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Sample records for cd8 t-cell responses

  1. Regulatory CD4+CD25+ T cells restrict memory CD8+ T cell responses.

    Science.gov (United States)

    Kursar, Mischo; Bonhagen, Kerstin; Fensterle, Joachim; Köhler, Anne; Hurwitz, Robert; Kamradt, Thomas; Kaufmann, Stefan H E; Mittrücker, Hans-Willi

    2002-12-16

    CD4+ T cell help is important for the generation of CD8+ T cell responses. We used depleting anti-CD4 mAb to analyze the role of CD4+ T cells for memory CD8+ T cell responses after secondary infection of mice with the intracellular bacterium Listeria monocytogenes, or after boost immunization by specific peptide or DNA vaccination. Surprisingly, anti-CD4 mAb treatment during secondary CD8+ T cell responses markedly enlarged the population size of antigen-specific CD8+ T cells. After boost immunization with peptide or DNA, this effect was particularly profound, and antigen-specific CD8+ T cell populations were enlarged at least 10-fold. In terms of cytokine production and cytotoxicity, the enlarged CD8+ T cell population consisted of functional effector T cells. In depletion and transfer experiments, the suppressive function could be ascribed to CD4+CD25+ T cells. Our results demonstrate that CD4+ T cells control the CD8+ T cell response in two directions. Initially, they promote the generation of a CD8+ T cell responses and later they restrain the strength of the CD8+ T cell memory response. Down-modulation of CD8+ T cell responses during infection could prevent harmful consequences after eradication of the pathogen.

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

    Science.gov (United States)

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

    2016-02-01

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

  3. Transcriptional regulation during CD8 T-cell immune responses.

    Science.gov (United States)

    Munitic, Ivana; Evaristo, César; Sung, Hsueh Cheng; Rocha, Benedita

    2010-01-01

    Naïve CD8 T cells differentiate in response to antigen stimulation. They acquire the capacity to express multiple effector molecules and mediate effector functions that contribute to infection control. Once antigen loads are reduced they revert progressively to a less activated status and eventually reach a steady-state referred to as "memory" that is very different from that of naive cells. Indeed, these "memory" cells are "ready-to-go" populations that acquired the capacity to respond more efficiently to antigen stimulation. They modify their cell cycle machinery in order to divide faster; they likely improve DNA repair and other cell survival mechanisms in order to survive during division and thus to generate much larger clones of effector cells; finally, they also mediate effector functions much faster. These modifications are the consequence of changes in the expression of multiple genes, i.e., on the utilization of a new transcription program.

  4. The Timing of Stimulation and IL-2 Signaling Regulate Secondary CD8 T Cell Responses

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    Khan, Shaniya H.; Martin, Matthew D.; Starbeck-Miller, Gabriel R.; Xue, Hai-Hui; Harty, John T.; Badovinac, Vladimir P.

    2015-01-01

    Abstract Memory CD8 T cells provide protection to immune hosts by eliminating pathogen-infected cells during re-infection. While parameters influencing the generation of primary (1°) CD8 T cells are well established, the factors controlling the development of secondary (2°) CD8 T cell responses remain largely unknown. Here, we address the mechanisms involved in the generation and development of 2° memory (M) CD8 T cells. We observed that the time at which 1° M CD8 T cells enter into immune response impacts their fate and differentiation into 2° M CD8 T cells. Late-entry of 1° M CD8 T cells into an immune response (relative to the onset of infection) not only facilitated the expression of transcription factors associated with memory formation in 2° effector CD8 T cells, but also influenced the ability of 2° M CD8 T cells to localize within the lymph nodes, produce IL-2, and undergo Ag-driven proliferation. The timing of stimulation of 1° M CD8 T cells also impacted the duration of expression of the high-affinity IL-2 receptor (CD25) on 2° effector CD8 T cells and their sensitivity to IL-2 signaling. Importantly, by blocking or enhancing IL-2 signaling in developing 2° CD8 T cells, we provide direct evidence for the role of IL-2 in controlling the differentiation of Ag-driven 2° CD8 T cell responses. Thus, our data suggest that the process of 1° M to 2° M CD8 T cell differentiation is not fixed and can be manipulated, a notion with relevance for the design of future prime-boost vaccination approaches. PMID:26431533

  5. Sustained CD8+ T-cell responses induced after acute parvovirus B19 infection in humans

    DEFF Research Database (Denmark)

    Norbeck, Oscar; Isa, Adiba; Pöhlmann, Christoph

    2005-01-01

    Murine models have suggested that CD8+ T-cell responses peak early in acute viral infections and are not sustained, but no evidence for humans has been available. To address this, we longitudinally analyzed the CD8+ T-cell response to human parvovirus B19 in acutely infected individuals. We...... observed striking CD8+ T-cell responses, which were sustained or even increased over many months after the resolution of acute disease, indicating that CD8+ T cells may play a prominent role in the control of parvovirus B19 and other acute viral infections of humans, including potentially those generated...

  6. CD8+T Cell Immune Response in Immunocompetent Mice during Zika Virus Infection.

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    Huang, Huarong; Li, Shihua; Zhang, Yongli; Han, Xiaojuan; Jia, Baoqian; Liu, Hongtao; Liu, Dandan; Tan, Shuguang; Wang, Qihui; Bi, Yuhai; Liu, William J; Hou, Baidong; Gao, George Fu; Zhang, Fuping

    2017-11-15

    Zika virus (ZIKV) infection causees neurologic complications, including Guillain-Barré syndrome in adults and central nervous system (CNS) abnormalities in fetuses. We investigated the immune response, especially the CD8 + T cell response in C57BL/6 (B6) wild-type (WT) mice, during ZIKV infection. We found that a robust CD8 + T cell response was elicited, major histocompatibility complex class I-restricted CD8 + T cell epitopes were identified, a tetramer that recognizes ZIKV-specific CD8 + T cells was developed, and virus-specific memory CD8 + T cells were generated in these mice. The CD8 + T cells from these infected mice were functional, as evidenced by the fact that the adoptive transfer of ZIKV-specific CD8 + T cells could prevent ZIKV infection in the CNS and was cross protective against dengue virus infection. Our findings provide comprehensive insight into immune responses against ZIKV and further demonstrate that WT mice could be a natural and easy-access model for evaluating immune responses to ZIKV infection. IMPORTANCE ZIKV infection has severe clinical consequences, including Guillain-Barré syndrome in adults, microcephaly, and congenital malformations in fetuses and newborn infants. Therefore, study of the immune response, especially the adaptive immune response to ZIKV infection, is important for understanding diseases caused by ZIKV infection. Here, we characterized the CD8 + T cell immune response to ZIKV in a comprehensive manner and identified ZIKV epitopes. Using the identified immunodominant epitopes, we developed a tetramer that recognizes ZIKV-specific CD8 + T cells in vivo , which simplified the detection and evaluation of ZIKV-specific immune responses. In addition, the finding that tetramer-positive memory CD8 + T cell responses were generated and that CD8 + T cells can traffic to a ZIKV-infected brain greatly enhances our understanding of ZIKV infection and provides important insights for ZIKV vaccine design. Copyright © 2017 American

  7. Time and Antigen-Stimulation History Influence Memory CD8 T Cell Bystander Responses.

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    Martin, Matthew D; Shan, Qiang; Xue, Hai-Hui; Badovinac, Vladimir P

    2017-01-01

    Memory CD8 T cells can be activated and induced to produce cytokines and increase stores of cytolytic proteins not only in response to cognate antigen (Ag) but also in response to inflammatory cytokines (bystander responses). Importantly, bystander memory CD8 T cell functions have been shown to be dependent upon memory CD8 T cell fitness, since exhausted CD8 T cells have diminished capacity to respond to inflammatory cues. While it is known that memory CD8 T cell functional abilities, including ability to produce cytokines in response to cognate Ag, change with time after initial Ag encounter and upon multiple Ag stimulations (e.g., primary vs. tertiary CD8 T cell responses), it is unknown if bystander memory CD8 T cell responses are influenced by time or by Ag-exposure history. Here, we examined time and Ag-stimulation history-dependent alterations in virus-specific memory CD8 T cell bystander functions in response to inflammatory cytokines and unrelated bacterial infection. We found that expression of cytokine receptors and ability to produce IFN-γ following heterologous infection or incubation with inflammatory cytokines decreases with time following initial Ag encounter and increases with additional Ag encounters, suggesting that the ability to sense inflammation and respond with bystander cytokine production is dependent on age and Ag-stimulation history of memory CD8 T cells. These data shed further light on the regulation of memory CD8 T cell effector functions and have important implications for the development of vaccines designed to elicit protective memory CD8 T cells.

  8. Human CD8(+) T-cell differentiation in response to viruses

    NARCIS (Netherlands)

    van Lier, René A. W.; ten Berge, Ineke J. M.; Gamadia, Laila E.

    2003-01-01

    CD8(+) T cells are essential in the defence against viruses. Recently, peptide-HLA class I tetramers have been used to study immune responses to viruses in humans. This approach has indicated consecutive stages of human CD8(+) T-cell development in acute viral infection and has illustrated the

  9. Shaping Successful and Unsuccessful CD8 T Cell Responses Following Infection

    OpenAIRE

    Cox, Maureen A.; Zajac, Allan J.

    2010-01-01

    CD8 T cells play a vital role in the immunological protection against intracellular pathogens. Ideally, robust effector responses are induced, which eradicate the pathogen, and durable memory CD8 T cells are also established, which help confer protection against subsequent reinfection. The quality and magnitude of these responses is dictated by multiple factors, including their initial interactions with professional antigen-presenting cells, as well as the cytokine milieu and availability of ...

  10. Regulation of the CD8+ T cell responses against Plasmodium liver stages in mice.

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    Morrot, Alexandre; Zavala, Fidel

    2004-12-01

    CD8+ T cells induced by immunization with Plasmodium sporozoites play a major role in protective immunity against parasite infection, inhibiting the development of liver stages. The activation of these T cells is initiated just a few hours after exposure to parasites and progresses rapidly through a tightly regulated program. Effector functions in CD8+ T are detectable as early as 24 h after immunization and this event is followed 24-48 h later by an accelerated expansion of the CD8+ T cell numbers which reaches a peak 4-5 days after priming. Concomitantly with the development of anti-parasite activity, CD8+ T cells acquire a self-regulatory role limiting the magnitude of the CD8+ T cell response. Once activated, CD8+ T cells strongly inhibit the priming of additional naive CD8+ T cells by competing for antigen presenting cells. On days 6-8 after immunization, a sudden contraction of this T cell response occurs due to programmed cell death of 70-80% of the activated cells. After this contraction phase, 15-20 days after priming, activated cells establish memory populations. The development and maintenance of these memory populations strictly depends on the presence of CD4+ T cells and IL-4, and probably also IL-7, IL-15 and IL-2. These cytokines, some of which are produced by CD4+ T cells, provide signals to prevents apoptosis and also induce the differentiation of memory sub-populations, most of which acquire definitive phenotypes 20-30 days after immunization.

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

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    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

  12. CD8(+) T Cells Produce the Chemokine CXCL10 in Response to CD27/CD70 Costimulation To Promote Generation of the CD8(+) Effector T Cell Pool

    NARCIS (Netherlands)

    Peperzak, Victor; Veraar, Elise A. M.; Xiao, Yanling; Babala, Nikolina; Thiadens, Klaske; Brugmans, Marieke; Borst, Jannie

    2013-01-01

    Various cell types can produce the chemokine CXCL10 in response to IFN-gamma stimulation. CXCL10 is generally viewed as a proinflammatory chemokine that promotes recruitment of CD8(+) and Th1-type CD4(+) effector T cells to infected or inflamed nonlymphoid tissues. We show that CXCL10 plays a role

  13. TCR Down-Regulation Controls Virus-Specific CD8+ T Cell Responses

    DEFF Research Database (Denmark)

    Bonefeld, Charlotte Menné; Haks, Mariëlle; Nielsen, Bodil

    2008-01-01

    The CD3gamma di-leucine-based motif plays a central role in TCR down-regulation. However, little is understood about the role of the CD3gamma di-leucine-based motif in physiological T cell responses. In this study, we show that the expansion in numbers of virus-specific CD8(+) T cells is impaired...... molecule Bcl-2. This resulted in a 2-fold reduction in the clonal expansion of virus-specific CD8(+) T cells during the acute phase of vesicular stomatitis virus and lymphocytic choriomeningitis virus infections. These results identify an important role of CD3gamma-mediated TCR down-regulation in virus......-specific CD8(+) T cell responses....

  14. TCR down-regulation controls virus-specific CD8+ T cell responses

    DEFF Research Database (Denmark)

    Bonefeld, Charlotte Menné; Haks, Mariëlle; Nielsen, Bodil

    2008-01-01

    The CD3gamma di-leucine-based motif plays a central role in TCR down-regulation. However, little is understood about the role of the CD3gamma di-leucine-based motif in physiological T cell responses. In this study, we show that the expansion in numbers of virus-specific CD8(+) T cells is impaired...... molecule Bcl-2. This resulted in a 2-fold reduction in the clonal expansion of virus-specific CD8(+) T cells during the acute phase of vesicular stomatitis virus and lymphocytic choriomeningitis virus infections. These results identify an important role of CD3gamma-mediated TCR down-regulation in virus......-specific CD8(+) T cell responses....

  15. Regulation of CD8+ T cell responses to retinal antigen by local FoxP3+ regulatory T cells

    Directory of Open Access Journals (Sweden)

    Scott W McPherson

    2012-06-01

    Full Text Available While pathogenic CD4 T cells are well known mediators of autoimmune uveoretinitis, CD8 T cells can also be uveitogenic. Since preliminary studies indicated that C57BL/6 mice were minimally susceptible to autoimmune uveoretinitis induction by CD8 T cells, the basis of the retinal disease resistance was sought. Mice that express β-galactosidase (βgal on a retina-specific promoter (arrβgal mice were backcrossed to mice expressing green fluorescent protein and diphtheria toxin receptor under control of the Foxp3 promoter (Foxp3-DTR/GFP mice, and to T cell receptor transgenic mice that produce βgal specific CD8 T cells (BG1 mice. These mice were used to explore the role of regulatory T cells in the resistance to retinal autoimmune disease. Experiments with T cells from double transgenic BG1 x Foxp3-DTR/GFP mice transferred into Foxp3-DTR/GFP x arrβgal mice confirmed that the retina was well protected from attempts to induce disease by adoptive transfer of activated BG1 T cells. The successful induction of retinal disease following unilateral intraocular administration of diphtheria toxin to deplete regulatory T cells showed that the protective activity was dependent on local, toxin-sensitive regulatory T cells; the opposite, untreated eye remained disease-free. Although there were very few Foxp3+ regulatory T cells in the parenchyma of quiescent retina, and they did not accumulate in retina, their depletion by local toxin administration led to disease susceptibility. We propose that these regulatory T cells modulate the pathogenic activity of βgal-specific CD8 T cells in the retinas of arrβgal mice on a local basis, allowing immunoregulation to be responsive to local conditions.

  16. Aberrantly Expressed Long Non-Coding RNAs In CD8+T Cells Response to Active Tuberculosis.

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    Fu, Yurong; Gao, Kunshan; Tao, Enxue; Li, Ruifang; Yi, Zhengjun

    2017-12-01

    Dysregulated expression of long noncoding RNAs (lncRNAs) has been demonstrated as being implicated in a variety of human diseases. In the study we aimed to determine lncRNA profile in CD8 + T cells response to active tuberculosis (TB). We examined the lncRNA expression by microarray in circulating CD8 + T cells isolated from patients with active TB and healthy controls. Change predictions to analysis was used to address functional roles of the deregulated mRNAs. Real-time quantitative PCR (RT-qPCR) was used to validate the microarray result. In total, 328 lncRNAs and 356 mRNAs were differentially expressed in TB CD8 + T cells. Upregulated mRNAs were mainly enriched in cAMP signaling pathway, calcium signaling pathway, and TGF-beta signaling pathway, while downregulated mRNAs were enriched in antigen processing and presentation and natural killer cell mediated cytotoxicity in TB CD8 + T cells. Interestingly, we found that heme oxygenase 1 (HMOX1) was decreased in active TB CD8 + T cells, while its nearby lincRNA XLOC_014219 was upregulated. Subsequent RT-qPCR results confirmed the changes. This is the first research addressing lncRNA expression profiles in active TB CD8 + T cells. The aberrantly expressed lncRNAs observed in the study may provide clues to the dysfunction of CD8 + T cells and so to the pathophysiological properties of active TB. Further studies should focus on the function of lncRNAs involved in active TB. J. Cell. Biochem. 118: 4275-4284, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  17. Polyfunctional response by ImmTAC (IMCgp100) redirected CD8+and CD4+T cells.

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    Boudousquie, Caroline; Bossi, Giovanna; Hurst, Jacob M; Rygiel, Karolina A; Jakobsen, Bent K; Hassan, Namir J

    2017-11-01

    The success of immune system-based cancer therapies depends on a broad immune response engaging a range of effector cells and mechanisms. Immune mobilizing monoclonal T cell receptors (TCRs) against cancer (ImmTAC™ molecules: fusion proteins consisting of a soluble, affinity enhanced TCR and an anti-CD3 scFv antibody) were previously shown to redirect CD8 + and CD4 + T cells against tumours. Here we present evidence that IMCgp100 (ImmTAC recognizing a peptide derived from the melanoma-specific protein, gp100, presented by HLA-A*0201) efficiently redirects and activates effector and memory cells from both CD8 + and CD4 + repertoires. Using isolated subpopulations of T cells, we find that both terminally differentiated and effector memory CD8 + T cells redirected by IMCgp100 are potent killers of melanoma cells. Furthermore, CD4 + effector memory T cells elicit potent cytotoxic activity leading to melanoma cell killing upon redirection by IMCgp100. The majority of T cell subsets belonging to both the CD8 + and CD4 + repertoires secrete key pro-inflammatory cytokines (tumour necrosis factor-α, interferon-γ, interleukin-6) and chemokines (macrophage inflammatory protein-1α-β, interferon-γ-inducible protein-10, monocyte chemoattractant protein-1). At an individual cell level, IMCgp100-redirected T cells display a polyfunctional phenotype, which is a hallmark of a potent anti-cancer response. This study demonstrates that IMCgp100 induces broad immune responses that extend beyond the induction of CD8 + T cell-mediated cytotoxicity. These findings are of particular importance because IMCgp100 is currently undergoing clinical trials as a single agent or in combination with check point inhibitors for patients with malignant melanoma. © 2017 The Authors. Immunology Published by John Wiley & Sons Ltd.

  18. Characterization of Human CD8 T Cell Responses in Dengue Virus-Infected Patients from India.

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    Chandele, Anmol; Sewatanon, Jaturong; Gunisetty, Sivaram; Singla, Mohit; Onlamoon, Nattawat; Akondy, Rama S; Kissick, Haydn Thomas; Nayak, Kaustuv; Reddy, Elluri Seetharami; Kalam, Haroon; Kumar, Dhiraj; Verma, Anil; Panda, HareKrushna; Wang, Siyu; Angkasekwinai, Nasikarn; Pattanapanyasat, Kovit; Chokephaibulkit, Kulkanya; Medigeshi, Guruprasad R; Lodha, Rakesh; Kabra, Sushil; Ahmed, Rafi; Murali-Krishna, Kaja

    2016-12-15

    Epidemiological studies suggest that India has the largest number of dengue virus infection cases worldwide. However, there is minimal information about the immunological responses in these patients. CD8 T cells are important in dengue, because they have been implicated in both protection and immunopathology. Here, we provide a detailed analysis of HLA-DR + CD38 + and HLA-DR - CD38 + effector CD8 T cell subsets in dengue patients from India and Thailand. Both CD8 T cell subsets expanded and expressed markers indicative of antigen-driven proliferation, tissue homing, and cytotoxic effector functions, with the HLA-DR + CD38 + subset being the most striking in these effector qualities. The breadth of the dengue-specific CD8 T cell response was diverse, with NS3-specific cells being the most dominant. Interestingly, only a small fraction of these activated effector CD8 T cells produced gamma interferon (IFN-γ) when stimulated with dengue virus peptide pools. Transcriptomics revealed downregulation of key molecules involved in T cell receptor (TCR) signaling. Consistent with this, the majority of these CD8 T cells remained IFN-γ unresponsive even after TCR-dependent polyclonal stimulation (anti-CD3 plus anti-CD28) but produced IFN-γ by TCR-independent polyclonal stimulation (phorbol 12-myristate 13-acetate [PMA] plus ionomycin). Thus, the vast majority of these proliferating, highly differentiated effector CD8 T cells probably acquire TCR refractoriness at the time the patient is experiencing febrile illness that leads to IFN-γ unresponsiveness. Our studies open novel avenues for understanding the mechanisms that fine-tune the balance between CD8 T cell-mediated protective versus pathological effects in dengue. Dengue is becoming a global public health concern. Although CD8 T cells have been implicated both in protection and in the cytokine-mediated immunopathology of dengue, how the balance is maintained between these opposing functions remains unknown. We

  19. Cross-reactive microbial peptides can modulate HIV-specific CD8+ T cell responses.

    Directory of Open Access Journals (Sweden)

    Christopher W Pohlmeyer

    Full Text Available Heterologous immunity is an important aspect of the adaptive immune response. We hypothesized that this process could modulate the HIV-1-specific CD8+ T cell response, which has been shown to play an important role in HIV-1 immunity and control. We found that stimulation of peripheral blood mononuclear cells (PBMCs from HIV-1-positive subjects with microbial peptides that were cross-reactive with immunodominant HIV-1 epitopes resulted in dramatic expansion of HIV-1-specific CD8+ T cells. Interestingly, the TCR repertoire of HIV-1-specific CD8+ T cells generated by ex vivo stimulation of PBMCs using HIV-1 peptide was different from that of cells stimulated with cross-reactive microbial peptides in some HIV-1-positive subjects. Despite these differences, CD8+ T cells stimulated with either HIV-1 or cross-reactive peptides effectively suppressed HIV-1 replication in autologous CD4+ T cells. These data suggest that exposure to cross-reactive microbial antigens can modulate HIV-1-specific immunity.

  20. Respiratory syncytial virus-specific CD8(+) memory T cell responses in elderly persons

    NARCIS (Netherlands)

    de Bree, GJ; Heidema, J; van Leeuwen, EMM; van Bleek, GM; Jonkers, RE; Jansen, HM; van Lier, RAW; Out, TA

    2005-01-01

    Background. We investigated respiratory syncytial virus (RSV)-specific CD8(+) memory T cell responses in healthy control participants (n = 31) and in patients with chronic obstructive pulmonary disease (COPD) n = 9), with respect to frequency, memory phenotype, and proliferative requirements.

  1. A dominant role for the immunoproteasome in CD8+ T cell responses to murine cytomegalovirus.

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    Sarah Hutchinson

    2011-02-01

    Full Text Available Murine cytomegalovirus (MCMV is an important animal model of human cytomegalovirus (HCMV, a β-Herpesvirus that infects the majority of the world's population and causes disease in neonates and immunocompromised adults. CD8(+ T cells are a major part of the immune response to MCMV and HCMV. Processing of peptides for presentation to CD8(+ T cells may be critically dependent on the immunoproteasome, expression of which is affected by MCMV. However, the overall importance of the immunoproteasome in the generation of immunodominant peptides from MCMV is not known. We therefore examined the role of the immunoproteasome in stimulation of CD8(+ T cell responses to MCMV - both conventional memory responses and those undergoing long-term expansion or "inflation". We infected LMP7(-/- and C57BL/6 mice with MCMV or with newly-generated recombinant vaccinia viruses (rVVs encoding the immunodominant MCMV protein M45 in either full-length or epitope-only minigene form. We analysed CD8(+ T cell responses using intracellular cytokine stain (ICS and MHC Class I tetramer staining for a panel of MCMV-derived epitopes. We showed a critical role for immunoproteasome in MCMV affecting all epitopes studied. Interestingly we found that memory "inflating" epitopes demonstrate reduced immunoproteasome dependence compared to non-inflating epitopes. M45-specific responses induced by rVVs remain immunoproteasome-dependent. These results help to define a critical restriction point for CD8(+ T cell epitopes in natural cytomegalovirus (CMV infection and potentially in vaccine strategies against this and other viruses.

  2. Temporal Dynamics of CD8+ T Cell Effector Responses during Primary HIV Infection

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    Demers, Korey R.; Makedonas, George; Buggert, Marcus; Eller, Michael A.; Ratcliffe, Sarah J.; Goonetilleke, Nilu; Li, Chris K.; Eller, Leigh Anne; Rono, Kathleen; Maganga, Lucas; Nitayaphan, Sorachai; Kibuuka, Hannah; Routy, Jean-Pierre; Slifka, Mark K.; Haynes, Barton F.; Bernard, Nicole F.; Robb, Merlin L.; Betts, Michael R.

    2016-01-01

    The loss of HIV-specific CD8+ T cell cytolytic function is a primary factor underlying progressive HIV infection, but whether HIV-specific CD8+ T cells initially possess cytolytic effector capacity, and when and why this may be lost during infection, is unclear. Here, we assessed CD8+ T cell functional evolution from primary to chronic HIV infection. We observed a profound expansion of perforin+ CD8+ T cells immediately following HIV infection that quickly waned after acute viremia resolution. Selective expression of the effector-associated transcription factors T-bet and eomesodermin in cytokine-producing HIV-specific CD8+ T cells differentiated HIV-specific from bulk memory CD8+ T cell effector expansion. As infection progressed expression of perforin was maintained in HIV-specific CD8+ T cells with high levels of T-bet, but not necessarily in the population of T-betLo HIV-specific CD8+ T cells that expand as infection progresses. Together, these data demonstrate that while HIV-specific CD8+ T cells in acute HIV infection initially possess cytolytic potential, progressive transcriptional dysregulation leads to the reduced CD8+ T cell perforin expression characteristic of chronic HIV infection. PMID:27486665

  3. CD8+ T-cell response against MUC1-derived peptides in gastrointestinal cancer survivors.

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    Dittmann, Jasmin; Keller-Matschke, Karin; Weinschenk, Toni; Kratt, Thomas; Heck, Tobias; Becker, Horst-Dieter; Stevanović, Stefan; Rammensee, Hans-Georg; Gouttefangeas, Cécile

    2005-08-01

    The tumor-associated antigens CEA, MUC1 and Her2/neu are broadly expressed in gastrointestinal tumors, and are attractive candidates for targeting by T-cell-based immunotherapy. However, little is known about the natural cytotoxic T-cell response of patients suffering from colorectal or gastric carcinoma against these three as well as other antigens. Using a quantitative reverse transcription-polymerase chain reaction-based assay for IFN-gamma, we analyzed the CD8+ T-cell repertoire present in the blood of HLA-A2+ gastrointestinal tumor survivors against five known epitopes derived from CEA, MUC1 and Her2/neu. The results show that most of the patients (16 from 22 tested) have detectable, peripheral CD8+ T cells directed against at least one of these three proteins. Interestingly, the majority of these patients reacts to the two MUC1-derived HLA-A*0201 epitopes tested (14 from 16), demonstrating that this protein represents one dominant target for CD8+ T cells in gastrointestinal cancer.

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

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    Shayla K Shorter

    Full Text Available 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.

  5. An unexpected antibody response to an engineered influenza virus modifies CD8+ T cell responses.

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    Thomas, Paul G; Brown, Scott A; Yue, Wen; So, Jenny; Webby, Richard J; Doherty, Peter C

    2006-02-21

    The ovalbumin(323-339) peptide that binds H2I-A(b) was engineered into the globular heads of hemagglutinin (H) molecules from serologically non-cross-reactive H1N1 and H3N2 influenza A viruses, the aim being to analyze recall CD4+ T cell responses in a virus-induced respiratory disease. Prime/challenge experiments with these H1ova and H3ova viruses in H2(b) mice gave the predicted, ovalbumin-specific CD4+ T cell response but showed an unexpectedly enhanced, early expansion of viral epitope-specific CD8+ T cells in spleen and a greatly diminished inflammatory process in the virus-infected respiratory tract. At the same time, the primary antibody response to the H3N2 challenge virus was significantly reduced, an effect that has been associated with preexisting neutralizing antibody in other experimental systems. Analysis of serum from the H1ova-primed mice showed low-level binding to H3ova but not to the wild-type H3N2 virus. Experiments with CD4+ T cell-depleted and Ig-/- mice indicated that this cross-reactive Ig is indeed responsible for the modified pathogenesis after respiratory challenge. Furthermore, the effect does not seem to be virus-dose related, although it does require infection. These findings suggest intriguing possibilities for vaccination and, at the same time, emphasize that engineered modifications in viruses may have unintended immunological consequences.

  6. CD8+ Treg cells suppress CD8+ T cell-responses by IL-10-dependent mechanism during H5N1 influenza virus infection

    Science.gov (United States)

    Zou, Qiang; Wu, Bing; Xue, Jia; Fan, Xiaoxu; Feng, Congcong; Geng, Shuang; Wang, Ming; Wang, Bin

    2014-01-01

    Although Treg-cell-mediated suppression during infection or autoimmunity has been described, functions of Treg cells during highly pathogenic avian influenza virus infection remain poorly characterized. Here we found that in Foxp3-GFP transgenic mice, CD8+ Foxp3+ Treg cells, but not CD4+ Foxp3+ Treg cells, were remarkably induced during H5N1 infection. In addition to expressing CD25, the CD8+ Foxp3+ Treg cells showed a high level of GITR and produced IL-10. In an adoptive transfer model, CD8+ Treg cells suppressed CD8+ T-cell responses and promoted H5N1 virus infection, resulting in enhanced mortality and increased virus load in the lung. Furthermore, in vitro neutralization of IL-10 and studies with IL-10R-deficient mice in vitro and in vivo demonstrated an important role for IL-10 production in the capacity of CD8+ Treg cells to inhibit CD8+ T-cell responses. Our findings identify a previously unrecognized role of CD8+ Treg cells in the negative regulation of CD8+ T-cell responses and suggest that modulation of CD8+ Treg cells may be a therapeutic strategy to control H5N1 viral infection. PMID:24114149

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

    Science.gov (United States)

    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

  8. Characterization of CD4 and CD8 T Cell Responses in MuSK Myasthenia Gravis

    Science.gov (United States)

    Yi, JS; Guidon, A; Sparks, S; Osborne, R; Juel, VC; Massey, JM; Sanders, DB; Weinhold, KJ; Guptill, JT

    2014-01-01

    Muscle specific tyrosine kinase myasthenia gravis (MuSK MG) is a form of autoimmune MG that predominantly affects women and has unique clinical features, including prominent bulbar weakness, muscle atrophy, and excellent response to therapeutic plasma exchange. Patients with MuSK MG have predominantly IgG4 autoantibodies directed against MuSK on the postsynaptic muscle membrane. Lymphocyte functionality has not been reported in this condition. The goal of this study was to characterize T-cell responses in patients with MuSK MG. Intracellular production of IFN-gamma, TNF-alpha, IL-2, IL-17, and IL-21 by CD4+ and CD8+ T-cells was measured by polychromatic flow cytometry in peripheral blood samples from 11 Musk MG patients and 10 healthy controls. Only one MuSK MG patient was not receiving immunosuppressive therapy. Regulatory T-cells (Treg) were also included in our analysis to determine if changes in T cell function were due to altered Treg frequencies. CD8+ T-cells from MuSK MG patients had higher frequencies of polyfunctional responses than controls, and CD4+ T-cells had higher IL-2, TNF-alpha, and IL-17. MuSK MG patients had a higher percentage of CD4+ T-cells producing combinations of IFN-gamma/IL-2/TNF-gamma, TNF-alpha/IL-2, and IFN-gamma/TNF-alpha. Interestingly, Treg numbers and CD39 expression were not different from control values. MuSK MG patients had increased frequencies of Th1 and Th17 cytokines and were primed for polyfunctional proinflammatory responses that cannot be explained by a defect in Treg function or number. PMID:24378287

  9. CD8 T-cells and E-cadherin in host responses against oropharyngeal candidiasis

    Science.gov (United States)

    Quimby, K.; Lilly, E.A.; Zacharek, M.; McNulty, K.; Leigh, J.E.; Vazquez, J.E.; Fidel, P.L.

    2011-01-01

    Oropharyngeal candidiasis (OPC) is the most common oral infection in HIV+ persons. Previous studies suggest a role for CD8+ T-cells against OPC when CD4+ T-cells are lost, but enhanced susceptibility to infection occurs when CD8+ T-cell migration is inhibited by reduced tissue E-cadherin. Objective Conduct a longitudinal study of tissue CD8+ T-cells and E-cadherin expression before, during, and after episodes of OPC. Methods Oral fungal burden was monitored and tissue was evaluated for CD8+ T-cells and E-cadherin over a one-year period in HIV+ persons with a history of, or an acute episode of OPC. Results While longitudinal analyses precluded formal interpretations, point prevalence analyses of the dataset revealed that when patients experiencing OPC were successfully treated, tissue E-cadherin expression was similar to patients who had not experienced OPC, and higher numbers of CD8+ T-cells were distributed throughout OPC− tissue under normal expression of E-cadherin. Conclusion These results suggest that 1) reduction in tissue E-cadherin expression in OPC+ patients is not permanent, and 2) high numbers of CD8+ T-cells can be distributed throughout OPC− tissue under normal E-cadherin expression. Together these results extend our previous studies and continue to support a role for CD8+ T-cells in host defense against OPC. PMID:21958417

  10. Blocking of PDL-1 interaction enhances primary and secondary CD8 T cell response to herpes simplex virus-1 infection.

    Directory of Open Access Journals (Sweden)

    Rudragouda Channappanavar

    Full Text Available The blocking of programmed death ligand-1 (PDL-1 has been shown to enhance virus-specific CD8 T cell function during chronic viral infections. Though, how PDL-1 blocking at the time of priming affects the quality of CD8 T cell response to acute infections is not well understood and remains controversial. This report demonstrates that the magnitude of the primary and secondary CD8 T cell responses to herpes simplex virus-1 (HSV-1 infection is subject to control by PDL-1. Our results showed that after footpad HSV-1 infection, PD-1 expression increases on immunodominant SSIEFARL peptide specific CD8 T cells. Additionally, post-infection, the level of PDL-1 expression also increases on CD11c+ dendritic cells. Intraperitoneal administration of anti-PDL-1 monoclonal antibody given one day prior to and three days after cutaneous HSV-1 infection, resulted in a marked increase in effector and memory CD8 T cell response to SSIEFARL peptide. This was shown by measuring the quantity and quality of SSIEFARL-specific CD8 T cells by making use of ex-vivo assays that determine antigen specific CD8 T cell function, such as intracellular cytokine assay, degranulation assay to measure cytotoxicity and viral clearance. Our results are discussed in terms of the beneficial effects of blocking PDL-1 interactions, while giving prophylactic vaccines, to generate a more effective CD8 T cell response to viral infection.

  11. Profiling the Targets of Protective CD8+ T Cell Responses to Infection

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    Joseph T. Bruder

    2017-12-01

    Full Text Available T cells are critical effectors of host immunity that target intracellular pathogens, such as the causative agents of HIV, tuberculosis, and malaria. The development of vaccines that induce effective cell-mediated immunity against such pathogens has proved challenging; for tuberculosis and malaria, many of the antigens targeted by protective T cells are not known. Here, we report a novel approach for screening large numbers of antigens as potential targets of T cells. Malaria provides an excellent model to test this antigen discovery platform because T cells are critical mediators of protection following immunization with live sporozoite vaccines and the specific antigen targets are unknown. We generated an adenovirus array by cloning 312 highly expressed pre-erythrocytic Plasmodium yoelii antigens into adenovirus vectors using high-throughput methodologies. The array was screened to identify antigen-specific CD8+ T cells induced by a live sporozoite vaccine regimen known to provide high levels of sterile protection mediated by CD8+ T cells. We identified 69 antigens that were targeted by CD8+ T cells induced by this vaccine regimen. The antigen that recalled the highest frequency of CD8+ T cells, PY02605, induced protective responses in mice, demonstrating proof of principle for this approach in identifying antigens for vaccine development.

  12. Induction of CD8+ T-cell responses against subunit antigens by the novel cationic liposomal CAF09 adjuvant

    DEFF Research Database (Denmark)

    Korsholm, Karen Smith; Hansen, Jon; Karlsen, Kasper

    2014-01-01

    Vaccines inducing cytotoxic T-cell responses are required to achieve protection against cancers and intracellular infections such as HIV and Hepatitis C virus. Induction of CD8+ T cell responses in animal models can be achieved by the use of viral vectors or DNA vaccines but so far without much...... clinical success. Here we describe the novel CD8+ T-cell inducing adjuvant, cationic adjuvant formulation (CAF) 09, consisting of dimethyldioctadecylammonium (DDA)-liposomes stabilized with monomycoloyl glycerol (MMG)-1 and combined with the TLR3 ligand, Poly(I:C). Different antigens from tuberculosis (TB......10.3, H56), HIV (Gag p24), HPV (E7) and the model antigen ovalbumin were formulated with CAF09 and administering these vaccines to mice resulted in a high frequency of antigen-specific CD8+ T cells. CAF09 was superior in its ability to induce antigen-specific CD8+ T cells as compared to other...

  13. Comparison of Vaccine-Induced Effector CD8 T Cell Responses Directed against Self- and Non-Self-Tumor Antigens

    DEFF Research Database (Denmark)

    Pedersen, Sara R; Sørensen, Maria R; Buus, Søren

    2013-01-01

    It is generally accepted that CD8 T cells play a major role in tumor control, yet vaccination aimed at eliciting potent CD8 T cell responses are rarely efficient in clinical trials. To try and understand why this is so, we have generated potent adenoviral vectors encoding the endogenous tumor Ags...... (TA) tyrosinase-related protein-2 (TRP-2) and glycoprotein 100 (GP100) tethered to the invariant chain (Ii). Using these vectors, we sought to characterize the self-TA-specific CD8 T cell response and compare it to that induced against non-self-Ags expressed from a similar vector platform...... construct expressing a foreign (viral) TA induced efficient tumor control. Analyzing the self-TA-specific CD8 T cells, we observed that these could be activated to produce IFN-γ and TNF-α. In addition, surface expression of phenotypic markers and inhibitory receptors, as well as in vivo cytotoxicity...

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

    Energy Technology Data Exchange (ETDEWEB)

    Fogg, Mark [Department of Medicine, Brigham and Women' s Hospital (United States); Murphy, John R. [Departments of Medicine and Microbiology, Boston University School of Medicine, Boston, MA 02118 (United States); Lorch, Jochen; Posner, Marshall [Department of Adult Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115 (United States); Wang, Fred, E-mail: fwang@research.bwh.harvard.edu [Department of Medicine, Brigham and Women' s Hospital (United States); Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115 (United States)

    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.

  15. Synthetic melanin bound to subunit vaccine antigens significantly enhances CD8+ T-cell responses.

    Directory of Open Access Journals (Sweden)

    Antoine F Carpentier

    Full Text Available Cytotoxic T-lymphocytes (CTLs play a key role in immunity against cancer; however, the induction of CTL responses with currently available vaccines remains difficult. Because several reports have suggested that pigmentation and immunity might be functionally linked, we investigated whether melanin can act as an adjuvant in vaccines. Short synthetic peptides (8-35 amino acids long containing T-cell epitopes were mixed with a solution of L-Dopa, a precursor of melanin. The mixture was then oxidized to generate nanoparticles of melanin-bound peptides. Immunization with melanin-bound peptides efficiently triggered CTL responses in mice, even against self-antigens and at a very low dose of peptides (microgram range. Immunization against a tumor antigen inhibited the growth of established tumors in mice, an effect that was abrogated by the depletion of CD8+ lymphocytes. These results demonstrate the efficacy of melanin as a vaccine adjuvant.

  16. IL-2 and IL-15 regulate CD8+ memory T-cell differentiation but are dispensable for protective recall responses.

    Science.gov (United States)

    Mathieu, Cédric; Beltra, Jean-Christophe; Charpentier, Tania; Bourbonnais, Sara; Di Santo, James P; Lamarre, Alain; Decaluwe, Hélène

    2015-12-01

    The ability to mount effective secondary responses is a cardinal feature of memory CD8(+) T cells. An understanding of the factors that regulate the generation and recall capacities of memory T cells remains to be ascertained. Several cues indicate that two highly related cytokines, IL-2 and IL-15, share redundant functions in this process. To establish their combined roles in memory CD8(+) T-cell development, maintenance, and secondary responses, we compared the outcome of adoptively transferred IL2Rβ(+/-) or IL2Rβ(-/-) CD8(+) T cells after an acute viral infection in mice. Our results demonstrate that both IL-2 and IL-15 signals condition the differentiation of primary and secondary short-lived effector cells by altering the transcriptional network governing lineage choices. These two cytokines also regulate the homeostasis of the memory T-cell pool, with effector memory CD8(+) T cells being the most sensitive to these two interleukins. Noticeably, the inability to respond to both cytokines limits the proliferation and survival of primary and secondary effectors cells, whereas it does not preclude potent cytotoxic functions and viral control either initially or upon rechallenge. Globally, these results indicate that lack of IL-2 and IL-15 signaling modulates the CD8(+) T-cell differentiation program but does not impede adequate effector functions. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Interplay between CD8α+ dendritic cells and monocytes in response to Listeria monocytogenes infection attenuates T cell responses.

    Directory of Open Access Journals (Sweden)

    Dilnawaz Kapadia

    2011-04-01

    Full Text Available During the course of a microbial infection, different antigen presenting cells (APCs are exposed and contribute to the ensuing immune response. CD8α(+ dendritic cells (DCs are an important coordinator of early immune responses to the intracellular bacteria Listeria monocytogenes (Lm and are crucial for CD8(+ T cell immunity. In this study, we examine the contribution of different primary APCs to inducing immune responses against Lm. We find that CD8α(+ DCs are the most susceptible to infection while plasmacytoid DCs are not infected. Moreover, CD8α(+ DCs are the only DC subset capable of priming an immune response to Lm in vitro and are also the only APC studied that do so when transferred into β2 microglobulin deficient mice which lack endogenous cross-presentation. Upon infection, CD11b(+ DCs primarily secrete low levels of TNFα while CD8α(+ DCs secrete IL-12 p70. Infected monocytes secrete high levels of TNFα and IL-12p70, cytokines associated with activated inflammatory macrophages. Furthermore, co-culture of infected CD8α(+ DCs and CD11b+ DCs with monocytes enhances production of IL-12 p70 and TNFα. However, the presence of monocytes in DC/T cell co-cultures attenuates T cell priming against Lm-derived antigens in vitro and in vivo. This suppressive activity of spleen-derived monocytes is mediated in part by both TNFα and inducible nitric oxide synthase (iNOS. Thus these monocytes enhance IL-12 production to Lm infection, but concurrently abrogate DC-mediated T cell priming.

  18. Estradiol-induced vaginal mucus inhibits antigen penetration and CD8(+) T cell priming in response to intravaginal immunization.

    Science.gov (United States)

    Seavey, Matthew M; Mosmann, Tim R

    2009-04-14

    Although vaginal immunization has been explored as a strategy to induce mucosal immunity in the female reproductive tract, this site displays unique immunological features that probably evolved to inhibit anti-paternal T cell responses after insemination to allow successful pregnancy. We previously demonstrated that estradiol, which induces an estrus-like state, prevented CD8(+) T cell priming during intravaginal immunization of mice. We now show that estradiol prevented antigen loading of vaginal antigen presenting cells (APCs) after intravaginal immunization. Histological examination confirmed that estradiol prevented penetration of peptide antigen into the vaginal wall. Removal of the estradiol-induced mucus barrier by mucinase partially restored antigen loading of vaginal APC and CD8(+) T cell proliferation in vivo. The estradiol-induced mucus barrier may thus prevent exposure to antigens delivered intravaginally, supplementing additional estradiol-dependent mechanism(s) that inhibit CD8(+) T cell priming after insemination or vaginal vaccination.

  19. Estradiol-induced vaginal mucus inhibits antigen penetration and CD8+ T cell priming in response to intravaginal immunization

    Science.gov (United States)

    Seavey, Matthew M.; Mosmann, Tim R.

    2010-01-01

    Although vaginal immunization has been explored as a strategy to induce mucosal immunity in the female reproductive tract, this site displays unique immunological features that probably evolved to inhibit anti-paternal T cell responses after insemination to allow successful pregnancy. We previously demonstrated that estradiol, which induces an estrus-like state, prevented CD8+ T cell priming during intravaginal immunization of mice. We now show that estradiol prevented antigen loading of vaginal antigen presenting cells (APC) after intravaginal immunization. Histological examination confirmed that estradiol prevented penetration of peptide antigen into the vaginal wall. Removal of the estradiol-induced mucus barrier by mucinase partially restored antigen loading of vaginal APC and CD8+ T cell proliferation in vivo. The estradiol-induced mucus barrier may thus prevent exposure to antigens delivered intravaginally, supplementing additional estradiol-dependent mechanism(s) that inhibit CD8+ T cell priming after insemination or vaginal vaccination. PMID:19428849

  20. A highly restricted T-cell receptor dominates the CD8+ T-cell response to parvovirus B19 infection in HLA-A*2402-positive individuals

    DEFF Research Database (Denmark)

    Kasprowicz, V; Isa, Adiba; Jeffery, K

    2006-01-01

    Six of seven HLA-A*2402-positive individuals with acute parvovirus B19 infections made vigorous CD8-positive cytotoxic T-cell (CTL) responses to the viral epitope FYTPLADQF. All responders showed highly focused T-cell receptor (TCR) usage, using almost exclusively BV5.1. The BV5.1 TCR dominated...

  1. Prospective analysis of human cytomegalovirus DNAemia and specific CD8+ T cell responses in lung transplant recipients.

    Science.gov (United States)

    Weseslindtner, L; Kerschner, H; Steinacher, D; Nachbagauer, R; Kundi, M; Jaksch, P; Simon, B; Hatos-Agyi, L; Scheed, A; Klepetko, W; Puchhammer-Stöckl, E

    2012-08-01

    In lung transplant recipients (LuTRs), human cytomegalovirus (HCMV) DNAemia may be associated with HCMV disease and reduced survival of the allograft. Because T cells are essential for controlling HCMV replication, we investigated in this prospective study whether the kinetics of plasma HCMV DNA loads in LuTRs are associated with HCMV-specific CD8+ T cell responses, which were longitudinally assessed using a standardized assay. Sixty-seven LuTRs were monitored during the first year posttransplantation, with a mean of 17 HCMV DNA PCR quantifications and 11.5 CD8+ T cell tests performed per patient. HCMV-specific CD8+ T cell responses displayed variable kinetics in different patients, differed significantly before the onset of HCMV DNAemia in LuTRs who subsequently experienced episodes of DNAemia with high (>1000 copies/mL) and low plasma DNA levels (p = 0.0046, Fisher's exact test), and were absent before HCMV disease. In HCMV-seropositive LuTRs, high-level DNAemia requiring preemptive therapy occurred more frequently when HCMV-specific CD8+ T cell responses fluctuated, were detected only after HCMV DNA detection, or remained undetectable (p = 0.0392, Fisher's exact test). Thus, our data indicate that HCMV-specific CD8+ T cells influence the magnitude of HCMV DNAemia episodes, and we propose that a standardized measurement of CD8+ T cell immunity might contribute to monitoring the immune status of LuTRs posttransplantation. © Copyright 2012 The American Society of Transplantation and the American Society of Transplant Surgeons.

  2. Recombinant yellow fever viruses elicit CD8+ T cell responses and protective immunity against Trypanosoma cruzi.

    Directory of Open Access Journals (Sweden)

    Raquel Tayar Nogueira

    Full Text Available Chagas' disease is a major public health problem affecting nearly 10 million in Latin America. Despite several experimental vaccines have shown to be immunogenic and protective in mouse models, there is not a current vaccine being licensed for humans or in clinical trial against T. cruzi infection. Towards this goal, we used the backbone of Yellow Fever (YF 17D virus, one of the most effective and well-established human vaccines, to express an immunogenic fragment derived from T. cruzi Amastigote Surface Protein 2 (ASP-2. The cDNA sequence of an ASP-2 fragment was inserted between E and NS1 genes of YF 17D virus through the construction of a recombinant heterologous cassette. The replication ability and genetic stability of recombinant YF virus (YF17D/ENS1/Tc was confirmed for at least six passages in Vero cells. Immunogenicity studies showed that YF17D/ENS1/Tc virus elicited neutralizing antibodies and gamma interferon (IFN-γ producing-cells against the YF virus. Also, it was able to prime a CD8(+ T cell directed against the transgenic T. cruzi epitope (TEWETGQI which expanded significantly as measured by T cell-specific production of IFN-γ before and after T. cruzi challenge. However, most important for the purposes of vaccine development was the fact that a more efficient protective response could be seen in mice challenged after vaccination with the YF viral formulation consisting of YF17D/ENS1/Tc and a YF17D recombinant virus expressing the TEWETGQI epitope at the NS2B-3 junction. The superior protective immunity observed might be due to an earlier priming of epitope-specific IFN-γ-producing T CD8(+ cells induced by vaccination with this viral formulation. Our results suggest that the use of viral formulations consisting of a mixture of recombinant YF 17D viruses may be a promising strategy to elicit protective immune responses against pathogens, in general.

  3. Increased CD8+ T cell response to Epstein-Barr virus lytic antigens in the active phase of multiple sclerosis.

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    Daniela F Angelini

    Full Text Available It has long been known that multiple sclerosis (MS is associated with an increased Epstein-Barr virus (EBV seroprevalence and high immune reactivity to EBV and that infectious mononucleosis increases MS risk. This evidence led to postulate that EBV infection plays a role in MS etiopathogenesis, although the mechanisms are debated. This study was designed to assess the prevalence and magnitude of CD8+ T-cell responses to EBV latent (EBNA-3A, LMP-2A and lytic (BZLF-1, BMLF-1 antigens in relapsing-remitting MS patients (n = 113 and healthy donors (HD (n = 43 and to investigate whether the EBV-specific CD8+ T cell response correlates with disease activity, as defined by clinical evaluation and gadolinium-enhanced magnetic resonance imaging. Using HLA class I pentamers, lytic antigen-specific CD8+ T cell responses were detected in fewer untreated inactive MS patients than in active MS patients and HD while the frequency of CD8+ T cells specific for EBV lytic and latent antigens was higher in active and inactive MS patients, respectively. In contrast, the CD8+ T cell response to cytomegalovirus did not differ between HD and MS patients, irrespective of the disease phase. Marked differences in the prevalence of EBV-specific CD8+ T cell responses were observed in patients treated with interferon-β and natalizumab, two licensed drugs for relapsing-remitting MS. Longitudinal studies revealed expansion of CD8+ T cells specific for EBV lytic antigens during active disease in untreated MS patients but not in relapse-free, natalizumab-treated patients. Analysis of post-mortem MS brain samples showed expression of the EBV lytic protein BZLF-1 and interactions between cytotoxic CD8+ T cells and EBV lytically infected plasma cells in inflammatory white matter lesions and meninges. We therefore propose that inability to control EBV infection during inactive MS could set the stage for intracerebral viral reactivation and disease relapse.

  4. Rapid selection of escape mutants by the first CD8 T cell responses in acute HIV-1 infection

    Energy Technology Data Exchange (ETDEWEB)

    Korber, Bette Tina Marie [Los Alamos National Laboratory

    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.

  5. Asymptomatic memory CD8+ T cells

    Science.gov (United States)

    Khan, Arif Azam; Srivastava, Ruchi; Lopes, Patricia Prado; Wang, Christine; Pham, Thanh T; Cochrane, Justin; Thai, Nhi Thi Uyen; Gutierrez, Lucas; BenMohamed, Lbachir

    2014-01-01

    Generation and maintenance of high quantity and quality memory CD8+ T cells determine the level of protection from viral, bacterial, and parasitic re-infections, and hence constitutes a primary goal for T cell epitope-based human vaccines and immunotherapeutics. Phenotypically and functionally characterizing memory CD8+ T cells that provide protection against herpes simplex virus type 1 and type 2 (HSV-1 and HSV-2) infections, which cause blinding ocular herpes, genital herpes, and oro-facial herpes, is critical for better vaccine design. We have recently categorized 2 new major sub-populations of memory symptomatic and asymptomatic CD8+ T cells based on their phenotype, protective vs. pathogenic function, and anatomical locations. In this report we are discussing a new direction in developing T cell-based human herpes vaccines and immunotherapeutics based on the emerging new concept of “symptomatic and asymptomatic memory CD8+ T cells.” PMID:24499824

  6. CD27 instructs CD4+ T cells to provide help for the memory CD8+ T cell response after protein immunization

    NARCIS (Netherlands)

    Xiao, Yanling; Peperzak, Victor; Keller, Anna M.; Borst, Jannie

    2008-01-01

    For optimal quality, memory CD8(+) T cells require CD4(+) T cell help. We have examined whether CD4(+) T cells require CD27 to deliver this help, in a model of intranasal OVA protein immunization. CD27 deficiency reduced the capacity of CD4(+) T cells to support Ag-specific CD8(+) T cell

  7. Differential immunodominance hierarchy of CD8+ T-cell responses in HLA-B*27

    DEFF Research Database (Denmark)

    Adland, Emily; Hill, Matilda; Lavandier, Nora

    2018-01-01

    The well-characterized association between HLA-B*27:05 and protection against HIV disease progression has been linked to immunodominant HLA-B*27:05- restricted CD8+ T-cell responses toward the conserved Gag KK10 (residues 263 to 272) and polymerase (Pol) KY9 (residues 901 to 909) epitopes. We stu...

  8. Redundancy of direct priming and cross-priming in tumor-specific CD8(+) T cell responses

    NARCIS (Netherlands)

    Wolkers, M. C.; Stoetter, G.; Vyth-Dreese, F. A.; Schumacher, T. N.

    2001-01-01

    Against a subset of human cancers, vigorous tumor-specific CD8(+) T cell responses can develop either spontaneously or upon allogeneic transplantation. However, the parameters that determine the induction of such pronounced anti-tumor immunity remain ill defined. To dissect the conditions required

  9. iNKT cells suppress the CD8+ T cell response to a murine Burkitt's-like B cell lymphoma.

    Directory of Open Access Journals (Sweden)

    Ryan L Bjordahl

    Full Text Available The T cell response to B cell lymphomas differs from the majority of solid tumors in that the malignant cells themselves are derived from B lymphocytes, key players in immune response. B cell lymphomas are therefore well situated to manipulate their surrounding microenvironment to enhance tumor growth and minimize anti-tumor T cell responses. We analyzed the effect of T cells on the growth of a transplantable B cell lymphoma and found that iNKT cells suppressed the anti-tumor CD8(+ T cell response. Lymphoma cells transplanted into syngeneic wild type (WT mice or Jalpha18(-/- mice that specifically lack iNKT cells grew initially at the same rate, but only the mice lacking iNKT cells were able to reject the lymphoma. This effect was due to the enhanced activity of tumor-specific CD8(+ T cells in the absence of iNKT cells, and could be partially reversed by reconstitution of iNKT cells in Jalpha 18(-/- mice. Treatment of tumor-bearing WT mice with alpha -galactosyl ceramide, an activating ligand for iNKT cells, reduced the number of tumor-specific CD8(+ T cells. In contrast, lymphoma growth in CD1d1(-/- mice that lack both iNKT and type II NKT cells was similar to that in WT mice, suggesting that type II NKT cells are required for full activation of the anti-tumor immune response. This study reveals a tumor-promoting role for iNKT cells and suggests their capacity to inhibit the CD8(+ T cell response to B cell lymphoma by opposing the effects of type II NKT cells.

  10. Archaeosome Adjuvant Overcomes Tolerance to Tumor-Associated Melanoma Antigens Inducing Protective CD8+ T Cell Responses

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    Lakshmi Krishnan

    2010-01-01

    Full Text Available Vesicles comprised of the ether glycerolipids of the archaeon Methanobrevibacter smithii (archaeosomes are potent adjuvants for evoking CD8+ T cell responses. We therefore explored the ability of archaeosomes to overcome immunologic tolerance to self-antigens. Priming and boosting of mice with archaeosome-antigen evoked comparable CD8+ T cell response and tumor protection to an alternate boosting strategy utilizing live bacterial vectors for antigen delivery. Vaccination with melanoma antigenic peptides TRP181-189 and Gp10025-33 delivered in archaeosomes resulted in IFN-γ producing antigen-specific CD8+ T cells with strong cytolytic capability and protection against subcutaneous B16 melanoma. Targeting responses against multiple antigens afforded prolonged median survival against melanoma challenge. Entrapment of multiple peptides within the same vesicle or admixed formulations were both effective at evoking CD8+ T cells against each antigen. Melanoma-antigen archaeosome formulations also afforded therapeutic protection against established B16 tumors when combined with depletion of T-regulatory cells. Overall, we demonstrate that archaeosome adjuvants constitute an effective choice for formulating cancer vaccines.

  11. Pentoxifylline reverses chronic experimental Chagasic cardiomyopathy in association with repositioning of abnormal CD8+ T-cell response.

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    Isabela Resende Pereira

    2015-03-01

    Full Text Available Chronic chagasic cardiomyopathy (CCC, the main clinical sign of Chagas disease, is associated with systemic CD8+ T-cell abnormalities and CD8-enriched myocarditis occurring in an inflammatory milieu. Pentoxifylline (PTX, a phosphodiesterase inhibitor, has immunoregulatory and cardioprotective properties. Here, we tested PTX effects on CD8+ T-cell abnormalities and cardiac alterations using a model of experimental Chagas' heart disease.C57BL/6 mice chronically infected by the Colombian Trypanosoma cruzi strain and presenting signs of CCC were treated with PTX. The downmodulation of T-cell receptors on CD8+ cells induced by T. cruzi infection was rescued by PTX therapy. Also, PTX reduced the frequency of CD8+ T-cells expressing activation and migration markers in the spleen and the activation of blood vessel endothelial cells and the intensity of inflammation in the heart tissue. Although preserved interferon-gamma production systemically and in the cardiac tissue, PTX therapy reduced the number of perforin+ cells invading this tissue. PTX did not alter parasite load, but hampered the progression of heart injury, improving connexin 43 expression and decreasing fibronectin overdeposition. Further, PTX reversed electrical abnormalities as bradycardia and prolonged PR, QTc and QRS intervals in chronically infected mice. Moreover, PTX therapy improved heart remodeling since reduced left ventricular (LV hypertrophy and restored the decreased LV ejection fraction.PTX therapy ameliorates critical aspects of CCC and repositioned CD8+ T-cell response towards homeostasis, reinforcing that immunological abnormalities are crucially linked, as cause or effect, to CCC. Therefore, PTX emerges as a candidate to treat the non-beneficial immune deregulation associated with chronic Chagas' heart disease and to improve prognosis.

  12. Pentoxifylline Reverses Chronic Experimental Chagasic Cardiomyopathy in Association with Repositioning of Abnormal CD8+ T-Cell Response

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    Pereira, Isabela Resende; Vilar-Pereira, Glaucia; Moreira, Otacilio Cruz; Ramos, Isalira Peroba; Gibaldi, Daniel; Britto, Constança; Moraes, Milton Ozório; Lannes-Vieira, Joseli

    2015-01-01

    Background Chronic chagasic cardiomyopathy (CCC), the main clinical sign of Chagas disease, is associated with systemic CD8+ T-cell abnormalities and CD8-enriched myocarditis occurring in an inflammatory milieu. Pentoxifylline (PTX), a phosphodiesterase inhibitor, has immunoregulatory and cardioprotective properties. Here, we tested PTX effects on CD8+ T-cell abnormalities and cardiac alterations using a model of experimental Chagas’ heart disease. Methodology/Principal Findings C57BL/6 mice chronically infected by the Colombian Trypanosoma cruzi strain and presenting signs of CCC were treated with PTX. The downmodulation of T-cell receptors on CD8+ cells induced by T. cruzi infection was rescued by PTX therapy. Also, PTX reduced the frequency of CD8+ T-cells expressing activation and migration markers in the spleen and the activation of blood vessel endothelial cells and the intensity of inflammation in the heart tissue. Although preserved interferon-gamma production systemically and in the cardiac tissue, PTX therapy reduced the number of perforin+ cells invading this tissue. PTX did not alter parasite load, but hampered the progression of heart injury, improving connexin 43 expression and decreasing fibronectin overdeposition. Further, PTX reversed electrical abnormalities as bradycardia and prolonged PR, QTc and QRS intervals in chronically infected mice. Moreover, PTX therapy improved heart remodeling since reduced left ventricular (LV) hypertrophy and restored the decreased LV ejection fraction. Conclusions/Significance PTX therapy ameliorates critical aspects of CCC and repositioned CD8+ T-cell response towards homeostasis, reinforcing that immunological abnormalities are crucially linked, as cause or effect, to CCC. Therefore, PTX emerges as a candidate to treat the non-beneficial immune deregulation associated with chronic Chagas' heart disease and to improve prognosis. PMID:25789471

  13. Prolonged antigen presentation is required for optimal CD8+ T cell responses against malaria liver stage parasites.

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    Ian A Cockburn

    2010-05-01

    Full Text Available Immunization with irradiated sporozoites is currently the most effective vaccination strategy against liver stages of malaria parasites, yet the mechanisms underpinning the success of this approach are unknown. Here we show that the complete development of protective CD8+ T cell responses requires prolonged antigen presentation. Using TCR transgenic cells specific for the malaria circumsporozoite protein, a leading vaccine candidate, we found that sporozoite antigen persists for over 8 weeks after immunization--a remarkable finding since irradiated sporozoites are incapable of replication and do not differentiate beyond early liver stages. Persisting antigen was detected in lymphoid organs and depends on the presence of CD11c+ cells. Prolonged antigen presentation enhanced the magnitude of the CD8+ T cell response in a number of ways. Firstly, reducing the time primed CD8+ T cells were exposed to antigen in vivo severely reduced the final size of the developing memory population. Secondly, fully developed memory cells expanded in previously immunized mice but not when transferred to naïve animals. Finally, persisting antigen was able to prime naïve cells, including recent thymic emigrants, to become functional effector cells capable of eliminating parasites in the liver. Together these data show that the optimal development of protective CD8+ T cell immunity against malaria liver stages is dependent upon the prolonged presentation of sporozoite-derived antigen.

  14. CD8 T cell persistence in treated HIV infection

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    Mudd, J. C.; Lederman, Michael M

    2014-01-01

    Purpose of review Many treated HIV infected persons maintain persistently high circulating CD8 T cell numbers, even after many years of therapy. Recent reports suggest that persistent CD8 T cell expansion is associated with higher risk of morbid non-AIDS events. Thus, assessing the mechanisms of CD8 T cell expansion and persistence may give insights into a feature of HIV disease that is clinically important. Recent findings Acute HIV infection is associated with activation and expansion of the CD8 T cell compartment. Expanded CD8 T cells persist throughout disease course and, in contrast to the plasticity that typically characterizes immune responses to most other pathogens, circulating CD8 T cell numbers do not normalize in many patients despite pharmacological suppression of HIV replication. We suspect that residual inflammation in treated HIV infection contributes to antigen-independent CD8 T cell expansion and persistence as most of these cells are not HIV-reactive. Summary Circulating CD8 T cell numbers remain abnormally elevated in many treated HIV-infected patients and this elevation is associated with adverse clinical events. Future studies will need to assess the mechanisms of CD8 T cell expansion and to define the role of CD8 lymphocytosis in the clinical course of treated HIV disease. PMID:25010897

  15. Persistent enteric murine norovirus infection is associated with functionally suboptimal virus-specific CD8 T cell responses.

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    Tomov, Vesselin T; Osborne, Lisa C; Dolfi, Douglas V; Sonnenberg, Gregory F; Monticelli, Laurel A; Mansfield, Kathleen; Virgin, Herbert W; Artis, David; Wherry, E John

    2013-06-01

    Norovirus (NV) gastroenteritis is a major contributor to global morbidity and mortality, yet little is known about immune mechanisms leading to NV control. Previous studies using the murine norovirus (MNV) model have established a key role for T cells in MNV clearance. Despite these advances, important questions remain regarding the magnitude, location, and dynamics of the MNV-specific T cell response. To address these questions, we identified MNV-specific major histocompatibility complex (MHC) class I immunodominant epitopes using an overlapping peptide screen. One of these epitopes (amino acids 519 to 527 of open reading frame 2 [ORF2(519-527)]) was highly conserved among all NV genogroups. Using MHC class I peptide tetramers, we tracked MNV-specific CD8 T cells in lymphoid and mucosal sites during infection with two MNV strains with distinct biological behaviors, the acutely cleared strain CW3 and the persistent strain CR6. Here, we show that enteric MNV infection elicited robust T cell responses primarily in the intestinal mucosa and that MNV-specific CD8 T cells dynamically regulated the expression of surface molecules associated with activation, differentiation, and homing. Furthermore, compared to MNV-CW3 infection, chronic infection with MNV-CR6 resulted in fewer and less-functional CD8 T cells, and this difference was evident as early as day 8 postinfection. Finally, MNV-specific CD8 T cells were capable of reducing the viral load in persistently infected Rag1(-/-) mice, suggesting that these cells are a crucial component of NV immunity. Collectively, these data provide fundamental new insights into the adaptive immune response to two closely related NV strains with distinct biological behaviors and bring us closer to understanding the correlates of protective antiviral immunity in the intestine.

