might precipitate serious autoimmune reactions and increase the likelihood of normal tissue complications. The selective modulation of Treg biology to maintain immune tolerance and control of normal tissue damage, while releasing the “brakes” on anti-tumor immune responses, is a worthy aim with promise for enhancing the therapeutic benefit of RT for cancer. PMID:22912933

  11. Favorable Outcomes in Patients with High Donor-Derived T Cell Count Following in vivo T Cell Depleted Reduced Intensity Allogeneic Stem Cell Transplantation

    PubMed Central

    Toor, Amir A.; Sabo, Roy T.; Chung, Harold M.; Roberts, Catherine; Manjili, Rose H.; Song, Shiyu; Williams, David C.; Edmiston, Wendy; Gatesman, Mandy L.; Edwards, Richard W.; Ferreira-Gonzalez, Andrea; Clark, William B.; Neale, Michael C.; McCarty, John M.; Manjili, Masoud H.

    2016-01-01

    Patients with hematological malignancies were conditioned using a rabbit anti-thymocyte globulin based reduced intensity conditioning regimen for allogeneic stem cell transplantation (SCT). Donor-derived CD3+ cell count (ddCD3), a product of CD3+ cell chimerism and absolute CD3+ cell count, when less than 110/μL, eight weeks post-transplant, predicted a high risk of sustained mixed chimerism and relapse. Alternatively, patients with a higher ddCD3 developed GVHD more frequently, and when partially chimeric, had higher rates of conversion to full donor chimerism upon withdrawal of immunosuppression. In conclusion, early data from a small cohort of patients indicates that ddCD3+ cell count at 8 weeks may be used to guide the decision-making process regarding withdrawal of immunosuppression and administration of donor lymphocyte infusion in partially T cell depleted reduced intensity regimens. PMID:22005648

  12. Selective Expansion of Allogeneic Regulatory T Cells by Hepatic Stellate Cells: Role of Endotoxin and Implications for Allograft Tolerance

    PubMed Central

    Dangi, Anil; Sumpter, Tina L.; Kimura, Shoko; Stolz, Donna B.; Murase, Noriko; Raimondi, Giorgio; Vodovotz, Yoram; Huang, Chao; Thomson, Angus W.; Gandhi, Chandrashekhar R.

    2012-01-01

    Hepatic stellate cells (HSCs) may play an important role in hepatic immune regulation by producing numerous cytokines/chemokines, and expressing Ag-presenting and T cell co-regulatory molecules. Due to disruption of the endothelial barrier during cold-ischemic storage and reperfusion of liver grafts, HSCs can interact directly with cells of the immune system. Endotoxin (LPS), levels of which increase in liver diseases and transplantation, stimulates the synthesis of many mediators by HSCs. We hypothesized that LPS-stimulated HSCs might promote hepatic tolerogenicity by influencing naturally-occurring immunosuppressive CD4+CD25+FoxP3+ regulatory T cells (Tregs). Following their portal venous infusion, allogeneic CD4+ T cells, including Tregs, were found closely associated with HSCs, and this association increased in LPS-treated livers. In vitro, both unstimulated and LPS-stimulated HSCs up-regulated Fas (CD95) expression on conventional CD4+ T cells and induced their apoptosis in a Fas/FasL-dependent manner. By contrast, HSCs induced Treg proliferation, which required cell-cell contact, and was MHC class II-dependent. This effect was augmented when HSCs were pretreated with LPS. LPS increased the expression of MHC class II, CD80 and CD86, and stimulated the production of IL-1α, IL-1β, IL-6, IL-10 and TNFα by HSCs. Interestingly, production of IL-1α, IL-1β, IL-6 and TNFα was strongly inhibited, but that of IL-10 enhanced, in LPS-pretreated HSC/Treg co-cultures. Adoptively transferred allogeneic HSCs migrated to the secondary lymphoid tissues and induced Treg expansion in lymph nodes. These data implicate endotoxins-stimulated HSCs as important immune regulators in liver transplantation by inducing selective expansion of tolerance-promoting Tregs, and reducing inflammation and allo-immunity. PMID:22427640

  13. The immunosuppressive compound 2-acetyl-4-tetrahydroxybutyl imidazole inhibits the allogeneic mixed lymphocyte reaction by sequestration of a recirculating subpopulation of T cells.

    PubMed Central

    Bradbury, M G; Doherty, K V; Parish, C R; Lyons, A B

    1996-01-01

    2-acetyl-4(5)-(1,2,3,4-tetrahydroxybutyl)imidazole (THI) is an immunosuppressive component of caramel food colouring that causes lymphopenia in mice and rats by an unknown mechanism. In this study we investigated some of the affects of THI on the murine immune system. Initially we showed that splenic T lymphocytes from mice treated with 50 mg/l THI in their drinking water were unable to launch a mixed lymphocyte reaction (MLR) against allogeneic stimulator cells, and had decreased and delayed interleukin-2 (IL-2) production. However, these T cells exhibited a normal proliferative response to concanavalin A (Con A), immobilized anti-CD3 monoclonal antibody (mAb) and anti-CD3 plus anti-CD28 mAb. Furthermore, the MLR response could be restored by the addition of IL-2 to the MLR culture. Homing studies using intravenous injection of fluorescence-labelled splenocytes showed that THI treatment decreased absolute numbers of labelled T and B lymphocytes in the blood and the spleen. Furthermore, these labelled cells reappeared in the blood and the spleen when mice were taken off THI, indicating that lymphocyte recirculation and splenic homing were modified reversibly by THI treatment. Cessation of THI treatment also resulted in a rapid reappearance of MLR responsiveness in the spleen, indicating that THI treatment does not functionally impair recirculating T cells. Collectively these data are compatible with the concept that a rapidly recirculating population of T cells, which produce IL-2 in an allogeneic MLR, are lost from the blood and spleen following THI treatment, and are sequestered in other, yet to be identified, tissues. PMID:8666439

  14. Antiviral Cd8+ T Cell Responses in Neonatal Mice

    PubMed Central

    Moser, Janice M.; Altman, John D.; Lukacher, Aron E.

    2001-01-01

    Polyoma virus is a potent oncogenic pathogen when inoculated into newborn mice of particular H-2k strains. Using Dk tetramers containing the dominant antipolyoma CD8+ T cell epitope, middle T protein (MT)389–397, and intracellular interferon γ staining, we enumerated MT389-specific CD8+ T cells in infected neonates having opposite susceptibilities to polyoma virus–induced tumors. In resistant mice, MT389-specific CD8+ T cells dramatically expanded during acute infection in neonates to a frequency rivaling that in adults; furthermore, in both neonatal and adult mice, this antipolyoma CD8+ T cell response exhibited nearly identical T cell receptor (TCR) functional avidities and TCR functional fingerprints. Susceptible mice mounted an MT389-specific CD8+ T cell response of only fourfold lower magnitude than resistant mice; but, in clear contrast to resistant mice, these CD8+ T cells lacked ex vivo MT389-specific cytotoxic activity. However, MT389-specific CD8+ T cells in resistant and susceptible mice expressed similar TCR avidities, perforin levels, and surface type O-glycan levels indicative of mature CD8+ T cell effectors. Upon in vitro restimulation with infected antigen-presenting cells, CD8+ T cells from acutely infected susceptible neonates acquired strong MT389-specific cytotoxicity. These findings indicate that polyoma-specific CD8+ T cells are armed with, but restrained from deploying, their cytotoxic effector function in mice susceptible to polyoma virus tumorigenesis. PMID:11238590

  15. T cells raised against allogeneic HLA-A2/CD20 kill primary follicular lymphoma and acute lymphoblastic leukemia cells.

    PubMed

    Abrahamsen, Ingerid Weum; Kjellevoll, Synneva; Greve-Isdahl, Margrethe; Mensali, Nadia; Wälchli, Sébastien; Kumari, Shraddha; Loland, Beate Fossum; Egeland, Torstein; Kolstad, Arne; Olweus, Johanna

    2012-04-15

    T cells mediating a graft-versus-leukemia/lymphoma effects without causing graft-versus-host disease would greatly improve the safety and applicability of hematopoietic stem cell transplantation. We recently demonstrated that highly peptide- and HLA-specific T cells can readily be generated against allogeneic HLA-A*02:01 in complex with a peptide from the B cell-restricted protein CD20. Here, we show that such CD20-specific T cells can easily be induced from naïve precursors in cord blood, demonstrating that they do not represent cross-reactive memory cells. The cells displayed high avidity and mediated potent cytotoxic effects on cells from patients with the CD20(pos) B cell malignancies follicular lymphoma (FL) and acute lymphoblastic leukemia (ALL). However, the cytotoxicity was consistently lower for cells from two of the ALL patients. The ALL cells that were less efficiently killed did not display lower surface expression of CD20 or HLA-A*02:01, or mutations in the CD20 sequence. Peptide pulsing fully restored the levels of cytotoxicity, indicating that they are indeed susceptible to T cell-mediated killing. Adoptive transfer of CD20-specific T cells to an HLA-A*02:01(pos) patient requires an HLA-A*02:01(neg) , but otherwise HLA identical, donor. A search clarified that donors meeting these criteria can be readily identified even for patients with rare haplotypes. The results bear further promise for the clinical utility of CD20-specific T cells in B cell malignancies. PMID:21630262

  16. H-2 restriction as a consequence of intentional priming: T cells of fully allogeneic chimeric mice as well as of normal mice respond to foreign antigens in the context of H-2 determinants not encountered on thymic epithelial cells.

    PubMed

    Stockinger, H; Pfizenmaier, K; Hardt, C; Rodt, H; Röllinghoff, M; Wagner, H

    1980-12-01

    Fully allogeneic chimeras were able to develop in vitro alloantigen-specific, as well as H-2-restricted, Sendai virus-specific cytotoxic T-lymphocyte (CTL) response. Depending on the immunization regimen used, Sendai virus-specific CTL responses were restricted to the H-2 antigens of either the stem cell donor or the thymus. Similarly, unprimed splenic T cells of normal mice were found to contain CTL-precursor cells that specifically reacted against Sendai virus or trinitrophenyl derivatives in the context of allogeneic major histocompatibility complex determinants that had not been encountered during their thymic differentiation. A frequency analysis of allogeneically versus syngeneically restricted virus-specific CTL precursors present in splenic T cells showed a ratio of about 1 to 6. These results provide evidence that H-2 restriction of trinitrophenyl- or Sendai virus-specific T cells is dictated by the complex type of the antigen-presenting cell and thus appears to be independent of the type of thymus in which the T cells have undergone maturation. PMID:6261255

  17. Peripheral blood and synovial fluid T cells differ in their response to alloantigens and recall antigens presented by dendritic cells.

    PubMed Central

    Stagg, A J; Harding, B; Hughes, R A; Keat, A; Knight, S C

    1991-01-01

    Properties of T cells from inflammatory lesions were analysed by comparing the response of peripheral blood (PB) and synovial fluid (SF) T cells from 19 patients with a range of arthropathies to enriched allogeneic dendritic cells (DC) in a primary mixed leucocyte reaction (MLR). In 17 patients the proliferative response of SF T cells was significantly (P less than 0.05) less than that of PB lymphocytes. The reduced response of SF T cells was observed in all disease categories studied and could not be attributed to differences in cell number requirements or response kinetics. Addition of recombinant interleukin-2 enhanced the response of SF T cells in a dose-dependent manner. Cell mixing experiments suggested that active suppression was not the underlying mechanism of the poor MLR response of SF T cells. In contrast to the MLR response. SF T cells were able to mount vigorous proliferative responses to recall antigen presented by autologous antigen-presenting cells. The possibility is discussed that T cells compartmentalized at inflammatory lesions are a unique population with a diminished ability to interact with DC and respond to primary stimuli but an ability to respond to secondary antigenic challenge. PMID:1826648

  18. 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…

  19. Graft-versus-lymphoma effect in refractory cutaneous T-cell lymphoma after reduced-intensity HLA-matched sibling allogeneic stem cell transplantation.

    PubMed

    Herbert, K E; Spencer, A; Grigg, A; Ryan, G; McCormack, C; Prince, H M

    2004-09-01

    Cutaneous T-cell lymphomas (CTCL) are rare diseases that, in their advanced stages or in transformation, have a poor prognosis. Autologous stem cell transplantation (Au-SCT) after high-dose therapy has yielded disappointing results. Allogeneic transplantation (allo-SCT) provides the potential advantage of an immune-mediated graft-versus-lymphoma (GVL) effect. Reduced-intensity allo-SCT potentially offers a GVL effect, but with diminished toxicity related to the induction regimen; however, published experience with this approach in CTCL is limited. We report a series of three patients (age 35-49) with advanced, refractory (n=2) or transformed (n=1) CTCL who underwent reduced-intensity allo-SCT in the context of active disease. All three survived the peri-transplant period and, despite later having disease relapse, all exhibited evidence of a GVL effect. Relapses of the disease were in the context of immune suppression for graft-versus-host disease (GVHD), and when immune suppression was reduced, responses were regained. A comparison is made of these results to those in a review of the published literature to date. We conclude that while a GVL can be achieved for CTCL with reduced-intensity allogeneic transplantation, the clinical benefits are short lived and novel approaches are required to obtain sustained remissions. PMID:15286686

  20. Longitudinal Requirement for CD4+ T Cell Help for Adenovirus Vector–Elicited CD8+ T Cell Responses

    PubMed Central

    Provine, Nicholas M.; Larocca, Rafael A.; Penaloza-MacMaster, Pablo; Borducchi, Erica N.; McNally, Anna; Parenteau, Lily R.; Kaufman, David R.

    2014-01-01

    Despite the widespread use of replication-incompetent recombinant adenovirus (Ad) vectors as candidate vaccine platforms, the mechanism by which these vectors elicit CD8+ T cell responses remains poorly understood. Our data demonstrate that induction and maintenance of CD8+ T cell responses by Ad vector immunization is longitudinally dependent on CD4+ T cell help for a prolonged period. Depletion of CD4+ T cells in wild type mice within the first 8 d following Ad immunization resulted in dramatically reduced induction of Ag-specific CD8+ T cells, decreased T-bet and eomesodermin expression, impaired KLRG1+ effector differentiation, and atypical expression of the memory markers CD127, CD27, and CD62L. Moreover, these CD8+ T cells failed to protect against a lethal recombinant Listeria monocytogenes challenge. Depletion of CD4+ T cells between weeks 1 and 4 following immunization resulted in increased contraction of memory CD8+ T cells. These data demonstrate a prolonged temporal requirement for CD4+ T cell help for vaccine-elicited CD8+ T cell responses in mice. These findings have important implications in the design of vaccines aimed at eliciting CD8+ T cell responses and may provide insight into the impaired immunogenicity of vaccines in the context of AIDS and other CD4+ T cell immune deficiencies. PMID:24778441

  1. To investigate the necessity of STRA6 upregulation in T cells during T cell immune responses.

    PubMed

    Terra, Rafik; Wang, Xuehai; Hu, Yan; Charpentier, Tania; Lamarre, Alain; Zhong, Ming; Sun, Hui; Mao, Jianning; Qi, Shijie; Luo, Hongyu; Wu, Jiangping

    2013-01-01

    Our earlier study revealed that STRA6 (stimulated by retinoic acid gene 6) was up-regulated within 3 h of TCR stimulation. STRA6 is the high-affinity receptor for plasma retinol-binding protein (RBP) and mediates cellular vitamin A uptake. We generated STRA6 knockout (KO) mice to assess whether such up-regulation was critical for T-cell activation, differentiation and function. STRA6 KO mice under vitamin A sufficient conditions were fertile without apparent anomalies upon visual inspection. The size, cellularity and lymphocyte subpopulations of STRA6 KO thymus and spleen were comparable to those of their wild type (WT) controls. KO and WT T cells were similar in terms of TCR-stimulated proliferation in vitro and homeostatic expansion in vivo. Naive KO CD4 cells differentiated in vitro into Th1, Th2, Th17 as well as regulatory T cells in an analogous manner as their WT counterparts. In vivo experiments revealed that anti-viral immune responses to lymphocytic choriomeningitis virus in KO mice were comparable to those of WT controls. We also demonstrated that STRA6 KO and WT mice had similar glucose tolerance. Total vitamin A levels are dramatically lower in the eyes of KO mice as compared to those of WT mice, but the levels in other organs were not significantly affected after STRA6 deletion under vitamin A sufficient conditions, indicating that the eye is the mouse organ most sensitive to the loss of STRA6. Our results demonstrate that 1) in vitamin A sufficiency, the deletion of STRA6 in T cells does no affect the T-cell immune responses so-far tested, including those depend on STAT5 signaling; 2) STRA6-independent vitamin A uptake compensated the lack of STRA6 in lymphoid organs under vitamin A sufficient conditions in mice; 3) STRA6 is critical for vitamin A uptake in the eyes even in vitamin A sufficiency. PMID:24391722

  2. To Investigate the Necessity of STRA6 Upregulation in T Cells during T Cell Immune Responses

    PubMed Central

    Charpentier, Tania; Lamarre, Alain; Zhong, Ming; Sun, Hui; Mao, Jianning; Qi, Shijie; Luo, Hongyu; Wu, Jiangping

    2013-01-01

    Our earlier study revealed that STRA6 (stimulated by retinoic acid gene 6) was up-regulated within 3 h of TCR stimulation. STRA6 is the high-affinity receptor for plasma retinol-binding protein (RBP) and mediates cellular vitamin A uptake. We generated STRA6 knockout (KO) mice to assess whether such up-regulation was critical for T-cell activation, differentiation and function. STRA6 KO mice under vitamin A sufficient conditions were fertile without apparent anomalies upon visual inspection. The size, cellularity and lymphocyte subpopulations of STRA6 KO thymus and spleen were comparable to those of their wild type (WT) controls. KO and WT T cells were similar in terms of TCR-stimulated proliferation in vitro and homeostatic expansion in vivo. Naive KO CD4 cells differentiated in vitro into Th1, Th2, Th17 as well as regulatory T cells in an analogous manner as their WT counterparts. In vivo experiments revealed that anti-viral immune responses to lymphocytic choriomeningitis virus in KO mice were comparable to those of WT controls. We also demonstrated that STRA6 KO and WT mice had similar glucose tolerance. Total vitamin A levels are dramatically lower in the eyes of KO mice as compared to those of WT mice, but the levels in other organs were not significantly affected after STRA6 deletion under vitamin A sufficient conditions, indicating that the eye is the mouse organ most sensitive to the loss of STRA6. Our results demonstrate that 1) in vitamin A sufficiency, the deletion of STRA6 in T cells does no affect the T-cell immune responses so-far tested, including those depend on STAT5 signaling; 2) STRA6-independent vitamin A uptake compensated the lack of STRA6 in lymphoid organs under vitamin A sufficient conditions in mice; 3) STRA6 is critical for vitamin A uptake in the eyes even in vitamin A sufficiency. PMID:24391722

  3. Trafficking, persistence, and activation state of adoptively transferred allogeneic and autologous SIV-specific CD8+ T-cell clones during acute and chronic SIV infection of rhesus macaques1

    PubMed Central

    Bolton, Diane L.; Minang, Jacob T.; Trivett, Matt; Song, Kaimei; Tuscher, Jennifer J.; Li, Yuan; Piatak, Michael; O'Connor, David; Lifson, Jeffrey D.; Roederer, Mario; Ohlen, Claes

    2009-01-01

    Despite multiple lines of evidence suggesting their involvement, the precise role of CD8+ T-cells in controlling HIV replication remains unclear. To determine whether CD8+ T cells can limit retroviral replication in the absence of other immune responses, we transferred 1-13 × 109 allogeneic in vitro expanded SIV-specific CD8+ T-cell clones matched for the relevant restricting MHC-I allele into rhesus macaques near the time of intravenous (i.v.) SIV challenge. Additionally, in vitro expanded autologous SIV-specific CD8+ T-cell clones were infused 4-9 months post-infection. Infused cells did not appreciably impact acute or chronic viral replication. The partially MHC-matched allogeneic cells were not detected in the blood or most tissues after 3 days but persisted longer in the lungs as assessed by bronchoalveolar lavage (BAL). Autologous cells transferred i.v. or intraperitoneally (i.p.) were found in BAL and blood samples for up to 8 weeks post-infusion. Interestingly, despite having a nominally activated phenotype (CD69+HLA-DR+), many of these cells persisted in the BAL without dividing. This suggests that expression of such markers by T cells at mucosal sites may not reflect recent activation, but may instead identify stable resident memory T cells. The lack of impact following transfer of such a large number of functional antigen-specific CD8+ T cells on SIV replication may reflect the magnitude of the immune response required to contain the virus. PMID:19949089

  4. Varicella-zoster virus glycoproteins B and E are major targets of CD4+ and CD8+ T cells reconstituting during zoster after allogeneic transplantation

    PubMed Central

    Kleemann, Patrick; Distler, Eva; Wagner, Eva M.; Thomas, Simone; Klobuch, Sebastian; Aue, Steffi; Schnürer, Elke; Schild, Hansjörg; Theobald, Matthias; Plachter, Bodo; Tenzer, Stefan; Meyer, Ralf G.; Herr, Wolfgang

    2012-01-01

    Background After allogeneic hematopoietic stem-cell transplantation patients are at increased risk for herpes zoster as long as varicella-zoster virus specific T-cell reconstitution is impaired. This study aimed to identify immunodominant varicella-zoster virus antigens that drive recovery of virus-specific T cells after transplantation. Design and Methods Antigens were purified from a varicella-zoster virus infected cell lysate by high-performance liquid chromatography and were identified by quantitative mass spectrometric analysis. To approximate in vivo immunogenicity for memory T cells, antigen preparations were consistently screened with ex vivo PBMC of varicella-zoster virus immune healthy individuals in sensitive interferon-γ ELISpot assays. Candidate virus antigens identified by the approach were genetically expressed in PBMC using electroporation of in vitro transcribed RNA encoding full-length proteins and were then analyzed for recognition by CD4+ and CD8+ memory T cells. Results Varicella-zoster virus encoded glycoproteins B and E, and immediate early protein 62 were identified in immunoreactive lysate material. Predominant CD4+ T-cell reactivity to these proteins was observed in healthy virus carriers. Furthermore, longitudinal screening in allogeneic stem-cell transplantation patients showed strong expansions of memory T cells recognizing glycoproteins B and E after onset of herpes zoster, while immediate early protein 62 reactivity remained moderate. Reactivity to viral glycoproteins boosted by acute zoster was mediated by both CD4+ and CD8+ T cells. Conclusions Our data demonstrate that glycoproteins B and E are major targets of varicella-zoster virus specific CD4+ and CD8+ T-cell reconstitution occurring during herpes zoster after allogeneic stem-cell transplantation. Varicella-zoster virus glycoproteins B and E might form the basis for novel non-hazardous zoster subunit vaccines suitable for immunocompromised transplant patients. PMID:22207687

  5. Regulation of antiviral T cell responses by type I interferons.

    PubMed

    Crouse, Josh; Kalinke, Ulrich; Oxenius, Annette

    2015-04-01

    Type I interferons (IFNs) are pro-inflammatory cytokines that are rapidly induced in different cell types during viral infections. The consequences of type I IFN signalling include direct antiviral activity, innate immune cell activation and regulation of adaptive immune responses. In this Review, we discuss recent conceptual advances in our understanding of indirect and direct regulation of T cell immunity by type I IFNs, which can either promote or inhibit T cell activation, proliferation, differentiation and survival. This regulation depends, to a large extent, on the timing of type I IFN exposure relative to T cell receptor signalling. Type I IFNs also provide activated T cells with resistance to natural killer cell-mediated elimination. PMID:25790790

  6. T cell responses in psoriasis and psoriatic arthritis.

    PubMed

    Diani, Marco; Altomare, Gianfranco; Reali, Eva

    2015-04-01

    According to the current view the histological features of psoriasis arise as a consequence of the interplay between T cells, dendritic cells and keratinocytes giving rise to a self-perpetuating loop that amplifies and sustains inflammation in lesional skin. In particular, myeloid dendritic cell secretion of IL-23 and IL-12 activates IL-17-producing T cells, Th22 and Th1 cells, leading to the production of inflammatory cytokines such as IL-17, IFN-γ, TNF and IL-22. These cytokines mediate effects on keratinocytes thus establishing the inflammatory loop. Unlike psoriasis the immunopathogenic features of psoriatic arthritis are poorly characterized and there is a gap in the knowledge of the pathogenic link between inflammatory T cell responses arising in the skin and the development of joint inflammation. Here we review the knowledge accumulated over the years from the early evidence of autoreactive CD8 T cells that was studied mainly in the years 1990s and 2000s to the recent findings of the role of Th17, Tc17 cells and γδ T cells in psoriatic disease pathogenesis. The review will also focus on common and distinguishing features of T cell responses in psoriatic plaques and in synovial fluid of patients with psoriatic arthritis. The integration of this information could help to distinguish the role played by T cells in the initiation phase of the disease from the role of T cells as downstream effectors sustaining inflammation in psoriatic plaques and potentially leading to disease manifestation in distant joints. PMID:25445403

  7. Diversity of T-cell responses

    NASA Astrophysics Data System (ADS)

    Stromberg, Sean P.; Carlson, Jean M.

    2013-04-01

    Using a dynamic model we study the adaptive immune response to a sequence of two infections. We incorporate lymphocyte diversity by modeling populations as continuous distributions in a multi-dimensional space. As expected, memory cells generated by the primary infection invoke a rapid response when the secondary infection is identical (homologous). When the secondary infection is different (heterologous), the memory cells have a positive effect or no effect at all depending on the similarity of the infections. This model displays ‘original antigenic sin’ where the average effector affinity for the heterologous infection is lower than it would be for a naive response, but in cases with original antigenic sin we see a reduction in pathogen density. We model pathology resulting from the immune system itself (immunopathology) but find that in cases of original antigenic sin, immunopathology is still reduced. Average effector affinity is not an accurate measure of the quality of an immune response. The effectivity, which is the total pathogen killing rate, provides a direct measure of quality. This quantity takes both affinity and magnitude into account.

  8. Mechanisms of Cyclic Nucleotide Phosphodiesterases in Modulating T Cell Responses in Murine Graft-versus-Host Disease

    PubMed Central

    Weber, Michael; Lupp, Corinna; Stein, Pamela; Kreft, Andreas; Bopp, Tobias; Wehler, Thomas C.; Schmitt, Edgar; Schild, Hansjörg; Radsak, Markus P.

    2013-01-01

    Graft-versus-host disease (GvHD) is a key contributor to the morbidity and mortality after allogeneic hematopoetic stem cell transplantation (HSCT). Regulatory Foxp3+ CD4+ T cells (Treg) suppress conventional T cell activation and can control GvHD. In our previous work, we demonstrate that a basic mechanism of Treg mediated suppression occurs by the transfer of cyclic adenosine monophosphate (cAMP) to responder cells. Whether this mechanism is relevant for Treg mediated suppression of GvHD is currently unknown. To address this question, bone marrow and T cells from C57BL/6 mice were transferred into lethally irradiated BALB/c recipients, and the course of GvHD and survival were monitored. Transplanted recipients developed severe GvHD that was strongly ameliorated by the transfer of donor Treg cells. Towards the underlying mechanisms, in vitro studies revealed that Treg communicated with DCs via gap junctions, resulting in functional inactivation of DC by a metabolic pathway involving cAMP that is modulated by the phosphodiesterase (PDE) 4 inhibitor rolipram. PDE2 or PDE3 inhibitors as well as rolipram suppressed allogeneic T cell activation, indirectly by enhancing Treg mediated suppression of DC activation and directly by inhibiting responder T cell proliferation. In line with this, we observed a cooperative suppression of GvHD upon Treg transfer and additional rolipram treatment. In conclusion, we propose that an important pathway of Treg mediated control of GvHD is based on a cAMP dependent mechanism. These data provide the basis for future concepts to manipulate allogeneic T cell responses to prevent GvHD. PMID:23483980

  9. Mechanisms of cyclic nucleotide phosphodiesterases in modulating T cell responses in murine graft-versus-host disease.

    PubMed

    Weber, Michael; Lupp, Corinna; Stein, Pamela; Kreft, Andreas; Bopp, Tobias; Wehler, Thomas C; Schmitt, Edgar; Schild, Hansjörg; Radsak, Markus P

    2013-01-01

    Graft-versus-host disease (GvHD) is a key contributor to the morbidity and mortality after allogeneic hematopoetic stem cell transplantation (HSCT). Regulatory Foxp3(+) CD4(+) T cells (Treg) suppress conventional T cell activation and can control GvHD. In our previous work, we demonstrate that a basic mechanism of Treg mediated suppression occurs by the transfer of cyclic adenosine monophosphate (cAMP) to responder cells. Whether this mechanism is relevant for Treg mediated suppression of GvHD is currently unknown. To address this question, bone marrow and T cells from C57BL/6 mice were transferred into lethally irradiated BALB/c recipients, and the course of GvHD and survival were monitored. Transplanted recipients developed severe GvHD that was strongly ameliorated by the transfer of donor Treg cells. Towards the underlying mechanisms, in vitro studies revealed that Treg communicated with DCs via gap junctions, resulting in functional inactivation of DC by a metabolic pathway involving cAMP that is modulated by the phosphodiesterase (PDE) 4 inhibitor rolipram. PDE2 or PDE3 inhibitors as well as rolipram suppressed allogeneic T cell activation, indirectly by enhancing Treg mediated suppression of DC activation and directly by inhibiting responder T cell proliferation. In line with this, we observed a cooperative suppression of GvHD upon Treg transfer and additional rolipram treatment. In conclusion, we propose that an important pathway of Treg mediated control of GvHD is based on a cAMP dependent mechanism. These data provide the basis for future concepts to manipulate allogeneic T cell responses to prevent GvHD. PMID:23483980

  10. Allogeneic hematopoietic cell transplantation for peripheral T-cell NHL results in long-term disease control

    PubMed Central

    Zain, Jasmine; Palmer, Joycelynne M.; Delioukina, Maria; Thomas, Sandra; Tsai, Ni-Chun; Nademanee, Auayporn; Popplewell, Leslie; Gaal, Karl; Senitzer, David; Kogut, Neil; O'Donnell, Margaret; Forman, Stephen J.

    2012-01-01

    The study analyzed outcomes of a consecutive case series of 37 patients with peripheral T-cell non-Hodgkin lymphoma, from related and unrelated donors, using allogeneic hematopoietic cell transplantation (allo-HCT), between the years 2000 and 2007. All patients were pretreated; the majority had either relapsed or progressive disease (n=25, 68%), 13 had cutaneous histologies (CTCL), and all were ineligible for autologous transplant. Fully ablative conditioning regimens were used in 13 patients while 24 patients underwent reduced intensity conditioning (RIC). At five years the overall survival (OS) and progression-free survival (PFS) probabilities were 52.2% and 46.5%, respectively. At the time of analysis, 9 (24.3%) patients had either relapsed (n=6) or progressed (n=3) post allo-HCT. The cumulative incidences of relapse/progression and non-relapse mortality at 5 years were 24.3% and 28.9%. No statistically significant variables for survival or relapse were discovered by univariate Cox-regression analysis of disease and patient characteristics; differences between CTCL and other histologies were not significant. The median follow-up of 64.0 months (range: 16.4–100.4) indicates a mature data-set with probable cure in the survivors. The relapse/progression curves reached and maintained plateaus after 1 year post-transplant, demonstrating that long-term disease control is possible after allo-HCT in PTCL patients with advanced disease. PMID:21699453

  11. Prevention of Allogeneic Cardiac Graft Rejection by Transfer of Ex Vivo Expanded Antigen-Specific Regulatory T-Cells

    PubMed Central

    Takasato, Fumika; Morita, Rimpei; Schichita, Takashi; Sekiya, Takashi; Morikawa, Yasuhide; Kuroda, Tatsuo; Niimi, Masanori; Yoshimura, Akihiko

    2014-01-01

    The rate of graft survival has dramatically increased using calcineurin inhibitors, however chronic graft rejection and risk of infection are difficult to manage. Induction of allograft-specific regulatory T-cells (Tregs) is considered an ideal way to achieve long-term tolerance for allografts. However, efficient in vitro methods for developing allograft-specific Tregs which is applicable to MHC full-mismatched cardiac transplant models have not been established. We compared antigen-nonspecific polyclonal-induced Tregs (iTregs) as well as antigen-specific iTregs and thymus-derived Tregs (nTregs) that were expanded via direct and indirect pathways. We found that iTregs induced via the indirect pathway had the greatest ability to prolong graft survival and suppress angiitis. Antigen-specific iTregs generated ex vivo via both direct and indirect pathways using dendritic cells from F1 mice also induced long-term engraftment without using MHC peptides. In antigen-specific Treg transferred models, activation of dendritic cells and allograft-specific CTL generation were suppressed. The present study demonstrated the potential of ex vivo antigen-specific Treg expansion for clinical cell-based therapeutic approaches to induce lifelong immunological tolerance for allogeneic cardiac transplants. PMID:24498362

  12. [Alleviation of palmoplantar pustulosis associated with adult T cell leukemia/lymphoma after allogeneic hematopoietic stem cell transplantation].

    PubMed

    Akasaka, Hiroshi; Imaizumi, Kisako; Sakane, Emiko; Tsunemine, Hiroko; Ito, Kiminari; Kodaka, Taiichi; Matsumoto, Mayumi; Matsuoka, Masao; Takahashi, Takayuki

    2012-08-01

    A 68-year-old female with palmoplantar pustulosis was referred to our hospital in July, 2009 because of liver dysfunction, a positive test for HTLV-1, and circulating abnormal lymphocytes with irregularly shaped nuclei. A diagnosis of acute type adult T cell leukemia/lymphoma (ATLL) was made based on generalized lymph node swelling and high levels of serum LDH, in addition to the findings described above. The associated palmoplantar pustulosis responded to some extent to antibiotics, steroid ointment, and narrow band UBV light irradiation. For ATLL, she was serially treated with CHOP chemotherapy, an LSG 15 protocol, and CytaBOM protocol with consequent partial remission. These chemotherapies did not affect the palmoplantar pustulosis. For ATLL in partial remission, we performed allogeneic peripheral blood stem cell transplantation (allo-PBSCT) from a related donor (HTLV-1-negative) with a conditioning regimen consisting of fludarabine, melphalan, and total body irradiation with 3 Gy in February, 2010. After the engraftment of donor hematopoietic cells, ATLL cells disappeared and the patient currently (as of April, 2012) remains in complete remission (CR). The residual palmoplantar pustulosis was further improved soon after allo-PBSCT and disappeared on Day 84 after transplantation. This refractory skin disease has also been in CR to date. PMID:22975820

  13. PD-1hiTIM-3+ T cells associate with and predict leukemia relapse in AML patients post allogeneic stem cell transplantation

    PubMed Central

    Kong, Y; Zhang, J; Claxton, D F; Ehmann, W C; Rybka, W B; Zhu, L; Zeng, H; Schell, T D; Zheng, H

    2015-01-01

    Prognosis of leukemia relapse post allogeneic stem cell transplantation (alloSCT) is poor and effective new treatments are urgently needed. T cells are pivotal in eradicating leukemia through a graft versus leukemia (GVL) effect and leukemia relapse is considered a failure of GVL. T-cell exhaustion is a state of T-cell dysfunction mediated by inhibitory molecules including programmed cell death protein 1 (PD-1) and T-cell immunoglobulin domain and mucin domain 3 (TIM-3). To evaluate whether T-cell exhaustion and inhibitory pathways are involved in leukemia relapse post alloSCT, we performed phenotypic and functional studies on T cells from peripheral blood of acute myeloid leukemia patients receiving alloSCT. Here we report that PD-1hiTIM-3+ cells are strongly associated with leukemia relapse post transplantation. Consistent with exhaustion, PD-1hiTIM-3+ T cells are functionally deficient manifested by reduced production of interleukin 2 (IL-2), tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ). In addition, these cells demonstrate a phenotype consistent with exhausted antigen-experienced T cells by losing TN and TEMRA subsets. Importantly, increase of PD-1hiTIM-3+ cells occurs before clinical diagnosis of leukemia relapse, suggesting their predictive value. Results of our study provide an early diagnostic approach and a therapeutic target for leukemia relapse post transplantation. PMID:26230954

  14. PD-1(hi)TIM-3(+) T cells associate with and predict leukemia relapse in AML patients post allogeneic stem cell transplantation.

    PubMed

    Kong, Y; Zhang, J; Claxton, D F; Ehmann, W C; Rybka, W B; Zhu, L; Zeng, H; Schell, T D; Zheng, H

    2015-01-01

    Prognosis of leukemia relapse post allogeneic stem cell transplantation (alloSCT) is poor and effective new treatments are urgently needed. T cells are pivotal in eradicating leukemia through a graft versus leukemia (GVL) effect and leukemia relapse is considered a failure of GVL. T-cell exhaustion is a state of T-cell dysfunction mediated by inhibitory molecules including programmed cell death protein 1 (PD-1) and T-cell immunoglobulin domain and mucin domain 3 (TIM-3). To evaluate whether T-cell exhaustion and inhibitory pathways are involved in leukemia relapse post alloSCT, we performed phenotypic and functional studies on T cells from peripheral blood of acute myeloid leukemia patients receiving alloSCT. Here we report that PD-1(hi)TIM-3(+) cells are strongly associated with leukemia relapse post transplantation. Consistent with exhaustion, PD-1(hi)TIM-3(+) T cells are functionally deficient manifested by reduced production of interleukin 2 (IL-2), tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ). In addition, these cells demonstrate a phenotype consistent with exhausted antigen-experienced T cells by losing TN and TEMRA subsets. Importantly, increase of PD-1(hi)TIM-3(+) cells occurs before clinical diagnosis of leukemia relapse, suggesting their predictive value. Results of our study provide an early diagnostic approach and a therapeutic target for leukemia relapse post transplantation. PMID:26230954

  15. Itk: The Rheostat of the T Cell Response

    PubMed Central

    Grasis, Juris A.; Tsoukas, Constantine D.

    2011-01-01

    The nonreceptor tyrosine kinase Itk plays a key role in TCR-initiated signaling that directly and significantly affects the regulation of PLCγ1 and the consequent mobilization of Ca2+. Itk also participates in the regulation of cytoskeletal reorganization as well as cellular adhesion, which is necessary for a productive T cell response. The functional cellular outcome of these molecular regulations by Itk renders it an important mediator of T cell development and differentiation. This paper encompasses the structure of Itk, the signaling parameters leading to Itk activation, and Itk effects on molecular pathways resulting in functional cellular outcomes. The incorporation of these factors persuades one to believe that Itk serves as a modulator, or rheostat, critically fine-tuning the T cell response. PMID:21747996

  16. ZFAT plays critical roles in peripheral T cell homeostasis and its T cell receptor-mediated response

    SciTech Connect

    Doi, Keiko; Fujimoto, Takahiro; Okamura, Tadashi; Ogawa, Masahiro; Tanaka, Yoko; Mototani, Yasumasa; Goto, Motohito; Ota, Takeharu; Matsuzaki, Hiroshi; Kuroki, Masahide; Tsunoda, Toshiyuki; Sasazuki, Takehiko; Shirasawa, Senji

    2012-08-17

    Highlights: Black-Right-Pointing-Pointer We generated Cd4-Cre-mediated T cell-specific Zfat-deficient mice. Black-Right-Pointing-Pointer Zfat-deficiency leads to reduction in the number of the peripheral T cells. Black-Right-Pointing-Pointer Impaired T cell receptor-mediated response in Zfat-deficient peripheral T cells. Black-Right-Pointing-Pointer Decreased expression of IL-7R{alpha}, IL-2R{alpha} and IL-2 in Zfat-deficient peripheral T cells. Black-Right-Pointing-Pointer Zfat plays critical roles in peripheral T cell homeostasis. -- Abstract: ZFAT, originally identified as a candidate susceptibility gene for autoimmune thyroid disease, has been reported to be involved in apoptosis, development and primitive hematopoiesis. Zfat is highly expressed in T- and B-cells in the lymphoid tissues, however, its physiological function in the immune system remains totally unknown. Here, we generated the T cell-specific Zfat-deficient mice and demonstrated that Zfat-deficiency leads to a remarkable reduction in the number of the peripheral T cells. Intriguingly, a reduced expression of IL-7R{alpha} and the impaired responsiveness to IL-7 for the survival were observed in the Zfat-deficient T cells. Furthermore, a severe defect in proliferation and increased apoptosis in the Zfat-deficient T cells following T cell receptor (TCR) stimulation was observed with a reduced IL-2R{alpha} expression as well as a reduced IL-2 production. Thus, our findings reveal that Zfat is a critical regulator in peripheral T cell homeostasis and its TCR-mediated response.

  17. Exposure to inhaled isobutyl nitrite reduces T cell-dependent responsiveness

    SciTech Connect

    Soderberg, L.S.F.; Barnett, J.B. )

    1991-03-11

    Isobutyl nitrite is a drug of abuse popular among male homosexuals and among adolescents. In order to approximate the nitrite exposures of inhalant abusers, mice were treated with 900 ppm isobutyl nitrite in an inhalation chamber for 45 min per day for 14 days. At 72 hr after the last exposure, mice were assayed for immune competence. Under these conditions, mice gained only half the weight of mice exposed to air. The spleens of nitrite exposed mice weighed 15% less and had 24% fewer cells per spleen than controls. Adjusted for equal cell numbers, T cell mitogenic and allogeneic proliferative responses were significantly reduce by 33% and 47%, respectively. Unstimulated spleen cells had elevated levels of IL-2 transcription following exposure to isobutyl nitrite suggesting that nitrite inhalation caused a nonspecific induction of T cells. In contrast, B cell proliferative responses to LPS were unaltered. Exposure to the nitrite reduced the frequency of T-dependent antibody plaque-forming cells (PFC) by 63% and the total number of reduced by 60% after as few as five daily exposures to isobutyl nitrite. Therefore, the data suggest that habitual inhalation of isobutyl nitrite impairs immune competence and that toxicity appears to be directed toward T cell functions.

  18. KIR2DS1-dependent acquisition of CCR7 and migratory properties by human NK cells interacting with allogeneic HLA-C2+ DCs or T-cell blasts.

    PubMed

    Marcenaro, Emanuela; Pesce, Silvia; Sivori, Simona; Carlomagno, Simona; Moretta, Lorenzo; Moretta, Alessandro

    2013-04-25

    Natural killer (NK) cells may capture the CCR7 chemokine receptor from allogeneic CCR7(+) cells by trogocytosis and acquire migrating properties in response to lymph node chemokines. This event is negatively regulated by inhibitory killer Ig-like receptors (KIRs) and NKG2A. In this study, we analyzed the role of the HLA-C2-specific activating receptor KIR2DS1 in the process of CCR7 uptake by NK cells interacting with different allogeneic CCR7(+) cells. Co-incubation of KIR2DS1(+) fresh NK cells or NK-cell clones with HLA-C2(+) CCR7(+) lymphoblastoid cell lines resulted in increased CCR7 uptake. Remarkably, KIR2DS1 expression represented a major advantage for acquiring CCR7 from HLA-C2(+) allogeneic dendritic cells (DCs) and T-cell blasts. These findings have important implications in haploidentical hematopoietic stem cell transplantation in which donor-derived (alloreactive) KIR2DS1(+) NK cells, upon CCR7 acquisition, become capable of migrating toward lymph nodes, where they may kill patient DCs and T cells, preventing graft-versus-host and host-versus-graft reactions. PMID:23449637

  19. T Cells

    MedlinePlus

    ... or turn off the immune response. Cytotoxic or “killer” T cells directly attack and destroy cells bearing ... involve selective activation of helper T cells and killer T cells, with a corresponding decrease in regulatory ...

  20. Enhancement of T cell responses as a result of synergy between lower doses of radiation and T cell stimulation.

    PubMed

    Spary, Lisa K; Al-Taei, Saly; Salimu, Josephine; Cook, Alexander D; Ager, Ann; Watson, H Angharad; Clayton, Aled; Staffurth, John; Mason, Malcolm D; Tabi, Zsuzsanna

    2014-04-01

    As a side effect of cancer radiotherapy, immune cells receive varying doses of radiation. Whereas high doses of radiation (>10 Gy) can lead to lymphopenia, lower radiation doses (2-4 Gy) represent a valid treatment option in some hematological cancers, triggering clinically relevant immunological changes. Based on our earlier observations, we hypothesized that lower radiation doses have a direct positive effect on T cells. In this study, we show that 0.6-2.4 Gy radiation enhances proliferation and IFN-γ production of PBMC or purified T cells induced by stimulation via the TCR. Radiation with 1.2 Gy also lowered T cell activation threshold and broadened the Th1 cytokine profile. Although radiation alone did not activate T cells, when followed by TCR stimulation, ERK1/2 and Akt phosphorylation increased above that induced by stimulation alone. These changes were followed by an early increase in glucose uptake. Naive (CD45RA(+)) or memory (CD45RA(-)) T cell responses to stimulation were boosted at similar rates by radiation. Whereas increased Ag-specific cytotoxic activity of a CD8(+) T cell line manifested in a 4-h assay (10-20% increase), highly significant (5- to 10-fold) differences in cytokine production were detected in 6-d Ag-stimulation assays of PBMC, probably as a net outcome of death of nonstimulated and enhanced response of Ag-stimulated T cells. T cells from patients receiving pelvic radiation (2.2-2.75 Gy) also displayed increased cytokine production when stimulated in vitro. We report in this study enhanced T cell function induced by synergistic radiation treatment, with potential physiological significance in a wide range of T cell responses. PMID:24600032

  1. Stop and go traffic to tune T cell responses.

    PubMed

    Dustin, Michael L

    2004-09-01

    Adaptive immune responses are initiated by interactions of T cells with antigen-presenting cells, but the basic nature of these interactions during an immune response in vivo has been a matter of speculation. While some in vitro systems provide evidence for stable interactions, referred to as immunological synapses, compelling evidence supports T cell activation through serial transient interactions. Deep tissue intravital and organ culture microscopy studies suggest that both modes of interaction are employed, but new issues have emerged. This review will discuss in vitro results that framed the hypotheses that are currently being tested in vivo. I present a model in which TCR stop signals compete with chemokine-mediated go signals to adjust the duration of immunological synapse formation and tune the immune response between tolerance and full activation. PMID:15357942

  2. Complement-induced regulatory T cells suppress T-cell responses but allow for dendritic-cell maturation

    PubMed Central

    Barchet, Winfried; Price, Jeffrey D.; Cella, Marina; Colonna, Marco; MacMillan, Sandra K.; Cobb, J. Perren; Thompson, Paul A.; Murphy, Kenneth M.; Atkinson, John P.; Kemper, Claudia

    2006-01-01

    Concurrent activation of the T-cell receptor (TCR) and complement regulator CD46 on human CD4+ T lymphocytes induces Tr1-like regulatory T cells that suppress through IL-10 secretion bystander T-cell proliferation. Here we show that, despite their IL-10 production, CD46-induced T-regulatory T cells (Tregs) do not suppress the activation/maturation of dendritic cells (DCs). DC maturation by complement/CD46-induced Tregs is mediated through simultaneous secretion of GM-CSF and soluble CD40L, factors favoring DC differentiation and reversing inhibitory effects of IL-10. Thus, CD46-induced Tregs produce a distinct cytokine profile that inhibits T-cell responses but leaves DC activation unimpaired. Such “DC-sparing” Tregs could be desirable at host/environment interfaces such as the gastrointestinal tract where their specific cytokine profile provides a mechanism that ensures unresponsiveness to commensal bacteria while maintaining reactivity to invading pathogens. PMID:16239430

  3. Allogeneic stem cell transplantation for advanced cutaneous T-cell lymphomas: a study from the French Society of Bone Marrow Transplantation and French Study Group on Cutaneous Lymphomas.

    PubMed

    de Masson, Adèle; Beylot-Barry, Marie; Bouaziz, Jean-David; Peffault de Latour, Régis; Aubin, François; Garciaz, Sylvain; d'Incan, Michel; Dereure, Olivier; Dalle, Stéphane; Dompmartin, Anne; Suarez, Felipe; Battistella, Maxime; Vignon-Pennamen, Marie-Dominique; Rivet, Jacqueline; Adamski, Henri; Brice, Pauline; François, Sylvie; Lissandre, Séverine; Turlure, Pascal; Wierzbicka-Hainaut, Ewa; Brissot, Eolia; Dulery, Rémy; Servais, Sophie; Ravinet, Aurélie; Tabrizi, Reza; Ingen-Housz-Oro, Saskia; Joly, Pascal; Socié, Gérard; Bagot, Martine

    2014-03-01

    The treatment of advanced stage primary cutaneous T-cell lymphomas remains challenging. In particular, large-cell transformation of mycosis fungoides is associated with a median overall survival of two years for all stages taken together. Little is known regarding allogeneic hematopoietic stem cell transplantation in this context. We performed a multicenter retrospective analysis of 37 cases of advanced stage primary cutaneous T-cell lymphomas treated with allogeneic stem cell transplantation, including 20 (54%) transformed mycosis fungoides. Twenty-four patients (65%) had stage IV disease (for mycosis fungoides and Sézary syndrome) or disseminated nodal or visceral involvement (for non-epidermotropic primary cutaneous T-cell lymphomas). After a median follow up of 29 months, 19 patients experienced a relapse, leading to a 2-year cumulative incidence of relapse of 56% (95%CI: 0.38-0.74). Estimated 2-year overall survival was 57% (95%CI: 0.41-0.77) and progression-free survival 31% (95%CI: 0.19-0.53). Six of 19 patients with a post-transplant relapse achieved a subsequent complete remission after salvage therapy, with a median duration of 41 months. A weak residual tumor burden before transplantation was associated with increased progression-free survival (HR=0.3, 95%CI: 0.1-0.8; P=0.01). The use of antithymocyte globulin significantly reduced progression-free survival (HR=2.9, 95%CI: 1.3-6.2; P=0.01) but also transplant-related mortality (HR=10(-7), 95%CI: 4.10(-8)-2.10(-7); P<0.001) in univariate analysis. In multivariate analysis, the use of antithymocyte globulin was the only factor significantly associated with decreased progression-free survival (P=0.04). Allogeneic stem cell transplantation should be considered in advanced stage primary cutaneous T-cell lymphomas, including transformed mycosis fungoides. PMID:24213148

  4. Mast Cells as Regulators of T Cell Responses

    PubMed Central

    Bulfone-Paus, Silvia; Bahri, Rajia

    2015-01-01

    Mast cells (MCs) are recognized to participate in the regulation of innate and adaptive immune responses. Owing to their strategic location at the host–environment interface, they control tissue homeostasis and are key cells for starting early host defense against intruders. Upon degranulation induced, e.g., by immunoglobulin E (IgE) and allergen-mediated engagement of the high-affinity IgE receptor, complement or certain neuropeptide receptors, MCs release a wide variety of preformed and newly synthesized products including proteases, lipid mediators, and many cytokines, chemokines, and growth factors. Interestingly, increasing evidence suggests a regulatory role for MCs in inflammatory diseases via the regulation of T cell activities. Furthermore, rather than only serving as effector cells, MCs are now recognized to induce T cell activation, recruitment, proliferation, and cytokine secretion in an antigen-dependent manner and to impact on regulatory T cells. This review synthesizes recent developments in MC–T cell interactions, discusses their biological and clinical relevance, and explores recent controversies in this field of MC research. PMID:26300882

  5. Mast Cells as Regulators of T Cell Responses.

    PubMed

    Bulfone-Paus, Silvia; Bahri, Rajia

    2015-01-01

    Mast cells (MCs) are recognized to participate in the regulation of innate and adaptive immune responses. Owing to their strategic location at the host-environment interface, they control tissue homeostasis and are key cells for starting early host defense against intruders. Upon degranulation induced, e.g., by immunoglobulin E (IgE) and allergen-mediated engagement of the high-affinity IgE receptor, complement or certain neuropeptide receptors, MCs release a wide variety of preformed and newly synthesized products including proteases, lipid mediators, and many cytokines, chemokines, and growth factors. Interestingly, increasing evidence suggests a regulatory role for MCs in inflammatory diseases via the regulation of T cell activities. Furthermore, rather than only serving as effector cells, MCs are now recognized to induce T cell activation, recruitment, proliferation, and cytokine secretion in an antigen-dependent manner and to impact on regulatory T cells. This review synthesizes recent developments in MC-T cell interactions, discusses their biological and clinical relevance, and explores recent controversies in this field of MC research. PMID:26300882

  6. 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. PMID:16416236

  7. Keratinocyte growth factor enhances DNA plasmid tumor vaccine responses after murine allogeneic bone marrow transplantation

    PubMed Central

    Jenq, Robert R.; King, Christopher G.; Volk, Christine; Suh, David; Smith, Odette M.; Rao, Uttam K.; Yim, Nury L.; Holland, Amanda M.; Lu, Sydney X.; Zakrzewski, Johannes L.; Goldberg, Gabrielle L.; Diab, Adi; Alpdogan, Onder; Penack, Olaf; Na, Il-Kang; Kappel, Lucy W.; Wolchok, Jedd D.; Houghton, Alan N.; Perales, Miguel-Angel

    2009-01-01

    Keratinocyte growth factor (KGF), which is given exogenously to allogeneic bone marrow transplantation (allo-BMT) recipients, supports thymic epithelial cells and increases thymic output of naive T cells. Here, we demonstrate that this improved T-cell reconstitution leads to enhanced responses to DNA plasmid tumor vaccination. Tumor-bearing mice treated with KGF and DNA vaccination have improved long-term survival and decreased tumor burden after allo-BMT. When assayed before vaccination, KGF-treated allo-BMT recipients have increased numbers of peripheral T cells, including CD8+ T cells with vaccine-recognition potential. In response to vaccination, KGF-treated allo-BMT recipients, compared with control subjects, generate increased numbers of tumor-specific CD8+ cells, as well as increased numbers of CD8+ cells producing interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α). We also found unanticipated benefits to antitumor immunity with the administration of KGF. KGF-treated allo-BMT recipients have an improved ratio of T effector cells to regulatory T cells, a larger fraction of effector cells that display a central memory phenotype, and effector cells that are derived from a broader T-cell–receptor repertoire. In conclusion, our data suggest that KGF can function as a potent vaccine adjuvant after allo-BMT through its effects on posttransplantation T-cell reconstitution. PMID:19011222

  8. Effect of selective T cell depletion of host and/or donor bone marrow on lymphopoietic repopulation, tolerance, and graft-vs-host disease in mixed allogeneic chimeras (B10 + B10. D2----B10)

    SciTech Connect

    Ildstad, S.T.; Wren, S.M.; Bluestone, J.A.; Barbieri, S.A.; Stephany, D.; Sachs, D.H.

    1986-01-01

    Reconstitution of lethally irradiated mice with a mixture of T cell-depleted syngeneic plus T cell-depleted allogeneic bone marrow (B10 + B10.D2----B10) leads to the induction of mixed lymphopoietic chimerism, excellent survivals, specific in vivo transplantation tolerance to subsequent donor strain skin grafts, and specific in vitro unresponsiveness to allogeneic donor lymphoid elements as assessed by mixed lymphocyte reaction (MLR) proliferative and cell-mediated lympholysis (CML) cytotoxicity assays. When B10 recipient mice received mixed marrow inocula in which the syngeneic component had not been T cell depleted, whether or not the allogeneic donor marrow was treated, they repopulated exclusively with host-type cells, promptly rejected donor-type skin allografts, and were reactive in vitro to the allogeneic donor by CML and MLR assays. In contrast, T cell depletion of the syngeneic component of the mixed marrow inocula resulted in specific acceptance of allogeneic donor strain skin grafts. Such animals were specifically unreactive to allogeneic donor lymphoid elements in vitro by CML and MLR, but were reactive to third party. When both the syngeneic and allogeneic marrow were T cell depleted, variable percentages of host- and donor-type lymphoid elements were detected in the mixed reconstituted host. When only the syngeneic bone marrow was T cell depleted, animals repopulated exclusively with donor-type cells. Although these animals had detectable in vitro anti-host (B10) reactivity by CML and MLR and reconstituted as fully allogeneic chimeras, they exhibited excellent survival and had no in vivo evidence for graft-vs-host disease. Experiments in which untreated donor spleen cells were added to the inocula in this last group suggest that the presence of T cell-depleted syngeneic bone marrow cells diminishes graft-vs-host disease and the mortality from it.

  9. T Cells' Immunological Synapses Induce Polarization of Brain Astrocytes In Vivo and In Vitro: A Novel Astrocyte Response Mechanism to Cellular Injury

    PubMed Central

    Barcia, Carlos; Sanderson, Nicholas S. R.; Barrett, Robert J.; Wawrowsky, Kolja; Kroeger, Kurt M.; Puntel, Mariana; Liu, Chunyan; Castro, Maria G.; Lowenstein, Pedro R.

