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Sample records for cd8 epitope display

  1. Novel CD8(+) cytotoxic T cell epitopes in bovine leukemia virus with cattle.

    Science.gov (United States)

    Bai, Lanlan; Takeshima, Shin-Nosuke; Isogai, Emiko; Kohara, Junko; Aida, Yoko

    2015-12-16

    Bovine leukemia virus (BLV) is associated with enzootic bovine leukosis and is closely related to human T cell leukemia virus (HTLV). The cytotoxic T lymphocyte (CTL) plays a key role in suppressing the progression of disease caused by BLV. T and B cell epitopes in BLV have been studied, but CD8(+) CTL epitopes remain poorly understood. We used a library of 115 synthetic peptides covering the entirety of the Env proteins (gp51 and gp30), the Gag proteins (p15, p24, and p12), and the Tax protein of BLV to identify 11 novel CD8(+) T cell epitopes (gp51N5, gp51N11, gp51N12, gp30N5, gp30N6, gp30N8, gp30N16, tax16, tax18, tax19, and tax20) in four calves experimentally infected with BLV. The number of CD8(+) T cell epitopes that could be identified in each calf correlated with the BLV proviral load. Interestingly, among the 11 epitopes identified, only gp51N11 was capable of inducing CD8(+) T cell-mediated cytotoxicity in all four calves, but it is not a suitable vaccine target because it shows a high degree of polymorphism according to the Wu-Kabat variability index. By contrast, no CTL epitopes were identified from the Gag structural protein. In addition, several epitopes were obtained from gp30 and Tax, indicating that cellular immunity against BLV is strongly targeted to these proteins. CD8(+) CTL epitopes from gp30 and Tax were less polymorphic than epitopes from. Indeed, peptides tax16, tax18, tax19, and tax20 include a leucine-rich activation domain that encompasses a transcriptional activation domain, and the gp30N16 peptide contains a proline-rich region that interacts with a protein tyrosine phosphatase SHP1 to regulate B cell activation. Moreover, at least one CD8(+) CTL epitope derived from gp30 was identified in each of the four calves. These results indicate that BLV gp30 may be the best candidate for the development of a BLV vaccine. PMID:26552001

  2. Novel CD8(+) cytotoxic T cell epitopes in bovine leukemia virus with cattle.

    Science.gov (United States)

    Bai, Lanlan; Takeshima, Shin-Nosuke; Isogai, Emiko; Kohara, Junko; Aida, Yoko

    2015-12-16

    Bovine leukemia virus (BLV) is associated with enzootic bovine leukosis and is closely related to human T cell leukemia virus (HTLV). The cytotoxic T lymphocyte (CTL) plays a key role in suppressing the progression of disease caused by BLV. T and B cell epitopes in BLV have been studied, but CD8(+) CTL epitopes remain poorly understood. We used a library of 115 synthetic peptides covering the entirety of the Env proteins (gp51 and gp30), the Gag proteins (p15, p24, and p12), and the Tax protein of BLV to identify 11 novel CD8(+) T cell epitopes (gp51N5, gp51N11, gp51N12, gp30N5, gp30N6, gp30N8, gp30N16, tax16, tax18, tax19, and tax20) in four calves experimentally infected with BLV. The number of CD8(+) T cell epitopes that could be identified in each calf correlated with the BLV proviral load. Interestingly, among the 11 epitopes identified, only gp51N11 was capable of inducing CD8(+) T cell-mediated cytotoxicity in all four calves, but it is not a suitable vaccine target because it shows a high degree of polymorphism according to the Wu-Kabat variability index. By contrast, no CTL epitopes were identified from the Gag structural protein. In addition, several epitopes were obtained from gp30 and Tax, indicating that cellular immunity against BLV is strongly targeted to these proteins. CD8(+) CTL epitopes from gp30 and Tax were less polymorphic than epitopes from. Indeed, peptides tax16, tax18, tax19, and tax20 include a leucine-rich activation domain that encompasses a transcriptional activation domain, and the gp30N16 peptide contains a proline-rich region that interacts with a protein tyrosine phosphatase SHP1 to regulate B cell activation. Moreover, at least one CD8(+) CTL epitope derived from gp30 was identified in each of the four calves. These results indicate that BLV gp30 may be the best candidate for the development of a BLV vaccine.

  3. Chemical Modification of Influenza CD8+ T-Cell Epitopes Enhances Their Immunogenicity Regardless of Immunodominance

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    van Beek, Josine; Hoppes, Rieuwert; Jacobi, Ronald H. J.; Hendriks, Marion; Kapteijn, Kim; Ouwerkerk, Casper; Rodenko, Boris; Ovaa, Huib; de Jonge, Jørgen

    2016-01-01

    T cells are essential players in the defense against infection. By targeting the MHC class I antigen-presenting pathway with peptide-based vaccines, antigen-specific T cells can be induced. However, low immunogenicity of peptides poses a challenge. Here, we set out to increase immunogenicity of influenza-specific CD8+ T cell epitopes. By substituting amino acids in wild type sequences with non-proteogenic amino acids, affinity for MHC can be increased, which may ultimately enhance cytotoxic CD8+ T cell responses. Since preventive vaccines against viruses should induce a broad immune response, we used this method to optimize influenza-specific epitopes of varying dominance. For this purpose, HLA-A*0201 epitopes GILGFVFTL, FMYSDFHFI and NMLSTVLGV were selected in order of decreasing MHC-affinity and dominance. For all epitopes, we designed chemically enhanced altered peptide ligands (CPLs) that exhibited greater binding affinity than their WT counterparts; even binding scores of the high affinity GILGFVFTL epitope could be improved. When HLA-A*0201 transgenic mice were vaccinated with selected CPLs, at least 2 out of 4 CPLs of each epitope showed an increase in IFN-γ responses of splenocytes. Moreover, modification of the low affinity epitope NMLSTVLGV led to an increase in the number of mice that responded. By optimizing three additional influenza epitopes specific for HLA-A*0301, we show that this strategy can be extended to other alleles. Thus, enhancing binding affinity of peptides provides a valuable tool to improve the immunogenicity and range of preventive T cell-targeted peptide vaccines. PMID:27333291

  4. Human CD8(+) T Cells Target Multiple Epitopes in Respiratory Syncytial Virus Polymerase.

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    Burbulla, Daniel; Günther, Patrick S; Peper, Janet K; Jahn, Gerhard; Dennehy, Kevin M

    2016-06-01

    Respiratory syncytial virus (RSV) infection is a serious health problem in young children, immunocompromised patients, and the elderly. The development of novel prevention strategies, such as a vaccine to RSV, is a high priority. One strategy is to design a peptide-based vaccine that activates appropriate CD8(+) T-cell responses. However, this approach is limited by the low number of RSV peptide epitopes defined to date that activate CD8(+) T cells. We aimed to identify peptide epitopes that are presented by common human leukocyte antigen types (HLA-A*01, -A*02, and -B*07). We identify one novel HLA-A*02-restricted and two novel HLA-A*01-restricted peptide epitopes from RSV polymerase. Peptide-HLA multimer staining of specific T cells from healthy donor peripheral blood mononuclear cell, the memory phenotype of such peptide-specific T cells ex vivo, and functional IFNγ responses in short-term stimulation assays suggest that these peptides are recognized during RSV infection. Such peptides are candidates for inclusion into a peptide-based RSV vaccine designed to stimulate defined CD8(+) T-cell responses.

  5. 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.

  6. Prediction of CD8+ Epitopes in Leishmania braziliensis Proteins Using EPIBOT: In Silico Search and In Vivo Validation.

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    Angelo Duarte

    Full Text Available Leishmaniasis is caused by intracellular Leishmania parasites that induce a T-cell mediated response associated with recognition of CD4+ and CD8+ T cell Line 1Lineepitopes. Identification of CD8+ antigenic determinants is crucial for vaccine and therapy development. Herein, we developed an open-source software dedicated to search and compile data obtained from currently available on line prediction algorithms.We developed a two-phase algorithm and implemented in an open source software called EPIBOT, that consolidates the results obtained with single prediction algorithms, generating a final output in which epitopes are ranked. EPIBOT was initially trained using a set of 831 known epitopes from 397 proteins from IEDB. We then screened 63 Leishmania braziliensis vaccine candidates with the EPIBOT trained tool to search for CD8+ T cell epitopes. A proof-of-concept experiment was conducted with the top eight CD8+ epitopes, elected by EPIBOT. To do this, the elected peptides were synthesized and validated for their in vivo cytotoxicity. Among the tested epitopes, three were able to induce lysis of pulsed-target cells.Our results show that EPIBOT can successfully search across existing prediction tools, generating a compiled list of candidate CD8+ epitopes. This software is fast and a simple search engine that can be customized to search over different MHC alleles or HLA haplotypes.

  7. Superior control of HIV-1 replication by CD8+ T cells targeting conserved epitopes: implications for HIV vaccine design.

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    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. Phase I Trial of a CD8+ T-Cell Peptide Epitope-Based Vaccine for Infectious Mononucleosis▿

    OpenAIRE

    Elliott, Suzanne L.; Suhrbier, Andreas; Miles, John J.; Lawrence, Greg; Pye, Stephanie J.; Le, Thuy T.; Rosenstengel, Andrew; Nguyen, Tam; Allworth, Anthony; Burrows, Scott R.; COX, JOHN; Pye, David; Moss, Denis J.; Bharadwaj, Mandvi

    2007-01-01

    A single blind, randomized, placebo-controlled, single-center phase I clinical trial of a CD8+ T-cell peptide epitope vaccine against infectious mononucleosis was conducted with 14 HLA B*0801-positive, Epstein-Barr virus (EBV)-seronegative adults. The vaccine comprised the HLA B*0801-restricted peptide epitope FLRGRAYGL and tetanus toxoid formulated in a water-in-oil adjuvant, Montanide ISA 720. FLRGRAYGL-specific responses were detected in 8/9 peptide-vaccine recipients and 0/4 placebo vacci...

  9. Identification of Candidate Tolerogenic CD8+ T Cell Epitopes for Therapy of Type 1 Diabetes in the NOD Mouse Model

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    Cailin Yu

    2016-01-01

    Full Text Available Type 1 diabetes is an autoimmune disease in which insulin-producing pancreatic islet β cells are the target of self-reactive B and T cells. T cells reactive with epitopes derived from insulin and/or IGRP are critical for the initiation and maintenance of disease, but T cells reactive with other islet antigens likely have an essential role in disease progression. We sought to identify candidate CD8+ T cell epitopes that are pathogenic in type 1 diabetes. Proteins that elicit autoantibodies in human type 1 diabetes were analyzed by predictive algorithms for candidate epitopes. Using several different tolerizing regimes using synthetic peptides, two new predicted tolerogenic CD8+ T cell epitopes were identified in the murine homolog of the major human islet autoantigen zinc transporter ZnT8 (aa 158–166 and 282–290 and one in a non-β cell protein, dopamine β-hydroxylase (aa 233–241. Tolerizing vaccination of NOD mice with a cDNA plasmid expressing full-length proinsulin prevented diabetes, whereas plasmids encoding ZnT8 and DβH did not. However, tolerizing vaccination of NOD mice with the proinsulin plasmid in combination with plasmids expressing ZnT8 and DβH decreased insulitis and enhanced prevention of disease compared to vaccination with the plasmid encoding proinsulin alone.

  10. Identification of Candidate Tolerogenic CD8+ T Cell Epitopes for Therapy of Type 1 Diabetes in the NOD Mouse Model

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    Yu, Cailin; Burns, Jeremy C.; Robinson, William H.; Utz, Paul J.; Ho, Peggy P.; Steinman, Lawrence; Frey, Alan B.

    2016-01-01

    Type 1 diabetes is an autoimmune disease in which insulin-producing pancreatic islet β cells are the target of self-reactive B and T cells. T cells reactive with epitopes derived from insulin and/or IGRP are critical for the initiation and maintenance of disease, but T cells reactive with other islet antigens likely have an essential role in disease progression. We sought to identify candidate CD8+ T cell epitopes that are pathogenic in type 1 diabetes. Proteins that elicit autoantibodies in human type 1 diabetes were analyzed by predictive algorithms for candidate epitopes. Using several different tolerizing regimes using synthetic peptides, two new predicted tolerogenic CD8+ T cell epitopes were identified in the murine homolog of the major human islet autoantigen zinc transporter ZnT8 (aa 158–166 and 282–290) and one in a non-β cell protein, dopamine β-hydroxylase (aa 233–241). Tolerizing vaccination of NOD mice with a cDNA plasmid expressing full-length proinsulin prevented diabetes, whereas plasmids encoding ZnT8 and DβH did not. However, tolerizing vaccination of NOD mice with the proinsulin plasmid in combination with plasmids expressing ZnT8 and DβH decreased insulitis and enhanced prevention of disease compared to vaccination with the plasmid encoding proinsulin alone. PMID:27069933

  11. Rapid Antigen Processing and Presentation of a Protective and Immunodominant HLA-B*27-restricted Hepatitis C Virus-specific CD8+ T-cell Epitope

    OpenAIRE

    Julia Schmidt; Iversen, Astrid K N; Stefan Tenzer; Emma Gostick; Price, David A.; Volker Lohmann; Ute Distler; Paul Bowness; Hansjörg Schild; Blum, Hubert E.; Paul Klenerman; Christoph Neumann-Haefelin; Robert Thimme

    2012-01-01

    HLA-B*27 exerts protective effects in hepatitis C virus (HCV) and human immunodeficiency virus (HIV) infections. While the immunological and virological features of HLA-B*27-mediated protection are not fully understood, there is growing evidence that the presentation of specific immunodominant HLA-B*27-restricted CD8+ T-cell epitopes contributes to this phenomenon in both infections. Indeed, protection can be linked to single immunodominant CD8+ T-cell epitopes and functional constraints on e...

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

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

    2014-01-01

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

  13. Differential presentation of endogenous and exogenous hepatitis B surface antigens influences priming of CD8(+) T cells in an epitope-specific manner.

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    Riedl, Petra; Reiser, Michael; Stifter, Katja; Krieger, Jana; Schirmbeck, Reinhold

    2014-07-01

    Little is known about whether presentation of endogenous and exogenous hepatitis B virus (HBV) surface antigens on APCs targeted by vaccination and/or virus-harboring hepatocytes influences de novo priming of CD8(+) T cells. We showed that surface antigen-expressing transfectants exclusively display a K(b) /S190 epitope, whereas cells pulsed with recombinant surface particles (rSPs) exclusively present a K(b) /S208 epitope to CD8(+) T cells. The differential presentation of these epitopes largely reflects the selective, but not exclusive, priming of K(b) /S190- and K(b) /S208-specific T cells in C57BL/6 mice by endogenous/DNA- or exogenous/protein-based vaccines, respectively. Silencing the K(b) /S190 epitope (K(b) /S190V194F ) in antigen-expressing vectors rescued the presentation of the K(b) /S208 epitope in stable transfectants and significantly enhanced priming of K(b) /S208-specific T cells in C57BL/6 mice. A K(b) /S190-mediated immunodominance operating in surface antigen-expressing cells, but not in rSP-pulsed cells, led to an efficient suppression in the presentation of the K(b) /S208 epitope and a consequent decrease in the priming of K(b) /S208-specific T cells. This K(b) /S190-mediated immunodominance also operated in 1.4HBV-S(mut) transgenic (tg) hepatocytes selectively expressing endogenous surface antigens and allowed priming of K(b) /S208- but not K(b) /S190-specific T cells in 1.4HBV-S(mut) tg mice. However, IFN-γ(+) K(b) /S208-specific T cells could not inhibit HBV replication in the liver of 1.4HBV-S(mut) tg mice. These results have practical implications for the design of T-cell-stimulating therapeutic vaccines. PMID:24723392

  14. Therapeutic polypeptides based on HBV core 18-27 epitope can induce CD8+ CTL-mediated cytotoxicity in HLA-A2+ human PBMCs

    Institute of Scientific and Technical Information of China (English)

    Tong-Dong Shi; Yu-Zhang Wu; Zheng-Cai Jia; Li-Yun Zou; Wei Zhou

    2004-01-01

    AIM: To explore how to improve the immunogenicity of HBcAg CTL epitope based polypeptides and to trigger an HBV-specific HLA I-restricted CD8+ T cell response in vitro.METHODS: A new panel of mimetic therapeutic peptides based on the immunodominant B cell epitope of HBV PreS218-24 region, the CTL epitope of HBcAg18-27 and the universal T helper epitope of tetanus toxoid (TT) 830-843was designed using computerized molecular design method and synthesized by Merrifield's solid-phase peptide synthesis.Their immunological properties of stimulating activation and proliferation of lymphocytes, of inducing TH1 polarization,CD8+ T cell magnification and HBV-specific CD8+ CTL mediated cytotoxicity were investigatedin vitro using HLAA2+ human peripheral blood mononuclear cells (PBMCs) from healthy donors and chronic hepatitis B patients.RESULTS: Results demonstrated that the therapeutic polypeptides based on immunodominant HBcAg18-27 CTL,PreS2 B- and universal TH epitopes could stimulate the activation and proliferation of lymphocytes, induce specifically and effectively CD8+ T cell expansion and vigorous HBVspecific CTL-mediated cytotoxicity in human PBMCs.CONCLUSION: It indicated that the introduction of immunodominant T helper plus B-epitopes with short and flexible linkers could dramatically improve the immunogenicity of short CTL epitopes in vitro.

  15. Programmed death-1 expression on HIV-1-specific CD8+ T cells is shaped by epitope specificity, T-cell receptor clonotype usage and antigen load

    DEFF Research Database (Denmark)

    Kløverpris, Henrik N; McGregor, Reuben; McLaren, James E;

    2014-01-01

    ) clonotypes within individual HIV-1-specific CD8+ T-cell populations was also apparent, independent of clonal dominance hierarchies. Positive correlations were detected between PD-1 expression and plasma viral load, which were reinforced by stratification for epitope sequence stability and dictated...... by effector memory CD8+ T cells. CONCLUSION: Collectively, these data suggest that PD-1 expression on HIV-1-specific CD8+ T cells tracks antigen load at the level of epitope specificity and TCR clonotype usage. These findings are important because they provide evidence that PD-1 expression levels......OBJECTIVES: Although CD8+ T cells play a critical role in the control of HIV-1 infection,their antiviral efficacy can be limited by antigenic variation and immune exhaustion.The latter phenomenon is characterized by the upregulation of multiple inhibitory receptors, such as programmed death-1 (PD-1...

  16. 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...... 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...... 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...

  17. Generation of functional CD8+ T Cells by human dendritic cells expressing glypican-3 epitopes

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    Farzaneh Farzin

    2010-05-01

    Full Text Available Abstract Background Glypican 3 (GPC-3 is an oncofoetal protein that is expressed in most hepatocellular carcinomas (HCC. Since it is a potential target for T cell immunotherapy, we investigated the generation of functional, GPC-3 specific T cells from peripheral blood mononuclear cells (PBMC. Methods Dendritic cells (DC were derived from adherent PBMC cultured at 37°C for 7 days in X-Vivo, 1% autologous plasma, and 800 u/ml GM-CSF plus 500 u/ml IL-4. Immature DC were transfected with 20 μg of in vitro synthesised GPC-3 mRNA by electroporation using the Easy-ject plus system (Equibio, UK (300 V, 150 μF and 4 ms pulse time, or pulsed with peptide, and subsequently matured with lipopolysaccharide (LPS. Six predicted GPC-3 peptide epitopes were synthesized using standard f-moc technology and tested for their binding affinity to HLA-A2.1 molecules using the cell line T2. Results DC transfected with GPC-3 mRNA but not control DC demonstrated strong intracellular staining for GPC-3 and in vitro generated interferon-gamma expressing T cells from autologous PBMC harvested from normal subjects. One peptide, GPC-3522-530 FLAELAYDL, fulfilled our criteria as a naturally processed, HLA-A2-restricted cytotoxic T lymphocyte (CTL epitope: i it showed high affinity binding to HLA-A2, in T2 cell binding assay; ii it was generated by the MHC class I processing pathway in DC transfected with GPC-3 mRNA, and iii HLA-A2 positive DC loaded with the peptide stimulated proliferation in autologous T cells and generated CTL that lysed HLA-A2 and GPC-3 positive target cells. Conclusions These findings demonstrate that electroporation of GPC-3 mRNA is an efficient method to load human monocyte-derived DC with antigen because in vitro they generated GPC-3-reactive T cells that were functional, as shown by interferon-gamma production. Furthermore, this study identified a novel naturally processed, HLA-A2-restricted CTL epitope, GPC-3522-530 FLAELAYDL, which can be used to

  18. Identification of conserved subdominant HIV Type 1 CD8(+) T Cell epitopes restricted within common HLA Supertypes for therapeutic HIV Type 1 vaccines

    DEFF Research Database (Denmark)

    Karlsson, Ingrid; Kløverpris, Henrik; Jensen, Kristoffer Jarlov;

    2012-01-01

    of a universal epitope peptide-based T cell vaccine with relevance for any geographic locations. The two major obstacles when designing such a vaccine are the high diversities of the HIV-1 genome and of the human major histocompatibility complex (MHC) class I. We selected 15 CD8-restricted epitopes predicted...... from conserved regions of HIV-1 that were subdominant (i.e., infrequently targeted) within natural infections. Moreover, the epitopes were predicted to be restricted to at least one of the five common HLA supertypes (HLA-A01, A02, A03, B07, and B44). Here, we validated the resulting peptide...

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

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    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.

  20. Elimination of immunodominant epitopes from multispecific DNA-based vaccines allows induction of CD8 T cells that have a striking antiviral potential

    DEFF Research Database (Denmark)

    Riedl, Petra; Wieland, Andreas; Lamberth, Kasper;

    2009-01-01

    Immunodominance limits the TCR diversity of specific antiviral CD8 T cell responses elicited by vaccination or infection. To prime multispecific T cell responses, we constructed DNA vaccines that coexpress chimeric, multidomain Ags (with CD8 T cell-defined epitopes of the hepatitis B virus (HBV......) surface (S), core (C), and polymerase (Pol) proteins and/or the OVA Ag as stress protein-capturing fusion proteins. Priming of mono- or multispecific, HLA-A*0201- or K(b)-restricted CD8 T cell responses by these DNA vaccines differed. K(b)/OVA(257-264)- and K(b)/S(190-197)-specific CD8 T cell responses...... did not allow priming of a K(b)/C(93-100)-specific CD8 T cell response in mice immunized with multidomain vaccines. Tolerance to the S- Ag in transgenic Alb/HBs mice (that express large amounts of transgene-encoded S- Ag in the liver) facilitated priming of subdominant, K(b)/C(93-100)-specific CD8 T...

  1. Identification of CD4+ and CD8+ T cell epitopes of woodchuck hepatitis virus core and surface antigens in BALB/c mice

    OpenAIRE

    Ochoa, L. (Laura); Otano, I. (Itziar); Vales, A.; Olagüe, C. (Cristina); Sarobe, P. (Pablo); Lasarte, J. J.; Menne, S; Prieto, J.; Gonzalez-Aseguinolaza, G

    2010-01-01

    A therapeutic vaccine against chronic hepatitis B virus (HBV) infection requires the development of a strong and multispecific Th1 cell immune response. Woodchucks chronically infected with the woodchuck hepatitis virus (WHV) closely resemble HBV infection and represent the best animal model for this hepadnavirus-induced disease. Using the BIMAS "HLA Peptide Binding Predictions" program, we have identified and further characterized novel H-2(d)-restricted CD8+ epitopes within the WHV core (pe...

  2. Identification of HLA-A*2402-restricted HCMV immediate early-1 (IE-1 epitopes as targets for CD8+ HCMV-specific cytotoxic T lymphocytes

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    Lee Sang-Guk

    2009-08-01

    Full Text Available Abstract Background To identify novel HLA-A*2402-restricted human cytomegalovirus (HCMV immediate early-1 (IE-1 epitopes for adoptive immunotherapy, we explored 120 overlapping 15-amino acid spanning IE-1. Methods These peptides were screened by measuring the frequency of polyclonal CD8+ T cells producing intracellular interferon-γ (IFN-γ using flow cytometry and the epitopes were validated with a HCMV-infected target Cr release cytotoxicity assay. Results Initial screening was performed with 12 mini-pools of 10 consecutive peptides made from 120 overlapping peptides15-amino acids in length that spanned IE-1. When peripheral blood mononuclear cells (PBMCs from HLA-A*2402 HCMV-seropositive donors were sensitized with each of the 12 mini-pools, mini-pools 1 and 2 induced the highest frequency of CD8+ cytotoxic T lymphocytes (CTLs producing IFN-γ. When PBMCs were stimulated with each of the twenty peptides belonging to mini-pools 1 and 2, peptides IE-11–15MESSAKRKMDPDNPD and IE-15–19AKRKMDPDNPDEGPS induced the greatest quantities of IFN-γ production and cytotoxicity of HLA-matched HCMV-infected fibroblasts. To determine the exact HLA-A*2402-restricted epitopes within the two IE-1 proteins, we synthesized a total of twenty-one overlapping 9- or 10 amino acid peptides spanning IE-11–15 and IE-15–19. Peptide IE-13–12SSAKRKMDPD induced the greatest quantities of IFN-γ production and target cell killing by CD8+ CTLs. Conclusion HCMV IE-13–12SSAKRKMDPD is a HLA-A*2402-restricted HCMV IE-1 epitope that can serve as a common target for CD8+ HCMV-specific CTLs.

  3. Strategy for eliciting antigen-specific CD8+ T cell-mediated immune response against a cryptic CTL epitope of merkel cell polyomavirus large T antigen

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    Gomez Bianca P

    2012-10-01

    Full Text Available Abstract Background Merkel cell carcinoma (MCC is a relatively new addition to the expanding category of oncovirus-induced cancers. Although still comparably rare, the number of cases has risen dramatically in recent years. Further complicating this trend is that MCC is an extremely aggressive neoplasm with poor patient prognosis and limited treatment options for advanced disease. The causative agent of MCC has been identified as the merkel cell polyomavirus (MCPyV. The MCPyV-encoded large T (LT antigen is an oncoprotein that is theorized to be essential for virus-mediated tumorigenesis and is therefore, an excellent MCC antigen for the generation of antitumor immune responses. As a foreign antigen, the LT oncoprotein avoids the obstacle of immune tolerance, which normally impedes the development of antitumor immunity. Ergo, it is an excellent target for anti-MCC immunotherapy. Since tumor-specific CD8+ T cells lead to better prognosis for MCC and numerous other cancers, we have generated a DNA vaccine that is capable of eliciting LT-specific CD8+ T cells. The DNA vaccine (pcDNA3-CRT/LT encodes the LT antigen linked to a damage-associated molecular pattern, calreticulin (CRT, as it has been demonstrated that the linkage of CRT to antigens promotes the induction of antigen-specific CD8+ T cells. Results The present study shows that DNA vaccine-induced generation of LT-specific CD8+ T cells is augmented by linking CRT to the LT antigen. This is relevant since the therapeutic effects of the pcDNA3-CRT/LT DNA vaccine is mediated by LT-specific CD8+ T cells. Mice vaccinated with the DNA vaccine produced demonstrably more LT-specific CD8+ T cells. The DNA vaccine was also able to confer LT-specific CD8+ T cell-mediated protective and therapeutic effects to prolong the survival of mice with LT-expressing tumors. In the interest of determining the LT epitope which most MCC-specific CD8+ T cells recognize, we identified the amino acid sequence of the

  4. Sequence conservation of subdominant HLA-A2-binding CTL epitopes in HIV-1 clinical isolates and CD8+ T-lymphocyte cross-recognition may explain the immune reaction in infected individuals

    DEFF Research Database (Denmark)

    Thorn, Mette; Tang, Sheila; Therrien, Dominic;

    2007-01-01

    genome sequenced HIV-1 from 11 HLA-A2(+) patients to examine the sequence variation of these natural epitopes and compared them with the patient's CD8(+) T-cell recall response. Often the epitope was conserved but only a few patients showed a CD8(+) T-cell recall response. This infrequent targeting may...... be explained by immune subdominance. CD8(+) T-cell recall response to a natural epitope could be measured despite sequence differences in the patient's virus. T-cell cross-reaction between such variants could be demonstrated in HLA-A2 transgenic mice. Nine infrequently targeted but conserved or cross...

  5. CD8(+) T-cell Cytotoxic Capacity Associated with Human Immunodeficiency Virus-1 Control Can Be Mediated through Various Epitopes and Human Leukocyte Antigen Types.

    Science.gov (United States)

    Migueles, Stephen A; Mendoza, Daniel; Zimmerman, Matthew G; Martins, Kelly M; Toulmin, Sushila A; Kelly, Elizabeth P; Peterson, Bennett A; Johnson, Sarah A; Galson, Eric; Poropatich, Kate O; Patamawenu, Andy; Imamichi, Hiromi; Ober, Alexander; Rehm, Catherine A; Jones, Sara; Hallahan, Claire W; Follmann, Dean A; Connors, Mark

    2015-01-01

    Understanding natural immunologic control over Human Immunodeficiency Virus (HIV)-1 replication, as occurs in rare long-term nonprogressors/elite controllers (LTNP/EC), should inform the design of efficacious HIV vaccines and immunotherapies. Durable control in LTNP/EC is likely mediated by highly functional virus-specific CD8(+) T-cells. Protective Human Leukocyte Antigen (HLA) class I alleles, like B*27 and B*57, are present in most, but not all LTNP/EC, providing an opportunity to investigate features shared by their HIV-specific immune responses. To better understand the contribution of epitope targeting and conservation to immune control, we compared the CD8(+) T-cell specificity and function of B*27/57(neg) LTNP/EC (n = 23), B*27/57(pos) LTNP/EC (n = 23) and B*27/57(neg) progressors (n = 13). Fine mapping revealed 11 previously unreported immunodominant responses. Although B*27/57(neg) LTNP/EC did not target more highly conserved epitopes, their CD8(+) T-cell cytotoxic capacity was significantly higher than progressors. Similar to B*27/57(pos) LTNP/EC, this superior cytotoxicity was mediated by preferential expansion of immunodominant responses and lysis through the predicted HLA. These findings suggest that increased CD8(+) T-cell cytotoxic capacity is a common mechanism of control in most LTNP/EC regardless of HLA type. They also suggest that potent cytotoxicity can be mediated through various epitopes and HLA molecules and could, in theory, be induced in most people. PMID:26137533

  6. CD8+ T-cell Cytotoxic Capacity Associated with Human Immunodeficiency Virus-1 Control Can Be Mediated through Various Epitopes and Human Leukocyte Antigen Types

    Directory of Open Access Journals (Sweden)

    Stephen A. Migueles

    2015-01-01

    Full Text Available Understanding natural immunologic control over Human Immunodeficiency Virus (HIV-1 replication, as occurs in rare long-term nonprogressors/elite controllers (LTNP/EC, should inform the design of efficacious HIV vaccines and immunotherapies. Durable control in LTNP/EC is likely mediated by highly functional virus-specific CD8+ T-cells. Protective Human Leukocyte Antigen (HLA class I alleles, like B*27 and B*57, are present in most, but not all LTNP/EC, providing an opportunity to investigate features shared by their HIV-specific immune responses. To better understand the contribution of epitope targeting and conservation to immune control, we compared the CD8+ T-cell specificity and function of B*27/57neg LTNP/EC (n = 23, B*27/57pos LTNP/EC (n = 23 and B*27/57neg progressors (n = 13. Fine mapping revealed 11 previously unreported immunodominant responses. Although B*27/57neg LTNP/EC did not target more highly conserved epitopes, their CD8+ T-cell cytotoxic capacity was significantly higher than progressors. Similar to B*27/57pos LTNP/EC, this superior cytotoxicity was mediated by preferential expansion of immunodominant responses and lysis through the predicted HLA. These findings suggest that increased CD8+ T-cell cytotoxic capacity is a common mechanism of control in most LTNP/EC regardless of HLA type. They also suggest that potent cytotoxicity can be mediated through various epitopes and HLA molecules and could, in theory, be induced in most people.

  7. A missing PD-L1/PD-1 coinhibition regulates diabetes induction by preproinsulin-specific CD8 T-cells in an epitope-specific manner.

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    Cornelia Schuster

    Full Text Available Coinhibitory PD-1/PD-L1 (B7-H1 interactions provide critical signals for the regulation of autoreactive T-cell responses. We established mouse models, expressing the costimulator molecule B7.1 (CD80 on pancreatic beta cells (RIP-B7.1 tg mice or are deficient in coinhibitory PD-L1 or PD-1 molecules (PD-L1(-/- and PD-1(-/- mice, to study induction of preproinsulin (ppins-specific CD8 T-cell responses and experimental autoimmune diabetes (EAD by DNA-based immunization. RIP-B7.1 tg mice allowed us to identify two CD8 T-cell specificities: pCI/ppins DNA exclusively induced K(b/A(12-21-specific CD8 T-cells and EAD, whereas pCI/ppinsΔA(12-21 DNA (encoding ppins without the COOH-terminal A(12-21 epitope elicited K(b/B(22-29-specific CD8 T-cells and EAD. Specific expression/processing of mutant ppinsΔA(12-21 (but not ppins in non-beta cells, targeted by intramuscular DNA-injection, thus facilitated induction of K(b/B(22-29-specific CD8 T-cells. The A(12-21 epitope binds K(b molecules with a very low avidity as compared with B(22-29. Interestingly, immunization of coinhibition-deficient PD-L1(-/- or PD-1(-/- mice with pCI/ppins induced K(b/A(12-21-monospecific CD8 T-cells and EAD but injections with pCI/ppinsΔA(12-21 did neither recruit K(b/B(22-29-specific CD8 T-cells into the pancreatic target tissue nor induce EAD. PpinsΔA(12-21/(K(b/B(22-29-mediated EAD was efficiently restored in RIP-B7.1(+/PD-L1(-/- mice, differing from PD-L1(-/- mice only in the tg B7.1 expression in beta cells. Alternatively, an ongoing beta cell destruction and tissue inflammation, initiated by ppins/(K(b/A(12-21-specific CD8 T-cells in pCI/ppins+pCI/ppinsΔA(12-21 co-immunized PD-L1(-/- mice, facilitated the expansion of ppinsΔA(12-21/(K(b/B(22-29-specific CD8 T-cells. CD8 T-cells specific for the high-affinity K(b/B(22-29- (but not the low-affinity K(b/A(12-21-epitope thus require stimulatory help from beta cells or inflamed islets to expand in PD-L1-deficient mice. The

  8. The generation of CD8+ T-cell population specific for vaccinia virus epitope involved in the antiviral protection against ectromelia virus challenge.

    Science.gov (United States)

    Gierynska, Malgorzata; Szulc-Dabrowska, Lidia; Dzieciatkowski, Tomasz; Golke, Anna; Schollenberger, Ada

    2015-12-01

    Eradication of smallpox has led to cessation of vaccination programs. This has rendered the human population increasingly susceptible not only to variola virus infection but also to infections with other representatives of Poxviridae family that cause zoonotic variola-like diseases. Thus, new approaches for designing improved vaccine against smallpox are required. Discovering that orthopoxviruses, e.g. variola virus, vaccinia virus, ectromelia virus, share common immunodominant antigen, may result in the development of such a vaccine. In our study, the generation of antigen-specific CD8(+) T cells in mice during the acute and memory phase of the immune response was induced using the vaccinia virus immunodominant TSYKFESV epitope and CpG oligodeoxynucleotides as adjuvants. The role of the generated TSYKFESV-specific CD8(+) T cells was evaluated in mice during ectromelia virus infection using systemic and mucosal model. Moreover, the involvement of dendritic cells subsets in the adaptive immune response stimulation was assessed. Our results indicate that the TSYKFESV epitope/TLR9 agonist approach, delivered systemically or mucosally, generated strong CD8(+) T-cell response when measured 10 days after immunization. Furthermore, the TSYKFESV-specific cell population remained functionally active 2 months post-immunization, and gave cross-protection in virally challenged mice, even though the numbers of detectable antigen-specific T cells decreased. PMID:26474845

  9. Sequence conservation of subdominant HLA-A2-binding CTL epitopes in HIV-1 clinical isolates and CD8+ T-lymphocyte cross-recognition may explain the immune reaction in infected individuals

    DEFF Research Database (Denmark)

    Thorn, Mette; Tang, Sheila; Therrien, Dominic;

    2007-01-01

    Cytotoxic T-lymphocytes (CTL) are critical for immune control of infection with human immunodeficiency virus type-1 (HIV-1) and searches for relevant CTL epitopes for immune therapy are ongoing. Recently, we identified 28 HLA-A2-binding HIV-1 CTL epitopes (1). In this follow-up study we fully...... genome sequenced HIV-1 from 11 HLA-A2(+) patients to examine the sequence variation of these natural epitopes and compared them with the patient's CD8(+) T-cell recall response. Often the epitope was conserved but only a few patients showed a CD8(+) T-cell recall response. This infrequent targeting may...... be explained by immune subdominance. CD8(+) T-cell recall response to a natural epitope could be measured despite sequence differences in the patient's virus. T-cell cross-reaction between such variants could be demonstrated in HLA-A2 transgenic mice. Nine infrequently targeted but conserved or cross...

  10. HLA-A*0201-restricted CD8+ cytotoxic T lymphocyte epitopes identified from herpes simplex virus glycoprotein D

    DEFF Research Database (Denmark)

    Chentoufi, Aziz Alami; Zhang, Xiuli; Lamberth, Kasper;

    2008-01-01

    . Consistent with this, in 33 sequentially studied HLA-A*0201-positive, HSV-1-seropositive, and/or HSV-2-seropositive healthy individuals, the most frequent and robust CD8+ T cell responses, assessed by IFN-gamma ELISPOT, CD107a/b cytotoxic degranulation, and tetramer assays, were directed mainly against gD53...

  11. Adoptive transfer of Mammaglobin-A epitope specific CD8 T cells combined with a single low dose of total body irradiation eradicates breast tumors.

    Science.gov (United States)

    Lerret, Nadine M; Rogozinska, Magdalena; Jaramillo, Andrés; Marzo, Amanda L

    2012-01-01

    Adoptive T cell therapy has proven to be beneficial in a number of tumor systems by targeting the relevant tumor antigen. The tumor antigen targeted in our model is Mammaglobin-A, expressed by approximately 80% of human breast tumors. Here we evaluated the use of adoptively transferred Mammaglobin-A specific CD8 T cells in combination with low dose irradiation to induce breast tumor rejection and prevent relapse. We show Mammaglobin-A specific CD8 T cells generated by DNA vaccination with all epitopes (Mammaglobin-A2.1, A2.2, A2.4 and A2.6) and full-length DNA in vivo resulted in heterogeneous T cell populations consisting of both effector and central memory CD8 T cell subsets. Adoptive transfer of spleen cells from all Mammaglobin-A2 immunized mice into tumor-bearing SCID/beige mice induced tumor regression but this anti-tumor response was not sustained long-term. Additionally, we demonstrate that only the adoptive transfer of Mammaglobin-A2 specific CD8 T cells in combination with a single low dose of irradiation prevents tumors from recurring. More importantly we show that this single dose of irradiation results in the down regulation of the macrophage scavenger receptor 1 on dendritic cells within the tumor and reduces lipid uptake by tumor resident dendritic cells potentially enabling the dendritic cells to present tumor antigen more efficiently and aid in tumor clearance. These data reveal the potential for adoptive transfer combined with a single low dose of total body irradiation as a suitable therapy for the treatment of established breast tumors and the prevention of tumor recurrence.

  12. 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

    investigated in a genetically diverse cohort of HIV-1 infected patients. Using a novel bioinformatic binding prediction method, we aimed to explain the pattern of epitope-specific CTL responses based on the patients' HLA genotype and autologous virus sequence quantitatively. Sequences covering predicted and...

  13. A novel HLA-B18 restricted CD8+ T cell epitope is efficiently cross-presented by dendritic cells from soluble tumor antigen.

    Directory of Open Access Journals (Sweden)

    Rona Y Zhao

    Full Text Available NY-ESO-1 has been a major target of many immunotherapy trials because it is expressed by various cancers and is highly immunogenic. In this study, we have identified a novel HLA-B*1801-restricted CD8(+ T cell epitope, NY-ESO-1(88-96 (LEFYLAMPF and compared its direct- and cross-presentation to that of the reported NY-ESO-1(157-165 epitope restricted to HLA-A*0201. Although both epitopes were readily cross-presented by DCs exposed to various forms of full-length NY-ESO-1 antigen, remarkably NY-ESO-1(88-96 is much more efficiently cross-presented from the soluble form, than NY-ESO-1(157-165. On the other hand, NY-ESO-1(157-165 is efficiently presented by NY-ESO-1-expressing tumor cells and its presentation was not enhanced by IFN-γ treatment, which induced immunoproteasome as demonstrated by Western blots and functionally a decreased presentation of Melan A(26-35; whereas NY-ESO-1(88-96 was very inefficiently presented by the same tumor cell lines, except for one that expressed high level of immunoproteasome. It was only presented when the tumor cells were first IFN-γ treated, followed by infection with recombinant vaccinia virus encoding NY-ESO-1, which dramatically increased NY-ESO-1 expression. These data indicate that the presentation of NY-ESO-1(88-96 is immunoproteasome dependent. Furthermore, a survey was conducted on multiple samples collected from HLA-B18(+ melanoma patients. Surprisingly, all the detectable responses to NY-ESO-1(88-96 from patients, including those who received NY-ESO-1 ISCOMATRIX™ vaccine were induced spontaneously. Taken together, these results imply that some epitopes can be inefficiently presented by tumor cells although the corresponding CD8(+ T cell responses are efficiently primed in vivo by DCs cross-presenting these epitopes. The potential implications for cancer vaccine strategies are further discussed.

  14. 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

  15. HLA-A2 and B35 restricted hantaan virus nucleoprotein CD8+ T-cell epitope-specific immune response correlates with milder disease in hemorrhagic fever with renal syndrome.

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    Ying Ma

    Full Text Available BACKGROUND: Hantaan virus (HTNV infection in humans is a serious public health concern in Asia. A potent T cell activation peptide vaccine from HTNV structure protein represents a promising immunotherapy for disease control. However, the T cell epitopes of the HTNV restricted by the HLA alleles and the role of epitope-specific T cell response after HTNV infection remain largely unexplored. METHODOLOGY/PRINCIPAL FINDINGS: Five well-conserved novel CD8(+ T-cell epitopes of the HTNV nucleoprotein restricted by the most popular HLA alleles in Chinese Han population were defined with interferon-γ enzyme-linked immunospot assay in 37 patients infected with HTNV during hospitalization. Two epitopes aa129-aa137 and aa131-aa139 restricted by HLA-A2 and B35, respectively, were selected to evaluate the epitope-specific CD8(+ T-cell response. HLA-peptide pentamer complex staining showed that the frequency of single epitope-specific CD8(+ T cell could be detected in patients (95% confidence interval for aa129-aa137: 0.080%-0.208%; for aa131-aa139: 0.030%-0.094%. The frequency of epitope-specific pentamer(+ CD8(+ T-cell response was much higher in mild/moderate patients than in severe/critical ones at the acute stage of the disease. Moreover, the frequency of epitope-specific CD8(+ T cells at acute stage was inversely associated with the peak level of serum creatinine and was positively associated with the nadir platelet counts during the hospitalization. The intracellular cytokine staining and the proliferation assay showed that the effective epitope-specific CD8(+ T cells were characterized with the production of interferon-γ, expression of CD69 and the strong capacity of proliferation. CONCLUSION/SIGNIFICANCE: The novel HLA class I restricted HTNV nucleoprotein epitopes-specific CD8(+ T-cell responses would be closely related with the progression and the severity of the disease, which could provide the first step toward effective peptide vaccine

  16. Generation of robust CD8+ T-cell responses against subdominant epitopes in conserved regions of HIV-1 by repertoire mining with mimotopes.

    Science.gov (United States)

    Schaubert, Keri L; Price, David A; Salkowitz, Janelle R; Sewell, Andrew K; Sidney, John; Asher, Tedi E; Blondelle, Sylvie E; Adams, Sharon; Marincola, Francesco M; Joseph, Aviva; Sette, Alessandro; Douek, Daniel C; Ayyavoo, Velpandi; Storkus, Walter; Leung, Ming-Ying; Ng, Hwee L; Yang, Otto O; Goldstein, Harris; Wilson, Darcy B; Kan-Mitchell, June

    2010-07-01

    HLA-A 0201-restricted virus-specific CD8(+) CTL do not appear to control HIV effectively in vivo. To enhance the immunogenicity of a highly conserved subdominant epitope, TV9 (TLNAWVKVV, p24 Gag(19-27)), mimotopes were designed by screening a large combinatorial nonapeptide library with TV9-specific CTL primed in vitro from healthy donors. A mimic peptide with a low binding affinity to HLA-A 0201, TV9p6 (KINAWIKVV), was studied further. Parallel cultures of in vitro-primed CTL showed that TV9p6 consistently activated cross-reactive and equally functional CTL as measured by cytotoxicity, cytokine production and suppression of HIV replication in vitro. Comparison of TCRB gene usage between CTL primed from the same donors with TV9 or TV9p6 revealed a degree of clonal overlap in some cases and an example of a conserved TCRB sequence encoded distinctly at the nucleotide level between individuals (a "public" TCR); however, in the main, distinct clonotypes were recruited by each peptide antigen. These findings indicate that mimotopes can mobilize functional cross-reactive clonotypes that are less readily recruited from the naïve T-cell pool by the corresponding WT epitope. Mimotope-induced repertoire diversification could potentially override subdominance under certain circumstances and enhance vaccine-induced responses to conserved but poorly immunogenic determinants within the HIV proteome. PMID:20432235

  17. A cytomegalovirus-based vaccine expressing a single tumor-specific CD8+ T-cell epitope delays tumor growth in a murine model of prostate cancer.

    Science.gov (United States)

    Klyushnenkova, Elena N; Kouiavskaia, Diana V; Parkins, Christopher J; Caposio, Patrizia; Botto, Sara; Alexander, Richard B; Jarvis, Michael A

    2012-06-01

    Cytomegalovirus (CMV) is a highly immunogenic virus that results in a persistent, life-long infection in the host typically with no ill effects. Certain unique features of CMV, including its capacity to actively replicate in the presence of strong host CMV-specific immunity, may give CMV an advantage compared with other virus-based vaccine delivery platforms. In the present study, we tested the utility of mouse CMV (mCMV)-based vaccines expressing human prostate-specific antigen (PSA) for prostate cancer immunotherapy in double-transgenic mice expressing PSA and HLA-DRB1*1501 (DR2bxPSA F1 mice). We assessed the capacity of 2 mCMV-based vectors to induce PSA-specific CD8 T-cell responses and affect the growth of PSA-expressing Transgenic Adenocarcinoma of the Mouse Prostate tumors (TRAMP-PSA). In the absence of tumor challenge, immunization with mCMV vectors expressing either a H2-D(b)-restricted epitope PSA(65-73) (mCMV/PSA(65-73)) or the full-length gene for PSA (mCMV/PSA(FL)) induced comparable levels of CD8 T-cell responses that increased (inflated) with time. Upon challenge with TRAMP-PSA tumor cells, animals immunized with mCMV/PSA(65-73) had delay of tumor growth and increased PSA-specific CD8 T-cell responses, whereas animals immunized with mCMV/PSA(FL) showed progressive tumor growth and no increase in number of splenic PSA(65-73)-specific T cells. The data show that a prototype CMV-based prostate cancer vaccine can induce an effective antitumor immune response in a "humanized" double-transgenic mouse model. The observation that mCMV/PSA(FL) is not effective against TRAMP-PSA is consistent with our previous findings that HLA-DRB1*1501-restricted immune responses to PSA are associated with suppression of effective CD8 T-cell responses to TRAMP-PSA tumors.

  18. Inferring Protective CD8+ T-Cell Epitopes for NS5 Protein of Four Serotypes of Dengue Virus Chinese Isolates Based on HLA-A, -B and -C Allelic Distribution: Implications for Epitope-Based Universal Vaccine Design.

    Directory of Open Access Journals (Sweden)

    Jiandong Shi

    Full Text Available Dengue is one of the most globally serious vector-borne infectious diseases in tropical and subtropical areas for which there are currently no effective vaccines. The most highly conserved flavivirus protein, NS5, is an indispensable target of CD8+ T-cells, making it an ideal vaccine design target. Using the Immune Epitope Database (IEDB, CD8+ T-cell epitopes of the dengue virus (DENV NS5 protein were predicted by genotypic frequency of the HLA-A,-B, and-C alleles in Chinese population. Antigenicity scores of all predicted epitopes were analyzed using VaxiJen v2.0. The IEDB analysis revealed that 116 antigenic epitopes for HLA-A (21,-B (53, and-C (42 had high affinity for HLA molecules. Of them, 14 had 90.97-99.35% conversancy among the four serotypes. Moreover, five candidate epitopes, including 200NS5210 (94.84%, A*11:01, 515NS5525 (98.71%, A*24:02, 225NS5232 (99.35%, A*33:03, 516NS5523 (98.71%, A*33:03, and 284NS5291 (98.06%, A*33:03, were presented by HLA-A. Four candidate epitopes, including 234NS5241 (96.77%, B*13:01, 92NS599 (98.06%, B*15:01, B*15:02, and B*46:01, 262NS5269 (92.90%, B*38:02, and 538NS5547 (90.97%, B*51:01, were presented by HLA-B. Another 9 candidate epitopes, including 514NS5522 (98.71%, C*01:02, 514NS5524 (98.71%, C*01:02 and C*14:02, 92NS599 (98.06%, C*03:02 and C*15:02, 362NS5369 (44.84%, C*03:04 and C*08:01, 225NS5232 (99.35%, C*04:01, 234NS5241(96.77%, C*04:01, 361NS5369 (94.84%, C*04:01, 515NS5522 (98.71%, C*14:02, 515NS5524 (98.71%, C*14:02, were presented by HLA-C. Further data showed that the four-epitope combination of 92NS599 (B*15:01, B*15:02, B*46:01, C*03:02 and C*15:02, 200NS5210 (A*11:01, 362NS5369 (C*03:04, C*08:01, and 514NS5524 (C*01:02, C*14:02 could vaccinate >90% of individuals in China. Further in vivo study of our inferred novel epitopes will be needed for a T-cell epitope-based universal vaccine development that may prevent all four China-endemic DENV serotypes.

  19. CD8(+ T cell cross-reactivity profiles and HIV-1 immune escape towards an HLA-B35-restricted immunodominant Nef epitope.

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    Chihiro Motozono

    Full Text Available Antigen cross-reactivity is an inbuilt feature of the T cell compartment. However, little is known about the flexibility of T cell recognition in the context of genetically variable pathogens such as HIV-1. In this study, we used a combinatorial library containing 24 billion octamer peptides to characterize the cross-reactivity profiles of CD8(+ T cells specific for the immunodominant HIV-1 subtype B Nef epitope VY8 (VPLRPMTY presented by HLA-B(*35∶01. In conjunction, we examined naturally occurring antigenic variations within the VY8 epitope. Sequence analysis of plasma viral RNA isolated from 336 HIV-1-infected individuals revealed variability at position (P 3 and P8 of VY8; Phe at P8, but not Val at P3, was identified as an HLA-B(*35∶01-associated polymorphism. VY8-specific T cells generated from several different HIV-1-infected patients showed unique and clonotype-dependent cross-reactivity footprints. Nonetheless, all T cells recognized both the index Leu and mutant Val at P3 equally well. In contrast, competitive titration assays revealed that the Tyr to Phe substitution at P8 reduced T cell recognition by 50-130 fold despite intact peptide binding to HLA-B(*35∶01. These findings explain the preferential selection of Phe at the C-terminus of VY8 in HLA-B(*35∶01(+ individuals and demonstrate that HIV-1 can exploit the limitations of T cell recognition in vivo.

  20. CD8 and CD4 epitope predictions in RV144: no strong evidence of a T-cell driven sieve effect in HIV-1 breakthrough sequences from trial participants.

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    Kalpana Dommaraju

    Full Text Available The modest protection afforded by the RV144 vaccine offers an opportunity to evaluate its mechanisms of protection. Differences between HIV-1 breakthrough viruses from vaccine and placebo recipients can be attributed to the RV144 vaccine as this was a randomized and double-blinded trial. CD8 and CD4 T cell epitope repertoires were predicted in HIV-1 proteomes from 110 RV144 participants. Predicted Gag epitope repertoires were smaller in vaccine than in placebo recipients (p = 0.019. After comparing participant-derived epitopes to corresponding epitopes in the RV144 vaccine, the proportion of epitopes that could be matched differed depending on the protein conservation (only 36% of epitopes in Env vs 84-91% in Gag/Pol/Nef for CD8 predicted epitopes or on vaccine insert subtype (55% against CRF01_AE vs 7% against subtype B. To compare predicted epitopes to the vaccine, we analyzed predicted binding affinity and evolutionary distance measurements. Comparisons between the vaccine and placebo arm did not reveal robust evidence for a T cell driven sieve effect, although some differences were noted in Env-V2 (0.022≤p-value≤0.231. The paucity of CD8 T cell responses identified following RV144 vaccination, with no evidence for V2 specificity, considered together both with the association of decreased infection risk in RV 144 participants with V-specific antibody responses and a V2 sieve effect, lead us to hypothesize that this sieve effect was not T cell specific. Overall, our results did not reveal a strong differential impact of vaccine-induced T cell responses among breakthrough infections in RV144 participants.

  1. Epitope-Specific Binder Design by Yeast Surface Display.

    Science.gov (United States)

    Mann, Jasdeep K; Park, Sheldon

    2015-01-01

    Yeast surface display is commonly used to engineer affinity and design novel molecular interaction. By alternating positive and negative selections, yeast display can be used to engineer binders that specifically interact with the target protein at a defined site. Epitope-specific binders can be useful as inhibitors if they bind the target molecule at functionally important sites. Therefore, an efficient method of engineering epitope specificity should help with the engineering of inhibitors. We describe the use of yeast surface display to design single domain monobodies that bind and inhibit the activity of the kinase Erk-2 by targeting a conserved surface patch involved in protein-protein interaction. The designed binders can be used to disrupt signaling in the cell and investigate Erk-2 function in vivo. The described protocol is general and can be used to design epitope-specific binders of an arbitrary protein. PMID:26060073

  2. Identification of a naturally processed cytotoxic CD8 T-cell epitope of coxsackievirus B4, presented by HLA-A2.1 and located in the PEVKEK region of the P2C nonstructural protein.

    Science.gov (United States)

    Varela-Calvino, Ruben; Skowera, Ania; Arif, Sefina; Peakman, Mark

    2004-12-01

    The adaptive immune system generates CD8 cytotoxic T lymphocytes (CTLs) as a major component of the protective response against viruses. Knowledge regarding the nature of the peptide sequences presented by HLA class I molecules and recognized by CTLs is thus important for understanding host-pathogen interactions. In this study, we focused on identification of a CTL epitope generated from coxsackievirus B4 (CVB4), a member of the enterovirus group responsible for several inflammatory diseases in humans and often implicated in the triggering and/or acceleration of the autoimmune disease type 1 diabetes. We identified a 9-mer peptide epitope that can be generated from the P2C nonstructural protein of CVB4 (P2C(1137-1145)) and from whole virus by antigen-presenting cells and presented by HLA-A2.1. This epitope is recognized by effector memory (gamma interferon [IFN-gamma]-producing) CD8 T cells in the peripheral blood at a frequency of responders that suggests that it is a major focus of the anti-CVB4 response. Short-term CD8 T-cell lines generated against P2C(1137-1145) are cytotoxic against peptide-loaded target cells. Of particular interest, the epitope lies within a region of viral homology with the diabetes-related autoantigen, glutamic acid decarboxylase-65 (GAD(65)). However, P2C(1137-1145)-specific cytotoxic T lymphocyte (CTL) lines were not activated to produce IFN-gamma by the GAD(65) peptide homologue and did not show cytotoxic activity in the presence of appropriately labeled targets. These results describe the first CD8 T-cell epitope of CVB4 that will prove useful in the study of CVB4-associated disease. PMID:15564450

  3. Identification of an HLA-A* 0201-restricted CD8+ T-cell epitope SSp-1 of SARS-CoV spike protein

    Institute of Scientific and Technical Information of China (English)

    Wang B; Yu Y; Wang X; Yang R; Cao X; Chen H; Jiang X; Zhang M; Wan T; Li N; Zhou X; Wu Y; Yang F

    2004-01-01

    A novel coronavirus, severe acute respiratory syndrome (SARS)-associated coronavirus (SARS-CoV), has been identified as the causal agent of SARS. Spike (S) protein is a major structural glycoprotein of the SARS virus and a potential target for SARS-specific cell-mediated immune responses. A panel of S protein-derived peptides was tested for their binding affinity to HLA-A * 0201 molecules. Peptides with high affinity for HLA-A * 0201 were then assessed for their capacity to elicit specific immune responses mediated by cytotoxic T lymphocytes (CTLs) both in vivo, in HLA-A2. 1/Kb transgenic mice, and in vitro, from peripheral blood lymphocytes (PBLs) harvested from healthy HLA-A2.1 + donors. SARS-CoV protein-derived peptide-1 (SSp-1 RLNEVAKNL), induced peptide-specific CTLs both in vivo (transgenic mice) and in vitro (human PBLs), which specifically released interferon-gamma (IFN-gamma) upon stimulation with SSp-1-pulsed autologous dendritic cells (DCs) or T2 cells. SSp-1-specific CTLs also lysed major histocompatibility complex (MHC)-matched tumor cell lines engineered to express S proteins. HLA-A * 0201-SSp-1 tetramer staining revealed the presence of significant populations of SSp-1-specific CTLs in SSp-1-induced CD8+ T cells. We propose that the newly identified epitope SSp-1 will help in the characterization of virus control mechanisms and immunopathology in SARS-CoV infection, and may be relevant to the development of immunotherapeutic approaches for SARS.

  4. Phage displaying epitope of Candida albicans HSP90 and serodiagnosis

    Institute of Scientific and Technical Information of China (English)

    杨琼; 王丽; 卢大宁; 邢沈阳; 尹东; 朱筱娟

    2004-01-01

    @@ Recently, the frequent use of immunosuppressants and chemotherapeutic drugs for cancers has caused an increase in the frequency of life-threatening systemic candidiasis.1 Studies by Matthews et al2 indicated HSP90 fragments are major targets for the immune system in infection due to C. albicans, and anti-epitope LKVIRK of HSP90 antibody is a serological marker for diagnosis of invasive candidiasis. Cloning and sequencing HSP90 antigen revealed that the linear epitope LKVIRK, localized near the C-terminus of the 47 kDa protein which circulates in the sera of patients with invasive candidiasis, as a heat-stable breakdown product of large more heat-labile antigen HSP90.2 In this study, epitope LKVIRK was displayed on the surface of phage fd to develop a new serological test for systemic candidiasis.

  5. MIMOX: a web tool for phage display based epitope mapping

    Directory of Open Access Journals (Sweden)

    Honda Wataru

    2006-10-01

    Full Text Available Abstract Background Phage display is widely used in basic research such as the exploration of protein-protein interaction sites and networks, and applied research such as the development of new drugs, vaccines, and diagnostics. It has also become a promising method for epitope mapping. Research on new algorithms that assist and automate phage display based epitope mapping has attracted many groups. Most of the existing tools have not been implemented as an online service until now however, making it less convenient for the community to access, utilize, and evaluate them. Results We present MIMOX, a free web tool that helps to map the native epitope of an antibody based on one or more user supplied mimotopes and the antigen structure. MIMOX was coded in Perl using modules from the Bioperl project. It has two sections. In the first section, MIMOX provides a simple interface for ClustalW to align a set of mimotopes. It also provides a simple statistical method to derive the consensus sequence and embeds JalView as a Java applet to view and manage the alignment. In the second section, MIMOX can map a single mimotope or a consensus sequence of a set of mimotopes, on to the corresponding antigen structure and search for all of the clusters of residues that could represent the native epitope. NACCESS is used to evaluate the surface accessibility of the candidate clusters; and Jmol is embedded to view them interactively in their 3D context. Initial case studies show that MIMOX can reproduce mappings from existing tools such as FINDMAP and 3DEX, as well as providing novel, rational results. Conclusion A web-based tool called MIMOX has been developed for phage display based epitope mapping. As a publicly available online service in this area, it is convenient for the community to access, utilize, and evaluate, complementing other existing programs. MIMOX is freely available at http://web.kuicr.kyoto-u.ac.jp/~hjian/mimox.

  6. Montanide, Poly I:C and nanoparticle based vaccines promote differential suppressor and effector cell expansion: a study of induction of CD8 T cells to a minimal Plasmodium berghei epitope

    Directory of Open Access Journals (Sweden)

    Kirsty Lee Wilson

    2015-02-01

    Full Text Available The development of practical and flexible vaccines to target liver stage malaria parasites would benefit from an ability to induce high levels of CD8 T cells to minimal peptide epitopes. Herein we compare different adjuvant and carrier systems in a murine model for induction of interferon gamma (IFN-γ producing CD8 T cells to the minimal immuno-dominant peptide epitope from the circumsporozoite protein (CSP of Plasmodium berghei, pb9 (SYIPSAEKI, referred to as KI. Two pro-inflammatory adjuvants, Montanide and Poly I:C, and a non-classical, non-inflammatory nanoparticle based carrier (polystyrene nanoparticles, PSNPs, were compared side-by-side for their ability to induce potentially protective CD8 T cell responses after two immunisations. KI in Montanide (Montanide + KI or covalently conjugated to PSNPs (PSNPs-KI induced such high responses, whereas adjuvanting with Poly I:C or PSNPs without conjugation was ineffective. This result was consistent with an observed induction of an immunosuppressed environment by Poly I:C in the draining lymph node (dLN 48 hours post injection, which was reflected by increased frequencies of myeloid derived suppressor cells (MDSC and a proportion of inflammation reactive regulatory T cells (Treg expressing the tumour necrosis factor receptor 2 (TNFR2, as well as decreased dendritic cell (DC maturation. The other inflammatory adjuvant, Montanide, also promoted proportional increases in the TNFR2+ Treg subpopulation, but not MDSCs, in the dLN. By contrast, injection with non-inflammatory PSNPs did not cause these changes. Induction of high CD8 T cell responses, using minimal peptide epitopes, can be achieved by non-inflammatory carrier nanoparticles, which in contrast to some conventional inflammatory adjuvants, do not expand either MDSCs or inflammation reactive Tregs at the site of priming.

  7. Automated Detection of Conformational Epitopes Using Phage Display Peptide Sequences

    Directory of Open Access Journals (Sweden)

    Surendra S Negi

    2009-01-01

    Full Text Available Background: Precise determination of conformational epitopes of neutralizing antibodies represents a key step in the rational design of novel vaccines. A powerful experimental method to gain insights on the physical chemical nature of conformational epitopes is the selection of linear peptides that bind with high affinities to a monoclonal antibody of interest by phage display technology. However, the structural characterization of conformational epitopes from these mimotopes is not straightforward, and in the past the interpretation of peptide sequences from phage display experiments focused on linear sequence analysis to find a consensus sequence or common sequence motifs.Results: We present a fully automated search method, EpiSearch that predicts the possible location of conformational epitopes on the surface of an antigen. The algorithm uses peptide sequences from phage display experiments as input, and ranks all surface exposed patches according to the frequency distribution of similar residues in the peptides and in the patch. We have tested the performance of the EpiSearch algorithm for six experimental data sets of phage display experiments, the human epidermal growth factor receptor-2 (HER-2/neu, the antibody mAb Bo2C11 targeting the C2 domain of FVIII, antibodies mAb 17b and mAb b12 of the HIV envelope protein gp120, mAb 13b5 targeting HIV-1 capsid protein and 80R of the SARS coronavirus spike protein. In all these examples the conformational epitopes as determined by the X-ray crystal structures of the antibody-antigen complexes, were found within the highest scoring patches of EpiSearch, covering in most cases more than 50% residues of experimental observed conformational epitopes. Input options of the program include mapping of a single peptide or a set of peptides on the antigen structure, and the results of the calculation can be visualized on our interactive web server.Availability: Users can access the EpiSearch from our web

  8. CD8(+) T cells specific to a single Yersinia pseudotuberculosis epitope restrict bacterial replication in the liver but fail to provide sterilizing immunity.