  16. Interferon-γ Prevents Death of Bystander Neurons during CD8 T Cell Responses in the Brain

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    Richter, Kirsten; Hausmann, Jürgen; Staeheli, Peter

    2009-01-01

    T cells restricted to neurotropic viruses are potentially harmful as their activity may result in the destruction of neurons. In the Borna disease virus (BDV) model, antiviral CD8 T cells entering the brain of infected mice cause neurological disease but no substantial loss of neurons unless the animals lack interferon-γ (IFN-γ). We show here that glutamate receptor antagonists failed to prevent BDV-induced neuronal loss in IFN-γ-deficient mice, suggesting that excitotoxicity resulting from glutamate receptor overstimulation is an unlikely explanation for the neuronal damage. Experiments with IFN-γ-deficient mice lacking eosinophils indicated that these cells, which specifically accumulate in the infected brains of IFN-γ-deficient mice, are not responsible for CA1 neuronal death. Interestingly, BDV-induced damage of CA1 neurons was reduced significantly in IFN-γ-deficient mice lacking perforin, suggesting a key role for CD8 T cells in this pathological process. Specific death of hippocampal CA1 neurons could be triggered by adoptive transfer of BDV-specific CD8 T cells from IFN-γ-deficient mice into uninfected mice that express transgene-encoded BDV antigen at high level in astrocytes. These results indicate that attack by CD8 T cells that cause the death of CA1 neurons might be directed toward regional astrocytes and that IFN-γ protects vulnerable CA1 neurons from collateral damage resulting from exposure to potentially toxic substances generated as a result of CD8 T cell-mediated impairment of astrocyte function. PMID:19359516

  17. Follicular Regulatory CD8 T Cells Impair the Germinal Center Response in SIV and Ex Vivo HIV Infection

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    Folkvord, Joy M.; Levy, David N.; Rakasz, Eva G.; Connick, Elizabeth

    2016-01-01

    During chronic HIV infection, viral replication is concentrated in secondary lymphoid follicles. Cytotoxic CD8 T cells control HIV replication in extrafollicular regions, but not in the follicle. Here, we show CXCR5hiCD44hiCD8 T cells are a regulatory subset differing from conventional CD8 T cells, and constitute the majority of CD8 T cells in the follicle. This subset, CD8 follicular regulatory T cells (CD8 TFR), expand in chronic SIV infection, exhibit enhanced expression of Tim-3 and IL-10, and express less perforin compared to conventional CD8 T cells. CD8 TFR modestly limit HIV replication in follicular helper T cells (TFH), impair TFH IL-21 production via Tim-3, and inhibit IgG production by B cells during ex vivo HIV infection. CD8 TFR induce TFH apoptosis through HLA-E, but induce less apoptosis than conventional CD8 T cells. These data demonstrate that a unique regulatory CD8 population exists in follicles that impairs GC function in HIV infection. PMID:27716848

  18. CD8+ T cells in Leishmania infections: friends or foes?

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    Simona eStager

    2012-01-01

    Full Text Available Host protection against several intracellular pathogens requires the induction of CD8+ T cell responses. CD8+ T cells are potent effector cells that can produce high amounts of pro-inflammatory cytokines and kill infected target cells efficiently. However, a protective role for CD8+ T cells during Leishmania infections is still controversial and largely depends on the infection model. In this review, we discuss the role of CD8+ T cells during various types Leishmania infections, following vaccination, and as potential immunotherapeutic targets.

  19. TRAV7-2*02 Expressing CD8T Cells Are Responsible for Palladium Allergy.

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    Takeda, Yuri; Suto, Yoshiko; Ito, Koyu; Hashimoto, Wataru; Nishiya, Tadashi; Ueda, Kyosuke; Narushima, Takayuki; Takahashi, Tetsu; Ogasawara, Kouetsu

    2017-05-31

    While metallic biomaterials have led to an improvement in the quality of life, metal allergies, especially to palladium (Pd), has caused a recent increase in allergic patients. Metal allergy is known to be a T cell-mediated delayed-type hypersensitivity (DTH); however, the pathogenic T cell subsets and the specific T cell receptor (TCR) have not been identified. Therefore, we attempted to identify the pathogenic T cells responsible for Pd allergy. We found that activating CD8T cells significantly increased and that the TRAV (TCRα variable) 7-2*02 chain skewed in Pd allergic mice. Furthermore, adoptive transfer experiments revealed that in vitro-cultured Pd-stimulated antigen presenting cells (APCs) function as memory APCs with recipient mice developing Pd allergy and that the frequency of TRAV7-2*02 increases the same as conventional Pd allergic mice. In contrast, neither proliferation of CD8T cells nor increasing of TRAV7-2*02 was observed in major histocompatibility complex I (MHC I)-deficient Pd-APCs transferred to mice. Taken together, we revealed that TRAV7-2*02-expressing CD8T cells are the pathogenic T cells for the development of Pd allergy. We also identified the CDR3 consensus motif of pathogenic TCRs as CAAXSGSWQLIF in TRAV7-2*02/TRAJ (TCRα junction)22*01 positive cells. These results suggest that the specific TCRs represent novel targets for the development of diagnostics and treatments for metal allergy.

  20. Intravenous immunoglobulin treatment responsiveness depends on the degree of CD8+ T cell activation in Kawasaki disease.

    Science.gov (United States)

    Ye, Qing; Gong, Fang-Qi; Shang, Shi-Qiang; Hu, Jian

    2016-10-01

    Kawasaki disease (KD) has become the most common cause of acquired heart disease in children and is also a risk factor for ischemic heart disease in adults. However, Kawasaki disease lacks specific laboratory diagnostic indices. Thus, this study analyzed the T cell activation profiles of Kawasaki disease and assessed their value in the diagnosis of Kawasaki disease and the prediction of intravenous immunoglobulin (IVIG) sensitivity. We analyzed human leukocyte antigen-DR (HLA-DR), CD69 and CD25 expression on peripheral blood CD4+ and CD8+ T cells during the acute phase of KD. We compared the percentages of HLA-DR+/CD69+/CD25+ T cells in the CD4+ and CD8+ T cell populations of IVIG-effective and IVIG-resistant groups. Receiver operating characteristic curves were used to assess the diagnostic value of the above parameters. The median percentage of CD8+HLA-DR+ T cells and the median ratio of CD8+HLA-DR+ T cells/CD8+CD25+ T cells were significantly elevated in the patient group compared with those in the control group during the acute phase of KD. Regarding the diagnosis of Kawasaki disease, the area under the ROC curve was 0.939 for the percentage of CD8+HLA-DR+ T cells. There was a significant difference in the ratio of CD8+HLA-DR+ T cells/CD8+CD69+ T cells between IVIG-resistant patients and IVIG-sensitive patients. Regarding IVIG sensitivity, the area under the ROC curve was 0.795 for it. Excessive CD8+ T cell activation, as well as an imbalance between CD8+ T cell activation and inhibition, underlies the pathogenesis of Kawasaki disease. The percentage of CD8+ HLA-DR+ T cells may be used as an index to diagnose Kawasaki disease. IVIG inhibits CD8+ T cell activation, but excessive CD8+ T cell activation may cause IVIG resistance. The ratio of CD8+HLA-DR+ T cells/CD8+CD69+ T cells may be used as a predictor of IVIG sensitivity. Copyright © 2016. Published by Elsevier Inc.

  1. Immunodominant Dengue Virus-Specific CD8+ T Cell Responses Are Associated with a Memory PD-1+ Phenotype.

    Science.gov (United States)

    de Alwis, Ruklanthi; Bangs, Derek J; Angelo, Michael A; Cerpas, Cristhiam; Fernando, Anira; Sidney, John; Peters, Bjoern; Gresh, Lionel; Balmaseda, Angel; de Silva, Aruna D; Harris, Eva; Sette, Alessandro; Weiskopf, Daniela

    2016-05-01

    Dengue disease is a large public health problem that mainly afflicts tropical and subtropical regions. Understanding of the correlates of protection against dengue virus (DENV) is poor and hinders the development of a successful human vaccine. The present study aims to define DENV-specific CD8(+)T cell responses in general and those of HLA alleles associated with dominant responses in particular. In human blood donors in Nicaragua, we observed a striking dominance of HLA B-restricted responses in general and of the allele B*35:01 in particular. Comparing these patterns to those in the general population of Sri Lanka, we found a strong correlation between restriction of the HLA allele and the breadth and magnitude of CD8(+)T cell responses, suggesting that HLA genes profoundly influence the nature of responses. The majority of gamma interferon (IFN-γ) responses were associated with effector memory phenotypes, which were also detected in non-B*35:01-expressing T cells. However, only the B*35:01 DENV-specific T cells were associated with marked expression of the programmed death 1 protein (PD-1). These cells did not coexpress other inhibitory receptors and were able to proliferate in response to DENV-specific stimulation. Thus, the expression of particular HLA class I alleles is a defining characteristic influencing the magnitude and breadth of CD8 responses, and a distinct, highly differentiated phenotype is specifically associated with dominant CD8(+)T cells. These results are of relevance for both vaccine design and the identification of robust correlates of protection in natural immunity. Dengue is an increasingly significant public health problem as its mosquito vectors spread over greater areas; no vaccines against the virus have yet been approved. An important step toward vaccine development is defining protective immune responses; toward that end, we here characterize the phenotype of the immunodominant T cell responses. These DENV-reactive T cells express

  2. Protective antibody and CD8+ T-cell responses to the Plasmodium falciparum circumsporozoite protein induced by a nanoparticle vaccine.

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    Stephen A Kaba

    Full Text Available The worldwide burden of malaria remains a major public health problem due, in part, to the lack of an effective vaccine against the Plasmodium falciparum parasite. An effective vaccine will most likely require the induction of antigen specific CD8(+ and CD4(+ T-cells as well as long-lasting antibody responses all working in concert to eliminate the infection. We report here the effective modification of a self-assembling protein nanoparticle (SAPN vaccine previously proven effective in control of a P. berghei infection in a rodent model to now present B- and T-cell epitopes of the human malaria parasite P. falciparum in a platform capable of being used in human subjects.To establish the basis for a SAPN-based vaccine, B- and CD8(+ T-cell epitopes from the P. falciparum circumsporozoite protein (PfCSP and the universal CD4 T-helper epitope PADRE were engineered into a versatile small protein (∼125 amino acids that self-assembles into a spherical nanoparticle repetitively displaying the selected epitopes. P. falciparum epitope specific immune responses were evaluated in mice using a transgenic P. berghei malaria parasite of mice expressing the human malaria full-length P. falciparum circumsporozoite protein (Tg-Pb/PfCSP. We show that SAPN constructs, delivered in saline, can induce high-titer, long-lasting (1 year protective antibody and poly-functional (IFNγ(+, IL-2(+ long-lived central memory CD8(+ T-cells. Furthermore, we demonstrated that these Ab or CD8(+ T-cells can independently provide sterile protection against a lethal challenge of the transgenic parasites.The SAPN construct induces long-lasting antibody and cellular immune responses to epitope specific sequences of the P. falciparum circumsporozoite protein (PfCSP and prevents infection in mice by a transgenic P. berghei parasite displaying the full length PfCSP.

  3. Different Vaccine Vectors Delivering the Same Antigen Elicit CD8+ T Cell Responses with Distinct Clonotype and Epitope Specificity

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    Honda, M.; Robinson, H.; Wang, R.; Kong, W.-P.; Kanekiyo, M.; Akahata, W.; Xu, L.; Matsuo, K.; Natarajan, K.; Asher, T. E.; Price, D. A.; Douek, D. C.; Margulies, D. H.; Nabel, G. J.

    2009-08-15

    Prime-boost immunization with gene-based vectors has been developed to generate more effective vaccines for AIDS, malaria, and tuberculosis. Although these vectors elicit potent T cell responses, the mechanisms by which they stimulate immunity are not well understood. In this study, we show that immunization by a single gene product, HIV-1 envelope, with alternative vector combinations elicits CD8{sup +} cells with different fine specificities and kinetics of mobilization. Vaccine-induced CD8{sup +} T cells recognized overlapping third V region loop peptides. Unexpectedly, two anchor variants bound H-2D{sup d} better than the native sequences, and clones with distinct specificities were elicited by alternative vectors. X-ray crystallography revealed major differences in solvent exposure of MHC-bound peptide epitopes, suggesting that processed HIV-1 envelope gave rise to MHC-I/peptide conformations recognized by distinct CD8{sup +} T cell populations. These findings suggest that different gene-based vectors generate peptides with alternative conformations within MHC-I that elicit distinct T cell responses after vaccination.

  4. Different Vaccine Vectors Delivering the Same Antigen Elicit CD8plus T Cell Responses with Distinct Clonotype and Epitope Specificity

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    M Honda; R Wang; W Kong; M Kanekiyo; Q Akahata; L Xu; K Matsuo; K Natarajan; H Robinson; et al.

    2011-12-31

    Prime-boost immunization with gene-based vectors has been developed to generate more effective vaccines for AIDS, malaria, and tuberculosis. Although these vectors elicit potent T cell responses, the mechanisms by which they stimulate immunity are not well understood. In this study, we show that immunization by a single gene product, HIV-1 envelope, with alternative vector combinations elicits CD8{sup +} cells with different fine specificities and kinetics of mobilization. Vaccine-induced CD8{sup +} T cells recognized overlapping third V region loop peptides. Unexpectedly, two anchor variants bound H-2D{sup d} better than the native sequences, and clones with distinct specificities were elicited by alternative vectors. X-ray crystallography revealed major differences in solvent exposure of MHC-bound peptide epitopes, suggesting that processed HIV-1 envelope gave rise to MHC-I/peptide conformations recognized by distinct CD8{sup +} T cell populations. These findings suggest that different gene-based vectors generate peptides with alternative conformations within MHC-I that elicit distinct T cell responses after vaccination.

  5. Vitamin D receptor signals regulate effector and memory CD8 T cell responses to infections in mice.

    Science.gov (United States)

    Yuzefpolskiy, Yevgeniy; Baumann, Florian M; Penny, Laura A; Studzinski, George P; Kalia, Vandana; Sarkar, Surojit

    2014-12-01

    Vitamin D insufficiency is associated with broad-ranging human disease sequelae such as bone disease, cancer, cardiovascular disease, allergy, autoimmune disorders, diabetes, and infectious diseases. Disease risk and severity of a large proportion of the nonskeletal disorders heavily involve the cytotoxic cluster of differentiation (CD) 8 T lymphocyte (CTL) arm of cellular adaptive immunity. Considering the importance of vitamin D in CTL-dependent diseases, there is a critical need for systematic in-depth explorations into the role of vitamin D deficiency in generation and maintenance of CTL immunity during infections and vaccinations. With the use of wild-type (WT) vitamin D-sufficient mice and the vitamin D receptor knockout (Vdr(-/-)) mouse model of in vivo deficiency of vitamin D signaling, we systematically analyzed the impact of vitamin D deficiency on antigen-specific effector and memory CD8 T cell responses to acute viral and bacterial infections. WT and Vdr(-/-) mice were infected with lymphocytic choriomeningitis virus, a natural mouse pathogen, and antigen-specific CTL responses were analyzed during priming, expansion, contraction, and memory phases. Magnitude, breadth, cytokine production, and localization of antiviral effector and memory CTLs to lymphoid and nonlymphoid tissues were specifically assessed. The absence of vitamin D signals led to 1) aberrant CD8 T cell effector differentiation (∼2-fold lower granzyme B and reduced B cell lymphoma 2; P ≤ 0.05) and enhanced contraction (∼15% increase; P ≤ 0.05) in antigen-specific CTLs; 2) a significantly restricted (P ≤ 0.05) breadth of the antigen-specific CD8 T cell effector and memory repertoire; and 3) preferential localization of effector (∼2.5-fold increase; P ≤ 0.01) and memory (∼5-fold increase; P ≤ 0.001) CD8 T cells to the lymph nodes compared to nonlymphoid tissues. Our data show a previously unrecognized impact of vitamin D deficiency on the quantity, quality, breadth, and

  6. Hesperidin Inhibits Inflammatory Response Induced by Aeromonas hydrophila Infection and Alters CD4+/CD8+ T Cell Ratio

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    Abdelaziz S. A. Abuelsaad

    2014-01-01

    Full Text Available Background. Aeromonas hydrophila is an opportunistic bacterial pathogen that is associated with a number of human diseases. Hesperidin (HES has been reported to exert antioxidant and anti-inflammatory activities. Objectives. The aim of this study was to investigate the potential effect of HES treatment on inflammatory response induced by A. hydrophila infection in murine. Methods. A. hydrophila-infected mice were treated with HES at 250 mg/kg b.wt./week for 4 consecutive weeks. Phagocytosis, reactive oxygen species production, CD4+/CD8+ T cell ratio, and CD14 expression on intestinal infiltrating monocytes were evaluated. The expression of E-selectin and intercellular adhesion molecule 1 on stimulated HUVECs and RAW macrophage was evaluated. Results. Percentage of CD4+ T cells in the intestinal tissues of infected treated mice was highly significantly increased; however, phagocytic index, ROS production, CD8+ T cells percentage, and CD14 expression on monocytes were significantly reduced. On the other hand, HES significantly inhibited A-LPS- and A-ECP-induced E-selectin and ICAM-1 expression on HUVECs and ICAM-1 expression on RAW macrophage. Conclusion. Present data indicated that HES has a potential role in the suppression of inflammatory response induced by A. hydrophila toxins through downmodulation of ROS production and CD14 and adhesion molecules expression, as well as increase of CD4+/CD8+ cell ratio.

  7. Functional signatures of human CD4 and CD8 T cell responses to Mycobacterium tuberculosis.

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    Teresa ePrezzemolo

    2014-04-01

    Full Text Available With 1.4 million deaths and 8.7 million new cases in 2011, tuberculosis (TB remains a global health care problem and together with HIV and Malaria represents the one of the three infectious diseases world-wild. Control of the global TB epidemic has been impaired by the lack of an effective vaccine, by the emergence of drug-resistant forms of Mycobacterium tuberculosis (Mtb and by the lack of sensitive and rapid diagnostics. It is estimated, by epidemiological reports, that one third of the world’s population is latently infected with Mtb, but the majority of infected individuals develops long-lived protective immunity, which controls and contains Mtb in a T cell-dependent manner. Development of TB disease results from interactions among the environment, the host, and the pathogen, and known risk factors include HIV coinfection, immunodeficiency, diabetes mellitus, overcrowding, malnutrition, and general poverty; therefore an effective T cell response determines whether the infection resolves or develops into clinically evident disease. Consequently, there is great interest in determining which T cells subsets mediate anti-mycobacterial immunity, delineating their effector functions. On the other hand, many aspects remain unsolved in understanding why some individuals are protected from Mtb infection while others go on to develop disease.Several studies have demonstrated that CD4+ T cells are involved in protection against Mtb, as supported by the evidence that CD4+ T cell depletion is responsible for Mtb reactivation in HIV-infected individuals. There are many subsets of CD4+ T cells, such as T-helper 1 (Th1, Th2, Th17, and regulatory T cells (Tregs, and all these subsets cooperate or interfere with each other to control infection; the dominant subset may differ between active and latent Mtb infection cases. Mtb-specific CD4+ Th1 cell response is considered to have a protective role for the ability to produce cytokines such as IFN- or TNF

  8. Strong vaccine-induced CD8 T-cell responses have cytolytic function in a chimpanzee clearing HCV infection.

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    Babs E Verstrepen

    Full Text Available A single correlate of effective vaccine protection against chronic HCV infection has yet to be defined. In this study, we analyzed T-cell responses in four chimpanzees, immunized with core-E1-E2-NS3 and subsequently infected with HCV1b. Viral clearance was observed in one animal, while the other three became chronically infected. In the animal that cleared infection, NS3-specific CD8 T-cell responses were observed to be more potent in terms of frequency and polyfunctionality of cytokine producing cells. Unique to this animal was the presence of killing-competent CD8 T-cells, specific for NS3 1258-1272, being presented by the chimpanzee MHC class I molecule Patr-A*03∶01, and a high affinity recognition of this epitope. In the animals that became chronically infected, T-cells were able to produce cytokines against the same peptide but no cytolysis could be detected. In conclusion, in the animal that was able to clear HCV infection not only cytokine production was observed but also cytolytic potential against specific MHC class I/peptide-combinations.

  9. Generalized Liver- and Blood-Derived CD8+ T-Cell Impairment in Response to Cytokines in Chronic Hepatitis C Virus Infection.

    Directory of Open Access Journals (Sweden)

    Stephanie C Burke Schinkel

    Full Text Available Generalized CD8+ T-cell impairment in chronic hepatitis C virus (HCV infection and the contribution of liver-infiltrating CD8+ T-cells to the immunopathogenesis of this infection remain poorly understood. It is hypothesized that this impairment is partially due to reduced CD8+ T-cell activity in response to cytokines such as IL-7, particularly within the liver. To investigate this, the phenotype and cytokine responsiveness of blood- and liver-derived CD8+ T-cells from healthy controls and individuals with HCV infection were compared. In blood, IL-7 receptor α (CD127 expression on bulk CD8+ T-cells in HCV infection was no different than controls yet was lower on central memory T-cells, and there were fewer naïve cells. IL-7-induced signalling through phosphorylated STAT5 was lower in HCV infection than in controls, and differed between CD8+ T-cell subsets. Production of Bcl-2 following IL-7 stimulation was also lower in HCV infection and inversely related to the degree of liver fibrosis. In liver-derived CD8+ T-cells, STAT5 activation could not be increased with cytokine stimulation and basal Bcl-2 levels of liver-derived CD8+ T-cells were lower than blood-derived counterparts in HCV infection. Therefore, generalized CD8+ T-cell impairment in HCV infection is characterized, in part, by impaired IL-7-mediated signalling and survival, independent of CD127 expression. This impairment is more pronounced in the liver and may be associated with an increased potential for apoptosis. This generalized CD8+ T-cell impairment represents an important immune dysfunction in chronic HCV infection that may alter patient health.

  10. Role of CD40 ligand and CD28 in induction and maintenance of antiviral CD8+ effector T cell responses

    DEFF Research Database (Denmark)

    Andreasen, Susanne; Christensen, Jeanette Erbo; Marker, O

    2000-01-01

    and extensively, whereas vesicular stomatitis virus (VSV) spreads poorly. We found that the primary response of CD40L-/- mice toward VSV is significantly impaired; proliferation of both CD4+ and CD8+ cells is reduced 2- to 3-fold, few CD8+ cells acquire an activated phenotype, and little functional activity...... is induced. Very similar results were obtained in VSV-infected, CD28-deficient mice. In contrast, neither CD40L nor CD28 was required for induction of a primary CD8+ response toward LCMV. Surprisingly, lack of CD4+ T cells had no impact on the primary immune response toward any of the viruses, even though...... the CD40 ligand dependence demonstrated for VSV would be expected to be associated with CD4 dependence. Upon coinfection of VSV-infected mice with LCMV, the requirement for CD40 ligand (but not CD28) could be partially bypassed, as evidenced by a 3-fold increase in the frequency of VSV-specific CD8+ T...

  11. T Cell Factor 1-Expressing Memory-like CD8(+) T Cells Sustain the Immune Response to Chronic Viral Infections.

    Science.gov (United States)

    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. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Antigen entrapped in the escheriosomes leads to the generation of CD4(+) helper and CD8(+) cytotoxic T cell response.

    Science.gov (United States)

    Syed, Faisal M; Khan, Masood A; Nasti, Tahseen H; Ahmad, Nadeem; Mohammad, Owais

    2003-06-02

    In previous study, we demonstrated the potential of Escherichia coli (E. coli) lipid liposomes (escheriosomes) to undergo membrane-membrane fusion with cytoplasmic membrane of the target cells including professional antigen presenting cells. Our present study demonstrates that antigen encapsulated in escheriosomes could be successfully delivered simultaneously to the cytosolic as well as endosomal processing pathways of antigen presenting cells, leading to the generation of both CD4(+) T-helper and CD8(+) cytotoxic T cell response. In contrast, encapsulation of same antigen in egg phosphatidyl-choline (egg PC) liposomes, just like antigen-incomplete Freund's adjuvant (IFA) complex, has inefficient access to the cytosolic pathway of MHC I-dependent antigen presentation and failed to generate antigen-specific CD8(+) cytotoxic T cell response. However, both egg PC liposomes as well as escheriosomes-encapsulated antigen elicited strong humoral immune response in immunized animals but antibody titre was significantly higher in the group of animals immunized with escheriosomes-encapsulated antigen. These results imply usage of liposome-based adjuvant as potential candidate vaccine capable of eliciting both cell-mediated as well as humoral immune responses. Furthermore, antigen entrapped in escheriosomes stimulates antigen-specific CD4(+) T cell proliferation and also enhances the level of IL-2, IFN-gamma and IL-4 in the immunized animals.

  13. MHC-based detection of antigen-specific CD8(+) T cell responses

    DEFF Research Database (Denmark)

    Hadrup, Sine Reker; Schumacher, Nana Maria Pii

    2010-01-01

    epitopes in limited biological material. These technologies are based on the joint binding of differentially labelled MHC multimers on the T cell surface, thereby providing each antigen-specific T cell population with a unique multicolour code. This strategy of 'combinatorial encoding' enables detection...... of many (at least 25) different T cell populations per sample and should be of broad value for both T cell epitope identification and immunomonitoring...

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

    DEFF Research Database (Denmark)

    Steffensen, Maria A; Pedersen, Louise Holm; Jahn, Marie Louise

    2016-01-01

    to a vaccine expressing the same Ag without its immunodominant epitope. We found that removal of the dominant epitope allowed the induction of CD8(+) T cell responses targeting at least two otherwise subdominant epitopes. Importantly, the overall magnitude of the induced T cell responses was similar, allowing......As a result of the difficulties in making efficient vaccines against genetically unstable viruses such as HIV, it has been suggested that future vaccines should preferentially target subdominant epitopes, the idea being that this should allow a greater breadth of the induced T cell response and......, hence, a greater efficiency in controlling escape variants. However, to our knowledge the evidence supporting this concept is limited at best. To improve upon this, we used the murine lymphocytic choriomeningitis virus model and adenoviral vectors to compare a vaccine expressing unmodified Ag...

  15. Reactivity toward Bifidobacterium longum and Enterococcus hirae demonstrate robust CD8+T cell response and better prognosis in HBV-related hepatocellular carcinoma.

    Science.gov (United States)

    Rong, Yihui; Dong, Zheng; Hong, Zhixian; Jin, Yun; Zhang, Wei; Zhang, Bailong; Mao, Wei; Kong, Huifang; Wang, Chunping; Yang, Bin; Gao, Xudong; Song, Zhenyu; Green, Susan E; Song, Haihan K; Wang, Hongbo; Lu, Yinying

    2017-09-15

    Recent studies suggest that several bacterial species are involved in tumor immunosurveillance and antitumor immunity. The role of bacteria in immune responses in HBV-related hepatocellular carcinoma (HCC) patients is still unknown. In this study, we examined the bacteria-reactive CD8 + T cell response in patients with HBV-related HCC. We found that circulating CD8 + T cells from healthy individuals demonstrated minimal or zero specificity toward a series of commensals and bacteria previously associated with antitumor effects, including Escherichia coli, Enterococcus faecium, Bifidobacterium longum, Bacteroides fragilis, and Enterococcus hirae. In contrast, the circulating CD8 + T cells from HBV-related HCC patients presented significantly elevated bacteria-reactive responses, albeit with high variations among different HCC individuals. Reactivity toward bacteria was also identified in tumor-infiltrating CD8 + T cells. These bacteria-reactive responses were not primarily induced by TLR ligand, but were dependent on the presence of antigen-presenting monocytes, and were MHC class I-restricted. Interestingly, we observed that the CD8 + T cell-to-Foxp3 + regulatory T cell ratio was positively correlated with the proportions of Bifidobacterium longum-reactive and Enterococcus hirae-reactive CD8 + T cells, while the frequency of PD-1 + CD8 + T cells was negatively correlated with the frequency of Enterococcus hirae-reactive CD8 + T cells. Furthermore, the disease-free survival time of HCC patients after tumor resection was positively correlated with the frequencies of Bifidobacterium longum-reactive and Enterococcus hirae-reactive CD8 + T cells. Together, these results suggested that certain bacterial species might present valuable antitumor effects. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Revealing the Complexity in CD8 T Cell Responses to Infection in Inbred C57B/6 versus Outbred Swiss Mice.

    Science.gov (United States)

    Martin, Matthew D; Danahy, Derek B; Hartwig, Stacey M; Harty, John T; Badovinac, Vladimir P

    2017-01-01

    Recent work has suggested that current mouse models may underrepresent the complexity of human immune responses. While most mouse immunology studies utilize inbred mouse strains, it is unclear if conclusions drawn from inbred mice can be extended to all mouse strains or generalized to humans. We recently described a "surrogate activation marker" approach that could be used to track polyclonal CD8 T cell responses in inbred and outbred mice and noted substantial discord in the magnitude and kinetics of CD8 T cell responses in individual outbred mice following infection. However, how the memory CD8 T cell response develops following infection and the correlates of memory CD8 T cell-mediated protection against re-infection in outbred mice remains unknown. In this study, we investigated development of pathogen-specific memory CD8 T cell responses in inbred C57B/6 and outbred National Institutes of Health Swiss mice following lymphocytic choriomeningitis virus or L. monocytogenes infection. Interestingly, the size of the memory CD8 T cell pool generated and rate of phenotypic progression was considerably more variable in individual outbred compared to inbred mice. Importantly, while prior infection provided both inbred and outbred cohorts of mice with protection against re-infection that was dependent on the dose of primary infection, levels of memory CD8 T cells generated and degree of protection against re-infection did not correlate with primary infection dose in all outbred mice. While variation in CD8 T cell responses to infection is not entirely surprising due to the genetic diversity present, analysis of infection-induced immunity in outbred hosts may reveal hidden complexity in CD8 T cell responses in genetically diverse populations and might help us further bridge the gap between mouse and human studies.

  17. IL4I1: an inhibitor of the CD8⁺ antitumor T-cell response in vivo.

    Science.gov (United States)

    Lasoudris, Fanette; Cousin, Céline; Prevost-Blondel, Armelle; Martin-Garcia, Nadine; Abd-Alsamad, Issam; Ortonne, Nicolas; Farcet, Jean-Pierre; Castellano, Flavia; Molinier-Frenkel, Valérie

    2011-06-01

    The L-phenylalanine oxidase IL4I1 inhibits T-cell proliferation in vitro through H(2) O(2) production, and is highly expressed in tumor-associated macrophages. IL4I1 is also detected by immunohistochemistry in neoplastic cells from several B-cell lymphomas and some non-lymphoid tumors. To evaluate IL4I1's effect on tumor growth, we developed a mouse melanoma model constitutively coexpressing IL4I1 and the GP33 epitope. After GP33 vaccination, tumors developed more frequently in mice injected with IL4I1-expressing cells in comparison with mice receiving control cells. Tumor escape was preceded by a rapid diminution of IFN-γ-producing cytotoxic antitumor CD8(+) T cells. Moreover, tumor incidence was already increased when only 20% of the injected cells expressed IL4I1. The minimal IL4I1 activities leading to tumor escape were close to those detected in human melanoma and mesothelioma. Thus, we demonstrate the immunosuppressive functions of IL4I1 in vivo and suggest that IL4I1 facilitates human tumor growth by inhibiting the CD8(+) antitumor T-cell response. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. IL4I1: an inhibitor of the CD8(+) antitumor T-cell response in vivo

    Science.gov (United States)

    Lasoudris, Fanette; Cousin, Céline; Prevost-Blondel, Armelle; Martin-Garcia, Nadine; Abd-Alsamad, Issam; Ortonne, Nicolas; Farcet, Jean-Pierre; Castellano, Flavia; Molinier-Frenkel, Valérie

    2011-01-01

    The L-phenylalanine oxidase IL4I1 inhibits T-cell proliferation in vitro through H2O2 production, and is highly expressed in tumor-associated macrophages. IL4I1 is also detected by immunohistochemistry in neoplastic cells from several B-cell lymphomas and some non-lymphoid tumors. To evaluate IL4I1 effect on tumor growth, we developed a mouse melanoma model constitutively coexpressing IL4I1 and the GP33 epitope. After GP33 vaccination, tumors developed more frequently in mice injected with IL4I1-expressing cells in comparison to mice receiving control cells. Tumor escape was preceded by a rapid diminution of IFN-γ producing cytotoxic antitumor CD8+ T cells. Moreover, tumor incidence was already increased when only 20% of the injected cells expressed IL4I1. The minimal IL4I1 activities leading to tumor escape were close to those detected in human melanoma and mesothelioma. Thus, we demonstrate the immunosuppressive functions of IL4I1 in vivo and suggest that IL4I1 facilitates human tumor growth by inhibiting the CD8+ antitumor T-cell response. PMID:21469114

  19. cAMP-responsive element modulator α (CREMα) trans-represses the transmembrane glycoprotein CD8 and contributes to the generation of CD3+CD4-CD8- T cells in health and disease.

    Science.gov (United States)

    Hedrich, Christian M; Rauen, Thomas; Crispin, Jose C; Koga, Tomohiro; Ioannidis, Christina; Zajdel, Melissa; Kyttaris, Vasileios C; Tsokos, George C

    2013-11-01

    T cell receptor-αβ(+) CD3(+)CD4(-)CD8(-) "double-negative" T cells are expanded in the peripheral blood of patients with systemic lupus erythematosus and autoimmune lymphoproliferative syndrome. In both disorders, double-negative T cells infiltrate tissues, induce immunoglobulin production, and secrete proinflammatory cytokines. Double-negative T cells derive from CD8(+) T cells through down-regulation of CD8 surface co-receptors. However, the molecular mechanisms orchestrating this process remain unclear. Here, we demonstrate that the transcription factor cAMP-responsive element modulator α (CREMα), which is expressed at increased levels in T cells from systemic lupus erythematosus patients, contributes to transcriptional silencing of CD8A and CD8B. We provide the first evidence that CREMα trans-represses a regulatory element 5' of the CD8B gene. Therefore, CREMα represents a promising candidate in the search for biomarkers and treatment options in diseases in which double-negative T cells contribute to the pathogenesis.

  20. Balancing immune protection and immune pathology by CD8+ T cell responses to influenza infection

    Directory of Open Access Journals (Sweden)

    Susu eDuan

    2016-02-01

    Full Text Available Influenza A virus (IAV is a significant human pathogen causing annual epidemics and periodic pandemics. CD8+ cytotoxic T lymphocyte (CTL-mediated immunity contributes to clearance of virus-infected cells; CTL immunity targeting the conserved internal proteins of IAVs is a key protection mechanism when neutralizing antibodies are absent during heterosubtypic IAV infection. However, CTL infiltration into the airways, their cytotoxicity, and the effects of produced pro-inflammatory cytokines can cause severe lung tissue injury, thereby contributing to immunopathology. Studies have discovered complicated and exquisite stimulatory and inhibitory mechanisms that regulate CTL magnitude and effector activities during IAV infection. Here, we review the state of knowledge on the roles of IAV-specific CTLs in immune protection and immunopathology during IAV infection in animal models, highlighting the key findings of various requirements and constraints regulating the balance of immune protection and pathology involved in CTL immunity. We also discuss the evidence of cross-reactive CTL immunity as a positive correlate of cross-subtype protection during secondary IAV infection in both animal and human studies. We argue that the effects of CTL immunity on protection and immunopathology depend on multiple layers of host and viral factors, including complex host mechanisms to regulate CTL magnitude and effector activity, the pathogenic nature of the IAV, the innate response milieu, and the host historical immune context of influenza infection. Future efforts are needed to further understand these key host and viral factors, especially to differentiate those that constrain optimally effective CTL anti-viral immunity from those necessary to restrain CTL-mediated nonspecific immunopathology in the various contexts of IAV infection, in order to develop better vaccination and therapeutic strategies for modifying protective CTL immunity.

  1. Analysis of the T Cell Response to Zika Virus and Identification of a Novel CD8+ T Cell Epitope in Immunocompetent Mice.

    Science.gov (United States)

    Pardy, Ryan D; Rajah, Maaran M; Condotta, Stephanie A; Taylor, Nathan G; Sagan, Selena M; Richer, Martin J

    2017-02-01

    Zika virus (ZIKV) is an emerging arbovirus of the Flaviviridae family. Although ZIKV infection is typically mild and self-limiting in healthy adults, infection has been associated with neurological symptoms such as Guillain-Barré syndrome, and a causal link has been established between fetal microcephaly and ZIKV infection during pregnancy. These risks, and the magnitude of the ongoing ZIKV pandemic, have created an urgent need for the development of animal models to study the immune response to ZIKV infection. Previous animal models have primarily focused on pathogenesis in immunocompromised mice. In this study, we provide a model of ZIKV infection in wild-type immunocompetent C57BL/6 mice, and have provided an analysis of the immune response to infection. We evaluated the activation of several innate immune cell types, and studied the kinetics, phenotype, and functionality of T cell responses to ZIKV infection. Our results demonstrate that ZIKV infection is mild in wild-type immunocompetent C57BL/6 mice, resulting in minimal morbidity. Our data establish that at the peak of the adaptive response, antigen-experienced CD4+ T cells polarize to a Th1 phenotype, and antigen-experienced CD8+ T cells exhibit an activated effector phenotype, producing both effector cytokines and cytolytic molecules. Furthermore, we have identified a novel ZIKV CD8+ T cell epitope in the envelope protein that is recognized by the majority of responding cells. Our model provides an important reference point that will help dissect the impact of polymorphisms in the circulating ZIKV strains on the immune response and ZIKV pathogenesis. In addition, the identification of a ZIKV epitope will allow for the design of tetramers to study epitope-specific T cell responses, and will have important implications for the design and development of ZIKV vaccine strategies.

  2. Analysis of the T Cell Response to Zika Virus and Identification of a Novel CD8+ T Cell Epitope in Immunocompetent Mice.

    Directory of Open Access Journals (Sweden)

    Ryan D Pardy

    2017-02-01

    Full Text Available Zika virus (ZIKV is an emerging arbovirus of the Flaviviridae family. Although ZIKV infection is typically mild and self-limiting in healthy adults, infection has been associated with neurological symptoms such as Guillain-Barré syndrome, and a causal link has been established between fetal microcephaly and ZIKV infection during pregnancy. These risks, and the magnitude of the ongoing ZIKV pandemic, have created an urgent need for the development of animal models to study the immune response to ZIKV infection. Previous animal models have primarily focused on pathogenesis in immunocompromised mice. In this study, we provide a model of ZIKV infection in wild-type immunocompetent C57BL/6 mice, and have provided an analysis of the immune response to infection. We evaluated the activation of several innate immune cell types, and studied the kinetics, phenotype, and functionality of T cell responses to ZIKV infection. Our results demonstrate that ZIKV infection is mild in wild-type immunocompetent C57BL/6 mice, resulting in minimal morbidity. Our data establish that at the peak of the adaptive response, antigen-experienced CD4+ T cells polarize to a Th1 phenotype, and antigen-experienced CD8+ T cells exhibit an activated effector phenotype, producing both effector cytokines and cytolytic molecules. Furthermore, we have identified a novel ZIKV CD8+ T cell epitope in the envelope protein that is recognized by the majority of responding cells. Our model provides an important reference point that will help dissect the impact of polymorphisms in the circulating ZIKV strains on the immune response and ZIKV pathogenesis. In addition, the identification of a ZIKV epitope will allow for the design of tetramers to study epitope-specific T cell responses, and will have important implications for the design and development of ZIKV vaccine strategies.

  3. Enhanced cross-presentation and improved CD8+ T cell responses after mannosylation of synthetic long peptides in mice.

    Science.gov (United States)

    Rauen, Judith; Kreer, Christoph; Paillard, Arlette; van Duikeren, Suzanne; Benckhuijsen, Willemien E; Camps, Marcel G; Valentijn, A Rob P M; Ossendorp, Ferry; Drijfhout, Jan W; Arens, Ramon; Burgdorf, Sven

    2014-01-01

    The use of synthetic long peptides (SLP) has been proven to be a promising approach to induce adaptive immune responses in vaccination strategies. Here, we analyzed whether the efficiency to activate cytotoxic T cells by SLP-based vaccinations can be increased by conjugating SLPs to mannose residues. We could demonstrate that mannosylation of SLPs results in increased internalization by the mannose receptor (MR) on murine antigen-presenting cells. MR-mediated internalization targeted the mannosylated SLPs into early endosomes, from where they were cross-presented very efficiently compared to non-mannosylated SLPs. The influence of SLP mannosylation was specific for cross-presentation, as no influence on MHC II-restricted presentation was observed. Additionally, we showed that vaccination of mice with mannosylated SLPs containing epitopes from either ovalbumin or HPV E7 resulted in enhanced proliferation and activation of antigen-specific CD8+ T cells. These findings demonstrate that mannosylation of SLPs augments the induction of a cytotoxic T cell response in vitro and in vivo and might be a promising approach to induce cytotoxic T cell responses in e.g. cancer therapy and anti-viral immunity.

  4. Diminished primary and secondary influenza virus-specific CD8(+) T-cell responses in CD4-depleted Ig(-/-) mice

    DEFF Research Database (Denmark)

    Riberdy, J M; Christensen, Jan Pravsgaard; Branum, K

    2000-01-01

    Optimal expansion of influenza virus nucleoprotein (D(b)NP(366))-specific CD8(+) T cells following respiratory challenge of naive Ig(-/-) microMT mice was found to require CD4(+) T-cell help, and this effect was also observed in primed animals. Absence of the CD4(+) population was consistently...

  5. Single-epitope DNA vaccination prevents exhaustion and facilitates a broad antiviral CD8+ T cell response during chronic viral infection

    DEFF Research Database (Denmark)

    Bartholdy, Christina; Stryhn, Anette; Christensen, Jan Pravsgaard

    2004-01-01

    a single dominant epitope may suppress the response to other viral epitopes, and this may lead to increased susceptibility to reinfection with escape variants circulating in the host population. To address these issues, we induced a memory response consisting solely of monospecific, CD8+ T cells by use...... of DNA vaccines encoding immunodominant epitopes of lymphocytic choriomeningitis virus (LCMV). We analyzed the spectrum of the CD8+ T cell response and the susceptibility to infection in H-2(b) and H-2(d) mice. Priming for a monospecific, CD8+ T cell response did not render mice susceptible to viral...... variants. Thus, vaccinated mice were protected against chronic infection with LCMV, and no evidence indicating biologically relevant viral escape was obtained. In parallel, a broad and sustained CD8+ T cell response was generated upon infection, and in H-2(d) mice epitope spreading was observed. Even after...

  6. Multiscale Modeling of the Early CD8 T-Cell Immune Response in Lymph Nodes: An Integrative Study

    Directory of Open Access Journals (Sweden)

    Sotiris A. Prokopiou

    2014-09-01

    Full Text Available CD8 T-cells are critical  in controlling infection by intracellular  pathogens. Upon encountering antigen presenting cells, T-cell receptor activation promotes the differentiation of naïve CD8 T-cells into strongly proliferating  activated and effector stages. We propose a 2D-multiscale computational model to study the maturation of CD8 T-cells in a lymph node controlled by their molecular profile. A novel molecular pathway is presented and converted into an ordinary differential  equation model, coupled with a cellular Potts model to describe cell-cell interactions. Key molecular  players such as activated IL2 receptor and Tbet levels  control the differentiation  from naïve into activated and effector stages, respectively,  while caspases and Fas-Fas ligand interactions control cell apoptosis.  Coupling  this molecular model to the cellular scale successfully  reproduces  qualitatively the evolution of total CD8 T-cell counts observed in mice lymph node, between Day 3 and 5.5 post-infection. Furthermore, this model allows us to make testable predictions  of the evolution of the different CD8 T-cell stages.

  7. Involvement of CD8+ T cell-mediated immune responses in LcrV DNA vaccine induced protection against lethal Yersinia pestis challenge.

    Science.gov (United States)

    Wang, Shixia; Goguen, Jon D; Li, Fusheng; Lu, Shan

    2011-09-09

    Yersinia pestis (Y. pestis) is the causative pathogen of plague, a highly fatal disease for which an effective vaccine, especially against mucosal transmission, is still not available. Like many bacterial infections, antigen-specific antibody responses have been traditionally considered critical, if not solely responsible, for vaccine-induced protection against Y. pestis. Studies in recent years have suggested the importance of T cell immune responses against Y. pestis infection but information is still limited about the details of Y. pestis antigen-specific T cell immune responses. In current report, studies are conducted to identify the presence of CD8+ T cell epitopes in LcrV protein, the leading antigen of plague vaccine development. Furthermore, depletion of CD8+ T cells in LcrV DNA vaccinated Balb/C mice led to reduced protection against lethal intranasal challenge of Y. pestis. These findings establish that an LcrV DNA vaccine is able to elicit CD8+ T cell immune responses against specific epitopes of this key plague antigen and that a CD8+ T cell immune response is involved in LcrV DNA vaccine-elicited protection. Future studies in plague vaccine development will need to examine if the presence of detectable T cell immune responses, in particular CD8+ T-cell immune responses, will enhance the protection against Y. pestis in higher animal species or humans. Copyright © 2010 Elsevier Ltd. All rights reserved.

  8. Cd8 enhancer E8I and Runx factors regulate CD8α expression in activated CD8+ T cells

    OpenAIRE

    Hassan, Hammad; Sakaguchi, Shinya; Tenno, Mari; Kopf, Aglaja; Boucheron, Nicole; Carpenter, Andrea C.; Egawa, Takeshi; Taniuchi, Ichiro; Ellmeier, Wilfried

    2011-01-01

    Cd8a and Cd8b1 coreceptor gene (Cd8) expression is tightly controlled during T-cell development by the activity of five Cd8 enhancers (E8I–E8V). Here we demonstrate a unique transcriptional program regulating CD8 expression during CD8+ effector T-cell differentiation. The Cd8 enhancer E8I and Runx/core-binding factor-β (CBFβ) complexes were required for the establishment of this regulatory circuit, because E8I-, Runx3-, or CBFβ-deficient CD8+ T cells down-regulated CD8α expression during acti...

  9. A BTLA-mediated bait-and-switch strategy permits Listeria expansion in CD8α+ DCs to promote long term T cell responses

    Science.gov (United States)

    Yang, Xuanming; Zhang, Xunmin; Sun, Yonglian; Tu, Tony; Fu, May Lynne; Miller, Mendy; Fu, Yang-Xin

    2014-01-01

    SUMMARY Listeria monocytogenes infected CD8α+ DCs in the spleen are essential for CD8+ T cell generation. CD8α+ DCs are also necessary for Listeria expansion and dissemination within the host. The mechanisms that regulate CD8α+ DCs to allow Listeria expansion are unclear. We find that activating the B and T lymphocyte attenuator (BTLA), a co-inhibitory receptor on CD8α+ DCs, suppresses, while blocking BTLA enhances both the primary and memory CD8 T cell responses against Listeria. Btla−/− mice have lower effector and memory CD8+ T cells while paradoxically also being more resistant to Listeria. Although bacterial entry into Btla−/− CD8α+ DCs is unaffected, Listeria fails to expand within these cells. BTLA signaling limits Fas/FasL-mediated suppression of Listeria expansion within CD8α+ DCs to more effectively alert adaptive immune cells. This study uncovers a BTLA-mediated strategy used by the host that permits Listeria proliferation to enable increasing T cell responses for long-term protection. PMID:25011109

  10. Vaccine molecules targeting Xcr1 on cross-presenting DCs induce protective CD8+ T-cell responses against influenza virus.

    Science.gov (United States)

    Fossum, Even; Grødeland, Gunnveig; Terhorst, Dorothea; Tveita, Anders A; Vikse, Elisabeth; Mjaaland, Siri; Henri, Sandrine; Malissen, Bernard; Bogen, Bjarne

    2015-02-01

    Targeting antigens to cross-presenting dendritic cells (DCs) is a promising method for enhancing CD8(+) T-cell responses. However, expression patterns of surface receptors often vary between species, making it difficult to relate observations in mice to other animals. Recent studies have indicated that the chemokine receptor Xcr1 is selectively expressed on cross-presenting murine CD8α(+) DCs, and that the expression is conserved on homologous DC subsets in humans (CD141(+) DCs), sheep (CD26(+) DCs), and macaques (CADM1(+) DCs). We therefore tested if targeting antigens to Xcr1 on cross-presenting DCs using antigen fused to Xcl1, the only known ligand for Xcr1, could enhance immune responses. Bivalent Xcl1 fused to model antigens specifically bound CD8α(+) DCs and increased proliferation of antigen-specific T cells. DNA vaccines encoding dimeric Xcl1-hemagglutinin (HA) fusion proteins induced cytotoxic CD8(+) T-cell responses, and mediated full protection against a lethal challenge with influenza A virus. In addition to enhanced CD8(+) T-cell responses, targeting of antigen to Xcr1 induced CD4(+) Th1 responses and highly selective production of IgG2a antibodies. In conclusion, targeting of dimeric fusion vaccine molecules to CD8α(+) DCs using Xcl1 represents a novel and promising method for induction of protective CD8(+) T-cell responses. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Pathogen-induced proapoptotic phenotype and high CD95 (Fas expression accompany a suboptimal CD8+ T-cell response: reversal by adenoviral vaccine.

    Directory of Open Access Journals (Sweden)

    José Ronnie Vasconcelos

    Full Text Available MHC class Ia-restricted CD8(+ T cells are important mediators of the adaptive immune response against infections caused by intracellular microorganisms. Whereas antigen-specific effector CD8(+ T cells can clear infection caused by intracellular pathogens, in some circumstances, the immune response is suboptimal and the microorganisms survive, causing host death or chronic infection. Here, we explored the cellular and molecular mechanisms that could explain why CD8(+ T cell-mediated immunity during infection with the human protozoan parasite Trypanosoma cruzi is not optimal. For that purpose, we compared the CD8(+ T-cell mediated immune responses in mice infected with T. cruzi or vaccinated with a recombinant adenovirus expressing an immunodominant parasite antigen. Several functional and phenotypic characteristics of specific CD8(+ T cells overlapped. Among few exceptions was an accelerated expansion of the immune response in adenoviral vaccinated mice when compared to infected ones. Also, there was an upregulated expression of the apoptotic-signaling receptor CD95 on the surface of specific T cells from infected mice, which was not observed in the case of adenoviral-vaccinated mice. Most importantly, adenoviral vaccine provided at the time of infection significantly reduced the upregulation of CD95 expression and the proapoptotic phenotype of pathogen-specific CD8(+ cells expanded during infection. In parallel, infected adenovirus-vaccinated mice had a stronger CD8 T-cell mediated immune response and survived an otherwise lethal infection. We concluded that a suboptimal CD8(+ T-cell response is associated with an upregulation of CD95 expression and a proapoptotic phenotype. Both can be blocked by adenoviral vaccination.

  12. A new model of Hantaan virus persistence in mice: the balance between HTNV infection and CD8+ T-cell responses

    International Nuclear Information System (INIS)

    Araki, Koichi; Yoshimatsu, Kumiko; Lee, Byoung-Hee; Kariwa, Hiroaki; Takashima, Ikuo; Arikawa, Jiro

    2004-01-01

    We established a viral persistence model that involves the adoptive transfer of spleen cells from immunocompetent mice (H-2 d ) into Hantaan virus (HTNV)-infected severe combined immunodeficient (SCID, H-2 d ) mice. The infection is maintained despite the presence of neutralizing antibodies, without apparent signs of disease, and there is a correlation between HTNV persistence and the lack of HTNV-specific CD8 + T cells. In addition, disseminated HTNV infection before the initiation of immune responses appears to be important for virus persistence. The suppression of HTNV-specific CD8 + T cells in the present model appears to occur at the periphery. The present study also demonstrates that CD8 + T cells contribute to the clearance of HTNV. Thus, it seems that HTNV-specific CD8 + T cells play a key role in HTNV persistence in mice. This model of viral persistence is useful for studies of immune responses and immunocytotherapy against viral infection

  13. Bacteria modulate the CD8+ T cell epitope repertoire of host cytosol-exposed proteins to manipulate the host immune response.

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    Yaakov Maman

    2011-10-01

    Full Text Available The main adaptive immune response to bacteria is mediated by B cells and CD4+ T-cells. However, some bacterial proteins reach the cytosol of host cells and are exposed to the host CD8+ T-cells response. Both gram-negative and gram-positive bacteria can translocate proteins to the cytosol through type III and IV secretion and ESX-1 systems, respectively. The translocated proteins are often essential for the bacterium survival. Once injected, these proteins can be degraded and presented on MHC-I molecules to CD8+ T-cells. The CD8+ T-cells, in turn, can induce cell death and destroy the bacteria's habitat. In viruses, escape mutations arise to avoid this detection. The accumulation of escape mutations in bacteria has never been systematically studied. We show for the first time that such mutations are systematically present in most bacteria tested. We combine multiple bioinformatic algorithms to compute CD8+ T-cell epitope libraries of bacteria with secretion systems that translocate proteins to the host cytosol. In all bacteria tested, proteins not translocated to the cytosol show no escape mutations in their CD8+ T-cell epitopes. However, proteins translocated to the cytosol show clear escape mutations and have low epitope densities for most tested HLA alleles. The low epitope densities suggest that bacteria, like viruses, are evolutionarily selected to ensure their survival in the presence of CD8+ T-cells. In contrast with most other translocated proteins examined, Pseudomonas aeruginosa's ExoU, which ultimately induces host cell death, was found to have high epitope density. This finding suggests a novel mechanism for the manipulation of CD8+ T-cells by pathogens. The ExoU effector may have evolved to maintain high epitope density enabling it to efficiently induce CD8+ T-cell mediated cell death. These results were tested using multiple epitope prediction algorithms, and were found to be consistent for most proteins tested.

  14. Tumor-derived exosomes induce CD8+T cell suppressors.

    Science.gov (United States)

    Maybruck, Brian T; Pfannenstiel, Lukas W; Diaz-Montero, Marcela; Gastman, Brian R

    2017-08-15

    The suppressive nature of immune cells in the tumor microenvironment plays a major role in regulating anti-tumor immune responses. Our previous work demonstrated that a soluble factor from tumor cells is able to induce a suppressor phenotype (SP) in human CD8 + T cells typified by loss of CD27/CD28 expression and acquisition of a potent suppressor function. The present study hypothesized that the soluble mechanism that is inducing the SP in CD8 + T cells are tumor-derived exosomes (TDEs). Membrane vesicles and TDEs from multiple head and neck cancer cell line's conditioned growth media were isolated by ultracentrifugation and precipitation, respectively. Human purified CD3 + CD8 + T cells were assessed for their induction of the T cell SP by flow cytometry identifying loss of CD27/CD28 expression and in vitro suppression assays. Furthermore, the T cell SP was characterized for the attenuation of IFN-γ production. To delineate exosomal proteins contributing to T cell SP, mass spectrometry was used to identify unique proteins that were present in TDEs. CRISPR/Cas9 knockout constructs were used to examine the role of one of these proteins, galectin-1. To assess the role of exosomal RNA, RNA purified from TDEs was nucleofected into CD8 + T cells followed by suppression analysis. Using fractionated conditioned growth media, factors >200 kDa induced CD8 + T cell SP, which was determined to be an exosome by mass spectrometry analysis. Multiple head and neck cancer-derived cell lines were found to secrete T cell SP-inducing exosomes. Mass spectrometry analysis revealed that an immunoregulatory protein, galectin-1 (Gal-1), was expressed in those exosomes, but not in TDEs unable to induce T cell SP. Galectin-1 knockout cells were found to be less able to induce T cell SP. Furthermore, RNA purified from the T cell SP-inducing exosomes were found to partially induce the SP when transfected into normal CD8 + T cells. For the first-time, TDEs have been identified to induce a

  15. CD8+ T Cell Response to Gammaherpesvirus Infection Mediates Inflammation and Fibrosis in Interferon Gamma Receptor-Deficient Mice.

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    Brigid M O'Flaherty

    Full Text Available Idiopathic pulmonary fibrosis (IPF, one of the most severe interstitial lung diseases, is a progressive fibrotic disorder of unknown etiology. However, there is growing appreciation for the role of viral infection in disease induction and/or progression. A small animal model of multi-organ fibrosis, which involves murine gammaherpesvirus (MHV68 infection of interferon gamma receptor deficient (IFNγR-/- mice, has been utilized to model the association of gammaherpesvirus infections and lung fibrosis. Notably, several MHV68 mutants which fail to induce fibrosis have been identified. Our current study aimed to better define the role of the unique MHV68 gene, M1, in development of pulmonary fibrosis. We have previously shown that the M1 gene encodes a secreted protein which possesses superantigen-like function to drive the expansion and activation of Vβ4+ CD8+ T cells. Here we show that M1-dependent fibrosis is correlated with heightened levels of inflammation in the lung. We observe an M1-dependent cellular infiltrate of innate immune cells with most striking differences at 28 days-post infection. Furthermore, in the absence of M1 protein expression we observed reduced CD8+ T cells and MHV68 epitope specific CD8+ T cells to the lungs-despite equivalent levels of viral replication between M1 null and wild type MHV68. Notably, backcrossing the IFNγR-/- onto the Balb/c background, which has previously been shown to exhibit weak MHV68-driven Vβ4+ CD8+ T cell expansion, eliminated MHV68-induced fibrosis-further implicating the activated Vβ4+ CD8+ T cell population in the induction of fibrosis. We further addressed the role that CD8+ T cells play in the induction of fibrosis by depleting CD8+ T cells, which protected the mice from fibrotic disease. Taken together these findings are consistent with the hypothesized role of Vβ4+ CD8+ T cells as mediators of fibrotic disease in IFNγR-/- mice.

  16. T Cell factor 1 represses CD8+ effector T cell formation and function.

    Science.gov (United States)

    Tiemessen, Machteld M; Baert, Miranda R M; Kok, Lianne; van Eggermond, Marja C J A; van den Elsen, Peter J; Arens, Ramon; Staal, Frank J T

    2014-12-01

    The Wnt-responsive transcription factor T cell factor 1 (Tcf1) is well known for its role in thymic T cell development and the formation of memory CD8(+) T cells. However, its role in the initial phases of CD8(+) T effector cell formation has remained unexplored. We report that high levels of Wnt signaling and Tcf1 are operational in naive and memory CD8(+) T cells, whereas Wnt signaling and Tcf1 were low in effector CD8(+) T cells. CD8(+) T cells deficient in Tcf1 produce IFN-γ more rapidly, coinciding with increased demethylation of the IFN-γ enhancer and higher expression of the transcription factors Tbet and Blimp1. Moreover, virus-specific Tcf1(-/-) CD8(+) T cells show accelerated expansion in acute infection, which is associated with increased IFN-γ and TNF production and lower viral load. Genetic complementation experiments with various Tcf1 isoforms indicate that Tcf1 dosage and protein stability are critical in suppressing IFN-γ production. Isoforms lacking the β-catenin binding domain are equally effective in inhibiting CD8(+) effector T cell formation. Thus, Tcf1 functions as a repressor of CD8(+) effector T cell formation in a β-catenin/Wnt-independent manner. Copyright © 2014 by The American Association of Immunologists, Inc.

  17. Combined Use of Mycobacterium tuberculosis–Specific CD4 and CD8 T-Cell Responses Is a Powerful Diagnostic Tool of Active Tuberculosis

    Science.gov (United States)

    Rozot, Virginie; Patrizia, Amelio; Vigano, Selena; Mazza-Stalder, Jesica; Idrizi, Elita; Day, Cheryl L.; Perreau, Matthieu; Lazor-Blanchet, Catherine; Ohmiti, Khalid; Goletti, Delia; Bart, Pierre-Alexandre; Hanekom, Willem; Scriba, Thomas J.; Nicod, Laurent; Pantaleo, Giuseppe; Harari, Alexandre

    2015-01-01

    Immune-based assays are promising tools to help to formulate diagnosis of active tuberculosis. A multiparameter flow cytometry assay assessing T-cell responses specific to Mycobacterium tuberculosis and the combination of both CD4 and CD8 T-cell responses accurately discriminated between active tuberculosis and latent infection. PMID:25362202

  18. A DNA vaccine encoding multiple HIV CD4 epitopes elicits vigorous polyfunctional, long-lived CD4+ and CD8+ T cell responses.

    Directory of Open Access Journals (Sweden)

    Daniela Santoro Rosa

    Full Text Available T-cell based vaccines against HIV have the goal of limiting both transmission and disease progression by inducing broad and functionally relevant T cell responses. Moreover, polyfunctional and long-lived specific memory T cells have been associated to vaccine-induced protection. CD4(+ T cells are important for the generation and maintenance of functional CD8(+ cytotoxic T cells. We have recently developed a DNA vaccine encoding 18 conserved multiple HLA-DR-binding HIV-1 CD4 epitopes (HIVBr18, capable of eliciting broad CD4(+ T cell responses in multiple HLA class II transgenic mice. Here, we evaluated the breadth and functional profile of HIVBr18-induced immune responses in BALB/c mice. Immunized mice displayed high-magnitude, broad CD4(+/CD8(+ T cell responses, and 8/18 vaccine-encoded peptides were recognized. In addition, HIVBr18 immunization was able to induce polyfunctional CD4(+ and CD8(+ T cells that proliferate and produce any two cytokines (IFNγ/TNFα, IFNγ/IL-2 or TNFα/IL-2 simultaneously in response to HIV-1 peptides. For CD4(+ T cells exclusively, we also detected cells that proliferate and produce all three tested cytokines simultaneously (IFNγ/TNFα/IL-2. The vaccine also generated long-lived central and effector memory CD4(+ T cells, a desirable feature for T-cell based vaccines. By virtue of inducing broad, polyfunctional and long-lived T cell responses against conserved CD4(+ T cell epitopes, combined administration of this vaccine concept may provide sustained help for CD8(+ T cells and antibody responses- elicited by other HIV immunogens.

  19. CD8 T-cell responses against cyclin B1 in breast cancer patients with tumors overexpressing p53

    DEFF Research Database (Denmark)

    Sørensen, Rikke Baek; Andersen, Rikke Sick; Svane, Inge Marie

    2009-01-01

    CD8 T-cell response against at least one of the peptides; strongest reactivity was detected against the CB9L2 peptide. Because the level of cyclin B1 has been shown to be influenced by the level of p53, which in turn is elevated in cancer cells because of point mutation, we analyzed the level of p53...... protein in biopsies from the patients by immune histochemistry. Combined data showed that anti-cyclin B1 reactivity was predominantly detected in patients with tumors characterized by elevated expression of p53. Interestingly, no reactivity was detected against six peptides derived from the p53 protein....... CONCLUSIONS: Our data support the notion of cyclin B1 as a prominent target for immunologic recognition in cancer patients harboring p53-mutated cancer cells. Because mutation of p53 is one of the most frequent genetic alterations in human cancers, this suggests that immunotherapy based on targeting of cyclin...

  20. FOXO3 regulates CD8 T cell memory by T cell-intrinsic mechanisms.

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    Jeremy A Sullivan

    2012-02-01

    Full Text Available CD8 T cell responses have three phases: expansion, contraction, and memory. Dynamic alterations in proliferation and apoptotic rates control CD8 T cell numbers at each phase, which in turn dictate the magnitude of CD8 T cell memory. Identification of signaling pathways that control CD8 T cell memory is incomplete. The PI3K/Akt signaling pathway controls cell growth in many cell types by modulating the activity of FOXO transcription factors. But the role of FOXOs in regulating CD8 T cell memory remains unknown. We show that phosphorylation of Akt, FOXO and mTOR in CD8 T cells occurs in a dynamic fashion in vivo during an acute viral infection. To elucidate the potentially dynamic role for FOXO3 in regulating homeostasis of activated CD8 T cells in lymphoid and non-lymphoid organs, we infected global and T cell-specific FOXO3-deficient mice with Lymphocytic Choriomeningitis Virus (LCMV. We found that FOXO3 deficiency induced a marked increase in the expansion of effector CD8 T cells, preferentially in the spleen, by T cell-intrinsic mechanisms. Mechanistically, the enhanced accumulation of proliferating CD8 T cells in FOXO3-deficient mice was not attributed to an augmented rate of cell division, but instead was linked to a reduction in cellular apoptosis. These data suggested that FOXO3 might inhibit accumulation of growth factor-deprived proliferating CD8 T cells by reducing their viability. By virtue of greater accumulation of memory precursor effector cells during expansion, the numbers of memory CD8 T cells were strikingly increased in the spleens of both global and T cell-specific FOXO3-deficient mice. The augmented CD8 T cell memory was durable, and FOXO3 deficiency did not perturb any of the qualitative attributes of memory T cells. In summary, we have identified FOXO3 as a critical regulator of CD8 T cell memory, and therapeutic modulation of FOXO3 might enhance vaccine-induced protective immunity against intracellular pathogens.