    2008-01-01

    Background Astrocytes usually respond to trauma, stroke, or neurodegeneration by undergoing cellular hypertrophy, yet, their response to a specific immune attack by T cells is poorly understood. Effector T cells establish specific contacts with target cells, known as immunological synapses, during clearance of virally infected cells from the brain. Immunological synapses mediate intercellular communication between T cells and target cells, both in vitro and in vivo. How target virally infected astrocytes respond to the formation of immunological synapses established by effector T cells is unknown. Findings Herein we demonstrate that, as a consequence of T cell attack, infected astrocytes undergo dramatic morphological changes. From normally multipolar cells, they become unipolar, extending a major protrusion towards the immunological synapse formed by the effector T cells, and withdrawing most of their finer processes. Thus, target astrocytes become polarized towards the contacting T cells. The MTOC, the organizer of cell polarity, is localized to the base of the protrusion, and Golgi stacks are distributed throughout the protrusion, reaching distally towards the immunological synapse. Thus, rather than causing astrocyte hypertrophy, antiviral T cells cause a major structural reorganization of target virally infected astrocytes. Conclusions Astrocyte polarization, as opposed to hypertrophy, in response to T cell attack may be due to T cells providing a very focused attack, and thus, astrocytes responding in a polarized manner. A similar polarization of Golgi stacks towards contacting T cells was also detected using an in vitro allogeneic model. Thus, different T cells are able to induce polarization of target astrocytes. Polarization of target astrocytes in response to immunological synapses may play an important role in regulating the outcome of the response of astrocytes to attacking effector T cells, whether during antiviral (e.g. infected during HIV, HTLV-1

  10. TCRVγ9 γδ T Cell Response to IL-33: A CD4 T Cell-Dependent Mechanism.

    PubMed

    Duault, Caroline; Franchini, Don Marc; Familliades, Julien; Cayrol, Corinne; Roga, Stéphane; Girard, Jean-Philippe; Fournié, Jean-Jacques; Poupot, Mary

    2016-01-01

    The availability of specific stimuli to induce the anticancer cytotoxicity of human TCRVγ9-expressing T lymphocytes has allowed the development of γδ T cell-based cancer immunotherapies. However, the stringent dependence of such strategies on the inherently toxic IL-2 has raised safety concerns for patients, justifying a search for alternative methods for inducing γδ T cell stimulation. IL-33 is a γ-chain receptor-independent cytokine of the IL-1 superfamily that is expressed by endothelial cells from a tumor microenvironment and can sustain Th1 and Th2 immune responses. Therefore, we investigated its ability to support the stimulation of human TCRVγ9(+) γδ T cells. In this study, we report that IL-33 efficiently sustained the in vitro activation of Vγ9 T lymphocytes by synthetic phosphoantigens, zoledronate, and a BTN3A1 Ab in the absence of an exogenous supply of IL-2. IL-33 was as potent as IL-2 in allowing the proliferative amplification of Vγ9 T cells isolated from PBMC following activation by the synthetic phosphoantigen bromohydrin pyrophosphate. IL-33 also induced an identical maturation into TNF-α- and IFN-γ-producing Th1 effector memory cells, and IL-33-stimulated cells showed an equivalent cytotoxicity for various tumor cells in vitro. Finally, we found that the bioactivity of IL-33 on the Vγ9 T cell was indirectly mediated through contact with CD4 T cells and IL-2 production by CD4 T cells and Vγ9 T cells themselves. These data posit IL-33 as an alternative to IL-2 for Vγ9 T cell-based cancer immunotherapies. PMID:26608919

  11. T cells recognizing leukemic CD34+ progenitor cells mediate the antileukemic effect of donor lymphocyte infusions for relapsed chronic myeloid leukemia after allogeneic stem cell transplantation

    PubMed Central

    Smit, Willem M.; Rijnbeek, Marion; van Bergen, Cornelis A. M.; Fibbe, Willem E.; Willemze, Roel; Falkenburg, J. H. Frederik

    1998-01-01

    Adoptive immunotherapy with donor lymphocyte infusions (DLI) is an effective treatment for relapsed chronic myeloid leukemia (CML) after allogeneic stem cell transplantation. To identify the effector and target cell populations responsible for the elimination of the leukemic cells in vivo we developed an assay to measure the frequency of T lymphocyte precursor cells capable of suppressing leukemic progenitor cells. Target cells in this assay were CML cells that were cultured in the presence of stem cell factor, interleukin 3, granulocyte–macrophage colony-stimulating factor, granulocyte colony-stimulating factor, and erythropoietin. [3H]thymidine incorporation at day 7 represented the proliferation of the progeny of the CD34+ CML progenitor cells, and not of the more mature CD34− CML cells. Effector cells were mononuclear cells, which were used in a limiting dilution analysis to measure the frequencies of CML progenitor cell-inhibitory lymphocyte precursors (PCILp) in peripheral blood of seven patients before and after DLI for relapsed CML. In the six patients who entered complete remission, a 5- to 100-fold increase of PCILp was found during the clinical response. In the patient with resistant relapse the frequency of PCILp was <10 per ml before and after DLI. Leukemia-reactive helper T lymphocyte precursor frequencies remained unchanged after DLI. A significant increase in cytotoxic T lymphocyte precursor frequency against more mature leukemic cells was found in only two responding patients. These results indicate that T cells specifically directed against CD34+ CML progenitor cells mediate the antileukemic effect of DLI. PMID:9707616

  12. Mechanistic Assessment of PD-1H Coinhibitory Receptor-Induced T-Cell Tolerance to Allogeneic Antigens1

    PubMed Central

    Flies, Dallas B.; Higuchi, Tomoe; Chen, Lieping

    2015-01-01

    PD-1H is a recently identified cell surface co-inhibitory molecule of the B7/CD28 immune modulatory gene family. We showed previously that single injection of a PD-1H agonistic monoclonal antibody (mAb) protected mice from graft versus host disease (GVHD). We report here two distinct mechanisms operate in PD-1H-induced T cell tolerance. First, signaling via PD-1H co-inhibitory receptor potently arrests allo-reactive donor T cells from activation and expansion in the initiation phase. Second, donor regulatory T cells are subsequently expanded to maintain long-term tolerance and GVHD suppression. Our study reveals the crucial function of PD-1H as a co-inhibitory receptor on allo-reactive T cells and its function in the regulation of T cell tolerance. Therefore, PD-1H may be a target for the modulation of allo-reactive T cells in GVHD and transplantation. PMID:25917101

  13. Dengue virus specific dual HLA binding T cell epitopes induce CD8+ T cell responses in seropositive individuals.

    PubMed

    Comber, Joseph D; Karabudak, Aykan; Huang, Xiaofang; Piazza, Paolo A; Marques, Ernesto T A; Philip, Ramila

    2014-01-01

    Dengue virus infects an estimated 300 million people each year and even more are at risk of becoming infected as the virus continues to spread into new areas. Despite the increase in viral prevalence, no anti-viral medications or vaccines are approved for treating or preventing infection. CD8+ T cell responses play a major role in viral clearance. Therefore, effective vaccines that induce a broad, multi-functional T cell response with substantial cross-reactivity between all virus serotypes can have major impacts on reducing infection rates and infection related complications. Here, we took an immunoproteomic approach to identify novel MHC class I restricted T cell epitopes presented by dengue virus infected cells, representing the natural and authentic targets of the T cell response. Using this approach we identified 4 novel MHC-I restricted epitopes: 2 with the binding motif for HLA-A24 molecules and 2 with both HLA-A2 and HLA-A24 binding motifs. These peptides were able to activate CD8+ T cell responses in both healthy, seronegative individuals and in seropositive individuals who have previously been infected with dengue virus. Importantly, the dual binding epitopes activated pre-existing T cell precursors in PBMCs obtained from both HLA-A2+ and HLA-A24+ seropositive individuals. Together, the data indicate that these epitopes are immunologically relevant T cell activating peptides presented on infected cells during a natural infection and therefore may serve as candidate antigens for the development of effective multi-serotype specific dengue virus vaccines. PMID:25668665

  14. Dengue virus specific dual HLA binding T cell epitopes induce CD8+ T cell responses in seropositive individuals

    PubMed Central

    Comber, Joseph D; Karabudak, Aykan; Huang, Xiaofang; Piazza, Paolo A; Marques, Ernesto T A; Philip, Ramila

    2015-01-01

    Dengue virus infects an estimated 300 million people each year and even more are at risk of becoming infected as the virus continues to spread into new areas. Despite the increase in viral prevalence, no anti-viral medications or vaccines are approved for treating or preventing infection. CD8+ T cell responses play a major role in viral clearance. Therefore, effective vaccines that induce a broad, multi-functional T cell response with substantial cross-reactivity between all virus serotypes can have major impacts on reducing infection rates and infection related complications. Here, we took an immunoproteomic approach to identify novel MHC class I restricted T cell epitopes presented by dengue virus infected cells, representing the natural and authentic targets of the T cell response. Using this approach we identified 4 novel MHC-I restricted epitopes: 2 with the binding motif for HLA-A24 molecules and 2 with both HLA-A2 and HLA-A24 binding motifs. These peptides were able to activate CD8+ T cell responses in both healthy, seronegative individuals and in seropositive individuals who have previously been infected with dengue virus. Importantly, the dual binding epitopes activated pre-existing T cell precursors in PBMCs obtained from both HLA-A2+ and HLA-A24+ seropositive individuals. Together, the data indicate that these epitopes are immunologically relevant T cell activating peptides presented on infected cells during a natural infection and therefore may serve as candidate antigens for the development of effective multi-serotype specific dengue virus vaccines. PMID:25668665

  15. Therapeutic blockade of LIGHT interaction with HVEM and LTβR attenuates in vivo cytotoxic allogeneic responses

    PubMed Central

    del Rio, Maria-Luisa; Fernandez-Renedo, Carlos; Scheu, Stefanie; Pfeffer, Klaus; Shintani, Yasushi; Kronenberg, Mitchell; Chaloin, Olivier; Schneider, Pascal; Rodriguez-Barbosa, Jose-Ignacio

    2016-01-01

    Background TNF/TNFR superfamily members conform a group of molecular interaction pathways of essential relevance during the process of T cell activation and differentiation towards effector cells and particularly for the maintenance phase of the immune response. Specific blockade of these interacting pathways, such as CD40/CD40L, contributes to modulate the deleterious outcome of allogeneic immune responses. We postulated that antagonizing the interaction of LIGHT expression on activated T cells with its receptors, HVEM and LTβR may decrease T cell-mediated allogeneic responses. Methods A flow cytometry competition assay was designed to identify anti-LIGHT monoclonal antibodies capable to prevent the interaction of mouse LIGHT with its receptors expressed on transfected cells. An antibody with the desired specificity was evaluated in a short-term in vivo allogeneic cytotoxic assay and tested for its ability to detect endogenous mouse LIGHT. Results We provide evidence for the first time that in mice, as previously described in humans, LIGHT protein is rapidly and transiently expressed after T cell activation, and this expression was stronger on CD8 T cells than on CD4 T cells. Two anti-LIGHT antibodies prevented interactions of mouse LIGHT with its two known receptors HVEM and LTβR. In vivo administration of anti-LIGHT antibody (clone 10F12) ameliorated host anti-donor short-term cytotoxic response in WT B6 mice, although to a lesser extent than that observed in LIGHT-deficient mice. Conclusions The therapeutic targeting of LIGHT may contribute to achieve a better control of cytotoxic responses refractory to current immunosuppressive drugs in transplantation. PMID:25226173

  16. Effects of T cell depletion in radiation bone marrow chimeras. I. Evidence for a donor cell population which increases allogeneic chimerism but which lacks the potential to produce GVHD

    SciTech Connect

    Sykes, M.; Sheard, M.; Sachs, D.H.

    1988-10-01

    The opposing problems of graft-vs-host disease (GVHD) and failure of alloengraftment present major obstacles to the application of bone marrow transplantation (BMT) across complete MHC barriers. The addition of syngeneic T-cell-depleted (TCD) bone marrow (BM) to untreated fully allogeneic marrow inocula in lethally irradiated mice has been previously shown to provide protection from GVHD. We have used this model to study the effects of allogeneic T cells on levels of chimerism in recipients of mixed marrow inocula. The results indicate that T cells in allogeneic BM inocula eliminate both coadministered recipient-strain and radioresistant host hematopoietic elements to produce complete allogeneic chimerism without clinical GVHD. To determine the role of GVH reactivity in this phenomenon, we performed similar studies in an F1 into parent combination, in which the genetic potential for GVHD is lacking. The presence of T cells in F1 marrow inocula led to predominant repopulation with F1 lymphocytes in such chimeras, even when coadministered with TCD-recipient-strain BM. These results imply that the ability of allogeneic BM cells removed by T cell depletion to increase levels of allochimerism may be mediated by a population which is distinct from that which produces GVHD. These results may have implications for clinical BM transplantation.

  17. Durable responses to ibrutinib in patients with relapsed CLL after allogeneic stem cell transplantation.

    PubMed

    Link, C S; Teipel, R; Heidenreich, F; Rücker-Braun, E; Schmiedgen, M; Reinhardt, J; Oelschlägel, U; von Bonin, M; Middeke, J M; Muetherig, A; Trautmann-Grill, K; Platzbecker, U; Bornhäuser, M; Schetelig, J

    2016-06-01

    Ibrutinib, a recently approved inhibitor of Bruton's tyrosine kinase (BTK), has shown great efficacy in patients with high-risk CLL. Nevertheless, there are few data regarding its use in patients who relapsed after allogeneic stem cell transplantation (alloSCT). We report clinical data from five CLL patients treated with ibrutinib for relapse after first or even second allogeneic transplantation. Additionally, we performed analyses on cytokine levels and direct measuring of CD4 Th1 and CD4 Th2 cells to evaluate possible clinically relevant immunomodulatory effects of ibrutinib. All patients achieved partial responses including one minimal residual disease (MRD)-negative remission. Within 1 year of follow-up, no relapse was observed. One patient died of severe pneumonia while on ibrutinib treatment. Beside this, no unexpected adverse events were observed. Flow cytometry and analyses of T cell-mediated cytokine levels (IL10 and TNFα) did not reveal substantial changes in T-cell distribution in favor of a CD4 Th1 T-cell shift in our patients. No acute exacerbation of GvHD was reported. In conclusion, these results support further evaluation of ibrutinib in CLL patients relapsing after alloSCT. PMID:26752141

  18. Hemolysin-producing Listeria monocytogenes affects the immune response to T-cell-dependent and T-cell-independent antigens.

    PubMed Central

    Hage-Chahine, C M; Del Giudice, G; Lambert, P H; Pechere, J C

    1992-01-01

    A murine experimental infection with a hemolysin-producing (Hly+) strain of Listeria monocytogenes and a non-hemolysin-producing (Hly-) mutant was used as an in vivo model to evaluate the role of hemolysin production in the immune response. No antilisterial antibodies were detectable following sublethal infection with Hly+ bacteria, but consistent antilisterial immunoglobulin G (IgG) and IgM antibody production was observed following sublethal infection with the Hly- mutant. Hly+ but not Hly- L. monocytogenes induced transient inhibition of antibody response to Hly- bacteria and to unrelated T-cell-dependent (tetanus toxoid) and T-cell-independent (pneumococcal polysaccharide 3) antigens. Transient inhibition of the activation of an antigen-specific T-cell clone was also observed following Hly+ infection of antigen-presenting cells but not following Hly- infection. These results suggest that hemolysin production by L. monocytogenes is an important factor in modulating the immune response to T-cell-dependent and T-cell-independent antigens in infected individuals. Images PMID:1548067

  19. A single exercise bout enhances the manufacture of viral-specific T-cells from healthy donors: implications for allogeneic adoptive transfer immunotherapy.

    PubMed

    Spielmann, Guillaume; Bollard, Catherine M; Kunz, Hawley; Hanley, Patrick J; Simpson, Richard J

    2016-01-01

    Cytomegalovirus (CMV) and Epstein-Barr virus (EBV) infections remain a major cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (HSCT). The adoptive transfer of donor-derived viral-specific cytotoxic T-cells (VSTs) is an effective treatment for controlling CMV and EBV infections after HSCT; however, new practical methods are required to augment the ex vivo manufacture of multi-VSTs from healthy donors. This study investigated the effects of a single exercise bout on the ex vivo manufacture of multi-VSTs. PBMCs isolated from healthy CMV/EBV seropositive participants before (PRE) and immediately after (POST) 30-minutes of cycling exercise were stimulated with CMV (pp65 and IE1) and EBV (LMP2A and BMLF1) peptides and expanded over 8 days. The number (fold difference from PRE) of T-cells specific for CMV pp65 (2.6), EBV LMP2A (2.5), and EBV BMLF1 (4.4) was greater among the VSTs expanded POST. VSTs expanded PRE and POST had similar phenotype characteristics and were equally capable of MHC-restricted killing of autologous target cells. We conclude that a single exercise bout enhances the manufacture of multi-VSTs from healthy donors without altering their phenotype or function and may serve as a simple and economical adjuvant to boost the production of multi-VSTs for allogeneic adoptive transfer immunotherapy. PMID:27181409

  20. A single exercise bout enhances the manufacture of viral-specific T-cells from healthy donors: implications for allogeneic adoptive transfer immunotherapy

    PubMed Central

    Spielmann, Guillaume; Bollard, Catherine M.; Kunz, Hawley; Hanley, Patrick J.; Simpson, Richard J.

    2016-01-01

    Cytomegalovirus (CMV) and Epstein-Barr virus (EBV) infections remain a major cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (HSCT). The adoptive transfer of donor-derived viral-specific cytotoxic T-cells (VSTs) is an effective treatment for controlling CMV and EBV infections after HSCT; however, new practical methods are required to augment the ex vivo manufacture of multi-VSTs from healthy donors. This study investigated the effects of a single exercise bout on the ex vivo manufacture of multi-VSTs. PBMCs isolated from healthy CMV/EBV seropositive participants before (PRE) and immediately after (POST) 30-minutes of cycling exercise were stimulated with CMV (pp65 and IE1) and EBV (LMP2A and BMLF1) peptides and expanded over 8 days. The number (fold difference from PRE) of T-cells specific for CMV pp65 (2.6), EBV LMP2A (2.5), and EBV BMLF1 (4.4) was greater among the VSTs expanded POST. VSTs expanded PRE and POST had similar phenotype characteristics and were equally capable of MHC-restricted killing of autologous target cells. We conclude that a single exercise bout enhances the manufacture of multi-VSTs from healthy donors without altering their phenotype or function and may serve as a simple and economical adjuvant to boost the production of multi-VSTs for allogeneic adoptive transfer immunotherapy. PMID:27181409

  1. IL-22 dampens the T cell response in experimental malaria

    PubMed Central

    Sellau, Julie; Alvarado, Catherine Fuentes; Hoenow, Stefan; Mackroth, Maria Sophie; Kleinschmidt, Dörte; Huber, Samuel; Jacobs, Thomas

    2016-01-01

    A tight regulation between the pro– and anti–inflammatory immune responses during plasmodial infection is of crucial importance, since a disruption leads to severe malaria pathology. IL-22 is a member of the IL-10 cytokine family, which is known to be highly important in immune regulation. We could detect high plasma levels of IL-22 in Plasmodium falciparum malaria as well as in Plasmodium berghei ANKA (PbA)-infected C57BL/6J mice. The deficiency of IL-22 in mice during PbA infection led to an earlier occurrence of cerebral malaria but is associated with a lower parasitemia compared to wt mice. Furthermore, at an early time point of infection T cells from PbA-infected Il22−/− mice showed an enhanced IFNγ but a diminished IL-17 production. Moreover, dendritic cells from Il22−/− mice expressed a higher amount of the costimulatory ligand CD86 upon infection. This finding can be corroborated in vitro since bone marrow-derived dendritic cells from Il22−/− mice are better inducers of an antigen-specific IFNγ response by CD8+ T cells. Even though there is no IL-22 receptor complex known on hematopoietic cells, our data suggest a link between IL-22 and the adaptive immune system which is currently not identified. PMID:27311945

  2. Selective T-cell Ablation with Bismuth-213 Labeled Anti-TCR Alpha Beta as Nonmyeloablative Conditionaing for Allogeneic Canine Marrow Transplantion

    SciTech Connect

    Bethge, W. A.; Wilbur, D. Scott; Storb, R.; Hamlin, Donald K.; Santos, E. B.; Brechbiel, M. W.; Fisher, Darrell R.; Sandmaier, B. M.

    2003-06-15

    Two major immunological barriers, the host versus graft (HVG) and the graft versus host (GVH) reaction, must be overcome for successful allogeneic hematopoietic stem cell transplantation. T-cells are involved in these barriers in the major histocompatibility complex-identical settings. We hypothesized that selective ablation of T-cells using radioimmunotherapy, together with postgrafting immunosuppression, would ensure stable allogeneic engraftment. We developed a canine model of nonmyeloablative marrow transplantation in which host immune reactions are impaired by a single dose of 2 Gy total body irradiation (TBI), and where both GVH and residual HVG reactions are controlled by postgrafting immunosuppression with mycophenolate mofetil (MMF) and cyclosporine (CSP). We substituted the alpha-emitter bismuth-213 linked to a monoclonal antibody against TCR(alpha,beta)using the metal-binding chelate CHX-A”-DTPA, for 2 Gy TBI. Biodistribution studies using a gamma-emitting indium-111-labeled anti-TCR mAb showed uptake primarily in blood, marrow, lymph nodes, spleen and liver. In a dosimetry study, 4 dogs were treated with 0.13-0.46 mg/kg TCR mAb labeled with 3.7-5.6 mCi/kg (137-207 MBq/kg) Bi-213. The treatment was administered in 6 injections on days -3 and -2 followed by transplantion of dog leukocyte antigen-identical marrow on day 0 and postgrafting immunosuppression with MMF and CSP. Therapy was well tolerated except for elevations of transaminases, which were transient in all but one dog. No other organ toxicities or signs of graft-versus-host-disease were noted. The dogs had prompt allogeneic hematopoietic engraftment and achieved stable mixed donor-host hematopoietic chimerism with donor contributions ranging from 5-55 % with >30 weeks follow up.

  3. Direct stimulation of T cells by type I IFN enhances the CD8+ T cell response during cross-priming.

    PubMed

    Le Bon, Agnes; Durand, Vanessa; Kamphuis, Elisabeth; Thompson, Clare; Bulfone-Paus, Silvia; Rossmann, Cornelia; Kalinke, Ulrich; Tough, David F

    2006-04-15

    Type I IFN (IFN-alphabeta), which is produced rapidly in response to infection, plays a key role in innate immunity and also acts as a stimulus for the adaptive immune response. We have investigated how IFN-alphabeta induces cross-priming, comparing CD8+ T cell responses generated against soluble protein Ags in the presence or absence of IFN-alphabeta. Injection of IFN-alpha was found to prolong the proliferation and expansion of Ag-specific CD8+ T cells, which was associated with marked up-regulation of IL-2 and IL-15 receptors on Ag-specific cells and expression of IL-15 in the draining lymph node. Surprisingly, neither IL-2 nor IL-15 was required for IFN-alpha-induced cross-priming. Conversely, expression of the IFN-alphabetaR by T cells was shown to be necessary for effective stimulation of the response by IFN-alpha. The finding that T cells represent direct targets of IFN-alphabeta-mediated stimulation reveals an additional mechanism by which the innate response to infection promotes adaptive immunity. PMID:16585561

  4. Regulation of the T Cell Response by CD39.

    PubMed

    Takenaka, Maisa C; Robson, Simon; Quintana, Francisco J

    2016-07-01

    The ectonucleoside triphosphate diphosphohydrolase 1 (ENTPD1, or CD39) catalyzes the phosphohydrolysis of extracellular ATP (eATP) and ADP (eADP) released under conditions of inflammatory stress and cell injury. CD39 generates AMP, which is in turn used by the ecto-5'-nucleotidase CD73 to synthesize adenosine. These ectonucleotidases have a major impact on the dynamic equilibrium of proinflammatory eATP and ADP nucleotides versus immunosuppressive adenosine nucleosides. Indeed, CD39 plays a dominant role in the purinergic regulation of inflammation and the immune response because its expression is influenced by genetic and environmental factors. We review the specific role of CD39 in the kinetic regulation of cellular immune responses in the evolution of disease. We focus on the effects of CD39 on T cells and explore potential clinical applications in autoimmunity, chronic infections, and cancer. PMID:27236363

  5. Complex T-Cell Receptor Repertoire Dynamics Underlie the CD8+ T-Cell Response to HIV-1

    PubMed Central

    Costa, Ana I.; Koning, Dan; Ladell, Kristin; McLaren, James E.; Grady, Bart P. X.; Schellens, Ingrid M. M.; van Ham, Petra; Nijhuis, Monique; Borghans, José A. M.; Keşmir, Can; Price, David A.

    2014-01-01

    ABSTRACT Although CD8+ T cells are important for the control of HIV-1 in vivo, the precise correlates of immune efficacy remain unclear. In this study, we conducted a comprehensive analysis of viral sequence variation and T-cell receptor (TCR) repertoire composition across multiple epitope specificities in a group of antiretroviral treatment-naive individuals chronically infected with HIV-1. A negative correlation was detected between changes in antigen-specific TCR repertoire diversity and CD8+ T-cell response magnitude, reflecting clonotypic expansions and contractions related to alterations in cognate viral epitope sequences. These patterns were independent of the individual, as evidenced by discordant clonotype-specific transitions directed against different epitopes in single subjects. Moreover, long-term asymptomatic HIV-1 infection was characterized by evolution of the TCR repertoire in parallel with viral replication. Collectively, these data suggest a continuous bidirectional process of adaptation between HIV-1 and virus-specific CD8+ T-cell clonotypes orchestrated at the TCR-antigen interface. IMPORTANCE We describe a relation between viral epitope mutation, antigen-specific T-cell expansion, and the repertoire of responding clonotypes in chronic HIV-1 infection. This work provides insights into the process of coadaptation between the human immune system and a rapidly evolving lentivirus. PMID:25320304

  6. Tumor sialylation impedes T cell mediated anti-tumor responses while promoting tumor associated-regulatory T cells

    PubMed Central

    Perdicchio, Maurizio; Cornelissen, Lenneke A. M.; Streng-Ouwehand, Ingeborg; Engels, Steef; Verstege, Marleen I.; Boon, Louis; Geerts, Dirk

    2016-01-01

    The increased presence of sialylated glycans on the tumor surface has been linked to poor prognosis, yet the effects on tumor-specific T cell immunity are hardly studied. We here show that hypersialylation of B16 melanoma substantially influences tumor growth by preventing the formation of effector T cells and facilitating the presence of high regulatory T cell (Treg) frequencies. Knock-down of the sialic acid transporter created “sialic acid low” tumors, that grew slower in-vivo than hypersialylated tumors, altered the Treg/Teffector balance, favoring immunological tumor control. The enhanced effector T cell response in developing “sialic acid low” tumors was preceded by and dependent on an increased influx and activity of Natural Killer (NK) cells. Thus, tumor hypersialylation orchestrates immune escape at the level of NK and Teff/Treg balance within the tumor microenvironment, herewith dampening tumor-specific T cell control. Reducing sialylation provides a therapeutic option to render tumors permissive to immune attack. PMID:26741508

  7. Tumor sialylation impedes T cell mediated anti-tumor responses while promoting tumor associated-regulatory T cells.

    PubMed

    Perdicchio, Maurizio; Cornelissen, Lenneke A M; Streng-Ouwehand, Ingeborg; Engels, Steef; Verstege, Marleen I; Boon, Louis; Geerts, Dirk; van Kooyk, Yvette; Unger, Wendy W J

    2016-02-23

    The increased presence of sialylated glycans on the tumor surface has been linked to poor prognosis, yet the effects on tumor-specific T cell immunity are hardly studied. We here show that hypersialylation of B16 melanoma substantially influences tumor growth by preventing the formation of effector T cells and facilitating the presence of high regulatory T cell (Treg) frequencies. Knock-down of the sialic acid transporter created "sialic acid low" tumors, that grew slower in-vivo than hypersialylated tumors, altered the Treg/Teffector balance, favoring immunological tumor control. The enhanced effector T cell response in developing "sialic acid low" tumors was preceded by and dependent on an increased influx and activity of Natural Killer (NK) cells. Thus, tumor hypersialylation orchestrates immune escape at the level of NK and Teff/Treg balance within the tumor microenvironment, herewith dampening tumor-specific T cell control. Reducing sialylation provides a therapeutic option to render tumors permissive to immune attack. PMID:26741508

  8. Impact of Pre-Transplant Anti-T Cell Globulin (ATG) on Immune Recovery after Myeloablative Allogeneic Peripheral Blood Stem Cell Transplantation

    PubMed Central

    Servais, Sophie; Menten-Dedoyart, Catherine; Beguin, Yves; Seidel, Laurence; Gothot, André; Daulne, Coline; Willems, Evelyne; Delens, Loïc; Humblet-Baron, Stéphanie; Hannon, Muriel; Baron, Frédéric

    2015-01-01

    Background Pre-transplant infusion of rabbit anti-T cell globulin (ATG) is increasingly used as prevention of graft-versus-host disease (GVHD) after allogeneic peripheral blood stem cell transplantation (PBSCT). However, the precise impact of pre-transplant ATG on immune recovery after PBSCT is still poorly documented. Methods In the current study, we compared immune recovery after myeloablative PBSCT in 65 patients who either received (n = 37) or did not (n = 28) pre-transplant ATG-Fresenius (ATG-F). Detailed phenotypes of circulating T, B, natural killer (NK) and invariant NKT (iNKT) cells were analyzed by multicolor flow cytometry at serial time-points from day 40 to day 365 after transplantation. Thymic function was also assessed by sjTREC quantification. Serious infectious events were collected up to 2 years post-transplantation. Results Pre-transplant ATG-F had a prolonged (for at least up to 1-year) and selective negative impact on the T-cell pool, while it did not impair the recovery of B, NK nor iNKT cells. Among T cells, ATG-F selectively compromised the recovery of naïve CD4+, central memory CD4+ and naïve CD8+ cells, while it spared effector memory T and regulatory T cells. Levels of sjTRECs were similar in both cohorts at 1-year after PBSCT, suggesting that ATG-F unlikely impaired thymopoiesis at long-term after PBSCT. Finally, the incidence and rate of serious infections were similar in both groups, while ATG-F patients had a lower incidence of grade II-IV acute graft-versus-host disease. Conclusions Pre-transplant ATG-F induces long-lasting modulation of the circulating T-cell pool after myeloablative PBSCT, that may participate in preventing graft-versus-host disease without deeply compromising anti-pathogen defenses. PMID:26098781

  9. AGING INFLUENCES THE RESPONSE OF T CELLS TO STIMULATION BY THE ELLAGITANNIN, OENOTHEIN B

    PubMed Central

    Ramstead, Andrew G.; Schepetkin, Igor A.; Todd, Kimberly; Loeffelholz, James; Berardinelli, James G.; Quinn, Mark T.; Jutila, Mark A.

    2015-01-01

    Several plant extracts, including certain polyphenols, prime innate lymphocytes and enhance responses to secondary stimuli. Oenothein B, a polyphenol isolated from Epilobium angustifolium and other plant sources, enhances IFNγ production by both bovine and human NK cells and T cells, alone and in response to secondary stimulation by cytokines or tumor cells. Innate immune cell responsiveness is known to be affected by aging, but whether polyphenol responses by these cells are also impacted by aging is not known. Therefore, we examined oenothein B responsiveness in T cells from cord blood, young, and adult donors. We found that oenothein B stimulates bovine and human T cells from individuals over a broad range of ages, as measured by increased IL-2Rα and CD69 expression. However, clear differences in induction of cytokine production by T cells were seen. In T cells from human cord blood and bovine calves, oenothein B was unable to induce IFNγ production. However, oenothein B induced IFNγ production by T cells from adult humans and cattle. In addition, oenothein B induced GM-CSF production by human adult T cells, but not cord blood T cells. Within the responsive T cell population, we found that CD45RO+ memory T cells expressed more cytokines in response to oenothein B than CD45RO− T cells. In summary, our data suggest that the immunostimulation of T cells by oenothein B is influenced by age, particularly with respect to immune cytokine production. PMID:25887271

  10. Aging influences the response of T cells to stimulation by the ellagitannin, oenothein B.

    PubMed

    Ramstead, Andrew G; Schepetkin, Igor A; Todd, Kimberly; Loeffelholz, James; Berardinelli, James G; Quinn, Mark T; Jutila, Mark A

    2015-06-01

    Several plant extracts, including certain polyphenols, prime innate lymphocytes and enhance responses to secondary stimuli. Oenothein B, a polyphenol isolated from Epilobium angustifolium and other plant sources, enhances IFNγ production by both bovine and human NK cells and T cells, alone and in response to secondary stimulation by cytokines or tumor cells. Innate immune cell responsiveness is known to be affected by aging, but whether polyphenol responses by these cells are also impacted by aging is not known. Therefore, we examined oenothein B responsiveness in T cells from cord blood, young, and adult donors. We found that oenothein B stimulates bovine and human T cells from individuals over a broad range of ages, as measured by increased IL-2Rα and CD69 expression. However, clear differences in induction of cytokine production by T cells were seen. In T cells from human cord blood and bovine calves, oenothein B was unable to induce IFNγ production. However, oenothein B induced IFNγ production by T cells from adult humans and cattle. In addition, oenothein B induced GM-CSF production by human adult T cells, but not cord blood T cells. Within the responsive T cell population, we found that CD45RO+ memory T cells expressed more cytokines in response to oenothein B than CD45RO- T cells. In summary, our data suggest that the immunostimulation of T cells by oenothein B is influenced by age, particularly with respect to immune cytokine production. PMID:25887271

  11. T-cell function, T-cell phenotype and its role in responsiveness to recombinant human erythropoietin in hemodialysis patients.

    PubMed

    Abdalla, M; Yassein, S; Darwish, K H

    2010-01-01

    Resistance to recombinant human erythropoietin (Epo) occurs in a small proportion of hemodialysis (HD) patients. In this study we investigated the relationship between T-cell phenotype (using flow cytometry), T-cell function (by measuring in vitro cytokine production) and responsiveness to Epo in HD patients and to compare the results with those from healthy controls. T-cell phenotypes were assessed and T-cell function was studied. The study included 24 chronic renal failure (CRF) patients on HD treated with rHuEPO as well as 14 normal control subjects. Dual-colour immunofluorescence and flow cytometry were used to compare the surface antigen expression on freshly isolated CD4+ and CD8+ T-cells from PBMC of the studied groups. Levels of a panel of selected cytokines (IL-4, IFN-gamma, slL-2R and IL-10) were determined in PBMC culture supernatants and in plasma samples (TNF-alpha, IFN-gamma, IL-6, slL-2R) using (ELISA) kits. Patients were followed-up for 24 months and a survival study was carried out. T-cells from poor responders showed increased proportions of CD4+/CD28- cells and CD8+/CD28- cells compared with both good responders and controls. Compared with their CD28+ counterparts, CD4+/CD28- T-cells produced significantly more IFN-gamma, enabling them to function as pro-inflammatory cells. There was no difference in secretion of IFN-gamma, slL-2R or IL-4 in PBMC cultures obtained from HD patients and controls. However, Unstimulated PBMC from poor responders generated increased levels of IL-10 poor compared with both good responders and controls. Plasma slL-2R and IL-6 were significantly elevated in both good and poor responders compared with controls. Plasma levels of IFN-gamma and TNF-alpha were undetectable in both HD patients and controls. In the follow up period, more deaths were occurring among the poor responders than the good responders. Based on the finding of the this study we may suggest that, in the absence of any obvious cause, poor response to Epo

  12. Graft rejection by cytolytic T cells. Specificity of the effector mechanism in the rejection of allogeneic marrow

    SciTech Connect

    Nakamura, H.; Gress, R.E. )

    1990-02-01

    Cellular effector mechanisms of allograft rejection remain incompletely described. Characterizing the rejection of foreign-marrow allografts rather than solid-organ grafts has the advantage that the cellular composition of the marrow graft, as a single cell suspension, can be altered to include cellular components with differing antigen expression. Rejection of marrow grafts is sensitive to lethal doses of radiation in the mouse but resistant to sublethal levels of radiation. In an effort to identify cells mediating host resistance, lymphocytes were isolated and cloned from spleens of mice 7 days after sublethal TBI (650 cGy) and inoculation with allogeneic marrow. All clones isolated were cytolytic with specificity for MHC encoded gene products of the allogeneic marrow donor. When cloned cells were transferred in vivo into lethally irradiated (1025 cGy) recipients unable to reject allogeneic marrow, results utilizing splenic 125IUdR uptake indicated that these MHC-specific cytotoxic clones could suppress marrow proliferation. In order to characterize the effector mechanism and the ability of the clones to affect final engraftment, double donor chimeras were constructed so that 2 target cell populations differing at the MHC from each other and from the host were present in the same marrow allograft. Results directly demonstrated an ability of CTL of host MHC type to mediate graft rejection and characterized the effector mechanism as one with specificity for MHC gene products.

  13. Altered T cell responses in children with autism

    PubMed Central

    Ashwood, Paul; Krakowiak, Paula; Hertz-Picciotto, Irva; Hansen, Robin; Pessah, Isaac N.; Van de Water, Judy

    2010-01-01

    Autism spectrum disorders (ASD) are characterized by impairment in social interactions, communication deficits, and restricted repetitive interests and behaviors. A potential etiologic role for immune dysfunction in ASD has been suggested. Dynamic adaptive cellular immune function was investigated in 66 children with a confirmed diagnosis of ASD and 73 confirmed typically developing (TD) controls 2–5 years-of-age. In vitro stimulation of peripheral blood mononuclear cells with PHA and tetanus was used to compare group-associated cellular responses. The production of GM-CSF, TNFα, and IL-13 were significantly increased whereas IL-12p40 was decreased following PHA stimulation in ASD relative to TD controls. Induced cytokine production was associated with altered behaviors in ASD children such that increased pro-inflammatory or TH1 cytokines were associated with greater impairments in core features of ASD as well as aberrant behaviors. In contrast, production of GM-CSF and TH2 cytokines were associated with better cognitive and adaptive function. Following stimulation, the frequency of CD3+, CD4+ and CD8+ T cells expressing activation markers CD134 and CD25 but not CD69, HLA-DR or CD137 were significantly reduced in ASD, and suggests an altered activation profile for T cells in ASD. Overall these data indicate significantly altered adaptive cellular immune function in children with ASD that may reflect dysfunctional immune activation, along with evidence that these perturbations may be linked to disturbances in behavior and developmental functioning. Further longitudinal analyzes of cellular immunity profiles would delineate the relationship between immune dysfunction and the progression of behavioral and developmental changes throughout the course of this disorder. PMID:20833247

  14. 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

  15. T-cell receptor excision circle levels after allogeneic stem cell transplantation are predictive of relapse in patients with acute myeloid leukemia and myelodysplastic syndrome.

    PubMed

    Uzunel, Mehmet; Sairafi, Darius; Remberger, Mats; Mattsson, Jonas; Uhlin, Michael

    2014-07-15

    In this retrospective study, 209 patients with malignant disease were analyzed for levels of T-cell receptor excision circles (TRECs) for the first 24 months after allogeneic stem cell transplantation. CD3(+) cells were separated by direct antibody-coupled magnetic beads, followed by DNA extraction according to a standard protocol. The δRec-ψJα signal joint TREC was measured with real-time quantitative PCR. Patients were grouped based on malignant disease: chronic myeloid leukemia, chronic lymphatic leukemia, acute myeloid leukemia (AML), acute lymphocytic leukemia (ALL), and myelodysplastic syndrome (MDS). Patients were further subdivided based on TREC levels below (low-TREC) or above (high-TREC) median at each time point. TREC levels were then correlated to relapse incidence and relapse-free survival (RFS). For patients with AML, low TREC levels 2 months post-transplantation were correlated to high relapse incidence at 5 years (P<0.05). In patients with chronic leukemia, high TREC levels were correlated with improved RFS (P<0.05). For patients with MDS, high TREC levels at 9 months post-transplantation were associated with higher RFS at 5 years (P<0.02) and lower relapse incidence (P<0.02). This study shows the potential use of TREC measurement in blood to predict relapse in patients with AML and MDS after allogeneic hematopoietic stem cell transplantation. PMID:24617310

  16. Impact of graft-versus-host disease on outcomes after allogeneic hematopoietic cell transplantation for adult T-cell leukemia: a retrospective cohort study.

    PubMed

    Kanda, Junya; Hishizawa, Masakatsu; Utsunomiya, Atae; Taniguchi, Shuichi; Eto, Tetsuya; Moriuchi, Yukiyoshi; Tanosaki, Ryuji; Kawano, Fumio; Miyazaki, Yasushi; Masuda, Masato; Nagafuji, Koji; Hara, Masamichi; Takanashi, Minoko; Kai, Shunro; Atsuta, Yoshiko; Suzuki, Ritsuro; Kawase, Takakazu; Matsuo, Keitaro; Nagamura-Inoue, Tokiko; Kato, Shunichi; Sakamaki, Hisashi; Morishima, Yasuo; Okamura, Jun; Ichinohe, Tatsuo; Uchiyama, Takashi

    2012-03-01

    Allogeneic hematopoietic cell transplantation (HCT) is an effective treatment for adult T-cell leukemia (ATL), raising the question about the role of graft-versus-leukemia effect against ATL. In this study, we retrospectively analyzed the effects of acute and chronic graft-versus-host disease (GVHD) on overall survival, disease-associated mortality, and treatment-related mortality among 294 ATL patients who received allogeneic HCT and survived at least 30 days posttransplant with sustained engraftment. Multivariate analyses treating the occurrence of GVHD as a time-varying covariate demonstrated that the development of grade 1-2 acute GVHD was significantly associated with higher overall survival (hazard ratio [HR] for death, 0.65; P = .018) compared with the absence of acute GVHD. Occurrence of either grade 1-2 or grade 3-4 acute GVHD was associated with lower disease-associated mortality compared with the absence of acute GVHD, whereas grade 3-4 acute GVHD was associated with a higher risk for treatment-related mortality (HR, 3.50; P < .001). The development of extensive chronic GVHD was associated with higher treatment-related mortality (HR, 2.75; P = .006) compared with the absence of chronic GVHD. Collectively, these results indicate that the development of mild-to-moderate acute GVHD confers a lower risk of disease progression and a beneficial influence on survival of allografted patients with ATL. PMID:22234682

  17. Regulatory T cells in tumor-associated tertiary lymphoid structures suppress anti-tumor T cell responses

    PubMed Central

    Joshi, Nikhil S.; Akama-Garren, Elliot H.; Lu, Yisi; Lee, Da-Yae; Chang, Gregory P.; Li, Amy; DuPage, Michel; Tammela, Tuomas; Kerper, Natanya R.; Farago, Anna F.; Robbins, Rebecca; Crowley, Denise M.; Bronson, Roderick T.; Jacks, Tyler

    2016-01-01

    SUMMARY Infiltration of regulatory T (Treg) cells into many tumor types correlates with poor patient prognoses. However, mechanisms of intratumoral Treg cell function remain to be elucidated. We investigated Treg cell function in a genetically-engineered mouse lung adenocarcinoma model and found Treg cells suppress anti-tumor responses in tumor-associated tertiary lymphoid structures (TA-TLS). TA-TLS have been described in human lung cancers, but their function remains to be determined. TLS in this model were spatially associated with >90% of tumors and facilitated interactions between T cells and tumor-antigen presenting dendritic cells (DCs). Costimulatory ligand expression by DCs and T cell proliferation rates increased in TA-TLS upon Treg cell depletion, leading to tumor destruction. Thus, we propose Treg cells in TA-TLS can inhibit endogenous immune responses against tumors, and targeting these cells may provide therapeutic benefit for cancer patients. PMID:26341400

  18. Antitumor Responses of Invariant Natural Killer T Cells

    PubMed Central

    Altman, Jennie B.; Benavides, Adriana D.; Das, Rupali; Bassiri, Hamid

    2015-01-01

    Natural killer T (NKT) cells are innate-like lymphocytes that were first described in the late 1980s. Since their initial description, numerous studies have collectively shed light on their development and effector function. These studies have highlighted the unique requirements for the activation of these lymphocytes and the functional responses that distinguish these cells from other effector lymphocyte populations such as conventional T cells and NK cells. This body of literature suggests that NKT cells play diverse nonredundant roles in a number of disease processes, including the initiation and propagation of airway hyperreactivity, protection against a variety of pathogens, development of autoimmunity, and mediation of allograft responses. In this review, however, we focus on the role of a specific lineage of NKT cells in antitumor immunity. Specifically, we describe the development of invariant NKT (iNKT) cells and the factors that are critical for their acquisition of effector function. Next, we delineate the mechanisms by which iNKT cells influence and modulate the activity of other immune cells to directly or indirectly affect tumor growth. Finally, we review the successes and failures of clinical trials employing iNKT cell-based immunotherapies and explore the future prospects for the use of such strategies. PMID:26543874

  19. Allogeneic stem-cell transplantation with reduced conditioning intensity as a novel immunotherapy and antiviral therapy for adult T-cell leukemia/lymphoma.

    PubMed

    Okamura, Jun; Utsunomiya, Atae; Tanosaki, Ryuji; Uike, Naokuni; Sonoda, Shunro; Kannagi, Mari; Tomonaga, Masao; Harada, Mine; Kimura, Nobuhiro; Masuda, Masato; Kawano, Fumio; Yufu, Yuji; Hattori, Hiroyoshi; Kikuchi, Hiroshi; Saburi, Yoshio

    2005-05-15

    Sixteen patients with adult T-cell leukemia/lymphoma (ATL) who were all over 50 years of age underwent allogeneic stem cell transplantation with reduced-conditioning intensity (RIST) from HLA-matched sibling donors after a conditioning regimen consisting of fludarabine (180 mg/m2), busulfan (8 mg/kg), and rabbit antithymocyte globulin (5 mg/kg). The observed regimen-related toxicities and nonhematologic toxicities were all found to be acceptable. Disease relapse was the main cause of treatment failure. Three patients who had a relapse subsequently responded to a rapid discontinuation of the immunosuppressive agent and thereafter achieved another remission. After RIST, the human T-cell leukemia virus type 1 (HTLV-1) proviral load became undetectable in 8 patients. RIST is thus considered to be a feasible treatment for ATL. Our data also suggest the presence of a possible graft-versus-ATL effect; an anti-HTLV-1 activity was also found to be associated with this procedure. PMID:15665110

  20. 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. PMID:27183636

  1. Dissociation of peripheral T cell responses from thymocyte negative selection by weak agonists supports a spare receptor model of T cell activation

    PubMed Central

    McNeil, Lisa K.; Evavold, Brian D.

    2002-01-01

    We have focused on stability of the peptide-MHC complex as a determining factor of ligand potency for thymocytes and peripheral CD4+ T cell responses. MHC variant peptides that have low affinities and fast dissociation rates are different in that they stimulate proliferation and cytolysis of mature T cells (classifying the variant peptides as weak agonists) but do not induce thymocyte negative selection. The MHC variant weak agonists require significant receptor reserve, because decreasing the level of T cell receptor on mature T cells blocks the proliferative response. These results demonstrate that peripheral T cells are more sensitive to MHC variant ligands by virtue of increased T cell receptor expression; in addition, the data support a T cell model of the spare receptor theory. PMID:11904393

  2. Skewed T cell receptor repertoire of Vδ1+ γδ T lymphocytes after human allogeneic haematopoietic stem cell transplantation and the potential role for Epstein–Barr virus-infected B cells in clonal restriction

    PubMed Central

    Fujishima, N; Hirokawa, M; Fujishima, M; Yamashita, J; Saitoh, H; Ichikawa, Y; Horiuchi, T; Kawabata, Y; Sawada, K-I

    2007-01-01

    The proliferation of Vδ1+ γδ T lymphocytes has been described in various infections including human immunodeficiency virus (HIV), cytomegalovirus (CMV) and malaria. However, the antigen specificity and functions of the human Vδ1+ T cells remain obscure. We sought to explore the biological role for this T cell subset by investigating the reconstitution of T cell receptor (TCR) repertoires of Vδ1+ γδ T lymphocytes after human allogeneic haematopoietic stem cell transplantation (HSCT). We observed skewed TCR repertoires of the Vδ1+ T cells in 27 of 44 post-transplant patients. Only one patient developed EBV-associated post-transplant lymphoproliferative disorder in the present patient cohort. The -WGI- amino acid motif was observed in CDR3 of clonally expanded Vδ1+ T cells in half the patients. A skew was also detected in certain healthy donors, and the Vδ1+ T cell clone derived from the donor mature T cell pool persisted in the recipient's blood even 10 years after transplant. This T cell clone expanded in vitro against stimulation with autologous EBV–lymphoblastoid cell lines (LCL), and the Vδ1+ T cell line expanded in vitro from the same patient showed cytotoxicity against autologous EBV–LCL. EBV-infected cells could also induce in vitro oligoclonal expansions of autologous Vδ1+ T cells from healthy EBV-seropositive individuals. These results suggest that human Vδ1+ T cells have a TCR repertoire against EBV-infected B cells and may play a role in protecting recipients of allogeneic HSCT from EBV-associated disease. PMID:17425654

  3. CD4+CD25+ regulatory T cell depletion improves the graft-versus-tumor effect of donor lymphocytes after allogeneic hematopoietic stem cell transplantation.

    PubMed

    Maury, Sébastien; Lemoine, François M; Hicheri, Yosr; Rosenzwajg, Michelle; Badoual, Cécile; Cheraï, Mustapha; Beaumont, Jean-Louis; Azar, Nabih; Dhedin, Nathalie; Sirvent, Anne; Buzyn, Agnès; Rubio, Marie-Thérèse; Vigouroux, Stéphane; Montagne, Olivier; Bories, Dominique; Roudot-Thoraval, Françoise; Vernant, Jean-Paul; Cordonnier, Catherine; Klatzmann, David; Cohen, José L

    2010-07-21

    Donor T cells play a pivotal role in the graft-versus-tumor effect after allogeneic hematopoietic stem cell transplantation. Regulatory T cells (T(reg)s) may reduce alloreactivity, the major component of the graft-versus-tumor effect. In the setting of donor lymphocyte infusion after hematopoietic stem cell transplantation, we postulated that T(reg) depletion could improve alloreactivity and likewise the graft-versus-tumor effect of donor T cells. The safety and efficacy of T(reg)-depleted donor lymphocyte infusion was studied in 17 adult patients with malignancy relapse after hematopoietic stem cell transplantation. All but one had previously failed to respond to at least one standard donor lymphocyte infusion, and none had experienced graft-versus-host disease. Two of the 17 patients developed graft-versus-host disease after their first T(reg)-depleted donor lymphocyte infusion and experienced a long-term remission of their malignancy. Four of the 15 patients who did not respond after a first T(reg)-depleted donor lymphocyte infusion received a second T(reg)-depleted donor lymphocyte infusion combined with lymphodepleting chemotherapy aimed to also eliminate recipient T(reg)s. All four developed acute-like graft-versus-host disease that was associated with a partial or complete and durable remission. In the whole cohort, graft-versus-host disease induction through T(reg) depletion was associated with improved survival. These results suggest that T(reg)-depleted donor lymphocyte infusion is a safe, feasible approach that induces graft-versus-host or graft-versus-tumor effects in alloreactivity-resistant patients. In patients not responding to this approach, the combination of chemotherapy-induced lymphodepletion of the recipient synergizes with the effect of T(reg)-depleted donor lymphocyte infusion. These findings offer a rational therapeutic approach for cancer cellular immunotherapy. PMID:20650872

  4. Measurement of CD8 and CD4 T Cell Responses in Mouse Lungs

    PubMed Central

    Fett, Craig; Zhao, Jincun; Perlman, Stanley

    2016-01-01

    Study of the adaptive immune response to a viral challenge in an animal model often includes analysis of the T cell response. Here we discuss in detail the methods that are used to characterize the CD8 and CD4 T cell response following viral challenge in the lung.

  5. Profiles of activation, differentiation-markers, or β-integrins on T cells contribute to predict T cells' antileukemic responses after stimulation with leukemia-derived dendritic cells.

    PubMed

    Vogt, Valentin; Schick, Julia; Ansprenger, Christian; Braeu, Marion; Kroell, Tanja; Kraemer, Doris; Köhne, Claus-Henning; Hausmann, Andreas; Buhmann, Raymund; Tischer, Johanna; Schmetzer, Helga

    2014-01-01

    and could serve to predict T cells' reactivity during stimulation. Refined analyses in the context of responses to immunotherapies are required. PMID:24911794

  6. Acetyl CoA Carboxylase 2 Is Dispensable for CD8+ T Cell Responses

    PubMed Central

    Lee, Jang Eun; Walsh, Matthew C.; Hoehn, Kyle L.; James, David E.; Wherry, E. John; Choi, Yongwon

    2015-01-01

    Differentiation of T cells is closely associated with dynamic changes in nutrient and energy metabolism. However, the extent to which specific metabolic pathways and molecular components are determinative of CD8+ T cell fate remains unclear. It has been previously established in various tissues that acetyl CoA carboxylase 2 (ACC2) regulates fatty acid oxidation (FAO) by inhibiting carnitine palmitoyltransferase 1 (CPT1), a rate-limiting enzyme of FAO in mitochondria. Here, we explore the cell-intrinsic role of ACC2 in T cell immunity in response to infections. We report here that ACC2 deficiency results in a marginal increase of cellular FAO in CD8+ T cells, but does not appear to influence antigen-specific effector and memory CD8+ T cell responses during infection with listeria or lymphocytic choriomeningitis virus. These results suggest that ACC2 is dispensable for CD8+ T cell responses. PMID:26367121

  7. Impact of Pretransplantation (18)F-Fluorodeoxyglucose-Positron Emission Tomography on Survival Outcomes after T Cell-Depleted Allogeneic Transplantation for Hodgkin Lymphoma.

    PubMed

    Reyal, Yasmin; Kayani, Irfan; Bloor, Adrian J C; Fox, Christopher P; Chakraverty, Ronjon; Sjursen, Ann-Marie; Fielding, Adele K; Ben Taylor, Marcus; Bishton, Mark J; Morris, Emma C; Thomson, Kirsty J; Russell, Nigel; Mackinnon, Stephen; Peggs, Karl S

    2016-07-01

    Pretransplant (18)F-fluorodeoxyglucose (FDG) positron emission tomography status is an important prognostic factor for outcomes after autologous stem cell transplantation (SCT) in Hodgkin lymphoma (HL), but its impact on outcomes after allogeneic SCT remains unclear. We retrospectively evaluated outcomes after T cell-depleted allogeneic SCT of 116 patients with nonprogressive HL according to pretransplant Deauville scores. Endpoints were overall survival (OS), progression-free survival (PFS), relapse rate (RR), and nonrelapse-related mortality (NRM). OS, PFS, and RR did not differ significantly between the Deauville 1 to 2 and Deauville 3 to 5 cohorts (OS: 77.5% versus 67.3%, P = .49; PFS: 59.4% versus 55.7%, P = .43; RR: 20.9% versus 22.6%, P = .28 at 4 years). Differences in PFS remained statistically nonsignificant when comparisons were made between Deauville 1 to 3 and Deauville 4 to 5 cohorts (60.9% versus 51.4%, P = .10), and RR remained very similar (21.5% versus 23.8%, P = .42). Multivariate analyses demonstrated trends toward significance for an effect of Deauville score on PFS (hazard ratio 1.82 for Deauville 4 to 5, P = .06) and for number of lines of prior therapy on OS (hazard ratio 2.34 for >5 lines, P = .10). The latter effect appeared to be driven by higher NRM rather than increased RR. Our findings suggest that Deauville score before allogeneic SCT in patients with nonprogressive HL has a relatively modest impact on survival outcomes in comparison with the impact in autologous SCT and that predictive values for the individual patient remain low, indicating that residual FDG-avid disease should not preclude allogeneic SCT. Furthermore, our findings bring into question the importance of attainment of metabolic complete response in this setting if it is at the expense of increasing NRM risk. PMID:27095691

  8. 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. PMID:26981393

  9. T cell responses against tumor associated antigens and prognosis in colorectal cancer patients.

    PubMed

    Nagorsen, Dirk; Scheibenbogen, Carmen; Letsch, Anne; Germer, Christoph-Thomas; Buhr, Heinz-Johannes; Hegewisch-Becker, Susanna; Rivoltini, Licia; Thiel, Eckhard; Keilholz, Ulrich

    2005-01-19

    INTRODUCTION: Spontaneous T cell responses against specific tumor-associated antigens (TAA) are frequently detected in peripheral blood of tumor patients of various histiotypes. However, little is known about whether these circulating, spontaneously occurring, TAA-reactive T cells influence the clinical course of disease. METHODS: Fifty-four HLA-A2 positive colorectal cancer patients had been analyzed for the presence of T cell responses against epitopes derived from the TAA Ep-CAM, her-2/neu, and CEA either by ELISPOT assay or by intracellular cytokine staining. Then, Kaplan-Meier survival analysis was performed comparing T-cell-responders and T-cell-non-responders. For comparison, a group of T-cell-non-responders was compiled stringently matched to T-cell-responders based on clinical criteria and also analyzed for survival. RESULTS: Sixteen out of 54 patients had a detectable T cell response against at least one of the three tested TAA. Two out of 21 patients (9.5%) with limited stage of disease (UICC I and II) and 14 out of 33 patients (42.4%) with advanced disease (UICC III and IV) were T cell response positive. Comparing all T-cell-responders (n = 16) and all T-cell-non-responders (n = 38), no survival difference was found. In an attempt to reduce the influence of confounding clinical factors, we then compared 16 responders and 16 non-responders in a matched group survival analysis; and again no survival difference was found (p = 0.7). CONCLUSION: In summary, we found no evidence that spontaneous peripheral T cell responses against HLA-A2-binding epitopes of CEA, her-2/neu and Ep-CAM are a strong prognostic factor for survival. PMID:15659244

  10. T cell responses against tumor associated antigens and prognosis in colorectal cancer patients

    PubMed Central

    Nagorsen, Dirk; Scheibenbogen, Carmen; Letsch, Anne; Germer, Christoph-Thomas; Buhr, Heinz-Johannes; Hegewisch-Becker, Susanna; Rivoltini, Licia; Thiel, Eckhard; Keilholz, Ulrich

    2005-01-01

    Introduction Spontaneous T cell responses against specific tumor-associated antigens (TAA) are frequently detected in peripheral blood of tumor patients of various histiotypes. However, little is known about whether these circulating, spontaneously occurring, TAA-reactive T cells influence the clinical course of disease. Methods Fifty-four HLA-A2 positive colorectal cancer patients had been analyzed for the presence of T cell responses against epitopes derived from the TAA Ep-CAM, her-2/neu, and CEA either by ELISPOT assay or by intracellular cytokine staining. Then, Kaplan-Meier survival analysis was performed comparing T-cell-responders and T-cell-non-responders. For comparison, a group of T-cell-non-responders was compiled stringently matched to T-cell-responders based on clinical criteria and also analyzed for survival. Results Sixteen out of 54 patients had a detectable T cell response against at least one of the three tested TAA. Two out of 21 patients (9.5%) with limited stage of disease (UICC I and II) and 14 out of 33 patients (42.4%) with advanced disease (UICC III and IV) were T cell response positive. Comparing all T-cell-responders (n = 16) and all T-cell-non-responders (n = 38), no survival difference was found. In an attempt to reduce the influence of confounding clinical factors, we then compared 16 responders and 16 non-responders in a matched group survival analysis; and again no survival difference was found (p = 0.7). Conclusion In summary, we found no evidence that spontaneous peripheral T cell responses against HLA-A2-binding epitopes of CEA, her-2/neu and Ep-CAM are a strong prognostic factor for survival. PMID:15659244

  11. THE INITIAL PHASE OF AN IMMUNE RESPONSE FUNCTIONS TO ACTIVATE REGULATORY T CELLS

    PubMed Central

    O’Gorman, William E.; Dooms, Hans; Thorne, Steve H.; Kuswanto, Wilson F.; Simonds, Erin F.; Krutzik, Peter O.; Nolan, Garry P.; Abbas, Abul K.

    2009-01-01

    An early reaction of CD4+ T lymphocytes to antigen is the production of cytokines, notably IL-2. In order to detect cytokine dependent responses, naive antigen-specific T cells were stimulated in vivo and the presence of phosphorylated STAT5 molecules was used to identify the cell populations responding to IL-2. Within hours of T-cell priming, IL-2-dependent STAT5 phosphorylation occurred primarily in Foxp3+ regulatory T cells. In contrast, the antigen-specific T cells received STAT5 signals only after repeated antigen exposure or memory differentiation. Regulatory T cells receiving IL-2 signals proliferated and developed enhanced suppressive activity. These results indicate that one of the earliest events in a T cell response is the activation of endogenous regulatory cells, potentially to prevent autoimmunity. PMID:19542444

  12. CD4+ T Cell Priming as Biomarker to Study Immune Response to Preventive Vaccines

    PubMed Central

    Ciabattini, Annalisa; Pettini, Elena; Medaglini, Donata

    2013-01-01

    T cell priming is a critical event in the initiation of the immune response to vaccination since it deeply influences both the magnitude and the quality of the immune response induced. CD4+ T cell priming, required for the induction of high-affinity antibodies and immune memory, represents a key target for improving and modulating vaccine immunogenicity. A major challenge in the study of in vivo T cell priming is due to the low frequency of antigen-specific T cells. This review discusses the current knowledge on antigen-specific CD4+ T cell priming in the context of vaccination, as well as the most advanced tools for the characterization of the in vivo T cell priming and the opportunities offered by the application of systems biology. PMID:24363656

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

    PubMed

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

    2016-01-01

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

  14. 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

  15. Mycobacterium bovis BCG Vaccination Induces Divergent Proinflammatory or Regulatory T Cell Responses in Adults

    PubMed Central

    Boer, Mardi C.; Prins, Corine; van Meijgaarden, Krista E.; van Dissel, Jaap T.; Joosten, Simone A.

    2015-01-01

    Mycobacterium bovis bacillus Calmette-Guérin (BCG), the only currently available vaccine against tuberculosis, induces variable protection in adults. Immune correlates of protection are lacking, and analyses on cytokine-producing T cell subsets in protected versus unprotected cohorts have yielded inconsistent results. We studied the primary T cell response, both proinflammatory and regulatory T cell responses, induced by BCG vaccination in adults. Twelve healthy adult volunteers who were tuberculin skin test (TST) negative, QuantiFERON test (QFT) negative, and BCG naive were vaccinated with BCG and followed up prospectively. BCG vaccination induced an unexpectedly dichotomous immune response in this small, BCG-naive, young-adult cohort: BCG vaccination induced either gamma interferon-positive (IFN-γ+) interleukin 2-positive (IL-2+) tumor necrosis factor α-positive (TNF-α+) polyfunctional CD4+ T cells concurrent with CD4+ IL-17A+ and CD8+ IFN-γ+ T cells or, in contrast, virtually absent cytokine responses with induction of CD8+ regulatory T cells. Significant induction of polyfunctional CD4+ IFN-γ+ IL-2+ TNF-α+ T cells and IFN-γ production by peripheral blood mononuclear cells (PBMCs) was confined to individuals with strong immunization-induced local skin inflammation and increased serum C-reactive protein (CRP). Conversely, in individuals with mild inflammation, regulatory-like CD8+ T cells were uniquely induced. Thus, BCG vaccination either induced a broad proinflammatory T cell response with local inflammatory reactogenicity or, in contrast, a predominant CD8+ regulatory T cell response with mild local inflammation, poor cytokine induction, and absent polyfunctional CD4+ T cells. Further detailed fine mapping of the heterogeneous host response to BCG vaccination using classical and nonclassical immune markers will enhance our understanding of the mechanisms and determinants that underlie the induction of apparently opposite immune responses and how these

  16. CARMA1 is necessary for optimal T cell responses in a murine model of allergic asthma.

    PubMed

    Ramadas, Ravisankar A; Roche, Marly I; Moon, James J; Ludwig, Thomas; Xavier, Ramnik J; Medoff, Benjamin D

    2011-12-15

    CARMA1 is a lymphocyte-specific scaffold protein necessary for T cell activation. Deletion of CARMA1 prevents the development of allergic airway inflammation in a mouse model of asthma due to a defect in naive T cell activation. However, it is unknown if CARMA1 is important for effector and memory T cell responses after the initial establishment of inflammation, findings that would be more relevant to asthma therapies targeted to CARMA1. In the current study, we sought to elucidate the role of CARMA1 in T cells that have been previously activated. Using mice in which floxed CARMA1 exons can be selectively deleted in T cells by OX40-driven Cre recombinase (OX40(+/Cre)CARMA1(F/F)), we report that CD4(+) T cells from these mice have impaired T cell reactivation responses and NF-κB signaling in vitro. Furthermore, in an in vivo recall model of allergic airway inflammation that is dependent on memory T cell function, OX40(+/Cre)CARMA1(F/F) mice have attenuated eosinophilic airway inflammation, T cell activation, and Th2 cytokine production. Using MHC class II tetramers, we demonstrate that the development and maintenance of Ag-specific memory T cells is not affected in OX40(+/Cre)CARMA1(F/F) mice. In addition, adoptive transfer of Th2-polarized OX40(+/Cre)CARMA1(F/F) Ag-specific CD4(+) T cells into wild-type mice induces markedly less airway inflammation in response to Ag challenge than transfer of wild-type Th2 cells. These data demonstrate a novel role for CARMA1 in effector and memory T cell responses and suggest that therapeutic strategies targeting CARMA1 could help treat chronic inflammatory disorders such as asthma. PMID:22075698

  17. Immune evasion of mantle cell lymphoma: expression of B7-H1 leads to inhibited T-cell response to and killing of tumor cells

    PubMed Central

    Wang, Lijuan; Qian, Jianfei; Lu, Yong; Li, Haiyan; Bao, Hanying; He, Donghua; Liu, Zhiqiang; Zheng, Yuhuan; He, Jin; Li, Yi; Neelapu, Sattva; Yang, Jing; Kwak, Larry W.; Yi, Qing; Cai, Zhen

    2013-01-01

    Clinical trials of immunotherapy in mantle cell lymphoma have not yet delivered desirable results, partly because of the inhibitory machinery of the tumor and its microenvironment. Here we investigated the role of B7-H1, a member of the B7 family of co-stimulatory/co-inhibitory ligands, in mantle cell lymphoma-mediated immunosuppression. Allogeneic CD3+, CD4+ and CD8+ T cells were purified and co-cultured with irradiated mantle cell lymphoma cells. Mantle cell lymphoma-reactive T-cell lines from HLA-A*0201+ healthy blood donors were generated after in vitro restimulation, and were subjected to functional tests. We found that B7-H1 expressed on mantle cell lymphoma cells was able to inhibit T-cell proliferation induced by the tumor cells, impair the generation of antigen-specific T-cell responses, and render mantle cell lymphoma cells resistant to T-cell-mediated cytolysis. Blocking or knocking down B7-H1 on mantle cell lymphoma cells enhanced T-cell responses and restored tumor-cell sensitivity to T-cell-mediated killing in vitro and in vivo. Knocking down B7-H1 on mantle cell lymphoma cells primed more CD4+ or CD8+ memory effector T cells. Our study demonstrates for the first time that lymphoma cell-expressed B7-H1 may lead to the suppression of host anti-tumor immune responses in mantle cell lymphoma and targeting tumor cell B7-H1 may represent a novel approach to improve the efficacy of immunotherapy in patients with mantle cell lymphoma. PMID:23508008

  18. Nab2 regulates secondary CD8+ T-cell responses through control of TRAIL expression

    PubMed Central

    Gerlach, Carmen; Arens, Ramon; Janssen, Edith M.; Fitzgerald, Patrick; Schumacher, Ton N.; Medema, Jan Paul; Green, Douglas R.; Schoenberger, Stephen P.