    Science.gov (United States)

    Shen, Haiqian; Gonzalez-Juarbe, Norberto; Blanchette, Krystle; Crimmins, Gregory; Bergman, Molly A; Isberg, Ralph R; Orihuela, Carlos J; Dube, Peter H

    2016-09-01

    CD8(+) T cells use contact-dependent cytolysis of target cells to protect the host against intracellular pathogens. We have previously shown that CD8(+) T cells and perforin are required to protect against the extracellular pathogen Yersinia pseudotuberculosis. Here we establish an experimental system where CD8(+) T cells specific to a single model antigen are the only memory response present at time of challenge. Using mice immunized with a vaccine strain of Listeria monocytogenes that expresses secreted ovalbumin (Lm-OVA), we show that OVA-specific CD8(+) T cells are generated and provide limited protection against challenge with virulent OVA(+)Y. pseudotuberculosis. Perforin expression by OVA-specific CD8(+) T cells was required, as Lm-OVA-immunized perforin-deficient mice showed higher bacterial burden as compared to Lm-OVA-immunized perforin-sufficient mice. Surprisingly, antigen-specific T cell protection waned over time, as Lm-OVA-immune mice eventually succumbed to Yersinia infection. Kinetic analysis of infection in mice with and without OVA-specific CD8(+) T cells revealed that bacterial numbers increased sharply in OVA-naïve mice until death, while OVA-immune mice held bacterial burden to a lower level throughout the duration of illness until death. Clonal analysis of bacterial populations in OVA-naïve and OVA-immune mice at distinct time points revealed equivalent and severe bottle-neck effects for bacteria in both sets of mice immediately after intravenous challenge, demonstrating a dominant role for other aspects of the immune system regardless of CD8(+) T cell status. These studies indicate that CD8(+) T cells against a single antigen can restrict Y. pseudotuberculosis colonization in a perforin-dependent manner, but ultimately are insufficient in their ability to provide sterilizing immunity and protect against death. PMID:27268148

  9. CD8(+) T cells specific to a single Yersinia pseudotuberculosis epitope restrict bacterial replication in the liver but fail to provide sterilizing immunity.

    Science.gov (United States)

    Shen, Haiqian; Gonzalez-Juarbe, Norberto; Blanchette, Krystle; Crimmins, Gregory; Bergman, Molly A; Isberg, Ralph R; Orihuela, Carlos J; Dube, Peter H

    2016-09-01

    CD8(+) T cells use contact-dependent cytolysis of target cells to protect the host against intracellular pathogens. We have previously shown that CD8(+) T cells and perforin are required to protect against the extracellular pathogen Yersinia pseudotuberculosis. Here we establish an experimental system where CD8(+) T cells specific to a single model antigen are the only memory response present at time of challenge. Using mice immunized with a vaccine strain of Listeria monocytogenes that expresses secreted ovalbumin (Lm-OVA), we show that OVA-specific CD8(+) T cells are generated and provide limited protection against challenge with virulent OVA(+)Y. pseudotuberculosis. Perforin expression by OVA-specific CD8(+) T cells was required, as Lm-OVA-immunized perforin-deficient mice showed higher bacterial burden as compared to Lm-OVA-immunized perforin-sufficient mice. Surprisingly, antigen-specific T cell protection waned over time, as Lm-OVA-immune mice eventually succumbed to Yersinia infection. Kinetic analysis of infection in mice with and without OVA-specific CD8(+) T cells revealed that bacterial numbers increased sharply in OVA-naïve mice until death, while OVA-immune mice held bacterial burden to a lower level throughout the duration of illness until death. Clonal analysis of bacterial populations in OVA-naïve and OVA-immune mice at distinct time points revealed equivalent and severe bottle-neck effects for bacteria in both sets of mice immediately after intravenous challenge, demonstrating a dominant role for other aspects of the immune system regardless of CD8(+) T cell status. These studies indicate that CD8(+) T cells against a single antigen can restrict Y. pseudotuberculosis colonization in a perforin-dependent manner, but ultimately are insufficient in their ability to provide sterilizing immunity and protect against death.

  10. The efficiency of human cytomegalovirus pp65(495-503) CD8+ T cell epitope generation is determined by the balanced activities of cytosolic and endoplasmic reticulum-resident peptidases.

    Science.gov (United States)

    Urban, Sabrina; Textoris-Taube, Kathrin; Reimann, Barbara; Janek, Katharina; Dannenberg, Tanja; Ebstein, Frédéric; Seifert, Christin; Zhao, Fang; Kessler, Jan H; Halenius, Anne; Henklein, Petra; Paschke, Julia; Cadel, Sandrine; Bernhard, Helga; Ossendorp, Ferry; Foulon, Thierry; Schadendorf, Dirk; Paschen, Annette; Seifert, Ulrike

    2012-07-15

    Control of human CMV (HCMV) infection depends on the cytotoxic activity of CD8(+) CTLs. The HCMV phosphoprotein (pp)65 is a major CTL target Ag and pp65(495-503) is an immunodominant CTL epitope in infected HLA-A*0201 individuals. As immunodominance is strongly determined by the surface abundance of the specific epitope, we asked for the components of the cellular Ag processing machinery determining the efficacy of pp65(495-503) generation, in particular, for the proteasome, cytosolic peptidases, and endoplasmic reticulum (ER)-resident peptidases. In vitro Ag processing experiments revealed that standard proteasomes and immunoproteasomes generate the minimal 9-mer peptide epitope as well as N-terminal elongated epitope precursors of different lengths. These peptides are largely degraded by the cytosolic peptidases leucine aminopeptidase and tripeptidyl peptidase II, as evidenced by increased pp65(495-503) epitope presentation after leucine aminopeptidase and tripeptidyl peptidase II knockdown. Additionally, with prolyl oligopeptidase and aminopeptidase B we identified two new Ag processing machinery components, which by destroying the pp65(495-503) epitope limit the availability of the specific peptide pool. In contrast to cytosolic peptidases, silencing of ER aminopeptidases 1 and 2 strongly impaired pp65(495-503)-specific T cell activation, indicating the importance of ER aminopeptidases in pp65(495-503) generation. Thus, cytosolic peptidases primarily interfere with the generation of the pp65(495-503) epitope, whereas ER-resident aminopeptidases enhance such generation. As a consequence, our experiments reveal that the combination of cytosolic and ER-resident peptidase activities strongly shape the pool of specific antigenic peptides and thus modulate MHC class I epitope presentation efficiency. PMID:22706083

  11. Identification of a nonameric H-2Kk-restricted CD8+ cytotoxic T lymphocyte epitope on the Plasmodium falciparum circumsporozoite protein

    DEFF Research Database (Denmark)

    Malik, A; Houghten, R; Corradin, G;

    1995-01-01

    Class I-restricted CD8+ cytotoxic T lymphocytes (CTL) against the circumsporozoite protein (CSP) protect mice against the rodent malaria parasite, Plasmodium yoelii, and vaccines designed to produce protective CTL against the P. falciparum CSP (PfCSP) are under development. Humans and B10.BR (H-2...

  12. Combination of In Silico Methods in the Search for Potential CD4(+) and CD8(+) T Cell Epitopes in the Proteome of Leishmania braziliensis.

    Science.gov (United States)

    E Silva, Rafael de Freitas; Ferreira, Luiz Felipe Gomes Rebello; Hernandes, Marcelo Zaldini; de Brito, Maria Edileuza Felinto; de Oliveira, Beatriz Coutinho; da Silva, Ailton Alvaro; de-Melo-Neto, Osvaldo Pompílio; Rezende, Antônio Mauro; Pereira, Valéria Rêgo Alves

    2016-01-01

    The leishmaniases are neglected tropical diseases widespread throughout the globe, which are caused by protozoans from the genus Leishmania and are transmitted by infected phlebotomine flies. The development of a safe and effective vaccine against these diseases has been seen as the best alternative to control and reduce the number of cases. To support vaccine development, this work has applied an in silico approach to search for high potential peptide epitopes able to bind to different major histocompatibility complex Class I and Class II (MHC I and MHC II) molecules from different human populations. First, the predicted proteome of Leishmania braziliensis was compared and analyzed by modern linear programs to find epitopes with the capacity to trigger an immune response. This approach resulted in thousands of epitopes derived from 8,000 proteins conserved among different Leishmania species. Epitopes from proteins similar to those found in host species were excluded, and epitopes from proteins conserved between different Leishmania species and belonging to surface proteins were preferentially selected. The resulting epitopes were then clustered, to avoid redundancies, resulting in a total of 230 individual epitopes for MHC I and 2,319 for MHC II. These were used for molecular modeling and docking with MHC structures retrieved from the Protein Data Bank. Molecular docking then ranked epitopes based on their predicted binding affinity to both MHC I and II. Peptides corresponding to the top 10 ranked epitopes were synthesized and evaluated in vitro for their capacity to stimulate peripheral blood mononuclear cells (PBMC) from post-treated cutaneous leishmaniasis patients, with PBMC from healthy donors used as control. From the 10 peptides tested, 50% showed to be immunogenic and capable to stimulate the proliferation of lymphocytes from recovered individuals.

  13. Combination of In Silico Methods in the Search for Potential CD4(+) and CD8(+) T Cell Epitopes in the Proteome of Leishmania braziliensis.

    Science.gov (United States)

    E Silva, Rafael de Freitas; Ferreira, Luiz Felipe Gomes Rebello; Hernandes, Marcelo Zaldini; de Brito, Maria Edileuza Felinto; de Oliveira, Beatriz Coutinho; da Silva, Ailton Alvaro; de-Melo-Neto, Osvaldo Pompílio; Rezende, Antônio Mauro; Pereira, Valéria Rêgo Alves

    2016-01-01

    The leishmaniases are neglected tropical diseases widespread throughout the globe, which are caused by protozoans from the genus Leishmania and are transmitted by infected phlebotomine flies. The development of a safe and effective vaccine against these diseases has been seen as the best alternative to control and reduce the number of cases. To support vaccine development, this work has applied an in silico approach to search for high potential peptide epitopes able to bind to different major histocompatibility complex Class I and Class II (MHC I and MHC II) molecules from different human populations. First, the predicted proteome of Leishmania braziliensis was compared and analyzed by modern linear programs to find epitopes with the capacity to trigger an immune response. This approach resulted in thousands of epitopes derived from 8,000 proteins conserved among different Leishmania species. Epitopes from proteins similar to those found in host species were excluded, and epitopes from proteins conserved between different Leishmania species and belonging to surface proteins were preferentially selected. The resulting epitopes were then clustered, to avoid redundancies, resulting in a total of 230 individual epitopes for MHC I and 2,319 for MHC II. These were used for molecular modeling and docking with MHC structures retrieved from the Protein Data Bank. Molecular docking then ranked epitopes based on their predicted binding affinity to both MHC I and II. Peptides corresponding to the top 10 ranked epitopes were synthesized and evaluated in vitro for their capacity to stimulate peripheral blood mononuclear cells (PBMC) from post-treated cutaneous leishmaniasis patients, with PBMC from healthy donors used as control. From the 10 peptides tested, 50% showed to be immunogenic and capable to stimulate the proliferation of lymphocytes from recovered individuals. PMID:27621732

  14. Combination of In Silico Methods in the Search for Potential CD4+ and CD8+ T Cell Epitopes in the Proteome of Leishmania braziliensis

    Science.gov (United States)

    e Silva, Rafael de Freitas; Ferreira, Luiz Felipe Gomes Rebello; Hernandes, Marcelo Zaldini; de Brito, Maria Edileuza Felinto; de Oliveira, Beatriz Coutinho; da Silva, Ailton Alvaro; de-Melo-Neto, Osvaldo Pompílio; Rezende, Antônio Mauro; Pereira, Valéria Rêgo Alves

    2016-01-01

    The leishmaniases are neglected tropical diseases widespread throughout the globe, which are caused by protozoans from the genus Leishmania and are transmitted by infected phlebotomine flies. The development of a safe and effective vaccine against these diseases has been seen as the best alternative to control and reduce the number of cases. To support vaccine development, this work has applied an in silico approach to search for high potential peptide epitopes able to bind to different major histocompatibility complex Class I and Class II (MHC I and MHC II) molecules from different human populations. First, the predicted proteome of Leishmania braziliensis was compared and analyzed by modern linear programs to find epitopes with the capacity to trigger an immune response. This approach resulted in thousands of epitopes derived from 8,000 proteins conserved among different Leishmania species. Epitopes from proteins similar to those found in host species were excluded, and epitopes from proteins conserved between different Leishmania species and belonging to surface proteins were preferentially selected. The resulting epitopes were then clustered, to avoid redundancies, resulting in a total of 230 individual epitopes for MHC I and 2,319 for MHC II. These were used for molecular modeling and docking with MHC structures retrieved from the Protein Data Bank. Molecular docking then ranked epitopes based on their predicted binding affinity to both MHC I and II. Peptides corresponding to the top 10 ranked epitopes were synthesized and evaluated in vitro for their capacity to stimulate peripheral blood mononuclear cells (PBMC) from post-treated cutaneous leishmaniasis patients, with PBMC from healthy donors used as control. From the 10 peptides tested, 50% showed to be immunogenic and capable to stimulate the proliferation of lymphocytes from recovered individuals.

  15. 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

    OBJECTIVE:: To investigate the potential to induce additional cytotoxic T-lymphocyte (CTL) immunity during chronic HIV-1 infection. DESIGN:: We selected infrequently targeted or subdominant but conserved HLA-A*0201-binding epitopes in Gag, Pol, Env, Vpu and Vif. These relatively immune silent epi...... lead to stronger and more durable cellular responses to selected epitopes with the potential to control viral replication and prevent disease in HIV-1-infected individuals....

  16. CD4-CD8-αβ and γδ T Cells Display Inflammatory and Regulatory Potentials during Human Tuberculosis

    Science.gov (United States)

    Pinheiro, Melina B.; Antonelli, Lis R.; Sathler-Avelar, Renato; Vitelli-Avelar, Danielle M.; Spindola-de-Miranda, Silvana; Guimarães, Tânia M. P. D.; Teixeira-Carvalho, Andrea; Martins-Filho, Olindo A.; Toledo, Vicente P. C. P.

    2012-01-01

    T-cells play an important role controlling immunity against pathogens and therefore influence the outcome of human diseases. Although most T-lymphocytes co-express either CD4 or CD8, a smaller T-cell subset found the in the human peripheral blood that expresses the αβ or γδ T-cell-receptor (TCR) lacks the CD4 and CD8 co-receptors. These double negative (DN) T-cells have been shown to display important immunological functions in human diseases. To better understand the role of DN T-cells in human Mycobacterium tuberculosis, we have characterized their frequency, activation and cytokine profile in a well-defined group of tuberculosis patients, categorized as severe and non-severe based on their clinical status. Our data showed that whereas high frequency of αβ DN T-cells observed in M. tuberculosis-infected patients are associated with disease severity, decreased proportion of γδ DN T-cells are found in patients with severe tuberculosis. Together with activation of CD4+ and CD8+ T-cells, higher frequencies of both αβ and γδ DN T-cells from tuberculosis patients also express the chronic activation marker HLA-DR. However, the expression of CD69, an early activation marker, is selectively observed in DN T-cells. Interestingly, while αβ and γδ DN T-cells from patients with non-severe tuberculosis display a pro-inflammatory cytokine profile, characterized by enhanced IFN-γ, the γδ DN T-cells from patients with severe disease express a modulatory profile exemplified by enhanced interleukin-10 production. Overall, our findings suggest that αβ and γδ DN T-cell present disparate immunoregulatory potentials and seems to contribute to the development/maintenance of distinct clinical aspects of TB, as part of the complex immunological network triggered by the TB infection. PMID:23239994

  17. CD4-CD8-αβ and γδ T cells display inflammatory and regulatory potentials during human tuberculosis.

    Directory of Open Access Journals (Sweden)

    Melina B Pinheiro

    Full Text Available T-cells play an important role controlling immunity against pathogens and therefore influence the outcome of human diseases. Although most T-lymphocytes co-express either CD4 or CD8, a smaller T-cell subset found the in the human peripheral blood that expresses the αβ or γδ T-cell-receptor (TCR lacks the CD4 and CD8 co-receptors. These double negative (DN T-cells have been shown to display important immunological functions in human diseases. To better understand the role of DN T-cells in human Mycobacterium tuberculosis, we have characterized their frequency, activation and cytokine profile in a well-defined group of tuberculosis patients, categorized as severe and non-severe based on their clinical status. Our data showed that whereas high frequency of αβ DN T-cells observed in M. tuberculosis-infected patients are associated with disease severity, decreased proportion of γδ DN T-cells are found in patients with severe tuberculosis. Together with activation of CD4(+ and CD8(+ T-cells, higher frequencies of both αβ and γδ DN T-cells from tuberculosis patients also express the chronic activation marker HLA-DR. However, the expression of CD69, an early activation marker, is selectively observed in DN T-cells. Interestingly, while αβ and γδ DN T-cells from patients with non-severe tuberculosis display a pro-inflammatory cytokine profile, characterized by enhanced IFN-γ, the γδ DN T-cells from patients with severe disease express a modulatory profile exemplified by enhanced interleukin-10 production. Overall, our findings suggest that αβ and γδ DN T-cell present disparate immunoregulatory potentials and seems to contribute to the development/maintenance of distinct clinical aspects of TB, as part of the complex immunological network triggered by the TB infection.

  18. SELECTION OF NEW EPITOPES FROM MONOVALENT DISPLAYED PHAGE OCTAPEPTIDE LIBRARY

    Institute of Scientific and Technical Information of China (English)

    李全喜; 王琰; 李竞; 王雅明; 徐建军; 王力民; 董志伟

    1998-01-01

    A library of 2×l07 random oetspaptides was constructed by use of phegemid-based monovaient phage display system. The randomly synthesized degenerated oilgodeoxyribonucleotides (oligos) were fused to the truncated gⅢ (p210-p408). Sequeraze analysis of 11 randomly chosen clones suggested that the degenerated inserts and its deduced amino acid (an) sequences are randomly distributed. The library was used to select binding paptides to the morroeloncl antlhody (mAb) 9E10, which recognizes a continuous decapaptide epitope of denatured human c-myc protein. After four to five rounds of panning, most of the eluted clones could bind to 9E10. Sequerlce analysis of the selected positive clones indlcated that the binding sequences could fall into two chsses, one class (clone 1) shares a consensus motif, ISE x x L, with c-mire decapeprider and the sequences of the other class are entirely different. The binding of both classes to 9E10 could be specifically lnhlhited by froe c-myc deeapeptide. The immunogenlcitF cff the phage peptide was further investigsted h5, construction of multivalent displayed phage peptides and immunization of animals with or without adjuvant. ELISA and competitive ELISA showed that anti-serum from both mice and rabbit immunized with either done could bind to the original antigen, c-myc decapeptide. These results denote that in spite of the dissimilarity of the selected psptides with c-myc decapeptide, they are capable of inducing similar immune respones in vivo, thus actually mimicking the antigen epitope.

  19. 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.

  20. HLA-A02:01-Restricted Epitopes Identified from the Herpes Simplex Virus Tegument Protein VP11/12 Preferentially Recall Polyfunctional Effector Memory CD8+ T Cells from Seropositive Asymptomatic Individuals and Protect “Humanized” HLA-A*02:01 Transgenic Mice Against Ocular Herpes

    Science.gov (United States)

    Srivastava, Ruchi; Khan, Arif A.; Spencer, Doran; Vahed, Hawa; Lopes, Patricia P.; Thai, Nhi Thi Uyen; Wang, Christine; Pham, Thanh T.; Huang, Jiawei; Scarfone, Vanessa M.; Nesburn, Anthony B.; Wechsler, Steven L.; BenMohamed, Lbachir

    2014-01-01

    The Herpes Simplex Virus type 1 virion tegument phosphoprotein 11/12 (HSV-1 VP11/12) is a major antigen targeted by CD8+ T cells from HSV-seropositive individuals. However, whether and which VP11/12-epitope-specific CD8+ T cells play a role in the “natural” protection seen in seropositive healthy asymptomatic (ASYMP) individuals (who have never had clinical herpes disease) remain to be determined. In this study, we used multiple prediction computer-assisted algorithms to identify 10 potential HLA-A*02:01-restricted CD8+ T cell epitopes from the 716 amino acids sequence of VP11/12. Three out of ten epitopes exhibited high to moderate binding affinity to HLA-A*02:01 molecules. In ten sequentially studied HLA-A*02:01 positive and HSV-1-seropositive ASYMP individuals, the most frequent, robust and polyfunctional effector CD8+ T-cell responses, as assessed by a combination of tetramer frequency, granzyme B, granzyme K, perforin, CD107a/b cytotoxic degranulation, IFN-γ and multiplex cytokines assays, were predominantly directed against three epitopes: VP11/1266–74, VP11/12220–228 and VP11/12702–710. Interestingly, ASYMP individuals had significantly higher proportion of CD45RAlowCCR7lowCD44highCD62LlowCD27lowCD28lowCD8+ effector memory T cells (TEM) specific to the three epitopes, compared to symptomatic (SYMP) individuals (with a history of numerous episodes of recurrent ocular herpetic disease). Moreover, immunization of HLA-A*02:01 transgenic mice with the three ASYMP CD8+ TEM cell epitopes induced robust and polyfunctional epitope-specific CD8+ TEM cells that were associated with a strong protective immunity against ocular herpes infection and disease. Our findings outline phenotypic and functional features of protective HSV-specific CD8+ T cells that should guide the development of an effective T-cell-based herpes vaccine. PMID:25617474

  1. Authentic display of a cholera toxin epitope by chimeric type 1 fimbriae

    DEFF Research Database (Denmark)

    Stentebjerg-Olesen, Bodil; Pallesen, Lars; Jensen, Lars Bogø;

    1997-01-01

    . Several of the chosen positions seemed amenable even for large foreign inserts; the chimeric proteins were exposed on the bacterial surface and the cholera toxin epitope was authentically displayed, i.e. it was recognized on bacteria by specific antiserum. Display of chimeric fimbriae was tested...

  2. Host and viral factors contributing to CD8+ T cell failure in hepatitis C virus infection

    Institute of Scientific and Technical Information of China (English)

    Christoph Neumann-Haefelin; Hans Christian Spangenberg; Hubert E Blum; Robert Thimme

    2007-01-01

    Virus-specific CD8+ T cells are thought to be the major anti-viral effector cells in hepatitis C virus (HCV)infection. Indeed, viral clearance is associated with vigorous CD8+ T cell responses targeting multiple epitopes. In the chronic phase of infection, HCV-specific CD8+ T cell responses are usually weak, narrowly focused and display often functional defects regarding cytotoxicity, cytokine production, and proliferative capacity. In the last few years, different mechanisms which might contribute to the failure of HCV-specific CD8+ T cells in chronic infection have been identified,including insufficient CD4+ help, deficient CD8+ T cell differentiation, viral escape mutations, suppression by viral factors, inhibitory cytokines, inhibitory ligands, and regulatory T cells. In addition, host genetic factors such as the host's human leukocyte antigen (HLA) background may play an important role in the efficiency of the HCVspecific CD8+ T cell response and thus outcome of infection. The growing understanding of the mechanisms contributing to T cell failure and persistence of HCV infection will contribute to the development of successful immunotherapeutical and -prophylactical strategies.

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

    Directory of Open Access Journals (Sweden)

    Stephen A Kaba

    Full Text Available BACKGROUND: 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. METHODOLOGY/PRINCIPAL FINDINGS: 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. CONCLUSION: 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.

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

    Science.gov (United States)

    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. PMID:27611868

  5. Self-assembling peptide for co-delivery of HIV-1 CD8+ T cells epitope and Toll-like receptor 7/8 agonists R848 to induce maturation of monocyte derived dendritic cell and augment polyfunctional cytotoxic T lymphocyte (CTL) response.

    Science.gov (United States)

    Ding, Yong; Liu, Jun; Lu, Sheng; Igweze, Justice; Xu, Wen; Kuang, Da; Zealey, Chris; Liu, Daheng; Gregor, Alex; Bozorgzad, Ardalan; Zhang, Lei; Yue, Elizabeth; Mujib, Shariq; Ostrowski, Mario; Chen, P

    2016-08-28

    Peptide based vaccine that incorporates one or several highly conserved CD8+ T cells epitopes to induce potent cytotoxic T lymphocyte (CTL) response is desirable for some infectious diseases, such as HIV-1 (human immunodeficiency virus-1), and cancers. However, the CD8+ T cells epitope is often weakly immunogenic, and thus requires a specific adjuvant or delivery system to enhance the efficiency. Here we investigated the use of self-assembling peptide EAK16-II based platform to achieve the co-delivery of CD8+ T cells epitope and TLR7/8 agonists (R848 or R837) for augmenting DCs maturation and HIV-1 specific CTL response. HIV-1 CTL epitope SL9 was conjugated with EAK16-II to obtain SL9-EAK16-II, which further spontaneously co-assembled with R848 or R837 in aqueous solution, forming co-assembled nanofibers. Fluorescence spectra and calorimetrical titration revealed the interaction between SL9-EAK16-II assemblies and R848 or R837 via hydrogen bonding and hydrophobic interaction, with the binding affinity (dissociation constant Kd) of 0.62μM or 0.53μM, respectively. Ex vivo generated DCs from HIV-1+ patients pulsed with the SL9-EAK16-II/R848 nanofibers stimulated significantly more polyfunctional SL9 specific CTLs, compared to the DCs pulsed with SL9 alone or the mixture of SL9 and TLR agonist. Furthermore, the nanofibers elicited stronger SL9 specific CTL response in vaccinated mice. Our findings suggest the self-assembling peptide EAK16-II might be used as a new delivery system for peptide based vaccines. PMID:27297778

  6. Epitope Mapping of Metuximab on CD147 Using Phage Display and Molecular Docking

    Directory of Open Access Journals (Sweden)

    Bifang He

    2013-01-01

    Full Text Available Metuximab is the generic name of Licartin, a new drug for radioimmunotherapy of hepatocellular carcinoma. Although it is known to be a mouse monoclonal antibody against CD147, the complete epitope mediating the binding of metuximab to CD147 remains unknown. We panned the Ph.D.-12 phage display peptide library against metuximab and got six mimotopes. The following bioinformatics analysis based on mimotopes suggested that metuximab recognizes a conformational epitope composed of more than 20 residues. The residues of its epitope may include T28, V30, K36, L38, K57, F74, D77, S78, D79, D80, Q81, G83, S86, N98, Q100, L101, H102, G103, P104, V131, P132, and K191. The homology modeling of metuximab and the docking of CD147 to metuximab were also performed. Based on the top one docking model, the epitope was predicted to contain 28 residues: AGTVFTTV (23–30, I37, D45, E84, V88, EPMGTANIQLH (92–102, VPP (131–133, Q164, and K191. Almost half of the residues predicted on the basis of mimotope analysis also appear in the docking result, indicating that both results are reliable. As the predicted epitopes of metuximab largely overlap with interfaces of CD147-CD147 interactions, a structural mechanism of metuximab is proposed as blocking the formation of CD147 dimer.

  7. Production and Purification of Recombinant Filamentous Bacteriophages Displaying Immunogenic Heterologous Epitopes.

    Science.gov (United States)

    Deng, Lei; Linero, Florencia; Saelens, Xavier

    2016-01-01

    Viruslike particles often combine high physical stability with robust immunogenicity. Furthermore, when such particles are based on bacteriophages, they can be produced in high amounts at minimal cost and typically will require only standard biologically contained facilities. We provide protocols for the characterization and purification of recombinant viruslike particles derived from filamentous bacteriophages. As an example, we focus on filamentous Escherichia coli fd phage displaying a conserved influenza A virus epitope that is fused genetically to the N-terminus of the major coat protein of this phage. A step-by-step procedure to obtain a high-titer, pure recombinant phage preparation is provided. We also describe a quality control experiment based on a biological readout of the purified fd phage preparation. These protocols together with the highlighted critical steps may facilitate generic implementation of the provided procedures for the display of other epitopes by recombinant fd phages.

  8. Immune hierarchy among HIV-1 CD8+ T cell epitopes delivered by dendritic cells depends on MHC-I binding irrespective of mode of loading and immunization in HLA-A*0201 mice

    DEFF Research Database (Denmark)

    Kloverpris, Henrik N; Karlsson, Ingrid; Thorn, Mette;

    2009-01-01

    , where the immune system responds to only a small number of the epitopes administered. To evaluate the feasibility of such vaccine strategies, we used the human leukocyte antigen (HLA)-A*0201 transgenic (tg) HHD murine in vivo model and immunized with dendritic cells pulsed with seven HIV-1-derived HLA...

  9. Phage display revisited: Epitope mapping of a monoclonal antibody directed against Neisseria meningitidis adhesin A using the PROFILER technology.

    Science.gov (United States)

    Cariccio, Veronica Lanza; Domina, Maria; Benfatto, Salvatore; Venza, Mario; Venza, Isabella; Faleri, Agnese; Bruttini, Marco; Bartolini, Erika; Giuliani, Marzia Monica; Santini, Laura; Brunelli, Brunella; Norais, Nathalie; Borgogni, Erica; Midiri, Angelina; Galbo, Roberta; Romeo, Letizia; Biondo, Carmelo; Masignani, Vega; Teti, Giuseppe; Felici, Franco; Beninati, Concetta

    2016-01-01

    There is a strong need for rapid and reliable epitope mapping methods that can keep pace with the isolation of increasingly larger numbers of mAbs. We describe here the identification of a conformational epitope using Phage-based Representation OF ImmunoLigand Epitope Repertoire (PROFILER), a recently developed high-throughput method based on deep sequencing of antigen-specific lambda phage-displayed libraries. A novel bactericidal monoclonal antibody (mAb 9F11) raised against Neisseria meningitidis adhesin A (NadA), an important component of the Bexsero(®) anti-meningococcal vaccine, was used to evaluate the technique in comparison with other epitope mapping methods. The PROFILER technology readily identified NadA fragments that were capable of fully recapitulating the reactivity of the entire antigen against mAb 9F11. Further analysis of these fragments using mutagenesis and hydrogen-deuterium exchange mass-spectrometry allowed us to identify the binding site of mAb 9F11 (A250-D274) and an adjoining sequence (V275-H312) that was also required for the full functional reconstitution of the epitope. These data suggest that, by virtue of its ability to detect a great variety of immunoreactive antigen fragments in phage-displayed libraries, the PROFILER technology can rapidly and reliably identify epitope-containing regions and provide, in addition, useful clues for the functional characterization of conformational mAb epitopes. PMID:26963435

  10. Multivalent display of minimal Clostridium difficile glycan epitopes mimics antigenic properties of larger glycans

    Science.gov (United States)

    Broecker, Felix; Hanske, Jonas; Martin, Christopher E.; Baek, Ju Yuel; Wahlbrink, Annette; Wojcik, Felix; Hartmann, Laura; Rademacher, Christoph; Anish, Chakkumkal; Seeberger, Peter H.

    2016-01-01

    Synthetic cell-surface glycans are promising vaccine candidates against Clostridium difficile. The complexity of large, highly antigenic and immunogenic glycans is a synthetic challenge. Less complex antigens providing similar immune responses are desirable for vaccine development. Based on molecular-level glycan–antibody interaction analyses, we here demonstrate that the C. difficile surface polysaccharide-I (PS-I) can be resembled by multivalent display of minimal disaccharide epitopes on a synthetic scaffold that does not participate in binding. We show that antibody avidity as a measure of antigenicity increases by about five orders of magnitude when disaccharides are compared with constructs containing five disaccharides. The synthetic, pentavalent vaccine candidate containing a peptide T-cell epitope elicits weak but highly specific antibody responses to larger PS-I glycans in mice. This study highlights the potential of multivalently displaying small oligosaccharides to achieve antigenicity characteristic of larger glycans. The approach may result in more cost-efficient carbohydrate vaccines with reduced synthetic effort. PMID:27091615

  11. Epitope mapping by random peptide phage display reveals essential residues for vaccinia extracellular enveloped virion spread

    Directory of Open Access Journals (Sweden)

    He Yong

    2012-09-01

    Full Text Available Abstract Background A33 is a type II integral membrane protein expressed on the extracellular enveloped form of vaccinia virus (VACV. Passive transfer of A33-directed monoclonal antibodies or vaccination with an A33 subunit vaccine confers protection against lethal poxvirus challenge in animal models. Homologs of A33 are highly conserved among members of the Orthopoxvirus genus and are potential candidates for inclusion in vaccines or assays targeting extracellular enveloped virus activity. One monoclonal antibody directed against VACV A33, MAb-1G10, has been shown to target a conformation-dependent epitope. Interestingly, while it recognizes VACV A33 as well as the corresponding variola homolog, it does not bind to the monkeypox homolog. In this study, we utilized a random phage display library to investigate the epitope recognized by MAb-1G10 that is critical for facilitating cell-to-cell spread of the vaccinia virus. Results By screening with linear or conformational random phage libraries, we found that phages binding to MAb-1G10 display the consensus motif CEPLC, with a disulfide bond formed between two cysteine residues required for MAb-1G10 binding. Although the phage motif contained no linear sequences homologous to VACV A33, structure modeling and analysis suggested that residue D115 is important to form the minimal epitope core. A panel of point mutants expressing the ectodomain of A33 protein was generated and analyzed by either binding assays such as ELISA and immunoprecipitation or a functional assessment by blocking MAb-1G10 mediated comet inhibition in cell culture. Conclusions These results confirm L118 as a component of the MAb-1G10 binding epitope, and further identify D115 as an essential residue. By defining the minimum conformational structure, as well as the conformational arrangement of a short peptide sequence recognized by MAb-1G10, these results introduce the possibility of designing small molecule mimetics that may

  12. Stepwise identification of HLA-A*0201-restricted CD8+ T-cell epitope peptides from herpes simplex virus type 1 genome boosted by a StepRank scheme.

    Science.gov (United States)

    Bi, Jianjun; Song, Rengang; Yang, Huilan; Li, Bingling; Fan, Jianyong; Liu, Zhongrong; Long, Chaoqin

    2011-01-01

    Identification of immunodominant epitopes is the first step in the rational design of peptide vaccines aimed at T-cell immunity. To date, however, it is yet a great challenge for accurately predicting the potent epitope peptides from a pool of large-scale candidates with an efficient manner. In this study, a method that we named StepRank has been developed for the reliable and rapid prediction of binding capabilities/affinities between proteins and genome-wide peptides. In this procedure, instead of single strategy used in most traditional epitope identification algorithms, four steps with different purposes and thus different computational demands are employed in turn to screen the large-scale peptide candidates that are normally generated from, for example, pathogenic genome. The steps 1 and 2 aim at qualitative exclusion of typical nonbinders by using empirical rule and linear statistical approach, while the steps 3 and 4 focus on quantitative examination and prediction of the interaction energy profile and binding affinity of peptide to target protein via quantitative structure-activity relationship (QSAR) and structure-based free energy analysis. We exemplify this method through its application to binding predictions of the peptide segments derived from the 76 known open-reading frames (ORFs) of herpes simplex virus type 1 (HSV-1) genome with or without affinity to human major histocompatibility complex class I (MHC I) molecule HLA-A*0201, and find that the predictive results are well compatible with the classical anchor residue theory and perfectly match for the extended motif pattern of MHC I-binding peptides. The putative epitopes are further confirmed by comparisons with 11 experimentally measured HLA-A*0201-restrcited peptides from the HSV-1 glycoproteins D and K. We expect that this well-designed scheme can be applied in the computational screening of other viral genomes as well. PMID:21072852

  13. Authentic display of a cholera toxin epitope by chimeric type 1 fimbriae: effects of insert position and host background

    DEFF Research Database (Denmark)

    Stentebjerg-Olesen, B; Pallesen, L; Jensen, LB;

    1997-01-01

    with respect to host background in three different Escherichia coli strains, i.e. an isogenic set of K-12 strains, differing in the presence of an indigenous fim gene cluster, as well as a wild-type isolate. Immunization of rabbits with purified chimeric fimbriae resulted in serum which specifically recognized......The potential of the major structural protein of type 1 fimbriae as a display system for heterologous sequences was tested. As a reporter-epitope, a heterologous sequence mimicking a neutralizing epitope of the cholera toxin B chain was inserted, in one or two copies, into four different positions....... Several of the chosen positions seemed amenable even for large foreign inserts; the chimeric proteins were exposed on the bacterial surface and the cholera toxin epitope was authentically displayed, i.e. it was recognized on bacteria by specific antiserum. Display of chimeric fimbriae was tested...

  14. High-throughput sequencing enhanced phage display enables the identification of patient-specific epitope motifs in serum

    DEFF Research Database (Denmark)

    Christiansen, Anders; Kringelum, Jens Vindahl; Hansen, Christian Skjødt;

    2015-01-01

    Phage display is a prominent screening technique with a multitude of applications including therapeutic antibody development and mapping of antigen epitopes. In this study, phages were selected based on their interaction with patient serum and exhaustively characterised by high-throughput sequenc...

  15. Tuberculosis-specific CD8 cells in HLA A*02-positive TB- and LTBI patients

    DEFF Research Database (Denmark)

    Fløe, Andreas; Brix, Liselotte; Wejse, Christian;

    Background: Understanding the CD8+ response against Mycobacterium tuberculosis (MTB) may be a key to improved TB diagnostics and vaccine development. Aims and Objectives: To detect a CD8+ T-cell response against Mycobacterium tuberculosis (MTB) in active tuberculosis (TB) and latent TB (LTBI), in...... candidates, from which we constructed MHC multimers (Dextramers). Peripheral blood mononuclear cells (PBMC) from 7 TB-patients, 16 LTBI patients and 8 MTB-exposed, IGRA-negative, healthy subjects (HE), all HLA A*02 positive, were stained with the Dextramers and with anti-CD8 and anti-CD3, and analyzed on a...... flow cytometer. The MTB epitopes were analyzed in 5 pools (3-7 epitopes each). Positive responses included >0.001 % of CD8+, CD3+ cells, supported by inspection of flow cytometry plots. Results: MTB-specific CD8+ T-cells were detected more often in TB patients (57%) than in LTBI patients (41%) and in...

  16. Rabbit hemorrhagic disease virus capsid, a versatile platform for foreign B-cell epitope display inducing protective humoral immune responses.

    Science.gov (United States)

    Moreno, Noelia; Mena, Ignacio; Angulo, Iván; Gómez, Yolanda; Crisci, Elisa; Montoya, María; Castón, José R; Blanco, Esther; Bárcena, Juan

    2016-01-01

    Virus-like particles (VLPs), comprised of viral structural proteins devoid of genetic material, are tunable nanoparticles that can be chemically or genetically engineered, to be used as platforms for multimeric display of foreign antigens. Here, we report the engineering of chimeric VLPs, derived from rabbit hemorrhagic disease virus (RHDV) for presentation of foreign B-cell antigens to the immune system. The RHDV capsid comprises 180 copies of a single capsid subunit (VP60). To evaluate the ability of chimeric RHDV VLPs to elicit protective humoral responses against foreign antigens, we tested two B-cell epitopes: a novel neutralizing B-cell epitope, derived from feline calicivirus capsid protein, and a well characterized B-cell epitope from the extracellular domain of influenza A virus M2 protein (M2e). We generated sets of chimeric RHDV VLPs by insertion of the foreign B-cell epitopes at three different locations within VP60 protein (which involved different levels of surface accessibility) and in different copy numbers per site. The immunogenic potential of the chimeric VLPs was analyzed in the mouse model. The results presented here indicated that chimeric RHDV VLPs elicit potent protective humoral responses against displayed foreign B-cell epitopes, demonstrated by both, in vitro neutralization and in vivo protection against a lethal challenge. PMID:27549017

  17. CD8+ Tregs in Lupus, Autoimmunity, and Beyond

    Science.gov (United States)

    Dinesh, Ravi K; Skaggs, Brian J; Cava, Antonio La; Hahn, Bevra H.; Singh, Ram Pyare

    2010-01-01

    While CD4+CD25high regulatory T cells (Tregs) have garnered much attention for their role in the maintenance of immune homeostasis, recent findings have shown that subsets of CD8+ T cells (CD8+ Tregs) display immunoregulatory functions as well. Both CD4+ Tregs and CD8+ Tregs appear impaired in number and/or function in several autoimmune diseases and in experimental animal models of autoimmunity, suggesting the possibility of immunotherapeutic targeting of these cells for improved management of autoimmune conditions. Our group has developed a strategy to induce CD8+ Tregs in autoimmune mice through the use of a tolerogenic self-peptide, and new information has been gained on the phenotype, function and role of induced CD8+ Tregs in autoimmunity. Here we present an overview of the role and mechanisms of action of CD8+ Tregs in autoimmunity, with a special focus on lupus. We also discuss the potential role of CD8+ Tregs in other diseases, including chronic infection and cancer. PMID:20385256

  18. Selection of a peptide mimicking neutralization epitope of hepatitis E virus with phage peptide display technology

    Institute of Scientific and Technical Information of China (English)

    Ying Gu; Jun Zhang; Ying-Bing Wang; Shao-Wei Li; Hai-Jie Yang; Wen-Xin Luo; Ning-Shao Xia

    2004-01-01

    AIM: To select the peptide mimicking the neutralization epitope of hepatitis E virus which bound to non-type-specific and conformational monoclonal antibodies (mAbs) 8C11 and 8H3 fromed 7-peptide phage display library, and expressed the peptide recombinant with HBcAg in E.coli, and to observe whether the recombinant HBcAg could still form virus like particle (VLP) and to test the activation of the recombinant polyprotein and chemo-synthesized peptide that was selected by mAb 8H3.METHODS: 8C11 and 8H3 were used to screen for binding peptides through a 7-peptide phage display library. After 4rounds of panning, monoclonal phages were selected and sequenced. The obtained dominant peptide coding sequences was then synthesized and inserted into amino acid 78 to 83 of hepatitis B core antigen (HBcAg), and then expressed in E. coli. Activity of the recombinant proteins was detected by Western blotting, VLPs of the recombinant polyproteins were tested by transmission electron microscopy and binding activity of the chemo-synthesized peptide was confirmed by BIAcore biosensor.RESULTS: Twenty-one positive monoclonal phages (10for 8CL1, and 11 for 8H3) were selected and the inserted fragments were sequenced. The DNA sequence coding for the obtained dominant peptides 8C11 (N′-His-Pro-Thr-LeuLeu-Arg-Ile-C′, named 8C11A) and 8H3 (N′-Ser-Ile-LeuPro- Tyr-Pro-Tyr-C′, named 8H3A) were then synthesized and cloned to the HBcAg vector, then expressed in E. coli.The recombinant proteins aggregated into homodimer or polymer on SDS-PAGE, and could bind to mAb 8C11 and 8H3 in Western blotting. At the same time, the recombinant polyprotein could form virus like particles (VLPs), which could be visualized on electron micrograph. The dominant peptide 8H3A selected by mAb 8H3 was further chemosynthesized, and its binding to mAb 8H3 could be detected by BIAcore biosensor.CONCLUSION: These results implicate that conformational neutralizing epitope can be partially modeled by a short

  19. 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...

  20. Involvement and prognosis value of CD8(+) T cells in giant cell arteritis.

    Science.gov (United States)

    Samson, Maxime; Ly, Kim Heang; Tournier, Benjamin; Janikashvili, Nona; Trad, Malika; Ciudad, Marion; Gautheron, Alexandrine; Devilliers, Hervé; Quipourt, Valérie; Maurier, François; Meaux-Ruault, Nadine; Magy-Bertrand, Nadine; Manckoundia, Patrick; Ornetti, Paul; Maillefert, Jean-Francis; Besancenot, Jean-François; Ferrand, Christophe; Mesturoux, Laura; Labrousse, François; Fauchais, Anne-Laure; Saas, Philippe; Martin, Laurent; Audia, Sylvain; Bonnotte, Bernard

    2016-08-01

    CD8(+) T cells participate in the pathogenesis of some vasculitides. However, little is known about their role in Giant Cell Arteritis (GCA). This study was conducted to investigate CD8(+) T cell involvement in the pathogenesis of GCA. Analyses were performed at diagnosis and after 3 months of glucocorticoid treatment in 34 GCA patients and 26 age-matched healthy volunteers. Percentages of CD8(+) T-cell subsets, spectratype analysis of the TCR Vβ families of CD8(+) T cells, levels of cytokines and chemokines and immunohistochemistry of temporal artery biopsies (TAB) were assessed. Among total CD8(+) T cells, percentages of circulating cytotoxic CD8 T lymphocytes (CTL, CD3(+)CD8(+)perforin(+)granzymeB(+)), Tc17 (CD3(+)CD8(+)IL-17(+)), CD63(+)CD8(+) T cells and levels of soluble granzymes A and B were higher in patients than in controls, whereas the percentage of Tc1 cells (CD3(+)CD8(+)IFN-γ(+)) was similar. Moreover, CD8(+) T cells displayed a restricted TCR repertoire in GCA patients. Percentages of circulating CTL, Tc17 and soluble levels of granzymes A and B decreased after treatment. CXCR3 expression on CD8(+) T cells and its serum ligands (CXCL9, -10, -11) were higher in patients. Analyses of TAB revealed high expression of CXCL9 and -10 associated with infiltration by CXCR3(+)CD8(+) T cells expressing granzyme B and TiA1. The intensity of the CD8 T-cell infiltrate in TAB was predictive of the severity of the disease. This study demonstrates the implication and the prognostic value of CD8(+) T-cells in GCA and suggests that CD8(+) T-cells are recruited within the vascular wall through an interaction between CXCR3 and its ligands. PMID:27236507

  1. CD4⁺ and CD8⁺ regulatory T cells (Tregs) are elevated and display an active phenotype in patients with chronic HCV mono-infection and HIV/HCV co-infection

    DEFF Research Database (Denmark)

    Hartling, H J; Gaardbo, J C; Ronit, A;

    2012-01-01

    The aim of this study was to examine regulatory T cells (Tregs) in peripheral blood and liver tissue in patients with chronic hepatitis C virus (HCV) mono-infection and in patients with HIV/HCV co-infection. In a cross-sectional study were included 51 patients with chronic HCV infection, 24...... patients with HIV/HCV co-infection and 24 healthy individuals. CD4⁺ and CD8⁺ Tregs were determined using flow cytometry. Fibrosis was examined by transient elastography. Inflammation, fibrosis and Tregs were determined in liver biopsies from 12 patients. Increased frequency of CD4⁺ and CD8⁺ Tregs was found...... in HIV/HCV co-infected patients [median: 6.4% (IQR: 5.7-6.9) and 1.0% (0.7-1.2), respectively] compared to HCV mono-infected patients [5.6% (4.2-6.3), P = 0.01 and 0.5% (0.3-0.7), P HCV mono-infected patients had increased frequencies of Tregs compared with healthy...

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

    Directory of Open Access Journals (Sweden)

    Sarah Hutchinson

    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.

  3. CD8 T cell response maturation defined by anentropic specificity and repertoire depth correlates with SIVΔnef-induced protection.

    Directory of Open Access Journals (Sweden)

    Sama Adnan

    2015-02-01

    Full Text Available The live attenuated simian immunodeficiency virus (LASIV vaccine SIVΔnef is one of the most effective vaccines in inducing protection against wild-type lentiviral challenge, yet little is known about the mechanisms underlying its remarkable protective efficacy. Here, we exploit deep sequencing technology and comprehensive CD8 T cell epitope mapping to deconstruct the CD8 T cell response, to identify the regions of immune pressure and viral escape, and to delineate the effect of epitope escape on the evolution of the CD8 T cell response in SIVΔnef-vaccinated animals. We demonstrate that the initial CD8 T cell response in the acute phase of SIVΔnef infection is mounted predominantly against more variable epitopes, followed by widespread sequence evolution and viral escape. Furthermore, we show that epitope escape expands the CD8 T cell repertoire that targets highly conserved epitopes, defined as anentropic specificity, and generates de novo responses to the escaped epitope variants during the vaccination period. These results correlate SIVΔnef-induced protection with expanded anentropic specificity and increased response depth. Importantly, these findings render SIVΔnef, long the gold standard in HIV/SIV vaccine research, as a proof-of-concept vaccine that highlights the significance of the twin principles of anentropic specificity and repertoire depth in successful vaccine design.

  4. Engineering Recombinant Reoviruses To Display gp41 Membrane-Proximal External-Region Epitopes from HIV-1

    Science.gov (United States)

    Boehme, Karl W.; Ikizler, Mine'; Iskarpatyoti, Jason A.; Wetzel, J. Denise; Willis, Jordan; Crowe, James E.; LaBranche, Celia C.; Montefiori, David C.

    2016-01-01

    ABSTRACT The gp41 membrane-proximal external region (MPER) is a target for broadly neutralizing antibody responses against human immunodeficiency virus type 1 (HIV-1). However, replication-defective virus vaccines currently under evaluation in clinical trials do not efficiently elicit MPER-specific antibodies. Structural modeling suggests that the MPER forms an α-helical coiled coil that is required for function and immunogenicity. To maintain the native MPER conformation, we used reverse genetics to engineer replication-competent reovirus vectors that displayed MPER sequences in the α-helical coiled-coil tail domain of viral attachment protein σ1. Sequences in reovirus strain type 1 Lang (T1L) σ1 were exchanged with sequences encoding HIV-1 strain Ba-L MPER epitope 2F5 or the entire MPER. Individual 2F5 or MPER substitutions were introduced at virion-proximal or virion-distal sites in the σ1 tail. Recombinant reoviruses containing heterologous HIV-1 sequences were viable and produced progeny yields comparable to those with wild-type virus. HIV-1 sequences were retained following 10 serial passages in cell culture, indicating that the substitutions were genetically stable. Recombinant viruses engineered to display the 2F5 epitope or full-length MPER in σ1 were recognized by purified 2F5 antibody. Inoculation of mice with 2F5-containing vectors or rabbits with 2F5- or MPER-containing vectors elicited anti-reovirus antibodies, but HIV-1-specific antibodies were not detected. Together, these findings indicate that heterologous sequences that form α-helices can functionally replace native sequences in the α-helical tail domain of reovirus attachment protein σ1. However, although these vectors retain native antigenicity, they were not immunogenic, illustrating the difficulty of experimentally inducing immune responses to this essential region of HIV-1. IMPORTANCE Vaccines to protect against HIV-1, the causative agent of AIDS, are not approved for use

  5. Features that shape CD8+ T-cell responses to viruses

    NARCIS (Netherlands)

    Correia de Almeida Fontaine Costa, A.I.

    2014-01-01

    CD8+ T cells, via their specific T-cell receptor (TCR), target infected cells when recognizing pathogen-derived peptides (epitopes) bound to class I major histocompatibility complex molecules (MHCI, or HLA-class I in humans). HLA-B is the most polymorphic of the classical HLA-I molecules. HLA-B-rest

  6. Multi-scale modeling of the CD8 immune response

    Science.gov (United States)

    Barbarroux, Loic; Michel, Philippe; Adimy, Mostafa; Crauste, Fabien

    2016-06-01

    During the primary CD8 T-Cell immune response to an intracellular pathogen, CD8 T-Cells undergo exponential proliferation and continuous differentiation, acquiring cytotoxic capabilities to address the infection and memorize the corresponding antigen. After cleaning the organism, the only CD8 T-Cells left are antigen-specific memory cells whose role is to respond stronger and faster in case they are presented this very same antigen again. That is how vaccines work: a small quantity of a weakened pathogen is introduced in the organism to trigger the primary response, generating corresponding memory cells in the process, giving the organism a way to defend himself in case it encounters the same pathogen again. To investigate this process, we propose a non linear, multi-scale mathematical model of the CD8 T-Cells immune response due to vaccination using a maturity structured partial differential equation. At the intracellular scale, the level of expression of key proteins is modeled by a delay differential equation system, which gives the speeds of maturation for each cell. The population of cells is modeled by a maturity structured equation whose speeds are given by the intracellular model. We focus here on building the model, as well as its asymptotic study. Finally, we display numerical simulations showing the model can reproduce the biological dynamics of the cell population for both the primary response and the secondary responses.

  7. Display of the Viral Epitopes on Lactococcus lactis: A Model for Food Grade Vaccine against EV71

    Directory of Open Access Journals (Sweden)

    Nadimpalli Ravi S. Varma

    2013-01-01

    Full Text Available In this study, we have developed a system for display of antigens of Enterovirus type 71 (EV71 on the cell surface of L. lactis. The viral capsid protein (VP1 gene from a local viral isolate was utilized as the candidate vaccine for the development of oral live vaccines against EV71 using L. lactis as a carrier. We expressed fusion proteins in E. coli and purified fusion proteins were incubated with L. lactis. We confirmed that mice orally fed with L. lactis displaying these fusion proteins on its surface were able to mount an immune response against the epitopes of EV71. This is the first example of an EV71 antigen displayed on the surface of a food grade organism and opens a new perspective for alternative vaccine strategies against the EV71. We believe that the method of protein docking utilized in this study will allow for more flexible presentations of short peptides and proteins on the surface of L. lactis to be useful as a delivery vehicle.

  8. Display of the Viral Epitopes on Lactococcus lactis: A Model for Food Grade Vaccine against EV71.

    Science.gov (United States)

    Varma, Nadimpalli Ravi S; Toosa, Haryanti; Foo, Hooi Ling; Alitheen, Noorjahan Banu Mohamed; Nor Shamsudin, Mariana; Arbab, Ali S; Yusoff, Khatijah; Abdul Rahim, Raha

    2013-01-01

    In this study, we have developed a system for display of antigens of Enterovirus type 71 (EV71) on the cell surface of L. lactis. The viral capsid protein (VP1) gene from a local viral isolate was utilized as the candidate vaccine for the development of oral live vaccines against EV71 using L. lactis as a carrier. We expressed fusion proteins in E. coli and purified fusion proteins were incubated with L. lactis. We confirmed that mice orally fed with L. lactis displaying these fusion proteins on its surface were able to mount an immune response against the epitopes of EV71. This is the first example of an EV71 antigen displayed on the surface of a food grade organism and opens a new perspective for alternative vaccine strategies against the EV71. We believe that the method of protein docking utilized in this study will allow for more flexible presentations of short peptides and proteins on the surface of L. lactis to be useful as a delivery vehicle.

  9. Schistosoma japonicum:Isolation and Identification of Peptides Mimicking Ferritin Epitopes from Phage Display Library

    Institute of Scientific and Technical Information of China (English)

    Lian-Fei TANG; Xin-Yuan YI; Xian-Fang ZENG; Lin-Qian WANG; Shun-Ke ZHANG

    2004-01-01

    In an attempt to isolate and identify the antigenic epitopes on ferritin of Schistosoma japonicum(SjFer)and to test their protective potentiality against Schistosomajaponicum(S.j),polyclonal antisera against SjFer was prepared to screen a 12-mer random peptide library.Three rounds of biopanning were performed and resulted in an enrichment.Six peptides selected randomly from the third elute were all found to be positive by evaluating the binding to anti-SjFer sera by ELISA and Western blotting.Three amino acid sequences were deduced from the six phage clones by sequencing.When they were used to vaccinate mice,the three peptides could induce significant reduction in adult worms(26.7% ,20.4%,and 25.9%)as well as in liver eggs per gram(LEPG)(40.0%,38.2%,and 40.8%).This result showed that three mimotopes on SjFer were obtained and they could induce significant protective efficacy against S.j.

  10. 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 show...

  11. Identification of two linear B-cell epitopes from West Nile virus NS1 by screening a phage-displayed random peptide library

    Directory of Open Access Journals (Sweden)

    Qin Yong-Li

    2011-07-01

    Full Text Available Abstract Background The West Nile virus (WNV nonstructural protein 1 (NS1 is an important antigenic protein that elicits protective antibody responses in animals and can be used for the serological diagnosis of WNV infection. Although previous work has demonstrated the vital role of WNV NS1-specific antibody responses, the specific epitopes in the NS1 have not been identified. Results The present study describes the identification of two linear B-cell epitopes in WNV NS1 through screening a phage-displayed random 12-mer peptide library with two monoclonal antibodies (mAbs 3C7 and 4D1 that directed against the NS1. The mAbs 3C7 and 4D1 recognized phages displaying peptides with the consensus motifs LTATTEK and VVDGPETKEC, respectively. Exact sequences of both motifs were found in the NS1 (895LTATTEK901 and 925VVDGPETKEC934. Further identification of the displayed B cell epitopes were conducted using a set of truncated peptides expressed as MBP fusion proteins. The data indicated that 896TATTEK901 and925VVDGPETKEC934 are minimal determinants of the linear B cell epitopes recognized by the mAbs 3C7 and 4D1, respectively. Antibodies present in the serum of WNV-positive horses recognized the minimal linear epitopes in Western blot analysis, indicating that the two peptides are antigenic in horses during infection. Furthermore, we found that the epitope recognized by 3C7 is conserved only among WNV strains, whereas the epitope recognized by 4D1 is a common motif shared among WNV and other members of Japanese encephalitis virus (JEV serocomplex. Conclusions We identified TATTEK and VVDGPETKEC as NS1-specific linear B-cell epitopes recognized by the mAbs 3C7 and 4D1, respectively. The knowledge and reagents generated in this study may have potential applications in differential diagnosis and the development of epitope-based marker vaccines against WNV and other viruses of JEV serocomplex.

  12. Mesenchymal stem cells differentially modulate effector CD8+ T cell subsets and exacerbate experimental autoimmune encephalomyelitis.

    Science.gov (United States)

    Glenn, Justin D; Smith, Matthew D; Calabresi, Peter A; Whartenby, Katharine A

    2014-10-01

    Mesenchymal stem cells (MSC) have emerged as a promising candidate for inflammatory suppression and disease amelioration, especially of neuro-inflammatory diseases such as multiple sclerosis (MS). Auto-reactive CD4+ and CD8+ T cells acquire pathogenic IFNγ-producing- (Type I) and IL-17A-producing- (Type 17) effector phenotypes in MS and its animal model experimental autoimmune encephalomyelitis (EAE). Although MSC have been extensively demonstrated to suppress pathogenic effector CD4+ T cells and CD4+ T cell-mediated EAE, surprisingly few studies have addressed their modulation of effector CD8+ T cells represented in MS or their impact on CD8+ T cell-mediated EAE. We find that MSC differentially modulate CD8+ T cell development depending on effector T cell subtype. MSC drive activated low-IFNγ producers toward an enhanced high-IFNγ Tc1-like phenotype but strongly inhibit the production of IL-17A and Tc17 polarization in vitro. These observations are underscored by differential MSC modulation of T cell activation, proliferation, and signature transcription factor up-regulation. In addition, effector CD8+ T cells co-cultured with MSC exhibited increased production of IL-2, a molecule known to enhance IFNγ, yet suppress IL-17A, production. Based on these in vitro effects on CD8+ T cells, we next evaluated their impact on the severity of EAE. To better evaluate CD8+ T cells, we immunized mice with MOG37-50 , which is a CD8-targeted epitope. Our results revealed a worsening of disease, consistent with their in vitro stimulation of Tc1 cells. These findings highlight the emerging duality of MSC in immune modulation and provide implications for their future use in immune-related diseases. PMID:24911892

  13. Decline of influenza-specific CD8+ T cell repertoire in healthy geriatric donors

    Directory of Open Access Journals (Sweden)

    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.

  14. Tumor necrosis factor alpha production from CD8+ T cells mediates oviduct pathological sequelae following primary genital Chlamydia muridarum infection.

    Science.gov (United States)

    Murthy, Ashlesh K; Li, Weidang; Chaganty, Bharat K R; Kamalakaran, Sangamithra; Guentzel, M Neal; Seshu, J; Forsthuber, Thomas G; Zhong, Guangming; Arulanandam, Bernard P

    2011-07-01

    The immunopathogenesis of Chlamydia trachomatis-induced oviduct pathological sequelae is not well understood. Mice genetically deficient in perforin (perforin(-/-) mice) or tumor necrosis factor alpha (TNF-α) production (TNF-α(-/-) mice) displayed comparable vaginal chlamydial clearance rates but significantly reduced oviduct pathology (hydrosalpinx) compared to that of wild-type mice. Since both perforin and TNF-α are effector mechanisms of CD8(+) T cells, we evaluated the role of CD8(+) T cells during genital Chlamydia muridarum infection and oviduct sequelae. Following vaginal chlamydial challenge, (i) mice deficient in TAP I (and therefore the major histocompatibility complex [MHC] I pathway and CD8(+) T cells), (ii) wild-type mice depleted of CD8(+) T cells, and (iii) mice genetically deficient in CD8 (CD8(-/-) mice) all displayed similar levels of vaginal chlamydial clearance but significantly reduced hydrosalpinx, compared to those of wild-type C57BL/6 mice, suggesting a role for CD8(+) T cells in chlamydial pathogenesis. Repletion of CD8(-/-) mice with wild-type or perforin(-/-), but not TNF-α(-/-), CD8(+) T cells at the time of challenge restored hydrosalpinx to levels observed in wild-type C57BL/6 mice, suggesting that TNF-α production from CD8(+) T cells is important for pathogenesis. Additionally, repletion of TNF-α(-/-) mice with TNF-α(+/+) CD8(+) T cells significantly enhanced the incidence of hydrosalpinx and oviduct dilatation compared to those of TNF-α(-/-) mice but not to the levels found in wild-type mice, suggesting that TNF-α production from CD8(+) T cells and non-CD8(+) cells cooperates to induce optimal oviduct pathology following genital chlamydial infection. These results provide compelling new evidence supporting the contribution of CD8(+) T cells and TNF-α production to Chlamydia-induced reproductive tract sequelae.

  15. Analysis of pectic epitopes recognised by hybridoma and phage display monoclonal antibodies using defined oligosaccharides, polysaccharides, and enzymatic degradation

    DEFF Research Database (Denmark)

    Willats, William George Tycho; Limberg, G.; Buchholt, H.C.;

    2000-01-01

    43) subject to fragmentation by endo-polygalacturonase II (PG II) and endo-pectin lyase (PL), was also studied. Time course analysis of PG II digestion of P41 revealed that JIM5 epitopes were rapidly degraded, but a low level of PAM1 and JIM7 epitopes existed even after extensive digestion......, indicating that some HG domains were more resistant to cleavage by PG II. The chromatographic separation of fragments produced by the complete digestion of P41 by pectin lyase indicated that a very restricted population of fragments contained the PAM1 epitope while a (1¿4)-ß- -galactan epitope occurring...

  16. HDAC1 controls CD8+ T cell homeostasis and antiviral response.

    Directory of Open Access Journals (Sweden)

    Roland Tschismarov

    Full Text Available Reversible lysine acetylation plays an important role in the regulation of T cell responses. HDAC1 has been shown to control peripheral T helper cells, however the role of HDAC1 in CD8+ T cell function remains elusive. By using conditional gene targeting approaches, we show that LckCre-mediated deletion of HDAC1 led to reduced numbers of thymocytes as well as peripheral T cells, and to an increased fraction of CD8+CD4- cells within the CD3/TCRβlo population, indicating that HDAC1 is essential for the efficient progression of immature CD8+CD4- cells to the DP stage. Moreover, CD44hi effector CD8+ T cells were enhanced in mice with a T cell-specific deletion of HDAC1 under homeostatic conditions and HDAC1-deficient CD44hi CD8+ T cells produced more IFNγ upon ex vivo PMA/ionomycin stimulation in comparison to wild-type cells. Naïve (CD44l°CD62L+ HDAC1-null CD8+ T cells displayed a normal proliferative response, produced similar amounts of IL-2 and TNFα, slightly enhanced amounts of IFNγ, and their in vivo cytotoxicity was normal in the absence of HDAC1. However, T cell-specific loss of HDAC1 led to a reduced anti-viral CD8+ T cell response upon LCMV infection and impaired expansion of virus-specific CD8+ T cells. Taken together, our data indicate that HDAC1 is required for the efficient generation of thymocytes and peripheral T cells, for proper CD8+ T cell homeostasis and for an efficient in vivo expansion and activation of CD8+ T cells in response to LCMV infection.

  17. Non-hematopoietic cells in lymph nodes drive memory CD8 T cell inflation during murine cytomegalovirus infection.

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    Nicole Torti

    2011-10-01

    Full Text Available During human and murine cytomegalovirus (MCMV infection an exceptionally large virus-specific CD8 T cell pool is maintained in the periphery lifelong. This anomalous response is only seen for specific subsets of MCMV-specific CD8 T cells which are referred to as 'inflationary T cells'. How memory CD8 T cell inflation is induced and maintained is unclear, though their activated phenotype strongly suggests an involvement of persistent antigen encounter during MCMV latency. To dissect the cellular and molecular requirements for memory CD8 T cell inflation, we have generated a transgenic mouse expressing an MHC class I-restricted T cell receptor specific for an immunodominant inflationary epitope of MCMV. Through a series of adoptive transfer experiments we found that memory inflation was completely dependent on antigen presentation by non-hematopoietic cells, which are also the predominant site of MCMV latency. In particular, non-hematopoietic cells selectively induced robust proliferation of inflationary CD8 T cells in lymph nodes, where a majority of the inflationary CD8 T cells exhibit a central-memory phenotype, but not in peripheral tissues, where terminally differentiated inflationary T cells accumulate. These results indicate that continuous restimulation of central memory CD8 T cells in the lymph nodes by infected non-hematopoietic cells ensures the maintenance of a functional effector CD8 T pool in the periphery, providing protection against viral reactivation events.

  18. Fully differentiated HIV-1 specific CD8+ T effector cells are more frequently detectable in controlled than in progressive HIV-1 infection.