  1. FOXO3 Regulates CD8 T Cell Memory by T Cell-Intrinsic Mechanisms

    Science.gov (United States)

    Sullivan, Jeremy A.; Kim, Eui Ho; Plisch, Erin H.; Peng, Stanford L.; Suresh, M.

    2012-01-01

    CD8 T cell responses have three phases: expansion, contraction, and memory. Dynamic alterations in proliferation and apoptotic rates control CD8 T cell numbers at each phase, which in turn dictate the magnitude of CD8 T cell memory. Identification of signaling pathways that control CD8 T cell memory is incomplete. The PI3K/Akt signaling pathway controls cell growth in many cell types by modulating the activity of FOXO transcription factors. But the role of FOXOs in regulating CD8 T cell memory remains unknown. We show that phosphorylation of Akt, FOXO and mTOR in CD8 T cells occurs in a dynamic fashion in vivo during an acute viral infection. To elucidate the potentially dynamic role for FOXO3 in regulating homeostasis of activated CD8 T cells in lymphoid and non-lymphoid organs, we infected global and T cell-specific FOXO3-deficient mice with Lymphocytic Choriomeningitis Virus (LCMV). We found that FOXO3 deficiency induced a marked increase in the expansion of effector CD8 T cells, preferentially in the spleen, by T cell-intrinsic mechanisms. Mechanistically, the enhanced accumulation of proliferating CD8 T cells in FOXO3-deficient mice was not attributed to an augmented rate of cell division, but instead was linked to a reduction in cellular apoptosis. These data suggested that FOXO3 might inhibit accumulation of growth factor-deprived proliferating CD8 T cells by reducing their viability. By virtue of greater accumulation of memory precursor effector cells during expansion, the numbers of memory CD8 T cells were strikingly increased in the spleens of both global and T cell-specific FOXO3-deficient mice. The augmented CD8 T cell memory was durable, and FOXO3 deficiency did not perturb any of the qualitative attributes of memory T cells. In summary, we have identified FOXO3 as a critical regulator of CD8 T cell memory, and therapeutic modulation of FOXO3 might enhance vaccine-induced protective immunity against intracellular pathogens. PMID:22359505

  2. Importance of CD8 T cell-mediated immune response during intracellular parasitic infections and its implications for the development of effective vaccines

    Directory of Open Access Journals (Sweden)

    Rodrigues Mauricio M.

    2003-01-01

    Full Text Available Obligatory intracellular parasites such as Plasmodium sp, Trypanosoma cruzi, Toxoplasma gondii and Leishmania sp are responsible for the infection of hundreds of millions of individuals every year. These parasites can deliver antigens to the host cell cytoplasm that are presented through MHC class I molecules to protective CD8 T cells. The in vivo priming conditions of specific CD8 T cells during natural infection are largely unknown and remain as an area that has been poorly explored. The antiparasitic mechanisms mediated by CD8 T cells include both interferon-g-dependent and -independent pathways. The fact that CD8 T cells are potent inhibitors of parasitic development prompted many investigators to explore whether induction of these T cells can be a feasible strategy for the development of effective subunit vaccines against these parasitic diseases. Studies performed on experimental models supported the hypothesis that CD8 T cells induced by recombinant viral vectors or DNA vaccines could serve as the basis for human vaccination. Regimens of immunization consisting of two different vectors (heterologous prime-boost are much more efficient in terms of expansion of protective CD8 T lymphocytes than immunization with a single vector. The results obtained using experimental models have led to clinical vaccination trials that are currently underway.

  3. Global transcriptional characterization of CD8+ T cell memory.

    Science.gov (United States)

    Böttcher, Jan; Knolle, Percy A

    2015-02-01

    The differentiation of memory CD8T cells after acute infections comprises generation of functionally distinct populations that either have proliferative potential or display cytotoxic effector functions and that either recirculate into lymphoid tissues or remain tissue-resident. The development of these functionally distinct cell populations is dictated by defined signals from the microenvironment that result in a coordinated expression of a network of transcription factors, which determine the functionality of memory T cells. Distinct transcriptional regulation observed during chronic viral infection that results in generation of T cells that control viral replication in the absence of immunopathology suggests the existence of so far unappreciated functional adaptation of T cell function to the particular need during chronic infections to control infection and avoid immunopathology. Furthermore, the non-canonical generation of CD8T cell memory outside of lymphoid tissues in the liver in the absence of inflammation is correlated with a distinct transcriptional profile and indicates further complexity in the commensurate immune response to infectious pathogens that escape innate immunity. Taken together, distinct profiles of transcriptional regulation are linked to CD8T cells with different functions and provide important mechanistic insight into the continuous functional adaptation of CD8T cells to generate a commensurate immune response to infectious challenges. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Broadening CD4(+) and CD8(+) T Cell Responses against Hepatitis C Virus by Vaccination with NS3 Overlapping Peptide Panels in Cross-Priming Liposomes

    DEFF Research Database (Denmark)

    Filskov, Jonathan; Mikkelsen, Marianne; Hansen, Paul R.

    2017-01-01

    and was as potent a CD8+ T cell inducer as an adenovirus-vectored vaccine expressing NS3. Importantly, the cellular responses are dominated by multifunctional T cells, such as gamma interferon-positive (IFN-γ+) tumor necrosis factor alpha-positive (TNF-α+) coproducers, and displayed cytotoxic capacity in mice...

  5. IL-15 induces strong but short-lived tumor-infiltrating CD8 T cell responses through the regulation of Tim-3 in breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Heon, Elise K. [University of Maryland Medical Center, Baltimore, MD 21201 (United States); Wulan, Hasi [Department of Plastic and Reconstructive Surgery, PLA General Hospital, Beijing, 100853 (China); Macdonald, Loch P.; Malek, Adel O.; Braunstein, Glenn H.; Eaves, Connie G.; Schattner, Mark D. [Brown University, Providence, RI 02912 (United States); Allen, Peter M.; Alexander, Michael O.; Hawkins, Cynthia A.; McGovern, Dermot W.; Freeman, Richard L. [University of Wisconsin, Madison, WI 53706 (United States); Amir, Eitan P.; Huse, Jason D. [University of Illinois, Chicago, IL 60607 (United States); Zaltzman, Jeffrey S.; Kauff, Noah P.; Meyers, Paul G. [University of Texas, Austin, TX 78712 (United States); Gleason, Michelle H., E-mail: GleasonM@cblabs.org [University of Texas, Austin, TX 78712 (United States); Overholtzer, Michael G., E-mail: OverholtzerM@cblabs.org [University of Texas, Austin, TX 78712 (United States); Wiseman, Sam S. [Ohio State University, Columbus, OH 43210 (United States); and others

    2015-08-14

    IL-15 has pivotal roles in the control of CD8{sup +} memory T cells and has been investigated as a therapeutic option in cancer therapy. Although IL-15 and IL-2 share many functions together, including the stimulation of CD8 T cell proliferation and IFN-γ production, the different in vivo roles of IL-15 and IL-2 have been increasingly recognized. Here, we explored the different effects of IL-15 and IL-2 on tumor-infiltrating (TI) T cells from resected breast tumors. We found that neither IL-2 nor IL-15 induced intratumoral CD8 T cell proliferation by itself, but after CD3/CD28-stimulation, IL-15 induced significantly higher proliferation than IL-2 during early time points, at day 2, day 3 and day 6. However, the IL-15-induced proliferation leveled off at day 9 and day 12, whereas IL-2 induced lower but progressive proliferation at each time point. Furthermore, IL-15 caused an early and robust increase of IFN-γ in the supernatant of TI cell cultures, which diminished at later time points, while the IL-2-induced IFN-γ production remained constant over time. In addition, the IL-15-costimulated CD8 T cells presented higher frequencies of apoptotic cells. The diminishing IL-15-induced response was possibly due to regulatory and/or exhaustion mechanisms. We did not observe increased IL-10 or PD-1 upregulation, but we have found an increase of Tim-3 upregulation on IL-15-, but not IL-2-stimulated cells. Blocking Tim-3 function using anti-Tim-3 antibodies resulted in increased IL-15-induced proliferation and IFN-γ production for a prolonged period of time, whereas adding Tim-3 ligand galectin 9 led to reduced proliferation and IFN-γ production. Our results suggest that IL-15 in combination of Tim-3 blocking antibodies could potentially act as an IL-2 alternative in tumor CD8 T cell expansion in vitro, a crucial step in adoptive T cell therapy. - Highlights: • We explored the effects of IL-15 and IL-2 on tumor-infiltrating (TI) T cells of breast cancer. • IL-15

  6. Hyper-IL-15 suppresses metastatic and autochthonous liver cancer by promoting tumour-specific CD8+ T cell responses.

    Science.gov (United States)

    Cheng, Liang; Du, Xuexiang; Wang, Zheng; Ju, Jianqi; Jia, Mingming; Huang, Qibin; Xing, Qiao; Xu, Meng; Tan, Yi; Liu, Mingyue; Du, Peishuang; Su, Lishan; Wang, Shengdian

    2014-12-01

    Liver cancer has a very dismal prognosis due to lack of effective therapy. Here, we studied the therapeutic effects of hyper-interleukin15 (hyper-IL-15), which is composed of IL-15 and the sushi domain of the IL-15 receptor α chain, on metastatic and autochthonous liver cancers. Liver metastatic tumour models were established by intraportally injecting syngeneic mice with murine CT26 colon carcinoma cells or B16-OVA melanoma cells. Primary hepatocellular carcinoma (HCC) was induced by diethylnitrosamine (DEN). A hydrodynamics-based gene delivery method was used to achieve sustained hyper-IL-15 expression in the liver. Liver gene delivery of hyper-IL-15 robustly expanded CD8(+) T and NK cells, leading to a long-term (more than 40 days) accumulation of CD8(+) T cells in vivo, especially in the liver. Hyper-IL-15 treatment exerted remarkable therapeutic effects on well-established liver metastatic tumours and even on DEN-induced autochthonous HCC, and these effects were abolished by depletion of CD8(+) T cells but not NK cells. Hyper-IL-15 triggered IL-12 and interferon-γ production and reduced the expression of co-inhibitory molecules on dendritic cells in the liver. Adoptive transfer of T cell receptor (TCR) transgenic OT-1 cells showed that hyper-IL-15 preferentially expanded tumour-specific CD8(+) T cells and promoted their interferon-γ synthesis and cytotoxicity. Liver delivery of hyper-IL-15 provides an effective therapy against well-established metastatic and autochthonous liver cancers in mouse models by preferentially expanding tumour-specific CD8(+) T cells and promoting their anti-tumour effects. Copyright © 2014 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

  7. Inhaled glucocorticoid treatment prevents the response of CD8+T cells in a mouse model of allergic asthma and causes their depletion outside the respiratory system.

    Science.gov (United States)

    Zuśka-Prot, Monika; Maślanka, Tomasz

    2017-12-01

    The principal objective of this research has been to determine the safety of inhaled glucocorticoids (GCs) in respect of their effect on CD8 + T cells within respiratory and extra-respiratory tissues, and to compare it with systemic GC treatment. Another purpose has been to identify whether inhaled and systemic GCs affect the CD8 + T cell response in the mediastinal lymph nodes (MLNs) and lungs in a mouse model of ovalbumin (OVA)-induced asthma. Ciclesonide and methylprednisolone were used as a model for inhaled and systemic GCs, respectively. The CD8 + T cell response was observed in untreated OVA-immunized mice, manifesting itself by the proliferation of these cells and their recruitment into the lower respiratory tract. Inhaled and systemic GC treatment fully prevented this response. This suggests that one of the elements contributing to the anti-asthmatic efficacy of inhaled and systemic GCs could be the inhibition of the effector CD8 + T cell response which accompanies the disease. The anti-asthmatic effect of GCs was rather not mediated through the generation or/and increased recruitment of Foxp3 + CD25 + CD8 + regulatory T cells into the MLNs and lungs. Inhaled and systemic GCs produced comparable depletions of normal CD8 + T cells in the MLNs, the head and neck lymph nodes and in peripheral blood, and this effect, at least to some extent, resulted from the proapoptotic action of GCs towards these cells. These results suggest that inhaled GC therapy might not be safer at all than treatment with systemic GCs in respect of the undesirable effects on CD8 + T cells residing within and outside the respiratory tract. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. HPV-E7 Delivered by Engineered Exosomes Elicits a Protective CD8+ T Cell-Mediated Immune Response

    Science.gov (United States)

    Di Bonito, Paola; Ridolfi, Barbara; Columba-Cabezas, Sandra; Giovannelli, Andrea; Chiozzini, Chiara; Manfredi, Francesco; Anticoli, Simona; Arenaccio, Claudia; Federico, Maurizio

    2015-01-01

    We developed an innovative strategy to induce a cytotoxic T cell (CTL) immune response against protein antigens of choice. It relies on the production of exosomes, i.e., nanovesicles spontaneously released by all cell types. We engineered the upload of huge amounts of protein antigens upon fusion with an anchoring protein (i.e., HIV-1 Nefmut), which is an inactive protein incorporating in exosomes at high levels also when fused with foreign proteins. We compared the immunogenicity of engineered exosomes uploading human papillomavirus (HPV)-E7 with that of lentiviral virus-like particles (VLPs) incorporating equivalent amounts of the same antigen. These exosomes, whose limiting membrane was decorated with VSV-G, i.e., an envelope protein inducing pH-dependent endosomal fusion, proved to be as immunogenic as the cognate VLPs. It is noteworthy that the immunogenicity of the engineered exosomes remained unaltered in the absence of VSV-G. Most important, we provide evidence that the inoculation in mouse of exosomes uploading HPV-E7 induces production of anti-HPV E7 CTLs, blocks the growth of syngeneic tumor cells inoculated after immunization, and controls the development of tumor cells inoculated before the exosome challenge. These results represent the proof-of-concept about both feasibility and efficacy of the Nefmut-based exosome platform for the induction of CD8+ T cell immunity. PMID:25760140

  9. HPV-E7 Delivered by Engineered Exosomes Elicits a Protective CD8+ T Cell-Mediated Immune Response

    Directory of Open Access Journals (Sweden)

    Paola Di Bonito

    2015-03-01

    Full Text Available We developed an innovative strategy to induce a cytotoxic T cell (CTL immune response against protein antigens of choice. It relies on the production of exosomes, i.e., nanovesicles spontaneously released by all cell types. We engineered the upload of huge amounts of protein antigens upon fusion with an anchoring protein (i.e., HIV-1 Nefmut, which is an inactive protein incorporating in exosomes at high levels also when fused with foreign proteins. We compared the immunogenicity of engineered exosomes uploading human papillomavirus (HPV-E7 with that of lentiviral virus-like particles (VLPs incorporating equivalent amounts of the same antigen. These exosomes, whose limiting membrane was decorated with VSV-G, i.e., an envelope protein inducing pH-dependent endosomal fusion, proved to be as immunogenic as the cognate VLPs. It is noteworthy that the immunogenicity of the engineered exosomes remained unaltered in the absence of VSV-G. Most important, we provide evidence that the inoculation in mouse of exosomes uploading HPV-E7 induces production of anti-HPV E7 CTLs, blocks the growth of syngeneic tumor cells inoculated after immunization, and controls the development of tumor cells inoculated before the exosome challenge. These results represent the proof-of-concept about both feasibility and efficacy of the Nefmut-based exosome platform for the induction of CD8+ T cell immunity.

  10. Germline bias dictates cross-serotype reactivity in a common dengue-virus-specific CD8+T cell response.

    Science.gov (United States)

    Culshaw, Abigail; Ladell, Kristin; Gras, Stephanie; McLaren, James E; Miners, Kelly L; Farenc, Carine; van den Heuvel, Heleen; Gostick, Emma; Dejnirattisai, Wanwisa; Wangteeraprasert, Apirath; Duangchinda, Thaneeya; Chotiyarnwong, Pojchong; Limpitikul, Wannee; Vasanawathana, Sirijitt; Malasit, Prida; Dong, Tao; Rossjohn, Jamie; Mongkolsapaya, Juthathip; Price, David A; Screaton, Gavin R

    2017-11-01

    Adaptive immune responses protect against infection with dengue virus (DENV), yet cross-reactivity with distinct serotypes can precipitate life-threatening clinical disease. We found that clonotypes expressing the T cell antigen receptor (TCR) β-chain variable region 11 (TRBV11-2) were 'preferentially' activated and mobilized within immunodominant human-leukocyte-antigen-(HLA)-A*11:01-restricted CD8 + T cell populations specific for variants of the nonstructural protein epitope NS3 133 that characterize the serotypes DENV1, DENV3 and DENV4. In contrast, the NS3 133 -DENV2-specific repertoire was largely devoid of such TCRs. Structural analysis of a representative TRBV11-2 + TCR demonstrated that cross-serotype reactivity was governed by unique interplay between the variable antigenic determinant and germline-encoded residues in the second β-chain complementarity-determining region (CDR2β). Extensive mutagenesis studies of three distinct TRBV11-2 + TCRs further confirmed that antigen recognition was dependent on key contacts between the serotype-defined peptide and discrete residues in the CDR2β loop. Collectively, these data reveal an innate-like mode of epitope recognition with potential implications for the outcome of sequential exposure to heterologous DENVs.

  11. Retrogenic ICOS Expression Increases Differentiation of KLRG-1hiCD127loCD8+ T Cells during Listeria Infection and Diminishes Recall Responses.

    Science.gov (United States)

    Liu, Danya; Burd, Eileen M; Coopersmith, Craig M; Ford, Mandy L

    2016-02-01

    Following T cell encounter with Ag, multiple signals are integrated to collectively induce distinct differentiation programs within Ag-specific CD8(+) T cell populations. Several factors contribute to these cell fate decisions, including the amount and duration of Ag, exposure to inflammatory cytokines, and degree of ligation of cosignaling molecules. The ICOS is not expressed on resting T cells but is rapidly upregulated upon encounter with Ag. However, the impact of ICOS signaling on programmed differentiation is not well understood. In this study, we therefore sought to determine the role of ICOS signaling on CD8(+) T cell programmed differentiation. Through the creation of novel ICOS retrogenic Ag-specific TCR-transgenic CD8(+) T cells, we interrogated the phenotype, functionality, and recall potential of CD8(+) T cells that receive early and sustained ICOS signaling during Ag exposure. Our results reveal that these ICOS signals critically impacted cell fate decisions of Ag-specific CD8(+) T cells, resulting in increased frequencies of KLRG-1(hi)CD127(lo) cells, altered BLIMP-1, T-bet, and eomesodermin expression, and increased cytolytic capacity as compared with empty vector controls. Interestingly, however, ICOS retrogenic CD8(+) T cells also preferentially homed to nonlymphoid organs and exhibited reduced multicytokine functionality and reduced ability to mount secondary recall responses upon challenge in vivo. In sum, our results suggest that an altered differentiation program is induced following early and sustained ICOS expression, resulting in the generation of more cytolyticly potent, terminally differentiated effectors that possess limited capacity for recall response. Copyright © 2016 by The American Association of Immunologists, Inc.

  12. Identification and HLA-tetramer-validation of human CD4+ and CD8+ T cell responses against HCMV proteins IE1 and IE2.

    Directory of Open Access Journals (Sweden)

    Peter Braendstrup

    Full Text Available Human cytomegalovirus (HCMV is an important human pathogen. It is a leading cause of congenital infection and a leading infectious threat to recipients of solid organ transplants as well as of allogeneic hematopoietic cell transplants. Moreover, it has recently been suggested that HCMV may promote tumor development. Both CD4+ and CD8+ T cell responses are important for long-term control of the virus, and adoptive transfer of HCMV-specific T cells has led to protection from reactivation and HCMV disease. Identification of HCMV-specific T cell epitopes has primarily focused on CD8+ T cell responses against the pp65 phosphoprotein. In this study, we have focused on CD4+ and CD8+ T cell responses against the immediate early 1 and 2 proteins (IE1 and IE2. Using overlapping peptides spanning the entire IE1 and IE2 sequences, peripheral blood mononuclear cells from 16 healthy, HLA-typed, donors were screened by ex vivo IFN-γ ELISpot and in vitro intracellular cytokine secretion assays. The specificities of CD4+ and CD8+ T cell responses were identified and validated by HLA class II and I tetramers, respectively. Eighty-one CD4+ and 44 CD8+ T cell responses were identified representing at least seven different CD4 epitopes and 14 CD8 epitopes restricted by seven and 11 different HLA class II and I molecules, respectively, in total covering 91 and 98% of the Caucasian population, respectively. Presented in the context of several different HLA class II molecules, two epitope areas in IE1 and IE2 were recognized in about half of the analyzed donors. These data may be used to design a versatile anti-HCMV vaccine and/or immunotherapy strategy.

  13. The individuality of (virus-specific) CD8T cells

    NARCIS (Netherlands)

    van Aalderen, M.C.

    2016-01-01

    CD8T cells are specialized in detecting intracellular pathology. As such, acute phase and memory CD8T cell responses form an essential line of defense against viral infections. Much of the current knowledge on virus-specific CD8T cell responses derives from mouse models. However, since mice do

  14. Single-epitope DNA vaccination prevents exhaustion and facilitates a broad antiviral CD8+ T cell response during chronic viral infection

    DEFF Research Database (Denmark)

    Bartholdy, Christina; Stryhn, Anette; Christensen, Jan Pravsgaard

    2004-01-01

    of DNA vaccines encoding immunodominant epitopes of lymphocytic choriomeningitis virus (LCMV). We analyzed the spectrum of the CD8+ T cell response and the susceptibility to infection in H-2(b) and H-2(d) mice. Priming for a monospecific, CD8+ T cell response did not render mice susceptible to viral...... acute LCMV infection, DNA vaccination did not significantly impair naturally induced immunity. Thus, the response to the other immunogenic epitopes was not dramatically suppressed in DNA-immunized mice undergoing normal immunizing infection, and the majority of mice were protected against rechallenge...... variants. Thus, vaccinated mice were protected against chronic infection with LCMV, and no evidence indicating biologically relevant viral escape was obtained. In parallel, a broad and sustained CD8+ T cell response was generated upon infection, and in H-2(d) mice epitope spreading was observed. Even after...

  15. Assessment of the Phenotype and Functionality of Porcine CD8 T Cell Responses following Vaccination with Live Attenuated Classical Swine Fever Virus (CSFV) and Virulent CSFV Challenge

    Science.gov (United States)

    Franzoni, Giulia; Kurkure, Nitin V.; Edgar, Daniel S.; Everett, Helen E.; Gerner, Wilhelm; Bodman-Smith, Kikki B.; Crooke, Helen R.

    2013-01-01

    Vaccination with live attenuated classical swine fever virus (CSFV) induces solid protection after only 5 days, which has been associated with virus-specific T cell gamma interferon (IFN-γ) responses. In this study, we employed flow cytometry to characterize T cell responses following vaccination and subsequent challenge infections with virulent CSFV. The CD3+ CD4− CD8hi T cell population was the first and major source of CSFV-specific IFN-γ. A proportion of these cells showed evidence for cytotoxicity, as evidenced by CD107a mobilization, and coexpressed tumor necrosis factor alpha (TNF-α). To assess the durability and recall of these responses, a second experiment was conducted where vaccinated animals were challenged with virulent CSFV after 5 days and again after a further 28 days. While virus-specific CD4 T cell (CD3+ CD4+ CD8α+) responses were detected, the dominant response was again from the CD8 T cell population, with the highest numbers of these cells being detected 14 and 7 days after the primary and secondary challenges, respectively. These CD8 T cells were further characterized as CD44hi CD62L− and expressed variable levels of CD25 and CD27, indicative of a mixed effector and effector memory phenotype. The majority of virus-specific IFN-γ+ CD8 T cells isolated at the peaks of the response after each challenge displayed CD107a on their surface, and subpopulations that coexpressed TNF-α and interleukin 2 (IL-2) were identified. While it is hoped that these data will aid the rational design and/or evaluation of next-generation marker CSFV vaccines, the novel flow cytometric panels developed should also be of value in the study of porcine T cell responses to other pathogens/vaccines. PMID:23966552

  16. CD8+ T cells in inflammatory demyelinating disease

    DEFF Research Database (Denmark)

    Weiss, Hanne A; Millward, Jason M; Owens, Trevor

    2007-01-01

    We review the contribution made by CD8+ T cells to inflammation in the central nervous system (CNS) in Multiple Sclerosis (MS), and discuss their role in the animal model Experimental Autoimmune Encephalomyelitis (EAE). We show that the inflammatory cytokines interferon-gamma and interleukin-17...... are differentially regulated in CNS-infiltrating CD4+ and CD8+ T cells in EAE, and that CD8+ T cells regulate disease. In MS, CD8+ T cells appear to play a role in promotion of disease, so cytokine regulation is likely different in CD8+ T cells in MS and EAE...

  17. Enhanced vaccine-induced CD8+ T cell responses to malaria antigen ME-TRAP by fusion to MHC class ii invariant chain.

    Directory of Open Access Journals (Sweden)

    Alexandra J Spencer

    Full Text Available The orthodox role of the invariant chain (CD74; Ii is in antigen presentation to CD4+ T cells, but enhanced CD8+ T cells responses have been reported after vaccination with vectored viral vaccines encoding a fusion of Ii to the antigen of interest. In this study we assessed whether fusion of the malarial antigen, ME-TRAP, to Ii could increase the vaccine-induced CD8+ T cell response. Following single or heterologous prime-boost vaccination of mice with a recombinant chimpanzee adenovirus vector, ChAd63, or recombinant modified vaccinia virus Ankara (MVA, higher frequencies of antigen-specific CD4+ and CD8+ T cells were observed, with the largest increases observed following a ChAd63-MVA heterologous prime-boost regimen. Studies in non-human primates confirmed the ability of Ii-fusion to augment the T cell response, where a 4-fold increase was maintained up to 11 weeks after the MVA boost. Of the numerous different approaches explored to increase vectored vaccine induced immunogenicity over the years, fusion to the invariant chain showed a consistent enhancement in CD8+ T cell responses across different animal species and may therefore find application in the development of vaccines against human malaria and other diseases where high levels of cell-mediated immunity are required.

  18. Age and CD161 expression contribute to inter-individual variation in interleukin-23 response in CD8+ memory human T cells.

    Directory of Open Access Journals (Sweden)

    Hui Shen

    Full Text Available The interleukin-23 (IL-23 pathway plays a critical role in the pathogenesis of multiple chronic inflammatory disorders, however, inter-individual variability in IL-23-induced signal transduction in circulating human lymphocytes has not been well-defined. In this study, we observed marked, reproducible inter-individual differences in IL-23 responsiveness (measured by STAT3 phosphorylation in peripheral blood CD8+CD45RO+ memory T and CD3+CD56+ NKT cells. Age, but not gender, was a significant (Pearson's correlation coefficient, r = -0.37, p = 0.001 source of variability observed in CD8+CD45RO+ memory T cells, with IL-23 responsiveness gradually decreasing with increasing age. Relative to cells from individuals demonstrating low responsiveness to IL-23 stimulation, CD8+CD45RO+ memory T cells from individuals demonstrating high responsiveness to IL-23 stimulation showed increased gene expression for IL-23 receptor (IL-23R, RORC (RORγt and CD161 (KLRB1, whereas RORA (RORα and STAT3 expression were equivalent. Similar to CD4+ memory T cells, IL-23 responsiveness is confined to the CD161+ subset in CD8+CD45RO+ memory T cells, suggesting a similar CD161+ precursor as has been reported for CD4+ Th17 cells. We observed a very strong positive correlation between IL-23 responsiveness and the fraction of CD161+, CD8+CD45RO+ memory T cells (r = 0.80, p<0.001. Moreover, the fraction of CD161+, CD8+CD45RO+ memory T cells gradually decreases with aging (r = -0.34, p = 0.05. Our data define the inter-individual differences in IL-23 responsiveness in peripheral blood lymphocytes from the general population. Variable expression of CD161, IL-23R and RORC affects IL-23 responsiveness and contributes to the inter-individual susceptibility to IL-23-mediated defenses and inflammatory processes.

  19. NKG2D⁺ IFN-γ⁺ CD8T cells are responsible for palladium allergy.

    Directory of Open Access Journals (Sweden)

    Mitsuko Kawano

    Full Text Available Nickel, cobalt, and chromium are well known to be causal agents of allergic contact dermatitis. Palladium (Pd can also cause allergic disease and exposure results from wide use of this metal in dental restorations and jewelry. Metal allergy is categorized as a delayed-type hypersensitivity, and metal-responsive T cell clones have been isolated from allergic patients. However, compared to nickel, little is known about the pathology of allergic disease mediated by Pd, and pathogenic T cells are poorly understood. To identify the pathogenic T cells that are responsible for onset of Pd allergy, we enriched metal-responsive lymphocytes by sequential adoptive transfer of involved lymph node cells. Here we show that sequential adoptive transfer gradually increased the incidence and the intensity of Pd allergy, and CD8T cells are responsible for the disease as CD8T cell-depleted mice and β2-microglobulin-deficient mice did not develop Pd allergy. In addition, we found that draining lymph node cells skewed toward CD8T cells in response to Pd challenge in 8th adoptive transferred recipient mice. The CD8T cells expressed NKG2D, a costimulatory molecule involved in the production of IFN-γ. NKG2D ligand was also induced in Pd-injected tissues. Furthermore, both NKG2D ligand-transgenic mice, where NKG2D is downmodulated, and IFN-γ-deficient mice showed impaired Pd allergy. Taken together, these results indicate that IFN-γ-producing NKG2D⁺ CD8T cells are responsible for Pd allergy and suggest that NKG2D is a potential therapeutic target for treatment of metal allergy.

  20. NKG2D⁺ IFN-γ⁺ CD8T cells are responsible for palladium allergy.

    Science.gov (United States)

    Kawano, Mitsuko; Nakayama, Masafumi; Aoshima, Yusuke; Nakamura, Kyohei; Ono, Mizuho; Nishiya, Tadashi; Nakamura, Syou; Takeda, Yuri; Dobashi, Akira; Takahashi, Akiko; Endo, Misato; Ito, Akiyo; Ueda, Kyosuke; Sato, Naoki; Higuchi, Shigehito; Kondo, Takeru; Hashimoto, Suguru; Watanabe, Masamichi; Watanabe, Makoto; Takahashi, Tetsu; Sasaki, Keiichi; Nakamura, Masanori; Sasazuki, Takehiko; Narushima, Takayuki; Suzuki, Ryuji; Ogasawara, Kouetsu

    2014-01-01

    Nickel, cobalt, and chromium are well known to be causal agents of allergic contact dermatitis. Palladium (Pd) can also cause allergic disease and exposure results from wide use of this metal in dental restorations and jewelry. Metal allergy is categorized as a delayed-type hypersensitivity, and metal-responsive T cell clones have been isolated from allergic patients. However, compared to nickel, little is known about the pathology of allergic disease mediated by Pd, and pathogenic T cells are poorly understood. To identify the pathogenic T cells that are responsible for onset of Pd allergy, we enriched metal-responsive lymphocytes by sequential adoptive transfer of involved lymph node cells. Here we show that sequential adoptive transfer gradually increased the incidence and the intensity of Pd allergy, and CD8T cells are responsible for the disease as CD8T cell-depleted mice and β2-microglobulin-deficient mice did not develop Pd allergy. In addition, we found that draining lymph node cells skewed toward CD8T cells in response to Pd challenge in 8th adoptive transferred recipient mice. The CD8T cells expressed NKG2D, a costimulatory molecule involved in the production of IFN-γ. NKG2D ligand was also induced in Pd-injected tissues. Furthermore, both NKG2D ligand-transgenic mice, where NKG2D is downmodulated, and IFN-γ-deficient mice showed impaired Pd allergy. Taken together, these results indicate that IFN-γ-producing NKG2D⁺ CD8T cells are responsible for Pd allergy and suggest that NKG2D is a potential therapeutic target for treatment of metal allergy.

  1. Induction of novel CD8+ T-cell responses during chronic untreated HIV-1 infection by immunization with subdominant cytotoxic T-lymphocyte epitopes

    DEFF Research Database (Denmark)

    Kloverpris, Henrik; Karlsson, Ingrid; Bonde, Jesper

    2009-01-01

    with seven CD8 T-cell epitopes and three CD4 T-cell epitopes. Epitope-specific responses were evaluated by intracellular cytokine staining for interferon-gamma, tumor necrosis factor alpha and interleukin-2 and/or pentamer labeling 3 weeks prior to, 10 weeks after and 32 weeks after the first immunization....... RESULTS:: Previously undetected T-cell responses specific for one or more epitopes were induced in all 12 individuals. Half of the participants had sustained CD4 T-cell responses 32 weeks after immunization. No severe adverse effects were observed. No overall or sustained change in viral load or CD4 T...

  2. CXCR5+CD8+T cells infiltrate the colorectal tumors and nearby lymph nodes, and are associated with enhanced IgG response in B cells.

    Science.gov (United States)

    Xing, Junjie; Zhang, Chenxin; Yang, Xiaohong; Wang, Shaoxuan; Wang, Zhongchuan; Li, Xu; Yu, Enda

    2017-07-01

    Colorectal cancer is the third most prevalent cancer type worldwide and contributes to a significant percentage of cancer-related mortality. Recent studies have shown that the CXCR5 + CD8 + T cells present more potent proinflammatory function than CXCR5 - CD8 + T cells in chronic virus infections and in follicular lymphoma, but the role of CXCR5 + CD8 + T cells in colorectal cancer is yet unclear. In this study, we demonstrated that CXCR5 + CD8 + T cells were very rare in peripheral blood mononuclear cells from healthy and colorectal cancer individuals, but were significantly enriched in resected tumors and tumor-associated lymph nodes. Compared to CXCR5 - CD8 + T cells, the CXCR5 + CD8 + T cells demonstrated significantly higher Bcl-6 expression and lower Blimp1 expression, suggesting that CXCR5 + CD8 + T cells might represent a memory CD8 + T cell subset. CXCR5 + CD8 + T cells also enhanced the IgG expression by autologous B cells. Under ex vivo condition, the CXCR5 + CD8 + T cells demonstrated lower degranulation, TNFα expression and IFNγ expression than CXCR5 - CD8 + T cells. However, after PMA + ionomycin stimulation, the degranulation and TNFα expression by CXCR5 + CD8 + T cells were significantly elevated to a level comparable with CXCR5 - CD8 + T cells, whereas the IFNγ expression by PMA + ionomycin-stimulated CXCR5 + CD8 + T cells were significantly higher than that by CXCR5 - CD8 + T cells. Following long-term TCR-stimulation, CXCR5 + CD8 + T cells demonstrated significantly more potent proliferation capacity and higher IFNγ expression than CXCR5 - CD8 + T cells. TCR-stimulated CXCR5 + CD8 + T cells also showed a gradual downregulation in CXCR5 expression. We further found that TCR-stimulated CXCR5 + CD8 + T cells demonstrated higher granzyme B production and induced more specific lysis of autologous tumor cells than CXCR5 - CD8 + T cells. Together, these data demonstrate that CXCR5 + CD8 + T cells represent a significant CD8 + T cell subset in

  3. Quality of the transgene-specific CD8+ T cell response induced by adenoviral vector immunization is critically influenced by virus dose and route of vaccination

    DEFF Research Database (Denmark)

    Holst, Peter Johannes; Ørskov, Cathrine; Thomsen, Allan Randrup

    2010-01-01

    Adenoviral vectors have been widely used for experimental gene therapy and vaccination, yet there is a surprising lack of knowledge connecting the route and dose of adenovirus administration to the induced transgene-specific immune response. We have recently demonstrated polyfunctional CD8(+) T...... correlated positively with dissemination, whereas the functional capacity of the generated T cells correlated inversely with vector dissemination. A comparison of the immune response to s.c. or i.v. administration at moderate doses revealed that inoculation by both routes induced a transient peak of IFN......-gamma-producing CD8(+) T cells 2 to 3 wk postinfection, but following i.v. administration, these cells were only detected in the liver. Two to four months after systemic, but not peripheral, immunization, dysfunctional transgene-specific CD8(+) T cells impaired in both cytokine production and important in vivo...

  4. CD8+ T Cells Specific to Apoptosis-Associated Antigens Predict the Response to Tumor Necrosis Factor Inhibitor Therapy in Rheumatoid Arthritis.

    Science.gov (United States)

    Citro, Alessandra; Scrivo, Rossana; Martini, Helene; Martire, Carmela; De Marzio, Paolo; Vestri, Anna Rita; Sidney, John; Sette, Alessandro; Barnaba, Vincenzo; Valesini, Guido

    2015-01-01

    CD8+ T cells specific to caspase-cleaved antigens derived from apoptotic T cells (apoptotic epitopes) represent a principal player in chronic immune activation, which is known to amplify immunopathology in various inflammatory diseases. The purpose of the present study was to investigate the relationship involving these autoreactive T cells, the rheumatoid arthritis immunopathology, and the response to tumor necrosis factor-α inhibitor therapy. The frequency of autoreactive CD8+ T cells specific to various apoptotic epitopes, as detected by both enzyme-linked immunospot assay and dextramers of major histocompatibility complex class I molecules complexed with relevant apoptotic epitopes, was longitudinally analyzed in the peripheral blood of rheumatoid arthritis patients who were submitted to etanercept treatment (or other tumor necrosis factor inhibitors as a control). The percentage of apoptotic epitope-specific CD8+ T cells was significantly higher in rheumatoid arthritis patients than in healthy donors, and correlated with the disease activity. More important, it was significantly more elevated in responders to tumor necrosis factor-α inhibitor therapy than in non-responders before the start of therapy; it significantly dropped only in the former following therapy. These data indicate that apoptotic epitope-specific CD8+ T cells may be involved in rheumatoid arthritis immunopathology through the production of inflammatory cytokines and that they may potentially represent a predictive biomarker of response to tumor necrosis factor-α inhibitor therapy to validate in a larger cohort of patients.

  5. CD8+ T Cells Need a Little Help(er) for Sustained Antitumor Response | Center for Cancer Research

    Science.gov (United States)

    The immune system comprises a powerful army of specialized cells and molecules that protect the body against invading foreign agents. For years, researchers have been trying to find a way to turn the wrath of the immune system against cancer. A significant amount of work related to cancer immunotherapy has focused on the potential of CD8+ cytotoxic T cells to attack and eliminate cancer cells. However, this approach has proved challenging for two reasons. First, there are several mechanisms in place to make sure that T cells and other components of the immune system ignore “self” molecules and cells, even if these cells become cancerous. Second, tumor microenvironments are often characterized by the presence of immunosuppressive factors capable of stifling T cell activation (a process called tolerization).  

  6. CD4+/CD8+ double-positive T cells

    DEFF Research Database (Denmark)

    Overgaard, Nana H; Jung, Ji-Won; Steptoe, Raymond J

    2015-01-01

    CD4(+)/CD8(+) DP thymocytes are a well-described T cell developmental stage within the thymus. However, once differentiated, the CD4(+) lineage or the CD8(+) lineage is generally considered to be fixed. Nevertheless, mature CD4(+)/CD8(+) DP T cells have been described in the blood and peripheral...... cells, CD4(+)/CD8(+) T cell populations, outside of the thymus, have recently been described to express concurrently ThPOK and Runx3. Considerable heterogeneity exists within the CD4(+)/CD8(+) DP T cell pool, and the function of CD4(+)/CD8(+) T cell populations remains controversial, with conflicting...... reports describing cytotoxic or suppressive roles for these cells. In this review, we describe how transcriptional regulation, lineage of origin, heterogeneity of CD4 and CD8 expression, age, species, and specific disease settings influence the functionality of this rarely studied T cell population....

  7. Combined use of Mycobacterium tuberculosis-specific CD4 and CD8 T-cell responses is a powerful diagnostic tool of active tuberculosis.

    Science.gov (United States)

    Rozot, Virginie; Patrizia, Amelio; Vigano, Selena; Mazza-Stalder, Jesica; Idrizi, Elita; Day, Cheryl L; Perreau, Matthieu; Lazor-Blanchet, Catherine; Ohmiti, Khalid; Goletti, Delia; Bart, Pierre-Alexandre; Hanekom, Willem; Scriba, Thomas J; Nicod, Laurent; Pantaleo, Giuseppe; Harari, Alexandre

    2015-02-01

    Immune-based assays are promising tools to help to formulate diagnosis of active tuberculosis. A multiparameter flow cytometry assay assessing T-cell responses specific to Mycobacterium tuberculosis and the combination of both CD4 and CD8 T-cell responses accurately discriminated between active tuberculosis and latent infection. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America.

  8. A role for granulocyte-macrophage colony-stimulating factor in the regulation of CD8{sup +} T cell responses to rabies virus

    Energy Technology Data Exchange (ETDEWEB)

    Wanjalla, Celestine N.; Goldstein, Elizabeth F.; Wirblich, Christoph [Department of Microbiology and Immunology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA 19107 (United States); Schnell, Matthias J., E-mail: matthias.schnell@jefferson.edu [Department of Microbiology and Immunology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA 19107 (United States); Jefferson Vaccine Center, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA 19107 (United States)

    2012-05-10

    Inflammatory cytokines have a significant role in altering the innate and adaptive arms of immune responses. Here, we analyzed the effect of GM-CSF on a RABV-vaccine vector co-expressing HIV-1 Gag. To this end, we immunized mice with RABV expressing HIV-1 Gag and GM-CSF and analyzed the primary and recall CD8{sup +} T cell responses. We observed a statistically significant increase in antigen presenting cells (APCs) in the spleen and draining lymph nodes in response to GM-CSF. Despite the increase in APCs, the primary and memory anti HIV-1 CD8{sup +} T cell response was significantly lower. This was partly likely due to lower levels of proliferation in the spleen. Animals treated with GM-CSF neutralizing antibodies restored the CD8{sup +} T cell response. These data define a role of GM-CSF expression, in the regulation of the CD8{sup +} T cell immune responses against RABV and has implications in the use of GM-CSF as a molecular adjuvant in vaccine development.

  9. Emergence of CD4+ and CD8+ Polyfunctional T Cell Responses Against Immunodominant Lytic and Latent EBV Antigens in Children With Primary EBV Infection

    Directory of Open Access Journals (Sweden)

    Janice K. P. Lam

    2018-03-01

    Full Text Available Long term carriers were shown to generate robust polyfunctional T cell (PFC responses against lytic and latent antigens of Epstein-Barr virus (EBV. However, the time of emergence of PFC responses against EBV antigens, pattern of immunodominance and difference between CD4+ and CD8+ T cell responses during various stages of EBV infection are not clearly understood. A longitudinal study was performed to assess the development of antigen-specific PFC responses in children diagnosed to have primary symptomatic (infectious mononucleosis [IM] and asymptomatic (AS EBV infection. Evaluation of IFN-γ secreting CD8+ T cell responses upon stimulation by HLA class I-specific peptides of EBV lytic and latent proteins by ELISPOT assay followed by assessment of CD4+ and CD8+ PFC responses upon stimulation by a panel of overlapping EBV peptides for co-expression of IFN-γ, TNF-α, IL-2, perforin and CD107a by flow cytometry were performed. Cytotoxicity of T cells against autologous lymphoblastoid cell lines (LCLs as well as EBV loads in PBMC and plasma were also determined. Both IM and AS patients had elevated PBMC and plasma viral loads which declined steadily during a 12-month period from the time of diagnosis whilst decrease in the magnitude of CD8+ T cell responses toward EBV lytic peptides in contrast to increase toward latent peptides was shown with no significant difference between those of IM and AS patients. Both lytic and latent antigen-specific CD4+ and CD8+ T cells demonstrated polyfunctionality (defined as greater or equal to three functions concurrent with enhanced cytotoxicity against autologous LCLs and steady decrease in plasma and PBMC viral loads over time. Immunodominant peptides derived from BZLF1, BRLF1, BMLF1 and EBNA3A-C proteins induced the highest proportion of CD8+ as well as CD4+ PFC responses. Diverse functional subtypes of both CD4+ and CD8+ PFCs were shown to emerge at 6–12 months. In conclusion, EBV antigen-specific CD4+ and CD

  10. Vaccination for 2009 pandemic H1N1 influenza A did not induce conserved epitope-specific memory CD8 T cell responses in HIV+ northern Thai children.

    Science.gov (United States)

    Chawansuntati, Kriangkrai; Aurpibul, Linda; Wipasa, Jiraprapa

    2015-09-11

    The influenza virus causes severe illness in susceptible populations, including children and people living with human immunodeficiency virus (HIV). Here, we investigated cell-mediated immune responses (CMI) against influenza CD8 T cell conserved epitopes in HIV-infected (HIV+) northern Thai children following the 2009 pandemic H1N1 influenza A vaccination. Sixty HIV+ children were vaccinated with two doses of the 2009 pandemic influenza vaccine and their CD8T cell responses were assessed. We found no significant differences in the increase of cytokines-producing and CD107a-expressing CD8+ T cells or CD8+ memory T cells in response to pooled conserved epitopes stimulation in vitro between children with different serologic responses to the vaccine at all time points of the study. Our results suggest that the 2009 pandemic H1N1 vaccine did not induce the conserved epitope-specific immune responses in HIV+ children. Vaccine design and vaccination strategy against influenza in these populations warrant further studies. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. An oral recombinant Salmonella enterica serovar Typhimurium mutant elicits systemic antigen-specific CD8+ T cell cytokine responses in mice

    Directory of Open Access Journals (Sweden)

    Chin'ombe Nyasha

    2009-04-01

    Full Text Available Abstract Background The induction of antigen-specific CD8+ T cell cytokine responses against an attenuated, oral recombinant Salmonella enterica serovar Typhimurium vaccine expressing a green fluorescent protein (GFP model antigen was investigated. A GFP expression plasmid was constructed in which the gfp gene was fused in-frame with the 5' domain of the Escherichia coli β-galactosidase α-gene fragment with expression under the lac promoter. Groups of mice were orally immunized three times with the bacteria and systemic CD8+ T cell cytokine responses were evaluated. Results High level of the GFP model antigen was expressed by the recombinant Salmonella vaccine vector. Systemic GFP-specific CD8+ T cell cytokine (IFN-γ and IL-4 immune responses were detected after mice were orally vaccinated with the bacteria. It was shown that 226 net IFN-γ and 132 net IL-4 GFP-specific SFUs/10e6 splenocytes were formed in an ELISPOT assay. The level of IFN-γ produced by GFP peptide-stimulated cells was 65.2-fold above background (p Conclusion These results suggested that a high expressing recombinant Salmonella vaccine given orally to mice would elicit antigen-specific CD8+ T cell responses in the spleen. Salmonella bacteria may, therefore, be used as potential mucosal vaccine vectors.

  12. The administration route is decisive for the ability of the vaccine adjuvant CAF09 to induce antigen-specific CD8(+) T-cell responses

    DEFF Research Database (Denmark)

    Schmidt, Signe Tandrup; Khadke, Swapnil; Korsholm, Karen Smith

    2016-01-01

    A prerequisite for vaccine-mediated induction of CD8(+) T-cell responses is the targeting of dendritic cell (DC) subsets specifically capable of cross-presenting antigen epitopes to CD8(+) T cells. Administration of a number of cationic adjuvants via the intraperitoneal (i.p.) route has been shown...... to result in strong CD8(+) T-cell responses, whereas immunization via e.g. the intramuscular (i.m.) or subcutaneous (s.c.) routes often stimulate weak CD8(+) T-cell responses. The hypothesis for this is that self-drainage of the adjuvant/antigen to the lymphoid organs, which takes place upon i...... i.p. immunization, as compared to after i.m. immunization. Studies with fluorescently labelled OVA+CAF09 demonstrated a preferential association of OVA+CAF09 to DCs/monocytes, as compared to macrophages and B cells, following i.p. immunization. Administration of OVA+CAF09 via the i.p. route did also...

  13. CXCR5+CD8+T cells potently infiltrate pancreatic tumors and present high functionality.

    Science.gov (United States)

    Bai, Minghui; Zheng, Youwei; Liu, Haichao; Su, Baowei; Zhan, Yong; He, Hua

    2017-12-01

    Despite continued improvement in conventional therapy, pancreatic cancer continues to be one of the deadliest tumors worldwide with abysmal 5-year survival rate. New immunotherapeutic strategies that aim at improving antitumor cytotoxic CD8 + T cell responses are being developed in solid tumors. To assist the development of immunotherapies, we investigated the CD8 + T cells in pancreatic cancer patients. Compared to healthy individuals, pancreatic cancer patients presented a significant enrichment in the frequency of CD8 + CXCR5 + T cells. In the tumor microenvironment, the frequencies of CD8 + CXCR5 + T cells were further increased. In most cases, over half of tumor-infiltrating CD8 + T cells were CD8 + CXCR5 + T cells. Compared to the circulating population, the tumor-infiltrating CD8 + CXCR5 + T cells expressed higher levels of PD-1 and TIM-3. Functional analyses demonstrated that upon CD3/CD28 activation, the percentages of TNF-expressing and IFN-γ-expressing cells in CD8 + CXCR5 + T cells were significantly higher than that in CD8 + CXCR5 - T cells. CD8 + CXCR5 + T cells also presented enhanced cytotoxicity than CD8 + CXCR5 - T cells. Upon PD-1 and TIM-3 blockade, the functions of CD8 + CXCR5 + T cells were further improved. The disease-free survival of pancreatic cancer patients following tumor resection was positively correlated with the frequencies of circulating and tumor-infiltrating CD8 + CXCR5 + T cells. Together, our study identified that CD8 + CXCR5 + T cells were a potent subset of CD8 + T cells that were highly enriched in pancreatic cancer patients and could respond to anti-PD-1/anti-TIM-3 blockade by further upregulation in function. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Neutrophil-dependent tumor rejection and priming of tumoricidal CD8+ T cell response induced by dendritic cells overexpressing CD95L.

    Science.gov (United States)

    Buonocore, Sofia; Haddou, Najate Ouled; Moore, Fabrice; Florquin, Sandrine; Paulart, Frédéric; Heirman, Carlo; Thielemans, Kris; Goldman, Michel; Flamand, Véronique

    2008-09-01

    Overexpression of CD95 (Fas/Apo-1) ligand (CD95L) has been shown to induce T cell tolerance but also, neutrophilic inflammation and rejection of allogeneic tissue. We explored the capacity of dendritic cells (DCs) genetically engineered to overexpress CD95L to induce an antitumor response. We first found that DCs overexpressing CD95L, in addition to MHC class I-restricted OVA peptides (CD95L-OVA-DCs), induced increased antigen-specific CD8(+) T cell responses as compared with DCs overexpressing OVA peptides alone. The enhanced T cell responses were associated with improved regression of a tumor expressing OVA, allowing survival of all animals. When DCs overexpressing CD95L (CD95L-DCs) were injected with the tumor expressing OVA, in vivo tumor proliferation was strikingly inhibited. A strong cellular apoptosis and a massive neutrophilic infiltrate developed in this setting. Neutrophil depletion prevented tumor regression as well as enhanced IFN-gamma production induced by CD95L-OVA-DCs. Furthermore, the CD8(+) T cell response induced by the coadministration of tumor cells and CD95L-DCs led to rejection of a tumor implanted at a distance from the DC injection site. In summary, DCs expressing CD95L promote tumor rejection involving neutrophil-mediated innate immunity and CD8(+) T cell-dependent adaptative immune responses.

  15. Differential Immunodominance Hierarchy of CD8+T-Cell Responses in HLA-B*27:05- and -B*27:02-Mediated Control of HIV-1 Infection.

    Science.gov (United States)

    Adland, Emily; Hill, Matilda; Lavandier, Nora; Csala, Anna; Edwards, Anne; Chen, Fabian; Radkowski, Marek; Kowalska, Justyna D; Paraskevis, Dimitrios; Hatzakis, Angelos; Valenzuela-Ponce, Humberto; Pfafferott, Katja; Williams, Ian; Pellegrino, Pierre; Borrow, Persephone; Mori, Masahiko; Rockstroh, Jürgen; Prado, Julia G; Mothe, Beatriz; Dalmau, Judith; Martinez-Picado, Javier; Tudor-Williams, Gareth; Frater, John; Stryhn, Anette; Buus, Soren; Teran, Gustavo Reyes; Mallal, Simon; John, Mina; Buchbinder, Susan; Kirk, Gregory; Martin, Jeffrey; Michael, Nelson; Fellay, Jacques; Deeks, Steve; Walker, Bruce; Avila-Rios, Santiago; Cole, David; Brander, Christian; Carrington, Mary; Goulder, Philip

    2018-02-15

    The well-characterized association between HLA-B*27:05 and protection against HIV disease progression has been linked to immunodominant HLA-B*27:05-restricted CD8 + T-cell responses toward the conserved Gag KK10 (residues 263 to 272) and polymerase (Pol) KY9 (residues 901 to 909) epitopes. We studied the impact of the 3 amino acid differences between HLA-B*27:05 and the closely related HLA-B*27:02 on the HIV-specific CD8 + T-cell response hierarchy and on immune control of HIV. Genetic epidemiological data indicate that both HLA-B*27:02 and HLA-B*27:05 are associated with slower disease progression and lower viral loads. The effect of HLA-B*27:02 appeared to be consistently stronger than that of HLA-B*27:05. In contrast to HLA-B*27:05, the immunodominant HIV-specific HLA-B*27:02-restricted CD8 + T-cell response is to a Nef epitope (residues 142 to 150 [VW9]), with Pol KY9 subdominant and Gag KK10 further subdominant. This selection was driven by structural differences in the F pocket, mediated by a polymorphism between these two HLA alleles at position 81. Analysis of autologous virus sequences showed that in HLA-B*27:02-positive subjects, all three of these CD8 + T-cell responses impose selection pressure on the virus, whereas in HLA-B*27:05-positive subjects, there is no Nef VW9-mediated selection pressure. These studies demonstrate that HLA-B*27:02 mediates protection against HIV disease progression that is at least as strong as or stronger than that mediated by HLA-B*27:05. In combination with the protective Gag KK10 and Pol KY9 CD8 + T-cell responses that dominate HIV-specific CD8 + T-cell activity in HLA-B*27:05-positive subjects, a Nef VW9-specific response is additionally present and immunodominant in HLA-B*27:02-positive subjects, mediated through a polymorphism at residue 81 in the F pocket, that contributes to selection pressure against HIV. IMPORTANCE CD8 + T cells play a central role in successful control of HIV infection and have the potential also to

  16. HBV-Derived Synthetic Long Peptide Can Boost CD4+ and CD8+ T-Cell Responses in Chronic HBV Patients Ex Vivo.

    Science.gov (United States)

    Dou, Yingying; van Montfoort, Nadine; van den Bosch, Aniek; de Man, Robert A; Zom, Gijs G; Krebber, Willem-Jan; Melief, Cornelis J M; Buschow, Sonja I; Woltman, Andrea M

    2018-02-14

    Vaccination with synthetic long peptides (SLP) is a promising new treatment strategy for chronic hepatitis B virus (CHB). SLP can induce broad T-cell responses for all HLA types. Here we investigated the ability of a prototype HBV-core (HBc)-sequence-derived SLP to boost HBV-specific T cells in CHB patients ex vivo. HBc-SLP was used to assess cross-presentation by monocyte-derived dendritic cells (moDC) and BDCA1+ blood myeloid DC (mDC) to engineered HBV-specific CD8+ T cells. Autologous SLP-loaded and toll-like receptor (TLR)-stimulated DC were used to activate patient HBc-specific CD8+ and CD4+ T cells. HBV-SLP was cross-presented by moDC, which was further enhanced by adjuvants. Patient-derived SLP-loaded moDC significantly increased autologous HBcAg18-27-specific CD8+ T cells and CD4+ T cells ex vivo. HBV-specific T cells were functional as they synthesized tumor necrosis factor-alpha and interferon-gamma. In 6/7 of patients blockade of PD-L1 further increased SLP effects. Also, importantly, patient-derived BDCA1+ mDC cross-presented and activated autologous T-cell responses ex vivo. As a proof of concept, we showed a prototype HBc-SLP can boost T-cell responses in patients ex vivo. These results pave the way for the development of a therapeutic SLP-based vaccine to induce effective HBV-specific adaptive immune responses in CHB patients. © The Author(s) 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

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

    Directory of Open Access Journals (Sweden)

    Xu A

    2017-06-01

    Full Text Available Aizhang Xu,1,2 Andrew Freywald,3 Yufeng Xie,4 Zejun Li,5 Jim Xiang1,2 1Cancer Research Cluster, Saskatchewan Cancer Agency, 2Department of Oncology, 3Department of Pathology, University of Saskatchewan, Saskatoon, SK, Canada; 4Department of Oncology, First Affiliated Hospital, Soochow University, Suzhou, 5Shanghai Veterinary Research Institute, Shanghai, China Abstract: Whether inflation of CD8+ memory T (mT cells, which is often derived from repeated prime-boost vaccinations or chronic viral infections in the elderly, would affect late CD8+ T-cell immunity is a long-standing paradox. We have previously established an animal model with mT-cell inflation by transferring ConA-stimulated monoclonal CD8+ T cells derived from Ova-specific T-cell-receptor transgenic OTI mice into irradiation-induced lymphopenic B6 mice. In this study, we also established another two animal models with mT-cell inflation by transferring, 1 ConA-stimulated monoclonal CD8+ T cells derived from lymphocytic choriomeningitis virus glycoprotein-specific T-cell-receptor transgenic P14 mice, and 2 ConA-stimulated polyclonal CD8+ T cells derived from B6.1 mice into B6 mice with irradiation-induced lymphopenia. We vaccinated these mice with recombinant Ova-expressing Listeria monocytogenes and Ova-pulsed dendritic cells, which stimulated CD4+ T cell-independent and CD4+ T-cell-dependent CD8+ T-cell responses, respectively, and assessed Ova-specific CD8+ T-cell responses by flow cytometry. We found that Ova-specific CD8+ T-cell responses derived from the latter but not the former vaccination were significantly reduced in mice with CD8+ mT-cell inflation compared to wild-type B6 mice. We determined that naïve CD8+ T cells purified from splenocytes of mice with mT-cell inflation had defects in cell proliferation upon stimulation in vitro and in vivo and upregulated T-cell anergy-associated Itch and GRAIL molecules. Taken together, our data reveal that CD8+ mT-cell inflation renders

  18. Broad and persistent Gag-specific CD8+ T-cell responses are associated with viral control but rarely drive viral escape during primary HIV-1 infection

    Science.gov (United States)

    Radebe, Mopo; Gounder, Kamini; Mokgoro, Mammekwa; Ndhlovu, Zaza M.; Mncube, Zenele; Mkhize, Lungile; van der Stok, Mary; Jaggernath, Manjeetha; Walker, Bruce D.; Ndung’u, Thumbi

    2015-01-01

    Objective We characterized protein-specific CD8+ T-cell immunodominance patterns during the first year of HIV-1 infection, and their impact on viral evolution and immune control. Methods We analyzed CD8+ T-cell responses to the full HIV-1 proteome during the first year of infection in eighteen antiretroviral-naïve individuals with acute HIV-1 subtype C infection, all identified prior to seroconversion. Ex vivo and cultured IFN-γ ELISPOT assays were performed and viruses from plasma were sequenced within defined CTL Gag epitopes. Results Nef-specific CD8+ T-cell responses were dominant during the first 4 weeks post infection and made up 40% of total responses at this time, yet by 1 year responses against this region had declined and Gag responses made up to 47% of all T-cell responses measured. An inverse correlation between the breadth of Gag-specific responses and viral load set point was evident at 26 weeks post infection (p=0.0081; r= −0.60) and beyond. An inverse correlation between the number of persistent responses targeting Gag and viral set point was also identified (p=0.01; r=−0.58). Gag-specific responses detectable by the cultured ELISPOT assay correlated negatively with viral load set point (p=0.0013; r=−0.91). Sequence evolution in targeted and non-targeted Gag epitopes in this cohort was infrequent. Conclusions These data underscore the importance of HIV-specific CD8+ T-cell responses, particularly to the Gag protein, in the maintenance of low viral load levels during primary infection and show that these responses are initially poorly elicited by natural infection. These data have implications for vaccine design strategies. PMID:25387316

  19. Sifting through CD8+T Cell Memory.

    Science.gov (United States)

    Martin, Matthew D; Badovinac, Vladimir P

    2016-12-20

    In this issue of Immunity, Gerlach et al. (2016) describe three distinct memory CD8 + T cell subsets based upon expression of the fractalkine receptor CX3CR1. Their findings revise the paradigm of effector and central memory T cells by revealing a subset of CD8 + memory T cells defined by intermediate levels of expression of CX3CR1 that conducts tissue surveillance. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Induction in Humans of CD8+ and CD4+ T Cell and Antibody Responses by Sequential Immunization with Malaria DNA and Recombinant Protein

    National Research Council Canada - National Science Library

    Wang, Ruobing; Epstein, Judith; Charoenvit, Yupin; Baraceros, Fe Maria; Rahardjo, Nancy; Gay, Tanya; Banania, Jo-Glenna; Chattopadhyay, Rana; Vega, Patricia de la; Richie, Thomas L

    2004-01-01

    .... falciparum DNA vaccines elicit CD8 T cells by these assays, but no protection. We report that sequential immunization with a PfCSP DNA vaccine and RTS,S/AS02A induced PfCSP-specific Abs and Th1 CD4 T cells, and CD8 cytotoxic and Tc1 T cells...

  1. CD4 and CD8 T cell response to the rHSP60 from Klebsiella pneumoniae in peripheral blood mononuclear cells from patients with ankylosing spondylitis.

    Science.gov (United States)

    Zambrano-Zaragoza, Francisco; García-Latorre, Ethel; Domínguez-López, María Lilia; Cancino-Díaz, Mario Eugenio; Burgos-Vargas, Rubén; Jiménez-Zamudio, Luis

    2005-01-01

    To determine the processing pathways used by peripheral blood mononuclear cells (PBMC) and present the rHSP60Kp, and the T cell subpopulations involved in the response, in patients with ankylosing spondylitis (AS) METHODS: The lymphoproliferative response to the rHSP60Kp in PBMC from 14 HLA-B27+ AS patients and 15 B27- healthy controls was assessed by 3H-TdR incorporation. The processing pathways for the rHSP60Kp were analyzed by 3H-TdR incorporation in fresh PBMC from patients using homologous PBMC preincubated with the antigen and specific inhibitors: chloroquine, N-acetyl-L-leucil-L-leucil-L-nor-leucinal (LLnL) or brefeldin A (BFA), fixed with p-formaldehyde (fixed APC). The CD4+/CD8+ T cell subpopulation activated with the antigen was determined by three colours flow cytometry in PBMC from patients. Eight out of fourteen patients showed positive lymphoproliferative responses to the rHSP60Kp while none of the healthy controls responded (p pathways are used. CD4+ and CD8+ T cells populations expressed CD69 when activated by the rHSP60Kp. Our results suggest that CD4 and CD8 T cells participate in the response to the rHSP60Kp in B27+ AS patients.

  2. CD8+ T cells in cutaneous leishmaniasis: The good, the bad and the ugly

    Science.gov (United States)

    Novais, Fernanda O.; Scott, Phillip

    2015-01-01

    CD8+ T lymphocytes are components of the adaptive immune response and play an important role in protection against many viral and bacterial infections. However, their role in parasitic infections is less well understood. In leishmaniasis, a disease caused by intracellular protozoan parasites of the genus Leishmania, CD8+ T cells have been shown to be protective. However, increasing evidence indicates that CD8+ T cells may also exacerbate disease. In this review, we will describe the situations where CD8+ T cells are either good or bad for the outcome of the infection, and attempt to reconcile the dual role played by CD8+ T cells in cutaneous leishmaniasis. PMID:25800274

  3. Pre-existing vector immunity does not prevent replication deficient adenovirus from inducing efficient CD8 T-cell memory and recall responses.

    Directory of Open Access Journals (Sweden)

    Maria Abildgaard Steffensen

    Full Text Available Adenoviral vectors have shown a great potential for vaccine development due to their inherent ability to induce potent and protective CD8 T-cell responses. However, a critical issue regarding the use of these vectors is the existence of inhibitory immunity against the most commonly used Ad5 vector in a large part of the human population. We have recently developed an improved adenoviral vaccine vector system in which the vector expresses the transgene tethered to the MHC class II associated invariant chain (Ii. To further evaluate the potential of this system, the concept of pre-existing inhibitory immunity to adenoviral vectors was revisited to investigate whether the inhibition previously seen with the Ad5 vector also applied to the optimized vector system. We found this to be the case, and antibodies dominated as the mechanism underlying inhibitory vector immunity. However, presence of CD8 T cells directed against epitopes in the adenoviral vector seemed to correlate with repression of the induced response in re-vaccinated B-cell deficient mice. More importantly, despite a repressed primary effector CD8 T-cell response in Ad5-immune animals subjected to vaccination, memory T cells were generated that provided the foundation for an efficient recall response and protection upon subsequent viral challenge. Furthermore, the transgene specific response could be efficiently boosted by homologous re-immunization. Taken together, these studies indicate that adenoviral vectors can be used to induce efficient CD8 T-cell memory even in individuals with pre-existing vector immunity.