    2012-01-01

    CD4+ Th cells are pivotal for the generation and maintenance of CD8+ T-cell responses. “Helped” CD8+ T cells receive signals during priming that prevent the induction of the proapoptotic molecule TNF-related apoptosis-inducing ligand (TRAIL) during reactivation, thereby enabling robust secondary expansion. Conversely, “helpless” CD8+ T cells primed in the absence of Th induce TRAIL expression after restimulation and undergo activation-induced cell death. In the present study, we investigated the molecular basis for the differential regulation of TRAIL in helped versus helpless CD8+ T cells by comparing their transcriptional profiles, and have identified a transcriptional corepressor, NGFI-A binding protein 2 (Nab2), that is selectively induced in helped CD8+ T cells. Enforced expression of Nab2 prevents TRAIL induction after restimulation of primary helpless CD8+ T cells, and expression of a dominant-negative form of Nab2 in helped CD8+ T cells impairs their secondary proliferative response that is reversible by TRAIL blockade. Finally, we observe that the CD8+ T-cell autocrine growth factor IL-2 coordinately increases Nab2 expression and decreases TRAIL expression. These findings identify Nab2 as a mediator of Th-dependent CD8+ T-cell memory responses through the regulation of TRAIL and the promotion of secondary expansion, and suggest a mechanism through which this operates. PMID:22128144

  19. Modulation of CNS autoimmune responses by CD8(+) T cells coincides with their oligoclonal expansion.

    PubMed

    Fischer, Henrike J; van den Brandt, Jens; Lingner, Thomas; Odoardi, Francesca; Flügel, Alexander; Weishaupt, Andreas; Reichardt, Holger M

    2016-01-15

    MS is a highly prevalent neuroinflammatory disease of presumed autoimmune origin. Clinical observations and animal studies suggest that CD8(+) T cells play an important role in MS but their exact mechanisms are ill defined. When we actively induced EAE in CD8 knock-out DA rats, or adoptively transferred encephalitogenic CD4(+) T cells into CD8 knock-out DA rats, the disease course was indistinguishable from controls. Since our previous findings had revealed that the absence of CD8(+) T cells in Lewis rats ameliorated EAE, we compared antigen-induced T cell differentiation in both strains. Disease onset and the composition of the draining lymph nodes were similar but T cell activation in DA rats was much weaker. Moreover, oligoclonal expansion of CD8(+) T cells was exclusively observed in Lewis but not in DA rats. This suggests that myelin-specific CD8(+) T cells are involved in the differentiation of encephalitogenic CD4(+) T cells in Lewis rats, whilst they do not impact CD4(+) T cell priming in DA rats. Hence, clonal expansion of CD8(+) T cells in secondary lymphoid organs appears to be linked to their ability to modulate CNS autoimmune responses. PMID:26711565

  20. MicroRNA-155 controls CD8+ T cell responses by regulating interferon signaling

    PubMed Central

    Gracias, Donald T.; Stelekati, Erietta; Hope, Jennifer L.; Boesteanu, Alina C.; Doering, Travis; Norton, Jillian; Mueller, Yvonne M.; Fraietta, Joseph A.; Wherry, E. John; Turner, Martin; Katsikis, Peter D.

    2013-01-01

    We show that microRNA-155 (miR-155) is upregulated in primary effector and effector memory CD8+ T cells but is low in naive and central memory cells. Anti-viral CD8+ T cell responses and viral clearance were impaired in miR-155 deficient (miR-155-KO) mice, and this defect was intrinsic to CD8+ T cells as miR-155-KO CD8+ T cells mounted greatly reduced primary and memory responses. Conversely, miR-155 overexpression augmented anti-viral CD8+ T cell responses in vivo. Gene expression profiling of miR-155-KO CD8+ T cells revealed increased type I interferon signaling and sensitivity. Inhibiting STAT1 or IRF7 increased miR-155-KO CD8+ T cell responses in vivo. We report a novel role for miR-155 in regulating IFN responsiveness and CD8+ T cell responses against pathogens in vivo. PMID:23603793

  1. Plasticity of γδ T Cells: Impact on the Anti-Tumor Response

    PubMed Central

    Lafont, Virginie; Sanchez, Françoise; Laprevotte, Emilie; Michaud, Henri-Alexandre; Gros, Laurent; Eliaou, Jean-François; Bonnefoy, Nathalie

    2014-01-01

    The tumor immune microenvironment contributes to tumor initiation, progression, and response to therapy. Among the immune cell subsets that play a role in the tumor microenvironment, innate-like T cells that express T cell receptors composed of γ and δ chains (γδ T cells) are of particular interest. γδ T cells can contribute to the immune response against many tumor types (lymphoma, myeloma, melanoma, breast, colon, lung, ovary, and prostate cancer) directly through their cytotoxic activity and indirectly by stimulating or regulating the biological functions of other cell types required for the initiation and establishment of the anti-tumor immune response, such as dendritic cells and cytotoxic CD8+ T cells. However, the notion that tumor-infiltrating γδ T cells are a good prognostic marker in cancer was recently challenged by studies showing that the presence of these cells in the tumor microenvironment was associated with poor prognosis in both breast and colon cancer. These findings suggest that γδ T cells may also display pro-tumor activities. Indeed, breast tumor-infiltrating γδ T cells could exert an immunosuppressive activity by negatively regulating dendritic cell maturation. Furthermore, recent studies demonstrated that signals from the microenvironment, particularly cytokines, can confer some plasticity to γδ T cells and promote their differentiation into γδ T cells with regulatory functions. This review focuses on the current knowledge on the functional plasticity of γδ T cells and its effect on their anti-tumor activities. It also discusses the putative mechanisms underlying γδ T cell expansion, differentiation, and recruitment in the tumor microenvironment. PMID:25538706

  2. Enhanced local and systemic anti-melanoma CD8+ T cell responses after memory T cell-based adoptive immunotherapy in mice

    PubMed Central

    Contreras, Amanda; Sen, Siddhartha; Tatar, Andrew J.; Mahvi, David A.; Meyers, Justin V.; Srinand, Prakrithi; Suresh, Marulasiddappa

    2016-01-01

    Adoptive cell transfer (ACT) melanoma immunotherapy typically employs acutely activated effector CD8+ T cells for their ability to rapidly recognize and clear antigen. We have previously observed that effector CD8+ T cells are highly susceptible to melanoma-induced suppression, whereas memory CD8+ T cells are not. Although memory T cells have been presumed to be potentially advantageous for ACT, the kinetics of local and systemic T cell responses after effector and memory ACT have not been compared. B16F10 melanoma cells stably transfected to express very low levels of the lymphocytic choriomeningitis virus (LCMV) peptide GP33 (B16GP33) were inoculated into syngeneic C57BL/6 mice. Equal numbers of bona fide naïve, effector, or memory phenotype GP33-specific CD8+ T cells were adoptively transferred into mice 1 day after B16GP33 inoculation. The efficacy of ACT immunotherapy was kinetically assessed using serial tumor measurements and flow cytometric analyses of local and systemic CD8+ T cell responses. Control of B16GP33 tumor growth, persistence of adoptively transferred CD8+ cells, intratumoral infiltration of CD8+ T cells, and systemic CD8+ T cell responsiveness to GP33 were strongest after ACT of memory CD8+ T cells. Following surgical tumor resection and melanoma tumor challenge, only mice receiving memory T cell-based ACT immunotherapy exhibited durable tumor-specific immunity. These findings demonstrate how the use of non-expanded memory CD8+ T cells may enhance ACT immunotherapeutic efficacy. PMID:27011014

  3. Enhanced local and systemic anti-melanoma CD8+ T cell responses after memory T cell-based adoptive immunotherapy in mice.

    PubMed

    Contreras, Amanda; Sen, Siddhartha; Tatar, Andrew J; Mahvi, David A; Meyers, Justin V; Srinand, Prakrithi; Suresh, Marulasiddappa; Cho, Clifford S

    2016-05-01

    Adoptive cell transfer (ACT) melanoma immunotherapy typically employs acutely activated effector CD8+ T cells for their ability to rapidly recognize and clear antigen. We have previously observed that effector CD8+ T cells are highly susceptible to melanoma-induced suppression, whereas memory CD8+ T cells are not. Although memory T cells have been presumed to be potentially advantageous for ACT, the kinetics of local and systemic T cell responses after effector and memory ACT have not been compared. B16F10 melanoma cells stably transfected to express very low levels of the lymphocytic choriomeningitis virus (LCMV) peptide GP33 (B16GP33) were inoculated into syngeneic C57BL/6 mice. Equal numbers of bona fide naïve, effector, or memory phenotype GP33-specific CD8+ T cells were adoptively transferred into mice 1 day after B16GP33 inoculation. The efficacy of ACT immunotherapy was kinetically assessed using serial tumor measurements and flow cytometric analyses of local and systemic CD8+ T cell responses. Control of B16GP33 tumor growth, persistence of adoptively transferred CD8+ cells, intratumoral infiltration of CD8+ T cells, and systemic CD8+ T cell responsiveness to GP33 were strongest after ACT of memory CD8+ T cells. Following surgical tumor resection and melanoma tumor challenge, only mice receiving memory T cell-based ACT immunotherapy exhibited durable tumor-specific immunity. These findings demonstrate how the use of non-expanded memory CD8+ T cells may enhance ACT immunotherapeutic efficacy. PMID:27011014

  4. Control of Immune Response to Allogeneic Embryonic Stem Cells by CD3 Antibody-Mediated Operational Tolerance Induction.

    PubMed

    Calderon, D; Prot, M; You, S; Marquet, C; Bellamy, V; Bruneval, P; Valette, F; de Almeida, P; Wu, J C; Pucéat, M; Menasché, P; Chatenoud, L

    2016-02-01

    Implantation of embryonic stem cells (ESCs) and their differentiated derivatives into allogeneic hosts triggers an immune response that represents a hurdle to clinical application. We established in autoimmunity and in transplantation that CD3 antibody therapy induces a state of immune tolerance. Promising results have been obtained with CD3 antibodies in the clinic. In this study, we tested whether this strategy can prolong the survival of undifferentiated ESCs and their differentiated derivatives in histoincompatible hosts. Recipients of either mouse ESC-derived embryoid bodies (EBs) or cardiac progenitors received a single short tolerogenic regimen of CD3 antibody. In immunocompetent mice, allogeneic EBs and cardiac progenitors were rejected within 20-25 days. Recipients treated with CD3 antibody showed long-term survival of implanted cardiac progenitors or EBs. In due course, EBs became teratomas, the growth of which was self-limited. Regulatory CD4(+)FoxP3(+) T cells and signaling through the PD1/PDL1 pathway played key roles in the CD3 antibody therapeutic effect. Gene profiling emphasized the importance of TGF-β and the inhibitory T cell coreceptor Tim3 to the observed effect. These results demonstrate that CD3 antibody administered alone promotes prolonged survival of allogeneic ESC derivatives and thus could prove useful for enhancing cell engraftment in the absence of chronic immunosuppression. PMID:26492394

  5. Comparable incidence and severity of cytomegalovirus infections following T cell-depleted allogeneic stem cell transplantation preceded by reduced intensity or myeloablative conditioning.

    PubMed

    Kalpoe, J S; van der Heiden, P L J; Vaessen, N; Claas, E C J; Barge, R M; Kroes, A C M

    2007-07-01

    Reports on infectious complications following reduced intensity conditioning (RIC) before allogeneic stem cell transplantation (allo-SCT) are equivocal. This prospective follow-up study compared the impact of cytomegalovirus (CMV) infections following RIC with fludarabine, ATG and busulphan or conventional myeloablative conditioning (MAC). Forty-eight RIC and 59 MAC patients were enrolled. The occurrence and severity of CMV infections within 100 days following allo-SCT were assessed, using plasma CMV DNA load kinetics. CMV DNAemia was observed in 21 RIC (60%) and in 19 MAC (44%) patients at risk for CMV. The mean CMV DNAemia free survival time was comparable following RIC and MAC: 70 days (95% (confidence interval) CI: 59-80 days) and 77 days (95% CI: 68-86 days), respectively (P=0.24). Parameters indicative for the level of CMV reactivation, including the area under the curve of CMV DNA load over time as well as the onset, the peak values and duration of CMV infection episodes, the numbers and duration of CMV treatment episodes and recurrent infections, were not different in both groups. During follow-up, none of the patients developed CMV disease. RIC with fludarabine, ATG and busulphan demonstrated safety comparable to conventional MAC with regard to frequency and severity of CMV infections within 100 days following T cell-depleted allo-SCT. PMID:17530007

  6. Dissecting memory T cell responses to TB: concerns using adoptive transfer into immunodeficient mice.

    PubMed

    Ancelet, Lindsay; Rich, Fenella J; Delahunt, Brett; Kirman, Joanna R

    2012-09-01

    Several studies have used adoptive transfer of purified T cell subsets into immunodeficient mice to determine the subset of T cells responsible for mediating protection against Mycobacterium tuberculosis. These studies suggested that CD62L(hi) memory CD4(+) T cells from BCG-vaccinated mice are key for protection against tuberculosis. Importantly, we observed that transfer of naïve CD4(+) T cells into Rag1-/- recipients protected against a mycobacterial challenge as well as transfer of BCG-experienced CD4(+) T cells. We found that transfer of total CD4(+) T cells from naïve mice or enriched CD62L(hi)CD4(+) T cells from BCG-vaccinated mice into Rag1-/- recipients induced severe colitis by 3 weeks post cell transfer, whereas transfer of CD62L(lo)CD4(+) T cells from BCG-vaccinated mice did not. Naïve and CD62L(hi)CD4(+) T cells proliferated extensively upon transfer and developed an activated effector phenotype in the lung, even in the absence of infectious challenge. The induction of colitis and systemic cytokine response induced by the transfer and subsequent activation of CD4(+) T cells from naïve mice or CD62L(hi)CD4(+) T cells from BCG-vaccinated mice, into immunodeficient recipients, may heighten their ability to protect against mycobacterial challenge. This raises doubts about the validity of this model to study CD4(+) T cell-mediated protection against tuberculosis. PMID:22738879

  7. Micronutrient supplementation and T-cell mediated immune responses in patients with tuberculosis in Tanzania

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Limited studies exist regarding whether incorporating micronutrient supplements during tuberculosis (TB) treatment may improve cell-mediated immune response. We examine the effect of micronutrient supplementation on lymphocyte proliferation response to mycobacteria or T cell mitogens in a randomize...

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

    SciTech Connect

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

    2013-07-05

    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. - 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.

  9. Cross-validation of IFN-γ Elispot assay for measuring alloreactive memory/effector T cell responses in renal transplant recipients.

    PubMed

    Bestard, O; Crespo, E; Stein, M; Lúcia, M; Roelen, D L; de Vaal, Y J; Hernandez-Fuentes, M P; Chatenoud, L; Wood, K J; Claas, F H; Cruzado, J M; Grinyó, J M; Volk, H D; Reinke, P

    2013-07-01

    Assessment of donor-specific alloreactive memory/effector T cell responses using an IFN-γ Elispot assay has been suggested to be a novel immune-monitoring tool for evaluating the cellular immune risk in renal transplantation. Here, we report the cross-validation data of the IFN-γ Elispot assay performed within different European laboratories taking part of the EU RISET consortium. For this purpose, development of a standard operating procedure (SOP), comparisons of lectures of IFN-γ plates assessing intra- and interlaboratory assay variability of allogeneic or peptide stimuli in both healthy and kidney transplant individuals have been the main objectives. We show that the use of a same SOP and count-settings of the Elispot bioreader allow low coefficient variation between laboratories. Frozen and shipped samples display slightly lower detectable IFN-γ frequencies than fresh samples. Importantly, a close correlation between different laboratories is obtained when measuring high frequencies of antigen-specific primed/memory T cell alloresponses. Interestingly, significant high donor-specific alloreactive T cell responses can be similarly detected among different laboratories in kidney transplant patients displaying histological patterns of acute T cell mediated rejection. In conclusion, assessment of circulating alloreactive memory/effector T cells using an INF-γ Elispot assay can be accurately achieved using the same SOP, Elispot bioreader and experienced technicians in kidney transplantation. PMID:23763435

  10. Differential Effect of MyD88 Signal in Donor T Cells on Graft-versus-Leukemia Effect and Graft-versus-Host Disease after Experimental Allogeneic Stem Cell Transplantation

    PubMed Central

    Lim, Ji-Young; Ryu, Da-Bin; Lee, Sung-Eun; Park, Gyeongsin; Choi, Eun Young; Min, Chang-Ki

    2015-01-01

    Despite the presence of toll like receptor (TLR) expression in conventional TCRαβ T cells, the direct role of TLR signaling via myeloid differentiation factor 88 (MyD88) within T lymphocytes on graft-versus-host disease (GVHD) and graft-versus-leukemia (GVL) effect after allogeneic stem cell transplantation (allo-SCT) remains unknown. In the allo-SCT model of C57BL/6 (H-2b) → B6D2F1 (H-2b/d), recipients received transplants of wild type (WT) T-cell-depleted (TCD) bone marrow (BM) and splenic T cells from either WT or MyD88 deficient (MyD88KO) donors. Host-type (H-2d) P815 mastocytoma or L1210 leukemia cells were injected either subcutaneously or intravenously to generate a GVHD/GVL model. Allogeneic recipients of MyD88KO T cells demonstrated a greater tumor growth without attenuation of GVHD severity. Moreover, GVHD-induced GVL effect, caused by increasing the conditioning intensity was also not observed in the recipients of MyD88KO T cells. In vitro, the absence of MyD88 in T cells resulted in defective cytolytic activity to tumor targets with reduced ability to produce IFN-γ or granzyme B, which are known to critical for the GVL effect. However, donor T cell expansion with effector and memory T-cell differentiation were more enhanced in GVHD hosts of MyD88KO T cells. Recipients of MyD88KO T cells experienced greater expansion of Foxp3- and IL4-expressing T cells with reduced INF-γ producing T cells in the spleen and tumor-draining lymph nodes early after transplantation. Taken together, these results highlight a differential role for MyD88 deficiency on donor T-cells, with decreased GVL effect without attenuation of the GVHD severity after experimental allo-SCT. PMID:26552489

  11. Differential Effect of MyD88 Signal in Donor T Cells on Graft-versus-Leukemia Effect and Graft-versus-Host Disease after Experimental Allogeneic Stem Cell Transplantation.

    PubMed

    Lim, Ji-Young; Ryu, Da-Bin; Lee, Sung-Eun; Park, Gyeongsin; Choi, Eun Young; Min, Chang-Ki

    2015-11-01

    Despite the presence of toll like receptor (TLR) expression in conventional TCRαβ T cells, the direct role of TLR signaling via myeloid differentiation factor 88 (MyD88) within T lymphocytes on graft-versus-host disease (GVHD) and graft-versus-leukemia (GVL) effect after allogeneic stem cell transplantation (allo-SCT) remains unknown. In the allo-SCT model of C57BL/6 (H-2(b)) → B6D2F1 (H-2(b/d)), recipients received transplants of wild type (WT) T-cell-depleted (TCD) bone marrow (BM) and splenic T cells from either WT or MyD88 deficient (MyD88KO) donors. Host-type (H-2(d)) P815 mastocytoma or L1210 leukemia cells were injected either subcutaneously or intravenously to generate a GVHD/GVL model. Allogeneic recipients of MyD88KO T cells demonstrated a greater tumor growth without attenuation of GVHD severity. Moreover, GVHD-induced GVL effect, caused by increasing the conditioning intensity was also not observed in the recipients of MyD88KO T cells. In vitro, the absence of MyD88 in T cells resulted in defective cytolytic activity to tumor targets with reduced ability to produce IFN-γ or granzyme B, which are known to critical for the GVL effect. However, donor T cell expansion with effector and memory T-cell differentiation were more enhanced in GVHD hosts of MyD88KO T cells. Recipients of MyD88KO T cells experienced greater expansion of Foxp3- and IL4-expressing T cells with reduced INF-γ producing T cells in the spleen and tumor-draining lymph nodes early after transplantation. Taken together, these results highlight a differential role for MyD88 deficiency on donor T-cells, with decreased GVL effect without attenuation of the GVHD severity after experimental allo-SCT. PMID:26552489

  12. Alloproliferative responses of purified CD4+ and CD8+ T cells to endothelial cells in the absence of contaminating accessory cells.

    PubMed

    Page, C S; Holloway, N; Smith, H; Yacoub, M; Rose, M L

    1994-06-15

    Human capillary endothelial cells (EC), unlike rodent, constitutively express MHC class II antigens, raising the question of whether they can cause direct stimulation of resting T cells. Although previous reports have demonstrated an alloproliferative response between cultured human EC and resting T lymphocytes, they have not stringently proven the absence of contaminating leukocytes in both stimulator and responder populations. Here, we have quantitated the number of contaminating leukocytes in serially passaged human umbilical vein endothelial cells (HUVEC) and have examined the ability of HUVEC and an EC line (EAhy.926) to cause allostimulation of positively selected CD4+ and CD8+ T cells. Contaminating CD45+ leukocytes were found in primary cultures at a mean level of 0.43 +/- 0.49%; by passages 3 and 4 there were less than 1/10,000 cells. CD4+ and CD8+ T cells were purified by positive selection on antibody-coated Dynabeads and residual DR+ cells were removed by complement-dependent lysis. They were shown to be depleted of monocytes by their failure to proliferate in response to OKT3 and PHA. Nevertheless, the same cells gave an unequivocal response to cytokine-treated, serially passaged HUVEC or EAhy.926 cells. The response of CD4+ but not CD8+ T cells was dependent upon pretreatment of HUVEC or EAhy.926 with human rIFN-gamma. Neither CD4+ nor CD8+ T cells responded to MHC class II-bearing fibroblasts or epithelial cells. The CD8+ T cells that recognized EC did not respond to spleen cells in an MLR. The results confirm that EC, unlike other non-bone-marrow-derived cells, have the ability to provide all the signals necessary for direct stimulation of resting allogeneic T cells. PMID:7912014

  13. Potentiating the antitumour response of CD8(+) T cells by modulating cholesterol metabolism.

    PubMed

    Yang, Wei; Bai, Yibing; Xiong, Ying; Zhang, Jin; Chen, Shuokai; Zheng, Xiaojun; Meng, Xiangbo; Li, Lunyi; Wang, Jing; Xu, Chenguang; Yan, Chengsong; Wang, Lijuan; Chang, Catharine C Y; Chang, Ta-Yuan; Zhang, Ti; Zhou, Penghui; Song, Bao-Liang; Liu, Wanli; Sun, Shao-cong; Liu, Xiaolong; Li, Bo-liang; Xu, Chenqi

    2016-03-31

    CD8(+) T cells have a central role in antitumour immunity, but their activity is suppressed in the tumour microenvironment. Reactivating the cytotoxicity of CD8(+) T cells is of great clinical interest in cancer immunotherapy. Here we report a new mechanism by which the antitumour response of mouse CD8(+) T cells can be potentiated by modulating cholesterol metabolism. Inhibiting cholesterol esterification in T cells by genetic ablation or pharmacological inhibition of ACAT1, a key cholesterol esterification enzyme, led to potentiated effector function and enhanced proliferation of CD8(+) but not CD4(+) T cells. This is due to the increase in the plasma membrane cholesterol level of CD8(+) T cells, which causes enhanced T-cell receptor clustering and signalling as well as more efficient formation of the immunological synapse. ACAT1-deficient CD8(+) T cells were better than wild-type CD8(+) T cells at controlling melanoma growth and metastasis in mice. We used the ACAT inhibitor avasimibe, which was previously tested in clinical trials for treating atherosclerosis and showed a good human safety profile, to treat melanoma in mice and observed a good antitumour effect. A combined therapy of avasimibe plus an anti-PD-1 antibody showed better efficacy than monotherapies in controlling tumour progression. ACAT1, an established target for atherosclerosis, is therefore also a potential target for cancer immunotherapy. PMID:26982734

  14. Potentiating the antitumour response of CD8+ T cells by modulating cholesterol metabolism

    PubMed Central

    Yang, Wei; Bai, Yibing; Xiong, Ying; Zhang, Jin; Chen, Shuokai; Zheng, Xiaojun; Meng, Xiangbo; Li, Lunyi; Wang, Jing; Xu, Chenguang; Yan, Chengsong; Wang, Lijuan; Chang, Catharine C. Y.; Chang, Ta-Yuan; Zhang, Ti; Zhou, Penghui; Song, Bao-Liang; Liu, Wanli; Sun, Shao-cong; Liu, Xiaolong; Li, Bo-liang; Xu, Chenqi

    2016-01-01

    CD8+ T cells have a central role in antitumour immunity, but their activity is suppressed in the tumour microenvironment1–4. Reactivating the cytotoxicity of CD8+ T cells is of great clinical interest in cancer immunotherapy. Here we report a new mechanism by which the antitumour response of mouse CD8+ T cells can be potentiated by modulating cholesterol metabolism. Inhibiting cholesterol esterification in T cells by genetic ablation or pharmacological inhibition of ACAT1, a key cholesterol esterification enzyme5, led to potentiated effector function and enhanced proliferation of CD8+ but not CD4+ T cells. This is due to the increase in the plasma membrane cholesterol level of CD8+ T cells, which causes enhanced T-cell receptor clustering and signalling as well as more efficient formation of the immunological synapse. ACAT1-deficient CD8+ T cells were better than wild-type CD8+ T cells at controlling melanoma growth and metastasis in mice. We used the ACAT inhibitor avasimibe, which was previously tested in clinical trials for treating atherosclerosis and showed a good human safety profile6,7, to treat melanoma in mice and observed a good antitumour effect. A combined therapy of avasimibe plus an anti-PD-1 antibody showed better efficacy than monotherapies in controlling tumour progression. ACAT1, an established target for atherosclerosis, is therefore also a potential target for cancer immunotherapy. PMID:26982734

  15. SV40 large T antigen-specific human T cell memory responses.

    PubMed

    Coleman, Sharon; Gibbs, Allen; Butchart, Eric; Mason, Malcolm D; Jasani, Bharat; Tabi, Zsuzsanna

    2008-08-01

    The continued presence of simian virus 40 (SV40), a monkey polyomavirus, in man is confirmed by the regular detection of SV40-specific antibodies in 5-10% of children who are unlikely to have received contaminated polio-vaccines. The aim of our experiments was to find cellular immunological evidence of SV40 infection in humans by testing memory T cell responses to SV40 large T antigen (Tag). As there is some indication that the virus may be present in malignant pleural mesothelioma (MPM) cells, we analyzed T cell responses in MPM patients and in healthy donors. The frequencies of responding T cells to overlapping Tag peptides were tested by cytokine flow cytometry. CD8+ T cells from 4 of 32 MPM patients responded (above twofold of control) to SV40 Tag peptides, while no positive responses were detected in 12 healthy donors. Within SV40 Tag we identified three 15 amino acid-long immunogenic sequences and one 9 amino acid-long T cell epitope (p138) (138FPSELLSFL146), the latter including a HLA-B7-restriction motif. T cell responses to p138 were SV40-specific as T cells stimulated with p138 did not cross-react with the corresponding sequences of Tag of human polyomaviruses BKV and JCV. Similarly, the relevant BKV and JCV Tag peptides did not generate T cell responses against SV40 TAg p138. Peptide-stimulated T cells also killed SV40 Tag-transfected target cells. This article demonstrates the presence, and provides a detailed analysis, of SV40-specific T cell memory in man. PMID:18551603

  16. Enumeration of Cytotoxic CD8 T Cells Ex Vivo during the Response to Listeria monocytogenes Infection▿

    PubMed Central

    Zaiss, Dietmar M. W.; Sijts, Alice J. A. M.; Mosmann, Tim R.

    2008-01-01

    Cytotoxicity is a key effector function of CD8 T cells. However, what proportion of antigen-specific CD8 T cells in vivo exert cytotoxic activity during a functional CD8 T-cell response to infection still remains unknown. We used the Lysispot assay to directly enumerate cytotoxic CD8 T cells from the spleen ex vivo during the immune response to infection with the intracellular bacterium Listeria monocytogenes. We demonstrate that not all antigen-responsive gamma interferon (IFN-γ)-secreting T cells display cytotoxic activity. Most CD8 T cells detected at early time points of the response were cytotoxic. This percentage continuously declined during both the expansion and contraction phases to about 50% at the peak and to <10% of IFN-γ-producing cells in the memory phase. As described for clonal expansion, this elaboration of a program of differentiation after an initial stimulus was not affected by antigen or CD4 help but, like proliferation, could be influenced by later reinfection. These data indicate that cytotoxic effector function during the response to infection is regulated independently from IFN-γ secretion or expansion or contraction of the overall CD8 T-cell response. PMID:18678661

  17. Correlations in the T-cell response to altered peptide ligands

    NASA Astrophysics Data System (ADS)

    Park, Jeong-Man; Deem, Michael W.

    2004-10-01

    The vertebrate immune system is a wonder of modern evolution. Occasionally, however, correlations within the immune system lead to inappropriate recruitment of pre-existing T-cells against novel viral diseases. We present a random energy theory for the correlations in the naive and memory T-cell immune responses. The nonlinear susceptibility of the random energy model to structural changes captures the correlations in the immune response to mutated antigens. We show how the sequence-level diversity of the T-cell repertoire drives the dynamics of the immune response against mutated viral antigens.

  18. Dectin-1 in the control of Th2-type T cell responses

    PubMed Central

    Upchurch, Katherine; Oh, SangKon; Joo, HyeMee

    2016-01-01

    Dendritic cells (DCs) are major antigen-presenting cells (APCs) that can induce and control host immune responses. DCs express pattern recognition receptors (PRRs), which can translate external and internal triggers into different types of T cell responses. The types of CD4+ T cell responses elicited by DCs (e.g., Th1, Th2, Th17, Th21, Th22 and regulatory T cells (Tregs)) are associated with either host immunity or inflammatory diseases, including allergic diseases and autoimmune diseases. In particular, the pathogenic functions of Th2-type T cells in allergic immune disorders have been well documented, although Th2-type T cell responses are crucial for immunity against certain parasite infections. Recent evidence also indicates that the inflammatory Th2 signatures in cancers, including breast and pancreatic cancers, are highly associated with poor clinical outcomes in patients. It is thus important to find cellular/molecular targets expressed in DCs that control such inflammatory Th2-type T cell responses. In a recent paper published in The Journal of Immunology, we demonstrated that Dectin-1 expressed on the two major human DC subsets, myeloid DCs (mDCs) and plasmacytoid DCs (pDCs), has opposing roles in the control of Th2-type CD4+ T cell responses. Dectin-1 expressed on mDCs decreases Th2-type CD4+ T cell responses, while Dectin-1 expressed on pDCs favors Th2-type CD4+ T cell responses. This finding expands our understanding of the roles of DCs and Dectin-1 expressed on DCs in the pathogenesis of Th2-associated diseases and in host immunity to microbial infections and cancers. PMID:27088111

  19. Receptor Pre-Clustering and T cell Responses: Insights into Molecular Mechanisms

    PubMed Central

    Castro, Mario; van Santen, Hisse M.; Férez, María; Alarcón, Balbino; Lythe, Grant; Molina-París, Carmen

    2014-01-01

    T cell activation, initiated by T cell receptor (TCR) mediated recognition of pathogen-derived peptides presented by major histocompatibility complex class I or II molecules (pMHC), shows exquisite specificity and sensitivity, even though the TCR–pMHC binding interaction is of low affinity. Recent experimental work suggests that TCR pre-clustering may be a mechanism via which T cells can achieve such high sensitivity. The unresolved stoichiometry of the TCR makes TCR–pMHC binding and TCR triggering, an open question. We formulate a mathematical model to characterize the pre-clustering of T cell receptors (TCRs) on the surface of T cells, motivated by the experimentally observed distribution of TCR clusters on the surface of naive and memory T cells. We extend a recently introduced stochastic criterion to compute the timescales of T cell responses, assuming that ligand-induced cross-linked TCR is the minimum signaling unit. We derive an approximate formula for the mean time to signal initiation. Our results show that pre-clustering reduces the mean activation time. However, additional mechanisms favoring the existence of clusters are required to explain the difference between naive and memory T cell responses. We discuss the biological implications of our results, and both the compatibility and complementarity of our approach with other existing mathematical models. PMID:24817867

  20. 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

  1. 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. PMID:27206765

  2. NADPH Oxidase-Derived Superoxide Provides a Third Signal for CD4 T Cell Effector Responses.

    PubMed

    Padgett, Lindsey E; Tse, Hubert M

    2016-09-01

    Originally recognized for their direct induced toxicity as a component of the innate immune response, reactive oxygen species (ROS) can profoundly modulate T cell adaptive immune responses. Efficient T cell activation requires: signal 1, consisting of an antigenic peptide-MHC complex binding with the TCR; signal 2, the interaction of costimulatory molecules on T cells and APCs; and signal 3, the generation of innate immune-derived ROS and proinflammatory cytokines. This third signal, in particular, has proven essential in generating productive and long-lasting immune responses. Our laboratory previously demonstrated profound Ag-specific hyporesponsiveness in the absence of NADPH oxidase-derived superoxide. To further examine the consequences of ROS deficiency on Ag-specific T cell responses, our laboratory generated the OT-II.Ncf1(m1J) mouse, possessing superoxide-deficient T cells recognizing the nominal Ag OVA323-339 In this study, we demonstrate that OT-II.Ncf1(m1J) CD4 T cells displayed a severe reduction in Th1 T cell responses, in addition to blunted IL-12R expression and severely attenuated proinflammatory chemokine ligands. Conversely, IFN-γ synthesis and IL-12R synthesis were rescued by the addition of exogenous superoxide via the paramagnetic superoxide donor potassium dioxide or superoxide-sufficient dendritic cells. Ultimately, these data highlight the importance of NADPH oxidase-derived ROS in providing a third signal for adaptive immune maturation by modulating the IL-12/IL-12R pathway and the novelty of the OT-II.Ncf1(m1J) mouse model to determine the role of redox-dependent signaling on effector responses. Thus, targeting ROS represents a promising therapeutic strategy in dampening Ag-specific T cell responses and T cell-mediated autoimmune diseases, such as type 1 diabetes. PMID:27474077

  3. Natural CD4+ T-Cell Responses against Indoleamine 2,3-Dioxygenase

    PubMed Central

    Munir, Shamaila; Larsen, Stine Kiaer; Iversen, Trine Zeeberg; Donia, Marco; Klausen, Tobias Wirenfeldt; Svane, Inge Marie; Straten, Per thor; Andersen, Mads Hald

    2012-01-01

    Background The enzyme indoleamine 2,3-dioxygenase (IDO) contributes to immune tolerance in a variety of settings. In cancer IDO is expressed within the tumor itself as well as in antigen-presenting cells in tumor-draining lymph nodes, where it endorses the establishment of peripheral immune tolerance to tumor antigens. Recently, we described cytotoxic CD8+ T-cell reactivity towards IDO-derived peptides. Methods and Findings In the present study, we show that CD4+ helper T cells additionally spontaneously recognize IDO. Hence, we scrutinized the vicinity of the previously described HLA-A*0201-restricted IDO-epitope for CD4+ T-cell epitopes. We demonstrated the presence of naturally occurring IDO-specific CD4+ T cells in cancer patients and to a lesser extent in healthy donors by cytokine release ELISPOT. IDO-reactive CD4+ T cells released IFN-γ, TNF-α, as well as IL-17. We confirm HLA class II-restriction by the addition of HLA class II specific blocking antibodies. In addition, we detected a trend between class I- and class II-restricted IDO responses and detected an association between IDO-specific CD4+ T cells and CD8+ CMV-responses. Finally, we could detect IL-10 releasing IDO-reactive CD4+ T cells. Conclusion IDO is spontaneously recognized by HLA class II-restricted, CD4+ T cells in cancer patients and in healthy individuals. IDO-specific T cells may participate in immune-regulatory networks where the activation of pro-inflammatory IDO-specific CD4+ responses may well overcome or delay the immune suppressive actions of the IDO-protein, which are otherwise a consequence of the early expression of IDO in maturing antigen presenting cells. In contrast, IDO-specific regulatory T cells may enhance IDO-mediated immune suppression. PMID:22539948

  4. CD4+ T cell-dependent and CD4+ T cell-independent cytokine-chemokine network changes in the immune responses of HIV-infected individuals.

    PubMed

    Arnold, Kelly B; Szeto, Gregory L; Alter, Galit; Irvine, Darrell J; Lauffenburger, Douglas A

    2015-10-20

    A vital defect in the immune systems of HIV-infected individuals is the loss of CD4(+) T cells, resulting in impaired immune responses. We hypothesized that there were CD4(+) T cell-dependent and CD4(+) T cell-independent alterations in the immune responses of HIV-1(+) individuals. To test this, we analyzed the secretion of cytokines and chemokines from stimulated peripheral blood mononuclear cell (PBMC) populations from HIV(+) donors, healthy donors, and healthy donors with CD4(+) T cells experimentally depleted. Multivariate analyses of 16 cytokines and chemokines at 6 and 72 hours after three stimuli (antibody-coated beads to stimulate T cells and R848 or lipopolysaccharide to stimulate innate immune cells) enabled integrative analysis of secreted profiles. Two major effects in HIV(+) PBMCs were not reproduced upon depletion of CD4(+) T cells in healthy PBMCs: (i) HIV(+) PBMCs maintained T cell-associated secreted profiles after T cell stimulation; (ii) HIV(+) PBMCs showed impaired interferon-γ (IFN-γ) secretion early after innate stimulation. These changes arose from hyperactive T cells and debilitated natural killer (NK) cell, respectively. Modeling and experiments showed that early IFN-γ secretion predicted later differences in secreted profiles in vitro. This effect was recapitulated in healthy PBMCs by blocking the IFN-γ receptor. Thus, we identified a critical deficiency in NK cell responses of HIV-infected individuals, independent of CD4(+) T cell depletion, which directs secreted profiles. Our findings illustrate a broad approach for identifying key disease-associated nodes in a multicellular, multivariate signaling network. PMID:26486173

  5. Modulation of heme oxygenase-1 by metalloporphyrins increases anti-viral T cell responses.

    PubMed

    Bunse, C E; Fortmeier, V; Tischer, S; Zilian, E; Figueiredo, C; Witte, T; Blasczyk, R; Immenschuh, S; Eiz-Vesper, B

    2015-02-01

    Heme oxygenase (HO)-1, the inducible isoform of HO, has immunomodulatory functions and is considered a target for therapeutic interventions. In the present study, we investigated whether modulation of HO-1 might have regulatory effects on in-vitro T cell activation. The study examined whether: (i) HO-1 induction by cobalt-protoporphyrin (CoPP) or inhibition by tin-mesoporphyrin (SnMP) can affect expansion and function of virus-specific T cells, (ii) HO-1 modulation might have a functional effect on other cell populations mediating effects on proliferating T cells [e.g. dendritic cells (DCs), regulatory T cells (T(regs)) and natural killer cells] and (iii) HO-1-modulated anti-viral T cells might be suitable for adoptive immunotherapy. Inhibition of HO-1 via SnMP in cytomegalovirus (CMV)pp65-peptide-pulsed peripheral blood mononuclear cells (PBMCs) led to increased anti-viral T cell activation and the generation of a higher proportion of effector memory T cells (CD45RA(-) CD62L(-)) with increased capability to secrete interferon (IFN)-γ and granzyme B. T(reg) depletion and SnMP exposure increased the number of anti-viral T cells 15-fold. To test the possibility that HO-1 modulation might be clinically applicable in conformity with good manufacturing practice (GMP), SnMP was tested in isolated anti-viral T cells using the cytokine secretion assay. Compared to control, SnMP treatment resulted in higher cell counts and purity without negative impact on quality and effector function [CD107a, IFN-γ and tumour necrosis factor (TNF)-α levels were stable]. These results suggest an important role of HO-1 in the modulation of adaptive immune responses. HO-1 inhibition resulted in markedly more effective generation of functionally active T cells suitable for adoptive T cell therapy. PMID:25196646

  6. Modulation of heme oxygenase-1 by metalloporphyrins increases anti-viral T cell responses

    PubMed Central

    Bunse, C E; Fortmeier, V; Tischer, S; Zilian, E; Figueiredo, C; Witte, T; Blasczyk, R; Immenschuh, S; Eiz-Vesper, B

    2015-01-01

    Heme oxygenase (HO)-1, the inducible isoform of HO, has immunomodulatory functions and is considered a target for therapeutic interventions. In the present study, we investigated whether modulation of HO-1 might have regulatory effects on in-vitro T cell activation. The study examined whether: (i) HO-1 induction by cobalt-protoporphyrin (CoPP) or inhibition by tin-mesoporphyrin (SnMP) can affect expansion and function of virus-specific T cells, (ii) HO-1 modulation might have a functional effect on other cell populations mediating effects on proliferating T cells [e.g. dendritic cells (DCs), regulatory T cells (Tregs) and natural killer cells] and (iii) HO-1-modulated anti-viral T cells might be suitable for adoptive immunotherapy. Inhibition of HO-1 via SnMP in cytomegalovirus (CMV)pp65-peptide-pulsed peripheral blood mononuclear cells (PBMCs) led to increased anti-viral T cell activation and the generation of a higher proportion of effector memory T cells (CD45RA− CD62L−) with increased capability to secrete interferon (IFN)-γ and granzyme B. Treg depletion and SnMP exposure increased the number of anti-viral T cells 15-fold. To test the possibility that HO-1 modulation might be clinically applicable in conformity with good manufacturing practice (GMP), SnMP was tested in isolated anti-viral T cells using the cytokine secretion assay. Compared to control, SnMP treatment resulted in higher cell counts and purity without negative impact on quality and effector function [CD107a, IFN-γ and tumour necrosis factor (TNF)-α levels were stable]. These results suggest an important role of HO-1 in the modulation of adaptive immune responses. HO-1 inhibition resulted in markedly more effective generation of functionally active T cells suitable for adoptive T cell therapy. PMID:25196646

  7. 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

  8. T-cell response relative to genotype and ethnicity during antiviral therapy for chronic hepatitis C.

    PubMed

    Kaplan, David E; Sugimoto, Kazushi; Ikeda, Fusao; Stadanlick, Jason; Valiga, Mary; Shetty, Kirti; Reddy, K Rajender; Chang, Kyong-Mi

    2005-06-01

    Viral genotype and host ethnicity are important predictors of viral clearance during antiviral therapy for chronic hepatitis C virus (HCV) infection. Based on the role of T cells in natural HCV clearance, we hypothesized that T cells may contribute to the genotypic and ethnic difference in treatment outcome. To test this hypothesis, T-cell response to HCV antigens (core, nonstructural NS3/4 and NS5) and control phytohemagglutinin (PHA) was monitored prospectively and was correlated with virological outcome in 41 patients chronically infected with HCV (27 genotype 1, 14 genotype 2 or 3; 19 black persons, 22 white persons) undergoing combined interferon alfa and ribavirin therapy. Interestingly, in patients with genotype 2 or 3 infection, enhanced virological response coincided with a greater T-cell response to HCV NS3/4 antigen at baseline (50% vs. 15%; P = .026) that augmented further during therapy (29% vs. 4%; P = .035) compared with genotype 1-infected patients. However, HCV-specific T-cell response remained weak in genotype 1-infected patients regardless of virological outcome or ethnicity. Furthermore, virological outcome was associated with a suppressed baseline proliferative response to phytohemagglutinin (P < .03) that increased during therapy (P < .003) independent of ethnicity or genotype. In conclusion, HCV-specific T-cell response was associated with HCV genotype but not with therapeutic clearance of HCV infection. The association between treatment outcome and phytohemagglutinin response suggests more global and antigen-nonspecific mechanisms for therapeutic HCV clearance. PMID:15915458

  9. 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.; Dong, Haidong

    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

  10. Litomosoides sigmodontis induces TGF-β receptor responsive, IL-10-producing T cells that suppress bystander T-cell proliferation in mice.

    PubMed

    Hartmann, Wiebke; Schramm, Christoph; Breloer, Minka

    2015-09-01

    Helminth parasites suppress immune responses to prolong their survival within the mammalian host. Thereby not only helminth-specific but also nonhelminth-specific bystander immune responses are suppressed. Here, we use the murine model of Litomosoides sigmodontis infection to elucidate the underlying mechanisms leading to this bystander T-cell suppression. When OT-II T cells specific for the third-party antigen ovalbumin are transferred into helminth-infected mice, these cells respond to antigen-specific stimulation with reduced proliferation compared to activation within non-infected mice. Thus, the presence of parasitic worms in the thoracic cavity translates to suppression of T cells with a different specificity at a different site. By eliminating regulatory receptors, cytokines, and cell populations from this system, we provide evidence for a two-staged process. Parasite products first engage the TGF-β receptor on host-derived T cells that are central to suppression. In a second step, host-derived T cells produce IL-10 and subsequently suppress the adoptively transferred OT-II T cells. Terminal suppression was IL-10-dependant but independent of intrinsic TGF-β receptor- or PD-1-mediated signaling in the suppressed OT-II T cells. Blockade of the same key suppression mediators, i.e. TGF-β- and IL-10 receptor, also ameliorated the suppression of IgG response to bystander antigen vaccination in L. sigmodontis-infected mice. PMID:26138667

  11. Kinetics and Phenotype of Vaccine-Induced CD8+ T-Cell Responses to Toxoplasma gondii▿

    PubMed Central

    Jordan, Kimberly A.; Wilson, Emma H.; Tait, Elia D.; Fox, Barbara A.; Roos, David S.; Bzik, David J.; Dzierszinski, Florence; Hunter, Christopher A.

    2009-01-01

    Multiple studies have established that the ability of CD8+ T cells to act as cytolytic effectors and produce gamma interferon is important in mediating resistance to the intracellular parasite Toxoplasma gondii. To better understand the generation of the antigen-specific CD8+ T-cell responses induced by T. gondii, mice were immunized with replication-deficient parasites that express the model antigen ovalbumin (OVA). Class I tetramers specific for SIINFEKL were used to track the OVA-specific endogenous CD8+ T cells. The peak CD8+ T-cell response was found at day 10 postimmunization, after which the frequency and numbers of antigen-specific cells declined. Unexpectedly, replication-deficient parasites were found to induce antigen-specific cells with faster kinetics than replicating parasites. The generation of optimal numbers of antigen-specific CD8+ effector T cells was found to require CD4+ T-cell help. At 7 days following immunization, antigen-specific cells were found to be CD62Llow, KLRG1+, and CD127low, and they maintained this phenotype for more than 70 days. Antigen-specific CD8+ effector T cells in immunized mice exhibited potent perforin-dependent OVA-specific cytolytic activity in vivo. Perforin-dependent cytolysis appeared to be the major cytolytic mechanism; however, a perforin-independent pathway that was not mediated via Fas-FasL was also detected. This study provides further insight into vaccine-induced cytotoxic T-lymphocyte responses that correlate with protective immunity to T. gondii and identifies a critical role for CD4+ T cells in the generation of protective CD8+ T-cell responses. PMID:19528214

  12. Kinetics and phenotype of vaccine-induced CD8+ T-cell responses to Toxoplasma gondii.

    PubMed

    Jordan, Kimberly A; Wilson, Emma H; Tait, Elia D; Fox, Barbara A; Roos, David S; Bzik, David J; Dzierszinski, Florence; Hunter, Christopher A

    2009-09-01

    Multiple studies have established that the ability of CD8(+) T cells to act as cytolytic effectors and produce gamma interferon is important in mediating resistance to the intracellular parasite Toxoplasma gondii. To better understand the generation of the antigen-specific CD8(+) T-cell responses induced by T. gondii, mice were immunized with replication-deficient parasites that express the model antigen ovalbumin (OVA). Class I tetramers specific for SIINFEKL were used to track the OVA-specific endogenous CD8(+) T cells. The peak CD8(+) T-cell response was found at day 10 postimmunization, after which the frequency and numbers of antigen-specific cells declined. Unexpectedly, replication-deficient parasites were found to induce antigen-specific cells with faster kinetics than replicating parasites. The generation of optimal numbers of antigen-specific CD8(+) effector T cells was found to require CD4(+) T-cell help. At 7 days following immunization, antigen-specific cells were found to be CD62L(low), KLRG1(+), and CD127(low), and they maintained this phenotype for more than 70 days. Antigen-specific CD8(+) effector T cells in immunized mice exhibited potent perforin-dependent OVA-specific cytolytic activity in vivo. Perforin-dependent cytolysis appeared to be the major cytolytic mechanism; however, a perforin-independent pathway that was not mediated via Fas-FasL was also detected. This study provides further insight into vaccine-induced cytotoxic T-lymphocyte responses that correlate with protective immunity to T. gondii and identifies a critical role for CD4(+) T cells in the generation of protective CD8(+) T-cell responses. PMID:19528214

  13. Responses of intraepithelial lymphocytes to T-cell mitogens: a comparison between murine and porcine responses.

    PubMed Central

    Wilson, A D; Stokes, C R; Bourne, F J

    1986-01-01

    Intraepithelial lymphocytes (IEL) were isolated from the small intestine of pigs. They showed a strong blastogenic response to the T-cell mitogens phytohaemagglutinin A (PHA), concanavalin A (Con A) and pokeweed mitogen (PWM); in contrast, mouse IEL responded weakly to these mitogens. The response of pig IEL was age-dependent, reaching adult levels by 9 weeks of age. Early weaning of pigs delayed the onset of this response. The effects of inflammatory mediators on the response of mouse IEL were also examined. PMID:3488265

  14. 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

  15. Epitope specific T-cell responses against influenza A in a healthy population.

    PubMed

    Savic, Miloje; Dembinski, Jennifer L; Kim, Yohan; Tunheim, Gro; Cox, Rebecca J; Oftung, Fredrik; Peters, Bjoern; Mjaaland, Siri

    2016-02-01

    Pre-existing human CD4(+) and CD8(+) T-cell-mediated immunity may be a useful correlate of protection against severe influenza disease. Identification and evaluation of common epitopes recognized by T cells with broad cross-reactivity is therefore important to guide universal influenza vaccine development, and to monitor immunological preparedness against pandemics. We have retrieved an optimal combination of MHC class I and class II restricted epitopes from the Immune Epitope Database (www.iedb.org), by defining a fitness score function depending on prevalence, sequence conservancy and HLA super-type coverage. Optimized libraries of CD4(+) and CD8(+) T-cell epitopes were selected from influenza antigens commonly present in seasonal and pandemic influenza strains from 1934 to 2009. These epitope pools were used to characterize human T-cell responses in healthy donors using interferon-γ ELISPOT assays. Upon stimulation, significant CD4(+) and CD8(+) T-cell responses were induced, primarily recognizing epitopes from the conserved viral core proteins. Furthermore, the CD4(+) and CD8(+) T cells were phenotypically characterized regarding functionality, cytotoxic potential and memory phenotype using flow cytometry. Optimized sets of T-cell peptide epitopes may be a useful tool to monitor the efficacy of clinical trials, the immune status of a population to predict immunological preparedness against pandemics, as well as being candidates for universal influenza vaccines. PMID:26489873

  16. Highly-Immunogenic Virally-Vectored T-cell Vaccines Cannot Overcome Subversion of the T-cell Response by HCV during Chronic Infection.

    PubMed

    Swadling, Leo; Halliday, John; Kelly, Christabel; Brown, Anthony; Capone, Stefania; Ansari, M Azim; Bonsall, David; Richardson, Rachel; Hartnell, Felicity; Collier, Jane; Ammendola, Virginia; Del Sorbo, Mariarosaria; Von Delft, Annette; Traboni, Cinzia; Hill, Adrian V S; Colloca, Stefano; Nicosia, Alfredo; Cortese, Riccardo; Klenerman, Paul; Folgori, Antonella; Barnes, Eleanor

    2016-01-01

    An effective therapeutic vaccine for the treatment of chronic hepatitis C virus (HCV) infection, as an adjunct to newly developed directly-acting antivirals (DAA), or for the prevention of reinfection, would significantly reduce the global burden of disease associated with chronic HCV infection. A recombinant chimpanzee adenoviral (ChAd3) vector and a modified vaccinia Ankara (MVA), encoding the non-structural proteins of HCV (NSmut), used in a heterologous prime/boost regimen induced multi-specific, high-magnitude, durable HCV-specific CD4+ and CD8+ T-cell responses in healthy volunteers, and was more immunogenic than a heterologous Ad regimen. We now assess the immunogenicity of this vaccine regimen in HCV infected patients (including patients with a low viral load suppressed with interferon/ribavirin therapy), determine T-cell cross-reactivity to endogenous virus, and compare immunogenicity with that observed previously in both healthy volunteers and in HCV infected patients vaccinated with the heterologous Ad regimen. Vaccination of HCV infected patients with ChAd3-NSmut/MVA-NSmut was well tolerated. Vaccine-induced HCV-specific T-cell responses were detected in 8/12 patients; however, CD4+ T-cell responses were rarely detected, and the overall magnitude of HCV-specific T-cell responses was markedly reduced when compared to vaccinated healthy volunteers. Furthermore, HCV-specific cells had a distinct partially-functional phenotype (lower expression of activation markers, granzyme B, and TNFα production, weaker in vitro proliferation, and higher Tim3 expression, with comparable Tbet and Eomes expression) compared to healthy volunteers. Robust anti-vector T-cells and antibodies were induced, showing that there is no global defect in immunity. The level of viremia at the time of vaccination did not correlate with the magnitude of the vaccine-induced T-cell response. Full-length, next-generation sequencing of the circulating virus demonstrated that T-cells were

  17. The host response to allogeneic and xenogeneic biological scaffold materials.

    PubMed

    Keane, Timothy J; Badylak, Stephen F

    2015-05-01

    The clinical use of biological scaffold materials has become commonplace. Such scaffolds are composed of extracellular matrix (ECM), or components of ECM, derived from allogeneic or xenogeneic tissues. Such scaffold materials vary widely in their source tissue, processing methods and sterilization methods. The success or failure of an ECM scaffold for a given application is dependent on the host response following implantation; a response that is largely mediated by the innate immune system and which is influenced by a numerous factors, including the processing methods used in the preparation of biological scaffolds. The present paper reviews various aspects of the host response to biological scaffolds and factors that affect this response. In addition, some of the logistical, regulatory and reconstructive implications associated with the use of biological scaffolds are discussed. PMID:24668694

  18. Mesenchymal Stromal Cells from Osteoarthritic Synovium Are a Distinct Population Compared to Their Bone-Marrow Counterparts regarding Surface Marker Distribution and Immunomodulation of Allogeneic CD4+ T-Cell Cultures

    PubMed Central

    Bucur, Florin; Moradi, Babak

    2016-01-01

    Introduction. The participation of an inflammatory joint milieu has been described in osteoarthritis (OA) pathogenesis. Mesenchymal stromal cells (MSCs) play an important role in modulating inflammatory processes. Based on previous studies in an allogeneic T-cell coculture model, we aimed at further determining the role of synovial MSCs in OA pathogenesis. Methods. Bone-marrow (BM) and synovial membrane (SM) MSCs from hip joints of late stage OA patients and CD4+ T-cells from healthy donors were analysed regarding surface marker expression before and after coculture. Proliferation upon CD3/CD28 stimulation and cytokine analyses were compared between MSCs. Results. SM-MSCs differed from BM-MSCs in several surface markers and their osteogenic differentiation potential. Cocultures of both MSCs with CD4+ T-cells resulted in recruitment of CD45RA+ FoxP3+ regulatory T-cells. Upon stimulation, only SM-MSCs suppressed CD4+ T-cell proliferation, while both SM-MSCs and BM-MSCs modified cytokine profiles through suppressing IL-2 and TNF-α as well as increasing IL-6 secretion. Conclusions. Synovial MSCs from OA joints are a unique fraction that can be distinguished from their bone-marrow derived counterparts. Their unique ability to suppress CD3/CD28 induced CD4+ T-cell proliferation makes them a potential target for future therapeutic approaches. PMID:27516777

  19. Mesenchymal Stromal Cells from Osteoarthritic Synovium Are a Distinct Population Compared to Their Bone-Marrow Counterparts regarding Surface Marker Distribution and Immunomodulation of Allogeneic CD4+ T-Cell Cultures.