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    Marylyn M Addo

    Full Text Available BACKGROUND: CD8+ T cells impact control of viral infections by direct elimination of infected cells and secretion of a number of soluble factors. In HIV-1 infection, persistent HIV-1 specific IFN-gamma+ CD8+ T cell responses are detected in the setting of disease progression, consistent with functional impairment in vivo. Recent data suggest that impaired maturation, as defined by the lineage markers CD45RA and CCR7, may contribute to a lack of immune control by these responses. METHODOLOGY/PRINCIPAL FINDINGS: We investigated the maturation phenotype of epitope-specific CD8+ T cell responses directed against HIV-1 in 42 chronically infected, untreated individuals, 22 of whom were "Controllers" (median 1140 RNA copies/ml plasma, range750000. Evaluation of a mean of 5 epitopes per person revealed that terminally differentiated CD8+ T cells directed against HIV-1 are more often seen in HIV-1 Controllers (16/22; 73% compared to HIV-1 progressors (7/20; 35%(p = 0.015, but the maturation state of epitope-specific responses within a given individual was quite variable. Maturation phenotype was independent of the HLA restriction or the specificity of a given CD8+ T cell response and individual epitopes associated with slow disease progression were not more likely to be terminally differentiated. CONCLUSIONS/SIGNIFICANCE: These data indicate that although full maturation of epitope-specific CD8+ T cell responses is associated with viral control, the maturation status of HIV-1 specific CD8+ T cell responses within a given individual are quite heterogeneous, suggesting epitope-specific influences on CD8+ T cell function.

  19. Adaptation of CD8 T cell responses to changing HIV-1 sequences in a cohort of HIV-1 infected individuals not selected for a certain HLA allele.

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    Julia Roider

    Full Text Available HIV evades CD8 T cell mediated pressure by viral escape mutations in targeted CD8 T cell epitopes. A viral escape mutation can lead to a decline of the respective CD8 T cell response. Our question was what happened after the decline of a CD8 T cell response and - in the case of viral escape - if a new CD8 T cell response towards the mutated antigen could be generated in a population not selected for certain HLA alleles. We studied 19 antiretroviral-naïve HIV-1 infected individuals with different disease courses longitudinally. A median number of 12 (range 2-24 CD8 T cell responses towards Gag and Nef were detected per study subject. A total of 30 declining CD8 T cell responses were studied in detail and viral sequence analyses showed amino acid changes in 25 (83% of these. Peptide titration assays and definition of optimal CD8 T cell epitopes revealed 12 viral escape mutations with one de-novo response (8%. The de-novo response, however, showed less effector functions than the original CD8 T cell response. In addition we identified 4 shifts in immunodominance. For one further shift in immunodominance, the mutations occurred outside the optimal epitope and might represent processing changes. Interestingly, four adaptations to the virus (the de-novo response and 3 shifts in immunodominance occurred in the group of chronically infected progressors. None of the subjects with adaptation to the changing virus carried the HLA alleles B57, B*58:01 or B27. Our results show that CD8 T cell responses adapt to the mutations of HIV. However it was limited to only 20% (5 out of 25 of the epitopes with viral sequence changes in a cohort not expressing protective HLA alleles.

  20. Adaptation of CD8 T cell responses to changing HIV-1 sequences in a cohort of HIV-1 infected individuals not selected for a certain HLA allele.

    Science.gov (United States)

    Roider, Julia; Kalteis, Anna-Lena; Vollbrecht, Thomas; Gloning, Lisa; Stirner, Renate; Henrich, Nadja; Bogner, Johannes R; Draenert, Rika

    2013-01-01

    HIV evades CD8 T cell mediated pressure by viral escape mutations in targeted CD8 T cell epitopes. A viral escape mutation can lead to a decline of the respective CD8 T cell response. Our question was what happened after the decline of a CD8 T cell response and - in the case of viral escape - if a new CD8 T cell response towards the mutated antigen could be generated in a population not selected for certain HLA alleles. We studied 19 antiretroviral-naïve HIV-1 infected individuals with different disease courses longitudinally. A median number of 12 (range 2-24) CD8 T cell responses towards Gag and Nef were detected per study subject. A total of 30 declining CD8 T cell responses were studied in detail and viral sequence analyses showed amino acid changes in 25 (83%) of these. Peptide titration assays and definition of optimal CD8 T cell epitopes revealed 12 viral escape mutations with one de-novo response (8%). The de-novo response, however, showed less effector functions than the original CD8 T cell response. In addition we identified 4 shifts in immunodominance. For one further shift in immunodominance, the mutations occurred outside the optimal epitope and might represent processing changes. Interestingly, four adaptations to the virus (the de-novo response and 3 shifts in immunodominance) occurred in the group of chronically infected progressors. None of the subjects with adaptation to the changing virus carried the HLA alleles B57, B*58:01 or B27. Our results show that CD8 T cell responses adapt to the mutations of HIV. However it was limited to only 20% (5 out of 25) of the epitopes with viral sequence changes in a cohort not expressing protective HLA alleles.

  1. DOCK8 deficiency impairs CD8 T cell survival and function in humans and mice

    Science.gov (United States)

    Randall, Katrina L.; Chan, Stephanie S.-Y.; Ma, Cindy S.; Fung, Ivan; Mei, Yan; Yabas, Mehmet; Tan, Andy; Arkwright, Peter D.; Al Suwairi, Wafaa; Lugo Reyes, Saul Oswaldo; Yamazaki-Nakashimada, Marco A.; de la Luz Garcia-Cruz, Maria; Smart, Joanne M.; Picard, Capucine; Okada, Satoshi; Jouanguy, Emmanuelle; Casanova, Jean-Laurent; Lambe, Teresa; Cornall, Richard J.; Russell, Sarah; Oliaro, Jane; Tangye, Stuart G.; Bertram, Edward M.

    2011-01-01

    In humans, DOCK8 immunodeficiency syndrome is characterized by severe cutaneous viral infections. Thus, CD8 T cell function may be compromised in the absence of DOCK8. In this study, by analyzing mutant mice and humans, we demonstrate a critical, intrinsic role for DOCK8 in peripheral CD8 T cell survival and function. DOCK8 mutation selectively diminished the abundance of circulating naive CD8 T cells in both species, and in DOCK8-deficient humans, most CD8 T cells displayed an exhausted CD45RA+CCR7− phenotype. Analyses in mice revealed the CD8 T cell abnormalities to be cell autonomous and primarily postthymic. DOCK8 mutant naive CD8 T cells had a shorter lifespan and, upon encounter with antigen on dendritic cells, exhibited poor LFA-1 synaptic polarization and a delay in the first cell division. Although DOCK8 mutant T cells underwent near-normal primary clonal expansion after primary infection with recombinant influenza virus in vivo, they showed greatly reduced memory cell persistence and recall. These findings highlight a key role for DOCK8 in the survival and function of human and mouse CD8 T cells. PMID:22006977

  2. A Numerically Subdominant CD8 T Cell Response to Matrix Protein of Respiratory Syncytial Virus Controls Infection with Limited Immunopathology.

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    Jie Liu

    2016-03-01

    Full Text Available CD8 T cells are involved in pathogen clearance and infection-induced pathology in respiratory syncytial virus (RSV infection. Studying bulk responses masks the contribution of individual CD8 T cell subsets to protective immunity and immunopathology. In particular, the roles of subdominant responses that are potentially beneficial to the host are rarely appreciated when the focus is on magnitude instead of quality of response. Here, by evaluating CD8 T cell responses in CB6F1 hybrid mice, in which multiple epitopes are recognized, we found that a numerically subdominant CD8 T cell response against DbM187 epitope of the virus matrix protein expressed high avidity TCR and enhanced signaling pathways associated with CD8 T cell effector functions. Each DbM187 T effector cell lysed more infected targets on a per cell basis than the numerically dominant KdM282 T cells, and controlled virus replication more efficiently with less pulmonary inflammation and illness than the previously well-characterized KdM282 T cell response. Our data suggest that the clinical outcome of viral infections is determined by the integrated functional properties of a variety of responding CD8 T cells, and that the highest magnitude response may not necessarily be the best in terms of benefit to the host. Understanding how to induce highly efficient and functional T cells would inform strategies for designing vaccines intended to provide T cell-mediated immunity.

  3. Qualitative and quantitative analysis of adenovirus type 5 vector-induced memory CD8 T cells

    DEFF Research Database (Denmark)

    Steffensen, Maria Abildgaard; Holst, Peter Johannes; Steengaard, Sanne Skovvang;

    2013-01-01

    It has been reported that adenovirus (Ad) primed CD8 T cells may display a distinct and partially exhausted phenotype. Given the practical implications of this claim, we decided to analyze in detail the quality of Ad-primed CD8 T cells directly comparing these cells to CD8 T cells induced through...... adenoviral boosting and, importantly, the generated secondary memory cells cannot be qualitatively differentiated from those induced by primary infection with replicating virus. Quantitatively, DNA priming prior to Ad-vaccination will lead to even higher numbers of memory cells. In this case, the vaccination...... an effective means to induce a substantially expanded, long-lived population of high-quality transgene-specific memory CD8 T cells....

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

    Directory of Open Access Journals (Sweden)

    2005-12-01

    Full Text Available 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 and intact proliferative capacity. Individuals tested many years after infection exhibited lower frequencies of B19-specific cytotoxic T lymphocytes, typically 0.05%-0.5% of CD8+ T cells, which were perforin, CD38, and CCR7 low. CONCLUSION: This is the first example to our knowledge of an "acute" human viral infection inducing a persistent activated CD8+ T cell response. The likely explanation--analogous to that for cytomegalovirus infection--is that this persistent response is due to low-level antigen exposure. CD8+ T cells may contribute to the long-term control of this significant pathogen and should be considered during vaccine development.

  5. 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...

  6. Characterization and functional analyses of a novel chicken CD8α variant X1 (CD8α1).

    Science.gov (United States)

    Truong, A D; Ban, J; Park, B; Hong, Y H; Lillehoj, H S

    2016-07-01

    We provide the first description of cloning and of structural and functional analysis of a novel variant in the chicken cluster of differentiation 8 alpha (CD8a) family, termed the CD8α X1 (CD8α1) gene. Multiple alignments of CD8α1 with known CD8α and CD8β sequences of other species revealed relatively low conservation of AA residues involved in the specific and unique structural domains among CD8α genes. For example, cysteine residues that are involved in disulfide bonding to form the V domain are conserved. In contrast, the O-linked glycosylation sites (XPXX motif) are not found in the chicken CD8α1 sequence, and the A β strand and complementarity-determining region 1 and 2 sequences are poorly conserved between chicken CD8α1 and avian CD8α. Furthermore, the alignment showed that the transmembrane regions show relatively high sequence similarity, whereas the cytoplasmic regions show relatively low similarity, indicating poor conservation. Moreover, the motif (CXCP) that is thought to be responsible for binding the p56 lymphocyte cell kinase subunit (p56) is missing in the CD8α1 sequence. The chicken CD8α1 genomic structure is similar to that of chicken CD8α, but their protein structures differ. Phylogenetic analysis showed that chicken CD8α1 grouped with known avian CD8α sequences but was somewhat distantly related to the CD8α molecules of other species. Moreover, we analyzed the signal transduction and cytokine response to CD8α1 treatment to determine the specific biological functions of chicken CD8α1 in immune cells. The results showed that chicken CD8α1 is a key regulator of the expression of genes that are associated and cooperate with transcription factors in the major histocompatibility complex class I and II promoter regions and activates Janus kinase (JAK) 1/2, signal transducer and activator of transcription (STAT), and suppressor of cytokine signaling (SOCS) 1 signaling-related genes. Immune cells that express functional CD8α1 induce

  7. 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....

  8. Variable epitope library carrying heavily mutated survivin-derived CTL epitope variants as a new class of efficient vaccine immunogen tested in a mouse model of breast cancer.

    Science.gov (United States)

    NoeDominguez-Romero, Allan; Zamora-Alvarado, Rubén; Servín-Blanco, Rodolfo; Pérez-Hernández, Erendira G; Castrillon-Rivera, Laura E; Munguia, Maria Elena; Acero, Gonzalo; Govezensky, Tzipe; Gevorkian, Goar; Manoutcharian, Karen

    2014-01-01

    The antigenic variability of tumor cells leading to dynamic changes in cancer epitope landscape along with escape from immune surveillance by down-regulating tumor antigen expression/presentation and immune tolerance are major obstacles for the design of effective vaccines. We have developed a novel concept for immunogen construction based on introduction of massive mutations within the epitopes targeting antigenically variable pathogens and diseases. Previously, we showed that these immunogens carrying large combinatorial libraries of mutated epitope variants, termed as variable epitope libraries (VELs), induce potent, broad and long lasting CD8+IFN-γ+ T-cell response as well as HIV-neutralizing antibodies. In this proof-of-concept study, we tested immunogenic properties and anti-tumor effects of the VELs bearing survivin-derived CTL epitope (GWEPDDNPI) variants in an aggressive metastatic mouse 4T1 breast tumor model. The constructed VELs had complexities of 10,500 and 8,000 individual members, generated as combinatorial M13 phage display and synthetic peptide libraries, respectively, with structural composition GWXPXDXPI, where X is any of 20 natural amino acids. Statistically significant tumor growth inhibition was observed in BALB/c mice immunized with the VELs in both prophylactic and therapeutic settings. Vaccinated mice developed epitope-specific spleen cell and CD8+ IFN-γ+ T-cell responses that recognize more than 50% of the panel of 87 mutated epitope variants, as demonstrated in T-cell proliferation assays and FACS analysis. These data indicate the feasibility of the application of this new class of immunogens based on VEL concept as an alternative approach for the development of molecular vaccines against cancer.

  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. Induction of humoral and cell-mediated immune responses by hepatitis B virus epitope displayed on the virus-like particles of prawn nodavirus.

    Science.gov (United States)

    Yong, Chean Yeah; Yeap, Swee Keong; Goh, Zee Hong; Ho, Kok Lian; Omar, Abdul Rahman; Tan, Wen Siang

    2015-02-01

    Hepatitis B virus (HBV) is a deadly pathogen that has killed countless people worldwide. Saccharomyces cerevisiae-derived HBV vaccines based upon hepatitis B surface antigen (HBsAg) is highly effective. However, the emergence of vaccine escape mutants due to mutations on the HBsAg and polymerase genes has produced a continuous need for the development of new HBV vaccines. In this study, the "a" determinant within HBsAg was displayed on the recombinant capsid protein of Macrobrachium rosenbergii nodavirus (MrNV), which can be purified easily in a single step through immobilized metal affinity chromatography (IMAC). The purified protein self-assembled into virus-like particles (VLPs) when observed under a transmission electron microscope (TEM). Immunization of BALB/c mice with this chimeric protein induced specific antibodies against the "a" determinant. In addition, it induced significantly more natural killer and cytotoxic T cells, as well as an increase in interferon gamma (IFN-γ) secretion, which are vital for virus clearance. Collectively, these findings demonstrated that the MrNV capsid protein is a potential carrier for the HBV "a" determinant, which can be further extended to display other foreign epitopes. This paper is the first to report the application of MrNV VLPs as a novel platform to display foreign epitopes. PMID:25416760

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

    Science.gov (United States)

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

    2005-10-01

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

  12. Secretion of Interleukin-17 by CD8+ T Cells Expressing CD146 (MCAM)

    OpenAIRE

    Dagur, Pradeep K; Biancotto, Angélique; Stansky, Elena; Sen, H. Nida; Nussenblatt, Robert B.; McCoy, J. Philip

    2014-01-01

    Interleukin-17 (IL-17) has been associated with the pathogenesis of numerous autoimmune diseases. CD4+ T cells secreting IL-17 are termed Th17 cells. CD8+ T cells, designated Tc17 cells, are also capable of secreting IL-17. Here we describe a population of Tc17 cells characterized by the expression of surface CD146, an endothelial adhesion molecule. These cells display signatures of a human Tc17 genotype and phenotype. Circulating CD8+CD146+ T cells are present in low levels in healthy adults...

  13. Clonal expansions of CD8+ T cells with IL-10 secreting capacity occur during chronic Mycobacterium tuberculosis infection.

    Directory of Open Access Journals (Sweden)

    Joshua C Cyktor

    Full Text Available The exact role of CD8(+ T cells during Mycobacterium tuberculosis (Mtb infection has been heavily debated, yet it is generally accepted that CD8(+ T cells contribute to protection against Mtb. In this study, however, we show that the Mtb-susceptible CBA/J mouse strain accumulates large numbers of CD8(+ T cells in the lung as infection progresses, and that these cells display a dysfunctional and immunosuppressive phenotype (PD-1(+, Tim-3(+, CD122(+. CD8(+ T cell expansions from the lungs of Mtb-infected CBA/J mice were also capable of secreting the immunosuppressive cytokine interleukin-10 (IL-10, although in vivo CD8(+ T cell depletion did not significantly alter Mtb burden. Further analysis revealed that pulmonary CD8(+ T cells from Mtb-infected CBA/J mice were clonally expanded, preferentially expressing T cell receptor (TcR Vβ chain 8 (8.2, 8.3 or Vβ 14. Although Vβ8(+ CD8(+ T cells were responsible for the majority of IL-10 production, in vivo depletion of Vβ8(+ did not significantly change the outcome of Mtb infection, which we hypothesize was a consequence of their dual IL-10/IFN-γ secreting profiles. Our data demonstrate that IL-10-secreting CD8(+ T cells can arise during chronic Mtb infection, although the significance of this T cell population in tuberculosis pathogenesis remains unclear.

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

    Directory of Open Access Journals (Sweden)

    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.

  15. Consensus nomenclature for CD8+ T cell phenotypes in cancer

    Science.gov (United States)

    Apetoh, Lionel; Smyth, Mark J.; Drake, Charles G.; Abastado, Jean-Pierre; Apte, Ron N.; Ayyoub, Maha; Blay, Jean-Yves; Bonneville, Marc; Butterfield, Lisa H.; Caignard, Anne; Castelli, Chiara; Cavallo, Federica; Celis, Esteban; Chen, Lieping; Colombo, Mario P.; Comin-Anduix, Begoña; Coukos, Georges; Dhodapkar, Madhav V.; Dranoff, Glenn; Frazer, Ian H.; Fridman, Wolf-Hervé; Gabrilovich, Dmitry I.; Gilboa, Eli; Gnjatic, Sacha; Jäger, Dirk; Kalinski, Pawel; Kaufman, Howard L.; Kiessling, Rolf; Kirkwood, John; Knuth, Alexander; Liblau, Roland; Lotze, Michael T.; Lugli, Enrico; Marincola, Francesco; Melero, Ignacio; Melief, Cornelis J.; Mempel, Thorsten R.; Mittendorf, Elizabeth A.; Odun, Kunle; Overwijk, Willem W.; Palucka, Anna Karolina; Parmiani, Giorgio; Ribas, Antoni; Romero, Pedro; Schreiber, Robert D.; Schuler, Gerold; Srivastava, Pramod K.; Tartour, Eric; Valmori, Danila; van der Burg, Sjoerd H.; van der Bruggen, Pierre; van den Eynde, Benoît J.; Wang, Ena; Zou, Weiping; Whiteside, Theresa L.; Speiser, Daniel E.; Pardoll, Drew M.; Restifo, Nicholas P.; Anderson, Ana C.

    2015-01-01

    Whereas preclinical investigations and clinical studies have established that CD8+ T cells can profoundly affect cancer progression, the underlying mechanisms are still elusive. Challenging the prevalent view that the beneficial effect of CD8+ T cells in cancer is solely attributable to their cytotoxic activity, several reports have indicated that the ability of CD8+ T cells to promote tumor regression is dependent on their cytokine secretion profile and their ability to self-renew. Evidence has also shown that the tumor microenvironment can disarm CD8+ T cell immunity, leading to the emergence of dysfunctional CD8+ T cells. The existence of different types of CD8+ T cells in cancer calls for a more precise definition of the CD8+ T cell immune phenotypes in cancer and the abandonment of the generic terms “pro-tumor” and “antitumor.” Based on recent studies investigating the functions of CD8+ T cells in cancer, we here propose some guidelines to precisely define the functional states of CD8+ T cells in cancer. PMID:26137416

  16. Masked selection: a straightforward and flexible approach for the selection of binders against specific epitopes and differentially expressed proteins by phage display.

    Science.gov (United States)

    Even-Desrumeaux, Klervi; Nevoltris, Damien; Lavaut, Marie Noelle; Alim, Karima; Borg, Jean-Paul; Audebert, Stéphane; Kerfelec, Brigitte; Baty, Daniel; Chames, Patrick

    2014-02-01

    Phage display is a well-established procedure to isolate binders against a wide variety of antigens that can be performed on purified antigens, but also on intact cells. As selection steps are performed in vitro, it is possible to focus the outcome of the selection on relevant epitopes by performing some additional steps, such as depletion or competitive elutions. However in practice, the efficiency of these steps is often limited and can lead to inconsistent results. We have designed a new selection method named masked selection, based on the blockade of unwanted epitopes to favor the targeting of relevant ones. We demonstrate the efficiency and flexibility of this method by selecting single-domain antibodies against a specific portion of a fusion protein, by selecting binders against several members of the seven transmembrane receptor family using transfected HEK cells, or by selecting binders against unknown breast cancer markers not expressed on normal samples. The relevance of this approach for antibody-based therapies was further validated by the identification of four of these markers, Epithelial cell adhesion molecule, Transferrin receptor 1, Metastasis cell adhesion molecule, and Sushi containing domain 2, using immunoprecipitation and mass spectrometry. This new phage display strategy can be applied to any type of antibody fragments or alternative scaffolds, and is especially suited for the rapid discovery and identification of cell surface markers. PMID:24361863

  17. 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.

  18. Thymic Nurse Cells Support CD4-CD8+ Thymocytes to Differentiate into CD4+CD8+ Cells

    Institute of Scientific and Technical Information of China (English)

    Aidong Li; Xueli Liu; Baochun Duan; Jie Ma

    2005-01-01

    Thymic nurse cells (TNCs) represent a unique microenvironment in the thymus for T cell maturation. In order to investigate the role of thymic nurse cells during T cell differentiation, a TNC clone, RWTE-1, which formed a typical complex with fetal thymocytes in vitro was established from normal Wistar rat. Hanging drop culture method was applied to reveal the interaction between TNCs and thymocytes. Our result revealed that eighty percent of immature CD4-CD8+ cells differentiated into CD4+CD8+ cells after a 12-hour hanging drop culture with RWTE-1. However, in a 12-hour culture of immature CD4-CD8+ cells with or without RWTE-1 supernatant, only 30% of the cells differentiated into CD4+CD8+ cells spontaneously. This observation led to the conclusion that RWTE-1 cell has the capacity to facilitate immature CD4-CD8+ thymocytes to differentiate into CD4+CD8+ T cells by direct interaction.

  19. Targeted suppression of autoreactive CD8+ T-cell activation using blocking anti-CD8 antibodies

    Science.gov (United States)

    Clement, Mathew; Pearson, James A.; Gras, Stephanie; van den Berg, Hugo A.; Lissina, Anya; Llewellyn-Lacey, Sian; Willis, Mark D.; Dockree, Tamsin; McLaren, James E.; Ekeruche-Makinde, Julia; Gostick, Emma; Robertson, Neil P.; Rossjohn, Jamie; Burrows, Scott R.; Price, David A.; Wong, F. Susan; Peakman, Mark; Skowera, Ania; Wooldridge, Linda

    2016-01-01

    CD8+ T-cells play a role in the pathogenesis of autoimmune diseases such as multiple sclerosis and type 1 diabetes. However, drugs that target the entire CD8+ T-cell population are not desirable because the associated lack of specificity can lead to unwanted consequences, most notably an enhanced susceptibility to infection. Here, we show that autoreactive CD8+ T-cells are highly dependent on CD8 for ligand-induced activation via the T-cell receptor (TCR). In contrast, pathogen-specific CD8+ T-cells are relatively CD8-independent. These generic differences relate to an intrinsic dichotomy that segregates self-derived and exogenous antigen-specific TCRs according to the monomeric interaction affinity with cognate peptide-major histocompatibility complex class I (pMHCI). As a consequence, “blocking” anti-CD8 antibodies can suppress autoreactive CD8+ T-cell activation in a relatively selective manner. These findings provide a rational basis for the development and in vivo assessment of novel therapeutic strategies that preferentially target disease-relevant autoimmune responses within the CD8+ T-cell compartment. PMID:27748447

  20. Bystander CD8 T-Cell-Mediated Demyelination is Interferon-γ-Dependent in a Coronavirus Model of Multiple Sclerosis

    OpenAIRE

    Dandekar, Ajai A.; Anghelina, Daniela; Perlman, Stanley

    2004-01-01

    Mice infected with the coronavirus mouse hepatitis virus, strain JHM (JHM) develop a disease that shares many histological characteristics with multiple sclerosis. We previously demonstrated that JHM-infected mice that only have CD8 T cells specific for an epitope not in the virus develop demyelination on specific activation of these cells. Herein we show that this process of bystander T-cell-mediated demyelination is interferon-γ (IFN-γ)-dependent. The absence of IFN-γ abrogated demyelinatio...

  1. 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

    The association between HLA-B 2705 and the immune control of human immunodeficiency virus type 1 (HIV-1) has previously been linked to the targeting of the HLA-B 2705-restricted Gag epitope KRWIILGLNK (KK10) by CD8(+) T cells. In order to better define the mechanisms of the HLA-B 2705 immune...... 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...... 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...

  2. 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.

  3. 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

  4. CD8+ TCR repertoire formation is guided primarily by the peptide component of the antigenic complex.

    Science.gov (United States)

    Koning, Dan; Costa, Ana I; Hoof, Ilka; Miles, John J; Nanlohy, Nening M; Ladell, Kristin; Matthews, Katherine K; Venturi, Vanessa; Schellens, Ingrid M M; Borghans, Jose A M; Kesmir, Can; Price, David A; van Baarle, Debbie

    2013-02-01

    CD8(+) T cells recognize infected or dysregulated cells via the clonotypically expressed αβ TCR, which engages Ag in the form of peptide bound to MHC class I (MHC I) on the target cell surface. Previous studies have indicated that a diverse Ag-specific TCR repertoire can be beneficial to the host, yet the determinants of clonotypic diversity are poorly defined. To better understand the factors that govern TCR repertoire formation, we conducted a comprehensive clonotypic analysis of CD8(+) T cell populations directed against epitopes derived from EBV and CMV. Neither pathogen source nor the restricting MHC I molecule were linked with TCR diversity; indeed, both HLA-A and HLA-B molecules were observed to interact with an overlapping repertoire of expressed TRBV genes. Peptide specificity, however, markedly impacted TCR diversity. In addition, distinct peptides sharing HLA restriction and viral origin mobilized TCR repertoires with distinct patterns of TRBV gene usage. Notably, no relationship was observed between immunodominance and TCR diversity. These findings provide new insights into the forces that shape the Ag-specific TCR repertoire in vivo and highlight a determinative role for the peptide component of the peptide-MHC I complex on the molecular frontline of CD8(+) T cell-mediated immune surveillance.

  5. Secretion of interleukin-17 by CD8+ T cells expressing CD146 (MCAM).

    Science.gov (United States)

    Dagur, Pradeep K; Biancotto, Angélique; Stansky, Elena; Sen, H Nida; Nussenblatt, Robert B; McCoy, J Philip

    2014-01-01

    Interleukin-17 (IL-17) has been associated with the pathogenesis of numerous autoimmune diseases. CD4+ T cells secreting IL-17 are termed Th17 cells. CD8+ T cells, designated Tc17 cells, are also capable of secreting IL-17. Here we describe a population of Tc17 cells characterized by the expression of surface CD146, an endothelial adhesion molecule. These cells display signatures of a human Tc17 genotype and phenotype. Circulating CD8+CD146+ T cells are present in low levels in healthy adults. Elevations in CD8+CD146+ T cells are found in Behcet's disease and birdshot retinochoroidopathy, which have been reported to have HLA class I associations. Sarcoidosis does not have a class I association and displays an increase in CD4+ CD146+ T cells but not in CD8+CD146+ T cells. CD146 on these cells may facilitate their ability to bind to, and migrate through, endothelium, as has been reported for CD4+CD146+ T cells. PMID:24681356

  6. A conformational epitope mapped in the bovine herpesvirus type 1 envelope glycoprotein B by phage display and the HSV-1 3D structure.

    Science.gov (United States)

    Almeida, Greyciele R; Goulart, Luiz Ricardo; Cunha-Junior, Jair P; Bataus, Luiz A M; Japolla, Greice; Brito, Wilia M E D; Campos, Ivan T N; Ribeiro, Cristina; Souza, Guilherme R L

    2015-08-01

    The selected dodecapeptide (1)DRALYGPTVIDH(12) from a phage-displayed peptide library and the crystal structure of the envelope glycoprotein B (Env gB) from Herpes Simplex Virus type 1 (HSV-1) led us to the identification of a new discontinuous epitope on the Bovine herpesvirus type 1 (BoHV-1) Env gB. In silico analysis revealed a short BoHV-1 gB motif ((338)YKRD(341)) within a epitope region, with a high similarity to the motifs shared by the dodecapeptide N-terminal region ((5)YxARD(1)) and HSV-1 Env gB ((326)YARD(329)), in which the (328)Arg residue is described to be a neutralizing antibody target. Besides the characterization of an antibody-binding site of the BoHV-1 Env gB, we have demonstrated that the phage-fused peptide has the potential to be used as a reagent for virus diagnosis by phage-ELISA assay, which discriminated BoHV-1 infected serum samples from negative ones. PMID:26267086

  7. Abnormal distribution of CD8 subpopulation in B-chronic lymphocytic leukemia identified by flow cytometry

    NARCIS (Netherlands)

    Terstappen, L.W.M.M.; Grooth, de B.G.; Berkel, van W.; Napel, ten C.H.H.

    1988-01-01

    We studied the occurrence of T-cell subpopulations for patients with B-cell chronic lymphocytic leukemia. The CD8+ population was divided into CD8+ suppressor (CD8a+) and CD8+ cytotoxic (CD8b+) lymphocytes using difference in orthogonal light scattering. Average CD4+/CD8+ratios determined for all p

  8. Induction of Specific CD8+ T Cells against Intracellular Bacteria by CD8+ T-Cell-Oriented Immunization Approaches

    Directory of Open Access Journals (Sweden)

    Toshi Nagata

    2010-01-01

    Full Text Available For protection against intracellular bacteria such as Mycobacterium tuberculosis and Listeria monocytogenes, the cellular arm of adaptive immunity is necessary. A variety of immunization methods have been evaluated and are reported to induce specific CD8+ T cells against intracellular bacterial infection. Modified BCG vaccines have been examined to enhance CD8+ T-cell responses. Naked DNA vaccination is a promising strategy to induce CD8+ T cells. In addition to this strategy, live attenuated intracellular bacteria such as Shigella, Salmonella, and Listeria have been utilized as carriers of DNA vaccines in animal models. Vaccination with dendritic cells pulsed with antigenic peptides or the cells introduced antigen genes by virus vectors such as retroviruses is also a powerful strategy. Furthermore, vaccination with recombinant lentivirus has been attempted to induce specific CD8+ T cells. Combinations of these strategies (prime-boost immunization have been studied for the efficient induction of intracellular bacteria-specific CD8+ T cells.

  9. 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; Jeffery, K; Broliden, 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...

  10. Associations of HLA-A, HLA-B and HLA-C Alleles Frequency with Prevalence of Herpes Simplex Virus Infections and Diseases Across Global Populations: Implication for the Development of an Universal CD8+ T-Cell Epitope-Based Vaccine

    Science.gov (United States)

    Samandary, Sarah; Kridane-Miledi, Hédia; Sandoval, Jacqueline S.; Choudhury, Zareen; Langa-Vives, Francina; Spencer, Doran; Chentoufi, Aziz A.; Lemonnier, François A.; BenMohamed, Lbachir

    2014-01-01

    A significant portion of the world’s population is infected with herpes simplex virus type 1 and/or type 2 (HSV-1 and/or HSV-2), that cause a wide range of diseases including genital herpes, oro-facial herpes, and the potentially blinding ocular herpes. While the global prevalence and distribution of HSV-1 and HSV-2 infections cannot be exactly established, the general trends indicate that: (i) HSV-1 infections are much more prevalent globally than HSV-2; (ii) Over half billion people worldwide are infected with HSV-2; (iii) the sub-Saharan African populations account for a disproportionate burden of genital herpes infections and diseases; (iv) the dramatic differences in the prevalence of herpes infections between regions of the world appear to be associated with differences in the frequencies of human leukocyte antigen (HLA) alleles. The present report: (i) analyzes the prevalence of HSV-1 and HSV-2 infections across various regions of the world; (ii) analyzes potential associations of common HLA-A, HLA-B and HLA-C alleles with the prevalence of HSV-1 and HSV-2 infections in the Caucasoid, Oriental, Hispanic and Black major populations; and (iii) discusses how our recently developed HLA-A, HLA-B, and HLA-C transgenic/H-2 class I null mice will help validate HLA/herpes prevalence associations. Overall, high prevalence of herpes infection and disease appears to be associated with high frequency of HLA-A*24, HLA-B*27, HLA-B*53 and HLA-B*58 alleles. In contrast, low prevalence of herpes infection and disease appears to be associated with high frequency of HLA-B*44 allele. The finding will aid in developing a T-cell epitope-based universal herpes vaccine and immunotherapy. PMID:24798939

  11. Specific Control of Immunity by Regulatory CD8 T Cells

    Institute of Scientific and Technical Information of China (English)

    XiaoleiTang; TrevorRFSmith

    2005-01-01

    T lymphocytes with dedicated suppressor function (Treg) play a crucial role in the homeostatic control of immunity in the periphery. Several Treg phenotypes have now been identified in the CD4 and CD8 T cell populations, suggesting their down-regulatory function in both human and animal models of autoimmunity, transplantation and tumor immunity. Here we will focus on the CD8 Treg population and their ability to specifically inhibit a pathogenic autoimmune response. This review will detail the current advances in the knowledge of CD8 Treg in the context of antigen specificity, phenotype, MHC restriction, mechanism of action, and priming. Cellular & Molecular Immunology. 2005;2(1):11-19.

  12. Characterization of CD8+ T cell differentiation following SIVΔnef vaccination by transcription factor expression profiling.

    Directory of Open Access Journals (Sweden)

    James M Billingsley

    2015-03-01

    Full Text Available The onset of protective immunity against pathogenic SIV challenge in SIVΔnef-vaccinated macaques is delayed for 15-20 weeks, a process that is related to qualitative changes in CD8+ T cell responses induced by SIVΔnef. As a novel approach to characterize cell differentiation following vaccination, we used multi-target qPCR to measure transcription factor expression in naïve and memory subsets of CD8++ T cells, and in SIV-specific CD8+ T cells obtained from SIVΔnef-vaccinated or wild type SIVmac239-infected macaques. Unsupervised clustering of expression profiles organized naïve and memory CD8+ T cells into groups concordant with cell surface phenotype. Transcription factor expression patterns in SIV-specific CD8+ T cells in SIVΔnef-vaccinated animals were distinct from those observed in purified CD8+ T cell subsets obtained from naïve animals, and were intermediate to expression profiles of purified central memory and effector memory T cells. Expression of transcription factors elicited by SIVΔnef vaccination also varied over time: cells obtained at later time points, temporally associated with greater protection, appeared more central-memory like than cells obtained at earlier time points, which appeared more effector memory-like. Expression of transcription factors associated with effector differentiation, such as ID2 and RUNX3, were decreased over time, while expression of transcription factors associated with quiescence or memory differentiation, such as TCF7, BCOR and EOMES, increased. CD8+ T cells specific for a more conserved epitope expressed higher levels of TBX21 and BATF, and appeared more effector-like than cells specific for an escaped epitope, consistent with continued activation by replicating vaccine virus. These data suggest transcription factor expression profiling is a novel method that can provide additional data complementary to the analysis of memory cell differentiation based on classical phenotypic markers

  13. 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.

  14. Production and Evaluation of Virus-Like Particles Displaying Immunogenic Epitopes of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV

    Directory of Open Access Journals (Sweden)

    Ambika Mosale Venkatesh Murthy

    2015-04-01

    Full Text Available Porcine reproductive and respiratory syndrome (PRRS is the most significant infectious disease currently affecting the swine industry worldwide. Several inactivated and modified live vaccines (MLV have been developed to curb PRRSV infections. However, the efficacy and safety of these vaccines are unsatisfactory, and hence, there is a strong demand for the development of new PRRS universal vaccines. Virus-like particle (VLP-based vaccines are gaining increasing acceptance compared to subunit vaccines, as they present the antigens in a more veritable conformation and are readily recognized by the immune system. Hepatitis B virus core antigen (HBcAg has been successfully used as a carrier for more than 100 viral sequences. In this study, hybrid HBcAg VLPs were generated by fusion of the conserved protective epitopes of PRRSV and expressed in E. coli. An optimized purification protocol was developed to obtain hybrid HBcAg VLP protein from the inclusion bodies. This hybrid HBcAg VLP protein self-assembled to 23-nm VLPs that were shown to block virus infection of susceptible cells when tested on MARC 145 cells. Together with the safety of non-infectious and non-replicable VLPs and the low cost of production through E. coli fermentation, this hybrid VLP could be a promising vaccine candidate for PRRS.

  15. Production and evaluation of virus-like particles displaying immunogenic epitopes of porcine reproductive and respiratory syndrome virus (PRRSV).

    Science.gov (United States)

    Murthy, Ambika Mosale Venkatesh; Ni, Yanyan; Meng, Xiangjin; Zhang, Chenming

    2015-01-01

    Porcine reproductive and respiratory syndrome (PRRS) is the most significant infectious disease currently affecting the swine industry worldwide. Several inactivated and modified live vaccines (MLV) have been developed to curb PRRSV infections. However, the efficacy and safety of these vaccines are unsatisfactory, and hence, there is a strong demand for the development of new PRRS universal vaccines. Virus-like particle (VLP)-based vaccines are gaining increasing acceptance compared to subunit vaccines, as they present the antigens in a more veritable conformation and are readily recognized by the immune system. Hepatitis B virus core antigen (HBcAg) has been successfully used as a carrier for more than 100 viral sequences. In this study, hybrid HBcAg VLPs were generated by fusion of the conserved protective epitopes of PRRSV and expressed in E. coli. An optimized purification protocol was developed to obtain hybrid HBcAg VLP protein from the inclusion bodies. This hybrid HBcAg VLP protein self-assembled to 23-nm VLPs that were shown to block virus infection of susceptible cells when tested on MARC 145 cells. Together with the safety of non-infectious and non-replicable VLPs and the low cost of production through E. coli fermentation, this hybrid VLP could be a promising vaccine candidate for PRRS. PMID:25874763

  16. Identification and HLA-Tetramer-Validation of Human CD4(+) and CD8(+) T Cell Responses against HCMV Proteins IE1 and IE2

    DEFF Research Database (Denmark)

    Braendstrup, Peter; Mortensen, Bo Kok; Justesen, Sune Frederik Lamdahl;

    2014-01-01

    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......-typed, donors were screened by ex vivo IFN-gamma 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...... 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....

  17. Generation and Regulation of CD8+ Regulatory T Cells

    Institute of Scientific and Technical Information of China (English)

    Linrong Lu; Harvey Cantor

    2008-01-01

    Research into the suppressive activity of CD4+FoxP3+ T regulatory cells (Treg) has defined a sublineage of CD4+ cells that contribute to self-tolerance and resistance to autoimmune disease. Much less attention has been given to the potential contribution of regulatory sublineages of CD8+ cells. Analysis of a small fraction of CD8+ cells that target autoreactive CD4+ cells through recognition of the MHC class Ib molecule Qa-1 in mouse and HLA-E in human has revitalized interest in CD8+ Treg. Here we summarize recent progress and future directions of research into the role of this CD8+ sublineage in resistance to autoimmune disease. Cellular & Molecular Immunology. 2008;5(6):401-406.

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

    Directory of Open Access Journals (Sweden)

    Bueno V.

    2002-01-01

    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. CD8 chemokine receptors in chronic obstructive pulmonary disease

    DEFF Research Database (Denmark)

    Smyth, L J C; Starkey, C; Gordon, F S;

    2008-01-01

    Increased lung CD8 cells and their expression of chemokine receptors CXCR3 and CCR5 have been previously reported in chronic obstructive pulmonary disease (COPD). Alterations of CD8-CCR3 and -CCR4 expression and their ligands in COPD patients have not been fully investigated. The objective......, smokers and healthy non-smokers (HNS). CCL5 and CCL11 levels were measured in BAL, and from the supernatants of lung resection explant cultures. CD8-CCR3 and -CCR5 expression (means) were increased in COPD patients (22% and 46% respectively) and smokers (20% and 45%) compared with HNS (3% and 22%); P ....05 for all comparisons. CD3CXCR3 expression was raised in smokers and COPD while CD8CXCR3 and CD3 and CD8 CCR4 expression was similar between groups. CD8CCR5 expression correlated to smoking pack years (r = 0.42, P = 0.01). COPD explants released more CCL5 compared with smokers (P = 0.02), while...

  20. 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

  1. Large scale analysis of pediatric antiviral CD8+ T cell populations reveals sustained, functional and mature responses

    Directory of Open Access Journals (Sweden)

    Northfield John

    2006-12-01

    Full Text Available Abstract Background Cellular immunity plays a crucial role in cytomegalovirus (CMV infection and substantial populations of CMV-specific T cells accumulate throughout life. However, although CMV infection occurs during childhood, relatively little is know about the typical quantity and quality of T cell responses in pediatric populations. Methods One thousand and thirty-six people (Male/Female = 594/442, Age: 0–19 yr.; 959 subjects, 20–29 yr.; 77 subjects were examined for HLA typing. All of 1036 subjects were tested for HLA-A2 antigen. Of 1036 subjects, 887 were also tested for HLA-A23, 24 antigens. In addition, 50 elderly people (Male/Female = 11/39, Age: 60–92 yr. were also tested for HLA-A2 antigen. We analyzed the CD8+ T cell responses to CMV, comparing these to responses in children and young. The frequencies, phenotype and function CD8+ T cells for two imunodominant epitopes from pp65 were measured. Results We observed consistently high frequency and phenotypically "mature" (CD27 low, CD28 low, CD45RA+ CMV-specific CD8+ T cell responses in children, including those studied in the first year of life. These CD8+ T cells retained functionality across all age groups, and showed evidence of memory "inflation" only in later adult life. Conclusion CMV consistently elicits a very strong CD8+ T cell response in infants and large pools of CMV specific CD8+ T cells are maintained throughout childhood. The presence of CMV may considerably mould the CD8+ T cell compartment over time, but the relative frequencies of CMV-specific cells do not show the evidence of a population-level increase during childhood and adulthood. This contrast with the marked expansion ("inflation" of such CD8+ T cells in older adults. This study indicates that large scale analysis of peptide specific T cell responses in infants is readily possible. The robust nature of the responses observed suggests vaccine strategies aimed at priming and boosting CD8+ T cells against

  2. 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.

  3. Display

    OpenAIRE

    Gaskell, Ivan

    2011-01-01

    The display of religious objects takes many forms. While sculpture on the exterior of religious buildings is visible for the long term, relics, cult images, and masquerades are shown only occasionally. One way of emphasizing the potency of an object is to reveal it infrequently. In many religious systems display is restricted, for some things are dangerous to inappropriate viewers, while others are too powerful to be seen by anyone. When access is possible, viewers value intimate encounter, u...

  4. The polyfunctionality of human memory CD8+ T cells elicited by acute and chronic virus infections is not influenced by age.

    Directory of Open Access Journals (Sweden)

    Alina Lelic

    Full Text Available As humans age, they experience a progressive loss of thymic function and a corresponding shift in the makeup of the circulating CD8+ T cell population from naïve to memory phenotype. These alterations are believed to result in impaired CD8+ T cell responses in older individuals; however, evidence that these global changes impact virus-specific CD8+ T cell immunity in the elderly is lacking. To gain further insight into the functionality of virus-specific CD8+ T cells in older individuals, we interrogated a cohort of individuals who were acutely infected with West Nile virus (WNV and chronically infected with Epstein Barr virus (EBV and Cytomegalovirus (CMV. The cohort was stratified into young (60 yrs groups. In the aged cohort, the CD8+ T cell compartment displayed a marked reduction in the frequency of naïve CD8+ T cells and increased frequencies of CD8+ T cells that expressed CD57 and lacked CD28, as previously described. However, we did not observe an influence of age on either the frequency of virus-specific CD8+ T cells within the circulating pool nor their functionality (based on the production of IFNγ, TNFα, IL2, Granzyme B, Perforin and mobilization of CD107a. We did note that CD8+ T cells specific for WNV, CMV or EBV displayed distinct functional profiles, but these differences were unrelated to age. Collectively, these data fail to support the hypothesis that immunosenescence leads to defective CD8+ T cell immunity and suggest that it should be possible to develop CD8+ T cell vaccines to protect aged individuals from infections with novel emerging viruses.

  5. Ex vivo SIV-specific CD8 T cell responses in heterozygous animals are primarily directed against peptides presented by a single MHC haplotype.

    Directory of Open Access Journals (Sweden)

    Justin M Greene

    Full Text Available The presence of certain MHC class I alleles is correlated with remarkable control of HIV and SIV, indicating that specific CD8 T cell responses can effectively reduce viral replication. It remains unclear whether epitopic breadth is an important feature of this control. Previous studies have suggested that individuals heterozygous at the MHC class I loci survive longer and/or progress more slowly than those who are homozygous at these loci, perhaps due to increased breadth of the CD8 T cell response. We used Mauritian cynomolgus macaques with defined MHC haplotypes and viral inhibition assays to directly compare CD8 T cell efficacy in MHC-heterozygous and homozygous individuals. Surprisingly, we found that cells from heterozygotes suppress viral replication most effectively on target cells from animals homozygous for only one of two potential haplotypes. The same heterozygous effector cells did not effectively inhibit viral replication as effectively on the target cells homozygous for the other haplotype. These results indicate that the greater potential breadth of CD8 T cell responses present in heterozygous animals does not necessarily lead to greater antiviral efficacy and suggest that SIV-specific CD8 T cell responses in heterozygous animals have a skewed focus toward epitopes restricted by a single haplotype.

  6. CD8α dendritic cells drive establishment of HSV-1 latency.

    Directory of Open Access Journals (Sweden)

    Kevin R Mott

    Full Text Available It is generally accepted that CD8 T cells play the key role to maintain HSV-1 latency in trigeminal ganglia of ocularly infected mice. Yet, comparably little is known about the role of innate immunity in establishment of viral latency. In the current study, we investigated whether CD8α DCs impact HSV-1 latency by examining latency in the trigeminal ganglia (TG of wild-type (WT C57BL/6 versus CD8α-/- (lack functional CD8 T cells and CD8α+ DCs, CD8β-/- (have functional CD8α+ T cells and CD8α+ DCs, and β2m-/- (lack functional CD8 T cells but have CD8α+ DCs mice as well as BXH2 (have functional CD8 T cells but lack CD8α+ DCs versus WT C3H (have functional CD8α T cells and CD8α+ DCs mice. We also determined whether the phenotype of CD8α-/- and BXH2 mice could be restored to that of WT mice by adoptive transfer of WT CD8+ T cells or bone marrow (BM derived CD8α+ DCs. Our results clearly demonstrate that CD8α DCs, rather than CD8 T cells, are responsible for enhanced viral latency and recurrences.

  7. Selective support of a mouse thymus epithelial cell line (MTEC1) to the viability and proliferation of CD4+CD8—,CD4—CD8—,and CD4+CD8+thymocytes in vitro

    Institute of Scientific and Technical Information of China (English)

    CHENWEIFENG; JAPINGATO; 等

    1992-01-01

    The MTEC1 cell line,established in our laboratory,is a normal epithelial cell line derived from thymus medulla of Balb/c mice and these cells constituteively produce multiple cytokines.The selection of thymic microenvironment on developing T cells was investigated in an in vitro system.Unseparated fresh thymocytes from Balb/c mice were cocultured with MTEC1 cells or/and MTEC1-SN,then,the viability,proliferation and phenotypes of cultured thymocytes were assessed.Without any exogenous stimulus,both MTEC1 cells and MTEC1-SN were able to maintain the viability of thymocytes,while only the MTEC1 cells,not the MTEC1-SN,could directly activate thymocytes to exhibit moderate proliferation,indicating that the proliferative signal is delivered through cell surface interatcions of MTEC1 cells and thymocytes.Phenotype analysis on FACS of viable thymocytes after coculture revealed that MTEC1 cells preferentially activate the subsets of CD4+ CD8-,CD4+ CD8+ and CD4- CD8- thymocytes;whereas MTEC1-SN preferentially maintained the viability of CD4+CD8- and CD4-CD8+ thymocyte subsets.For the Con A-activated thymocytes.both MTEC1 cells and MTEC1-SN provided accessory signal(s) to significantly increase the number of viable cells and to markedly enhance the proliferation of thymocytes with virtually equal potency,phenotyped as CD4+CD8-,CD4-CD8+,and CD4-CD8-subests,In summary,MTEC1 cells displayed Selection of thymic epithelial cells on thymocyte subsets. selective support to the different thymocyte subsets,and the selectivity is dependent on the status of thymocytes.

  8. Efficacious Early Antiviral Activity of HIV Gag- and Pol-Specific HLA-B*2705-Restricted CD8+ T Cells ▿

    OpenAIRE

    Payne, Rebecca P.; Kløverpris, Henrik; Sacha, Jonah B.; Brumme, Zabrina; Brumme, Chanson; Buus, Søren; Sims, Stuart; Hickling, Stephen; Riddell, Lynn; Chen, Fabian; Luzzi, Graz; Edwards, Anne; Phillips, Rodney; Prado, Julia G.; Goulder, Philip J. R.

    2010-01-01

    The association between HLA-B*2705 and the immune control of human immunodeficiency virus type 1 (HIV-1) has previously been linked to the targeting of the HLA-B*2705-restricted Gag epitope KRWIILGLNK (KK10) by CD8+ T cells. In order to better define the mechanisms of the HLA-B*2705 immune 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*...

  9. CD8-positive mycosis fungoides masquerading as pyoderma gangrenosum

    Directory of Open Access Journals (Sweden)

    Maitrayee Saha

    2016-01-01

    Full Text Available Mycosis fungoides (MF, a primary cutaneous T-cell lymphoma, accounts for <1% of non-Hodgkin lymphomas. The diagnosis of classic MF is based on a constellation of typical clinical presentation, histopathology, immunohistochemistry, and T-cell monoclonality detected by molecular studies. Rarely, atypical clinical presentation may occur. The typical immunohistochemical phenotype is, CD2 +ve, CD3 +ve, CD5 +ve, CD4 +ve, and CD8 − ve. Here, we report a rare case of CD8 +ve MF in a 43-year-male patient who was clinically diagnosed as pyoderma gangrenosum initially. The atypical presentation and rarity of such case have prompted this report.

  10. CD8-positive Mycosis Fungoides Masquerading as Pyoderma Gangrenosum.

    Science.gov (United States)

    Saha, Maitrayee; Jain, Bhawna Bhutoria; Chattopadhyay, Sarbani; Podder, Indrashis

    2016-01-01

    Mycosis fungoides (MF), a primary cutaneous T-cell lymphoma, accounts for <1% of non-Hodgkin lymphomas. The diagnosis of classic MF is based on a constellation of typical clinical presentation, histopathology, immunohistochemistry, and T-cell monoclonality detected by molecular studies. Rarely, atypical clinical presentation may occur. The typical immunohistochemical phenotype is, CD2 +ve, CD3 +ve, CD5 +ve, CD4 +ve, and CD8 - ve. Here, we report a rare case of CD8 +ve MF in a 43-year-male patient who was clinically diagnosed as pyoderma gangrenosum initially. The atypical presentation and rarity of such case have prompted this report.

  11. A novel immunodominant CD8+ T cell response restricted by a common HLA-C allele targets a conserved region of Gag HIV-1 clade CRF01_AE infected Thais.

    Directory of Open Access Journals (Sweden)

    Supranee Buranapraditkun

    Full Text Available BACKGROUND: CD8+ T cell responses play an important role in the control of HIV-1. The extensive sequence diversity of HIV-1 represents a critical hurdle to developing an effective HIV-1 vaccine, and it is likely that regional-specific vaccine strains will be required to overcome the diversity of the different HIV-1 clades distributed world-wide. Unfortunately, little is known about the CD8+ T cell responses against CRF01_AE, which is responsible for the majority of infections in Southeast Asia. METHODOLOGY/PRINCIPAL FINDINGS: To identify dominant CD8+ T cell responses recognized in HIV-1 clade CRF01_AE infected subjects we drew upon data from an immunological screen of 100 HIV-1 clade CRF01_AE infected subjects using IFN-gamma ELISpot to characterize a novel immunodominant CD8+ T cell response in HIV-1 Gag restricted by HLA-Cw*0102 (p24, (277YSPVSILDI(285, YI9. Over 75% of Cw*0102+ve subjects targeted this epitope, representing the strongest response in more than a third of these individuals. This novel CD8 epitope was located in a highly conserved region of HIV-1 Gag known to contain immunodominant CD8 epitopes, which are restricted by HLA-B*57 and -B*27 in clade B infection. Nonetheless, viral escape in this epitope was frequently observed in Cw*0102+ve subjects, suggestive of strong selection pressure being exerted by this common CD8+ T cell response. CONCLUSIONS/SIGNIFICANCE: As HLA-Cw*0102 is frequently expressed in the Thai population (allelic frequency of 16.8%, this immunodominant Cw*0102-restricted Gag epitope may represent an attractive candidate for vaccines specific to CRF01_AE and may help facilitate further studies of immunopathogenesis in this understudied HIV-1 clade.

  12. 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.

  13. A new EV71 VP3 epitope in norovirus P particle vector displays neutralizing activity and protection in vivo in mice.

    Science.gov (United States)

    Jiang, Liping; Fan, Rongjun; Sun, Shiyang; Fan, Peihu; Su, Weiheng; Zhou, Yan; Gao, Feng; Xu, Fei; Kong, Wei; Jiang, Chunlai

    2015-11-27

    Enterovirus 71 (EV71) and Coxsackievirus A16 (CVA16), as the main agents causing hand, foot and mouth disease (HFMD), have become a serious public health concern in the Asia-Pacific region. Recently, various neutralizing B cell epitopes of EV71 were identified as targets for promising vaccine candidates. Structural studies of Picornaviridae indicated that potent immunodominant epitopes typically lie in the hypervariable loop of capsid surfaces. However, cross-neutralizing antibodies and cross-protection between EV71 and CVA16 have not been observed. Therefore, we speculated that divergent sequences of the two viruses are key epitopes for inducing protective neutralizing responses. In this study, we selected 10 divergent epitope candidates based on alignment of the EV71 and CVA16 P1 amino acid sequences using the Multalin interface page, and these epitopes are conserved among all subgenotypes of EV71. Simultaneously, by utilizing the norovirus P particle as a novel vaccine delivery carrier, we identified the 71-6 epitope (amino acid 176-190 of VP3) as a conformational neutralizing epitope against EV71 in an in vitro micro-neutralization assay as well as an in vivo protection assay in mice. Altogether, these results indicated that the incorporation of the 71-6 epitope into the norovirus P domain can provide a promising candidate for an effective synthetic peptide-based vaccine against EV71.

  14. A new EV71 VP3 epitope in norovirus P particle vector displays neutralizing activity and protection in vivo in mice.

    Science.gov (United States)

    Jiang, Liping; Fan, Rongjun; Sun, Shiyang; Fan, Peihu; Su, Weiheng; Zhou, Yan; Gao, Feng; Xu, Fei; Kong, Wei; Jiang, Chunlai

    2015-11-27

    Enterovirus 71 (EV71) and Coxsackievirus A16 (CVA16), as the main agents causing hand, foot and mouth disease (HFMD), have become a serious public health concern in the Asia-Pacific region. Recently, various neutralizing B cell epitopes of EV71 were identified as targets for promising vaccine candidates. Structural studies of Picornaviridae indicated that potent immunodominant epitopes typically lie in the hypervariable loop of capsid surfaces. However, cross-neutralizing antibodies and cross-protection between EV71 and CVA16 have not been observed. Therefore, we speculated that divergent sequences of the two viruses are key epitopes for inducing protective neutralizing responses. In this study, we selected 10 divergent epitope candidates based on alignment of the EV71 and CVA16 P1 amino acid sequences using the Multalin interface page, and these epitopes are conserved among all subgenotypes of EV71. Simultaneously, by utilizing the norovirus P particle as a novel vaccine delivery carrier, we identified the 71-6 epitope (amino acid 176-190 of VP3) as a conformational neutralizing epitope against EV71 in an in vitro micro-neutralization assay as well as an in vivo protection assay in mice. Altogether, these results indicated that the incorporation of the 71-6 epitope into the norovirus P domain can provide a promising candidate for an effective synthetic peptide-based vaccine against EV71. PMID:26529072

  15. HLA-B7-restricted islet epitopes are differentially recognized in type 1 diabetic children and adults and form weak peptide-HLA complexes

    DEFF Research Database (Denmark)

    Scotto, Matthieu; Afonso, Georgia; Østerbye, Thomas;

    2012-01-01

    and healthy subjects. Some epitopes were highly immunodominant and specific to either T1D children (GAD(530-538); 44% T cell-positive patients) or adults (GAD(311-320); 38%). All epitopes displayed weak binding affinity and stability for HLA-B7 compared with HLA-A2-restricted ones, a general feature of HLA-B7......1D children and adults, and are recognized by IFN-γ(+)TGF-β(+)CD8(+) T cells. These features may explain the T1D-protective effect of HLA-B7. The novel epitopes identified should find valuable applications for immune staging of HLA-B7(+) individuals....

  16. Adoptive immunotherapy via CD4+ versus CD8+ T cells

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    Vy Phan-Lai

    2016-04-01

    Full Text Available The goal of cancer immunotherapy is to induce specific and durable antitumor immunity. Adoptive T cell therapy (ACT has garnered wide interest, particularly in regard to strategies to improve T cell efficacy in trials. There are many types of T cells (and subsets which can be selected for use in ACT. CD4+ T cells are critical for the regulation, activation and aid of host defense mechanisms and, importantly, for enhancing the function of tumor-specific CD8+ T cells. To date, much research in cancer immunotherapy has focused on CD8+ T cells, in melanoma and other cancers. Both CD4+ T cells and CD8+ T cells have been evaluated as ACT in mice and humans, and both are effective at eliciting antitumor responses. IL-17 producing CD4+ T cells are a new subset of CD4+ T cells to be evaluated in ACT models. This review discusses the benefits of adoptive immunotherapy mediated by CD8+ and CD4+ cells. It also discusses the various type of T cells, source of T cells, and ex vivo cytokine growth factors for augmenting clinical efficacy of ACT. [Biomed Res Ther 2016; 3(4.000: 588-595

  17. High Frequencies of Anti-Host Reactive CD8+ T Cells Ignore Non-Hematopoietic Antigen after Bone Marrow Transplantation in a Murine Model

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    Asmae Gassa

    2016-03-01

    Full Text Available Background: Graft versus host disease (GvHD occurs in 20% of cases with patients having an MHC I matched bone marrow transplantation (BMT. Mechanisms causing this disease remain to be studied. Methods: Here we used a CD8+ T cell transgenic mouse line (P14/CD45.1+ and transgenic DEE mice bearing ubiquitously the glycoprotein 33-41 (GP33 antigen derived from the major lymphocytic choriomeningitis virus (LCMV epitope to study mechanisms of tolerance in anti-host reactive CD8+ T cells after BMT. Results: We found that anti-host reactive CD8+ T cells (P14 T cells were not negatively selected in the thymus and that they were present in wild type (WT recipient mice as well as in DEE recipient mice. Anti-host reactive CD8+ T cells ignored the GP33 antigen expressed ubiquitously by host cells but they could be activated ex vivo via LCMV-infection. Lipopolysaccharides (LPS induced transient cell damage in DEE mice bearing anti-host reactive CD8+ T cells after BMT, suggesting that induction of host inflammatory response could break antigen ignorance. Introducing the GP33 antigen into BM cells led to deletion of anti-host reactive CD8+ T cells. Conclusion: We found that after BMT anti-host reactive CD8+ T cells ignored host antigen in recipients and that they were only deleted when host antigen was present in hematopoietic cells. Moreover, LPS-induced immune activation contributed to induction of alloreactivity of anti-host reactive CD8+ T cells after BMT.

  18. T Cell Help Amplifies Innate Signals in CD8+ DCs for Optimal CD8+ T Cell Priming

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    Marie Greyer

    2016-01-01

    Full Text Available DCs often require stimulation from CD4+ T cells to propagate CD8+ T cell responses, but precisely how T cell help optimizes the priming capacity of DCs and why this appears to differ between varying types of CD8+ T cell immunity remains unclear. We show that CD8+ T cell priming upon HSV-1 skin infection depended on DCs receiving stimulation from both IFN-α/β and CD4+ T cells to provide IL-15. This was not an additive effect but resulted from CD4+ T cells amplifying DC production of IL-15 in response to IFN-α/β. We also observed that increased innate stimulation reversed the helper dependence of CD8+ T cell priming and that the innate stimulus, rather than the CD4+ T cells themselves, determined how “help’” was integrated into the priming response by DCs. These findings identify T cell help as a flexible means to amplify varying suboptimal innate signals in DCs.

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

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    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.

  20. Splenectomy alters distribution and turnover but not numbers or protective capacity of de novo generated memory CD8 T cells.

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    Marie eKim

    2014-11-01

    Full Text Available The spleen is a highly compartmentalized lymphoid organ that allows for efficient antigen presentation and activation of immune responses. Additionally, the spleen itself functions to remove senescent red blood cells, filter bacteria, and sequester platelets. Splenectomy, commonly performed after blunt force trauma or splenomegaly, has been shown to increase risk of certain bacterial and parasitic infections years after removal of the spleen. Although previous studies report defects in memory B cells and IgM titers in splenectomized patients, the effect of splenectomy on CD8 T cell responses and memory CD8 T cell function remains ill defined. Using TCR-transgenic P14 cells, we demonstrate that homeostatic proliferation and representation of pathogen-specific memory CD8 T cells in the blood are enhanced in splenectomized compared to sham surgery mice. Surprisingly, despite the enhanced turnover, splenectomized mice displayed no changes in total memory CD8 T cell numbers nor impaired protection against lethal dose challenge with Listeria monocytogenes. Thus, our data suggest that memory CD8 T cell maintenance and function remain intact in the absence of the spleen.

  1. Profound protection against respiratory challenge with a lethal H7N7 influenza A virus by increasing the magnitude of CD8(+) T-cell memory

    DEFF Research Database (Denmark)

    Christensen, Jan Pravsgaard; Doherty, P C; Branum, K C;

    2000-01-01

    The recall of CD8(+) T-cell memory established by infecting H-2(b) mice with an H1N1 influenza A virus provided a measure of protection against an extremely virulent H7N7 virus. The numbers of CD8(+) effector and memory T cells specific for the shared, immunodominant D(b)NP(366) epitope were...... greatly increased subsequent to the H7N7 challenge, and though lung titers remained as high as those in naive controls for 5 days or more, the virus was cleared more rapidly. Expanding the CD8(+) memory T-cell pool (10%) by sequential priming with two different influenza A viruses (H3N2-->H1N1...

  2. Cloning analysis of HBV-specific CD8 T cell receptor gene in patients with acute hepatitis B

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    Ning DING

    2011-05-01

    Full Text Available Objective To investigate the molecular mechanism of T cell receptor(TCR in CD8 T cell-mediated immune response to HBV in patients with acute hepatitis B(AHB.Methods Peripheral blood mononuclear cells(PBMCs were collected from HLA-A2-positive AHB patients.To determine HBsAg183-191 and HBsAg335-343-specific CD8 T cell frequencies,the PBMCs were stained by fluorescence-labeled anti-CD3,anti-CD8 and pentamers,and analyzed by flow cytometry.PBMCs from 6 patients were stimulated with epitopic peptide HBsAg335-343 in vitro for 3 to 4 weeks.HBV-specific CD8 T cells were isolated by magnetic activated cell sorting followed by flow florescence activated cell sorting.The mRNA of sorted cells was extracted after expanding by IL-2,anti-CD3 and anti-CD8.The full-length gene fragments of variable region of TCR α and β chains were gained by 5’-RACE,and then cloned and sequenced(≥50 clones for single chain of each sample.The gene families of TCR α and β chains were identified and the sequence characters of CDR3 were compared.Results Analysis of more than 600 cloned gene sequences of TCR α and β chains showed that the proliferated HBV-specific CD8 T cells from 6 AHB patients presented a predominant expression in TCR α and chains,with 2-4 α chain families and 1-4 chain families in each case.The α2,α14,α15,β3,β13 and 23 families were detected in more than one case.The chain genes were all 13 for all tested clones in one case.For the same α chain or-chain family,CDR3 sequences tended to be identical in one case but different among cases.Conclusions HBV-specific CD8 T cells with antigenic peptide-induced proliferation present predominance in the usage of TCR α and β chains.This property might be one of the important molecular factors influencing anti-HBV immunity.

  3. Two novel neutralizing antigenic epitopes of the s1 subunit protein of a QX-like avian infectious bronchitis virus strain Sczy3 as revealed using a phage display peptide library.

