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Sample records for cd8 epitope display

  1. CYTOMEGALOVIRUS VECTORS VIOLATE CD8+ T CELL EPITOPE RECOGNITION PARADIGMS

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    Hansen, Scott G.; Sacha, Jonah B.; Hughes, Colette M.; Ford, Julia C.; Burwitz, Benjamin J.; Scholz, Isabel; Gilbride, Roxanne M.; Lewis, Matthew S.; Gilliam, Awbrey N.; Ventura, Abigail B.; Malouli, Daniel; Xu, Guangwu; Richards, Rebecca; Whizin, Nathan; Reed, Jason S.

    2013-01-01

    CD8+ T cell responses focus on a small fraction of pathogen- or vaccine-encoded peptides, and for some pathogens, these restricted recognition hierarchies limit the effectiveness of anti-pathogen immunity. We found that simian immunodeficiency virus (SIV) protein-expressing Rhesus Cytomegalovirus (RhCMV) vectors elicit SIV-specific CD8+ T cells that recognize unusual, diverse and highly promiscuous epitopes, including dominant responses to epitopes restricted by class II major histocompatibil...

  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. PMID:26552001

  3. 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; Dasgupta, Gargi; Bettahi, Ilham; Nguyen, Alex; Wu, Michelle; Zhu, Xiaoming; Mohebbi, Amir; Buus, Soren; Wechsler, Steven L; Nesburn, Anthony B; BenMohamed, Lbachir

    2008-01-01

    epitopes identified to date. In this study, we screened the HSV-1 gD amino acid sequence for HLA-A*0201-restricted epitopes using several predictive computational algorithms and identified 10 high probability CD8+ T cell epitopes. Synthetic peptides corresponding to four of these epitopes, each nine to 10...

  4. 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

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

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

    2016-01-01

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

  6. 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.

  7. 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.

  8. Human lymph-node CD8+ T cells display an altered phenotype during systemic autoimmunity

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    Ramwadhdoebe, Tamara H; Hähnlein, Janine; van Kuijk, Bo J; Choi, Ivy Y; van Boven, Leonard J; Gerlag, Danielle M; Tak, Paul P; van Baarsen, Lisa G

    2016-01-01

    Although many studies are focused on auto-reactive CD4+ T cells, the precise role of CD8+ T cells in autoimmunity is poorly understood. The objective of this study is to provide more insight into the phenotype and function CD8+ T cells during the development of autoimmune disease by studying CD8+ T cells in human lymph-node biopsies and peripheral blood obtained during the earliest phases of rheumatoid arthritis (RA). Here, we show that lymphoid pro-inflammatory CD8+ T cells exhibit a less-responsive phenotype already during the earliest phases of autoimmunity compared with healthy individuals. We found an increase in CD8+ memory T cells in lymphoid tissue during the earliest phases of autoimmunity, even before clinical onset of RA, accompanied by an increased frequency of non-circulating or recently activated (CD69+) CD8+ T cells in lymphoid tissue and peripheral blood. Importantly, lymphoid pro-inflammatory CD8+IL-17A+ T cells displayed a decreased capacity of cytokine production, which was related to disease activity in early RA patients. In addition, a decreased frequency of regulatory CD8+IL-10+ T cells in peripheral blood was also related to disease activity in early RA patients. Our results suggest that different CD8+ T-cell subsets are affected already during the earliest phases of systemic autoimmunity. PMID:27195110

  9. 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

  10. 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...

  11. 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.

  12. 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

  13. 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; Thomsen, Allan Randrup

    2004-01-01

    Induction of a monospecific antiviral CD8+ T cell response may pose a risk to the host due to the narrow T cell response induced. At the individual level, this may result in selection of CD8+ T cell escape variants, particularly during chronic viral infection. Second, prior immunization toward a...... single dominant epitope may suppress the response to other viral epitopes, and this may lead to increased susceptibility to reinfection with escape variants circulating in the host population. To address these issues, we induced a memory response consisting solely of monospecific, CD8+ T cells by use of...... DNA vaccines encoding immunodominant epitopes of lymphocytic choriomeningitis virus (LCMV). We analyzed the spectrum of the CD8+ T cell response and the susceptibility to infection in H-2(b) and H-2(d) mice. Priming for a monospecific, CD8+ T cell response did not render mice susceptible to viral...