  4. DNA vaccines encoding antigen targeted to MHC class II induce influenza specific CD8+ T cell responses, enabling faster resolution of influenza disease.

    Directory of Open Access Journals (Sweden)

    Laura Lambert

    2016-08-01

    Full Text Available Current influenza vaccines are effective but imperfect, failing to cover against emerging strains of virus and requiring seasonal administration to protect against new strains. A key step to improving influenza vaccines is to improve our understanding of vaccine induced protection. Whilst it is clear that antibodies play a protective role, vaccine induced CD8+ T cells can improve protection. To further explore the role of CD8+ T cells we used a DNA vaccine that encodes antigen dimerised to an immune cell targeting module. Immunising CB6F1 mice with the DNA vaccine in a heterologous prime boost regime with the seasonal protein vaccine improved the resolution of influenza disease compared to protein alone. This improved disease resolution was dependent on CD8+ T cells. However, DNA vaccine regimes that induced CD8+ T cells alone were not protective and did not boost the protection provided by protein. The MHC targeting module used was an anti-I-Ed single chain antibody specific to the BALB/c strain of mice. To test the role of MHC targeting we compared the response between BALB/c, C57BL/6 mice and an F1 cross of the two strains (CB6F1. BALB/c mice were protected, C57BL/6 were not and the F1 had an intermediate phenotype; showing that the targeting of antigen is important in the response. Based on these findings, and in agreement with other studies using different vaccines, we conclude that in addition to antibody, inducing a protective CD8 response is important in future influenza vaccines.

  5. DNA Vaccines Encoding Antigen Targeted to MHC Class II Induce Influenza-Specific CD8+ T Cell Responses, Enabling Faster Resolution of Influenza Disease

    Science.gov (United States)

    Lambert, Laura; Kinnear, Ekaterina; McDonald, Jacqueline U.; Grodeland, Gunnveig; Bogen, Bjarne; Stubsrud, Elisabeth; Lindeberg, Mona M.; Fredriksen, Agnete Brunsvik; Tregoning, John S.

    2016-01-01

    Current influenza vaccines are effective but imperfect, failing to cover against emerging strains of virus and requiring seasonal administration to protect against new strains. A key step to improving influenza vaccines is to improve our understanding of vaccine-induced protection. While it is clear that antibodies play a protective role, vaccine-induced CD8+ T cells can improve protection. To further explore the role of CD8+ T cells, we used a DNA vaccine that encodes antigen dimerized to an immune cell targeting module. Immunizing CB6F1 mice with the DNA vaccine in a heterologous prime-boost regime with the seasonal protein vaccine improved the resolution of influenza disease compared with protein alone. This improved disease resolution was dependent on CD8+ T cells. However, DNA vaccine regimes that induced CD8+ T cells alone were not protective and did not boost the protection provided by protein. The MHC-targeting module used was an anti-I-Ed single chain antibody specific to the BALB/c strain of mice. To test the role of MHC targeting, we compared the response between BALB/c, C57BL/6 mice, and an F1 cross of the two strains (CB6F1). BALB/c mice were protected, C57BL/6 were not, and the F1 had an intermediate phenotype; showing that the targeting of antigen is important in the response. Based on these findings, and in agreement with other studies using different vaccines, we conclude that, in addition to antibody, inducing a protective CD8 response is important in future influenza vaccines. PMID:27602032

  6. DNA Vaccines Encoding Antigen Targeted to MHC Class II Induce Influenza-Specific CD8(+) T Cell Responses, Enabling Faster Resolution of Influenza Disease.

    Science.gov (United States)

    Lambert, Laura; Kinnear, Ekaterina; McDonald, Jacqueline U; Grodeland, Gunnveig; Bogen, Bjarne; Stubsrud, Elisabeth; Lindeberg, Mona M; Fredriksen, Agnete Brunsvik; Tregoning, John S

    2016-01-01

    Current influenza vaccines are effective but imperfect, failing to cover against emerging strains of virus and requiring seasonal administration to protect against new strains. A key step to improving influenza vaccines is to improve our understanding of vaccine-induced protection. While it is clear that antibodies play a protective role, vaccine-induced CD8(+) T cells can improve protection. To further explore the role of CD8(+) T cells, we used a DNA vaccine that encodes antigen dimerized to an immune cell targeting module. Immunizing CB6F1 mice with the DNA vaccine in a heterologous prime-boost regime with the seasonal protein vaccine improved the resolution of influenza disease compared with protein alone. This improved disease resolution was dependent on CD8(+) T cells. However, DNA vaccine regimes that induced CD8(+) T cells alone were not protective and did not boost the protection provided by protein. The MHC-targeting module used was an anti-I-E(d) single chain antibody specific to the BALB/c strain of mice. To test the role of MHC targeting, we compared the response between BALB/c, C57BL/6 mice, and an F1 cross of the two strains (CB6F1). BALB/c mice were protected, C57BL/6 were not, and the F1 had an intermediate phenotype; showing that the targeting of antigen is important in the response. Based on these findings, and in agreement with other studies using different vaccines, we conclude that, in addition to antibody, inducing a protective CD8 response is important in future influenza vaccines.

  7. Effects of wear particles of polyether-ether-ketone and cobalt-chromium-molybdenum on CD4- and CD8-T-cell responses.

    Science.gov (United States)

    Du, Zhe; Wang, Shujun; Yue, Bing; Wang, Ying; Wang, You

    2018-02-16

    T-cells, second only to macrophages, are often considered as the potential cells involved in debris-related failure of arthroplasty. Here, we assessed the effects of particulate wear debris on T-cells and inflammatory reactions. Blood samples from 25 donors were incubated with polyether-ether-ketone (PEEK) and cobalt-chromium-molybdenum (CoCrMo) particles generated by custom cryo-milling and pulverization. The T-cell phenotypes were assessed using immunostaining and flow cytometry. For the in vivo study, 0.1 mL of each particle suspension (approximately 1.0 × 10 8 wear particles) was injected into murine knee joints; the synovium and spleen were collected one week after the operation for histological examination and immunofluorescence staining. The T-cell responses observed included low-level activation of Th1, Th2, Th17, and CD8+ pathways after 72 h of co-culture of the particles with peripheral blood mononuclear cells. Obvious CD8+ T-cell responses were observed in local synovium and peripheral spleen, with higher inflammatory cytokine expression in the CoCrMo group. Relatively minor cytotoxic and immunological reactions were observed in vitro , with PEEK and CoCrMo particle-induced immune responses being primarily mediated by CD8+ T-cells, rather than CD4+ T-cells, in vivo . Overall, PEEK wear particles induced fewer inflammatory reactions than CoCrMo particles. This study verified that PEEK was suitable as a potential alternative for metals in total knee replacements in terms of the immunological reaction to PEEK particles, and shed light on the effects of wear particles from polymer and metal-based implants on immune responses.

  8. Oxidative stress drives CD8+T-cell skin trafficking in patients with vitiligo through CXCL16 upregulation by activating the unfolded protein response in keratinocytes.

    Science.gov (United States)

    Li, Shuli; Zhu, Guannan; Yang, Yuqi; Jian, Zhe; Guo, Sen; Dai, Wei; Shi, Qiong; Ge, Rui; Ma, Jingjing; Liu, Ling; Li, Kai; Luan, Qi; Wang, Gang; Gao, Tianwen; Li, Chunying

    2017-07-01

    In patients with vitiligo, an increased reactive oxygen species (ROS) level has been proved to be a key player during disease initiation and progression in melanocytes. Nevertheless, little is known about the effects of ROS on other cells involved in the aberrant microenvironment, such as keratinocytes and the following immune events. CXCL16 is constitutively expressed in keratinocytes and was recently found to mediate homing of CD8 + T cells in human skin. We sought to explicate the effect of oxidative stress on human keratinocytes and its capacity to drive CD8 + T-cell trafficking through CXCL16 regulation. We first detected putative T-cell skin-homing chemokines and ROS in serum and lesions of patients with vitiligo. The production of candidate chemokines was detected by using quantitative real-time PCR and ELISA in keratinocytes exposed to H 2 O 2 . Furthermore, the involved mediators were analyzed by using quantitative real-time PCR, Western blotting, ELISA, and immunofluorescence. Next, we tested the chemotactic migration of CD8 + T cells from patients with vitiligo mediated by the CXCL16-CXCR6 pair using the transwell assay. CXCL16 expression increased and showed a positive correlation with oxidative stress levels in serum and lesions of patients with vitiligo. The H 2 O 2 -induced CXCL16 expression was due to the activation of 2 unfolded protein response pathways: kinase RNA (PKR)-like ER kinase-eukaryotic initiation factor 2α and inositol-requiring enzyme 1α-X-box binding protein 1. CXCL16 produced by stressed keratinocytes induced migration of CXCR6 + CD8 + T cells derived from patients with vitiligo. CXCR6 + CD8 + T-cell skin infiltration is accompanied by melanocyte loss in lesions of patients with vitiligo. Our study demonstrated that CXCL16-CXCR6 mediates CD8 + T-cell skin trafficking under oxidative stress in patients with vitiligo. The CXCL16 expression in human keratinocytes induced by ROS is, at least in part, caused by unfolded protein response

  9. Conditional ligands for Asian HLA variants facilitate the definition of CD8+ T-cell responses in acute and chronic viral diseases

    DEFF Research Database (Denmark)

    Chang, Cynthia X L; Tan, Anthony T; Or, Ming Yan

    2013-01-01

    exchange was accomplished for all variants as demonstrated by an ELISA-based MHC stability assay. HLA tetramers with redirected specificity could detect antigen-specific CD8(+) T-cell responses against human cytomegalovirus, hepatitis B (HBV), dengue virus (DENV), and Epstein-Barr virus (EBV) infections....... The potential of this population-centric HLA library was demonstrated with the characterization of seven novel T-cell epitopes from severe acute respiratory syndrome coronavirus, HBV, and DENV. Posthoc analysis revealed that the majority of responses would be more readily identified by our unbiased discovery...

  10. CD4+CD25+ regulatory T cells control CD8+ T-cell effector differentiation by modulating IL-2 homeostasis

    Science.gov (United States)

    McNally, Alice; Hill, Geoffrey R.; Sparwasser, Tim; Thomas, Ranjeny; Steptoe, Raymond J.

    2011-01-01

    CD4+CD25+ regulatory T cells (Treg) play a crucial role in the regulation of immune responses. Although many mechanisms of Treg suppression in vitro have been described, the mechanisms by which Treg modulate CD8+ T cell differentiation and effector function in vivo are more poorly defined. It has been proposed, in many instances, that modulation of cytokine homeostasis could be an important mechanism by which Treg regulate adaptive immunity; however, direct experimental evidence is sparse. Here we demonstrate that CD4+CD25+ Treg, by critically regulating IL-2 homeostasis, modulate CD8+ T-cell effector differentiation. Expansion and effector differentiation of CD8+ T cells is promoted by autocrine IL-2 but, by competing for IL-2, Treg limit CD8+ effector differentiation. Furthermore, a regulatory loop exists between Treg and CD8+ effector T cells, where IL-2 produced during CD8+ T-cell effector differentiation promotes Treg expansion. PMID:21502514

  11. Mechanisms regulating expansion of CD8+ T cells during HIV-1 infection.

    Science.gov (United States)

    Nasi, A; Chiodi, F

    2018-03-01

    Abnormal immune activation and expansion of CD8+ T cells, especially of memory and effector phenotypes, take place during HIV-1 infection, and these abnormal features persist during administration of antiretroviral therapy (ART) to infected patients. The molecular mechanisms for CD8+ T-cell expansion remain poorly characterized. In this article, we review the literature addressing features of CD8+ T-cell immune pathology and present an integrated view on the mechanisms leading to abnormal CD8+ T-cell expansion during HIV-1 infection. The expression of molecules important for directing the homing of CD8+ T cells between the circulation and lymphoid tissues, in particular CCR5 and CXCR3, is increased in CD8+ T cells in circulation and in inflamed tissues during HIV-1 infection; these disturbances in the homing capacity of CD8+ T cells have been linked to increased CD8+ T-cell proliferation. The production of IL-15, a cytokine responsible for physiological proliferation of CD8+ T cells, is increased in lymphoid tissues during HIV-1 infection as result of microbial translocation and severe inflammation. IL-15, and additional inflammatory cytokines, may lead to deregulated proliferation of CD8+ T cells and explain the accumulation of CD8+ T cells in circulation. The decreased capacity of CD8+ T cells to localize to gut-associated lymphoid tissue also contributes to the accumulation of these cells in blood. Control of inflammation, through ART administration during primary HIV-1 infection or therapies aimed at controlling inflammation during HIV-1 infection, is pivotal to prevent abnormal expansion of CD8+ T cells during HIV-1 infection. © 2018 The Association for the Publication of the Journal of Internal Medicine.

  12. GTL001, a bivalent therapeutic vaccine against human papillomavirus 16 and 18, induces antigen-specific CD8+ T cell responses leading to tumor regression.

    Directory of Open Access Journals (Sweden)

    Michaël Esquerré

    Full Text Available Prophylactic vaccines are available for women and girls not yet infected with HPV, but women already infected with HPV need a treatment to prevent progression to high-grade cervical lesions and cancer. GTL001 is a bivalent therapeutic vaccine for eradicating HPV-infected cells that contains HPV16 E7 and HPV18 E7 both fused to detoxified adenylate cyclase from Bordetella pertussis, which binds specifically to CD11b+ antigen-presenting cells. This study examined the ability of therapeutic vaccination with GTL001 adjuvanted with topical imiquimod cream to induce functional HPV16 E7- and HPV18 E7-specific CD8+ T cell responses.Binding of GTL001 to human CD11b was assessed by a cell-based competition binding assay. Cellular immunogenicity of intradermal vaccination with GTL001 was assessed in C57BL/6 mice by enzyme-linked immunospot assay and in vivo killing assays. In vivo efficacy of GTL001 vaccination was investigated in the TC-1 murine HPV16 E7-expressing tumor model.GTL001 bound specifically to the human CD11b/CD18 receptor. GTL001 adjuvanted with topical 5% imiquimod cream induced HPV16 E7 and HPV18 E7-specific CD8+ T cell responses. This CD8+ T-cell response mediated in vivo killing of HPV E7-expressing cells. In the HPV16 E7-expressing tumor model, GTL001 adjuvanted with imiquimod but not imiquimod alone or a combination of unconjugated HPV16 E7 and HPV18 E7 caused complete tumor regression.GTL001 adjuvanted with topical 5% imiquimod is immunogenic and induces HPV16 E7 and HPV18 E7-specific CD8+ T cell responses that can kill HPV E7-expressing cells and eliminate HPV E7-expressing tumors.

  13. The CD8 and CD4 T-cell response against Kaposi's sarcoma-associated herpesvirus is skewed towards early and late lytic antigens.

    Directory of Open Access Journals (Sweden)

    Rebecca C Robey

    Full Text Available Kaposi's sarcoma-associated herpesvirus (KSHV is causally related to Kaposi's sarcoma (KS, the most common malignancy in untreated individuals with HIV/AIDS. The adaptive T-cell immune response against KSHV has not been fully characterized. To achieve a better understanding of the antigenic repertoire of the CD8 and CD4 T-cell responses against KSHV, we constructed a library of lentiviral expression vectors each coding for one of 31 individual KSHV open reading frames (ORFs. We used these to transduce monocyte-derived dendritic cells (moDCs isolated from 14 KSHV-seropositive (12 HIV-positive and 7 KSHV-seronegative (4 HIV-positive individuals. moDCs were transduced with up to 3 KSHV ORFs simultaneously (ORFs grouped according to their expression during the viral life cycle. Transduced moDCs naturally process the KSHV genes and present the resulting antigens in the context of MHC class I and II. Transduced moDCs were cultured with purified autologous T cells and the CD8 and CD4 T-cell proliferative responses to each KSHV ORF (or group was assessed using a CFSE dye-based assay. Two pools of early lytic KSHV genes ([ORF8/ORF49/ORF61] and [ORF59/ORF65/K4.1] were frequently-recognized targets of both CD8 and CD4 T cells from KSHV seropositive individuals. One pool of late lytic KSHV genes ([ORF28/ORF36/ORF37] was a frequently-recognized CD8 target and another pool of late genes ([ORF33/K1/K8.1] was a frequently-recognized CD4 target. We report that both the CD8 and CD4 T-cell responses against KSHV are skewed towards genes expressed in the early and late phases of the viral lytic cycle, and identify some previously unknown targets of these responses. This knowledge will be important to future immunological investigations into KSHV and may eventually lead to the development of better immunotherapies for KSHV-related diseases.

  14. NKG2D stimulation of CD8(+) T cells during priming promotes their capacity to produce cytokines in response to viral infection in mice

    NARCIS (Netherlands)

    Kavazovic, Inga; Lenartic, Maja; Jelencic, Vedrana; Jurkovic, Slaven; Lemmermann, Niels A. W.; Jonjic, Stipan; Polic, Bojan; Wensveen, Felix M.

    2017-01-01

    Natural killer group 2 member D (NKG2D) is an activating receptor that is expressed on most cytotoxic cells of the immune system, including NK cells, , and CD8(+) T cells. It is still a matter of debate whether and how NKG2D mediates priming of CD8(+) T cells in vivo, due to a lack of studies where

  15. Recombinant influenza virus expressing HIV-1 p24 capsid protein induces mucosal HIV-specific CD8 T-cell responses.

    Science.gov (United States)

    Tan, Hyon-Xhi; Gilbertson, Brad P; Jegaskanda, Sinthujan; Alcantara, Sheilajen; Amarasena, Thakshila; Stambas, John; McAuley, Julie L; Kent, Stephen J; De Rose, Robert

    2016-02-24

    Influenza viruses are promising mucosal vaccine vectors for HIV but their use has been limited by difficulties in engineering the expression of large amounts of foreign protein. We developed recombinant influenza viruses incorporating the HIV-1 p24 gag capsid into the NS-segment of PR8 (H1N1) and X31 (H3N2) influenza viruses with the use of multiple 2A ribosomal skip sequences. Despite the insertion of a sizable HIV-1 gene into the influenza genome, recombinant viruses were readily rescued to high titers. Intracellular expression of p24 capsid was confirmed by in vitro infection assays. The recombinant influenza viruses were subsequently tested as mucosal vaccines in BALB/c mice. Recombinant viruses were attenuated and safe in immunized mice. Systemic and mucosal HIV-specific CD8 T-cell responses were elicited in mice that were immunized via intranasal route with a prime-boost regimen. Isolated HIV-specific CD8 T-cells displayed polyfunctional cytokine and degranulation profiles. Mice boosted via intravaginal route induced recall responses from the distal lung mucosa and developed heightened HIV-specific CD8 T-cell responses in the vaginal mucosa. These findings demonstrate the potential utility of recombinant influenza viruses as vaccines for mucosal immunity against HIV-1 infection. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. TLR1/2 activation during heterologous prime-boost vaccination (DNA-MVA enhances CD8+ T Cell responses providing protection against Leishmania (Viannia.

    Directory of Open Access Journals (Sweden)

    Asha Jayakumar

    2011-06-01

    Full Text Available Leishmania (Viannia parasites present particular challenges, as human and murine immune responses to infection are distinct from other Leishmania species, indicating a unique interaction with the host. Further, vaccination studies utilizing small animal models indicate that modalities and antigens that prevent infection by other Leishmania species are generally not protective.Using a newly developed mouse model of chronic L. (Viannia panamensis infection and the heterologous DNA prime - modified vaccinia virus Ankara (MVA boost vaccination modality, we examined whether the conserved vaccine candidate antigen tryparedoxin peroxidase (TRYP could provide protection against infection/disease.Heterologous prime - boost (DNA/MVA vaccination utilizing TRYP antigen can provide protection against disease caused by L. (V. panamensis. However, protection is dependent on modulating the innate immune response using the TLR1/2 agonist Pam3CSK4 during DNA priming. Prime-boost vaccination using DNA alone fails to protect. Prior to infection protectively vaccinated mice exhibit augmented CD4 and CD8 IFNγ and memory responses as well as decreased IL-10 and IL-13 responses. IL-13 and IL-10 have been shown to be independently critical for disease in this model. CD8 T cells have an essential role in mediating host defense, as CD8 depletion reversed protection in the vaccinated mice; vaccinated mice depleted of CD4 T cells remained protected. Hence, vaccine-induced protection is dependent upon TLR1/2 activation instructing the generation of antigen specific CD8 cells and restricting IL-13 and IL-10 responses.Given the general effectiveness of prime-boost vaccination, the recalcitrance of Leishmania (Viannia to vaccine approaches effective against other species of Leishmania is again evident. However, prime-boost vaccination modality can with modulation induce protective responses, indicating that the delivery system is critical. Moreover, these results suggest that

  17. Integrated NY-ESO-1 antibody and CD8+ T-cell responses correlate with clinical benefit in advanced melanoma patients treated with ipilimumab.

    Science.gov (United States)

    Yuan, Jianda; Adamow, Matthew; Ginsberg, Brian A; Rasalan, Teresa S; Ritter, Erika; Gallardo, Humilidad F; Xu, Yinyan; Pogoriler, Evelina; Terzulli, Stephanie L; Kuk, Deborah; Panageas, Katherine S; Ritter, Gerd; Sznol, Mario; Halaban, Ruth; Jungbluth, Achim A; Allison, James P; Old, Lloyd J; Wolchok, Jedd D; Gnjatic, Sacha

    2011-10-04

    Ipilimumab, a monoclonal antibody against cytotoxic T lymphocyte antigen 4 (CTLA-4), has been shown to improve survival in patients with advanced metastatic melanoma. It also enhances immunity to NY-ESO-1, a cancer/testis antigen expressed in a subset of patients with melanoma. To characterize the association between immune response and clinical outcome, we first analyzed NY-ESO-1 serum antibody by ELISA in 144 ipilimumab-treated patients with melanoma and found 22 of 140 (16%) seropositive at baseline and 31 of 144 (22%) seropositive following treatment. These NY-ESO-1-seropositive patients had a greater likelihood of experiencing clinical benefit 24 wk after ipilimumab treatment than NY-ESO-1-seronegative patients (P = 0.02, relative risk = 1.8, two-tailed Fisher test). To understand why some patients with NY-ESO-1 antibody failed to experience clinical benefit, we analyzed NY-ESO-1-specific CD4(+) and CD8(+) T-cell responses by intracellular multicytokine staining in 20 NY-ESO-1-seropositive patients and found a surprising dissociation between NY-ESO-1 antibody and CD8 responses in some patients. NY-ESO-1-seropositive patients with associated CD8(+) T cells experienced more frequent clinical benefit (10 of 13; 77%) than those with undetectable CD8(+) T-cell response (one of seven; 14%; P = 0.02; relative risk = 5.4, two-tailed Fisher test), as well as a significant survival advantage (P = 0.01; hazard ratio = 0.2, time-dependent Cox model). Together, our data suggest that integrated NY-ESO-1 immune responses may have predictive value for ipilimumab treatment and argue for prospective studies in patients with established NY-ESO-1 immunity. The current findings provide a strong rationale for the clinical use of modulators of immunosuppression with concurrent approaches to favor tumor antigen-specific immune responses, such as vaccines or adoptive transfer, in patients with cancer.

  18. The role of CD8+ T cells during allograft rejection

    Directory of Open Access Journals (Sweden)

    V. Bueno

    2002-11-01

    Full Text Available Organ transplantation can be considered as replacement therapy for patients with end-stage organ failure. The percent of one-year allograft survival has increased due, among other factors, to a better understanding of the rejection process and new immunosuppressive drugs. Immunosuppressive therapy used in transplantation prevents activation and proliferation of alloreactive T lymphocytes, although not fully preventing chronic rejection. Recognition by recipient T cells of alloantigens expressed by donor tissues initiates immune destruction of allogeneic transplants. However, there is controversy concerning the relative contribution of CD4+ and CD8+ T cells to allograft rejection. Some animal models indicate that there is an absolute requirement for CD4+ T cells in allogeneic rejection, whereas in others CD4-depleted mice reject certain types of allografts. Moreover, there is evidence that CD8+ T cells are more resistant to immunotherapy and tolerance induction protocols. An intense focal infiltration of mainly CD8+CTLA4+ T lymphocytes during kidney rejection has been described in patients. This suggests that CD8+ T cells could escape from immunosuppression and participate in the rejection process. Our group is primarily interested in the immune mechanisms involved in allograft rejection. Thus, we believe that a better understanding of the role of CD8+ T cells in allograft rejection could indicate new targets for immunotherapy in transplantation. Therefore, the objective of the present review was to focus on the role of the CD8+ T cell population in the rejection of allogeneic tissue.

  19. Mosaic vaccines elicit CD8+ T cell responses in monkeys that confer immune coverage of diverse HIV strains

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Will [Los Alamos National Laboratory; Korber, Bette [Los Alamos National Laboratory

    2009-01-01

    Creation of a successful HIV vaccine will require the development of a strategy to generate cellular immunity with sufficient cross-clade breadth to deal with the extreme genetic diversity of the virus. Polyvalent mosaic immunogens derived from in silica recombination of natural strains of HIV are designed to induce cellular immune responses that maximally cover the sequence diversity of circulating virus isolates. Immunization of rhesus monkeys with plasmid DNA and recombinant vaccinia virus vaccine constructs expressing either consensus immunogens or polyvalent mosaic immunogens elicited a CD4+ T lymphocyte-biased response with comparably broad epitope-specific total T lymphocyte specificities. However, immunization with the mosaic immunogens induced HIV-specific CD8+ T lymphocyte responses with markedly greater depth and breadth. Therefore, the use of polyvalent mosaic immunogens is a promising strategy for a global vaccine for HIV.

  20. Tumor Cell Clone Expressing the Membrane-bound Form of IL-12p35 Subunit Stimulates Antitumor Immune Responses Dominated by CD8(+) T Cells.

    Science.gov (United States)

    Lim, Hoyong; Do, Seon Ah; Park, Sang Min; Kim, Young Sang

    2013-04-01

    IL-12 is a secretory heterodimeric cytokine composed of p35 and p40 subunits. IL-12 p35 and p40 subunits are sometimes produced as monomers or homodimers. IL-12 is also produced as a membrane-bound form in some cases. In this study, we hypothesized that the membrane-bound form of IL-12 subunits may function as a costimulatory signal for selective activation of TAA-specific CTL through direct priming without involving antigen presenting cells and helper T cells. MethA fibrosarcoma cells were transfected with expression vectors of membrane-bound form of IL-12p35 (mbIL-12p35) or IL-12p40 subunit (mbIL-12p40) and were selected under G418-containing medium. The tumor cell clones were analyzed for the expression of mbIL-12p35 or p40 subunit and for their stimulatory effects on macrophages. The responsible T-cell subpopulation for antitumor activity of mbIL-12p35 expressing tumor clone was also analyzed in T cell subset-depleted mice. Expression of transfected membrane-bound form of IL-12 subunits was stable during more than 3 months of in vitro culture, and the chimeric molecules were not released into culture supernatants. Neither the mbIL-12p35-expressing tumor clones nor mbIL-12p40-expressing tumor clones activated macrophages to secrete TNF-α. Growth of mbIL-12p35-expressing tumor clones was more accelerated in the CD8(+) T cell-depleted mice than in CD4(+) T cell-depleted or normal mice. These results suggest that CD8(+) T cells could be responsible for the rejection of mbIL-12p35-expressing tumor clone, which may bypass activation of antigen presenting cells and CD4(+) helper T cells.

  1. Effector and memory CD8+ T cells as seen in immunity to malaria.

    Science.gov (United States)

    Morrot, Alexandre; Zavala, Fidel

    2004-10-01

    Transgenic (Tg) mice carrying a T-cell receptor (TCR) specific for a CD8(+) T-cell epitope expressed in pre-erythrocytic stages of Plasmodium yoelii has proven to be a valuable tool to advance our understanding of this anti-parasite T-cell response, as it occurs in vivo. The visualization of CD8(+) T cells in vivo and ex vivo greatly facilitated research aimed at characterizing basic features of this T-cell response such as the kinetics of differentiation and proliferation and the in vivo antigen presentation. Importantly, this research unveiled the existence of early self-regulatory mechanisms controlling the magnitude of the CD8(+) T-cell response and also identified CD4(+) T cells as critical elements in the development of memory populations. This review discusses our recent research using Tg mice and highlights our progress in understanding the CD8(+) T-cell-mediated immunity against malaria liver stages.

  2. Impact of inflammatory cytokines on effector and memory CD8+ T cells

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    Marie eKim

    2014-06-01

    Full Text Available Inflammatory cytokines have long been recognized to produce potent APCs to elicit robust T cell responses for protective immunity. The impact of inflammatory cytokine signaling directly on T cells, however, has only recently been appreciated. Although much remains to be learned, the CD8 T cell field has made considerable strides in understanding the effects of inflammatory cytokines throughout the CD8 T cell response. Key findings first identified IL-12 and type I interferons as ‘signal 3’ cytokines, emphasizing their importance in generating optimal CD8 T cell responses. Separate investigations revealed another inflammatory cytokine, IL-15, to play a critical role in memory CD8 T cell maintenance. These early studies highlighted potential regulators of CD8 T cells, but were unable to provide mechanistic insight into how these inflammatory cytokines enhanced CD8 T cell-mediated immunity. Here, we describe the mechanistic advances that have been made in our lab regarding the role of ‘signal 3’ cytokines and IL-15 in optimizing effector and memory CD8 T cell number and function. Furthermore, we assess initial progress on the role of cytokines, such as TGF-β, in generation of recently described resident memory CD8 T cell populations.

  3. Three phases of CD8 T cell response in the lung following H1N1 influenza infection and sphingosine 1 phosphate agonist therapy.

    Directory of Open Access Journals (Sweden)

    Melanie P Matheu

    Full Text Available Influenza-induced lung edema and inflammation are exacerbated by a positive feedback loop of cytokine and chemokine production termed a 'cytokine storm', a hallmark of increased influenza-related morbidity and mortality. Upon infection, an immune response is rapidly initiated in the lungs and draining lymph node, leading to expansion of virus-specific effector cells. Using two-photon microscopy, we imaged the dynamics of dendritic cells (DC and virus-specific eGFP(+CD8(+ T cells in the lungs and draining mediastinal lymph nodes during the first two weeks following influenza infection. Three distinct phases of T cell and CD11c(+ DC behavior were revealed: 1 Priming, facilitated by the arrival of lung DCs in the lymph node and characterized by antigen recognition and expansion of antigen-specific CD8(+ T cells; asymmetric T cell division in contact with DCs was frequently observed. 2 Clearance, during which DCs re-populate the lung and T cells leave the draining lymph node and re-enter the lung tissue where enlarged, motile T cells come into contact with DCs and form long-lived interactions. 3 Maintenance, characterized by T-cell scanning of the lung tissue and dissociation from local antigen presenting cells; the T cells spend less time in association with DCs and migrate rapidly on collagen. A single dose of a sphingosine-1-phosphate receptor agonist, AAL-R, sufficient to suppress influenza-induced cytokine-storm, altered T cell and DC behavior during influenza clearance, delaying T cell division, cellular infiltration in the lung, and suppressing T-DC interactions in the lung. Our results provide a detailed description of T cell and DC choreography and dynamics in the lymph node and the lung during influenza infection. In addition, we suggest that phase lags in T cell and DC dynamics induced by targeting S1P receptors in vivo may attenuate the intensity of the immune response and can be manipulated for therapeutic benefit.

  4. MEK kinase 1 is a negative regulator of virus-specific CD8(+) T cells

    DEFF Research Database (Denmark)

    Labuda, Tord; Christensen, Jan Pravsgaard; Rasmussen, Susanne

    2006-01-01

    in the generation of a virus-specific immune response. Mekk1(DeltaKD) mice challenged with vesicular stomatitis virus (VSV) showed a fourfold increase in splenic CD8(+) T cell numbers. In contrast, the number of splenic T cells in infected WT mice was only marginally increased. The CD8(+) T cell expansion in Mekk1...... proliferation, since a significantly higher percentage of virus-specific Mekk1(DeltaKD) CD8(+) T cells incorporated BrdU as compared to virus-specific WT CD8(+) T cells. In contrast, similar levels of apoptosis were detected in Mekk1(DeltaKD) and WT T cells following VSV infection. These results strongly...... suggest that MEKK1 plays a negative regulatory role in the expansion of virus-specific CD8(+) T cells in vivo....

  5. Pre-existing vector immunity does not prevent replication deficient adenovirus from inducing efficient CD8 T-cell memory and recall responses

    DEFF Research Database (Denmark)

    Steffensen, Maria Abildgaard; Jensen, Benjamin Anderschou Holbech; Holst, Peter Johannes

    2012-01-01

    in a large part of the human population. We have recently developed an improved adenoviral vaccine vector system in which the vector expresses the transgene tethered to the MHC class II associated invariant chain (Ii). To further evaluate the potential of this system, the concept of pre-existing inhibitory...... directed against epitopes in the adenoviral vector seemed to correlate with repression of the induced response in re-vaccinated B-cell deficient mice. More importantly, despite a repressed primary effector CD8 T-cell response in Ad5-immune animals subjected to vaccination, memory T cells were generated......8 T-cell memory even in individuals with pre-existing vector immunity....

  6. Just-in-time vaccines: Biomineralized calcium phosphate core-immunogen shell nanoparticles induce long-lasting CD8(+) T cell responses in mice.

    Science.gov (United States)

    Zhou, Weibin; Moguche, Albanus O; Chiu, David; Murali-Krishna, Kaja; Baneyx, François

    2014-04-01

    Distributed and on-demand vaccine production could be game-changing for infectious disease treatment in the developing world by providing new therapeutic opportunities and breaking the refrigeration "cold chain". Here, we show that a fusion protein between a calcium phosphate binding domain and the model antigen ovalbumin can mineralize a biocompatible adjuvant in a single step. The resulting 50 nm calcium phosphate core-immunogen shell particles are comparable to soluble protein in inducing ovalbumin-specific antibody response and class switch recombination in mice. However, single dose vaccination with nanoparticles leads to higher expansion of ovalbumin-specific CD8(+) T cells upon challenge with an influenza virus bearing the ovalbumin-derived SIINFEKL peptide, and these cells produce high levels of IFN-γ. Furthermore, mice exhibit a robust antigen-specific CD8(+) T cell recall response when challenged with virus 8 months post-immunization. These results underscore the promise of immunogen-controlled adjuvant mineralization for just-in-time manufacturing of effective T cell vaccines. This paper reports that a fusion protein between a calcium phosphate binding domain and the model antigen ovalbumin can mineralize into a biocompatible adjuvant in a single step, enabling distributed and on-demand vaccine production and eliminating the need for refrigeration of vaccines. The findings highlight the possibility of immunogen-controlled adjuvant mineralization for just-in-time manufacturing of effective T cell vaccines. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Effect of administration timing of postchemotherapy granulocyte colony-stimulating factor on host-immune cell recovery and CD8+T-cell response.

    Science.gov (United States)

    Salem, Mohamed Labib; Nassef, Mohamed; Abdel Salam, Soha G R; Zidan, Abdelaziz; Mahmoud, Mohamed H; Badr, Gamal; Rubinstein, Mark; Cole, David

    2016-11-01

    Granulocyte colony-stimulating factor (G-CSF), a hematopoietic growth factor, is a standard supportive therapy given during cancer treatment. It induces acceleration in neutrophil recovery through stimulation of mobilization of hematopoietic progenitors. Given that the latter is also induced by chemotherapy itself, the timing of administration of G-CSF postchemotherapy might impact the resultant overall effects. The present study aimed to determine the optimal timing of G-CSF postchemotherapy to exert its optimal effects on the immune cell recovery and its impact on antigen-specific CD8 + T-cell response. B6 mice were treated once with cyclophosphamide (4 mg/mouse; CTX) and then daily with G-CSF (5 g/mouse) from Days 1-5, 2-5 or 5-9 post-CTX treatment. The total numbers of various immune cell types were analyzed on Days 7, 9 and 12 post-CTX treatment. To evaluate effects on CD8 + T-cell response, a pmel-1 transgenic mouse model was used in combination with prime boost peptide vaccination therapy. The total number of white blood cells (WBC), neutrophils, monocytes, lymphocytes, granulocytes and dendritic cells (DC) were significantly increased after G-CSF treatment in particular when G-CSF was administered from Days 2-5 post-CTX treatment. Application of this timing of G-CSF and CTX treatment after adoptive transfer of T-cells followed by prime-boost vaccination with antigenic peptide did not block the expansion of the donor pmel-1 CD8 + T-cells. In conclusion, adjusting the timing of treatment with G-CSF postchemotherapy can optimize its promoting effects on recovery of myeloid cells without altering the associated antigen-specific immunity.

  8. Comprehensive Analysis of Cytomegalovirus pp65 Antigen-Specific CD8+ T Cell Responses According to Human Leukocyte Antigen Class I Allotypes and Intraindividual Dominance

    Directory of Open Access Journals (Sweden)

    Seung-Joo Hyun

    2017-11-01

    Full Text Available To define whether individual human leukocyte antigen (HLA class I allotypes are used preferentially in human cytomegalovirus (CMV-specific cytotoxic T lymphocyte responses, CD8+ T cell responses restricted by up to six HLA class I allotypes in an individual were measured in parallel using K562-based artificial antigen-presenting cells expressing both CMV pp65 antigen and one of 32 HLA class I allotypes (7 HLA-A, 14 HLA-B, and 11 HLA-C present in 50 healthy Korean donors. The CD8+ T cell responses to pp65 in the HLA-C allotypes were lower than responses to those in HLA-A and -B allotypes and there was no difference between the HLA-A and HLA-B loci. HLA-A*02:01, -B*07:02, and -C*08:01 showed the highest magnitude and frequency of immune responses to pp65 at each HLA class I locus. However, HLA-A*02:07, -B*59:01, -B*58:01, -B*15:11, -C*03:02, and -C*02:02 did not show any immune responses. Although each individual has up to six different HLA allotypes, 46% of the donors showed one allotype, 24% showed two allotypes, and 2% showed three allotypes that responded to pp65. Interestingly, the frequencies of HLA-A alleles were significantly correlated with the positivity of specific allotypes. Our results demonstrate that specific HLA class I allotypes are preferentially used in the CD8+ T cell immune response to pp65 and that a hierarchy among HLA class I allotypes is present in an individual.

  9. CD8+ T-cell responses to tumor-associated antigens correlate with superior relapse-free survival after allo-SCT.

    Science.gov (United States)

    Kapp, M; Stevanović, S; Fick, K; Tan, S M; Loeffler, J; Opitz, A; Tonn, T; Stuhler, G; Einsele, H; Grigoleit, G U

    2009-03-01

    The GVL effect following allo-SCT is one of the most prominent examples showing the ability of the immune system to eliminate malignant hematological diseases. Tumor-associated Ags (TAA), for instance WT1 and proteinase-3, have been proposed as targets for T cells to establish a GVL effect. Here, we examined an additional TAA (MUC1) as a possible T-cell target of GVL-related immune responses. We have defined new peptide epitopes from the MUC1 Ag to broaden patients' screening and to expand the repertoire of immunologic monitoring as well as for therapeutic approaches in the future. Twenty-eight patients after allo-SCT have been screened for T-cell responses toward TAA (proteinase-3, WT1, MUC1). We could detect a significant relationship between relapse and the absence of a TAA-specific T-cell response, whereby only 2/13 (15%) patients with TAA-specific CTL relapsed, in contrast to 9/15 (60%) patients without TAA-specific CTL responses (P<0.05). In conclusion, CD8(+) T-cell responses directed to TAA might contribute to the GVL effect. These observations highlight both the importance and the potential of immunotherapeutic approaches after allo-SCT.

  10. Microneedle Array Design Determines the Induction of Protective Memory CD8+ T Cell Responses Induced by a Recombinant Live Malaria Vaccine in Mice

    Science.gov (United States)

    Carey, John B.; Pearson, Frances E.; Vrdoljak, Anto; McGrath, Marie G.; Crean, Abina M.; Walsh, Patrick T.; Doody, Timothy; O'Mahony, Conor; Hill, Adrian V. S.; Moore, Anne C.

    2011-01-01

    Background Vaccine delivery into the skin has received renewed interest due to ease of access to the immune system and microvasculature, however the stratum corneum (SC), must be breached for successful vaccination. This has been achieved by removing the SC by abrasion or scarification or by delivering the vaccine intradermally (ID) with traditional needle-and-syringes or with long microneedle devices. Microneedle patch-based transdermal vaccine studies have predominantly focused on antibody induction by inactivated or subunit vaccines. Here, our principal aim is to determine if the design of a microneedle patch affects the CD8+ T cell responses to a malaria antigen induced by a live vaccine. Methodology and Findings Recombinant modified vaccinia virus Ankara (MVA) expressing a malaria antigen was percutaneously administered to mice using a range of silicon microneedle patches, termed ImmuPatch, that differed in microneedle height, density, patch area and total pore volume. We demonstrate that microneedle arrays that have small total pore volumes induce a significantly greater proportion of central memory T cells that vigorously expand to secondary immunization. Microneedle-mediated vaccine priming induced significantly greater T cell immunity post-boost and equivalent protection against malaria challenge compared to ID vaccination. Notably, unlike ID administration, ImmuPatch-mediated vaccination did not induce inflammatory responses at the site of immunization or in draining lymph nodes. Conclusions/Significance This study demonstrates that the design of microneedle patches significantly influences the magnitude and memory of vaccine-induced CD8+ T cell responses and can be optimised for the induction of desired immune responses. Furthermore, ImmuPatch-mediated delivery may be of benefit to reducing unwanted vaccine reactogenicity. In addition to the advantages of low cost and lack of pain, the development of optimised microneedle array designs for the induction

  11. Microneedle array design determines the induction of protective memory CD8+ T cell responses induced by a recombinant live malaria vaccine in mice.

    Directory of Open Access Journals (Sweden)

    John B Carey

    Full Text Available Vaccine delivery into the skin has received renewed interest due to ease of access to the immune system and microvasculature, however the stratum corneum (SC, must be breached for successful vaccination. This has been achieved by removing the SC by abrasion or scarification or by delivering the vaccine intradermally (ID with traditional needle-and-syringes or with long microneedle devices. Microneedle patch-based transdermal vaccine studies have predominantly focused on antibody induction by inactivated or subunit vaccines. Here, our principal aim is to determine if the design of a microneedle patch affects the CD8(+ T cell responses to a malaria antigen induced by a live vaccine.Recombinant modified vaccinia virus Ankara (MVA expressing a malaria antigen was percutaneously administered to mice using a range of silicon microneedle patches, termed ImmuPatch, that differed in microneedle height, density, patch area and total pore volume. We demonstrate that microneedle arrays that have small total pore volumes induce a significantly greater proportion of central memory T cells that vigorously expand to secondary immunization. Microneedle-mediated vaccine priming induced significantly greater T cell immunity post-boost and equivalent protection against malaria challenge compared to ID vaccination. Notably, unlike ID administration, ImmuPatch-mediated vaccination did not induce inflammatory responses at the site of immunization or in draining lymph nodes.This study demonstrates that the design of microneedle patches significantly influences the magnitude and memory of vaccine-induced CD8(+ T cell responses and can be optimised for the induction of desired immune responses. Furthermore, ImmuPatch-mediated delivery may be of benefit to reducing unwanted vaccine reactogenicity. In addition to the advantages of low cost and lack of pain, the development of optimised microneedle array designs for the induction of T cell responses by live vaccines aids

  12. Persistent Low-Level Replication of SIVΔnef Drives Maturation of Antibody and CD8 T Cell Responses to Induce Protective Immunity against Vaginal SIV Infection.

    Directory of Open Access Journals (Sweden)

    Sama Adnan

    2016-12-01

    Full Text Available Defining the correlates of immune protection conferred by SIVΔnef, the most effective vaccine against SIV challenge, could enable the design of a protective vaccine against HIV infection. Here we provide a comprehensive assessment of immune responses that protect against SIV infection through detailed analyses of cellular and humoral immune responses in the blood and tissues of rhesus macaques vaccinated with SIVΔnef and then vaginally challenged with wild-type SIV. Despite the presence of robust cellular immune responses, animals at 5 weeks after vaccination displayed only transient viral suppression of challenge virus, whereas all macaques challenged at weeks 20 and 40 post-SIVΔnef vaccination were protected, as defined by either apparent sterile protection or significant suppression of viremia in infected animals. Multiple parameters of CD8 T cell function temporally correlated with maturation of protection, including polyfunctionality, phenotypic differentiation, and redistribution to gut and lymphoid tissues. Importantly, we also demonstrate the induction of a tissue-resident memory population of SIV-specific CD8 T cells in the vaginal mucosa, which was dependent on ongoing low-level antigenic stimulation. Moreover, we show that vaginal and serum antibody titers inversely correlated with post-challenge peak viral load, and we correlate the accumulation and affinity maturation of the antibody response to the duration of the vaccination period as well as to the SIVΔnef antigenic load. In conclusion, maturation of SIVΔnef-induced CD8 T cell and antibody responses, both propelled by viral persistence in the gut mucosa and secondary lymphoid tissues, results in protective immune responses that are able to interrupt viral transmission at mucosal portals of entry as well as potential sites of viral dissemination.

  13. Anti-viral CD8 T cells and the cytokines that they love

    Science.gov (United States)

    Cox, Maureen A.; Kahan, Shannon M.; Zajac, Allan J.

    2013-01-01

    Viral infections cause an immunological disequilibrium that provokes CD8 T cell responses. These cells play critical roles in purging acute infections, limiting persistent infections, and conferring life-long protective immunity. At every stage of the response anti-viral CD8 T cells are sensitive to signals from cytokines. Initially cytokines operate as immunological warning signs that inform of the presence of an infection, and also influence the developmental choices of the responding cells. Later during the course of the response other sets of cytokines support the survival and maintenance of the differentiated anti-viral CD8 T cells. Although many cytokines promote virus-specific CD8 T cells, other cytokines can suppress their activities and thus favor viral persistence. In this review we discuss how select cytokines act to regulate anti-viral CD8 T cells throughout the response and influence the outcome of viral infections. PMID:23217625

  14. Unopposed Production of Granulocyte-Macrophage Colony-Stimulating Factor by Tumors Inhibits CD8+ T Cell Responses by Dysregulating Antigen-Presenting Cell Maturation1

    OpenAIRE

    Bronte, Vincenzo; Chappell, Dale B.; Apolloni, Elisa; Cabrelle, Anna; Wang, Michael; Hwu, Patrick; Restifo, Nicholas P.

    1999-01-01

    Tumor cells gene-modified to produce GM-CSF potently stimulate antitumor immune responses, in part, by causing the growth and differentiation of dendritic cells (DC). However, GM-CSF-modified tumor cells must be γ-irradiated or they will grow progressively, killing the host. We observed that 23 of 75 (31%) human tumor lines and two commonly used mouse tumor lines spontaneously produced GM-CSF. In mice, chronic GM-CSF production by tumors suppressed Ag-specific CD8+ T cell responses. Interesti...

  15. Immune Checkpoint Function of CD85j in CD8 T Cell Differentiation and Aging.

    Science.gov (United States)

    Gustafson, Claire E; Qi, Qian; Hutter-Saunders, Jessica; Gupta, Sheena; Jadhav, Rohit; Newell, Evan; Maecker, Holden; Weyand, Cornelia M; Goronzy, Jörg J

    2017-01-01

    Aging is associated with an increased susceptibility to infection and a failure to control latent viruses thought to be driven, at least in part, by alterations in CD8 T cell function. The aging T cell repertoire is characterized by an accumulation of effector CD8 T cells, many of which express the negative regulatory receptor CD85j. To define the biological significance of CD85j expression on CD8 T cells and to address the question whether presence of CD85j in older individuals is beneficial or detrimental for immune function, we examined the specific attributes of CD8 T cells expressing CD85j as well as the functional role of CD85j in antigen-specific CD8 T cell responses during immune aging. Here, we show that CD85j is mainly expressed by terminally differentiated effector (TEMRAs) CD8 T cells, which increase with age, in cytomegalovirus (CMV) infection and in males. CD85j + CMV-specific cells demonstrate clonal expansion. However, TCR diversity is similar between CD85j + and CD85j - compartments, suggesting that CD85j does not directly impact the repertoire of antigen-specific cells. Further phenotypic and functional analyses revealed that CD85j identifies a specific subset of CMV-responsive CD8 T cells that coexpress a marker of senescence (CD57) but retain polyfunctional cytokine production and expression of cytotoxic mediators. Blocking CD85j binding enhanced proliferation of CMV-specific CD8 T cells upon antigen stimulation but did not alter polyfunctional cytokine production. Taken together, these data demonstrate that CD85j characterizes a population of "senescent," but not exhausted antigen-specific effector CD8 T cells and indicates that CD85j is an important checkpoint regulator controlling expansion of virus-specific T cells during aging. Inhibition of CD85j activity may be a mechanism to promote stronger CD8 T cell effector responses during immune aging.

  16. Memory CD8+ T cells protect dendritic cells from CTL killing

    NARCIS (Netherlands)

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

    2008-01-01

    CD8(+) T cells have been shown to be capable of either suppressing or promoting immune responses. To reconcile these contrasting regulatory functions, we compared the ability of human effector and memory CD8(+) T cells to regulate survival and functions of dendritic cells (DC). We report that, in

  17. Comparative analysis of CD8 expressed on mature CD4+ CD8+ T cell clones cultured with IL-4 and that on CD8+ T cell clones: implication for functional significance of CD8 beta

    NARCIS (Netherlands)

    Hori, T.; Paliard, X.; de Waal Malefijt, R.; Ranes, M.; Spits, H.

    1991-01-01

    Interleukin (IL-4) can induce CD8 expression on mature CD4+ T cells. To study this phenomenon in more detail, we characterized CD8 expressed on IL-4-induced CD4+ CD8+ (double positive) T cell clones in comparison with that on CD8+ T cell clones. Using 2ST8-5H7 mAb that detects CD8 beta expression,

  18. Just-in-time vaccines: Biomineralized calcium phosphate core-immunogen shell nanoparticles induce long-lasting CD8+ T cell responses in mice

    Science.gov (United States)

    Zhou, Weibin; Moguche, Albanus; Chiu, David; Murali-Krishna, Kaja; Baneyx, François

    2014-01-01

    Distributed and on-demand vaccine production could be game-changing for infectious disease treatment in the developing world by providing new therapeutic opportunities and breaking the refrigeration “cold chain”. Here, we show that a fusion protein between a calcium phosphate binding domain and the model antigen ovalbumin can mineralize a biocompatible adjuvant in a single step. The resulting 50 nm calcium phosphate core-immunogen shell particles are comparable to soluble protein in inducing ovalbumin-specific antibody response and class switch recombination in mice. However, single dose vaccination with nanoparticles leads to higher expansion of ovalbumin-specific CD8+ T cells upon challenge with an influenza virus bearing the ovalbumin-derived SIINFEKL peptide, and these cells produce high levels of IFN-γ. Furthermore, mice exhibit a robust antigen-specific CD8+ T cell recall response when challenged with virus 8 months post-immunization. These results underscore the promise of immunogen-controlled adjuvant mineralization for just-in-time manufacturing of effective T cell vaccines. PMID:24275478

  19. NKG2D stimulation of CD8+T cells during priming promotes their capacity to produce cytokines in response to viral infection in mice.

    Science.gov (United States)

    Kavazović, Inga; Lenartić, Maja; Jelenčić, Vedrana; Jurković, Slaven; Lemmermann, Niels A W; Jonjić, Stipan; Polić, Bojan; Wensveen, Felix M

    2017-07-01

    Natural killer group 2 member D (NKG2D) is an activating receptor that is expressed on most cytotoxic cells of the immune system, including NK cells, γδ, and CD8 + T cells. It is still a matter of debate whether and how NKG2D mediates priming of CD8 + T cells in vivo, due to a lack of studies where NKG2D is eliminated exclusively in these cells. Here, we studied the impact of NKG2D on effector CD8 + T-cell formation. NKG2D deficiency that is restricted to murine CD8 + T cells did not impair antigen-specific T-cell expansion following mouse CMV and lymphocytic choriomeningitis virus infection, but reduced their capacity to produce cytokines. Upon infection, conventional dendritic cells induce NKG2D ligands, which drive cytokine production on CD8 + T cells via the Dap10 signaling pathway. T-cell development, homing, and proliferation were not affected by NKG2D deficiency and cytotoxicity was only impaired when strong T-cell receptor (TCR) stimuli were used. Transfer of antigen-specific CD8 + T cells demonstrated that NKG2D deficiency attenuated their capacity to reduce viral loads. The inability of NKG2D-deficient cells to produce cytokines could be overcome with injection of IL-15 superagonist during priming. In summary, our data show that NKG2D has a nonredundant role in priming of CD8 + T cells to produce antiviral cytokines. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Monocyte-derived dendritic cells are essential for CD8+ T cell activation and anti-tumor responses after local immunotherapy

    Directory of Open Access Journals (Sweden)

    Sabine eKuhn

    2015-11-01

    Full Text Available Tumors harbor several populations of dendritic cells with the ability to prime tumor-specific T cells. However, these T cells mostly fail to differentiate into armed effectors and are unable to control tumor growth. We have previously shown that treatment with immunostimulatory agents at the tumor site can activate anti-tumor immune responses, and is associated with the appearance of a population of monocyte-derived dendritic cells in the tumor and tumor-draining lymph node. Here we use dendritic cell or monocyte depletion and monocyte transfer to show that these monocyte-derived dendritic cells are critical to the activation of anti-tumor immune responses. Treatment with the immunostimulatory agents Monosodium Urate crystals and Mycobacterium smegmatis induced the accumulation of monocytes in the draining lymph node, their upregulation of CD11c and MHCII, and expression of iNOS, TNFα and IL12p40. Blocking monocyte entry into the lymph node and tumor through neutralization of the chemokine CCL2 or inhibition of Colony Stimulating Factor-1 receptor signaling prevented the generation of monocyte-derived dendritic cells, the infiltration of tumor-specific T cells into the tumor, and anti-tumor responses. In a reciprocal fashion, monocytes transferred into mice depleted of CD11c+ cells were sufficient to rescue CD8+ T cell priming in lymph node and delay tumor growth. Thus monocytes exposed to the appropriate conditions become powerful activators of tumor-specific CD8+ T cells and anti-tumor immunity.

  1. IRF8-dependent DCs play a key role in the regulation of CD8 T cell responses to epithelialderived antigen in the steady state but not in inflammation

    DEFF Research Database (Denmark)

    Joeris, Thorsten; Gomez-Casado, C.; Holmkvist, P.

    2016-01-01

    towards epithelial-derived antigens is crucial to maintain tissue homeostasis. In contrast, infection of IECs by intracellular pathogens requires induction of cytotoxic CD8 T cells (CTLs) towards epithelialassociated, pathogen-derived antigens. Currently, little is known about the regulation of CD8 T...

  2. CXCR5+CD8+T cells could induce the death of tumor cells in HBV-related hepatocellular carcinoma.

    Science.gov (United States)

    Jin, Yun; Lang, Cuicui; Tang, Jianzhong; Geng, Jiawei; Song, Haihan K; Sun, Zhiwei; Wang, Jinfeng

    2017-12-01

    The follicular CXCR5 + CD8 + T cells have recently emerged as a critical cell type in mediating peripheral tolerance as well as antiviral immune responses during chronic infections. In this study, we investigated the function of CXCR5 + CD8 + T cells in HBV-related hepatocellular carcinoma patients. Compared to CXCR5 - CD8 + T cells, CXCR5 + CD8 + T cells presented elevated PD-1 expression but reduced Tim-3 and CTLA-4 expression. Upon anti-CD3/CD28 stimulation, CXCR5 + CD8 + T cells demonstrated higher proliferation potency than CXCR5 - CD8 + T cells, especially after PD-1 blockade. CXCR5 + CD8 + T cells also demonstrated significantly higher granzyme B synthesis and release, as well as higher level of degranulation. Tumor cells were more readily eliminated by CXCR5 + CD8 + T cells than by CXCR5 - CD8 + T cells. Interestingly, we found that B cells were more resistant to CXCR5 + CD8 + T cell-mediated killing than tumor cells, possibly through IL-10-mediated protection. In addition, the CXCR5 + CD8 + T cell-mediated cytotoxic effects on tumor cells could be significantly enhanced by PD-L1 blockade. Together, we presented that in patients with in HBV-related hepatocellular carcinoma, CXCR5 + CD8 + T cells could mediate tumor cell death more potently than the CXCR5 - CD8 + T cells in vitro while the autologous B cells were protected. Copyright © 2017. Published by Elsevier B.V.

  3. Role of CD8+ regulatory T cells in organ transplantation

    Directory of Open Access Journals (Sweden)

    Jiyan Su

    2014-01-01

    Full Text Available CD8 + T cells are regulatory T cells (Tregs that suppress both alloimmunity and autoimmunity in many animal models. This class of regulatory cells includes the CD8 + CD28 - , CD8 + CD103 + , CD8 + FoxP3 + and CD8 + CD122 + subsets. The mechanisms of action of these regulatory cells are not fully understood; however, the secretion of immunosuppressive cytokines, such as interleukin (IL-4, IL-10 and transforming growth factor beta (TGF-β as well as the direct killing of target cells via Fas L/Fas and the perforin/granzyme B pathways have been demonstrated in various models. Further studies are necessary to fully understand the mechanisms underlying the suppressive effects of Tregs and to provide experimental support for potential clinical trials. We recently observed that CD8 + CD122 + Tregs more potently suppressed allograft rejection compared to their CD4 + CD25 + counterparts, supporting the hypothesis that CD8 + Tregs may represent a new and promising Treg family that can be targeted to prevent allograft rejection in the clinic. In this review, we summarize the progress in the field during the past 7-10 years and discuss CD8 + Treg phenotypes, mechanisms of action, and their potential clinical applications; particularly in composite tissue transplants in burn and trauma patients.

  4. A Pathogenic Role for CD8+ T Cells in a Spontaneous Model of Demyelinating Disease

    DEFF Research Database (Denmark)

    Brisebois, Marcel; Zehntner, Simone P.; Estrada, José

    2006-01-01

    Transgenic (Tg) mice that overexpress the costimulatory ligand B7.2/CD86 on microglia spontaneously develop a T cell-mediated demyelinating disease. Characterization of the inflammatory infiltrates in the nervous tissue revealed a predominance of CD8+ T cells, suggesting a prominent role of this T...... cell subset in the pathology. In this study, we show that the same neurological disease occurred in Tg mice deficient in the generation of CD4+ T cells, with an earlier time of onset. Analysis of the CD8+ T cell repertoire at early stage of disease revealed the presence of selected clonal expansions...... pathogenesis. Collectively, our data indicate that the spontaneous demyelinating disease in this animal model occurs as a consequence of an inflammatory response initiated through the activation of CNS-specific CD8+ T cells by Tg expression of B7.2 within the target organ. Thus, autoreactive CD8+ T cells can...

  5. Reduced thymic maturation but normal effector function of CD8+ T cells in CD8 beta gene-targeted mice

    OpenAIRE

    1994-01-01

    CD8 is a cell surface glycoprotein on major histocompatibility complex class I-restricted T cells. Thymocytes and most peripheral T cells express CD8 as heterodimers of CD8 alpha and CD8 beta. The intestinal intraepithelial lymphocytes (IEL), which have been suggested to be generated extrathymically, express CD8 predominantly as homodimers of CD8 alpha. We have generated CD8 beta gene-targeted mice. CD8 alpha+ T cell population in the thymus and in most peripheral lymphoid organs was reduced ...

  6. Immediate Dysfunction of Vaccine-Elicited CD8+ T Cells Primed in the Absence of CD4+ T Cells

    Science.gov (United States)

    Provine, Nicholas M.; Larocca, Rafael A.; Aid, Malika; Penaloza-MacMaster, Pablo; Badamchi-Zadeh, Alexander; Borducchi, Erica N.; Yates, Kathleen B.; Abbink, Peter; Kirilova, Marinela; Ng’ang’a, David; Bramson, Jonathan; Haining, W. Nicholas

    2016-01-01

    CD4+ T cell help is critical for optimal CD8+ T cell memory differentiation and maintenance in many experimental systems. In addition, many reports have identified reduced primary CD8+ T cell responses in the absence of CD4+ T cell help, which often coincides with reduced Ag or pathogen clearance. In this study, we demonstrate that absence of CD4+ T cells at the time of adenovirus vector immunization of mice led to immediate impairments in early CD8+ T cell functionality and differentiation. Unhelped CD8+ T cells exhibited a reduced effector phenotype, decreased ex vivo cytotoxicity, and decreased capacity to produce cytokines. This dysfunctional state was imprinted within 3 d of immunization. Unhelped CD8+ T cells expressed elevated levels of inhibitory receptors and exhibited transcriptomic exhaustion and anergy profiles by gene set enrichment analysis. Dysfunctional, impaired effector differentiation also occurred following immunization of CD4+ T cell–deficient mice with a poxvirus vector. This study demonstrates that following priming with viral vectors, CD4+ T cell help is required to promote both the expansion and acquisition of effector functions by CD8+ T cells, which is accomplished by preventing immediate dysfunction. PMID:27448585

  7. Delayed contraction of the CD8+ T cell response toward lymphocytic choriomeningitis virus infection in mice lacking serglycin

    DEFF Research Database (Denmark)

    Grujic, Mirjana; Christensen, Jan P; Sørensen, Maria R

    2008-01-01

    (-/-)) mice with lymphocytic choriomeningitis virus (LCMV). Wt and SG(-/-) mice cleared 10(3) PFU of highly invasive LCMV with the same kinetics, and the CD8(+) T lymphocytes from wt and SG(-/-) animals did not differ in GrB, perforin, IFN-gamma, or TNF-alpha content. However, when a less invasive LCMV strain...

  8. Identification of heme oxygenase-1-specific regulatory CD8+ T cells in cancer patients

    DEFF Research Database (Denmark)

    Andersen, Mads Hald; Sørensen, Rikke Baek; Brimnes, Marie K

    2009-01-01

    Treg deficiencies are associated with autoimmunity. Conversely, CD4+ and CD8+ Tregs accumulate in the tumor microenvironment and are associated with prevention of antitumor immunity and anticancer immunotherapy. Recently, CD4+ Tregs have been much studied, but little is known about CD8+ Tregs...... and the antigens they recognize. Here, we describe what we believe to be the first natural target for CD8+ Tregs. Naturally occurring HLA-A2-restricted CD8+ T cells specific for the antiinflammatory molecule heme oxygenase-1 (HO-1) were able to suppress cellular immune responses with outstanding efficacy. HO-1......-specific CD8+ T cells were detected ex vivo and in situ among T cells from cancer patients. HO-1-specific T cells isolated from the peripheral blood of cancer patients inhibited cytokine release, proliferation, and cytotoxicity of other immune cells. Notably, the inhibitory effect of HO-1-specific T cells...

  9. CD8+ T cell migration to the skin requires CD4+ help in a murine model of contact hypersensitivity.

    Directory of Open Access Journals (Sweden)

    Nanna Fyhrquist

    Full Text Available The relative roles of CD4+ and CD8+ T cells in contact hypersensitivity responses have not been fully solved, and remain an important question. Using an adoptive transfer model, we investigated the role of the respective T cell subset. Magnetic bead separated CD4+ and CD8+ T cells from oxazolone sensitized C57BL/6 mice were transferred into RAG-/- mice, followed by hapten challenge and analysis of inflammatory parameters at 24 hours post exposure. The CD4+ T cell recipient mice developed partial contact hypersensitivity responses to oxazolone. CD8+ T cells caused significant amplification of the response in recipients of both CD4+ and CD8+ T cells including ear swelling, type 1 inflammatory mediators, and cell killing. Unexpectedly, CD8+ T cells were not sufficient to mediate contact hypersensitivity, although abundantly present in the lymph nodes in the CD8+ T cell reconstituted mice. There were no signs of inflammation at the site of hapten exposure, indicating impaired recruitment of CD8+ T cells in the absence of CD4+ T cells. These data show that CD4+ T cells mediate contact hypersensitivity to oxazolone, but CD8+ T cells contribute with the most potent effector mechanisms. Moreover, our results suggest that CD4+ T cell function is required for the mobilization of CD8+ effector T cells to the site of hapten exposure. The results shed new light on the relative importance of CD4+ and CD8+ T cells during the effector phase of contact hypersensitivity.