    PubMed

    Hagmann, Sebastien; Rimmele, Claudia; Bucur, Florin; Dreher, Thomas; Zeifang, Felix; Moradi, Babak; Gotterbarm, Tobias

    2016-01-01

    Introduction. The participation of an inflammatory joint milieu has been described in osteoarthritis (OA) pathogenesis. Mesenchymal stromal cells (MSCs) play an important role in modulating inflammatory processes. Based on previous studies in an allogeneic T-cell coculture model, we aimed at further determining the role of synovial MSCs in OA pathogenesis. Methods. Bone-marrow (BM) and synovial membrane (SM) MSCs from hip joints of late stage OA patients and CD4+ T-cells from healthy donors were analysed regarding surface marker expression before and after coculture. Proliferation upon CD3/CD28 stimulation and cytokine analyses were compared between MSCs. Results. SM-MSCs differed from BM-MSCs in several surface markers and their osteogenic differentiation potential. Cocultures of both MSCs with CD4+ T-cells resulted in recruitment of CD45RA+ FoxP3+ regulatory T-cells. Upon stimulation, only SM-MSCs suppressed CD4+ T-cell proliferation, while both SM-MSCs and BM-MSCs modified cytokine profiles through suppressing IL-2 and TNF-α as well as increasing IL-6 secretion. Conclusions. Synovial MSCs from OA joints are a unique fraction that can be distinguished from their bone-marrow derived counterparts. Their unique ability to suppress CD3/CD28 induced CD4+ T-cell proliferation makes them a potential target for future therapeutic approaches. PMID:27516777

  20. Functional Heterogeneity in CD4(+) T Cell Responses Against a Bacterial Pathogen.

    PubMed

    Milam, Ashley Viehmann; Allen, Paul M

    2015-01-01

    To investigate how CD4(+) T cells function against a bacterial pathogen, we generated a Listeria monocytogenes-specific CD4(+) T cell model. In this system, two TCRtg mouse lines, LLO56 and LLO118, recognize the same immunodominant epitope (LLO190-205) of L. monocytogenes and have identical in vitro responses. However, in vivo LLO56 and LLO118 display vastly different responses during both primary and secondary infection. LLO118 dominates in the primary response and in providing CD8 T cell help. LLO56 predominates in the secondary response. We have also shown that both specific [T cell receptor (TCR)-mediated] and non-specific stimuli (bypassing the TCR) elicit distinct responses from the two transgenics, leading us to conclude that the strength of self-pMHC signaling during development tightly dictates the cell's future response in the periphery. Herein, we review our findings in this transfer system, focusing on the contribution of the immunomodulatory molecule CD5 and the importance of self-interaction in peripheral maintenance of the cell. We also discuss the manner in which individual TCR affinities to foreign and self-pMHC contribute to the outcome of an immune response; our assertion is that there exists a spectrum of possible T cell responses to recognition of cognate antigen during infection, adding immense diversity to the immune system's response to pathogens. PMID:26697015

  1. B cell priming for extrafollicular antibody responses requires Bcl-6 expression by T cells.

    PubMed

    Lee, Sau K; Rigby, Robert J; Zotos, Dimitra; Tsai, Louis M; Kawamoto, Shimpei; Marshall, Jennifer L; Ramiscal, Roybel R; Chan, Tyani D; Gatto, Dominique; Brink, Robert; Yu, Di; Fagarasan, Sidonia; Tarlinton, David M; Cunningham, Adam F; Vinuesa, Carola G

    2011-07-01

    T follicular helper cells (Tfh cells) localize to follicles where they provide growth and selection signals to mutated germinal center (GC) B cells, thus promoting their differentiation into high affinity long-lived plasma cells and memory B cells. T-dependent B cell differentiation also occurs extrafollicularly, giving rise to unmutated plasma cells that are important for early protection against microbial infections. Bcl-6 expression in T cells has been shown to be essential for the formation of Tfh cells and GC B cells, but little is known about its requirement in physiological extrafollicular antibody responses. We use several mouse models in which extrafollicular plasma cells can be unequivocally distinguished from those of GC origin, combined with antigen-specific T and B cells, to show that the absence of T cell-expressed Bcl-6 significantly reduces T-dependent extrafollicular antibody responses. Bcl-6(+) T cells appear at the T-B border soon after T cell priming and before GC formation, and these cells express low amounts of PD-1. Their appearance precedes that of Bcl-6(+) PD-1(hi) T cells, which are found within the GC. IL-21 acts early to promote both follicular and extrafollicular antibody responses. In conclusion, Bcl-6(+) T cells are necessary at B cell priming to form extrafollicular antibody responses, and these pre-GC Tfh cells can be distinguished phenotypically from GC Tfh cells. PMID:21708925

  2. Rapamycin Impairs Antitumor CD8+ T-cell Responses and Vaccine-Induced Tumor Eradication.

    PubMed

    Chaoul, Nada; Fayolle, Catherine; Desrues, Belinda; Oberkampf, Marine; Tang, Alexandre; Ladant, Daniel; Leclerc, Claude

    2015-08-15

    The metabolic sensor mTOR broadly regulates cell growth and division in cancer cells, leading to a significant focus on studies of rapamycin and its analogues as candidate anticancer drugs. However, mTOR inhibitors have failed to produce useful clinical efficacy, potentially because mTOR is also critical in T cells implicated in immunosurveillance. Indeed, recent studies using rapamycin have demonstrated the important role of mTOR in differentiation and induction of the CD8+ memory in T-cell responses associated with antitumor properties. In this study, we demonstrate that rapamycin harms antitumor immune responses mediated by T cells in the setting of cancer vaccine therapy. Specifically, we analyzed how rapamycin affects the antitumor efficacy of a human papilloma virus E7 peptide vaccine (CyaA-E7) capable of eradicating tumors in the TC-1 mouse model of cervical cancer. In animals vaccinated with CyaA-E7, rapamycin administration completely abolished recruitment of CD8+ T cells into TC-1 tumors along with the ability of the vaccine to reduce infiltration of T regulatory cells and myeloid-derived suppressor cells. Moreover, rapamycin completely abolished vaccine-induced cytotoxic T-cell responses and therapeutic activity. Taken together, our results demonstrate the powerful effects of mTOR inhibition in abolishing T-cell-mediated antitumor immune responses essential for the therapeutic efficacy of cancer vaccines. PMID:26122844

  3. Regulatory T Cell Infusion Can Enhance Memory T Cell and Alloantibody Responses in Lymphodepleted Nonhuman Primate Heart Allograft Recipients.

    PubMed

    Ezzelarab, M B; Zhang, H; Guo, H; Lu, L; Zahorchak, A F; Wiseman, R W; Nalesnik, M A; Bhama, J K; Cooper, D K C; Thomson, A W

    2016-07-01

    The ability of regulatory T cells (Treg) to prolong allograft survival and promote transplant tolerance in lymphodepleted rodents is well established. Few studies, however, have addressed the therapeutic potential of adoptively transferred, CD4(+) CD25(+) CD127(-) Foxp3(+) (Treg) in clinically relevant large animal models. We infused ex vivo-expanded, functionally stable, nonselected Treg (up to a maximum cumulative dose of 1.87 billion cells) into antithymocyte globulin-lymphodepleted, MHC-mismatched cynomolgus monkey heart graft recipients before homeostatic recovery of effector T cells. The monkeys also received tacrolimus, anti-interleukin-6 receptor monoclonal antibodies and tapered rapamycin maintenance therapy. Treg administration in single or multiple doses during the early postsurgical period (up to 1 month posttransplantation), when host T cells were profoundly depleted, resulted in inferior graft function compared with controls. This was accompanied by increased incidences of effector memory T cells, enhanced interferon-γ production by host CD8(+) T cells, elevated levels of proinflammatory cytokines, and antidonor alloantibodies. The findings caution against infusion of Treg during the early posttransplantation period after lymphodepletion. Despite marked but transient increases in Treg relative to endogenous effector T cells and use of reputed "Treg-friendly" agents, the host environment/immune effector mechanisms instigated under these conditions can perturb rather than favor the potential therapeutic efficacy of adoptively transferred Treg. PMID:26700196

  4. Clonal analysis of the T-cell response to in vivo expressed Mycobacterium tuberculosis protein Rv2034, using a CD154 expression based T-cell cloning method.

    PubMed

    Commandeur, Susanna; Coppola, Mariateresa; Dijkman, Karin; Friggen, Annemieke H; van Meijgaarden, Krista E; van den Eeden, Susan J F; Wilson, Louis; van der Ploeg-van Schip, Jolien J; Franken, Kees L M C; Geluk, Annemieke; Ottenhoff, Tom H M

    2014-01-01

    Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), remains a leading cause of death worldwide. A better understanding of the role of CD4+ and CD8+ T cells, which are both important to TB protection, is essential to unravel the mechanisms of protection and to identify the key antigens seen by these T cells. We have recently identified a set of in vivo expressed Mtb genes (IVE-TB) which is expressed during in vivo pulmonary infection in mice, and shown that their encoded antigens are potently recognized by polyclonal T cells from tuberculin skin test-positive, in vitro ESAT-6/CFP10-responsive individuals. Here we have cloned T cells specific for one of these newly identified in vivo expressed Mtb (IVE-TB) antigens, Rv2034. T cells were enriched based on the expression of CD154 (CD40L), which represents a new method for selecting antigen-specific (low frequency) T cells independent of their specific function. An Rv2034-specific CD4+ T-cell clone expressed the Th1 markers T-bet, IFN-γ, TNF-α, IL-2 and the cytotoxicity related markers granzyme B and CD107a as measured by flow cytometry. The clone specifically recognized Rv2034 protein, Rv2034 peptide p81-100 and Mtb lysate. Remarkably, while the recognition of the dominant p81-100 epitope was HLA-DR restricted, the T-cell clone also recognized a neighboring epitope (p88-107) in an HLA-DR- as well as HLA-DQ1-restricted fashion. Importantly, the T-cell clone was able to inhibit Mtb outgrowth from infected monocytes significantly. The characterization of the polyfunctional and Mtb inhibitory T-cell response to IVE-TB Rv2034 at the clonal level provides detailed further insights into the potential of IVE-TB antigens as new vaccine candidate antigens in TB. Our new approach allowed the identification of T-cell subsets that likely play a significant role in controlling Mtb infection, and can be applied to the analysis of T-cell responses in patient populations. PMID:24905579

  5. Clonal Analysis of the T-Cell Response to In Vivo Expressed Mycobacterium tuberculosis Protein Rv2034, Using a CD154 Expression Based T-Cell Cloning Method

    PubMed Central

    Commandeur, Susanna; Coppola, Mariateresa; Dijkman, Karin; Friggen, Annemieke H.; van Meijgaarden, Krista E.; van den Eeden, Susan J. F.; Wilson, Louis; van der Ploeg-van Schip, Jolien J.; Franken, Kees L. M. C.; Geluk, Annemieke; Ottenhoff, Tom H. M.

    2014-01-01

    Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), remains a leading cause of death worldwide. A better understanding of the role of CD4+ and CD8+ T cells, which are both important to TB protection, is essential to unravel the mechanisms of protection and to identify the key antigens seen by these T cells. We have recently identified a set of in vivo expressed Mtb genes (IVE-TB) which is expressed during in vivo pulmonary infection in mice, and shown that their encoded antigens are potently recognized by polyclonal T cells from tuberculin skin test-positive, in vitro ESAT-6/CFP10-responsive individuals. Here we have cloned T cells specific for one of these newly identified in vivo expressed Mtb (IVE-TB) antigens, Rv2034. T cells were enriched based on the expression of CD154 (CD40L), which represents a new method for selecting antigen-specific (low frequency) T cells independent of their specific function. An Rv2034-specific CD4+ T-cell clone expressed the Th1 markers T-bet, IFN-γ, TNF-α, IL-2 and the cytotoxicity related markers granzyme B and CD107a as measured by flow cytometry. The clone specifically recognized Rv2034 protein, Rv2034 peptide p81–100 and Mtb lysate. Remarkably, while the recognition of the dominant p81–100 epitope was HLA-DR restricted, the T-cell clone also recognized a neighboring epitope (p88–107) in an HLA-DR- as well as HLA-DQ1-restricted fashion. Importantly, the T-cell clone was able to inhibit Mtb outgrowth from infected monocytes significantly. The characterization of the polyfunctional and Mtb inhibitory T-cell response to IVE-TB Rv2034 at the clonal level provides detailed further insights into the potential of IVE-TB antigens as new vaccine candidate antigens in TB. Our new approach allowed the identification of T-cell subsets that likely play a significant role in controlling Mtb infection, and can be applied to the analysis of T-cell responses in patient populations. PMID:24905579

  6. Naïve T Cell Homeostasis Regulated by Stress Responses and TCR Signaling

    PubMed Central

    Kamimura, Daisuke; Atsumi, Toru; Stofkova, Andrea; Nishikawa, Naoki; Ohki, Takuto; Suzuki, Hironao; Katsunuma, Kokichi; Jiang, Jing-jing; Bando, Hidenori; Meng, Jie; Sabharwal, Lavannya; Ogura, Hideki; Hirano, Toshio; Arima, Yasunobu; Murakami, Masaaki

    2015-01-01

    The survival of naïve T cells is believed to require signals from TCR–pMHC interactions and cytokines such as IL-7. In contrast, signals that negatively impact naïve T cell survival are less understood. We conducted a forward genetic screening of mice and found a mutant mouse line with reduced number of naïve T cells (T-Red mice). T-Red mice have a point mutation in the Kdelr1 gene, and their naïve T cells show enhanced integrated stress response (ISR), which eventually induces their apoptosis. Therefore, naïve T cells require a KDEL receptor-mediated mechanism that efficiently relieves cellular stress for their survival in vivo. Interestingly, naïve T cells expressing TCR with higher affinity/avidity to self-antigens survive in T-Red mice, suggesting the possible link between TCR-mediated survival and ISR-induced apoptosis. In this article, we discuss the regulation of naïve T cell homeostasis, keeping special attention on the ISR and TCR signal. PMID:26734005

  7. Primary proliferative and cytotoxic T-cell responses to HIV induced in vitro by human dendritic cells.

    PubMed Central

    Macatonia, S E; Patterson, S; Knight, S C

    1991-01-01

    In earlier studies, primary proliferative and cytotoxic T-cell (CTL) responses to influenza virus were produced in vitro by using mouse dendritic cells (DC) pulsed with virus or viral peptide as the stimulus for syngeneic T cells in 20-microliters hanging-drop cultures. We have now adapted this system for producing primary responses with cells from non-immune donors to produce primary proliferative and CTL responses to human immunodeficiency virus I (HIV) and to HIV peptides in vitro using cells from normal human peripheral blood. All donors in this study were laboratory personnel with no history of HIV infection. DC enriched from peripheral blood were exposed to HIV in vitro and small numbers were added to T lymphocytes in 20-microliters hanging drops. Proliferative responses to virus-infected DC were obtained after 3 days in culture. After 6 days, CTL were obtained that killed virus-infected autologous--but not allogeneic--phytohaemagglutinin (PHA)-stimulated blast cells. Proliferative and CTL responses were obtained using cells from 14 random donors expressing a spectrum of major histocompatibility complex (MHC) types but the CTL, once produced, showed killing restricted by the MHC class I type. Treatment of cultures with monoclonal antibody (mAb) to CD4-positive cells at the beginning of culture blocked the development of both proliferative and CTL responses, but treatment after 5 days had no effect on the CTL activity. Treatment with MCA to CD8-positive cells at the beginning of culture did not block proliferation significantly, but treatment either before or after the 5-day culture period blocked CTL responses. Collaboration between proliferating CD4-positive cells and CD8-positive cells may thus be required to produce CTL of the CD8 phenotype. DC exposed to HIV also produced CTL that killed autologous blast cells pulsed with gp120 envelope glycoprotein. However, DC infected with whole virus did not produce CTL that lysed target cells pulsed with a synthetic

  8. Invariant NKT cells regulate the CD8 T cell response during Theiler's virus infection.

    PubMed

    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 1250 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

  9. The Use of Fluorescent Target Arrays for Assessment of T Cell Responses In vivo

    PubMed Central

    Quah, Benjamin J. C.; Wijesundara, Danushka K.; Ranasinghe, Charani; Parish, Christopher R.

    2014-01-01

    The ability to monitor T cell responses in vivo is important for the development of our understanding of the immune response and the design of immunotherapies. Here we describe the use of fluorescent target array (FTA) technology, which utilizes vital dyes such as carboxyfluorescein succinimidyl ester (CFSE), violet laser excitable dyes (CellTrace Violet: CTV) and red laser excitable dyes (Cell Proliferation Dye eFluor 670: CPD) to combinatorially label mouse lymphocytes into >250 discernable fluorescent cell clusters. Cell clusters within these FTAs can be pulsed with major histocompatibility (MHC) class-I and MHC class-II binding peptides and thereby act as target cells for CD8+ and CD4+ T cells, respectively. These FTA cells remain viable and fully functional, and can therefore be administered into mice to allow assessment of CD8+ T cell-mediated killing of FTA target cells and CD4+ T cell-meditated help of FTA B cell target cells in real time in vivo by flow cytometry. Since >250 target cells can be assessed at once, the technique allows the monitoring of T cell responses against several antigen epitopes at several concentrations and in multiple replicates. As such, the technique can measure T cell responses at both a quantitative (e.g. the cumulative magnitude of the response) and a qualitative (e.g. functional avidity and epitope-cross reactivity of the response) level. Herein, we describe how these FTAs are constructed and give an example of how they can be applied to assess T cell responses induced by a recombinant pox virus vaccine. PMID:24998253

  10. Insights into the Relationship between Toll Like Receptors and Gamma Delta T Cell Responses

    PubMed Central

    Dar, Asif Amin; Patil, Rushikesh Sudam; Chiplunkar, Shubhada Vivek

    2014-01-01

    The tumor microenvironment is an important aspect of cancer biology that contributes to tumor initiation, tumor progression and responses to therapy. The composition and characteristics of the tumor microenvironment vary widely and are important in determining the anti-tumor immune response. Successful immunization requires activation of both innate and adaptive immunity. Generally, immune system is compromised in patients with cancer due to immune suppression, loss of tumor antigen expression and dysfunction of antigen presenting cells (APC). Thus, therapeutic immunization leading to cancer regression remains a significant challenge. Certain cells of the immune system, including dendritic cells (DCs) and gamma delta (γδ) T cells are capable of driving potent anti-tumor responses. The property of MHC-unrestricted cytotoxicity, high potential of cytokine release, tissue tropism and early activation in infections and malignant disease makes γδ T cells as an emerging candidate for immunotherapy. Various strategies are being developed to enhance anti-tumor immune responses of γδ T cells and DCs one of them is the use of novel adjuvants like toll like receptors (TLR) agonists, which enhance γδ T cell function directly or through DC activation, which has ability to prime γδ T cells. TLR agonists are being used clinically either alone or in combination with tumor antigens and has shown initial success in both enhancing immune responses and eliciting anti-tumor activity. TLR activated γδ T cells and DCs nurture each other’s activation. This provides a potent base for first line of defense and manipulation of the adaptive response against pathogens and cancer. The available data provides a strong rationale for initiating combinatorial therapy for the treatment of diseases and this review will summarize the application of adjuvants (TLRs) for boosting immune response of γδ T cells to treat cancer and infectious diseases and their use in combinatorial therapy

  11. Human T cell responses to Japanese encephalitis virus in health and disease.

    PubMed

    Turtle, Lance; Bali, Tanushka; Buxton, Gemma; Chib, Savita; Chan, Sajesh; Soni, Mohammed; Hussain, Mohammed; Isenman, Heather; Fadnis, Prachi; Venkataswamy, Manjunatha M; Satishkumar, Vishali; Lewthwaite, Penny; Kurioka, Ayako; Krishna, Srinivasa; Shankar, M Veera; Ahmed, Riyaz; Begum, Ashia; Ravi, Vasanthapuram; Desai, Anita; Yoksan, Sutee; Fernandez, Stefan; Willberg, Christian B; Kloverpris, Henrik N; Conlon, Christopher; Klenerman, Paul; Satchidanandam, Vijaya; Solomon, Tom

    2016-06-27

    Japanese encephalitis (JE) virus (JEV) is an important cause of encephalitis in children of South and Southeast Asia. However, the majority of individuals exposed to JEV only develop mild symptoms associated with long-lasting adaptive immunity. The related flavivirus dengue virus (DENV) cocirculates in many JEV-endemic areas, and clinical data suggest cross-protection between DENV and JEV. To address the role of T cell responses in protection against JEV, we conducted the first full-breadth analysis of the human memory T cell response using a synthetic peptide library. Ex vivo interferon-γ (IFN-γ) responses to JEV in healthy JEV-exposed donors were mostly CD8(+) and targeted nonstructural (NS) proteins, whereas IFN-γ responses in recovered JE patients were mostly CD4(+) and targeted structural proteins and the secreted protein NS1. Among patients, a high quality, polyfunctional CD4(+) T cell response was associated with complete recovery from JE. T cell responses from healthy donors showed a high degree of cross-reactivity to DENV that was less apparent in recovered JE patients despite equal exposure. These data reveal divergent functional CD4(+) and CD8(+) T cell responses linked to different clinical outcomes of JEV infection, associated with distinct targeting and broad flavivirus cross-reactivity including epitopes from DENV, West Nile, and Zika virus. PMID:27242166

  12. Immune Modulation of the T Cell Response in Asthma through Wnt10b.

    PubMed

    Trischler, Jordis; Shiomi, Takayuki; Turner, Damian L; Sklepkiewicz, Piotr L; Goldklang, Monica P; Tanaka, Kenji F; Xu, Ming; Farber, Donna L; D'Armiento, Jeanine M

    2016-04-01

    Asthma is a chronic inflammatory disease, which is characterized by activation of CD4(+) T helper 2 cells orchestrating an allergic airway response. Whereas the role of Wnt family members in regulating T cell maintenance and maturation is established, their contribution to T cell activation in allergic asthma is not known. We hypothesized that Wnt10b plays a role in the modulation of the allergic airway response and affects T cell activation and polarization. Using an in vivo house dust mite asthma model, Wnt10b-deficient (Wnt10b(-/-)) mice were allergen-sensitized and inflammation, as well as T cell activation, was studied in vivo and in vitro. Wnt10b(-/-) mice exhibited an augmented inflammatory phenotype with an increase in eosinophils in the bronchoalveolar lavage and IL-4 and IL-13 in the lungs when compared with wild-type mice. In vitro studies confirmed an increased T helper type 2 polarization and increased T cell activation of Wnt10b(-/-) cells. Accordingly, the percentage of naive T cells was elevated by the addition of recombinant Wnt10b protein. Finally, Wnt10b(-/-) mice exhibited an increase in the percentage of effector T cells in the lungs after house dust mite sensitization, which indicated a heightened activation state, measured by an increased percentage of CD69(hi)CD11a(hi) cells. These findings suggest that Wnt10b plays an important role in regulating asthmatic airway inflammation through modification of the T cell response and is a prospective target in the disease process. PMID:26436894

  13. Costimulation Endows Immunotherapeutic CD8 T Cells with IL-36 Responsiveness during Aerobic Glycolysis.

    PubMed

    Tsurutani, Naomi; Mittal, Payal; St Rose, Marie-Clare; Ngoi, Soo Mun; Svedova, Julia; Menoret, Antoine; Treadway, Forrest B; Laubenbacher, Reinhard; Suárez-Ramírez, Jenny E; Cauley, Linda S; Adler, Adam J; Vella, Anthony T

    2016-01-01

    CD134- and CD137-primed CD8 T cells mount powerful effector responses upon recall, but even without recall these dual-costimulated T cells respond to signal 3 cytokines such as IL-12. We searched for alternative signal 3 receptor pathways and found the IL-1 family member IL-36R. Although IL-36 alone did not stimulate effector CD8 T cells, in combination with IL-12, or more surprisingly IL-2, it induced striking and rapid TCR-independent IFN-γ synthesis. To understand how signal 3 responses functioned in dual-costimulated T cells we showed that IL-2 induced IL-36R gene expression in a JAK/STAT-dependent manner. These data help delineate a sequential stimulation process where IL-2 conditioning must precede IL-36 for IFN-γ synthesis. Importantly, this responsive state was transient and functioned only in effector T cells capable of aerobic glycolysis. Specifically, as the effector T cells metabolized glucose and consumed O2, they also retained potential to respond through IL-36R. This suggests that T cells use innate receptor pathways such as the IL-36R/axis when programmed for aerobic glycolysis. To explore a function for IL-36R in vivo, we showed that dual costimulation therapy reduced B16 melanoma tumor growth while increasing IL-36R gene expression. In summary, cytokine therapy to eliminate tumors may target effector T cells, even outside of TCR specificity, as long as the effectors are in the correct metabolic state. PMID:26573834

  14. Oligoclonal CD4+ T Cells Promote Host Memory Immune Responses to Zwitterionic Polysaccharide of Streptococcus pneumoniae▿

    PubMed Central

    Groneck, Laura; Schrama, David; Fabri, Mario; Stephen, Tom Li; Harms, Fabian; Meemboor, Sonja; Hafke, Helena; Bessler, Martina; Becker, Jürgen C.; Kalka-Moll, Wiltrud M.

    2009-01-01

    Zwitterionic polysaccharides of the normal flora bacteria represent a novel class of antigens in that they correct systemic CD4+ T-cell deficiencies and direct lymphoid organogenesis during colonization of the host. Presentation of these polysaccharides to CD4+ T cells depends on major histocompatibility complex class II- and DM-dependent retrograde transport from lysosomes to the cell surface. Yet the phenotype and clonality of the immune response to the polysaccharide in the mature host immune system have not been studied. Using the zwitterionic capsular polysaccharide Sp1 of Streptococcus pneumoniae, a transient member of the bacterial flora, in an experimental mouse model of cellular immunity, we demonstrated the accumulation of TH1- and TH17-polarized CD4+ CD44high CD62low CD25− memory T cells. Subcutaneous immunization with Sp1 resulted in an increase of serum immunoglobulin G (IgG), predominantly of the IgG1 subclass, and suggested the presence of a humoral memory response to the polysaccharide. CD4+ T cells stimulated with polysaccharide in vitro and in vivo showed a nonrestricted pattern for the T-cell receptor (TCR) β-chain variable region, as demonstrated by semiquantitative reverse transcription-PCR and flow cytometry. Clonotype mapping of in vivo and in vitro polysaccharide-activated CD4+ T cells revealed clonotypic TCR transcripts. Taken together, the data show the induction of clonal expansion of CD4+ T cells by polysaccharides of commensal bacteria. Cellular and humoral memory host responses imply the ability of these polysaccharides to mediate the expansion of T cells via recognition within the CDR3 region of the TCR. PMID:19546196

  15. Lipoproteins are Major Targets of the Polyclonal Human T-cell Response to M. tuberculosis1

    PubMed Central

    Seshadri, Chetan; Turner, Marie T.; Lewinsohn, David M.; Moody, D. Branch; Van Rhijn, Ildiko

    2012-01-01

    Most vaccines and basic studies of T cell epitopes in M. tuberculosis emphasize water soluble proteins that are secreted into the extracellular space and presented in the context of MHC Class II. Much less is known about the role of antigens retained within the cell wall. We used polyclonal T cells from infected humans to probe for responses to immunodominant antigens in the M. tuberculosis cell wall. We found that the magnitude of response to secreted or cell wall intrinsic compounds was similar among healthy controls, patients with latent tuberculosis, and patients with active tuberculosis. Individual responses to secreted antigens and cell wall extract were strongly correlated (r2=0.495, p=0.001), suggesting that T cells responding to cell wall and secreted antigens are present at similar frequency. Surprisingly, T cell stimulatory factors intrinsic to the cell wall partition into organic solvents; however, these responses are not explained by CD1-mediated presentation of lipids. Instead, we find that molecules soluble in organic solvents are dependent upon MHC Class II and recognized by IFN-γ secreting CD4+ T cells. We reasoned that MHC Class II dependent antigens extracting into lipid mixtures might be found among triacylated lipoproteins present in mycobacteria. We used M. tuberculosis lacking prolipoprotein signal peptidase A (lspA), an enzyme required for lipoprotein synthesis, to demonstrate loss of polyclonal T cell responses. Our results demonstrate the use of bacterial genetics to identify lipoproteins as an unexpected and immunodominant class of cell wall-associated antigens targeted by the polyclonal human T cell response to M. tuberculosis. PMID:23197260

  16. CD4+ T cell responses to self- and mutated p53 determinants during tumorigenesis in mice.

    PubMed

    Fedoseyeva, E V; Boisgérault, F; Anosova, N G; Wollish, W S; Arlotta, P; Jensen, P E; Ono, S J; Benichou, G

    2000-06-01

    We analyzed CD4+ T helper responses to wild-type (wt) and mutated (mut) p53 protein in normal and tumor-bearing mice. In normal mice, we observed that although some self-p53 determinants induced negative selection of p53-reactive CD4+ T cells, other p53 determinants (cryptic) were immunogenic. Next, BALB/c mice were inoculated with J774 syngeneic tumor cell line expressing mut p53. BALB/c tumor-bearing mice mounted potent CD4+ T cell responses to two formerly cryptic peptides on self-p53. This response was characterized by massive production of IL-5, a Th2-type lymphokine. Interestingly, we found that T cell response was induced by different p53 peptides depending upon the stage of cancer. Mut p53 gene was shown to contain a single mutation resulting in the substitution of a tyrosine by a histidine at position 231 of the protein. Two peptides corresponding to wt and mutated sequences of this region were synthesized. Both peptides bound to the MHC class II-presenting molecule (Ed) with similar affinities. However, only mut p53.225-239 induced T cell responses in normal BALB/c mice, a result strongly suggesting that high-affinity wt p53.225-239 autoreactive T cells had been eliminated in these mice. Surprisingly, CD4+ T cell responses to both mut and wt p53.225-239 peptides were recorded in J774 tumor-bearing mice, a phenomenon attributed to the recruitment of low-avidity p53.225-239 self-reactive T cells. PMID:10820239

  17. 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

  18. Gamma delta T cells recognize haptens and mount a hapten-specific response

    PubMed Central

    Zeng, Xun; Meyer, Christina; Wei, Yu-Ling; Chien, Yueh-hsiu

    2014-01-01

    The ability to recognize small organic molecules and chemical modifications of host molecules is an essential capability of the adaptive immune system, which until now was thought to be mediated mainly by B cell antigen receptors. Here we report that small molecules, such as cyanine 3 (Cy3), a synthetic fluorescent molecule, and 4-hydroxy-3-nitrophenylacetyl (NP), one of the most noted haptens, are γδ T cell antigens, recognized directly by specific γδ TCRs. Immunization with Cy3 conjugates induces a rapid Cy3-specific γδ T cell IL-17 response. These results expand the role of small molecules and chemical modifications in immunity and underscore the role of γδ T cells as unique adaptive immune cells that couple B cell-like antigen recognition capability with T cell effector function. DOI: http://dx.doi.org/10.7554/eLife.03609.001 PMID:25255099

  19. Overcoming Memory T cell Responses for Induction of Delayed Tolerance in Nonhuman Primates

    PubMed Central

    Yamada, Y.; Boskovic, S.; Aoyama, A.; Murakami, T.; Putheti, P.; Smith, R. N.; Ochiai, T.; Nadazdin, O.; Koyama, I.; Boenisch, O.; Najafian, N.; Bhasin, M.K.; Colvin, R. B.; Madsen, J. C.; Strom, T. B.; Sachs, D. H.; Benichou, G.; Cosimi, A. B.; Kawai, T.

    2011-01-01

    The presence of alloreactive memory T cells is a major barrier for induction of tolerance in primates. In theory, delaying conditioning for tolerance induction until after organ transplantation could further decrease the efficacy of the regimen, since pre-existing alloreactive memory T cells might be stimulated by the transplanted organ. Here, we show that such “delayed tolerance” can be induced in nonhuman primates through the mixed chimerism approach, if specific modifications to overcome/avoid donor-specific memory T cell responses are provided. These modifications include adequate depletion of CD8+ memory T cells and timing of donor bone marrow administration to minimize levels of pro-inflammatory cytokines. Using this modified approach, mixed chimerism was induced successfully in 11 of 13 recipients of previously placed renal allografts and long-term survival without immunosuppression could be achieved in at least 6 of these 11 animals. PMID:22053723

  20. A mathematical model for a T cell fate decision algorithm during immune response.

    PubMed

    Arias, Clemente F; Herrero, Miguel A; Acosta, Francisco J; Fernandez-Arias, Cristina

    2014-05-21

    We formulate and analyze an algorithm of cell fate decision that describes the way in which division vs. apoptosis choices are made by individual T cells during an infection. Such model involves a minimal number of known biochemical mechanisms: it basically relies on the interplay between cell division and cell death inhibitors on one hand, and membrane receptors on the other. In spite of its simplicity, the proposed decision algorithm is able to account for some significant facts in immune response. At the individual level, the existence of T cells that continue to replicate in the absence of antigen and the possible occurrence of T cell apoptosis in the presence of antigen are predicted by the model. Moreover, the latter is shown to yield an emergent collective behavior, the observed delay in clonal contraction with respect to the end of antigen stimulation, which is shown to arise just from individual T cell decisions made according to the proposed mechanism. PMID:24512913

  1. A diametric role for OX40 in the response of effector/memory CD4+ T cells and regulatory T cells to alloantigen

    PubMed Central

    Kinnear, Gillian; Wood, Kathryn J.; Fallah-Arani, Farnaz; Jones, Nick D.

    2013-01-01

    OX40 is a member of the TNFR superfamily that has potent costimulatory properties. Although the impact of blockade of the OX40-OX40L pathway has been well documented in models of autoimmune disease, its effect on the rejection of allografts is less well defined. Here we show that the alloantigen-mediated activation of naïve and memory CD4+ T cells results in the induction of OX40 expression and that blockade of OX40-OX40L interactions prevents skin allograft rejection mediated by either subset of T cells. Moreover, a blocking anti-OX40 was found to have no effect on the activation and proliferation of T cells, but rather effector T cells failed to accumulate in peripheral lymph nodes and subsequently migrate to skin allografts. This was found to be the result of an enhanced degree of cell death amongst proliferating effector cells. In clear contrast, blockade of OX40-OX40L interactions at the time of exposure to alloantigen enhanced the ability of regulatory T cells to suppress T cell responses to alloantigen by supporting rather than diminishing regulatory T cell survival. These data show that OX40-OX40L signalling contributes to the evolution of the adaptive immune response to an allograft via the differential control of alloreactive effector and regulatory T cell survival. Moreover, these data serve to further highlight OX40 and OX40L as therapeutic targets to assist the induction of tolerance to allografts and self-antigens. PMID:23817421

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

    SciTech Connect

    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 highly 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.

  3. Adoptive immunotherapy with unselected or EBV-specific T cells for biopsy-proven EBV+ lymphomas after allogeneic hematopoietic cell transplantation

    PubMed Central

    Doubrovina, Ekaterina; Oflaz-Sozmen, Banu; Prockop, Susan E.; Kernan, Nancy A.; Abramson, Sara; Teruya-Feldstein, Julie; Hedvat, Cyrus; Chou, Joanne F.; Heller, Glenn; Barker, Juliet N.; Boulad, Farid; Castro-Malaspina, Hugo; George, Diane; Jakubowski, Ann; Koehne, Guenther; Papadopoulos, Esperanza B.; Scaradavou, Andromachi; Small, Trudy N.; Khalaf, Ramzi; Young, James W.

    2012-01-01

    We evaluated HLA-compatible donor leukocyte infusions (DLIs) and HLA-compatible or HLA-disparate EBV-specific T cells (EBV-CTLs) in 49 hematopoietic cell transplantation recipients with biopsy-proven EBV-lymphoproliferative disease (EBV-LPD). DLIs and EBV-CTLs each induced durable complete or partial remissions in 73% and 68% of treated patients including 74% and 72% of patients surviving ≥ 8 days after infusion, respectively. Reversible acute GVHD occurred in recipients of DLIs (17%) but not EBV-CTLs. The probability of complete response was significantly lower among patients with multiorgan involvement. In responders, DLIs and EBV-CTLs regularly induced exponential increases in EBV-specific CTL precursor (EBV-CTLp) frequencies within 7-14 days, with subsequent clearance of EBV viremia and resolution of disease. In nonresponders, EBV-CTLps did not increase and EBV viremia persisted. Treatment failures were correlated with impaired T-cell recognition of tumor targets. Either donor-derived EBV-CTLs that had been sensitized with autologous BLCLs transformed by EBV strain B95.8 could not lyse spontaneous donor-derived EBV-transformed BLCLs expanded from the patient's blood or biopsied tumor or they failed to lyse their targets because they were selectively restricted by HLA alleles not shared by the EBV-LPD. Therefore, either unselected DLIs or EBV-specific CTLs can eradicate both untreated and Rituxan-resistant lymphomatous EBV-LPD, with failures ascribable to impaired T-cell recognition of tumor-associated viral antigens or their presenting HLA alleles. PMID:22138512

  4. 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

  5. Enhanced natural killer-cell and T-cell responses to influenza A virus during pregnancy

    PubMed Central

    Kay, Alexander W.; Fukuyama, Julia; Aziz, Natali; Dekker, Cornelia L.; Mackey, Sally; Swan, Gary E.; Davis, Mark M.; Holmes, Susan; Blish, Catherine A.

    2014-01-01

    Pregnant women experience increased morbidity and mortality after influenza infection, for reasons that are not understood. Although some data suggest that natural killer (NK)- and T-cell responses are suppressed during pregnancy, influenza-specific responses have not been previously evaluated. Thus, we analyzed the responses of women that were pregnant (n = 21) versus those that were not (n = 29) immediately before inactivated influenza vaccination (IIV), 7 d after vaccination, and 6 wk postpartum. Expression of CD107a (a marker of cytolysis) and production of IFN-γ and macrophage inflammatory protein (MIP) 1β were assessed by flow cytometry. Pregnant women had a significantly increased percentage of NK cells producing a MIP-1β response to pH1N1 virus compared with nonpregnant women pre-IIV [median, 6.66 vs. 0.90% (P = 0.0149)] and 7 d post-IIV [median, 11.23 vs. 2.81% (P = 0.004)], indicating a heightened chemokine response in pregnant women that was further enhanced by the vaccination. Pregnant women also exhibited significantly increased T-cell production of MIP-1β and polyfunctionality in NK and T cells to pH1N1 virus pre- and post-IIV. NK- and T-cell polyfunctionality was also enhanced in pregnant women in response to the H3N2 viral strain. In contrast, pregnant women had significantly reduced NK- and T-cell responses to phorbol 12-myristate 13-acetate and ionomycin. This type of stimulation led to the conclusion that NK- and T-cell responses during pregnancy are suppressed, but clearly this conclusion is not correct relative to the more biologically relevant assays described here. Robust cellular immune responses to influenza during pregnancy could drive pulmonary inflammation, explaining increased morbidity and mortality. PMID:25246558

  6. Complexity of the primary genetic response to mitogenic activation of human T cells

    SciTech Connect

    Zipfel, P.F.; Siebenlist, U. ); Irving, S.G.; Kelly, K. )

    1989-03-01

    The authors describe the isolation and characterization of more than 60 novel cDNA clones that constitute part of the immediate genetic response to resting human peripheral blood T cells after mitogen activation. This primary response was highly complex, both in the absolute number of inducible genes and in the diversity of regulation. Although most of the genes expressed in activated T cells were shared with the activation response of normal human fibroblasts, a significant number were more restricted in tissue specificity and thus likely encode or effect the differentiated functions of activated T cells. The activatable genes could be further differentiated on the basis of kinetics of induction, response to cycloheximide, and sensitivity to the immunosuppressive drug cylcosporin A. It is of note that cyclosporin A inhibited the expression of more than 10 inducible genes, which suggests that this drug has a broad genetic mechanism of action.

  7. Complexity of the primary genetic response to mitogenic activation of human T cells.

    PubMed Central

    Zipfel, P F; Irving, S G; Kelly, K; Siebenlist, U

    1989-01-01

    We describe the isolation and characterization of more than 60 novel cDNA clones that constitute part of the immediate genetic response to resting human peripheral blood T cells after mitogen activation. This primary response was highly complex, both in the absolute number of inducible genes and in the diversity of regulation. Although most of the genes expressed in activated T cells were shared with the activation response of normal human fibroblasts, a significant number were more restricted in tissue specificity and thus likely encode or effect the differentiated functions of activated T cells. The activatable genes could be further differentiated on the basis of kinetics of induction, response to cycloheximide, and sensitivity to the immunosuppressive drug cyclosporin A. It is of note that cyclosporin A inhibited the expression of more than 10 inducible genes, which suggests that this drug has a broad genetic mechanism of action. Images PMID:2498643

  8. CIP2A Promotes T-Cell Activation and Immune Response to Listeria monocytogenes Infection.

    PubMed

    Côme, Christophe; Cvrljevic, Anna; Khan, Mohd Moin; Treise, Irina; Adler, Thure; Aguilar-Pimentel, Juan Antonio; Au-Yeung, Byron; Sittig, Eleonora; Laajala, Teemu Daniel; Chen, Yiling; Oeder, Sebastian; Calzada-Wack, Julia; Horsch, Marion; Aittokallio, Tero; Busch, Dirk H; Ollert, Markus W; Neff, Frauke; Beckers, Johannes; Gailus-Durner, Valerie; Fuchs, Helmut; Hrabě de Angelis, Martin; Chen, Zhi; Lahesmaa, Riitta; Westermarck, Jukka

    2016-01-01

    The oncoprotein Cancerous Inhibitor of Protein Phosphatase 2A (CIP2A) is overexpressed in most malignancies and is an obvious candidate target protein for future cancer therapies. However, the physiological importance of CIP2A-mediated PP2A inhibition is largely unknown. As PP2A regulates immune responses, we investigated the role of CIP2A in normal immune system development and during immune response in vivo. We show that CIP2A-deficient mice (CIP2AHOZ) present a normal immune system development and function in unchallenged conditions. However when challenged with Listeria monocytogenes, CIP2AHOZ mice display an impaired adaptive immune response that is combined with decreased frequency of both CD4+ T-cells and CD8+ effector T-cells. Importantly, the cell autonomous effect of CIP2A deficiency for T-cell activation was confirmed. Induction of CIP2A expression during T-cell activation was dependent on Zap70 activity. Thus, we reveal CIP2A as a hitherto unrecognized mediator of T-cell activation during adaptive immune response. These results also reveal CIP2AHOZ as a possible novel mouse model for studying the role of PP2A activity in immune regulation. On the other hand, the results also indicate that CIP2A targeting cancer therapies would not cause serious immunological side-effects. PMID:27100879

  9. Memory T cell responses targeting the SARS coronavirus persist up to 11 years post-infection.

    PubMed

    Ng, Oi-Wing; Chia, Adeline; Tan, Anthony T; Jadi, Ramesh S; Leong, Hoe Nam; Bertoletti, Antonio; Tan, Yee-Joo

    2016-04-12

    Severe acute respiratory syndrome (SARS) is a highly contagious infectious disease which first emerged in late 2002, caused by a then novel human coronavirus, SARS coronavirus (SARS-CoV). The virus is believed to have originated from bats and transmitted to human through intermediate animals such as civet cats. The re-emergence of SARS-CoV remains a valid concern due to the continual persistence of zoonotic SARS-CoVs and SARS-like CoVs (SL-CoVs) in bat reservoirs. In this study, the screening for the presence of SARS-specific T cells in a cohort of three SARS-recovered individuals at 9 and 11 years post-infection was carried out, and all memory T cell responses detected target the SARS-CoV structural proteins. Two CD8(+) T cell responses targeting the SARS-CoV membrane (M) and nucleocapsid (N) proteins were characterized by determining their HLA restriction and minimal T cell epitope regions. Furthermore, these responses were found to persist up to 11 years post-infection. An absence of cross-reactivity of these CD8(+) T cell responses against the newly-emerged Middle East respiratory syndrome coronavirus (MERS-CoV) was also demonstrated. The knowledge of the persistence of SARS-specific celullar immunity targeting the viral structural proteins in SARS-recovered individuals is important in the design and development of SARS vaccines, which are currently unavailable. PMID:26954467

  10. Resolution of Chlamydia trachomatis Infection Is Associated with a Distinct T Cell Response Profile.

    PubMed

    Picard, Michele D; Bodmer, Jean-Luc; Gierahn, Todd M; Lee, Alexander; Price, Jessica; Cohane, Kenya; Clemens, Veronica; DeVault, Victoria L; Gurok, Galina; Kohberger, Robert; Higgins, Darren E; Siber, George R; Flechtner, Jessica Baker; Geisler, William M

    2015-11-01

    Chlamydia trachomatis is the causative agent of the most frequently reported bacterial sexually transmitted infection, the total burden of which is underestimated due to the asymptomatic nature of the infection. Untreated C. trachomatis infections can cause significant morbidities, including pelvic inflammatory disease and tubal factor infertility (TFI). The human immune response against C. trachomatis, an obligate intracellular bacterium, is poorly characterized but is thought to rely on cell-mediated immunity, with CD4(+) and CD8(+) T cells implicated in protection. In this report, we present immune profiling data of subjects enrolled in a multicenter study of C. trachomatis genital infection. CD4(+) and CD8(+) T cells from subjects grouped into disease-specific cohorts were screened using a C. trachomatis proteomic library to identify the antigen specificities of recall T cell responses after natural exposure by measuring interferon gamma (IFN-γ) levels. We identified specific T cell responses associated with the resolution of infection, including unique antigens identified in subjects who spontaneously cleared infection and different antigens associated with C. trachomatis-related sequelae, such as TFI. These data suggest that novel and unique C. trachomatis T cell antigens identified in individuals with effective immune responses can be considered as targets for vaccine development, and by excluding antigens associated with deleterious sequelae, immune-mediated pathologies may be circumvented. PMID:26446421

  11. 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

  12. Role of acid sphingomyelinase bioactivity in human CD4+ T-cell activation and immune responses

    PubMed Central

    Bai, A; Kokkotou, E; Zheng, Y; Robson, S C

    2015-01-01

    Acid sphingomyelinase (ASM), a lipid hydrolase enzyme, has the potential to modulate various cellular activation responses via the generation of ceramide and by interaction with cellular receptors. We have hypothesized that ASM modulates CD4+ T-cell receptor activation and impacts immune responses. We first observed interactions of ASM with the intracellular domains of both CD3 and CD28. ASM further mediates T-cell proliferation after anti-CD3/CD28 antibody stimulation and alters CD4+ T-cell activation signals by generating ceramide. We noted that various pharmacological inhibitors of ASM or knockdown of ASM using small hairpin RNA inhibit CD3/CD28-mediated CD4+ T-cell proliferation and activation. Furthermore, such blockade of ASM bioactivity by biochemical inhibitors and/or molecular-targeted knockdown of ASM broadly abrogate T-helper cell responses. In conclusion, we detail immune, pivotal roles of ASM in adaptive immune T-cell responses, and propose that these pathways might provide novel targets for the therapy of autoimmune and inflammatory diseases. PMID:26203857

  13. CIP2A Promotes T-Cell Activation and Immune Response to Listeria monocytogenes Infection

    PubMed Central

    Cvrljevic, Anna; Khan, Mohd Moin; Treise, Irina; Adler, Thure; Aguilar-Pimentel, Juan Antonio; Au-Yeung, Byron; Sittig, Eleonora; Laajala, Teemu Daniel; Chen, Yiling; Oeder, Sebastian; Calzada-Wack, Julia; Horsch, Marion; Aittokallio, Tero; Busch, Dirk H.; Ollert, Markus W.; Neff, Frauke; Beckers, Johannes; Gailus-Durner, Valerie; Fuchs, Helmut; de Angelis, Martin Hrabě; Chen, Zhi; Lahesmaa, Riitta; Westermarck, Jukka

    2016-01-01

    The oncoprotein Cancerous Inhibitor of Protein Phosphatase 2A (CIP2A) is overexpressed in most malignancies and is an obvious candidate target protein for future cancer therapies. However, the physiological importance of CIP2A-mediated PP2A inhibition is largely unknown. As PP2A regulates immune responses, we investigated the role of CIP2A in normal immune system development and during immune response in vivo. We show that CIP2A-deficient mice (CIP2AHOZ) present a normal immune system development and function in unchallenged conditions. However when challenged with Listeria monocytogenes, CIP2AHOZ mice display an impaired adaptive immune response that is combined with decreased frequency of both CD4+ T-cells and CD8+ effector T-cells. Importantly, the cell autonomous effect of CIP2A deficiency for T-cell activation was confirmed. Induction of CIP2A expression during T-cell activation was dependent on Zap70 activity. Thus, we reveal CIP2A as a hitherto unrecognized mediator of T-cell activation during adaptive immune response. These results also reveal CIP2AHOZ as a possible novel mouse model for studying the role of PP2A activity in immune regulation. On the other hand, the results also indicate that CIP2A targeting cancer therapies would not cause serious immunological side-effects. PMID:27100879

  14. Pretransplant immediately early-1-specific T cell responses provide protection for CMV infection after kidney transplantation.

    PubMed

    Bestard, O; Lucia, M; Crespo, E; Van Liempt, B; Palacio, D; Melilli, E; Torras, J; Llaudó, I; Cerezo, G; Taco, O; Gil-Vernet, S; Grinyó, J M; Cruzado, J M

    2013-07-01

    Cytomegalovirus (CMV) infection is still a major complication after kidney transplantation. Although cytotoxic CMV-specific T cells play a crucial role controlling CMV survival and replication, current pretransplant risk assessment for CMV infection is only based on donor/recipient (IgG)-serostatus. Here, we evaluated the usefulness of monitoring pre- and 6-month CMV-specific T cell responses against two dominant CMV antigens (IE-1 and pp65) and a CMV lysate, using an IFN-γ Elispot, for predicting the advent of CMV infection in two cohorts of 137 kidney transplant recipients either receiving routine prophylaxis (n = 39) or preemptive treatment (n = 98). Incidence of CMV antigenemia/disease within the prophylaxis and preemptive group was 28%/20% and 22%/12%, respectively. Patients developing CMV infection showed significantly lower anti-IE-1-specific T cell responses than those that did not in both groups (p < 0.05). In a ROC curve analysis, low pretransplant anti-IE-1-specific T cell responses predicted the risk of both primary and late-onset CMV infection with high sensitivity and specificity (AUC > 0.70). Furthermore, when using most sensitive and specific Elispot cut-off values, a higher than 80% and 90% sensitivity and negative predictive value was obtained, respectively. Monitoring IE-1-specific T cell responses before transplantation may be useful for predicting posttransplant risk of CMV infection, thus potentially guiding decision-making regarding CMV preventive treatment. PMID:23711167

  15. Characterization of Immunodominant BK Polyomavirus 9mer Epitope T Cell Responses.

    PubMed

    Cioni, M; Leboeuf, C; Comoli, P; Ginevri, F; Hirsch, H H

    2016-04-01

    Uncontrolled BK polyomavirus (BKPyV) replication in kidney transplant recipients (KTRs) causes polyomavirus-associated nephropathy and allograft loss. Reducing immunosuppression is associated with clearing viremia and nephropathy and increasing BKPyV-specific T cell responses in most patients; however, current immunoassays have limited sensitivity, target mostly CD4(+) T cells, and largely fail to predict onset and clearance of BKPyV replication. To characterize BKPyV-specific CD8(+) T cells, bioinformatics were used to predict 9mer epitopes in the early viral gene region (EVGR) presented by 14 common HLAs in Europe and North America. Thirty-nine EVGR epitopes were experimentally confirmed by interferon-γ enzyme-linked immunospot assays in at least 30% of BKPyV IgG-seropositive healthy participants. Most 9mers clustered in domains, and some were presented by more than one HLA class I, as typically seen for immunodominant epitopes. Specific T cell binding using MHC class I streptamers was demonstrated for 21 of 39 (54%) epitopes. In a prospective cohort of 118 pediatric KTRs, 19 patients protected or recovering from BKPyV viremia were experimentally tested, and 13 epitopes were validated. Single HLA mismatches were not associated with viremia, suggesting that failing immune control likely involves multiple factors including maintenance immunosuppression. Combining BKPyV load and T cell assays using immunodominant epitopes may help in evaluating risk and reducing immunosuppression and may lead to safe adoptive T cell transfer. PMID:26663765

  16. Human cytomegalovirus elicits fetal γδ T cell responses in utero

    PubMed Central

    Brouwer, Margreet; Donner, Catherine; Liesnard, Corinne; Tackoen, Marie; Van Rysselberge, Michel; Twité, Nicolas; Goldman, Michel; Marchant, Arnaud; Willems, Fabienne

    2010-01-01

    The fetus and infant are highly susceptible to viral infections. Several viruses, including human cytomegalovirus (CMV), cause more severe disease in early life compared with later life. It is generally accepted that this is a result of the immaturity of the immune system. γδ T cells are unconventional T cells that can react rapidly upon activation and show major histocompatibility complex–unrestricted activity. We show that upon CMV infection in utero, fetal γδ T cells expand and become differentiated. The expansion was restricted to Vγ9-negative γδ T cells, irrespective of their Vδ chain expression. Differentiated γδ T cells expressed high levels of IFN-γ, transcription factors T-bet and eomes, natural killer receptors, and cytotoxic mediators. CMV infection induced a striking enrichment of a public Vγ8Vδ1-TCR, containing the germline-encoded complementary-determining-region-3 (CDR3) δ1–CALGELGDDKLIF/CDR3γ8–CATWDTTGWFKIF. Public Vγ8Vδ1-TCR–expressing cell clones produced IFN-γ upon coincubation with CMV-infected target cells in a TCR/CD3-dependent manner and showed antiviral activity. Differentiated γδ T cells and public Vγ8Vδ1-TCR were detected as early as after 21 wk of gestation. Our results indicate that functional fetal γδ T cell responses can be generated during development in utero and suggest that this T cell subset could participate in antiviral defense in early life. PMID:20368575

  17. Bystander T cells participate in specific response to cockroach antigen (CR) in vitro.

    PubMed

    Walters, C S; Tackey, R N; Reece, E; Paluvoi, S

    2003-02-01

    Allergic reactions due to whole body, body parts and fecal products of cockroach (CR) are characterized by inflammatory reaction that may lead to symptoms of rhinitis or asthma in atopic individuals. Although the majority of T cells at the site of CR hypersensitivity are not antigen specific, the cellular subset and cytokine receptors that participate and control the outcome of the reaction have not been fully studied. In this study, we have used fluorescent activated cell sorter (FACS) analysis to characterize the activation marker and cytokine profile of antigen specific and bystander T cells after in vitro stimulation of peripheral blood lymphocytes with whole body extract of CR antigen. There was significant enhancement of CD69 on blast and bystander T cells in all atopic subjects compared to non-atopics. Both antigen specific and bystander T cells showed increased expression of HLA-DR, CD25 and CD71 in 9 of 11 atopic patients compared to control. There was also an increase in CD45RA+ and a decrease in CD45RO+ cells following antigen stimulation. These results correlated with the increase in the early apoptotic cells observed in patients as measured by Annexin V stain. Our data revealed that there was no difference in the expression of CD95 in both stimulated and bystander T cells. However, there was enhancement of FasL by CR antigen, suggesting that the increased apoptosis that was observed was probably due to the Fas/FasL interaction. Positive intracellular IL2, IL-4 and IFN-gamma in T cells were observed in only the antigen specific blast cells in 83% of patients studied. These results suggest interplay of memory T cell response, apoptosis, and activated bystander T cells activities in maintaining cellular homeostasis during allergic reaction in cockroach sensitive atopic subjects. PMID:12722946

  18. Viral Escape Mutant Epitope Maintains TCR Affinity for Antigen yet Curtails CD8 T Cell Responses

    PubMed Central

    Shorter, Shayla K.; Schnell, Frederick J.; McMaster, Sean R.; Pinelli, David F.; Andargachew, Rakieb; Evavold, Brian D.

    2016-01-01

    T cells have the remarkable ability to recognize antigen with great specificity and in turn mount an appropriate and robust immune response. Critical to this process is the initial T cell antigen recognition and subsequent signal transduction events. This antigen recognition can be modulated at the site of TCR interaction with peptide:major histocompatibility (pMHC) or peptide interaction with the MHC molecule. Both events could have a range of effects on T cell fate. Though responses to antigens that bind sub-optimally to TCR, known as altered peptide ligands (APL), have been studied extensively, the impact of disrupting antigen binding to MHC has been highlighted to a lesser extent and is usually considered to result in complete loss of epitope recognition. Here we present a model of viral evasion from CD8 T cell immuno-surveillance by a lymphocytic choriomeningitis virus (LCMV) escape mutant with an epitope for which TCR affinity for pMHC remains high but where the antigenic peptide binds sub optimally to MHC. Despite high TCR affinity for variant epitope, levels of interferon regulatory factor-4 (IRF4) are not sustained in response to the variant indicating differences in perceived TCR signal strength. The CD8+ T cell response to the variant epitope is characterized by early proliferation and up-regulation of activation markers. Interestingly, this response is not maintained and is characterized by a lack in IL-2 and IFNγ production, increased apoptosis and an abrogated glycolytic response. We show that disrupting the stability of peptide in MHC can effectively disrupt TCR signal strength despite unchanged affinity for TCR and can significantly impact the CD8+ T cell response to a viral escape mutant. PMID:26915099

  19. T cell proliferative responses to molecular fractions of periodontopathic bacteria.

    PubMed Central

    Ivanyi, L; Newman, H N; Marsh, P D

    1991-01-01

    Soluble antigenic preparations of Veillonella parvula and Bacteroides gingivalis were separated by SDS-PAGE and used after electroblotting and solubilization for in vitro lymphocyte stimulation in 13 patients with severe periodontitis and 12 controls. The cellular responses of controls and patients to V. parvula antigens were represented by four main proliferation-inducing fractions with 74-66, 52-46, 22-19 and 12 kD mol. wt. These fractions induced slightly enhanced DNA synthesis in lymphocytes from eight patients who failed to respond to whole antigenic extract. Lymphocyte samples from Veillonella whole extract unresponsive patients were also examined for in vitro proliferation by B. gingivalis fractions. Almost all stimulatory activities could be classified into five regions of 84-74, 35-31, 28-25, 17-15 and 12 kD. PMID:1988218

  20. Self-recognition specificity expressed by T cells from nude mice. Absence of detectable Ia-restricted T cells in nude mice that do exhibit self-K/D-restricted T cell responses

    SciTech Connect

    Kruisbeek, A.M.; Davis, M.L.; Matis, L.A.; Longo, D.L.

    1984-09-01

    The presence in athymic nude mice of precursor T cells with self-recognition specificity for either H-2 K/D or H-2 I region determinants was investigated. Chimeras were constructed of lethally irradiated parental mice receiving a mixture of F1 nude mouse (6-8 wk old) spleen and bone marrow cells. The donor inoculum was deliberately not subjected to any T cell depletion procedure, so that any potential major histocompatibility complex-committed precursor T cells were allowed to differentiate and expand in the normal parental recipients. 3 mo after reconstitution, the chimeras were immunized with several protein antigens in complete Freund's adjuvant in the footpads and their purified draining lymph node T cells tested 10 d later for ability to recognize antigen on antigen-presenting cells of either parental haplotype. Also, their spleen and lymph node cells were tested for ability to generate a cytotoxic T lymphocyte (CTL) response to trinitrophenyl (TNP)-modified stimulator cells of either parental haplotype. It was demonstrated that T cell proliferative responses of these F1(nude)----parent chimeras were restricted solely to recognizing parental host I region determinants as self and expressed the Ir gene phenotype of the host. In contrast, CTL responses could be generated (in the presence of interleukin 2) to TNP-modified stimulator cells of either parental haplotype. Thus these results indicate that nude mice which do have CTL with self-specificity for K/D region determinants lack proliferating T cells with self-specificity for I region determinants. These results provide evidence for the concepts that development of the I region-restricted T cell repertoire is strictly an intrathymically determined event and that young nude mice lack the unique thymic elements responsible for edu

  1. Bovine central memory T cells are highly proliferative in response to bovine tuberculosis infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Long-term (i.e., 14d) cultured IFN-gamma ELISPOT assays of PBMC are used as a correlate of T cell central memory (Tcm) responses in cattle and humans. With bovine tuberculosis, vaccine-elicited Tcm responses correlate with protection against experimental Mycobacterium bovis infection. The objective ...

  3. Bovine central memory T cells are highly proliferative in response to bovine tuberculosis infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  5. Memory and effector CD8 T-cell responses after nanoparticle vaccination of melanoma patients.