    Science.gov (United States)

    Zou, Nianli; Xia, Jing; Wang, Fuyan; Duan, Zhenzhen; Miao, Dan; Yan, Qigui; Cao, Sanjie; Wen, Xintian; Liu, Ping; Huang, Yong

    2015-11-15

    The spike (S) protein of the infectious bronchitis virus (IBV) plays a central role in the pathogenicity, the immune antibody production, serotype and the tissue tropism. In this study, we generate 11 monoclonal antibodies (mAbs) against S1 subunit of IBV Sczy3 strain, and two mAbs 1D5 and 6A12 were positive in indirect ELISA against both His-S1 protein and the purified whole viral antigen. MAb 6A12 and 1D5 could recognized by other 10 IBV strains (IBVs) from five different genotypes, except that 1D5 had a relatively low reaction with two of the 10 tested IBVs. End-point neutralizing assay performed in chicken embro kidney (CEK) cells revealed that the neutralization titer of 6A12 and 1D5 against Sczy3 reached 1:44.7 and 1:40.6, respectively. After screening a phage display peptide library and peptide scanning, we identified two linear B-cell epitopes that were recognized by the mAbs 1D5 and 6A12, which corresponded to the amino acid sequences (87)PPQGMAW(93) and (412)IQTRTEP(418), respectively, in the IBV S1 subunit. Sequences comparison revealed that epitope (412)IQTRTEP(418) was conserved among IBVs, while the epitope (87)PPQGMAW(93) was relatively variable among IBVs. The novel mAbs and the epitopes identified will be useful for developing diagnostic assays for IBV infections.

  4. Contrasting roles for CD4 vs. CD8 T-cells in a murine model of virally induced "T1 black hole" formation.

    Science.gov (United States)

    Pirko, Istvan; Chen, Yi; Lohrey, Anne K; McDole, Jeremiah; Gamez, Jeffrey D; Allen, Kathleen S; Pavelko, Kevin D; Lindquist, Diana M; Dunn, R Scott; Macura, Slobodan I; Johnson, Aaron J

    2012-01-01

    MRI is sensitive to tissue pathology in multiple sclerosis (MS); however, most lesional MRI findings have limited correlation with disability. Chronic T1 hypointense lesions or "T1 black holes" (T1BH), observed in a subset of MS patients and thought to represent axonal damage, show moderate to strong correlation with disability. The pathogenesis of T1BH remains unclear. We previously reported the first and as of yet only model of T1BH formation in the Theiler's murine encephalitis virus induced model of acute CNS neuroinflammation induced injury, where CD8 T-cells are critical mediators of axonal damage and related T1BH formation. The purpose of this study was to further analyze the role of CD8 and CD4 T-cells through adoptive transfer experiments and to determine if the relevant CD8 T-cells are classic epitope specific lymphocytes or different subsets. C57BL/6 mice were used as donors and RAG-1 deficient mice as hosts in our adoptive transfer experiments. In vivo 3-dimensional MRI images were acquired using a 7 Tesla small animal MRI system. For image analysis, we used semi-automated methods in Analyze 9.1; transfer efficiency was monitored using FACS of brain infiltrating lymphocytes. Using a peptide depletion method, we demonstrated that the majority of CD8 T-cells are classic epitope specific cytotoxic cells. CD8 T-cell transfer successfully restored the immune system's capability to mediate T1BH formation in animals that lack adaptive immune system, whereas CD4 T-cell transfer results in an attenuated phenotype with significantly less T1BH formation. These findings demonstrate contrasting roles for these cell types, with additional evidence for a direct pathogenic role of CD8 T-cells in our model of T1 black hole formation. PMID:22348089

  5. Contrasting roles for CD4 vs. CD8 T-cells in a murine model of virally induced "T1 black hole" formation.

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    Istvan Pirko

    Full Text Available MRI is sensitive to tissue pathology in multiple sclerosis (MS; however, most lesional MRI findings have limited correlation with disability. Chronic T1 hypointense lesions or "T1 black holes" (T1BH, observed in a subset of MS patients and thought to represent axonal damage, show moderate to strong correlation with disability. The pathogenesis of T1BH remains unclear. We previously reported the first and as of yet only model of T1BH formation in the Theiler's murine encephalitis virus induced model of acute CNS neuroinflammation induced injury, where CD8 T-cells are critical mediators of axonal damage and related T1BH formation. The purpose of this study was to further analyze the role of CD8 and CD4 T-cells through adoptive transfer experiments and to determine if the relevant CD8 T-cells are classic epitope specific lymphocytes or different subsets. C57BL/6 mice were used as donors and RAG-1 deficient mice as hosts in our adoptive transfer experiments. In vivo 3-dimensional MRI images were acquired using a 7 Tesla small animal MRI system. For image analysis, we used semi-automated methods in Analyze 9.1; transfer efficiency was monitored using FACS of brain infiltrating lymphocytes. Using a peptide depletion method, we demonstrated that the majority of CD8 T-cells are classic epitope specific cytotoxic cells. CD8 T-cell transfer successfully restored the immune system's capability to mediate T1BH formation in animals that lack adaptive immune system, whereas CD4 T-cell transfer results in an attenuated phenotype with significantly less T1BH formation. These findings demonstrate contrasting roles for these cell types, with additional evidence for a direct pathogenic role of CD8 T-cells in our model of T1 black hole formation.

  6. The nucleocapsid protein of Rift Valley fever virus is a potent human CD8+ T cell antigen and elicits memory responses.

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    Weidong Xu

    Full Text Available There is no licensed human vaccine currently available for Rift Valley Fever Virus (RVFV, a Category A high priority pathogen and a serious zoonotic threat. While neutralizing antibodies targeting the viral glycoproteins are protective, they appear late in the course of infection, and may not be induced in time to prevent a natural or bioterrorism-induced outbreak. Here we examined the immunogenicity of RVFV nucleocapsid (N protein as a CD8(+ T cell antigen with the potential for inducing rapid protection after vaccination. HLA-A*0201 (A2-restricted epitopic determinants were identified with N-specific CD8(+ T cells from eight healthy donors that were primed with dendritic cells transduced to express N, and subsequently expanded in vitro by weekly re-stimulations with monocytes pulsed with 59 15mer overlapping peptides (OLPs across N. Two immunodominant epitopes, VT9 (VLSEWLPVT, N(121-129 and IL9 (ILDAHSLYL, N165-173, were defined. VT9- and IL9-specific CD8(+ T cells identified by tetramer staining were cytotoxic and polyfunctional, characteristics deemed important for viral control in vivo. These peptides induced specific CD8(+ T cell responses in A2-transgenic mice, and more importantly, potent N-specific CD8(+ T cell reactivities, including VT9- and IL9-specific ones, were mounted by mice after a booster vaccination with the live attenuated RVF MP-12. Our data suggest that the RVFV N protein is a potent human T cell immunogen capable of eliciting broad, immunodominant CD8(+ T cell responses that are potentially protective. Understanding the immune responses to the nucleocapsid is central to the design of an effective RVFV vaccine irrespective of whether this viral protein is effective as a stand-alone immunogen or only in combination with other RVFV antigens.

  7. Therapeutic potential of CD8+ cytotoxic T lymphocytes in SLE☆

    Science.gov (United States)

    Puliaeva, I.; Puliaev, R.; Via, C.S.

    2011-01-01

    Recent evidence supports the idea that following a break in tolerance, CD8 cytotoxic T lymphocytes (CTL) may be an important but unrecognized mechanism for limiting expansion of autoreactive B cells. Failure of this mechanism could allow persistence of CD4 T cell driven polyclonal B cell activation resulting in clinical lupus. Although CD8 CTL failure may occur early in disease, work in mice supports the concept that therapeutic CTL enhancement may be both practical and beneficial in lupus. Devising such therapy for humans will first require an understanding of the in vivo mechanisms critical in CTL expansion and down regulation, particularly in the lupus setting which may differ from CTL generation in other clinical settings (e.g. tumors, infections). PMID:18725326

  8. CD8+ T Cell Immunodominance in Lymphocytic Choriomeningitis Virus Infection Is Modified in the Presence of Toll-Like Receptor Agonists ▿

    OpenAIRE

    Siddiqui, Sarah; Basta, Sameh

    2011-01-01

    Currently, we have limited understanding of how Toll-like receptor (TLR) engagement by microbial products influences the immune response during a concurrent virus infection. In this study, we established that dual TLR2 plus TLR3 (designated TLR2+3) stimulation alters the immunodominance hierarchies of lymphocytic choriomeningitis virus (LCMV) epitopes by reducing NP396-specific CD8+ T cell responses and shifting it to a subdominant position. The shift in immunodominance occurred due to a redu...

  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. Programming CD8+ T cells for effective immunotherapy

    OpenAIRE

    Hinrichs, Christian S.; Gattinoni, Luca; Restifo, Nicholas P

    2006-01-01

    The differentiation state of CD8+ T cells has emerged as a crucial determinant of their ability to respond to tumor and infection. Signals from T-cell receptors, co-stimulatory molecules and cytokine receptors direct the differentiation process. These signals ‘program’ sustained and heritable gene expression patterns that govern progressive differentiation and lineage commitment. The epigenetic mechanisms by which T cells are programmed are just beginning to be elucidated. Understanding the m...

  11. Variable epitope libraries: new vaccine immunogens capable of inducing broad human immunodeficiency virus type 1-neutralizing antibody response.

    Science.gov (United States)

    Charles-Niño, Claudia; Pedroza-Roldan, Cesar; Viveros, Monica; Gevorkian, Goar; Manoutcharian, Karen

    2011-07-18

    The extreme antigenic variability of human immunodeficiency virus (HIV) leads to immune escape of the virus, representing a major challenge in the design of effective vaccine. We have developed a novel concept for immunogen construction based on introduction of massive mutations within the epitopes targeting antigenically variable pathogens and diseases. Previously, we showed that these immunogens carrying large combinatorial libraries of mutated epitope variants, termed as variable epitope libraries (VELs), induce potent, broad and long lasting CD8+IFN-γ+ T-cell response. Moreover, we demonstrated that these T cells recognize more than 50% of heavily mutated variants (5 out of 10 amino acid positions were mutated in each epitope variant) of HIV-1 gp120 V3 loop-derived cytotoxic T lymphocyte epitope (RGPGRAFVTI) in mice. The constructed VELs had complexities of 10000 and 12500 individual members, generated as plasmid DNA or as M13 phage display combinatorial libraries, respectively, and with structural composition RGPGXAXXXX or XGXGXAXVXI, where X is any of 20 natural amino acids. Here, we demonstrated that sera from mice immunized with these VELs are capable of neutralizing 5 out of 10 viral isolates from Tier 2 reference panel of subtype B envelope clones, including HIV-1 isolates which are known to be resistant to neutralization by several potent monoclonal antibodies, described previously. These data indicate the feasibility of the application of immunogens based on VEL concept as an alternative approach for the development of molecular vaccines against antigenically variable pathogens.

  12. Distribution, characterization, and induction of CD8+ regulatory T cells and IL-17-producing CD8+ T cells in nasopharyngeal carcinoma

    OpenAIRE

    Li Jiang; Huang Zhou-Feng; Xiong Geng; Mo Hao-Yuan; Qiu Fang; Mai Hai-Qiang; Chen Qiu-Yan; He Jia; Chen Shu-peng; Zheng Li-Min; Qian Chao-Nan; Zeng Yi-Xin

    2011-01-01

    Abstract Background CD8+ effector cells often have an antitumor function in patients with cancer. However, CD8+Foxp3+ regulatory T cells (Tcregs) and interleukin (IL)-17-producing CD8+ T cells (Tc17 cells) also derive from the CD8+ T cell lineage. Their role in the antitumor response remains largely unknown. In the present study, we aimed to investigate the distribution, characterization, and generation of CD8+ Tcregs and Tc17 cells in NPC patients. Methods Peripheral blood and tumor biopsy t...

  13. Impact of clonal competition for peptide-MHC complexes on the CD8[superscript +] T-cell repertoire selection in a persistent viral infection

    Energy Technology Data Exchange (ETDEWEB)

    Wynn, Katherine K.; Fulton, Zara; Cooper, Leanne; Silins, Sharon L.; Gras, Stephanie; Archbold, Julia K.; Tynan, Fleur E.; Miles, John J.; McCluskey, James; Burrows, Scott R.; Rossjohn, Jamie; Khanna, Rajiv (Monash); (Queensland Inst. of Med. Rsrch.); (Melbourne)

    2008-04-29

    CD8{sup +} T-cell responses to persistent viral infections are characterized by the accumulation of an oligoclonal T-cell repertoire and a reduction in the naive T-cell pool. However, the precise mechanism for this phenomenon remains elusive. Here we show that human cytomegalovirus (HCMV)-specific CD8{sup +} T cells recognizing distinct epitopes from the pp65 protein and restricted through an identical HLA class I allele (HLA B*3508) exhibited either a highly conserved public T-cell repertoire or a private, diverse T-cell response, which was uniquely altered in each donor following in vitro antigen exposure. Selection of a public T-cell receptor (TCR) was coincident with an atypical major histocompatibility complex (MHC)-peptide structure, in that the epitope adopted a helical conformation that bulged from the peptide-binding groove, while a diverse TCR profile was observed in response to the epitope that formed a flatter, more 'featureless' landscape. Clonotypes with biased TCR usage demonstrated more efficient recognition of virus-infected cells, a greater CD8 dependency, and were more terminally differentiated in their phenotype when compared with the T cells expressing diverse TCR. These findings provide new insights into our understanding on how the biology of antigen presentation in addition to the structural features of the pMHC-I might shape the T-cell repertoire and its phenotype.

  14. Two Theileria parva CD8 T cell antigen genes are more variable in buffalo than cattle parasites, but differ in pattern of sequence diversity.

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    Roger Pelle

    Full Text Available BACKGROUND: Theileria parva causes an acute fatal disease in cattle, but infections are asymptomatic in the African buffalo (Syncerus caffer. Cattle can be immunized against the parasite by infection and treatment, but immunity is partially strain specific. Available data indicate that CD8(+ T lymphocyte responses mediate protection and, recently, several parasite antigens recognised by CD8(+ T cells have been identified. This study set out to determine the nature and extent of polymorphism in two of these antigens, Tp1 and Tp2, which contain defined CD8(+ T-cell epitopes, and to analyse the sequences for evidence of selection. METHODOLOGY/PRINCIPAL FINDINGS: Partial sequencing of the Tp1 gene and the full-length Tp2 gene from 82 T. parva isolates revealed extensive polymorphism in both antigens, including the epitope-containing regions. Single nucleotide polymorphisms were detected at 51 positions (∼12% in Tp1 and in 320 positions (∼61% in Tp2. Together with two short indels in Tp1, these resulted in 30 and 42 protein variants of Tp1 and Tp2, respectively. Although evidence of positive selection was found for multiple amino acid residues, there was no preferential involvement of T cell epitope residues. Overall, the extent of diversity was much greater in T. parva isolates originating from buffalo than in isolates known to be transmissible among cattle. CONCLUSIONS/SIGNIFICANCE: The results indicate that T. parva parasites maintained in cattle represent a subset of the overall T. parva population, which has become adapted for tick transmission between cattle. The absence of obvious enrichment for positively selected amino acid residues within defined epitopes indicates either that diversity is not predominantly driven by selection exerted by host T cells, or that such selection is not detectable by the methods employed due to unidentified epitopes elsewhere in the antigens. Further functional studies are required to address this latter

  15. CD8-dependent CTL require co-engagement of CD8 and the TCR for phosphatidylinositol hydrolysis, but CD8-independent CTL do not and can kill in the absence of phosphatidylinositol hydrolysis.

    Science.gov (United States)

    Knall, C; Smith, P A; Potter, T A

    1995-06-01

    Most instances of MHC class I recognition and target cell killing by CD8+ CTL require the involvement of CD8. The role of CD8 in these events may be both for adhesion of the CTL with the APC, as well as for signal transduction through the TCR. The precise mechanism by which CD8 mediates signal transduction remains enigmatic. Similarly, it is unclear whether only the CD8 molecules which bind to the same class I molecule as the TCR contribute to signaling in the T cell responding to antigen. We have investigated the requirement for co-engagement of CD8 and the TCR in the induction of the hydrolysis of phosphatidylinositol-4,5-bisphosphate (PIP2) during the interaction of CTL and APC transfected with either wild-type or mutant (CD8 non-binding) class I molecules. Our results show that for conventional CD8-dependent killing co-engagement of both CD8 and the TCR is required to initiate PIP2 hydrolysis. This requirement for co-engagement, however, can be overcome by a high density of ligand, such as that provided by high concentrations of exogenous peptide. In such situations, the binding of CD8 to non-antigenic class I molecules can elicit PIP2 hydrolysis. Therefore, during interactions between CTL and APC, which generally occur at low concentrations of antigenic peptide, triggering of PIP2 hydrolysis requires TCR and CD8 co-engagement, and the binding of CD8 to non-antigenic class I molecules does not contribute significantly to signaling within the T cell.(ABSTRACT TRUNCATED AT 250 WORDS)

  16. Spontaneous CD8 T cell responses against the melanocyte differentiation antigen RAB38/NY-MEL-1 in melanoma patients.

    Science.gov (United States)

    Walton, Senta M; Gerlinger, Marco; de la Rosa, Olga; Nuber, Natko; Knights, Ashley; Gati, Asma; Laumer, Monika; Strauss, Laura; Exner, Carolin; Schäfer, Niklaus; Urosevic, Mirjana; Dummer, Reinhard; Tiercy, Jean-Marie; Mackensen, Andreas; Jaeger, Elke; Lévy, Frédéric; Knuth, Alexander; Jäger, Dirk; Zippelius, Alfred

    2006-12-01

    The melanocyte differentiation Ag RAB38/NY-MEL-1 was identified by serological expression cloning (SEREX) and is expressed in the vast majority of melanoma lesions. The immunogenicity of RAB38/NY-MEL-1 has been corroborated previously by the frequent occurrence of specific Ab responses in melanoma patients. To elucidate potential CD8 T cell responses, we applied in vitro sensitization with overlapping peptides spanning the RAB38/NY-MEL-1 protein sequence and the reverse immunology approach. The identified peptide RAB38/NY-MEL-1(50-58) exhibited a marked response in ELISPOT assays after in vitro sensitization of CD8 T cells from HLA-A *0201(+) melanoma patients. In vitro digestion assays using purified proteasomes provided evidence of natural processing of RAB38/NY-MEL-1(50-58) peptide. Accordingly, monoclonal RAB38/NY-MEL-1(50-58)-specific T cell populations were capable of specifically recognizing HLA-A2(+) melanoma cell lines expressing RAB38/NY-MEL-1. Applying fluorescent HLA-A2/RAB38/NY-MEL-1(50-58) multimeric constructs, we were able to document a spontaneously developed memory/effector CD8 T cell response against this peptide in a melanoma patient. To elucidate the Ag-processing pathway, we demonstrate that RAB38/NY-MEL-1(50-58) is produced efficiently by the standard proteasome and the immunoproteasome. In addition to the identification of a RAB38/NY-MEL-1-derived immunogenic CD8 T cell epitope, this study is instrumental for both the onset and monitoring of future RAB38/NY-MEL-1-based vaccination trials. PMID:17114498

  17. A vaccine encoding conserved promiscuous HIV CD4 epitopes induces broad T cell responses in mice transgenic to multiple common HLA class II molecules.

    Directory of Open Access Journals (Sweden)

    Susan Pereira Ribeiro

    Full Text Available Current HIV vaccine approaches are focused on immunogens encoding whole HIV antigenic proteins that mainly elicit cytotoxic CD8+ responses. Mounting evidence points toward a critical role for CD4+ T cells in the control of immunodeficiency virus replication, probably due to cognate help. Vaccine-induced CD4+ T cell responses might, therefore, have a protective effect in HIV replication. In addition, successful vaccines may have to elicit responses to multiple epitopes in a high proportion of vaccinees, to match the highly variable circulating strains of HIV. Using rational vaccine design, we developed a DNA vaccine encoding 18 algorithm-selected conserved, "promiscuous" (multiple HLA-DR-binding B-subtype HIV CD4 epitopes - previously found to be frequently recognized by HIV-infected patients. We assessed the ability of the vaccine to induce broad T cell responses in the context of multiple HLA class II molecules using different strains of HLA class II- transgenic mice (-DR2, -DR4, -DQ6 and -DQ8. Mice displayed CD4+ and CD8+ T cell responses of significant breadth and magnitude, and 16 out of the 18 encoded epitopes were recognized. By virtue of inducing broad responses against conserved CD4+ T cell epitopes that can be recognized in the context of widely diverse, common HLA class II alleles, this vaccine concept may cope both with HIV genetic variability and increased population coverage. The vaccine may thus be a source of cognate help for HIV-specific CD8+ T cells elicited by conventional immunogens, in a wide proportion of vaccinees.

  18. The expression of CD8α discriminates distinct T cell subsets in teleost fish.

    Science.gov (United States)

    Takizawa, Fumio; Dijkstra, Johannes Martinus; Kotterba, Paul; Korytář, Tomáš; Kock, Holger; Köllner, Bernd; Jaureguiberry, Beltran; Nakanishi, Teruyuki; Fischer, Uwe

    2011-07-01

    CD8, belonging to the TCR complex, is the main marker molecule of CTLs. Although CD8 genes have been detected in many fish species, the analysis of teleost CD8+ cells has been limited because of the lack of antibodies. Using newly established mAbs against rainbow trout CD8α, we found high ratios of CD8α+ cells in trout thymus, gill and intestine, but relatively low abundance in pronephros, spleen and blood. Accordingly, tissue sections revealed many CD8α+ cells in thymus, numerous intra- and subepithelial CD8α+ cells in intestine and gill and few scattered CD8α+ cells in spleen and pronephros. In secondary lymphoid tissues, CD8α+ lymphocytes, which did not react with anti-thrombocyte or anti-IgM mAbs, expressed CD8α, CD8β and TCRα, while Ig and CD4 transcripts were found in CD8α⁻ lymphocytes. In contrast, considerable CD4 expression in CD8α+ thymocytes suggests the presence of double-positive early T cells. Highly expressed TCRγ, LAG3 and CTLA4 in CD8α+ lymphocytes imply that they constitute a heterogeneous population different from found in non-mucosal tissues. PHA stimulation resulted in an up-regulation of CTL effector genes (perforin, granulysin and IFN-γ) in CD8α+ pronephrocytes, while both Th1 (IFN-γ) and Th2 (IL-4/13A) cytokines were up-regulated in CD8α⁻ pronephrocytes. Although the basic characteristics of CD8α+ lymphocytes seem similar in teleost and mammals, features such as the low proportion of teleost CD8α+ lymphocytes in blood and their high abundance in respiratory tissue reveal a unique dynamics and distribution. PMID:21352850

  19. Increased percentage of CD8 CD28– suppressor lymphocytes in peripheral blood and skin infiltrates correlates with advanced disease in patients with cutaneous T-cell lymphomas

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    Donata Urbaniak-Kujda

    2009-07-01

    Full Text Available Introduction: T cells with the CD8 CD28– phenotype are CD8 lymphocytes with regulatory function. Their increased numbers were observed in infections, autoimmune and neoplastic diseases, and in elderly healthy individuals. CD8 CD28– lymphocyte levels in patients with cutaneous T-cell lymphoma (CTCL has not yet been described. The aim of the study was to determine their levels in these patients’ peripheral blood and cutaneous infiltrates and their relation to the clinical stage of disease.Material/Methods: Forty-one untreated patients, 26 males and 15 females, with CTCL were enrolled in the study. CD8 CD28– lymphocyte levels were determined by flow cytometry in peripheral blood and by immunochemistry in skin infiltrates.Results: The percentage of CD8 CD28– lymphocytes in the peripheral blood of the patients was significantly higher than in the controls. Patients with advanced disease displayed a higher percentage of CD8 CD28– lymphocytes in the peripheral blood and skin than did the individuals with early stages of the disease. Moreover, positive correlations between CD8 CD28– lymphocyte level in peripheral blood and age, clinical stage, and the levels in the skin infiltrates was revealed. Additionally, the percentage of CD8 CD28– T cells in the skin infiltrates correlated positively with age and clinical stage of the disease.Conclusions: These data suggest that CD8 CD28– lymphocytes play an important role in the development of immunotolerance in the progression of cutaneous T-cell lymphoma.

  20. Perivascular Arrest of CD8+ T Cells Is a Signature of Experimental Cerebral Malaria.

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    Tovah N Shaw

    Full Text Available There is significant evidence that brain-infiltrating CD8+ T cells play a central role in the development of experimental cerebral malaria (ECM during Plasmodium berghei ANKA infection of C57BL/6 mice. However, the mechanisms through which they mediate their pathogenic activity during malaria infection remain poorly understood. Utilizing intravital two-photon microscopy combined with detailed ex vivo flow cytometric analysis, we show that brain-infiltrating T cells accumulate within the perivascular spaces of brains of mice infected with both ECM-inducing (P. berghei ANKA and non-inducing (P. berghei NK65 infections. However, perivascular T cells displayed an arrested behavior specifically during P. berghei ANKA infection, despite the brain-accumulating CD8+ T cells exhibiting comparable activation phenotypes during both infections. We observed T cells forming long-term cognate interactions with CX3CR1-bearing antigen presenting cells within the brains during P. berghei ANKA infection, but abrogation of this interaction by targeted depletion of the APC cells failed to prevent ECM development. Pathogenic CD8+ T cells were found to colocalize with rare apoptotic cells expressing CD31, a marker of endothelial cells, within the brain during ECM. However, cellular apoptosis was a rare event and did not result in loss of cerebral vasculature or correspond with the extensive disruption to its integrity observed during ECM. In summary, our data show that the arrest of T cells in the perivascular compartments of the brain is a unique signature of ECM-inducing malaria infection and implies an important role for this event in the development of the ECM-syndrome.

  1. High Frequency of CD8 Positive Lymphocyte Infiltration Correlates with Lack of Lymph Node Involvement in Early Rectal Cancer

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    Silvio Däster

    2014-01-01

    Full Text Available Aims. A trend towards local excision of early rectal cancers has prompted us to investigate if immunoprofiling might help in predicting lymph node involvement in this subgroup. Methods. A tissue microarray of 126 biopsies of early rectal cancer (T1 and T2 was stained for several immunomarkers of the innate and the adaptive immune response. Patients’ survival and nodal status were analyzed and correlated with infiltration of the different immune cells. Results. Of all tested markers, only CD8 (P=0.005 and TIA-1 (P=0.05 were significantly more frequently detectable in early rectal cancer biopsies of node negative as compared to node positive patients. Although these two immunomarkers did not display prognostic effect “per se,” CD8+ and, marginally, TIA-1 T cell infiltration could predict nodal involvement in univariate logistic regression analysis (OR 0.994; 95% CI 0.992–0.996; P=0.009 and OR 0.988; 95% CI 0.984–0.994; P=0.05, resp.. An algorithm significantly predicting the nodal status in early rectal cancer based on CD8 together with vascular invasion and tumor border configuration could be calculated (P<0.00001. Conclusion. Our data indicate that in early rectal cancers absence of CD8+ T-cell infiltration helps in predicting patients’ nodal involvement.

  2. CD8+ Cell Anti-HIV Activity Rapidly Increases Upon Discontinuation of Early Antiretroviral Therapy

    OpenAIRE

    Killian, M. Scott; Roop, Jeremy; Ng, Sharon; Frederick M Hecht; Levy, Jay A.

    2009-01-01

    CD8+ lymphocytes can suppress HIV replication without killing the infected cells. This CD8+ cell noncytotoxic anti-HIV response (CNAR) is associated with a beneficial clinical course. In this longitudinal study of 16 participants in the Options Project at UCSF, we measured the ability of CD8+ lymphocytes to suppress HIV replication in CD4+ cells during primary HIV infection, early antiretroviral therapy, and after treatment. CD8+ lymphocytes from subjects with untreated primary HIV-1 in...

  3. Expansion of quiescent lung adenocarcinoma CD8+ T cells by MUC1-8-mer peptide-T2 cell-β2 microglobulin complexes.

    Science.gov (United States)

    Atzin-Méndez, J A; López-González, J S; Báez, R; Arenas-Del Angel, M C; Montaño, L F; Silva-Adaya, D; Lascurain, R; Gorocica, P

    2016-01-01

    Adoptive immunotherapy requires the isolation of CD8+ T cells specific for tumor-associated antigens, their expansion in vitro and their transfusion to the patient to mediate a therapeutic effect. MUC1 is an important adenocarcinoma antigen immunogenic for T cells. The MUC1-derived SAPDTRPA (MUC1-8-mer) peptide is a potent epitope recognized by CD8+ T cells in murine models. Likewise, the T2 cell line has been used as an antigen-presenting cell to activate CD8+ T cells, but so far MUC1 has not been assessed in this context. We evaluated whether the MUC1-8-mer peptide can be presented by T2 cells to expand CD25+CD8+ T cells isolated from HLA-A2+ lung adenocarcinoma patients with stage III or IV tumors. The results showed that MUC1-8-mer peptide-loaded T2 cells activated CD8+ T cells from cancer HLA-A2+ patients when anti-CD2, anti-CD28 antibodies and IL-2 were added. The percentage of CD25+CD8+ T cells was 3-fold higher than those in the non-stimulated cells (P=0.018). HLA-A2+ patient cells showed a significant difference (2.3-fold higher) in activation status than HLA-A2+ healthy control cells (P=0.04). Moreover, 77.6% of MUC1-8-mer peptide-specific CD8+ T cells proliferated following a second stimulation with MUC1-8-mer peptide-loaded T2 cells after 10 days of cell culture. There were significant differences in the percentage of basal CD25+CD8+ T cells in relation to the cancer stage; this difference disappeared after MUC1-8-mer peptide stimulation. In conclusion, expansion of CD25+CD8+ T cells by MUC1-8 peptide-loaded T2 cells plus costimulatory signals via CD2, CD28 and IL-2 can be useful in adoptive immunotherapy.

  4. 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...

  5. Antigenic topology of the P29 surface lipoprotein of Mycoplasma fermentans: differential display of epitopes results in high-frequency phase variation.

    Science.gov (United States)

    Theiss, P; Karpas, A; Wise, K S

    1996-05-01

    Antibodies to P29, a major lipid-modified surface protein of Mycoplasma fermentans, reveal phase variation of surface epitopes occurring with high frequency in clonal lineages of the organism. This occurs despite continuous expression of the entire epitope-bearing P29 product (detected by Western immunoblotting) and contrasts with phase variation of other surface antigens mediated by differential expression of proteins. To understand the structure and antigenic topology of P29, the single-copy p29 gene from strain PG18 was cloned and sequenced. The gene encodes a prolipoprotein containing a signal sequence predicted to be modified with lipid and cleaved at the N-terminal Cys-1 residue of the mature P29 lipoprotein. The remaining 218-residue hydrophilic sequence of P29 is predicted to be located external to the single plasma membrane. Additional Cys residues at positions 91 and 128 in the mature protein were shown to form a 36-residue disulfide loop by selectively labeling sulfhydryl groups that were liberated only after chemical reduction of monomeric P29. Two nearly identical charged amino acid sequences occurred in P29, within the disulfide loop and upstream of this structure. Two distinct epitopes binding different monoclonal antibodies were associated with opposite ends of the P29 protein, by mapping products expressed in Escherichia coli from PCR-generated 3' deletion mutations of the p29 gene. Each monoclonal antibody detected high-frequency and noncoordinate changes in accessibility of the corresponding epitopes in colony immunoblots of clonal variants, yet sequencing of the p29 gene from these variants and analysis of disulfide bonds revealed no associated changes in the primary sequence or disulfide loop structure of P29. These results suggest that P29 surface epitope variation may involve masking of selected regions of P29, possibly by other surface components undergoing phase variation by differential expression. Differential masking may be an important

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

    Science.gov (United States)

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

    2016-02-01

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

  7. The Breadth of Expandable Memory CD8+ T Cells Inversely Correlates with Residual Viral Loads in HIV Elite Controllers

    Science.gov (United States)

    Ndhlovu, Zaza M.; Stampouloglou, Eleni; Cesa, Kevin; Mavrothalassitis, Orestes; Alvino, Donna Marie; Li, Jonathan Z.; Wilton, Shannon; Karel, Daniel; Piechocka-Trocha, Alicja; Chen, Huabiao; Pereyra, Florencia

    2015-01-01

    ABSTRACT Previous studies have shown that elite controllers with minimal effector T cell responses harbor a low-frequency, readily expandable, highly functional, and broadly directed memory population. Here, we interrogated the in vivo relevance of this cell population by investigating whether the breadth of expandable memory responses is associated with the magnitude of residual viremia in individuals achieving durable suppression of HIV infection. HIV-specific memory CD8+ T cells were expanded by using autologous epitopic and variant peptides. Viral load was measured by an ultrasensitive single-copy PCR assay. Following expansion, controllers showed a greater increase in the overall breadth of Gag responses than did untreated progressors (P = 0.01) as well as treated progressors (P = 0.0003). Nef- and Env-specific memory cells expanded poorly for all groups, and their expanded breadths were indistinguishable among groups (P = 0.9 for Nef as determined by a Kruskal-Wallis test; P = 0.6 for Env as determined by a Kruskal-Wallis test). More importantly, we show that the breadth of expandable, previously undetectable Gag-specific responses was inversely correlated with residual viral load (r = −0.6; P = 0.009). Together, these data reveal a direct link between the abundance of Gag-specific expandable memory responses and prolonged maintenance of low-level viremia. Our studies highlight a CD8+ T cell feature that would be desirable in a vaccine-induced T cell response. IMPORTANCE Many studies have shown that the rare ability of some individuals to control HIV infection in the absence of antiretroviral therapy appears to be heavily dependent upon special HIV-specific killer T lymphocytes that are able to inhibit viral replication. The identification of key features of these immune cells has the potential to inform rational HIV vaccine design. This study shows that a special subset of killer lymphocytes, known as central memory CD8+ T lymphocytes, is at least

  8. Pleural mesothelial cells promote expansion of IL-17-producing CD8+ T cells in tuberculous pleural effusion.

    Science.gov (United States)

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

    2013-05-01

    IL-17-producing CD8(+) T lymphocytes (Tc17 cells) have recently been detected in many cancers and autoimmune diseases. However, the possible implication of Tc17 cells in tuberculous pleural effusion remains unclarified. In this study, distribution and phenotypic features of Tc17 cells in both tuberculous pleural effusion (TPE) and peripheral blood from patients with tuberculosis were determined. The effects of proinflammatory cytokines and local accessory cells (pleural mesothelial cells) on Tc17 cell expansion were also explored. We found that TPE contained more Tc17 cells than the blood. Compared with IFN-γ-producing CD8(+) T cells, Tc17 cells displayed higher expression of chemokine receptors (CCRs) and lower expression of cytotoxic molecules. In particularly, Tc17 cells in TPE exhibited high expression levels of CCR6, which could migrate in response to CCL20. Furthermore, IL-1β, IL-6, IL-23, or their various combinations could promote Tc17 cell expansion from CD8(+) T cells, whereas the proliferative response of Tc17 cells to above cytokines was lower than that of Th17 cells. Pleural mesothelial cells (PMCs) were able to stimulate Tc17 cell expansion via cell contact in an IL-1β/IL-6/IL-23 independent fashion. Thus this study demonstrates that Tc17 cells marks a subset of non-cytotoxic, CCR6(+) CD8(+) T lymphocytes with low proliferative capacity. The overrepresentation of Tc17 cells in TPE may be due to Tc17 cell expansion stimulated by pleural proinflammatory cytokines and to recruitment of Tc17 cells from peripheral blood. Additionally, PMCs may promote the production of IL-17 by CD8(+) T cells at sites of TPE via cell-cell interactions. PMID:23299924

  9. Activation of CD8-dependent cytotoxic T lymphocyte adhesion and degranulation by peptide class I antigen complexes.

    Science.gov (United States)

    Kane, K P; Mescher, M F

    1993-06-01

    Activation of CTL requires engagement of both the TCR and the CD8 coreceptor. Immobilized class I proteins and in vitro-formed peptide class I Ag complexes have been used to examine the relative contributions of TCR and CD8 to the adhesion and response of cloned, class I-restricted CTL. The extent of degranulation was found to be directly proportional to the concentration of peptide used to pulse class I, suggesting that activation is a direct function of TCR occupancy level. In contrast, activation of degranulation as a function of the amount of class I on the surface displayed a marked threshold density dependence. Essentially the same density dependence was found for the response of CTL to fluid phase anti-TCR mAb and non-Ag class I, indicating that CD8-class I interaction must exceed a threshold before effective cosignaling can occur. Adhesion and degranulation of CTL was minimal in response to in vitro peptide-class I complexes prepared at a class I density below the threshold. However, the same density of peptide class I initiated both adhesion and response if additional non-Ag class I was coimmobilized on the same surface at levels above threshold. Thus, when surface levels of peptide class I complex are low, as is likely to be the case under physiologic conditions, the level of TCR occupancy achieved is, by itself, insufficient to mediate cell adhesion or activate degranulation. The results demonstrate, however, that low TCR occupancy is sufficient to provide the signal to prime CD8. Provided that the surface density of class I is sufficiently high, CD8 then mediates strong adhesion and provides the costimulatory signal(s) to activate response.

  10. Enhanced Th1/Th17 Functions of CD161+ CD8+ T Cells in Mucosal Tissues of Rhesus Macaques.

    Directory of Open Access Journals (Sweden)

    Namita Rout

    Full Text Available Expression of the C-type lectin-like receptor CD161 by human T cells is associated with type-17 responses, which play critical regulatory roles in immunity and inflammation at mucosal sites. However, the functions of CD161-expressing T cells in macaques, the pre-clinical model of several human diseases, remain unknown. This study examined the phenotypic and functional characteristics of CD161+ T cells in peripheral blood, mucosal tissues and lymph nodes of rhesus macaques. Majority of CD161-expressing T cells in peripheral blood and lung/intestinal mucosal tissues of rhesus macaques were found to be CD8+CD4- in phenotype. There was a significant enrichment of CD161+CD8+ T cells in the lungs and colonic mucosa (16.1%±6.6 and 16.8%±5.7 in comparison to peripheral blood (4.2%±1.2 and mesenteric lymph nodes (1.3%±0.8. Regardless of the tissue compartment, CD161+CD8+ T cells mainly comprised of γδ T cells and TCR Vα7.2+ MAIT cells (up to 80%, and displayed Th1 and Th17 cytokine responses to mitogen stimulation. Mucosal CD161+CD8+ T cells were characterized by very high expression of CD69, a recent activation marker that is preferentially expressed on tissue resident cells. Furthermore, lung and colonic mucosal CD161+CD8+ T cells showed enhanced IFN-γ, IL-17, and Perforin production in comparison to those in blood. Thus, macaque CD161+CD8+ T cells represent mucosal tissue-homing innate-like CD8+ T-cell populations with Th1/Th17 type cytokine and cytotoxic effector functions that can potentially enhance the recruitment of adaptive immune cells and control initial pathogen burden/dissemination in tissues. Analysis of their role in early immune responses to mucosal pathogens will be valuable in the design of vaccines and therapeutics.

  11. CD4+ T Cell Help Guides Formation of CD103+ Lung-Resident Memory CD8+ T Cells during Influenza Viral Infection

    Science.gov (United States)

    Laidlaw, Brian J.; Zhang, Nianzhi; Marshall, Heather D.; Staron, Mathew M.; Guan, Tianxia; Hu, Yinghong; Cauley, Linda S.; Craft, Joe; Kaech, Susan M.

    2014-01-01

    SUMMARY Tissue-resident memory T (Trm) cells provide enhanced protection against infection at mucosal sites. Here we found that CD4+ T cells are important for the formation of functional lung-resident CD8+ T cells after influenza virus infection. In the absence of CD4+ T cells, CD8+ T cells displayed reduced expression of CD103 (Itgae), were mislocalized away from airway epithelia, and demonstrated an impaired ability to recruit CD8+ T cells to the lung air-ways upon heterosubtypic challenge. CD4+ T cell-derived interferon-γ was necessary for generating lung-resident CD103+ CD8+ Trm CD8 T cells. Furthermore, expression of the transcription factor T-bet was increased in “unhelped” lung Trm cells, and a reduction in T-bet rescued CD103 expression in the absence of CD4+ T cell help. Thus, CD4+ T cell-dependent signals are important to limit expression of T-bet and allow for the development of CD103+ CD8+ Trm cells in the lung airways following respiratory infection. PMID:25308332

  12. 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.

  13. 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

    Science.gov (United States)

    Ersching, Jonatan; Vasconcelos, José R.; Ferreira, Camila P.; Caetano, Braulia C.; Machado, Alexandre V.; Bruna–Romero, Oscar; Baron, Monique A.; Ferreira, Ludmila R. P.; Cunha-Neto, Edécio; Rock, Kenneth L.

    2016-01-01

    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. PMID:27128676

  14. 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.

  15. 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

    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......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...

  16. Avian Influenza Viruses, Inflammation, and CD8+ T Cell Immunity

    Science.gov (United States)

    Wang, Zhongfang; Loh, Liyen; Kedzierski, Lukasz; Kedzierska, Katherine

    2016-01-01

    Avian influenza viruses (AIVs) circulate naturally in wild aquatic birds, infect domestic poultry, and are capable of causing sporadic bird-to-human transmissions. AIVs capable of infecting humans include a highly pathogenic AIV H5N1, first detected in humans in 1997, and a low pathogenic AIV H7N9, reported in humans in 2013. Both H5N1 and H7N9 cause severe influenza disease in humans, manifested by acute respiratory distress syndrome, multi-organ failure, and high mortality rates of 60% and 35%, respectively. Ongoing circulation of H5N1 and H7N9 viruses in wild birds and poultry, and their ability to infect humans emphasizes their epidemic and pandemic potential and poses a public health threat. It is, thus, imperative to understand the host immune responses to the AIVs so we can control severe influenza disease caused by H5N1 or H7N9 and rationally design new immunotherapies and vaccines. This review summarizes our current knowledge on AIV epidemiology, disease symptoms, inflammatory processes underlying the AIV infection in humans, and recent studies on universal pre-existing CD8+ T cell immunity to AIVs. Immune responses driving the host recovery from AIV infection in patients hospitalized with severe influenza disease are also discussed. PMID:26973644

  17. Origin of CD8+ Effector and Memory T Cell Subsets

    Institute of Scientific and Technical Information of China (English)

    Christian Stemberger; Michael Neuenhahn; Veit R.Buchholz; Dirk H.Busch

    2007-01-01

    It is well accepted that CD8+ T cells play a pivotal role in providing protection against infection with intracellular pathogens and some tumors. In many cases protective immunity is maintained for long periods of time (immunological memory). Over the past years, it has become evident that in order to fulfill these multiple tasks,distinct subsets of effector and memory T cells have to be generated. Until today, however, little is known about the underlying mechanisms of subset differentiation and the timing of lineage fate decisions. In this context, it is of special importance to determine at which level of clonal expansion functional and phenotypical heterogeneity is achieved. Different models for T cell subset diversification have been proposed; these differ mainly in the time point during priming and clonal expansion (prior, during, or beyond the first cell division) when differentiation programs are induced. Recently developed single-cell adoptive transfer technology has allowed us to demonstrate that individual precursor cell still bears the full plasticity to develop into a plethora different T cell subsets. This observation targets the shaping of T cell subset differentiation towards factors that are still operative beyond the first cell division. These findings have important implications for vaccine development, as the modulation of differentiation patterns towards distinct subsets could become a powerful strategy to enhance the efficacy and quality of vaccines.

  18. P. falciparum and P. vivax Epitope-Focused VLPs Elicit Sterile Immunity to Blood Stage Infections.

    Directory of Open Access Journals (Sweden)

    David C Whitacre

    Full Text Available In order to design P. falciparum preerythrocytic vaccine candidates, a library of circumsporozoite (CS T and B cell epitopes displayed on the woodchuck hepatitis virus core antigen (WHcAg VLP platform was produced. To test the protective efficacy of the WHcAg-CS VLPs, hybrid CS P. berghei/P. falciparum (Pb/Pf sporozoites were used to challenge immunized mice. VLPs carrying 1 or 2 different CS repeat B cell epitopes and 3 VLPs carrying different CS non-repeat B cell epitopes elicited high levels of anti-insert antibodies (Abs. Whereas, VLPs carrying CS repeat B cell epitopes conferred 98% protection of the liver against a 10,000 Pb/Pf sporozoite challenge, VLPs carrying the CS non-repeat B cell eptiopes were minimally-to-non-protective. One-to-three CS-specific CD4/CD8 T cell sites were also fused to VLPs, which primed CS-specific as well as WHcAg-specific T cells. However, a VLP carrying only the 3 T cell domains failed to protect against a sporozoite challenge, indicating a requirement for anti-CS repeat Abs. A VLP carrying 2 CS repeat B cell epitopes and 3 CS T cell sites in alum adjuvant elicited high titer anti-CS Abs (endpoint dilution titer >1x10(6 and provided 80-100% protection against blood stage malaria. Using a similar strategy, VLPs were constructed carrying P. vivax CS repeat B cell epitopes (WHc-Pv-78, which elicited high levels of anti-CS Abs and conferred 99% protection of the liver against a 10,000 Pb/Pv sporozoite challenge and elicited sterile immunity to blood stage infection. These results indicate that immunization with epitope-focused VLPs carrying selected B and T cell epitopes from the P. falciparum and P. vivax CS proteins can elicit sterile immunity against blood stage malaria. Hybrid WHcAg-CS VLPs could provide the basis for a bivalent P. falciparum/P. vivax malaria vaccine.

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

    Science.gov (United States)

    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

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

    OpenAIRE

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

    2013-01-01

    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+...

  1. Phage displaying peptides mimic schistosoma antigenic epitopes selected by rat natural antibodies and protective immunity induced by their immunization in mice

    Institute of Scientific and Technical Information of China (English)

    Min Wang; Xin-Yuan Yi; Xian-Ping Li; Dong-Ming Zhou; McReynolds Larry; Xian-Fang Zeng

    2005-01-01

    AIM: To obtain the short peptides mimic antigenic epitopes selected by rat natural antibodies to schistosomes, and to explore their immunoprotection against schistosomiasis in mice.METHODS: Adults worm antigens (AWA) were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and enzyme-linked transferred immunoblotting methods with normal SD rat sera (NRS). The killing effects on schistosomula with fresh and heat-inactivated sera from SD rats were observed. Then the purified IgG from sera of SD rats was used to biopan a phage random peptide library and 20 randomly selected positive clones were detected by ELISA and 2 of them were sequenced.Sixty female mice were immunized thrice with positive phage clones (0, 2nd, 4th wk). Each mouse was challenged with 40 cercariae, and all mice were killed 42 d after challenge. The worms and the liver eggs were counted. RESULTS: NRS could specifically react to the molecules of 75 000, 47 000, 34 500 and 23 000 of AWA. Sera from SD rats showed that the mortality rate of schistosomula was 76.2%, and when the sera were heat-inactivated in vitro, the mortality rate was decreased to 41.0% after being cultured for 48 h. The specific phages bound to IgG were enriched about 300-folds after three rounds of biopanning. Twenty clones were detected by ELISA, 19 of them bound to the specific IgG of rat sera. Immunization with these epitopes was carried out in mice. Compared with the control groups, the mixture of two mimic peptides could induce 34.9% (P = 0.000) worm reduction and 67.6% (P = 0.000) total liver egg reduction in mice. Two different mimic peptides could respectively induce 31.0% (P = 0.001), 14.5% (P = 0.074) worm reduction and 61.2% (P = 0.000), 35.7% (P = 0.000) total liver egg reduction. The specific antibody could be induced by immunization of the mimic peptides, and the antibody titer in immunized mice reached more than 1:6 400 as detected by ELISA.CONCLUSION: Specific peptides mimic antigenic

  2. Human cytomegalovirus microRNA miR-US4-1 inhibits CD8+ T cell response by targeting the aminopeptidase ERAP1

    OpenAIRE

    Kim, Sungchul; Lee, Sanghyun; Shin, Jinwook; Kim, Youngkyun; Evnouchidou, Irini; Kim, Donghyun; Kim, Young-Kook; Kim, Young-Eui; Ahn, Jin-Hyun; Riddell, Stanley R; Stratikos, Efstratios; Kim, V. Narry; Ahn, Kwangseog

    2011-01-01

    The major histocompatibility complex (MHC) class I molecules present peptides on the cell surface by CD8+ T cells, which is critical for killing of virally infected or transformed cells. Precursors of MHC class I-presented peptides are trimmed to mature epitopes by endoplasmic reticulum aminopeptidase 1 (ERAP1). The US2-US11 genomic region of human cytomegalovirus (HCMV) is dispensable for viral replication and harbors 3 microRNAs (miRNAs). We show here the HCMV miR-US4-1 specifically down-re...

  3. Peripheral canine CD4(+)CD8(+) double-positive T cells - unique amongst others.

    Science.gov (United States)

    von Buttlar, Heiner; Bismarck, Doris; Alber, Gottfried

    2015-12-15

    T lymphocytes co-expressing CD4 and CD8 ("double-positive T cells") are commonly associated with a thymic developmental stage of T cells. Their first description in humans and pigs as extrathymic T cells with a memory phenotype almost 30 years ago came as a surprise. Meanwhile peripheral double-positive T cells have been described in a growing number of different species. In this review we highlight novel data from our very recent studies on canine peripheral double-positive T cells which point to unique features of double-positive T cells in the dog. In contrast to porcine CD4(+)CD8(+) T cells forming a homogenous cellular population based on their expression of CD4 and CD8α, canine CD4(+)CD8(+) T cells can be divided into three different cellular subsets with distinct expression levels of CD4 and CD8α. Double-positive T cells expressing CD8β are present in humans and dogs but absent in swine. Moreover, canine CD4(+)CD8(+) T cells can not only develop from CD4(+) single-positive T cells but also from CD8(+) single-positive T cells. Together, this places canine CD4(+)CD8(+) T cells closer to their human than porcine counterparts since human double-positive T cells also appear to be heterogeneous in their CD4 and CD8α expression and have both CD4(+) and CD8(+) T cells as progenitor cells. However, CD4(+) single-positive T cells are the more potent progenitors for canine double-positive T cells, whereas CD8(+) single-positive T cells are more potent progenitors for human double-positive T cells. Canine double-positive T cells have an activated phenotype and may have as yet unrecognized roles in vivo in immunity to infection or in inflammatory diseases such as chronic infection, autoimmunity, allergy, or cancer.

  4. Control of mucosal virus infection by influenza nucleoprotein-specific CD8+ cytotoxic T lymphocytes

    Directory of Open Access Journals (Sweden)

    Couch Robert B

    2007-06-01

    Full Text Available Abstract Background MHC class I-restricted CD8+ cytotoxic T lymphocytes (CTL are thought to play a major role in clearing virus and promoting recovery from influenza infection and disease. This has been demonstrated for clearance of influenza virus from the lungs of infected mice. However, human influenza infection is primarily a respiratory mucosal infection involving the nasopharynx and tracheobronchial tree. The role of CD8+ CTL directed toward the influenza nucleoprotein (NP in defense against influenza virus infection at the respiratory mucosa was evaluated in two separate adoptive transfer experiments. Methods Influenza nucleoprotein (NP-specific CD8+ CTL were generated from splenocytes obtained from Balb/c mice previously primed with influenza A/Taiwan/1/86 (H1N1 infection or with influenza A/PR/8/34 (H1N1-derived NP plasmid DNA vaccine followed by infection with A/Hong Kong/68 (H3N2 virus. After in vitro expansion by exposure to an influenza NP-vaccinia recombinant, highly purified CD8+ T cells exhibited significant lysis in vitro of P815 target cells infected with A/Hong Kong/68 (H3N2 virus while the CD8- fraction (CD4+ T cells, B cells and macrophages had no CTL activity. Purified CD8+ and CD8- T cells (1 × 107 were injected intravenously or interperitoneally into naive mice four hours prior to intranasal challenge with A/HK/68 (H3N2 virus. Results The adoptively transferred NP-vaccinia-induced CD8+ T cells caused significant reduction of virus titers in both the lungs and nasal passages when compared to CD8- cells. Neither CD8+ nor CD8- T cells from cultures stimulated with HIV gp120-vaccinia recombinant reduced virus titers. Conclusion The present data demonstrate that influenza NP-specific CD8+ CTL can play a direct role in clearance of influenza virus from the upper respiratory mucosal surfaces.

  5. The closely related CD103+ dendritic cells (DCs) and lymphoid-resident CD8+ DCs differ in their inflammatory functions.

    Science.gov (United States)

    Jiao, Zhijun; Bedoui, Sammy; Brady, Jamie L; Walter, Anne; Chopin, Michael; Carrington, Emma M; Sutherland, Robyn M; Nutt, Stephen L; Zhang, Yuxia; Ko, Hyun-Ja; Wu, Li; Lew, Andrew M; Zhan, Yifan

    2014-01-01

    Migratory CD103+ and lymphoid-resident CD8+ dendritic cells (DCs) share many attributes, such as dependence on the same transcription factors, cross-presenting ability and expression of certain surface molecules, such that it has been proposed they belong to a common sub-lineage. The functional diversity of the two DC types is nevertheless incompletely understood. Here we reveal that upon skin infection with herpes simplex virus, migratory CD103+ DCs from draining lymph nodes were more potent at inducing Th17 cytokine production by CD4+ T cells than CD8+ DCs. This superior capacity to drive Th17 responses was also evident in CD103+ DCs from uninfected mice. Their differential potency to induce Th17 differentiation was reflected by higher production of IL-1β and IL-6 by CD103+ DCs compared with CD8+ DCs upon stimulation. The two types of DCs from isolated lymph nodes also differ in expression of certain pattern recognition receptors. Furthermore, elevated levels of GM-CSF, typical of those found in inflammation, substantially increased the pool size of CD103+ DCs in lymph nodes and skin. We argue that varied levels of GM-CSF may explain the contrasting reports regarding the positive role of GM-CSF in regulating development of CD103+ DCs. Together, we find that these two developmentally closely-related DC subsets display functional differences and that GM-CSF has differential effect on the two types of DCs.

  6. The closely related CD103+ dendritic cells (DCs and lymphoid-resident CD8+ DCs differ in their inflammatory functions.

    Directory of Open Access Journals (Sweden)

    Zhijun Jiao

    Full Text Available Migratory CD103+ and lymphoid-resident CD8+ dendritic cells (DCs share many attributes, such as dependence on the same transcription factors, cross-presenting ability and expression of certain surface molecules, such that it has been proposed they belong to a common sub-lineage. The functional diversity of the two DC types is nevertheless incompletely understood. Here we reveal that upon skin infection with herpes simplex virus, migratory CD103+ DCs from draining lymph nodes were more potent at inducing Th17 cytokine production by CD4+ T cells than CD8+ DCs. This superior capacity to drive Th17 responses was also evident in CD103+ DCs from uninfected mice. Their differential potency to induce Th17 differentiation was reflected by higher production of IL-1β and IL-6 by CD103+ DCs compared with CD8+ DCs upon stimulation. The two types of DCs from isolated lymph nodes also differ in expression of certain pattern recognition receptors. Furthermore, elevated levels of GM-CSF, typical of those found in inflammation, substantially increased the pool size of CD103+ DCs in lymph nodes and skin. We argue that varied levels of GM-CSF may explain the contrasting reports regarding the positive role of GM-CSF in regulating development of CD103+ DCs. Together, we find that these two developmentally closely-related DC subsets display functional differences and that GM-CSF has differential effect on the two types of DCs.

  7. Qualitative and quantitative analysis of adenovirus type 5 vector-induced memory CD8 T cells: not as bad as their reputation.

    Science.gov (United States)

    Steffensen, Maria Abildgaard; Holst, Peter Johannes; Steengaard, Sanne Skovvang; Jensen, Benjamin Anderschou Holbech; Bartholdy, Christina; Stryhn, Anette; Christensen, Jan Pravsgaard; Thomsen, Allan Randrup

    2013-06-01

    It has been reported that adenovirus (Ad)-primed CD8 T cells may display a distinct and partially exhausted phenotype. Given the practical implications of this claim, we decided to analyze in detail the quality of Ad-primed CD8 T cells by directly comparing these cells to CD8 T cells induced through infection with lymphocytic choriomeningitis virus (LCMV). We found that localized immunization with intermediate doses of Ad vector induces a moderate number of functional CD8 T cells which qualitatively match those found in LCMV-infected mice. The numbers of these cells may be efficiently increased by additional adenoviral boosting, and, importantly, the generated secondary memory cells cannot be qualitatively differentiated from those induced by primary infection with replicating virus. Quantitatively, DNA priming prior to Ad vaccination led to even higher numbers of memory cells. In this case, the vaccination led to the generation of a population of memory cells characterized by relatively low CD27 expression and high CD127 and killer cell lectin-like receptor subfamily G member 1 (KLRG1) expression. These memory CD8 T cells were capable of proliferating in response to viral challenge and protecting against infection with live virus. Furthermore, viral challenge was followed by sustained expansion of the memory CD8 T-cell population, and the generated memory cells did not appear to have been driven toward exhaustive differentiation. Based on these findings, we suggest that adenovirus-based prime-boost regimens (including Ad serotype 5 [Ad5] and Ad5-like vectors) represent an effective means to induce a substantially expanded, long-lived population of high-quality transgene-specific memory CD8 T cells.

  8. CD8+ T cells induce platelet clearance in the liver via platelet desialylation in immune thrombocytopenia

    Science.gov (United States)

    Qiu, Jihua; Liu, Xuena; Li, Xiaoqing; Zhang, Xu; Han, Panpan; Zhou, Hai; Shao, Linlin; Hou, Yu; Min, Yanan; Kong, Zhangyuan; Wang, Yawen; Wei, Yu; Liu, Xinguang; Ni, Heyu; Peng, Jun; Hou, Ming

    2016-01-01

    In addition to antiplatelet autoantibodies, CD8+ cytotoxic T lymphocytes (CTLs) play an important role in the increased platelet destruction in immune thrombocytopenia (ITP). Recent studies have highlighted that platelet desialylation leads to platelet clearance via hepatocyte asialoglycoprotein receptors (ASGPRs). Whether CD8+ T cells induce platelet desialylation in ITP remains unclear. Here, we investigated the cytotoxicity of CD8+ T cells towards platelets and platelet desialylation in ITP. We found that the desialylation of fresh platelets was significantly higher in ITP patients with positive cytotoxicity of CD8+ T cells than those without cytotoxicity and controls. In vitro, CD8+ T cells from ITP patients with positive cytotoxicity induced significant platelet desialylation, neuraminidase-1 expression on the platelet surface, and platelet phagocytosis by hepatocytes. To study platelet survival and clearance in vivo, CD61 knockout mice were immunized and their CD8+ splenocytes were used. Platelets co-cultured with these CD8+ splenocytes demonstrated decreased survival in the circulation and increased phagocytosis in the liver. Both neuraminidase inhibitor and ASGPRs competitor significantly improved platelet survival and abrogated platelet clearance caused by CD8+ splenocytes. These findings suggest that CD8+ T cells induce platelet desialylation and platelet clearance in the liver in ITP, which may be a novel mechanism of ITP. PMID:27321376

  9. 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...

  10. CD8(+) T cells induce platelet clearance in the liver via platelet desialylation in immune thrombocytopenia.

    Science.gov (United States)

    Qiu, Jihua; Liu, Xuena; Li, Xiaoqing; Zhang, Xu; Han, Panpan; Zhou, Hai; Shao, Linlin; Hou, Yu; Min, Yanan; Kong, Zhangyuan; Wang, Yawen; Wei, Yu; Liu, Xinguang; Ni, Heyu; Peng, Jun; Hou, Ming

    2016-01-01

    In addition to antiplatelet autoantibodies, CD8(+) cytotoxic T lymphocytes (CTLs) play an important role in the increased platelet destruction in immune thrombocytopenia (ITP). Recent studies have highlighted that platelet desialylation leads to platelet clearance via hepatocyte asialoglycoprotein receptors (ASGPRs). Whether CD8(+) T cells induce platelet desialylation in ITP remains unclear. Here, we investigated the cytotoxicity of CD8(+) T cells towards platelets and platelet desialylation in ITP. We found that the desialylation of fresh platelets was significantly higher in ITP patients with positive cytotoxicity of CD8(+) T cells than those without cytotoxicity and controls. In vitro, CD8(+) T cells from ITP patients with positive cytotoxicity induced significant platelet desialylation, neuraminidase-1 expression on the platelet surface, and platelet phagocytosis by hepatocytes. To study platelet survival and clearance in vivo, CD61 knockout mice were immunized and their CD8(+) splenocytes were used. Platelets co-cultured with these CD8(+) splenocytes demonstrated decreased survival in the circulation and increased phagocytosis in the liver. Both neuraminidase inhibitor and ASGPRs competitor significantly improved platelet survival and abrogated platelet clearance caused by CD8(+) splenocytes. These findings suggest that CD8(+) T cells induce platelet desialylation and platelet clearance in the liver in ITP, which may be a novel mechanism of ITP. PMID:27321376

  11. CD8αα innate-type lymphocytes in the intestinal epithelium mediate mucosal immunity

    OpenAIRE

    Kaer, Luc Van; Scott Algood, Holly M.; Singh, Kshipra; Parekh, Vrajesh V.; Greer, Michael J.; Piazuelo, M. Blanca; Weitkamp, Jörn-Hendrik; Matta, Pranathi; Chaturvedi, Rupesh; Wilson, Keith T.; Olivares-Villagómez, Danyvid

    2014-01-01

    Innate immune responses are critical for mucosal immunity. Here we describe an innate lymphocyte population, iCD8α cells, characterized by expression of CD8α homodimers. iCD8α cells exhibit innate functional characteristics such as the capacity to engulf and kill bacteria. Development of iCD8α cells depends on expression of interleukin-2 receptor γ chain (IL-2Rγc), IL-15, and the major histocompatibility complex (MHC) class Ib protein H2-T3, also known as the thymus leukemia antigen or TL. Wh...

  12. CD8+ T cells cause disability and axon loss in a mouse model of multiple sclerosis.

    Directory of Open Access Journals (Sweden)

    Chandra Deb

    Full Text Available BACKGROUND: The objective of this study was to test the hypothesis that CD8+ T cells directly mediate motor disability and axon injury in the demyelinated central nervous system. We have previously observed that genetic deletion of the CD8+ T cell effector molecule perforin leads to preservation of motor function and preservation of spinal axons in chronically demyelinated mice. METHODOLOGY/PRINCIPAL FINDINGS: To determine if CD8+ T cells are necessary and sufficient to directly injure demyelinated axons, we adoptively transferred purified perforin-competent CD8+ spinal cord-infiltrating T cells into profoundly demyelinated but functionally preserved perforin-deficient host mice. Transfer of CD8+ spinal cord-infiltrating T cells rapidly and irreversibly impaired motor function, disrupted spinal cord motor conduction, and reduced the number of medium- and large-caliber spinal axons. Likewise, immunodepletion of CD8+ T cells from chronically demyelinated wildtype mice preserved motor function and limited axon loss without altering other disease parameters. CONCLUSIONS/SIGNIFICANCE: In multiple sclerosis patients, CD8+ T cells outnumber CD4+ T cells in active lesions and the number of CD8+ T cells correlates with the extent of ongoing axon injury and functional disability. Our findings suggest that CD8+ T cells may directly injure demyelinated axons and are therefore a viable therapeutic target to protect axons and motor function in patients with multiple sclerosis.

  13. Protective effects of tea polyphenols against the destruction of melanocytes by CD8+ T ceils from vitiligo patients%茶多酚对CD8+T细胞杀伤白癜风患者黑素细胞的保护作用研究

    Institute of Scientific and Technical Information of China (English)

    欧阳杰; 吴纪龙; 周妙妮; 付丽芳; 许爱娥

    2013-01-01

    Objective To evaluate the protective effects of tea polyphenols against the destruction of melanocytes by CD8+ T cells from vitiligo patients.Methods Skin tissue was resected from the margin of vitiligo lesions followed by the isolation and culture of CD8+ T lymphocytes,and from the normal skin of vitiligo patients followed by the isolation and culture of melanocytes.Flow cytometry was carried out to evaluate the purity of CD8+ T cells.The melanocytes were cocultured with the CD8 + T cells at different ratios followed by the evaluation of killing effect of CD8+ T cells.Various concentrations (200 and 400 μg/ml) of tea polyphenols were added into the co-culture system of CD8+ T cells and melanocytes at a ratio of 5 ∶ 1 followed by an additional culture of 48 hours.Then,flow cytometry was performed to detect the apoptosis in melanocytes in the coculture system.Results CD8+ T lymphocytes were successfully obtained from the marginal area of vitiligo lesions with a purity of more than 90%,which highly expressed the antigens CD137 and CD69.The coculture with CD8+ T cells markedly accelerated the apoptosis in melanocytes,while the accelerative effect was inhibited by tea polyphenols of 200 and 400 μg/ml.Conclusions The CD8+ T cells infiltrating the edge of vitiligo lesions display a potential destructive effect on autologous melanocytes from vitiligo patients,and tea polyphenols have a protective effect against the destruction of melanocytes by CD8+ T cells.%目的 探讨茶多酚对CD8+T细胞杀伤白癜风患者黑素细胞的保护作用.方法 取白癜风患者白斑边缘处皮片组织,培养CD8+T淋巴细胞,细胞纯度用流式细胞仪进行鉴定,通过和黑素细胞共培养验证其针对黑素细胞的杀伤作用.将不同浓度茶多酚加入CD8+T细胞和黑素细胞共培养的体系,用流式细胞仪检测黑素细胞的凋亡.结果 取白癜风皮损边缘表皮组织中成功培养CD8+T淋巴细胞,纯度达90%

  14. Identification of T. gondii epitopes, adjuvants, & host genetic factors that influence protection of mice & humans

    OpenAIRE

    Tan, Tze Guan; Mui, Ernest; Cong, Hua; Witola, William; Montpetit, Alexandre; Muench, Stephen P.; Sidney, John; Alexander, Jeff; Sette, Alessandro; Grigg, Michael; Maewal, Ajesh; McLeod, Rima

    2010-01-01

    Toxoplasma gondii is an intracellular parasite that causes severe neurologic and ocular disease in immune-compromised and congenitally infected individuals. There is no vaccine protective against human toxoplasmosis. Herein, immunization of Ld mice with HF10 (HPGSVNEFDF) with palmitic acid moieties or a monophosphoryl lipid A derivative elicited potent IFN-γ production from Ld-restricted CD8+ T cells in vitro and protected mice. CD8+ T cell peptide epitopes from T. gondii dense granule protei...