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

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    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...

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

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    Yaakov Maman

    2011-10-01

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

  16. 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

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

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

    2011-12-31

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-08-15

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

  19. 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

  20. 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; Ladell, Kristin; Buus, Anette Stryhn; Koofhethile, Catherine; Brener, Jacqui; Chen, Fabian; Riddell, Lynn; Graziano, Luzzi; Klenerman, Paul; Leslie, Alasdair; Buus, Søren; Price, David A; Goulder, Philip

    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 are......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...

  1. 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

  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. 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...

  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

    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.

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

    Directory of Open Access Journals (Sweden)

    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

  7. 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; Buus, Anette Stryhn; Buus, Søren; Karlsson, Annika; Vinner, Lasse; Goulder, Philip; Fomsgaard, Anders

    2012-01-01

    The high HIV-1 prevalence, up to 4.6% in Guinea-Bissau, West Africa, makes it a relevant location for testing of therapeutic vaccines. With the aim of performing a clinical study in Guinea-Bissau, after first testing the vaccine for safety in Denmark, Europe, we here describe the design 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...

  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. Gene Expression Driven by a Strong Viral Promoter in MVA Increases Vaccination Efficiency by Enhancing Antibody Responses and Unmasking CD8+ T Cell Epitopes

    Directory of Open Access Journals (Sweden)

    Pablo D. Becker

    2014-07-01

    Full Text Available Viral vectors are promising tools for vaccination strategies and immunotherapies. However, CD8+ T cell responses against pathogen-derived epitopes are usually limited to dominant epitopes and antibody responses to recombinant encoded antigens (Ags are mostly weak. We have previously demonstrated that the timing of viral Ag expression in infected professional Ag-presenting cells strongly shapes the epitope immunodominance hierarchy. T cells recognizing determinants derived from late viral proteins have a clear disadvantage to proliferate during secondary responses. In this work we evaluate the effect of overexpressing the recombinant Ag using the modified vaccinia virus early/late promoter H5 (mPH5. Although the Ag-expression from the natural promoter 7.5 (P7.5 and the mPH5 seemed similar, detailed analysis showed that mPH5 not only induces higher expression levels than P7.5 during early phase of infection, but also Ag turnover is enhanced. The strong overexpression during the early phase leads to broader CD8 T cell responses, while preserving the priming efficiency of stable Ags. Moreover, the increase in Ag-secretion favors the induction of strong antibody responses. Our findings provide the rationale to develop new strategies for fine-tuning the responses elicited by recombinant modified vaccinia virus Ankara by using selected promoters to improve the performance of this viral vector.

  10. Cytomegalovirus Misleads Its Host by Priming of CD8 T Cells Specific for an Epitope Not Presented in Infected Tissues

    OpenAIRE

    Holtappels, Rafaela; Podlech, Jürgen; Pahl-Seibert, Marcus-Folker; Jülch, Markus; Thomas, Doris; Simon, Christian O.; Wagner, Markus; Reddehase, Matthias J.

    2004-01-01

    Cytomegaloviruses (CMVs) code for several proteins that inhibit the presentation of antigenic peptides to CD8 T cells. Although the molecular mechanisms of CMV interference with the major histocompatibility complex class I pathway are long understood, surprisingly little evidence exists to support a role in vivo. Here we document the first example of the presentation of an antigenic peptide being blocked by a CMV immune evasion protein in organs relevant to CMV disease. Although this Db-restr...

  11. 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...

  12. 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.

    Directory of Open Access Journals (Sweden)

    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

  13. 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.

  14. Activated human gammadelta T cells as stimulators of specific CD8+ T-cell responses to subdominant Epstein Barr virus epitopes: potential for immunotherapy of cancer.