  10. Bcl-2 Allows Effector and Memory CD8+ T Cells To Tolerate Higher Expression of Bim

    Science.gov (United States)

    Kurtulus, Sema; Tripathi, Pulak; Moreno-Fernandez, Maria E.; Sholl, Allyson; Katz, Jonathan D.; Grimes, H. Leighton; Hildeman, David A.

    2014-01-01

    As acute infections resolve, most effector CD8+ T cells die, whereas some persist and become memory T cells. Recent work showed that subsets of effector CD8+ T cells, identified by reciprocal expression of killer cell lectin-like receptor G1 (KLRG1) and CD127, have different lifespans. Similar to previous reports, we found that effector CD8+ T cells reported to have a longer lifespan (i.e., KLRG1lowCD127high) have increased levels of Bcl-2 compared with their shorter-lived KLRG1highCD127low counterparts. Surprisingly, we found that these effector KLRG1lowCD127high CD8+ T cells also had increased levels of Bim compared with KLRG1highCD127low cells. Similar effects were observed in memory cells, in which CD8+ central memory T cells expressed higher levels of Bim and Bcl-2 than did CD8+ effector memory T cells. Using both pharmacologic and genetic approaches, we found that survival of both subsets of effector and memory CD8+ T cells required Bcl-2 to combat the proapoptotic activity of Bim. Interestingly, inhibition or absence of Bcl-2 led to significantly decreased expression of Bim in surviving effector and memory T cells. In addition, manipulation of Bcl-2 levels by IL-7 or IL-15 also affected expression of Bim in effector CD8+ T cells. Finally, we found that Bim levels were significantly increased in effector CD8+ T cells lacking Bax and Bak. Together, these data indicate that cells having the highest levels of Bim are selected against during contraction of the response and that Bcl-2 determines the level of Bim that effector and memory T cells can tolerate. PMID:21451108

  11. Chronic activation profile of circulating CD8+ T cells in Sézary syndrome.

    Science.gov (United States)

    Torrealba, Marina Passos; Manfrere, Kelly Cristina; Miyashiro, Denis R; Lima, Josenilson F; de M Oliveira, Luana; Pereira, Nátalli Z; Cury-Martins, Jade; Pereira, Juliana; Duarte, Alberto J S; Sato, Maria N; Sanches, José A

    2018-01-09

    Sézary syndrome (SS) is a leukemic variant of cutaneous T cell lymphoma (CTCL), and the neoplastic CD4+ T cells of SS patients undergo intense clonal proliferation. Although Sézary cells have been studied extensively, studies on adaptive immunity regarding CD8+T cells are scarce. This study aimed to investigate activation marker expression in CD8+ T cells according to the differentiation stages and IL-7/IL7Rα axis responses of patients with SS. Moreover, this study aimed to verify the soluble forms of CD38, sCD127 and IL-7 in serum. Although the SS patients of our cohort had reduced numbers of CD8+ T cells, they exhibited higher percentages of CD8+CD38+ T cells, mainly effector/memory CD8+ T cells, than the control group. In contrast, down-regulated expression of the activation markers CD127/IL-7R and CD26 was found in the CD8+ T cells of SS patients. High serum levels of sCD38 and sCD127 and scarce serum levels of IL-7 were detected, emphasizing the immune activation status of SS patients. Moreover, CD8+ T cells from SS patients exhibited IL-7 unresponsiveness to STAT5 phosphorylation and Bcl-2 expression, and IL-7 priming partially restored IFNγ production. Our findings showed a chronic activation profile of CD8+ T cells, as an attenuated cytotoxic profile and impaired IL-7 responsiveness was observed, suggesting chronic activation status of CD8+ T cells in SS patients.

  12. Effector CD8+T cell-derived interleukin-10 enhances acute liver immunopathology.

    Science.gov (United States)

    Fioravanti, Jessica; Di Lucia, Pietro; Magini, Diletta; Moalli, Federica; Boni, Carolina; Benechet, Alexandre Pierre; Fumagalli, Valeria; Inverso, Donato; Vecchi, Andrea; Fiocchi, Amleto; Wieland, Stefan; Purcell, Robert; Ferrari, Carlo; Chisari, Francis V; Guidotti, Luca G; Iannacone, Matteo

    2017-09-01

    Besides secreting pro-inflammatory cytokines, chemokines and effector molecules, effector CD8 + T cells that arise upon acute infection with certain viruses have been shown to produce the regulatory cytokine interleukin (IL)-10 and, therefore, contain immunopathology. Whether the same occurs during acute hepatitis B virus (HBV) infection and role that IL-10 might play in liver disease is currently unknown. Mouse models of acute HBV pathogenesis, as well as chimpanzees and patients acutely infected with HBV, were used to analyse the role of CD8 + T cell-derived IL-10 in liver immunopathology. Mouse HBV-specific effector CD8 + T cells produce significant amounts of IL-10 upon in vivo antigen encounter. This is corroborated by longitudinal data in a chimpanzee acutely infected with HBV, where serum IL-10 was readily detectable and correlated with intrahepatic CD8 + T cell infiltration and liver disease severity. Unexpectedly, mouse and human CD8 + T cell-derived IL-10 was found to act in an autocrine/paracrine fashion to enhance IL-2 responsiveness, thus preventing antigen-induced HBV-specific effector CD8 + T cell apoptosis. Accordingly, the use of mouse models of HBV pathogenesis revealed that the IL-10 produced by effector CD8 + T cells promoted their own intrahepatic survival and, thus supported, rather than suppressed liver immunopathology. Effector CD8 + T cell-derived IL-10 enhances acute liver immunopathology. Altogether, these results extend our understanding of the cell- and tissue-specific role that IL-10 exerts in immune regulation. Lay summary: Interleukin-10 is mostly regarded as an immunosuppressive cytokine. We show here that HBV-specific CD8 + T cells produce IL-10 upon antigen recognition and that this cytokine enhances CD8 + T cell survival. As such, IL-10 paradoxically promotes rather than suppresses liver disease. Copyright © 2017 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

  13. Peptide specific expansion of CD8(+) T cells by recombinant plate bound MHC/peptide complexes

    DEFF Research Database (Denmark)

    Schmidt, Esben G W; Buus, Soren; Thorn, Mette

    2009-01-01

    Development of methods for efficient in vitro stimulation and expansion of peptide specific CD8(+) T cells is compelling not only with respect to adoptive T cell therapy but also regarding analysis of T cell responses and search for new immunogenic peptides. In the present study, a new approach...... cells (NA-PBMCs) with PB-MHC/CMVp resulted in significant expansion of CMVp specific CD8(+) T cells, which was comparable to that achieved by CMVp pulsed mature dendritic cells (DCs). By repeated exposure of NA-PBMCs to PB-MHC/CMVp more than 60% CMVp specific CD8(+) T cells, representing a 240-fold...... expansion, were reached after only two stimulations. Although stimulation with PB-MHC/CMVp clearly demonstrated efficient peptide specific expansion of CD8(+) T cells, there was a tendency to proliferative exhaustion of the cells after 3-4 stimulations. Thus, it will be of interest to examine the effect...

  14. Involvement of CD8+ T Cells in Multiple Sclerosis

    Science.gov (United States)

    Salou, Marion; Nicol, Bryan; Garcia, Alexandra; Laplaud, David-Axel

    2015-01-01

    Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system characterized by focal demyelination patches associated with inflammatory infiltrates containing T lymphocytes. For decades, CD4+ T cells have been recognized as playing a major role in the disease, especially in animal models, which has led to the development of several therapies. However, interest has recently developed in the involvement of CD8+ T cells in MS following the analysis of infiltrating T cells in human brain lesions. A broad range of evidence now suggests that the pathological role of this T cell subset in MS may have been underestimated. In this review, we summarize the literature implicating CD8+ T cells in the pathophysiology of MS. We present data from studies in the fields of genetics, anatomopathology and immunology, mainly in humans but also in animal models of MS. Altogether, this strongly suggests that CD8+ T cells may be major effectors in the disease process, and that the development of treatments specifically targeting this subset would be germane. PMID:26635816

  15. Characterization of CD8+ T-Cell Responses in the Peripheral Blood and Skin Injection Sites of Melanoma Patients Treated with mRNA Electroporated Autologous Dendritic Cells (TriMixDC-MEL

    Directory of Open Access Journals (Sweden)

    Daphné Benteyn

    2013-01-01

    Full Text Available Treatment of melanoma patients with mRNA electroporated dendritic cells (TriMixDC-MEL stimulates T-cell responses against the presented tumor-associated antigens (TAAs. In the current clinical trials, melanoma patients with systemic metastases are treated, requiring priming and/or expansion of preexisting TAA-specific T cells that are able to migrate to both the skin and internal organs. We monitored the presence of TAA-specific CD8+ T cells infiltrating the skin at sites of intradermal TriMixDC-MEL injection (SKILs and within the circulation of melanoma patients treated in two clinical trials. In 10 out of fourteen (71% patients screened, CD8+ T cells recognizing any of the four TAA presented by TriMixDC-MEL cellular vaccine were found in both compartments. In total, 30 TAA-specific T-cell responses were detected among the SKILs and 29 among peripheral blood T cells, of which 24 in common. A detailed characterization of the antigen specificity of CD8+ T-cell populations in four patients indicates that the majority of the epitopes detected were only recognized by CD8+ T cells derived from either skin biopsies or peripheral blood, indicating that some compartmentalization occurs after TriMix-DC therapy. To conclude, functional TAA-specific CD8+ T cells distribute both to the skin and peripheral blood of patients after TriMixDC-MEL therapy.

  16. Autophagy is a critical regulator of memory CD8+ T cell formation

    Science.gov (United States)

    Puleston, Daniel J; Zhang, Hanlin; Powell, Timothy J; Lipina, Elina; Sims, Stuart; Panse, Isabel; Watson, Alexander S; Cerundolo, Vincenzo; Simon, Anna Katharina

    2014-01-01

    During infection, CD8+ T cells initially expand then contract, leaving a small memory pool providing long lasting immunity. While it has been described that CD8+ T cell memory formation becomes defective in old age, the cellular mechanism is largely unknown. Autophagy is a major cellular lysosomal degradation pathway of bulk material, and levels are known to fall with age. In this study, we describe a novel role for autophagy in CD8+ T cell memory formation. Mice lacking the autophagy gene Atg7 in T cells failed to establish CD8+ T cell memory to influenza and MCMV infection. Interestingly, autophagy levels were diminished in CD8+ T cells from aged mice. We could rejuvenate CD8+ T cell responses in elderly mice in an autophagy dependent manner using the compound spermidine. This study reveals a cell intrinsic explanation for poor CD8+ T cell memory in the elderly and potentially offers novel immune modulators to improve aged immunity. DOI: http://dx.doi.org/10.7554/eLife.03706.001 PMID:25385531

  17. Mast-Cell-Derived TNF Amplifies CD8+ Dendritic Cell Functionality and CD8+ T Cell Priming

    Directory of Open Access Journals (Sweden)

    Jan Dudeck

    2015-10-01

    Full Text Available Mast cells are critical promoters of adaptive immunity in the contact hypersensitivity model, but the mechanism of allergen sensitization is poorly understood. Using Mcpt5-CreTNFFL/FL mice, we show here that the absence of TNF exclusively in mast cells impaired the expansion of CD8+ T cells upon sensitization and the T-cell-driven adaptive immune response to elicitation. T cells primed in the absence of mast cell TNF exhibited a diminished efficiency to transfer sensitization to naive recipients. Specifically, mast cell TNF promotes CD8+ dendritic cell (DC maturation and migration to draining lymph nodes. The peripherally released mast cell TNF further critically boosts the CD8+ T-cell-priming efficiency of CD8+ DCs, thereby linking mast cell effects on T cells to DC modulation. Collectively, our findings identify the distinct potential of mast cell TNF to amplify CD8+ DC functionality and CD8+ T-cell-dominated adaptive immunity, which may be of great importance for immunotherapy and vaccination approaches.

  18. Blocking Tumor Necrosis Factor α Enhances CD8 T-cell-Dependent Immunity in Experimental Melanoma.

    Science.gov (United States)

    Bertrand, Florie; Rochotte, Julia; Colacios, Céline; Montfort, Anne; Tilkin-Mariamé, Anne-Françoise; Touriol, Christian; Rochaix, Philippe; Lajoie-Mazenc, Isabelle; Andrieu-Abadie, Nathalie; Levade, Thierry; Benoist, Hervé; Ségui, Bruno

    2015-07-01

    TNF plays a dual, still enigmatic role in melanoma, either acting as a cytotoxic cytokine or favoring a tumorigenic inflammatory microenvironment. Herein, the tumor growth of melanoma cell lines expressing major histocompatibility complex class I molecules at high levels (MHC-I(high)) was dramatically impaired in TNF-deficient mice, and this was associated with enhanced tumor-infiltrating CD8(+) T lymphocytes. Immunodepletion of CD8 T cells fully restored melanoma growth in TNF(-/-) mice. Systemic administration of Etanercept inhibited MHC-I(high) melanoma growth in immunocompetent but not in immunodeficient (IFNγ(-/-), nude, or CD8(-/-)) mice. MHC-I(high) melanoma growth was also reduced in mice lacking TNF-R1, but not TNF-R2. TNF(-/-) and TNF-R1(-/-) mice as well as Etanercept-treated WT mice displayed enhanced intratumor content of high endothelial venules surrounded by high CD8(+) T-cell density. Adoptive transfer of activated TNF-R1-deficient or -proficient CD8(+) T cells in CD8-deficient mice bearing B16K1 tumors demonstrated that TNF-R1 deficiency facilitates the accumulation of live CD8(+) T cells into the tumors. Moreover, in vitro experiments indicated that TNF triggered activated CD8(+) T cell death in a TNF-R1-dependent manner, likely limiting the accumulation of tumor-infiltrating CD8(+) T cells in TNF/TNF-R1-proficient animals. Collectively, our observations indicate that TNF-R1-dependent TNF signaling impairs tumor-infiltrating CD8(+) T-cell accumulation and may serve as a putative target to favor CD8(+) T-cell-dependent immune response in melanoma. ©2015 American Association for Cancer Research.

  19. Antigen Exposure History Defines CD8 T Cell Dynamics and Protection during Localized Pulmonary Infections

    Science.gov (United States)

    Van Braeckel-Budimir, Natalija; Martin, Matthew D.; Hartwig, Stacey M.; Legge, Kevin L.; Badovinac, Vladimir P.; Harty, John T.

    2017-01-01

    Unlike systemic infections, little is known about the role of repeated localized infections on (re)shaping pathogen-specific memory CD8 T cell responses. Here, we used primary (1°) and secondary (2°) intranasal influenza virus infections of mice as a model to study intrinsic memory CD8 T cell properties. We show that secondary antigen exposure, relative to a single infection, generates memory CD8 T cell responses of superior magnitude in multiple tissue compartments including blood, spleen, draining lymph nodes, and lung. Unexpectedly, regardless of the significantly higher number of 2° memory CD8 T cells, similar degree of protection against pulmonary challenge was observed in both groups of mice containing 1° or 2° memory CD8 T cells. Mechanistically, using pertussis toxin-induced migration block, we showed that superior antigen-driven proliferation and ability to relocate to the site of infection allowed 1° memory CD8 T cells to accumulate in the infected lung during the first few days after challenge, compensating for the initially lower cell numbers. Taken together, the history of antigen exposures to localized pulmonary infections, through altering basic cell biology, dictates dynamic properties of protective memory CD8 T cell responses. This knowledge has important implications for a design of novel and an improvement of existing vaccines and immunization strategies. PMID:28191007

  20. Role of Different Subpopulations of CD8+T Cells during HIV Exposure and Infection.

    Science.gov (United States)

    Gonzalez, Sandra Milena; Taborda, Natalia Andrea; Rugeles, María Teresa

    2017-01-01

    During HIV infection, specific responses exhibited by CD8 + T cells are crucial to establish an early, effective, and sustained viral control, preventing severe immune alterations and organ dysfunction. Several CD8 + T cells subsets have been identified, exhibiting differences in terms of activation, functional profile, and ability to limit HIV replication. Some of the most important CD8 + T cells subsets associated with viral control, production of potent antiviral molecules, and strong polyfunctional responses include Th1-like cytokine pattern and Tc17 cells. In addition, the expression of specific activation markers has been also associated with a more effective response of CD8 + T cells, as evidenced in HLA-DR + CD38 - cells. CD8 + T cells in both, peripheral blood and gut mucosa, are particularly important in individuals with a resistant phenotype, including HIV-exposed seronegative individuals (HESNs), long-term non-progressors (LTNPs) and HIV-controllers. Although the role of CD8 + T cells has been extensively explored in the context of an established HIV-1 infection, the presence of HIV-specific cells with effector abilities and a defined functional profile in HESNs, remain poorly understood. Here, we reviewed studies carried out on different subpopulations of CD8 + T cells in relation with natural resistance to HIV infection and progression.

  1. Induction of CD8 T-cell responses restricted to multiple HLA class I alleles in a cancer patient by immunization with a 20-mer NY-ESO-1f (NY-ESO-1 91-110) peptide.

    Science.gov (United States)

    Eikawa, Shingo; Kakimi, Kazuhiro; Isobe, Midori; Kuzushima, Kiyotaka; Luescher, Immanuel; Ohue, Yoshihiro; Ikeuchi, Kazuhiro; Uenaka, Akiko; Nishikawa, Hiroyoshi; Udono, Heiichiro; Oka, Mikio; Nakayama, Eiichi

    2013-01-15

    Immunogenicity of a long 20-mer NY-ESO-1f peptide vaccine was evaluated in a lung cancer patient TK-f01, immunized with the peptide with Picibanil OK-432 and Montanide ISA-51. We showed that internalization of the peptide was necessary to present CD8 T-cell epitopes on APC, contrasting with the direct presentation of the short epitope. CD8 T-cell responses restricted to all five HLA class I alleles were induced in the patient after the peptide vaccination. Clonal analysis showed that B*35:01 and B*52:01-restricted CD8 T-cell responses were the two dominant responses. The minimal epitopes recognized by A*24:02, B*35:01, B*52:01 and C*12:02-restricted CD8 T-cell clones were defined and peptide/HLA tetramers were produced. NY-ESO-1 91-101 on A*24:02, NY-ESO-1 92-102 on B*35:01, NY-ESO-1 96-104 on B*52:01 and NY-ESO-1 96-104 on C*12:02 were new epitopes first defined in this study. Identification of the A*24:02 epitope is highly relevant for studying the Japanese population because of its high expression frequency (60%). High affinity CD8 T-cells recognizing tumor cells naturally expressing the epitopes and matched HLA were induced at a significant level. The findings suggest the usefulness of a long 20-mer NY-ESO-1f peptide harboring multiple CD8 T-cell epitopes as an NY-ESO-1 vaccine. Characterization of CD8 T-cell responses in immunomonitoring using peptide/HLA tetramers revealed that multiple CD8 T-cell responses comprised the dominant response. Copyright © 2012 UICC.

  2. CD8 T cell memory: it takes all kinds

    Directory of Open Access Journals (Sweden)

    Stephen Christopher Jameson

    2012-11-01

    Full Text Available Understanding the mechanisms that regulate the differentiation and maintenance of CD8+ memory T cells is fundamental to the development of effective T cell based vaccines. Memory cell differentiation is influenced by the cytokines that accompany T cell priming, the history of previous antigen encounters, and the tissue sites into which memory cells migrate. These cues combine to influence the developing CD8+ memory pool, and recent work has revealed the importance of multiple transcription factors, metabolic molecules, and surface receptors in revealing the type of memory cell that is generated. Paired with increasingly meticulous subsetting and sorting of memory populations, we now know the CD8+ memory pool to be phenotypically and functionally heterogeneous in nature. This includes both recirculating and tissue resident memory populations, and cells with varying degrees of inherent longevity and protective function. These data point to the importance of tailored vaccine design. Here we discuss how the diversity of the memory CD8+ T cell pool challenges the notion that ‘one size fits all’ for pathogen control, and how distinct memory subsets may be suited for distinct aspects of protective immunity.

  3. Age-Related Changes in CD8 T Cell Homeostasis and Immunity to Infection

    Science.gov (United States)

    Nikolich-Zugich, Janko; Li, Gang; Uhrlaub, Jennifer L.; Renkema, Kristin R.; Smithey, Megan J.

    2012-01-01

    Studies of CD8 T cell responses to vaccination or infection with various pathogens in both animal models and human subjects have revealed a markedly consistent array of age-related defects. In general, recent work shows that aged CD8 T cell responses are decreased in magnitude, and show poor differentiation into effector cells, with a reduced arsenal of effector functions. Here we review potential mechanisms underlying these defects. We specifically address phenotypic and numeric changes to the naïve CD8 T cell precursor pool, the impact of persistent viral infection(s) and inflammation, and contributions of the aging environment in which these cells are activated. PMID:22554418

  4. A Mycobacterium bovis BCG-Naked DNA Prime-Boost Vaccination Strategy Induced CD4+ and CD8+ T-Cell Response against Mycobacterium tuberculosis Immunogens

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    Miao Lu

    2014-01-01

    Full Text Available Mycobacterium tuberculosis infection is still a major global public health problem. Presently the only tuberculosis (TB vaccine available is Bacille Calmette-Guérin (BCG, although it fails to adequately protect against pulmonary TB in adults. To solve this problem, the development of a new effective vaccine is urgently desired. BCG-prime DNA-booster vaccinations strategy has been shown to induce greater protection against tuberculosis (TB than BCG alone. Some studies have demonstrated that the two genes (Rv1769 and Rv1772 are excellent T-cell antigens and could induce T-cell immune responses. In this research, we built BCG-C or BCG-P prime-recombination plasmid PcDNA3.1-Rv1769 or PcDNA3.1-Rv1772 boost vaccinations strategy to immunize BALB/c mice and evaluated its immunogenicity. The data suggests that the BCG-C+3.1-72 strategy could elicit the most long-lasting and strongest Th1-type cellular immune responses and the BCG-C+3.1-69 strategy could induce the high level CD8+ T-cell response at certain time points. These findings support the ideas that the prime-boost strategy as a combination of vaccines may be better than a single vaccine for protection against tuberculosis.

  5. Neonatal CD8+ T-cell differentiation is dependent on interleukin-12.

    LENUS (Irish Health Repository)

    McCarron, Mark J

    2012-02-01

    Neonatal CD8(+) T-cell activation is significantly impaired compared with that in adults. Recent studies have demonstrated that interleukin (IL)-12 is necessary as a third signal, in addition to antigen and co-stimulation, to authorize the differentiation of naive CD8(+) T cells. We examined whether human neonatal CD8(+) T cells, which possess an exclusively naive T-cell phenotype, required a third signal to authorize a productive T-cell response. IL-12 enhanced activated naive CD8(+) T-cell survival, expansion, CD25 expression, and IL-2 production. Activated CD8(+) T cells produced interferon-gamma and intracellular granzyme B and were cytotoxic only in the presence of IL-12. Sustained IL-12 signaling for 72 hours was required for optimal interferon-gamma production. IL-12, in concert with T cell receptor (TCR) stimulation, sustained late-stage (48-72 hours) intracellular phosphorylation and particularly total protein levels of the proximal TCR components, Lck, and CD3xi. The requirement for a third signal for productive human neonatal CD8(+) T-cell differentiation may have implications for neonatal vaccination strategies.

  6. CD4+ T cell effects on CD8+ T cell location defined using bioluminescence.

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    Mitra Azadniv

    2011-01-01

    Full Text Available T lymphocytes of the CD8+ class are critical in delivering cytotoxic function and in controlling viral and intracellular infections. These cells are "helped" by T lymphocytes of the CD4+ class, which facilitate their activation, clonal expansion, full differentiation and the persistence of memory. In this study we investigated the impact of CD4+ T cells on the location of CD8+ T cells, using antibody-mediated CD4+ T cell depletion and imaging the antigen-driven redistribution of bioluminescent CD8+ T cells in living mice. We documented that CD4+ T cells influence the biodistribution of CD8+ T cells, favoring their localization to abdominal lymph nodes. Flow cytometric analysis revealed that this was associated with an increase in the expression of specific integrins. The presence of CD4+ T cells at the time of initial CD8+ T cell activation also influences their biodistribution in the memory phase. Based on these results, we propose the model that one of the functions of CD4+ T cell "help" is to program the homing potential of CD8+ T cells.

  7. Regulation of Gag- and Env-Specific CD8+ T Cell Responses in ART-Naïve HIV-Infected Patients: Potential Implications for Individualized Immunotherapy.

    Science.gov (United States)

    Prebensen, Christian; Lind, Andreas; Dyrhol-Riise, Anne-Ma; Kvale, Dag

    2016-01-01

    Strategies to develop a functional cure for HIV infection will likely require boosting of effector T cell responses to eliminate reactivated, latently infected cells. We have recently explored an assay for assessing antigen-specific regulation of T cell proliferation, which was related to clinical progression in untreated patients and to vaccine efficacy in two trials of therapeutic Gag-based vaccines. We here expand the same assay to further investigate regulation mediated by various inhibitory pathways. Peripheral blood mononuclear cells from 26 asymptomatic HIV-infected, antiretroviral therapy-naïve patients were stimulated with Gag and Env overlapping peptide panels for 5 days. Monoclonal antibodies (mAbs) blocking inhibitory mediators interleukin (IL) 10, transforming growth factor (TGF) β, programmed death ligand (PD-L) 1 and herpes virus entry mediator (HVEM) were added to parallel cultures. Functional T cell regulation (FTR) was defined as the difference in proliferation between stimulated cultures with and without blocking mAbs. FTR was detected in 54% of patients. Blockade of IL-10/PD-L1 and IL10/TGF-β detected all cases with Gag- and Env-associated FTR, respectively. In accordance with previous findings, isolated Env FTR was associated with higher plasma HIV RNA and lower CD4 counts, while patients with both Gag and Env FTR also had higher Gag- and Env-specific proliferative CD8+ T cell responses. There was no association between FTR and frequencies of activated regulatory T cells. In conclusion, we observed substantial heterogeneity in FTR between patients, inhibitory pathways and HIV antigens. FTR may help to individualize immunomodulation and warrants further assessment in clinical immunotherapy trials.

  8. In silico analysis of six known Leishmania major antigens and in vitro evaluation of specific epitopes eliciting HLA-A2 restricted CD8 T cell response.

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    Negar Seyed

    2011-09-01

    Full Text Available BACKGROUND: As a potent CD8(+ T cell activator, peptide vaccine has found its way in vaccine development against intracellular infections and cancer, but not against leishmaniasis. The first step toward a peptide vaccine is epitope mapping of different proteins according to the most frequent HLA types in a population. METHODS AND FINDINGS: Six Leishmania (L. major-related candidate antigens (CPB,CPC,LmsTI-1,TSA,LeIF and LPG-3 were screened for potential CD8(+ T cell activating 9-mer epitopes presented by HLA-A*0201 (the most frequent HLA-A allele. Online software including SYFPEITHI, BIMAS, EpiJen, Rankpep, nHLApred, NetCTL and Multipred were used. Peptides were selected only if predicted by almost all programs, according to their predictive scores. Pan-A2 presentation of selected peptides was confirmed by NetMHCPan1.1. Selected peptides were pooled in four peptide groups and the immunogenicity was evaluated by in vitro stimulation and intracellular cytokine assay of PBMCs from HLA-A2(+ individuals recovered from L. major. HLA-A2(- individuals recovered from L. major and HLA-A2(+ healthy donors were included as control groups. Individual response of HLA-A2(+ recovered volunteers as percent of CD8(+/IFN-γ(+ T cells after in vitro stimulation against peptide pools II and IV was notably higher than that of HLA-A2(- recovered individuals. Based on cutoff scores calculated from the response of HLA-A2(- recovered individuals, 31.6% and 13.3% of HLA-A2(+ recovered persons responded above cutoff in pools II and IV, respectively. ELISpot and ELISA results confirmed flow cytometry analysis. The response of HLA-A2(- recovered individuals against peptide pools I and III was detected similar and even higher than HLA-A2(+ recovered individuals. CONCLUSION: Using in silico prediction we demonstrated specific response to LmsTI-1 (pool II and LPG-3- (pool IV related peptides specifically presented in HLA-A*0201 context. This is among the very few reports

  9. Comparison of human memory CD8 T cell responses to adenoviral early and late proteins in peripheral blood and lymphoid tissue.

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    Amita Joshi

    Full Text Available Treatment of invasive adenovirus (Ad disease in hematopoietic stem cell transplant (SCT recipients with capsid protein hexon-specific donor T cells is under investigation. We propose that cytotoxic T cells (CTLs targeted to the late protein hexon may be inefficient in vivo because the early Ad protein E3-19K downregulates HLA class I antigens in infected cells. In this study, CD8+ T cells targeted to highly conserved HLA A2-restricted epitopes from the early regulatory protein DNA polymerase (P-977 and late protein hexon (H-892 were compared in peripheral blood (PB and tonsils of naturally infected adults. In tonsils, epitope-specific pentamers detected a significantly higher frequency of P-977+CD8+ T cells compared to H-892+CD8+ T cells; this trend was reversed in PB. Tonsil epitope-specific CD8+ T cells expressed IFN-γ and IL-2 but not perforin or TNF-α, whereas PB T cells were positive for IFN-γ, TNF-α, and perforin. Tonsil epitope-specific T cells expressed lymphoid homing marker CCR7 and exhibited lower levels of the activation marker CD25 but higher proliferative potential than PB T cells. Finally, in parallel with the kinetics of mRNA expression, P-977-specific CTLs lysed targets as early as 8 hrs post infection. In contrast, H-892-specific CTLs did not kill unless infected fibroblasts were pretreated with IFN-γ to up regulate HLA class I antigens, and cytotoxicity was delayed until 16-24 hours. These data show that, in contrast to hexon CTLs, central memory type DNA polymerase CTLs dominate the lymphoid compartment and kill fibroblasts earlier after infection without requiring exogenous IFN-γ. Thus, use of CTLs targeted to both early and late Ad proteins may improve the efficacy of immunotherapy for life-threatening Ad disease in SCT recipients.

  10. Designing CD8+ T cell vaccines: it's not rocket science (yet).

    Science.gov (United States)

    Yewdell, Jonathan W

    2010-06-01

    CD8+ T cells play important roles in clearing viral infections and eradicating tumors. Designing vaccines that elicit effective CD8+ T cell responses requires a thorough knowledge of the pathways of antigen presentation in vivo. Here, I review recent progress in understanding the activation of naïve CD8+ T cells in vivo, with particular emphasis on cross-priming, the presentation of protein antigens acquired by dendritic cells from their environment. With the rapid advances in this area of research, the dawn of rational vaccine design is at hand. Published by Elsevier Ltd.

  11. Decreased CD8+ T cell response to Epstein-Barr virus infected B cells in multiple sclerosis is not due to decreased HLA class I expression on B cells or monocytes

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    Csurhes Peter A

    2011-08-01

    Full Text Available Abstract Background Patients with multiple sclerosis (MS have a decreased frequency of CD8+ T cells reactive to their own Epstein-Barr virus (EBV infected B cells. We have proposed that this might predispose to the development of MS by allowing EBV-infected autoreactive B cells to accumulate in the central nervous system. The decreased CD8+ T cell response to EBV results from a general CD8+ T cell deficiency and also a decreased proportion of EBV-specific T cells within the total CD8+ T cell population. Because decreased HLA class I expression on monocytes and B cells has been reported in MS and could influence the generation and effector function of EBV-specific CD8+ T cells, the present study was undertaken to measure the expression of HLA molecules on B cells and monocytes in patients with MS. Methods We used flow cytometry to determine the proportions of T cells, natural killer cells, B cells and monocytes in peripheral blood mononuclear cells (PBMC and to quantify the expression of HLA molecules on T cells, B cells and monocytes of 59 healthy subjects and 62 patients with MS who had not received corticosteroids or immunomodulatory therapy in the previous 3 months. Results The levels of HLA class I and class II molecules expressed on T cells, B cells and monocytes were normal in patients with MS, with the exception of two patients with secondary progressive MS with very low class II expression on B cells. In confirmation of previous studies we also found that the percentage of CD8+ T cells was significantly decreased whereas the percentage of CD4+ T cells and the CD4:CD8 ratio were significantly increased in patients with MS compared to healthy subjects. Conclusions The decreased CD8+ T cell response to EBV-infected B cells in MS patients is not due to decreased HLA class I expression on monocytes or B cells. In a small proportion of patients decreased HLA class II expression on B cells might impair the CD8+ T cell response to EBV by

  12. CD4 and CD8 T cell responses to the M. tuberculosis Ag85B-TB10.4 promoted by adjuvanted subunit, adenovector or heterologous prime boost vaccination

    DEFF Research Database (Denmark)

    Elvang, Tara; Christensen, Jan P; Billeskov, Rolf

    2009-01-01

    and CD8 T cells. METHODS AND FINDINGS: To compare CD4 and CD8 responses against Ag85B-TB10.4 (H4), H4 was delivered as a subunit vaccine in cationic liposomes (CAF01), expressed in Ad5 (Ad-H4) or as a heterologous prime boost vaccination. H4/CAF01 induced primarily CD4 T cells and Ad-H4 gave......BACKGROUND: Although CD4 T cells are crucial for defense against M.tb, it is still not clear whether the optimal response against M.tb in fact involves both CD4 and CD8 T cells. To test this, we used a new vaccine strategy that generated a strong balanced T cell response consisting of both CD4...... on the priming of CD4 and CD8 cells and in terms of the protective capacity of the vaccine, and therefore represent an interesting new vaccine strategy against M.tb. However, CD4 and CD8 T cells respond very differently to live M.tb challenge, in a manner which supports the consensus that CD4 T cells do play...

  13. Unopposed production of granulocyte-macrophage colony-stimulating factor by tumors inhibits CD8+ T cell responses by dysregulating antigen-presenting cell maturation.

    Science.gov (United States)

    Bronte, V; Chappell, D B; Apolloni, E; Cabrelle, A; Wang, M; Hwu, P; Restifo, N P

    1999-05-15

    Tumor cells gene-modified to produce GM-CSF potently stimulate antitumor immune responses, in part, by causing the growth and differentiation of dendritic cells (DC). However, GM-CSF-modified tumor cells must be gamma-irradiated or they will grow progressively, killing the host. We observed that 23 of 75 (31%) human tumor lines and two commonly used mouse tumor lines spontaneously produced GM-CSF. In mice, chronic GM-CSF production by tumors suppressed Ag-specific CD8+ T cell responses. Interestingly, an inhibitory population of adherent CD11b(Mac-1)/Gr-1 double-positive cells caused the observed impairment of CD8+ T cell function upon direct cell-to-cell contact. The inhibitory cells were positive for some markers associated with Ag presenting cells, like F4/80, but were negative for markers associated with fully mature DC like DEC205, B7. 2, and MHC class II. We have previously reported that a similar or identical population of inhibitory "immature" APC was elicited after immunization with powerful recombinant immunogens. We show here that these inhibitory cells can be elicited by the administration of recombinant GM-CSF alone, and, furthermore, that they can be differentiated ex vivo into "mature" APC by the addition of IL-4 and GM-CSF. Thus, tumors may be able to escape from immune detection by producing "unopposed" GM-CSF, thereby disrupting the balance of cytokines needed for the maturation of fully functional DC. Further, CD11b/Gr-1 double-positive cells may function as "inhibitory" APC under the influence of GM-CSF alone.

  14. Unopposed Production of Granulocyte-Macrophage Colony-Stimulating Factor by Tumors Inhibits CD8+ T Cell Responses by Dysregulating Antigen-Presenting Cell Maturation1

    Science.gov (United States)

    Bronte, Vincenzo; Chappell, Dale B.; Apolloni, Elisa; Cabrelle, Anna; Wang, Michael; Hwu, Patrick; Restifo, Nicholas P.

    2008-01-01

    Tumor cells gene-modified to produce GM-CSF potently stimulate antitumor immune responses, in part, by causing the growth and differentiation of dendritic cells (DC). However, GM-CSF-modified tumor cells must be γ-irradiated or they will grow progressively, killing the host. We observed that 23 of 75 (31%) human tumor lines and two commonly used mouse tumor lines spontaneously produced GM-CSF. In mice, chronic GM-CSF production by tumors suppressed Ag-specific CD8+ T cell responses. Interestingly, an inhibitory population of adherent CD11b(Mac-1)/Gr-1 double-positive cells caused the observed impairment of CD8+ T cell function upon direct cell-to-cell contact. The inhibitory cells were positive for some markers associated with Ag presenting cells, like F4/80, but were negative for markers associated with fully mature DC like DEC205, B7.2, and MHC class II. We have previously reported that a similar or identical population of inhibitory “immature” APC was elicited after immunization with powerful recombinant immunogens. We show here that these inhibitory cells can be elicited by the administration of recombinant GM-CSF alone, and, furthermore, that they can be differentiated ex vivo into “mature” APC by the addition of IL-4 and GM-CSF. Thus, tumors may be able to escape from immune detection by producing “unopposed” GM-CSF, thereby disrupting the balance of cytokines needed for the maturation of fully functional DC. Further, CD11b/Gr-1 double-positive cells may function as “inhibitory” APC under the influence of GM-CSF alone. PMID:10229805

  15. Tumor-Induced CD8+ T-Cell Dysfunction in Lung Cancer Patients

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    Heriberto Prado-Garcia

    2012-01-01

    Full Text Available Lung cancer is the leading cause of cancer deaths worldwide and one of the most common types of cancers. The limited success of chemotherapy and radiotherapy regimes have highlighted the need to develop new therapies like antitumor immunotherapy. CD8+ T-cells represent a major arm of the cell-mediated anti-tumor response and a promising target for developing T-cell-based immunotherapies against lung cancer. Lung tumors, however, have been considered to possess poor immunogenicity; even so, lung tumor-specific CD8+ T-cell clones can be established that possess cytotoxicity against autologous tumor cells. This paper will focus on the alterations induced in CD8+ T-cells by lung cancer. Although memory CD8+ T-cells infiltrate lung tumors, in both tumor-infiltrating lymphocytes (TILs and malignant pleural effusions, these cells are dysfunctional and the effector subset is reduced. We propose that chronic presence of lung tumors induces dysfunctions in CD8+ T-cells and sensitizes them to activation-induced cell death, which may be associated with the poor clinical responses observed in immunotherapeutic trials. Getting a deeper knowledge of the evasion mechanisms lung cancer induce in CD8+ T-cells should lead to further understanding of lung cancer biology, overcome tumor evasion mechanisms, and design improved immunotherapeutic treatments for lung cancer.

  16. Lymph node targeting of BCG vaccines amplifies CD4 and CD8 T-cell responses and protection against Mycobacterium tuberculosis.

    Science.gov (United States)

    Waeckerle-Men, Ying; Bruffaerts, Nicolas; Liang, Yuan; Jurion, Fabienne; Sander, Peter; Kündig, Thomas M; Huygen, Kris; Johansen, Pål

    2013-02-04

    Vaccination with Mycobacterium bovis BCG provides limited protection against pulmonary tuberculosis and a risk of dissemination in immune-compromised vaccinees. For the development of new TB vaccines that stimulate strong T-cell responses a variety of strategies is being followed, especially recombinant BCG and attenuated M. tuberculosis. The objective of the current study was to test potential benefits of vaccination through direct lymph-node targeting of wildtype BCG; the recommended route of vaccination with BCG is intradermal. C57BL/6 mice were immunised with BCG by intradermal, subcutaneous or intralymphatic injections. Cellular immune responses and protection against M. tuberculosis were determined. Intralymphatic vaccination was 100-1000 times more effective in stimulating BCG-specific immune responses than intradermal or subcutaneous immunisation. Intralymphatic administration stimulated high frequencies of mycobacterium-specific lymphocytes with strong proliferating capacity and production of TNF-α, IL-2, IL-17 and, especially, IFN-γ secretion by. CD4 and CD8 T cells. Most importantly, intralymphatic vaccination with 2×10(3)CFU BCG induced sustained protection against M. tuberculosis in intratracheally challenged C57BL/6 mice, whereas subcutaneous vaccination with 2×10(5)CFU BCG conferred only a transient protection. Hence, direct administration of M. bovis BCG to lymph nodes demonstrates that efficient targeting to lymph nodes may help to overcome the efficacy problems of vaccination with BCG. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Modulation of CD4+and CD8+T Cell Function and Cytokine Responses in Strongyloides stercoralis Infection by Interleukin-27 (IL-27) and IL-37.

    Science.gov (United States)

    Anuradha, Rajamanickam; Munisankar, Saravanan; Bhootra, Yukthi; Dolla, Chandrakumar; Kumaran, Paul; Nutman, Thomas B; Babu, Subash

    2017-11-01

    Strongyloides stercoralis infection is associated with diminished antigen-specific Th1- and Th17-associated responses and enhanced Th2-associated responses. Interleukin-27 (IL-27) and IL-37 are two known anti-inflammatory cytokines that are highly expressed in S. stercoralis infection. We therefore wanted to examine the role of IL-27 and IL-37 in regulating CD4 + and CD8 + T cell responses in S. stercoralis infection. To this end, we examined the frequency of Th1/Tc1, Th2/Tc2, Th9/Tc9, Th17/Tc17, and Th22/Tc22 cells in 15 S. stercoralis -infected individuals and 10 uninfected individuals stimulated with parasite antigen following IL-27 or IL-37 neutralization. We also examined the production of prototypical type 1, type 2, type 9, type 17, and type 22 cytokines in the whole-blood supernatants. Our data reveal that IL-27 or IL-37 neutralization resulted in significantly enhanced frequencies of Th1/Tc1, Th2/Tc2, Th17/Tc17, Th9, and Th22 cells with parasite antigen stimulation. There was no induction of any T cell response in uninfected individuals following parasite antigen stimulation and IL-27 or IL-37 neutralization. Moreover, we also observed increased production of gamma interferon (IFN-γ), IL-5, IL-9, IL-17, and IL-22 and decreased production of IL-10 following IL-27 and IL-37 neutralization and parasite antigen stimulation in whole-blood cultures. Thus, we demonstrate that IL-27 and IL-37 limit the induction of particular T cell subsets along with cytokine responses in S. stercoralis infections, which suggest the importance of IL-27 and IL-37 in immune modulation in a chronic helminth infection. Copyright © 2017 American Society for Microbiology.

  18. Role of perforin secretion from CD8+ T-cells in neuronal cytotoxicity in multiple sclerosis.

    Science.gov (United States)

    Zhao, Daidi; Feng, Fuqiang; Zhao, Cong; Wu, Fang; Ma, Chao; Bai, Yanan; Guo, Jun; Li, Hongzeng

    2018-01-01

    Multiple sclerosis (MS) is the most prevalent autoimmune disease of the central nervous system, and is characterized by inflammation and myelin damage. The immune system initiates the autoimmune response, although the mechanisms of neuronal damage have not been elucidated. The purpose of the present study was to investigate autoreactive CD4+ and CD8 + T lymphocytes, in conjunction with other inflammatory cells and cytokines in active MS lesions. EAE animal models was established by plantar injections of MBP (200 μg per rat). Purified CD4+ or CD8+ T-cells were isolated from heparinized peripheral blood (EAE animals and control animals) via negative selection. To examine effects of presence of autoreactive CD4+ and CD8+ T lymphocytes, we carried out ELISA, Western blot analysis and TUNEL. In addition, we examined the direct effects of various factors on neuronal cell death using MTT assay. The data revealed that CD8+ T-cells were more toxic to neurons compared to CD4+ T-cells, in both the MBP and EAE conditions. Bax was greater increased when neurons were co-cultured with CD8+ T-cells in the MBP group. There is a significant increase in IL-17 secretion by CD4+ T-cells in both the MBP group and EAE group. Neuronal viability were affected by Perforin (1.5 μg/mL). The present study extends previous research by demonstrating the role of CD8+ T-cells in MS and supports perforin secretion by CD8+ T-cells as a potential therapeutic factor. Furthermore, we determined that CD4 + T-cells can enhance CD8 + T-cell neuronal cytotoxicity via induction of intense inflammation.

  19. CD40L Expression Allows CD8+ T Cells to Promote Their Own Expansion and Differentiation through Dendritic Cells

    Directory of Open Access Journals (Sweden)

    Neil Q. Tay

    2017-11-01

    Full Text Available CD8+ T cells play an important role in providing protective immunity against a wide range of pathogens, and a number of different factors control their activation. Although CD40L-mediated CD40 licensing of dendritic cells (DCs by CD4+ T cells is known to be necessary for the generation of a robust CD8+ T cell response, the contribution of CD8+ T cell-expressed CD40L on DC licensing is less clear. We have previously shown that CD8+ T cells are able to induce the production of IL-12 p70 by DCs in a CD40L-dependent manner, providing some evidence that CD8+ T cell-mediated activation of DCs is possible. To better understand the role of CD40L on CD8+ T cell responses, we generated and characterized CD40L-expressing CD8+ T cells both in vitro and in vivo. We found that CD40L was expressed on 30–50% of effector CD8+ T cells when stimulated and that this expression was transient. The expression of CD40L on CD8+ T cells promoted the proliferation and differentiation of both the CD40L-expressing CD8+ T cells and the bystander effector CD8+ T cells. This process occurred via a cell-extrinsic manner and was mediated by DCs. These data demonstrate the existence of a mechanism where CD8+ T cells and DCs cooperate to maximize CD8+ T cell responses.

  20. CD40L Expression Allows CD8+T Cells to Promote Their Own Expansion and Differentiation through Dendritic Cells.

    Science.gov (United States)

    Tay, Neil Q; Lee, Debbie C P; Chua, Yen Leong; Prabhu, Nayana; Gascoigne, Nicholas R J; Kemeny, David M

    2017-01-01

    CD8 + T cells play an important role in providing protective immunity against a wide range of pathogens, and a number of different factors control their activation. Although CD40L-mediated CD40 licensing of dendritic cells (DCs) by CD4 + T cells is known to be necessary for the generation of a robust CD8 + T cell response, the contribution of CD8 + T cell-expressed CD40L on DC licensing is less clear. We have previously shown that CD8 + T cells are able to induce the production of IL-12 p70 by DCs in a CD40L-dependent manner, providing some evidence that CD8 + T cell-mediated activation of DCs is possible. To better understand the role of CD40L on CD8 + T cell responses, we generated and characterized CD40L-expressing CD8 + T cells both in vitro and in vivo . We found that CD40L was expressed on 30-50% of effector CD8 + T cells when stimulated and that this expression was transient. The expression of CD40L on CD8 + T cells promoted the proliferation and differentiation of both the CD40L-expressing CD8 + T cells and the bystander effector CD8 + T cells. This process occurred via a cell-extrinsic manner and was mediated by DCs. These data demonstrate the existence of a mechanism where CD8 + T cells and DCs cooperate to maximize CD8 + T cell responses.

  1. CD8+ T cells complement antibodies in protecting against yellow fever virus.

    Science.gov (United States)

    Bassi, Maria R; Kongsgaard, Michael; Steffensen, Maria A; Fenger, Christina; Rasmussen, Michael; Skjødt, Karsten; Finsen, Bente; Stryhn, Anette; Buus, Søren; Christensen, Jan P; Thomsen, Allan R

    2015-02-01

    The attenuated yellow fever (YF) vaccine (YF-17D) was developed in the 1930s, yet little is known about the protective mechanisms underlying its efficiency. In this study, we analyzed the relative contribution of cell-mediated and humoral immunity to the vaccine-induced protection in a murine model of YF-17D infection. Using different strains of knockout mice, we found that CD4(+) T cells, B cells, and Abs are required for full clinical protection of vaccinated mice, whereas CD8(+) T cells are dispensable for long-term survival after intracerebral challenge. However, by analyzing the immune response inside the infected CNS, we observed an accelerated T cell influx into the brain after intracerebral challenge of vaccinated mice, and this T cell recruitment correlated with improved virus control in the brain. Using mice deficient in B cells we found that, in the absence of Abs, YF vaccination can still induce some antiviral protection, and in vivo depletion of CD8(+) T cells from these animals revealed a pivotal role for CD8(+) T cells in controlling virus replication in the absence of a humoral response. Finally, we demonstrated that effector CD8(+) T cells also contribute to viral control in the presence of circulating YF-specific Abs. To our knowledge, this is the first time that YF-specific CD8(+) T cells have been demonstrated to possess antiviral activity in vivo. Copyright © 2015 by The American Association of Immunologists, Inc.

  2. Interdisciplinary Analysis of HIV-Specific CD8(+) T Cell Responses against Variant Epitopes Reveals Restricted TCR Promiscuity

    DEFF Research Database (Denmark)

    Hoof, Ilka; Perez, C.L.; Buggert, M.

    2010-01-01

    HIV-1 specific CTL responses play a key role in limiting viral replication. CTL responses are sensitive to viral escape mutations, which influence recognition of the virus. Although CTLs have been shown to recognize epitope variants, the extent of this cross-reactivity has not been quantitatively...

  3. HPV-E7 delivered by engineered exosomes elicits a protective CD8T cell-mediated immune response.

    Science.gov (United States)

    Di Bonito, Paola; Ridolfi, Barbara; Columba-Cabezas, Sandra; Giovannelli, Andrea; Chiozzini, Chiara; Manfredi, Francesco; Anticoli, Simona; Arenaccio, Claudia; Federico, Maurizio

    2015-03-09

    We developed an innovative strategy to induce a cytotoxic T cell (CTL) immune response against protein antigens of choice. It relies on the production of exosomes, i.e., nanovesicles spontaneously released by all cell types. We engineered the upload of huge amounts of protein antigens upon fusion with an anchoring protein (i.e., HIV-1 Nefmut), which is an inactive protein incorporating in exosomes at high levels also when fused with foreign proteins. We compared the immunogenicity of engineered exosomes uploading human papillomavirus (HPV)-E7 with that of lentiviral virus-like particles (VLPs) incorporating equivalent amounts of the same antigen. These exosomes, whose limiting membrane was decorated with VSV-G, i.e., an envelope protein inducing pH-dependent endosomal fusion, proved to be as immunogenic as the cognate VLPs. It is noteworthy that the immunogenicity of the engineered exosomes remained unaltered in the absence of VSV-G. Most important, we provide evidence that the inoculation in mouse of exosomes uploading HPV-E7 induces production of anti-HPV E7 CTLs, blocks the growth of syngeneic tumor cells inoculated after immunization, and controls the development of tumor cells inoculated before the exosome challenge. These results represent the proof-of-concept about both feasibility and efficacy of the Nefmut-based exosome platform for the induction of CD8+ T cell immunity.

  4. Antibody-targeted NY-ESO-1 to mannose receptor or DEC-205 in vitro elicits dual human CD8+ and CD4+ T cell responses with broad antigen specificity.

    Science.gov (United States)

    Tsuji, Takemasa; Matsuzaki, Junko; Kelly, Marcus P; Ramakrishna, Venky; Vitale, Laura; He, Li-Zhen; Keler, Tibor; Odunsi, Kunle; Old, Lloyd J; Ritter, Gerd; Gnjatic, Sacha

    2011-01-15

    Immunization of cancer patients with vaccines containing full-length tumor Ags aims to elicit specific Abs and both CD4(+) and CD8(+) T cells. Vaccination with protein Ags, however, often elicits only CD4(+) T cell responses without inducing Ag-specific CD8(+) T cells, as exogenous protein is primarily presented to CD4(+) T cells. Recent data revealed that Ab-mediated targeting of protein Ags to cell surface receptors on dendritic cells could enhance the induction of both CD4(+) and CD8(+) T cells. We investigated in this study if these observations were applicable to NY-ESO-1, a cancer-testis Ag widely used in clinical cancer vaccine trials. We generated two novel targeting proteins consisting of the full-length NY-ESO-1 fused to the C terminus of two human mAbs against the human mannose receptor and DEC-205, both internalizing molecules expressed on APC. These targeting proteins were evaluated for their ability to activate NY-ESO-1-specific human CD4(+) and CD8(+) T cells in vitro. Both targeted NY-ESO-1 proteins rapidly bound to their respective targets on APC. Whereas nontargeted and Ab-targeted NY-ESO-1 proteins similarly activated CD4(+) T cells, cross-presentation to CD8(+) T cells was only efficiently induced by targeted NY-ESO-1. In addition, both mannose receptor and DEC-205 targeting elicited specific CD4(+) and CD8(+) T cells from PBLs of cancer patients. Receptor-specific delivery of NY-ESO-1 to APC appears to be a promising vaccination strategy to efficiently generate integrated and broad Ag-specific immune responses against NY-ESO-1 in cancer patients.

  5. Prolonged activation of virus-specific CD8+T cells after acute B19 infection

    DEFF Research Database (Denmark)

    Isa, Adiba; Kasprowicz, Victoria; Norbeck, Oscar

    2005-01-01

    BACKGROUND: Human parvovirus B19 (B19) is a ubiquitous and clinically significant pathogen, causing erythema infectiosum, arthropathy, transient aplastic crisis, and intrauterine fetal death. The phenotype of CD8+ T cells in acute B19 infection has not been studied previously. METHODS AND FINDINGS......: The number and phenotype of B19-specific CD8+ T cell responses during and after acute adult infection was studied using HLA-peptide multimeric complexes. Surprisingly, these responses increased in magnitude over the first year post-infection despite resolution of clinical symptoms and control of viraemia......, with T cell populations specific for individual epitopes comprising up to 4% of CD8+ T cells. B19-specific T cells developed and maintained an activated CD38+ phenotype, with strong expression of perforin and CD57 and downregulation of CD28 and CD27. These cells possessed strong effector function...

  6. Immune responses to Epstein?Barr virus: molecular interactions in the virus evasion of CD8+ T cell immunity

    OpenAIRE

    Rowe, Martin; Zuo, Jianmin

    2010-01-01

    Persistent viruses have mechanisms for modulating the host immune responses that are essential for achieving a lifelong virus?host balance while minimizing the viral pathogenicity. Here we review some of the immune-modulating mechanisms evolved by the ubiquitous but potentially oncogenic Epstein?Barr virus, with particular emphasis on the molecular mechanisms of genes interfering with HLA class I antigen presentation.

  7. Oligoclonal CD8+ T cells play a critical role in the development of hypertension.

    Science.gov (United States)

    Trott, Daniel W; Thabet, Salim R; Kirabo, Annet; Saleh, Mohamed A; Itani, Hana; Norlander, Allison E; Wu, Jing; Goldstein, Anna; Arendshorst, William J; Madhur, Meena S; Chen, Wei; Li, Chung-I; Shyr, Yu; Harrison, David G

    2014-11-01

    Recent studies have emphasized a role of adaptive immunity, and particularly T cells, in the genesis of hypertension. We sought to determine the T-cell subtypes that contribute to hypertension and renal inflammation in angiotensin II-induced hypertension. Using T-cell receptor spectratyping to examine T-cell receptor usage, we demonstrated that CD8(+) cells, but not CD4(+) cells, in the kidney exhibited altered T-cell receptor transcript lengths in Vβ3, 8.1, and 17 families in response to angiotensin II-induced hypertension. Clonality was not observed in other organs. The hypertension caused by angiotensin II in CD4(-/-) and MHCII(-/-) mice was similar to that observed in wild-type mice, whereas CD8(-/-) mice and OT1xRAG-1(-/-) mice, which have only 1 T-cell receptor, exhibited a blunted hypertensive response to angiotensin II. Adoptive transfer of pan T cells and CD8(+) T cells but not CD4(+)/CD25(-) cells conferred hypertension to RAG-1(-/-) mice. In contrast, transfer of CD4(+)/CD25(+) cells to wild-type mice receiving angiotensin II decreased blood pressure. Mice treated with angiotensin II exhibited increased numbers of kidney CD4(+) and CD8(+) T cells. In response to a sodium/volume challenge, wild-type and CD4(-/-) mice infused with angiotensin II retained water and sodium, whereas CD8(-/-) mice did not. CD8(-/-) mice were also protected against angiotensin-induced endothelial dysfunction and vascular remodeling in the kidney. These data suggest that in the development of hypertension, an oligoclonal population of CD8(+) cells accumulates in the kidney and likely contributes to hypertension by contributing to sodium and volume retention and vascular rarefaction. © 2014 American Heart Association, Inc.

  8. DNGR-1 is dispensable for CD8+ T-cell priming during respiratory syncytial virus infection.

    Science.gov (United States)

    Durant, Lydia R; Pereira, Catherine; Boakye, Aime; Makris, Spyridon; Kausar, Fahima; Goritzka, Michelle; Johansson, Cecilia

    2014-08-01

    During respiratory syncytial virus (RSV) infection CD8(+) T cells both assist in viral clearance and contribute to immunopathology. CD8(+) T cells recognize viral peptides presented by dendritic cells (DCs), which can directly present viral antigens when infected or, alternatively, "cross-present" antigens after endocytosis of dead or dying infected cells. Mouse CD8α(+) and CD103(+) DCs excel at cross-presentation, in part because they express the receptor DNGR-1 that detects dead cells by binding to exposed F-actin and routes internalized cell debris into the cross-presentation pathway. As RSV causes death in infected epithelial cells, we tested whether cross-presentation via DNGR-1 is necessary for CD8(+) T-cell responses to the virus. DNGR-1-deficient or wild-type mice were intranasally inoculated with RSV and the magnitude of RSV-specific CD8(+) T-cell induction was measured. We found that during live RSV infection, cross-presentation via DNGR-1 did not have a major role in the generation of RSV-specific CD8(+) T-cell responses. However, after intranasal immunization with dead cells infected with RSV, a dependence on DNGR-1 for RSV-specific CD8(+) T-cell responses was observed, confirming the ascribed role of the receptor. Thus, direct presentation by DCs may be the major pathway initiating CD8(+) T-cell responses to RSV, while DNGR-1-dependent cross-presentation has no detectable role. © 2014 The Authors. European Journal of Immunology published by Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Aging promotes acquisition of naive-like CD8+ memory T cell traits and enhanced functionalities

    Science.gov (United States)

    Davenport, Bennett; Nguyen, Tom; Victorino, Francisco; Haist, Kelsey; Jhun, Kevin; Karimpour-Fard, Anis; Hunter, Lawrence; Kedl, Ross; Clambey, Eric T.

    2016-01-01

    Protective T cell memory is an acquired trait that is contingent upon the preservation of its constituents and therefore vulnerable to the potentially deleterious effects of organismal aging. Here, however, we have found that long-term T cell memory in a natural murine host-pathogen system can substantially improve over time. Comprehensive molecular, phenotypic, and functional profiling of aging antiviral CD8+ memory T cells (CD8+ TM) revealed a pervasive remodeling process that promotes the gradual acquisition of distinct molecular signatures, of increasingly homogeneous phenotypes, and of diversified functionalities that combine to confer a CD8+ TM–autonomous capacity for enhanced recall responses and immune protection. Notably, the process of CD8+ TM aging is characterized by a progressive harmonization of memory and naive T cell traits, is broadly amenable to experimental acceleration or retardation, and serves as a constitutional component for the “rebound model” of memory T cell maturation. By casting CD8+ TM populations within the temporal framework of their slowly evolving properties, this model establishes a simple ontogenetic perspective on the principal organization of CD8+ T cell memory that may directly inform the development of improved diagnostic, prophylactic, and therapeutic modalities. PMID:27617858

  10. Neutrophil trails guide influenza-specific CD8T cells in the airways.

    Science.gov (United States)

    Lim, Kihong; Hyun, Young-Min; Lambert-Emo, Kris; Capece, Tara; Bae, Seyeon; Miller, Richard; Topham, David J; Kim, Minsoo

    2015-09-04

    During viral infections, chemokines guide activated effector T cells to infection sites. However, the cells responsible for producing these chemokines and how such chemokines recruit T cells are unknown. Here, we show that the early recruitment of neutrophils into influenza-infected trachea is essential for CD8(+) T cell-mediated immune protection in mice. We observed that migrating neutrophils leave behind long-lasting trails that are enriched in the chemokine CXCL12. Experiments with granulocyte-specific CXCL12 conditionally depleted mice and a CXCR4 antagonist revealed that CXCL12 derived from neutrophil trails is critical for virus-specific CD8(+) T cell recruitment and effector functions. Collectively, these results suggest that neutrophils deposit long-lasting, chemokine-containing trails, which may provide both chemotactic and haptotactic cues for efficient CD8(+) T cell migration and localization in influenza-infected tissues. Copyright © 2015, American Association for the Advancement of Science.

  11. Neutrophil trails guide influenza-specific CD8+ T cells in the airways

    Science.gov (United States)

    Lim, Kihong; Hyun, Young-Min; Lambert-Emo, Kris; Capece, Tara; Bae, Seyeon; Miller, Richard; Topham, David J.; Kim, Minsoo

    2016-01-01

    During viral infections, chemokines guide activated effector T cells to infection sites. However, the cells responsible for producing these chemokines and how such chemokines recruit T cells is unknown. Here, we show that the early recruitment of neutrophils into influenza-infected trachea is essential for CD8+ T cell-mediated immune protection in mice. We observed that migrating neutrophils leave behind long-lasting trails that are enriched in the chemokine CXCL12. Experiments with granulocyte-specific CXCL12 conditional knock-out mice and a CXCR4 antagonist revealed that CXCL12 derived from neutrophil trails is critical for virus-specific CD8+ T cell recruitment and effector functions. Collectively, these results suggest neutrophils deposit long-lasting, chemokine-containing trails, which may provide both chemotactic and haptotactic cues for efficient CD8+ T cell migration and localization in influenza-infected tissues. PMID:26339033

  12. Memory CD8(+) T Cells: Innate-Like Sensors and Orchestrators of Protection.

    Science.gov (United States)

    Lauvau, Grégoire; Boutet, Marie; Williams, Tere M; Chin, Shu Shien; Chorro, Laurent

    2016-06-01

    Recent findings have revealed roles for systemic and mucosa-resident memory CD8(+) T cells in the orchestration of innate immune responses critical to host defense upon microbial infection. Here we integrate these findings into the current understanding of the molecular and cellular signals controlling memory CD8(+) T cell reactivation and the mechanisms by which these cells mediate effective protection in vivo. The picture that emerges presents memory CD8(+) T cells as early sensors of danger signals, mediating protective immunity both through licensing of cellular effectors of the innate immune system and via the canonical functions associated with memory T cells. We discuss implications for the development of T cell vaccines and therapies and highlight important areas in need of further investigation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Memory CD8+ T Cells: Innate-Like Sensors and Orchestrators of Protection

    Science.gov (United States)

    Lauvau, Grégoire; Boutet, Marie; Williams, Tere M.; Chin, Mandy Shu Shien; Chorro, Laurent

    2016-01-01

    Recent findings have revealed roles for systemic and mucosal-resident memory CD8+ T cells in the orchestration of innate immune responses critical to host defense upon microbial infection. Here we integrate these findings into the current understanding of the molecular and cellular signals controlling memory CD8+ T cell reactivation, and the mechanisms by which these cells mediate effective protection in vivo. The picture that emerges presents memory CD8+ T cells as early sensors of danger signals, mediating protective immunity both through licensing of cellular effectors of the innate immune system and via the canonical functions associated with memory T cells. We discuss implications to the development of T cell vaccines and therapies, and highlight important areas in need of further investigation. PMID:27131432

  14. CD8 T Cell Sensory Adaptation Dependent on TCR Avidity for Self-Antigens

    DEFF Research Database (Denmark)

    Marquez, M.-E.; Ellmeier, W.; Sanchez-Guajardo, Vanesa Maria

    2005-01-01

    Adaptation of the T cell activation threshold may be one mechanism to control autoreactivity. To investigate its occurrence in vivo, we engineered a transgenic mouse model with increased TCR-dependent excitability by expressing a Zap70 gain-of-function mutant (ZAP-YEEI) in postselection CD8...... thymocytes and T cells. Increased basal phosphorylation of the Zap70 substrate linker for activation of T cells was detected in ZAP-YEEI-bearing CD8 T cells. However, these cells were not activated, but had reduced levels of TCR and CD5. Moreover, they produced lower cytokine amounts and showed faster......-YEEI suggested that signal tuning occurred during thymic maturation. Importantly, although P14 ﰌ ZAP-YEEI peripheral CD8 T cells were reduced in number and showed lower Ag-induced cytokine production and limited lymphopenia-driven proliferation, the peripheral survival/ expansion and Ag responsiveness of HY ﰌ...