    PubMed

    Speiser, Daniel E; Schwarz, Katrin; Baumgaertner, Petra; Manolova, Vania; Devevre, Estelle; Sterry, Wolfram; Walden, Peter; Zippelius, Alfred; Conzett, Katrin Baumann; Senti, Gabriela; Voelter, Verena; Cerottini, Jean-Philippe; Guggisberg, David; Willers, Jörg; Geldhof, Christine; Romero, Pedro; Kündig, Thomas; Knuth, Alexander; Dummer, Reinhard; Trefzer, Uwe; Bachmann, Martin F

    2010-10-01

    Induction of cytotoxic CD8 T-cell responses is enhanced by the exclusive presentation of antigen through dendritic cells, and by innate stimuli, such as toll-like receptor ligands. On the basis of these 2 principles, we designed a vaccine against melanoma. Specifically, we linked the melanoma-specific Melan-A/Mart-1 peptide to virus-like nanoparticles loaded with A-type CpG, a ligand for toll-like receptor 9. Melan-A/Mart-1 peptide was cross-presented, as shown in vitro with human dendritic cells and in HLA-A2 transgenic mice. A phase I/II study in stage II-IV melanoma patients showed that the vaccine was well tolerated, and that 14/22 patients generated ex vivo detectable T-cell responses, with in part multifunctional T cells capable to degranulate and produce IFN-γ, TNF-α, and IL-2. No significant influence of the route of immunization (subcutaneous versus intradermal) nor dosing regimen (weekly versus daily clusters) could be observed. It is interesting to note that, relatively large fractions of responding specific T cells exhibited a central memory phenotype, more than what is achieved by other nonlive vaccines. We conclude that vaccination with CpG loaded virus-like nanoparticles is associated with a human CD8 T-cell response with properties of a potential long-term immune protection from the disease. PMID:20842051

  6. Effector, Memory, and Dysfunctional CD8+ T Cell Fates in the Antitumor Immune Response

    PubMed Central

    2016-01-01

    The adaptive immune system plays a pivotal role in the host's ability to mount an effective, antigen-specific immune response against tumors. CD8+ tumor-infiltrating lymphocytes (TILs) mediate tumor rejection through recognition of tumor antigens and direct killing of transformed cells. In growing tumors, TILs are often functionally impaired as a result of interaction with, or signals from, transformed cells and the tumor microenvironment. These interactions and signals can lead to transcriptional, functional, and phenotypic changes in TILs that diminish the host's ability to eradicate the tumor. In addition to effector and memory CD8+ T cells, populations described as exhausted, anergic, senescent, and regulatory CD8+ T cells have been observed in clinical and basic studies of antitumor immune responses. In the context of antitumor immunity, these CD8+ T cell subsets remain poorly characterized in terms of fate-specific biomarkers and transcription factor profiles. Here we discuss the current characterization of CD8+ T cell fates in antitumor immune responses and discuss recent insights into how signals in the tumor microenvironment influence TIL transcriptional networks to promote CD8+ T cell dysfunction. PMID:27314056

  7. Distribution of T Cells in Rainbow Trout (Oncorhynchus mykiss) Skin and Responsiveness to Viral Infection

    PubMed Central

    Leal, Esther; Granja, Aitor G.; Zarza, Carlos; Tafalla, Carolina

    2016-01-01

    Although the skin constitutes the first line of defense against waterborne pathogens, there is a great lack of information regarding the skin associated lymphoid tissue (SALT) and whether immune components of the skin are homogeneously distributed through the surface of the fish is still unknown. In the current work, we have analyzed the transcription of several immune genes throughout different rainbow trout (Oncorhynchus mykiss) skin areas. We found that immunoglobulin and chemokine gene transcription levels were higher in a skin area close to the gills. Furthermore, this skin area as well as other anterior sections also transcribed significantly higher levels of many different immune genes related to T cell immunity such as T cell receptor α (TCRα), TCRγ, CD3, CD4, CD8, perforin, GATA3, Tbet, FoxP3, interferon γ (IFNγ), CD40L and Eomes in comparison to posterior skin sections. In agreement with these results, immunohistochemical analysis revealed that anterior skin areas had a higher concentration of CD3+ T cells and flow cytometry analysis confirmed that the percentage of CD8+ T lymphocytes was also higher in anterior skin sections. These results demonstrate for the first time that T cells are not homogeneously distributed throughout the teleost skin. Additionally, we studied the transcriptional regulation of these and additional T cell markers in response to a bath infection with viral hemorrhagic septicemia virus (VHSV). We found that VHSV regulated the transcription of several of these T cell markers in both the skin and the spleen; with some differences between anterior and posterior skin sections. Altogether, our results point to skin T cells as major players of teleost skin immunity in response to waterborne viral infections. PMID:26808410

  8. Distribution of T Cells in Rainbow Trout (Oncorhynchus mykiss) Skin and Responsiveness to Viral Infection.

    PubMed

    Leal, Esther; Granja, Aitor G; Zarza, Carlos; Tafalla, Carolina

    2016-01-01

    Although the skin constitutes the first line of defense against waterborne pathogens, there is a great lack of information regarding the skin associated lymphoid tissue (SALT) and whether immune components of the skin are homogeneously distributed through the surface of the fish is still unknown. In the current work, we have analyzed the transcription of several immune genes throughout different rainbow trout (Oncorhynchus mykiss) skin areas. We found that immunoglobulin and chemokine gene transcription levels were higher in a skin area close to the gills. Furthermore, this skin area as well as other anterior sections also transcribed significantly higher levels of many different immune genes related to T cell immunity such as T cell receptor α (TCRα), TCRγ, CD3, CD4, CD8, perforin, GATA3, Tbet, FoxP3, interferon γ (IFNγ), CD40L and Eomes in comparison to posterior skin sections. In agreement with these results, immunohistochemical analysis revealed that anterior skin areas had a higher concentration of CD3(+) T cells and flow cytometry analysis confirmed that the percentage of CD8(+) T lymphocytes was also higher in anterior skin sections. These results demonstrate for the first time that T cells are not homogeneously distributed throughout the teleost skin. Additionally, we studied the transcriptional regulation of these and additional T cell markers in response to a bath infection with viral hemorrhagic septicemia virus (VHSV). We found that VHSV regulated the transcription of several of these T cell markers in both the skin and the spleen; with some differences between anterior and posterior skin sections. Altogether, our results point to skin T cells as major players of teleost skin immunity in response to waterborne viral infections. PMID:26808410

  9. 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

  10. 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

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

    PubMed

    Saghaug, Christina Skår; Sørnes, Steinar; Peirasmaki, Dimitra; Svärd, Staffan; Langeland, Nina; Hanevik, Kurt

    2016-01-01

    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

  12. 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

  13. Impact of ageing on the response and repertoire of influenza virus-specific CD4 T cells

    PubMed Central

    2014-01-01

    Background Ageing has been shown to reduce CD8 T cell repertoire diversity and immune responses against influenza virus infection in mice. In contrast, less is known about the impact of ageing on CD4 T cell repertoire diversity and immune response to influenza virus infection. Results The CD4 T cell response was followed after infection of young and aged C57BL/6 mice with influenza virus using a tetramer specific for an immunodominant MHC class II epitope of the influenza virus nucleoprotein. The appearance of virus-specific CD4 T cells in the lung airways of aged mice was delayed compared to young mice, but the overall peak number and cytokine secretion profile of responding CD4 T cells was not greatly perturbed. In addition, the T cell repertoire of responding cells, determined using T cell receptor Vβ analysis, failed to show the profound effect of age we previously described for CD8 T cells. The reduced impact of age on influenza-specific CD4 T cells was consistent with a reduced effect of age on the overall CD4 compared with the CD8 T cell repertoire in specific pathogen free mice. Aged mice that were thymectomized as young adults showed an enhanced loss of the epitope-specific CD4 T cell response after influenza virus infection compared with age-matched sham-thymectomized mice, suggesting that a reduced repertoire can contribute to impaired responsiveness. Conclusions The diversity of the CD4 T cell repertoire and response to influenza virus is not as profoundly impaired by ageing in C57BL/6 mice as previously shown for CD8 T cells. However, adult thymectomy enhanced the impact of ageing on the response. Understanding the impact of ageing on CD4 T cell responses to influenza virus infection is an important prerequisite for developing better vaccines for the elderly. PMID:24999367

  14. Early innate responses to pathogens: pattern recognition by unconventional human T-cells

    PubMed Central

    Liuzzi, Anna Rita; McLaren, James E; Price, David A; Eberl, Matthias

    2015-01-01

    Although typically viewed as a feature of innate immune responses, microbial pattern recognition is increasingly acknowledged as a function of particular cells nominally categorized within the adaptive immune system. Groundbreaking research over the past three years has shown how unconventional human T-cells carrying invariant or semi-invariant TCRs that are not restricted by classical MHC molecules sense microbial compounds via entirely novel antigen presenting pathways. This review will focus on the innate-like recognition of non-self metabolites by Vγ9/Vδ2 T-cells, mucosal-associated invariant T (MAIT) cells and germline-encoded mycolyl-reactive (GEM) T-cells, with an emphasis on early immune responses in acute infection. PMID:26182978

  15. KAP1 Regulates Gene Networks Controlling T cell Development and Responsiveness

    PubMed Central

    Santoni de Sio, F.R.; Barde, I.; Offner, S.; Kapopoulou, A.; Genolet, R.; Corsinotti, A.; Bojkowska, K.; Thomas, J.H.; Luescher, I.; Pinschewer, D.; Harris, N.; Trono, D.

    2016-01-01

    The modulation of chromatin status at specific genomic loci controls lymphoid differentiation. Here, we investigated the role played in this process by KAP1, the universal cofactor of KRAB-containing zinc finger proteins (KRAB-ZFP), a tetrapod-restricted family of transcriptional repressors. T lymphoid KAP1 knockout mice displayed expansions of specific T cell populations, with impaired responses to stimulation and deregulation of genes involved in cell survival, cytoskeletal rearrangement, and immune signalling. Furthermore, chromatin studies demonstrate that KAP1 directly regulates the expression of a number of these genes, among which Foxo1 seemed of particular interest. Likely at least partly responsible for these effects, a small number of KRAB/ZFPs are selectively expressed in T cells. These results reveal the as-of-yet unsuspected importance of the KRAB/KAP1 epigenetic regulation system for T cell differentiation and function. PMID:22872677

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

    PubMed Central

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

    2015-01-01

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

  17. Otud7b facilitates T cell activation and inflammatory responses by regulating Zap70 ubiquitination.

    PubMed

    Hu, Hongbo; Wang, Hui; Xiao, Yichuan; Jin, Jin; Chang, Jae-Hoon; Zou, Qiang; Xie, Xiaoping; Cheng, Xuhong; Sun, Shao-Cong

    2016-03-01

    Signal transduction from the T cell receptor (TCR) is crucial for T cell-mediated immune responses and, when deregulated, also contributes to the development of autoimmunity. How TCR signaling is regulated is incompletely understood. In this study, we demonstrate a ubiquitin-dependent mechanism in which the deubiquitinase Otud7b has a crucial role in facilitating TCR signaling. Upon TCR ligation, Otud7b is rapidly recruited to the tyrosine kinase Zap70, a central mediator of TCR-proximal signaling. Otud7b deficiency attenuates the activation of Zap70 and its downstream pathways and impairs T cell activation and differentiation, rendering mice refractory to T cell-mediated autoimmune and inflammatory responses. Otud7b facilitated Zap70 activation by deubiquitinating Zap70, thus preventing the association of Zap70 with the negative-regulatory phosphatases Sts1 and Sts2. These findings establish Otud7b as a positive regulator of TCR-proximal signaling and T cell activation, highlighting the importance of deubiquitination in regulating Zap70 function. PMID:26903241

  18. 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

  19. Cytotoxic T cell responses to human telomerase reverse transcriptase in patients with hepatocellular carcinoma.

    PubMed

    Mizukoshi, Eishiro; Nakamoto, Yasunari; Marukawa, Yohei; Arai, Kuniaki; Yamashita, Tatsuya; Tsuji, Hirokazu; Kuzushima, Kiyotaka; Takiguchi, Masafumi; Kaneko, Shuichi

    2006-06-01

    Human telomerase reverse transcriptase, hTERT, has been identified as the catalytic enzyme required for telomere elongation. hTERT is expressed in most tumor cells but seldom expressed in most human adult cells. It has been reported that 80% to 90% of hepatocellular carcinomas (HCCs) express hTERT, making the enzyme a potential target in immunotherapy for HCC. In the current study, we identified hTERT-derived, HLA-A*2402-restricted cytotoxic T cell (CTL) epitopes and analyzed hTERT-specific CTL responses in patients with HCC. Peptides containing the epitopes showed high affinity to bind HLA-A*2402 in a major histocompatibility complex binding assay and were able to induce hTERT-specific CTLs in both hTERT cDNA-immunized HLA-A*2402/Kb transgenic mice and patients with HCC. The CTLs were able to kill hepatoma cell lines depending on hTERT expression levels in an HLA-A*2402-restricted manner and induced irrespective of hepatitis viral infection. The number of single hTERT epitope-specific T cells detected by ELISPOT assay was 10 to 100 specific cells per 3 x 10(5) PBMCs, and positive T cell responses were observed in 6.9% to 12.5% of HCC patients. hTERT-specific T cell responses were observed even in the patients with early stages of HCC. The frequency of hTERT/tetramer+ CD8+ T cells in the tumor tissue of patients with HCC was quite high, and they were functional. In conclusion, these results suggest that hTERT is an attractive target for T-cell-based immunotherapy for HCC, and the identified hTERT epitopes may be valuable both for immunotherapy and for analyzing host immune responses to HCC. PMID:16729333

  20. The tortoise and the hare: slowly evolving T-cell responses take hastily evolving KIR

    PubMed Central

    van Bergen, Jeroen; Koning, Frits

    2010-01-01

    The killer cell immunoglobulin-like receptor (KIR) locus comprises a variable and rapidly evolving set of genes encoding multiple inhibitory and activating receptors. The activating receptors recently evolved from the inhibitory receptors and both bind HLA class I and probably also class I-like structures induced by viral infection. Although generally considered natural killer (NK) cell receptors, KIR are also expressed by a large fraction of effector memory T cells, which slowly accumulate during human life. These effector memory cells are functionally similar to NK cells, as they are immediate effector cells that are cytotoxic and produce IFN-γ. However, different rules apply to NK and T cells with respect to KIR expression and function. For example, KIR tend to modulate signals driven by the T-cell receptor (TCR) rather than to act independently, and use different signal transduction pathways to modulate only a subset of effector functions. The most important difference may lie in the rules governing tolerance: while NK cells with activating KIR binding self-HLA are hyporesponsive, the same is unlikely to apply to T cells. We argue that the expression of activating KIR on virus-specific T cells carrying TCR that weakly cross-react with autoantigens can unleash the autoreactive potential of these cells. This may be the case in rheumatoid arthritis, where cytomegalovirus-specific KIR2DS2+ T cells might cause vasculitis. Thus, the rapid evolution of activating KIR may have allowed for efficient NK-cell control of viruses, but may also have increased the risk that slowly evolving T-cell responses to persistent pathogens derail into autoimmunity. PMID:20722764

  1. Discriminating Protective from Nonprotective Plasmodium-Specific CD8+ T Cell Responses.

    PubMed

    Doll, Katherine L; Pewe, Lecia L; Kurup, Samarchith P; Harty, John T

    2016-05-15

    Despite decades of research, malaria remains a global health crisis. Current subunit vaccine approaches do not provide efficient long-term, sterilizing immunity against Plasmodium infections in humans. Conversely, whole parasite vaccinations with their larger array of target Ags have conferred long-lasting sterilizing protection to humans. Similar studies in rodent models of malaria reveal that CD8(+) T cells play a critical role in liver-stage immunity after whole parasite vaccination. However, it is unknown whether all CD8(+) T cell specificities elicited by whole parasite vaccination contribute to protection, an issue of great relevance for enhanced subunit vaccination. In this article, we show that robust CD8(+) T cell responses of similar phenotype are mounted after prime-boost immunization against Plasmodium berghei glideosome-associated protein 5041-48-, sporozoite-specific protein 20318-325-, thrombospondin-related adhesion protein (TRAP) 130-138-, or circumsporozoite protein (CSP) 252-260-derived epitopes in mice, but only CSP252-260- and TRAP130-138-specific CD8(+) T cells provide sterilizing immunity and reduce liver parasite burden after sporozoite challenge. Further, CD8(+) T cells specific to sporozoite surface-expressed CSP and TRAP proteins, but not intracellular glideosome-associated protein 50 and sporozoite-specific protein 20, efficiently recognize sporozoite-infected hepatocytes in vitro. These results suggest that: 1) protection-relevant antigenic targets, regardless of their immunogenic potential, must be efficiently presented by infected hepatocytes for CD8(+) T cells to eliminate liver-stage Plasmodium infection; and 2) proteins expressed on the surface of sporozoites may be good target Ags for protective CD8(+) T cells. PMID:27084099

  2. Molecular Mechanisms Involved in the Aging of the T-cell Immune Response

    PubMed Central

    Moro-García, Marco Antonio; Alonso-Arias, Rebeca; López-Larrea, Carlos

    2012-01-01

    T-lymphocytes play a central role in the effector and regulatory mechanisms of the adaptive immune response. Upon exiting the thymus they begin to undergo a series of phenotypic and functional changes that continue throughout the lifetime and being most pronounced in the elderly. The reason postulated for this is that the dynamic processes of repeated interaction with cognate antigens lead to multiple division cycles involving a high degree of cell differentiation, senescence, restriction of the T-cell receptor (TCR) repertoire, and cell cycle arrest. This cell cycle arrest is associated with the loss of telomere sequences from the ends of chromosomes. Telomere length is reduced at each cell cycle, and critically short telomeres recruit components of the DNA repair machinery and trigger replicative senescence or apoptosis. Repetitively stimulated T-cells become refractory to telomerase induction, suffer telomere erosion and enter replicative senescence. The latter is characterized by the accumulation of highly differentiated T-cells with new acquired functional capabilities, which can be caused by aberrant expression of genes normally suppressed by epigenetic mechanisms in CD4+ or CD8+ T-cells. Age-dependent demethylation and overexpression of genes normally suppressed by DNA methylation have been demonstrated in senescent subsets of T-lymphocytes. Thus, T-cells, principally CD4+CD28null T-cells, aberrantly express genes, including those of the KIR gene family and cytotoxic proteins such as perforin, and overexpress CD70, IFN-γ, LFA-1 and others. In summary, owing to a lifetime of exposure to and proliferation against a variety of pathogens, highly differentiated T-cells suffer molecular modifications that alter their cellular homeostasis mechanisms. PMID:23730199

  3. Interplay between T Cell Receptor Binding Kinetics and the Level of Cognate Peptide Presented by Major Histocompatibility Complexes Governs CD8+ T Cell Responsiveness*

    PubMed Central

    Irving, Melita; Zoete, Vincent; Hebeisen, Michael; Schmid, Daphné; Baumgartner, Petra; Guillaume, Philippe; Romero, Pedro; Speiser, Daniel; Luescher, Immanuel; Rufer, Nathalie; Michielin, Olivier

    2012-01-01

    Through a rational design approach, we generated a panel of HLA-A*0201/NY-ESO-1157–165-specific T cell receptors (TCR) with increasing affinities of up to 150-fold from the wild-type TCR. Using these TCR variants which extend just beyond the natural affinity range, along with an extreme supraphysiologic one having 1400-fold enhanced affinity, and a low-binding one, we sought to determine the effect of TCR binding properties along with cognate peptide concentration on CD8+ T cell responsiveness. Major histocompatibility complexes (MHC) expressed on the surface of various antigen presenting cells were peptide-pulsed and used to stimulate human CD8+ T cells expressing the different TCR via lentiviral transduction. At intermediate peptide concentration we measured maximum cytokine/chemokine secretion, cytotoxicity, and Ca2+ flux for CD8+ T cells expressing TCR within a dissociation constant (KD) range of ∼1–5 μm. Under these same conditions there was a gradual attenuation in activity for supraphysiologic affinity TCR with KD < ∼1 μm, irrespective of CD8 co-engagement and of half-life (t1/2 = ln 2/koff) values. With increased peptide concentration, however, the activity levels of CD8+ T cells expressing supraphysiologic affinity TCR were gradually restored. Together our data support the productive hit rate model of T cell activation arguing that it is not the absolute number of TCR/pMHC complexes formed at equilibrium, but rather their productive turnover, that controls levels of biological activity. Our findings have important implications for various immunotherapies under development such as adoptive cell transfer of TCR-engineered CD8+ T cells, as well as for peptide vaccination strategies. PMID:22549784

  4. Dynamical System Modeling to Simulate Donor T Cell Response to Whole Exome Sequencing-Derived Recipient Peptides Demonstrates Different Alloreactivity Potential in HLA-Matched and -Mismatched Donor-Recipient Pairs.

    PubMed

    Abdul Razzaq, Badar; Scalora, Allison; Koparde, Vishal N; Meier, Jeremy; Mahmood, Musa; Salman, Salman; Jameson-Lee, Max; Serrano, Myrna G; Sheth, Nihar; Voelkner, Mark; Kobulnicky, David J; Roberts, Catherine H; Ferreira-Gonzalez, Andrea; Manjili, Masoud H; Buck, Gregory A; Neale, Michael C; Toor, Amir A

    2016-05-01

    Immune reconstitution kinetics and subsequent clinical outcomes in HLA-matched recipients of allogeneic stem cell transplantation (SCT) are variable and difficult to predict. Considering SCT as a dynamical system may allow sequence differences across the exomes of the transplant donors and recipients to be used to simulate an alloreactive T cell response, which may allow better clinical outcome prediction. To accomplish this, whole exome sequencing was performed on 34 HLA-matched SCT donor-recipient pairs (DRPs) and the nucleotide sequence differences translated to peptides. The binding affinity of the peptides to the relevant HLA in each DRP was determined. The resulting array of peptide-HLA binding affinity values in each patient was considered as an operator modifying a hypothetical T cell repertoire vector, in which each T cell clone proliferates in accordance with the logistic equation of growth. Using an iterating system of matrices, each simulated T cell clone's growth was calculated with the steady-state population being proportional to the magnitude of the binding affinity of the driving HLA-peptide complex. Incorporating competition between T cell clones responding to different HLA-peptide complexes reproduces a number of features of clinically observed T cell clonal repertoire in the simulated repertoire, including sigmoidal growth kinetics of individual T cell clones and overall repertoire, Power Law clonal frequency distribution, increase in repertoire complexity over time with increasing clonal diversity, and alteration of clonal dominance when a different antigen array is encountered, such as in SCT. The simulated, alloreactive T cell repertoire was markedly different in HLA-matched DRPs. The patterns were differentiated by rate of growth and steady-state magnitude of the simulated T cell repertoire and demonstrate a possible correlation with survival. In conclusion, exome wide sequence differences in DRPs may allow simulation of donor alloreactive T

  5. Continuum model of T-cell avidity: Understanding autoreactive and regulatory T-cell responses in type 1 diabetes.

    PubMed

    Jaberi-Douraki, Majid; Pietropaolo, Massimo; Khadra, Anmar

    2015-10-21

    Type 1 diabetes (T1D) is an autoimmune disease that results from the destruction of insulin-secreting pancreatic β cells, leading to abolition of insulin secretion and onset of diabetes. Cytotoxic CD4(+) and CD8(+) T cells, activated by antigen presenting cells (APCs), are both implicated in disease onset and progression. Regulatory T cells (Tregs), on the other hand, play a leading role in regulating immunological tolerance and resistant homoeostasis in T1D by suppressing effector T cells (Teffs). Recent data indicates that after activation, conventional Teffs transiently produce interleukin IL-2, a cytokine that acts as a growth factor for both Teffs and Tregs. Tregs suppress Teffs through IL-2 deprivation, competition and Teff conversion into inducible Tregs (iTregs). To investigate the interactions of these components during T1D progression, a mathematical model of T-cell dynamics is developed as a predictor of β-cell loss, with the underlying hypothesis that avidity of Teffs and Tregs, i.e., the binding affinity of T-cell receptors to peptide-major histocompatibility complexes on host cells, is continuum. The model is used to infer a set of criteria that determines susceptibility to T1D in high risk subjects. Our findings show that diabetes onset is guided by the absence of Treg-to-Teff dominance at specific high avidities, rather than over the whole range of avidity, and that the lack of overall dominance of Teffs-to-Tregs over time is the underlying cause of the "honeymoon period", the remission phase observed in some T1D patients. The model also suggests that competition between Teffs and Tregs is more effective than Teff-induction into iTregs in suppressing Teffs, and that a prolonged full width at half maximum of IL-2 release is a necessary condition for curbing disease onset. Finally, the model provides a rationale for observing rapid and slow progressors of T1D based on modest heterogeneity in the kinetic parameters. PMID:26271890

  6. Elevated and cross-responsive CD1a-reactive T cells in bee and wasp venom allergic individuals.

    PubMed

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

    2016-01-01

    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

  7. 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

  8. Gender-specific differences in PPARγ regulation of follicular helper T cell responses with estrogen

    PubMed Central

    Park, Hong-Jai; Park, Hyeon-Soo; Lee, Jae-Ung; Bothwell, Alfred L. M.; Choi, Je-Min

    2016-01-01

    Peroxisome proliferator-activated receptor gamma (PPARγ), a master regulator of adipocyte differentiation, has recently been connected with effector T cells, though its role is still not clear. Here, we investigated the roles of PPARγ in follicular helper T (TFH) cell responses regarding gender specificity. NP-OVA immunization in female but not male CD4-PPARγKO mice induced higher proportions of TFH cells and germinal center (GC) B cells following immunization than were seen in wild type mice. Treatment with the PPARγ agonist pioglitazone significantly reduced TFH cell responses in female mice while pioglitazone and estradiol (E2) co-treatment ameliorated TFH cells and GC responses in male mice. E2 treatment significantly enhanced PPARγ expression in male T cells, while T cell activation in the estrus but not in the diestrus stage of the menstrual cycle of females was inhibited by pioglitazone, suggesting that an estrogen-sufficient environment is important for PPARγ-mediated T cell regulation. These results demonstrate gender-based differences in sensitivities of PPARγ in TFH responses. These findings suggest that appropriate function of PPARγ is required in the regulation of female GC responses and that therapeutic strategies for autoimmune diseases using PPARγ agonists need to be tailored accordingly. PMID:27335315

  9. Ultrasensitivity in the Cofilin Signaling Module: A Mechanism for Tuning T Cell Responses

    PubMed Central

    Ramirez-Munoz, Rocio; Castro-Sánchez, Patricia; Roda-Navarro, Pedro

    2016-01-01

    Ultrasensitivity allows filtering weak activating signals and responding emphatically to small changes in stronger stimuli. In the presence of positive feedback loops, ultrasensitivity enables the existence of bistability, which convert graded stimuli into switch-like, sometimes irreversible, responses. In this perspective, we discuss mechanisms that can potentially generate a bistable response in the phosphorylation/dephosphorylation monocycle that regulates the activity of cofilin in dynamic actin networks. We pay particular attention to the phosphatase Slingshot-1 (SSH-1), which is involved in a reciprocal regulation and a positive feedback loop for cofilin activation. Based on these signaling properties and experimental evidences, we propose that bistability in the cofilin signaling module might be instrumental in T cell responses to antigenic stimulation. Initially, a switch-like response in the amount of active cofilin as a function of SSH-1 activation might assist in controlling the naïve T cell specificity and sensitivity. Second, high concentrations of active cofilin might endow antigen-experienced T cells with faster and more efficient responses. We discuss the cofilin function in the context of T cell receptor triggering and spatial regulation of plasma membrane signaling molecules. PMID:26925064

  10. Ultrasensitivity in the Cofilin Signaling Module: A Mechanism for Tuning T Cell Responses.

    PubMed

    Ramirez-Munoz, Rocio; Castro-Sánchez, Patricia; Roda-Navarro, Pedro

    2016-01-01

    Ultrasensitivity allows filtering weak activating signals and responding emphatically to small changes in stronger stimuli. In the presence of positive feedback loops, ultrasensitivity enables the existence of bistability, which convert graded stimuli into switch-like, sometimes irreversible, responses. In this perspective, we discuss mechanisms that can potentially generate a bistable response in the phosphorylation/dephosphorylation monocycle that regulates the activity of cofilin in dynamic actin networks. We pay particular attention to the phosphatase Slingshot-1 (SSH-1), which is involved in a reciprocal regulation and a positive feedback loop for cofilin activation. Based on these signaling properties and experimental evidences, we propose that bistability in the cofilin signaling module might be instrumental in T cell responses to antigenic stimulation. Initially, a switch-like response in the amount of active cofilin as a function of SSH-1 activation might assist in controlling the naïve T cell specificity and sensitivity. Second, high concentrations of active cofilin might endow antigen-experienced T cells with faster and more efficient responses. We discuss the cofilin function in the context of T cell receptor triggering and spatial regulation of plasma membrane signaling molecules. PMID:26925064

  11. Gender-specific differences in PPARγ regulation of follicular helper T cell responses with estrogen.

    PubMed

    Park, Hong-Jai; Park, Hyeon-Soo; Lee, Jae-Ung; Bothwell, Alfred L M; Choi, Je-Min

    2016-01-01

    Peroxisome proliferator-activated receptor gamma (PPARγ), a master regulator of adipocyte differentiation, has recently been connected with effector T cells, though its role is still not clear. Here, we investigated the roles of PPARγ in follicular helper T (TFH) cell responses regarding gender specificity. NP-OVA immunization in female but not male CD4-PPARγ(KO) mice induced higher proportions of TFH cells and germinal center (GC) B cells following immunization than were seen in wild type mice. Treatment with the PPARγ agonist pioglitazone significantly reduced TFH cell responses in female mice while pioglitazone and estradiol (E2) co-treatment ameliorated TFH cells and GC responses in male mice. E2 treatment significantly enhanced PPARγ expression in male T cells, while T cell activation in the estrus but not in the diestrus stage of the menstrual cycle of females was inhibited by pioglitazone, suggesting that an estrogen-sufficient environment is important for PPARγ-mediated T cell regulation. These results demonstrate gender-based differences in sensitivities of PPARγ in TFH responses. These findings suggest that appropriate function of PPARγ is required in the regulation of female GC responses and that therapeutic strategies for autoimmune diseases using PPARγ agonists need to be tailored accordingly. PMID:27335315

  12. Circulating γδ T Cells in Response to Salmonella enterica Serovar Enteritidis Exposure in Chickens

    PubMed Central

    Berndt, Angela; Pieper, Jana; Methner, Ulrich

    2006-01-01

    γδ T cells are considered crucial to the outcome of various infectious diseases. The present study was undertaken to characterize γδ (T-cell receptor 1+ [TCR1+]) T cells phenotypically and functionally in avian immune response. Day-old chicks were orally immunized with Salmonella enterica serovar Enteritidis live vaccine or S. enterica serovar Enteritidis wild-type strain and infected using the S. enterica serovar Enteritidis wild-type strain on day 44 of life. Between days 3 and 71, peripheral blood was examined flow cytometrically for the occurrence of γδ T-cell subpopulations differentiated by the expression of T-cell antigens. Three different TCR1+ cell populations were found to display considerable variation regarding CD8α antigen expression: (i) CD8α+high TCR1+ cells, (ii) CD8α+dim TCR1+ cells, and (iii) CD8α− TCR1+ cells. While most of the CD8α+high TCR1+ cells expressed the CD8αβ heterodimeric antigen, the majority of the CD8α+dim TCR1+ cells were found to express the CD8αα homodimeric form. After immunization, a significant increase of CD8αα+high γδ T cells was observed within the CD8α+high TCR1+ cell population. Quantitative reverse transcription-PCR revealed reduced interleukin-7 receptor α (IL-7Rα) and Bcl-x expression and elevated IL-2Rα mRNA expression of the CD8αα+high γδ T cells. Immunohistochemical analysis demonstrated a significant increase of CD8α+ and TCR1+ cells in the cecum and spleen and a decreased percentage of CD8β+ T cells in the spleen after Salmonella immunization. After infection of immunized animals, immune reactions were restricted to intestinal tissue. The study showed that Salmonella immunization of very young chicks is accompanied by an increase of CD8αα+high γδ T cells in peripheral blood, which are probably activated, and thus represent an important factor for the development of a protective immune response to Salmonella organisms in chickens. PMID:16790770

  13. Myeloid Dendritic Cells (DCs) of Mice Susceptible to Paracoccidioidomycosis Suppress T Cell Responses whereas Myeloid and Plasmacytoid DCs from Resistant Mice Induce Effector and Regulatory T Cells

    PubMed Central

    Pina, Adriana; Frank de Araujo, Eliseu; Felonato, Maíra; Loures, Flávio V.; Feriotti, Claudia; Bernardino, Simone; Barbuto, José Alexandre M.

    2013-01-01

    The protective adaptive immune response in paracoccidioidomycosis, a mycosis endemic among humans, is mediated by T cell immunity, whereas impaired T cell responses are associated with severe, progressive disease. The early host response to Paracoccidioides brasiliensis infection is not known since the disease is diagnosed at later phases of infection. Our laboratory established a murine model of infection where susceptible mice reproduce the severe disease, while resistant mice develop a mild infection. This work aimed to characterize the influence of dendritic cells in the innate and adaptive immunity of susceptible and resistant mice. We verified that P. brasiliensis infection induced in bone marrow-derived dendritic cells (DCs) of susceptible mice a prevalent proinflammatory myeloid phenotype that secreted high levels of interleukin-12 (IL-12), tumor necrosis factor alpha, and IL-β, whereas in resistant mice, a mixed population of myeloid and plasmacytoid DCs secreting proinflammatory cytokines and expressing elevated levels of secreted and membrane-bound transforming growth factor β was observed. In proliferation assays, the proinflammatory DCs from B10.A mice induced anergy of naïve T cells, whereas the mixed DC subsets from resistant mice induced the concomitant proliferation of effector and regulatory T cells (Tregs). Equivalent results were observed during pulmonary infection. The susceptible mice displayed preferential expansion of proinflammatory myeloid DCs, resulting in impaired proliferation of effector T cells. Conversely, the resistant mice developed myeloid and plasmacytoid DCs that efficiently expanded gamma interferon-, IL-4-, and IL-17-positive effector T cells associated with increased development of Tregs. Our work highlights the deleterious effect of excessive innate proinflammatory reactions and provides new evidence for the importance of immunomodulation during pulmonary paracoccidioidomycosis. PMID:23340311

  14. Human gamma delta T-cell recognition of Yersinia enterocolitica.

    PubMed Central

    Young, J L; Goodall, J C; Beacock-Sharp, H; Gaston, J S

    1997-01-01

    We have studied the human gamma delta T-cell response to Yersinia enterocolitica, a facultative intracellular bacterium which causes gastroenteritis and, particularly in human leucocyte antigen (HLA)-B27+ individuals, reactive arthritis (ReA). A marked proliferation of that cytotoxic gamma delta T cells is seen when Yersinia-infected lymphoblastoid cell lines or fixed intact Yersinia are added to cultures of mononuclear cells derived from the synovial fluid of ReA patients or from the peripheral blood of healthy donors. In contrast, heat-inactivated Yersinia fail to stimulate the gamma delta T-cell response. The gamma delta T-cell lines generated killed both autologous and allogeneic infected cell lines. Interestingly, a T-cell line generated from synovial fluid mononuclear cells (SFMC) killed infected autologous cell lines and a cell line matched for HLA-B27 less well than infected allogeneic target cells. gamma delta T-cell clones isolated from this line were found to express V gamma 9V delta 2 T-cell receptor (TCR) and also killed infected mismatched cells more efficiently than autologous targets. Moreover, from experiments using major histocompatability complex (MHC)-deficient cell lines, it was apparent that target cell recognition was MHC independent. Our results suggest that gamma delta T cells can be involved in immunity to Yersinia enterocolitica and should be taken into account when considering immunopathological mechanisms leading to reactive arthritis. PMID:9378487

  15. The T cell response to persistent herpes virus infections in common variable immunodeficiency.

    PubMed

    Raeiszadeh, M; Kopycinski, J; Paston, S J; Diss, T; Lowdell, M; Hardy, G A D; Hislop, A D; Workman, S; Dodi, A; Emery, V; Webster, A D

    2006-11-01

    We show that at least half of patients with common variable immunodeficiency (CVID) have circulating CD8(+) T cells specific for epitopes derived from cytomegalovirus (CMV) and/or the Epstein-Barr virus (EBV). Compared to healthy age-matched subjects, more CD8(+) T cells in CVID patients were committed to CMV. Despite previous reports of defects in antigen presentation and cellular immunity in CVID, specific CD4(+) and CD8(+) T cells produced interferon (IFN)-gamma after stimulation with CMV peptides, and peripheral blood mononuclear cells secreted perforin in response to these antigens. In CVID patients we found an association between a high percentage of circulating CD8(+) CD57(+) T cells containing perforin, CMV infection and a low CD4/CD8 ratio, suggesting that CMV may have a major role in the T cell abnormalities described previously in this disease. We also show preliminary evidence that CMV contributes to the previously unexplained severe enteropathy that occurs in about 5% of patients. PMID:17034575

  16. Cell intrinsic role of NF-κB-inducing kinase in regulating T cell-mediated immune and autoimmune responses

    PubMed Central

    Li, Yanchuan; Wang, Hui; Zhou, Xiaofei; Xie, Xiaoping; Chen, Xiang; Jie, Zuliang; Zou, Qiang; Hu, Hongbo; Zhu, Lele; Cheng, Xuhong; Brightbill, Hans D; Wu, Lawren C.; Wang, Linfang; Sun, Shao-Cong

    2016-01-01

    NF-κB inducing kinase (NIK) is a central component of the noncanonical NF-κB signaling pathway. Although NIK has been extensively studied for its function in the regulation of lymphoid organ development and B-cell maturation, the role of NIK in regulating T cell functions remains unclear and controversial. Using T cell-conditional NIK knockout mice, we here demonstrate that although NIK is dispensable for thymocyte development, it has a cell-intrinsic role in regulating the homeostasis and function of peripheral T cells. T cell-specific NIK ablation reduced the frequency of effector/memory-like T cells and impaired T cell responses to bacterial infection. The T cell-conditional NIK knockout mice were also defective in generation of inflammatory T cells and refractory to the induction of a T cell-dependent autoimmune disease, experimental autoimmune encephalomyelitis. Our data suggest a crucial role for NIK in mediating the generation of effector T cells and their recall responses to antigens. Together, these findings establish NIK as a cell-intrinsic mediator of T cell functions in both immune and autoimmune responses. PMID:26912039

  17. RIG-I Signaling Is Critical for Efficient Polyfunctional T Cell Responses during Influenza Virus Infection.

    PubMed

    Kandasamy, Matheswaran; Suryawanshi, Amol; Tundup, Smanla; Perez, Jasmine T; Schmolke, Mirco; Manicassamy, Santhakumar; Manicassamy, Balaji

    2016-07-01

    Retinoic acid inducible gene-I (RIG-I) is an innate RNA sensor that recognizes the influenza A virus (IAV) RNA genome and activates antiviral host responses. Here, we demonstrate that RIG-I signaling plays a crucial role in restricting IAV tropism and regulating host immune responses. Mice deficient in the RIG-I-MAVS pathway show defects in migratory dendritic cell (DC) activation, viral antigen presentation, and priming of CD8+ and CD4+ T cell responses during IAV infection. These defects result in decreased frequency of polyfunctional effector T cells and lowered protection against heterologous IAV challenge. In addition, our data show that RIG-I activation is essential for protecting epithelial cells and hematopoietic cells from IAV infection. These diverse effects of RIG-I signaling are likely imparted by the actions of type I interferon (IFN), as addition of exogenous type I IFN is sufficient to overcome the defects in antigen presentation by RIG-I deficient BMDC. Moreover, the in vivo T cell defects in RIG-I deficient mice can be overcome by the activation of MDA5 -MAVS via poly I:C treatment. Taken together, these findings demonstrate that RIG-I signaling through MAVS is critical for determining the quality of polyfunctional T cell responses against IAV and for providing protection against subsequent infection from heterologous or novel pandemic IAV strains. PMID:27438481

  18. RIG-I Signaling Is Critical for Efficient Polyfunctional T Cell Responses during Influenza Virus Infection

    PubMed Central

    Kandasamy, Matheswaran; Suryawanshi, Amol; Tundup, Smanla; Perez, Jasmine T.; Schmolke, Mirco; Manicassamy, Santhakumar; Manicassamy, Balaji

    2016-01-01

    Retinoic acid inducible gene-I (RIG-I) is an innate RNA sensor that recognizes the influenza A virus (IAV) RNA genome and activates antiviral host responses. Here, we demonstrate that RIG-I signaling plays a crucial role in restricting IAV tropism and regulating host immune responses. Mice deficient in the RIG-I-MAVS pathway show defects in migratory dendritic cell (DC) activation, viral antigen presentation, and priming of CD8+ and CD4+ T cell responses during IAV infection. These defects result in decreased frequency of polyfunctional effector T cells and lowered protection against heterologous IAV challenge. In addition, our data show that RIG-I activation is essential for protecting epithelial cells and hematopoietic cells from IAV infection. These diverse effects of RIG-I signaling are likely imparted by the actions of type I interferon (IFN), as addition of exogenous type I IFN is sufficient to overcome the defects in antigen presentation by RIG-I deficient BMDC. Moreover, the in vivo T cell defects in RIG-I deficient mice can be overcome by the activation of MDA5 –MAVS via poly I:C treatment. Taken together, these findings demonstrate that RIG-I signaling through MAVS is critical for determining the quality of polyfunctional T cell responses against IAV and for providing protection against subsequent infection from heterologous or novel pandemic IAV strains. PMID:27438481

  19. Polyfunctional CD4 T cells in the response to bovine tuberculosis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Polyfunctional CD4 T cells simultaneously produce interferon-gamma (IFN-gamma), interleukin-2 (IL-2) and tumor necrosis factor-alpha (TNF-alpha) and play relevant roles in several chronic infections, including human TB and HIV. However, the assessment of this response in bovine infections was not fe...

  20. CALORIE RESTRICTION ENHANCES T CELL MEDIATED IMMUNE RESPONSE IN OVERWEIGHT MEN AND WOMEN

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It is well known that dietary energy restriction prolongs lifespan and enhances immune responsiveness in a wide range of laboratory animals. However, information on the applicability of these results to humans is limited. In this study we examined the effects of calorie restriction on T cell mediate...

  1. Mycolactone suppresses T cell responsiveness by altering both early signaling and posttranslational events.

    PubMed

    Boulkroun, Sheerazed; Guenin-Macé, Laure; Thoulouze, Maria-Isabel; Monot, Marc; Merckx, Anaïs; Langsley, Gordon; Bismuth, Georges; Di Bartolo, Vincenzo; Demangel, Caroline

    2010-02-01

    Mycolactone is a diffusible lipid toxin produced by Mycobacterium ulcerans, the causative agent of a necrotizing skin disease referred to as Buruli ulcer. Intriguingly, patients with progressive lesions display a systemic suppression of Th1 responses that resolves on surgical excision of infected tissues. In this study, we examined the effects of mycolactone on the functional biology of T cells and identified two mechanisms by which mycolactone suppresses cell responsiveness to antigenic stimulation. At noncytotoxic concentrations, mycolactone blocked the activation-induced production of cytokines by a posttranscriptional, mammalian target of rapamycin, and cellular stress-independent mechanism. In addition, mycolactone triggered the lipid-raft association and activation of the Src-family kinase, Lck. Mycolactone-mediated hyperactivation of Lck resulted in the depletion of intracellular calcium stores and downregulation of the TCR, leading to impaired T cell responsiveness to stimulation. These biochemical alterations were not observed when T cells were exposed to other bacterial lipids, or to structurally related immunosuppressors. Mycolactone thus constitutes a novel type of T cell immunosuppressive agent, the potent activity of which may explain the defective cellular responses in Buruli ulcer patients. PMID:20042571

  2. Innate lymphoid cells regulate CD4+ T-cell responses to intestinal commensal bacteria.

    PubMed

    Hepworth, Matthew R; Monticelli, Laurel A; Fung, Thomas C; Ziegler, Carly G K; Grunberg, Stephanie; Sinha, Rohini; Mantegazza, Adriana R; Ma, Hak-Ling; Crawford, Alison; Angelosanto, Jill M; Wherry, E John; Koni, Pandelakis A; Bushman, Frederic D; Elson, Charles O; Eberl, Gérard; Artis, David; Sonnenberg, Gregory F

    2013-06-01

    Innate lymphoid cells (ILCs) are a recently characterized family of immune cells that have critical roles in cytokine-mediated regulation of intestinal epithelial cell barrier integrity. Alterations in ILC responses are associated with multiple chronic human diseases, including inflammatory bowel disease, implicating a role for ILCs in disease pathogenesis. Owing to an inability to target ILCs selectively, experimental studies assessing ILC function have predominantly used mice lacking adaptive immune cells. However, in lymphocyte-sufficient hosts ILCs are vastly outnumbered by CD4(+) T cells, which express similar profiles of effector cytokines. Therefore, the function of ILCs in the presence of adaptive immunity and their potential to influence adaptive immune cell responses remain unknown. To test this, we used genetic or antibody-mediated depletion strategies to target murine ILCs in the presence of an adaptive immune system. We show that loss of retinoic-acid-receptor-related orphan receptor-γt-positive (RORγt(+)) ILCs was associated with dysregulated adaptive immune cell responses against commensal bacteria and low-grade systemic inflammation. Remarkably, ILC-mediated regulation of adaptive immune cells occurred independently of interleukin (IL)-17A, IL-22 or IL-23. Genome-wide transcriptional profiling and functional analyses revealed that RORγt(+) ILCs express major histocompatibility complex class II (MHCII) and can process and present antigen. However, rather than inducing T-cell proliferation, ILCs acted to limit commensal bacteria-specific CD4(+) T-cell responses. Consistent with this, selective deletion of MHCII in murine RORγt(+) ILCs resulted in dysregulated commensal bacteria-dependent CD4(+) T-cell responses that promoted spontaneous intestinal inflammation. These data identify that ILCs maintain intestinal homeostasis through MHCII-dependent interactions with CD4(+) T cells that limit pathological adaptive immune cell responses to commensal

  3. CD4(+)and CD8(+)T-cell reactions against leukemia-associated- or minor-histocompatibility-antigens in AML-patients after allogeneic SCT.

    PubMed

    Steger, Brigitte; Milosevic, Slavoljub; Doessinger, Georg; Reuther, Susanne; Liepert, Anja; Braeu, Marion; Schick, Julia; Vogt, Valentin; Schuster, Friedhelm; Kroell, Tanja; Busch, Dirk H; Borkhardt, Arndt; Kolb, Hans-Jochem; Tischer, Johanna; Buhmann, Raymund; Schmetzer, Helga

    2014-04-01

    T-cells play an important role in the remission-maintenance in AML-patients (pts) after SCT, however the role of LAA- (WT1, PR1, PRAME) or minor-histocompatibility (mHag, HA1) antigen-specific CD4(+) and CD8(+)T-cells is not defined. A LAA/HA1-peptide/protein stimulation, cloning and monitoring strategy for specific CD8(+)/CD4(+)T-cells in AML-pts after SCT is given. Our results show that (1) LAA-peptide-specific CD8+T-cells are detectable in every AML-pt after SCT. CD8(+)T-cells, recognizing two different antigens detectable in 5 of 7 cases correlate with long-lasting remissions. Clonal TCR-Vβ-restriction exemplarily proven by spectratyping in PRAME-specific CD8(+)T-cells; high PRAME-peptide-reactivity was CD4(+)-associated, as shown by IFN-γ-release. (2) Two types of antigen-presenting cells (APCs) were tested for presentation of LAA/HA1-proteins to CD4(+)T-cells: miniEBV-transduced lymphoblastoid cells (B-cell-source) and CD4-depleted MNC (source for B-cell/monocyte/DC). We provide a refined cloning-system for proliferating, CD40L(+)CD4(+)T-cells after LAA/HA1-stimulation. CD4(+)T-cells produced cytokines (GM-CSF, IFN-γ) upon exposure to LAA/HA1-stimulation until after at least 7 restimulations and demonstrated cytotoxic activity against naive blasts, but not fibroblasts. Antileukemic activity of unstimulated, stimulated or cloned CD4(+)T-cells correlated with defined T-cell-subtypes and the clinical course of the disease. In conclusion we provide immunological tools to enrich and monitor LAA/HA1-CD4(+)- and CD8(+)T-cells in AML-pts after SCT and generate data with relevant prognostic value. We were able to demonstrate the presence of LAA-peptide-specific CD8(+)T-cell clones in AML-pts after SCT. In addition, we were also able to enrich specific antileukemic reactive CD4(+)T-cells without GvH-reactivity upon repeated LAA/HA1-protein stimulation and limiting dilution cloning. PMID:24315637

  4. Cord blood T cells mediate enhanced antitumor effects compared with adult peripheral blood T cells.

    PubMed

    Hiwarkar, Prashant; Qasim, Waseem; Ricciardelli, Ida; Gilmour, Kimberly; Quezada, Sergio; Saudemont, Aurore; Amrolia, Persis; Veys, Paul

    2015-12-24

    Unrelated cord blood transplantation (CBT) without in vivo T-cell depletion is increasingly used to treat high-risk hematologic malignancies. Following T-replete CBT, naïve CB T cells undergo rapid peripheral expansion with memory-effector differentiation. Emerging data suggest that unrelated CBT, particularly in the context of HLA mismatch and a T-replete graft, may reduce leukemic relapse. To study the role of CB T cells in mediating graft-versus-tumor responses and dissect the underlying immune mechanisms for this, we compared the ability of HLA-mismatched CB and adult peripheral blood (PB) T cells to eliminate Epstein-Barr virus (EBV)-driven human B-cell lymphoma in a xenogeneic NOD/SCID/IL2rg(null) mouse model. CB T cells mediated enhanced tumor rejection compared with equal numbers of PB T cells, leading to improved survival in the CB group (P < .0003). Comparison of CB T cells that were autologous vs allogeneic to the lymphoma demonstrated that this antitumor effect was mediated by alloreactive rather than EBV-specific T cells. Analysis of tumor-infiltrating lymphocytes demonstrated that CB T cells mediated this enhanced antitumor effect by rapid infiltration of the tumor with CCR7(+)CD8(+) T cells and prompt induction of cytotoxic CD8(+) and CD4(+) T-helper (Th1) T cells in the tumor microenvironment. In contrast, in the PB group, this antilymphoma effect is impaired because of delayed tumoral infiltration of PB T cells and a relative bias toward suppressive Th2 and T-regulatory cells. Our data suggest that, despite being naturally programmed toward tolerance, reconstituting T cells after unrelated T-replete CBT may provide superior Tc1-Th1 antitumor effects against high-risk hematologic malignancies. PMID:26450984

  5. Clonal expansion of antitumor T cells in breast cancer correlates with response to neoadjuvant chemotherapy

    PubMed Central

    Park, Jae-Hyun; Jang, Miran; Tarhan, Yunus Emre; Katagiri, Toyomasa; Sasa, Mitsunori; Miyoshi, Yasuo; Kalari, Krishna R.; Suman, Vera J.; Weinshilboum, Richard; Wang, Liewei; Boughey, Judy C.; Goetz, Matthew P.; Nakamura, Yusuke

    2016-01-01

    The immune microenvironment of tumor plays a critical role in therapeutic responses to chemotherapy. Cancer tissues are composed of a complex network between anti-tumor and pro-tumor immune cells and molecules; therefore a comprehensive analysis of the tumor immune condition is imperative for better understanding of the roles of the immune microenvironment in anticancer treatment response. In this study, we performed T cell receptor (TCR) repertoire analysis of tumor infiltrating T cells (TILs) in cancer tissues of pre- and post-neoadjuvant chemotherapy (NAC) from 19 breast cancer patients; five cases showed CR (complete response), ten showed PR (partial response), and four showed SD/PD (stable disease/progressive disease) to the treatment. From the TCR sequencing results, we calculated the diversity index of the TCRβ chain and found that clonal expansion of TILs could be detected in patients who showed CR or PR to NAC. Noteworthy, the diversity of TCR was further reduced in the post-NAC tumors of CR patients. Our quantitative RT-PCR also showed that expression ratio of CD8/Foxp3 was significantly elevated in the post-NAC tumors of CR cases (p=0.0032), indicating that antitumor T cells were activated and enriched in these tumors. Collectively, our findings suggest that the clonal expansion of antitumor T cells may be a critical factor associated with response to chemotherapy and that their TCR sequences might be applicable for the development of TCR-engineered T cells treatment for individual breast cancer patients when their tumors relapse. PMID:27278091

  6. T cells from the tumor microenvironment of patients with progressive myeloma can generate strong, tumor-specific cytolytic responses to autologous, tumor-loaded dendritic cells

    NASA Astrophysics Data System (ADS)

    Dhodapkar, Madhav V.; Krasovsky, Joseph; Olson, Kara

    2002-10-01

    Most untreated cancer patients develop progressive tumors. We tested the capacity of T lymphocytes from patients with clinically progressive, multiple myeloma to develop killer function against fresh autologous tumor. In this malignancy, it is feasible to reproducibly evaluate freshly isolated tumor cells and T cells from the marrow tumor environment. When we did this with seven consecutive patients, with all clinical stages of disease, we did not detect reactivity to autologous cancer cells. However, both cytolytic and IFN--producing responses to autologous myeloma were generated in six of seven patients after stimulation ex vivo with dendritic cells that had processed autologous tumor cells. The antitumor effectors recognized fresh autologous tumor but not nontumor cells in the bone marrow, myeloma cell lines, dendritic cells loaded with tumor-derived Ig, or allogeneic tumor. Importantly, these CD8+ effectors developed with similar efficiency by using T cells from both the blood and the bone marrow tumor environment. Therefore, even in the setting of clinical tumor progression, the tumor bed of myeloma patients contains T cells that can be activated readily by dendritic cells to kill primary autologous tumor.

  7. Lethal giant larvae-1 deficiency enhances the CD8(+) effector T-cell response to antigen challenge in vivo.

    PubMed

    Ramsbottom, Kelly M; Sacirbegovic, Faruk; Hawkins, Edwin D; Kallies, Axel; Belz, Gabrielle T; Van Ham, Vanessa; Haynes, Nicole M; Durrant, Michael J; Humbert, Patrick O; Russell, Sarah M; Oliaro, Jane

    2016-03-01

    Lethal giant larvae-1 (Lgl-1) is an evolutionary conserved protein that regulates cell polarity in diverse lineages; however, the role of Lgl-1 in the polarity and function of immune cells remains to be elucidated. To assess the role of Lgl-1 in T cells, we generated chimeric mice with a hematopoietic system deficient for Lgl-1. Lgl-1 deficiency did not impair the activation or function of peripheral CD8(+) T cells in response to antigen presentation in vitro, but did skew effector and memory T-cell differentiation. When challenged with antigen-expressing virus or tumor, Lgl-1-deficient mice displayed altered T-cell responses. This manifested in a stronger antiviral and antitumor effector CD8(+) T-cell response, the latter resulting in enhanced control of MC38-OVA tumors. These results reveal a novel role for Lgl-1 in the regulation of virus-specific T-cell responses and antitumor immunity. PMID:26391810

  8. MicroRNA-17-92 controls T-cell responses in graft-versus-host disease and leukemia relapse in mice.

    PubMed

    Wu, Yongxia; Heinrichs, Jessica; Bastian, David; Fu, Jianing; Nguyen, Hung; Schutt, Steven; Liu, Yuejun; Jin, Junfei; Liu, Chen; Li, Qi-Jing; Xia, Changqing; Yu, Xue-Zhong

    2015-09-10

    MicroRNAs (miRs) play important roles in orchestrating many aspects of the immune response. The miR-17-92 cluster, which encodes 6 miRs including 17, 18a, 19a, 20a, 19b-1, and 92-1, is among the best characterized of these miRs. The miR-17-92 cluster has been shown to regulate a variety of immune responses including infection, tumor, and autoimmunity, but the role of this cluster in T-cell response to alloantigens has not been previously explored. By using major histocompatibility complex (MHC)-matched, -mismatched, and haploidentical murine models of allogeneic bone marrow transplantation (allo-BMT), we demonstrate that the expression of miR-17-92 on donor T cells is essential for the induction of graft-versus-host disease (GVHD), but dispensable for the graft-versus-leukemia (GVL) effect. The miR-17-92 plays a major role in promoting CD4 T-cell activation, proliferation, survival, and Th1 differentiation, while inhibiting Th2 and iTreg differentiation. Alternatively, miR-17-92 may promote migration of CD8 T cells to GVHD target organs, but has minimal impact on CD8 T-cell proliferation, survival, or cytolytic function, which could contribute to the preserved GVL effect mediated by T cells deficient for miR-17-92. Furthermore, we evaluated a translational approach and found that systemic administration of antagomir to block miR-17 or miR-19b in this cluster significantly inhibited alloreactive T-cell expansion and interferon-γ (IFNγ) production, and prolonged the survival in recipients afflicted with GVHD while preserving the GVL effect. Taken together, the current work provides a strong rationale and demonstrates the feasibility to target miR-17-92 for the control of GVHD while preserving GVL activity after allo-BMT. PMID:26138686

  9. Full-breadth analysis of CD8+ T-cell responses in acute hepatitis C virus infection and early therapy.

    PubMed

    Lauer, Georg M; Lucas, Michaela; Timm, Joerg; Ouchi, Kei; Kim, Arthur Y; Day, Cheryl L; Schulze Zur Wiesch, Julian; Paranhos-Baccala, Glaucia; Sheridan, Isabelle; Casson, Deborah R; Reiser, Markus; Gandhi, Rajesh T; Li, Bin; Allen, Todd M; Chung, Raymond T; Klenerman, Paul; Walker, Bruce D

    2005-10-01

    Multispecific CD8(+) T-cell responses are thought to be important for the control of acute hepatitis C virus (HCV) infection, but to date little information is actually available on the breadth of responses at early time points. Additionally, the influence of early therapy on these responses and their relationships to outcome are controversial. To investigate this issue, we performed comprehensive analysis of the breadth and frequencies of virus-specific CD8(+) T-cell responses on the single epitope level in eight acutely infected individuals who were all started on early therapy. During the acute phase, responses against up to five peptides were identified. During therapy, CD8(+) T-cell responses decreased rather than increased as virus was controlled, and no new specificities emerged. A sustained virological response following completion of treatment was independent of CD8(+) T-cell responses, as well as CD4(+) T-cell responses. Rapid recrudescence also occurred despite broad CD8(+) T-cell responses. Importantly, in vivo suppression of CD3(+) T cells using OKT3 in one subject did not result in recurrence of viremia. These data suggest that broad CD8(+) T-cell responses alone may be insufficient to contain HCV replication, and also that early therapy is effective independent of such responses. PMID:16189000

  10. Long-Term Non-Progression and Broad HIV-1-Specific Proliferative T-Cell Responses

    PubMed Central

    Imami, Nesrina; Westrop, Samantha J.; Grageda, Nathali; Herasimtschuk, Anna A.

    2013-01-01

    Complex mechanisms underlying the maintenance of fully functional, proliferative, HIV-1-specific T-cell responses involve processes from early T-cell development through to the final stages of T-cell differentiation and antigen recognition. Virus-specific proliferative CD4 and CD8 T-cell responses, important for the control of infection, are observed in some HIV-1+ patients during early stages of disease, and are maintained in long-term non-progressing subjects. In the vast majority of HIV-1+ patients, full immune functionality is lost when proliferative HIV-1-specific T-cell responses undergo a variable progressive decline throughout the course of chronic infection. This appears irreparable despite administration of potent combination antiretroviral therapy, which to date is non-curative, necessitating life-long administration and the development of effective, novel, therapeutic interventions. While a sterilizing cure, involving clearance of virus from the host, remains a primary aim, a “functional cure” may be a more feasible goal with considerable impact on worldwide HIV-1 infection. Such an approach would enable long-term co-existence of host and virus in the absence of toxic and costly drugs. Effective immune homeostasis coupled with a balanced response appropriately targeting conserved viral antigens, in a manner that avoids hyperactivation and exhaustion, may prove to be the strongest correlate of durable viral control. This review describes novel concepts underlying full immune functionality in the context of HIV-1 infection, which may be utilized in future strategies designed to improve upon existing therapy. The aim will be to induce long-term non-progressor or elite controller status in every infected host, through immune-mediated control of viremia and reduction of viral reservoirs, leading to lower HIV-1 transmission rates. PMID:23459797

  11. 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

  12. Only a Subset of Phosphoantigen-responsive γ9δ2 T cells Mediate Protective TB Immunity1

    PubMed Central

    Spencer, Charles Thomas; Abate, Getahun; Blazevic, Azra; Hoft, Daniel F.

    2009-01-01

    Mycobacterium tuberculosis and M. bovis-BCG induce potent expansions of human memory Vγ9+Vδ2+ T cells capable of IFN-γ production, cytolytic activity and mycobacterial growth inhibition. Certain phosphoantigens expressed by mycobacteria can stimulate γ9δ2 T cell expansions, suggesting that purified or synthetic forms of these phosphoantigens may be useful alone or as components of new vaccines or immunotherapeutics. However, we show that while mycobacteria-activated γ9δ2 T cells potently inhibit intracellular mycobacterial growth, phosphoantigen-activated γ9δ2 T cells fail to inhibit mycobacteria, although both develop similar effector cytokine and cytolytic functional capacities. γ9δ2 T cells receiving TLR-mediated co-stimulation during phosphoantigen activation also failed to inhibit mycobacterial growth. We hypothesized that mycobacteria express antigens, other than the previously identified phosphoantigens, that induce protective subsets of γ9δ2 T cells. Testing this hypothesis, we compared the TCR sequence diversity of γ9δ2 T cells expanded with BCG-infected versus phosphoantigen-treated DC. BCG-stimulated γ9δ2 T cells displayed a more restricted TCR diversity than phosphoantigen-activated γ9δ2 T cells. In addition, only a subset of phosphoantigen-activated γ9δ2 T cells functionally responded to mycobacteria-infected DC. Furthermore, differential inhibitory functions of BCG- and phosphoantigen-activated γ9δ2 T cells were confirmed at the clonal level and were not due to differences in TCR avidity. Our results demonstrate that BCG infection can activate and expand protective subsets of phosphoantigen responsive γ9δ2 T cells, and provide the first indication that γ9δ2 T cells can develop pathogen specificity similar to αβ T cells. Specific targeting of protective γ9δ2 T cell subsets will be important for future tuberculosis vaccines. PMID:18802050

  13. The CD3-zeta chimeric antigen receptor overcomes TCR Hypo-responsiveness of human terminal late-stage T cells.

    PubMed

    Rappl, Gunter; Riet, Tobias; 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

  14. 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.

  15. Induction of CD8+ T cell responses through targeting of antigen to Dectin-2.

    PubMed

    Carter, Robert W; Thompson, Clare; Reid, Delyth M; Wong, Simon Y C; Tough, David F

    2006-02-01

    Targeted delivery of antigens to dendritic cells (DC) can be used to optimise immunisation. We investigated whether the efficacy with which immune responses are induced can be improved by targeting Ags to a C-type lectin receptor, Dectin-2. When anti-Dectin-2 mAbs were injected s.c., mAb binding was detected on a low percentage of DC in the draining lymph node. Ag conjugated to anti-Dectin-2 mAbs was presented efficiently to CD8+ T cells in vivo and elicited CD8+ T cell responses at low doses where free Ag failed to induce a response. The results reveal Dectin-2 as a potential targeting molecule for immunisation. PMID:16781694

  16. Breaking tolerance to self, circulating natural killer cells expressing inhibitory KIR for non-self HLA exhibit effector function after T cell-depleted allogeneic hematopoietic cell transplantation.