    Science.gov (United States)

    Landmeier, Silke; Altvater, Bianca; Pscherer, Sibylle; Juergens, Heribert; Varnholt, Lena; Hansmeier, Anna; Bollard, Catherine M; Moosmann, Andreas; Bisping, Guido; Rossig, Claudia

    2009-04-01

    The efficacy of current cancer vaccines is limited by the functional heterogeneity and poor availability and expansion of professional antigen-presenting cells (APCs). Besides their potent innate effector properties, gammadelta T cells have been suggested to be involved in the initiation and maintenance of adaptive immune responses. Here, we investigated the capacity of human gammadelta T cells to induce expansion of virus-specific T cells to Epstein Barr virus (EBV) antigens. Aminobisphosphonate-stimulated human peripheral blood-derived gammadelta T cells (Vgamma2+Vdelta2+) acquired a dual phenotype characteristic for both APCs and effector memory T cells. Coincubation of activated gammadelta T cells pulsed with human leukocyte antigen-restricted epitopes of either the highly stimulatory EBV lytic cycle antigen Bam H1 Z fragment leftward open reading frame or the tumor-associated latent EBV antigen latent membrane protein 2a (LMP2a) with autologous peripheral blood lymphocytes induced selective expansion of peptide-specific, fully functional CD3CD8 cytolytic effector memory T cells. Furthermore, gammadelta T APCs efficiently processed and presented endogenous antigen, as demonstrated by the capacity of LMP2a gene-transduced gammadelta T cells to induce expansion of T cells with broad specificity for various LMP2a peptides. The capacity of autologous gammadelta T cells to induce LMP2a-specific autologous cytotoxic T lymphocytes was confirmed in 2 patients with Hodgkin lymphoma. In summary, bisphosphonate-activated human gammadelta T cells stimulate expansion of cytotoxic effector T cells specific for both subdominant and dominant viral epitopes and thus show promise as a novel source of efficient APCs for immunotherapy of viral and malignant disease. PMID:19242369

  15. Activated human γδ T cells as stimulators of specific CD8+ T cell responses to subdominant Epstein Barr virus (EBV) epitopes: Potential for immunotherapy of cancer

    Science.gov (United States)

    Landmeier, Silke; Altvater, Bianca; Pscherer, Sibylle; Juergens, Heribert; Varnholt, Lena; Hansmeier, Anna; Bollard, Catherine M.; Moosmann, Andreas; Bisping, Guido; Rossig, Claudia

    2011-01-01

    The efficacy of current cancer vaccines is limited by the functional heterogeneity and poor availability and expansion of professional antigen-presenting cells (APCs). Besides their potent innate effector properties, γδ T cells have been suggested to be involved in the initiation and maintenance of adaptive immune responses. Here, we investigated the capacity of human γδ T cells to induce expansion of virus-specific T cells to Epstein Barr virus (EBV) antigens. Aminobisphosphonate-stimulated human peripheral blood-derived γδ T cells (Vγ9+Vδ2+) acquired a dual phenotype characteristic for both APCs and effector memory T cells. Coincubation of activated γδ T cells pulsed with HLA-restricted epitopes of either the highly stimulatory EBV lytic cycle antigen BZLF-1 or the tumor-associated latent EBV antigen LMP2a with autologous peripheral blood lymphocytes induced selective expansion of peptide-specific, fully functional CD3+CD8+ cytolytic effector memory T cells. Furthermore, γδ T-APCs efficiently processed and presented endogenous antigen, as demonstrated by the capacity of LMP2a gene-transduced γδ T cells to induce expansion of T cells with broad specificity for various LMP2a peptides. The capacity of autologous γδ T cells to induce LMP2a-specific autologous CTLs was confirmed in two patients with Hodgkin lymphoma. In summary, bisphosphonate-activated human γδ T cells stimulate expansion of cytotoxic effector T cells specific for both subdominant and dominant viral epitopes and thus show promise as a novel source of efficient APCs for immunotherapy of viral and malignant disease. PMID:19242369

  16. Hepatitis B virus core antigen epitopes presented by HLA-A2 single-chain trimers induce functional epitope-specific CD8+ T-cell responses in HLA-A2.1/Kb transgenic mice.