  15. 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...... approach than through the application of state-of-the-art epitope prediction. This flow cytometry-based technology therefore holds considerable promise for monitoring clinically relevant antigen-specific T-cell responses in populations of distinct ethnicity....

  16. Cytometry by time-of-flight shows combinatorial cytokine expression and virus-specific cell niches within a continuum of CD8+ T cell phenotypes.

    Science.gov (United States)

    Newell, Evan W; Sigal, Natalia; Bendall, Sean C; Nolan, Garry P; Davis, Mark M

    2012-01-27

    Cytotoxic CD8(+) T lymphocytes directly kill infected or aberrant cells and secrete proinflammatory cytokines. By using metal-labeled probes and mass spectrometric analysis (cytometry by time-of-flight, or CyTOF) of human CD8(+) T cells, we analyzed the expression of many more proteins than previously possible with fluorescent labels, including surface markers, cytokines, and antigen specificity with modified peptide-MHC tetramers. With 3-dimensional principal component analysis (3D-PCA) to display phenotypic diversity, we observed a relatively uniform pattern of variation in all subjects tested, highlighting the interrelatedness of previously described subsets and the continuous nature of CD8(+) T cell differentiation. These data also showed much greater complexity in the CD8(+) T cell compartment than previously appreciated, including a nearly combinatorial pattern of cytokine expression, with distinct niches occupied by virus-specific cells. This large degree of functional diversity even between cells with the same specificity gives CD8(+) T cells a remarkable degree of flexibility in responding to pathogens. PMID:22265676

  17. Modified tumour antigen-encoding mRNA facilitates the analysis of naturally occurring and vaccine-induced CD4 and CD8 T cells in cancer patients.

    Science.gov (United States)

    Knights, Ashley J; Nuber, Natko; Thomson, Christopher W; de la Rosa, Olga; Jäger, Elke; Tiercy, Jean-Marie; van den Broek, Maries; Pascolo, Steve; Knuth, Alexander; Zippelius, Alfred

    2009-03-01

    The development of effective anti-cancer vaccines requires precise assessment of vaccine-induced immunity. This is often hampered by low ex vivo frequencies of antigen-specific T cells and limited defined epitopes. This study investigates the applicability of modified, in vitro-transcribed mRNA encoding a therapeutically relevant tumour antigen to analyse T cell responses in cancer patients. In this study transfection of antigen presenting cells, by mRNA encoding the tumour antigen NY-ESO-1, was optimised and applied to address spontaneous and vaccine-induced T cell responses in cancer patients. Memory CD8+ T cells from lung cancer patients having detectable humoral immune responses directed towards NY-ESO-1 could be efficiently detected in peripheral blood. Specific T cells utilised a range of different T cell receptors, indicating a polyclonal response. Specific killing of a panel of NY-ESO-1 expressing tumour cell lines indicates recognition restricted to several HLA allelic variants, including a novel HLA-B49 epitope. Using a modified mRNA construct targeting the translated antigen to the secretory pathway, detection of NY-ESO-1-specific CD4+ T cells in patients could be enhanced, which allowed the in-depth characterisation of established T cell clones. Moreover, broad CD8+ and CD4+ T cell responses covering multiple epitopes were detected following mRNA stimulation of patients treated with a recombinant vaccinia/fowlpox NY-ESO-1 vaccine. This approach allows for a precise monitoring of responses to tumour antigens in a setting that addresses the breadth and magnitude of antigen-specific T cell responses, and that is not limited to a particular combination of known epitopes and HLA-restrictions. PMID:18663444

  18. Loss of viral fitness and cross-recognition by CD8+ T cells limit HCV escape from a protective HLA-B27–restricted human immune response

    OpenAIRE

    Dazert, Eva; Neumann-Haefelin, Christoph; Bressanelli, Stéphane; Fitzmaurice, Karen; Kort, Julia; Timm, Jörg; McKiernan, Susan; Kelleher, Dermot; Gruener, Norbert; Tavis, John E.; Rosen, Hugo R.; Shaw, Jaqueline; Bowness, Paul; Blum, Hubert E.; Klenerman, Paul

    2009-01-01

    There is an association between expression of the MHC class I molecule HLA-B27 and protection following human infection with either HIV or HCV. In both cases, protection has been linked to HLA-B27 presentation of a single immunodominant viral peptide epitope to CD8+ T cells. If HIV mutates the HLA-B27–binding anchor of this epitope to escape the protective immune response, the result is a less-fit virus that requires additional compensatory clustered mutations. Here, we sought to determine wh...

  19. Epitope DNA vaccines against tuberculosis: spacers and ubiquitin modulates cellular immune responses elicited by epitope DNA vaccine

    Institute of Scientific and Technical Information of China (English)

    Wang QM; Sun SH; Hu ZL; Zhou FJ; Yin M; Xiao CJ; Zhang JC

    2005-01-01

    Cell-mediated immune responses are crucial in the protection against tuberculosis. In this study, we constructed epitope DNA vaccines (p3-M-38) encoding cytotoxic T lymphocyte (CTL) epitopes of MPT64 and 38 kDa proteins of Mycobacterium tuberculosis. In order to observe the influence of spacer sequence (Ala-Ala-Tyr) or ubiquitin (UbGR) on the efficacy of the two CTL epitopes, we also constructed DNA vaccines, p3-M-S(spacer)-38, p3-Ub (UbGR)-M-S-38 and p3-Ub-M-38. The immune responses elicited by the four DNA vaccines were tested in C57BL/6 (H-2b) mice. The cytotoxicity of T cells was detected by LDH-release method and by enzyme-linked immunospot assay for epitope-specific cells secreting interferon-gamma. The results showed that DNA immunization with p3-M-38 vaccine could induce epitope-specific CD8+ CTL response and that the spacer sequence (AAY) only enhanced M epitope presentation. The protein-targeting sequence (UbGR) enhanced the immunogenicity of the two epitopes. The finding that defined spacer sequences at C-terminus and protein-targeting degradation modulated the immune response of epitope string DNA vaccines will be of importance for the further development of multi-epitope DNA vaccines against tuberculosis.

  20. Linfocitos T citotóxicos CD8+ en la leishmaniasis cutánea CD8+ cytotoxic lymphocytes in cutaneous leishmaniasis

    Directory of Open Access Journals (Sweden)

    Joselín Hernández-Ruiz

    2006-10-01

    Full Text Available OBJETIVO: Examinar la bibliografía relacionada con la participación de los linfocitos T CD8+ en la reacción inmunitaria a especies de Leishmania causantes de leishmaniasis cutánea. En esta enfermedad se ha resaltado la intervención de macrófagos, células dendríticas, NK y células T CD4+; sin embargo, es poco lo que se conoce de las células T CD8+. Los trabajos en modelos murinos señalan que la participación de las células CD8+ sucede a través de la producción de IFN-gamma, aunque su capacidad citotóxica puede desempeñar una función importante, como lo demuestran los hallazgos en seres humanos. La forma como se activan las células citotóxicas CD8+ es un enigma. Es posible que las células dendríticas realicen esa labor a través de mecanismos que incluyen transpresentación de antígenos. Comprender la contribución de este subtipo celular en la respuesta inmunitaria a Leishmania aportará novedosos conocimientos sobre la fisiopatogenia de la leishmaniasis, lo cual hará posible desarrollar nuevos enfoques terapéuticos para esta parasitosis.OBJECTIVE: Review of the literature on the role of CD8+ T cell in the immune response against Leishmania species that cause cutaneous leishmaniasis. The role of macrophages, dendritic cells, CD4 T cells and NK cells has been extensively analyzed in leishmaniasis, yet very little knowledge has been gained on CD8+ T cells in this disease. Murine models of leishmaniasis suggest that CD8+ T cells participate through IFNg production, yet their cytotoxic capacity may also play a crucial role, as has been found in human disease. It is an enigma what mechanisms underlie the CD8+ T cell activation. It is possible that dendritic cells activate CD8+ T cells through mechanisms that include antigen traspresentation. A better understanding of CD8+ T cells in the immune response against Leishmania will undoubtedly provide new insights into the physiopathogenesis of the disease that could lead to new

  1. CD3(+)CD8(+)CD28(-) T Lymphocytes in Patients with Lupus Nephritis.

    Science.gov (United States)

    Żabińska, Marcelina; Krajewska, Magdalena; Kościelska-Kasprzak, Katarzyna; Klinger, Marian

    2016-01-01

    The results of studies on the CD3(+)CD8(+)CD28(-) cells in SLE are inconsistent since several analyses describe CD3(+)CD8(+)CD28(-) as either immunosuppressive or cytotoxic. The aim of this study is to inquire whether the quantitative changes of CD3(+)CD8(+)CD28(-) T lymphocytes subpopulation are related to the clinical status of patients with lupus nephritis. Evaluation of Foxp3 expression on CD3(+)CD8(+)CD28(-) cells may shed some light on functional properties of these cells. 54 adult SLE patients and 19 sex and age matched healthy volunteers were enrolled in the study. There were 15 patients in inactive (SLEDAI ≤ 5) and 39 in active (SLEDAI > 5) phase of disease. We determined absolute count of CD3(+)CD8(+)CD28(-) and CD3(+)CD8(+)CD28(-)Foxp3(+) subpopulations by flow cytometry. We observed a statistically significant increase in absolute count and percentage of CD3(+)CD8(+)CD28(-) in SLE patients compared to HC (p < 0.001). Moreover there was significant positive correlation between increasing absolute count of CD3(+)CD8(+)CD28(-) cells and disease activity measured by SLEDAI (rs = 0.281, p = 0.038). Active LN patients had increased absolute count of CD3(+)CD8(+)CD28(-) cells compared to HC. Positive correlation of CD3(+)CD8(+)CD28(-) number with disease activity, and lack of Foxp3 expression on these cells, suggests that CD3(+)CD8(+)CD28(-) lymphocytes might be responsible for an increased proinflammatory response in the exacerbation of SLE. PMID:27446964

  2. Cross-clade conservation of HIV type 1 Nef immunodominant regions recognized by CD8+ T cells of HIV type 1 CRF02_AG-infected Ivorian (West Africa).

    Science.gov (United States)

    Inwoley, André; Recordon-Pinson, Patricia; Dupuis, Marion; Gaston, Jessintha; Genête, Mathieu; Minga, Albert; Letourneur, Franck; Rouet, François; Choppin, Jeannine; Fleury, Hervé; Guillet, Jean-Gérard; Andrieu, Muriel

    2005-07-01

    Most HIV vaccine trials in the world are conducted with clade B while most circulating viral strains in Africa are non-B subtypes. We determined whether CD8+ T cells from HIV-1 intersubtype CRF02_AG-infected Ivorian individuals were able to recognize clade B epitopes. CD8+ T cell responses of nine HIV-1 intersubtype CRF02_AG-infected Ivorian patients and nine HIV-1 subtype B-infected French patients were studied using pools of HIV-1 clade B peptides (110 well-defined HIV CD8+ T cell epitopes) in an ELISPOT IFN-gamma assay. There was no difference in the number of recognized peptide pools between Ivorian and French cohorts (mean of four pools in both cases). Ivorian individuals had generated CD8+ T cell responses cross-reactive against HIV-1 subtype B and some individual peptides had been identified. Furthermore, sequence analysis of nef HIV genes of the Ivorian patients and nef cloning in two patients revealed very few variations between HIV- 1 intersubtype CRF02_AG and subtype B in nef immunodominant regions included in HIV clade B lipopeptide vaccines, currently tested in France.

  3. Distribution, characterization, and induction of CD8+ regulatory T cells and IL-17-producing CD8+ T cells in nasopharyngeal carcinoma

    Directory of Open Access Journals (Sweden)

    Li Jiang

    2011-11-01

    Full Text Available Abstract Background CD8+ effector cells often have an antitumor function in patients with cancer. However, CD8+Foxp3+ regulatory T cells (Tcregs and interleukin (IL-17-producing CD8+ T cells (Tc17 cells also derive from the CD8+ T cell lineage. Their role in the antitumor response remains largely unknown. In the present study, we aimed to investigate the distribution, characterization, and generation of CD8+ Tcregs and Tc17 cells in NPC patients. Methods Peripheral blood and tumor biopsy tissues from 21 newly diagnosed patients with nasopharyngeal carcinoma (NPC were collected, along with peripheral blood from 21 healthy donors. The biological characteristics of Tcregs and Tc17 cells from blood and tumor tissues were examined by intracellular staining, tetramer staining and fluorescence-activated cell sorting (FACS analysis. The suppressive function of Tcregs was investigated using a proliferation assay that involved co-culture of sorted CD8+CD25+ T cells with naïve CD4+ T cells in vitro. Results We observed an increased prevalence of Tcregs and Tc17 cells among tumor-infiltrating lymphocytes (TILs and different distribution among peripheral blood mononuclear cells (PBMCs in NPC patients. Cytokine profiles showed that the Tcregs expressed a high level of IL-10 and low level of transforming growth factor β, whereas Tc17 cells expressed a high level of tumor necrosis factor α. Interestingly, both subsets expressed a high level of interferon γ in TILs, and the Tcregs suppressed naïve CD4+ T cell proliferation by a cell contact-dependent mechanism in vitro. Moreover, we demonstrated the existence of Epstein-Barr virus latent membrane protein (LMP 1 and LMP2 antigen-specific Tcregs in NPC. Conclusions Our data provide new insights into the composition and function of CD8+ T-cell subsets in NPC, which may have an important influence on NPC immunotherapy.

  4. Why Do CD8+ T Cells become Indifferent to Tumors: A Dynamic Modeling Approach.

    Science.gov (United States)

    Campbell, Colin; Zhang, Ranran; Haley, Jeremy S; Liu, Xin; Loughran, Thomas; Schell, Todd D; Albert, Réka; Thakar, Juilee

    2011-01-01

    CD8+ T cells have the potential to influence the outcome of cancer pathogenesis, including complete tumor eradication or selection of malignant tumor escape variants. The Simian virus 40 large T-antigen (Tag) oncoprotein promotes tumor formation in Tag-transgenic mice and also provides multiple target determinants (sites) for responding CD8+ T cells in C57BL/6 (H-2(b)) mice. To understand the in vivo quantitative dynamics of CD8+ T cells after encountering Tag, we constructed a dynamic model from in vivo-generated data to simulate the interactions between Tag-expressing cells and CD8+ T cells in distinct scenarios including immunization of wild-type C57BL/6 mice and of Tag-transgenic mice that develop various tumors. In these scenarios the model successfully reproduces the dynamics of both the Tag-expressing cells and antigen-specific CD8+ T cell responses. The model predicts that the tolerance of the site-specific T cells is dependent on their apoptosis rates and that the net growth of CD8+ T cells is altered in transgenic mice. We experimentally validate both predictions. Our results indicate that site-specific CD8+ T cells have tissue-specific apoptosis rates affecting their tolerance to the tumor antigen. Moreover, the model highlights differences in apoptosis rates that contribute to compromised CD8+ T cell responses and tumor progression, knowledge of which is essential for development of cancer immunotherapy. PMID:21808621

  5. Heterogeneity in the differentiation and function of CD8⁺ T cells.

    Science.gov (United States)

    Mittrücker, Hans-Willi; Visekruna, Alexander; Huber, Magdalena

    2014-12-01

    It is well established that CD8(+) T cells constitute an important branch of adaptive immunity contributing to clearance of intracellular pathogens and providing long-term protection. These functions are mostly fulfilled by the best characterized subpopulation of CD8(+) T cells, the cytotoxic T lymphocytes (also called Tc1 cells), owing to their ability to kill infected cells and to secrete cytokines such as interferon-γ and tumor necrosis factor-α. However, there is growing evidence for alternative CD8(+) T cell fates influencing CD4(+) T-cell-mediated responses in the context of allergy, autoimmunity and infections. Thus, like subpopulations of CD4(+) T cells, also CD8(+) T cells under particular conditions acquire the expression of interleukin (IL)-4, IL-5, IL-9, IL-13, IL-17 or suppressive activity and thereby influence immune responses. The process of CD8(+) T-cell differentiation is dictated by antigen strength, co-stimulatory molecules and cytokines. These environmental cues induce transcription factors further specifying CD8(+) T-cell decision into Tc1, Tc2, Tc9, Tc17 or CD8(+) T regulatory fate. Here, we discuss our current understanding about functional diversity of effector CD8(+) T cells and contribution of transcription factors to this process. PMID:24879097

  6. 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

    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...

  7. Why Do CD8 + T Cells Become Indifferent To Tumors: A Dynamic Modeling Approach

    Directory of Open Access Journals (Sweden)

    Colin eCampbell

    2011-07-01

    Full Text Available CD8+ T cells have the potential to influence the outcome of cancer pathogenesis, including complete tumor eradication or selection of malignant tumor escape variants. The Simian virus 40 large T-antigen oncoprotein promotes tumor formation in T-antigen transgenic mice and also provides multiple target determinants (sites for responding CD8+ T cells in C57BL/6 (H-2b mice. To understand the in vivo quantitative dynamics of CD8+ T cells after encountering T-antigen, we constructed a dynamic model from in vivo-generated data to simulate the interactions between T-antigen expressing cells and CD8+ T cells in distinct scenarios including immunization of wild type C57BL/6 mice and of T-antigen transgenic mice that develop various tumors. In these scenarios the model successfully reproduces the dynamics of both the T-antigen-expressing cells and antigen specific CD8+ T cell responses. The model predicts that the tolerance of the site-specific T cells is dependent on their apoptosis rates and that the net growth of CD8+ T cells is altered in transgenic mice. We experimentally validate both predictions. Our results indicate that site-specific CD8+ T cells have tissue-specific apoptosis rates affecting their tolerance to the tumor antigen. Moreover, the model highlights differences in apoptosis rates that contribute to compromised CD8+ T cell responses and tumor progression, knowledge of which is essential for development of cancer immunotherapy.

  8. The Herpes Simplex Virus Latency-Associated Transcript Gene Is Associated with a Broader Repertoire of Virus-Specific Exhausted CD8+ T Cells Retained within the Trigeminal Ganglia of Latently Infected HLA Transgenic Rabbits

    Science.gov (United States)

    Srivastava, Ruchi; Dervillez, Xavier; Khan, Arif A.; Chentoufi, Aziz A.; Chilukuri, Sravya; Shukr, Nora; Fazli, Yasmin; Ong, Nicolas N.; Afifi, Rasha E.; Osorio, Nelson; Geertsema, Roger; Nesburn, Anthony B.

    2016-01-01

    ABSTRACT Persistent pathogens, such as herpes simplex virus 1 (HSV-1), have evolved a variety of immune evasion strategies to avoid being detected and destroyed by the host's immune system. A dynamic cross talk appears to occur between the HSV-1 latency-associated transcript (LAT), the only viral gene that is abundantly transcribed during latency, and the CD8+ T cells that reside in HSV-1 latently infected human and rabbit trigeminal ganglia (TG). The reactivation phenotype of TG that are latently infected with wild-type HSV-1 or with LAT-rescued mutant (i.e., LAT+ TG) is significantly higher than TG latently infected with LAT-null mutant (i.e., LAT− TG). Whether LAT promotes virus reactivation by selectively shaping a unique repertoire of HSV-specific CD8+ T cells in LAT+ TG is unknown. In the present study, we assessed the frequency, function, and exhaustion status of TG-resident CD8+ T cells specific to 40 epitopes derived from HSV-1 gB, gD, VP11/12, and VP13/14 proteins, in human leukocyte antigen (HLA-A*0201) transgenic rabbits infected ocularly with LAT+ versus LAT– virus. Compared to CD8+ T cells from LAT– TG, CD8+ T cells from LAT+ TG (i) recognized a broader selection of nonoverlapping HSV-1 epitopes, (ii) expressed higher levels of PD-1, TIM-3, and CTLA-4 markers of exhaustion, and (iii) produced less tumor necrosis factor alpha, gamma interferon, and granzyme B. These results suggest a novel immune evasion mechanism by which the HSV-1 LAT may contribute to the shaping of a broader repertoire of exhausted HSV-specific CD8+ T cells in latently infected TG, thus allowing for increased viral reactivation. IMPORTANCE A significantly larger repertoire of dysfunctional (exhausted) HSV-specific CD8+ T cells were found in the TG of HLA transgenic rabbits latently infected with wild-type HSV-1 or with LAT-rescued mutant (i.e., LAT+ TG) than in a more restricted repertoire of functional HSV-specific CD8+ T cells in the TG of HLA transgenic rabbits latently

  9. CD152 (CTLA-4) regulates effector functions of CD8+ T lymphocytes by repressing Eomesodermin.

    Science.gov (United States)

    Hegel, Johannes K; Knieke, Karin; Kolar, Paula; Reiner, Steven L; Brunner-Weinzierl, Monika C

    2009-03-01

    CD8(+) T lymphocytes are required for effective host defense against pathogens and also for mediating effector responses against uncontrolled proliferating self-tissues. In this study, we determine that individual CD8(+) T cells are tightly controlled in their effector functions by CD152 (CTLA-4). We demonstrate that signals induced by CD152 reduce the frequency of IFN-gamma and granzyme B expressing CD8(+) T cells independently of the transcription factors T-bet or cKrox by selectively inhibiting accumulation of Eomesodermin mRNA and protein. Ectopic expression of Eomesodermin reversed the CD152-mediated inhibition of effector molecule production. Additionally, enhanced cytotoxicity of individual CD8(+) T cells differentiated in the absence of CD152 signaling was determined in vivo. These novel insights extend our understanding of how immune responses of CD8(+) T cells are selectively modulated.

  10. Immunogenicity of adenovirus-derived porcine parvovirus-like particles displaying B and T cell epitopes of foot-and-mouth disease.

    Science.gov (United States)

    Pan, Qunxing; Wang, Hui; Ouyang, Wei; Wang, Xiaoli; Bi, Zhenwei; Xia, Xingxia; Wang, Yongshan; He, Kongwang

    2016-01-20

    Virus-like particles (VLPs) vaccines combine many of the advantages of whole-virus vaccines and recombinant subunit vaccines, integrating key features that underlay their immunogenicity, safety and protective potential. We have hypothesized here the effective insertion of the VP1 epitopes (three amino acid residues 21-40, 141-160 and 200-213 in VP1, designated VPe) of foot-and-mouth disease (FMDV) within the external loops of PPV VP2 could be carried out without altering assembly based on structural and antigenic data. To investigate the possibility, development of two recombinant adenovirus rAd-PPV:VP2-FMDV:VPe a or rAd-PPV:VP2-FMDV:VPe b were expressed in HEK-293 cells. Out of the two insertion strategies tested, one of them tolerated an insert of 57 amino acids in one of the four external loops without disrupting the VLPs assembly. Mice were inoculated with the two recombinant adenoviruses, and an immunogenicity study showed that the highest levels of FMDV-specific humoral responses and T cell proliferation could be induced by rAd-PPV:VP2-FMDV:VPe b expressing hybrid PPV:VLPs (FMDV) in the absence of an adjuvant. Then, the protective efficacy of inoculating swine with rAd-PPV:VP2-FMDV:VPe b was tested. All pigs inoculated with rAd-PPV:VP2-FMDV:VPe b were protected from viral challenge, meanwhile the neutralizing antibody titers were significantly higher than those in the group inoculated with swine FMD type O synthetic peptide vaccine. Our results clearly demonstrate the potential usefulness of adenovirus-derived PPV VLPs as a vaccine strategy in prevention of FMDV. PMID:26685093

  11. Protective and Pathogenic Roles of CD8+ T Lymphocytes in Murine Orientia tsutsugamushi Infection

    Science.gov (United States)

    Hauptmann, Matthias; Kolbaum, Julia; Lilla, Stefanie; Wozniak, David; Gharaibeh, Mohammad; Fleischer, Bernhard; Keller, Christian A.

    2016-01-01

    T cells are known to contribute to immune protection against scrub typhus, a potentially fatal infection caused by the obligate intracellular bacterium Orientia (O.) tsutsugamushi. However, the contribution of CD8+ T cells to protection and pathogenesis during O. tsutsugamushi infection is still unknown. Using our recently developed BALB/c mouse model that is based on footpad inoculation of the human-pathogenic Karp strain, we show that activated CD8+ T cells infiltrate spleen and lung during the third week of infection. Depletion of CD8+ T cells with monoclonal antibodies resulted in uncontrolled pathogen growth and mortality. Adoptive transfer of CD8+ T cells from infected animals protected naïve BALB/c mice from lethal outcome of intraperitoneal challenge. In C57Bl/6 mice, the pulmonary lymphocyte compartment showed an increased percentage of CD8+ T cells for at least 135 days post O. tsutsugamushi infection. Depletion of CD8+ T cells at 84 days post infection caused reactivation of bacterial growth. In CD8+ T cell-deficient beta 2-microglobulin knockout mice, bacterial replication was uncontrolled, and all mice succumbed to the infection, despite higher serum IFN-γ levels and stronger macrophage responses in liver and lung. Moreover, we show that CD8+ T cells but not NKT cells were required for hepatocyte injury: elevated concentrations of serum alanine aminotransferase and infection-induced subcapsular necrotic liver lesions surrounded by macrophages were found in C57Bl/6 and CD1d-deficient mice, but not in beta 2-microglobulin knockout mice. In the lungs, peribronchial macrophage infiltrations also depended on CD8+ T cells. In summary, our results demonstrate that CD8+ T cells restrict growth of O. tsutsugamushi during acute and persistent infection, and are required to protect from lethal infections in BALB/c and C57BL/6 mice. However, they also elicit specific pathologic tissue lesions in liver and lung. PMID:27606708

  12. Identification of Hitherto Undefined B-Cell Epitopes by Antibodies in the Sera of Vitiligo Patients Using Phage-Display Peptide Library

    Directory of Open Access Journals (Sweden)

    Zohreh Jadali

    2003-12-01

    Full Text Available A random 12 mers phage library was used to screen a pool of immunoglo¬bulin fractions obtained from vitiligo patients. Subsequent to panning experiments, a panel of affinity selected phage from vitiligo patients were obtained. This panel was tested using an ELIS A for their reactivity with pooled sera from patients and normal controls. Among the 16 randomly selected clones, two of clones showed distinct positive reactivity with the patient's sera compared with controls. The peptides displayed by these phages expressed the following amino acid sequences: SHMPLANQYQWA and NHVQAWEQFWDS. Thus, screening with phage-displayed random peptide library of vitiligo sera can reveal peptide sequences that mimic vitiligo-related self-antigen.

  13. Design and evaluation of a multi-epitope assembly Peptide (MEAP against herpes simplex virus type 2 infection in BALB/c mice

    Directory of Open Access Journals (Sweden)

    Pan Mingjie

    2011-05-01

    Full Text Available Abstract Background Human herpes simplex virus (HSV 1 and 2 causes oral, ocular, or genital infections, which remains a significant health problem worldwide. HSV-1 and -2 infections in humans range from localized skin infections of the oral, ocular, and genital regions to severe and often disseminated infections in immunocompromised hosts. Epitope based vaccination is a promising mean to achieve protective immunity and to avoid infections with Human herpes simplex virus type 2 (HSV-2. Methods The twelve selected epitopes, six B cell epitopes from different glycoprotein of HSV-2 (amino acid residues 466-473 (EQDRKPRN from envelope glycoprotein B, 216-223 (GRTDRPSA from C, 6-18 (DPSLKMADPNRFR from D, 483-491 (DPPERPDSP from E, 572-579 (EPPDDDDS from G and 286-295 (CRRRYRRPRG from I glycoprotein of HSV-2, four CD4+ T cell epitopes (amino acid residues 21-28 (NLPVLDQL from D, 162-177 (KDVTVSQVWFGHRYSQ from B, 205-224 (KAYQQGVTVDSIGMLPRFIP from D and 245-259 (KPPYTSTLLPPELSD from D and two CD8+ T cell epitopes (amino acid residues 10-20 (KMADPNRFRGK from D and 268-276 (ALLEDPAGT from D, are responsible for the elicitation of the neutralizing antibodies and cytotoxic T lymphocytes (CTLs that impart protective immunity to the host. In this study, all above epitopes were inserted into the extracellular fragment (amino acid residues 1-290 of HSV-2 glycoprotein D to construct multi-epitope assembly peptides (MEAPs by replacing some non-epitope amino acid sequences. The epitope independency of the MEAPs was predicted by three-dimensional software algorithms. The gene of the selected MEAP was expressed in E.coli BL21(DE3, and its protective efficacy against HSV-2 infection was assessed in BALB/c mice. Results The MEAP, with each inserted epitopes independently displayed on the molecule surface, was selected as candidate proteins. The results showed that the MEAP was highly immunogenic and could elicit high titer neutralizing antibodies and cell

  14. 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.

  15. G0S2 modulates homeostatic proliferation of naïve CD8⁺ T cells and inhibits oxidative phosphorylation in mitochondria.

    Science.gov (United States)

    Lee, Ping-Hsien; Yamada, Takeshi; Park, Chun Shik; Shen, Ye; Puppi, Monica; Lacorazza, H Daniel

    2015-08-01

    Since its discovery, diverse functions have been attributed to the G0/G1 switch gene 2 (G0S2), from lipid metabolism to control of cell proliferation. Our group showed for the first time that G0S2 promotes quiescence in hematopoietic stem cells by interacting with and retaining nucleolin around the nucleus. Herein, we report the role of G0S2 in the differentiation and function of CD8(+) T cells examined in mice with an embryonic deletion of the G0s2 gene. G0S2 expression in naïve CD8(+) T cells decreased immediately after T-cell receptor activation downstream of the mitogen-activated protein kinase, calcium/calmodulin, phosphatidylinositol 3'-kinase and mammalian target of rapamycin pathways. Surprisingly, G0S2-null naïve CD8(+) T cells displayed increased basal and spare respiratory capacity that was not associated with increased mitochondrial biogenesis but with increased phosphorylation of AMP-activated protein kinase α. Naïve CD8(+) T cells showed increased proliferation in response to in vitro activation and in vivo lymphopenia; however, naïve CD8(+) T cells expressing the OT-1 transgene exhibited normal differentiation of naïve cells to effector and memory CD8(+) T cells upon infection with Listeria monocytogenes in a wild-type or a G0s2-null environment, with increased circulating levels of free fatty acids. Collectively, our results suggest that G0S2 inhibits energy production by oxidative phosphorylation to fine-tune proliferation in homeostatic conditions. PMID:25666096

  16. Human MAIT and CD8αα cells develop from a pool of type-17 precommitted CD8+ T cells

    OpenAIRE

    Walker, Lucy J.; Kang, Yu-Hoi; Smith, Matthew O.; Tharmalingham, Hannah; Ramamurthy, Narayan; Fleming, Vicki M.; Sahgal, Natasha; Leslie, Alistair; Oo, Ye; Geremia, Alessandra; Scriba, Thomas J.; Hanekom, Willem A; Lauer, Georg M.; Lantz, Olivier; Adams, David H

    2012-01-01

    Human mucosal associated invariant T (MAIT) CD8+ and Tc17 cells are important tissue-homing cell populations, characterized by high expression of CD161 (++) and type-17 differentiation, but their origins and relationships remain poorly defined. By transcriptional and functional analyses, we demonstrate that a pool of polyclonal, precommitted type-17 CD161++CD8αβ+ T cells exist in cord blood, from which a prominent MAIT cell (TCR Vα7.2+) population emerges post-natally. During this expansion, ...

  17. 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.

  18. Tissue signatures influence the activation of intrahepatic CD8+ T cells against malaria sporozoites

    Directory of Open Access Journals (Sweden)

    Alexandre eMorrot

    2014-08-01

    Full Text Available Plasmodium sporozoites and liver stages express antigens that are targeted to the MHC-Class I antigen-processing pathway. After the introduction of Plasmodium sporozoites by Anopheles mosquitoes, bone marrow-derived dendritic cells in skin-draining lymph nodes are the first cells to cross-present parasite antigens and elicit specific CD8+ T cells. One of these antigens is the immunodominant circumsporozoite protein (CSP. The CD8+ T cell-mediated protective immune response against CSP is dependent on the interleukin loop involving IL-4 receptor expression on CD8+ cells and IL-4 secretion by CD4+ T cell helpers. In a few days, these CD8+ T cells re-circulate to secondary lymphoid organs and the liver. In the liver, the hepatic sinusoids are enriched with cells, such as dendritic, sinusoidal endothelial and Kupffer cells, that are able to cross-present MHC class I antigens to intrahepatic CD8+ T cells. Specific CD8+ T cells actively find infected hepatocytes and target intra-cellular parasites through mechanisms that are both Interferon-g-dependent and -independent. Immunity is mediated by CD8+ T effector or effector-memory cells and, when present in high numbers, these cells can provide sterilizing immunity. Human vaccination trials with recombinant formulations or attenuated sporozoites have yet to achieve the high numbers of specific effector T cells that are required for sterilizing immunity. In spite of the limited number of specific CD8+ T cells, attenuated sporozoites provided multiple times by the endovenous route provided a high degree of protective immunity. These observations highlight that CD8+ T cells may be useful for improving antibody-mediated protective immunity to pre-erythrocytic stages of malaria parasites.

  19. CD3+CD8+CD161high Tc17 cells are depleted in HIV-infection

    DEFF Research Database (Denmark)

    Gaardbo, Julie Christine; Hartling, Hans Jakob; Thorsteinsson, Kristina;

    2012-01-01

    CD8+ Tc17 cells with pro-inflammatory properties have only recently been acknowledged, and Tc17 cells in HIV-infection are undescribed. CD3+CD8+CD161 Tc17 cells and the production of Interleukin-17 were examined in untreated and treated HIV-infected patients, HIV-HCV co-infected patients and...... healthy controls. Depletion of CD3+CD8+CD161 Tc17 cells and diminished production of Interleukin-17 in HIV-infected patients was found. The level of Tc17 cells was associated with the level of the CD4+ count in treated patients....

  20. CD3+CD8+CD161high Tc17 cells are depleted in HIV-infection.

    Science.gov (United States)

    Gaardbo, Julie Christine; Hartling, Hans Jakob; Thorsteinsson, Kristina; Ullum, Henrik; Nielsen, Susanne Dam

    2013-02-20

    CD8 Tc17 cells with pro-inflammatory properties have only recently been acknowledged, and Tc17 cells in HIV-infection are not described. CD3CD8CD161 Tc17 cells and the production of interleukin (IL)-17 were examined in untreated and treated HIV-infected patients, HIV-hepatitis C virus co-infected patients, and healthy controls. Depletion of CD3CD8CD161 Tc17 cells and diminished production of IL-17 in HIV-infected patients were found. The level of Tc17 cells was associated with the CD4 cell count in treated patients. PMID:23135168

  1. IL-17A secretion by CD8+ T cells supports Th17-mediated autoimmune encephalomyelitis

    OpenAIRE

    Huber, Magdalena; Heink, Sylvia; Pagenstecher, Axel; Reinhard, Katharina; Ritter, Josephine; Visekruna, Alexander; Guralnik, Anna; Bollig, Nadine; Jeltsch, Katharina; Heinemann, Christina; Wittmann, Eva; Buch, Thorsten; da Costa, Olivia Prazeres; Brüstle, Anne; Brenner, Dirk

    2012-01-01

    IL-17–producing CD8+ T (Tc17) cells are detectible in multiple sclerosis (MS) lesions; however, their contribution to the disease is unknown. To identify functions of Tc17 cells, we induced EAE, a murine model of MS, in mice lacking IFN regulatory factor 4 (IRF4). IRF4-deficient mice failed to generate Tc17 and Th17 cells and were resistant to EAE. After adoptive transfer of WT CD8+ T cells and subsequent immunization for EAE induction in these mice, the CD8+ T cells developed a Tc17 phenotyp...

  2. CD8+ Lymphocytes Can Control HIV Infection in vitro by Suppressing Virus Replication

    Science.gov (United States)

    Walker, Christopher M.; Moody, Dewey J.; Stites, Daniel P.; Levy, Jay A.

    1986-12-01

    Lymphocytes bearing the CD8 marker were shown to suppress replication of human immunodeficiency virus (HIV) in peripheral blood mononuclear cells. The effect was dose-dependent and most apparent with autologous lymphocytes; it did not appear to be mediated by a cytotoxic response. This suppression of HIV replication could be demonstrated by the addition of CD8+ cells at the initiation of virus production as well as after several weeks of virus replication by cultured cells. The observations suggest a potential approach to therapy in which autologous CD8 lymphocytes could be administered to individuals to inhibit HIV replication and perhaps progression of disease.

  3. Memory CD8+ T cell differentiation in viral infection: A cell for all seasons

    Institute of Scientific and Technical Information of China (English)

    Henry Radziewicz; Luke Uebelhoer; Bertram Bengsch; Arash Grakoui

    2007-01-01

    Chronic viral infections such as hepatitis B virus (HBV),hepatitis C virus (HCV) and human immunodeficiency virus (HIV) are major global health problems affecting more than 500 million people worldwide. Virus-specific CD8+ T cells play an important role in the course and outcome of these viral infections and it is hypothesized that altered or impaired differentiation of virusspecific CD8+ T cells contributes to the development of persistence and/or disease progression. A deeper understanding of the mechanisms responsible for functional differentiation of CD8+ T cells is essential for the generation of successful therapies aiming to strengthen the adaptive component of the immune system.

  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...... 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. A Single CD8+ T Cell Epitope Sets the Long-Term Latent Load of a Murid Herpesvirus

    OpenAIRE

    Sofia Marques; Marta Alenquer; Stevenson, Philip G.; J. Pedro Simas

    2008-01-01

    Author Summary Persistent viruses present a major challenge to the immune response. Gamma-herpesviruses are a prime example, and the archetypal family member, Epstein-Barr virus (EBV), has been studied for many years. A major unanswered question with EBV is why long-term virus loads—a key pathogenesis outcome—vary so widely between individuals. As most EBV studies are necessarily descriptive, the murid gamma-herpesvirus MuHV-4 provides an important focus of pathogenesis research. Here, we use...

  6. Identification of Cytotoxic T Lymphocyte Epitopes on Swine Viruses: Multi-Epitope Design for Universal T Cell Vaccine

    OpenAIRE

    Liao, Yu-Chieh; Lin, Hsin-Hung; Lin, Chieh-Hua; Chung, Wen-Bin

    2013-01-01

    Classical swine fever (CSF), foot-and-mouth disease (FMD) and porcine reproductive and respiratory syndrome (PRRS) are the primary diseases affecting the pig industry globally. Vaccine induced CD8+ T cell-mediated immune response might be long-lived and cross-serotype and thus deserve further attention. Although large panels of synthetic overlapping peptides spanning the entire length of the polyproteins of a virus facilitate the detection of cytotoxic T lymphocyte (CTL) epitopes, it is an ex...

  7. Direct presentation is sufficient for an efficient anti-viral CD8+ T cell response.

    Directory of Open Access Journals (Sweden)

    Ren-Huan Xu

    2010-02-01

    Full Text Available The extent to which direct- and cross-presentation (DP and CP contribute to the priming of CD8(+ T cell (T(CD8+ responses to viruses is unclear mainly because of the difficulty in separating the two processes. Hence, while CP in the absence of DP has been clearly demonstrated, induction of an anti-viral T(CD8+ response that excludes CP has never been purposely shown. Using vaccinia virus (VACV, which has been used as the vaccine to rid the world of smallpox and is proposed as a vector for many other vaccines, we show that DP is the main mechanism for the priming of an anti-viral T(CD8+ response. These findings provide important insights to our understanding of how one of the most effective anti-viral vaccines induces immunity and should contribute to the development of novel vaccines.

  8. CD8+ T Cells Complement Antibodies in Protecting against Yellow Fever Virus

    DEFF Research Database (Denmark)

    Bassi, Maria R; Kongsgaard, Michael; Steffensen, Maria A;

    2015-01-01

    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......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...

  9. Label Free Detection of CD4+ and CD8+ T Cells Using the Optofluidic Ring Resonator

    Directory of Open Access Journals (Sweden)

    John T. Gohring

    2010-06-01

    Full Text Available We have demonstrated label free detection of CD4+ and CD8+ T-Lymphocyte whole cells and CD4+ T-Lymphocyte cell lysis using the optofluidic ring resonator (OFRR sensor. The OFRR sensing platform incorporates microfluidics and photonics in a setup that utilizes small sample volume and achieves a fast detection time. In this work, white blood cells were isolated from healthy blood and the concentrations were adjusted to match T-Lymphocyte levels of individuals infected with HIV. Detection was accomplished by immobilizing CD4 and CD8 antibodies on the inner surface of the OFRR. Sensing results show excellent detection of CD4+ and CD8+ T-Lymphocyte cells at medically significant concentrations with a detection time of approximately 30 minutes. This work will lead to a rapid and low-cost sensing device that can provide a CD4 and CD8 count as a measure of HIV progression.

  10. T cytotoxic-1 CD8+ T cells are effector cells against pneumocystis in mice.

    Science.gov (United States)

    McAllister, Florencia; Mc Allister, Florencia; Steele, Chad; Zheng, Mingquan; Young, Erana; Shellito, Judd E; Marrero, Luis; Kolls, Jay K

    2004-01-15

    Host defenses are profoundly compromised in HIV-infected hosts due to progressive depletion of CD4+ T lymphocytes. A hallmark of HIV infection is Pneumocystis carinii (PC) pneumonia. Recently, CD8+ T cells, which are recruited to the lung in large numbers in response to PC infection, have been associated with some level of host defense as well as contributing to lung injury in BALB/c mice. In this study, we show that CD8+ T cells that have a T cytotoxic-1 response to PC in BALB/c mice, as determined by secretion of IFN-gamma, have in vitro killing activity against PC and effect clearance of the organism in adoptive transfer studies. Moreover, non-T cytotoxic-1 CD8+ T cells lacked in vitro effector activity and contributed to lung injury upon adoptive transfer. This dichotomous response in CD8+ T cell response may in part explain the clinical heterogeneity in the severity of PC pneumonia.

  11. Praziquantel facilitates IFN-γ-producing CD8+ T cells (Tc1 and IL-17-producing CD8+ T cells (Tc17 responses to DNA vaccination in mice.

    Directory of Open Access Journals (Sweden)

    Qiang Zou

    Full Text Available BACKGROUND: CD8(+ cytotoxic T lymphocytes (CTLs are crucial for eliminating hepatitis B virus (HBV infected cells. DNA vaccination, a novel therapeutic strategy for chronic virus infection, has been shown to induce CTL responses. However, accumulated data have shown that CTLs could not be effectively induced by HBV DNA vaccination. METHODOLOGY/PRINCIPAL FINDINGS: Here, we report that praziquantel (PZQ, an anti-schistoma drug, could act as an adjuvant to overcome the lack of potent CTL responses by HBV DNA vaccination in mice. PZQ in combination with HBV DNA vaccination augmented the induction of CD8(+ T cell-dependent and HBV-specific delayed hypersensitivity responses (DTH in C57BL/6 mice. Furthermore, the induced CD8(+ T cells consisted of both Tc1 and Tc17 subtypes. By using IFN-γ knockout (KO mice and IL-17 KO mice, both cytokines were found to be involved in the DTH. The relevance of these findings to HBV immunization was established in HBsAg transgenic mice, in which PZQ also augmented the induction of HBV-specific Tc1 and Tc17 cells and resulted in reduction of HBsAg positive hepatocytes. Adoptive transfer experiments further showed that PZQ-primed CD8(+ T cells from wild type mice, but not the counterpart from IFN-γ KO or IL-17 KO mice, resulted in elimination of HBsAg positive hepatocytes. CONCLUSIONS/SIGNIFICANCE: Our results suggest that PZQ is an effective adjuvant to facilitate Tc1 and Tc17 responses to HBV DNA vaccination, inducing broad CD8(+ T cell-based immunotherapy that breaks tolerance to HBsAg.

  12. Inhibiting glycolytic metabolism enhances CD8+ T cell memory and antitumor function

    OpenAIRE

    Sukumar, Madhusudhanan; Liu, Jie; Ji, Yun; Subramanian, Murugan; Crompton, Joseph G.; Yu, Zhiya; Roychoudhuri, Rahul; Palmer, Douglas C.; Muranski, Pawel; Karoly, Edward D; Mohney, Robert P.; Klebanoff, Christopher A.; Lal, Ashish; Finkel, Toren; Restifo, Nicholas P.

    2013-01-01

    Naive CD8+ T cells rely upon oxidation of fatty acids as a primary source of energy. After antigen encounter, T cells shift to a glycolytic metabolism to sustain effector function. It is unclear, however, whether changes in glucose metabolism ultimately influence the ability of activated T cells to become long-lived memory cells. We used a fluorescent glucose analog, 2-NBDG, to quantify glucose uptake in activated CD8+ T cells. We found that cells exhibiting limited glucose incorporation had ...

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

    OpenAIRE

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

    2009-01-01

    Multiple studies have established that the ability of CD8+ T cells to act as cytolytic effectors and produce gamma interferon is important in mediating resistance to the intracellular parasite Toxoplasma gondii. To better understand the generation of the antigen-specific CD8+ T-cell responses induced by T. gondii, mice were immunized with replication-deficient parasites that express the model antigen ovalbumin (OVA). Class I tetramers specific for SIINFEKL were used to track the OVA-specific ...

  14. Protective CD8+ T lymphocytes in primates immunized with malaria sporozoites.

    Directory of Open Access Journals (Sweden)

    Walter R Weiss

    Full Text Available Live attenuated malaria vaccines are more potent than the recombinant protein, bacterial or viral platform vaccines that have been tested, and an attenuated sporozoite vaccine against falciparum malaria is being developed for humans. In mice, attenuated malaria sporozoite vaccines induce CD8(+ T cells that kill parasites developing in the liver. We were curious to know if CD8(+ T cells were also important in protecting primates against malaria. We immunized 9 rhesus monkeys with radiation attenuated Plasmodium knowlesi sporozoites, and found that 5 did not develop blood stage infections after challenge with live sporozoites. We then injected 4 of these protected monkeys with cM-T807, a monoclonal antibody to the CD8 molecule which depletes T cells. The fifth monkey received equivalent doses of normal IgG. In 3 of the 4 monkeys receiving cM-T807 circulating CD8(+ T cells were profoundly depleted. When re-challenged with live sporozoites all 3 of these depleted animals developed blood stage malaria. The fourth monkey receiving cM-T807 retained many circulating CD8(+ T cells. This monkey, and the vaccinated monkey receiving normal IgG, did not develop blood stage malaria at re-challenge with live sporozoites. Animals were treated with antimalarial drugs and rested for 4 months. During this interval CD8(+ T cells re-appeared in the circulation of the depleted monkeys. When all vaccinated animals received a third challenge with live sporozoites, all 5 monkeys were once again protected and did not develop blood stage malaria infections. These data indicate that CD8(+ T cells are important effector cells protecting monkeys against malaria sporozoite infection. We believe that malaria vaccines which induce effector CD8+ T cells in humans will have the best chance of protecting against malaria.

  15. Cish actively silences TCR signaling in CD8+ T cells to maintain tumor tolerance

    OpenAIRE

    Douglas C Palmer; Guittard, Geoffrey C.; Franco, Zulmarie; Crompton, Joseph G.; Eil, Robert L; Patel, Shashank J.; Ji, Yun; van Panhuys, Nicholas; Klebanoff, Christopher A.; Sukumar, Madhusudhanan; Clever, David; Chichura, Anna; Roychoudhuri, Rahul; Varma, Rajat; Wang, Ena

    2015-01-01

    Improving the functional avidity of effector T cells is critical in overcoming inhibitory factors within the tumor microenvironment and eliciting tumor regression. We have found that Cish, a member of the suppressor of cytokine signaling (SOCS) family, is induced by TCR stimulation in CD8+ T cells and inhibits their functional avidity against tumors. Genetic deletion of Cish in CD8+ T cells enhances their expansion, functional avidity, and cytokine polyfunctionality, resulting in pronounced a...

  16. 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.

  17. Molecular Programming of Tumor-Infiltrating CD8+ T Cells and IL15 Resistance.

    Science.gov (United States)

    Doedens, Andrew L; Rubinstein, Mark P; Gross, Emilie T; Best, J Adam; Craig, David H; Baker, Megan K; Cole, David J; Bui, Jack D; Goldrath, Ananda W

    2016-09-01

    Despite clinical potential and recent advances, durable immunotherapeutic ablation of solid tumors is not routinely achieved. IL15 expands natural killer cell (NK), natural killer T cell (NKT) and CD8(+) T-cell numbers and engages the cytotoxic program, and thus is under evaluation for potentiation of cancer immunotherapy. We found that short-term therapy with IL15 bound to soluble IL15 receptor α-Fc (IL15cx; a form of IL15 with increased half-life and activity) was ineffective in the treatment of autochthonous PyMT murine mammary tumors, despite abundant CD8(+) T-cell infiltration. Probing of this poor responsiveness revealed that IL15cx only weakly activated intratumoral CD8(+) T cells, even though cells in the lung and spleen were activated and dramatically expanded. Tumor-infiltrating CD8(+) T cells exhibited cell-extrinsic and cell-intrinsic resistance to IL15. Our data showed that in the case of persistent viral or tumor antigen, single-agent systemic IL15cx treatment primarily expanded antigen-irrelevant or extratumoral CD8(+) T cells. We identified exhaustion, tissue-resident memory, and tumor-specific molecules expressed in tumor-infiltrating CD8(+) T cells, which may allow therapeutic targeting or programming of specific subsets to evade loss of function and cytokine resistance, and, in turn, increase the efficacy of IL2/15 adjuvant cytokine therapy. Cancer Immunol Res; 4(9); 799-811. ©2016 AACR.

  18. Differential remodeling of a T-cell transcriptome following CD8-versus CD3-induced signaling

    Institute of Scientific and Technical Information of China (English)

    S Hussain I Abidi; Tao Dong; Mai T Vuong; Vattipally B Sreenu; Sarah L Rowland-Jones; Edward J Evans; Simon J Davis

    2008-01-01

    CD8 engagement with class I major histocompatibility antigens greatly enhances T-cell activation,but it is not clear how this is achieved.We address the question of whether or not the antibody-mediated ligation of CD8 alone induces transcriptional remodeling in a T-cell clone,using serial analysis of gene expression.Even though it fails to induce overt phenotypic changes,we find that CD8 ligation profoundly alters transcription in the T-cell clone,at a scale comparable to that induced by antibody-mediated ligation of CD3.The character of the resulting changes is distinct,however,with the net effect ofCD8 ligation being substantially inhibitory.We speculate that ligating CD8 induces weak,T-cell receptor (TCR)-mediated inhibitory signals reminiscent of the effects of TCR antagonists.Our results imply that CD8 ligation alone is incapable of activating the T-cell clone because it fails to fully induce NFAT-dependent transcription.

  19. Salmonella impairs CD8 T cell response through PD-1: PD-L axis.

    Science.gov (United States)

    López-Medina, Marcela; Carrillo-Martín, Ismael; Leyva-Rangel, Jessica; Alpuche-Aranda, Celia; Ortiz-Navarrete, Vianney

    2015-12-01

    We have shown that Salmonella remains for a long period of time within B cells, plasma cells, and bone marrow B cell precursors, which might allow persistence and dissemination of infection. Nonetheless, how infected cells evade CD8 T cell response has not been characterized. Evidence indicates that some pathogens exploit the PD-1: PD-L (PD-L1 and PD-L2) interaction to inhibit CD8 T cells response to contribute the chronicity of the infection. To determine whether the PD-1: PD-L axis plays a role during Salmonella infection; we evaluated PD-1 expression in antigen-specific CD8 T cells and PD-1 ligands in Salmonella-infected cells. Our results show that infected B cells and macrophages express continuously co-stimulatory (CD40, CD80, and CD86) and inhibitory molecules (PD-L1 and PD-L2) in early and late stages of chronic Salmonella infection, while antigen-specific CD8 T cells express in a sustained manner PD-1 in the late stages of infection. Blocking this axis restores the ability of the CD8 T cells to proliferate and eliminate primary infected APCs. Therefore, a continuous PD-1: PDL interaction might be a mechanism employed by Salmonella to negatively regulate Salmonella-specific CD8 T cell cytotoxic response in order to remain within the host for a long period of time.

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

    Directory of Open Access Journals (Sweden)

    Mitra Azadniv

    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.

  1. IL-17-Expressing CD4+ and CD8+ T Lymphocytes in Human Toxoplasmosis

    Directory of Open Access Journals (Sweden)

    Jéssica Líver Alves Silva

    2014-01-01

    Full Text Available This study aimed to measure the synthesis of Th1 and Th2 cytokines by mononuclear cells after culture with live T. gondii and identified Th17 (CD4+ and Tc17 (CD8+ cells in toxoplasma-seronegative and toxoplasma-seropositive parturient and nonpregnant women. Cytometric bead arrays were used to measure cytokine levels (IL-2, TNF-α, IFN-γ, IL-4, IL-5, and IL-10; immunophenotyping was used to characterize Th17 and Tc17 cells, and the cells were stained with antibodies against CD4+ and CD8+ T cells expressing IL-17. The addition of tachyzoites to cell cultures induced the synthesis of IL-5, IL-10, and TNF-α by cells from seronegative parturient women and of IL-5 and IL-10 by cells from seropositive, nonpregnant women. We observed a lower level of IL-17-expressing CD4+ and CD8+ T lymphocytes in cultures of cells from seronegative and seropositive parturient and nonpregnant women that were stimulated with tachyzoites, whereas analysis of the CD4+ and CD8+ T cell populations showed a higher level of CD4+ T cells compared with CD8+ T cells. These results suggest that the cytokine pattern and IL-17-expressing CD4+ and CD8+ T lymphocytes may have important roles in the inflammatory response to T. gondii, thus contributing to the maintenance of pregnancy and control of parasite invasion and replication.

  2. Specific immunotherapy generates CD8(+) CD196(+) T cells to suppress lung cancer growth in mice.

    Science.gov (United States)

    Zhang, Jian; Liu, Jing; Chen, Huiguo; Wu, Weibin; Li, Xiaojun; Wu, Yonghui; Wang, Zhigang; Zhang, Kai; Li, Yun; Weng, Yimin; Liao, Hongying; Gu, Lijia

    2016-08-01

    That specific immunotherapy can inhibit cancer growth has been recognized; its efficiency is to be improved. This study aimed to inhibit lung cancer (LC) growth in a mouse model by using an LC-specific vaccination. In this study, a LC mouse model was created by adoptive transplantation with LC cells. The tumor-bearing mice were vaccinated with LC cell extracts plus adjuvant TNBS or adoptive transplantation with specific CD8(+) CD196(+) T cells. The results showed that the vaccination with LC extracts (LCE)/TNBS markedly inhibited the LC growth and induced CD8(+) CD196(+) T cells in LC tissue and the spleen. These CD8(+) CD196(+) T cells proliferated and produce high levels of perforin upon exposure to LCE and specifically induced LC cell apoptosis. Exposure to TNBS induced RAW264.7 cells to produce macrophage inflammatory protein-3α; the latter activated signal transducer and activator of transcription 3 and further induced perforin expression in the CD8(+) CD196(+) T cells. Adoptive transfer with specific CD8(+) CD196(+) T cells suppressed LC growth in mice. In conclusion, immunization with LC extracts and TNBS can induce LC-specific CD8(+) CD196(+) T cells in LC-bearing mice and inhibit LC growth. PMID:26910585

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

    Directory of Open Access Journals (Sweden)

    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.

  4. Apoptotic CD8 T-lymphocytes disable macrophage-mediated immunity to Trypanosoma cruzi infection.

    Science.gov (United States)

    Cabral-Piccin, M P; Guillermo, L V C; Vellozo, N S; Filardy, A A; Pereira-Marques, S T; Rigoni, T S; Pereira-Manfro, W F; DosReis, G A; Lopes, M F

    2016-01-01

    Chagas disease is caused by infection with the protozoan Trypanosoma cruzi. CD8 T-lymphocytes help to control infection, but apoptosis of CD8 T cells disrupts immunity and efferocytosis can enhance parasite infection within macrophages. Here, we investigate how apoptosis of activated CD8 T cells affects M1 and M2 macrophage phenotypes. First, we found that CD8 T-lymphocytes and inflammatory monocytes/macrophages infiltrate peritoneum during acute T. cruzi infection. We show that treatment with anti-Fas ligand (FasL) prevents lymphocyte apoptosis, upregulates type-1 responses to parasite antigens, and reduces infection in macrophages cocultured with activated CD8 T cells. Anti-FasL skews mixed M1/M2 macrophage profiles into polarized M1 phenotype, both in vitro and following injection in infected mice. Moreover, inhibition of T-cell apoptosis induces a broad reprogramming of cytokine responses and improves macrophage-mediated immunity to T. cruzi. The results indicate that disposal of apoptotic CD8 T cells increases M2-macrophage differentiation and contributes to parasite persistence. PMID:27195678

  5. Adoptive immunotherapy of cancer with polyclonal, 108-fold hyperexpanded, CD4+ and CD8+ T cells

    Directory of Open Access Journals (Sweden)

    Kim Julian A

    2004-11-01

    Full Text Available Abstract T cell-mediated cancer immunotherapy is dose dependent and optimally requires participation of antigen-specific CD4+ and CD8+ T cells. Here, we isolated tumor-sensitized T cells and activated them in vitro using conditions that led to greater than 108-fold numerical hyperexpansion of either the CD4+ or CD8+ subset while retaining their capacity for in vivo therapeutic efficacy. Murine tumor-draining lymph node (TDLN cells were segregated to purify the CD62Llow subset, or the CD4+ subset thereof. Cells were then propagated through multiple cycles of anti-CD3 activation with IL-2 + IL-7 for the CD8+ subset, or IL-7 + IL-23 for the CD4+ subset. A broad repertoire of TCR Vβ families was maintained throughout hyperexpansion, which was similar to the starting population. Adoptive transfer of hyper-expanded CD8+ T cells eliminated established pulmonary metastases, in an immunologically specific fashion without the requirement for adjunct IL-2. Hyper-expanded CD4+ T cells cured established tumors in intracranial or subcutaneous sites that were not susceptible to CD8+ T cells alone. Because accessibility and antigen presentation within metastases varies according to anatomic site, maintenance of a broad repertoire of both CD4+ and CD8+ T effector cells will augment the overall systemic efficacy of adoptive immunotherapy.

  6. Inhibiting glycolytic metabolism enhances CD8+ T cell memory and antitumor function

    Science.gov (United States)

    Sukumar, Madhusudhanan; Liu, Jie; Ji, Yun; Subramanian, Murugan; Crompton, Joseph G.; Yu, Zhiya; Roychoudhuri, Rahul; Palmer, Douglas C.; Muranski, Pawel; Karoly, Edward D.; Mohney, Robert P.; Klebanoff, Christopher A.; Lal, Ashish; Finkel, Toren; Restifo, Nicholas P.; Gattinoni, Luca

    2013-01-01

    Naive CD8+ T cells rely upon oxidation of fatty acids as a primary source of energy. After antigen encounter, T cells shift to a glycolytic metabolism to sustain effector function. It is unclear, however, whether changes in glucose metabolism ultimately influence the ability of activated T cells to become long-lived memory cells. We used a fluorescent glucose analog, 2-NBDG, to quantify glucose uptake in activated CD8+ T cells. We found that cells exhibiting limited glucose incorporation had a molecular profile characteristic of memory precursor cells and an increased capacity to enter the memory pool compared with cells taking up high amounts of glucose. Accordingly, enforcing glycolytic metabolism by overexpressing the glycolytic enzyme phosphoglycerate mutase-1 severely impaired the ability of CD8+ T cells to form long-term memory. Conversely, activation of CD8+ T cells in the presence of an inhibitor of glycolysis, 2-deoxyglucose, enhanced the generation of memory cells and antitumor functionality. Our data indicate that augmenting glycolytic flux drives CD8+ T cells toward a terminally differentiated state, while its inhibition preserves the formation of long-lived memory CD8+ T cells. These results have important implications for improving the efficacy of T cell–based therapies against chronic infectious diseases and cancer. PMID:24091329

  7. Identification of Autoantigen Epitopes in Alopecia Areata.

    Science.gov (United States)

    Wang, Eddy H C; Yu, Mei; Breitkopf, Trisia; Akhoundsadegh, Noushin; Wang, Xiaojie; Shi, Feng-Tao; Leung, Gigi; Dutz, Jan P; Shapiro, Jerry; McElwee, Kevin J

    2016-08-01

    Alopecia areata (AA) is believed to be a cell-mediated autoimmune hair loss disease. Both CD4 and cytotoxic CD8 T cells (CTLs) are important for the onset and progression of AA. Hair follicle (HF) keratinocyte and/or melanocyte antigen epitopes are suspected potential targets of autoreactive CTLs, but the specific epitopes have not yet been identified. We investigated the potential for a panel of known epitopes, expressed by HF keratinocytes and melanocytes, to induce activation of CTL populations in peripheral blood mononuclear cells. Specific synthetic epitopes derived from HF antigens trichohyalin and tyrosinase-related protein-2 induced significantly higher frequencies of response in AA CTLs compared with healthy controls (IFN-gamma secretion). Apoptosis assays revealed conditioned media from AA peripheral blood mononuclear cells stimulated with trichohyalin peptides elevated the expression of apoptosis markers in primary HF keratinocytes. A cytokine array revealed higher expression of IL-13 and chemokine ligand 5 (CCL5, RANTES) from AA peripheral blood mononuclear cells stimulated with trichohyalin peptides compared with controls. The data indicate that AA affected subjects present with an increased frequency of CTLs responsive to epitopes originating from keratinocytes and melanocytes; the activated CTLs secreted soluble factors that induced apoptosis in HF keratinocytes. Potentially, CTL response to self-antigen epitopes, particularly trichohyalin epitopes, could be a prognostic marker for human AA. PMID:27094591

  8. Measurement of HCV-Specific CD8(+) Cytotoxic T-Cell Activities in the Peripheral Blood by Europium Release Assay.

    Science.gov (United States)

    Imawari, M

    1999-01-01

    Peripheral blood mononuclear cells (PBMC) contain NK cells, cytotoxic T-lymphocytes (CTL), helper T-cells, and B-cells that respond to viral infection and act to eliminate the virus from infected individuals. CTLs are not only thought to be a major host defense against viral infection, but are also implicated in the immunopathogenesis. Classical CTLs are CD8(+) and recognize endogenously synthesized and processed antigen in association with a human leukocyte antigen (HLA) class I molecule. The antigens are usually 8-10 amino acids long. HCV-specific CTLs have been demonstrated in the peripheral blood of some of patients with HCV infection by stimulating PBMC with the HCV synthetic peptides (1). The peptides were synthesized as overlapping peptides to encompass a certain region of the HCV antigen (1), on the basis of antigenicity prediction from the amino acid composition of HCV (2), or on the basis of the HLA binding motifs in the HCV antigen (3). Several minimal and optimal epitopes in the HCV antigen and their HLA restriction of recognition by CTLs have been defined. Recently, it has been reported that HCV-specific CTLs may suppress the outgrowth of HCV (4). In this chapter, methods will be discussed that demonstrate HCV-specific CTLs in the peripheral blood of patients with HCV infection. We use nonradioisotope europium (Eu) for assay of CTL activities. PMID:21374383

  9. CD8{sup +}CD25{sup +} T cells reduce atherosclerosis in apoE(−/−) mice

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-01-17

    Highlights: •The role of a sub-population of CD8{sup +} T cells with suppressor functions was investigated in atherosclerosis. •CD8{sup +}CD25{sup +} T cells from adult apoE(−/−) mice had phenotype characteristics of T suppressor cells. •These CD8{sup +}CD25{sup +} T cells reduced CD4{sup +} T cell proliferation and CD8{sup +} cytotoxic activity in vitro. •Adoptive transfer of CD8{sup +}CD25{sup +} T cells significantly reduced atherosclerosis. •CD8{sup +}CD25{sup +} T cells have a suppressive function in atherosclerosis. -- Abstract: Background: It is increasingly evident that CD8{sup +} T cells are involved in atherosclerosis but the specific subtypes have yet to be defined. CD8{sup +}CD25{sup +} 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{sup +}CD25{sup +} T cells in experimental atherosclerosis were investigated in this study. Methods and results: CD8{sup +}CD25{sup +} 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{sup +}CD25{sup +} T cells from apoE(−/−) mice. Depletion of CD8{sup +}CD25{sup +} from total CD8{sup +} T cells rendered higher cytolytic activity of the remaining CD8{sup +}CD25{sup −} T cells. Adoptive transfer of CD8{sup +}CD25{sup +} T cells into apoE(−/−) mice suppressed the proliferation of splenic CD4{sup +} T cells and significantly reduced atherosclerosis in recipient mice. Conclusions: Our study has identified an athero-protective role for CD8{sup +}CD25{sup +} T cells in experimental atherosclerosis.