    PubMed

    Yu, Junli; Venstrom, Jeffrey M; Liu, Xiao-Rong; Pring, James; Hasan, Reenat S; O'Reilly, Richard J; Hsu, Katharine C

    2009-04-16

    Alloreactive natural killer (NK) cells are an important influence on hematopoietic stem cell transplantation (HSCT) outcome. In HLA-mismatched HSCT, alloreactivity occurs when licensed donor NK cells expressing inhibitory killer Ig-like receptors (KIR) for donor MHC class I ligands recognize the lack of the class I ligands in the mismatched recipient ("missing self"). Studies in HLA-matched HSCT, however, have also demonstrated improved outcome in patients lacking class I ligands for donor inhibitory KIR ("missing ligand"), indicating that classically nonlicensed donor NK cells expressing KIR for non-self MHC class I ligands may exhibit functional competence in HSCT. We examined NK function in 16 recipients of T cell-depleted allografts from HLA-identical or KIR-ligand matched donors after myeloablative therapy. After HSCT, nonlicensed NK cells expressing inhibitory KIR for non-self class I exhibit robust intracellular IFN-gamma and cytotoxic response to target cells lacking cognate ligand, gradually becoming tolerized to self by day 100. These findings could not be correlated with cytokine environment or phenotypic markers of NK development, nor could they be attributed to non-KIR receptors such as CD94/NKG2A. These findings confirm that NK alloreactivity can occur in HLA-matched HSCT, where tolerance to self is either acquired by the stem cell-derived NK cell after exiting the bone marrow or where tolerance to self can be temporarily overcome. PMID:19179302

  17. Protective Vaccine-Induced CD4+ T Cell-Independent B Cell Responses against Rabies Infection

    PubMed Central

    Dorfmeier, Corin L.; Lytle, Andrew G.; Dunkel, Amber L.; Gatt, Anthony

    2012-01-01

    A major goal in rabies virus (RV) research is to develop a single-dose postexposure prophylaxis (PEP) that would simplify vaccination protocols, reduce costs associated with rabies prevention in humans, and save lives. Live replication-deficient RV-based vaccines are emerging as promising single-dose vaccines to replace currently licensed inactivated RV-based vaccines. Nonetheless, little is known about how effective B cells develop in response to live RV-based vaccination. Understanding this fundamental property of rabies immunology may help in developing a single-dose RV vaccine. Typically, vaccines induce B cells secreting high-affinity, class-switched antibodies during germinal center (GC) reactions; however, there is a lag time between vaccination and the generation of GC B cells. In this report, we show that RV-specific antibodies are detected in mice immunized with live but not inactivated RV-based vaccines before B cells displaying a GC B cell phenotype (B220+GL7hiCD95hi) are formed, indicating a potential role for T cell-independent and early extrafollicular T cell-dependent antibody responses in the protection against RV infection. Using two mouse models of CD4+ T cell deficiency, we show that B cells secreting virus-neutralizing antibodies (VNAs) are induced via T cell-independent mechanisms within 4 days postimmunization with a replication-deficient RV-based vaccine. Importantly, mice that are completely devoid of T cells (B6.129P2-Tcrβtm1Mom Tcrδtm1Mom/J) show protection against pathogenic challenge shortly after immunization with a live replication-deficient RV-based vaccine. We show that vaccines that can exploit early pathways of B cell activation and development may hold the key for the development of a single-dose RV vaccine wherein the rapid induction of VNA is critical. PMID:22896601

  18. Mucosal and systemic T cell response in mice intragastrically infected with Neospora caninum tachyzoites

    PubMed Central

    2013-01-01

    The murine model has been widely used to study the host immune response to Neospora caninum. However, in most studies, the intraperitoneal route was preferentially used to establish infection. Here, C57BL/6 mice were infected with N. caninum tachyzoites by the intragastric route, as it more closely resembles the natural route of infection through the gastrointestinal tract. The elicited T-cell mediated immune response was evaluated in the intestinal epithelium and mesenteric lymph nodes (MLN). Early upon the parasitic challenge, IL-12 production by conventional and plasmacytoid dendritic cells was increased in MLN. Accordingly, increased proportions and numbers of TCRαβ+CD8+IFN-γ+ lymphocytes were detected, not only in the intestinal epithelium and MLN, but also in the spleen of the infected mice. In this organ, IFN-γ-producing TCRαβ+CD4+ T cells were also found to increase in the infected mice, however later than CD8+ T cells. Interestingly, splenic and MLN CD4+CD25+ T cells sorted from infected mice presented a suppressive activity on in vitro T cell proliferation and cytokine production above that of control counterparts. These results altogether indicate that, by producing IFN-γ, TCRαβ+CD8+ cells contribute for local and systemic host protection in the earliest days upon infection established through the gastrointestinal tract. Nevertheless, they also provide substantial evidence for a parasite-driven reinforcement of T regulatory cell function which may contribute for parasite persistence in the host and might represent an additional barrier to overcome towards effective vaccination. PMID:23937079

  19. Der p 1-pulsed myeloid and plasmacytoid dendritic cells from house dust mite-sensitized allergic patients dysregulate the T cell response.

    PubMed

    Charbonnier, Anne-Sophie; Hammad, Hamida; Gosset, Philippe; Stewart, Geoffrey A; Alkan, Sefik; Tonnel, André-Bernard; Pestel, Joël

    2003-01-01

    Although reports suggest that dendritic cells (DC) are involved in the allergic reaction characterized by a T helper cell type 2 (Th2) profile, the role of myeloid (M-DC) and plasmacytoid DC (P-DC), controlling the balance Th1/Th2, remains unknown. Here, we showed that in Dermatophagoides pteronyssinus (Dpt)-sensitized allergic patients and in healthy donors, M-DC displayed a higher capacity to capture Der p 1, a major allergen of Dpt, than did P-DC. However, Der p 1-pulsed M-DC from healthy subjects overexpressed CD80 and secreted interleukin (IL)-10, whereas M-DC from allergic patients did not. In contrast, with Der p 1-pulsed P-DC from both groups, no increase in human leukocyte antigen-DR, CD80, and CD86 and no IL-10 secretion were detected. When cocultured with allogeneic naive CD4(+) T cells from healthy donors, Der p 1-pulsed M-DC from allergic patients favored a Th1 profile [interferon (IFN)-gamma(high)/IL-4(low)] and Der p 1-pulsed P-DC, a Th2 profile (IFN-gamma(low)/IL-4(high)). In healthy donors, no T cell polarization (IFN-gamma(low)/IL-4(low)) was induced by Der p 1-pulsed M-DC or P-DC, but in response to Der p 1-pulsed M-DC, T cells secreted IL-10. The neutralization of IL-10 produced by Der p 1-pulsed M-DC from healthy donors led to an inhibition of IL-10 production by T cells and a polarization toward a type 1. Thus, IL-10 produced by M-DC might be an essential mediator controlling the balance between tolerance and allergic status. In addition, P-DC could contribute to the steady state in healthy donors or to the development of a Th2 response in allergic donors. PMID:12525566

  20. Precision cancer immunotherapy: optimizing dendritic cell-based strategies to induce tumor antigen-specific T-cell responses against individual patient tumors.

    PubMed

    Osada, Takuya; Nagaoka, Koji; Takahara, Masashi; Yang, Xiao Yi; Liu, Cong-Xiao; Guo, Hongtao; Roy Choudhury, Kingshuk; Hobeika, Amy; Hartman, Zachary; Morse, Michael A; Lyerly, H Kim

    2015-05-01

    Most dendritic cell (DC)-based vaccines have loaded the DC with defined antigens, but loading with autologos tumor-derived antigens would generate DCs that activate personalized tumor-specific T-cell responses. We hypothesized that DC matured with an optimized combination of reagents and loaded with tumor-derived antigens using a clinically feasible electroporation strategy would induce potent antitumor immunity. We first studied the effects on DC maturation and antigen presentation of the addition of picibanil (OK432) to a combination of zoledronic acid, tumor necrosis factor-α, and prostaglandin E2. Using DC matured with the optimized combination, we tested 2 clinically feasible sources of autologous antigen for electroloading, total tumor mRNA or total tumor lysate, to determine which stimulated more potent antigen-specific T cells in vitro and activated more potent antitumor immunity in vivo. The combination of tumor necrosis factor-α/prostaglandin E2/zoledronic acid/OK432 generated DC with high expression of maturation markers and antigen-specific T-cell stimulatory function in vitro. Mature DC electroloaded with tumor-derived mRNA [mRNA electroporated dendritic cell (EPDC)] induced greater expansion of antigen-specific T cells in vitro than DC electroloaded with tumor lysate (lysate EPDC). In a therapeutic model of MC38-carcinoembryonic antigen colon cancer-bearing mice, vaccination with mRNA EPDC induced the most efficient anti-carcinoembryonic antigen cellular immune response, which significantly suppressed tumor growth. In conclusion, mature DC electroloaded with tumor-derived mRNA are a potent cancer vaccine, especially useful when specific tumor antigens for vaccination have not been identified, allowing autologous tumor, and if unavailable, allogeneic cell lines to be used as an unbiased source of antigen. Our data support clinical testing of this strategy. PMID:25839441

  1. Polyfunctional cytokine responses by central memory CD4+T cells in response to bovine tuberculosis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    CD4 T cells are crucial in immunity to tuberculosis (TB). Polyfunctional CD4 T cells simultaneously produce interferon-gamma (IFN-gamma), interleukin-2 (IL-2) and tumor necrosis factor-alpha (TNF-alpha) and play relevant roles in several chronic infections, including human TB and HIV. Mycobacterium ...

  2. Polyfunctional cytokine responses by central memory CD4*T cells in response to bovine tuberculosis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    CD4 T cells are crucial in immunity to tuberculosis (TB). Polyfunctional CD4 T cells simultaneously produce interferon-gamma (IFN-gamma), interleukin-2 (IL-2) and tumor necrosis factor-alpha (TNF-alpha) and play relevant roles in several chronic infections, including human TB. Mycobacterium bovis in...

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

    PubMed Central

    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

    2015-01-01

    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. PMID:26870818

  4. 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. PMID:26870818

  5. Immunity to leprosy. II. Genetic control of murine T cell proliferative responses to Mycobacterium leprae.

    PubMed

    Douglas-Jones, A G; Watson, J D

    1985-10-01

    T cell proliferative responses to Mycobacterium leprae were measured after immunization of mice at the base of the tail with antigen and challenging lymphocytes from draining lymph nodes in culture with M. leprae. This T cell response to M. leprae has been compared in 18 inbred strains of mice. C57BL/10J mice were identified as low responder mice. The congenic strains B10.M and B10.Q were found to be high responders, whereas B10.BR and B10.P were low responders. F1 (B10.M X C57BL/10J) and F1 (B10.Q X C57BL/10J) hybrid mice were found to be low responders, similar to the C57BL/10J parent, indicating that the low responsive trait is dominant. Whereas B10.BR mice were shown to be low responders to M. leprae, B10.AKM and B10.A(2R) were clearly high responders, indicating that the H-2D region influences the magnitude of the T cell proliferative response. Gene complementation within the H-2 region was evident. Genes outside the H-2 region were also shown to influence the response to M. leprae. C3H/HeN were shown to be high responder mice, whereas other H-2k strains, BALB.K, CBA/N, and B10.BR, were low responders. Gene loci that influence the T cell proliferation assay have been discussed and were compared to known background genes which may be important for the growth of intracellular parasites. Because mycobacteria are intracellular parasites for antigen-presenting cells, genes that affect bacterial growth in these cells will also influence subsequent immune responses of the host. PMID:3928757

  6. T-cell response to phorbol ester PMA and calcium ionophore A23187 in Down's syndrome.

    PubMed

    Bertotto, A; Crupi, S; Arcangeli, C; Gerli, R; Scalise, F; Fabietti, G; Agea, E; Vaccaro, R

    1989-11-01

    The proliferative response of purified T cells to anti-CD2 monoclonal antibodies (T112 plus T113) was found to be markedly reduced in 12 subjects with Down's syndrome (DS). The addition of phorbol ester PMA, which activates Ca2+/phospholipid-dependent enzyme protein kinase C, or calcium ionophore A23187, which increases intracytosolic free Ca2+ concentration, enhanced, but did not normalize, the defective anti-CD2-mediated T-cell mitogenesis. In contrast, the proliferation of resting lymphocytes from trisomic patients was comparable to that of the control cells when PMA and A23187 were used as co-blastogenic reagents. Because PMA and A23187 together bypass the early activation pathways and promote T-cell growth through the direct induction of membrane interleukin 2 (IL-2) receptor expression and IL-2 synthesis and secretion, it could reasonably be hypothesized that the faulty DS T-cell activation induced by antigen or mitogen is due to a deranged transmembrane signal transduction, rather than a defect in the later intracellular events. PMID:2573952

  7. Tumor-associated neutrophils stimulate T cell responses in early-stage human lung cancer

    PubMed Central

    Eruslanov, Evgeniy B.; Bhojnagarwala, Pratik S.; Quatromoni, Jon G.; Stephen, Tom Li; Ranganathan, Anjana; Deshpande, Charuhas; Akimova, Tatiana; Vachani, Anil; Litzky, Leslie; Hancock, Wayne W.; Conejo-Garcia, José R.; Feldman, Michael; Albelda, Steven M.; Singhal, Sunil

    2014-01-01

    Infiltrating inflammatory cells are highly prevalent within the tumor microenvironment and mediate many processes associated with tumor progression; however, the contribution of specific populations remains unclear. For example, the nature and function of tumor-associated neutrophils (TANs) in the cancer microenvironment is largely unknown. The goal of this study was to provide a phenotypic and functional characterization of TANs in surgically resected lung cancer patients. We found that TANs constituted 5%–25% of cells isolated from the digested human lung tumors. Compared with blood neutrophils, TANs displayed an activated phenotype (CD62LloCD54hi) with a distinct repertoire of chemokine receptors that included CCR5, CCR7, CXCR3, and CXCR4. TANs produced substantial quantities of the proinflammatory factors MCP-1, IL-8, MIP-1α, and IL-6, as well as the antiinflammatory IL-1R antagonist. Functionally, both TANs and neutrophils isolated from distant nonmalignant lung tissue were able to stimulate T cell proliferation and IFN-γ release. Cross-talk between TANs and activated T cells led to substantial upregulation of CD54, CD86, OX40L, and 4-1BBL costimulatory molecules on the neutrophil surface, which bolstered T cell proliferation in a positive-feedback loop. Together our results demonstrate that in the earliest stages of lung cancer, TANs are not immunosuppressive, but rather stimulate T cell responses. PMID:25384214

  8. Polyfunctional cytokine production by central memory T cells from cattle in response to Mycobacterium bovis infection and BCG vaccination

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Polyfunctional T cells simultaneously produce IFN-gamma, IL-2 and TNF-alpha and play relevant roles in several chronic infections, including TB. Mycobacterium bovis infection of cattle elicits ex vivo polyfunctional T cell responses. Vaccine-elicited IFN-gamma Tcm (CD4+ CD45RO+ CCR7+) responses corr...

  9. Oncolytic vesicular stomatitis virus quantitatively and qualitatively improves primary CD8(+) T-cell responses to anticancer vaccines.

    PubMed

    Bridle, Byram W; Clouthier, Derek; Zhang, Liang; Pol, Jonathan; Chen, Lan; Lichty, Brian D; Bramson, Jonathan L; Wan, Yonghong

    2013-08-01

    The ability of heterologous prime-boost vaccination to elicit robust CD8(+) T cell responses has been well documented. In contrast, relatively little is known about how this immunotherapeutic strategy impacts the functional qualities of expanded T cells in the course of effector and memory responses. Using vesicular stomatitis virus (VSV) as a boosting vector in mice, we demonstrate that a massive secondary expansion of CD8(+) T cells can be achieved shortly after priming with recombinant adenoviral vectors. Importantly, VSV-boosted CD8(+) T cells were more potent than those primed by adenoviruses only, as measured by cytokine production, granzyme B expression, and functional avidity. Upon adoptive transfer, equivalent numbers of VSV-expanded CD8(+) T cells were more effective (on a per-cell basis) in mediating antitumor and antiviral immunity than T cells only primed with adenoviruses. Furthermore, VSV boosting accelerated the progression of expanded CD8(+) T lymphocytes to a central memory phenotype, thereby altering the effector memory profile typically associated with adenoviral vaccination. Finally, the functional superiority of VSV-expanded T cells remained evident 100 d after boosting, suggesting that VSV-driven immunological responses are of sufficient duration for therapeutic applications. Our data strongly support the choice of VSV as a boosting vector in prime-boost vaccination strategies, enabling a rapid amplification of CD8(+) T cells and improving the quality of expanded T cells during both early and late immunological responses. PMID:24083086

  10. Alterations in Regulatory T Cells Induced by Specific Oligosaccharides Improve Vaccine Responsiveness in Mice

    PubMed Central

    Schijf, Marcel A.; Kerperien, JoAnn; Bastiaans, Jacqueline; Szklany, Kirsten; Meerding, Jenny; Hofman, Gerard; Boon, Louis; van Wijk, Femke; Garssen, Johan; van’t Land, Belinda

    2013-01-01

    Prophylactic vaccinations are generally performed to protect naïve individuals with or without suppressed immune responsiveness. In a mouse model for Influenza vaccinations the specific alterations of CD4+CD25+Foxp3+ regulatory T-cells (Tregs) in the immune modulation induced by orally supplied oligosaccharides containing scGOS/lcFOS/pAOS was assessed. This dietary intervention increased vaccine specific DTH responses. In addition, a significant increased percentage of T-bet+ (Th1) activated CD69+CD4+ T cells (p<0.001) and reduced percentage of Gata-3+ (Th2) activated CD69+CD4+T cells (p<0.001) was detected in the mesenteric lymph nodes (MLN) of mice receiving scGOS/lcFOS/pAOS compared to control mice. Although no difference in the number or percentage of Tregs (CD4+Foxp3+) could be determined after scGOS/lcFOS/pAOS intervention, the percentage of CXCR3 + /T-bet+ (Th1-Tregs) was significantly reduced (p<0.05) in mice receiving scGOS/lcFOS/pAOS as compared to mice receiving placebo diets. Moreover, although no absolute difference in suppressive capacity could be detected, an alteration in cytokine profile suggests a regulatory T cell shift towards a reducing Th1 suppression profile, supporting an improved vaccination response. In conclusion These data are indicative for improved vaccine responsiveness due to reduced Th1 suppressive capacity in the Treg population of mice fed the oligosaccharide specific diet, showing compartmentalization within the Treg population. The modulation of Tregs to control immune responses provides an additional arm of intervention using alternative strategies possibly leading to the development of improved vaccines. PMID:24073243

  11. Interleukin-7 Modulates Anti-Tumor CD8+ T Cell Responses via Its Action on Host Cells

    PubMed Central

    Deiser, Katrin; Stoycheva, Diana; Bank, Ute; Blankenstein, Thomas; Schüler, Thomas

    2016-01-01

    The adoptive transfer of antigen-specific CD8+ T cells is a promising approach for the treatment of chronic viral and malignant diseases. In order to improve adoptive T cell therapy (ATT) of cancer, recent strategies aim at the antibody-based blockade of immunosuppressive signaling pathways in CD8+ T cells. Alternatively, adjuvant effects of immunostimulatory cytokines might be exploited to improve therapeutic CD8+ T cell responses. For example, Interleukin-7 (IL-7) is a potent growth, activation and survival factor for CD8+ T cells that can be used to improve virus- and tumor-specific CD8+ T cell responses. Although direct IL-7 effects on CD8+ T cells were studied extensively in numerous models, the contribution of IL-7 receptor-competent (IL-7R+) host cells remained unclear. In the current study we provide evidence that CD8+ T cell-mediated tumor rejection in response to recombinant IL-7 (rIL-7) therapy is strictly dependent on IL-7R+ host cells. On the contrary, CD8+ T cell expansion is independent of host IL-7R expression. If, however, rIL-7 therapy and peptide vaccination are combined, host IL-7R signaling is crucial for CD8+ T cell expansion. Unexpectedly, maximum CD8+ T cell expansion relies mainly on IL-7R signaling in non-hematopoietic host cells, similar to the massive accumulation of dendritic cells and granulocytes. In summary, we provide evidence that IL-7R+ host cells are major targets of rIL-7 that modulate therapeutic CD8+ T cell responses and the outcome of rIL-7-assisted ATT. This knowledge may have important implications for the design and optimization of clinical ATT protocols. PMID:27447484

  12. Interleukin-7 Modulates Anti-Tumor CD8+ T Cell Responses via Its Action on Host Cells.

    PubMed

    Deiser, Katrin; Stoycheva, Diana; Bank, Ute; Blankenstein, Thomas; Schüler, Thomas

    2016-01-01

    The adoptive transfer of antigen-specific CD8+ T cells is a promising approach for the treatment of chronic viral and malignant diseases. In order to improve adoptive T cell therapy (ATT) of cancer, recent strategies aim at the antibody-based blockade of immunosuppressive signaling pathways in CD8+ T cells. Alternatively, adjuvant effects of immunostimulatory cytokines might be exploited to improve therapeutic CD8+ T cell responses. For example, Interleukin-7 (IL-7) is a potent growth, activation and survival factor for CD8+ T cells that can be used to improve virus- and tumor-specific CD8+ T cell responses. Although direct IL-7 effects on CD8+ T cells were studied extensively in numerous models, the contribution of IL-7 receptor-competent (IL-7R+) host cells remained unclear. In the current study we provide evidence that CD8+ T cell-mediated tumor rejection in response to recombinant IL-7 (rIL-7) therapy is strictly dependent on IL-7R+ host cells. On the contrary, CD8+ T cell expansion is independent of host IL-7R expression. If, however, rIL-7 therapy and peptide vaccination are combined, host IL-7R signaling is crucial for CD8+ T cell expansion. Unexpectedly, maximum CD8+ T cell expansion relies mainly on IL-7R signaling in non-hematopoietic host cells, similar to the massive accumulation of dendritic cells and granulocytes. In summary, we provide evidence that IL-7R+ host cells are major targets of rIL-7 that modulate therapeutic CD8+ T cell responses and the outcome of rIL-7-assisted ATT. This knowledge may have important implications for the design and optimization of clinical ATT protocols. PMID:27447484

  13. Cyclic dinucleotides modulate human T-cell response through monocyte cell death.

    PubMed

    Tosolini, Marie; Pont, Frédéric; Verhoeyen, Els; Fournié, Jean-Jacques

    2015-12-01

    Cyclic dinucleotides, a class of microbial messengers, have been recently identified in bacteria, but their activity in humans remains largely unknown. Here, we have studied the function of cyclic dinucleotides in humans. We found that c-di-AMP and cGAMP, two adenosine-based cyclic dinucleotides, activated T lymphocytes in an unusual manner through monocyte cell death. c-di-AMP and cGAMP induced the selective apoptosis of human monocytes, and T lymphocytes were activated by the direct contact with these dying monocytes. The ensuing T-cell response comprised cell-cycle exit, phenotypic maturation into effector memory cells and proliferation arrest, but not cell death. This quiescence was transient since T cells remained fully responsive to further restimulation. Together, our results depict a novel activation pattern for human T lymphocytes: a transient quiescence induced by c-di-AMP- or cGAMP-primed apoptotic monocytes. PMID:26460927

  14. Response of lung γδ T cells to experimental sepsis in mice

    PubMed Central

    Hirsh, Mark; Dyugovskaya, Larissa; Kaplan, Viktoria; Krausz, Michael M

    2004-01-01

    γδ T cells link innate and adaptive immune systems and may regulate host defence. Their role in systemic inflammation induced by trauma or infection (sepsis) is still obscured. The present study was aimed to investigate functions of lung γδ T cells and their response to experimental sepsis. Mice were subjected to caecal ligation and puncture (CLP) to induce sepsis and acute lung injury (ALI), or to the sham operation. Animals were killed 1, 4, and 7 days postoperatively; lungs were examined by histology, and isolated cells were studied by flow cytometry. Absolute number of γδ T cells progressively increased in lungs during sepsis, and reached a seven-fold increase at day 7 after CLP (3·84 ± 0·41 × 105/lung; P = 0·0002 versus sham). A cellular dysfunction was revealed one day after CLP, as manifested by low cytolytic activity (22·3 ± 7·1%; P < 0·05 versus sham), low interferon-γ (IFN-γ; 8·5 ± 2·5%; P < 0·05 versus control) and interleukin-10 (IL-10) expression, and high tumour necrosis factor-α expression (19·5 ± 1·7%; P < 0·05 versus control). The restoration of cytotoxicity, and increase in IFN-γ and IL-10 expression was observed at day 7 of CLP-induced sepsis. In summary, our results demonstrate significant progressive accumulation of γδ T cells in lungs during CLP-induced ALI. The temporary functional suppression of lung γδ T cells found early after CLP may influence the outcome of sepsis, possibly being associated with uncontrolled inflammatory lung damage. PMID:15096194

  15. Deficient EBV-Specific B- and T-Cell Response in Patients with Chronic Fatigue Syndrome

    PubMed Central

    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. PMID:24454857

  16. Early CD4+ T Cell Responses Are Associated with Subsequent CD8+ T Cell Responses to an rAd5-Based Prophylactic Prime-Boost HIV Vaccine Strategy

    PubMed Central

    Lhomme, Edouard; Richert, Laura; Moodie, Zoe; Pasin, Chloé; Kalams, Spyros A.; Morgan, Cecilia; Self, Steve; De Rosa, Stephen C.; Thiébaut, Rodolphe

    2016-01-01

    Introduction Initial evaluation of a candidate vaccine against HIV includes an assessment of the vaccine’s ability to generate immune responses. However, the dynamics of vaccine-induced immune responses are unclear. We hypothesized that the IFN-γ producing cytotoxic CD8+ (CD8+ IFN-γ+) T cell responses could be predicted by early IL-2 producing CD4+ (CD4+ IL-2+) helper T cell responses, and we evaluated this hypothesis using data from a phase I/II prophylactic HIV vaccine trial. The objective was to assess the dynamics and correlations between CD4+ IL-2+ T cell and CD8+ IFN-γ+ T cell responses after vaccination with a recombinant adenoviral serotype 5 (rAd5) HIV vaccine. Methods We analyzed data from the HVTN 068 HIV vaccine trial, which evaluated the immunogenicity of two different strategies for prime and boost vaccination (rAd5-rAd5 vaccine versus DNA-rAd5) in 66 healthy volunteers. Spearman correlations between immunogenicity markers across time-points were calculated. CD8+ IFN-γ+ T cell response in the rAd5-rAd5 arm was modeled as a function of CD4+ IL-2+ T cell response and time using mixed effects regression models. Results Moderate to high correlations (r = 0.48–0.76) were observed in the rAd5-rAd5 arm between the CD4+ IL-2+ T cell response at week 2 and later CD8+ IFN-γ+ T cell responses (weeks 2–52). Regression models confirmed this relationship with a significant association between the two markers: for a 1.0% increase in CD4+ IL-2+ T cells at week 2 post-prime, a 0.3% increase in CD8+ IFN-γ+ T cell responses across subsequent time points, including post-boost time points, was observed (p<0.01). Conclusion These results suggest an early and leading role of CD4+ T cells in the cellular response to the rAd5-rAd5 vaccine and in particular the stimulation of cytotoxic CD8+ T cell responses. These results could inform better timing of CD4+ T cell measurements in future clinical trials. PMID:27124598

  17. Gamma delta T cell responses associated with the development of tuberculosis in health care workers.

    PubMed

    Ordway, Diane J; Pinto, Luisa; Costa, Leonor; Martins, Marta; Leandro, Clara; Viveiros, Miguel; Amaral, Leonard; Arroz, Maria J; Ventura, Fernando A; Dockrell, Hazel M

    2005-03-01

    This study evaluated T cell immune responses to purified protein derivative (PPD) and Mycobacterium tuberculosis (Mtb) in health care workers who remained free of active tuberculosis (HCWs w/o TB), health care workers who went on to develop active TB (HCWs w/TB), non-health care workers who were TB free (Non-HCWs) and tuberculosis patients presenting with minimal (Min TB) or advanced (Adv TB) disease. Peripheral blood mononuclear cells (PBMC) were stimulated with Mtb and PPD and the expression of T cell activation markers CD25+ and HLA-DR+, intracellular IL-4 and IFN-gamma production and cytotoxic responses were evaluated. PBMC from HCWs who developed TB showed decreased percentages of cells expressing CD8+CD25+ in comparison to HCWs who remained healthy. HCWs who developed TB showed increased gammadelta TCR+ cell cytotoxicity and decreased CD3+gammadelta TCR- cell cytotoxicity in comparison to HCWs who remained healthy. PBMC from TB patients with advanced disease showed decreased percentages of CD25+CD4+ and CD25+CD8+ T cells that were associated with increased IL-4 production in CD8+ and gammadelta TCR+ phenotypes, in comparison with TB patients presenting minimal disease. TB patients with advanced disease showed increased gammadelta TCR+ cytotoxicity and reduced CD3+gammadelta TCR- cell cytotoxicity. Our results suggest that HCWs who developed TB show an early compensatory mechanism involving an increase in lytic responses of gammadelta TCR+ cells which did not prevent TB. PMID:15708307

  18. Public T cell receptors confer high-avidity CD4 responses to HIV controllers.

    PubMed

    Benati, Daniela; Galperin, Moran; Lambotte, Olivier; Gras, Stéphanie; Lim, Annick; Mukhopadhyay, Madhura; Nouël, Alexandre; Campbell, Kristy-Anne; Lemercier, Brigitte; Claireaux, Mathieu; Hendou, Samia; Lechat, Pierre; de Truchis, Pierre; Boufassa, Faroudy; Rossjohn, Jamie; Delfraissy, Jean-François; Arenzana-Seisdedos, Fernando; Chakrabarti, Lisa A

    2016-06-01

    The rare patients who are able to spontaneously control HIV replication in the absence of therapy show signs of a particularly efficient cellular immune response. To identify the molecular determinants that underlie this response, we characterized the T cell receptor (TCR) repertoire directed at Gag293, the most immunoprevalent CD4 epitope in the HIV-1 capsid. HIV controllers from the ANRS CODEX cohort showed a highly skewed TCR repertoire that was characterized by a predominance of TRAV24 and TRBV2 variable genes, shared CDR3 motifs, and a high frequency of public clonotypes. The most prevalent public clonotypes generated TCRs with affinities at the higher end of values reported for naturally occurring TCRs. The high-affinity Gag293-specific TCRs were cross-restricted by up to 5 distinct HLA-DR alleles, accounting for the expression of these TCRs in HIV controllers of diverse genetic backgrounds. Transfer of these TCRs to healthy donor CD4+ T cells conferred high antigen sensitivity and polyfunctionality, thus recapitulating key features of the controller CD4 response. Transfer of a high-affinity Gag293-specific TCR also redirected CD8+ T cells to target HIV-1 capsid via nonconventional MHC II restriction. Together, these findings indicate that TCR clonotypes with superior functions are associated with HIV control. Amplification or transfer of such clonotypes may contribute to immunotherapeutic approaches aiming at a functional HIV cure. PMID:27111229

  19. Mcl-1 antagonizes Bax/Bak to promote effector CD4+ and CD8+ T-cell responses

    PubMed Central

    Tripathi, P; Koss, B; Opferman, J T; Hildeman, D A

    2013-01-01

    Members of the Bcl-2 family have critical roles in regulating tissue homeostasis by modulating apoptosis. Anti-apoptotic molecules physically interact and restrain pro-apoptotic family members preventing the induction of cell death. However, the specificity of the functional interactions between pro- and anti-apoptotic Bcl-2 family members remains unclear. The pro-apoptotic Bcl-2 family member Bcl-2 interacting mediator of death (Bim) has a critical role in promoting the death of activated, effector T cells following viral infections. Although Bcl-2 is an important Bim antagonist in effector T cells, and Bcl-xL is not required for effector T-cell survival, the roles of other anti-apoptotic Bcl-2 family members remain unclear. Here, we investigated the role of myeloid cell leukemia sequence 1 (Mcl-1) in regulating effector T-cell responses in vivo. We found, at the peak of the response to lymphocytic choriomeningitis virus (LCMV) infection, that Mcl-1 expression was increased in activated CD4+ and CD8+ T cells. Retroviral overexpression of Mcl-1-protected activated T cells from death, whereas deletion of Mcl-1 during the course of infection led to a massive loss of LCMV-specific CD4+ and CD8+ T cells. Interestingly, the co-deletion of Bim failed to prevent the loss of Mcl-1-deficient T cells. Furthermore, lck-driven overexpression of a Bcl-xL transgene only partially rescued Mcl-1-deficient effector T cells suggesting a lack of redundancy between the family members. In contrast, additional loss of Bax and Bak completely rescued Mcl-1-deficient effector T-cell number and function, without enhancing T-cell proliferation. These data suggest that Mcl-1 is critical for promoting effector T-cell responses, but does so by combating pro-apoptotic molecules beyond Bim. PMID:23558951

  20. Egr3 Induces a Th17 Response by Promoting the Development of γδ T Cells

    PubMed Central

    Parkinson, Rose M.; Collins, Samuel L.; Horton, Maureen R.; Powell, Jonathan D.

    2014-01-01

    The transcription factor Early Growth Response 3 (Egr3) has been shown to play an important role in negatively regulating T cell activation and promoting T cell anergy in Th1 cells. However, its role in regulating other T helper subsets has yet to be described. We sought to determine the role of Egr3 in a Th17 response using transgenic mice that overexpress Egr3 in T cells (Egr3 TG). Splenocytes from Egr3 TG mice demonstrated more robust generation of Th17 cells even under non-Th17 skewing conditions. We found that while Egr3 TG T cells were not intrinsically more likely to become Th17 cells, the environment encountered by these cells was more conducive to Th17 development. Further analysis revealed a considerable increase in the number of γδ T cells in both the peripheral lymphoid organs and mucosal tissues of Egr3 TG mice, a cell type which normally accounts for only a small fraction of peripheral lymphocytes. Consistent with this marked increase in peripheral γδ T cells, thymocytes from Egr3 TG mice also appear biased toward γδ T cell development. Coculture of these Egr3-induced γδ T cells with wildtype CD4+ T cells increases Th17 differentiation, and Egr3 TG mice are more susceptible to bleomycin-induced lung inflammation. Overall our findings strengthen the role for Egr3 in promoting γδ T cell development and show that Egr3-induced γδ T cells are both functional and capable of altering the adaptive immune response in a Th17-biased manner. Our data also demonstrates that the role played by Egr3 in T cell activation and differentiation is more complex than previously thought. PMID:24475259

  1. Regulatory T Cells Suppress Natural Killer Cells during Plasmid DNA Vaccination in Mice, Blunting the CD8+ T Cell Immune Response by the Cytokine TGFβ

    PubMed Central

    Frimpong-Boateng, Kwesi; van Rooijen, Nico; Geiben-Lynn, Ralf

    2010-01-01

    Background CD4+CD25+ regulatory T cells (Tregs) suppress adaptive T cell-mediated immune responses to self- and foreign-antigens. Tregs may also suppress early innate immune responses to vaccine antigens and might decrease vaccine efficacy. NK and NKT cells are the first responders after plasmid DNA vaccination and are found at the site of inoculation. Earlier reports demonstrated that NKT cells could improve plasmid DNA efficacy, a phenomenon not found for NK cells. In fact, it has been shown that under certain disease conditions, NK cells are suppressed by Tregs via their release of IL-10 and/or TGFβ. Therefore, we tested the hypothesis that NK cell function is suppressed by Tregs in the setting of plasmid DNA vaccination. Methodology/Principal Findings In this study we show that Tregs directly inhibit NK cell function during plasmid DNA vaccination by suppressing the potentially 10-fold, NK cell-mediated, augmentation of plasmid DNA antigen-specific CD8+ T cells. We found that this phenomenon is dependent on the secretion of cytokine TGFβ by Tregs, and independent of IL-10. Conclusions Our data indicate a crucial function for Tregs in blocking plasmid DNA vaccine-elicited immune responses, revealing potentially novel strategies for improving the efficiency of plasmid DNA vaccines including chemical- or antibody-induced localized blockage of Treg-mediated suppression of NK cells at the site of plasmid DNA vaccine inoculation. PMID:20808850

  2. Erbb2 DNA vaccine combined with regulatory T cell deletion enhances antibody response and reveals latent low-avidity T cells: potential and limits of its therapeutic efficacy.

    PubMed

    Rolla, Simona; Ria, Francesco; Occhipinti, Sergio; Di Sante, Gabriele; Iezzi, Manuela; Spadaro, Michela; Nicolò, Chiara; Ambrosino, Elena; Merighi, Irene Fiore; Musiani, Piero; Forni, Guido; Cavallo, Federica

    2010-06-01

    Rat (r)Erbb2 transgenic BALB-neuT mice genetically predestined to develop multiple invasive carcinomas allow an assessment of the potential of a vaccine against the stages of cancer progression. Because of rErbb2 expression in the thymus and its overexpression in the mammary gland, CD8(+) T cell clones reacting at high avidity with dominant rErbb2 epitopes are deleted in these mice. In BALB-neuT mice with diffuse and invasive in situ lesions and almost palpable carcinomas, a temporary regulatory T cells depletion combined with anti-rErbb2 vaccine markedly enhanced the anti-rErbb2 Ab response and allowed the expansion of latent pools of low-avidity CD8(+) T cells bearing TCRs repertoire reacting with the rErbb2 dominant peptide. This combination of a higher Ab response and activation of a low-avidity cytotoxic response persistently blocked tumor progression at stages in which the vaccine alone was ineffective. However, when diffuse and invasive microscopic cancers become almost palpable, this combination was no longer able to secure a significant extension of mice survival. PMID:20435927

  3. Multipotent Mesenchymal Stromal Cells Synergize With Costimulation Blockade in the Inhibition of Immune Responses and the Induction of Foxp3+ Regulatory T Cells

    PubMed Central

    Tibell, Annika; Ljung, Karin; Saito, Yu; Gronlund, Anna; Osterholm, Cecilia; Holgersson, Jan; Lundgren, Torbjörn; Ericzon, Bo-Göran; Corbascio, Matthias; Kumagai-Braesch, Makiko

    2014-01-01

    Multipotent mesenchymal stromal cell (MSC) therapy and costimulation blockade are two immunomodulatory strategies being developed concomitantly for the treatment of immunological diseases. Both of these strategies have the capacity to inhibit immune responses and induce regulatory T cells; however, their ability to synergize remains largely unexplored. In order to study this, MSCs from C57BL/6 (H2b) mice were infused together with fully major histocompatibility complex-mismatched Balb/c (H2d) allogeneic islets into the portal vein of diabetic C57BL/6 (H2b) mice, which were subsequently treated with costimulation blockade for the first 10 days after transplantation. Mice receiving both recipient-type MSCs, CTLA4Ig, and anti-CD40L demonstrated indefinite graft acceptance, just as did most of the recipients receiving MSCs and CTLA4Ig. Recipients of MSCs only rejected their grafts, and fewer than one half of the recipients treated with costimulation blockade alone achieved permanent engraftment. The livers of the recipients treated with MSCs plus costimulation blockade contained large numbers of islets surrounded by Foxp3+ regulatory T cells. These recipients showed reduced antidonor IgG levels and a glucose tolerance similar to that of naïve nondiabetic mice. Intrahepatic lymphocytes and splenocytes from these recipients displayed reduced proliferation and interferon-γ production when re-exposed to donor antigen. MSCs in the presence of costimulation blockade prevented dendritic cell maturation, inhibited T cell proliferation, increased Foxp3+ regulatory T cell numbers, and increased indoleamine 2,3-dioxygenase activity. These results indicate that MSC infusion and costimulation blockade have complementary immune-modulating effects that can be used for a broad number of applications in transplantation, autoimmunity, and regenerative medicine. PMID:25313200

  4. Maturation of monocyte derived dendritic cells with OK432 boosts IL-12p70 secretion and conveys strong T-cell responses

    PubMed Central

    2011-01-01

    Background Design of tumour specific immunotherapies using the patients' own dendritic cells (DC) is a fast advancing scientific field. The functional qualities of the DC generated in vitro are critical, and today's gold standard for maturation is a cytokine cocktail consisting of IL-1β, IL-6, TNF-α and PGE2 generating cells lacking IL-12p70 production. OK432 is an immunotherapeutic agent derived from killed Streptococcus pyogenes that has been used clinically to treat malignant and benign neoplasms for decades. Methods In this study, we analysed the effects of OK432 on DC maturation, DC migration, cytokine and chemokine secretion as well as T-cell stimulatory capacity, and compared it to the cytokine cocktail alone and combinations of OK432 with the cytokine cocktail. Results OK432 induced a marked up-regulation of CD40 on the cell surface as well as a strong inflammatory response from the DC with significantly more secretion of 19 different cytokines and chemokines compared to the cytokine cocktail. Interestingly, secretion of IL-15 and IL-12p70 was detected at high concentrations after maturation of DC with OK432. However, the OK432 treated DC did not migrate as well as DC treated with cytokine cocktail in a transwell migration assay. During allogeneic T-cell stimulation OK432 treated DC induced proliferation of over 50 percent of CD4 and 30 percent of CD8 T-cells for more than two cell divisions, whereas cytokine cocktail treated DC induced proliferation of 12 and 11 percent of CD4 and CD8 T-cells, respectively. Conclusions The clinically approved compound OK432 has interesting properties that warrants its use in DC immunotherapy and should be considered as a potential immunomodulating agent in cancer immunotherapy. PMID:21208424

  5. Immunodominant CD4+ T-cell responses to influenza A virus in healthy individuals focus on matrix 1 and nucleoprotein.

    PubMed

    Chen, Li; Zanker, Damien; Xiao, Kun; Wu, Chao; Zou, Quanming; Chen, Weisan

    2014-10-01

    Antigen-specific CD4(+) T cells are essential for effective virus-specific host responses, with recent human challenge studies (in volunteers) establishing their importance for influenza A virus (IAV)-specific immunity. However, while many IAV CD4(+) T cell epitopes have been identified, few are known to stimulate immunodominant CD4(+) T cell responses. Moreover, much remains unclear concerning the major antigen(s) responded to by the human CD4(+) T cells and the extents and magnitudes of these responses. We initiated a systematic screen of immunodominant CD4(+) T cell responses to IAV in healthy individuals. Using in vitro expanded-multispecificity IAV-specific T cell lines and individual IAV protein antigens produced by recombinant vaccinia viruses, we found that the internal matrix protein 1 (M1) and nucleoprotein (NP) were the immunodominant targets of CD4(+) T cell responses. Ten epitopes derived from M1 and NP were definitively characterized. Furthermore, epitope sequence conservation analysis established that immunodominance correlated with an increased frequency of mutations, reflecting the fact that these prominent epitopes are under greater selective pressure. Such evidence that particular CD4(+) T cells are important for protection/recovery is of value for the development of novel IAV vaccines and for our understanding of different profiles of susceptibility to these major pathogens. Importance: Influenza virus causes half a million deaths annually. CD4(+) T cell responses have been shown to be important for protection against influenza and for recovery. CD4(+) T cell responses are also critical for efficient CD8(+) T cell response and antibody response. As immunodominant T cells generally play a more important role, characterizing these immunodominant responses is critical for influenza vaccine development. We show here that the internal matrix protein 1 (M1) and nucleoprotein (NP), rather than the surface proteins reported previously, are the

  6. 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

  7. Transient CD4+ T Cell Depletion Results in Delayed Development of Functional Vaccine-Elicited Antibody Responses

    PubMed Central

    Provine, Nicholas M.; Badamchi-Zadeh, Alexander; Bricault, Christine A.; Penaloza-MacMaster, Pablo; Larocca, Rafael A.; Borducchi, Erica N.; Seaman, Michael S.

    2016-01-01

    ABSTRACT We have recently demonstrated that CD4+ T cell help is required at the time of adenovirus (Ad) vector immunization for the development of functional CD8+ T cell responses, but the temporal requirement for CD4+ T cell help for the induction of antibody responses remains unclear. Here we demonstrate that induction of antibody responses in C57BL/6 mice can occur at a time displaced from the time of Ad vector immunization by depletion of CD4+ T cells. Transient depletion of CD4+ T cells at the time of immunization delays the development of antigen-specific antibody responses but does not permanently impair their development or induce tolerance against the transgene. Upon CD4+ T cell recovery, transgene-specific serum IgG antibody titers develop and reach a concentration equivalent to that in undepleted control animals. These delayed antibody responses exhibit no functional defects with regard to isotype, functional avidity, expansion after boosting immunization, or the capacity to neutralize a simian immunodeficiency virus (SIV) Env-expressing pseudovirus. The development of this delayed transgene-specific antibody response is temporally linked to the expansion of de novo antigen-specific CD4+ T cell responses, which develop after transient depletion of CD4+ T cells. These data demonstrate that functional vaccine-elicited antibody responses can be induced even if CD4+ T cell help is provided at a time markedly separated from the time of vaccination. IMPORTANCE CD4+ T cells have a critical role in providing positive help signals to B cells, which promote robust antibody responses. The paradigm is that helper signals must be provided immediately upon antigen exposure, and their absence results in tolerance against the antigen. Here we demonstrate that, in contrast to the current model that the absence of CD4+ T cell help at priming results in long-term antibody nonresponsiveness, antibody responses can be induced by adenovirus vector immunization or alum

  8. Immunodominant CD4+ T-Cell Responses to Influenza A Virus in Healthy Individuals Focus on Matrix 1 and Nucleoprotein

    PubMed Central

    Chen, Li; Zanker, Damien; Xiao, Kun; Wu, Chao; Zou, Quanming

    2014-01-01

    ABSTRACT Antigen-specific CD4+ T cells are essential for effective virus-specific host responses, with recent human challenge studies (in volunteers) establishing their importance for influenza A virus (IAV)-specific immunity. However, while many IAV CD4+ T cell epitopes have been identified, few are known to stimulate immunodominant CD4+ T cell responses. Moreover, much remains unclear concerning the major antigen(s) responded to by the human CD4+ T cells and the extents and magnitudes of these responses. We initiated a systematic screen of immunodominant CD4+ T cell responses to IAV in healthy individuals. Using in vitro expanded-multispecificity IAV-specific T cell lines and individual IAV protein antigens produced by recombinant vaccinia viruses, we found that the internal matrix protein 1 (M1) and nucleoprotein (NP) were the immunodominant targets of CD4+ T cell responses. Ten epitopes derived from M1 and NP were definitively characterized. Furthermore, epitope sequence conservation analysis established that immunodominance correlated with an increased frequency of mutations, reflecting the fact that these prominent epitopes are under greater selective pressure. Such evidence that particular CD4+ T cells are important for protection/recovery is of value for the development of novel IAV vaccines and for our understanding of different profiles of susceptibility to these major pathogens. IMPORTANCE Influenza virus causes half a million deaths annually. CD4+ T cell responses have been shown to be important for protection against influenza and for recovery. CD4+ T cell responses are also critical for efficient CD8+ T cell response and antibody response. As immunodominant T cells generally play a more important role, characterizing these immunodominant responses is critical for influenza vaccine development. We show here that the internal matrix protein 1 (M1) and nucleoprotein (NP), rather than the surface proteins reported previously, are the immunodominant

  9. Lessons from T cell responses to virus induced tumours for cancer eradication in general.

    PubMed

    Melief, C J; Kast, W M

    1992-01-01

    Immunotherapy of virus induced tumours by adoptive transfer of virus specific cytotoxic T cells (CTL) is now feasible in experimental murine systems. These CTL recognize viral peptide sequences of defined length presented in the groove of MHC class I molecules. Effective eradication of large tumour masses requires coadministration of IL-2. In essence, T cell immunity against virus induced tumours does not differ from anti-viral T cell immunity in general. Tumour escape strategies are numerous but, in various instances, can be counteracted by defined measures. Initiation of CTL responses against poorly immunogenic non-virus induced tumours (the majority of human cancer) requires novel strategies to overcome T cell inertia. Rather than waiting to see whether tumour specific CTL (against unknown antigens) can be cultured from TIL, we propose an alternative strategy in which CTL are raised against target molecules of choice, including differentiation antigens of restricted tissue distribution (autoantigens) or mutated/overexpressed oncogene products. The various steps proposed include: (a) identification of target molecules of choice; (b) identification in these target molecules of MHC allele specific peptide motifs involved in peptide binding to MHC molecules; (c) evaluation of actual binding of such peptides to specific MHC class I molecules; (d) in vitro CTL response induction by such peptides, presented either by highly efficient antigen presenting cells (such as processing defective cells, which carry empty MHC class I molecules) loaded with a single peptide or by dendritic cells, both cell types being capable of primary CTL response induction in vitro and (e) adoptive transfer of tumour specific CTL generated in vivo or, more conveniently, vaccination with immunodominant peptides. The latter possibility seems to be feasible because peptide vaccination with a single immunodominant viral peptide can install CTL memory and confer protection against lethal virus

  10. Purification of Plasmodium Sporozoites Enhances Parasite-Specific CD8+ T Cell Responses.

    PubMed

    Billman, Zachary P; Seilie, Annette M; Murphy, Sean C

    2016-08-01

    Malaria infection caused by Plasmodium parasites continues to cause enormous morbidity and mortality in areas where it is endemic, and there is no licensed vaccine capable of inducing sterile protection. Hyperimmunization with attenuated whole sporozoites can induce sterile protective immune responses targeting preerythrocytic antigens. Most animal models of hyperimmunization rely on sporozoites dissected from mosquito salivary glands and injected without further purification. In BALB/c mice, repeated small doses of P. yoelii sporozoites progressively expand the population of sporozoite-specific CD8(+) T cells. In this study, large secondary doses of unpurified sporozoites unexpectedly led to contraction of sporozoite-specific CD8(+) T cell responses in sporozoite-primed mice. While sporozoite-primed CD8(+) T cells alternatively can be expanded by secondary exposure to Listeria monocytogenes expressing recombinant Plasmodium antigens, such expansion was potently inhibited by coinjection of large doses of unpurified sporozoites and by uninfected salivary glands alone. Purification of sporozoites away from mosquito salivary gland debris by density gradient centrifugation eliminated salivary gland-associated inhibition. Thus, the inhibitory effect appears to be due to exposure to uninfected mosquito salivary glands rather than sporozoites. To further assess the effect of salivary gland exposure on later sporozoite vaccinations, mice were immunized with uninfected salivary glands from a single mosquito. Compared to naive mice, salivary gland presensitization reduced subsequent liver burdens by 71%. These data show that a component(s) in mosquito salivary glands reduces liver infection, thereby limiting antigen dose and contributing to lower-magnitude T cell responses. These findings suggest that sporozoite immunogenicity studies be performed using purified sporozoites whenever feasible. PMID:27217420

  11. Mathematical Model Reveals the Role of Memory CD8 T Cell Populations in Recall Responses to Influenza.

    PubMed

    Zarnitsyna, Veronika I; Handel, Andreas; McMaster, Sean R; Hayward, Sarah L; Kohlmeier, Jacob E; Antia, Rustom

    2016-01-01

    The current influenza vaccine provides narrow protection against the strains included in the vaccine, and needs to be reformulated every few years in response to the constantly evolving new strains. Novel approaches are directed toward developing vaccines that provide broader protection by targeting B and T cell epitopes that are conserved between different strains of the virus. In this paper, we focus on developing mathematical models to explore the CD8 T cell responses to influenza, how they can be boosted, and the conditions under which they contribute to protection. Our models suggest that the interplay between spatial heterogeneity (with the virus infecting the respiratory tract and the immune response being generated in the secondary lymphoid organs) and T cell differentiation (with proliferation occurring in the lymphoid organs giving rise to a subpopulation of resident T cells in the respiratory tract) is the key to understand the dynamics of protection afforded by the CD8 T cell response to influenza. Our results suggest that the time lag for the generation of resident T cells in the respiratory tract and their rate of decay following infection are the key factors that limit the efficacy of CD8 T cell responses. The models predict that an increase in the level of central memory T cells leads to a gradual decrease in the viral load, and, in contrast, there is a sharper protection threshold for the relationship between the size of the population of resident T cells and protection. The models also suggest that repeated natural influenza infections cause the number of central memory CD8 T cells and the peak number of resident memory CD8 T cells to reach their plateaus, and while the former is maintained, the latter decays with time since the most recent infection. PMID:27242779

  12. Mathematical Model Reveals the Role of Memory CD8 T Cell Populations in Recall Responses to Influenza

    PubMed Central

    Zarnitsyna, Veronika I.; Handel, Andreas; McMaster, Sean R.; Hayward, Sarah L.; Kohlmeier, Jacob E.; Antia, Rustom

    2016-01-01

    The current influenza vaccine provides narrow protection against the strains included in the vaccine, and needs to be reformulated every few years in response to the constantly evolving new strains. Novel approaches are directed toward developing vaccines that provide broader protection by targeting B and T cell epitopes that are conserved between different strains of the virus. In this paper, we focus on developing mathematical models to explore the CD8 T cell responses to influenza, how they can be boosted, and the conditions under which they contribute to protection. Our models suggest that the interplay between spatial heterogeneity (with the virus infecting the respiratory tract and the immune response being generated in the secondary lymphoid organs) and T cell differentiation (with proliferation occurring in the lymphoid organs giving rise to a subpopulation of resident T cells in the respiratory tract) is the key to understand the dynamics of protection afforded by the CD8 T cell response to influenza. Our results suggest that the time lag for the generation of resident T cells in the respiratory tract and their rate of decay following infection are the key factors that limit the efficacy of CD8 T cell responses. The models predict that an increase in the level of central memory T cells leads to a gradual decrease in the viral load, and, in contrast, there is a sharper protection threshold for the relationship between the size of the population of resident T cells and protection. The models also suggest that repeated natural influenza infections cause the number of central memory CD8 T cells and the peak number of resident memory CD8 T cells to reach their plateaus, and while the former is maintained, the latter decays with time since the most recent infection. PMID:27242779

  13. Age related decline in the proliferative response of human T cells to OKT3 stimulation

    SciTech Connect

    Chrest, F.; Nagel, J.; Adler, W.

    1986-03-05

    The level of the in vitro proliferative response of human peripheral blood mononuclear cells (PBMC) to the OKT3 monoclonal antibody is directly related to the level of monocyte representation in the cell population. The responses to OKT3 stimulation of PBMC obtained from different individual are difficult to interpret due to variable percentage representation of monocytes. To eliminate this problem purified T cells from humans of various ages were incubated with 2 ng/ml OKT3 antibody and 10% purified autologous monocytes. The /sup 3/H-TdR incorporation of 1 x 10/sup 5/ T cells at 72 hrs of culture was 69,939 +/- 6085 (SEM) cpm for young individuals (mean age 35 yrs) and 33,163 +/- 2962 cpm for healthy elderly individuals (mean age 78 yrs). In addition, IL2 receptors were measured using two color fluorescence and flow cytometry with phycoerythrin conjugated anti-IL2 receptor antibody and FITC conjugated OKT11 antibody. The percentage of cells expressing IL2 receptors was 46% for the cells from the young individuals and 23% for cells from old individuals. These results suggest that the age related decline in the proliferative ability of T cells is partially due to a decreased expression of IL2 receptors and that proliferation and IL2 receptor expression is under the control of monocyte accessory cells.