  15. Transcription factor regulation of CD8+ T-cell memory and exhaustion.

    Science.gov (United States)

    Angelosanto, Jill M; Wherry, E John

    2010-07-01

    During an infection, antigen-specific CD8+ T cells undergo numerous cellular and transcriptional changes as they develop from naive T cells into effector and memory cells. However, when the antigen persists in a chronic infection, the cellular programs governing effector and memory development are influenced by chronic stimulation, and dysfunctional or exhausted CD8+ T cells are generated. Recently, exhausted CD8+ T cells were found to differ dramatically from naive and functional memory CD8+ T cells on a transcriptional level, demonstrating that exposure to chronic antigen can impact T cells at a fundamental level. While transcriptional changes in CD8+ T cells during memory development is currently a topic of particular interest, the transcriptional changes related to exhaustion and other forms of T-cell dysfunction have received less attention. New computational methods are not only uncovering important transcription factors in these developmental processes but are also going further to define and connect these transcription factors into transcriptional modules that work in parallel to control cell fate and state. Understanding the molecular processes behind the development of CD8+ T-cell memory and exhaustion should not only increase our understanding of the immune system but also could reveal therapeutic targets and treatments for infectious and immunological diseases. Here, we provide a basic overview of acute and chronic viral infections and the transcription factors known to influence the development of virus-specific T cells in both settings. We also discuss recent innovations in genomic and computational tools that could be used to enhance the way we understand the development of T-cell responses to infectious disease.

  16. Polymyalgia rheumatica is characterized by pro-inflammatory, senescent CD8+ T cells

    NARCIS (Netherlands)

    Van Der Geest, K.; Abdulahad, W.; Huitema, M.; Kroesen, B.; Rutgers, A.; Brouwer, E.; Boots, A.

    2013-01-01

    Background Polymyalgia rheumatica (PMR) is a frequent, inflammatory rheumatic disease affecting elderly people. Previous studies suggest that T cell mediated immune responses contribute to PMR. However, little is known about CD4+ and CD8+ T cell subsets and their function in PMR. Furthermore, it

  17. A glycolipid adjuvant, 7DW8-5, enhances CD8+ T cell responses induced by an adenovirus-vectored malaria vaccine in non-human primates.

    Science.gov (United States)

    Padte, Neal N; Boente-Carrera, Mar; Andrews, Chasity D; McManus, Jenny; Grasperge, Brooke F; Gettie, Agegnehu; Coelho-dos-Reis, Jordana G; Li, Xiangming; Wu, Douglass; Bruder, Joseph T; Sedegah, Martha; Patterson, Noelle; Richie, Thomas L; Wong, Chi-Huey; Ho, David D; Vasan, Sandhya; Tsuji, Moriya

    2013-01-01

    A key strategy to a successful vaccine against malaria is to identify and develop new adjuvants that can enhance T-cell responses and improve protective immunity. Upon co-administration with a rodent malaria vaccine in mice, 7DW8-5, a recently identified novel analog of α-galactosylceramide (α-GalCer), enhances the level of malaria-specific protective immune responses more strongly than the parent compound. In this study, we sought to determine whether 7DW8-5 could provide a similar potent adjuvant effect on a candidate human malaria vaccine in the more relevant non-human primate (NHP) model, prior to committing to clinical development. The candidate human malaria vaccine, AdPfCA (NMRC-M3V-Ad-PfCA), consists of two non-replicating recombinant adenoviral (Ad) vectors, one expressing the circumsporozoite protein (CSP) and another expressing the apical membrane antigen-1 (AMA1) of Plasmodium falciparum. In several phase 1 clinical trials, AdPfCA was well tolerated and demonstrated immunogenicity for both humoral and cell-mediated responses. In the study described herein, 25 rhesus macaques received prime and boost intramuscular (IM) immunizations of AdPfCA alone or with an ascending dose of 7DW8-5. Our results indicate that 7DW8-5 is safe and well-tolerated and provides a significant enhancement (up to 9-fold) in malaria-specific CD8+ T-cell responses after both priming and boosting phases, supporting further clinical development.

  18. A glycolipid adjuvant, 7DW8-5, enhances CD8+ T cell responses induced by an adenovirus-vectored malaria vaccine in non-human primates.

    Directory of Open Access Journals (Sweden)

    Neal N Padte

    Full Text Available A key strategy to a successful vaccine against malaria is to identify and develop new adjuvants that can enhance T-cell responses and improve protective immunity. Upon co-administration with a rodent malaria vaccine in mice, 7DW8-5, a recently identified novel analog of α-galactosylceramide (α-GalCer, enhances the level of malaria-specific protective immune responses more strongly than the parent compound. In this study, we sought to determine whether 7DW8-5 could provide a similar potent adjuvant effect on a candidate human malaria vaccine in the more relevant non-human primate (NHP model, prior to committing to clinical development. The candidate human malaria vaccine, AdPfCA (NMRC-M3V-Ad-PfCA, consists of two non-replicating recombinant adenoviral (Ad vectors, one expressing the circumsporozoite protein (CSP and another expressing the apical membrane antigen-1 (AMA1 of Plasmodium falciparum. In several phase 1 clinical trials, AdPfCA was well tolerated and demonstrated immunogenicity for both humoral and cell-mediated responses. In the study described herein, 25 rhesus macaques received prime and boost intramuscular (IM immunizations of AdPfCA alone or with an ascending dose of 7DW8-5. Our results indicate that 7DW8-5 is safe and well-tolerated and provides a significant enhancement (up to 9-fold in malaria-specific CD8+ T-cell responses after both priming and boosting phases, supporting further clinical development.

  19. CD4+ T cell help has an epitope-dependent impact on CD8+ T cell memory inflation during murine cytomegalovirus infection.

    Science.gov (United States)

    Snyder, Christopher M; Loewendorf, Andrea; Bonnett, Elizabeth L; Croft, Michael; Benedict, Chris A; Hill, Ann B

    2009-09-15

    Murine CMV (MCMV) establishes a systemic, low-level persistent infection resulting in the accumulation of CD8(+) T cells specific for a subset of viral epitopes, a process called memory inflation. Although replicating virus is rarely detected in chronically infected C57BL/6 mice, these inflationary cells display a phenotype suggestive of repeated Ag stimulation, and they remain functional. CD4(+) T cells have been implicated in maintaining the function and/or number of CD8(+) T cells in other chronic infections. Moreover, CD4(+) T cells are essential for complete control of MCMV. Thus, we wondered whether CD4(+) T cell deficiency would result in impaired MCMV-specific CD8(+) T cell responses. Here we show that CD4(+) T cell deficiency had an epitope-specific impact on CD8(+) T cell memory inflation. Of the three codominant T cell responses during chronic infection, only accumulation of the late-appearing IE3-specific CD8(+) T cells was substantially impaired in CD4(+) T cell-deficient mice. Moreover, the increased viral activity did not drive increased CD8(+) T cell division or substantial dysfunction in any MCMV-specific population that we studied. These data show that CD4(+) T cell help is needed for inflation of a response that develops only during chronic infection but is otherwise dispensable for the steady state maintenance and function of MCMV-specific CD8(+) T cells.

  20. Nonspecific CD8+T Cells and Dendritic Cells/Macrophages Participate in Formation of CD8+T Cell-Mediated Clusters against Malaria Liver-Stage Infection.

    Science.gov (United States)

    Akbari, Masoud; Kimura, Kazumi; Bayarsaikhan, Ganchimeg; Kimura, Daisuke; Miyakoda, Mana; Juriasingani, Smriti; Yuda, Masao; Amino, Rogerio; Yui, Katsuyuki

    2018-04-01

    CD8 + T cells are the major effector cells that protect against malaria liver-stage infection, forming clusters around Plasmodium -infected hepatocytes and eliminating parasites after a prolonged interaction with these hepatocytes. We aimed to investigate the roles of specific and nonspecific CD8 + T cells in cluster formation and protective immunity. To this end, we used Plasmodium berghei ANKA expressing ovalbumin as well as CD8 + T cells from transgenic mice expressing a T cell receptor specific for ovalbumin (OT-I) and CD8 + T cells specific for an unrelated antigen, respectively. While antigen-specific CD8 + T cells were essential for cluster formation, both antigen-specific and nonspecific CD8 + T cells joined the clusters. However, nonspecific CD8 + T cells did not significantly contribute to protective immunity. In the livers of infected mice, specific CD8 + T cells expressed high levels of CD25, compatible with a local, activated effector phenotype. In vivo imaging of the liver revealed that specific CD8 + T cells interact with CD11c + cells around infected hepatocytes. The depletion of CD11c + cells virtually eliminated the clusters in the liver, leading to a significant decrease in protection. These experiments reveal an essential role of hepatic CD11c + dendritic cells and presumably macrophages in the formation of CD8 + T cell clusters around Plasmodium -infected hepatocytes. Once cluster formation is triggered by parasite-specific CD8 + T cells, specific and unrelated activated CD8 + T cells join the clusters in a chemokine- and dendritic cell-dependent manner. Nonspecific CD8 + T cells seem to play a limited role in protective immunity against Plasmodium parasites. Copyright © 2018 American Society for Microbiology.

  1. Measuring the diaspora for virus-specific CD8+ T cells

    Science.gov (United States)

    Marshall, Dana R.; Turner, Stephen J.; Belz, Gabrielle T.; Wingo, Suzette; Andreansky, Samita; Sangster, Mark Y.; Riberdy, Janice M.; Liu, Tiebin; Tan, Ming; Doherty, Peter C.

    2001-01-01

    The CD8+ T cell diaspora has been analyzed after secondary challenge with an influenza A virus that replicates only in the respiratory tract. Numbers of DbNP366- and DbPA224-specific CD8+ T cells were measured by tetramer staining at the end of the recall response, then followed sequentially in the lung, lymph nodes, spleen, blood, and other organs. The extent of clonal expansion did not reflect the sizes of the preexisting memory T cell pools. Although the high-frequency CD8+ tetramer+ populations in the pneumonic lung and mediastinal lymph nodes fell rapidly from peak values, the “whole mouse” virus-specific CD8+ T cell counts decreased only 2-fold over the 4 weeks after infection, then subsided at a fairly steady rate to reach a plateau at about 2 months. The largest numbers were found throughout in the spleen, then the bone marrow. The CD8+DbNP366+ and CD8+DbPA224+ sets remained significantly enlarged for at least 4 months, declining at equivalent rates while retaining the nucleoprotein > acid polymerase immunodominance hierarchy characteristic of the earlier antigen-driven phase. Lowest levels of the CD69 “activation marker” were detected consistently on virus-specific CD8+ T cells in the blood, then the spleen. Those in the bone marrow and liver were intermediate, and CD69hi T cells were very prominent in the regional lymph nodes and the nasal-associated lymphoid tissue. Any population of “resting” CD8+ memory T cells is thus phenotypically heterogeneous, widely dispersed, and subject to broad homeostatic and local environmental effects irrespective of epitope specificity or magnitude. PMID:11344265

  2. Establishment of memory CD8+ T cells with live attenuated influenza virus across different vaccination doses.

    Science.gov (United States)

    Wang, Zhongfang; Kedzierski, Lukasz; Nuessing, Simone; Chua, Brendon Yew Loong; Quiñones-Parra, Sergio M; Huber, Victor C; Jackson, David C; Thomas, Paul G; Kedzierska, Katherine

    2016-12-01

    FluMist has been used in children and adults for more than 10 years. As pre-existing CD8+ T cell memory pools can provide heterologous immunity against distinct influenza viruses, it is important to understand influenza-specific CD8+ T cell responses elicited by different live attenuated influenza virus (LAIV) regimens. In this study, we immunized mice intranasally with two different doses of live-attenuated PR8 virus (PR8 ts, H1N1), low and high, and then assessed protective efficacy by challenging animals with heterosubtypic X31-H3N2 virus at 6 weeks post-vaccination. Different LAIV doses elicited influenza-specific CD8+ T cell responses in lungs and spleen, but unexpectedly not in bronchoalveolar lavage. Interestingly, the immunodominance hierarchy at the acute phase after immunization varied depending on the LAIV dose; however, these differences disappeared at 6 weeks post-vaccination, resulting in generation of comparable CD8+ T cell memory pools. After vaccination with either dose, sufficient numbers of specific CD8+ T cells were generated for recall and protection of mice against heterosubtypic H1N1→H3N2 challenge. As a result, immunized mice displayed reduced weight loss, diminished inflammatory responses and lower viral titres in lungs, when compared to unvaccinated animals. Interestingly, the higher dose led to enhanced viral clearance on day 5 post-challenge, though this was not associated with increased CD8+ T cell responses, but with higher levels of non-neutralizing antibodies against the priming virus. Our study suggests that, while different LAIV doses result in distinct immune profiles, even a low dose produces sufficient protective CD8+ T cell memory against challenge infection, though the high dose results in more rapid viral clearance and reduced inflammation.

  3. Self-class I MHC molecules support survival of naive CD8 T cells, but depress their functional sensitivity through regulation of CD8 expression levels.

    Science.gov (United States)

    Takada, Kensuke; Jameson, Stephen C

    2009-09-28

    Previous studies have suggested that naive CD8 T cells require self-peptide-major histocompatability complex (MHC) complexes for maintenance. However, interpretation of such studies is complicated because of the involvement of lymphopenic animals, as lymphopenia drastically alters naive T cell homeostasis and function. In this study, we explored naive CD8 T cell survival and function in nonlymphopenic conditions by using bone marrow chimeric donors and hosts in which class I MHC expression is absent or limited to radiosensitive versus radioresistant cells. We found that long-term survival of naive CD8 T cells (but not CD4 T cells) was impaired in the absence of class I MHC. However, distinct from this effect, class I MHC deprivation also enhanced naive CD8 T cell responsiveness to low-affinity (but not high-affinity) peptide-MHC ligands. We found that this improved sensitivity was a consequence of up-regulated CD8 levels, which was mediated through a transcriptional mechanism. Hence, our data suggest that, in a nonlymphopenic setting, self-class I MHC molecules support CD8 T cell survival, but that these interactions also attenuate naive T cell sensitivity by dynamic tuning of CD8 levels.

  4. CD8+ T cells in human autoimmune arthritis : The unusual suspects

    NARCIS (Netherlands)

    Petrelli, Alessandra; Van Wijk, Femke

    2016-01-01

    CD8+ T cells are key players in the body's defence against viral infections and cancer. To date, data on the role of CD8+ T cells in autoimmune diseases have been scarce, especially when compared with the wealth of research on CD4+ T cells. However, growing evidence suggests that CD8+ T-cell

  5. Dendritic cells exposed to MVA-based HIV-1 vaccine induce highly functional HIV-1-specific CD8(+ T cell responses in HIV-1-infected individuals.

    Directory of Open Access Journals (Sweden)

    Núria Climent

    Full Text Available Currently, MVA virus vectors carrying HIV-1 genes are being developed as HIV-1/AIDS prophylactic/therapeutic vaccines. Nevertheless, little is known about the impact of these vectors on human dendritic cells (DC and their capacity to present HIV-1 antigens to human HIV-specific T cells. This study aimed to characterize the interaction of MVA and MVA expressing the HIV-1 genes Env-Gag-Pol-Nef of clade B (referred to as MVA-B in human monocyte-derived dendritic cells (MDDC and the subsequent processes of HIV-1 antigen presentation and activation of memory HIV-1-specific T lymphocytes. For these purposes, we performed ex vivo assays with MDDC and autologous lymphocytes from asymptomatic HIV-infected patients. Infection of MDDC with MVA-B or MVA, at the optimal dose of 0.3 PFU/MDDC, induced by itself a moderate degree of maturation of MDDC, involving secretion of cytokines and chemokines (IL1-ra, IL-7, TNF-α, IL-6, IL-12, IL-15, IL-8, MCP-1, MIP-1α, MIP-1β, RANTES, IP-10, MIG, and IFN-α. MDDC infected with MVA or MVA-B and following a period of 48 h or 72 h of maturation were able to migrate toward CCL19 or CCL21 chemokine gradients. MVA-B infection induced apoptosis of the infected cells and the resulting apoptotic bodies were engulfed by the uninfected MDDC, which cross-presented HIV-1 antigens to autologous CD8(+ T lymphocytes. MVA-B-infected MDDC co-cultured with autologous T lymphocytes induced a highly functional HIV-specific CD8(+ T cell response including proliferation, secretion of IFN-γ, IL-2, TNF-α, MIP-1β, MIP-1α, RANTES and IL-6, and strong cytotoxic activity against autologous HIV-1-infected CD4(+ T lymphocytes. These results evidence the adjuvant role of the vector itself (MVA and support the clinical development of prophylactic and therapeutic anti-HIV vaccines based on MVA-B.

  6. Visualizing early splenic memory CD8+ T cells reactivation against intracellular bacteria in the mouse.

    Directory of Open Access Journals (Sweden)

    Marc Bajénoff

    Full Text Available Memory CD8(+ T cells represent an important effector arm of the immune response in maintaining long-lived protective immunity against viruses and some intracellular bacteria such as Listeria monocytogenes (L.m. Memory CD8(+ T cells are endowed with enhanced antimicrobial effector functions that perfectly tail them to rapidly eradicate invading pathogens. It is largely accepted that these functions are sufficient to explain how memory CD8(+ T cells can mediate rapid protection. However, it is important to point out that such improved functional features would be useless if memory cells were unable to rapidly find the pathogen loaded/infected cells within the infected organ. Growing evidences suggest that the anatomy of secondary lymphoid organs (SLOs fosters the cellular interactions required to initiate naive adaptive immune responses. However, very little is known on how the SLOs structures regulate memory immune responses. Using Listeria monocytogenes (L.m as a murine infection model and imaging techniques, we have investigated if and how the architecture of the spleen plays a role in the reactivation of memory CD8(+ T cells and the subsequent control of L.m growth. We observed that in the mouse, memory CD8(+ T cells start to control L.m burden 6 hours after the challenge infection. At this very early time point, L.m-specific and non-specific memory CD8(+ T cells localize in the splenic red pulp and form clusters around L.m infected cells while naïve CD8(+ T cells remain in the white pulp. Within these clusters that only last few hours, memory CD8(+ T produce inflammatory cytokines such as IFN-gamma and CCL3 nearby infected myeloid cells known to be crucial for L.m killing. Altogether, we describe how memory CD8(+ T cells trafficking properties and the splenic micro-anatomy conjugate to create a spatio-temporal window during which memory CD8(+ T cells provide a local response by secreting effector molecules around infected cells.

  7. On the role of CD8+ T cells in determining recovery time from influenza virus infection

    Directory of Open Access Journals (Sweden)

    Pengxing Cao

    2016-12-01

    Full Text Available Myriad experiments have identified an important role for CD8+ T cell response mechanisms in determining recovery from influenza A virus infection. Animal models of influenza infection further implicate multiple elements of the immune response in defining the dynamical characteristics of viral infection. To date, influenza virus models, while capturing particular aspects of the natural infection history, have been unable to reproduce the full gamut of observed viral kinetic behaviour in a single coherent framework. Here, we introduce a mathematical model of influenza viral dynamics incorporating innate, humoral and cellular immune components and explore its properties with a particular emphasis on the role of cellular immunity. Calibrated against a range of murine data, our model is capable of recapitulating observed viral kinetics from a multitude of experiments. Importantly, the model predicts a robust exponential relationship between the level of effector CD8+ T cells and recovery time, whereby recovery time rapidly decreases to a fixed minimum recovery time with an increasing level of effector CD8+ T cells. We find support for this relationship in recent clinical data from influenza A(H7N9 hospitalized patients. The exponential relationship implies that people with a lower level of naive CD8+ T cells may receive significantly more benefit from induction of additional effector CD8+ T cells arising from immunological memory, itself established through either previous viral infection or T cell-based vaccines.

  8. Targeting CD8+ T-cell tolerance for cancer immunotherapy.

    Science.gov (United States)

    Jackson, Stephanie R; Yuan, Jinyun; Teague, Ryan M

    2014-01-01

    In the final issue of Science in 2013, the American Association of Science recognized progress in the field of cancer immunotherapy as the 'Breakthrough of the Year.' The achievements were actually twofold, owing to the early success of genetically engineered chimeric antigen receptors (CAR) and to the mounting clinical triumphs achieved with checkpoint blockade antibodies. While fundamentally very different, the common thread of these independent strategies is the ability to prevent or overcome mechanisms of CD8(+) T-cell tolerance for improved tumor immunity. Here we discuss how circumventing T-cell tolerance has provided experimental insights that have guided the field of clinical cancer immunotherapy to a place where real breakthroughs can finally be claimed.

  9. CD8αα expression marks terminally differentiated human CD8+ T cells expanded in chronic viral infection

    Directory of Open Access Journals (Sweden)

    Lucy Jane Walker

    2013-08-01

    Full Text Available The T cell co-receptor CD8αβ enhances T cell sensitivity to antigen, however studies indicate CD8αα has the converse effect and acts as a co-repressor. Using a combination of Thymic Leukaemia antigen (TL tetramer, which directly binds CD8αα, anti-CD161 and anti-Vα7.2 antibodies we have been able for the first time to clearly define CD8αα expression on human CD8 T cells subsets. In healthy controls CD8αα is most highly expressed by CD161 bright (CD161++ mucosal associated invariant T (MAIT cells, with CD8αα expression highly restricted to the TCR Vα7.2+ cells of this subset. We also identified CD8αα-expressing populations within the CD161 mid (CD161+ and negative (CD161- non-MAIT CD8 T cell subsets and show TL-tetramer binding to correlate with expression of CD8β at low levels in the context of maintained CD8α expression (CD8α+CD8βlow. In addition, we found CD161-CD8α+CD8βlow populations to be significantly expanded in the peripheral blood of HIV-1 and hepatitis B (mean of 47% and 40% of CD161- T cells respectively infected individuals. Such CD8αα expressing T cells are an effector-memory population (CD45RA-, CCR7-, CD62L- that express markers of activation and maturation (HLA-DR+, CD28-, CD27-, CD57+ and are functionally distinct, expressing greater levels of TNF-α and IFN-γ on stimulation and perforin at rest than their CD8α+CD8βhigh counterparts. Antigen-specific T cells in HLA-B*4201+HIV-1 infected patients are found within both the CD161-CD8α+CD8βhigh and CD161-CD8α+CD8βlow populations. Overall we have clearly defined CD8αα expressing human T cell subsets using the TL-tetramer, and have demonstrated CD161-CD8α+CD8βlow populations, highly expanded in disease settings, to co-express CD8αβ and CD8αα. Co-expression of CD8αα on CD8αβ T cells may impact on their overall function in-vivo and contribute to the distinctive phenotype of highly differentiated populations in HBV and HIV-1 infection.

  10. Attrition of memory CD8 T cells during sepsis requires LFA-1.

    Science.gov (United States)

    Serbanescu, Mara A; Ramonell, Kimberly M; Hadley, Annette; Margoles, Lindsay M; Mittal, Rohit; Lyons, John D; Liang, Zhe; Coopersmith, Craig M; Ford, Mandy L; McConnell, Kevin W

    2016-11-01

    CD8 T cell loss and dysfunction have been implicated in the increased susceptibility to opportunistic infections during the later immunosuppressive phase of sepsis, but CD8 T cell activation and attrition in early sepsis remain incompletely understood. With the use of a CLP model, we assessed CD8 T cell activation at 5 consecutive time points and found that activation after sepsis results in a distinct phenotype (CD69 + CD25 int CD62L HI ) independent of cognate antigen recognition and TCR engagement and likely through bystander-mediated cytokine effects. Additionally, we observed that sepsis concurrently results in the preferential depletion of a subset of memory-phenotype CD8 T cells that remain "unactivated" (i.e., fail to up-regulate activation markers) by apoptosis. Unactivated CD44 HI OT-I cells were spared from sepsis-induced attrition, as were memory-phenotype CD8 T cells of mice treated with anti-LFA-1 mAb, 1 h after CLP. Perhaps most importantly, we demonstrate that attrition of memory phenotype cells may have a pathologic significance, as elevated IL-6 levels were associated with decreased numbers of memory-phenotype CD8 T cells in septic mice, and preservation of this subset after administration of anti-LFA-1 mAb conferred improved survival at 7 d. Taken together, these data identify potentially modifiable responses of memory-phenotype CD8 T cells in early sepsis and may be particularly important in the application of immunomodulatory therapies in sepsis. © Society for Leukocyte Biology.

  11. Hierarchy Low CD4+/CD8+ T-Cell Counts and IFN-? Responses in HIV-1+ Individuals Correlate with Active TB and/or M.tb Co-Infection

    OpenAIRE

    Shao, Lingyun; Zhang, Xinyun; Gao, Yan; Xu, Yunya; Zhang, Shu; Yu, Shenglei; Weng, Xinhua; Shen, Hongbo; Chen, Zheng W.; Jiang, Weimin; Zhang, Wenhong

    2016-01-01

    Objective Detailed studies of correlation between HIV-M.tb co-infection and hierarchy declines of CD8+/CD4+ T-cell counts and IFN-? responses have not been done. We conducted case-control studies to address this issue. Methods 164 HIV-1-infected individuals comprised of HIV-1+ATB, HIV-1+LTB and HIV-1+TB- groups were evaluated. Immune phenotyping and complete blood count (CBC) were employed to measure CD4+ and CD8+ T-cell counts; T.SPOT.TB and intracellular cytokine staining (ICS) were utilize...

  12. Co-administration of α-GalCer analog and TLR4 agonist induces robust CD8+ T-cell responses to PyCS protein and WT-1 antigen and activates memory-like effector NKT cells

    OpenAIRE

    Coelho-dos-Reis, Jordana G.; Huang, Jing; Tsao, Tiffany; Pereira, Felipe V.; Funakoshi, Ryota; Nakajima, Hiroko; Sugiyama, Haruo; Tsuji, Moriya

    2016-01-01

    In the present study, the combined adjuvant effect of 7DW8-5, a potent α-GalCer-analog, and monophosphoryl lipid A (MPLA), a TLR4 agonist, on the induction of vaccine-induced CD8+ T-cell responses and protective immunity was evaluated. Mice were immunized with peptides corresponding to the CD8+ T-cell epitopes of a malaria antigen, a circumsporozoite protein of Plasmodium yoelii, and a tumor antigen, a Wilms Tumor antigen-1 (WT-1), together with 7DW8-5 and MPLA, as an adjuvant. These immuniza...

  13. The Significance of Tumor Necrosis Factor Receptor Type II in CD8+Regulatory T Cells and CD8+Effector T Cells.

    Science.gov (United States)

    Ye, Lin-Lin; Wei, Xiao-Shan; Zhang, Min; Niu, Yi-Ran; Zhou, Qiong

    2018-01-01

    Tumor necrosis factor (TNF) is a pleiotropic cytokine that has both pro-inflammatory and anti-inflammatory functions. The biological functions of TNF are mediated by two receptors, TNF receptor type I (TNFR1) and TNF receptor type II (TNFR2). TNFR1 is expressed universally on almost all cell types and has been extensively studied, whereas TNFR2 is mainly restricted to immune cells and some tumor cells and its role is far from clarified. Studies have shown that TNFR2 mediates the stimulatory activity of TNF on CD4 + Foxp3 + regulatory T cells (Tregs) and CD8 + Foxp3 + Tregs, and is involved in the phenotypic stability, proliferation, activation, and suppressive activity of Tregs. TNFR2 can also be expressed on CD8 + effector T cells (Teffs), which delivers an activation signal and cytotoxic ability to CD8 + Teffs during the early immune response, as well as an apoptosis signal to terminate the immune response. TNFR2-induced abolition of TNF receptor-associated factor 2 (TRAF2) degradation may play an important role in these processes. Consequently, due to the distribution of TNFR2 and its pleiotropic effects, TNFR2 appears to be critical to keeping the balance between Tregs and Teffs, and may be an efficient therapeutic target for tumor and autoimmune diseases. In this review, we summarize the biological functions of TNFR2 expressed on CD8 + Foxp3 + Tregs and CD8 + Teffs, and highlight how TNF uses TNFR2 to coordinate the complex events that ultimately lead to efficient CD8 + T cell-mediated immune responses.

  14. CD8+CD25+ T cells reduce atherosclerosis in apoE(−/−) mice

    International Nuclear Information System (INIS)

    Zhou, Jianchang; Dimayuga, Paul C.; Zhao, Xiaoning; Yano, Juliana; Lio, Wai Man; Trinidad, Portia; Honjo, Tomoyuki; Cercek, Bojan; Shah, Prediman K.; Chyu, Kuang-Yuh

    2014-01-01

    Highlights: •The role of a sub-population of CD8 + T cells with suppressor functions was investigated in atherosclerosis. •CD8 + CD25 + T cells from adult apoE(−/−) mice had phenotype characteristics of T suppressor cells. •These CD8 + CD25 + T cells reduced CD4 + T cell proliferation and CD8 + cytotoxic activity in vitro. •Adoptive transfer of CD8 + CD25 + T cells significantly reduced atherosclerosis. •CD8 + CD25 + T cells have a suppressive function in atherosclerosis. -- Abstract: Background: It is increasingly evident that CD8 + T cells are involved in atherosclerosis but the specific subtypes have yet to be defined. CD8 + CD25 + T cells exert suppressive effects on immune signaling and modulate experimental autoimmune disorders but their role in atherosclerosis remains to be determined. The phenotype and functional role of CD8 + CD25 + T cells in experimental atherosclerosis were investigated in this study. Methods and results: CD8 + CD25 + T cells were observed in atherosclerotic plaques of apoE(−/−) mice fed hypercholesterolemic diet. Characterization by flow cytometric analysis and functional evaluation using a CFSE-based proliferation assays revealed a suppressive phenotype and function of splenic CD8 + CD25 + T cells from apoE(−/−) mice. Depletion of CD8 + CD25 + from total CD8 + T cells rendered higher cytolytic activity of the remaining CD8 + CD25 − T cells. Adoptive transfer of CD8 + CD25 + T cells into apoE(−/−) mice suppressed the proliferation of splenic CD4 + T cells and significantly reduced atherosclerosis in recipient mice. Conclusions: Our study has identified an athero-protective role for CD8 + CD25 + T cells in experimental atherosclerosis

  15. Contributions of CD8 T cells to the pathogenesis of mouse adenovirus type 1 respiratory infection.

    Science.gov (United States)

    Molloy, Caitlyn T; Andonian, Jennifer S; Seltzer, Harrison M; Procario, Megan C; Watson, Michael E; Weinberg, Jason B

    2017-07-01

    CD8 T cells are key components of the immune response to viruses, but their roles in the pathogenesis of adenovirus respiratory infection have not been characterized. We used mouse adenovirus type 1 (MAV-1) to define CD8 T cell contributions to the pathogenesis of adenovirus respiratory infection. CD8 T cell deficiency in β2m -/- mice had no effect on peak viral replication in lungs, but clearance of virus was delayed in β2m -/- mice. Virus-induced weight loss and increases in bronchoalveolar lavage fluid total protein, IFN-γ, TNF-α, IL-10, CCL2, and CCL5 concentrations were less in β2m -/- mice than in controls. CD8 T cell depletion had similar effects on virus clearance, weight loss, and inflammation. Deficiency of IFN-γ or perforin had no effect on viral replication or inflammation, but perforin-deficient mice were partially protected from weight loss. CD8 T cells promote MAV-1-induced pulmonary inflammation via a mechanism that is independent of direct antiviral effects. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Age-related changes in CD8 T cell homeostasis and immunity to infection.

    Science.gov (United States)

    Nikolich-Žugich, Janko; Li, Gang; Uhrlaub, Jennifer L; Renkema, Kristin R; Smithey, Megan J

    2012-10-01

    Studies of CD8 T cell responses to vaccination or infection with various pathogens in both animal models and human subjects have revealed a markedly consistent array of age-related defects. In general, recent work shows that aged CD8 T cell responses are decreased in magnitude, and show poor differentiation into effector cells, with a reduced arsenal of effector functions. Here we review potential mechanisms underlying these defects. We specifically address phenotypic and numeric changes to the naïve CD8 T cell precursor pool, the impact of persistent viral infection(s) and inflammation, and contributions of the aging environment in which these cells are activated. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Identification of Theileria lestoquardi Antigens Recognized by CD8+ T Cells.

    Science.gov (United States)

    Goh, Shan; Ngugi, Daniel; Lizundia, Regina; Hostettler, Isabel; Woods, Kerry; Ballingall, Keith; MacHugh, Niall D; Morrison, W Ivan; Weir, Willie; Shiels, Brian; Werling, Dirk

    2016-01-01

    As part of an international effort to develop vaccines for Theileria lestoquardi, we undertook a limited screen to test T. lestoquardi orthologues of antigens recognised by CD8+ T lymphocyte responses against T. annulata and T. parva in cattle. Five MHC defined sheep were immunized by live T. lestoquardi infection and their CD8+ T lymphocyte responses determined. Thirteen T. lestoquardi orthologues of T. parva and T. annulata genes, previously shown to be targets of CD8+ T lymphocyte responses of immune cattle, were expressed in autologous fibroblasts and screened for T cell recognition using an IFNγ assay. Genes encoding T. lestoquardi antigens Tl8 (putative cysteine proteinase, 349 aa) or Tl9 (hypothetical secreted protein, 293 aa) were recognise by T cells from one animal that displayed a unique MHC class I genotype. Antigenic 9-mer peptide epitopes of Tl8 and Tl9 were identified through peptide scans using CD8+ T cells from the responding animal. These experiments identify the first T. lestoquardi antigens recognised by CD8+ T cell responses linked to specific MHC class I alleles.

  18. Identification of Theileria lestoquardi Antigens Recognized by CD8+ T Cells.

    Directory of Open Access Journals (Sweden)

    Shan Goh

    Full Text Available As part of an international effort to develop vaccines for Theileria lestoquardi, we undertook a limited screen to test T. lestoquardi orthologues of antigens recognised by CD8+ T lymphocyte responses against T. annulata and T. parva in cattle. Five MHC defined sheep were immunized by live T. lestoquardi infection and their CD8+ T lymphocyte responses determined. Thirteen T. lestoquardi orthologues of T. parva and T. annulata genes, previously shown to be targets of CD8+ T lymphocyte responses of immune cattle, were expressed in autologous fibroblasts and screened for T cell recognition using an IFNγ assay. Genes encoding T. lestoquardi antigens Tl8 (putative cysteine proteinase, 349 aa or Tl9 (hypothetical secreted protein, 293 aa were recognise by T cells from one animal that displayed a unique MHC class I genotype. Antigenic 9-mer peptide epitopes of Tl8 and Tl9 were identified through peptide scans using CD8+ T cells from the responding animal. These experiments identify the first T. lestoquardi antigens recognised by CD8+ T cell responses linked to specific MHC class I alleles.

  19. The possible role of virus-specific CD8(+) memory T cells in decidual tissue

    NARCIS (Netherlands)

    van Egmond, A.; van der Keur, C.; Swings, G. M. J. S.; Scherjon, S. A.; Claas, F. H. J.

    The most abundant lymphocyte present in decidual tissue is the CD8(+) T cell. It has been shown that most decidual CD8(+) T cells have an effector -memory phenotype, but expressed reduced levels of perforin and granzyme B compared with the peripheral CD8(+) effector -memory T cells. The specificity

  20. Tumor Progression Locus 2 Promotes Induction of IFNλ, Interferon Stimulated Genes and Antigen-Specific CD8+ T Cell Responses and Protects against Influenza Virus.

    Directory of Open Access Journals (Sweden)

    Teneema Kuriakose

    2015-08-01

    Full Text Available Mitogen-activated protein kinase (MAP cascades are important in antiviral immunity through their regulation of interferon (IFN production as well as virus replication. Although the serine-threonine MAP kinase tumor progression locus 2 (Tpl2/MAP3K8 has been implicated as a key regulator of Type I (IFNα/β and Type II (IFNγ IFNs, remarkably little is known about how Tpl2 might contribute to host defense against viruses. Herein, we investigated the role of Tpl2 in antiviral immune responses against influenza virus. We demonstrate that Tpl2 is an integral component of multiple virus sensing pathways, differentially regulating the induction of IFNα/β and IFNλ in a cell-type specific manner. Although Tpl2 is important in the regulation of both IFNα/β and IFNλ, only IFNλ required Tpl2 for its induction during influenza virus infection both in vitro and in vivo. Further studies revealed an unanticipated function for Tpl2 in transducing Type I IFN signals and promoting expression of interferon-stimulated genes (ISGs. Importantly, Tpl2 signaling in nonhematopoietic cells is necessary to limit early virus replication. In addition to early innate alterations, impaired expansion of virus-specific CD8+ T cells accompanied delayed viral clearance in Tpl2-/- mice at late time points. Consistent with its critical role in facilitating both innate and adaptive antiviral responses, Tpl2 is required for restricting morbidity and mortality associated with influenza virus infection. Collectively, these findings establish an essential role for Tpl2 in antiviral host defense mechanisms.

  1. The Combined Deficiency of Immunoproteasome Subunits Affects Both the Magnitude and Quality of Pathogen- and Genetic Vaccination-Induced CD8+ T Cell Responses to the Human Protozoan Parasite Trypanosoma cruzi.

    Directory of Open Access Journals (Sweden)

    Jonatan Ersching

    2016-04-01

    Full Text Available The β1i, β2i and β5i immunoproteasome subunits have an important role in defining the repertoire of MHC class I-restricted epitopes. However, the impact of combined deficiency of the three immunoproteasome subunits in the development of protective immunity to intracellular pathogens has not been investigated. Here, we demonstrate that immunoproteasomes play a key role in host resistance and genetic vaccination-induced protection against the human pathogen Trypanosoma cruzi (the causative agent of Chagas disease, immunity to which is dependent on CD8+ T cells and IFN-γ (the classical immunoproteasome inducer. We observed that infection with T. cruzi triggers the transcription of immunoproteasome genes, both in mice and humans. Importantly, genetically vaccinated or T. cruzi-infected β1i, β2i and β5i triple knockout (TKO mice presented significantly lower frequencies and numbers of splenic CD8+ effector T cells (CD8+CD44highCD62Llow specific for the previously characterized immunodominant (VNHRFTLV H-2Kb-restricted T. cruzi epitope. Not only the quantity, but also the quality of parasite-specific CD8+ T cell responses was altered in TKO mice. Hence, the frequency of double-positive (IFN-γ+/TNF+ or single-positive (IFN-γ+ cells specific for the H-2Kb-restricted immunodominant as well as subdominant T. cruzi epitopes were higher in WT mice, whereas TNF single-positive cells prevailed among CD8+ T cells from TKO mice. Contrasting with their WT counterparts, TKO animals were also lethally susceptible to T. cruzi challenge, even after an otherwise protective vaccination with DNA and adenoviral vectors. We conclude that the immunoproteasome subunits are key determinants in host resistance to T. cruzi infection by influencing both the magnitude and quality of CD8+ T cell responses.

  2. Memory programming in CD8+ T-cell differentiation is intrinsic and is not determined by CD4 help

    Science.gov (United States)

    Kim, Juhyun; Jeong Ryu, Su; Oh, Keunhee; Ju, Ji-Min; Yeong Jeon, Ji; Nam, Giri; Lee, Dong-Sup; Kim, Hang-Rae; Young Kim, Joo; Chang, Jun; Sproule, Thomas; Choi, Kyungho; Roopenian, Derry; Young Choi, Eun

    2015-01-01

    CD8+ T cells activated without CD4+ T-cell help are impaired in memory expansion. To understand the underlying cellular mechanism, here we track the dynamics of helper-deficient CD8+ T-cell response to a minor histocompatibility antigen by phenotypic and in vivo imaging analyses. Helper-deficient CD8+ T cells show reduced burst expansion, rapid peripheral egress, delayed antigen clearance and continuous activation, and are eventually exhausted. Contrary to the general consensus that CD4 help encodes memory programmes in CD8+ T cells and helper-deficient CD8+ T cells are abortive, these cells can differentiate into effectors and memory precursors. Importantly, accelerating antigen clearance or simply increasing the burst effector size enables generation of memory cells by CD8+ T cells, regardless of CD4 help. These results suggest that the memory programme is CD8+ T-cell-intrinsic, and provide insight into the role of CD4 help in CD8+ T-cell responses. PMID:26272364

  3. Hierarchy Low CD4+/CD8+ T-Cell Counts and IFN-γ Responses in HIV-1+ Individuals Correlate with Active TB and/or M.tb Co-Infection.

    Science.gov (United States)

    Shao, Lingyun; Zhang, Xinyun; Gao, Yan; Xu, Yunya; Zhang, Shu; Yu, Shenglei; Weng, Xinhua; Shen, Hongbo; Chen, Zheng W; Jiang, Weimin; Zhang, Wenhong

    2016-01-01

    Detailed studies of correlation between HIV-M.tb co-infection and hierarchy declines of CD8+/CD4+ T-cell counts and IFN-γ responses have not been done. We conducted case-control studies to address this issue. 164 HIV-1-infected individuals comprised of HIV-1+ATB, HIV-1+LTB and HIV-1+TB- groups were evaluated. Immune phenotyping and complete blood count (CBC) were employed to measure CD4+ and CD8+ T-cell counts; T.SPOT.TB and intracellular cytokine staining (ICS) were utilized to detect ESAT6, CFP10 or PPD-specific IFN-γ responses. There were significant differences in median CD4+ T-cell counts between HIV-1+ATB (164/μL), HIV-1+LTB (447/μL) and HIV-1+TB- (329/μL) groups. Hierarchy low CD4+ T-cell counts (500/μL) were correlated significantly with active TB but not M.tb co-infection. Interestingly, hierarchy low CD8+ T-cell counts were not only associated significantly with active TB but also with M.tb co-infection (Pcounts and effector function in HIV-1-infected individuals are correlated with both M.tb co-infection and active TB. Hierarchy low CD4+ T-cell counts and Th1 effector function in HIV-1+ individuals are associated with increased frequencies of active TB, but not M.tb co-infection.

  4. Induction of CD8(+) T cell responses and protective efficacy following microneedle-mediated delivery of a live adenovirus-vectored malaria vaccine.

    Science.gov (United States)

    Pearson, Frances E; O'Mahony, Conor; Moore, Anne C; Hill, Adrian V S

    2015-06-22

    There is an urgent need for improvements in vaccine delivery technologies. This is particularly pertinent for vaccination programmes within regions of limited resources, such as those required for adequate provision for disposal of used needles. Microneedles are micron-sized structures that penetrate the stratum corneum of the skin, creating temporary conduits for the needle-free delivery of drugs or vaccines. Here, we aimed to investigate immunity induced by the recombinant simian adenovirus-vectored vaccine ChAd63.ME-TRAP; currently undergoing clinical assessment as a candidate malaria vaccine, when delivered percutaneously by silicon microneedle arrays. In mice, we demonstrate that microneedle-mediated delivery of ChAd63.ME-TRAP induced similar numbers of transgene-specific CD8(+) T cells compared to intradermal (ID) administration with needle-and-syringe, following a single immunisation and after a ChAd63/MVA heterologous prime-boost schedule. When mice immunised with ChAd63/MVA were challenged with live Plasmodium berghei sporozoites, microneedle-mediated ChAd63.ME-TRAP priming demonstrated equivalent protective efficacy as did ID immunisation. Furthermore, responses following ChAd63/MVA immunisation correlated with a specific design parameter of the array used ('total array volume'). The level of transgene expression at the immunisation site and skin-draining lymph node (dLN) was also linked to total array volume. These findings have implications for defining silicon microneedle array design for use with live, vectored vaccines. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Methotrexate-Loaded Four-Arm Star Amphiphilic Block Copolymer Elicits CD8+ T Cell Response against a Highly Aggressive and Metastatic Experimental Lymphoma.

    Science.gov (United States)

    Hira, Sumit Kumar; Ramesh, Kalyan; Gupta, Uttam; Mitra, Kheyanath; Misra, Nira; Ray, Biswajit; Manna, Partha Pratim

    2015-09-16

    We have synthesized a well-defined four-arm star amphiphilic block copolymer [poly(DLLA)-b-poly(NVP)]4 [star-(PDLLA-b-PNVP)4] that consists of D,L-lactide (DLLA) and N-vinylpyrrolidone (NVP) via the combination of ring-opening polymerization (ROP) and xanthate-mediated reversible addition-fragmentation chain transfer (RAFT) polymerization. Synthesis of the polymer was verified by 1H NMR spectroscopy and gel permeation chromatography (GPC). The amphiphilic four-arm star block copolymer forms spherical micelles in water as demonstrated by transmission electron microscopy (TEM) and 1H NMR spectroscopy. Pyrene acts as a probe to ascertain the critical micellar concentration (cmc) by using fluorescence spectroscopy. Methotrexate (MTX)-loaded polymeric micelles of star-(PDLLA15-b-PNVP10)4 amphiphilic block copolymer were prepared and characterized by fluorescence and TEM studies. Star-(PDLLA15-b-PNVP10)4 copolymer was found to be significantly effective with respect to inhibition of proliferation and lysis of human and murine lymphoma cells. The amphiphilic block copolymer causes cell death in parental and MTX-resistant Dalton lymphoma (DL) and Raji cells. The formulation does not cause hemolysis in red blood cells and is tolerant to lymphocytes compared to free MTX. Therapy with MTX-loaded star-(PDLLA15-b-PNVP10)4 amphiphilic block copolymer micelles prolongs the life span of animals with neoplasia by reducing the tumor load, preventing metastasis and augmenting CD8+ T cell-mediated adaptive immune responses.

  6. Neuroantigen-specific autoregulatory CD8+ T cells inhibit autoimmune demyelination through modulation of dendritic cell function.

    Directory of Open Access Journals (Sweden)

    Venkatesh P Kashi

    Full Text Available Experimental autoimmune encephalomyelitis (EAE is a well-established murine model of multiple sclerosis, an immune-mediated demyelinating disorder of the central nervous system (CNS. We have previously shown that CNS-specific CD8+ T cells (CNS-CD8+ ameliorate EAE, at least in part through modulation of CNS-specific CD4+ T cell responses. In this study, we show that CNS-CD8+ also modulate the function of CD11c+ dendritic cells (DC, but not other APCs such as CD11b+ monocytes or B220+ B cells. DC from mice receiving either myelin oligodendrocyte glycoprotein-specific CD8+ (MOG-CD8+ or proteolipid protein-specific CD8+ (PLP-CD8+ T cells were rendered inefficient in priming T cell responses from naïve CD4+ T cells (OT-II or supporting recall responses from CNS-specific CD4+ T cells. CNS-CD8+ did not alter DC subset distribution or MHC class II and CD86 expression, suggesting that DC maturation was not affected. However, the cytokine profile of DC from CNS-CD8+ recipients showed lower IL-12 and higher IL-10 production. These functions were not modulated in the absence of immunization with CD8-cognate antigen, suggesting an antigen-specific mechanism likely requiring CNS-CD8-DC interaction. Interestingly, blockade of IL-10 in vitro rescued CD4+ proliferation and in vivo expression of IL-10 was necessary for the suppression of EAE by MOG-CD8+. These studies demonstrate a complex interplay between CNS-specific CD8+ T cells, DC and pathogenic CD4+ T cells, with important implications for therapeutic interventions in this disease.

  7. B cells regulate thymic CD8+T cell differentiation in lupus-prone mice.

    Science.gov (United States)

    Xing, Chen; Zhu, Gaizhi; Xiao, He; Fang, Ying; Liu, Xiaoling; Han, Gencheng; Chen, Guojiang; Hou, Chunmei; Shen, Beifen; Li, Yan; Ma, Ning; Wang, Renxi

    2017-10-27

    Previous studies have shown that under normal physiological conditions thymic B cells play a critical function in T cell negative selection. We tested the effect of thymic B cells on thymic T-cell differentiation in autoimmune diseases including systemic lupus erythematosus (SLE). We found that thymic B cells and CD8 - CD4 + and CD4 - CD8 + T cells increased, whereas CD4 + CD8 + T cells decreased in lupus-prone mice. Once B cells were reduced, the change was reversed. Furthermore, we found that B cells blocked thymic immature single positive (ISP) CD4 - CD8 + CD3 lo/- RORγt - T cells progression into CD4 + CD8 + T cells. Interestingly, we found a novel population of thymic immature T cells (CD4 - CD8 + CD3 lo RORγt + ) that were induced into mature CD4 - CD8 + CD3 + RORγt + T cells by B cells in lupus-prone mice. Importantly, we found that IgG, produced by thymic B cells, played a critical role in the differentiation of thymic CD8 + ISP and mature RORγt + CD8 + T cells in lupus-prone mice. In conclusion, B cells blocked the differentiation from thymic CD8 + ISP and induced the differentiation of a novel immature CD4 - CD8 + CD3 lo RORγt + T cells into mature RORγt + CD8 + T cells by secreting IgG antibody in lupus-prone mice.

  8. Cognate CD4 T-cell licensing of dendritic cells heralds anti-cytomegalovirus CD8 T-cell immunity after human allogeneic umbilical cord blood transplantation.

    Science.gov (United States)

    Flinsenberg, T W H; Spel, L; Jansen, M; Koning, D; de Haar, C; Plantinga, M; Scholman, R; van Loenen, M M; Nierkens, S; Boon, L; van Baarle, D; Heemskerk, M H M; Boelens, J J; Boes, M

    2015-01-15

    Reactivation of human cytomegalovirus (CMV) is hazardous to patients undergoing allogeneic cord blood transplantation (CBT), lowering survival rates by approximately 25%. While antiviral treatment ameliorates viremia, complete viral control requires CD8+ T-cell-driven immunity. Mouse studies suggest that cognate antigen-specific CD4+ T-cell licensing of dendritic cells (DCs) is required to generate effective CD8+ T-cell responses. For humans, this was not fully understood. We here show that CD4+ T cells are essential for licensing of human DCs to generate effector and memory CD8+ T-cell immunity against CMV in CBT patients. First, we show in CBT recipients that clonal expansion of CMV-pp65-specific CD4+ T cells precedes the rise in CMV-pp65-specific CD8+ T cells. Second, the elicitation of CMV-pp65-specific CD8+ T cells from rare naive precursors in cord blood requires DC licensing by cognate CMV-pp65-specific CD4+ T cells. Finally, also CD8+ T-cell memory responses require CD4+ T-cell-mediated licensing of DCs in our system, by secretion of gamma interferon (IFN-γ) by pp65-specific CD4+ T cells. Together, these data show that human DCs require licensing by cognate antigen-specific CD4+ T cells to elicit effective CD8+ T-cell-mediated immunity and fight off viral reactivation in CBT patients. Survival rates after stem cell transplantation are lowered by 25% when patients undergo reactivation of cytomegalovirus (CMV) that they harbor. Immune protection against CMV is mostly executed by white blood cells called killer T cells. We here show that for generation of optimally protective killer T-cell responses that respond to CMV, the early elicitation of help from a second branch of CMV-directed T cells, called helper T cells, is required. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  9. Programmed death 1 is highly expressed on CD8+CD57+T cells in patients with stable multiple sclerosis and inhibits their cytotoxic response to Epstein-Barr virus.

    Science.gov (United States)

    Cencioni, Maria T; Magliozzi, Roberta; Nicholas, Richard; Ali, Rehiana; Malik, Omar; Reynolds, Richard; Borsellino, Giovanna; Battistini, Luca; Muraro, Paolo A

    2017-12-01

    Growing evidence points to a deregulated response to Epstein-Barr virus (EBV) in the central nervous system of patients with multiple sclerosis (MS) as a possible cause of disease. We have investigated the response of a subpopulation of effector CD8 + T cells to EBV in 36 healthy donors and in 35 patients with MS in active and inactive disease. We have measured the expression of markers of degranulation, the release of cytokines, cytotoxicity and the regulation of effector functions by inhibitory receptors, such as programmed death 1 (PD-1) and human inhibitor receptor immunoglobulin-like transcript 2 (ILT2). We demonstrate that polyfunctional cytotoxic CD8 + CD57 + T cells are able to kill EBV-infected cells in healthy donors. In contrast, an anergic exhaustion-like phenotype of CD8 + CD57 + T cells with high expression of PD-1 was observed in inactive patients with MS compared with active patients with MS or healthy donors. Detection of CD8 + CD57 + T cells in meningeal inflammatory infiltrates from post-mortem MS tissue confirmed the association of this cell phenotype with the disease pathological process. The overall results suggest that ineffective immune control of EBV in patietns with MS during remission may be one factor preceding and enabling the reactivation of the virus in the central nervous system and may cause exacerbation of the disease. © 2017 John Wiley & Sons Ltd.

  10. A Human Trypanosome Suppresses CD8+ T Cell Priming by Dendritic Cells through the Induction of Immune Regulatory CD4+ Foxp3+ T Cells.

    Science.gov (United States)

    Ersching, Jonatan; Basso, Alexandre Salgado; Kalich, Vera Lucia Garcia; Bortoluci, Karina Ramalho; Rodrigues, Maurício M

    2016-06-01

    Although CD4+ Foxp3+ T cells are largely described in the regulation of CD4+ T cell responses, their role in the suppression of CD8+ T cell priming is much less clear. Because the induction of CD8+ T cells during experimental infection with Trypanosoma cruzi is remarkably delayed and suboptimal, we raised the hypothesis that this protozoan parasite actively induces the regulation of CD8+ T cell priming. Using an in vivo assay that eliminated multiple variables associated with antigen processing and dendritic cell activation, we found that injection of bone marrow-derived dendritic cells exposed to T. cruzi induced regulatory CD4+ Foxp3+ T cells that suppressed the priming of transgenic CD8+ T cells by peptide-loaded BMDC. This newly described suppressive effect on CD8+ T cell priming was independent of IL-10, but partially dependent on CTLA-4 and TGF-β. Accordingly, depletion of Foxp3+ cells in mice infected with T. cruzi enhanced the response of epitope-specific CD8+ T cells. Altogether, our data uncover a mechanism by which T. cruzi suppresses CD8+ T cell responses, an event related to the establishment of chronic infections.

  11. A Human Trypanosome Suppresses CD8+ T Cell Priming by Dendritic Cells through the Induction of Immune Regulatory CD4+ Foxp3+ T Cells

    Science.gov (United States)

    Ersching, Jonatan; Basso, Alexandre Salgado; Kalich, Vera Lucia Garcia; Bortoluci, Karina Ramalho

    2016-01-01

    Although CD4+ Foxp3+ T cells are largely described in the regulation of CD4+ T cell responses, their role in the suppression of CD8+ T cell priming is much less clear. Because the induction of CD8+ T cells during experimental infection with Trypanosoma cruzi is remarkably delayed and suboptimal, we raised the hypothesis that this protozoan parasite actively induces the regulation of CD8+ T cell priming. Using an in vivo assay that eliminated multiple variables associated with antigen processing and dendritic cell activation, we found that injection of bone marrow-derived dendritic cells exposed to T. cruzi induced regulatory CD4+ Foxp3+ T cells that suppressed the priming of transgenic CD8+ T cells by peptide-loaded BMDC. This newly described suppressive effect on CD8+ T cell priming was independent of IL-10, but partially dependent on CTLA-4 and TGF-β. Accordingly, depletion of Foxp3+ cells in mice infected with T. cruzi enhanced the response of epitope-specific CD8+ T cells. Altogether, our data uncover a mechanism by which T. cruzi suppresses CD8+ T cell responses, an event related to the establishment of chronic infections. PMID:27332899

  12. CMV-specific CD8 T Cell Differentiation and Localization: Implications for Adoptive Therapies

    Directory of Open Access Journals (Sweden)

    Corinne J Smith

    2016-09-01

    Full Text Available Human cytomegalovirus (HCMV is a ubiquitous virus that causes chronic infection, and thus is one of the most common infectious complications of immune suppression. Adoptive transfer of HCMV-specific T cells has emerged as an effective method to reduce the risk for HCMV infection and/or reactivation by restoring immunity in transplant recipients. However, the CMV-specific CD8+ T cell response is comprised of a heterogenous mixture of subsets with distinct functions and localization and it is not clear if current adoptive immunotherapy protocols can reconstitute the full spectrum of CD8+ T cell immunity. The aim of this review is to briefly summarize the role of these T cell subsets in CMV immunity and to describe how current adoptive immunotherapy practices might affect their reconstitution in patients. The bulk of the CMV-specific CD8+ T cell population is made up of terminally differentiated effector T cells with immediate effector function and a short life span. Self-renewing memory T cells within the CMV-specific population retain the capacity to expand and differentiate upon challenge and are important for the long-term persistence of the CD8+ T cell response. Finally mucosal organs, which are frequent sites of CMV reactivation, are primarily inhabited by tissue resident memory T cells, which do not recirculate. Future work on adoptive transfer strategies may need to focus on striking a balance between the formation of these subsets to ensure the development of long lasting and protective immune responses that can access the organs affected by CMV disease.

  13. Peptide pool immunization and CD8+ T cell reactivity

    DEFF Research Database (Denmark)

    Rasmussen, Susanne B; Harndahl, Mikkel N; Buus, Anette Stryhn

    2013-01-01

    Mice were immunized twice with a pool of five peptides selected among twenty 8-9-mer peptides for their ability to form stable complexes at 37°C with recombinant H-2K(b) (half-lives 10-15h). Vaccine-induced immunity of splenic CD8(+) T cells was studied in a 24h IFNγ Elispot assay. Surprisingly......, IFNγ spot-formation was observed without addition of peptide to the assay culture at 3 weeks and 3 months after immunization. To clarify if IFNγ spot formation in the absence of peptide exposure ex vivo is caused by the peptide-pool per se, mice were immunized with single peptides. Three of the five...... peptides induced normal peptide immunity i.e. the specific T cell reactivity in the Elispot culture was strictly dependent on exposure to the immunizing peptide ex vivo. However, immunization with two of the peptides, a VSV- and a Mycobacterium-derived peptide, resulted in IFNγ spot formation without...

  14. Critical role for CD1d-restricted invariant NKT cells in stimulating intrahepatic CD8 T-cell responses to liver antigen

    NARCIS (Netherlands)

    Sprengers, Dave; Sillé, Fenna C. M.; Derkow, Katja; Besra, Gurdyal S.; Janssen, Harry L. A.; Schott, Eckart; Boes, Marianne

    2008-01-01

    V alpha14 invariant natural killer T cells (iNKT) are localized in peripheral tissues such as the liver rather than lymphoid tissues. Therefore, their role in modulating the stimulation of conventional, major histocompatibility complex (MHC)-restricted T-cell responses has remained ambiguous. We

  15. Prostaglandin E2 promotes features of replicative senescence in chronically activated human CD8+ T cells.

    Directory of Open Access Journals (Sweden)

    Jennifer P Chou

    Full Text Available Prostaglandin E2 (PGE2, a pleiotropic immunomodulatory molecule, and its free radical catalyzed isoform, iso-PGE2, are frequently elevated in the context of cancer and chronic infection. Previous studies have documented the effects of PGE2 on the various CD4+ T cell functions, but little is known about its impact on cytotoxic CD8+ T lymphocytes, the immune cells responsible for eliminating virally infected and tumor cells. Here we provide the first demonstration of the dramatic effects of PGE2 on the progression of human CD8+ T cells toward replicative senescence, a terminal dysfunctional state associated multiple pathologies during aging and chronic HIV-1 infection. Our data show that exposure of chronically activated CD8+ T cells to physiological levels of PGE2 and iso-PGE2 promotes accelerated acquisition of markers of senescence, including loss of CD28 expression, increased expression of p16 cell cycle inhibitor, reduced telomerase activity, telomere shortening and diminished production of key cytotoxic and survival cytokines. Moreover, the CD8+ T cells also produced higher levels of reactive oxygen species, suggesting that the resultant oxidative stress may have further enhanced telomere loss. Interestingly, we observed that even chronic activation per se resulted in increased CD8+ T cell production of PGE2, mediated by higher COX-2 activity, thus inducing a negative feedback loop that further inhibits effector function. Collectively, our data suggest that the elevated levels of PGE2 and iso-PGE2, seen in various cancers and HIV-1 infection, may accelerate progression of CD8+ T cells towards replicative senescence in vivo. Inhibition of COX-2 activity may, therefore, provide a strategy to counteract this effect.

  16. Phenotypic alteration of CD8+ T cells in chronic lymphocytic leukemia is associated with epigenetic reprogramming.

    Science.gov (United States)

    Wu, Jiazhu; Xu, Xiaojing; Lee, Eun-Joon; Shull, Austin Y; Pei, Lirong; Awan, Farrukh; Wang, Xiaoling; Choi, Jeong-Hyeon; Deng, Libin; Xin, Hong-Bo; Zhong, Wenxun; Liang, Jinhua; Miao, Yi; Wu, Yujie; Fan, Lei; Li, Jianyong; Xu, Wei; Shi, Huidong

    2016-06-28

    Immunosuppression is a prevalent clinical feature in chronic lymphocytic leukemia (CLL) patients, with many patients demonstrating increased susceptibility to infections as well as increased failure of an antitumor immune response. However, much is currently not understood regarding the precise mechanisms that attribute to this immunosuppressive phenotype in CLL. To provide further clarity to this particular phenomenon, we analyzed the T-cell profile of CLL patient samples within a large cohort and observed that patients with an inverted CD4/CD8 ratio had a shorter time to first treatment as well as overall survival. These observations coincided with higher expression of the immune checkpoint receptor PD-1 in CLL patient CD8+ T cells when compared to age-matched healthy donors. Interestingly, we discovered that increased PD-1 expression in CD8+ T cells corresponds with decreased DNA methylation levels in a distal upstream locus of the PD-1 gene PDCD1. Further analysis using luciferase reporter assays suggests that the identified PDCD1 distal upstream region acts as an enhancer for PDCD1 transcription and this region becomes demethylated during activation of naïve CD8+ T cells by anti-CD3/anti-CD28 antibodies and IL2. Finally, we conducted a genome-wide DNA methylation analysis comparing CD8+ T cells from CLL patients against healthy donors and identified additional differentially methylated genes with known immune regulatory functions including CCR6 and KLRG1. Taken together, our findings reveal the occurrence of epigenetic reprogramming taking place within CLL patient CD8+ T cells and highlight the potential mechanism of how immunosuppression is accomplished in CLL.

  17. Bystander activation and anti-tumor effects of CD8+ T cells following Interleukin-2 based immunotherapy is independent of CD4+ T cell help.

    Directory of Open Access Journals (Sweden)

    Arta M Monjazeb

    Full Text Available We have previously demonstrated that immunotherapy combining agonistic anti-CD40 and IL-2 (IT results in synergistic anti-tumor effects. IT induces expansion of highly cytolytic, antigen-independent "bystander-activated" (CD8(+CD44high T cells displaying a CD25(-NKG2D(+ phenotype in a cytokine dependent manner, which were responsible for the anti-tumor effects. While much attention has focused on CD4(+ T cell help for antigen-specific CD8(+ T cell expansion, little is known regarding the role of CD4(+ T cells in antigen-nonspecific bystander-memory CD8(+ T cell expansion. Utilizing CD4 deficient mouse models, we observed a significant expansion of bystander-memory T cells following IT which was similar to the non-CD4 depleted mice. Expanded bystander-memory CD8(+ T cells upregulated PD-1 in the absence of CD4(+ T cells which has been published as a hallmark of exhaustion and dysfunction in helpless CD8(+ T cells. Interestingly, compared to CD8(+ T cells from CD4 replete hosts, these bystander expanded cells displayed comparable (or enhanced cytokine production, lytic ability, and in vivo anti-tumor effects suggesting no functional impairment or exhaustion and were enriched in an effector phenotype. There was no acceleration of the post-IT contraction phase of the bystander memory CD8(+ response in CD4-depleted mice. The response was independent of IL-21 signaling. These results suggest that, in contrast to antigen-specific CD8(+ T cell expansion, CD4(+ T cell help is not necessary for expansion and activation of antigen-nonspecific bystander-memory CD8(+ T cells following IT, but may play a role in regulating conversion of these cells from a central memory to effector phenotype. Additionally, the expression of PD-1 in this model appears to be a marker of effector function and not exhaustion.

  18. Streptococcus salivarius-mediated CD8+T cell stimulation required antigen presentation by macrophages in oral squamous cell carcinoma.