  10. Discovery of common marburgvirus protective epitopes in a BALB/c mouse model

    Directory of Open Access Journals (Sweden)

    Olinger Gene G

    2009-08-01

    Full Text Available Abstract Background Marburg virus (MARV causes acute hemorrhagic fever that is often lethal, and no licensed vaccines are available for preventing this deadly viral infection. The immune mechanisms for protection against MARV are poorly understood, but previous studies suggest that both antibodies and T cells are required. In our study, we infected BALB/c mice with plaque-purified, nonlethal MARV and used overlapping peptides to map H2d-restricted CD8+ T-cell epitopes. Methods Splenocytes from mice infected with nonlethal MARV were harvested and stimulated with multiple overlapping 15-mer peptide pools, and reactive CD8+ T cells were evaluated for antigen specificity by measuring upregulation of CD44 and interferon-γ expression. After confirming positive reactivity to specific 15-mer peptides, we used extrapolated 9-mer epitopes to evaluate the induction of cytotoxic T-cell responses and protection from lethal MARV challenge in BALB/c mice. Results We discovered a CD8+ T-cell epitope within both the MARV glycoprotein (GP and nucleoprotein (NP that triggered cytotoxic T-cell responses. These responses were also protective when epitope-specific splenocytes were transferred into naïve animals. Conclusion Epitope mapping of MARV GP, NP, and VP40 provides the first evidence that specific MARV-epitope induction of cellular immune responses is sufficient to combat infection. Establishment of CD8+ T-cell epitopes that are reactive to MARV proteins provides an important research tool for dissecting the significance of cellular immune responses in BALB/c mice infected with MARV.

  11. Identification of cytotoxic T lymphocyte epitopes on swine viruses: multi-epitope design for universal T cell vaccine.

    Directory of Open Access Journals (Sweden)

    Yu-Chieh Liao

    Full Text Available Classical swine fever (CSF, foot-and-mouth disease (FMD and porcine reproductive and respiratory syndrome (PRRS are the primary diseases affecting the pig industry globally. Vaccine induced CD8(+ T cell-mediated immune response might be long-lived and cross-serotype and thus deserve further attention. Although large panels of synthetic overlapping peptides spanning the entire length of the polyproteins of a virus facilitate the detection of cytotoxic T lymphocyte (CTL epitopes, it is an exceedingly costly and cumbersome approach. Alternatively, computational predictions have been proven to be of satisfactory accuracy and are easily performed. Such a method enables the systematic identification of genome-wide CTL epitopes by incorporating epitope prediction tools in analyzing large numbers of viral sequences. In this study, we have implemented an integrated bioinformatics pipeline for the identification of CTL epitopes of swine viruses including the CSF virus (CSFV, FMD virus (FMDV and PRRS virus (PRRSV and assembled these epitopes on a web resource to facilitate vaccine design. Identification of epitopes for cross protections to different subtypes of virus are also reported in this study and may be useful for the development of a universal vaccine against such viral infections among the swine population. The CTL epitopes identified in this study have been evaluated in silico and possibly provide more and wider protection in compared to traditional single-reference vaccine design. The web resource is free and open to all users through http://sb.nhri.org.tw/ICES.

  12. 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.

  13. Phenotypic and Functional Alterations in Circulating Memory CD8 T Cells with Time after Primary Infection.

    Directory of Open Access Journals (Sweden)

    Matthew D Martin

    2015-10-01

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

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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  1. File list: Unc.Bld.20.AllAg.CD8-Positive_T-Lymphocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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  4. File list: ALL.Bld.20.AllAg.CD8-Positive_T-Lymphocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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  18. Differential requirement of CD28 costimulation for activation of murine CD8+ intestinal intraepithelial lymphocyte subsets and lymph node cells.

    Science.gov (United States)

    Gelfanov, V; Lai, Y G; Gelfanova, V; Dong, J Y; Su, J P; Liao, N S

    1995-07-01

    The CD8+CD4- (CD8+) murine small intestinal intraepithelial lymphocytes (IELs) contain two subpopulations, one expressing alpha alpha-CD8 homodimers and another alpha beta-CD8 heterodimers. In this study, plate-bound anti-TCR beta-chain (TCR-beta) mAb alone or combined with anti-CD28 mAb is used as a model system to study activation requirement of these two CD8+ IEL subsets. In contrast to CD8+ lymph node (LN) cells that require both TCR and CD28 triggering for activation, alpha beta-CD8+ IELs proliferate and produce IL-2 and IFN-gamma when stimulated with anti-TCR-beta mAb alone, and soluble CTLA-4 Ig has no effect on their responses. On the other hand, alpha alpha-CD8+ IELs neither make IL-2 or IFN-gamma nor proliferate even when both stimuli are provided. However, alpha alpha-CD8+ IELs are capable of proliferation in both CD8+ IEL subsets is lower than in CD8+ LN cells, which contributes to the weaker and delayed response of CD8+ IELs. PMID:7602124

  19. 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...

  20. Proteome-wide screening reveals immunodominance in the CD8 T cell response against classical swine fever virus with antigen-specificity dependent on MHC class I haplotype expression.

    Directory of Open Access Journals (Sweden)

    Giulia Franzoni

    Full Text Available Vaccination with live attenuated classical swine fever virus (CSFV vaccines induces a rapid onset of protection which has been associated with virus-specific CD8 T cell IFN-γ responses. In this study, we assessed the specificity of this response, by screening a peptide library spanning the CSFV C-strain vaccine polyprotein to identify and characterise CD8 T cell epitopes. Synthetic peptides were pooled to represent each of the 12 CSFV proteins and used to stimulate PBMC from four pigs rendered immune to CSFV by C-strain vaccination and subsequently challenged with the virulent Brescia strain. Significant IFN-γ expression by CD8 T cells, assessed by flow cytometry, was induced by peptide pools representing the core, E2, NS2, NS3 and NS5A proteins. Dissection of these antigenic peptide pools indicated that, in each instance, a single discrete antigenic peptide or pair of overlapping peptides was responsible for the IFN-γ induction. Screening and titration of antigenic peptides or truncated derivatives identified the following antigenic regions: core₂₄₁₋₂₅₅ PESRKKLEKALLAWA and NS3₁₉₀₂₋₁₉₁₂ VEYSFIFLDEY, or minimal length antigenic peptides: E2₉₉₆₋₁₀₀₃ YEPRDSYF, NS2₁₂₂₃₋₁₂₃₀ STVTGIFL and NS5A₃₀₇₀₋₃₀₇₈ RVDNALLKF. The epitopes are highly conserved across CSFV strains and variable sequence divergence was observed with related pestiviruses. Characterisation of epitope-specific CD8 T cells revealed evidence of cytotoxicity, as determined by CD107a mobilisation, and a significant proportion expressed TNF-α in addition to IFN-γ. Finally, the variability in the antigen-specificity of these immunodominant CD8 T cell responses was confirmed to be associated with expression of distinct MHC class I haplotypes. Moreover, recognition of NS₁₂₂₃₋₁₂₃₀ STVTGIFL and NS3₁₉₀₂₋₁₉₁₂ VEYSFIFLDEY by a larger group of C-strain vaccinated animals showed

  1. Nanoelectroablation of Murine Tumors Triggers a CD8-Dependent Inhibition of Secondary Tumor Growth.

    Directory of Open Access Journals (Sweden)

    Richard Nuccitelli

    Full Text Available We have used both a rat orthotopic hepatocellular carcinoma model and a mouse allograft tumor model to study liver tumor ablation with nanosecond pulsed electric fields (nsPEF. We confirm that nsPEF treatment triggers apoptosis in rat liver tumor cells as indicated by the appearance of cleaved caspase 3 and 9 within two hours after treatment. Furthermore we provide evidence that nsPEF treatment leads to the translocation of calreticulin (CRT to the cell surface which is considered a damage-associated molecular pattern indicative of immunogenic cell death. We provide direct evidence that nanoelectroablation triggers a CD8-dependent inhibition of secondary tumor growth by comparing the growth rate of secondary orthotopic liver tumors in nsPEF-treated rats with that in nsPEF-treated rats depleted of CD8+ cytotoxic T-cells. The growth of these secondary tumors was severely inhibited as compared to tumor growth in CD8-depleated rats, with their average size only 3% of the primary tumor size after the same one-week growth period. In contrast, when we depleted CD8+ T-cells the second tumor grew more robustly, reaching 54% of the size of the first tumor. In addition, we demonstrate with immunohistochemistry that CD8+ T-cells are highly enriched in the secondary tumors exhibiting slow growth. We also showed that vaccinating mice with nsPEF-treated isogenic tumor cells stimulates an immune response that inhibits the growth of secondary tumors in a CD8+-dependent manner. We conclude that nanoelectroablation triggers the production of CD8+ cytotoxic T-cells resulting in the inhibition of secondary tumor growth.

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

    Science.gov (United States)

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

    2009-09-01

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

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

    Science.gov (United States)

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

    2009-01-01

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

  4. The Relationship between B-cell Epitope and Mimotope Sequences.

    Science.gov (United States)

    Zhang, Chunhua; Li, Yunyun; Tang, Weina; Zhou, Zhiguo; Sun, Pingping; Ma, Zhiqiang

    2016-01-01

    B-cell epitope is a group of residues which is on the surface of an antigen. It invokes humoral responses. Locating B-cell epitope is important for effective vaccine design, and the development of diagnostic reagents. Mimotope-based B-cell epitope prediction method is a kind of conformational B-cell epitope prediction, and the core idea of the method is mapping the mimotope sequences which are obtained from a random phage display library. However, current mimotope-based B-cell epitope prediction methods cannot maintain a high degree of satisfaction in the circumstances of employing only mimotope sequences. In this study, we did a multi-perspective analysis on parameters for conformational B-cell epitopes and characteristics between epitope and mimotope on a benchmark datasets which contains 67 mimotope sets, corresponding to 40 unique complex structures. In these 67 cases, there are 25 antigen-antibody complexes and 42 protein-protein interactions. We analyzed the two parts separately. The results showed the mimotope sequences do have some epitope features, but there are also some epitope properties that mimotope sequences do not contain. In addition, the numbers of epitope segments with different lengths were obviously different between the antigen-antibody complexes and the protein-protein interactions. This study reflects how similar do mimotope sequence and genuine epitopes have; and evaluates existing mimotope-based B-cell epitope prediction methods from a novel viewpoint. PMID:26715528

  5. Neuropilin-1 expression is induced on tolerant self-reactive CD8+ T cells but is dispensable for the tolerant phenotype.

    Directory of Open Access Journals (Sweden)

    Stephanie R Jackson

    Full Text Available Establishing peripheral CD8(+ T cell tolerance is vital to avoid immune mediated destruction of healthy self-tissues. However, it also poses a major impediment to tumor immunity since tumors are derived from self-tissue and often induce T cell tolerance and dysfunction. Thus, understanding the mechanisms that regulate T cell tolerance versus immunity has important implications for human health. Signals received from the tissue environment largely dictate whether responding T cells become activated or tolerant. For example, induced expression and subsequent ligation of negative regulatory receptors on the surface of self-reactive CD8(+ T cells are integral in the induction of tolerance. We utilized a murine model of T cell tolerance to more completely define the molecules involved in this process. We discovered that, in addition to other known regulatory receptors, tolerant self-reactive CD8(+ T cells distinctly expressed the surface receptor neuropilin-1 (Nrp1. Nrp1 was highly induced in response to self-antigen, but only modestly when the same antigen was encountered under immune conditions, suggesting a possible mechanistic link to T cell tolerance. We also observed a similar Nrp1 expression profile on human tumor infiltrating CD4(+ and CD8(+ T cells. Despite high expression on tolerant CD8(+ T cells, our studies revealed that Nrp1 had no detectable role in the tolerant phenotype. Specifically, Nrp1-deficient T cells displayed the same functional defects as wild-type self-reactive T cells, lacking in vivo cytolytic potential, IFNγ production, and antitumor responses. While reporting mostly negative data, our findings have therapeutic implications, as Nrp1 is now being targeted for human cancer therapy in clinical trials, but the precise molecular pathways and immune cells being engaged during treatment remain incompletely defined.

  6. Praziquantel Facilitates IFN-γ-Producing CD8+ T Cells (Tc1) and IL-17-Producing CD8+ T Cells (Tc17) Responses to DNA Vaccination in Mice

    OpenAIRE

    Qiang Zou; Xin Yao; Jin Feng; Zhinan Yin; Richard Flavell; Yanxin Hu; Guoxing Zheng; Jin Jin; Youmin Kang; Bing Wu; Xiaoxuan Liang; Congcong Feng; Hu Liu; Weiyi Li; Xianzheng Wang

    2011-01-01

    BACKGROUND: CD8(+) cytotoxic T lymphocytes (CTLs) are crucial for eliminating hepatitis B virus (HBV) infected cells. DNA vaccination, a novel therapeutic strategy for chronic virus infection, has been shown to induce CTL responses. However, accumulated data have shown that CTLs could not be effectively induced by HBV DNA vaccination. METHODOLOGY/PRINCIPAL FINDINGS: Here, we report that praziquantel (PZQ), an anti-schistoma drug, could act as an adjuvant to overcome the lack of potent CTL res...

  7. Structural Basis of the CD8[alpha beta]/MHC Class I Interaction: Focused Recognition Orients CD8[beta] to a T Cell Proximal Position[superscript 1,2

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Rui; Natarajan, Kannan; Margulies, David H.; (NIH)

    2009-09-18

    In the immune system, B cells, dendritic cells, NK cells, and T lymphocytes all respond to signals received via ligand binding to receptors and coreceptors. Although the specificity of T cell recognition is determined by the interaction of T cell receptors with MHC/peptide complexes, the development of T cells in the thymus and their sensitivity to Ag are also dependent on coreceptor molecules CD8 (for MHC class I (MHCI)) and CD4 (for MHCII). The CD8{alpha}{beta} heterodimer is a potent coreceptor for T cell activation, but efforts to understand its function fully have been hampered by ignorance of the structural details of its interactions with MHCI. In this study we describe the structure of CD8{alpha}{beta} in complex with the murine MHCI molecule H-2D{sup d} at 2.6 {angstrom} resolution. The focus of the CD8{alpha}{beta} interaction is the acidic loop (residues 222-228) of the {alpha}3 domain of H-2D{sup d}. The {beta} subunit occupies a T cell membrane proximal position, defining the relative positions of the CD8{alpha} and CD8{beta} subunits. Unlike the CD8{alpha}{alpha} homodimer, CD8{alpha}{beta} does not contact the MHCI {alpha}{sub 2}- or {beta}{sub 2}-microglobulin domains. Movements of the CD8{alpha} CDR2 and CD8{beta} CDR1 and CDR2 loops as well as the flexibility of the H-2D{sup d} CD loop facilitate the monovalent interaction. The structure resolves inconclusive data on the topology of the CD8{alpha}{beta}/MHCI interaction, indicates that CD8{beta} is crucial in orienting the CD8{alpha}{beta} heterodimer, provides a framework for understanding the mechanistic role of CD8{alpha}{beta} in lymphoid cell signaling, and offers a tangible context for design of structurally altered coreceptors for tumor and viral immunotherapy.

  8. CD8+ T cells as a source of IFN-γ production in human cutaneous leishmaniasis.

    Directory of Open Access Journals (Sweden)

    Mahmoud Nateghi Rostami

    Full Text Available BACKGROUND: In human leishmaniasis Th1/Th2 dichotomy similar to murine model is not clearly defined and surrogate marker(s of protection is not yet known. In this study, Th1/Th2 cytokines (IL-5, IL-10, IL-13 and IFN-γ profile induced by purified CD4(+/CD8(+ T cells in response to Leishmania antigens were assessed at transcript and protein levels in 14 volunteers with a history of self-healing cutaneous leishmaniasis (HCL and compared with 18 healthy control volunteers. METHODOLOGY/PRINCIPAL FINDINGS: CD4(+/CD8(+/CD14(+ cells were purified from peripheral blood using magnetic beads; CD4(+/CD8(+ T cells were co-cultured with autologous CD14(+ monocytes in the presence of soluble Leishmania antigens (SLA. Stimulation of either CD4(+ T cells or CD8(+ T cells of HCL volunteers with SLA induced a significantly (P<0.05 higher IFN-γ production compared with the cells of controls. Upregulation of IFN-γ gene expression in CD4(+ cells (P<0.001 and CD8(+ cells (P = 0.006 of HCL volunteers was significantly more than that of controls. Significantly (P<0.05 higher fold-expression of IFN-γ gene was seen in CD4(+ cells than in CD8(+ cells. In HCL volunteers a significantly (P = 0.014 higher number of CD4(+ cells were positive for intracellular IFN-γ production than CD8(+ cells. CONCLUSIONS/SIGNIFICANCE: Collectively, the volunteers have shown maintenance of specific long-term immune responses characterized by a strong reaction to leishmanin skin test and IFN-γ production. The dominant IFN-γ response was the result of expansion of both CD4(+ and CD8(+ T cells. The results suggested that immune response in protected individuals with a history of zoonotic cutaneous leishmaniasis (ZCL due to L. major is mediated not only through the expansion of antigen-specific IFN-γ producing CD4(+ Th1 cells, but also through IFN-γ producing CD8(+ T cells.

  9. Memory CD8(+) T Cells Require Increased Concentrations of Acetate Induced by Stress for Optimal Function.

    Science.gov (United States)

    Balmer, Maria L; Ma, Eric H; Bantug, Glenn R; Grählert, Jasmin; Pfister, Simona; Glatter, Timo; Jauch, Annaïse; Dimeloe, Sarah; Slack, Emma; Dehio, Philippe; Krzyzaniak, Magdalena A; King, Carolyn G; Burgener, Anne-Valérie; Fischer, Marco; Develioglu, Leyla; Belle, Réka; Recher, Mike; Bonilla, Weldy V; Macpherson, Andrew J; Hapfelmeier, Siegfried; Jones, Russell G; Hess, Christoph

    2016-06-21

    How systemic metabolic alterations during acute infections impact immune cell function remains poorly understood. We found that acetate accumulates in the serum within hours of systemic bacterial infections and that these increased acetate concentrations are required for optimal memory CD8(+) T cell function in vitro and in vivo. Mechanistically, upon uptake by memory CD8(+) T cells, stress levels of acetate expanded the cellular acetyl-coenzyme A pool via ATP citrate lyase and promoted acetylation of the enzyme GAPDH. This context-dependent post-translational modification enhanced GAPDH activity, catalyzing glycolysis and thus boosting rapid memory CD8(+) T cell responses. Accordingly, in a murine Listeria monocytogenes model, transfer of acetate-augmented memory CD8(+) T cells exerted superior immune control compared to control cells. Our results demonstrate that increased systemic acetate concentrations are functionally integrated by CD8(+) T cells and translate into increased glycolytic and functional capacity. The immune system thus directly relates systemic metabolism with immune alertness. PMID:27212436

  10. Immunological tolerance to muscle autoantigens involves peripheral deletion of autoreactive CD8+ T cells.

    Directory of Open Access Journals (Sweden)

    Emilie Franck

    Full Text Available Muscle potentially represents the most abundant source of autoantigens of the body and can be targeted by a variety of severe autoimmune diseases. Yet, the mechanisms of immunological tolerance toward muscle autoantigens remain mostly unknown. We investigated this issue in transgenic SM-Ova mice that express an ovalbumin (Ova neo-autoantigen specifically in skeletal muscle. We previously reported that antigen specific CD4(+ T cell are immunologically ignorant to endogenous Ova in this model but can be stimulated upon immunization. In contrast, Ova-specific CD8(+ T cells were suspected to be either unresponsive to Ova challenge or functionally defective. We now extend our investigations on the mechanisms governing CD8(+ tolerance in SM-Ova mice. We show herein that Ova-specific CD8(+ T cells are not detected upon challenge with strongly immunogenic Ova vaccines even after depletion of regulatory T cells. Ova-specific CD8(+ T cells from OT-I mice adoptively transferred to SM-Ova mice started to proliferate in vivo, acquired CD69 and PD-1 but subsequently down-regulated Bcl-2 and disappeared from the periphery, suggesting a mechanism of peripheral deletion. Peripheral deletion of endogenous Ova-specific cells was formally demonstrated in chimeric SM-Ova mice engrafted with bone marrow cells containing T cell precursors from OT-I TCR-transgenic mice. Thus, the present findings demonstrate that immunological tolerance to muscle autoantigens involves peripheral deletion of autoreactive CD8(+ T cells.

  11. Cutting edge: neuronal recognition by CD8 T cells elicits central diabetes insipidus.

    Science.gov (United States)

    Scheikl, Tanja; Pignolet, Béatrice; Dalard, Cécile; Desbois, Sabine; Raison, Danièle; Yamazaki, Masanori; Saoudi, Abdelhadi; Bauer, Jan; Lassmann, Hans; Hardin-Pouzet, Hélène; Liblau, Roland S

    2012-05-15

    An increasing number of neurologic diseases is associated with autoimmunity. The immune effectors contributing to the pathogenesis of such diseases are often unclear. To explore whether self-reactive CD8 T cells could attack CNS neurons in vivo, we generated a mouse model in which the influenza virus hemagglutinin (HA) is expressed specifically in CNS neurons. Transfer of cytotoxic anti-HA CD8 T cells induced an acute but reversible encephalomyelitis in HA-expressing recipient mice. Unexpectedly, diabetes insipidus developed in surviving animals. This robust phenotype was associated with preferential accumulation of cytotoxic CD8 T cells in the hypothalamus, upregulation of MHC class I molecules, and destruction of vasopressin-expressing neurons. IFN-γ production by the pathogenic CD8 T cells was necessary for MHC class I upregulation by hypothalamic neurons and their destruction. This novel mouse model, in combination with related human data, supports the concept that autoreactive CD8 T cells can trigger central diabetes insipidus. PMID:22504649

  12. Dynamic Imaging of CD8(+) T cells and dendritic cells during infection with Toxoplasma gondii.

    Science.gov (United States)

    John, Beena; Harris, Tajie H; Tait, Elia D; Wilson, Emma H; Gregg, Beth; Ng, Lai Guan; Mrass, Paulus; Roos, David S; Dzierszinski, Florence; Weninger, Wolfgang; Hunter, Christopher A

    2009-07-01

    To better understand the initiation of CD8(+) T cell responses during infection, the primary response to the intracellular parasite Toxoplasma gondii was characterized using 2-photon microscopy combined with an experimental system that allowed visualization of dendritic cells (DCs) and parasite specific CD8(+) T cells. Infection with T. gondii induced localization of both these populations to the sub-capsular/interfollicular region of the draining lymph node and DCs were required for the expansion of the T cells. Consistent with current models, in the presence of cognate antigen, the average velocity of CD8(+) T cells decreased. Unexpectedly, infection also resulted in modulation of the behavior of non-parasite specific T cells. This TCR-independent process correlated with the re-modeling of the lymph node micro-architecture and changes in expression of CCL21 and CCL3. Infection also resulted in sustained interactions between the DCs and CD8(+) T cells that were visualized only in the presence of cognate antigen and were limited to an early phase in the response. Infected DCs were rare within the lymph node during this time frame; however, DCs presenting the cognate antigen were detected. Together, these data provide novel insights into the earliest interaction between DCs and CD8(+) T cells and suggest that cross presentation by bystander DCs rather than infected DCs is an important route of antigen presentation during toxoplasmosis.

  13. Dynamic Imaging of CD8(+ T cells and dendritic cells during infection with Toxoplasma gondii.

    Directory of Open Access Journals (Sweden)

    Beena John

    2009-07-01

    Full Text Available To better understand the initiation of CD8(+ T cell responses during infection, the primary response to the intracellular parasite Toxoplasma gondii was characterized using 2-photon microscopy combined with an experimental system that allowed visualization of dendritic cells (DCs and parasite specific CD8(+ T cells. Infection with T. gondii induced localization of both these populations to the sub-capsular/interfollicular region of the draining lymph node and DCs were required for the expansion of the T cells. Consistent with current models, in the presence of cognate antigen, the average velocity of CD8(+ T cells decreased. Unexpectedly, infection also resulted in modulation of the behavior of non-parasite specific T cells. This TCR-independent process correlated with the re-modeling of the lymph node micro-architecture and changes in expression of CCL21 and CCL3. Infection also resulted in sustained interactions between the DCs and CD8(+ T cells that were visualized only in the presence of cognate antigen and were limited to an early phase in the response. Infected DCs were rare within the lymph node during this time frame; however, DCs presenting the cognate antigen were detected. Together, these data provide novel insights into the earliest interaction between DCs and CD8(+ T cells and suggest that cross presentation by bystander DCs rather than infected DCs is an important route of antigen presentation during toxoplasmosis.

  14. A secreted form of the human lymphocyte cell surface molecule CD8 arises from alternative splicing

    Energy Technology Data Exchange (ETDEWEB)

    Giblin, P.; Kavathas, P. (Yale Univ. School of Medicine, New Haven, CT (USA)); Ledbetter, J.A. (Oncogen, Seattle, WA (USA))

    1989-02-01

    The human lymphocyte differentiation antigen CD8 is encoded by a single gene that gives rise to a 33- to 34-kDa glycoprotein expressed on the cell surface as a dimer and in higher molecular mass forms. The authors demonstrate that the mRNA is alternatively spliced so that an exon encoding a transmembrane domain is deleted. This gives rise to a 30-kDa molecule that is secreted and exists primarily as a monomer. mRNA corresponding to both forms is present in peripheral blood lymphocytes, Con A-activated peripheral blood lymphocytes, and three CD8{sup +} T-cell lines, with the membrane form being the major species. However, differences in the ratio of mRNA for membrane CD8 and secreted CD8 exist. In addition, the splicing pattern observed differs from the pattern found for the mouse CD8 gene. This mRNA is also alternatively spliced, but an exon encoding a cytoplasmic region is deleted, giving rise to a cell surface molecule that differs in its cytoplasmic tail from the protein encoded by the longer mRNA. Neither protein is secreted. This is one of the first examples of a different splicing pattern between two homologous mouse and human genes giving rise to very different proteins. This represents one mechanism of generating diversity during speciation.

  15. Bystander suppression of allergic airway inflammation by lung resident memory CD8+ T cells

    Science.gov (United States)

    Marsland, Benjamin J.; Harris, Nicola L.; Camberis, Mali; Kopf, Manfred; Hook, Sarah M.; Le Gros, Graham

    2004-04-01

    CD8+ memory T cells have recently been recognized as playing a key role in natural immunity against unrelated viral infections, a phenomenon referred to as "heterologous antiviral immunity." We now provide data that the cellular immunological interactions that underlie such heterologous immunity can play an equally important role in regulating T helper 2 immune responses and protecting mucosal surfaces from allergen-induced inflammation. Our data show that CD8+ T cells, either retained in the lung after infection with influenza virus, or adoptively transferred via the intranasal route can suppress allergic airway inflammation. The suppression is mediated by IFN-, which acts to reduce the activation level, T helper 2 cytokine production, airways hyperresponsiveness, and migration of allergen-specific CD4+ T cells into the lung, whereas the systemic and draining lymph node responses remain unchanged. Of note, adoptive transfer of previously activated transgenic CD8+ T cells conferred protection against allergic airway inflammation, even in the absence of specific-antigen. Airway resident CD8+ T cells produced IFN- when directly exposed to conditioned media from activated dendritic cells or the proinflammatory cytokines IL-12 and IL-18. Taken together these data indicate that effector/memory CD8+ T cells present in the airways produce IFN- after inflammatory stimuli, independent of specific-antigen, and as a consequence play a key role in modifying the degree and frequency of allergic responses in the lung.

  16. Peripheral tolerance through clonal deletion of mature CD4-CD8+ T cells.

    Science.gov (United States)

    Carlow, D A; Teh, S J; van Oers, N S; Miller, R G; Teh, H S

    1992-05-01

    Transgenic mice bearing the alpha beta transgenes encoding a defined T cell receptor specific for the male (H-Y) antigen presented by the H-2Db class I MHC molecule were used to study mechanisms of peripheral tolerance. Female transgenic mice produce large numbers of functionally homogeneous CD8+ male antigen-reactive T cells in the thymus that subsequently accumulate in the peripheral lymphoid organs. We have used three experimental approaches to show that male reactive CD8+ T cells can be eliminated from peripheral lymphoid organs after exposure to male antigen. (i) In female transgenic mice that were neonatally tolerized with male spleen cells, male reactive CD8+ T cells continued to be produced in large numbers in the thymus but were virtually absent in the lymph nodes. (ii) Injection of thymocytes from female transgenic mice into female mice neonatally tolerized with the male antigen, or into normal male mice, led to the specific elimination of male-reactive CD8+ T cells in the lymph nodes. (iii) Four days after male lymphoid cells were injected intravenously into female transgenic mice, male antigen-reactive CD8+ T cells recovered from the lymph nodes of recipient mice were highly apoptotic when compared to CD4+ (non-male reactive) T cells. These data indicate that tolerance to extrathymic antigen can be achieved through elimination of mature T cells in the peripheral lymphoid organs.

  17. An IFN-gamma-IL-18 signaling loop accelerates memory CD8+ T cell proliferation.

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    Yoshiko Iwai

    Full Text Available Rapid proliferation is one of the important features of memory CD8(+ T cells, ensuring rapid clearance of reinfection. Although several cytokines such as IL-15 and IL-7 regulate relatively slow homeostatic proliferation of memory T cells during the maintenance phase, it is unknown how memory T cells can proliferate more quickly than naïve T cells upon antigen stimulation. To examine antigen-specific CD8(+ T cell proliferation in recall responses in vivo, we targeted a model antigen, ovalbumin(OVA, to DEC-205(+ dendritic cells (DCs with a CD40 maturation stimulus. This led to the induction of functional memory CD8(+ T cells, which showed rapid proliferation and multiple cytokine production (IFN-gamma, IL-2, TNF-alpha during the secondary challenge to DC-targeted antigen. Upon antigen-presentation, IL-18, an IFN-gamma-inducing factor, accumulated at the DC:T cell synapse. Surprisingly, IFN-gamma receptors were required to augment IL-18 production from DCs. Mice genetically deficient for IL-18 or IFN-gamma-receptor 1 also showed delayed expansion of memory CD8(+ T cells in vivo. These results indicate that a positive regulatory loop involving IFN-gamma and IL-18 signaling contributes to the accelerated memory CD8(+ T cell proliferation during a recall response to antigen presented by DCs.

  18. Functional maturation of twomurine medullary-type CD8SP thymocytes

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    TCRab+CD4-CD8+ thymocytes are heterogeneity. They may undergo phenotypic and functional maturation within thymic medulla. Medullary-type CD8SP thymocytes were divided into seven subsets based on phenotypic analysis, and their precursor-progeny relationship along with the differential pathway was also delineated. To further testify the validity of the maturation pathway, we purified 6C10-CD69+ cells representing the early stage and 6C10-Qa-2+ cells representing the later stage among medullary-type CD8SP thymocytes and compared their functional matura-tion levels. CD8+ T cells of spleen were used as the control. It is shown that there is no obvious difference of proliferation ability among these three subsets; however, intracytoplasmic cytokine assay shows that there is a hierarchy of IFN-g and TNFa secretion among these subsets, strikingly comparable to their phenotypic status among medullary type CD8SP thymocytes. The bioassays of IL-2 and IFN-g in culture su-pernatant give the similar results.

  19. Bystander activation of CD8+ T lymphocytes during experimental mycobacterial infection.

    Science.gov (United States)

    Gilbertson, Brad; Germano, Susie; Steele, Pauline; Turner, Steven; Fazekas de St Groth, Barbara; Cheers, Christina

    2004-12-01

    Infection of C57BL/6 mice with Mycobacterium avium leads to the activation of both CD4+ and CD8+ gamma interferon (IFN-gamma)-producing T cells, although the CD8+ cells play no role in protection against infection. Using transfer of different lines of transgenic T cells with T-cell receptors (TCRs) which recognize irrelevant antigens, we show here that transferred CD8+ T cells from two of the three lines were activated to the same degree as the host cells, suggesting that the majority of the IFN-gamma-producing CD8+ T cells of the host represented bystander activation. The third line, specific for the male HY antigen, showed no activation. Activation required the participation of the CD28 coreceptor on T cells and was unaffected by the removal of CD44(hi) (memory phenotype) T cells. The transferred CD8+ T cells proliferated in vivo, although this was not essential for IFN-gamma production. Taken together, these data are highly reminiscent of homeostatic proliferation of TCR transgenic T cells upon transfer to lymphopenic hosts, and suggest low-affinity stimulation through the TCR, possibly by self peptides. The findings are discussed in relation to homeostatic proliferation and their significance in the possible induction of autoimmune disease.

  20. Memory CD8+ T Cells: Orchestrators and Key Players of Innate Immunity?

    Science.gov (United States)

    Lauvau, Grégoire; Goriely, Stanislas

    2016-09-01

    Over the past decades, the dichotomy between innate and adaptive immune responses has largely dominated our understanding of immunology. Upon primary encounter with microbial pathogens, differentiation of adaptive immune cells into functional effectors usually takes several days or even longer, making them contribute to host protection only late during primary infection. However, once generated, antigen-experienced T lymphocytes can persist in the organism and constitute a pool of memory cells that mediate fast and effective protection to a recall infection with the same microbial pathogen. Herein, we challenge this classical paradigm by highlighting the "innate nature" of memory CD8+ T cells. First, within the thymus or in the periphery, naïve CD8+ T cells may acquire phenotypic and functional characteristics of memory CD8+ T cells independently of challenge with foreign antigens. Second, both the "unconventional" and the "conventional" memory cells can rapidly express protective effector functions in response to sets of inflammatory cytokines and chemokines signals, independent of cognate antigen triggering. Third, memory CD8+ T cells can act by orchestrating the recruitment, activation, and licensing of innate cells, leading to broad antimicrobial states. Thus, collectively, memory CD8+ T cells may represent important actors of innate immune defenses.

  1. A secreted form of the human lymphocyte cell surface molecule CD8 arises from alternative splicing

    International Nuclear Information System (INIS)

    The human lymphocyte differentiation antigen CD8 is encoded by a single gene that gives rise to a 33- to 34-kDa glycoprotein expressed on the cell surface as a dimer and in higher molecular mass forms. The authors demonstrate that the mRNA is alternatively spliced so that an exon encoding a transmembrane domain is deleted. This gives rise to a 30-kDa molecule that is secreted and exists primarily as a monomer. mRNA corresponding to both forms is present in peripheral blood lymphocytes, Con A-activated peripheral blood lymphocytes, and three CD8+ T-cell lines, with the membrane form being the major species. However, differences in the ratio of mRNA for membrane CD8 and secreted CD8 exist. In addition, the splicing pattern observed differs from the pattern found for the mouse CD8 gene. This mRNA is also alternatively spliced, but an exon encoding a cytoplasmic region is deleted, giving rise to a cell surface molecule that differs in its cytoplasmic tail from the protein encoded by the longer mRNA. Neither protein is secreted. This is one of the first examples of a different splicing pattern between two homologous mouse and human genes giving rise to very different proteins. This represents one mechanism of generating diversity during speciation

  2. Effect of ranitidine on soluble interleukin 2 receptors and CD8 molecules in surgical patients

    DEFF Research Database (Denmark)

    Nielsen, Hans Jørgen; Mynster, T; Jensen, S;

    1994-01-01

    transfusion were similar in the two groups. Serum concentrations of soluble IL-2 receptor and CD8 were measured before operation (day 0) and in the morning of postoperative days 1, 3 and 9 using commercial enzyme-linked immunosorbent assay kits. In patients treated with ranitidine, the serum level of soluble......The effect of perioperative immunomodulation with the H2-receptor antagonist ranitidine on postoperative changes in soluble interleukin (IL) 2 receptor and soluble CD8 levels was assessed in 24 patients undergoing major elective abdominal surgery. Eleven patients were randomized to receive...... developed postoperative infectious complications. No significant differences were shown in soluble CD8 concentration during the postoperative period. The postoperative change in soluble IL-2 receptor level may reflect lymphocyte activation status; ranitidine appears to promote activation of mainly CD4...

  3. Thymoproteasomes produce unique peptide motifs for positive selection of CD8(+) T cells.

    Science.gov (United States)

    Sasaki, Katsuhiro; Takada, Kensuke; Ohte, Yuki; Kondo, Hiroyuki; Sorimachi, Hiroyuki; Tanaka, Keiji; Takahama, Yousuke; Murata, Shigeo

    2015-01-01

    Positive selection in the thymus provides low-affinity T-cell receptor (TCR) engagement to support the development of potentially useful self-major histocompatibility complex class I (MHC-I)-restricted T cells. Optimal positive selection of CD8(+) T cells requires cortical thymic epithelial cells that express β5t-containing thymoproteasomes (tCPs). However, how tCPs govern positive selection is unclear. Here we show that the tCPs produce unique cleavage motifs in digested peptides and in MHC-I-associated peptides. Interestingly, MHC-I-associated peptides carrying these tCP-dependent motifs are enriched with low-affinity TCR ligands that efficiently induce the positive selection of functionally competent CD8(+) T cells in antigen-specific TCR-transgenic models. These results suggest that tCPs contribute to the positive selection of CD8(+) T cells by preferentially producing low-affinity TCR ligand peptides.

  4. Exhaustion of Activated CD8 T Cells Predicts Disease Progression in Primary HIV-1 Infection.

    Science.gov (United States)

    Hoffmann, Matthias; Pantazis, Nikos; Martin, Genevieve E; Hickling, Stephen; Hurst, Jacob; Meyerowitz, Jodi; Willberg, Christian B; Robinson, Nicola; Brown, Helen; Fisher, Martin; Kinloch, Sabine; Babiker, Abdel; Weber, Jonathan; Nwokolo, Nneka; Fox, Julie; Fidler, Sarah; Phillips, Rodney; Frater, John

    2016-07-01

    The rate at which HIV-1 infected individuals progress to AIDS is highly variable and impacted by T cell immunity. CD8 T cell inhibitory molecules are up-regulated in HIV-1 infection and associate with immune dysfunction. We evaluated participants (n = 122) recruited to the SPARTAC randomised clinical trial to determine whether CD8 T cell exhaustion markers PD-1, Lag-3 and Tim-3 were associated with immune activation and disease progression. Expression of PD-1, Tim-3, Lag-3 and CD38 on CD8 T cells from the closest pre-therapy time-point to seroconversion was measured by flow cytometry, and correlated with surrogate markers of HIV-1 disease (HIV-1 plasma viral load (pVL) and CD4 T cell count) and the trial endpoint (time to CD4 count approaches. PMID:27415828

  5. Analisis perilaku dinamik pada sel T CD4+ dan sel T CD8+ terhadap infeksi mikobakterium

    Directory of Open Access Journals (Sweden)

    Alfi Nur Rochmatin

    2014-05-01

    Full Text Available Model matematika pada infeksi mikobakterium tuberkulosis yang berbentuk sistem persamaan diferensial nonlinear orde satu. Penelitian ini telah mengkonstruksi model matematika pada interaksi makrofag, sel T CD4+ dan sel T CD8+ dengan pengaruh usia. Solusi numerik pada model matematika ini dengan menggunakan ODE 45 berbantuan matlab. Analisis kestabilan diamati melalui titik tetap dengan mencari matriks jacobian dan nilai eigen dari titik tetap tersebut, maka dapat diperoleh bahwa semua titik tetap tersebut tidak stabil. Berdasarkan analisis perilaku dinamik pada sel T CD4+ dan sel T CD8+pada usia muda dan usia tua maka akan diperoleh bahwa sel T CD4+dan sel T CD8+ lebih banyak mempengaruhi populasi bakteri mikobakterium tuberkulosis dari pada saat usia muda

  6. Location and dynamics of the immunodominant CD8 T cell response to SIVΔnef immunization and SIVmac251 vaginal challenge.

    Directory of Open Access Journals (Sweden)

    Arun K Sasikala-Appukuttan

    Full Text Available Live-attenuated SIV vaccines (LAVs have been the most effective to date in preventing or partially controlling infection by wild-type SIV in non-human primate models of HIV-1 transmission to women acting by mechanisms of protection that are not well understood. To gain insights into mechanisms of protection by LAVs that could aid development of effective vaccines to prevent HIV-1 transmission to women, we used in situ tetramer staining to determine whether increased densities or changes in the local distribution of SIV-specific CD8 T cells correlated with the maturation of SIVΔnef vaccine-induced protection prior to and after intra-vaginal challenge with wild-type SIVmac251. We evaluated the immunodominant Mamu-A1*001:01/Gag (CM9 and Mamu-A1*001:01/Tat (SL8 epitope response in genital and lymphoid tissues, and found that tetramer+ cells were present at all time points examined. In the cervical vaginal tissues, most tetramer+ cells were distributed diffusely throughout the lamina propria or co-localized with other CD8 T cells within lymphoid aggregates. The distribution and densities of the tetramer+ cells at the portal of entry did not correlate with the maturation of protection or change after challenge. Given these findings, we discuss the possibility that changes in other aspects of the immune system, including the quality of the resident population of virus-specific effector CD8 T cells could contribute to maturation of protection, as well as the potential for vaccine strategies that further increase the size and quality of this effector population to prevent HIV-1 transmission.

  7. Exploring the induction of preproinsulin-specific Foxp3+ CD4+ Treg cells that inhibit CD8+ T cell-mediated autoimmune diabetes by DNA vaccination

    Science.gov (United States)

    Stifter, Katja; Schuster, Cornelia; Schlosser, Michael; Boehm, Bernhard Otto; Schirmbeck, Reinhold

    2016-01-01

    DNA vaccination is a promising strategy to induce effector T cells but also regulatory Foxp3+ CD25+ CD4+ Treg cells and inhibit autoimmune disorders such as type 1 diabetes. Little is known about the antigen requirements that facilitate priming of Treg cells but not autoreactive effector CD8+ T cells. We have shown that the injection of preproinsulin (ppins)-expressing pCI/ppins vector into PD-1- or PD-L1-deficient mice induced Kb/A12-21-monospecific CD8+ T cells and autoimmune diabetes. A pCI/ppinsΔA12-21 vector (lacking the critical Kb/A12-21 epitope) did not induce autoimmune diabetes but elicited a systemic Foxp3+ CD25+ Treg cell immunity that suppressed diabetes induction by a subsequent injection of the diabetogenic pCI/ppins. TGF-β expression was significantly enhanced in the Foxp3+ CD25+ Treg cell population of vaccinated/ppins-primed mice. Ablation of Treg cells in vaccinated/ppins-primed mice by anti-CD25 antibody treatment abolished the protective effect of the vaccine and enabled diabetes induction by pCI/ppins. Adoptive transfer of Treg cells from vaccinated/ppins-primed mice into PD-L1−/− hosts efficiently suppressed diabetes induction by pCI/ppins. We narrowed down the Treg-stimulating domain to a 15-residue ppins76–90 peptide. Vaccine-induced Treg cells thus play a crucial role in the control of de novo primed autoreactive effector CD8+ T cells in this diabetes model. PMID:27406624

  8. Exploring the induction of preproinsulin-specific Foxp3(+) CD4(+) Treg cells that inhibit CD8(+) T cell-mediated autoimmune diabetes by DNA vaccination.

    Science.gov (United States)

    Stifter, Katja; Schuster, Cornelia; Schlosser, Michael; Boehm, Bernhard Otto; Schirmbeck, Reinhold

    2016-01-01

    DNA vaccination is a promising strategy to induce effector T cells but also regulatory Foxp3(+) CD25(+) CD4(+) Treg cells and inhibit autoimmune disorders such as type 1 diabetes. Little is known about the antigen requirements that facilitate priming of Treg cells but not autoreactive effector CD8(+) T cells. We have shown that the injection of preproinsulin (ppins)-expressing pCI/ppins vector into PD-1- or PD-L1-deficient mice induced K(b)/A12-21-monospecific CD8(+) T cells and autoimmune diabetes. A pCI/ppinsΔA12-21 vector (lacking the critical K(b)/A12-21 epitope) did not induce autoimmune diabetes but elicited a systemic Foxp3(+) CD25(+) Treg cell immunity that suppressed diabetes induction by a subsequent injection of the diabetogenic pCI/ppins. TGF-β expression was significantly enhanced in the Foxp3(+) CD25(+) Treg cell population of vaccinated/ppins-primed mice. Ablation of Treg cells in vaccinated/ppins-primed mice by anti-CD25 antibody treatment abolished the protective effect of the vaccine and enabled diabetes induction by pCI/ppins. Adoptive transfer of Treg cells from vaccinated/ppins-primed mice into PD-L1(-/-) hosts efficiently suppressed diabetes induction by pCI/ppins. We narrowed down the Treg-stimulating domain to a 15-residue ppins76-90 peptide. Vaccine-induced Treg cells thus play a crucial role in the control of de novo primed autoreactive effector CD8(+) T cells in this diabetes model. PMID:27406624

  9. The Presence of HLA-E-Restricted, CMV-Specific CD8+ T Cells in the Blood of Lung Transplant Recipients Correlates with Chronic Allograft Rejection.

    Directory of Open Access Journals (Sweden)

    Lucy C Sullivan

    Full Text Available The human cytomegalovirus (CMV immune evasion protein, UL40, shares an identical peptide sequence with that found in the leader sequence of many human leukocyte antigen (HLA-C alleles and when complexed with HLA-E, can modulate NK cell functions via interactions with the CD94-NKG2 receptors. However the UL40-derived sequence can also be immunogenic, eliciting robust CD8+ T cell responses. In the setting of solid organ transplantation these T cells may not only be involved in antiviral immunity but also can potentially contribute to allograft rejection when the UL40 epitope is also present in allograft-encoded HLA. Here we assessed 15 bilateral lung transplant recipients for the presence of HLA-E-restricted UL40 specific T cells by tetramer staining of peripheral blood mononuclear cells (PBMC. UL40-specific T cells were observed in 7 patients post-transplant however the magnitude of the response varied significantly between patients. Moreover, unlike healthy CMV seropositive individuals, longitudinal analyses revealed that proportions of such T cells fluctuated markedly. Nine patients experienced low-grade acute cellular rejection, of which 6 also demonstrated UL40-specific T cells. Furthermore, the presence of UL40-specific CD8+ T cells in the blood was significantly associated with allograft dysfunction, which manifested as Bronchiolitis Obliterans Syndrome (BOS. Therefore, this study suggests that minor histocompatibility antigens presented by HLA-E can represent an additional risk factor following lung transplantation.

  10. Tomatine Adjuvantation of Protective Immunity to a Major Pre-erythrocytic Vaccine Candidate of Malaria is Mediated via CD8+ T Cell Release of IFN-γ

    Directory of Open Access Journals (Sweden)

    Karen G. Heal

    2010-01-01

    Full Text Available The glycoalkaloid tomatine, derived from the wild tomato, can act as a powerful adjuvant to elicit an antigen-specific cell-mediated immune response to the circumsporozoite (CS protein, a major pre-erythrocytic stage malaria vaccine candidate antigen. Using a defined MHC-class-I-restricted CS epitope in a Plasmodium berghei rodent model, antigen-specific cytotoxic T lymphocyte activity and IFN-γ secretion ex vivo were both significantly enhanced compared to responses detected from similarly stimulated splenocytes from naive and tomatine-saline-immunized mice. Further, through lymphocyte depletion it is demonstrated that antigen-specific IFN-γ is produced exclusively by the CD8+ T cell subset. We conclude that the processing of the P. berghei CS peptide as an exogenous antigen and its presentation via MHC class I molecules to CD8+ T cells leads to an immune response that is an in vitro correlate of protection against pre-erythrocytic malaria. Further characterization of tomatine as an adjuvant in malaria vaccine development is indicated.

  11. Tumor-infiltrating CD8+ lymphocytes effect on clinical outcome of muco-cutaneous melanoma

    Directory of Open Access Journals (Sweden)

    Mahtab Rahbar

    2015-01-01

    Full Text Available Background: Recent data have changed our views of prognostic factors in cutaneous melanoma, while some newer methods have yielded better prognostic information. Tumor-infiltrating lymphocytes are believed to represent the immune reaction/response to melanoma cells which is often found in melanocytic cancer. Aim and Objective: We carried out an analysis, aiming to establish pooled estimates for clinical outcomes based on the presence of CD8+ T cell in melanocytic cancer. Materials and Methods: We have included 42 patients with primary cutaneous melanocytic cancer without preoperative treatments in our study. We next analyzed the proliferative activity of CD8+ T cells that infiltrated in tumor cell nests. The intratumoral and adjacent to invasive margin of tumor CD+ T-cell infiltration were analyzed which could also reflect antitumor immunity. Results: The total number of CD8+ cells especially adjacent to invasive margin of tumor was positively correlated with anatomical tumor thickness (P < .001 and not correlated with patient′s age and sex. The stage of tumor which is related to vascular-neural invasion, regional lymph nodes involvement and tumor thickness shows positive correlation with CD8+ infiltration in tumor (P < .004, P < .005, P < .001, respectively. Acral melanoma shows more CD8 lymphocytes infiltration and also recurrence rate of tumor (P < .005. Conclusion: We believe that CD8+ T-cell infiltration in primary cutaneous melanocytic cancer represents the immune reaction/response to melanoma which could be an important new therapy for melanoma although more research is needed on this treatment modality.

  12. Multiple Redundant Effector Mechanisms of CD8+ T Cells Protect against Influenza Infection

    OpenAIRE

    Hamada, Hiromasa; Bassity, Elizabeth; Flies, Amanda; Strutt, Tara M.; Garcia-Hernandez, Maria de Luz; McKinstry, K. Kai; Zou, Tie; Swain, Susan L.; Dutton, Richard W.

    2012-01-01

    We have previously shown that mice challenged with a lethal dose of PR8-OVAI are protected by injection of 4 to 8 × 106 in vitro - generated Tc1 or Tc17 CD8+ effectors. Viral load, lung damage and loss of lung function are all reduced following transfer. Weight loss is reduced and survival increased. We sought here to define the mechanism of this protection. CD8+ effectors exhibit multiple effector activities, perforin-, FasL- and TRAIL- mediated cytotoxicity, secretion of multiple cytokin...

  13. IL-17-Expressing CD4 + and CD8 + T Lymphocytes in Human Toxoplasmosis

    OpenAIRE

    Jéssica Líver Alves Silva; Karine Rezende-Oliveira; Marcos Vinicius da Silva; César Gómez-Hernández; Bethânea Crema Peghini; Neide Maria Silva; José Roberto Mineo; Virmondes Rodrigues Júnior

    2014-01-01

    This study aimed to measure the synthesis of Th1 and Th2 cytokines by mononuclear cells after culture with live T. gondii and identified Th17 (CD4+) and Tc17 (CD8+) cells in toxoplasma-seronegative and toxoplasma-seropositive parturient and nonpregnant women. Cytometric bead arrays were used to measure cytokine levels (IL-2, TNF-α, IFN-γ, IL-4, IL-5, and IL-10); immunophenotyping was used to characterize Th17 and Tc17 cells, and the cells were stained with antibodies against CD4+ and CD8+ T c...

  14. Function, phenotype and development of human CD161+CD8 T cells

    OpenAIRE

    Walker, Lucy Jane; Klenerman, Paul; Barnes, Eleanor

    2012-01-01

    Tc17 cells and the semi-invariant human mucosal associated invariant T (MAIT) cells are important CD8+ tissue-homing cell populations. Both are characterized by high expression of CD161 (++) and type-17 differentiation, yet their origins and relationships remain poorly defined. By transcriptional and functional analyses it is demonstrated that a pool of polyclonal, pre-committed type-17 CD161++CD8αβ+ T cells exists in cord blood, from which a prominent MAIT cell (TCR Vα7.2+/Vβ2 or 13.2) popul...

  15. miR-150 Regulates Differentiation and Cytolytic Effector Function in CD8+ T cells

    OpenAIRE

    Smith, Norah L.; Wissink, Erin M.; Andrew Grimson; Rudd, Brian D.

    2015-01-01

    MicroRNAs regulate most mammalian genes, and they control numerous aspects of immune system development and function. Their precise roles in the CD8+ T cell response, however, remain unclear. In this report, we show that in the absence of the microRNA miR-150, CD8+ T cells fail to undergo robust expansion and differentiation into short-lived terminal effector cells in response to primary infection with Listeria monocytogenes or Vaccinia virus. Notably, even after transitioning into the memory...

  16. 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...... of thymocytes. The majority of the IL-15-grown CD8(+) CD56(+) cells were CD45R0(+), representing a memory phenotype, and showed high expression of the IL-15R-complex and high numbers of CD69(+) cells. Moreover, cytotoxic activity was confined to this cell population....

  17. Characterization of virus-primed CD8+ T cells with a type 1 cytokine profile

    DEFF Research Database (Denmark)

    Christensen, Jan Pravsgaard; Stenvang, J P; Marker, O;

    1996-01-01

    . Phenotypically, the main cytokine-producing cell subset is found to be CD8+ cells targeted for homing to inflammatory sites (VLA-4hiL-selectinlo) of which 30-40% were positive by intracellular staining for IFN-gamma. This subset also contains all T cells with a cytotoxic potential as measured by redirected...... demonstrate that systemic virus infection may exert marked perturbation of the CD8+ T cell population resulting in generation of a long-lived subset of primed cells with important effector potential....

  18. Role of CD8^+ T Cells in Murine Experimental Allergic Encephalomyelitis

    Science.gov (United States)

    Jiang, Hong; Zhang, Sheng-Le; Pernis, Benvenuto

    1992-05-01

    The course of experimental allergic encephalomyelitis (EAE), an animal model for multiple sclerosis, is affected by immunoregulatory T lymphocytes. When animals are immunized with encephalitogenic peptide of myelin basic protein and recover from the first episode of EAE, they become resistant to a second induction of this disease. Animals depleted of CD8^+ T cells by antibody-mediated clearance were used to examine the role of CD8^+ T cells in EAE. These cells were found to be major participants in the resistance to a second induction of EAE but were not essential for spontaneous recovery from the first episode of the disease.

  19. Expression and immunoreactivity of HCV/HBV epitopes

    Institute of Scientific and Technical Information of China (English)

    Xin-Yu Xiong; Xiao Liu; Yuan-Ding Chen

    2005-01-01

    AIM: To develop the epitope-based vaccines to prevent Hepatitis C virus (HCV)/Hepatitis B virus (HBV) infections.METHODS: The HCV core epitopes C1 STNPKPQRKTKRNTNRRPQD (residuals aa2-21) and C2 VKFPGGGQIVGGVYLLPRR (residuals aa22-40), envelope epitope E GHRMAWDMMMNWSP (residuals aa315-328) and HBsAg epitope S CTTPAQGNSMFPSCCCTKPTDGNC (residuals aa124-147) were displayed in five different sites of the flock house virus capsid protein as a vector, and expressed in E. coli cells (pET-3 system).Immunoreactivity of the epitopes with anti-HCV and anti-HBV antibodies in the serum from hepatitis C and hepatitis B patients were determined.RESULTS: The expressed chimeric protein carrying the HCV epitopes C1, C2, E (two times), L3C1-I2E-L1C2-L2E could react with anti-HCV antibodies. The expressed chimeric protein carrying the HBV epitopes S, I3S could react with anti-HBs antibodies. The expressed chimeric proteins carrying the HCV epitopes C1, C2, E plus HBV epitope S, L3C1-I2E-L1C2-L2E-I3S could react with antiHCV and anti-HBs antibodies.CONCLUSION: These epitopes have highly specific and sensitive immunoreaction and are useful in the development of epitope-based vaccines.

  20. 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.

  1. 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 rem

  2. Cutting edge: membrane lymphotoxin regulates CD8(+) T cell-mediated intestinal allograft rejection.

    Science.gov (United States)

    Guo, Z; Wang, J; Meng, L; Wu, Q; Kim, O; Hart, J; He, G; Zhou, P; Thistlethwaite, J R; Alegre, M L; Fu, Y X; Newell, K A

    2001-11-01

    Blocking the CD28/B7 and/or CD154/CD40 costimulatory pathways promotes long-term allograft survival in many transplant models where CD4(+) T cells are necessary for rejection. When CD8(+) T cells are sufficient to mediate rejection, these approaches fail, resulting in costimulation blockade-resistant rejection. To address this problem we examined the role of lymphotoxin-related molecules in CD8(+) T cell-mediated rejection of murine intestinal allografts. Targeting membrane lymphotoxin by means of a fusion protein, mAb, or genetic mutation inhibited rejection of intestinal allografts by CD8(+) T cells. This effect was associated with decreased monokine induced by IFN-gamma (Mig) and secondary lymphoid chemokine (SLC) gene expression within allografts and spleens respectively. Blocking membrane lymphotoxin did not inhibit rejection mediated by CD4(+) T cells. Combining disruption of membrane lymphotoxin and treatment with CTLA4-Ig inhibited rejection in wild-type mice. These data demonstrate that membrane lymphotoxin is an important regulatory molecule for CD8(+) T cells mediating rejection and suggest a strategy to avoid costimulation blockade-resistant rejection. PMID:11673481

  3. 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

    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...

  4. 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...

  5. The viral context instructs the redundancy of costimulatory pathways in driving CD8(+) T cell expansion.

    Science.gov (United States)

    Welten, Suzanne P M; Redeker, Anke; Franken, Kees L M C; Oduro, Jennifer D; Ossendorp, Ferry; Čičin-Šain, Luka; Melief, Cornelis J M; Aichele, Peter; Arens, Ramon

    2015-01-01

    Signals delivered by costimulatory molecules are implicated in driving T cell expansion. The requirements for these signals, however, vary from dispensable to essential in different infections. We examined the underlying mechanisms of this differential T cell costimulation dependence and found that the viral context determined the dependence on CD28/B7-mediated costimulation for expansion of naive and memory CD8(+) T cells, indicating that the requirement for costimulatory signals is not imprinted. Notably, related to the high-level costimulatory molecule expression induced by lymphocytic choriomeningitis virus (LCMV), CD28/B7-mediated costimulation was dispensable for accumulation of LCMV-specific CD8(+) T cells because of redundancy with the costimulatory pathways induced by TNF receptor family members (i.e., CD27, OX40, and 4-1BB). Type I IFN signaling in viral-specific CD8(+) T cells is slightly redundant with costimulatory signals. These results highlight that pathogen-specific conditions differentially and uniquely dictate the utilization of costimulatory pathways allowing shaping of effector and memory antigen-specific CD8(+) T cell responses. PMID:26263500

  6. miR-150 Regulates Differentiation and Cytolytic Effector Function in CD8+ T cells.

    Science.gov (United States)

    Smith, Norah L; Wissink, Erin M; Grimson, Andrew; Rudd, Brian D

    2015-01-01

    MicroRNAs regulate most mammalian genes, and they control numerous aspects of immune system development and function. Their precise roles in the CD8+ T cell response, however, remain unclear. In this report, we show that in the absence of the microRNA miR-150, CD8+ T cells fail to undergo robust expansion and differentiation into short-lived terminal effector cells in response to primary infection with Listeria monocytogenes or Vaccinia virus. Notably, even after transitioning into the memory pool, miR-150(-/-) cells still mount a weaker recall response to secondary infection, and remain less differentiated than their wild-type counterparts. Transcriptome analysis shows miR-150 gene targets are globally upregulated in cells lacking miR-150, and amongst these targets, we found misregulation of genes associated with proliferation and effector cell function. These transcriptome data suggest that miR-150 deficient CD8+ T cells are less efficient in killing infected cells, which we validate experimentally. Together, these results reveal a cell-intrinsic role for miR-150 in the regulation of effector CD8+ T cell fate and function. PMID:26549197

  7. Human yeast-specific CD8 T lymphocytes show a nonclassical effector molecule profile.

    Science.gov (United States)

    Breinig, Tanja; Scheller, Nicoletta; Glombitza, Birgit; Breinig, Frank; Meyerhans, Andreas

    2012-05-01

    Pathogenic yeast and fungi represent a major group of human pathogens. The consequences of infections are diverse and range from local, clinically uncomplicated mycosis of the skin to systemic, life-threatening sepsis. Despite extensive MHC class I-restricted frequencies of yeast-specific CD8 T lymphocytes in healthy individuals and the essential role of the cell-mediated immunity in controlling infections, the characteristics and defense mechanisms of antifungal effector cells are still unclear. Here, we describe the direct analysis of yeast-specific CD8 T lymphocytes in whole blood from healthy individuals. They show a unique, nonclassical phenotype expressing granulysin and granzyme K in lytic granules instead of the major effector molecules perforin and granzyme B. After stimulation in whole blood, yeast-specific CD8 T cells degranulated and, upon cultivation in the presence of IL-2, their granula were refilled with granulysin rather than with perforin and granzyme B. Moreover, yeast-specific stimulation through dendritic cells but not by yeast cells alone led to degranulation of the effector cells. As granulysin is the only effector molecule in lytic granules known to have antifungal properties, our data suggest yeast-specific CD8 T cells to be a nonclassical effector population whose antimicrobial effector machinery seems to be tailor-made for the efficient elimination of fungi as pathogens.

  8. IL-6 trans-Signaling-Dependent Rapid Development of Cytotoxic CD8+ T Cell Function

    Directory of Open Access Journals (Sweden)

    Jan P. Böttcher

    2014-09-01

    Full Text Available Immune control of infections with viruses or intracellular bacteria relies on cytotoxic CD8+ T cells that use granzyme B (GzmB for elimination of infected cells. During inflammation, mature antigen-presenting dendritic cells instruct naive T cells within lymphoid organs to develop into effector T cells. Here, we report a mechanistically distinct and more rapid process of effector T cell development occurring within 18 hr. Such rapid acquisition of effector T cell function occurred through cross-presenting liver sinusoidal endothelial cells (LSECs in the absence of innate immune stimulation and known costimulatory signaling. Rather, interleukin-6 (IL-6 trans-signaling was required and sufficient for rapid induction of GzmB expression in CD8+ T cells. Such LSEC-stimulated GzmB-expressing CD8+ T cells further responded to inflammatory cytokines, eliciting increased and protracted effector functions. Our findings identify a role for IL-6 trans-signaling in rapid generation of effector function in CD8+ T cells that may be beneficial for vaccination strategies.

  9. Cutting Edge: ACVRL1 Signaling Augments CD8α+ Dendritic Cell Development.

    Science.gov (United States)

    Verma, Rohit; Jaiswal, Hemant; Chauhan, Kuldeep Singh; Kaushik, Monika; Tailor, Prafullakumar

    2016-08-15

    Dendritic cells (DCs) are a collection of different subtypes, each of which is characterized by specific surface markers, gene-expression patterns, and distinct functions. Members of the IFN regulatory factor family play critical roles in DC development and functions. Recently, Irf8 was shown to activate TGF-β signaling, which led to exacerbated neuroinflammation in the experimental autoimmune encephalomyelitis mouse model. We analyzed the effect of Irf8 on TGF-β/bone morphogenetic protein pathway-specific genes in DCs and identified Acvrl1, a type I TGF-β superfamily receptor, as a gene strongly induced by Irf8 expression. Among various DC subtypes, Acvrl1 is differentially expressed in CD8α(+) DCs. ACVRL1 signaling augmented Irf8-directed classical CD8α(+) DC development. Irf8 expression is essential for plasmacytoid DC and CD8α(+) DC development, and this study demonstrates that ACVRL1 signaling plays a pivotal role whereby it suppresses plasmacytoid DC development while enhancing that of CD8α(+) DCs, thus contributing to DC diversity development. PMID:27421479

  10. Perforin and Fas in murine gammaherpesvirus-specific CD8(+) T cell control and morbidity

    DEFF Research Database (Denmark)

    Topham, D J; Cardin, R C; Christensen, Jan Pravsgaard;

    2001-01-01

    The immune system uses both virus-specific T cells and B cells to control the acute and latent phases of respiratory infection with the murine gammaherpesvirus 68 (gammaHV-68). We sought to further define the important effector mechanisms for CD8(+) T cells. First, depletion of the CD4(+) T cells...