  14. Impairment of T cell development and acute inflammatory response in HIV-1 Tat transgenic mice

    PubMed Central

    Fiume, Giuseppe; Scialdone, Annarita; Albano, Francesco; Rossi, Annalisa; Maria Tuccillo, Franca; Rea, Domenica; Palmieri, Camillo; Caiazzo, Elisabetta; Cicala, Carla; Bellevicine, Claudio; Falcone, Cristina; Vecchio, Eleonora; Pisano, Antonio; Ceglia, Simona; Mimmi, Selena; Iaccino, Enrico; Laurentiis, Annamaria de; Pontoriero, Marilena; Agosti, Valter; Troncone, Giancarlo; Mignogna, Chiara; Palma, Giuseppe; Arra, Claudio; Mallardo, Massimo; Maria Buonaguro, Franco; Scala, Giuseppe; Quinto, Ileana

    2015-01-01

    Immune activation and chronic inflammation are hallmark features of HIV infection causing T-cell depletion and cellular immune dysfunction in AIDS. Here, we addressed the issue whether HIV-1 Tat could affect T cell development and acute inflammatory response by generating a transgenic mouse expressing Tat in lymphoid tissue. Tat-Tg mice showed thymus atrophy and the maturation block from DN4 to DP thymic subpopulations, resulting in CD4+ and CD8+ T cells depletion in peripheral blood. In Tat-positive thymus, we observed the increased p65/NF-κB activity and deregulated expression of cytokines/chemokines and microRNA-181a-1, which are involved in T-lymphopoiesis. Upon LPS intraperitoneal injection, Tat-Tg mice developed an abnormal acute inflammatory response, which was characterized by enhanced lethality and production of inflammatory cytokines. Based on these findings, Tat-Tg mouse could represent an animal model for testing adjunctive therapies of HIV-1-associated inflammation and immune deregulation. PMID:26343909

  15. Impairment of T cell development and acute inflammatory response in HIV-1 Tat transgenic mice.

    PubMed

    Fiume, Giuseppe; Scialdone, Annarita; Albano, Francesco; Rossi, Annalisa; Tuccillo, Franca Maria; Rea, Domenica; Palmieri, Camillo; Caiazzo, Elisabetta; Cicala, Carla; Bellevicine, Claudio; Falcone, Cristina; Vecchio, Eleonora; Pisano, Antonio; Ceglia, Simona; Mimmi, Selena; Iaccino, Enrico; de Laurentiis, Annamaria; Pontoriero, Marilena; Agosti, Valter; Troncone, Giancarlo; Mignogna, Chiara; Palma, Giuseppe; Arra, Claudio; Mallardo, Massimo; Buonaguro, Franco Maria; Scala, Giuseppe; Quinto, Ileana

    2015-01-01

    Immune activation and chronic inflammation are hallmark features of HIV infection causing T-cell depletion and cellular immune dysfunction in AIDS. Here, we addressed the issue whether HIV-1 Tat could affect T cell development and acute inflammatory response by generating a transgenic mouse expressing Tat in lymphoid tissue. Tat-Tg mice showed thymus atrophy and the maturation block from DN4 to DP thymic subpopulations, resulting in CD4(+) and CD8(+) T cells depletion in peripheral blood. In Tat-positive thymus, we observed the increased p65/NF-κB activity and deregulated expression of cytokines/chemokines and microRNA-181a-1, which are involved in T-lymphopoiesis. Upon LPS intraperitoneal injection, Tat-Tg mice developed an abnormal acute inflammatory response, which was characterized by enhanced lethality and production of inflammatory cytokines. Based on these findings, Tat-Tg mouse could represent an animal model for testing adjunctive therapies of HIV-1-associated inflammation and immune deregulation. PMID:26343909

  16. Leukemia-associated activating mutation of Flt3 expands dendritic cells and alters T cell responses.

    PubMed

    Lau, Colleen M; Nish, Simone A; Yogev, Nir; Waisman, Ari; Reiner, Steven L; Reizis, Boris

    2016-03-01

    A common genetic alteration in acute myeloid leukemia is the internal tandem duplication (ITD) in FLT3, the receptor for cytokine FLT3 ligand (FLT3L). Constitutively active FLT3-ITD promotes the expansion of transformed progenitors, but also has pleiotropic effects on hematopoiesis. We analyzed the effect of FLT3-ITD on dendritic cells (DCs), which express FLT3 and can be expanded by FLT3L administration. Pre-leukemic mice with the Flt3(ITD) knock-in allele manifested an expansion of classical DCs (cDCs) and plasmacytoid DCs. The expansion originated in DC progenitors, was cell intrinsic, and was further enhanced in Flt3(ITD/ITD) mice. The mutation caused the down-regulation of Flt3 on the surface of DCs and reduced their responsiveness to Flt3L. Both canonical Batf3-dependent CD8(+) cDCs and noncanonical CD8(+) cDCs were expanded and showed specific alterations in their expression profiles. Flt3(ITD) mice showed enhanced capacity to support T cell proliferation, including a cell-extrinsic expansion of regulatory T (T reg) cells. Accordingly, these mice restricted alloreactive T cell responses during graft-versus-host reaction, but failed to control autoimmunity without T reg cells. Thus, the FLT3-ITD mutation directly affects DC development, indirectly modulating T cell homeostasis and supporting T reg cell expansion. We hypothesize that this effect of FLT3-ITD might subvert immunosurveillance and promote leukemogenesis in a cell-extrinsic manner. PMID:26903243

  17. Possible involvement of soluble B7-H4 in T cell-mediated inflammatory immune responses.

    PubMed

    Kamimura, Yosuke; Kobori, Hiroko; Piao, Jinhua; Hashiguchi, Masaaki; Matsumoto, Koichiro; Hirose, Sachiko; Azuma, Miyuki

    2009-11-13

    B7-H4, a newly identified B7 family molecule, is reported to regulate T cell activation. However, the expression and function of B7-H4 remain controversial. Here, we demonstrated that B7-H4 expression in immune cells was undetectable at both the transcription and cell-surface protein levels. B7-H4 transfectants augmented anti-CD3 mAb-induced re-directed cytotoxicity and this was inhibited by anti-B7-H4 mAb. In a hapten-induced contact hypersensitivity model, treatment with anti-B7-H4 mAb at sensitization, but not at challenge, efficiently suppressed the ear swelling and CD8(+) T cell activation assessed by CD25 expression and IFN-gamma production. We found that cells expressing B7-H4 secreted soluble B7-H4 and the serum B7-H4 level increased with disease progression in lupus-prone and collagen-induced arthritis autoimmune mice and after the antigen challenge in allergic inflammatory diseases. Our results suggest a different action of B7-H4 in T cell-mediated inflammatory responses and the possible involvement of soluble B7-H4 in inflammatory immune responses. PMID:19723502

  18. Obstacles and opportunities for targeting the effector T cell response in type 1 diabetes.

    PubMed

    Buckner, Jane H; Nepom, Gerald T

    2016-07-01

    Autoreactive lymphocytes display a programmed set of characteristic effector functions and phenotypic markers that, in combination with antigen-specific profiling, provide a detailed picture of the adaptive immune response in Type 1 diabetes (T1D). The CD4+ T cell effector compartment (referred to as "Teff" in this article) has been extensively analyzed, particularly because the HLA genes most strongly associated with T1D are MHC class II alleles that form restriction elements for CD4+ T cell recognition. This "guilt by association" can now be revisited in terms of specific immune mechanisms and specific forms of T cell recognition that are displayed by Teff found in subjects with T1D. In this review, we describe properties of Teff that correlate with T1D, and discuss several characteristics that advance our understanding of disease persistence and progression. Focusing on functional disease-associated immunological pathways within these Teff suggests a rationale for next-generation clinical trials with targeted interventions. Indeed, immune modulation therapies in T1D that do not address these properties of Teff are unlikely to achieve durable clinical response. PMID:26948997

  19. T-cell modulation of the antibody response to bacterial polysaccharide antigens.

    PubMed Central

    Taylor, C E; Bright, R

    1989-01-01

    Pretreatment of mice with subimmunogenic doses of meningococcal polysaccharide (MP), Pseudomonas aeruginosa lipopolysaccharide (PA), or Streptococcus mutans polysaccharide (SM) resulted in suppression of antibody response. The transfer of putative suppressor T cells (Ts cells) from donor mice primed with a subimmunogenic dose of MP to naive recipients at the time of immunization with MP substantially reduced the magnitude of the antibody response. Also, the infusion of B cells taken from animals immunized with either MP or PA suppressed the antibody response of naive recipients to MP or PA, respectively, relative to controls, suggesting that Ts cells respond to determinants on immune B cells. We observed that the injection of concanavalin A or phytohemagglutinin (two lectins known to augment the activity of amplifier T cells [Ta cells]) 2 days postimmunization enhanced the antibody response to MP and SM. In addition, Ta-cell activity was transferred to naive animals by using spleen cells. Although the administration of phytohemagglutinin at the time of immunization with MP also resulted in increased antibody response, the injection of concanavalin A simultaneous with immunization resulted in a suppression of the antibody response to MP. Although Ts cells generated in response to pneumococcal polysaccharide type III were found to respond to monoclonal antibody Ly-m22, Ta cells responded to monoclonal antibodies L3T4 and Ia but not to Ly-m22. These studies suggest that Ta and Ts cells can modulate the antibody response to MP, SM, and PA in a positive and negative manner, respectively. PMID:2462536

  20. Biomarkers on patient T cells diagnose active tuberculosis and monitor treatment response

    PubMed Central

    Adekambi, Toidi; Ibegbu, Chris C.; Cagle, Stephanie; Kalokhe, Ameeta S.; Wang, Yun F.; Hu, Yijuan; Day, Cheryl L.; Ray, Susan M.; Rengarajan, Jyothi

    2015-01-01

    BACKGROUND. The identification and treatment of individuals with tuberculosis (TB) is a global public health priority. Accurate diagnosis of pulmonary active TB (ATB) disease remains challenging and relies on extensive medical evaluation and detection of Mycobacterium tuberculosis (Mtb) in the patient’s sputum. Further, the response to treatment is monitored by sputum culture conversion, which takes several weeks for results. Here, we sought to identify blood-based host biomarkers associated with ATB and hypothesized that immune activation markers on Mtb-specific CD4+ T cells would be associated with Mtb load in vivo and could thus provide a gauge of Mtb infection. METHODS. Using polychromatic flow cytometry, we evaluated the expression of immune activation markers on Mtb-specific CD4+ T cells from individuals with asymptomatic latent Mtb infection (LTBI) and ATB as well as from ATB patients undergoing anti-TB treatment. RESULTS. Frequencies of Mtb-specific IFN-γ+CD4+ T cells that expressed immune activation markers CD38 and HLA-DR as well as intracellular proliferation marker Ki-67 were substantially higher in subjects with ATB compared with those with LTBI. These markers accurately classified ATB and LTBI status, with cutoff values of 18%, 60%, and 5% for CD38+IFN-γ+, HLA-DR+IFN-γ+, and Ki-67+IFN-γ+, respectively, with 100% specificity and greater than 96% sensitivity. These markers also distinguished individuals with untreated ATB from those who had successfully completed anti-TB treatment and correlated with decreasing mycobacterial loads during treatment. CONCLUSION. We have identified host blood-based biomarkers on Mtb-specific CD4+ T cells that discriminate between ATB and LTBI and provide a set of tools for monitoring treatment response and cure. TRIAL REGISTRATION. Registration is not required for observational studies. FUNDING. This study was funded by Emory University, the NIH, and the Yerkes National Primate Center. PMID:25822019

  1. Aspartate-β-hydroxylase induces epitope-specific T cell responses in hepatocellular carcinoma.

    PubMed

    Tomimaru, Yoshito; Mishra, Sasmita; Safran, Howard; Charpentier, Kevin P; Martin, William; De Groot, Anne S; Gregory, Stephen H; Wands, Jack R

    2015-03-01

    Hepatocellular carcinoma (HCC) has a poor prognosis due to high recurrence rate. Aspartate-β-hydroxylase (ASPH) is a highly conserved transmembrane protein, which is over expressed in HCC and promotes a malignant phenotype. The capability of ASPH protein-derived HLA class I and II peptides to generate antigen specific CD4(+) and CD8(+) immune responses is unknown. Therefore, these studies aim to define the epitope specific components required for a peptide based candidate vaccine. Monocyte-derived dendritic cells (DCs) generated from the peripheral blood mononuclear cells (PBMCs) of HCC patients were loaded with ASPH protein. Helper CD4(+) T cells and CD8(+) cytotoxic T lymphocytes (CTLs) were co-incubated with the DCs; T cell activation was evaluated by flow cytometric analysis. Immunoinformatics tools were used to predict HLA class I- and class II-restricted ASPH sequences, and the corresponding peptides were synthesized. The immunogenicity of each peptide in cultures of human PBMCs was determined by IFN-γ ELISpot assay. ASPH protein-loaded DCs activated both CD4(+) and CD8(+) T cells contained within the PBMC population derived from HCC patients. Furthermore, the predicted HLA class I- and class II-restricted ASPH peptides were significantly immunogenic. Both HLA class I- and class II-restricted peptides derived from ASPH induce T cell activation in HCC. We observed that ASPH protein and related peptides were highly immunogenic in patients with HCC and produce the type of cellular immune responses required for generation of anti-tumor activity. PMID:25629522

  2. Rapid and strong human CD8+ T cell responses to vaccination with peptide, IFA, and CpG oligodeoxynucleotide 7909.

    PubMed

    Speiser, Daniel E; Liénard, Danielle; Rufer, Nathalie; Rubio-Godoy, Verena; Rimoldi, Donata; Lejeune, Ferdy; Krieg, Arthur M; Cerottini, Jean-Charles; Romero, Pedro

    2005-03-01

    The induction of potent CD8+ T cell responses by vaccines to fight microbes or tumors remains a major challenge, as many candidates for human vaccines have proved to be poorly immunogenic. Deoxycytidyl-deoxyguanosin oligodeoxynucleotides (CpG ODNs) trigger Toll-like receptor 9, resulting in dendritic cell maturation that can enhance immunogenicity of peptide-based vaccines in mice. We tested whether a synthetic ODN, CpG 7909, could improve human tumor antigen-specific CD8+ T cell responses. Eight HLA-A2+ melanoma patients received 4 monthly vaccinations of low-dose CpG 7909 mixed with melanoma antigen A (Melan-A; identical to MART-1) analog peptide and incomplete Freund's adjuvant. All patients exhibited rapid and strong antigen-specific T cell responses: the frequency of Melan-A-specific T cells reached over 3% of circulating CD8+ T cells. This was one order of magnitude higher than the frequency seen in 8 control patients treated similarly but without CpG and 1-3 orders of magnitude higher than that seen in previous studies with synthetic vaccines. The enhanced T cell populations consisted primarily of effector memory cells, which in part secreted IFN- and expressed granzyme B and perforin ex vivo. In vitro, T cell clones recognized and killed melanoma cells in an antigen-specific manner. Thus, CpG 7909 is an efficient vaccine adjuvant that promotes strong antigen-specific CD8+ T cell responses in humans. PMID:15696196

  3. T cell responses in calves to a primary Eimeria bovis infection: phenotypical and functional changes.

    PubMed

    Hermosilla, C; Bürger, H J; Zahner, H

    1999-07-01

    The study aimed to characterize T cell responses in calves to a primary E. bovis infection. For this purpose, peripheral blood lymphocytes (PBL) were isolated from six infected calves and three controls during prepatency (Day 12 post infection (p.i.), patency (Day 25 p.i.) and postpatency (Day 35 p.i.). In addition, lymphocytes were isolated from various lymphatic organs (lnn. cervicales superficiales, lnn. jejunales craniales, lnn. jejunales caudales, lnn. caecales, lnn. colici, Peyer's patches (PP) and spleen) at necropsy (Day 35 p.i.). FACS analyses determined the proportions of CD4+-, CD8+-, CD2+-, and gammadelta+-T cells. Proliferative responses of the cells after stimulation with Concanavalin A (Con A) and an E. bovis-merozoite I antigen (EbAg) were measured. Furthermore, in situ hybridization experiments were performed for the detection of IL-2 and IL-4 mRNA in histological sections of lymphatic organs. Proportions of CD4+-, CD8+- and CD2+-expressing PBL were significantly increased 12 days p.i. in infected calves. While the proportions of CD4+- and CD8+-PBL declined until day 25 p.i. and finally reached control values, proportions of activated PBL (CD2+-T cells) remained at a high level throughout the observation period. Those of gammadelta+-PBL, in contrast, remained unaffected. The proportions of CD4+-, gammadelta+- and CD2+-T cells in lymphatic organs were significantly increased in comparison to uninfected controls, when determined 35 days p.i. Concerning the proportions of CD8+-T cells of the organs, however, there were no differences between the groups. PBL and cells from lymphatic organs except those from the PP showed strong proliferative response to the mitogen Con A, without a significant difference between the groups. Reactions to EbAg in contrast differed significantly between controls and E. bovis infected calves. Proliferation responses of PBL of infected animals were highest 12 days p.i.; subsequently they decreased and 35 days p.i. they were

  4. Alterations in lipid raft composition and dynamics contribute to abnormal T cell responses in systemic lupus erythematosus.

    PubMed

    Krishnan, Sandeep; Nambiar, Madhusoodana P; Warke, Vishal G; Fisher, Carolyn U; Mitchell, Jeanne; Delaney, Nancy; Tsokos, George C

    2004-06-15

    In response to appropriate stimulation, T lymphocytes from systemic lupus erythematosus (SLE) patients exhibit increased and faster intracellular tyrosine phosphorylation and free calcium responses. We have explored whether the composition and dynamics of lipid rafts are responsible for the abnormal T cell responses in SLE. SLE T cells generate and possess higher amounts of ganglioside-containing lipid rafts and, unlike normal T cells, SLE T cell lipid rafts include FcRgamma and activated Syk kinase. IgM anti-CD3 Ab-mediated capping of TCR complexes occurs more rapidly in SLE T cells and concomitant with dramatic acceleration of actin polymerization kinetics. The significance of these findings is evident from the observation that cross-linking of lipid rafts evokes earlier and higher calcium responses in SLE T cells. Thus, we propose that alterations in the lipid raft signaling machinery represent an important mechanism that is responsible for the heightened and accelerated T cell responses in SLE. PMID:15187166

  5. Regulatory T cells require the phosphatase PTEN to restrain type 1 and follicular helper T-cell responses

    PubMed Central

    Shrestha, Sharad; Yang, Kai; Guy, Cliff; Vogel, Peter; Neale, Geoffrey; Chi, Hongbo

    2015-01-01

    The interplay between effector and regulatory T (Treg) cells is crucial for adaptive immunity, but how Treg control diverse effector responses is elusive. We found that the phosphatase PTEN links Treg stability to repression of TH1 and TFH (follicular helper) responses. Depletion of PTEN in Treg resulted in excessive TFH and germinal center responses and spontaneous inflammatory disease. These defects are considerably blocked by deletion of Interferon-γ, indicating coordinated control of TH1 and TFH responses. Mechanistically, PTEN maintains Treg stability and metabolic balance between glycolysis and mitochondrial fitness. Moreover, PTEN deficiency upregulates mTORC2-Akt activity, and loss of this activity restores PTEN-deficient Treg function. Our studies establish a PTEN-mTORC2 axis that maintains Treg stability and coordinates Treg-mediated control of effector responses. PMID:25559258

  6. Flow Cytometric Analysis of Protective T-Cell Response Against Pulmonary Coccidioides Infection.

    PubMed

    Hung, Chiung-Yu; Wozniak, Karen L; Cole, Garry T

    2016-01-01

    The incidence of systemic fungal infections has increased throughout the world, spurring much interest in developing effective vaccines. Coccidioidomycosis, also known as San Joaquin Valley fever, is a potentially life-threatening respiratory mycosis. A vaccine against Coccidioides infection would contribute significantly to the well-being of the approx. 30 million residents in the Southwestern USA as well as the multitude of travelers who annually visit the endemic regions. We have applied a live, attenuated vaccine (∆T) to explore the nature of vaccine immunity in mice after intranasal challenge with a potentially lethal dose of Coccidioides spores. Coccidioides spores are airborne and highly infectious for mammalian hosts and classified as a biosafety level 3 agent. T cells are critical in the development of protective immunity against a variety of microorganisms as well as the development of autoimmune disease and allergic responses. Profiles of cytokines detected in lung homogenates of ∆T-vaccinated mice were indicative of a mixed Th1, Th2, and Th17 immune response. We have developed an intracellular cytokine staining and flow cytometric (ICS) technique to measure activated CD4(+) and CD8(+) T cells and IFN-γ-, IL-4-, IL-5-, and IL-17A-producing T cells in the lungs of mice that are challenged with a potentially lethal dose of Coccidioides spores. The numbers of pulmonary Th1 and Th17 cells during the first 2 weeks post-challenge showed a progressive increase in vaccinated mice and corresponded with reduction of fungal burden. In this protocol, we describe the methodology for culture and isolation of the live, attenuated ΔT spores of Coccidioides used to vaccinate mice, preparation of pulmonary cells, and staining protocol for cell surface markers and intracellular cytokines. This is the most reliable and robust procedure to measure frequencies and numbers of each selected T-cell subsets in lungs of vaccinated versus control mice and can be readily

  7. Human cord blood T-cell receptor alpha beta cell responses to protein antigens of Paracoccidioides brasiliensis yeast forms.

    PubMed Central

    Munk, M E; Kaufmann, S H

    1995-01-01

    Paracoccidioides brasiliensis causes a chronic granulomatous mycosis, prevalent in South America, and cell-mediated immunity represents the principal mode of protection against this fungal infection. We investigated the response of naive cord blood T cells to P. brasiliensis lysates. Our results show: (1) P. brasiliensis stimulates T-cell expansion, interleukin-2 (IL-2) production and differentiation into cytotoxic T cells; (2) T-cell stimulation depends on P. brasiliensis processing and major histocompatibility complex (MHC) class II expression; (3) the responsive T-cell population expresses alpha beta T-cell receptors (TCR) with different V beta gene products, CD4 and CD45RO; (4) the P. brasiliensis components involved in T-cell expansion primarily reside in a high molecular weight (100,000 MW) and a low molecular weight (< 1000 MW) protein fraction. These results indicate that protein antigens of P. brasiliensis stimulate cord blood CD4 alpha beta T cells, independent from in vivo presensitization, and thus question direct correlation of positive in vitro responses with protective immunity in vivo. PMID:7890308

  8. Chemokine-mediated redirection of T cells constitutes a critical mechanism of glucocorticoid therapy in autoimmune CNS responses

    PubMed Central

    Schweingruber, Nils; Fischer, Henrike J.; Fischer, Lisa; van den Brandt, Jens; Karabinskaya, Anna; Labi, Verena; Villunger, Andreas; Kretzschmar, Benedikt; Huppke, Peter; Simons, Mikael; Tuckermann, Jan P.; Flügel, Alexander

    2016-01-01

    Glucocorticoids (GCs) are the standard therapy for treating multiple sclerosis (MS) patients suffering from an acute relapse. One of the main mechanisms of gC action is held to be the induction of T cell apoptosis leading to reduced lymphocyte infiltration into the CNS, yet our analysis of experimental autoimmune encephalomyelitis (EAE) in three different strains of genetically manipulated mice has revealed that the induction of T cell apoptosis is not essential for the therapeutic efficacy of GCs. Instead, we identified the redirection of T cell migration in response to chemokines as a new therapeutic principle of GC action. GCs inhibited the migration of T cells towards CCL19 while they enhanced their responsiveness towards CXCL12. Importantly, blocking CXCR4 signaling in vivo by applying Plerixafor® strongly impaired the capacity of GCs to interfere with EAE, as revealed by an aggravated disease course, more pronounced CNS infiltration and a more dispersed distribution of the infiltrating T cells throughout the parenchyma. Our observation that T cells lacking the GC receptor were refractory to CXCL12 further underscores the importance of this pathway for the treatment of EAE by GCs. Importantly, methylprednisolone pulse therapy strongly increased the capacity of peripheral blood T cells from MS patients of different subtypes to migrate towards CXCL12. This indicates that modulation of T cell migration is an important mechanistic principle responsible for the efficacy of high-dose GC therapy not only of EAE but also of MS. PMID:24488308

  9. Multifunctional Analysis of CD4+ T-Cell Response as Immune-Based Model for Tuberculosis Detection

    PubMed Central

    Lichtner, Miriam; Mascia, Claudia; Sauzullo, Ilaria; Mengoni, Fabio; Vita, Serena; Marocco, Raffaella; Belvisi, Valeria; Russo, Gianluca; Vullo, Vincenzo; Mastroianni, Claudio M.

    2015-01-01

    Mono- and multifunctional specific CD4+ and CD8+ T-cell responses were evaluated to improve the immune-based detection of active tuberculosis (TB) and latent infection (LTBI). We applied flow cytometry to investigate cytokines profile (IFN-γ, TNF-α, and IL-2) of T cells after stimulation with TB antigens in 28 TB-infected subjects (18 active TB and 10 LTBI) and 10 uninfected controls. Cytokines production by CD4+ T cells at single-cell levels was higher in TB-infected subjects than uninfected controls (P < 0.0001). Assigning to activated CD4+ T cells, producing any of the three cytokines, a cut-off >0.45%, it was possible to differentiate TB-infected (>0.45%) by uninfected subjects (<0.45%). Among TB-infected subjects, the frequencies of multifunctional CD4+ T cells, simultaneously producing all 3 cytokines, are lower in active TB than LTBI subjects (P = 0.003). Thus, assigning to triple-positive CD4+ T cells a cut-off <0.182%, TB-infected individuals could be classified as active TB subjects (<0.182%) or LTBI subjects (>0.182%). The magnitude of CD8+ T-cell responses showed no differences between active TB and LTBI. Multifunctional CD4+ T-cell responses could have the potential to identify at single time point subjects without TB infection and patients having active or latent TB. PMID:26339657

  10. T-cell immune responses to Bordetella pertussis infection and vaccination.

    PubMed

    Fedele, Giorgio; Cassone, Antonio; Ausiello, Clara Maria

    2015-10-01

    The recent immunological investigations, stemming from the studies performed in the nineties within the clinical trials of the acellular pertussis vaccines, have highlighted the important role played by T-cell immunity to pertussis in humans. These studies largely confirmed earlier investigations in the murine respiratory infection models that humoral immunity alone is not sufficient to confer protection against Bordetella pertussis infection and that T-cell immunity is required. Over the last years, knowledge of T-cell immune response to B. pertussis has expanded broadly, taking advantage of the general progress in the understanding of anti-bacterial immunity and of refinements in methods to approach immunological investigations. In particular, experimental models of B. pertussis infection highlighted the cooperative role played by T-helper (Th)1 and Th17 cells for protection. Furthermore, the new baboon experimental model suggested a plausible explanation for the differences observed in the strength and persistence of protective immunity induced by the acellular or whole-cell pertussis vaccines and natural infection in humans, contributing to explain the upsurge of recent pertussis outbreaks. Despite the progress, open questions remain, the answer to them will possibly provide better tools to fight one of the hardest-to-control vaccine preventable disease. PMID:26242279

  11. Galectin-8 Ameliorates Murine Autoimmune Ocular Pathology and Promotes a Regulatory T Cell Response

    PubMed Central

    Sampson, James F.; Hasegawa, Eiichi; Mulki, Lama; Suryawanshi, Amol; Jiang, Shuhong; Chen, Wei-Sheng; Rabinovich, Gabriel A.; Connor, Kip M.; Panjwani, Noorjahan

    2015-01-01

    Galectins have emerged as potent immunoregulatory agents that control chronic inflammation through distinct mechanisms. Here, we report that treatment with Galectin-8 (Gal-8), a tandem-repeat member of the galectin family, reduces retinal pathology and prevents photoreceptor cell damage in a murine model of experimental autoimmune uveitis. Gal-8 treatment increased the number of regulatory T cells (Treg) in both the draining lymph node (dLN) and the inflamed retina. Moreover, a greater percentage of Treg cells in the dLN and retina of Gal-8 treated animals expressed the inhibitory coreceptor cytotoxic T lymphocyte antigen (CTLA)-4, the immunosuppressive cytokine IL-10, and the tissue-homing integrin CD103. Treg cells in the retina of Gal-8-treated mice were primarily inducible Treg cells that lack the expression of neuropilin-1. In addition, Gal-8 treatment blunted production of inflammatory cytokines by retinal T helper type (TH) 1 and TH17 cells. The effect of Gal-8 on T cell differentiation and/or function was specific for tissues undergoing an active immune response, as Gal-8 treatment had no effect on T cell populations in the spleen. Given the need for rational therapies for managing human uveitis, Gal-8 emerges as an attractive therapeutic candidate not only for treating retinal autoimmune diseases, but also for other TH1- and TH17-mediated inflammatory disorders. PMID:26126176

  12. Regulatory T cells in the humoral response of protein deficient mice.

    PubMed

    Price, P; Turner, K J

    1979-01-01

    Cell suspensions from the spleen or thymus of mice fed normally or mice that were protein deficient were injected into mice from each dietary group and also syngeneic nudes. Antigen, polyvinyl pyrrolidone (PVP), was injected at the stage of cell transfer and the antibody titres of the recipient animals were compared with those of control animals given only antigen. The regime was repeated using cell suspensions from donor animals which had been primed with antigen. These experiments showed that spleen cells were suppressive only when transferred from deficient to normal mice. Thymocytes generally lacked suppressive effects, except when given to irradiated mice also injected with "normal" spleen cells. However, thymocytes from deficient mice were marginally enhancing in nude mice, deficient mice and older "normals". To explain these results, it is suggested that responses to PVP are determined by distinct "suppressor-inducing" and "suppressor" T cells which act via helper T cells. The latter probably affect B cells directly and largely influence IgG production. It also appears likely that the ratio of helper to suppressor (inducer and effector) T cells is increased by protein deficiency. PMID:311719

  13. Differential regulation of human T cell responsiveness by mucosal versus blood monocytes.

    PubMed

    Qiao, L; Braunstein, J; Golling, M; Schürmann, G; Autschbach, F; Möller, P; Meuer, S

    1996-04-01

    Human intestinal T lymphocytes are constantly exposed to a large number of foreign antigens without developing a systemic immune response. One crucial mechanisms leading to this intestinal hyporesponsiveness is based on impaired signal transduction through the T cell receptor/CD3 complex in lamina propria T lymphocytes (LP-T). In this study, we addressed the question whether a lack of co-stimulatory/progression signals might also contribute to LP-T hyporesponsiveness. To this end, isolated human monocyte populations from the intestinal lamina propria were obtained and their phenotypes as well as their capacity to promote T cell activation studied. Here, we demonstrate that lamina propria macrophages (LP-MO), in contrast to peripheral blood monocytes (PB-MO), do not support proliferation of either LP-T or PB-T. This may be due to the low expression of ligands (CD54, CD58, CD80) for the T cell accessory receptors CD11/18, CD2 and CD28/CTLA-4 on mucosal macrophages. Thus, down-regulation of both recognition/competence and co-stimulatory/progression signals contribute to intestinal hypo- or unresponsiveness. PMID:8625989

  14. CD1c tetramers detect ex vivo T cell responses to processed phosphomycoketide antigens

    PubMed Central

    Ly, Dalam; Kasmar, Anne G.; Cheng, Tan-Yun; de Jong, Annemieke; Huang, Shouxiong; Roy, Sobhan; Bhatt, Apoorva; van Summeren, Ruben P.; Altman, John D.; Jacobs, William R.; Adams, Erin J.; Minnaard, Adriaan J.; Porcelli, Steven A.

    2013-01-01

    CD1c is expressed with high density on human dendritic cells (DCs) and B cells, yet its antigen presentation functions are the least well understood among CD1 family members. Using a CD1c-reactive T cell line (DN6) to complete an organism-wide survey of M. tuberculosis lipids, we identified C32 phosphomycoketide (PM) as a previously unknown molecule and a CD1c-presented antigen. CD1c binding and presentation of mycoketide antigens absolutely required the unusual, mycobacteria-specific lipid branching patterns introduced by polyketide synthase 12 (pks12). Unexpectedly, one TCR responded to diversely glycosylated and unglycosylated forms of mycoketide when presented by DCs and B cells. Yet cell-free systems showed that recognition was mediated only by the deglycosylated phosphoantigen. These studies identify antigen processing of a natural bacterial antigen in the human CD1c system, indicating that cells act on glycolipids to generate a highly simplified neoepitope composed of a sugar-free phosphate anion. Using knowledge of this processed antigen, we generated human CD1c tetramers, and demonstrate that CD1c–PM complexes stain T cell receptors (TCRs), providing direct evidence for a ternary interaction among CD1c-lipid-TCR. Furthermore, PM-loaded CD1c tetramers detect fresh human T cells from peripheral blood, demonstrating a polyclonal response to PM antigens in humans ex vivo. PMID:23530121

  15. Distinctive in vitro effects of T-cell growth cytokines on cytomegalovirus-stimulated T-cell responses of HIV-infected HAART recipients

    SciTech Connect

    Patterson, Julie; Jesser, Renee; Weinberg, Adriana

    2008-08-15

    Functional immune reconstitution is limited after HAART, maintaining the interest in adjunctive immune-modulators. We compared in vitro the effects of the {gamma}-chain T-cell growth cytokines IL-2, IL-4, IL-7 and IL-15 on cytomegalovirus-stimulated cell-mediated immunity. IL-2 and IL-15 increased cytomegalovirus-specific lymphocyte proliferation in HAART recipients, whereas IL-4 and IL-7 did not. The boosting effect of IL-2 and IL-15 on proliferation correlated with their ability to prevent late apoptosis. However, IL-2 increased the frequency of cells in early apoptosis, whereas IL-15 increased the frequency of fully viable cells. Both IL-2 and IL-15 increased cytomegalovirus-induced CD4{sup +} and CD8{sup +} T-cell proliferation and the synthesis of Th1 and pro-inflammatory cytokines and chemokines. However, only IL-2 increased the frequency of regulatory T cells and Th2 cytokine production, both of which have the potential to attenuate antiviral immune responses. Overall, compared to other {gamma}-chain cytokines, IL-15 had the most favorable profile for boosting antiviral cell-mediated immunity.

  16. Intramuscular Therapeutic Vaccination Targeting HPV16 Induces T Cell Responses That Localize in Mucosal Lesions

    PubMed Central

    Jotova, Iveta; Wu, T. C.; Wang, Chenguang; Desmarais, Cindy; Boyer, Jean D.; Tycko, Benjamin; Robins, Harlan S.; Clark, Rachael A.; Trimble, Cornelia L.

    2014-01-01

    About 25% of high-grade cervical intraepithelial neoplasias (CIN2/3) caused by human papillomavirus serotype 16 (HPV16) undergo complete spontaneous regression. However, to date, therapeutic vaccination strategies for HPV disease have yielded limited success when measured by their ability to induce robust peripheral blood T cell responses to vaccine antigen. We report marked immunologic changes in the target lesion microenvironment after intramuscular therapeutic vaccination targeting HPV16 E6/E7 antigens, in subjects with CIN2/3 who had modest detectable responses in circulating T lymphocytes. Histologic and molecular changes, including markedly (average threefold) increased intensity of CD8+ T cell infiltrates in both the stromal and epithelial compartments, suggest an effector response to vaccination. Postvaccination cervical tissue immune infiltrates included organized tertiary lymphoid-like structures in the stroma subjacent to residual intraepithelial lesions and, unlike infiltrates in unvaccinated lesions, showed evidence of proliferation induced by recognition of cognate antigen. At a molecular level, these histologic changes in the stroma were characterized by increased expression of genes associated with immune activation (CXCR3) and effector function (Tbet and IFNβ), and were also associated with an immunologic signature in the overlying dysplastic epithelium. High-throughput T cell receptor sequencing of unmanipulated specimens identified clonal expansions in the tissue that were not readily detectable in peripheral blood. Together, these findings indicate that peripheral therapeutic vaccination to HPV antigens can induce a robust tissue-localized effector immune response, and that analyses of immune responses at sites of antigen are likely to be much more informative than analyses of cells that remain in the circulation. PMID:24477000

  17. Intramuscular therapeutic vaccination targeting HPV16 induces T cell responses that localize in mucosal lesions.

    PubMed

    Maldonado, Leonel; Teague, Jessica E; Morrow, Matthew P; Jotova, Iveta; Wu, T C; Wang, Chenguang; Desmarais, Cindy; Boyer, Jean D; Tycko, Benjamin; Robins, Harlan S; Clark, Rachael A; Trimble, Cornelia L

    2014-01-29

    About 25% of high-grade cervical intraepithelial neoplasias (CIN2/3) caused by human papillomavirus serotype 16 (HPV16) undergo complete spontaneous regression. However, to date, therapeutic vaccination strategies for HPV disease have yielded limited success when measured by their ability to induce robust peripheral blood T cell responses to vaccine antigen. We report marked immunologic changes in the target lesion microenvironment after intramuscular therapeutic vaccination targeting HPV16 E6/E7 antigens, in subjects with CIN2/3 who had modest detectable responses in circulating T lymphocytes. Histologic and molecular changes, including markedly (average threefold) increased intensity of CD8(+) T cell infiltrates in both the stromal and epithelial compartments, suggest an effector response to vaccination. Postvaccination cervical tissue immune infiltrates included organized tertiary lymphoid-like structures in the stroma subjacent to residual intraepithelial lesions and, unlike infiltrates in unvaccinated lesions, showed evidence of proliferation induced by recognition of cognate antigen. At a molecular level, these histologic changes in the stroma were characterized by increased expression of genes associated with immune activation (CXCR3) and effector function (Tbet and IFNβ), and were also associated with an immunologic signature in the overlying dysplastic epithelium. High-throughput T cell receptor sequencing of unmanipulated specimens identified clonal expansions in the tissue that were not readily detectable in peripheral blood. Together, these findings indicate that peripheral therapeutic vaccination to HPV antigens can induce a robust tissue-localized effector immune response, and that analyses of immune responses at sites of antigen are likely to be much more informative than analyses of cells that remain in the circulation. PMID:24477000

  18. T-cell responses to human papillomavirus type 16 among women with different grades of cervical neoplasia

    PubMed Central

    Steele, J C; Mann, C H; Rookes, S; Rollason, T; Murphy, D; Freeth, M G; Gallimore, P H; Roberts, S

    2005-01-01

    Infection with high-risk genital human papillomavirus (HPV) types is a major risk factor for the development of cervical intraepithelial neoplasia (CIN) and invasive cervical carcinoma. The design of effective immunotherapies requires a greater understanding of how HPV-specific T-cell responses are involved in disease clearance and/or progression. Here, we have investigated T-cell responses to five HPV16 proteins (E6, E7, E4, L1 and L2) in women with CIN or cervical carcinoma directly ex vivo. T-cell responses were observed in the majority (78%) of samples. The frequency of CD4+ responders was far lower among those with progressive disease, indicating that the CD4+ T-cell response might be important in HPV clearance. CD8+ reactivity to E6 peptides was dominant across all disease grades, inferring that E6-specific CD8+ T cells are not vitally involved in disease clearance. T-cell responses were demonstrated in the majority (80%) of cervical cancer patients, but are obviously ineffective. Our study reveals significant differences in HPV16 immunity during progressive CIN. We conclude that the HPV-specific CD4+ T-cell response should be an important consideration in immunotherapy design, which should aim to target preinvasive disease. PMID:15986031

  19. Increased Immune Response Variability during Simultaneous Viral Coinfection Leads to Unpredictability in CD8 T Cell Immunity and Pathogenesis

    PubMed Central

    Kenney, Laurie L.; Cornberg, Markus; Chen, Alex T.; Emonet, Sebastien; de la Torre, Juan Carlos

    2015-01-01

    ABSTRACT T cell memory is usually studied in the context of infection with a single pathogen in naive mice, but how memory develops during a coinfection with two pathogens, as frequently occurs in nature or after vaccination, is far less studied. Here, we questioned how the competition between immune responses to two viruses in the same naive host would influence the development of CD8 T cell memory and subsequent disease outcome upon challenge. Using two different models of coinfection, including the well-studied lymphocytic choriomeningitis (LCMV) and Pichinde (PICV) viruses, several differences were observed within the CD8 T cell responses to either virus. Compared to single-virus infection, coinfection resulted in substantial variation among mice in the size of epitope-specific T cell responses to each virus. Some mice had an overall reduced number of virus-specific cells to either one of the viruses, and other mice developed an immunodominant response to a normally subdominant, cross-reactive epitope (nucleoprotein residues 205 to 212, or NP205). These changes led to decreased protective immunity and enhanced pathology in some mice upon challenge with either of the original coinfecting viruses. In mice with PICV-dominant responses, during a high-dose challenge with LCMV clone 13, increased immunopathology was associated with a reduced number of LCMV-specific effector memory CD8 T cells. In mice with dominant cross-reactive memory responses, during challenge with PICV increased immunopathology was directly associated with these cross-reactive NP205-specific CD8 memory cells. In conclusion, the inherent competition between two simultaneous immune responses results in significant alterations in T cell immunity and subsequent disease outcome upon reexposure. IMPORTANCE Combination vaccines and simultaneous administration of vaccines are necessary to accommodate required immunizations and maintain vaccination rates. Antibody responses generally correlate with

  20. Impact of T cell chimerism on clinical outcome in 117 patients who underwent allogeneic stem cell transplantation with a busulfan-containing reduced-intensity conditioning regimen.

    PubMed

    Saito, Bungo; Fukuda, Takahiro; Yokoyama, Hiroki; Kurosawa, Saiko; Takahashi, Toshihiro; Fuji, Shigeo; Takahashi, Noriko; Tajima, Kinuko; Kim, Sung-Won; Mori, Shin-Ichiro; Tanosaki, Ryuji; Takaue, Yoichi; Heike, Yuji

    2008-10-01

    Within the concept of reduced-intensity stem cell transplantation (RIST) there is a wide range of different regimens used, and little information is available on the clinical impact of chimerism status in patients conditioned with a busulfan-containing regimen. Therefore, we retrospectively reviewed lineage-specific chimerism and the subsequent clinical outcome in 117 patients (median age, 55 years; range: 29-68) who underwent busulfan-containing RIST. The conditioning regimen consisted of busulfan (oral 8 mg/kg or i.v. 6.4 mg/kg) and fludarabine (180 mg/m(2), n = 64) or cladribine (0.66 mg/kg, n = 53), with or without 2-4 Gy total-body irridiation (TBI) (n = 26) or antihuman T-lymphocyte immunoglobulin (ATG; 5-10 mg/kg; n = 31). Chimerism was evaluated with peripheral blood samples taken on days 30, 60, and 90 after transplantation by polymerase chain reaction (PCR)-based amplification of polymorphic short tandem repeat regions. The median follow-up of surviving patients was 1039 days (153-2535). The percent donor-chimerism was significantly higher in granulocyte than T cell fraction throughout the entire course, and the median (mean) values were, respectively, 100% (96%) versus 95% (83%), 100% (98%) versus 100% (89%), and 100% (98%) versus 100% (91%) at days 30, 60, and 90 after RIST. In a multivariate analysis, having received <2 types of chemotherapy regimens before RIST was the only factor that was significantly associated with low donor T cell chimerism (<60%) at day 30 (hazard ratio [HR]: 6.1; 95% confidence interval [CI], 2.1-18.4; P < .01). The median percentage of donor T cell chimerism at day 30 was 9% (0%-63%) in 5 patients who experienced graft failure, which was significantly lower than that (97%; 15%-100%) in the rest of the patients (P < .01). No correlation was found between the kinetics of T cell chimerism and the occurrence of acute or chronic GVHD (aGVHD, cGVHD). The stem cell source and the addition of TBI or ATG were not associated with the

  1. Indoleamine 2,3-Dioxygenase (IDO) Activity During the Primary Immune Response to Influenza Infection Modifies the Memory T Cell Response to Influenza Challenge

    PubMed Central

    Sage, Leo K.; Fox, Julie M.; Mellor, Andrew L.; Tompkins, Stephen M.

    2014-01-01

    Abstract The generation of a heterosubtypic memory T cell response is important for cross-protective immunity against unrelated strains of influenza virus. One way to facilitate the generation of the memory T cell population is to control the activity of immune modulatory agents. The enzyme, indoleamine 2,3-dioxygenase (IDO), is upregulated during influenza infection by the interferon response where IDO activity depletes tryptophan required in T cell response. In this study, IDO activity was pharmacologically inhibited with 1-methyl-tryptophan (1MT) during the primary response to influenza virus infection and the effect on the memory T cell response was evaluated. 1MT treatment improved the memory T cell response to influenza virus challenge by increasing interferon gamma expression by CD4 and CD8 T cells, and numbers of lung virus-specific CD8+ T cells, and increased the Th1 response as well as modifying the immunodominance hierarchy to increase the number of subdominant epitope specific CD8+ T cells, a feature which may be linked to decreased regulatory T cell function. These changes also accompanied evidence of accelerated lung tissue repair upon virus challenge. These findings suggest that modulation of IDO activity could be exploited in influenza vaccine development to enhance memory T cell responses and reduce disease burden. PMID:24702331

  2. Regulation of Adaptive NK Cells and CD8 T Cells by HLA-C Correlates with Allogeneic Hematopoietic Cell Transplantation and with Cytomegalovirus Reactivation.

    PubMed

    Horowitz, Amir; Guethlein, Lisbeth A; Nemat-Gorgani, Neda; Norman, Paul J; Cooley, Sarah; Miller, Jeffrey S; Parham, Peter

    2015-11-01

    Mass cytometry was used to investigate the effect of CMV reactivation on lymphocyte reconstitution in hematopoietic cell transplant patients. For eight transplant recipients (four CMV negative and four CMV positive), we studied PBMCs obtained 6 mo after unrelated donor hematopoietic cell transplantation (HCT). Forty cell-surface markers, distinguishing all major leukocyte populations in PBMC, were analyzed with mass cytometry. This group included 34 NK cell markers. Compared with healthy controls, transplant recipients had higher HLA-C expression on CD56(-)CD16(+) NK cells, B cells, CD33(bright) myeloid cells, and CD4CD8 T cells. The increase in HLA-C expression was greater for CMV-positive HCT recipients than for CMV negative recipients. Present in CMV-positive HCT recipients, but not in CMV-negative HCT recipients or controls, is a population of killer cell Ig-like receptor (KIR)-expressing CD8 T cells not previously described. These CD8 T cells coexpress CD56, CD57, and NKG2C. The HCT recipients also have a population of CD57(+)NKG2A(+) NK cells that preferentially express KIR2DL1. An inverse correlation was observed between the frequencies of CD57(+)NKG2C(+) NK cells and CD57(+)NKG2A(+) NK cells. Although CD57(+)NKG2A(+) NK cells are less abundant in CMV-positive recipients, their phenotype is of a more activated cell than the CD57(+)NKG2A(+) NK cells of controls and CMV-negative HCT recipients. These data demonstrate that HCT and CMV reactivation are associated with an increased expression of HLA-C. This could influence NK cell education during lymphocyte reconstitution. The increased inhibitory KIR expression by proliferating CMV-specific CD8 T cells suggests regulatory interactions between HLA-C and KIR might promote Graft-versus-Leukemia effects following transplantation. PMID:26416275

  3. PKC-Theta is a Novel SC35 Splicing Factor Regulator in Response to T Cell Activation

    PubMed Central

    McCuaig, Robert Duncan; Dunn, Jennifer; Li, Jasmine; Masch, Antonia; Knaute, Tobias; Schutkowski, Mike; Zerweck, Johannes; Rao, Sudha

    2015-01-01

    Alternative splicing of nuclear pre-mRNA is essential for generating protein diversity and regulating gene expression. While many immunologically relevant genes undergo alternative splicing, the role of regulated splicing in T cell immune responses is largely unexplored, and the signaling pathways and splicing factors that regulate alternative splicing in T cells are poorly defined. Here, we show using a combination of Jurkat T cells, human primary T cells, and ex vivo naïve and effector virus-specific T cells isolated after influenza A virus infection that SC35 phosphorylation is induced in response to stimulatory signals. We show that SC35 colocalizes with RNA polymerase II in activated T cells and spatially overlaps with H3K27ac and H3K4me3, which mark transcriptionally active genes. Interestingly, SC35 remains coupled to the active histone marks in the absence of continuing stimulatory signals. We show for the first time that nuclear PKC-θ co-exists with SC35 in the context of the chromatin template and is a key regulator of SC35 in T cells, directly phosphorylating SC35 peptide residues at RNA recognition motif and RS domains. Collectively, our findings suggest that nuclear PKC-θ is a novel regulator of the key splicing factor SC35 in T cells. PMID:26594212

  4. Genome-wide analysis of T cell responses during acute and latent simian varicella virus infections in rhesus macaques.

    PubMed

    Haberthur, Kristen; Kraft, Aubrey; Arnold, Nicole; Park, Byung; Meyer, Christine; Asquith, Mark; Dewane, Jesse; Messaoudi, Ilhem

    2013-11-01

    Varicella zoster virus (VZV) is the etiological agent of varicella (chickenpox) and herpes zoster (HZ [shingles]). Clinical observations suggest that VZV-specific T cell immunity plays a more critical role than humoral immunity in the prevention of VZV reactivation and development of herpes zoster. Although numerous studies have characterized T cell responses directed against select VZV open reading frames (ORFs), a comprehensive analysis of the T cell response to the entire VZV genome has not yet been conducted. We have recently shown that intrabronchial inoculation of young rhesus macaques with simian varicella virus (SVV), a homolog of VZV, recapitulates the hallmarks of acute and latent VZV infection in humans. In this study, we characterized the specificity of T cell responses during acute and latent SVV infection. Animals generated a robust and broad T cell response directed against both structural and nonstructural viral proteins during acute infection in bronchoalveolar lavage (BAL) fluid and peripheral blood. During latency, T cell responses were detected only in the BAL fluid and were lower and more restricted than those observed during acute infection. Interestingly, we identified a small set of ORFs that were immunogenic during both acute and latent infection in the BAL fluid. Given the close genome relatedness of SVV and VZV, our studies highlight immunogenic ORFs that may be further investigated as potential components of novel VZV vaccines that specifically boost T cell immunity. PMID:23986583

  5. CD4+ T cell STAT3 phosphorylation precedes acute GVHD, and subsequent Th17 tissue invasion correlates with GVHD severity and therapeutic response

    PubMed Central

    Betts, Brian C.; Sagatys, Elizabeth M.; Veerapathran, Anandharaman; Lloyd, Mark C.; Beato, Francisca; Lawrence, Harshani R.; Yue, Binglin; Kim, Jongphil; Sebti, Said M.; Anasetti, Claudio; Pidala, Joseph

    2015-01-01

    Th17 cells contribute to severe GVHD in murine bone marrow transplantation. Targeted deletion of the RORγt transcription factor or blockade of the JAK2-STAT3 axis suppresses IL-17 production and alloreactivity by Th17 cells. Here, we show that pSTAT3 Y705 is increased significantly in CD4+ T cells among human recipients of allogeneic HCT before the onset of Grade II–IV acute GVHD. Examination of target-organ tissues at the time of GVHD diagnosis indicates that the amount of RORγt + Th17 cells is significantly higher in severe GVHD. Greater accumulation of tissue-resident Th17 cells also correlates with the use of MTX- compared with Rapa-based GVHD prophylaxis, as well as a poor therapeutic response to glucocorticoids. RORγt is optimally suppressed by concurrent neutralization of TORC1 with Rapa and inhibition of STAT3 activation with S3I-201, supporting that mTOR- and STAT3-dependent pathways converge upon RORγt gene expression. Rapa-resistant T cell proliferation can be totally inhibited by STAT3 blockade during initial allosensitization. We conclude that STAT3 signaling and resultant Th17 tissue accumulation are closely associated with acute GVHD onset, severity, and treatment outcome. Future studies are needed to validate the association of STAT3 activity in acute GVHD. Novel GVHD prevention strategies that incorporate dual STAT3 and mTOR inhibition merit investigation. PMID:25663681

  6. Active role of T cells in promoting an in vitro autoantibody response to self erythrocytes in NZB mice.

    PubMed Central

    Miller, R D; Calkins, C E

    1988-01-01

    The in vitro anti-self erythrocyte antibody response of NZB spleen cells appears to be influenced directly by T cells. Thy-1+, L3T4+ helper T cells are required for: (i) the generation in vitro of MRBC-specific IgM and IgG AFC by spleen cells from 'autoimmune' (9-12-month old) NZB mice and (ii) the generation in vitro of MRBC-specific IgM and IgG AFC by spleen cells depleted of suppressor cells from pre-autoimmune (2-3-months-old) NZB mice which show no clinical signs of an anti-MRBC response. It is evident from the present and previous studies that the anti-MRBC autoantibody response is regulated in pre-autoimmune spleen cell populations by Ly2+ T cells. Ly2-T cells from both pre-autoimmune and autoimmune mice in sufficient numbers can overcome this normal regulation and promote the anti-MRBC response in cultures of unfractionated pre-autoimmune spleen cells. Ly2- T cells isolated from autoimmune NZB mice were consistently more active in this than the Ly2- T cells isolated from pre-autoimmune mice, suggesting an enrichment of MRBC-reactive Ly2- T cells in autoimmune NZB mice. The Ly2- T cells from autoimmune NZB mice greatly enhance the autoimmune anti-MRBC response relative to a modest enhancement of the response to a foreign antigen, SRBC, produced by the same cells. These data indicate that T cells play an important role both in supporting the autoantibody response to MRBC and in disrupting tolerance, leading to autoimmunity in NZB mice. PMID:2966765

  7. T Cell Factor 1-Expressing Memory-like CD8(+) T Cells Sustain the Immune Response to Chronic Viral Infections.

    PubMed

    Utzschneider, Daniel T; Charmoy, Mélanie; Chennupati, Vijaykumar; Pousse, Laurène; Ferreira, Daniela Pais; Calderon-Copete, Sandra; Danilo, Maxime; Alfei, Francesca; Hofmann, Maike; Wieland, Dominik; Pradervand, Sylvain; Thimme, Robert; Zehn, Dietmar; Held, Werner

    2016-08-16

    Chronic infections promote the terminal differentiation (or "exhaustion") of T cells and are thought to preclude the formation of memory T cells. In contrast, we discovered a small subpopulation of virus-specific CD8(+) T cells that sustained the T cell response during chronic infections. These cells were defined by, and depended on, the expression of the transcription factor Tcf1. Transcriptome analysis revealed that this population shared key characteristics of central memory cells but lacked an effector signature. Unlike conventional memory cells, Tcf1-expressing T cells displayed hallmarks of an "exhausted" phenotype, including the expression of inhibitory receptors such as PD-1 and Lag-3. This population was crucial for the T cell expansion that occurred in response to inhibitory receptor blockade during chronic infection. These findings identify a memory-like T cell population that sustains T cell responses and is a prime target for therapeutic interventions to improve the immune response in chronic infections. PMID:27533016

  8. Antibody and T Cell Responses to Fusobacterium nucleatum and Treponema denticola in Health and Chronic Periodontitis

    PubMed Central

    Shin, Jieun; Kho, Sang-A; Choi, Yun S.; Kim, Yong C.; Rhyu, In-Chul; Choi, Youngnim

    2013-01-01

    The characteristics of the T cell response to the members of oral flora are poorly understood. We characterized the antibody and T cell responses to FadA and Td92, adhesins from Fusobacterium nucleatum, an oral commensal, and Treponema denticola, a periodontal pathogen, respectively. Peripheral blood and saliva were obtained from healthy individuals and patients with untreated chronic periodontitis (CP, n = 11 paris) and after successful treatment of the disease (n = 9). The levels of antigen-specific antibody were measured by ELISA. In plasma, IgG1 was the most abundant isotype of Ab for both Ags, followed by IgA and then IgG4. The levels of FadA-specific salivary IgA (sIgA) were higher than Td92-specific sIgA and the FadA-specific IgA levels observed in plasma. However, the periodontal health status of the individuals did not affect the levels of FadA- or Td92-specific antibody. Even healthy individuals contained FadA- and Td92-specific CD4+ T cells, as determined by the detection of intracytoplasmic CD154 after short-term in vitro stimulation of peripheral blood mononuclear cells (PBMCs) with the antigens. Patients with CP tended to possess increased numbers of FadA- and Td92-specific CD4+ T cells but reduced numbers of Td92-specific Foxp3+CD4+ Tregs than the healthy subjects. Both FadA and Td92 induced the production of IFNγ and IL-10 but inhibited the secretion of IL-4 by PBMCs. In conclusion, F. nucleatum induced Th3 (sIgA)- and Th1 (IFNγ and IgG1)-dominant immune responses, whereas T. denticola induced a Th1 (IFNγ and IgG1)-dominant response. This IFNγ-dominant cytokine response was impaired in CP patients, and the Td92-induced IFNγ levels were negatively associated with periodontal destruction in patients. These findings may provide new insights into the homeostatic interaction between the immune system and oral bacteria and the pathogenesis of periodontitis. PMID:23335969

  9. T cell mediated immune responses in patients with tuberculous lymphadenitis from Butajira, southern Ethiopia.

    PubMed

    Habte, Abebe; Geletu, Mulu; Olobo, Joseph Okao; Kidane, Dawit; Negesse, Yohannes; Yassin, Mohammed Ahmed; Kifle, Bereda; Abate, Getahun; Harboe, Morten; Aseff, Abraham

    2004-04-01

    The control of tuberculosis (TB) requires improved vaccines in addition to chemotherapy. It is essential to understand the immune response in tuberculosis to successfully evaluate potential vaccines. Current investigations have focused on immune responses in pulmonary forms. We studied the T-cell response of peripheral blood mononuclear cells (PBMC) from HIV-infected (n=8) and non-infected patients (n=19) with lymph node tuberculosis to PPD and short-term culture filtrates (ST-CF) of M. tuberculosis. PBMC from HIV-negative TB lymphadenitis patients proliferated in response to both antigens (p<0.001) and produced variably higher levels of IFN-gamma compared to healthy controls (p=0.02) (n=19) from the same area. Such responses were suppressed in HIV co-infected subjects. The results indicate that circulating PBMC in the apparently localized form of tuberculous lymphadenitis react to mycobacterial antigens in a similar pattern as those of patients with pulmonary disease. PMID:16895017

  10. Paternal antigen-specific proliferating regulatory T cells are increased in uterine-draining lymph nodes just before implantation and in pregnant uterus just after implantation by seminal plasma-priming in allogeneic mouse pregnancy.

    PubMed

    Shima, Tomoko; Inada, Kumiko; Nakashima, Akitoshi; Ushijima, Akemi; Ito, Mika; Yoshino, Osamu; Saito, Shigeru

    2015-04-01

    Paternal antigen-specific regulatory T (PA-specific Treg) cells play an important role in feto-maternal tolerance. To detect the PA-specific Tregs, female BALB/c mice were mated with male DBA/2 mice. Mls Ia antigen on DBA/2 mice is recognized by the T-cell receptor Vβ6; thus, CD4(+)Foxp3(+)Vβ6(+) cells are recognized as PA-specific Treg cells. CD4(+)CD25(+)Vβ6(+) cells effectively suppressed the allo-reactive proliferation of lymphocytes compared with that of CD4(+)CD25(+)Vβ6(-) cells. Vβ6(+) PA-specific Treg cells expressed CCR4 and CCR5 on their surface. The frequency of Ki67(+) PA-specific Treg cells among Treg cells was significantly increased in draining lymph nodes on day 3.5 post-coitus (pc; 6.8±1.1%, p<0.05) and day 5.5 pc (7.2±1.1%, p<0.05) in allogeneic pregnant mice compared with that in nonpregnant mice (2.7±0.2%). The frequency of Ki67(+) PA-specific Treg cells in the uterus increased significantly after day 5.5 pc in allogeneic pregnant mice compared with that in nonpregnant mice (8.8±2.8% vs. 1.2±1.3%, p<0.05). However, Ki67(-)PA-specific Tregs did not change during pregnancy. To analyze the role of seminal fluid or sperm in Treg expansion, female BALB/c mice were mated with vasectomized DBA/2 male mice (VAS) or seminal vesicle-excised DBA/2 male mice (SVX). The frequency of Ki67(+) PA-specific Treg cells did not increase in draining lymph nodes or uterus in BALB/c×DBA/2 (SVX) allogeneic mating mice. These findings suggest that the priming by seminal fluid is important for the induction of proliferating PA-specific Tregs in uterine-draining lymph nodes just before implantation and pregnant uterus after implantation, resulting in successful implantation and the maintenance of allogeneic pregnancy. PMID:25817463

  11. Lupus-Prone Mice Fail to Raise Antigen-Specific T Cell Responses to Intracellular Infection

    PubMed Central

    Lieberman, Linda A.; Tsokos, George C.

    2014-01-01

    Systemic lupus erythematosus (SLE) is characterized by multiple cellular abnormalities culminating in the production of autoantibodies and immune complexes, resulting in tissue inflammation and organ damage. Besides active disease, the main cause of morbidity and mortality in SLE patients is infections, including those from opportunistic pathogens. To understand the failure of the immune system to fend off infections in systemic autoimmunity, we infected the lupus-prone murine strains B6.lpr and BXSB with the intracellular parasite Toxoplasma gondii and survival was monitored. Furthermore, mice were sacrificed days post infection and parasite burden and cellular immune responses such as cytokine production and cell activation were assessed. Mice from both strains succumbed to infection acutely and we observed greater susceptibility to infection in older mice. Increased parasite burden and a defective antigen-specific IFN-gamma response were observed in the lupus-prone mice. Furthermore, T cell:dendritic cell co-cultures established the presence of an intrinsic T cell defect responsible for the decreased antigen-specific response. An antigen-specific defect in IFN- gamma production prevents lupus-prone mice from clearing infection effectively. This study reveals the first cellular insight into the origin of increased susceptibility to infections in SLE disease and may guide therapeutic approaches. PMID:25360768

  12. T-cell proliferative response to human papillomavirus type 16 peptides: relationship to cervical intraepithelial neoplasia.

    PubMed Central

    Nakagawa, M; Stites, D P; Farhat, S; Judd, A; Moscicki, A B; Canchola, A J; Hilton, J F; Palefsky, J M

    1996-01-01

    The incidence of human papillomavirus (HPV)-related cervical intraepithelial neoplasia (CIN) and cervical cancer is increased with immunodeficiency, but the role of immune response, including cell-mediated immunity, in disease prevention is not well understood. In this study, T-cell proliferative responses to six synthetic peptides with predicted immunogenic determinants from the HPV-16 E4, E6, E7, and L1 open reading frames were analyzed in 22 sexually active women with new-onset CIN and 65 sexually active women without cervical disease, characterized by cytology, colposcopy, and HPV testing. T-cell proliferative responses were demonstrated to all six HPV-16 peptides. Although not statistically significant, rates of reactivity to E6 (24-45) were higher among sexually active women without disease (26%) than among women with current CIN (7%), as was the overall number of peptides stimulating a response. Women with CIN may not respond to selected HPV antigens as well as women without disease do. PMID:8991637

  13. Mechanism of HIV-1 Tat induced inhibition of antigen-specific T cell responsiveness.

    PubMed

    Subramanyam, M; Gutheil, W G; Bachovchin, W W; Huber, B T

    1993-03-15

    HIV-1 Tat has been shown to have an inhibitory effect on the Ag-specific responsiveness of human peripheral T cells. We have previously demonstrated that this retroviral protein binds to and partially inhibits the enzymatic activity of dipeptidyl aminopeptidase type IV (DP IV), also known as CD26, which is expressed on a variety of mammalian tissue, including T lymphocytes. A number of studies have implicated a role for DP IV in the activation of T lymphocytes. By utilizing HIV-1 Tat, as well as ProboroPro, a potent and specific boronic acid analog inhibitor of DP IV, we show here that blocking DP IV partially inactivates Ag and anti-CD3-mediated T cell proliferation. Neither mitogen nor anti-CD2 mediated proliferation of T lymphocytes, however, is impaired by blocking DP IV. The target molecule for the inhibition induced by both compounds was confirmed by the finding that soluble DP IV neutralized the reduced Ag responsiveness. The Ag-specific inhibition could be overcome by the addition of exogenous IL-2, suggesting that blocking or inactivation of DP IV results in a state of anergy, probably by interfering with the delivery or amplification of a signal necessary for IL-2 production. This is further substantiated by the finding that costimulation of human PBMC via the CD28 molecule, which initiates a non-TCR-dependent signaling pathway, overcomes the reduced Ag responsiveness induced by Tat and ProboroPro. The fact that ProboroPro has no impact on stimulation of T cells with PMA and ionomycin implies that blocking DP IV is influencing events before the activation of protein kinase C and Ca2+ flux. These results suggest that DP IV is necessary for amplification of signals generated by the engagement of the TCR-CD3 complex by nominal Ag. PMID:8095514

  14. Heterogeneous MHC II restriction pattern of autoreactive desmoglein 3 specific T cell responses in pemphigus vulgaris patients and normals.

    PubMed

    Hertl, M; Karr, R W; Amagai, M; Katz, S I

    1998-04-01

    Pemphigus vulgaris is a life threatening bullous autoimmune disease of the skin mediated by autoantibodies against desmoglein 3 (Dsg3) on epidermal keratinocytes. Pemphigus vulgaris patients exhibit T cell responses against Dsg3 that may serve as a target to modulate the production of pathogenic autoantibodies. Healthy carriers of major histocompatibility complex class II alleles identical or similar to those that are highly prevalent in pemphigus vulgaris, namely DRbeta1*0402 and DRbeta1*1401, also mount T cell responses against Dsg3. We thus wanted to determine whether these prevalent major histocompatibility complex class II alleles restricted Dsg3 specific T cell responses. A CD4+ T cell line from the DRbeta1*0402+ patient PV9 was stimulated by Dsg3 with DRbeta1*0402+ L cells as antigen-presenting cells. A CD4+ T cell line and six CD4+ T cell clones from the DR11/14+ patient PV8, and six CD4+ T cell clones from the DR11+ healthy donor C6, required DR11/ DQbeta1*0301+ peripheral blood mononuclear cells but not DR11+ L cells as antigen-presenting cells and were strongly inhibited by anti-DQ antibodies, indicating that they were restricted by HLA-DQbeta1*0301. A CD4+ T cell line and three T cell clones from the DR11+ healthy donor C11 were differentially stimulated by Dsg3 with L cells expressing one of several DR11 alleles. T cell recognition of Dsg3 was thus not only restricted by the pemphigus vulgaris associated DRbeta1*0402 allele, but also by several DR11 alleles, some of which are highly homologous to DRbeta1*0402, and by HLA-DQbeta1*0301. PMID:9540980

  15. Development of an IFNγ ELISPOT for the analysis of the human T cell response against mumps virus.

    PubMed

    Han, Wanda G H; Emmelot, Maarten E; Jaadar, Haziz; Ten Hulscher, Hinke I; van Els, Cécile A C M; Kaaijk, Patricia

    2016-04-01

    In the last decade, mumps virus (MuV) causes outbreaks in highly vaccinated populations. Sub-optimal T cell immunity may play a role in the susceptibility to mumps in vaccinated individuals. T cell responses to mumps virus have been demonstrated, yet the quality of the MuV-specific T cell response has not been analyzed using single cell immunological techniques. Here we developed an IFNγ ELISPOT assay to assess MuV-specific T cell responses in peripheral blood mononuclear cells (PBMC) of healthy (vaccinated) donors and mumps patients. Various in vitro MuV-specific stimulation methods of PBMC were compared, using either live or inactivated MuV alone or MuV-infected autologous antigen presenting cells, i.e. Epstein Barr Virus-transformed B lymphoblastoid cell lines (EBV-BLCL) or (mitogen pre-activated) PBMC, for their ability to recall IFNγ-producing responder cells measured by ELISPOT. For the detection of MuV-specific T cell responses, direct exposure (24h) to live MuV was the preferred stimulation method when assay sensitivity and practical reasons were considered. Notably, flowcytometric confirmation of data revealed that primarily T cells and NK cells produce IFNγ upon live MuV stimulation. Depleting PBMC from CD56(+) NK cells prior to stimulation with live MuV led to the enumeration of MuV-specific T cell responses by ELISPOT. Our assay constitutes a tool to evaluate memory MuV-specific T cell responses in MuV vaccinated or infected persons. Furthermore, this study provides evidence that live MuV not only induces IFNγ production by T cells, but also by NK cells. PMID:26872407

  16. 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

  17. Unconventional Human T Cells Accumulate at the Site of Infection in Response to Microbial Ligands and Induce Local Tissue Remodeling

    PubMed Central

    Liuzzi, Anna Rita; Kift-Morgan, Ann; Lopez-Anton, Melisa; Friberg, Ida M.; Zhang, Jingjing; Brook, Amy C.; Roberts, Gareth W.; Donovan, Kieron L.; Colmont, Chantal S.; Toleman, Mark A.; Bowen, Timothy; Johnson, David W.; Topley, Nicholas; Moser, Bernhard; Fraser, Donald J.