    Science.gov (United States)

    Wang, Jie; Yang, Lina; Mao, Xiaohe; Li, Zaiye; Lin, Xiaoyu; Jiang, Canhua

    2018-05-15

    It has been shown that the peripheral blood mononuclear cells (PBMCs) from oral squamous cell carcinoma (OSCC) patients presented cytotoxic CD8 T cell response against Streptococcus salivarius (S. salivarius), of which the frequency was positively associated with recurrence-free survival in OSCC patients. To identify the conditions required for regulating S. salivarius-specific CD8 T cell-mediated cytotoxicity, we selectively depleted individual components of the PBMCs, and observed that the depletion of monocytes/macrophages, but not other immune cell subsets, significantly downregulated the S. salivarius-specific CD8 T cell cytotoxicity. Monocyte/macrophage alone was sufficient to reconstitute optimal granzyme B expression from S. salivarius-specific CD8 T cells. Also, both the memory and the naive CD8 T cells reacted to S. salivarius-stimulation, with the memory CD8 T cells presenting significantly higher S. salivarius-reactivity. Using M1- and M2-polarized macrophages from circulating monocytes, we found that M1-polarized macrophages, with significantly higher IL-12 expression and significantly lower IL-10 and MHC class II molecule expression, was more effective at promoting granzyme B responses in CD8 T cells, and required CD80/CD86 costimulating molecules for optimal responses. Interestingly, the tumor-associated macrophages (TAMs) from resected tumors presented characteristics of M2-polarized macrophages with high MHC class II expression and low IL-12 secretion. The frequency of tumor-infiltrating S. salivarius-specific cytotoxic CD8 T cell was inversely correlated with the level of IL-10 secretion and the MHC class II molecule expression in autologous TAMs. Together, we demonstrated that monocyte/macrophages presented essential antigen-presentation and costimulatory roles in CD8 T cell-mediated S. salivarius-specific granzyme B responses, and the polarization of macrophages could influence the potency of CD8 T cell responses. Copyright © 2018 Elsevier Inc

  19. Exhaustion of the CD8+T Cell Compartment in Patients with Mutations in Phosphoinositide 3-Kinase Delta.

    Science.gov (United States)

    Wentink, Marjolein W J; Mueller, Yvonne M; Dalm, Virgil A S H; Driessen, Gertjan J; van Hagen, P Martin; van Montfrans, Joris M; van der Burg, Mirjam; Katsikis, Peter D

    2018-01-01

    Pathogenic gain-of-function mutations in the gene encoding phosphoinositide 3-kinase delta (PI3Kδ) cause activated PI3Kδ syndrome (APDS), a disease characterized by humoral immunodeficiency, lymphadenopathy, and an inability to control persistent viral infections including Epstein-Barr virus (EBV) and cytomegalovirus (CMV) infections. Understanding the mechanisms leading to impaired immune response is important to optimally treat APDS patients. Immunosenescence of CD8 + T cells was suggested to contribute to APDS pathogenesis. However, the constitutive activation of T cells in APDS may also result in T cell exhaustion. Therefore, we studied exhaustion of the CD8 + T cell compartment in APDS patients and compared them with healthy controls and HIV patients, as a control for exhaustion. The subset distribution of the T cell compartment of APDS patients was comparable with HIV patients with decreased naive CD4 + and CD8 + T cells and increased effector CD8 + T cells. Like in HIV + patients, expression of activation markers and inhibitory receptors CD160, CD244, and programmed death receptor (PD)-1 on CD8 + T cells was increased in APDS patients, indicating exhaustion. EBV-specific CD8 + T cells from APDS patients exhibited an exhausted phenotype that resembled HIV-specific CD8 + T cells in terms of inhibitory receptor expression. Inhibition of PD-1 on EBV-specific CD8 + T cells from APDS patients enhanced in vitro proliferation and effector cytokine production. Based on these results, we conclude that total and EBV-specific CD8 + T cells from APDS patients are characterized by T cell exhaustion. Furthermore, PD-1 checkpoint inhibition may provide a possible therapeutic approach to support the immune system of APDS patients to control EBV and CMV.

  20. Liposome-Coupled Peptides Induce Long-Lived Memory CD8+ T Cells Without CD4+ T Cells

    OpenAIRE

    Taneichi, Maiko; Tanaka, Yuriko; Kakiuchi, Terutaka; Uchida, Tetsuya

    2010-01-01

    CD8(+) T cells provide broad immunity to viruses, because they are able to recognize all types of viral proteins. Therefore, the development of vaccines capable of inducing long-lived memory CD8(+) T cells is desired to prevent diseases, especially those for which no vaccines currently exist. However, in designing CD8(+) T cell vaccines, the role of CD4(+) T cells in the induction and maintenance of memory CD8(+) T cells remains uncertain. In the present study, the necessity or not of CD4(+) ...

  1. Cytotoxic T lymphocyte response to herpes simplex virus type 1 is composed of both CD8+ and CD4+ T cell phenotypes in acute and memory states

    International Nuclear Information System (INIS)

    Niemialtowski, Marek G.; Rouse, Barry T.

    1994-01-01

    Mice were infected via the cornea with HSV-1. Next, draining lymph nodes (DLN) and spleen cells were analyzed at various times post infection for the presence of cytotoxic T lymphocyte precursors (CTL-p) of both the CD8 + and CD4 + phenotypes. Responses were greatest in the DLN, but memory CTL persisted in the spleen and were undetectable in DLN by 60 days. On all occasions, the frequency of CD8 + CTL outnumbered CD4 + CTL. The murine CTL responses to HSV-1 differ from those in man where CD4 + MHC class II restricted CTL appear to dominate the response at least in the memory phase. (author). 28 refs, 2 figs, 1 tab

  2. Persistently open chromatin at effector gene loci in resting memory CD8+ T cells independent of transcriptional status1

    OpenAIRE

    Zediak, Valerie P.; Johnnidis, Jonathan B.; Wherry, E. John; Berger, Shelley L.

    2011-01-01

    Memory CD8+ T cells are characterized by more rapid and robust effector function upon infection compared with naïve T cells, but factors governing effector gene responsiveness are incompletely understood. We sought to understand transcriptional control of the effector genes Ifng, Gzmb and Prf1 in murine memory CD8+ T cells by characterizing their transcriptional profiles and chromatin states during LCMV infection. Each effector gene has a distinct transcriptional profile in resting memory cel...

  3. CD8+ T Cell-Mediated Immunity during Trypanosoma cruzi Infection: A Path for Vaccine Development?

    Science.gov (United States)

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

    2014-01-01

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

  4. CD8+ T Cell-Mediated Immunity during Trypanosoma cruzi Infection: A Path for Vaccine Development?

    Directory of Open Access Journals (Sweden)

    Fernando dos Santos Virgilio

    2014-01-01

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

  5. CD8(+) T-cell Immune Evasion Enables Oncolytic Virus Immunotherapy.

    Science.gov (United States)

    Pourchet, Aldo; Fuhrmann, Steven R; Pilones, Karsten A; Demaria, Sandra; Frey, Alan B; Mulvey, Matthew; Mohr, Ian

    2016-03-01

    Although counteracting innate defenses allows oncolytic viruses (OVs) to better replicate and spread within tumors, CD8(+) T-cells restrict their capacity to trigger systemic anti-tumor immune responses. Herpes simplex virus-1 (HSV-1) evades CD8(+) T-cells by producing ICP47, which limits immune recognition of infected cells by inhibiting the transporter associated with antigen processing (TAP). Surprisingly, removing ICP47 was assumed to benefit OV immuno-therapy, but the impact of inhibiting TAP remains unknown because human HSV-1 ICP47 is not effective in rodents. Here, we engineer an HSV-1 OV to produce bovine herpesvirus UL49.5, which unlike ICP47, antagonizes rodent and human TAP. Significantly, UL49.5-expressing OVs showed superior efficacy treating bladder and breast cancer in murine models that was dependent upon CD8(+) T-cells. Besides injected subcutaneous tumors, UL49.5-OV reduced untreated, contralateral tumor size and metastases. These findings establish TAP inhibitor-armed OVs that evade CD8(+) T-cells as an immunotherapy strategy to elicit potent local and systemic anti-tumor responses.

  6. Killing of targets by CD8 T cells in the mouse spleen follows the law of mass action.

    Directory of Open Access Journals (Sweden)

    Vitaly V Ganusov

    2011-01-01

    Full Text Available It has been difficult to correlate the quality of CD8 T cell responses with protection against viral infections. To investigate the relationship between efficacy and magnitude of T cell responses, we quantify the rate at which individual CD8 effector and memory T cells kill target cells in the mouse spleen. Using mathematical modeling, we analyze recent data on the loss of target cells pulsed with three different peptides from the mouse lymphocytic choriomeningitis virus (LCMV in mouse spleens with varying numbers of epitope-specific CD8 T cells. We find that the killing of targets follows the law of mass-action, i.e., the death rate of individual target cells remains proportional to the frequency (or the total number of specific CD8 T cells in the spleen despite the fact that effector cell densities and effector to target ratios vary about a 1000-fold. The killing rate of LCMV-specific CD8 T cells is largely independent of T cell specificity and differentiation stage. Our results thus allow one to calculate the critical T cell concentration at which growth of a virus with a given replication rate can be prevented from the start of infection by memory CD8 T cell response.

  7. Killing of targets by CD8 T cells in the mouse spleen follows the law of mass action.

    Science.gov (United States)

    Ganusov, Vitaly V; Barber, Daniel L; De Boer, Rob J

    2011-01-24

    It has been difficult to correlate the quality of CD8 T cell responses with protection against viral infections. To investigate the relationship between efficacy and magnitude of T cell responses, we quantify the rate at which individual CD8 effector and memory T cells kill target cells in the mouse spleen. Using mathematical modeling, we analyze recent data on the loss of target cells pulsed with three different peptides from the mouse lymphocytic choriomeningitis virus (LCMV) in mouse spleens with varying numbers of epitope-specific CD8 T cells. We find that the killing of targets follows the law of mass-action, i.e., the death rate of individual target cells remains proportional to the frequency (or the total number) of specific CD8 T cells in the spleen despite the fact that effector cell densities and effector to target ratios vary about a 1000-fold. The killing rate of LCMV-specific CD8 T cells is largely independent of T cell specificity and differentiation stage. Our results thus allow one to calculate the critical T cell concentration at which growth of a virus with a given replication rate can be prevented from the start of infection by memory CD8 T cell response.

  8. IL-27p28 Production by XCR1+ Dendritic Cells and Monocytes Effectively Predicts Adjuvant-Elicited CD8+ T Cell Responses.

    Science.gov (United States)

    Kilgore, Augustus M; Welsh, Seth; Cheney, Elizabeth E; Chitrakar, Alisha; Blain, Trevor J; Kedl, Benjamin J; Hunter, Chris A; Pennock, Nathan D; Kedl, Ross M

    2018-01-01

    It is well accepted that the innate response is a necessary prerequisite to the formation of the adaptive response. This is true for T cell responses against infections or adjuvanted subunit vaccination. However, specific innate parameters with predictive value for the magnitude of an adjuvant-elicited T cell response have yet to be identified. We previously reported how T cell responses induced by subunit vaccination were dependent on the cytokine IL-27. These findings were unexpected, given that T cell responses to an infection typically increase in the absence of IL-27. Using a novel IL-27p28-eGFP reporter mouse, we now show that the degree to which an adjuvant induces IL-27p28 production from dendritic cells and monocytes directly predicts the magnitude of the T cell response elicited. To our knowledge, these data are the first to identify a concrete innate correlate of vaccine-elicited cellular immunity, and they have significant practical and mechanistic implications for subunit vaccine biology.

  9. Local induction of immunosuppressive CD8+ T cells in the gut-associated lymphoid tissues.

    Science.gov (United States)

    Fleissner, Diana; Hansen, Wiebke; Geffers, Robert; Buer, Jan; Westendorf, Astrid M

    2010-10-20

    In contrast to intestinal CD4(+) regulatory T cells (T(regs)), the generation and function of immunomodulatory intestinal CD8(+) T cells is less well defined. To dissect the immunologic mechanisms of CD8(+) T cell function in the mucosa, reactivity against hemagglutinin (HA) expressed in intestinal epithelial cells of mice bearing a MHC class-I-restricted T-cell-receptor specific for HA was studied. HA-specific CD8(+) T cells were isolated from gut-associated tissues and phenotypically and functionally characterized for the expression of Foxp3(+) and their suppressive capacity. We demonstrate that intestinal HA expression led to peripheral induction of HA-specific CD8(+)Foxp3(+) T cells. Antigen-experienced CD8(+) T cells in this transgenic mouse model suppressed the proliferation of CD8(+) and CD4(+) T cells in vitro. Gene expression analysis of suppressive HA-specific CD8(+) T cells revealed a specific up-regulation of CD103, Nrp1, Tnfrsf9 and Pdcd1, molecules also expressed on CD4(+) T(reg) subsets. Finally, gut-associated dendritic cells were able to induce HA-specific CD8(+)Foxp3(+) T cells. We demonstrate that gut specific antigen presentation is sufficient to induce CD8(+) T(regs)in vivo which may maintain intestinal homeostasis by down-modulating effector functions of T cells.

  10. Local induction of immunosuppressive CD8+ T cells in the gut-associated lymphoid tissues.

    Directory of Open Access Journals (Sweden)

    Diana Fleissner

    Full Text Available BACKGROUND: In contrast to intestinal CD4(+ regulatory T cells (T(regs, the generation and function of immunomodulatory intestinal CD8(+ T cells is less well defined. To dissect the immunologic mechanisms of CD8(+ T cell function in the mucosa, reactivity against hemagglutinin (HA expressed in intestinal epithelial cells of mice bearing a MHC class-I-restricted T-cell-receptor specific for HA was studied. METHODOLOGY AND PRINCIPAL FINDINGS: HA-specific CD8(+ T cells were isolated from gut-associated tissues and phenotypically and functionally characterized for the expression of Foxp3(+ and their suppressive capacity. We demonstrate that intestinal HA expression led to peripheral induction of HA-specific CD8(+Foxp3(+ T cells. Antigen-experienced CD8(+ T cells in this transgenic mouse model suppressed the proliferation of CD8(+ and CD4(+ T cells in vitro. Gene expression analysis of suppressive HA-specific CD8(+ T cells revealed a specific up-regulation of CD103, Nrp1, Tnfrsf9 and Pdcd1, molecules also expressed on CD4(+ T(reg subsets. Finally, gut-associated dendritic cells were able to induce HA-specific CD8(+Foxp3(+ T cells. CONCLUSION AND SIGNIFICANCE: We demonstrate that gut specific antigen presentation is sufficient to induce CD8(+ T(regsin vivo which may maintain intestinal homeostasis by down-modulating effector functions of T cells.

  11. Epigenetic landscapes reveal transcription factors that regulate CD8+ T cell differentiation.

    Science.gov (United States)

    Yu, Bingfei; Zhang, Kai; Milner, J Justin; Toma, Clara; Chen, Runqiang; Scott-Browne, James P; Pereira, Renata M; Crotty, Shane; Chang, John T; Pipkin, Matthew E; Wang, Wei; Goldrath, Ananda W

    2017-05-01

    Dynamic changes in the expression of transcription factors (TFs) can influence the specification of distinct CD8 + T cell fates, but the observation of equivalent expression of TFs among differentially fated precursor cells suggests additional underlying mechanisms. Here we profiled the genome-wide histone modifications, open chromatin and gene expression of naive, terminal-effector, memory-precursor and memory CD8 + T cell populations induced during the in vivo response to bacterial infection. Integration of these data suggested that the expression and binding of TFs contributed to the establishment of subset-specific enhancers during differentiation. We developed a new bioinformatics method using the PageRank algorithm to reveal key TFs that influence the generation of effector and memory populations. The TFs YY1 and Nr3c1, both constitutively expressed during CD8 + T cell differentiation, regulated the formation of terminal-effector cell fates and memory-precursor cell fates, respectively. Our data define the epigenetic landscape of differentiation intermediates and facilitate the identification of TFs with previously unappreciated roles in CD8 + T cell differentiation.

  12. Epigenetic landscapes reveal transcription factors regulating CD8+ T cell differentiation

    Science.gov (United States)

    Yu, Bingfei; Zhang, Kai; Milner, J. Justin; Toma, Clara; Chen, Runqiang; Scott-Browne, James P.; Pereira, Renata M.; Crotty, Shane; Chang, John T.; Pipkin, Matthew E.; Wang, Wei; Goldrath, Ananda W.

    2017-01-01

    Dynamic changes in the expression of transcription factors (TFs) can influence specification of distinct CD8+ T cell fates, but the observation of equivalent expression of TF among differentially-fated precursor cells suggests additional underlying mechanisms. Here, we profiled genome-wide histone modifications, open chromatin and gene expression of naive, terminal-effector, memory-precursor and memory CD8+ T cell populations induced during the in vivo response to bacterial infection. Integration of these data suggested that TF expression and binding contributed to establishment of subset-specific enhancers during differentiation. We developed a new bioinformatics method using the PageRank algorithm to reveal novel TFs influencing the generation of effector and memory populations. The TFs YY1 and Nr3c1, both constitutively expressed during CD8+ T cell differentiation, regulated the formation of terminal-effector and memory-precursor cell-fates, respectively. Our data define the epigenetic landscape of differentiation intermediates, facilitating identification of TFs with previously unappreciated roles in CD8+ T cell differentiation. PMID:28288100

  13. MicroRNA Expression Patterns of CD8+ T Cells in Acute and Chronic Brucellosis

    Science.gov (United States)

    Budak, Ferah; Bal, S. Haldun; Tezcan, Gulcin; Guvenc, Furkan; Akalin, E. Halis; Goral, Guher; Deniz, Gunnur

    2016-01-01

    Although our knowledge about Brucella virulence factors and the host response increase rapidly, the mechanisms of immune evasion by the pathogen and causes of chronic disease are still unknown. Here, we aimed to investigate the immunological factors which belong to CD8+ T cells and their roles in the transition of brucellosis from acute to chronic infection. Using miRNA microarray, more than 2000 miRNAs were screened in CD8+ T cells of patients with acute or chronic brucellosis and healthy controls that were sorted from peripheral blood with flow cytometry and validated through qRT-PCR. Findings were evaluated using GeneSpring GX (Agilent) 13.0 software and KEGG pathway analysis. Expression of two miRNAs were determined to display a significant fold change in chronic group when compared with acute or control groups. Both miRNAs (miR-126-5p and miR-4753-3p) were decreased (p 2). These miRNAs have the potential to be the regulators of CD8+ T cell-related marker genes for chronic brucellosis infections. The differentially expressed miRNAs and their predicted target genes are involved in MAPK signaling pathway, cytokine-cytokine receptor interactions, endocytosis, regulation of actin cytoskeleton, and focal adhesion indicating their potential roles in chronic brucellosis and its progression. It is the first study of miRNA expression analysis of human CD8+ T cells to clarify the mechanism of inveteracy in brucellosis. PMID:27824867

  14. Phenotypes and functions of persistent Sendai virus-induced antibody forming cells and CD8+ T cells in diffuse nasal-associated lymphoid tissue typify lymphocyte responses of the gut.

    Science.gov (United States)

    Rudraraju, Rajeev; Surman, Sherri; Jones, Bart; Sealy, Robert; Woodland, David L; Hurwitz, Julia L

    2011-02-20

    Lymphocytes of the diffuse nasal-associated lymphoid tissue (d-NALT) are uniquely positioned to tackle respiratory pathogens at their point-of-entry, yet are rarely examined after intranasal (i.n.) vaccinations or infections. Here we evaluate an i.n. inoculation with Sendai virus (SeV) for elicitation of virus-specific antibody forming cells (AFCs) and CD8(+) T cells in the d-NALT. Virus-specific AFCs and CD8(+) T cells each appeared by day 7 after SeV inoculation and persisted for 8 months, explaining the long-sustained protection against respiratory virus challenge conferred by this vaccine. AFCs produced IgM, IgG1, IgG2a, IgG2b and IgA, while CD8+ T cells were cytolytic and produced low levels of cytokines. Phenotypic analyses of virus-specific T cells revealed striking similarities with pathogen-specific immune responses in the intestine, highlighting some key features of adaptive immunity at a mucosal site. Copyright © 2010 Elsevier Inc. All rights reserved.

  15. Codon optimization of the human papillomavirus E7 oncogene induces a CD8+ T cell response to a cryptic epitope not harbored by wild-type E7.

    Directory of Open Access Journals (Sweden)

    Felix K M Lorenz

    Full Text Available Codon optimization of nucleotide sequences is a widely used method to achieve high levels of transgene expression for basic and clinical research. Until now, immunological side effects have not been described. To trigger T cell responses against human papillomavirus, we incubated T cells with dendritic cells that were pulsed with RNA encoding the codon-optimized E7 oncogene. All T cell receptors isolated from responding T cell clones recognized target cells expressing the codon-optimized E7 gene but not the wild type E7 sequence. Epitope mapping revealed recognition of a cryptic epitope from the +3 alternative reading frame of codon-optimized E7, which is not encoded by the wild type E7 sequence. The introduction of a stop codon into the +3 alternative reading frame protected the transgene product from recognition by T cell receptor gene-modified T cells. This is the first experimental study demonstrating that codon optimization can render a transgene artificially immunogenic through generation of a dominant cryptic epitope. This finding may be of great importance for the clinical field of gene therapy to avoid rejection of gene-corrected cells and for the design of DNA- and RNA-based vaccines, where codon optimization may artificially add a strong immunogenic component to the vaccine.

  16. Selective accumulation of differentiated CD8+ T cells specific for respiratory viruses in the human lung

    NARCIS (Netherlands)

    de Bree, Godelieve J.; van Leeuwen, Ester M. M.; Out, Theo A.; Jansen, Henk M.; Jonkers, René E.; van Lier, René A. W.

    2005-01-01

    The lungs are frequently challenged by viruses, and resident CD8(+) T cells likely contribute to the surveillance of these pathogens. To obtain insight into local T cell immunity to respiratory viruses in humans, we determined the specificity, phenotype, and function of lung-residing CD8(+) T cells

  17. Mitochondria-Endoplasmic Reticulum Contact Sites Function as Immunometabolic Hubs that Orchestrate the Rapid Recall Response of Memory CD8+T Cells.

    Science.gov (United States)

    Bantug, Glenn R; Fischer, Marco; Grählert, Jasmin; Balmer, Maria L; Unterstab, Gunhild; Develioglu, Leyla; Steiner, Rebekah; Zhang, Lianjun; Costa, Ana S H; Gubser, Patrick M; Burgener, Anne-Valérie; Sauder, Ursula; Löliger, Jordan; Belle, Réka; Dimeloe, Sarah; Lötscher, Jonas; Jauch, Annaïse; Recher, Mike; Hönger, Gideon; Hall, Michael N; Romero, Pedro; Frezza, Christian; Hess, Christoph

    2018-03-01

    Glycolysis is linked to the rapid response of memory CD8 + T cells, but the molecular and subcellular structural elements enabling enhanced glucose metabolism in nascent activated memory CD8 + T cells are unknown. We found that rapid activation of protein kinase B (PKB or AKT) by mammalian target of rapamycin complex 2 (mTORC2) led to inhibition of glycogen synthase kinase 3β (GSK3β) at mitochondria-endoplasmic reticulum (ER) junctions. This enabled recruitment of hexokinase I (HK-I) to the voltage-dependent anion channel (VDAC) on mitochondria. Binding of HK-I to VDAC promoted respiration by facilitating metabolite flux into mitochondria. Glucose tracing pinpointed pyruvate oxidation in mitochondria, which was the metabolic requirement for rapid generation of interferon-γ (IFN-γ) in memory T cells. Subcellular organization of mTORC2-AKT-GSK3β at mitochondria-ER contact sites, promoting HK-I recruitment to VDAC, thus underpins the metabolic reprogramming needed for memory CD8 + T cells to rapidly acquire effector function. Copyright © 2018 Elsevier Inc. All rights reserved.

  18. CD8+ T cells Sabotage their own Memory Potential through IFN-γ-dependent modification of the IL-12/IL-15Rα axis on Dendritic Cells

    Science.gov (United States)

    Kohlhapp, Frederick J.; Zloza, Andrew; O’Sullivan, Jeremy A.; Moore, Tamson V.; Lacek, Andrew T.; Jagoda, Michael C.; McCracken, James; Cole, David J.; Guevara-Patiño, José A.

    2012-01-01

    CD8+ T cell responses have been shown to be regulated by dendritic cells (DCs) and CD4+ T cells leading to the tenet that CD8+ T cells play a passive role in their own differentiation. In contrast, by using a DNA vaccination model, to separate the events of vaccination from those of CD8+ T cell priming, we demonstrate that CD8+ T cells, themselves, actively limit their own memory potential through CD8+ T cell-derived IFN-γ-dependent modification of the IL-12/IL-15Rα axis on DCs. Such CD8+ T cell-driven cytokine alterations result in increased T-bet and decreased Bcl-2 expression, and thus decreased memory progenitor formation. These results identify an unrecognized role for CD8+ T cells in the regulation of their own effector differentiation fate and a previously uncharacterized relationship between the balance of inflammation and memory formation. PMID:22430740

  19. Expanded CD8 T-cell sharing between periphery and CNS in multiple sclerosis

    Science.gov (United States)

    Salou, Marion; Garcia, Alexandra; Michel, Laure; Gainche-Salmon, Anne; Loussouarn, Delphine; Nicol, Bryan; Guillot, Flora; Hulin, Philippe; Nedellec, Steven; Baron, Daniel; Ramstein, Gérard; Soulillou, Jean-Paul; Brouard, Sophie; Nicot, Arnaud B; Degauque, Nicolas; Laplaud, David A

    2015-01-01

    Objective In multiple sclerosis (MS), central nervous system (CNS), cerebrospinal fluid (CSF), and blood display TCR clonal expansions of CD8+ T cells. These clones have been assumed – but never demonstrated – to be similar in the three compartments. Addressing this key question is essential to infer the implication of peripheral clonally expanded CD8+ T cells in the disease. Methods For the first time, TCR Vβ repertoire from paired blood (purified CD8+ and CD4+ T cells), CSF and CNS (22 lesions, various inflammatory and demyelination statuses) samples from three MS patients was studied using complementary determining region 3 (CDR3) spectratyping and high-throughput sequencing. In parallel, blood and CNS clonally expanded CD8+ T cells were characterized by fluorescent staining. Results TCR Vβ repertoire analysis revealed strong sharing of predominant T-cell clones between CNS lesions, CSF, and blood CD8+ T cells. In parallel, we showed that blood oligoclonal CD8+ T cells exhibit characteristics of pathogenic cells, as they displayed a bias toward a memory phenotype in MS patients, with increased expression of CCR5, CD11a and Granzyme B (GZM-B) compared to non oligoclonal counterparts. CNS-infiltrating T cells were mainly CD8 expressing CD11a and GZM-B. Interpretation This study highlights the predominant implication of CD8+ T cells in MS pathophysiology and demonstrates that potentially aggressive CD8+ T cells can be easily identified and characterized from blood and CSF samples. PMID:26125037

  20. Notch signaling pathway dampens tumor-infiltrating CD8+T cells activity in patients with colorectal carcinoma.

    Science.gov (United States)

    Yu, Weifeng; Wang, Yanjun; Guo, Peng

    2018-01-01

    CD8 + T cells play critical role in controlling the metastasis and prognosis of cancer. Controversy remains as to the contribution of Notch signaling pathway in modulation of CD8 + T cells activity and development of tumorigenesis. Thus, the aim of the current study was to investigate the immunoregulatory role of Notch signaling pathway to peripheral and tumor-infiltrating CD8 + T cells in patients with colorectal carcinoma. A total of 46 patients with colorectal carcinoma and 20 health individuals were enrolled, and CD8 + T cells were purified from both peripheral bloods and carcinoma specimens. Cytolytic and noncytolytic functions of CD8 + T cells in response to Notch signaling inhibition were evaluated by measurements of lactate dehydrogenase release and proinflammatory cytokines production in both direct and indirect contact co-culture system to target HT29 cells. Cellular proliferation and inhibitory receptors expression in CD8 + T cells were also assessed by CCK-8 method and flow cytometry. There was no remarkable difference in percentage of CD8 + T cells between healthy individuals and patients with colorectal carcinoma. Notch1/2 and Hes1/5 mRNAs were elevated expressed in tumor-infiltrating CD8 + T cells in patients with colorectal carcinoma, however, did not correlated with tumor differentiation or stages. CD8 + T cells from healthy individuals presented stronger cytotoxicity, which was not affected by Notch signaling inhibitor. Inhibition of Notch signaling pathway not only promoted cytotoxicity of tumor-infiltrating CD8 + T cells, but also enhanced proinflammatory cytokines (including IFN-γ, TNF-α, IL-1β, IL-6, and IL-8) production by CD8 + T cells from patients with colorectal carcinoma. This process was accompanied by decreased expression of PD-1 in CD8 + T cells without influencing cellular proliferation. Our results indicated a potential immunosuppressive property of Notch signaling pathway, which dampened both cytolytic and noncytolytic functions

  1. A color-coded reporter model to study the effect of immunosuppressants on CD8+ T-cell memory in antitumor and alloimmune responses.

    Science.gov (United States)

    Rovira, Jordi; Sabet-Baktach, Manije; Eggenhofer, Elke; Lantow, Margareta; Koehl, Gudrun E; Schlitt, Hans J; Campistol, Josep M; Geissler, Edward K; Kroemer, Alexander

    2013-01-15

    Mammalian target of rapamycin (mTOR) inhibitors possess anticancer properties potentially useful in reducing posttransplantation malignancy. Besides controlling tumor-sensitive proliferative and angiogenic effects, mTOR influences transcription factors T-bet and Eomesodermin (Eomes) in CD8 cytotoxic T cells (Tc), which are key in rejecting tumors, and allografts. To study the role of mTOR in tumor and transplant immunity in an antigen-specific way, we used T-cell receptor transgenic B6.OTI recipients, B6.OVA.TG donors, and OVA-B16F10 melanoma cells. For tracking color-coded OTI-Tc cells associated with antitumor and alloimmunity in vivo, CD8-OTI transgenic reporter mice were created by crossbreeding DsRed-expressing B6.Nagy mice with B6.OTI mice. The role of mTOR in regulating the differentiation and function of alloreactive Tc cells in vitro was explored by stimulating OTI-Tc cells with ovalbumin-transgenic antigen-presenting cells in the presence of rapamycin or tacrolimus. Rapamycin, but not tacrolimus, induced a pro-antitumor phenotypic shift from CD62LCD44 effector memory Tc cells to CD62LCD44 central memory Tc cells, which featured up-regulated levels of T-bet and Eomes and preserved levels of interferon-γ and perforin. For future investigations, an in vivo model was established whereby DsRedOTI-Tc cells adoptively transferred into B6 mice bearing either a ovalbumin-transgenic mouse skin transplant or OVA-B16F10 tumor could be traced by fluorescence-activated cell sorting analysis as effector or memory Tc cells in transplant and tumor tissues. mTOR, but not calcineurin, inhibition spares antitumoral memory Tc cells by distinctively regulating T-bet and Eomes. This finding is now testable in a new tumor transplant model, which incorporates DsRedOTI-Tc cell tracing, opening the way to study the differential effects of immunosuppressants in posttransplantation malignancy.

  2. Identification of Zika virus epitopes reveals immunodominant and protective roles for dengue virus cross-reactive CD8+T cells.

    Science.gov (United States)

    Wen, Jinsheng; Tang, William Weihao; Sheets, Nicholas; Ellison, Julia; Sette, Alessandro; Kim, Kenneth; Shresta, Sujan

    2017-03-13

    CD8 + T cells play an important role in controlling Flavivirus infection, including Zika virus (ZIKV). Here, we have identified 25 HLA-B*0702-restricted epitopes and 1 HLA-A*0101-restricted epitope using interferon (IFN)-γ enzyme-linked immunospot (ELISPOT) and intracellular cytokine staining (ICS) in ZIKV-infected IFN-α/β receptor-deficient HLA transgenic mice. The cross-reactivity of ZIKV epitopes to dengue virus (DENV) was tested using IFN-γ-ELISPOT and IFN-γ-ICS on CD8 + T cells from DENV-infected mice, and five cross-reactive HLA-B*0702-binding peptides were identified by both assays. ZIKV/DENV cross-reactive CD8 + T cells in DENV-immune mice expanded post ZIKV challenge and dominated in the subsequent CD8 + T cell response. ZIKV challenge following immunization of mice with ZIKV-specific and ZIKV/DENV cross-reactive epitopes elicited CD8 + T cell responses that reduced infectious ZIKV levels, and CD8 + T cell depletions confirmed that CD8 + T cells mediated this protection. These results identify ZIKV-specific and ZIKV/DENV cross-reactive epitopes and demonstrate both an altered immunodominance pattern in the DENV-immune setting relative to naive, as well as a protective role for epitope-specific CD8 + T cells against ZIKV. These results have important implications for ZIKV vaccine development and provide a mouse model for evaluating anti-ZIKV CD8 + T cell responses of human relevance.

  3. Selective Expression of CCR10 and CXCR3 by Circulating Human Herpes Simplex Virus-Specific CD8 T Cells.

    Science.gov (United States)

    Hensel, Michael T; Peng, Tao; Cheng, Anqi; De Rosa, Stephen C; Wald, Anna; Laing, Kerry J; Jing, Lichen; Dong, Lichun; Magaret, Amalia S; Koelle, David M

    2017-10-01

    Herpes simplex virus (HSV) infection is restricted to epithelial cells and neurons and is controlled by CD8 T cells. These cells both traffic to epithelial sites of recurrent lytic infection and to ganglia and persist at the dermal-epidermal junction for up to 12 weeks after lesion resolution. We previously showed that cutaneous lymphocyte-associated antigen (CLA), a functional E-selectin ligand (ESL), is selectively expressed on circulating HSV-2-specific CD8 T cells. CLA/ESL mediates adhesion of T cells to inflamed vascular endothelium. Later stages in T-cell homing involve chemokines (Ch) and lymphocyte chemokine receptors (ChR) for vascular wall arrest and diapedesis. Several candidate ChR have been implicated in skin homing. We measured cell surface ChR on HSV-specific human peripheral blood CD8 T cells and extended our studies to HSV-1. We observed preferential cell surface expression of CCR10 and CXCR3 by HSV-specific CD8 T cells compared to CD8 T cells specific for control viruses, Epstein-Barr virus (EBV) and cytomegalovirus (CMV), and compared to bulk memory CD8 T cells. CXCR3 ligand mRNA levels were selectively increased in skin biopsy specimens from persons with recurrent HSV-2, while the mRNA levels of the CCR10 ligand CCL27 were equivalent in lesion and control skin. Our data are consistent with a model in which CCL27 drives baseline recruitment of HSV-specific CD8 T cells expressing CCR10, while interferon-responsive CXCR3 ligands recruit additional cells in response to virus-driven inflammation. IMPORTANCE HSV-2 causes very localized recurrent infections in the skin and genital mucosa. Virus-specific CD8 T cells home to the site of recurrent infection and participate in viral clearance. The exit of T cells from the blood involves the use of chemokine receptors on the T-cell surface and chemokines that are present in infected tissue. In this study, circulating HSV-2-specific CD8 T cells were identified using specific fluorescent tetramer reagents

  4. Co-administration of α-GalCer analog and TLR4 agonist induces robust CD8(+) T-cell responses to PyCS protein and WT-1 antigen and activates memory-like effector NKT cells.

    Science.gov (United States)

    Coelho-Dos-Reis, Jordana G; Huang, Jing; Tsao, Tiffany; Pereira, Felipe V; Funakoshi, Ryota; Nakajima, Hiroko; Sugiyama, Haruo; Tsuji, Moriya

    2016-07-01

    In the present study, the combined adjuvant effect of 7DW8-5, a potent α-GalCer-analog, and monophosphoryl lipid A (MPLA), a TLR4 agonist, on the induction of vaccine-induced CD8(+) T-cell responses and protective immunity was evaluated. Mice were immunized with peptides corresponding to the CD8(+) T-cell epitopes of a malaria antigen, a circumsporozoite protein of Plasmodium yoelii, and a tumor antigen, a Wilms Tumor antigen-1 (WT-1), together with 7DW8-5 and MPLA, as an adjuvant. These immunization regimens were able to induce higher levels of CD8(+) T-cell responses and, ultimately, enhanced levels of protection against malaria and tumor challenges compared to the levels induced by immunization with peptides mixed with 7DW8-5 or MPLA alone. Co-administration of 7DW8-5 and MPLA induces activation of memory-like effector natural killer T (NKT) cells, i.e. CD44(+)CD62L(-)NKT cells. Our study indicates that 7DW8-5 greatly enhances important synergistic pathways associated to memory immune responses when co-administered with MPLA, thus rendering this combination of adjuvants a novel vaccine adjuvant formulation. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Co-administration of α-GalCer analog and TLR4 agonist induces robust CD8+ T-cell responses to PyCS protein and WT-1 antigen and activates memory-like effector NKT cells

    Science.gov (United States)

    Coelho-dos-Reis, Jordana G.; Huang, Jing; Tsao, Tiffany; Pereira, Felipe V.; Funakoshi, Ryota; Nakajima, Hiroko; Sugiyama, Haruo; Tsuji, Moriya

    2016-01-01

    In the present study, the combined adjuvant effect of 7DW8-5, a potent α-GalCer-analog, and monophosphoryl lipid A (MPLA), a TLR4 agonist, on the induction of vaccine-induced CD8+ T-cell responses and protective immunity was evaluated. Mice were immunized with peptides corresponding to the CD8+ T-cell epitopes of a malaria antigen, a circumsporozoite protein of Plasmodium yoelii, and a tumor antigen, a Wilms Tumor antigen-1 (WT-1), together with 7DW8-5 and MPLA, as an adjuvant. These immunization regimens were able to induce higher levels of CD8+ T-cell responses and, ultimately, enhanced levels of protection against malaria and tumor challenges compared to the levels induced by immunization with peptides mixed with 7DW8-5 or MPLA alone. Co-administration of 7DW8-5 and MPLA induces activation of memory-like effector natural killer T (NKT) cells, i.e. CD44+CD62L−NKT cells. Our study indicates that 7DW8-5 greatly enhances important synergistic pathways associated to memory immune responses when co-administered with MPLA, thus rendering this combination of adjuvants a novel vaccine adjuvant formulation. PMID:27132023

  6. Acquired transcriptional programming in functional and exhausted virus-specific CD8 T cells.

    Science.gov (United States)

    Youngblood, Ben; Wherry, E John; Ahmed, Rafi

    2012-01-01

    Failure to control viral infections such as HIV results in T-cell receptor (TCR) and inhibitory receptor driven exhaustion of antigen-specific T cells. Persistent signaling by these receptors during chronic viral infection sculpts the transcriptional regulatory programs of virus-specific T cells. The resulting gene expression profile is tailored to temper the potentially damaging effector functions of cytotoxic T cells and adapt them to an antigen-rich and inflammation-rich environment. Here we review recent studies investigating mechanisms of transcriptional regulation of effector, functional memory, and exhausted T-cell functions during acute versus chronic infections. Patterns of gene expression in virus-specific CD8 T cells are a result of a combination of pro and inhibitory signals from antigen presentation (TCR-mediated) and co-inhibitory receptor ligation (PD-1, 2B4). Further, memory-specific transcriptional regulation of 2B4 expression and signaling impose a self-limiting secondary effector response to a prolonged viral infection. Additionally, differentiation of functional memory CD8 T cells is coupled with acquisition of a repressive epigenetic program for PD-1 expression. However, chronic infection provides a signal that blocks the acquisition of these epigenetic modifications reinforcing the suppression of cytotoxic lymphocyte (CTL) functions in exhausted cells. Current findings suggest that the mechanism(s) that delineate functional memory versus exhaustion are coupled with acquisition of transcriptional programs at the effector stage of differentiation, reinforced by cessation or persistence of TCR signaling.

  7. Airway epithelial cell-derived insulin-like growth factor-1 triggers skewed CD8(+) T cell polarization.

    Science.gov (United States)

    Zou, Jian-Yong; Huang, Shao-hong; Li, Yun; Chen, Hui-guo; Rong, Jian; Ye, Sheng

    2014-10-01

    Skewed CD8(+) T cell responses are important in airway inflammation. This study investigates the role of the airway epithelial cell-derived insulin-like growth factor 1 (IGF1) in contributing to CD8(+) T cell polarization. Expression of IGF1 in the airway epithelial cell line, RPMI2650 cells, was assessed by quantitative real time RT-PCR and Western blotting. The role of IGF1 in regulating CD8(+) T cell activation was observed by coculture of mite allergen-primed RPMI2650 cells and naïve CD8(+) T cells. CD8(+) T cell polarization was assessed by the carboxyfluorescein succinimidyl ester-dilution assay and the determination of cytotoxic cytokine levels in the culture medium. Exposure to mite allergen, Der p1, increased the expression of IGF1 by RPMI2650 cells. The epithelial cell-derived IGF1 prevented the activation-induced cell death by inducing the p53 gene hypermethylation. Mite allergen-primed RPMI2650 cells induced an antigen-specific CD8(+) T cell polarization. We conclude that mite allergens induce airway epithelial cell line, RPMI2650 cells, to produce IGF1; the latter contributes to antigen-specific CD8(+) T cell polarization. © 2014 International Federation for Cell Biology.

  8. Alloprimed CD8+ T cells Regulate Alloantibody and Eliminate Alloprimed B cells through Perforin- and FasL-dependent mechanisms

    Science.gov (United States)

    Zimmerer, J.M.; Pham, T.A.; Wright, C.L.; Tobin, K.J.; Sanghavi, P.B.; Elzein, S.M.; Sanders, V.M.; Bumgardner, G.L.

    2014-01-01

    While it is well known that CD4+ T cells and B cells collaborate for antibody production, our group previously reported that CD8+ T cells downregulate alloantibody responses following transplantation. However, the exact mechanism involved in CD8+ T cell-mediated downregulation of alloantibody remains unclear. We also reported that alloantibody production is enhanced when either perforin or FasL is deficient in transplant recipients. Here, we report that CD8+ T cell-deficient transplant recipient mice (high alloantibody producers) exhibit an increased number of primed B cells compared to wild-type transplant recipients. Furthermore, CD8+ T cells require FasL, perforin, and allospecificity to downregulate posttransplant alloantibody production. In vivo CD8-mediated clearance of alloprimed B cells was also FasL- and perforin-dependent. In vitro data demonstrated that recipient CD8+ T cells directly induce apoptosis of alloprimed IgG1+ B cells in co-culture in an allospecific and MHC class I-dependent fashion. Altogether these data are consistent with the interpretation that CD8+ T cells downregulate posttransplant alloantibody production by FasL- and perforin-dependent direct elimination of alloprimed IgG1+ B cells. PMID:24472191

  9. Incomplete effector/memory differentiation of antigen-primed CD8+ T cells in gene gun DNA-vaccinated mice

    DEFF Research Database (Denmark)

    Bartholdy, Christina; Stryhn, Anette; Hansen, Nils Jacob Vest

    2003-01-01

    DNA vaccination is an efficient way to induce CD8+ T cell memory, but it is still unclear to what extent such memory responses afford protection in vivo. To study this, we induced CD8+ memory responses directed towards defined viral epitopes, using DNA vaccines encoding immunodominant MHC class I...

  10. Decreased Expression of T-Cell Costimulatory Molecule CD28 on CD4 and CD8 T Cells of Mexican Patients with Pulmonary Tuberculosis

    Directory of Open Access Journals (Sweden)

    German Bernal-Fernandez

    2010-01-01

    Full Text Available Patients with tuberculosis frequently develop anergy, a state of T-cell hyporesponsiveness in which defective T-cell costimulation could be a factor. To know if the expression of T-cell costimulatory molecules was altered in tuberculosis, we analyzed the peripheral blood T-cell phenotype of 23 Mexican patients with pulmonary tuberculosis. There was severe CD4 (P<.001 and CD8 (P<.01 lymphopenia and upregulation of costimulatory molecule CD30 on CD4 and CD8 T cells (P<.05; this increase was higher in relapsing tuberculosis. The main finding was severe downregulation of the major costimulatory molecule CD28 on both CD8 and CD4 T cells (P<.001. Depletion of the CD4/CD28 subset, a hitherto undescribed finding, is relevant because CD4 T cells constitute the main arm of the cell-mediated antimycobacterial immune response.

  11. [Oxidized low-density lipoprotein modulates differentiation of murine memory CD8+T cell subpopulations].

    Science.gov (United States)

    Zheng, Hua; Lin, Ze-Hang; Zhang, Yan-Mei; Zhou, Chen-Fei; Liu, Xuan; Wu, Sha

    2017-08-20

    To investigate effect of oxidized low-density lipoprotein (ox-LDL) on memory CD8 + T cell subpopulation differentiation in mice with autoimmune diabetes. Cultured splenic CD8 + T cells from pre-diabetic NOD mice isolated with magnetic beads were treated with 30 µg/mL ox-LDL and 10 U/mL interleukin-2 (IL-2) for 24 h and the control cells were treated with IL-2 only. Flow cytometry was used to determine the percentage of splenic CD8 + IFN-γ + T cells, expressions of CD8, CD44 and CD62L on the T cells, and the activation of T cell factor-1 (TCF-1) and STAT-3. The CD127 + memory T cells were purified and transplanted into the pre-diabetic NOD mice via the tail vein, and the blood glucose was recorded weekly and survival time of the mice was monitored. Treatment with ox-LDL significantly reduced islet β cell-specific cytotoxic CD8 + T cells as compared with the control group [(0.7∓0.03)% vs (2.7∓0.14)%, Peffector memory CD8 + T cells (Tem) in the total memory CD8 + T cells was reduced [(10.3∓0.71)% vs (30.3∓1.36)%, Pmemory T cells was significantly increased [(72.3∓3.8)% vs (55.1∓2.61)%, Pmemory T cells in pre-diabetic NOD mice obviously inhibited the increase of blood glucose and prolonged the survival time of the mice (Ptranscriptional factors TCF-1 and phosphorylation of STAT-3, inhibits the formation of effector memory CD8 + T cells with long-term cytotoxicity, but promote the generation of stem cell-like memory CD8 + T cells, which result in suppression of islet β cell-specific effector cytotoxic CD8 + T cell differentiation to lessen autoimmune injury to the islet β cells.

  12. Interleukin-7 augments CD8+T cells function and promotes viral clearance in chronic hepatitis C virus infection.

    Science.gov (United States)

    Hou, Huanrong; Kang, Yi; Zeng, Yanli; Li, Yukui; Shang, Jia

    2018-02-01

    Interleukin (IL)-7 is a potent proliferation, activation, and survival cytokine for CD8 + T cells to improve viral and tumor specific CD8 + T cell responses. However, the role of IL-7 in regulation of dysfunctional hepatitis C virus (HCV)-specific CD8 + T cells was not fully elucidated. Thus, a total of 53 patients with chronic hepatitis C and 24 healthy individuals were enrolled in the current study. Serum IL-7 and its receptor α chain CD127 expression was measured. The modulatory function of IL-7 to CD8 + T cells was investigated in both direct and indirect contact co-culture with HCVcc-infected Huh7.5 cells. Both serum IL-7 and CD127 expression on CD8 + T cells was significantly reduced in chronic HCV-infected patients, which was negatively correlated with HCV RNA. Stimulation of IL-7 promoted both cytotoxicity and cytokines (interferon-γ, tumor necrosis factor-α, and IL-2) production of CD8 + T cells from patients with chronic hepatitis C. Moreover, IL-7 increased proliferation of CD8 + T cells, while downregulated a critical repressor of cytokine signaling, suppressor of cytokine signaling 3 (SOCS3). The IL-7-mediated enhancement effects to CD8 + T cells were dependent on IL-6 production. The current data suggested that IL-7 induced both cytolytic and noncytolytic functions of CD8 + T cells probably via repression of SOCS3. IL-7 might be considered as one of the therapeutic candidates for treatment of chronic HCV infection. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Presentation of an immunodominant immediate-early CD8+ T cell epitope resists human cytomegalovirus immunoevasion.

    Directory of Open Access Journals (Sweden)

    Stefanie Ameres

    Full Text Available Control of human cytomegalovirus (HCMV depends on CD8+ T cell responses that are shaped by an individual's repertoire of MHC molecules. MHC class I presentation is modulated by a set of HCMV-encoded proteins. Here we show that HCMV immunoevasins differentially impair T cell recognition of epitopes from the same viral antigen, immediate-early 1 (IE-1, that are presented by different MHC class I allotypes. In the presence of immunoevasins, HLA-A- and HLA-B-restricted T cell clones were ineffective, but HLA-C*0702-restricted T cell clones recognized and killed infected cells. Resistance of HLA-C*0702 to viral immunoevasins US2 and US11 was mediated by the alpha3 domain and C-terminal region of the HLA heavy chain. In healthy donors, HLA-C*0702-restricted T cells dominated the T cell response to IE-1. The same HLA-C allotype specifically protected infected cells from attack by NK cells that expressed a corresponding HLA-C-specific KIR. Thus, allotype-specific viral immunoevasion allows HCMV to escape control by NK cells and HLA-A- and HLA-B-restricted T cells, while the virus becomes selectively vulnerable to an immunodominant population of HLA-C-restricted T cells. Our work identifies a T cell population that may be of particular efficiency in HCMV-specific immunotherapy.

  14. Magnitude and kinetics of CD8+ T cell activation during hyperacute HIV infection impacts viral set point

    Science.gov (United States)

    Ndhlovu, Zaza; Kamya, Philomena; Mewalal, Nikoshia; Kløverpris, Henrik N.; Nkosi, Thandeka; Pretorius, Karyn; Laher, Faatima; Ogunshola, Funsho; Chopera, Denis; Shekhar, Karthik; Ghebremichael, Musie; Ismail, Nasreen; Moodley, Amber; Malik, Amna; Leslie, Alasdair; Goulder, Philip J.R; Buus, Søren; Chakraborty, Arup; Dong, Krista; Ndung’u, Thumbi; Walker, Bruce D.

    2015-01-01

    Summary CD8+ T cells contribute to the control of HIV, but it is not clear whether initial immune responses modulate the viral set point. We screened high-risk uninfected women twice a week for plasma HIV RNA and identified twelve hyperacute infections. Onset of viremia elicited a massive HIV-specific CD8+ T cell response, with limited bystander activation of non-HIV memory CD8+ T cells. HIV-specific CD8+ T cells secreted little interferon-γ, underwent rapid apoptosis and failed to upregulate the interleukin 7 receptor, known to be important for T cell survival. The rapidity to peak CD8+ T cell activation and the absolute magnitude of activation induced by the exponential rise in viremia were inversely correlated with set point viremia. These data indicate that rapid, high magnitude HIV-induced CD8+ T cell responses are crucial for subsequent immune control of acute infection, which has important implications for HIV vaccine design. PMID:26362266

  15. HIV-Specific CD8+ T Cell-Mediated Viral Suppression Correlates With the Expression of CD57

    DEFF Research Database (Denmark)

    Jensen, Sanne S; Tingstedt, Jeanette Linnea; Larsen, Tine Kochendorf

    2016-01-01

    BACKGROUND: Virus-specific CD8(+) T-cell responses are believed to play an important role in the control of HIV-1 infection; however, what constitutes an effective HIV-1 CD8(+) T-cell response remains a topic of debate. The ex vivo viral suppressive capacity was measured of CD8(+) T cells from 44...... HIV-1-positive individuals. The phenotypic and cytokine profiles, and also the specificity of the CD8(+) T cells, were correlated with the suppression of HIV-1 replication. We also aimed to determine whether antiretroviral therapy (ART) had any positive effect on the HIV-1 suppressive CD8(+) T cells....... METHOD: Ex vivo suppression assay was used to evaluate the ability of CD8(+) T cells to suppress HIV-1 replication in autologous CD4(+) T cells. The CD107a, interferon-γ, interleukin-2, tumor necrosis factor-α (TNF-α), and macrophage inflammatory protein-1β (MIP-1β) responses to HIV-1 were evaluated...

  16. CD8+ T cells mediate recovery and immunopathology in West Nile virus encephalitis.

    Science.gov (United States)

    Wang, Yang; Lobigs, Mario; Lee, Eva; Müllbacher, Arno

    2003-12-01

    C57BL/6J mice infected intravenously with the Sarafend strain of West Nile virus (WNV) develop a characteristic central nervous system (CNS) disease, including an acute inflammatory reaction. Dose response studies indicate two distinct kinetics of mortality. At high doses of infection (10(8) PFU), direct infection of the brain occurred within 24 h, resulting in 100% mortality with a 6-day mean survival time (MST), and there was minimal destruction of neural tissue. A low dose (10(3) PFU) of infection resulted in 27% mortality (MST, 11 days), and virus could be detected in the CNS 7 days postinfection (p.i.). Virus was present in the hypogastric lymph nodes and spleens at days 4 to 7 p.i. Histology of the brains revealed neuronal degeneration and inflammation within leptomeninges and brain parenchyma. Inflammatory cell infiltration was detectable in brains from day 4 p.i. onward in the high-dose group and from day 7 p.i. in the low-dose group, with the severity of infiltration increasing over time. The cellular infiltrates in brain consisted predominantly of CD8(+), but not CD4(+), T cells. CD8(+) T cells in the brain and the spleen expressed the activation markers CD69 early and expressed CD25 at later time points. CD8(+) T-cell-deficient mice infected with 10(3) PFU of WNV showed increased mortalities but prolonged MST and early infection of the CNS compared to wild-type mice. Using high doses of virus in CD8-deficient mice leads to increased survival. These results provide evidence that CD8(+) T cells are involved in both recovery and immunopathology in WNV infection.

  17. Antigen-Encoding Bone Marrow Terminates Islet-Directed Memory CD8+ T-Cell Responses to Alleviate Islet Transplant Rejection

    DEFF Research Database (Denmark)

    Coleman, Miranda; Jessup, Claire F.; Bridge, Jennifer A.

    2016-01-01

    Islet-specific memory T cells arise early in type 1 diabetes (T1D), persist for long periods, perpetuate disease, and are rapidly reactivated by islet transplantation. As memory T cells are poorly controlled by “conventional” therapies, memory T cell–mediated attack is a substantial challenge in ...... responses, and this can alleviate destruction of antigen-expressing islets. This addresses a key challenge facing islet transplantation and, importantly, the clinical application of personalized β-cell replacement therapies using patient-derived stem cells.......Islet-specific memory T cells arise early in type 1 diabetes (T1D), persist for long periods, perpetuate disease, and are rapidly reactivated by islet transplantation. As memory T cells are poorly controlled by “conventional” therapies, memory T cell–mediated attack is a substantial challenge...... in islet transplantation, and this will extend to application of personalized approaches using stem cell–derived replacement β-cells. New approaches are required to limit memory autoimmune attack of transplanted islets or replacement β-cells. Here, we show that transfer of bone marrow encoding cognate...

  18. Regulation of CD8+T Cells and Antitumor Immunity by Notch Signaling.

    Science.gov (United States)

    Tsukumo, Shin-Ichi; Yasutomo, Koji

    2018-01-01

    Cancer immunosurveillance is critical for the elimination of neoplastic cells. In addition, recent advances in immunological checkpoint blockade drugs have revealed the importance of the immune system in cancer treatment. As a component of the immune system, CD8 + T cells have important roles in suppressing tumors. CD8 + T cells can kill tumor cells with cytotoxic molecules, such as granzymes and perforin. IFNγ, which is produced by CD8 + T cells, can increase the expression of MHC class I antigens by tumor cells, thereby rendering them better targets for CD8 + T cells. IFNγ also has crucial functions in enhancing the antitumor abilities of other immune cells. Therefore, it has been hypothesized that antitumor immunity could be improved by modulating the activity of CD8 + T cells. The Notch pathway regulates CD8 + T cells in multiple ways. It directly upregulates mRNA expression of granzyme B and perforin, enhances differentiation toward short-lived effector cells, and maintains memory T cells. Intriguingly, CD8 + T cell-specific Notch2 deletion impairs antitumor immunity, whereas the stimulation of the Notch pathway can increase tumor suppression. In this review, we will summarize the roles of the Notch pathway in CD8 + T cells and discuss issues and implications for its use in antitumor immunity.

  19. Genetic adjuvantation of recombinant MVA with CD40L potentiates CD8 T cell mediated immunity

    Directory of Open Access Journals (Sweden)

    Henning eLauterbach

    2013-08-01

    Full Text Available Modified vaccinia Ankara (MVA is a safe and promising viral vaccine vector that is currently investigated in several clinical and pre-clinical trials. In contrast to inactivated or sub-unit vaccines, MVA is able to induce strong humoral as well as cellular immune responses. In order to further improve its CD8 T cell inducing capacity, we genetically adjuvanted MVA with the coding sequence of murine CD40L, a member of the tumor necrosis factor (TNF superfamily. Immunization of mice with this new vector led to strongly enhanced primary and memory CD8 T cell responses. Concordant with the enhanced CD8 T cell response, we could detect stronger activation of dendritic cells and higher systemic levels of innate cytokines (including IL-12p70 early after immunization. Interestingly, acquisition of memory characteristics (i.e., IL-7R expression was accelerated after immunization with MVA-CD40L in comparison to non-adjuvanted MVA. Furthermore, the generated CTLs also showed improved functionality as demonstrated by intracellular cytokine staining and in vivo killing activity. Importantly, the superior CTL response after a single MVA-CD40L immunization was able to protect B cell deficient mice against a fatal infection with ectromelia virus. Taken together, we show that genetic adjuvantation of MVA can change strength, quality and functionality of innate and adaptive immune responses. These data should facilitate a rational vaccine design with a focus on rapid induction of large numbers of CD8 T cells able to protect against specific diseases.

  20. IRF9 Prevents CD8+T Cell Exhaustion in an Extrinsic Manner during Acute Lymphocytic Choriomeningitis Virus Infection.

    Science.gov (United States)

    Huber, Magdalena; Suprunenko, Tamara; Ashhurst, Thomas; Marbach, Felix; Raifer, Hartmann; Wolff, Svenja; Strecker, Thomas; Viengkhou, Barney; Jung, So Ri; Obermann, Hannah-Lena; Bauer, Stefan; Xu, Haifeng C; Lang, Philipp A; Tom, Adomati; Lang, Karl S; King, Nicholas J C; Campbell, Iain L; Hofer, Markus J

    2017-11-15

    Effective CD8 + T cell responses play an important role in determining the course of a viral infection. Overwhelming antigen exposure can result in suboptimal CD8 + T cell responses, leading to chronic infection. This altered CD8 + T cell differentiation state, termed exhaustion, is characterized by reduced effector function, upregulation of inhibitory receptors, and altered expression of transcription factors. Prevention of overwhelming antigen exposure to limit CD8 + T cell exhaustion is of significant interest for the control of chronic infection. The transcription factor interferon regulatory factor 9 (IRF9) is a component of type I interferon (IFN-I) signaling downstream of the IFN-I receptor (IFNAR). Using acute infection of mice with lymphocytic choriomeningitis virus (LCMV) strain Armstrong, we show here that IRF9 limited early LCMV replication by regulating expression of interferon-stimulated genes and IFN-I and by controlling levels of IRF7, a transcription factor essential for IFN-I production. Infection of IRF9- or IFNAR-deficient mice led to a loss of early restriction of viral replication and impaired antiviral responses in dendritic cells, resulting in CD8 + T cell exhaustion and chronic infection. Differences in the antiviral activities of IRF9- and IFNAR-deficient mice and dendritic cells provided further evidence of IRF9-independent IFN-I signaling. Thus, our findings illustrate a CD8 + T cell-extrinsic function for IRF9, as a signaling factor downstream of IFNAR, in preventing overwhelming antigen exposure resulting in CD8 + T cell exhaustion and, ultimately, chronic infection. IMPORTANCE During early viral infection, overwhelming antigen exposure can cause functional exhaustion of CD8 + T cells and lead to chronic infection. Here we show that the transcription factor interferon regulatory factor 9 (IRF9) plays a decisive role in preventing CD8 + T cell exhaustion. Using acute infection of mice with LCMV strain Armstrong, we found that IRF9

  1. Quantifying biomass changes of single CD8+ T cells during antigen specific cytotoxicity.

    Directory of Open Access Journals (Sweden)

    Thomas A Zangle

    Full Text Available Existing approaches that quantify cytotoxic T cell responses rely on bulk or surrogate measurements which impede the direct identification of single activated T cells of interest. Single cell microscopy or flow cytometry methodologies typically rely on fluorescent labeling, which limits applicability to primary cells such as human derived T lymphocytes. Here, we introduce a quantitative method to track single T lymphocyte mediated cytotoxic events within a mixed population of cells using live cell interferometry (LCI, a label-free microscopy technique that maintains cell viability. LCI quantifies the mass distribution within individual cells by measuring the phase shift caused by the interaction of light with intracellular biomass. Using LCI, we imaged cytotoxic T cells killing cognate target cells. In addition to a characteristic target cell mass decrease of 20-60% over 1-4 h following attack by a T cell, there was a significant 4-fold increase in T cell mass accumulation rate at the start of the cytotoxic event and a 2-3 fold increase in T cell mass relative to the mass of unresponsive T cells. Direct, label-free measurement of CD8+ T and target cell mass changes provides a kinetic, quantitative assessment of T cell activation and a relatively rapid approach to identify specific, activated patient-derived T cells for applications in cancer immunotherapy.

  2. FoxO1 Controls Effector to Memory Transition and Maintenance of Functional CD8 T-Cell Memory

    Science.gov (United States)

    Tejera, Melba Marie; Kim, Eui Ho; Sullivan, Jeremy A.; Plisch, Erin H.; Suresh, M.

    2013-01-01

    During a T cell response, naïve CD8 T cells differentiate into effector cells. Subsequently, a subset of effector cells termed memory precursor effector cells (MPECs) further differentiates into functionally mature memory CD8 T cells. The transcriptional network underlying this carefully scripted process is not well understood. Here, we report that the transcription factor FoxO1 plays an integral role in facilitating effector to memory transition and functional maturation of memory CD4 and CD8 T cells. We find that FoxO1 is not required for differentiation of effector cells, but in the absence of FoxO1, memory CD8 T cells displayed features of senescence and progressive attrition in polyfunctionality, which in turn led to impaired recall responses and poor protective immunity. These data suggest that FoxO1 is essential for maintenance of functional CD8 T cell memory and protective immunity. Under competing conditions in bone marrow chimeric mice, FoxO1-deficiency did not perturb clonal expansion or effector differentiation. Instead, FoxO1-deficient MPECs failed to survive and form memory CD8 T cells. Mechanistically, FoxO1 deficiency perturbed the memory CD8 T-cell transcriptome, characterized by pronounced alterations in the expression of genes that encode transcription factors (including Tcf7), effector molecules, cell cycle regulators and proteins that regulate fatty acid, purine and pyramidine metabolism and mitochondrial functions. We propose that FoxO1 is a key regulator that reprograms and steers the differentiation of effector cells to functionally competent memory cells. These findings have provided fundamental insights into the mechanisms that regulate the quality of CD8 T-cell memory to intracellular pathogens. PMID:23733882

  3. Tumor Necrosis Factor (TNF) Receptor Superfamily Member 1b on CD8+ T Cells and TNF Receptor Superfamily Member 1a on Non-CD8+ T Cells Contribute Significantly to Upper Genital Tract Pathology Following Chlamydial Infection.

    Science.gov (United States)

    Manam, Srikanth; Thomas, Joshua D; Li, Weidang; Maladore, Allison; Schripsema, Justin H; Ramsey, Kyle H; Murthy, Ashlesh K

    2015-06-15

    We demonstrated previously that tumor necrosis factor α (TNF-α)-producing Chlamydia-specific CD8(+) T cells cause oviduct pathological sequelae. In the current study, we used wild-type C57BL/6J (WT) mice with a deficiency in genes encoding TNF receptor superfamily member 1a (TNFR1; TNFR1 knockout [KO] mice), TNF receptor superfamily member 1b (TNFR2; TNFR2 KO mice), and both TNFR1 and TNFR2 (TNFR1/2 double KO [DKO] mice) and mix-match adoptive transfers of CD8(+) T cells to study chlamydial pathogenesis. TNFR1 KO, TNFR2 KO, and TNFR1/2 DKO mice displayed comparable clearance of primary or secondary genital Chlamydia muridarum infection but significantly reduced oviduct pathology, compared with WT animals. The Chlamydia-specific total cellular cytokine response in splenic and draining lymph nodes and the antibody response in serum were comparable between the WT and KO animals. However, CD8(+) T cells from TNFR2 KO mice displayed significantly reduced activation (CD11a expression and cytokine production), compared with TNFR1 KO or WT animals. Repletion of TNFR2 KO mice with WT CD8(+) T cells but not with TNFR2 KO CD8(+) T cells and repletion of TNFR1 KO mice with either WT or TNFR1 KO CD8(+) T cells restored oviduct pathology to WT levels in both KO groups. Collectively, these results demonstrate that TNFR2-bearing CD8(+) T cells and TNFR1-bearing non-CD8(+) T cells contribute significantly to oviduct pathology following genital chlamydial infection. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  4. CD103 is a marker for alloantigen-induced regulatory CD8+ T cells

    NARCIS (Netherlands)

    Uss, Elena; Rowshani, Ajda T.; Hooibrink, Berend; Lardy, Neubury M.; van Lier, René A. W.; ten Berge, Ineke J. M.

    2006-01-01

    The alphaEbeta7 integrin CD103 may direct lymphocytes to its ligand E-cadherin. CD103 is expressed on T cells in lung and gut and on allograft-infiltrating T cells. Moreover, recent studies have documented expression of CD103 on CD4+ regulatory T cells. Approximately 4% of circulating CD8+ T cells

  5. CD8+ T cell profiles in patients with rheumatoid arthritis and their relationship to disease activity

    NARCIS (Netherlands)

    Carvalheiro, Helena; Duarte, Cátia; Silva-Cardoso, Sandra; Da Silva, José A P; Souto-Carneiro, M. Margarida

    2015-01-01

    Objective. CD8+ T cells are abundant in rheumatoid arthritis (RA). However, their role in disease pathogenesis is poorly defined. This study was undertaken to investigate the relationship between disease activity and CD8+ T cell phenotypes, production of cytokines, and production of cytotoxic

  6. Interleukin-4 mediates CD8 induction on human CD4+ T-cell clones

    NARCIS (Netherlands)

    Paliard, X.; Malefijt, R. W.; de Vries, J. E.; Spits, H.