  11. Influence of race on microsatellite instability and CD8+ T cell infiltration in colon cancer.

    Directory of Open Access Journals (Sweden)

    John M Carethers

    Full Text Available African American patients with colorectal cancer show higher mortality than their Caucasian counterparts. Biology might play a partial role, and prior studies suggest a higher prevalence for microsatellite instability (MSI among cancers from African Americans, albeit patients with MSI cancers have improved survival over patients with non-MSI cancers, counter to the outcome observed for African American patients. CD8+ T cell infiltration of colon cancer is postively correlated with MSI tumors, and is also related to improved outcome. Here, we utilized a 503-person, population-based colon cancer cohort comprising 45% African Americans to determine, under blinded conditions from all epidemiological data, the prevalence of MSI and associated CD8+ T cell infiltration within the cancers. Among Caucasian cancers, 14% were MSI, whereas African American cancers demonstrated 7% MSI (P = 0.009. Clinically, MSI cancers between races were similar; among microsatellite stable cancers, African American patients were younger, female, and with proximal cancers. CD8+ T cells were higher in MSI cancers (88.0 vs 30.4/hpf, P<0.0001, but was not different between races. Utilizing this population-based cohort, African American cancers show half the MSI prevalence of Caucasians without change in CD8+ T cell infiltration which may contribute towards their higher mortality from colon cancer.

  12. Functional impairment of Tax-specific but not cytomegalovirus-specific CD8+ T lymphocytes in a minor population of asymptomatic human T-cell leukemia virus type 1-carriers

    Directory of Open Access Journals (Sweden)

    Takamori Ayako

    2011-12-01

    Full Text Available Abstract Background Human T-cell leukemia virus type 1 (HTLV-1 causes adult T-cell leukemia (ATL and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP in a small percentage of infected individuals. ATL is often associated with general immune suppression and an impaired HTLV-1-specific T-cell response, an important host defense system. We previously found that a small fraction of asymptomatic HTLV-1-carriers (AC already showed impaired T-cell responses against the major target antigen, Tax. However, it is unclear whether the impaired HTLV-1 Tax-specific T-cell response in these individuals is an HTLV-1-specific phenomenon, or merely reflects general immune suppression. In this study, in order to characterize the impaired HTLV-1-specific T-cell response, we investigated the function of Tax-specific CD8+ T-cells in various clinical status of HTLV-1 infection. Results By using tetramers consisting of HLA-A*0201, -A*2402, or -A*1101, and corresponding Tax epitope peptides, we detected Tax-specific CD8+ T-cells in the peripheral blood from 87.0% of ACs (n = 20/23 and 100% of HAM/TSP patients (n = 18/18 tested. We also detected Tax-specific CD8+ T-cells in 38.1% of chronic type ATL (cATL patients (n = 8/21, although its frequencies in peripheral blood CD8+ T cells were significantly lower than those of ACs or HAM/TSP patients. Tax-specific CD8+ T-cells detected in HAM/TSP patients proliferated well in culture and produced IFN-γ when stimulated with Tax peptides. However, such functions were severely impaired in the Tax-specific CD8+ T-cells detected in cATL patients. In ACs, the responses of Tax-specific CD8+ T-cells were retained in most cases. However, we found one AC sample whose Tax-specific CD8+ T-cells hardly produced IFN-γ, and failed to proliferate and express activation (CD69 and degranulation (CD107a markers in response to Tax peptide. Importantly, the same AC sample contained cytomegalovirus (CMV pp65-specific CD8+ T

  13. Exhaustion of Activated CD8 T Cells Predicts Disease Progression in Primary HIV-1 Infection.

    Directory of Open Access Journals (Sweden)

    Matthias Hoffmann

    2016-07-01

    Full Text Available The rate at which HIV-1 infected individuals progress to AIDS is highly variable and impacted by T cell immunity. CD8 T cell inhibitory molecules are up-regulated in HIV-1 infection and associate with immune dysfunction. We evaluated participants (n = 122 recruited to the SPARTAC randomised clinical trial to determine whether CD8 T cell exhaustion markers PD-1, Lag-3 and Tim-3 were associated with immune activation and disease progression. Expression of PD-1, Tim-3, Lag-3 and CD38 on CD8 T cells from the closest pre-therapy time-point to seroconversion was measured by flow cytometry, and correlated with surrogate markers of HIV-1 disease (HIV-1 plasma viral load (pVL and CD4 T cell count and the trial endpoint (time to CD4 count <350 cells/μl or initiation of antiretroviral therapy. To explore the functional significance of these markers, co-expression of Eomes, T-bet and CD39 was assessed. Expression of PD-1 on CD8 and CD38 CD8 T cells correlated with pVL and CD4 count at baseline, and predicted time to the trial endpoint. Lag-3 expression was associated with pVL but not CD4 count. For all exhaustion markers, expression of CD38 on CD8 T cells increased the strength of associations. In Cox models, progression to the trial endpoint was most marked for PD-1/CD38 co-expressing cells, with evidence for a stronger effect within 12 weeks from confirmed diagnosis of PHI. The effect of PD-1 and Lag-3 expression on CD8 T cells retained statistical significance in Cox proportional hazards models including antiretroviral therapy and CD4 count, but not pVL as co-variants. Expression of 'exhaustion' or 'immune checkpoint' markers in early HIV-1 infection is associated with clinical progression and is impacted by immune activation and the duration of infection. New markers to identify exhausted T cells and novel interventions to reverse exhaustion may inform the development of novel immunotherapeutic approaches.

  14. HIV感染者调节性T细胞消耗可导致HIV特异CD8+细胞凋亡%Treg Cells Depletion Can Lead to HIV-specific CD8 + Cells Apoptosis in HIV Patients

    Institute of Scientific and Technical Information of China (English)

    焦艳梅; 福军亮; 张政; 计云霞; 王蕊; 张彤; 陈德喜; 吴昊

    2011-01-01

    Objective To investigate whether the decrease of CD4 + CD25 + FoxP3 + cells (Treg) can lead to HIV-specific CD8 +cells apoptosis in HIV patients. Methods We characterized Tregs among 75 antiviral-na(i)ve HIV-I-infected individuals in this study.Treg and CD8 + cell activation and apoptosis were detected and its relevance was analyzed; Treg cells and CD8 + cells were simultaneously purified and then co-cultured in vitro, and HIV-specific CD8 + cell apoptosis was detected with pentamer and annexin V. Results Absolute counts of circulating Treg was inversely correlated with up-regulated activation and apoptosis of CD8 + T cells. In addition, Tregs were found to suppress HIV peptite-induced apoptosis of HIV-specific CD8 + T cells. Conclusion These findings indicate that the decrease in Tregs closely correlate with increased apoptosis of CD8 + T cells, especially with HIV specific CD8 + T cells.%目的 了解在HIV感染患者CD4+CD25+FoxP3+调节性T细胞(Treg)的降低是否能够引起HIV特异CD8+细胞过度凋亡.方法 本研究对75例没有治疗的HIV患者进行研究,检测其外周血中Treg细胞计数及CD8+细胞的活化及凋亡情况并分析其相关性;同时纯化Treg细胞及CD8+细胞,在体外进行共培养,用五聚体检测HIV特异CD8+细胞的活化情况.结果 在HIV感染患者,Treg细胞与CD8+细胞的活化及凋亡呈负相关,Treg细胞能够抑制HIV特异的CD8+细胞的凋亡.结论 HIV感染患者Treg细胞的降低可导致CD8+细胞、尤其HIV特异CD8+细胞的凋亡增加.

  15. Recombinant mammaglobin A adenovirus-infected dendritic cells induce mammaglobin A-specific CD8+ cytotoxic T lymphocytes against breast cancer cells in vitro.

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    Huixia Cui

    Full Text Available Mammaglobin A (MGBA is a novel breast cancer-associated antigen almost exclusively over-expressed in primary and metastatic human breast cancers, making it a potential therapeutic target for breast cancer. The development of dendritic cell (DC-induced tumor antigen specific CD8(+ cytotoxic T lymphocytes (CTLs may hold promise in cancer immunotherapy. In this study we constructed recombinant replication-defective adenoviral (Ad vectors encoding MGBA and evaluated their ability to trigger anti-tumor immunity in vitro. DCs were isolated from the human peripheral blood monocyte cells (PBMCs of two HLA-A33(+ healthy female volunteers, and infected with adenovirus carrying MGBA cDNA (Ad-MGBA. After that, the Ad-MGBA-infected DCs were used to stimulate CD8(+ CTLs in vitro and the latter was used for co-culture with breast cancer cell lines. The data revealed that infection with Ad-MGBA improved DC maturation and up-regulated the expression of co-stimulatory molecules and the secretion of interleukin-12 (IL-12, but down-regulated interleukin-10 (IL-10 secretion from DCs. Ad-MGBA-infected DC-stimulated CD8(+CTLs displayed the highest cytotoxicity towards HLA-A33(+/MGBA(+ breast cancer MDA-MB-415 cells compared with other CD8(+CTL populations, and compared with the cytotoxicity towards HLA-A33(-/MGBA(+ breast cancer HBL-100 cells and HLA-A33(-/MGBA(- breast cancer MDA-MB 231 cells. In addition, Ad-MGBA-infected DC-stimulated CD8(+ CTLs showed a high level of IFNγ secretion when stimulated with HLA-A33(+/MGBA(+ breast cancer MDA-MB-415 cells, but not when stimulated with HLA-A33(-/MGBA(+ HBL-100 and HLA-A33(-/MGBA(-MDA-MB-231 cells. In addition, killing of CD8(+CTLs against breast cancer was in a major histocompability complex (MHC-limited pattern. Finally, the data also determined the importance of TNF-α in activating DCs and T cells. These data together suggest that MGBA recombinant adenovirus-infected DCs could induce specific anti-tumor immunity

  16. CD4 on CD8+ T cells directly enhances effector function and is a target for HIV infection

    Science.gov (United States)

    Kitchen, Scott G.; Jones, Nicole R.; Laforge, Stuart; Whitmire, Jason K.; Vu, Bien-Aimee; Galic, Zoran; Brooks, David G.; Brown, Stephen J.; Kitchen, Christina M. R.; Zack, Jerome A.

    2004-06-01

    Costimulation of purified CD8+ T lymphocytes induces de novo expression of CD4, suggesting a previously unrecognized function for this molecule in the immune response. Here, we report that the CD4 molecule plays a direct role in CD8+ T cell function by modulating expression of IFN- and Fas ligand, two important CD8+ T cell effector molecules. CD4 expression also allows infection of CD8 cells by HIV, which results in down-regulation of the CD4 molecule and impairs the induction of IFN-, Fas ligand, and the cytotoxic responses of activated CD8+ T cells. Thus, the CD4 molecule plays a direct role in CD8 T cell function, and infection of these cells by HIV provides an additional reservoir for the virus and also may contribute to the immunodeficiency seen in HIV disease.

  17. Flow Cytometric Analysis of Leishmania Reactive CD4+/CD8+ Lymphocyte Proliferation in Cutaneous Leishmaniasis

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    H Keshavarz

    2008-12-01

    Full Text Available Background: Determination of the division history of T cells in vitro is helpful in the study of effector mechanisms against infections. Technique described here uses the intracellular fluorescent label carboxyfluorescein diacetate succinimidyl ester (CFSE to monitor the proliferation. Methods: In a cross sectional study, blood samples were collected from 7 volunteers with history of cutaneous leishmania­sis (CL and one healthy control from endemic areas in Isfahan province who referred to the Center for Research and Training in Skin Diseases and Leprosy (CRTSDL, then CD4+/CD8+ lymphocytes and CD14+ monocytes were isolated from peri­pheral blood mononuclear cells (PBMC using mAbs and magnetic nanoparticles. CFSE labeled CD4+ or CD8+ lympho­cytes cultured with autologous monocytes in the presence of PHA, SLA, live Leishmania major or as control with­out sti­mulation. Cells were harvested after 7 days and were analyzed using flow cytometry. Results: Five consecutive divisions were monitored separately. Stimulation of CD4+ or CD8+ lymphocytes from CL sub­jects with SLA showed a significant difference in proliferation comparing with unstimulated cells (P< 0.05. The signifi­cant difference in the percentages of CD4+ cells stimulated with SLA was revealed at different divisions for each subject. In CD8+ lymphocyte, significant stronger stimulation of SLA was evident later in the proliferation process. The mean number of divisions in both CD4+/CD8+ lymphocytes stimulated with SLA was significantly greater than when stimulated with live L. major (P=0.007 / P=0.012, respectively Conclusion: The percentage of divided cells might be calculated separately in each division. The cells remained active following CFSE staining and there is possibility of functional analysis simultaneously.

  18. Interferon-alpha administration enhances CD8+ T cell activation in HIV infection.

    Directory of Open Access Journals (Sweden)

    Maura Manion

    Full Text Available BACKGROUND: Type I interferons play important roles in innate immune defense. In HIV infection, type I interferons may delay disease progression by inhibiting viral replication while at the same time accelerating disease progression by contributing to chronic immune activation. METHODS: To investigate the effects of type I interferons in HIV-infection, we obtained cryopreserved peripheral blood mononuclear cell samples from 10 subjects who participated in AIDS Clinical Trials Group Study 5192, a trial investigating the activity of systemic administration of IFNα for twelve weeks to patients with untreated HIV infection. Using flow cytometry, we examined changes in cell cycle status and expression of activation antigens by circulating T cells and their maturation subsets before, during and after IFNα treatment. RESULTS: The proportion of CD38+HLA-DR+CD8+ T cells increased from a mean of 11.7% at baseline to 24.1% after twelve weeks of interferon treatment (p = 0.006. These frequencies dropped to an average of 20.1% six weeks after the end of treatment. In contrast to CD8+ T cells, the frequencies of activated CD4+ T cells did not change with administration of type I interferon (mean percentage of CD38+DR+ cells = 2.62% at baseline and 2.17% after 12 weeks of interferon therapy. As plasma HIV levels fell with interferon therapy, this was correlated with a "paradoxical" increase in CD8+ T cell activation (p<0.001. CONCLUSION: Administration of type I interferon increased expression of the activation markers CD38 and HLA DR on CD8+ T cells but not on CD4+ T cells of HIV+ persons. These observations suggest that type I interferons may contribute to the high levels of CD8+ T cell activation that occur during HIV infection.

  19. Manipulating Memory CD8 T Cell Numbers by Timed Enhancement of IL-2 Signals.

    Science.gov (United States)

    Kim, Marie T; Kurup, Samarchith P; Starbeck-Miller, Gabriel R; Harty, John T

    2016-09-01

    As a result of the growing burden of tumors and chronic infections, manipulating CD8 T cell responses for clinical use has become an important goal for immunologists. In this article, we show that dendritic cell (DC) immunization coupled with relatively early (days 1-3) or late (days 4-6) administration of enhanced IL-2 signals increase peak effector CD8 T cell numbers, but only early IL-2 signals enhance memory numbers. IL-2 signals delivered at relatively late time points drive terminal differentiation and marked Bim-mediated contraction and do not increase memory T cell numbers. In contrast, early IL-2 signals induce effector cell metabolic profiles that are more conducive to memory formation. Of note, downregulation of CD80 and CD86 was observed on DCs in vivo following early IL-2 treatment. Mechanistically, early IL-2 treatment enhanced CTLA-4 expression on regulatory T cells, and CTLA-4 blockade alongside IL-2 treatment in vivo prevented the decrease in CD80 and CD86, supporting a cell-extrinsic role for CTLA-4 in downregulating B7 ligand expression on DCs. Finally, DC immunization followed by early IL-2 treatment and anti-CTLA-4 blockade resulted in lower memory CD8 T cell numbers compared with the DC+early IL-2 treatment group. These data suggest that curtailed signaling through the B7-CD28 costimulatory axis during CD8 T cell activation limits terminal differentiation and preserves memory CD8 T cell formation; thus, it should be considered in future T cell-vaccination strategies. PMID:27439516

  20. Immunosuppression of canine renal allograft recipients by CD4 and CD8 monoclonal antibodies

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    Watson, C.J.E.; Davies, H.S.; Rebello, P.R.U.B.; McNair, R.; Rasmussen, A.; Calne, R.Y.; Metcalfe, S.M. (Department of Surgery, University of Cambridge (United Kingdom)); Cobbold, S.P.; Thiru, S.; Waldmann, H. (Department of Pathology, University of Cambridge (United Kingdom))

    1994-01-01

    A state of tolerance to MHC mismatched allografts can be generated in rodents by treatment with CD4 and CD8 monoclonal antibodies (mAb). In order to transpose this type of therapy to large animals and ultimately to the clinic, a suitable model is required. To this end we have generated a series of mAb to the canine CD4, CD8, and Thy-l antigens and have tested their ability to prevent rejection of renal allografts. Donor-recipient pairs were selected from a colony of mongrel dogs in which untreated rejection of two haplotype-mismatched kidneys occurred by day 7 (defined as a serum creatinine > 300 [mu]mol/l). Therapy with either the CD4 or the CD8 mAb, using no other immunosuppression, did not prolong graft survival. Depletion of T cells by a Thy-l mAb prior to surgery only extended graft survival to day 9. However, treating with combinations of mAb up to day 10 (CD4 plus Thy-l; CD4 plus CD8; or CD4 plus CD8 plus Thy-l) prolonged renal allograft function up to 25 days. Combination of the triple mAb therapy with a sub-therapeutic immunosuppressive drug regimen (cyclosporin A plus azathioprine that alone gave a median survival of 15 days) favored survival to a median of 38 days. This protocol also inhibited the antiglobulin response that had curtailed the effects of mAb treatment, opening the way to more extended, and potentially tolerizing, mAb plus drug regimens. (au) (23 refs.).

  1. HIV-specific CD8+ T cells: serial killers condemned to die?

    Science.gov (United States)

    Petrovas, Constantinos; Mueller, Yvonne M; Katsikis, Peter D

    2004-04-01

    An increasing body of evidence supports a key role for cytotoxic CD8+ T cells (CTL) in controlling HIV infection. Although a vigorous HIV-specific CD8+ T cell response is raised during the primary infection, these cells ultimately fail to control virus and prevent disease progression. The failure of CTL to control HIV infection has been attributed to a number of strategies HIV employs to evade the immune system. Recently, intrinsic defects in the CTL themselves have been proposed to contribute to the failure of CTL to control HIV. HIV-specific CD8+ T cells differ in their effector/memory phenotype from other virus-specific CD8+ T cells indicating that their differentiation status differs. This altered differentiation may affect effector functions as well as homing properties of these cells. Other studies have indicated that activation of HIV-specific CTL may be impaired and this contributes to their dysfunction. The effector function of these CTL may also be affected. There are conflicting reports about their ability to kill, whereas IFNgamma production does not appear to be impaired in these cells. In this review we focus on recent work indicating that apoptosis may be an important mechanism through which HIV evades the CTL response. In particular, HIV-specific CD8+ T cells are highly susceptible to CD95/Fas-induced apoptosis. This leads to the hypothesis that virus-specific cytotoxic T cells can be eliminated upon binding CD95L/FasL on HIV-infected cells. Understanding the intrinsic defects of CTL in HIV infection could lead to new therapeutic strategies and optimized vaccination protocols that enhance the HIV-specific cytotoxic response.

  2. Phage display and immunological identification of efficient T- and B-combined antigenic epitopes in Helicobacter pylori adhesin A%幽门螺杆菌黏附素A有效T和B联合抗原表位噬菌体展示和抗原性测定

    Institute of Scientific and Technical Information of China (English)

    罗冬娇; 严瑾; 冯雪鸣; 丁威; 俞利平; 陈小囡; 严杰

    2010-01-01

    目的 分析并确定幽门螺杆菌黏附素A(HpaA)分子中有效T细胞和B细胞联合(T/B)抗原表位.方法 重组表达HpaA(rHpaA)并免疫家兔制备抗血清.采用生物信息学技术预测和分析HpaA分子中T细胞和B细胞表位,PCB扩增T/B联合表位肽片段并构建其噬菌体展示系统.采用PEG/NaCl沉淀法提纯展示了T/B联合表位的重组噬菌体PⅢ蛋白(rPⅢ).分别以商品化幽门螺杆菌全菌IgG抗体和rHpaA抗血清为一抗,采用Western blot和ELISA对rPⅢ蛋白中展示的T/B联合表位进行筛选和鉴定.采用MTT检测rHpaA免疫小鼠脾细胞在不同重组噬菌体蛋白刺激下的增殖情况.结果 HpaA分子中共有5个T/B联合表位:HpaA10、HpaA37、HpaA79、HpaA116和HpaA143.所有T/B联合表位均成功地展示于M13噬菌体PⅢ蛋白表面.Western blot、ELISA和淋巴细胞增殖试验结果 均显示,HpaA116是优势抗原表位,HpaA37和HpaA79为有效抗原表位,HpaA10和HpaA143为无效抗原表位.结论 本研究成功地构建了幽门螺杆菌HpaA的T/B联合表位肽噬菌体展示系统.HpaA37和HpaA79,尤其是HpaA116是HpaA有效T/B联合抗原表位.%Objective To analyze and determine the efficient T- and B-combined (T/B) antigenic epitopes in Helicobacter pylori adhesin A. Methods Recombinant HpaA (rHpaA) was expressed for immunizing rabbit to generate antiserum. T- and B-cell epitopes in HpaA molecule were predicted by using bioinformatic technique. The segments to encode T/B combined epitope peptides were amplified by PCR and the phage display systems of T/B combined epitopes were subsequently constructed. PEG/NaCl precipitation method was applied to extract the recombinant phage PⅢ (rPⅢ) that displayed T/B combined epitopes. By using either commercial IgG against whole-cell of Helicobacter pylori or rHpaA antiserum as the primary antibody, the T/B combined epitopes displayed in rP Ⅲ s were screened and identified by Western blot and ELISA. MTT was applied to

  3. NS1 specific CD8+ T-cells with effector function and TRBV11 dominance in a patient with parvovirus B19 associated inflammatory cardiomyopathy.

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    Mathias Streitz

    Full Text Available BACKGROUND: Parvovirus B19 (B19V is the most commonly detected virus in endomyocardial biopsies (EMBs from patients with inflammatory cardiomyopathy (DCMi. Despite the importance of T-cells in antiviral defense, little is known about the role of B19V specific T-cells in this entity. METHODOLOGY AND PRINCIPAL FINDINGS: An exceptionally high B19V viral load in EMBs (115,091 viral copies/mug nucleic acids, peripheral blood mononuclear cells (PBMCs and serum was measured in a DCMi patient at initial presentation, suggesting B19V viremia. The B19V viral load in EMBs had decreased substantially 6 and 12 months afterwards, and was not traceable in PBMCs and the serum at these times. Using pools of overlapping peptides spanning the whole B19V proteome, strong CD8(+ T-cell responses were elicited to the 10-amino-acid peptides SALKLAIYKA (19.7% of all CD8(+ cells and QSALKLAIYK (10% and additional weaker responses to GLCPHCINVG (0.71% and LLHTDFEQVM (0.06%. Real-time RT-PCR of IFNgamma secretion-assay-enriched T-cells responding to the peptides, SALKLAIYKA and GLCPHCINVG, revealed a disproportionately high T-cell receptor Vbeta (TRBV 11 expression in this population. Furthermore, dominant expression of type-1 (IFNgamma, IL2, IL27 and T-bet and of cytotoxic T-cell markers (Perforin and Granzyme B was found, whereas gene expression indicating type-2 (IL4, GATA3 and regulatory T-cells (FoxP3 was low. CONCLUSIONS: Our results indicate that B19V Ag-specific CD8(+ T-cells with effector function are involved in B19V associated DCMi. In particular, a dominant role of TRBV11 and type-1/CTL effector cells in the T-cell mediated antiviral immune response is suggested. The persistence of B19V in the endomyocardium is a likely antigen source for the maintenance of CD8(+ T-cell responses to the identified epitopes.

  4. File list: InP.Bld.05.AllAg.CD8-Positive_T-Lymphocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  5. File list: InP.Bld.10.AllAg.CD8-Positive_T-Lymphocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available InP.Bld.10.AllAg.CD8-Positive_T-Lymphocytes hg19 Input control Blood CD8-Positive T...-Lymphocytes SRX183914,SRX1142249,SRX183915,SRX1142310,SRX1142246,SRX1142313 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/InP.Bld.10.AllAg.CD8-Positive_T-Lymphocytes.bed ...

  6. File list: InP.Bld.20.AllAg.CD8-Positive_T-Lymphocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available InP.Bld.20.AllAg.CD8-Positive_T-Lymphocytes hg19 Input control Blood CD8-Positive T...-Lymphocytes SRX183915,SRX183914,SRX1142246,SRX1142249,SRX1142310,SRX1142313 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/InP.Bld.20.AllAg.CD8-Positive_T-Lymphocytes.bed ...

  7. File list: InP.Bld.50.AllAg.CD8-Positive_T-Lymphocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available InP.Bld.50.AllAg.CD8-Positive_T-Lymphocytes hg19 Input control Blood CD8-Positive T...-Lymphocytes SRX183915,SRX183914,SRX1142249,SRX1142310,SRX1142246,SRX1142313 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/InP.Bld.50.AllAg.CD8-Positive_T-Lymphocytes.bed ...

  8. A false expression of CD8 antigens on CD4+ T cells in a routine flow cytometry analysis.

    Directory of Open Access Journals (Sweden)

    Danuta Kowalczyk

    2006-09-01

    Full Text Available The two-colour flow cytometry method applied in a routine enumeration of peripheral blood T lymphocyte subsets reveals that in some patients the entire population of CD4+ lymphocytes seems to express CD8 determinants as well. However, expression of the CD8 antigens on the cell surface is much lower in comparison with typical CD8+ cells. Moreover, in one-colour staining with an anti-CD8 antibody, cells with weak CD8 expression are not observed and only one typical population of CD8+ lymphocytes is seen. Investigating this phenomenon, we showed that after washing patient cells in RPMI before CD4/CD8 staining, the CD4+ T cell population did not show CD8 "co-expression". These results suggest that CD4+ lymphocytes, which seem to co-express CD8 antigen, in fact do not have this antigen on their surface. Moreover, after the addition of patient plasma to healthy donor cells prior to CD4/CD8 staining, a weak CD8 expression on normal CD4+ cells was noticed. Therefore we can assume that the agent(s causing this phenomenon is/are present in the plasma of some patients. Altogether, these observations suggest that this phenomenon is nonspecific and probably results from cross-linking of anti-CD8 mAbs with anti-CD4 mAbs caused by factor(s present in plasma of some patient. However, identification of that/these factor(s requires further research.

  9. Cell-autonomous role of TGFβ and IL-2 receptors in CD4+ and CD8+ inducible regulatory T-cell generation during GVHD.

    Science.gov (United States)

    Sawamukai, Norifumi; Satake, Atsushi; Schmidt, Amanda M; Lamborn, Ian T; Ojha, Priti; Tanaka, Yoshiya; Kambayashi, Taku

    2012-06-01

    FoxP3(+) regulatory T cells (Tregs) suppress GVHD while preserving graft-versus-tumor effects, making them an attractive target for GVHD therapy. The donor-derived Treg pool can potentially be derived from the expansion of preexisting natural Tregs (nTregs) or from de novo generation of inducible Tregs (iTregs) from donor Tconvs in the transplantation recipient. Using an MHC-mismatched model of acute GVHD, in the present study we found that the Treg pool was comprised equally of donor-derived nTregs and iTregs. Experiments using various combinations of T cells from wild-type and FoxP3-deficient mice suggested that both preexisting donor nTregs and the generation of iTregs in the recipient mice contribute to protection against GVHD. Surprisingly, CD8(+)FoxP3(+) T cells represented approximately 70% of the iTreg pool. These CD8(+)FoxP3(+) T cells shared phenotypic markers with their CD4(+) counterparts and displayed suppressive activity, suggesting that they were bona fide iTregs. Both CD4(+) and CD8(+) Tregs appeared to be protective against GVHD-induced lethality and required IL-2 and TGFβ receptor expression for their generation. These data illustrate the complex makeup of the donor-derived FoxP3(+) Treg pool in allogeneic recipients and their potential role in protection against GVHD.

  10. A Critical Role of IL-21-Induced BATF in Sustaining CD8-T-Cell-Mediated Chronic Viral Control

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    Gang Xin

    2015-11-01

    Full Text Available Control of chronic viral infections by CD8 T cells is critically dependent on CD4 help. In particular, helper-derived IL-21 plays a key role in sustaining the CD8 T cell response; however, the molecular pathways by which IL-21 sustains CD8 T cell immunity remain unclear. We demonstrate that IL-21 causes a phenotypic switch of transcription factor expression in CD8 T cells during chronic viral infection characterized by sustained BATF expression. Importantly, BATF expression during chronic infection is both required for optimal CD8 T cell persistence and anti-viral effector function and sufficient to rescue “unhelped” CD8 T cells. Mechanistically, BATF sustains the response by cooperating with IRF4, an antigen-induced transcription factor that is also critically required for CD8 T cell maintenance, to preserve Blimp-1 expression and thereby sustain CD8 T cell effector function. Collectively, these data suggest that CD4 T cells “help” the CD8 response during chronic infection via IL-21-induced BATF expression.

  11. Relevance of long-lived CD8+ T effector memory (TEM cells for protective immunity elicited by heterologous prime-boost vaccination.

    Directory of Open Access Journals (Sweden)

    José Ronnie Vasconcelos

    2012-12-01

    Full Text Available Owing to the importance of major histocompatibility complex class Ia–restricted CD8+ T cells for host survival following viral, bacterial, fungal, or parasitic infection, it has become largely accepted that these cells should be considered in the design of a new generation of vaccines. For the past 20 years, solid evidence has been provided that the heterologous prime-boost regimen achieves the best results in terms of induction of long-lived protective CD8+ T cells against a variety of experimental infections. Although this regimen has often been used experimentally, as is the case for many vaccines, the mechanism behind the efficacy of this vaccination regimen is still largely unknown. The main purpose of this review is to examine the characteristics of the protective CD8+ T cells generated by this vaccination regimen. Part of its efficacy certainly relies on the generation and maintenance of large numbers of specific lymphocytes. Other specific characteristics may also be important, and studies on this direction have only recently been initiated. So far, the characterization of these protective, long-lived T cell populations suggests that there is a high frequency of polyfunctional T cells; these cells cover a large breadth and display a T effector memory (TEM phenotype. These TEM cells are capable of proliferating after an infectious challenge and are highly refractory to apoptosis due to a control of the expression of pro-apoptotic receptors such as CD95. Also, they do not undergo significant long-term immunological erosion. Understanding the mechanisms that control the generation and maintenance of the protective activity of these long-lived TEM cells will certainly provide important insights into the physiology of CD8+ T cells and pave the way for the design of new or improved vaccines..

  12. Parasite fate and involvement of infected cells in the induction of CD4+ and CD8+ T cell responses to Toxoplasma gondii.

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    Christopher D Dupont

    2014-04-01

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

  13. Epitope diversification driven by non-tumor epitope-specific Th1 and Th17 mediates potent antitumor reactivity.

    Science.gov (United States)

    Ichikawa, Kosuke; Kagamu, Hiroshi; Koyama, Kenichi; Miyabayashi, Takao; Koshio, Jun; Miura, Satoru; Watanabe, Satoshi; Yoshizawa, Hirohisa; Narita, Ichiei

    2012-09-21

    MHC class I-restricted peptide-based vaccination therapies have been conducted to treat cancer patients, because CD8⁺ CTL can efficiently induce apoptosis of tumor cells in an MHC class I-restricted epitope-specific manner. Interestingly, clinical responders are known to demonstrate reactivity to epitopes other than those used for vaccination; however, the mechanism underlying how antitumor T cells with diverse specificity are induced is unclear. In this study, we demonstrated that dendritic cells (DCs) that engulfed apoptotic tumor cells in the presence of non-tumor MHC class II-restricted epitope peptides, OVA(323-339), efficiently presented tumor-associated antigens upon effector-dominant CD4⁺ T cell balance against regulatory T cells (Treg) for the OVA(323-339) epitope. Th1 and Th17 induced tumor-associated antigens presentation of DC, while Th2 ameliorated tumor-antigen presentation for CD8⁺ T cells. Blocking experiments with anti-IL-23p19 antibody and anti-IL-23 receptor indicated that an autocrine mechanism of IL-23 likely mediated the diverted tumor-associated antigens presentation of DC. Tumor-associated antigens presentation of DC induced by OVA(323-339) epitope-specific CD4⁺ T cells resulted in facilitated antitumor immunity in both priming and effector phase in vivo. Notably, this immunotherapy did not require pretreatment to reduce Treg induced by tumor. This strategy may have clinical implications for designing effective antitumor immunotherapies.

  14. Impact of HIV on CD8+ T cell CD57 expression is distinct from that of CMV and aging.

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    Sulggi A Lee

    Full Text Available Chronic antigenic stimulation by cytomegalovirus (CMV is thought to increase "immunosenesence" of aging, characterized by accumulation of terminally differentiated CD28- CD8+ T cells and increased CD57, a marker of proliferative history. Whether chronic HIV infection causes similar effects is currently unclear.We compared markers of CD8+ T cell differentiation (e.g., CD28, CD27, CCR7, CD45RA and CD57 expression on CD28- CD8+ T cells in healthy HIV-uninfected adults with and without CMV infection and in both untreated and antiretroviral therapy (ART-suppressed HIV-infected adults with asymptomatic CMV infection.Compared to HIV-uninfected adults without CMV (n=12, those with asymptomatic CMV infection (n=31 had a higher proportion of CD28-CD8+ T cells expressing CD57 (P=0.005. Older age was also associated with greater proportions of CD28-CD8+ T cells expressing CD57 (rho: 0.47, P=0.007. In contrast, untreated HIV-infected CMV+ participants (n=55 had much lower proportions of CD28- CD8+ cells expressing CD57 than HIV-uninfected CMV+ participants (P<0.0001 and were enriched for less well-differentiated CD28- transitional memory (TTR CD8+ T cells (P<0.0001. Chronically HIV-infected adults maintaining ART-mediated viral suppression (n=96 had higher proportions of CD28-CD8+ T cells expressing CD57 than untreated patients (P<0.0001, but continued to have significantly lower levels than HIV-uninfected controls (P=0.001. Among 45 HIV-infected individuals initiating their first ART regimen, the proportion of CD28-CD8+ T cells expressing CD57 declined (P<0.0001, which correlated with a decline in percent of transitional memory CD8+ T cells, and appeared to be largely explained by a decline in CD28-CD57- CD8+ T cell counts rather than an expansion of CD28-CD57+ CD8+ T cell counts.Unlike CMV and aging, which are associated with terminal differentiation and proliferation of effector memory CD8+ T cells, HIV inhibits this process, expanding less well

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

    Science.gov (United States)

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

    2016-01-01

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

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

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    Katrin Deiser

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

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

    Science.gov (United States)

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

    2016-01-01

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

  18. Transforming Growth Factor-β Protein Inversely Regulates in Vivo Differentiation of Interleukin-17 (IL-17)-producing CD4+ and CD8+ T Cells

    OpenAIRE

    Dwivedi, Ved Prakash; Tousif, Sultan; Bhattacharya, Debapriya; Prasad, Durbaka Vijay Raghva; Kaer, Luc Van; Das, Jyoti; Das, Gobardhan

    2011-01-01

    TGF-β is a pleiotropic cytokine that predominantly exerts inhibitory functions in the immune system. Unexpectedly, the in vitro differentiation of both Th17 and Tc17 cells requires TGF-β. However, animals that are impaired in TGF-β signaling (TGF-βRIIDN mice) display multiorgan autoimmune disorders. Here we show that CD4+ T cells from TGF-βRIIDN mice are resistant to Th17 cell differentiation and, paradoxically, that CD8+ T cells from these animals spontaneously acquire an IL-17-producing phe...

  19. Targeting Transcriptional Regulators of CD8+ T Cell Dysfunction to Boost Anti-Tumor Immunity.

    Science.gov (United States)

    Waugh, Katherine A; Leach, Sonia M; Slansky, Jill E

    2015-01-01

    Transcription is a dynamic process influenced by the cellular environment: healthy, transformed, and otherwise. Genome-wide mRNA expression profiles reflect the collective impact of pathways modulating cell function under different conditions. In this review we focus on the transcriptional pathways that control tumor infiltrating CD8+ T cell (TIL) function. Simultaneous restraint of overlapping inhibitory pathways may confer TIL resistance to multiple mechanisms of suppression traditionally referred to as exhaustion, tolerance, or anergy. Although decades of work have laid a solid foundation of altered transcriptional networks underlying various subsets of hypofunctional or "dysfunctional" CD8+ T cells, an understanding of the relevance in TIL has just begun. With recent technological advances, it is now feasible to further elucidate and utilize these pathways in immunotherapy platforms that seek to increase TIL function.

  20. Targeting Transcriptional Regulators of CD8+ T Cell Dysfunction to Boost Anti-Tumor Immunity

    Directory of Open Access Journals (Sweden)

    Katherine A. Waugh

    2015-09-01

    Full Text Available Transcription is a dynamic process influenced by the cellular environment: healthy, transformed, and otherwise. Genome-wide mRNA expression profiles reflect the collective impact of pathways modulating cell function under different conditions. In this review we focus on the transcriptional pathways that control tumor infiltrating CD8+ T cell (TIL function. Simultaneous restraint of overlapping inhibitory pathways may confer TIL resistance to multiple mechanisms of suppression traditionally referred to as exhaustion, tolerance, or anergy. Although decades of work have laid a solid foundation of altered transcriptional networks underlying various subsets of hypofunctional or “dysfunctional” CD8+ T cells, an understanding of the relevance in TIL has just begun. With recent technological advances, it is now feasible to further elucidate and utilize these pathways in immunotherapy platforms that seek to increase TIL function.

  1. Intravacuolar Membranes Regulate CD8 T Cell Recognition of Membrane-Bound Toxoplasma gondii Protective Antigen.

    Science.gov (United States)

    Lopez, Jodie; Bittame, Amina; Massera, Céline; Vasseur, Virginie; Effantin, Grégory; Valat, Anne; Buaillon, Célia; Allart, Sophie; Fox, Barbara A; Rommereim, Leah M; Bzik, David J; Schoehn, Guy; Weissenhorn, Winfried; Dubremetz, Jean-François; Gagnon, Jean; Mercier, Corinne; Cesbron-Delauw, Marie-France; Blanchard, Nicolas

    2015-12-15

    Apicomplexa parasites such as Toxoplasma gondii target effectors to and across the boundary of their parasitophorous vacuole (PV), resulting in host cell subversion and potential presentation by MHC class I molecules for CD8 T cell recognition. The host-parasite interface comprises the PV limiting membrane and a highly curved, membranous intravacuolar network (IVN) of uncertain function. Here, using a cell-free minimal system, we dissect how membrane tubules are shaped by the parasite effectors GRA2 and GRA6. We show that membrane association regulates access of the GRA6 protective antigen to the MHC I pathway in infected cells. Although insertion of GRA6 in the PV membrane is key for immunogenicity, association of GRA6 with the IVN limits presentation and curtails GRA6-specific CD8 responses in mice. Thus, membrane deformations of the PV regulate access of antigens to the MHC class I pathway, and the IVN may play a role in immune modulation. PMID:26628378

  2. Delivery of Exogenous Antigens to Induce Cytotoxic CD8+ T Lymphocyte Responses

    Directory of Open Access Journals (Sweden)

    Julia Kim

    2010-01-01

    Full Text Available Vaccines intended to induce a cytotoxic CD8+ T-cell response are highly sought after. However, some of these vaccines can be problematic if they replicate in the host. An alternative strategy is to exploit cross-presentation of exogenous antigens to express peptides on major histocompatibility complex (MHC class I molecules. During cross-presentation, the delivered exogenous antigen can be taken up and processed through diverse mechanisms. Here, we will discuss the recent advances regarding the complex nature of the cross-priming process and the models that reflect its relevance in vivo. Moreover, we summarize current data that explore potential adjuvants and vaccine vectors that deliver antigens to activate CD8+ T cells relying on cross-presentation.

  3. Childhood mycosis fungoides with a CD8+ CD56+ cytotoxic immunophenotype.

    Science.gov (United States)

    Poppe, Heiko; Kerstan, Andreas; Böckers, Martin; Goebeler, Matthias; Geissinger, Eva; Rosenwald, Andreas; Hamm, Henning

    2015-04-01

    Primary cutaneous T-cell lymphomas mostly occur in patients of middle and higher age. Their rarity and an oftentimes atypical clinical presentation in childhood as well as the reluctance of taking biopsies in children are reasons for a delayed diagnosis. We report the case of an 11-year-old boy with a 7-year history of slowly progressive CD8+CD56+ mycosis fungoides of the cytotoxic immunophenotype. His trunk and extremities were affected by extensive pale-erythematous patches and plaques with fine scaling. In addition, several poikilodermatous lesions were present on his thighs. Improvement was achieved by topical mometasone furoate treatment. On the basis of our observation, a brief review on cutaneous T-cell lymphomas in childhood and on CD8+ subtypes in particular is given. Clinicopathological correlation is crucial for establishing the correct diagnosis and for estimation of the prognosis.

  4. STAT3 Regulates Proliferation and Survival of CD8+ T Cells: Enhances Effector Responses to HSV-1 Infection, and Inhibits IL-10+ Regulatory CD8+ T Cells in Autoimmune Uveitis

    Directory of Open Access Journals (Sweden)

    Cheng-Rong Yu

    2013-01-01

    Full Text Available STAT3 regulates CD4+ T cell survival and differentiation. However, its effects on CD8+ T cells are not well understood. Here, we show that in comparison to WT CD8+ T cells, STAT3-deficient CD8+ T cells exhibit a preactivated memory-like phenotype, produce more IL-2, proliferate faster, and are more sensitive to activation-induced cell death (AICD. The enhanced proliferation and sensitivity to AICD correlated with downregulation of class-O forkhead transcription factors (FoxO1, FoxO3A, , , Bcl-2, OX-40, and upregulation of FasL, Bax, and Bad. We examined whether STAT3-deficient CD8+ T cells can mount effective response during herpes simplex virus (HSV-1 infection and experimental autoimmune uveitis (EAU. Compared to WT mice, HSV-1-infected STAT3-deficient mice (STAT3KO produced less IFN- and virus-specific KLRG-1+ CD8+ T cells. STAT3KO mice are also resistant to EAU and produced less IL-17-producing Tc17 cells. Resistance of STAT3KO to EAU correlated with marked expansion of IL-10-producing regulatory CD8+ T cells (CD8-Treg implicated in recovery from autoimmune encephalomyelitis. Thus, increases of IL-6-induced STAT3 activation observed during inflammation may inhibit expansion of CD8-Tregs, thereby impeding recovery from uveitis. These results suggest that STAT3 is a potential therapeutic target for upregulating CD8+ T cell-mediated responses to viruses and suggest the successful therapeutic targeting of STAT3 as treatment for uveitis, derived, in part, from promoting CD8-Treg expansion.

  5. AMPKα1: A glucose sensor that controls CD8 T-cell memory

    OpenAIRE

    Finlay, David

    2013-01-01

    The adenosine monophosphate-activated protein kinase (AMPK) is activated by antigen receptor signals and energy stress in T cells. In many cell types, AMPK can maintain energy homeostasis and can enforce quiescence to limit energy demands. We consequently evaluated the importance of AMPK for controlling the transition of metabolically active effector CD8 T lymphocytes to the metabolically quiescent catabolic memory T cells during the contraction phase of the immune response. We show that AMPK...

  6. A distinct subset of self-renewing human memory CD8+ T cells survives cytotoxic chemotherapy

    OpenAIRE

    Turtle, Cameron J.; Swanson, Hillary M.; Fujii, Nobuharu; Estey, Elihu H.; Riddell, Stanley R.

    2009-01-01

    The mechanisms that maintain human T cell memory during normal and perturbed homeostasis are not fully understood. The repeated induction of profound lymphocytopenia in patients undergoing multiple cycles of cytotoxic chemotherapy infrequently results in severe infections with viruses controlled by memory T cells, suggesting that some memory T cells survive chemotherapy and restore immunity. Here we identify a distinct subpopulation of memory CD8+ T cells with the ability to rapidly efflux an...

  7. Differential Frequency of CD8+ T Cell Subsets in Multiple Sclerosis Patients with Various Clinical Patterns.

    Science.gov (United States)

    Salehi, Zahra; Doosti, Rozita; Beheshti, Masoumeh; Janzamin, Ehsan; Sahraian, Mohammad Ali; Izad, Maryam

    2016-01-01

    Recent evidence points to a pathogenic role for CD8+ cytotoxic T (Tc) cells in Multiple sclerosis (MS). Based on cytokine profile, Tc cells can be divided into different subsets: IFN-γ (Tc1), IL-4 (Tc2), IL-10 (Tc10), IL-17 (Tc17), IL-21 (Tc21), IL-22 (Tc22) and TNF-α producing cells. In this study we evaluated the frequency of Tc cell subsets and the serum level of Tc17 differentiation cytokines in MS patients with different clinical patterns. We analyzed Tc cell subsets percentage in peripheral blood of relapsing-remitting (RRMS) (n = 28), secondary-progressive (SPMS) (n = 10) and primary-progressive (PPMS) (n = 4) MS patients in comparison to healthy controls (n = 15) using flow cytometry. Serum level of TGF-β, IL-6 and IL-23 were measured by ELISA. We showed elevated levels of Tc1 and Tc17 cells in SPMS and RRMS patients in relapse phase, respectively (P = 0.04). Interestingly, the percentage of TNF-α producing CD8+ T cells in relapse and remission phase of RRMS and SPMS patients were higher than controls (P = 0.01, P = 0.004, P = 0.01, respectively) and Tc21 increased in remission phase of RRMS compared to SPMS (P = 0.03). We also found higher frequency of CD8+ IFN-γ+ TNF-α+ IL-17+ T cells in relapse phase of RRMS compared to remission phase, SPMS patients and controls (P = 0.01, P = 0.004 and P = 0.02, respectively). TGF- β increased in sera of RRMS patients in remission phase (P = 0.03) and SPMS (P = 0.05) compared to healthy subjects. Increased level of Tc17 and CD8+ IFN-γ+ TNF-α+ IL-17+ T cells in relapse phase highlights the critical role of IL-17 in RRMS pathogenesis. PMID:27467597

  8. Dengue virus-specific cross-reactive CD8+ human cytotoxic T lymphocytes.

    OpenAIRE

    Bukowski, J F; Kurane, I; Lai, C J; Bray, M; Falgout, B; Ennis, F A

    1989-01-01

    Stimulation with live dengue virus of peripheral blood mononuclear cells from a dengue virus type 4-immune donor generated virus-specific, serotype-cross-reactive, CD8+, class I-restricted cytotoxic T lymphocytes (CTL) capable of lysing dengue virus-infected cells and cells pulsed with dengue virus antigens of all four serotypes. These CTL lysed autologous fibroblasts infected with vaccinia virus-dengue virus recombinant viruses containing the E gene or several nonstructural dengue virus type...

  9. Intravacuolar Membranes Regulate CD8 T Cell Recognition of Membrane-Bound Toxoplasma gondii Protective Antigen

    OpenAIRE

    Jodie Lopez; Amina Bittame; Céline Massera; Virginie Vasseur; Grégory Effantin; Anne Valat; Célia Buaillon; Sophie Allart; Barbara A. Fox; Leah M. Rommereim; David J. Bzik; Guy Schoehn; Winfried Weissenhorn; Jean-François Dubremetz; Jean Gagnon

    2015-01-01

    Apicomplexa parasites such as Toxoplasma gondii target effectors to and across the boundary of their parasitophorous vacuole (PV), resulting in host cell subversion and potential presentation by MHC class I molecules for CD8 T cell recognition. The host-parasite interface comprises the PV limiting membrane and a highly curved, membranous intravacuolar network (IVN) of uncertain function. Here, using a cell-free minimal system, we dissect how membrane tubules are shaped by the parasite effecto...

  10. Human mesenchymal stem cells are susceptible to lysis by CD8(+) T cells and NK cells.

    Science.gov (United States)

    Crop, Meindert J; Korevaar, Sander S; de Kuiper, Ronella; IJzermans, Jan N M; van Besouw, Nicole M; Baan, Carla C; Weimar, Willem; Hoogduijn, Martin J

    2011-01-01

    There is growing interest in the use of mesenchymal stem cells (MSCs) to improve the outcome of organ transplantation. The immunogenicity of MSCs is, however, unclear and is important for the efficacy of MSC therapy and for potential sensitization against donor antigens. We investigated the susceptibility of autologous and allogeneic MSCs for lysis by CD8(+) T-lymphocytes and NK cells in a kidney transplant setting. MSCs were derived from adipose tissue of human kidney donors and were CD90(+), CD105(+), CD166(+), and HLA class I(+). They showed differentiation ability and immunosuppressive capacity. Lysis of MSCs by peripheral blood mononuclear cells (PBMCs), FACS-sorted CD8(+) T cells, and NK cells was measured by europium release assay. Allogeneic MSCs were susceptible for lysis by cytotoxic CD8(+) T cells and NK cells, while autologous MSCs were lysed by NK cells only. NK cell-mediated lysis was inversely correlated with the expression of HLA class I on MSCs. Lysis of autologous MSCs was not dependent on culturing of MSCs in FBS, and MSCs in suspension as well as adherent to plastic were lysed by NK cells. Pretransplant recipient PBMCs did not lyse donor MSCs, but PBMCs isolated 3, 6, and 12 months after transplantation showed increasing lysing ability. After 12 months, CD8(+) T-cell-mediated lysis of donor MSCs persisted, indicating there was no evidence for desensitization against donor MSCs. Lysis of MSCs is important to take into account when MSCs are considered for clinical application. Our results suggest that the HLA background of MSCs and timing of MSC administration are important for the efficacy of MSC therapy. PMID:21396164

  11. Pharmacologic Induction of CD8+ T Cell Memory: Better Living Through Chemistry

    OpenAIRE

    Gattinoni, Luca; Klebanoff, Christopher A.; Restifo, Nicholas P

    2009-01-01

    The generation of a robust population of memory T cells is critical for effective vaccine and cell-based therapies to prevent and treat infectious diseases and cancer. A series of recent papers have established a new, cell-intrinsic approach in which small molecules target key metabolic and developmental pathways to enhance the formation and maintenance of highly functional CD8+ memory T cells. These findings raise the exciting new possibility of using small molecules, many of which are alrea...

  12. Defect of CD8+ Memory T Cells Developed in Absence of IL-12 Priming for Secondary Expansion

    Institute of Scientific and Technical Information of China (English)

    Zhenmin Ye; Shulin Xu; Terence Moyana; Jicheng Yang; Jim Xiang

    2008-01-01

    IL-12 priming plays an important role in stimulation of CD8+ effector T cells and development of CD8+ memory T (Tm) cells. However, the functional alteration of CD8+ Tm cells developed in the absence of IL-12 priming is elusive.In this study, we investigated the capacity of secondary expansion of CD8+ Tm cells developed from transgenic OT I CD8+ T cells. The latter cells were in vitro and in vivo stimulated by ovalbumin (OVA)-puised dendritic cells [DCOVA and (IL-12-/-)DCOVA] derived from wild-type C57BL/6 and IL-12 gene knockout mice, respectively. We demonstrated that IL-12 priming is important not only in CD8+ T cell clonal expansion, but also in generation of CD8+ Tm cells with the capacity of secondary expansion upon antigen re-encounter. However, IL-12 signaling is not involved in CD8+ Tm cell survival and recall responses. Therefore, this study provides useful information for vaccine design and development.

  13. TGF-β and IL-21 cooperatively stimulate activated CD8(+) T cells to differentiate into Tc17 cells.

    Science.gov (United States)

    Chen, Hsin-Wei; Tsai, Jy-Ping; Yao, Tsung-You; Hsieh, Chia-Ling; Chen, I-Hua; Liu, Shin-Jen

    2016-06-01

    TGF-β together with IL-21 or IL-6 can drive the differentiation of naïve CD8(+) T cells into IL-17-producing CD8(+) T cells. These IL-17-producing CD8(+) T cells are termed Tc17 cells. Tc17 cells preserve plasticity under various conditions in vitro and in vivo. IFN-γ-producing CD8(+) T cells are termed Tc1 cells. However, Tc1 cells are considered relatively stable. In the present study, we show that the combination of TGF-β plus IL-21, but not IL-6, converts Tc1 cells into Tc17 cells; this conversion is associated with elevated RORα, RORγt, and Batf mRNA levels. These results indicate that Tc1 cells are skewed to the Tc17 cell phenotype under TGF-β plus IL-21-polarizing conditions. Furthermore, IL-6R is expressed on naïve, but not activated, CD8(+) T cells. In contrast, IL-21R is expressed on both naïve and activated CD8(+) T cells. Thus, differential expression profiles of IL-6R and IL-21R on naïve and activated CD8(+) T cells may be one mechanism by which TGF-β plus IL-21, but not IL-6, can drive activated CD8(+) T cells to differentiate into IL-17-producing cells. Taken together, these results provide a novel viewpoint for the plasticity of Tc1 cells. PMID:27085379

  14. 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.

  15. Naive CD8 T-Cells Initiate Spontaneous Autoimmunity to a Sequestered Model Antigen of the Central Nervous System

    Science.gov (United States)

    Na, Shin-Young; Cao, Yi; Toben, Catherine; Nitschke, Lars; Stadelmann, Christine; Gold, Ralf; Schimpl, Anneliese; Hunig, Thomas

    2008-01-01

    In multiple sclerosis, CD8 T-cells are thought play a key pathogenetic role, but mechanistic evidence from rodent models is limited. Here, we have tested the encephalitogenic potential of CD8 T-cells specific for the model antigen ovalbumin (OVA) sequestered in oligodendrocytes as a cytosolic molecule. We show that in these "ODC-OVA" mice, the…

  16. 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...

  17. Immune outcomes in the liver: Is CD8 T cell fate determined by the environment?

    Science.gov (United States)

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

    2015-10-01

    The liver is known for its tolerogenic properties. This unique characteristic is associated with persistent infection of the liver by the hepatitis B and C viruses. Improper activation of cellular adaptive immune responses within the liver and immune exhaustion over time both contribute to ineffective cytotoxic T cell responses to liver-expressed antigens in animal models, and likely play a role in incomplete clearance of chronic hepatitis virus infections in humans. However, under some conditions, functional immune responses can be elicited against hepatic antigens, resulting in control of hepatotropic infections. In order to develop improved therapeutics in immune-mediated chronic liver diseases, including viral hepatitis, it is essential to understand how intrahepatic immunity is regulated. This review focuses on CD8 T cell immunity directed towards foreign antigens expressed in the liver, and explores how the liver environment dictates the outcome of intrahepatic CD8 T cell responses. Potential strategies to rescue unresponsive CD8 T cells in the liver are also discussed.

  18. Tc17 CD8+ T cells potentiate Th1-mediated autoimmune diabetes in a mouse model.

    Science.gov (United States)

    Saxena, Amit; Desbois, Sabine; Carrié, Nadège; Lawand, Myriam; Mars, Lennart T; Liblau, Roland S

    2012-09-15

    An increase in IL-17-producing CD8+ T (Tc17) cells has been reported in the peripheral blood of children with recent onset type 1 diabetes (T1D), but their contribution to disease pathogenesis is still unknown. To directly study the pathogenic potential of β cell-specific Tc17 cells, we used an experimental model of T1D based on the expression of the neo-self Ag hemagglutinin (HA) in the β cells of the pancreas. When transferred alone, the IL-17-producing HA-specific CD8+ T cells homed to the pancreatic lymph nodes without causing any pancreatic infiltration or tissue destruction. When transferred together with small numbers of diabetogenic HA-specific CD4+ T cells, a strikingly different phenotype developed. Under these conditions, Tc17 cells sustained disease progression, driving the destruction of β-islet cells, causing hyperglycemia and ultimately death. Disease progression did not correlate with functional or numerical alterations among the HA-specific CD4+ T cells. Rather, the transferred CD8+ T cells accumulated in the pancreatic islets and a considerable fraction converted, under the control of IL-12, to an IFN-γ-producing phenotype. Our data indicate that Tc17 cells are not diabetogenic but can potentiate a Th1-mediated disease. Plasticity of the Tc17 lineage is associated with transition to overt disease in this experimental model of T1D. PMID:22904307

  19. PSGL-1 regulates the migration and proliferation of CD8(+) T cells under homeostatic conditions.

    Science.gov (United States)

    Veerman, Krystle M; Carlow, Douglas A; Shanina, Iryna; Priatel, John J; Horwitz, Marc S; Ziltener, Hermann J

    2012-02-15

    P-selectin glycoprotein ligand-1 (PSGL-1), a heavily glycosylated sialomucin expressed on most leukocytes, has dual function as a selectin ligand for leukocyte rolling on vascular selectins expressed in inflammation and as a facilitator of resting T cell homing into lymphoid organs. In this article, we document disturbances in T cell homeostasis present in PSGL-1(null) mice. Naive CD4(+) and CD8(+) T cell frequencies were profoundly reduced in blood, whereas T cell numbers in lymph nodes and spleen were at or near normal levels. Although PSGL-1(null) T cells were less efficient at entering lymph nodes, they also remained in lymph nodes longer than PSGL-1(+/+) T cells, suggesting that PSGL-1 supports T cell egress. In addition, PSGL-1(null) CD8(+) T cell proliferation was observed under steady-state conditions and PSGL-1(null) CD8(+) T cells were found to be hyperresponsive to homeostatic cytokines IL-2, IL-4, and IL-15. Despite these disturbances in T cell homeostasis, PSGL-1(null) mice exhibited a normal acute response (day 8) to lymphocytic choriomeningitis virus infection but generated an increased frequency of memory T cells (day 40). Our observations demonstrate a novel pleiotropic influence of PSGL-1 deficiency on several aspects of T cell homeostasis that would not have been anticipated based on the mild phenotype of PSGL-1(null) mice. These potentially offsetting effects presumably account for the near-normal cellularity seen in lymph nodes of PSGL-1(null) mice.

  20. PD-1 expression on dendritic cells suppresses CD8+ T cell function and antitumor immunity

    Science.gov (United States)

    Lim, Tong Seng; Chew, Valerie; Sieow, Je Lin; Goh, Siting; Yeong, Joe Poh-Sheng; Soon, Ai Ling; Ricciardi-Castagnoli, Paola

    2016-01-01

    ABSTRACT Programmed death one (PD-1) is a well-established co-inhibitory regulator that suppresses proliferation and cytokine production of T cells. Despite remarkable progress in delineating the functional roles of PD-1 on T lymphocytes, little is known about the regulatory role of PD-1 expressed on myeloid cells such as dendritic cells (DCs). Here, we show that CD8+ T cells can be more potently activated to secrete IL-2 and IFNγ by PD-1-deficient DCs compared to wild-type DCs. Adoptive transfer of PD-1-deficient DCs demonstrated their superior capabilities in inducing antigen-specific CD8+ T cell proliferation in vivo. In addition, we provide first evidence demonstrating the existence of peripheral blood DCs and CD11c+ tumor-infiltrating myeloid cells that co-express PD-1 in patients with hepatocellular carcinoma (HCC). The existence of PD-1-expressing HCC-infiltrating DCs (HIDCs) was further supported in a mouse model of HCC. Intratumoral transfer of PD-1-deficient DCs rendered recipient mice resistant to the growth of HCC by promoting tumor-infiltrating CD8+ effector T cells to secrete perforin and granzyme B. This novel finding provides a deeper understanding of the role of PD-1 in immune regulation and has significant implications for cancer immunotherapies targeting PD-1. PMID:27141339

  1. Characteristics of TCRαβ+CD4-CD8- thymocytes in fetal thymic organ culture

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    TCRαβ+CD4-CD8- (TCR+ DN) thymocytes at different developmental periods, i.e. after either 9 or 18 days of culture in the fetal thymic organ culture (FTOC) system, were characterized in the properties of phenotype, proliferation, differentiation and apoptosis. The results showed that anti-CD3 mAb significantly promoted proliferation of TCRαβ+ DN cells generated after 18 days of culture in FTOC, whereas the cells generated after 9 days of culture responded to anti-CD3 mAb by proliferation weakly. IL-7 efficiently induced TCRαβ+ DN cells at day 9 of FTOC to differentiate into TCRαβ+CD4+/CD8+ SP cells without detectable transitional stage of TCRαβ+CD4+CD8+ (DP) cells. In contrast, fewer TCRαβ+ DN cells generated after 18 days of FTOC were induced to differentiate into SP cells. The thymic stromal cell line MTEC5 cells synergized with IL-7 to promote the differentiation of TCRαβ+ DN cells. In addition, TCRαβ+ DN cells were shown to be less susceptible to apoptosis compared with the other major thymocyte subsets. Taken together, these data have provided insight into the characteristics of TCRαβ+ DN thymocytes.

  2. 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.

  3. Adjuvanted multi-epitope vaccines protect HLA-A*11:01 transgenic mice against Toxoplasma gondii

    Science.gov (United States)

    El Bissati, Kamal; Chentoufi, Aziz A.; Krishack, Paulette A.; Zhou, Ying; Woods, Stuart; Dubey, Jitender P.; Vang, Lo; Lykins, Joseph; Broderick, Kate E.; Mui, Ernest; Suzuki, Yasuhiro; Sa, Qila; Bi, Stephanie; Cardona, Nestor; Verma, Shiv K.; Frazeck, Laura; Reardon, Catherine A.; Sidney, John; Alexander, Jeff; Sette, Alessandro; Vedvick, Tom; Fox, Chris; Guderian, Jeffrey A.; Reed, Steven; Roberts, Craig W.

    2016-01-01

    We created and tested multi-epitope DNA or protein vaccines with TLR4 ligand emulsion adjuvant (gluco glucopyranosyl lipid adjuvant in a stable emulsion [GLA-SE]) for their ability to protect against Toxoplasma gondii in HLA transgenic mice. Our constructs each included 5 of our best down-selected CD8+ T cell–eliciting epitopes, a universal CD4+ helper T lymphocyte epitope (PADRE), and a secretory signal, all arranged for optimal MHC-I presentation. Their capacity to elicit immune and protective responses was studied using immunization of HLA-A*11:01 transgenic mice. These multi-epitope vaccines increased memory CD8+ T cells that produced IFN-γ and protected mice against parasite burden when challenged with T. gondii. Endocytosis of emulsion-trapped protein and cross presentation of the antigens must account for the immunogenicity of our adjuvanted protein. Thus, our work creates an adjuvanted platform assembly of peptides resulting in cross presentation of CD8+ T cell–eliciting epitopes in a vaccine that prevents toxoplasmosis.

  4. CD11b expression as a marker to distinguish between recently activated effector CD8(+) T cells and memory cells

    DEFF Research Database (Denmark)

    Christensen, Jeanette Erbo; Ørding Andreasen, Susanne; Christensen, Jan Pravsgaard;

    2001-01-01

    subset. Polyclonal virus-specific effector and memory CD8(+) T cells from lymphocytic choriomeningitis- and vesicular stomatitis virus-infected mice were visualized through staining for intracellular IFN-gamma or binding of MHC-peptide tetramers, and Mac-1 expression was evaluated. Naive T cells and most......CD8(+) T cells in different activation states have been difficult to identify phenotypically. In this study we have investigated whether Mac-1 (CD11b) expression can be used as a criterion to distinguish between recently activated effector cells and memory cells belonging to the CD8(+) T cell...... virus-specific memory CD8(+) T cells express little or no Mac-1 independent of the virus model employed. In contrast, the majority of CD8(+) T cells present during acute infection express a significant level of Mac-1 and, similarly, Mac-1 expression is found on secondary effectors generated in response...