    2016-01-01

    The antimicrobial responsiveness and function of unconventional human T cells are poorly understood, with only limited access to relevant specimens from sites of infection. Peritonitis is a common and serious complication in individuals with end-stage kidney disease receiving peritoneal dialysis. By analyzing local and systemic immune responses in peritoneal dialysis patients presenting with acute bacterial peritonitis and monitoring individuals before and during defined infectious episodes, our data show that Vγ9/Vδ2+ γδ T cells and mucosal-associated invariant T cells accumulate at the site of infection with organisms producing (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate and vitamin B2, respectively. Such unconventional human T cells are major producers of IFN-γ and TNF-α in response to these ligands that are shared by many microbial pathogens and affect the cells lining the peritoneal cavity by triggering local inflammation and inducing tissue remodeling with consequences for peritoneal membrane integrity. Our data uncover a crucial role for Vγ9/Vδ2 T cells and mucosal-associated invariant T cells in bacterial infection and suggest that they represent a useful predictive marker for important clinical outcomes, which may inform future stratification and patient management. These findings are likely to be applicable to other acute infections where local activation of unconventional T cells contributes to the antimicrobial inflammatory response. PMID:27527598

  18. Micronutrient supplementation and T cell-mediated immune responses in patients with tuberculosis in Tanzania.

    PubMed

    Kawai, K; Meydani, S N; Urassa, W; Wu, D; Mugusi, F M; Saathoff, E; Bosch, R J; Villamor, E; Spiegelman, D; Fawzi, W W

    2014-07-01

    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

  19. Regulatory T Cells Modulate Th17 Responses in Tuberculin skin test positive (TST+) individuals

    PubMed Central

    Babu, Subash; Bhat, Sajid Q.; Kumar, N. Pavan; Kumaraswami, V.; Nutman, Thomas B.

    2009-01-01

    Background The factors governing latency in tuberculosis (TB) are not well understood but appear to include pathogen and host factors. We have used Tuberculin skin test positivity as a tool to study cytokine responses in latent TB. Methods To identify host factors important in maintenance of TST positivity, we examined mycobacteria-specific immune responses of tuberculin skin test positive (TST+; latent TB) or negative (TST−; healthy) individuals in South India where skin test positivity can define TB latency. Results While PPD- and Mycobacterium tuberculosis culture filtrate Ag-specific Th1 and Th2 cytokines were not significantly different between the two groups, the Th17 cytokines—IL-17 and IL-23—were significantly decreased in TST+ individuals compared with the TST− individuals. This Th17 cytokine modulation was associated with significantly increased expression of CTLA-4 and Foxp3. Although CTLA-4 blockade failed to restore full production of IL-17 and IL-23 in TST+ individuals, depletion of regulatory T cells significantly increased production of these cytokines. Conclusion TST positivity is characterized by increased activity of regulatory T cells and a coincident downregulation of the Th17 response. PMID:19929695

  20. A Stochastic Model for CD4+ T Cell Proliferation and Dissemination Network in Primary Immune Response

    PubMed Central

    Boianelli, Alessandro; Pettini, Elena; Prota, Gennaro; Medaglini, Donata; Vicino, Antonio

    2015-01-01

    The study of the initial phase of the adaptive immune response after first antigen encounter provides essential information on the magnitude and quality of the immune response. This phase is characterized by proliferation and dissemination of T cells in the lymphoid organs. Modeling and identifying the key features of this phenomenon may provide a useful tool for the analysis and prediction of the effects of immunization. This knowledge can be effectively exploited in vaccinology, where it is of interest to evaluate and compare the responses to different vaccine formulations. The objective of this paper is to construct a stochastic model based on branching process theory, for the dissemination network of antigen-specific CD4+ T cells. The devised model is validated on in vivo animal experimental data. The model presented has been applied to the vaccine immunization context making references to simple proliferation laws that take into account division, death and quiescence, but it can also be applied to any context where it is of interest to study the dynamic evolution of a population. PMID:26301680

  1. Passive Immunotherapy for Retroviral Disease: Influence of Major Histocompatibility Complex Type and T-Cell Responsiveness

    NASA Astrophysics Data System (ADS)

    Hasenkrug, Kim J.; Brooks, Diane M.; Chesebro, Bruce

    1995-11-01

    Administration of virus-specific antibodies is known to be an effective early treatment for some viral infections. Such immunotherapy probably acts by antibody-mediated neutralization of viral infectivity and is often thought to function independently of T-cell-mediated immune responses. In the present experiments, we studied passive antibody therapy using Friend murine leukemia virus complex as a model for an immunosuppressive retroviral disease in adult mice. The results showed that antibody therapy could induce recovery from a well-established retroviral infection. However, the success of therapy was dependent on the presence of both CD4^+ and CD8^+ T lymphocytes. Thus, cell-mediated responses were required for recovery from infection even in the presence of therapeutic levels of antibody. The major histocompatibility type of the mice was also an important factor determining the relative success of antibody therapy in this system, but it was less critical for low-dose than for high-dose infections. Our results imply that limited T-cell responsiveness as dictated by major histocompatibility genes and/or stage of disease may have contributed to previous immunotherapy failures in AIDS patients. Possible strategies to improve the efficacy of future therapies are discussed.

  2. Kinetics of T-cell receptor binding to peptide/I-Ek complexes: correlation of the dissociation rate with T-cell responsiveness.

    PubMed Central

    Matsui, K; Boniface, J J; Steffner, P; Reay, P A; Davis, M M

    1994-01-01

    Recognition by T-cell antigen receptors (TCRs) of processed peptides bound to major histocompatibility complex (MHC) molecules is required for the initiation of most T-lymphocyte responses. Despite the availability of soluble forms of TCRs and MHC heterodimers, this interaction has proven difficult to study directly due to the very low affinity. We report here on the kinetics of TCR binding to peptide/MHC complexes in a cell-free system using surface plasmon resonance. The apparent association rates for the interactions of related peptide/MHC complexes to one such TCR are relatively slow (900-3000 M-1.s-1) and dissociation rates are very fast (0.3-0.06 s-1) with t1/2 of 2-12 s at 25 degrees C. The calculated affinity of the engineered soluble molecules compares well with previously reported competition data for native TCRs or competition data reported here for native peptide/MHC complexes, indicating that these soluble heterodimers bind in the same manner as the original molecules expressed on cells. We also find that the peptide variants which give weaker T-cell stimulatory responses have similar affinities but distinctly faster dissociation rates compared with the original peptide (when loaded onto the MHC molecule) and that this later property may be responsible for their lower activity. This has implications for both downstream signaling events and models of TCR-peptide antagonists. PMID:7809136

  3. Functional differences in hepatitis C virus nonstructural (NS) 3/4A- and 5A-specific T cell responses

    PubMed Central

    Holmström, Fredrik; Chen, Margaret; Balasiddaiah, Anangi; Sällberg, Matti; Ahlén, Gustaf; Frelin, Lars

    2016-01-01

    The hepatitis C virus nonstructural (NS) 3/4A and NS5A proteins are major targets for the new direct-acting antiviral compounds. Both viral proteins have been suggested as modulators of the response to the host cell. We have shown that NS3/4A- and NS5A-specific T cell receptors confer different effector functions, and that killing of NS3/4A-expressing hepatocytes is highly dependent on IFN-γ. We here characterize the functional differences in the T cell responses to NS3/4A and NS5A. NS3/4A- and NS5A-specific T cells could be induced at various frequencies in wild-type-, NS3/4A-, and NS5A-transgenic mice. Priming of NS5A-specific T cells required a high DNA dose, and was unlike NS3/4A dependent on both CD4+ and CD8+ T cells, but less influenced by CD25+/GITR+ regulatory T cells. The presence of IL-12 greatly improved specific CD8+ T cell priming by NS3/4A but not by NS5A, suggesting a less dependence of IFN-γ for NS5A. This notion was supported by the observation that NS5A-specific T cells could eliminate NS5A-expressing hepatocytes also in the absence of IFN-γ-receptor-2. This supports that NS3/4A- and NS5A-specific T cells become activated and eliminate antigen expressing, or infected hepatocytes, by distinct mechanisms, and that NS5A-specific T cells show an overall less dependence of IFN-γ. PMID:27141891

  4. Common Ewing sarcoma-associated antigens fail to induce natural T cell responses in both patients and healthy individuals.

    PubMed

    Altvater, Bianca; Kailayangiri, Sareetha; Theimann, Nadine; Ahlmann, Martina; Farwick, Nicole; Chen, Christiane; Pscherer, Sibylle; Neumann, Ilka; Mrachatz, Gabriele; Hansmeier, Anna; Hardes, Jendrik; Gosheger, Georg; Juergens, Heribert; Rossig, Claudia

    2014-10-01

    Disseminated or relapsed Ewing sarcoma (EwS) has remained fatal in the majority of patients. A promising approach to preventing relapse after conventional therapy is to establish tumor antigen-specific immune control. Efficient and specific T cell memory against the tumor depends on the expansion of rare T cells with native specificity against target antigens overexpressed by the tumor. Candidate antigens in EwS include six-transmembrane epithelial antigen of the prostate-1 (STEAP1), and the human cancer/testis antigens X-antigen family member 1 (XAGE1) and preferentially expressed antigen in melanoma (PRAME). Here, we screened normal donors and EwS patients for the presence of circulating T cells reactive with overlapping peptide libraries of these antigens by IFN-γ Elispot analysis. The majority of 22 healthy donors lacked detectable memory T cell responses against STEAP1, XAGE1 and PRAME. Moreover, ex vivo detection of T cells specific for these antigens in both blood and bone marrow were limited to a minority of EwS patients and required nonspecific T cell prestimulation. Cytotoxic T cells specific for the tumor-associated antigens were efficiently and reliably generated by in vitro priming using professional antigen-presenting cells and optimized cytokine stimulation; however, these T cells failed to interact with native antigen processed by target cells and with EwS cells expressing the antigen. We conclude that EwS-associated antigens fail to induce efficient T cell receptor (TCR)-mediated antitumor immune responses even under optimized conditions. Strategies based on TCR engineering could provide a more effective means to manipulating T cell immunity toward targeted elimination of tumor cells. PMID:24973179

  5. Association of γδ T Cell Compartment Size to Disease Activity and Response to Therapy in SLE

    PubMed Central

    Ma, Hongshuang; Yuan, Yi; Zhao, Ling; Ye, Zhuang; Xu, Jiandong; Li, Man; Jiang, Zhenyu; Jiang, Yanfang

    2016-01-01

    Objective Although γδT cells are widely recognized as pivotal elements in immune-mediated diseases, their role in the pathogenesis of SLE and therapeutic outcome remains under explored. The current study aims to characterize the γδT cell compartment in SLE and correlate its status to disease severity and response to therapy. Methods Human peripheral blood-derived γδ T cells were isolated from 14 healthy volunteers and 22 SLE patients (before and after 4 and 12 weeks following the onset of glucocorticoids (GC), mycophenolatemofetil (MMF) orhydroxychloroquine (HCQ) treatment). The γδ T cells were characterized using flow cytometry. In addition, serum concentration of IFN-γ, TNF-α, IL-2, IL-4, IL-6, IL-10 and IL-17A was determined by cytometric bead array (CBA). Results The SLEDAI scores dropped significantly following therapy in a subset of patients (responders–R) but not in some (non- responders–NR). Peripheral blood γδ T cells in general, and γ9+δ T cells and TNF-α/IL-17-secreting CD4-CD8-γδ T cell subsets in particular, were decreased in SLE compared to healthy controls. The numbers of the γδ T cell subsets reached levels similar to those of healthy controls following therapy in R but not in NR. Serum IL-6, IL-10 and IL-17 but not IFN-γ and TNF-α were significantly increased in SLE compared to the healthy controls and exhibited differential changes following therapy. In addition, inverse correlation was observed between SLEDAI scores and γδ T cell compartments, especially with TNF-α+γδT cells, TNF-α+γ9+δT cells and IL17+CD4-CD8-γδT cells subsets. Differential correlation patterns were also observed between serum cytokine levels and various γδ T cell compartments. Conclusions A strong association exists between γδ T cell compartments and SLE pathogenesis, disease severity and response to therapy. PMID:27333282

  6. Large scale analysis of pediatric antiviral CD8+ T cell populations reveals sustained, functional and mature responses

    PubMed Central

    Komatsu, Haruki; Inui, Ayano; Sogo, Tsuyoshi; Fujisawa, Tomoo; Nagasaka, Hironori; Nonoyama, Shigeaki; Sierro, Sophie; Northfield, John; Lucas, Michaela; Vargas, Anita; Klenerman, Paul

    2006-01-01

    Background Cellular immunity plays a crucial role in cytomegalovirus (CMV) infection and substantial populations of CMV-specific T cells accumulate throughout life. However, although CMV infection occurs during childhood, relatively little is know about the typical quantity and quality of T cell responses in pediatric populations. Methods One thousand and thirty-six people (Male/Female = 594/442, Age: 0–19 yr.; 959 subjects, 20–29 yr.; 77 subjects) were examined for HLA typing. All of 1036 subjects were tested for HLA-A2 antigen. Of 1036 subjects, 887 were also tested for HLA-A23, 24 antigens. In addition, 50 elderly people (Male/Female = 11/39, Age: 60–92 yr.) were also tested for HLA-A2 antigen. We analyzed the CD8+ T cell responses to CMV, comparing these to responses in children and young. The frequencies, phenotype and function CD8+ T cells for two imunodominant epitopes from pp65 were measured. Results We observed consistently high frequency and phenotypically "mature" (CD27 low, CD28 low, CD45RA+) CMV-specific CD8+ T cell responses in children, including those studied in the first year of life. These CD8+ T cells retained functionality across all age groups, and showed evidence of memory "inflation" only in later adult life. Conclusion CMV consistently elicits a very strong CD8+ T cell response in infants and large pools of CMV specific CD8+ T cells are maintained throughout childhood. The presence of CMV may considerably mould the CD8+ T cell compartment over time, but the relative frequencies of CMV-specific cells do not show the evidence of a population-level increase during childhood and adulthood. This contrast with the marked expansion ("inflation") of such CD8+ T cells in older adults. This study indicates that large scale analysis of peptide specific T cell responses in infants is readily possible. The robust nature of the responses observed suggests vaccine strategies aimed at priming and boosting CD8+ T cells against major pathogens

  7. Loss of immunization-induced epitope-specific CD4 T-cell response following anaplasma marginale infection requires presence of the T-cell epitope on the pathogen and is not associated with an increase in lymphocytes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have shown that in cattle previously immunized with outer membrane proteins, infection with Anaplasma marginale induces a functionally exhausted CD4 T-cell response to the A. marginale immunogen. Furthermore, T-cell responses following infection in nonimmunized cattle had a delayed onset and were...

  8. Agonistic Anti-TIGIT Treatment Inhibits T Cell Responses in LDLr Deficient Mice without Affecting Atherosclerotic Lesion Development

    PubMed Central

    Foks, Amanda C.; Ran, Ingrid A.; Frodermann, Vanessa; Bot, Ilze; van Santbrink, Peter J.; Kuiper, Johan; van Puijvelde, Gijs H. M.

    2013-01-01

    Objective Co-stimulatory and co-inhibitory molecules are mainly expressed on T cells and antigen presenting cells and strongly orchestrate adaptive immune responses. Whereas co-stimulatory molecules enhance immune responses, signaling via co-inhibitory molecules dampens the immune system, thereby showing great therapeutic potential to prevent cardiovascular diseases. Signaling via co-inhibitory T cell immunoglobulin and ITIM domain (TIGIT) directly inhibits T cell activation and proliferation, and therefore represents a novel therapeutic candidate to specifically dampen pro-atherogenic T cell reactivity. In the present study, we used an agonistic anti-TIGIT antibody to determine the effect of excessive TIGIT-signaling on atherosclerosis. Methods and Results TIGIT was upregulated on CD4+ T cells isolated from mice fed a Western-type diet in comparison with mice fed a chow diet. Agonistic anti-TIGIT suppressed T cell activation and proliferation both in vitro and in vivo. However, agonistic anti-TIGIT treatment of LDLr−/− mice fed a Western-type diet for 4 or 8 weeks did not affect atherosclerotic lesion development in comparison with PBS and Armenian Hamster IgG treatment. Furthermore, elevated percentages of dendritic cells were observed in the blood and spleen of agonistic anti-TIGIT-treated mice. Additionally, these cells showed an increased activation status but decreased IL-10 production. Conclusions Despite the inhibition of splenic T cell responses, agonistic anti-TIGIT treatment does not affect initial atherosclerosis development, possibly due to increased activity of dendritic cells. PMID:24376654

  9. Privileged Antigen Presentation in Splenic B Cell Follicles Maximizes T Cell Responses in Prime-Boost Vaccination.

    PubMed

    Bridle, Byram W; Nguyen, Andrew; Salem, Omar; Zhang, Liang; Koshy, Sandeep; Clouthier, Derek; Chen, Lan; Pol, Jonathan; Swift, Stephanie L; Bowdish, Dawn M E; Lichty, Brian D; Bramson, Jonathan L; Wan, Yonghong

    2016-06-01

    Effector T cells (TEFF) are a barrier to booster vaccination because they can rapidly kill Ag-bearing APCs before memory T cells are engaged. We report in this study that i.v. delivery of rhabdoviral vectors leads to direct infection of follicular B cells in the spleen, where the earliest evidence of secondary T cell responses was observed. This allows booster immunizations to rapidly expand CD8(+) central memory T cells (TCM) during the acute phase of the primary response that is dominated by TEFF Interestingly, although the ablation of B cells before boosting with rhabdoviral vectors diminishes the expansion of memory T cells, B cells do not present Ags directly. Instead, depletion of CD11c(+) dendritic cells abrogates secondary T cell expansion, suggesting that virus-infected follicular B cells may function as an Ag source for local DCs to subsequently capture and present the Ag. Because TCM are located within B cell follicles in the spleen whereas TEFF cannot traffic through follicular regions, Ag production and presentation by follicular APCs represent a unique mechanism to secure engagement of TCM during an ongoing effector response. Our data offer insights into novel strategies for rapid expansion of CD8(+) T cells using prime-boost vaccines by targeting privileged sites for Ag presentation. PMID:27183620

  10. Suppressor cell hyperactivity relative to allogeneic lymphocyte proliferation as a manifestation of defective T-T-cell interactions in systemic lupus erythematosus

    SciTech Connect

    Stenina, M.A.; Potapova, A.A.; Biryukov, A.V.; Skripnik, A.Yu.; Cheredeev, A.N.

    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.

  11. Role of T cell TGF beta signaling in intestinal cytokine responses and helminthic immune modulation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Colonization with helminthic parasites down-regulates inflammation in murine colitis and improves activity scores in human inflammatory bowel disease. Helminths induce mucosal regulatory T cells, which are important for intestinal immunologic homeostasis. Regulatory T cell function involves cytoki...

  12. Two Distinct Functional Patterns of Hepatitis C Virus (HCV)-Specific T Cell Responses in Seronegative, Aviremic Patients

    PubMed Central

    Nam, Seung Joo; Park, Jung Tak; Kim, Hyon-Suk; Choi, Kyu Hun; Kim, Beom Seok; Shin, Eui-Cheol

    2013-01-01

    In hepatitis C Virus (HCV) high-risk groups, HCV-specific T cell responses have been detected in seronegative, aviremic persons who have no evidence of HCV infection. Herein, we investigated functional profiles of HCV-specific T-cell responses in seronegative, aviremic patients of a HCV high-risk group. Seventy seven hemodialysis patients with chronic renal disease were analyzed by IFN-γ ELISpot assays, and eight of 71 (11.3%) seronegative, aviremic patients displayed HCV-specific T-cell responses. Their HCV-specific memory T cells were characterized by assessing cytokine polyfunctionality, known to provide antiviral protection. By intracellular staining of IFN-γ, TNF-α, IL-2 and MIP-1β, we identified two distinct populations in the seronegative, aviremic patients: polyfunctional responders and TNF-α-predominant responders. In further analysis, occult HCV infection was excluded as a cause of the HCV-specific T cell response via secondary nested RT-PCR of HCV RNA in peripheral blood mononuclear cell samples. HCV-specific T cells targeted multiple epitopes including non-structural proteins in a single patient, implying that their T cells might have been primed by HCV proteins synthesized within the host. We conclude that HCV-specific memory T cells of seronegative, aviremic patients arise from authentic HCV replication in the host, but not from current occult HCV infection. By functional pattern of HCV-specific T cells, there are two distinct populations in these patients: polyfunctional responders and TNF-α-predominant responders. PMID:23638039

  13. Peptide-MHC Cellular Microarray with Innovative Data Analysis System for Simultaneously Detecting Multiple CD4 T-Cell Responses

    PubMed Central

    Ge, Xinhui; Gebe, John A.; Bollyky, Paul L.; James, Eddie A.; Yang, Junbao; Stern, Lawrence J.; Kwok, William W.

    2010-01-01

    Background Peptide:MHC cellular microarrays have been proposed to simultaneously characterize multiple Ag-specific populations of T cells. The practice of studying immune responses to complicated pathogens with this tool demands extensive knowledge of T cell epitopes and the availability of peptide:MHC complexes for array fabrication as well as a specialized data analysis approach for result interpretation. Methodology/Principal Findings We co-immobilized peptide:DR0401 complexes, anti-CD28, anti-CD11a and cytokine capture antibodies on the surface of chamber slides to generate a functional array that was able to detect rare Ag-specific T cell populations from previously primed in vitro T cell cultures. A novel statistical methodology was also developed to facilitate batch processing of raw array-like data into standardized endpoint scores, which linearly correlated with total Ag-specific T cell inputs. Applying these methods to analyze Influenza A viral antigen-specific T cell responses, we not only revealed the most prominent viral epitopes, but also demonstrated the heterogeneity of anti-viral cellular responses in healthy individuals. Applying these methods to examine the insulin producing beta-cell autoantigen specific T cell responses, we observed little difference between autoimmune diabetic patients and healthy individuals, suggesting a more subtle association between diabetes status and peripheral autoreactive T cells. Conclusions/Significance The data analysis system is reliable for T cell specificity and functional testing. Peptide:MHC cellular microarrays can be used to obtain multi-parametric results using limited blood samples in a variety of translational settings. PMID:20634998

  14. T-Cell Responses Are Associated with Survival in Acute Melioidosis Patients

    PubMed Central

    Jenjaroen, Kemajittra; Chumseng, Suchintana; Sumonwiriya, Manutsanun; Ariyaprasert, Pitchayanant; Chantratita, Narisara; Sunyakumthorn, Piyanate; Hongsuwan, Maliwan; Wuthiekanun, Vanaporn; Fletcher, Helen A.; Teparrukkul, Prapit; Limmathurotsakul, Direk; Day, Nicholas P. J.; Dunachie, Susanna J.

    2015-01-01

    Background Melioidosis is an increasingly recognised cause of sepsis and death across South East Asia and Northern Australia, caused by the bacterium Burkholderia pseudomallei. Risk factors include diabetes, alcoholism and renal disease, and a vaccine targeting at-risk populations is urgently required. A better understanding of the protective immune response in naturally infected patients is essential for vaccine design. Methods We conducted a longitudinal clinical and immunological study of 200 patients with melioidosis on admission, 12 weeks (n = 113) and 52 weeks (n = 65) later. Responses to whole killed B. pseudomallei were measured in peripheral blood mononuclear cells (PBMC) by interferon-gamma (IFN-γ) ELIspot assay and flow cytometry and compared to those of control subjects in the region with diabetes (n = 45) and without diabetes (n = 43). Results We demonstrated strong CD4+ and CD8+ responses to B. pseudomallei during acute disease, 12 weeks and 52 weeks later. 28-day mortality was 26% for melioidosis patients, and B. pseudomallei-specific cellular responses in fatal cases (mean 98 IFN-γ cells per million PBMC) were significantly lower than those in the survivors (mean 142 IFN-γ cells per million PBMC) in a multivariable logistic regression model (P = 0.01). A J-shaped curve association between circulating neutrophil count and mortality was seen with an optimal count of 4000 to 8000 neutrophils/μl. Melioidosis patients with known diabetes had poor diabetic control (median glycated haemoglobin HbA1c 10.2%, interquartile range 9.2–13.1) and showed a stunted B. pseudomallei-specific cellular response during acute illness compared to those without diabetes. Conclusions The results demonstrate the role of both CD4+ and CD8+ T-cells in protection against melioidosis, and an interaction between diabetes and cellular responses. This supports development of vaccine strategies that induce strong T-cell responses for the control of intracellular pathogens such

  15. 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

  16. Skin tumor responsiveness to interleukin-2 treatment and CD8 Foxp3+ T cell expansion in an immunocompetent mouse model.

    PubMed

    Foureau, David M; McKillop, Iain H; Jones, Chase P; Amin, Asim; White, Richard L; Salo, Jonathan C

    2011-09-01

    Recombinant human interleukin-2 (rhIL-2) therapy is approved for treating patients with advanced melanoma yet significant responses are observed in only 10-15% of patients. Interleukin-2 induces Foxp3 expression in activated human CD8 T cells in vitro and expands circulating CD8 Foxp3+ T cells in melanoma patients. Employing IL-2 responsive (B16-F1, B16-BL6, JB/MS, MCA-205) and nonresponsive (JB/RH, B16-F10) subcutaneous tumor mouse models, we evaluated CD8 Foxp3+ T cell distribution and changes in response to rhIL-2 (50,000 U, i.p. or s.q., twice daily for 5 days). In tumor-free mice and subcutaneous tumor-bearing mouse models, CD8 Foxp3+ T cells were a rare but naturally occurring cell subset. Primarily located in skin-draining lymph nodes, CD8 Foxp3+ T cells expressed both activated T cell (CD28(+), CD44(+)) and Treg (CTLA4(+), PD1(lo/var), NKG2A(+/var)) markers. Following treatment with rhIL-2, a dramatic increase in CD8 Foxp3+ T cell prevalence was observed in the circulation and tumor-draining lymph nodes (TD.LNs) of animals bearing IL-2 nonresponsive tumors, while no significant changes were observed in the circulation and TD.LNs of animals bearing IL-2 responsive tumors. These findings suggest expansion of CD8 Foxp3+ T cell population in response to rhIL-2 treatment may serve as an early marker for tumor responsiveness to immunotherapy in an immune competent model. Additionally, these data may provide insight to predict response in patients with melanoma undergoing rhIL-2 treatment. PMID:21638127

  17. MPLA incorporation into DC-targeting glycoliposomes favours anti-tumour T cell responses.

    PubMed

    Boks, Martine A; Ambrosini, Martino; Bruijns, Sven C; Kalay, Hakan; van Bloois, Louis; Storm, Gert; Garcia-Vallejo, Juan J; van Kooyk, Yvette

    2015-10-28

    Dendritic cells (DC) are attractive targets for cancer immunotherapy as they initiate strong and long-lived tumour-specific T cell responses. DC can be effectively targeted in vivo with tumour antigens by using nanocarriers such as liposomes. Cross-presentation of tumour antigens is enhanced with strong adjuvants such as TLR ligands. However, often these adjuvants have off-target effects, and would benefit from a DC-specific targeting strategy, similar to the tumour antigen. The goal of this study was to develop a strategy for specifically targeting DC with tumour antigen and adjuvant by using glycoliposomes. We have generated liposomes containing the glycan Lewis(Le)(X) which is highly specific for the C-type lectin receptor DC-SIGN expressed by DC. Le(X)-modified liposomes were taken up by human monocyte-derived DC in a DC-SIGN-specific manner. As adjuvants we incorporated the TLR ligands Pam3CySK4, Poly I:C, MPLA and R848 into liposomes and compared their adjuvant capacity on DC. Incorporation of the TLR4 ligand MPLA into glycoliposomes induced DC maturation and production of pro-inflammatory cytokines, in a DC-SIGN-specific manner, and DC activation was comparable to administration of soluble MPLA. Incorporation of MPLA into glycoliposomes significantly enhanced antigen cross-presentation of the melanoma tumour antigen gp100280-288 peptide to CD8(+) T cells compared to non-glycosylated MPLA liposomes. Importantly, antigen cross-presentation of the gp100280-288 peptide was significantly higher using MPLA glycoliposomes compared to the co-administration of soluble MPLA with glycoliposomes. Taken together, our data demonstrates that specific targeting of a gp100 tumour antigen and the adjuvant MPLA to DC-SIGN-expressing DC enhances the uptake of peptide-containing liposomes, the activation of DC, and induces tumour antigen-specific CD8(+) T cell responses. These data demonstrate that adjuvant-containing glycoliposome-based vaccines targeting DC-SIGN(+) DC

  18. Gamma delta T cells and the immune response to respiratory syncytial virus infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    'd T cells are a subset of nonconventional T cells that play a critical role in bridging the innate and adaptive arms of the immune system. 'd T cells are particularly abundant in ruminant species and may constitute of up 60% of the circulating lymphocyte pool in young cattle. The frequency of circ...

  19. Direct Presentation Is Sufficient for an Efficient Anti-Viral CD8+ T Cell Response

    PubMed Central

    Xu, Ren-Huan; Remakus, Sanda; Ma, Xueying; Roscoe, Felicia; Sigal, Luis J.

    2010-01-01

    The extent to which direct- and cross-presentation (DP and CP) contribute to the priming of CD8+ T cell (TCD8+) responses to viruses is unclear mainly because of the difficulty in separating the two processes. Hence, while CP in the absence of DP has been clearly demonstrated, induction of an anti-viral TCD8+ response that excludes CP has never been purposely shown. Using vaccinia virus (VACV), which has been used as the vaccine to rid the world of smallpox and is proposed as a vector for many other vaccines, we show that DP is the main mechanism for the priming of an anti-viral TCD8+ response. These findings provide important insights to our understanding of how one of the most effective anti-viral vaccines induces immunity and should contribute to the development of novel vaccines. PMID:20169189

  20. Alarmin’ Immunologists: IL-33 as a Putative Target for Modulating T Cell-Dependent Responses

    PubMed Central

    Gajardo Carrasco, Tania; Morales, Rodrigo A.; Pérez, Francisco; Terraza, Claudia; Yáñez, Luz; Campos-Mora, Mauricio; Pino-Lagos, Karina

    2015-01-01

    IL-33 is a known member of the IL-1 cytokine superfamily classically named “atypical” due to its diverse functions. The receptor for this cytokine is the ST2 chain (or IL-1RL1), part of the IL-1R family, and the accessory chain IL-1R. ST2 can be found as both soluble and membrane-bound forms, property that explains, at least in part, its wide range of functions. IL-33 has increasingly gained our attention as a potential target to modulate immune responses. At the beginning, it was known as one of the participants during the development of allergic states and other Th2-mediated responses and it is now accepted that IL-33 contributes to Th1-driven pathologies as demonstrated in animal models of experimental autoimmune encephalomyelitis (EAE), collagen-induced arthritis, and trinitrobenzene sulfonic acid-induced experimental colitis, among others. Interestingly, current data are placing IL-33 as a novel regulator of immune tolerance by affecting regulatory T cells (Tregs); although the mechanism is not fully understood, it seems that dendritic cells and myeloid suppressor-derived cells may be cooperating in the generation and/or establishment of IL-33-mediated tolerance. Here, we review the most updated literature on IL-33, its role on T cell biology, and its impact in immune tolerance. PMID:26082774

  1. 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

  2. CD8 T Cell-Independent Antitumor Response and Its Potential for Treatment of Malignant Gliomas.

    PubMed

    Murphy, Katherine A; Griffith, Thomas S

    2016-01-01

    Malignant brain tumors continue to represent a devastating diagnosis with no real chance for cure. Despite an increasing list of potential salvage therapies, standard-of-care for these patients has not changed in over a decade. Immunotherapy has been seen as an exciting option, with the potential to offer specific and long lasting tumor clearance. The "gold standard" in immunotherapy has been the development of a tumor-specific CD8 T cell response to potentiate tumor clearance and immunological memory. While many advances have been made in the field of immunotherapy, few therapies have seen true success. Many of the same principles used to develop immunotherapy in tumors of the peripheral organs have been applied to brain tumor immunotherapy. The immune-specialized nature of the brain should call into question whether this approach is appropriate. Recent results from our own experiments require a rethinking of current dogma. Perhaps a CD8 T cell response is not sufficient for an organ as immunologically unique as the brain. Examination of previously elucidated principles of the brain's immune-specialized status and known immunological preferences should generate discussion and experimentation to address the failure of current therapies. PMID:27472363

  3. Specific CD8+ T cell response immunotherapy for hepatocellular carcinoma and viral hepatitis

    PubMed Central

    Moreno-Cubero, Elia; Larrubia, Juan-Ramón

    2016-01-01

    Hepatocellular carcinoma (HCC), chronic hepatitis B (CHB) and chronic hepatitis C (CHC) are characterized by exhaustion of the specific CD8+ T cell response. This process involves enhancement of negative co-stimulatory molecules, such as programmed cell death protein-1 (PD-1), cytotoxic T-lymphocyte antigen-4 (CTLA-4), 2B4, Tim-3, CD160 and LAG-3, which is linked to intrahepatic overexpression of some of the cognate ligands, such as PD-L1, on antigen presenting cells and thereby favouring a tolerogenic environment. Therapies that disrupt these negative signalling mechanisms represent promising therapeutic tools with the potential to restore reactivity of the specific CD8+ T cell response. In this review we discuss the impressive in vitro and in vivo results that have been recently achieved in HCC, CHB and CHC by blocking these negative receptors with monoclonal antibodies against these immune checkpoint modulators. The article mainly focuses on the role of CTLA-4 and PD-1 blocking monoclonal antibodies, the first ones to have reached clinical practice. The humanized monoclonal antibodies against CTLA-4 (tremelimumab and ipilimumab) and PD-1 (nivolumab and pembrolizumab) have yielded good results in testing of HCC and chronic viral hepatitis patients. Trelimumab, in particular, has shown a significant increase in the time to progression in HCC, while nivolumab has shown a remarkable effect on hepatitis C viral load reduction. The research on the role of ipilimumab, nivolumab and pembrolizumab on HCC is currently underway.

  4. Broadly targeted CD8+ T cell responses restricted by major histocompatibility complex E

    DOE PAGESBeta

    Hansen, Scott G.; Wu, Helen L.; Burwits, Benjamin J.; Hughes, Colette M.; Hammond, Katherine B.; Ventura, Abigail B.; Reed, Jason S.; Gilbride, Roxanne M.; Ainslie, Emily; Morrow, David W.; et al

    2016-02-12

    Major histocompatibility complex (MHC)-E is a highly conserved, ubiquitously expressed, nonclassical, MHC-Ib molecule with limited polymorphism primarily involved in regulation of NK cell reactivity via interaction with NKG2/CD94 receptors. We found that vaccination of rhesus macaques with Rh157.5/.4 gene-deleted rhesus Cytomegalovirus (RhCMV) vectors uniquely diverts MHC-E function to presentation of highly diverse peptide epitopes to CD8α/β+ T cells, approximately 4 distinct epitopes per 100 amino acids, in all tested protein antigens. Computational structural analysis revealed that a relatively stable, open binding groove in MHC-E attains broad peptide binding specificity by imposing a similar backbone configuration on bound peptides with fewmore » restrictions based on amino acid side chains. Since MHC-E is up-regulated on cells infected with HIV/SIV and other persistent viruses to evade NK cell activity, MHC-E-restricted CD8+ T cell responses have the potential to exploit pathogen immune evasion adaptations, a capability that might endow these unconventional responses with superior efficacy.« less

  5. Specific CD8(+) T cell response immunotherapy for hepatocellular carcinoma and viral hepatitis.

    PubMed

    Moreno-Cubero, Elia; Larrubia, Juan-Ramón

    2016-07-28

    Hepatocellular carcinoma (HCC), chronic hepatitis B (CHB) and chronic hepatitis C (CHC) are characterized by exhaustion of the specific CD8(+) T cell response. This process involves enhancement of negative co-stimulatory molecules, such as programmed cell death protein-1 (PD-1), cytotoxic T-lymphocyte antigen-4 (CTLA-4), 2B4, Tim-3, CD160 and LAG-3, which is linked to intrahepatic overexpression of some of the cognate ligands, such as PD-L1, on antigen presenting cells and thereby favouring a tolerogenic environment. Therapies that disrupt these negative signalling mechanisms represent promising therapeutic tools with the potential to restore reactivity of the specific CD8(+) T cell response. In this review we discuss the impressive in vitro and in vivo results that have been recently achieved in HCC, CHB and CHC by blocking these negative receptors with monoclonal antibodies against these immune checkpoint modulators. The article mainly focuses on the role of CTLA-4 and PD-1 blocking monoclonal antibodies, the first ones to have reached clinical practice. The humanized monoclonal antibodies against CTLA-4 (tremelimumab and ipilimumab) and PD-1 (nivolumab and pembrolizumab) have yielded good results in testing of HCC and chronic viral hepatitis patients. Trelimumab, in particular, has shown a significant increase in the time to progression in HCC, while nivolumab has shown a remarkable effect on hepatitis C viral load reduction. The research on the role of ipilimumab, nivolumab and pembrolizumab on HCC is currently underway. PMID:27605882

  6. Broadly targeted CD8⁺ T cell responses restricted by major histocompatibility complex E.

    PubMed

    Hansen, Scott G; Wu, Helen L; Burwitz, Benjamin J; Hughes, Colette M; Hammond, Katherine B; Ventura, Abigail B; Reed, Jason S; Gilbride, Roxanne M; Ainslie, Emily; Morrow, David W; Ford, Julia C; Selseth, Andrea N; Pathak, Reesab; Malouli, Daniel; Legasse, Alfred W; Axthelm, Michael K; Nelson, Jay A; Gillespie, Geraldine M; Walters, Lucy C; Brackenridge, Simon; Sharpe, Hannah R; López, César A; Früh, Klaus; Korber, Bette T; McMichael, Andrew J; Gnanakaran, S; Sacha, Jonah B; Picker, Louis J

    2016-02-12

    Major histocompatibility complex E (MHC-E) is a highly conserved, ubiquitously expressed, nonclassical MHC class Ib molecule with limited polymorphism that is primarily involved in the regulation of natural killer (NK) cells. We found that vaccinating rhesus macaques with rhesus cytomegalovirus vectors in which genes Rh157.5 and Rh157.4 are deleted results in MHC-E-restricted presentation of highly varied peptide epitopes to CD8αβ(+) T cells, at ~4 distinct epitopes per 100 amino acids in all tested antigens. Computational structural analysis revealed that MHC-E provides heterogeneous chemical environments for diverse side-chain interactions within a stable, open binding groove. Because MHC-E is up-regulated to evade NK cell activity in cells infected with HIV, simian immunodeficiency virus, and other persistent viruses, MHC-E-restricted CD8(+) T cell responses have the potential to exploit pathogen immune-evasion adaptations, a capability that might endow these unconventional responses with superior efficacy. PMID:26797147

  7. Intestinal T-cell Responses in Celiac Disease – Impact of Celiac Disease Associated Bacteria

    PubMed Central

    Sjöberg, Veronika; Sandström, Olof; Hedberg, Maria; Hammarström, Sten; Hernell, Olle; Hammarström, Marie-Louise

    2013-01-01

    A hallmark of active celiac disease (CD), an inflammatory small-bowel enteropathy caused by permanent intolerance to gluten, is cytokine production by intestinal T lymphocytes. Prerequisites for contracting CD are that the individual carries the MHC class II alleles HLA-DQ2 and/or HLA-DQ8 and is exposed to gluten in the diet. Dysbiosis in the resident microbiota has been suggested to be another risk factor for CD. In fact, rod shaped bacteria adhering to the small intestinal mucosa were frequently seen in patients with CD during the “Swedish CD epidemic” and bacterial candidates could later be isolated from patients born during the epidemic suggesting long-lasting changes in the gut microbiota. Interleukin-17A (IL-17A) plays a role in both inflammation and anti-bacterial responses. In active CD IL-17A was produced by both CD8+ T cells (Tc17) and CD4+ T cells (Th17), with intraepithelial Tc17 cells being the dominant producers. Gluten peptides as well as CD associated bacteria induced IL-17A responses in ex vivo challenged biopsies from patients with inactive CD. The IL-17A response was suppressed in patients born during the epidemic when a mixture of CD associated bacteria was added to gluten, while the reverse was the case in patients born after the epidemic. Under these conditions Th17 cells were the dominant producers. Thus Tc17 and Th17 responses to gluten and bacteria seem to pave the way for the chronic disease with interferon-γ-production by intraepithelial Tc1 cells and lamina propria Th1 cells. The CD associated bacteria and the dysbiosis they might cause in the resident microbiota may be a risk factor for CD either by directly influencing the immune responses in the mucosa or by enhancing inflammatory responses to gluten. PMID:23326425

  8. Increased Membrane Cholesterol in Lymphocytes Diverts T-Cells toward an Inflammatory Response

    PubMed Central

    Surls, Jacqueline; Nazarov-Stoica, Cristina; Kehl, Margaret; Olsen, Cara; Casares, Sofia; Brumeanu, Teodor-D.

    2012-01-01

    Cell signaling for T-cell growth, differentiation, and apoptosis is initiated in the cholesterol-rich microdomains of the plasma membrane known as lipid rafts. Herein, we investigated whether enrichment of membrane cholesterol in lipid rafts affects antigen-specific CD4 T-helper cell functions. Enrichment of membrane cholesterol by 40–50% following squalene administration in mice was paralleled by an increased number of resting CD4 T helper cells in periphery. We also observed sensitization of the Th1 differentiation machinery through co-localization of IL-2Rα, IL-4Rα, and IL-12Rβ2 subunits with GM1 positive lipid rafts, and increased STAT-4 and STAT-5 phosphorylation following membrane cholesterol enrichment. Antigen stimulation or CD3/CD28 polyclonal stimulation of membrane cholesterol-enriched, resting CD4 T-cells followed a path of Th1 differentiation, which was more vigorous in the presence of increased IL-12 secretion by APCs enriched in membrane cholesterol. Enrichment of membrane cholesterol in antigen-specific, autoimmune Th1 cells fostered their organ-specific reactivity, as confirmed in an autoimmune mouse model for diabetes. However, membrane cholesterol enrichment in CD4+ Foxp3+ T-reg cells did not alter their suppressogenic function. These findings revealed a differential regulatory effect of membrane cholesterol on the function of CD4 T-cell subsets. This first suggests that membrane cholesterol could be a new therapeutic target to modulate the immune functions, and second that increased membrane cholesterol in various physiopathological conditions may bias the immune system toward an inflammatory Th1 type response. PMID:22723880

  9. Lack of IL-15 results in the suboptimal priming of CD4+ T cell response against an intracellular parasite

    PubMed Central

    Combe, Crescent L.; Moretto, Magali M.; Schwartzman, Joseph D.; Gigley, Jason P.; Bzik, David J.; Khan, Imtiaz A.

    2006-01-01

    IFN-γ-producing CD4+ T cells, although important for protection against acute Toxoplasma gondii infection, can cause gut pathology, which may prove to be detrimental for host survival. Here we show that mice lacking IL-15 gene develop a down-regulated IFN-γ-producing CD4+ T cell response against the parasite, which leads to a reduction in gut necrosis and increased level of survival against infection. Moreover, transfer of immune CD4+ T cells from WT to IL-15−/− mice reversed inhibition of gut pathology and caused mortality equivalent to levels of parental WT mice. Down-regulated CD4+ T cell response in the absence of IL-15, manifested as reduced antigen-specific proliferation, was due to defective priming of the T cell subset by dendritic cells (DCs) of these animals. When stimulated with antigen-pulsed DCs from WT mice, CD4+ T cells from IL-15−/− mice were primed optimally, and robust proliferation of these cells was observed. A defect in the DCs of knockout mice was further confirmed by their reduced ability to produce IL-12 upon stimulation with Toxoplasma lysate antigen. Addition of exogenous IL-15 to DC cultures from knockout mice led to increased IL-12 production by these cells and restored their ability to prime an optimal parasite-specific CD4+ T cell response. To our knowledge, this is the first demonstration of the role of IL-15 in the development of CD4+ T cell immunity against an intracellular pathogen. Furthermore, based on these observations, targeting of IL-15 should have a beneficial effect on individuals suffering from CD4+ T cell-mediated autoimmune diseases. PMID:16614074

  10. Lack of IL-15 results in the suboptimal priming of CD4+ T cell response against an intracellular parasite.

    PubMed

    Combe, Crescent L; Moretto, Magali M; Schwartzman, Joseph D; Gigley, Jason P; Bzik, David J; Khan, Imtiaz A

    2006-04-25

    IFN-gamma-producing CD4+ T cells, although important for protection against acute Toxoplasma gondii infection, can cause gut pathology, which may prove to be detrimental for host survival. Here we show that mice lacking IL-15 gene develop a down-regulated IFN-gamma-producing CD4+ T cell response against the parasite, which leads to a reduction in gut necrosis and increased level of survival against infection. Moreover, transfer of immune CD4+ T cells from WT to IL-15-/- mice reversed inhibition of gut pathology and caused mortality equivalent to levels of parental WT mice. Down-regulated CD4+ T cell response in the absence of IL-15, manifested as reduced antigen-specific proliferation, was due to defective priming of the T cell subset by dendritic cells (DCs) of these animals. When stimulated with antigen-pulsed DCs from WT mice, CD4+ T cells from IL-15-/- mice were primed optimally, and robust proliferation of these cells was observed. A defect in the DCs of knockout mice was further confirmed by their reduced ability to produce IL-12 upon stimulation with Toxoplasma lysate antigen. Addition of exogenous IL-15 to DC cultures from knockout mice led to increased IL-12 production by these cells and restored their ability to prime an optimal parasite-specific CD4+ T cell response. To our knowledge, this is the first demonstration of the role of IL-15 in the development of CD4+ T cell immunity against an intracellular pathogen. Furthermore, based on these observations, targeting of IL-15 should have a beneficial effect on individuals suffering from CD4+ T cell-mediated autoimmune diseases. PMID:16614074

  11. Naive human T cells are activated and proliferate in response to the heme oxygenase-1 inhibitor tin mesoporphyrin.

    PubMed

    Burt, Trevor D; Seu, Lillian; Mold, Jeffrey E; Kappas, Attallah; McCune, Joseph M

    2010-11-01

    Heme oxygenase-1 (HO-1) and its catabolic by-products have potent anti-inflammatory activity in many models of disease. It is not known, however, if HO-1 also plays a role in the homeostatic control of T cell activation and proliferation. We demonstrate here that the HO-1 inhibitor tin mesoporphyrin (SnMP) induces activation, proliferation, and maturation of naive CD4(+) and CD8(+) T cells via interactions with CD14(+) monocytes in vitro. This response is dependent upon interactions of T cells with MHC class I and II on the surface of CD14(+) monocytes. Furthermore, CD4(+)CD25(+)FoxP3(+) regulatory T cells were able to suppress this proliferation, even though their suppressive activity was itself impaired by SnMP. Given the magnitude of the Ag-independent T cell response induced by SnMP, we speculate that HO-1 plays an important role in dampening nonspecific T cell activation. Based on these findings, we propose a potential role for HO-1 in the control of naive T cell homeostatic proliferation. PMID:20921523

  12. Naive CD4(+) T cell frequency varies for different epitopes and predicts repertoire diversity and response magnitude.

    PubMed

    Moon, James J; Chu, H Hamlet; Pepper, Marion; McSorley, Stephen J; Jameson, Stephen C; Kedl, Ross M; Jenkins, Marc K

    2007-08-01

    Cell-mediated immunity stems from the proliferation of naive T lymphocytes expressing T cell antigen receptors (TCRs) specific for foreign peptides bound to host major histocompatibility complex (MHC) molecules. Because of the tremendous diversity of the T cell repertoire, naive T cells specific for any one peptide:MHC complex (pMHC) are extremely rare. Thus, it is not known how many naive T cells of any given pMHC specificity exist in the body or how that number influences the immune response. By using soluble pMHC class II (pMHCII) tetramers and magnetic bead enrichment, we found that three different pMHCII-specific naive CD4(+) T cell populations vary in frequency from 20 to 200 cells per mouse. Moreover, naive population size predicted the size and TCR diversity of the primary CD4(+) T cell response after immunization with relevant peptide. Thus, variation in naive T cell frequencies can explain why some peptides are stronger immunogens than others. PMID:17707129

  13. Rapid selection of escape mutants by the first CD8 T cell responses in acute HIV-1 infection

    SciTech Connect

    Korber, Bette Tina Marie

    2008-01-01

    The recent failure of a vaccine that primes T cell responses to control primary HIV-1 infection has raised doubts about the role of CD8+ T cells in early HIV-1 infection. We studied four patients who were identified shortly after HIV-1 infection and before seroconversion. In each patient there was very rapid selection of multiple HIV-1 escape mutants in the transmitted virus by CD8 T cells, including examples of complete fixation of non-synonymous substitutions within 2 weeks. Sequencing by single genome amplification suggested that the high rate of virus replication in acute infection gave a selective advantage to virus molecules that contained simultaneous and gained sequential T cell escape mutations. These observations show that whilst early HIV-1 specific CD8 T cells can act against virus, rapid escape means that these T cell responses are unlikely to benefit the patient and may in part explain why current HIV-1 T cell vaccines may not be protective.

  14. Comprehensive analysis of dengue virus-specific responses supports an HLA-linked protective role for CD8+ T cells

    PubMed Central

    Weiskopf, Daniela; Angelo, Michael A.; de Azeredo, Elzinandes L.; Sidney, John; Greenbaum, Jason A.; Fernando, Anira N.; Broadwater, Anne; Kolla, Ravi V.; De Silva, Aruna D.; de Silva, Aravinda M.; Mattia, Kimberly A.; Doranz, Benjamin J.; Grey, Howard M.; Shresta, Sujan; Peters, Bjoern; Sette, Alessandro

    2013-01-01

    The role of CD8+ T cells in dengue virus infection and subsequent disease manifestations is not fully understood. According to the original antigenic sin theory, skewing of T-cell responses induced by primary infection with one serotype causes less effective response upon secondary infection with a different serotype, predisposing individuals to severe disease. A comprehensive analysis of CD8+ responses in the general population from the Sri Lankan hyperendemic area, involving the measurement of ex vivo IFNγ responses associated with more than 400 epitopes, challenges the original antigenic sin theory. Although skewing of responses toward primary infecting viruses was detected, this was not associated with impairment of responses either qualitatively or quantitatively. Furthermore, we demonstrate higher magnitude and more polyfunctional responses for HLA alleles associated with decreased susceptibility to severe disease, suggesting that a vigorous response by multifunctional CD8+ T cells is associated with protection from dengue virus disease. PMID:23580623

  15. EBV LMP2A-specific T Cell Immune Responses Elicited by Dendritic Cells Loaded with LMP2A Protein

    PubMed Central

    Chen, Yun; Sun, Hua; Liu, Genyan; Wang, Bing; Wang, Fang; Sun, Beicheng; Yao, Kun

    2009-01-01

    Type II Epstein-Barr virus (EBV) associated malignancies such as nasopharyngeal carcinoma and non-Hodgkin's lymphomas consistently express latent membrane 2A (LMP2A) proteins, which have been suggested to be an ideal target for immunotherapy. In previous studies we have demonstrated that using LMP2A protein loaded dendritic cells, the most powerful antigen processing cells in the body can elicit specific and robust anti-tumor cellular immune response in vitro. In this paper, we further investigated the T cell profile of the anti-tumor immune response. We found that LMP2A specific CD4+ and CD8+ T cells could be stimulated by LMP2A protein loaded dendritic cells (DCs). The Th1 type immune response is dominant in the immune response mediated by LMP2A specific CD4+ T cells. The CD8+ cytotoxic T cells can lyse LMP2A bearing cells effectively and specifically. The CD8+ cytotoxic T cells can also secrete high level of intracellular IFN-γ, which indicates these cells are EBV-LMP2A specific cytotoxic T cells. Altogether, our studies proved that LMP2A protein loaded DCs can elicit anti-tumor cellular immune responses efficiently. This study provides a rationale for the DC-based immunotherapy against EBV-LMP2A expressing malignancies. PMID:19728928

  16. Oral vaccination with lipid-formulated BCG induces a long-lived, multifunctional CD4(+) T cell memory immune response.

    PubMed

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

    2012-01-01

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

  17. Aldehyde Dehydrogenase Expression Drives Human Regulatory T Cell Resistance to Posttransplantation Cyclophosphamide

    PubMed Central

    Kanakry, Christopher G.; Ganguly, Sudipto; Zahurak, Marianna; Bolaños-Meade, Javier; Thoburn, Christopher; Perkins, Brandy; Fuchs, Ephraim J.; Jones, Richard J.; Hess, Allan D.; Luznik, Leo

    2014-01-01

    High-dose, posttransplantation cyclophosphamide (PTCy) is an effective strategy for preventing graft-versus-host disease (GVHD) after allogeneic blood or marrow transplantation (alloBMT). However, the mechanisms by which PTCy modulates alloimmune responses are not well understood. We studied early T cell reconstitution in patients undergoing alloBMT with PTCy and the effects of mafosfamide, a cyclophosphamide (Cy) analog, on CD4+ T cells in allogeneic mixed lymphocyte reactions (MLRs) in vitro. Patients exhibited reductions in naïve, potentially alloreactive conventional CD4+ T cells with relative preservation of memory CD4+Foxp3+ T cells. In particular, CD4+CD45RA−Foxp3+hi effector regulatory T cells (Tregs) recovered rapidly after alloBMT and, unexpectedly, were present at higher levels in patients with GVHD. CD4+Foxp3+ T cells from patients and from allogeneic MLRs expressed relatively high levels of aldehyde dehydrogenase (ALDH), the major in vivo mechanism of Cy resistance. Treatment of MLR cultures with the ALDH inhibitor diethylaminobenzaldehyde reduced the activation and proliferation of CD4+ T cells and sensitized Tregs to mafosfamide. Finally, removing Tregs from peripheral blood lymphocyte grafts obviated PTCy's GVHD-protective effect in a xenogeneic transplant model. Together, these findings suggest that Treg resistance to Cy through expression of ALDH may contribute to the clinical activity of PTCy in preventing GVHD. PMID:24225944

  18. Association of Neisseria gonorrhoeae Opa(CEA) with dendritic cells suppresses their ability to elicit an HIV-1-specific T cell memory response.

    PubMed

    Yu, Qigui; Chow, Edith M C; McCaw, Shannon E; Hu, Ningjie; Byrd, Daniel; Amet, Tohti; Hu, Sishun; Ostrowski, Mario A; Gray-Owen, Scott D

    2013-01-01

    Infection with Neisseria gonorrhoeae (N. gonorrhoeae) can trigger an intense local inflammatory response at the site of infection, yet there is little specific immune response or development of immune memory. Gonococcal surface epitopes are known to undergo antigenic variation; however, this is unlikely to explain the weak immune response to infection since individuals can be re-infected by the same serotype. Previous studies have demonstrated that the colony opacity-associated (Opa) proteins on the N. gonorrhoeae surface can bind human carcinoembryonic antigen-related cellular adhesion molecule 1 (CEACAM1) on CD4⁺ T cells to suppress T cell activation and proliferation. Interesting in this regard, N. gonorrhoeae infection is associated with impaired HIV-1 (human immunodeficiency virus type 1)-specific cytotoxic T-lymphocyte (CTL) responses and with transient increases in plasma viremia in HIV-1-infected patients, suggesting that N. gonorrhoeae may also subvert immune responses to co-pathogens. Since dendritic cells (DCs) are professional antigen presenting cells (APCs) that play a key role in the induction of an adaptive immune response, we investigated the effects of N. gonorrhoeae Opa proteins on human DC activation and function. While morphological changes reminiscent of DC maturation were evident upon N. gonorrhoeae infection, we observed a marked downregulation of DC maturation marker CD83 when the gonococci expressing CEACAM1-specific Opa(CEA), but not other Opa variants. Consistent with a gonococcal-induced defect in maturation, Opa(CEA) binding to CEACAM1 reduced the DCs' capacity to stimulate an allogeneic T cell proliferative response. Moreover, Opa(CEA)-expressing N. gonorrhoeae showed the potential to impair DC-dependent development of specific adaptive immunity, since infection with Opa(CEA)-positive gonococci suppressed the ability of DCs to stimulate HIV-1-specific memory CTL responses. These results reveal a novel mechanism to explain why

  19. L-Arginine depletion blunts anti-tumor T cell responses by inducing myeloid-derived suppressor cells

    PubMed Central

    Fletcher, Matthew; Ramirez, Maria E.; Sierra, Rosa A.; Raber, Patrick; Thevenot, Paul; Al-Khami, Amir A.; Sanchez-Pino, Dulfary; Hernandez, Claudia; Wyczechowska, Dorota D.; Ochoa, Augusto C.; Rodriguez, Paulo C.

    2014-01-01

    Enzymatic depletion of the non-essential amino acid L-Arginine (L-Arg) in cancer patients by the administration of a pegylated form of the catabolic enzyme arginase I (peg-Arg I) has shown some promise as a therapeutic approach. However, L-Arg deprivation also suppresses T-cell responses in tumors. In this study, we sought to reconcile these observations by conducting a detailed analysis of the effects of peg-Arg I on normal T-cells. Strikingly, we found that peg-Arg I blocked proliferation and cell cycle progression in normal activated T-cells without triggering apoptosis or blunting T-cell activation. These effects were associated with an inhibition of aerobic glycolysis in activated T-cells, but not with significant alterations in mitochondrial oxidative respiration, which thereby regulated survival of T-cells exposed to peg-Arg I. Further mechanistic investigations showed that addition of citrulline, a metabolic precursor for L-Arg, rescued the anti-proliferative effects of peg-Arg I on T-cells in vitro. Moreover, serum levels of citrulline increased after in vivo administration of peg-Arg I. In support of the hypothesis that peg-Arg I acted indirectly to block T-cell responses in vivo, peg-Arg I inhibited T-cell proliferation in mice by inducing accumulation of myeloid-derived suppressor cells (MDSC). MDSC induction by peg-Arg I occurred through the general control non-repressed-2 eIF2α kinase. Moreover, we found that peg-Arg I enhanced the growth of tumors in mice in a manner that correlated with higher MDSC numbers. Taken together, our results highlight the risks of the L-Arg-depleting therapy for cancer treatment and suggest a need for co-targeting MDSC in such therapeutic settings. PMID:25406192

  20. 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

  1. [Use of heat shock of antigen-presenting cells for functional testing of allospecificity memory T-cells].

    PubMed

    Kazanskiĭ, D B; Petrishchev, V N; Shtil', A A; Chernysheva, A D; Sernova, N V; Abronina, I F; Pobezinskiĭ, L A; Agafonova, E L

    1999-02-01

    For many years, the search for the appropriate method of testing the functional activity of the memory T-cells was an urgent problem and determined progress in the study of immunological memory. We proposed simple methods of functional testing the memory of CD8+ T-cells specific to the H-2Kb alloantigen based on measuring their proliferation in response to heat-treated allogenic splenocytes and cells of allogenic tumors in vitro. Primary proliferative response to the alloantigen was shown not to develop when the allogenic antigen-presenting cells were subjected to an acute (45 degrees C, 1 h) or moderate (42 degrees C, 30 min) heat shock. The block of the primary allogenic response of naive T-lymphocytes to the heated splenocytes could not be abrogated by the addition of exogenous IL-2 and was not due to deletion or suppression of antigen-reactive clones. On the contrary, the long-lived memory CD8+ T-cells induced in the course of the primary in vivo response were capable of proliferation in response to heat-treated allogenic stimulators carrying the same immunizing antigen. The different response of the naive T-cells and memory T-cells to the allogenic stimulators subjected to a heat shock might be due to a strict dependence of the naive T-cells on the inducing co-stimulation provided by the B7 ligand, whose expression was suppressed in the cultures containing the heat-treated stimulator cells. These results probably suggest that a specific immunoregulatory mechanism exists that is based on a disorder in costimulatory functions due to the cellular stress-response induced in the ant