    1988-01-01

    CD4 and CD8 antigens are simultaneously expressed on most of the cortical thymocytes, that weakly express the T-cell antigen receptor(TCR)/CD3 complex. Mature peripheral T cells, however, strongly express the TCR complex and are positive for either CD4 or CD8. Nevertheless, a small percentage of

  7. Human CD8 T cells generated in vitro from hematopoietic stem cells are functionally mature

    Directory of Open Access Journals (Sweden)

    Zúñiga-Pflücker Juan

    2011-03-01

    Full Text Available Abstract Background T cell development occurs within the highly specialized thymus. Cytotoxic CD8 T cells are critical in adaptive immunity by targeting virally infected or tumor cells. In this study, we addressed whether functional CD8 T cells can be generated fully in vitro using human umbilical cord blood (UCB hematopoietic stem cells (HSCs in coculture with OP9-DL1 cells. Results HSC/OP9-DL1 cocultures supported the differentiation of CD8 T cells, which were TCR/CD3hi CD27hi CD1aneg and thus phenotypically resembled mature functional CD8 single positive thymocytes. These in vitro-generated T cells also appeared to be conventional CD8 cells, as they expressed high levels of Eomes and low levels of Plzf, albeit not identical to ex vivo UCB CD8 T cells. Consistent with the phenotypic and molecular characterization, upon TCR-stimulation, in vitro-generated CD8 T cells proliferated, expressed activation markers (MHC-II, CD25, CD38, secreted IFN-γ and expressed Granzyme B, a cytotoxic T-cell effector molecule. Conclusion Taken together, the ability to direct human hematopoietic stem cell or T-progenitor cells towards a mature functional phenotype raises the possibility of establishing cell-based treatments for T-immunodeficiencies by rapidly restoring CD8 effector function, thereby mitigating the risks associated with opportunistic infections.

  8. Activated iNKT cells promote memory CD8+ T cell differentiation during viral infection.

    Directory of Open Access Journals (Sweden)

    Emma C Reilly

    Full Text Available α-Galactosylceramide (α-GalCer is the prototypical lipid ligand for invariant NKT cells. Recent studies have proposed that α-GalCer is an effective adjuvant in vaccination against a range of immune challenges, however its mechanism of action has not been completely elucidated. A variety of delivery methods have been examined including pulsing dendritic cells with α-GalCer to optimize the potential of α-GalCer. These methods are currently being used in a variety of clinical trials in patients with advanced cancer but cannot be used in the context of vaccine development against pathogens due to their complexity. Using a simple delivery method, we evaluated α-GalCer adjuvant properties, using the mouse model for cytomegalovirus (MCMV. We measured several key parameters of the immune response to MCMV, including inflammation, effector, and central memory CD8(+ T cell responses. We found that α-GalCer injection at the time of the infection decreases viral titers, alters the kinetics of the inflammatory response, and promotes both increased frequencies and numbers of virus-specific memory CD8(+ T cells. Overall, our data suggest that iNKT cell activation by α-GalCer promotes the development of long-term protective immunity through increased fitness of central memory CD8(+ T cells, as a consequence of reduced inflammation.

  9. CD103+tumor-infiltrating lymphocytes are tumor-reactive intraepithelial CD8+T cells associated with prognostic benefit and therapy response in cervical cancer

    NARCIS (Netherlands)

    Komdeur, Fenne L.; Prins, Thalina M.; van de Wall, Stephanie; Plat, Annechien; Wisman, G. Bea A.; Hollema, Harry; Daemen, Toos; Church, David N.; De Bruyn, Marco; Nijman, Hans W.

    2017-01-01

    Human papilloma virus (HPV)-induced cervical cancer constitutively expresses viral E6/E7 oncoproteins and is an excellent target for T cell-based immunotherapy. However, not all tumor-infiltrating T cells confer equal benefit to patients, with epithelial T cells being superior to stromal T cells.To

  10. CD103+ tumor-infiltrating lymphocytes are tumor-reactive intraepithelial CD8+ T cells associated with prognostic benefit and therapy response in cervical cancer

    NARCIS (Netherlands)

    Komdeur, F.L.; Prins, T.M.; Wall, S. van de; Plat, A.; Wisman, G.B.; Hollema, H.; Daemen, T.; Church, D.N.; Bruyn, M. de; Nijman, H.W.

    2017-01-01

    Human papilloma virus (HPV)-induced cervical cancer constitutively expresses viral E6/E7 oncoproteins and is an excellent target for T cell-based immunotherapy. However, not all tumor-infiltrating T cells confer equal benefit to patients, with epithelial T cells being superior to stromal T cells. To

  11. Differential virus-specific CD8+T-cell epitope repertoire in hepatitis C virus genotype 1 versus 4.

    Science.gov (United States)

    Luxenburger, Hendrik; Graß, Franziska; Baermann, Janina; Boettler, Tobias; Marget, Matthias; Emmerich, Florian; Panning, Marcus; Thimme, Robert; Nitschke, Katja; Neumann-Haefelin, Christoph

    2018-02-03

    Virus-specific CD8 + T-cell responses play an important role in the outcome of hepatitis C virus (HCV) infection. To date, most HCV-specific CD8 + T-cell epitopes have been defined in HCV genotype 1 infection. In contrast, the HCV genotype 4-specific CD8 + T-cell response is poorly defined. Here, we analysed whether known HCV-specific CD8 + T-cell epitopes are also recognized in HCV genotype 4-infected patients and set out to identify the first HCV genotype 4-specific CD8 + T-cell epitopes. We studied patients chronically infected with HCV genotype 1 (n = 20) or 4 (n = 21) using 91 well-described HCV-specific epitope peptides. In addition, we analysed 24 genotype 4-infected patients using 40 epitope candidates predicted using an in silico approach. HCV-specific CD8 + T-cell responses targeting previously described epitopes were detectable in the majority of genotype 1-infected patients (11 of 20). In contrast, patients infected with HCV genotype 4 rarely targeted these epitopes (4 of 21; P = .0247). Importantly, we were able to identify eight novel HCV genotype 4-specific CD8 + T-cell epitopes. Only one of these epitopes was shared between genotype 1 and genotype 4. These results indicate that there is little overlap between CD8 + T-cell repertoires targeting HCV genotype 1 and 4. Prophylactic vaccination studies based on HCV genotype 1 are currently underway. However, in countries with the highest prevalence of HCV infection, such as Egypt, most patients are infected with HCV genotype 4. Thus, prophylactic vaccination strategies need to be adapted to HCV genotype 4 before their application to regions where HCV genotype 4 is endemic. © 2018 John Wiley & Sons Ltd.

  12. Dichotomous Roles of Programmed Cell Death 1 on HIV-Specific CXCR5+and CXCR5-CD8+T Cells during Chronic HIV Infection.

    Science.gov (United States)

    Jiao, Yan-Mei; Yang, Hong-Ge; Huang, Hui-Huang; Tu, Bo; Xing, Shao-Jun; Mao, Lin; Xia, Wei; He, Ran; Zhang, Ji-Yuan; Xu, Ruo-Nan; Jin, Lei; Shi, Ming; Xu, Zhe; Qin, En-Qiang; Wang, Xi-Cheng; Wu, Hao; Ye, Lilin; Wang, Fu-Sheng

    2017-01-01

    CXCR5 + CD8 + T cells have been demonstrated to play an important role in the control of chronic viral replication; however, the relationship between CXCR5 + CD8 + T cells, HIV disease progression, and programmed cell death 1 (PD-1) expression profile on CXCR5 + CD8 + T cells during HIV infection remain poorly understood. We enrolled a total of 101 HIV patients, including 62 typical progressors, 26 complete responders (CRs), and 13 immune non-responders (INRs). Flow cytometric analysis, immunohistochemical staining, and relative function (i.e., cytokine secretion and PD-1 blockade) assays were performed to analyze the properties of CXCR5 + CD8 + T cells. HIV-specific CXCR5 + CD8 + T cells in the peripheral blood and distribution of CXCR5 + CD8 + T cells in the lymph node (LN) were negatively correlated with disease progression during chronic HIV infection. PD-1 was highly expressed on CXCR5 + CD8 + T cells and positively associated with peripheral CD4 + T cell counts. Functionally, IFN-γ and TNF-α production of CXCR5 + CD8 + T cells were reduced by PD-1 pathway blockade, but the production of IFN-γ and TNF-α from CXCR5 - CD8 + T cells increased in response to TCR stimulation. Interestingly, PD-1 expression was constantly retained on CXCR5 + CD8 + T cells while significantly decreased on CXCR5 - CD8 + T cells after successful antiretroviral treatment in chronic HIV-infected patients. PD-1 + CXCR5 + CD8 + T cells are functional cytotoxic T cells during chronic HIV infection. PD-1 + CXCR5 + CD8 + T cells may represent a novel therapeutic strategy for the disease.

  13. A Glycolipid Adjuvant, 7DW8-5, Enhances CD8+ T Cell Responses Induced by an Adenovirus-Vectored Malaria Vaccine in Non-Human Primates

    OpenAIRE

    Padte, Neal N.; Boente-Carrera, Mar; Andrews, Chasity D.; McManus, Jenny; Grasperge, Brooke F.; Gettie, Agegnehu; Coelho-dos-Reis, Jordana G.; Li, Xiangming; Wu, Douglass; Bruder, Joseph T.; Sedegah, Martha; Patterson, Noelle; Richie, Thomas L.; Wong, Chi-Huey; Ho, David D.

    2013-01-01

    A key strategy to a successful vaccine against malaria is to identify and develop new adjuvants that can enhance T-cell responses and improve protective immunity. Upon co-administration with a rodent malaria vaccine in mice, 7DW8-5, a recently identified novel analog of α-galactosylceramide (α-GalCer), enhances the level of malaria-specific protective immune responses more strongly than the parent compound. In this study, we sought to determine whether 7DW8-5 could provide a similar potent ad...

  14. Combining regulatory T cell depletion and inhibitory receptor blockade improves reactivation of exhausted virus-specific CD8+ T cells and efficiently reduces chronic retroviral loads.

    Directory of Open Access Journals (Sweden)

    Kirsten K Dietze

    Full Text Available Chronic infections with human viruses, such as HIV and HCV, or mouse viruses, such as LCMV or Friend Virus (FV, result in functional exhaustion of CD8(+ T cells. Two main mechanisms have been described that mediate this exhaustion: expression of inhibitory receptors on CD8(+ T cells and expansion of regulatory T cells (Tregs that suppress CD8(+ T cell activity. Several studies show that blockage of one of these pathways results in reactivation of CD8(+ T cells and partial reduction in chronic viral loads. Using blocking antibodies against PD-1 ligand and Tim-3 and transgenic mice in which Tregs can be selectively ablated, we compared these two treatment strategies and combined them for the first time in a model of chronic retrovirus infection. Blocking inhibitory receptors was more efficient than transient depletion of Tregs in reactivating exhausted CD8(+ T cells and reducing viral set points. However, a combination therapy was superior to any single treatment and further augmented CD8(+ T cell responses and resulted in a sustained reduction in chronic viral loads. These results demonstrate that Tregs and inhibitory receptors are non-overlapping factors in the maintenance of chronic viral infections and that immunotherapies targeting both pathways may be a promising strategy to treat chronic infectious diseases.

  15. Killing of targets by effector CD8 T cells in the mouse spleen follows the law of mass action

    Energy Technology Data Exchange (ETDEWEB)

    Ganusov, Vitaly V [Los Alamos National Laboratory

    2009-01-01

    In contrast with antibody-based vaccines, it has been difficult to measure the efficacy of T cell-based vaccines and to correlate the efficacy of CD8 T cell responses with protection again viral infections. In part, this difficulty is due to poor understanding of the in vivo efficacy of CD8 T cells produced by vaccination. Using a: recently developed experimental method of in vivo cytotoxicity we have investigated quantitative aspects of killing of peptide-pulsed targets by effector and memory CD8 T cells, specific to three epitopes of lymphocytic choriomeningitis virus (LCMV), in the mouse spleen. By analyzing data on killing of targets with varying number of epitope-specific effector and memory CD8 T cells, we find that killing of targets by effectors follows the law of mass-action, that is the death rate of peptide-pulsed targets is proportional to the frequency of CTLs in the spleen. In contrast, killing of targets by memory CD8 T cells does not follow the mass action law because the death rate of targets saturates at high frequencies of memory CD8 T cells. For both effector and memory cells, we also find little support for the killing term that includes the decrease of the death rate of targets with target cell density. Interestingly, our analysis suggests that at low CD8 T cell frequencies, memory CD8 T cells on the per capita basis are more efficient at killing peptide-pulsed targets than effectors, but at high frequencies, effectors are more efficient killers than memory T cells. Comparison of the estimated killing efficacy of effector T cells with the value that is predicted from theoretical physics and based on motility of T cells in lymphoid tissues, suggests that limiting step in the killing of peptide-pulsed targets is delivering the lethal hit and not finding the target. Our results thus form a basis for quantitative understanding of the process of killing of virus-infected cells by T cell responses in tissues and can be used to correlate the

  16. IL-2 complex treatment amplifies CD8+T cell mediated immunity following herpes simplex virus-1 infection.

    Science.gov (United States)

    Rajasagi, Naveen K; Rouse, Barry T

    2016-12-01

    CD8 + T cells play an important role in controlling numerous virus infections and some tumors and therefore several strategies have been adopted to modulate CD8 + T cell responses. One such approach includes treatment with IL-2 bound to a monoclonal antibody against IL-2 (IL-2 complex) which was shown to enhance CD8 + T cell responses and provide protection against some cancers and pathogens. This report analyses the value of IL-2 complex therapy to protect against a cutaneous virus infection as occurs with herpes simplex virus-1 (HSV-1) infection. Treatment with IL-2 complex after infection reduced virus levels and lesion severity in a zosteriform model of HSV infection in mice. Furthermore, IL-2 complex treatment expanded HSV-1-gB epitope-specific CD8 + T cells, IFN-γ and TNF-α producing CD8 + T cells as well as cells that produced more than one cytokine. In addition, IL-2 complex therapy recipients showed enhanced cytolytic activity of CD8 + T cells as shown by increased granzyme B expression and lytic granule release. Taken, together, these studies demonstrate that IL-2 complex therapy can be useful to boost protection against a cutaneous virus infection. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  17. Effector CD8^+ T cells migrate via chemokine-enhanced generalized L'evy walks

    Science.gov (United States)

    Banigan, Edward; Harris, Tajie; Christian, David; Liu, Andrea; Hunter, Christopher

    2012-02-01

    Chemokines play a central role in regulating processes essential to the immune function of T cells, such as their migration within lymphoid tissues and targeting of pathogens in sites of inflammation. In order to understand the role of the chemokine CXCL10 during chronic infection by the parasite T. gondii, we analyze tracks of migrating CD8^+ T cells in brain tissue. Surprisingly, we find that T cell motility is not described by a Brownian walk, but instead is consistent with a generalized L'evy walk consisting of L'evy-distributed runs alternating with pauses of L'evy-distributed durations. According to our model, this enables T cells to find rare targets more than an order of magnitude more efficiently than Brownian random walkers. The chemokine CXCL10 increases the migration speed without changing the character of the walk statistics. Thus, CD8^+ T cells use an efficient search strategy to facilitate an effective immune response, and CXCL10 aids them in shortening the average time to find rare targets.

  18. CXCR5-Dependent Entry of CD8 T Cells into Rhesus Macaque B-Cell Follicles Achieved through T-Cell Engineering.

    Science.gov (United States)

    Ayala, Victor I; Deleage, Claire; Trivett, Matthew T; Jain, Sumiti; Coren, Lori V; Breed, Matthew W; Kramer, Joshua A; Thomas, James A; Estes, Jacob D; Lifson, Jeffrey D; Ott, David E

    2017-06-01

    major source of this residual virus. While effective CD8 T-cell responses can control viral replication in conjunction with drug therapy or in rare cases spontaneously, most antiviral CD8 T cells do not enter B-cell follicles, and those that do fail to robustly control viral replication in the T FH population. Thus, these sites are a sanctuary and a reservoir for replicating AIDS viruses. Here, we demonstrate that engineering unselected CD8 T cells to express CXCR5, a chemokine receptor on T FH associated with B-cell follicle localization, redirects them into B-cell follicles. These proof of principle results open a pathway for directing engineered antiviral T cells into these viral sanctuaries to help eliminate this source of persistent virus. Copyright © 2017 American Society for Microbiology.

  19. CD8+ T-Cells as Immune Regulators of Multiple Sclerosis

    Science.gov (United States)

    Sinha, Sushmita; Boyden, Alexander W.; Itani, Farah R.; Crawford, Michael P.; Karandikar, Nitin J.

    2015-01-01

    The vast majority of studies regarding the immune basis of MS (and its animal model, EAE) have largely focused on CD4+ T-cells as mediators and regulators of disease. Interestingly, CD8+ T-cells represent the predominant T-cell population in human MS lesions and are oligoclonally expanded at the site of pathology. However, their role in the autoimmune pathologic process has been both understudied and controversial. Several animal models and MS patient studies support a pathogenic role for CNS-specific CD8+ T-cells, whereas we and others have demonstrated a regulatory role for these cells in disease. In this review, we describe studies that have investigated the role of CD8+ T-cells in MS and EAE, presenting evidence for both pathogenic and regulatory functions. In our studies, we have shown that cytotoxic/suppressor CD8+ T-cells are CNS antigen-specific, MHC class I-restricted, IFNγ- and perforin-dependent, and are able to inhibit disease. The clinical relevance for CD8+ T-cell suppressive function is best described by a lack of their function during MS relapse, and importantly, restoration of their suppressive function during quiescence. Furthermore, CD8+ T-cells with immunosuppressive functions can be therapeutically induced in MS patients by glatiramer acetate (GA) treatment. Unlike CNS-specific CD8+ T-cells, these immunosuppressive GA-induced CD8+ T-cells appear to be HLA-E restricted. These studies have provided greater fundamental insight into the role of autoreactive as well as therapeutically induced CD8+ T-cells in disease amelioration. The clinical implications for these findings are immense and we propose that this natural process can be harnessed toward the development of an effective immunotherapeutic strategy. PMID:26697014

  20. Cytomegalovirus vector expressing RAE-1γ induces enhanced anti-tumor capacity of murine CD8+T cells.

    Science.gov (United States)

    Tršan, Tihana; Vuković, Kristina; Filipović, Petra; Brizić, Ana Lesac; Lemmermann, Niels A W; Schober, Kilian; Busch, Dirk H; Britt, William J; Messerle, Martin; Krmpotić, Astrid; Jonjić, Stipan

    2017-08-01

    Designing CD8 + T-cell vaccines, which would provide protection against tumors is still considered a great challenge in immunotherapy. Here we show the robust potential of cytomegalovirus (CMV) vector expressing the NKG2D ligand RAE-1γ as CD8 + T cell-based vaccine against malignant tumors. Immunization with the CMV vector expressing RAE-1γ, delayed tumor growth or even provided complete protection against tumor challenge in both prophylactic and therapeutic settings. Moreover, a potent tumor control in mice vaccinated with this vector can be further enhanced by blocking the immune checkpoints TIGIT and PD-1. CMV vector expressing RAE-1γ potentiated expansion of KLRG1 + CD8 + T cells with enhanced effector properties. This vaccination was even more efficient in neonatal mice, resulting in the expansion and long-term maintenance of epitope-specific CD8 + T cells conferring robust resistance against tumor challenge. Our data show that immunomodulation of CD8 + T-cell responses promoted by herpesvirus expressing a ligand for NKG2D receptor can provide a powerful platform for the prevention and treatment of CD8 + T-cell sensitive tumors. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. A molecular threshold for effector CD8+ T cell differentiation controlled by transcription factors Blimp-1 and T-bet

    Science.gov (United States)

    Xin, Annie; Masson, Frederick; Liao, Yang; Preston, Simon; Guan, Tianxia; Gloury, Renee; Olshansky, Moshe; Lin, Jian-Xin; Li, Peng; Speed, Terence P; Smyth, Gordon K; Ernst, Matthias; Leonard, Warren J; Pellegrini, Marc; Kaech, Susan M; Nutt, Stephen L; Shi, Wei; Belz, Gabrielle T; Kallies, Axel

    2017-01-01

    T cell responses are guided by cytokines that induce transcriptional regulators, which ultimately control differentiation of effector and memory T cells. However, it is unknown how the activities of these molecular regulators are coordinated and integrated during the differentiation process. Using genetic approaches and transcriptional profiling of antigen-specific CD8+ T cells, we reveal a common program of effector differentiation that is regulated by IL-2 and IL-12 signaling and the combined activities of the transcriptional regulators Blimp-1 and T-bet. The loss of both T-bet and Blimp-1 leads to abrogated cytotoxic function and ectopic IL-17 production in CD8+ T cells. Overall, our data reveal two major overlapping pathways of effector differentiation governed by the availability of Blimp-1 and T-bet and suggest a model for cytokine-induced transcriptional changes that combine, quantitatively and qualitatively, to promote robust effector CD8+ T cell differentiation. PMID:26950239

  2. A molecular threshold for effector CD8(+) T cell differentiation controlled by transcription factors Blimp-1 and T-bet.

    Science.gov (United States)

    Xin, Annie; Masson, Frederick; Liao, Yang; Preston, Simon; Guan, Tianxia; Gloury, Renee; Olshansky, Moshe; Lin, Jian-Xin; Li, Peng; Speed, Terence P; Smyth, Gordon K; Ernst, Matthias; Leonard, Warren J; Pellegrini, Marc; Kaech, Susan M; Nutt, Stephen L; Shi, Wei; Belz, Gabrielle T; Kallies, Axel

    2016-04-01

    T cell responses are guided by cytokines that induce transcriptional regulators, which ultimately control differentiation of effector and memory T cells. However, it is unknown how the activities of these molecular regulators are coordinated and integrated during the differentiation process. Using genetic approaches and transcriptional profiling of antigen-specific CD8(+) T cells, we reveal a common program of effector differentiation that is regulated by IL-2 and IL-12 signaling and the combined activities of the transcriptional regulators Blimp-1 and T-bet. The loss of both T-bet and Blimp-1 leads to abrogated cytotoxic function and ectopic IL-17 production in CD8(+) T cells. Overall, our data reveal two major overlapping pathways of effector differentiation governed by the availability of Blimp-1 and T-bet and suggest a model for cytokine-induced transcriptional changes that combine, quantitatively and qualitatively, to promote robust effector CD8(+) T cell differentiation.

  3. CXCR5+ CD8+ T Cells Indirectly Offer B Cell Help and Are Inversely Correlated with Viral Load in Chronic Hepatitis B Infection.

    Science.gov (United States)

    Jiang, Hang; Li, Linhai; Han, Jiang; Sun, Zhiwei; Rong, Yihui; Jin, Yun

    2017-04-01

    Treatment options for chronic hepatitis B (CHB) infection are extremely limited. CXCR5 + CD8 + T cell is a novel cell subtype and could possess strong cytotoxic properties in HIV infection. In this study, we investigated the role of CXCR5 + CD8 + T cells in CHB patients. Compared to healthy individuals, both CHB patients and hepatitis B virus (HBV)-infected hepatocellular carcinoma patients presented significant upregulation of CXCR5 + CD8 + T cells in peripheral blood, in which CXCR5 + CD8 + T cells were negatively correlated with the frequency of CXCR5 + CD4 + T cells in CHB patients. After PMA+ionomycin stimulation, CXCR5 + CD8 + T cells from CHB patients presented significantly higher transcription level of interferon gamma (IFN-γ), interleukin 10 (IL-10), and IL-21, as well as higher IL-10 and IL-21 protein secretion, than CXCR5 - CD8 + T cells. Unlike CXCR5 + CD4 + T cells, when incubated with naive CD19 + CD27 - B cells, CXCR5 + CD8 + T cells alone did not upregulate IgM, IgG, and IgA secretion. However, addition of CXCR5 + CD8 + T cells in B cell-CXCR5 + CD4 + T cell coculture significantly increased the levels of secreted IgG and IgA, demonstrating that CXCR5 + CD8 + T cell could indirectly offer B cell help. Furthermore, high frequencies of CXCR5 + CD8 + T cells tended to associate with low HBV DNA load, and the frequency of CXCR5 + CD8 + T cells was negatively correlated with alanine aminotransferase (ALT) level. Together, these results suggested that CXCR5 + CD8 + T cells were involved in the antiviral immune responses in CHB and could potentially serve as a therapeutic candidate.

  4. Differentially Expressed Potassium Channels Are Associated with Function of Human Effector Memory CD8+T Cells.

    Science.gov (United States)

    Sim, Ji Hyun; Kim, Kyung Soo; Park, Hyoungjun; Kim, Kyung-Jin; Lin, Haiyue; Kim, Tae-Joo; Shin, Hyun Mu; Kim, Gwanghun; Lee, Dong-Sup; Park, Chan-Wook; Lee, Dong Hun; Kang, Insoo; Kim, Sung Joon; Cho, Chung-Hyun; Doh, Junsang; Kim, Hang-Rae

    2017-01-01

    The voltage-gated potassium channel, Kv1.3, and the Ca 2+ -activated potassium channel, KCa3.1, regulate membrane potentials in T cells, thereby controlling T cell activation and cytokine production. However, little is known about the expression and function of potassium channels in human effector memory (EM) CD8 + T cells that can be further divided into functionally distinct subsets based on the expression of the interleukin (IL)-7 receptor alpha (IL-7Rα) chain. Herein, we investigated the functional expression and roles of Kv1.3 and KCa3.1 in EM CD8 + T cells that express high or low levels of the IL-7 receptor alpha chain (IL-7Rα high and IL-7Rα low , respectively). In contrast to the significant activity of Kv1.3 and KCa3.1 in IL-7Rα high EM CD8 + T cells, IL-7Rα low EM CD8 + T cells showed lower expression of Kv1.3 and insignificant expression of KCa3.1. Kv1.3 was involved in the modulation of cell proliferation and IL-2 production, whereas KCa3.1 affected the motility of EM CD8 + T cells. The lower motility of IL-7Rα low EM CD8 + T cells was demonstrated using transendothelial migration and motility assays with intercellular adhesion molecule 1- and/or chemokine stromal cell-derived factor-1α-coated surfaces. Consistent with the lower migration property, IL-7Rα low EM CD8 + T cells were found less frequently in human skin. Stimulating IL-7Rα low EM CD8 + T cells with IL-2 or IL-15 increased their motility and recovery of KCa3.1 activity. Our findings demonstrate that Kv1.3 and KCa3.1 are differentially involved in the functions of EM CD8 + T cells. The weak expression of potassium channels in IL-7Rα low EM CD8 + T cells can be revived by stimulation with IL-2 or IL-15, which restores the associated functions. This study suggests that IL-7Rα high EM CD8 + T cells with functional potassium channels may serve as a reservoir for effector CD8 + T cells during peripheral inflammation.

  5. Aberrant Expression of MHC Class II in Melanoma Attracts Inflammatory Tumor-Specific CD4+ T- Cells, Which Dampen CD8+ T-cell Antitumor Reactivity

    DEFF Research Database (Denmark)

    Donia, Marco; Andersen, Rikke; Kjeldsen, Julie W

    2015-01-01

    populations and correspondingly expanded autologous tumor-infiltrating lymphocytes (TIL), we show how MHC class II expression on melanoma cells associates with strong MHC class II-restricted CD4(+) T-cell responses that are specific for tumors. Notably, we found that tumor-specific CD4(+) T-cell responses...... were dominated by TNF production. TNF reduced CD8(+) T-cell activation in IFNγ-rich environments resembling a tumor site. Conversely, direct CD4(+) T-cell responses had no influence on either the proliferation or viability of melanoma cells. Taken together, our results illustrate a novel immune escape...... mechanism that can be activated by aberrant expression of MHC class II molecules, which by attracting tumor-specific CD4(+) T cells elicit a local inflammatory response dominated by TNF that, in turn, inhibits cytotoxic CD8(+) T-cell responses...

  6. CD160-Associated CD8 T-Cell Functional Impairment Is Independent of PD-1 Expression

    Science.gov (United States)

    Viganò, Selena; Banga, Riddhima; Bellanger, Florence; Pellaton, Céline; Farina, Alex; Comte, Denis; Harari, Alexandre; Perreau, Matthieu

    2014-01-01

    Expression of co-inhibitory molecules is generally associated with T-cell dysfunction in chronic viral infections such as HIV or HCV. However, their relative contribution in the T-cell impairment remains unclear. In the present study, we have evaluated the impact of the expression of co-inhibitory molecules such as 2B4, PD-1 and CD160 on the functions of CD8 T-cells specific to influenza, EBV and CMV. We show that CD8 T-cell populations expressing CD160, but not PD-1, had reduced proliferation capacity and perforin expression, thus indicating that the functional impairment in CD160+ CD8 T cells may be independent of PD-1 expression. The blockade of CD160/CD160-ligand interaction restored CD8 T-cell proliferation capacity, and the extent of restoration directly correlated with the ex vivo proportion of CD160+ CD8 T cells suggesting that CD160 negatively regulates TCR-mediated signaling. Furthermore, CD160 expression was not up-regulated upon T-cell activation or proliferation as compared to PD-1. Taken together, these results provide evidence that CD160-associated CD8 T-cell functional impairment is independent of PD-1 expression. PMID:25255144

  7. In vivo proliferation of naïve and memory influenza-specific CD8(+) T cells

    DEFF Research Database (Denmark)

    Flynn, K J; Riberdy, J M; Christensen, Jan Pravsgaard

    1999-01-01

    The virus-specific CD8(+) T cell response has been analyzed through the development, effector, and recovery phases of primary and secondary influenza pneumonia. Apparently, most, if not all, memory T cells expressing clonotypic receptors that bind a tetrameric complex of influenza nucleoprotein (NP......)(366-374) peptide+H-2D(b) (NPP) are induced to divide during the course of this localized respiratory infection. The replicative phase of the recall response ends about the time that virus can no longer be recovered from the lung, whereas some primary CD8(+)NPP(+) T cells may proliferate for a few more...

  8. Efficacious early antiviral activity of HIV Gag- and Pol-specific HLA-B 2705-restricted CD8+ T cells

    DEFF Research Database (Denmark)

    Payne, Rebecca P; Kløverpris, Henrik; Sacha, Jonah B

    2010-01-01

    control of HIV, we first characterized the CD8(+) T-cell responses of nine highly active antiretroviral therapy (HAART)-naïve B 2705-positive subjects. Unexpectedly, we observed a strong response to an HLA-B 2705-restricted Pol epitope, KRKGGIGGY (KY9), in 8/9 subjects. The magnitude of the KY9 response...... by the respective CD8(+) T-cell response. By comparing inhibitions of viral replication by CD8(+) T cells specific for the Gag KK10, Pol KY9, and Vpr VL9 HLA-B 2705-restricted epitopes, we observed a consistent hierarchy of antiviral efficacy (Gag KK10 > Pol KY9 > Vpr VL9). This hierarchy was associated with early...... recognition of HIV-1-infected cells, within 6 h of infection, by KK10- and KY9-specific CD8(+) T cells but not until 18 h postinfection by VL9-specific CD8(+) T cells. There was no association between antiviral efficacy and proliferative capacity, cytotoxicity, polyfunctionality, or T-cell receptor (TCR...

  9. Persistent CMV infection correlates with disease activity and dominates the phenotype of peripheral CD8+ T cells in psoriasis.

    Science.gov (United States)

    Weitz, Mario; Kiessling, Corinna; Friedrich, Markus; Prösch, Susanna; Höflich, Conny; Kern, Florian; Volk, Hans-Dieter; Sterry, Wolfram; Asadullah, Khusru; Döcke, Wolf-Dietrich

    2011-07-01

    Previously, we have reported a frequent association of active plaque psoriasis with inflammation-mediated cytomegalovirus (CMV) reactivation. This study aimed at characterizing the impact of CMV infection on psoriasis disease activity and peripheral cellular adaptive immune response. Twenty nine patients with active plaque psoriasis and 29 healthy controls were analysed for CMV-serostatus, CMV-antigenaemia, frequencies of peripheral CMV-specific T cells and the immunophenotype of peripheral CD8+ T cells. (i) Psoriasis severity was higher in CMV-seropositive patients and positively correlated to the severity of CMV-antigenaemia. (ii) In comparison to CMV-seropositive healthy controls, CMV-seropositive psoriasis patients showed a reduced frequency of circulating CMV-specific T cells that increased under effective antipsoriatic therapy. (iii) The immunophenotype of peripheral CD8+ T cells was dominated by CMV-seroprevalence. (iv) Selective analysis of CMV-seronegative psoriasis patients revealed a strong expansion of a - probably early activated - CD8+ T-cell population with the yet undescribed differentiation phenotype 'CD45RA-dim/CD11a-dim'. Under effective antipsoriatic therapy this population decreased in parallel to an increase of effector differentiated CD8+ T cells. Taken together with our previous results of inflammation-mediated CMV reactivation in psoriasis, our data support the concept of an interactive relationship between psoriasis and CMV infection which may be mediated by peripheral CD8+ T cells. © 2011 John Wiley & Sons A/S.

  10. Functional properties of peripheral CD8T cells in patients with repeated implantation failure.

    Science.gov (United States)

    Yin, Biao; Zeng, Yong; Wu, Tonghua; Yu, Shuyi; Xu, Jian; Liu, Su; Diao, Lianghui; Zhao, Zhenfu; Liang, Desheng; Li, Yuye

    2017-08-01

    CD8 + T cells are the main candidates to recognize and respond to fetal HLA-C at the fetal-maternal interface, but data on the amount of peripheral CD8 + T cells and their functions during the window of implantation in recurrent implantation failure (RIF) patients are limited. Peripheral blood was obtained from 56 women with RIF and 16 fertile women in the mid-luteal phase of the menstrual cycle, and the CD8 + T cells were determined by FACS analysis. No statistical differences in the proportion of peripheral CD8 + T cells were observed among the women with RIF and the control group. However, the levels of IFN-γ + and TNF-α + CD8 + T cells in the RIF group were significantly higher than those in the control group. The cytolytic activity and regulatory proportion of CD8 + T cells in RIF were similar to that in the control group. Our data indicated that the elevated expression levels of IFN-γ and TNF-α in peripheral CD8 + T cells may contribute to an impaired immune tolerance in women with RIF. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. Topical treatment of all-trans retinoic acid inhibits murine melanoma partly by promoting CD8+T-cell immunity.

    Science.gov (United States)

    Yin, Wei; Song, Yan; Liu, Qing; Wu, Yunyun; He, Rui

    2017-10-01

    All-trans retinoic acid (atRA), the main biologically active metabolite of vitamin A, has been implicated in immunoregulation and anti-cancer. A recent finding that vitamin A could decrease the risk of melanoma in humans indicates the beneficial role of atRA in melanoma. However, it remains unknown whether topical application of atRA could inhibit melanoma growth by influencing tumour immunity. We demonstrate topical application of tretinoin ointment (atRA as the active ingredient) effectively inhibited B16F10 melanoma growth. This is accompanied by markedly enhanced CD8 + T-cell responses, as evidenced by significantly increased proportions of effector CD8 + T cells expressing granzyme B, tumour necrosis factor-α, or interferon-γ, and Ki67 + proliferating CD8 + T cells in atRA-treated tumours compared with vaseline controls. Furthermore, topical atRA treatment promoted the differentiation of effector CD8 + T cells in draining lymph nodes (DLN) of tumour-bearing mice. Interestingly, atRA did not affect tumoral CD4 + T-cell response, and even inhibited the differentiation of interferon-γ-expressing T helper type 1 cells in DLN. Importantly, we demonstrated that the tumour-inhibitory effect of atRA was partly dependent on CD8 + T cells, as CD8 + T-cell depletion restored tumour volumes in atRA-treated mice, which, however, was still significantly smaller than those in vaseline-treated mice. Finally, we demonstrated that atRA up-regulated MHCI expression in B16F10 cells, and DLN cells from tumour-bearing mice had a significantly higher killing rate when culturing with atRA-treated B16F10 cells. Hence, our study demonstrates that topical atRA treatment effectively inhibits melanoma growth partly by promoting the differentiation and the cytotoxic function of effector CD8 + T cells. © 2017 John Wiley & Sons Ltd.

  12. Effector CD4 and CD8 T Cells and Their Role in the Tumor Microenvironment

    DEFF Research Database (Denmark)

    Hadrup, Sine; Donia, Marco; thor Straten, Per

    2012-01-01

    T cells in tumors-the so-called tumor infiltrating lymphocytes (TIL) have been studied intensively over the past years. Compelling evidence point to a clinical relevance for high numbers of T cells at the tumor site with CD8 memory T cells as a key denominator for overall survival (OS) in patients...... with colo-rectal cancer (CRC), and also for others solid cancers. These data goes hand in hand with studies of clonality of TIL showing the T cells among TIL are expanded clonally, and also that tumor specific T cells of CD4 as well as CD8 type are enriched at the tumor site. The tumor microenvironment...

  13. T Cell Receptor Vβ Staining Identifies the Malignant Clone in Adult T cell Leukemia and Reveals Killing of Leukemia Cells by Autologous CD8+ T cells.

    Directory of Open Access Journals (Sweden)

    Aileen G Rowan

    2016-11-01

    Full Text Available There is growing evidence that CD8+ cytotoxic T lymphocyte (CTL responses can contribute to long-term remission of many malignancies. The etiological agent of adult T-cell leukemia/lymphoma (ATL, human T lymphotropic virus type-1 (HTLV-1, contains highly immunogenic CTL epitopes, but ATL patients typically have low frequencies of cytokine-producing HTLV-1-specific CD8+ cells in the circulation. It remains unclear whether patients with ATL possess CTLs that can kill the malignant HTLV-1 infected clone. Here we used flow cytometric staining of TCRVβ and cell adhesion molecule-1 (CADM1 to identify monoclonal populations of HTLV-1-infected T cells in the peripheral blood of patients with ATL. Thus, we quantified the rate of CD8+-mediated killing of the putative malignant clone in ex vivo blood samples. We observed that CD8+ cells from ATL patients were unable to lyse autologous ATL clones when tested directly ex vivo. However, short in vitro culture restored the ability of CD8+ cells to kill ex vivo ATL clones in some donors. The capacity of CD8+ cells to lyse HTLV-1 infected cells which expressed the viral sense strand gene products was significantly enhanced after in vitro culture, and donors with an ATL clone that expressed the HTLV-1 Tax gene were most likely to make a detectable lytic CD8+ response to the ATL cells. We conclude that some patients with ATL possess functional tumour-specific CTLs which could be exploited to contribute to control of the disease.

  14. Characterization of a single peptide derived from cytochrome P4501B1 that elicits spontaneous human leukocyte antigen (HLA)-A1 as well as HLA-B35 restricted CD8 T-cell responses in cancer patients

    DEFF Research Database (Denmark)

    Kvistborg, P.; Hadrup, S.R.; Andersen, M.H.

    2008-01-01

    Cytochrome P450 1B1 (CYP1B1) is widely expressed in human malignancies, but silent in most normal tissues. Importantly, the protein is believed to play an important role in the survival and growth of cancer cells in a stressed environment, e.g., as a result of hypoxia or chemotherapy. Thus......, targeting of CYP1B1 represents a potentially successful strategy in the treatment of metastatic cancer, e.g., by therapeutic vaccination. Herein, we describe the characterization of a novel peptide from the CYP1B1 protein (CYP240), which is spontaneously recognized by CD8 T cells in cancer patients....... Rare but strong responses were detected in HLA-A1-positive patients, and more frequent responses were detected in HLA-B35-positive patients. No reactivity against the peptide could be detected in healthy donors. Furthermore, we demonstrated that peptide-specific T cells were able to lyze target cells...

  15. Prolonged antigen presentation by immune complex–binding dendritic cells programs the proliferative capacity of memory CD8 T cells

    Science.gov (United States)

    León, Beatriz; Ballesteros-Tato, André; Randall, Troy D.

    2014-01-01

    The commitment of naive CD8 T cells to effector or memory cell fates can occur after a single day of antigenic stimulation even though virus-derived antigens (Ags) are still presented by DCs long after acute infection is resolved. However, the effects of extended Ag presentation on CD8 T cells are undefined and the mechanisms that regulate prolonged Ag presentation are unknown. We showed that the sustained presentation of two different epitopes from influenza virus by DCs prevented the premature contraction of the primary virus-specific CD8 T cell response. Although prolonged Ag presentation did not alter the number of memory CD8 T cells that developed, it was essential for programming the capacity of these cells to proliferate, produce cytokines, and protect the host after secondary challenge. Importantly, prolonged Ag presentation by DCs was dependent on virus-specific, isotype-switched antibodies (Abs) that facilitated the capture and cross-presentation of viral Ags by FcγR-expressing DCs. Collectively, our results demonstrate that B cells and Abs can regulate the quality and functionality of a subset of antiviral CD8 T cell memory responses and do so by promoting sustained Ag presentation by DCs during the contraction phase of the primary T cell response. PMID:25002751

  16. NOD1 cooperates with TLR2 to enhance T cell receptor-mediated activation in CD8 T cells.

    Directory of Open Access Journals (Sweden)

    Blandine C Mercier

    Full Text Available Pattern recognition receptors (PRR, like Toll-like receptors (TLR and NOD-like receptors (NLR, are involved in the detection of microbial infections and tissue damage by cells of the innate immune system. Recently, we and others have demonstrated that TLR2 can additionally function as a costimulatory receptor on CD8 T cells. Here, we establish that the intracytosolic receptor NOD1 is expressed and functional in CD8 T cells. We show that C12-iEDAP, a synthetic ligand for NOD1, has a direct impact on both murine and human CD8 T cells, increasing proliferation and effector functions of cells activated via their T cell receptor (TCR. This effect is dependent on the adaptor molecule RIP2 and is associated with an increased activation of the NF-κB, JNK and p38 signaling pathways. Furthermore, we demonstrate that NOD1 stimulation can cooperate with TLR2 engagement on CD8 T cells to enhance TCR-mediated activation. Altogether our results indicate that NOD1 might function as an alternative costimulatory receptor in CD8 T cells. Our study provides new insights into the function of NLR in T cells and extends to NOD1 the recent concept that PRR stimulation can directly control T cell functions.

  17. Accumulation of cytolytic CD8{sup +} T cells in B16-melanoma and proliferation of mature T cells in TIS21-knockout mice after T cell receptor stimulation

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Min Sook [Department of Biochemistry and Molecular Biology, Ajou University School of Medicine, 164, World cul-ro, Yeongtong-gu, Suwon, Gyeonggi-do 443-380 (Korea, Republic of); Woo, Min-Yeong [Department of Microbiology, Ajou University School of Medicine, 164, World cul-ro, Yeongtong-gu, Suwon, Gyeonggi-do 443-380 (Korea, Republic of); Department of Biomedical Sciences, The Graduate School, Ajou University (Korea, Republic of); Kwon, Daeho [Department of Microbiology, Kwandong University College of Medicine, Gangneung, Gangwon-do 210-701 (Korea, Republic of); Hong, Allen E. [Department of Biochemistry and Molecular Biology, Ajou University School of Medicine, 164, World cul-ro, Yeongtong-gu, Suwon, Gyeonggi-do 443-380 (Korea, Republic of); Song, Kye Yong [Department of Pathology, Chung-Ang University College of Medicine, Dongjak-gu, Seoul 156-756 (Korea, Republic of); Park, Sun [Department of Microbiology, Ajou University School of Medicine, 164, World cul-ro, Yeongtong-gu, Suwon, Gyeonggi-do 443-380 (Korea, Republic of); Lim, In Kyoung [Department of Biochemistry and Molecular Biology, Ajou University School of Medicine, 164, World cul-ro, Yeongtong-gu, Suwon, Gyeonggi-do 443-380 (Korea, Republic of)

    2014-10-01

    In vivo and in vitro effects of TIS21 gene on the mature T cell activation and antitumor activities were explored by employing MO5 melanoma orthograft and splenocytes isolated from the TIS21-knockout (KO) mice. Proliferation and survival of mature T cells were significantly increased in the KO than the wild type (WT) cells, indicating that TIS21 inhibits the rate of mature T cell proliferation and its survival. In MO5 melanoma orthograft model, the KO mice recruited much more CD8{sup +} T cells into the tumors at around day 14 after tumor cell injection along with reduced tumor volumes compared with the WT. The increased frequency of granzyme B{sup +} CD8{sup +} T cells in splenocytes of the KO mice compared with the WT may account for antitumor-immunity of TIS21 gene in the melanoma orthograft. In contrast, reduced frequencies of CD107a{sup +} CD8{sup +} T cells in the splenocytes of KO mice may affect the loss of CD8{sup +} T cell infiltration in the orthograft at around day 19. These results indicate that TIS21 exhibits antiproliferative and proapoptotic effects in mature T cells, and differentially affects the frequencies of granzyme B{sup +} CD8{sup +} T-cells and CD107a{sup +} CD8{sup +} T-cells, thus transiently regulating in vivo anti-tumor immunity. - Highlights: • Constitutive expression of TIS21 in splenocytes and upregulation by TCR stimulation. • Proliferation of mature T-cells in spleen of TIS21KO mice after TCR stimulation. • Inhibition of cell death in mature T-cells of TIS21KO mice compared with the wild type. • Inhibition of melanoma growth in TIS21KO mice and CD8{sup +} T cell infiltration in tumor. • Reduction of CD 107{sup +}CD8{sup +} T cells, but increased granzyme B{sup +} CD8{sup +} T cells in TIS21KO mice.

  18. Cognate antigen stimulation generates potent CD8+ inflammatory effector T cells.

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    Hsueh-Cheng eSung

    2013-12-01

    Full Text Available Inflammatory reactions are believed to be triggered by innate signals and have a major protective role by recruiting innate immunity cells, favoring lymphocyte activation and differentiation, and thus contributing to the sequestration and elimination of the injurious stimuli. Although certain lymphocyte types such as TH17 cells co-participate in inflammatory reactions, their generation from the naïve pool requires the pre-existence of an inflammatory milieu. In this context, inflammation is always regarded as beginning with an innate response that may be eventually perpetuated and amplified by certain lymphocyte types. In contrast, we here show that even in sterile immunizations or in MyD88 deficient mice, CD8 T cells produce a burst of pro-inflammatory cytokines and chemokines. These functions follow opposite rules to the classic CD8 effector functions since they are generated prior to cell expansion and decline before antigen elimination. As few as 56 CD8+ inflammatory effector cells in a lymph node can mobilize 107 cells in 24h, including lymphocytes, natural killer cells and several accessory cell types involved in inflammatory reactions. Thus, although inflammation modulates cognate responses, CD8 cognate responses also initiate local inflammatory reactions.

  19. IL-15 promotes activation and expansion of CD8+ T cells in HIV-1 infection

    OpenAIRE

    Younes, Souheil-Antoine; Freeman, Michael L.; Mudd, Joseph C.; Shive, Carey L.; Reynaldi, Arnold; Panigrahi, Soumya; Estes, Jacob D.; Deleage, Claire; Lucero, Carissa; Anderson, Jodi; Schacker, Timothy W.; Davenport, Miles P.; McCune, Joseph M.; Hunt, Peter W.; Lee, Sulggi A.

    2016-01-01

    In HIV-1–infected patients, increased numbers of circulating CD8+ T cells are linked to increased risk of morbidity and mortality. Here, we identified a bystander mechanism that promotes CD8 T cell activation and expansion in untreated HIV-1–infected patients. Compared with healthy controls, untreated HIV-1–infected patients have an increased population of proliferating, granzyme B+, CD8+ T cells in circulation. Vβ expression and deep sequencing of CDR3 revealed that in untreated HIV-1 infect...

  20. Decline of influenza-specific CD8+ T cell repertoire in healthy geriatric donors

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    Ramachandra Lakshmi

    2011-08-01

    Full Text Available Abstract Background While influenza vaccination results in protective antibodies against primary infections, clearance of infection is primarily mediated through CD8+ T cells. Studying the CD8+ T cell response to influenza epitopes is crucial in understanding the disease associated morbidity and mortality especially in at risk populations such as the elderly. We compared the CD8+ T cell response to immunodominant and subdominant influenza epitopes in HLA-A2+ control, adult donors, aged 21-42, and in geriatric donors, aged 65 and older. Results We used a novel artificial Antigen Presenting Cell (aAPC based stimulation assay to reveal responses that could not be detected by enzyme-linked immunosorbent spot (ELISpot. 14 younger control donors and 12 geriatric donors were enrolled in this study. The mean number of influenza-specific subdominant epitopes per control donor detected by ELISpot was only 1.4 while the mean detected by aAPC assay was 3.3 (p = 0.0096. Using the aAPC assay, 92% of the control donors responded to at least one subdominant epitopes, while 71% of control donors responded to more than one subdominant influenza-specific response. 66% of geriatric donors lacked a subdominant influenza-specific response and 33% of geriatric donors responded to only 1 subdominant epitope. The difference in subdominant response between age groups is statistically significant (p = 0.0003. Conclusion Geriatric donors lacked the broad, multi-specific response to subdominant epitopes seen in the control donors. Thus, we conclude that aging leads to a decrease in the subdominant influenza-specific CTL responses which may contribute to the increased morbidity and mortality in older individuals.

  1. Essential role of CD11a in CD8+ T-cell accumulation and activation in adipose tissue

    Science.gov (United States)

    T-cells, particularly CD8+ T-cells, are major participants in obesity-linked adipose tissue inflammation. We examined the mechanisms of CD8+ T-cell accumulation and activation in adipose tissue and the role of CD11a, a beta2 integrin. CD8+ T-cells in adipose tissue of obese mice showed activated phe...

  2. The Microbiota Contributes to CD8+ T Cell Activation and Nutrient Malabsorption following Intestinal Infection with Giardia duodenalis.

    Science.gov (United States)

    Keselman, Aleksander; Li, Erqiu; Maloney, Jenny; Singer, Steven M

    2016-10-01

    Giardia duodenalis is a noninvasive luminal pathogen that impairs digestive function in its host in part by reducing intestinal disaccharidase activity. This enzyme deficiency has been shown in mice to require CD8(+) T cells. We recently showed that both host immune responses and parasite strain affected disaccharidase levels during murine giardiasis. However, high doses of antibiotics were used to facilitate infections in that study, and we therefore decided to systematically examine the effects of antibiotic use on pathogenesis and immune responses in the mouse model of giardiasis. We found that antibiotic treatment did not overtly increase the parasite burden but significantly limited the disaccharidase deficiency observed in infected mice. Moreover, while infected mice had more activated CD8(+) αβ T cells in the small intestinal lamina propria, this increase was absent in antibiotic-treated mice. Infection also led to increased numbers of CD4(+) αβ T cells in the lamina propria and activation of T cell receptor γδ-expressing intraepithelial lymphocytes (IEL), but these changes were not affected by antibiotics. Finally, we show that activated CD8(+) T cells express gamma interferon (IFN-γ) and granzymes but that granzymes are not required for sucrase deficiency. We conclude that CD8(+) T cells become activated in giardiasis through an antibiotic-sensitive process and contribute to reduced sucrase activity. These are the first data directly demonstrating activation of CD8(+) T cells and γδ T cells during Giardia infections. These data also demonstrate that disruption of the intestinal microbiota by antibiotic treatment prevents pathological CD8(+) T cell activation in giardiasis. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  3. Metabolic reprogramming towards aerobic glycolysis correlates with greater proliferative ability and resistance to metabolic inhibition in CD8 versus CD4 T cells.

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    Yilin Cao

    Full Text Available T lymphocytes (T cells undergo metabolic reprogramming after activation to provide energy and biosynthetic materials for growth, proliferation and differentiation. Distinct T cell subsets, however, adopt metabolic programs specific to support their needs. As CD4 T cells coordinate adaptive immune responses while CD8 T cells become cytotoxic effectors, we compared activation-induced proliferation and metabolic reprogramming of these subsets. Resting CD4 and CD8 T cells were metabolically similar and used a predominantly oxidative metabolism. Following activation CD8 T cells proliferated more rapidly. Stimulation led both CD4 and CD8 T cells to sharply increase glucose metabolism and adopt aerobic glycolysis as a primary metabolic program. Activated CD4 T cells, however, remained more oxidative and had greater maximal respiratory capacity than activated CD8 T cells. CD4 T cells were also associated with greater levels of ROS and increased mitochondrial content, irrespective of the activation context. CD8 cells were better able, however, to oxidize glutamine as an alternative fuel source. The more glycolytic metabolism of activated CD8 T cells correlated with increased capacity for growth and proliferation, along with reduced sensitivity of cell growth to metabolic inhibition. These specific metabolic programs may promote greater growth and proliferation of CD8 T cells and enhance survival in diverse nutrient conditions.

  4. Blimp-1–mediated CD4 T cell exhaustion causes CD8 T cell dysfunction during chronic toxoplasmosis

    Science.gov (United States)

    Cobb, Dustin A.; Bhadra, Rajarshi

    2016-01-01

    CD8, but not CD4, T cells are considered critical for control of chronic toxoplasmosis. Although CD8 exhaustion has been previously reported in Toxoplasma encephalitis (TE)–susceptible model, our current work demonstrates that CD4 not only become exhausted during chronic toxoplasmosis but this dysfunction is more pronounced than CD8 T cells. Exhausted CD4 population expressed elevated levels of multiple inhibitory receptors concomitant with the reduced functionality and up-regulation of Blimp-1, a transcription factor. Our data demonstrates for the first time that Blimp-1 is a critical regulator for CD4 T cell exhaustion especially in the CD4 central memory cell subset. Using a tamoxifen-dependent conditional Blimp-1 knockout mixed bone marrow chimera as well as an adoptive transfer approach, we show that CD4 T cell–intrinsic deletion of Blimp-1 reversed CD8 T cell dysfunction and resulted in improved pathogen control. To the best of our knowledge, this is a novel finding, which demonstrates the role of Blimp-1 as a critical regulator of CD4 dysfunction and links it to the CD8 T cell dysfunctionality observed in infected mice. The critical role of CD4-intrinsic Blimp-1 expression in mediating CD4 and CD8 T cell exhaustion may provide a rational basis for designing novel therapeutic approaches. PMID:27481131

  5. A molecular threshold for effector CD8+ T cell differentiation controlled by transcription factors Blimp-1 and T-bet

    OpenAIRE

    Xin, Annie; Masson, Frederick; Liao, Yang; Preston, Simon; Guan, Tianxia; Gloury, Renee; Olshansky, Moshe; Lin, Jian-Xin; Li, Peng; Speed, Terence P; Smyth, Gordon K; Ernst, Matthias; Leonard, Warren J; Pellegrini, Marc; Kaech, Susan M

    2016-01-01

    T cell responses are guided by cytokines that induce transcriptional regulators, which ultimately control differentiation of effector and memory T cells. However, it is unknown how the activities of these molecular regulators are coordinated and integrated during the differentiation process. Using genetic approaches and transcriptional profiling of antigen-specific CD8+ T cells, we reveal a common program of effector differentiation that is regulated by IL-2 and IL-12 signaling and the combin...

  6. Latent HIV reservoirs exhibit inherent resistance to elimination by CD8+ T cells.

    Science.gov (United States)

    Huang, Szu-Han; Ren, Yanqin; Thomas, Allison S; Chan, Dora; Mueller, Stefanie; Ward, Adam R; Patel, Shabnum; Bollard, Catherine M; Cruz, Conrad Russell; Karandish, Sara; Truong, Ronald; Macedo, Amanda B; Bosque, Alberto; Kovacs, Colin; Benko, Erika; Piechocka-Trocha, Alicja; Wong, Hing; Jeng, Emily; Nixon, Douglas F; Ho, Ya-Chi; Siliciano, Robert F; Walker, Bruce D; Jones, R Brad

    2018-02-01

    The presence of persistent, latent HIV reservoirs in CD4+ T cells obstructs current efforts to cure infection. The so-called kick-and-kill paradigm proposes to purge these reservoirs by combining latency-reversing agents with immune effectors such as cytotoxic T lymphocytes. Support for this approach is largely based on success in latency models, which do not fully reflect the makeup of latent reservoirs in individuals on long-term antiretroviral therapy (ART). Recent studies have shown that CD8+ T cells have the potential to recognize defective proviruses, which comprise the vast majority of all infected cells, and that the proviral landscape can be shaped over time due to in vivo clonal expansion of infected CD4+ T cells. Here, we have shown that treating CD4+ T cells from ART-treated individuals with combinations of potent latency-reversing agents and autologous CD8+ T cells consistently reduced cell-associated HIV DNA, but failed to deplete replication-competent virus. These CD8+ T cells recognized and potently eliminated CD4+ T cells that were newly infected with autologous reservoir virus, ruling out a role for both immune escape and CD8+ T cell dysfunction. Thus, our results suggest that cells harboring replication-competent HIV possess an inherent resistance to CD8+ T cells that may need to be addressed to cure infection.

  7. Superior control of HIV-1 replication by CD8+ T cells targeting conserved epitopes: implications for HIV vaccine design.

    Directory of Open Access Journals (Sweden)

    Pratima Kunwar

    Full Text Available A successful HIV vaccine will likely induce both humoral and cell-mediated immunity, however, the enormous diversity of HIV has hampered the development of a vaccine that effectively elicits both arms of the adaptive immune response. To tackle the problem of viral diversity, T cell-based vaccine approaches have focused on two main strategies (i increasing the breadth of vaccine-induced responses or (ii increasing vaccine-induced responses targeting only conserved regions of the virus. The relative extent to which set-point viremia is impacted by epitope-conservation of CD8(+ T cell responses elicited during early HIV-infection is unknown but has important implications for vaccine design. To address this question, we comprehensively mapped HIV-1 CD8(+ T cell epitope-specificities in 23 ART-naïve individuals during early infection and computed their conservation score (CS by three different methods (prevalence, entropy and conseq on clade-B and group-M sequence alignments. The majority of CD8(+ T cell responses were directed against variable epitopes (p<0.01. Interestingly, increasing breadth of CD8(+ T cell responses specifically recognizing conserved epitopes was associated with lower set-point viremia (r = - 0.65, p = 0.009. Moreover, subjects possessing CD8(+ T cells recognizing at least one conserved epitope had 1.4 log10 lower set-point viremia compared to those recognizing only variable epitopes (p = 0.021. The association between viral control and the breadth of conserved CD8(+ T cell responses may be influenced by the method of CS definition and sequences used to determine conservation levels. Strikingly, targeting variable versus conserved epitopes was independent of HLA type (p = 0.215. The associations with viral control were independent of functional avidity of CD8(+ T cell responses elicited during early infection. Taken together, these data suggest that the next-generation of T-cell based HIV-1 vaccines should focus

  8. Induction of cytotoxic CD8+CD56+ T cells from human thymocytes by interleukin-15

    DEFF Research Database (Denmark)

    Thulesen, S; Nissen, Mogens Holst; Ødum, N

    2001-01-01

    CD8(+) CD56(+) cells isolated from human peripheral blood lymphocytes have been shown recently to represent a population of cytotoxic active T cells. However, it is not known if these cells are intrathymically or extrathymically developed or how these cells are influenced by growth factors....... In the present study, we investigated the effects of interleukin-2 (IL-2) and IL-15 on human thymocytes with respect to development of CD8(+) CD56(+) T cells. Freshly isolated thymocytes contain few CD8(+) CD56(+) cells, but the number of these cells increases significantly when thymocytes are grown...... in the presence of IL-15 or IL-2. However, IL-15 induced a significantly higher fraction of CD8(+) CD56(+) cells compared with IL-2. Thus, although IL-2 and IL-15 are known to have a number of redundant functions, we here demonstrate that IL-15 is superior to IL-2 in inducing CD8(+) CD56(+) T cells from cultures...

  9. CD8+ Tumor-Infiltrating T Cells Are Trapped in the Tumor-Dendritic Cell Network

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    Alexandre Boissonnas

    2013-01-01

    Full Text Available Chemotherapy enhances the antitumor adaptive immune T cell response, but the immunosuppressive tumor environment often dominates, resulting in cancer relapse. Antigen-presenting cells such as tumor-associated macrophages (TAMs and tumor dendritic cells (TuDCs are the main protagonists of tumor-infiltrating lymphocyte (TIL immuno-suppression. TAMs have been widely investigated and are associated with poor prognosis, but the immuno-suppressive activity of TuDCs is less well understood. We performed two-photon imaging of the tumor tissue to examine the spatiotemporal interactions between TILs and TuDCs after chemotherapy. In a strongly immuno-suppressive murine tumor model, cyclophosphamide-mediated chemotherapy transiently enhanced the antitumor activity of adoptively transferred ovalbumin-specific CD8+ T cell receptor transgenic T cells (OTI but barely affected TuDC compartment within the tumor. Time lapse imaging of living tumor tissue showed that TuDCs are organized as a mesh with dynamic interconnections. Once infiltrated into the tumor parenchyma, OTI T cells make antigen-specific and long-lasting contacts with TuDCs. Extensive analysis of TIL infiltration on histologic section revealed that after chemotherapy the majority of OTI T cells interact with TuDCs and that infiltration is restricted to TuDC-rich areas. We propose that the TuDC network exerts antigen-dependent unproductive retention that trap T cells and limit their antitumor effectiveness.

  10. Accelerated aging in HIV/AIDS: novel biomarkers of senescent human CD8+ T cells.

    Directory of Open Access Journals (Sweden)

    Jennifer P Chou

    Full Text Available Clinical evaluation of immune reconstitution and health status during HIV-1 infection and anti-retroviral therapy (ART is largely based on CD4+ T cell counts and viral load, measures that fail to take into account the CD8+ T cell subset, known to show features of accelerated aging in HIV disease. Here, we compare adenosine deaminase (ADA, glucose uptake receptor 1 (GLUT1, and leucine-rich repeat neuronal 3 (LRRN3 to CD38 expression and telomerase activity, two strong predictors of HIV disease progression. Our analysis revealed that reduced ADA, telomerase activity and LRRN3 gene expression were significantly associated with high CD38 and HLA-DR in CD8+ T cells, with % ADA+ cells being the most robust predictor of CD8+ T cell activation. Our results suggest that ADA, LRRN3 and telomerase activity in CD8+ T cells may serve as novel, clinically relevant biomarkers of immune status in HIV-1 infection, specifically by demonstrating the degree to which CD8+ T cells have progressed to the end stage of replicative senescence. Since chronological aging itself leads to the accumulation of senescent CD8+ T cells, the prolonged survival and resultant increased age of the HIV+ population may synergize with the chronic immune activation to exacerbate both immune decline and age-associated pathologies. The identification and future validation of these new biomarkers may lead to fresh immune-based HIV treatments.

  11. The Loss of TET2 Promotes CD8+T Cell Memory Differentiation.

    Science.gov (United States)

    Carty, Shannon A; Gohil, Mercy; Banks, Lauren B; Cotton, Renee M; Johnson, Matthew E; Stelekati, Erietta; Wells, Andrew D; Wherry, E John; Koretzky, Gary A; Jordan, Martha S

    2018-01-01

    T cell differentiation requires appropriate regulation of DNA methylation. In this article, we demonstrate that the methylcytosine dioxygenase ten-eleven translocation (TET)2 regulates CD8 + T cell differentiation. In a murine model of acute viral infection, TET2 loss promotes early acquisition of a memory CD8 + T cell fate in a cell-intrinsic manner without disrupting Ag-driven cell expansion or effector function. Upon secondary recall, TET2-deficient memory CD8 + T cells demonstrate superior pathogen control. Genome-wide methylation analysis identified a number of differentially methylated regions in TET2-deficient versus wild-type CD8 + T cells. These differentially methylated regions did not occur at the loci of differentially expressed memory markers; rather, several hypermethylated regions were identified in known transcriptional regulators of CD8 + T cell memory fate. Together, these data demonstrate that TET2 is an important regulator of CD8 + T cell fate decisions. Copyright © 2017 by The American Association of Immunologists, Inc.

  12. CD8 T cells express randomly selected KIRs with distinct specificities compared with NK cells

    Science.gov (United States)

    Béziat, Vivien; Cichocki, Frank; Liu, Lisa L.; Levine, Jeffrey; Larsson, Stella; Koup, Richard A.; Anderson, Stephen K.; Ljunggren, Hans-Gustaf

    2012-01-01

    Epistatic interactions between killer cell immunoglobulin-like receptors (KIRs) and their cognate HLA class I ligands have important implications for reproductive success, antiviral immunity, susceptibility to autoimmune conditions and cancer, as well as for graft-versus-leukemia reactions in settings of allogeneic stem cell transplantation. Although CD8 T cells are known to acquire KIRs when maturing from naive to terminally differentiated cells, little information is available about the constitution of KIR repertoires on human CD8 T cells. Here, we have performed a high-resolution analysis of KIR expression on CD8 T cells. The results show that most CD8 T cells po