  5. Viral sequestration of antigen subverts cross presentation to CD8(+ T cells.

    Directory of Open Access Journals (Sweden)

    Eric F Tewalt

    2009-05-01

    Full Text Available Virus-specific CD8(+ T cells (T(CD8+ are initially triggered by peptide-MHC Class I complexes on the surface of professional antigen presenting cells (pAPC. Peptide-MHC complexes are produced by two spatially distinct pathways during virus infection. Endogenous antigens synthesized within virus-infected pAPC are presented via the direct-presentation pathway. Many viruses have developed strategies to subvert direct presentation. When direct presentation is blocked, the cross-presentation pathway, in which antigen is transferred from virus-infected cells to uninfected pAPC, is thought to compensate and allow the generation of effector T(CD8+. Direct presentation of vaccinia virus (VACV antigens driven by late promoters does not occur, as an abortive infection of pAPC prevents production of these late antigens. This lack of direct presentation results in a greatly diminished or ablated T(CD8+ response to late antigens. We demonstrate that late poxvirus antigens do not enter the cross-presentation pathway, even when identical antigens driven by early promoters access this pathway efficiently. The mechanism mediating this novel means of viral modulation of antigen presentation involves the sequestration of late antigens within virus factories. Early antigens and cellular antigens are cross-presented from virus-infected cells, as are late antigens that are targeted to compartments outside of the virus factories. This virus-mediated blockade specifically targets the cross-presentation pathway, since late antigen that is not cross-presented efficiently enters the MHC Class II presentation pathway. These data are the first to describe an evasion mechanism employed by pathogens to prevent entry into the cross-presentation pathway. In the absence of direct presentation, this evasion mechanism leads to a complete ablation of the T(CD8+ response and a potential replicative advantage for the virus. Such mechanisms of viral modulation of antigen presentation

  6. Human purified CD8+ T cells: Ex vivo expansion model to generate a maximum yield of functional cytotoxic cells.

    Science.gov (United States)

    Al-Shanti, Nasser; Aldahoudi, Ziyad

    2007-01-01

    CD8+ T cells are a critical component of the cellular immune response. They play an important role in the control of viral infection and eliminating cells with malignant potential. However, attempts to generate and expand human CD8+ T cells in vitro for an adoptive immunotherapy have been conducted with limitation of the very low frequency of CD8+ T cells in blood. Therefore, several expansion protocols have been developed to obtain large and efficient numbers of human CD8+ T cells for use in adoptive immunotherapies. In this study various common culture conditions using different cytokines IL-2, IL-4, IL-7, IL-10, IL-12 and IL-15 and autologous feeders and sera were investigated to expand human purified CD8+ T cells. The importance and the influence of these factors on the growth and phenotype of CD8+ T cell were assessed by serially sampling cultures using flow cytometry. We demonstrated that combination of IL-2 (50 U/ml) and autologous feeders induced maximal CD8+ T cell proliferation (40-50 folds) compared to other cytokines. Immunophenotypic analysis of cultured cells showed that expanded CD8+ T cells were activated and differentiated. Furthermore our expansion model also demonstrated that expanded CD8+ T cells are functionally cytotoxic active by killing Allogeneic LCLs cells. In conclusion, we have developed a reliable, simple method that uses minimal cell numbers to generate a high yield of functional cytotoxic CD8+ T cells, which can be used for the development of cellular immunotherapies. PMID:17190652

  7. Tumor-specific CD4+ T cells maintain effector and memory tumor-specific CD8+ T cells

    Science.gov (United States)

    Church, Sarah E; Jensen, Shawn M; Antony, Paul A; Restifo, Nicholas P; Fox, Bernard A

    2014-01-01

    Immunotherapies that augment antitumor T cells have had recent success for treating patients with cancer. Here we examined whether tumor-specific CD4+ T cells enhance CD8+ T-cell adoptive immunotherapy in a lymphopenic environment. Our model employed physiological doses of tyrosinase-related protein 1-specific CD4+ transgenic T cells-CD4+ T cells and pmel-CD8+ T cells that when transferred individually were subtherapeutic; however, when transferred together provided significant (p ≤ 0.001) therapeutic efficacy. Therapeutic efficacy correlated with increased numbers of effector and memory CD8+ T cells with tumor-specific cytokine expression. When combined with CD4+ T cells, transfer of total (naïve and effector) or effector CD8+ T cells were highly effective, suggesting CD4+ T cells can help mediate therapeutic effects by maintaining function of activated CD8+ T cells. In addition, CD4+ T cells had a pronounced effect in the early posttransfer period, as their elimination within the first 3 days significantly (p < 0.001) reduced therapeutic efficacy. The CD8+ T cells recovered from mice treated with both CD8+ and CD4+ T cells had decreased expression of PD-1 and PD-1-blockade enhanced the therapeutic efficacy of pmel-CD8 alone, suggesting that CD4+ T cells help reduce CD8+ T-cell exhaustion. These data support combining immunotherapies that elicit both tumor-specific CD4+ and CD8+ T cells for treatment of patients with cancer. PMID:24114780

  8. Brief Report: Enhanced Normalization of CD4/CD8 Ratio With Earlier Antiretroviral Therapy at Primary HIV Infection

    Science.gov (United States)

    Inshaw, Jamie; Kaleebu, Pontiano; Cooper, David; Ramjee, Gita; Schechter, Mauro; Tambussi, Giuseppe; Fox, Julie; Samuel, Miriam; Miro, Jose M.; Weber, Jonathan; Porter, Kholoud; Fidler, Sarah

    2016-01-01

    Background: Total CD4+ T-cell counts predict HIV disease progression but do not necessarily reflect normalization of immune function. CD4/CD8 ratio is a marker of immune dysfunction, a prognostic indicator for non-AIDS mortality, and reflects viral reservoir size. Despite antiretroviral therapy (ART), recovery of CD4/CD8 ratio in chronic HIV infection is incomplete; we hypothesize enhanced CD4/CD8 ratio recovery with earlier treatment initiation in recently infected individuals. Methods: CD4+ count and CD4/CD8 ratio were analyzed using data from 2 cohorts: SPARTAC trial and the UK HIV Seroconverters Cohort where primary HIV infection (PHI) was defined as within 6 months from estimated date of infection. Using time-to-event methods and Cox proportional hazard models, we examined the effect of CD4/CD8 ratio at seroconversion on disease progression (CD4 1.0). Findings: Of 573 seroconverters, 482 (84%) had abnormal CD4/CD8 ratios at HIV seroconversion. Individuals with higher CD4/CD8 ratio at seroconversion were significantly less likely to reach the disease progression endpoint [adjusted hazard ratio (aHR) (95% CI) = 0.52 (0.32 to 0.82), P = 0.005]. The longer the interval between seroconversion and ART initiation [HR (95% CI) = 0.98 per month increase (0.97, 0.99), P < 0.001], the less likely the CD4/CD8 ratio normalization. ART initiation within 6 months from seroconversion was significantly more likely to normalize [HR (95% CI) = 2.47 (1.67 to 3.67), P < 0.001] than those initiating later. Interpretation: Most individuals presenting in PHI have abnormal CD4/CD8 ratios. The sooner the ART is initiated in PHI, the greater the probability of achieving normal CD4/CD8 ratio. PMID:27070122

  9. Targeting of conserved gag-epitopes in early HIV infection is associated with lower plasma viral load and slower CD4+ T cell depletion

    DEFF Research Database (Denmark)

    Perez, Carina L.; Milush, Jeffrey M.; Buggert, Marcus;

    2013-01-01

    a significantly lower median viral load over time compared to patients with responses targeting a variable epitope (0.63 log10 difference). Furthermore, the rate of CD4+ T cell decline was slower for subjects targeting a conserved epitope (0.85% per month) compared to subjects targeting a variable epitope (1......We aimed to investigate whether the character of the immunodominant HIV-Gag peptide (variable or conserved) targeted by CD8+ T cells in early HIV infection would influence the quality and quantity of T cell responses, and whether this would affect the rate of disease progression. Treatment......-naive HIV-infected study subjects within the OPTIONS cohort at the University of California, San Francisco, were monitored from an estimated 44 days postinfection for up to 6 years. CD8+ T cells responses targeting HLA-matched HIV-Gag-epitopes were identified and characterized by multicolor flow cytometry...

  10. Enhanced normalisation of CD4/CD8 ratio with early antiretroviral therapy in primary HIV infection

    Directory of Open Access Journals (Sweden)

    John Thornhill

    2014-11-01

    Full Text Available Introduction: Despite normalization of total CD4 counts, ongoing immune dysfunction is noted amongst those on antiretroviral therapy (ART. Low CD4/CD8 ratio is associated with a high risk of AIDS and non-AIDS events and may act as a marker of immune senescence [1]. This ratio is improved by ART although normalization is uncommon (~7% [2]. The probability of normalization of CD4 count is improved with immediate ART initiation in primary HIV infection (PHI [3]. We examined whether CD4/CD8 ratio similarly normalized in immediate vs. deferred ART at PHI. Material and Methods: Using data from the SPARTAC trial and the UK Register of HIV Seroconverters, we examined the effect of ART with time (continuous from HIV seroconversion (SC on CD4/CD8 ratio (≥1 adjusted for sex, risk group, ethnicity, enrolment from an African site and both CD4 count and age at ART initiation. We also examined that effect by dichotomizing HIV duration at ART initiation (ART started within six months of SC: early ART; ART initiated>six months after SC: deferred. We also considered time to CD4 count normalization (≥900 cells/mm3. Results: In total, 353 initiated ART with median (IQR 97.9 (60.5, 384.5 days from estimated seroconversion; 253/353 early ART, 100 deferred ART. At one year after starting ART, 114/253 (45% early ART had normalized CD4/8 ratio, compared with 11/99 (11% in the deferred group, whilst 83/253 (33% of early ART had normalized CD4 counts, compared with 3/99 (3% in the deferred group. Individuals initiating within six months of PHI were significantly more likely to reach normal ratio than those initiating later (HR, 95% CI 2.96, 1.75 – 5.01, p<0.001. The longer after SC ART was initiated, the reduced likelihood of achieving normalization of CD4/CD8 ratio (HR 0.98, 95% CI 0.96 – 0.99 for each 30-day increase. CD4 count at ART initiation was also associated with normalization, as expected (HR 1.002, 95% CI 1.001 – 1.002, p<0.001. There was an

  11. Identification of prostate-specific G-protein coupled receptor as a tumor antigen recognized by CD8(+ T cells for cancer immunotherapy.

    Directory of Open Access Journals (Sweden)

    Satoko Matsueda

    Full Text Available BACKGROUND: Prostate cancer is the most common cancer among elderly men in the US, and immunotherapy has been shown to be a promising strategy to treat patients with metastatic castration-resistant prostate cancer. Efforts to identify novel prostate specific tumor antigens will facilitate the development of effective cancer vaccines against prostate cancer. Prostate-specific G-protein coupled receptor (PSGR is a novel antigen that has been shown to be specifically over-expressed in human prostate cancer tissues. In this study, we describe the identification of PSGR-derived peptide epitopes recognized by CD8(+ T cells in an HLA-A2 dependent manner. METHODOLOGY/PRINCIPAL FINDINGS: Twenty-one PSGR-derived peptides were predicted by an immuno-informatics approach based on the HLA-A2 binding motif. These peptides were examined for their ability to induce peptide-specific T cell responses in peripheral blood mononuclear cells (PBMCs obtained from either HLA-A2(+ healthy donors or HLA-A2(+ prostate cancer patients. The recognition of HLA-A2 positive and PSGR expressing LNCaP cells was also tested. Among the 21 PSGR-derived peptides, three peptides, PSGR3, PSGR4 and PSGR14 frequently induced peptide-specific T cell responses in PBMCs from both healthy donors and prostate cancer patients. Importantly, these peptide-specific T cells recognized and killed LNCaP prostate cancer cells in an HLA class I-restricted manner. CONCLUSIONS/SIGNIFICANCE: We have identified three novel HLA-A2-restricted PSGR-derived peptides recognized by CD8(+ T cells, which, in turn, recognize HLA-A2(+ and PSGR(+ tumor cells. The PSGR-derived peptides identified may be used as diagnostic markers as well as immune targets for development of anticancer vaccines.

  12. Conservation analysis of dengue virust-cell epitope-based vaccine candidates using peptide block entropy

    DEFF Research Database (Denmark)

    Olsen, Lars Rønn; Zhang, Guang Lan; Keskin, Derin B.;

    2011-01-01

    Broad coverage of the pathogen population is particularly important when designing CD8+ T-cell epitope vaccines against viral pathogens. Traditional approaches are based on combinations of highly conserved T-cell epitopes. Peptide block entropy analysis is a novel approach for assembling sets....... In contrast, the benchmark study by Khan et al. (2008) resulted in 165 conserved 9-mer peptides. Many of the conserved blocks are located consecutively in the proteins. Connecting these blocks resulted in 78 conserved regions. Of the 1551 blocks of 9-mer peptides 110 comprised predicted HLA binder sets...

  13. STAT3 Regulates Proliferation and Survival of CD8+ T Cells: Enhances Effector Responses to HSV-1 Infection, and Inhibits IL-10+ Regulatory CD8+ T Cells in Autoimmune Uveitis

    OpenAIRE

    Cheng-Rong Yu; Dambuza, Ivy M.; Yong-Jun Lee; Frank, Gregory M.; Egwuagu, Charles E.

    2013-01-01

    STAT3 regulates CD4+ T cell survival and differentiation. However, its effects on CD8+ T cells are not well understood. Here, we show that in comparison to WT CD8+ T cells, STAT3-deficient CD8+ T cells exhibit a preactivated memory-like phenotype, produce more IL-2, proliferate faster, and are more sensitive to activation-induced cell death (AICD). The enhanced proliferation and sensitivity to AICD correlated with downregulation of class-O forkhead transcription factors (FoxO1, FoxO3A), p21wa...

  14. Regulation of CD4⁺ and CD8⁺ effector responses by Sprouty-1.

    Directory of Open Access Journals (Sweden)

    Sam Collins

    Full Text Available TCR-induced NF-AT activation leads to the expression of both activating and inhibitory proteins. Previously, we had identified Egr-2 and Egr-3 as NF-AT-induced transcription factors which promote the inhibition of T cell activation. In this report we identify Sprouty1 as a downstream target of Egr-3. CD4⁺ T cells lacking Spry1 demonstrate enhanced proliferation and cytokine production. Likewise, Spry1(Flox/Flox Lck Cre CD8⁺ T cells display increased cytolytic activity. Mechanistically, Spry1 acts at the level of PLC-γ promoting the inhibition of both Ca⁺⁺ induced NF-AT activation and MAP-kinase induced AP-1 activation while sparing NF-κB signaling. In vivo, mice in which Spry1 is selectively deleted in T cells demonstrate enhanced responses to a tumor vaccine and subsequently reject tumors more robustly than Wt mice. These findings suggest that targeting Spry1 might prove to be a novel means of enhancing tumor immunotherapy.

  15. Regulation of A1 by OX40 contributes to CD8(+ T cell survival and anti-tumor activity.

    Directory of Open Access Journals (Sweden)

    Fengyang Lei

    Full Text Available The TNFR family member OX40 (CD134 is critical for optimal clonal expansion and survival of T cells. However, the intracellular targets of OX40 in CD8 T cells are not fully understood. Here we show that A1, a Bcl-2 family protein, is regulated by OX40 in effector CD8 T cells. In contrast to wild-type T cells, OX40-deficient CD8 T cells failed to maintain A1 expression driven by antigen. Conversely, enforced OX40 stimulation promoted A1 expression. In both situations, the expression of A1 directly correlated with CD8 T cell survival. In addition, exogenous expression of A1 in OX40-deficient CD8 T cells reversed their survival defect in vitro and in vivo. Moreover, forced expression of A1 in CD8 T cells from OX40-deficient mice restored the ability of these T cells to suppress tumor growth in a murine model. These results indicate that OX40 signals regulate CD8 T cell survival at least in part through maintaining expression of the anti-apoptotic molecule A1, and provide new insight into the mechanism by which OX40 may impact anti-tumor immunity.

  16. Batf3 and Id2 have a synergistic effect on Irf8-directed classical CD8α+ dendritic cell development

    KAUST Repository

    Jaiswal, Hemant

    2013-11-13

    Dendritic cells (DCs) are heterogeneous cell populations represented by different subtypes, each varying in terms of gene expression patterns and specific functions. Recent studies identified transcription factors essential for the development of different DC subtypes, yet molecular mechanisms for the developmental program and functions remain poorly understood. In this study, we developed and characterized a mouse DC progenitor-like cell line, designated DC9, from Irf8-/- bone marrow cells as a model for DC development and function. Expression of Irf8 in DC9 cells led to plasmacytoid DCs and CD8α+ DC-like cells, with a concomitant increase in plasmacytoid DC- and CD8α+ DC-specific gene transcripts and induction of type I IFNs and IL12p40 following TLR ligand stimulation. Irf8 expression in DC9 cells led to an increase in Id2 and Batf3 transcript levels, transcription factors shown to be important for the development of CD8α+ DCs. We show that, without Irf8 , expression of Id2 and Batf3 was not sufficient for directing classical CD8α+ DC development. When coexpressed with Irf8, Batf3 and Id2 had a synergistic effect on classical CD8α+ DC development. We demonstrate that Irf8 is upstream of Batf3 and Id2 in the classical CD8α+ DC developmental program and define the hierarchical relationship of transcription factors important for classical CD8α+ DC development.

  17. Expression, purification, crystallization and preliminary X-ray diffraction analysis of rhesus macaque CD8αα homodimer

    International Nuclear Information System (INIS)

    CD8α exodomain protein, a crucial immune-system factor in rhesus macaque (M. mulatta), one of the best animal models for vaccine design, was assembled and crystallized. The full structure data will contribute to future studies of immune responses in rhesus macaques. As a T-cell co-receptor, CD8 binds to MHC class I molecules and plays a pivotal role in the activation of cytotoxic T lymphocytes. To date, structures of CD8 have been solved for two different mammals: human and mouse. The infection of rhesus macaques (Macaca mulatta) by simian immunodeficiency virus (SIV) is the best animal model for studying HIV. In this study, the rhesus macaque CD8 (rCD8) αα homodimer was obtained and rCD8α exodomain protein crystals were successfully obtained for further structural analysis. Diffraction data were collected to a resolution of 2.4 Å. The crystal belonged to space group P212121, with unit-cell parameters a = 46.52, b = 56.28, c = 82.40 Å. These data will facilitate further studies on the structural differences between these CD8 structures and the cellular immune responses of rhesus macaque

  18. The Prognostic Significance of FoxP3+ T Cells and CD8+ T Cells in Colorectal Carcinomas.

    Science.gov (United States)

    Argon, Asuman; Vardar, Enver; Kebat, Tulu; Erdinç, Ömer; Erkan, Nazif

    2016-01-01

    Recent studies report that tumor microenvironment effects prognosis of colorectal cancers. We analyzed the densities of FoxP3+ cells and CD8+ cells, the ratio of FoxP3+/CD8+ cells and the relationship between these parameters, clinicopathological features, and prognosis. A total of 186 colorectal adenocarcinoma were evaluated in terms of clinicopathological features. Immunohistochemically, densities of intratumoral (IT; IT-FoxP3) and nontumoral (NT; NT-FoxP3) FoxP3+ cells and IT-CD8 and NT-CD8 CD8+ cells were calculated. The ratio of Foxp3/CD8 was recorded. IT-FoxP3 and the ratio of IT-FoxP3/IT-CD8 were higher than NT-FoxP3 and the ratio of NT-FoxP3/NT-CD8, respectively. In multivariate analysis, high FoxP3+ cell density is the most important predictive marker after clinical stage and surgical margin positivity in disease-free survival and the most important predictive marker after clinical stage in overall survival (OS). Short OS time was correlated with clinical stage, decrease in IT-FoxP3, increasing age, number of metastatic lymph nodes, surgical margin positivity, satellite tumor nodule, medullary carcinoma, and the number of pericolorectal lymph nodes. The ratio of FoxP3/CD8 increased noticeably in the IT area, but no relationship was found with survival. The relationships of the cells with one another in the tumor microenvironment seem to have many secrets. Studies in large series supported by molecular techniques can illuminate those secrets to some extent. PMID:27481490

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

    Science.gov (United States)

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

    2016-08-01

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

  20. Characterization of Diabetogenic CD8+ T Cells: IMMUNE THERAPY WITH METABOLIC BLOCKADE.

    Science.gov (United States)

    Garyu, Justin W; Uduman, Mohamed; Stewart, Alex; Rui, Jinxiu; Deng, Songyan; Shenson, Jared; Staron, Matt M; Kaech, Susan M; Kleinstein, Steven H; Herold, Kevan C

    2016-05-20

    Type 1 diabetes mellitus is caused by the killing of insulin-producing β cells by CD8+T cells. The disease progression, which is chronic, does not follow a course like responses to conventional antigens such as viruses, but accelerates as glucose tolerance deteriorates. To identify the unique features of the autoimmune effectors that may explain this behavior, we analyzed diabetogenic CD8+ T cells that recognize a peptide from the diabetes antigen IGRP (NRP-V7-reactive) in prediabetic NOD mice and compared them to others that shared their phenotype (CD44(+)CD62L(lo)PD-1(+)CXCR3(+)) but negative for diabetes antigen tetramers and to LCMV (lymphocytic choriomeningitis)-reactive CD8+ T cells. There was an increase in the frequency of the NRP-V7-reactive cells coinciding with the time of glucose intolerance. The T cells persisted in hyperglycemic NOD mice maintained with an insulin pellet despite destruction of β cells. We compared gene expression in the three groups of cells compared with the other two subsets of cells, and the NRP-V7-reactive cells exhibited gene expression of memory precursor effector cells. They had reduced cellular proliferation and were less dependent on oxidative phosphorylation. When prediabetic NOD mice were treated with 2-deoxyglucose to block aerobic glycolysis, there was a reduction in the diabetes antigen versus other cells of similar phenotype and loss of lymphoid cells infiltrating the islets. In addition, treatment of NOD mice with 2-deoxyglucose resulted in improved β cell granularity. These findings identify a link between metabolic disturbances and autoreactive T cells that promotes development of autoimmune diabetes. PMID:26994137

  1. CD4(+)/CD8(+) T-lymphocyte Ratio: Effects of Rehydration before Exercise in Dehydrated Men

    Science.gov (United States)

    Greenleaf, John E.; Jackson, Catherine G. R.; Lawless, Desales

    1995-01-01

    Effects of fluid ingestion on CD4+/CD8+ T-lymphocyte cell ratios were measured in four dehydrated men (ages 30-46 yr) before and after 70 min of supine submaximal (71 % VO(sub 2max) lower extremity cycle exercise. Just before exercise, Evans blue dye was injected for measurement of plasma volume. The subjects then drank one of six fluid formulations (12 ml/kg) in 3-4 min. All six mean post-hydration (pre-exercise) CD4+/CD8+ ratios (Becton-Dickinson Fluorescence Activated Cell Sorter and FACScan Consort-30 software program were below the normal range of 1.2-1.5; mean (+/- SE) and range were 0.77 +/- 0.12 and 0.39-1.15, respectively. The post-exercise ratios increased: mean = 1.36 =/- 0.15 (P less than 0.05) and range = 0.98-1.98. Regression of mean CD4+/CD8+ ratios on mean plasma osmolality resulted in pre- and post-exercise correlation coefficients of -0.76 (P less than 0.10) and -0.92 (P less than 0.01), respectively. The decreased pre-exercise ratios (after drinking) were probably not caused by the Evans blue dye but appeared to be associated more with the stress (osmotic) of dehydration. The increased post-exercise ratios to normal levels accompanied the rehydration and were not due to the varied electrolyte and osmotic concentrations of the ingested fluids or to the varied vascular volume shifts during exercise. Thus, the level of subject hydration and plasma osmotality may be factors involved in the mechanism of immune system modulation induced by exercise.

  2. Acellular pertussis booster in adolescents induces Th1 and memory CD8+ T cell immune response.

    Directory of Open Access Journals (Sweden)

    Nikolaus Rieber

    Full Text Available In a number of countries, whole cell pertussis vaccines (wcP were replaced by acellular vaccines (aP due to an improved reactogenicity profile. Pertussis immunization leads to specific antibody production with the help of CD4(+ T cells. In earlier studies in infants and young children, wcP vaccines selectively induced a Th1 dominated immune response, whereas aP vaccines led to a Th2 biased response. To obtain data on Th1 or Th2 dominance of the immune response in adolescents receiving an aP booster immunization after a wcP or aP primary immunization, we analyzed the concentration of Th1 (IL-2, TNF-α, INF-γ and Th2 (IL-4, IL-5, IL-10 cytokines in supernatants of lymphocyte cultures specifically stimulated with pertussis antigens. We also investigated the presence of cytotoxic T cell responses against the facultative intracellular bacterium Bordetella pertussis by quantifying pertussis-specific CD8(+ T cell activation following the aP booster immunization. Here we show that the adolescent aP booster vaccination predominantly leads to a Th1 immune response based on IFNgamma secretion upon stimulation with pertussis antigen, irrespective of a prior whole cell or acellular primary vaccination. The vaccination also induces an increase in peripheral CD8(+CD69(+ activated pertussis-specific memory T cells four weeks after vaccination. The Th1 bias of this immune response could play a role for the decreased local reactogenicity of this adolescent aP booster immunization when compared to the preceding childhood acellular pertussis booster. Pertussis-specific CD8(+ memory T cells may contribute to protection against clinical pertussis.

  3. Adhesion versus coreceptor function of CD4 and CD8: role of the cytoplasmic tail in coreceptor activity.

    OpenAIRE

    Miceli, M C; Von Hoegen, P.; Parnes, J R

    1991-01-01

    CD4 and CD8 play an important role in T-cell recognition and activation; however, their mechanisms of action are not well understood. We compare the effects of expressing CD4 and CD8 alpha either individually or together in a class II-restricted T-cell hybridoma. We also compare the effects of expressing truncated forms of CD4 or CD8 alpha that do not have a cytoplasmic tail and thus do not associate with the T-cell-specific tyrosine kinase p56lck, which has been implicated in T-cell activati...

  4. Human and Mouse CD8+CD25+FOXP3+ Regulatory T Cells at Steady State and during Interleukin-2 Therapy

    OpenAIRE

    Churlaud, Guillaume; Pitoiset, Fabien; Jebbawi, Fadi; Lorenzon, Roberta; Bellier, Bertrand; Rosenzwajg, Michelle; Klatzmann, David

    2015-01-01

    International audience In addition to CD4+ regulatory T cells (Tregs), CD8+ suppressor T cells are emerging as an important subset of regulatory T cells. Diverse populations of CD8+ T cells with suppressive activities have been described. Among them, a small population of CD8+CD25+FOXP3+ T cells is found both in mice and humans. In contrast to thymic-derived CD4+CD25+FOXP3+ Tregs, their origin and their role in the pathophysiology of autoimmune diseases (AIDs) are less understood. We repor...

  5. Osteoclast activated FoxP3+ CD8+ T-cells suppress bone resorption in vitro.

    Directory of Open Access Journals (Sweden)

    Zachary S Buchwald

    Full Text Available BACKGROUND: Osteoclasts are the body's sole bone resorbing cells. Cytokines produced by pro-inflammatory effector T-cells (T(EFF increase bone resorption by osteoclasts. Prolonged exposure to the T(EFF produced cytokines leads to bone erosion diseases such as osteoporosis and rheumatoid arthritis. The crosstalk between T-cells and osteoclasts has been termed osteoimmunology. We have previously shown that under non-inflammatory conditions, murine osteoclasts can recruit naïve CD8 T-cells and activate these T-cells to induce CD25 and FoxP3 (Tc(REG. The activation of CD8 T-cells by osteoclasts also induced the cytokines IL-2, IL-6, IL-10 and IFN-γ. Individually, these cytokines can activate or suppress osteoclast resorption. PRINCIPAL FINDINGS: To determine the net effect of Tc(REG on osteoclast activity we used a number of in vitro assays. We found that Tc(REG can potently and directly suppress bone resorption by osteoclasts. Tc(REG could suppress osteoclast differentiation and resorption by mature osteoclasts, but did not affect their survival. Additionally, we showed that Tc(REG suppress cytoskeletal reorganization in mature osteoclasts. Whereas induction of Tc(REG by osteoclasts is antigen-dependent, suppression of osteoclasts by Tc(REG does not require antigen or re-stimulation. We demonstrated that antibody blockade of IL-6, IL-10 or IFN-γ relieved suppression. The suppression did not require direct contact between the Tc(REG and osteoclasts. SIGNIFICANCE: We have determined that osteoclast-induced Tc(REG can suppress osteoclast activity, forming a negative feedback system. As the CD8 T-cells are activated in the absence of inflammatory signals, these observations suggest that this regulatory loop may play a role in regulating skeletal homeostasis. Our results provide the first documentation of suppression of osteoclast activity by CD8 regulatory T-cells and thus, extend the purview of osteoimmunology.

  6. Alpha 4 integrin directs virus-activated CD8+ T cells to sites of infection

    DEFF Research Database (Denmark)

    Christensen, Jan Pravsgaard; Andersson, E C; Scheynius, A;

    1995-01-01

    This article examines the role of VLA-4 in directing lymphocytes to sites of viral infection using the murine lymphocytic choriomeningitis virus infection (LCMV) as the model system. This virus by itself induces little or no inflammation, but in most mouse/virus strain combinations a potent T cell...... response is induced, which is associated with marked CD8+ cell-mediated inflammation. Two expressions of LCMV-induced inflammation were studied: meningitis induced by intracerebral infection and adoptive transfer of virus-specific delayed-type hypersensitivity. Our previous studies have shown that LCMV...

  7. Tc17 CD8 T Cells: Functional Plasticity and Subset Diversity1

    OpenAIRE

    Yen, Hung-Rong; Harris, Timothy J.; Wada, Satoshi; Grosso, Joseph F.; Getnet, Derese; Goldberg, Monica V.; Liang, Kai-Li; Bruno, Tullia C.; Pyle, Kristin J.; Chan, Siaw-Li; Anders, Robert A.; Trimble, Cornelia L.; Adler, Adam J.; Lin, Tzou-Yien; Pardoll, Drew M.

    2009-01-01

    IL-17-secreting CD8 T cells (Tc17) have been described in several settings, but little is known regarding their functional characteristics. While Tc1 cells produced IFN-γ and efficiently killed targets, Tc17 cells lacked lytic function in vitro. Interestingly, the small numbers of IFN-γ-positive or IL-17/IFN-γ-double-positive cells generated under Tc17 conditions also lacked lytic activity and expressed a similar pattern of cell surface proteins to IL-17-producing cells. As is the case for Th...

  8. PD-1 expression on dendritic cells suppresses CD8+ T cell function and antitumor immunity

    OpenAIRE

    Lim, Tong Seng; Chew, Valerie; Sieow, Je Lin; Goh, Siting; Yeong, Joe Poh-Sheng; Soon, Ai Ling; Ricciardi-Castagnoli, Paola

    2015-01-01

    Programmed death one (PD-1) is a well-established co-inhibitory regulator that suppresses proliferation and cytokine production of T cells. Despite remarkable progress in delineating the functional roles of PD-1 on T lymphocytes, little is known about the regulatory role of PD-1 expressed on myeloid cells such as dendritic cells (DCs). Here, we show that CD8+ T cells can be more potently activated to secrete IL-2 and IFNγ by PD-1-deficient DCs compared to wild-type DCs. Adoptive transfer of P...

  9. Requirements for Peptide-induced T Cell Receptor Downregulation on Naive CD8+ T Cells

    OpenAIRE

    Cai, Zeling; Kishimoto, Hidehiro; Brunmark, Anders; Jackson, Michael R.; Peterson, Per A.; Sprent, Jonathan

    1997-01-01

    The requirements for inducing downregulation of α/β T cell receptor (TCR) molecules on naive major histocompatibility complex class I–restricted T cells was investigated with 2C TCR transgenic mice and defined peptides as antigen. Confirming previous results, activation of 2C T cells in response to specific peptides required CD8 expression on the responder cells and was heavily dependent upon costimulation provided by either B7-1 or ICAM-1 on antigen-presenting cells (APC). These stringent re...

  10. Some epitopes conservation in non structural 3 protein dengue virus serotype 4

    Directory of Open Access Journals (Sweden)

    Tegar A. P. Siregar

    2016-03-01

    Full Text Available AbstrakLatar belakang: Protein Non Struktural 3 (NS3 virus dengue menginduksi respon antibodi netralisasidan respon sel T CD4+ dan CD8+, serta berperan dalam replikasi virus. Protein NS3 memiliki epitopepitopsel T dan B yang terdapat perbedaan kelestarian pada berbagai strain virus dengue serotipe 4(DENV-4. Penelitian ini bertujuan untuk mengetahui kelestarian epitop sel T dan B pada protein NS3DENV-4 strain-strain dunia dan keempat serotipe virus dengue strain Indonesia.Metode: Penelitian ini dilakukan di Departemen Mikrobiologi Fakultas Kedokteran UI sejak Juni 2013 - April2014. Sekuens asam amino NS3 DENV-4 strain 081 didapatkan setelah produk PCR gen NS3 DENV-4 081disekuensing. Epitop-epitop sel T dan sel B protein NS3 DENV-4 081 dianalisis dan dibandingkan dengansekuens asam amino protein NS3 dari 124 strain DENV-4 di dunia dan keempat serotipe DENV strain Indonesia.Strain-strain dunia merupakan strain yang ada di benua Amerika (Venezuela, Colombia, dll dan Asia (Cina,Singapura, dll. Referensi posisi epitop sel T dan B protein NS3 diperoleh dari laporan penelitian terdahulu.Hasil: Delapan epitop sel T dan 2 epitop sel B dari protein NS3 DENV-4 081 ternyata identik dan lestaripada protein NS3 dari 124 strain DENV-4 dunia. Epitop sel B di posisi asam amino 537-544 pada proteinNS3 DENV-4 081 ternyata identik dan lestari dengan epitop sel B protein NS3 dari keempat serotipeDENV strain Indonesia.Kesimpulan: Kelestarian yang luas dari epitop sel T dan B pada hampir seluruh strain DENV-4 dunia danserotipe-serotipe DENV strain Indonesia. (Health Science Journal of Indonesia 2015;6:126-31Kata kunci: virus dengue, protein NS3, epitop sel T, epitop sel B AbstractBackground: Non Structural 3 (NS3 protein of dengue virus (DENV is known to induce antibody, CD4+and CD8+ T cell responses, and playing role in viral replication. NS3 protein has T and B cell epitopes,which has conservation difference between DENV-4 strains. This study aimed to identify

  11. Structure and Function of HLA-A*02-Restricted Hantaan Virus Cytotoxic T-Cell Epitope That Mediates Effective Protective Responses in HLA-A2.1/K(b) Transgenic Mice.

    Science.gov (United States)

    Ma, Ying; Cheng, Linfeng; Yuan, Bin; Zhang, Yusi; Zhang, Chunmei; Zhang, Yun; Tang, Kang; Zhuang, Ran; Chen, Lihua; Yang, Kun; Zhang, Fanglin; Jin, Boquan

    2016-01-01

    Hantavirus infections cause severe emerging diseases in humans and are associated with high mortality rates; therefore, they have become a global public health concern. Our previous study showed that the CD8(+) T-cell epitope aa129-aa137 (FVVPILLKA, FA9) of the Hantaan virus (HTNV) nucleoprotein (NP), restricted by human leukocyte antigen (HLA)-A*02, induced specific CD8(+) T-cell responses that controlled HTNV infection in humans. However, the in vivo immunogenicity of peptide FA9 and the effect of FA9-specific CD8(+) T-cell immunity remain unclear. Here, based on a detailed structural analysis of the peptide FA9/HLA-A*0201 complex and functional investigations using HLA-A2.1/K(b) transgenic (Tg) mice, we found that the overall structure of the peptide FA9/HLA-A*0201 complex displayed a typical MHC class I fold with Val2 and Ala9 as primary anchor residues and Val3 and Leu7 as secondary anchor residues that allow peptide FA9 to bind tightly with an HLA-A*0201 molecule. Residues in the middle portion of peptide FA9 extruding out of the binding groove may be the sites that allow for recognition by T-cell receptors. Immunization with peptide FA9 in HLA-A2.1/K(b) Tg mice induced FA9-specific cytotoxic T-cell responses characterized by the induction of high expression levels of interferon-γ, tumor necrosis factor-α, granzyme B, and CD107a. In an HTNV challenge trial, significant reductions in the levels of both the antigens and the HTNV RNA loads were observed in the liver, spleen, and kidneys of Tg mice pre-vaccinated with peptide FA9. Thus, our findings highlight the ability of HTNV epitope-specific CD8(+) T-cell immunity to control HTNV and support the possibility that the HTNV-NP FA9 peptide, naturally processed in vivo in an HLA-A*02-restriction manner, may be a good candidate for the development HTNV peptide vaccines. PMID:27551282

  12. Structure and Function of HLA-A*02-Restricted Hantaan Virus Cytotoxic T-Cell Epitope That Mediates Effective Protective Responses in HLA-A2.1/Kb Transgenic Mice

    Science.gov (United States)

    Ma, Ying; Cheng, Linfeng; Yuan, Bin; Zhang, Yusi; Zhang, Chunmei; Zhang, Yun; Tang, Kang; Zhuang, Ran; Chen, Lihua; Yang, Kun; Zhang, Fanglin; Jin, Boquan

    2016-01-01

    Hantavirus infections cause severe emerging diseases in humans and are associated with high mortality rates; therefore, they have become a global public health concern. Our previous study showed that the CD8+ T-cell epitope aa129–aa137 (FVVPILLKA, FA9) of the Hantaan virus (HTNV) nucleoprotein (NP), restricted by human leukocyte antigen (HLA)-A*02, induced specific CD8+ T-cell responses that controlled HTNV infection in humans. However, the in vivo immunogenicity of peptide FA9 and the effect of FA9-specific CD8+ T-cell immunity remain unclear. Here, based on a detailed structural analysis of the peptide FA9/HLA-A*0201 complex and functional investigations using HLA-A2.1/Kb transgenic (Tg) mice, we found that the overall structure of the peptide FA9/HLA-A*0201 complex displayed a typical MHC class I fold with Val2 and Ala9 as primary anchor residues and Val3 and Leu7 as secondary anchor residues that allow peptide FA9 to bind tightly with an HLA-A*0201 molecule. Residues in the middle portion of peptide FA9 extruding out of the binding groove may be the sites that allow for recognition by T-cell receptors. Immunization with peptide FA9 in HLA-A2.1/Kb Tg mice induced FA9-specific cytotoxic T-cell responses characterized by the induction of high expression levels of interferon-γ, tumor necrosis factor-α, granzyme B, and CD107a. In an HTNV challenge trial, significant reductions in the levels of both the antigens and the HTNV RNA loads were observed in the liver, spleen, and kidneys of Tg mice pre-vaccinated with peptide FA9. Thus, our findings highlight the ability of HTNV epitope-specific CD8+ T-cell immunity to control HTNV and support the possibility that the HTNV-NP FA9 peptide, naturally processed in vivo in an HLA-A*02-restriction manner, may be a good candidate for the development HTNV peptide vaccines. PMID:27551282

  13. Repeated epitope in the recombinant epitope-peptide could enhance ELDKWA-epitope-specific antibody response

    Institute of Scientific and Technical Information of China (English)

    LIU Zuqiang; WANG Zuguang; CHEN Yinghua

    2005-01-01

    Based on the hypothesis suggested by us that epitope-vaccine may be a new strategy against HIV mutation, we have studied several neutralizing epitopes on HIV envelope proteins. However we do not know whether a repeated epitope in a recombinant epitope-peptide can enhance epitope-specific antibody response or not. ELDKWA-epitope (aa669-674) on the C-domain of HIV-1 gp41 is a neutralizing epitope defined by the monoclonal antibody (mAb) 2F5 with broad neutralizing activity. In this study, we designed and prepared a series of the recombinant epitope-peptides bearing 1, 4 and 8 copies of ELDKWA-epitope respectively. In the comparison of the antisera induced by the three recombinant antigens, an obviously increased titre of ELDKWA-epitope-specific antibody was observed in the case of four and eight repeated epitopes. In flow cytometry analysis, the epitope-specific antibodies in both antisera showed stronger activity to bind the transfected CHO-WT cells that stably express HIV-1 envelope glycoprotein on the cell surfaces. These experimental results indicated that repeated epitope in the recombinant epitope-peptide could enhance ELDKWA-epitope-specific antibody response, which could contribute to designing an effective recombinant epitope-vaccine.

  14. HIV-infected individuals with low CD4/CD8 ratio despite effective antiretroviral therapy exhibit altered T cell subsets, heightened CD8+ T cell activation, and increased risk of non-AIDS morbidity and mortality.

    Directory of Open Access Journals (Sweden)

    Sergio Serrano-Villar

    2014-05-01

    Full Text Available A low CD4/CD8 ratio in elderly HIV-uninfected adults is associated with increased morbidity and mortality. A subset of HIV-infected adults receiving effective antiretroviral therapy (ART fails to normalize this ratio, even after they achieve normal CD4+ T cell counts. The immunologic and clinical characteristics of this clinical phenotype remain undefined. Using data from four distinct clinical cohorts and three clinical trials, we show that a low CD4/CD8 ratio in HIV-infected adults during otherwise effective ART (after CD4 count recovery above 500 cells/mm3 is associated with a number of immunological abnormalities, including a skewed T cell phenotype from naïve toward terminally differentiated CD8+ T cells, higher levels of CD8+ T cell activation (HLADR+CD38+ and senescence (CD28- and CD57+CD28-, and higher kynurenine/tryptophan ratio. Changes in the peripheral CD4/CD8 ratio are also reflective of changes in gut mucosa, but not in lymph nodes. In a longitudinal study, individuals who initiated ART within six months of infection had greater CD4/CD8 ratio increase compared to later initiators (>2 years. After controlling for age, gender, ART duration, nadir and CD4 count, the CD4/CD8 ratio predicted increased risk of morbidity and mortality. Hence, a persistently low CD4/CD8 ratio during otherwise effective ART is associated with increased innate and adaptive immune activation, an immunosenescent phenotype, and higher risk of morbidity/mortality. This ratio may prove useful in monitoring response to ART and could identify a unique subset of individuals needed of novel therapeutic interventions.

  15. Phenotypic and Functional Analysis of LCMV gp33-41-Specific CD8 T Cells Elicited by Multiple Peptide Immunization in Mice Revealed the Up-regulation of PD-1 Expression on Antigen Specific CD8 T Cells

    Institute of Scientific and Technical Information of China (English)

    Yi Liu; Lihui Xu; Yiqun Jiang; Jianfang Sun; Xianhui He

    2007-01-01

    The phenotype and function of antigen-specific CD8 T cells are closely associated with the efficacy of a therapeutic vaccination. Here we showed that multiple immunizations with LCMV gp33-41 peptide (KAV) in Freund's adjuvant could induce KAV-specific CD8 T cells with low expression of CD127 and CD62L molecules. The inhibitory receptor PD-1 was also expressed on a substantial part of KAV-specific CD8 T cells, and its expression level on KAV-specific CD8 T cells in spleen and lymph nodes was much higher when compared to those in peripheral blood. Furthermore, KAV-specific CD8 T cells could specifically kill KAV-pulsed target cells in vivo but the efficiency was low. These data suggest that prime-boost vaccination schedule with peptide in Freund's adjuvant can elicit antigen-specific CD8 T cells of effector-like phenotype with partial functional exhaustion, which may only provide short-term protection against the pathogen.

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

    Science.gov (United States)

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

    2015-08-15

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

  17. CD8 T Cell–Independent Antitumor Response and Its Potential for Treatment of Malignant Gliomas

    Science.gov (United States)

    Murphy, Katherine A.; Griffith, Thomas S.

    2016-01-01

    Malignant brain tumors continue to represent a devastating diagnosis with no real chance for cure. Despite an increasing list of potential salvage therapies, standard-of-care for these patients has not changed in over a decade. Immunotherapy has been seen as an exciting option, with the potential to offer specific and long lasting tumor clearance. The “gold standard” in immunotherapy has been the development of a tumor-specific CD8 T cell response to potentiate tumor clearance and immunological memory. While many advances have been made in the field of immunotherapy, few therapies have seen true success. Many of the same principles used to develop immunotherapy in tumors of the peripheral organs have been applied to brain tumor immunotherapy. The immune-specialized nature of the brain should call into question whether this approach is appropriate. Recent results from our own experiments require a rethinking of current dogma. Perhaps a CD8 T cell response is not sufficient for an organ as immunologically unique as the brain. Examination of previously elucidated principles of the brain’s immune-specialized status and known immunological preferences should generate discussion and experimentation to address the failure of current therapies. PMID:27472363

  18. CD8 T Cell-Independent Antitumor Response and Its Potential for Treatment of Malignant Gliomas.

    Science.gov (United States)

    Murphy, Katherine A; Griffith, Thomas S

    2016-01-01

    Malignant brain tumors continue to represent a devastating diagnosis with no real chance for cure. Despite an increasing list of potential salvage therapies, standard-of-care for these patients has not changed in over a decade. Immunotherapy has been seen as an exciting option, with the potential to offer specific and long lasting tumor clearance. The "gold standard" in immunotherapy has been the development of a tumor-specific CD8 T cell response to potentiate tumor clearance and immunological memory. While many advances have been made in the field of immunotherapy, few therapies have seen true success. Many of the same principles used to develop immunotherapy in tumors of the peripheral organs have been applied to brain tumor immunotherapy. The immune-specialized nature of the brain should call into question whether this approach is appropriate. Recent results from our own experiments require a rethinking of current dogma. Perhaps a CD8 T cell response is not sufficient for an organ as immunologically unique as the brain. Examination of previously elucidated principles of the brain's immune-specialized status and known immunological preferences should generate discussion and experimentation to address the failure of current therapies. PMID:27472363

  19. Cutting Edge: Resident Memory CD8 T Cells Express High-Affinity TCRs.

    Science.gov (United States)

    Frost, Elizabeth L; Kersh, Anna E; Evavold, Brian D; Lukacher, Aron E

    2015-10-15

    Tissue-resident memory T (TRM) cells serve as vanguards of antimicrobial host defense in nonlymphoid tissues, particularly at barrier epithelia and in organs with nonrenewable cell types (e.g., brain). In this study, we asked whether an augmented ability to sense Ag complemented their role as early alarms of pathogen invasion. Using mouse polyomavirus, we show that brain-resident mouse polyomavirus-specific CD8 T cells, unlike memory cells in the spleen, progressively increase binding to MHC class I tetramers and CD8 coreceptor expression. Using the two-dimensional micropipette adhesion-frequency assay, we show that TRM cells in brain, as well as in kidney, express TCRs with up to 20-fold higher affinity than do splenic memory T cells, whereas effector cells express TCRs of similar high affinity in all organs. Together, these data demonstrate that TRM cells retain high TCR affinity, which endows them with the high Ag sensitivity needed for front-line defense against infectious agents. PMID:26371252

  20. CD8 positive T cells express IL-17 in patients with chronic obstructive pulmonary disease

    Directory of Open Access Journals (Sweden)

    Eidelman David H

    2011-04-01

    Full Text Available Abstract Background Chronic obstructive pulmonary disease (COPD is a progressive and irreversible chronic inflammatory disease of the lung. The nature of the immune reaction in COPD raises the possibility that IL-17 and related cytokines may contribute to this disorder. This study analyzed the expression of IL-17A and IL-17F as well as the phenotype of cells producing them in bronchial biopsies from COPD patients. Methods Bronchoscopic biopsies of the airway were obtained from 16 COPD subjects (GOLD stage 1-4 and 15 control subjects. Paraffin sections were used for the investigation of IL-17A and IL-17F expression in the airways by immunohistochemistry, and frozen sections were used for the immunofluorescence double staining of IL-17A or IL-17F paired with CD4 or CD8. In order to confirm the expression of IL-17A and IL-17F at the mRNA level, a quantitative RT-PCR was performed on the total mRNA extracted from entire section or CD8 positive cells selected by laser capture microdissection. Results IL-17F immunoreactivity was significantly higher in the bronchial biopsies of COPD patients compared to control subjects (P P P P Conclusion These findings support the notion that Th17 cytokines could play important roles in the pathogenesis of COPD, raising the possibility of using this mechanism as the basis for novel therapeutic approaches.

  1. Intravacuolar Membranes Regulate CD8 T Cell Recognition of Membrane-Bound Toxoplasma gondii Protective Antigen

    Directory of Open Access Journals (Sweden)

    Jodie Lopez

    2015-12-01

    Full Text Available Apicomplexa parasites such as Toxoplasma gondii target effectors to and across the boundary of their parasitophorous vacuole (PV, resulting in host cell subversion and potential presentation by MHC class I molecules for CD8 T cell recognition. The host-parasite interface comprises the PV limiting membrane and a highly curved, membranous intravacuolar network (IVN of uncertain function. Here, using a cell-free minimal system, we dissect how membrane tubules are shaped by the parasite effectors GRA2 and GRA6. We show that membrane association regulates access of the GRA6 protective antigen to the MHC I pathway in infected cells. Although insertion of GRA6 in the PV membrane is key for immunogenicity, association of GRA6 with the IVN limits presentation and curtails GRA6-specific CD8 responses in mice. Thus, membrane deformations of the PV regulate access of antigens to the MHC class I pathway, and the IVN may play a role in immune modulation.

  2. The Qa-1 Dependent CD8+ T Cell Mediated Regulatory Pathway

    Institute of Scientific and Technical Information of China (English)

    Hong Jiang

    2005-01-01

    The immune system has evolved a variety of regulatory mechanisms to ensure the peripheral self-tolerance as well as the optimal capacity to elicit effective anti-infection immunity. At present, there is no satisfactory conceptual framework to explain how the peripheral immunity is regulated at a biological system level, which enables the immune system to perform its essential functions to mount effective immunity to virtually any foreign antigens but avoid harmful immune responses to self. In this regard, during the past few years, an "affinity/avidity model of peripheral T cell regulation" has been proposed and tested, which opens up a new paradigm to understand how the peripheral immunity, to both self and foreign antigens, is regulated. The paradigm is based on the discovery of a subset CD8+ T cells with TCRs which specifically recognize a unique set of self-peptides presented by the MHC class Ib molecule Qa-1 differentially expressed on T cells as a function of the affinity/avidity of T cell activation.These Qa-1 restricted CD8+ T cells represent an example of how the immune system utilizes a unified mechanism to regulate adaptive immunity to both self and foreign antigens. Thus, by selectively down-regulating T cells of intermediate affinity/avidity, to any antigens, the immune system controls the adaptive immunity without the necessity to distinguish self from non-self in the periphery at the level of T cell regulation.

  3. Proliferation of CD8-positive T cells in blood vessels of rat renal allografts.

    Science.gov (United States)

    Grau, V; Fuchs-Moll, G; Wilker, S; Weimer, R; Padberg, W

    2011-09-01

    It is still disputed in which anatomical compartments of allograft recipients T-cells proliferate. After experimental renal transplantation, host monocytes and lymphocytes accumulate in the lumina of graft blood vessels. In this study, we test the hypothesis that T lymphocytes proliferate in the vascular bed of the graft. Kidneys were transplanted in the Dark Agouti to Lewis rat strain combination, an established experimental model for acute rejection. Isogeneic transplantation was performed as a control. Cells in the S-phase of mitosis were detected in situ three days posttransplantation by pulse-labeling with BrdU and by immunohistochemical detection of the proliferating cell nuclear antigen (PCNA). More than 20% of all T-cells in the lumina of allograft blood vessels incorporated BrdU and approximately 30% of them expressed PCNA. In the blood vessels of isografts as well as in other organs of allograft recipients, only few BrdU(+) cells were detected. A majority of the BrdU(+) cells in graft blood vessels expressed CD8. In conclusion, we demonstrate that CD8(+) T lymphocytes proliferate in the lumina of the blood vessels of renal allografts during the onset of acute rejection.

  4. Linear fidelity in quantification of anti-viral CD8+ T cells.

    Science.gov (United States)

    Flesch, Inge E A; Hollett, Natasha A; Wong, Yik Chun; Tscharke, David C

    2012-01-01

    Enumeration of anti-viral CD8(+) T cells to make comparisons between mice, viruses and vaccines is a frequently used approach, but controversy persists as to the most appropriate methods. Use of peptide-MHC tetramers (or variants) and intracellular staining for cytokines, in particular IFNγ, after a short ex vivo stimulation are now common, as are a variety of cytotoxicity assays, but few direct comparisons have been made. It has been argued that use of tetramers leads to the counting of non-functional T cells and that measurement of single cytokines will fail to identify cells with alternative functions. Further, the linear range of these methods has not been tested and this is required to give confidence that relative quantifications can be compared across samples. Here we show for two acute virus infections and CD8(+) T cells activated in vitro that DimerX (a tetramer variant) and intracellular staining for IFNγ, alone or in combination with CD107 to detect degranulation, gave comparable results at the peak of the response. Importantly, these methods were highly linear over nearly two orders of magnitude. In contrast, in vitro and in vivo assays for cytotoxicity were not linear, suffering from high background killing, plateaus in maximal killing and substantial underestimation of differences in magnitude of responses. PMID:22745779

  5. Linear fidelity in quantification of anti-viral CD8+ T cells.

    Directory of Open Access Journals (Sweden)

    Inge E A Flesch

    Full Text Available Enumeration of anti-viral CD8(+ T cells to make comparisons between mice, viruses and vaccines is a frequently used approach, but controversy persists as to the most appropriate methods. Use of peptide-MHC tetramers (or variants and intracellular staining for cytokines, in particular IFNγ, after a short ex vivo stimulation are now common, as are a variety of cytotoxicity assays, but few direct comparisons have been made. It has been argued that use of tetramers leads to the counting of non-functional T cells and that measurement of single cytokines will fail to identify cells with alternative functions. Further, the linear range of these methods has not been tested and this is required to give confidence that relative quantifications can be compared across samples. Here we show for two acute virus infections and CD8(+ T cells activated in vitro that DimerX (a tetramer variant and intracellular staining for IFNγ, alone or in combination with CD107 to detect degranulation, gave comparable results at the peak of the response. Importantly, these methods were highly linear over nearly two orders of magnitude. In contrast, in vitro and in vivo assays for cytotoxicity were not linear, suffering from high background killing, plateaus in maximal killing and substantial underestimation of differences in magnitude of responses.

  6. Sustained CD8+ T cell memory inflation after infection with a single-cycle cytomegalovirus.

    Directory of Open Access Journals (Sweden)

    Christopher M Snyder

    2011-10-01

    Full Text Available Cytomegalovirus (CMV is a β-herpesvirus that establishes a lifelong latent or persistent infection. A hallmark of chronic CMV infection is the lifelong persistence of large numbers of virus-specific CD8+ effector/effector memory T cells, a phenomenon called "memory inflation". How the virus continuously stimulates these T cells without being eradicated remains an enigma. The prevailing view is that CMV establishes a low grade "smoldering" infection characterized by tiny bursts of productive infection which are rapidly extinguished, leaving no detectable virus but replenishing the latent pool and leaving the immune system in a highly charged state. However, since abortive reactivation with limited viral gene expression is known to occur commonly, we investigated the necessity for virus reproduction in maintaining the inflationary T cell pool. We inhibited viral replication or spread in vivo using two different mutants of murine CMV (MCMV. First, famcyclovir blocked the replication of MCMV encoding the HSV Thymidine Kinase gene, but had no impact on the CD8+ T cell memory inflation once the infection was established. Second, MCMV that lacks the essential glycoprotein L, and thus is completely unable to spread from cell to cell, also drove memory inflation if the virus was administered systemically. Our data suggest that CMV which cannot spread from the cells it initially infects can repeatedly generate viral antigens to drive memory inflation without suffering eradication of the latent genome pool.

  7. 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...... in mice with a mutated CD3gamma di-leucine-based motif. The CD3gamma mutation did not impair early TCR signaling, nor did it compromise recruitment or proliferation of virus-specific T cells, but it increased the apoptosis rate of the activated T cells by increasing down-regulation of the...... antiapoptotic 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...

  8. 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...... in mice with a mutated CD3gamma di-leucine-based motif. The CD3gamma mutation did not impair early TCR signaling, nor did it compromise recruitment or proliferation of virus-specific T cells, but it increased the apoptosis rate of the activated T cells by increasing down-regulation of the...... antiapoptotic 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...

  9. HLA-E-restricted cross-recognition of allogeneic endothelial cells by CMV-associated CD8 T cells: a potential risk factor following transplantation.

    Directory of Open Access Journals (Sweden)

    Mathilde Allard

    Full Text Available Although association between CMV infection and allograft rejection is well admitted, the precise mechanisms involved remain uncertain. Here, we report the characterization of an alloreactive HLA-E-restricted CD8 T cell population that was detected in the PBL of a kidney transplant patient after its CMV conversion. This monoclonal CD8 T cell population represents a sizable fraction in the blood (3% of PBL and is characterized by an effector-memory phenotype and the expression of multiple NK receptors. Interestingly, these unconventional T cells display HLA-E-dependent reactivity against peptides derived from the leader sequences of both various HCMV-UL40 and allogeneic classical HLA-I molecules. Consequently, while HLA-E-restricted CD8 T cells have potential to contribute to the control of CMV infection in vivo, they may also directly mediate graft rejection through recognition of peptides derived from allogeneic HLA-I molecules on graft cells. Therefore, as HLA-E expression in nonlymphoid organs is mainly restricted to endothelial cells, we investigated the reactivity of this HLA-E-restricted T cell population towards allogeneic endothelial cells. We clearly demonstrated that CMV-associated HLA-E-restricted T cells efficiently recognized and killed allogeneic endothelial cells in vitro. Moreover, our data indicate that this alloreactivity is tightly regulated by NK receptors, especially by inhibitory KIR2DL2 that strongly prevents TCR-induced activation through recognition of HLA-C molecules. Hence, a better evaluation of the role of CMV-associated HLA-E-restricted T cells in transplantation and of the impact of HLA-genotype, especially HLA-C, on their alloreactivity may determine whether they indeed represent a risk factor following organ transplantation.

  10. CD3+CD8+CD161high Tc17 cells are depleted in HIV-Infection and related to the level of immune reconstitution

    Directory of Open Access Journals (Sweden)

    S Nielsen

    2012-11-01

    Full Text Available Purpose: The existence of CD8+cells with pro-inflammatory properties referred to as Tc17 cells has recently been acknowledged. While it is evident that CD4+pro-inflammatory IL-17-producing Th17 cells are important in the regulation of chronic viral infections, the role of Tc17 cells is largely unknown. Tc17 cells are characterized by expression of high levels of CD161 (CD161high. We hypothesized that Tc17 cells are involved in immune regulation in HIV- infection. Methods: 67 HIV-infected patients were included in a cross-sectional study. All patients had nadir CD4 counts<200 cells/µL, fully suppressed viral loads, and had been on cART for at least 2 years. Three groups were defined: Immunological Non Responders (INR, CD4 counts<200 cells/µL, Intermediate Responders (IR, CD4 counts 200–500 cells/µL, and Responders (RES, CD4 counts>500 cells/µL. Percentages of CD8+cells expressing CD3+CD8+CD161high were evaluated using flow cytometry. Additionally, Production of IL-17 in phytohaemagglutinin(PHA-stimulated peripheral blood was determined by Luminex. For statistics Kruskall Wallis test followed by Mann-Whitney U test was used. Data are given as medians. Summary of results: INR had lower levels of Tc17 cells compared to IR, RES and controls (0.4%, 1.0%, 2.1%, 6.1%, p values<0.05. All HIV-infected patients had lower levels than controls (p values<0.0001. Furthermore, all HIV-infected patients displayed lower production of IL-17 in peripheral blood compared to controls (p values<0.001.

  11. T cell metabolism. The protein LEM promotes CD8⁺ T cell immunity through effects on mitochondrial respiration.

    Science.gov (United States)

    Okoye, Isobel; Wang, Lihui; Pallmer, Katharina; Richter, Kirsten; Ichimura, Takahuru; Haas, Robert; Crouse, Josh; Choi, Onjee; Heathcote, Dean; Lovo, Elena; Mauro, Claudio; Abdi, Reza; Oxenius, Annette; Rutschmann, Sophie; Ashton-Rickardt, Philip G

    2015-05-29

    Protective CD8(+) T cell-mediated immunity requires a massive expansion in cell number and the development of long-lived memory cells. Using forward genetics in mice, we identified an orphan protein named lymphocyte expansion molecule (LEM) that promoted antigen-dependent CD8(+) T cell proliferation, effector function, and memory cell generation in response to infection with lymphocytic choriomeningitis virus. Generation of LEM-deficient mice confirmed these results. Through interaction with CR6 interacting factor (CRIF1), LEM controlled the levels of oxidative phosphorylation (OXPHOS) complexes and respiration, resulting in the production of pro-proliferative mitochondrial reactive oxygen species (mROS). LEM provides a link between immune activation and the expansion of protective CD8(+) T cells driven by OXPHOS and represents a pathway for the restoration of long-term protective immunity based on metabolically modified cytotoxic CD8(+) T cells.

  12. 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...... correlated with diminished recruitment of virus-specific CD8(+) T cells to the infected lung, delayed virus clearance, and increased morbidity. The splenic CD8(+) set generated during the recall response in Ig(-/-) mice primed at least 6 months previously showed a normal profile of gamma interferon...... production subsequent to short-term, in vitro stimulation with viral peptide, irrespective of a concurrent CD4(+) T-cell response. Both the magnitude and the localization profiles of virus-specific CD8(+) T cells, though perhaps not their functional characteristics, are thus modified in mice lacking CD4(+) T...

  13. Detection of CD4+ and CD8 + T-lymphocytes with the optofluidic ring resonator (OFRR) biosensor

    Science.gov (United States)

    Gohring, John T.; Fan, Xudong

    2009-05-01

    We have demonstrated the use of the Opto-Fluidic ring resonator (OFRR) to achieve the label-free detection of CD4+ and CD8+ T-Lymphocytes. The OFRR sensing technology combines microfluidics and optical sensing in a small platform that achieves rapid detection. In this work, white blood cells were obtained from healthy blood and the concentration altered to reflect CD4 and CD8 concentrations of HIV infected individuals. The OFRR was modified to effectively capture these receptors located on T-Lymphocytes and obtain a sensing signal through interaction with an evanescent field. Results show isolation of CD4+ and CD8+ T-Lymphocytes at medically significant levels. This work will lead to a device that can provide a CD4 and CD8 count to measure HIV progression in a low cost sensing setup.

  14. Prevalence of Oral Manifestations and Their Association with CD4/CD8 Ratio and HIV Viral Load in South India

    Directory of Open Access Journals (Sweden)

    Sharma Gaurav

    2011-01-01

    Full Text Available The objective of the present research was to determine the prevalence of oral manifestations in an HIV infected population from south India and evaluate their association with HIV viral load and CD4/CD8 ratio. Intraoral examination of 103 patients, whose CD4/CD8 ratio was available, were conducted. HIV viral loads were available for thirty patients only. The prevalence of oral manifestations was 80.6% (83/103. The most common oromucosal lesion was erythematous candidiasis (EC (38.8% followed by melanotic hyperpigmentation (35.9%. Patients having any oral manifestation had a mean CD4/CD8 ratio of 0.24. EC had positive predictive value of 85.0% for CD4/CD8 ratio 20,000 copies/mL (20,000 copies/mL.

  15. Changes of CD8+CD28- T regulatory cells in rat model of colitis induced by 2,4-dinitrofluorobenzene

    Institute of Scientific and Technical Information of China (English)

    Wen-Bin Xiao; Yu-Lan Liu

    2003-01-01

    AIM: To determine the changes of CD8+ T subsets especially CD8+CD28- T regulatory cells in rat model of experimental colitis induced by 2,4-dinitrofiuorobenzene (DNFB).METHODS: The rat model of experimental colitis was induced by enema with DNFB. Ten days later, colonic intraepithelial and splenic lymphocytes were isolated from colitis animals (n=16) and controls (n=8). The proportion of CD8+ T cells, CD8+CD28+ T cells and CD8+CD28- T regulatory cells were determined by flow cytometry.RESULTS: The model of experimental colitis was successfully established by DNFB that was demonstrated by bloody diarrhea, weight loss and colonic histopathology. The proportion of CD8+ T cells in either splenic or colonic intraepithelial lymphocytes was not significantly different between colitis animals and controls (spleen: 34.6±7.24 % vs33.5±9.41%,colon: 14.0±8.93 % vs 18.0±4.06 %, P>0.05). But CD8+CD28-T regulatory cells from colitis animals were significantly more than those from controls (spleen: 11.3±2.26 % vs5.64±1.01%,colon: 6.50±5.37 % vs 1.07±0.65 %, P<0.05). In contrast,CD8+CD28+ T cells from colitis animals were less than those from controls (spleen: 23.3±6.14 % vs27.8±9.70 %, P=0.06;colon: 7.52±4.18 % vs 16.9±4.07 %, P<0.05). The proportion of CD8+CD28- T regulatory cells in splenic and colonintraepithelial CD8+ T cells from colitis animals was higher than that from controls (spleen: 33.3±5.49 % vs 18.4±7.26 %,colon: 46.0±14.3 % vs6.10±3.72 %, P<0.005).CONCLUSION: Experimental colitis of rats can be induced by DNFB with simplicity and good reproducibility. The proportion of CD8+CD28- T regulatory cells in rats with experimental colitis is increased, which may be associated with the pathogenesis of colitis.

  16. Induction of a Cross-Reactive CD8+ T Cell Response following Foot-and-Mouth Disease Virus Vaccination▿

    OpenAIRE

    Guzman, Efrain; Taylor, Geraldine; Charleston, Bryan; Ellis, Shirley A

    2010-01-01

    Foot-and-mouth disease virus (FMDV) causes a highly contagious infection in cloven-hoofed animals. Current inactivated FMDV vaccines generate short-term, serotype-specific protection, mainly through neutralizing antibody. An improved understanding of the mechanisms of protective immunity would aid design of more effective vaccines. We have previously reported the presence of virus-specific CD8+ T cells in FMDV-vaccinated and -infected cattle. In the current study, we aimed to identify CD8+ T ...

  17. Characterization of Liver CD8 T Cell Subsets that are Associated with Protection Against Pre-erythrocytic Plasmodium Parasites.

    Science.gov (United States)

    Zarling, Stasya; Krzych, Urszula

    2015-01-01

    Murine models of malaria, such as Plasmodium berghei (Pb) and Plasmodium yoelii (Py), have been used for decades to identify correlates of protection associated with immunization using radiation-attenuated sporozoites (RAS). To date, RAS is the only known immunization regimen to consistently deliver 100 % sterilizing immunity and is considered the "gold standard" of protection against malaria. The ability to isolate lymphocytes directly from the liver of immune mice has facilitated the identification of correlates of protection at the site of infection. Liver CD