    Science.gov (United States)

    Zhang, Yuxia; Li, Shu; Shan, Ming; Pan, Xuwen; Zhuang, Ke; He, Lihua; Gould, Keith; Tien, Po

    2007-05-01

    The potency of CD8+ cytotoxic T lymphocyte (CTL) responses toward core antigen has been shown to affect the outcomes of hepatitis B virus (HBV) infection. Since single-chain trimers (SCT) composed of peptide epitope beta2-microglobulin (beta2m) and major histocompatibility complex (MHC) class I heavy chain covalently linked together in a single molecule have been shown to stimulate efficient CTL responses, we investigated the properties of human leucocyte antigen (HLA)-A2 SCTs encoding the HBV core antigen (HBcAg) epitopes C(18-27) and C(107-115). Transfection of NIH-3T3 cells with pcDNA3.0-SCT-C(18-27) and SCT-C(107-115) leads to stable presentation of HBcAg epitopes at the cell surface. HLA-A2.1/Kb transgenic mice vaccinated with the SCT constructs, either as a DNA vaccine alone or followed by a boost with recombinant vaccinia virus, were shown to generate HBcAg-specific CTL responses by enzyme-linked immunospot assay (ELISPOT) and in vitro interferon-gamma release experiments. HBcAg-specific CTLs from vaccinated HLA-A2.1/Kb transgenic mice were able to inhibit HBV surface and e antigen expression as indicated by HepG2.2.15 cells. Our data indicate that a DNA vaccine encoding a human HLA-A2 SCT with HBV epitopes can lead to stable, enhanced HBV core antigen presentation, and may be useful for the control of HBV infection in HLA-A2-positive HBV carriers. PMID:17244158

  17. 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

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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; Buus, Søren; Fomsgaard, Anders

    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......-A*0201 binding CTL epitopes. The seven peptides were simultaneously presented on the same dendritic cell (DC) or on separate DCs before immunization to one or different lymphoid compartments. Data from this study showed that the T-cell response, as measured by cytolytic activity and gamma-interferon (IFN......-gamma)-producing CD8(+) T cells, mainly focused on two of seven administered epitopes. The magnitude of individual T-cell responses induced by immunization with multiple peptides correlated with their individual immunogenicity that depended on major histocompatibility class I binding and was not influenced by mode of...

  3. 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

  4. 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; Buus, Søren; Lemonnier, Francois; Reifenberg, Kurt; Reimann, Jörg; Schirmbeck, Reinhold

    2009-01-01

    ) 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...

  5. 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

  6. 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

  7. 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.

  8. 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; Buus, S; Berzofsky, J A; Hoffman, S L

    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-2k......) mice have been shown to have CD8+ CTL activity against a 23-amino-acid region of the PfCSP (residues 368 to 390 from the PfCSP 7G8 sequence) that is too long to bind directly to class I major histocompatibility complex molecules. To identify within this 23-amino-acid peptide a shorter peptide that...... binds to an H-2k class I major histocompatibility molecule, a primarily CD8+ (97.8%) T-cell line (PfCSP TCL.1) was produced by immunizing B10.BR mice with recombinant vaccinia virus expressing the PfCSP and stimulating in vitro spleen cells from these immunized mice with L cells transfected with the Pf...

  9. 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.

  10. 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

  11. 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.

  12. 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.......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...... epitopes were modified as anchor-optimized peptides to improve immunogenicity and delivered on autologous monocyte-derived dendritic cells (MDDCs). METHODS:: Twelve treatment-naïve HLA-A*0201 HIV-1-infected Danish individuals received 1 x 10 MDDCs subcutaneously (s.c.) (weeks 0, 2, 4 and 8), pulsed with...

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

    OpenAIRE

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

    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 investigat...

  14. 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.

  15. 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

    inserted. 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...

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

    DEFF Research Database (Denmark)

    Stentebjerg-Olesen, Bodil; Pallesen, Lars; Jensen, Lars Bogø; Christiansen, Gunnar; Klemm, Per

    inserted. 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...

  17. 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.

  18. Epitope mapping porcine reproductive and respiratory syndrome virus by phage display: the nsp2 fragment of the replicase polyprotein contains a cluster of B-cell epitopes

    DEFF Research Database (Denmark)

    Oleksiewicz, M.B.; Bøtner, Anette; Toft, P.; Normann, Preben; Storgaard, Torben

    2001-01-01

    We screened phage display libraries of porcine reproductive and respiratory syndrome virus (PRRSV) protein fragments with sera from experimentally infected pigs to identify linear B-cell epitopes that are commonly recognized during infection in vivo. We identified 10 linear epitope sites (ES) 11 to...

  19. 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.

  20. 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.

  1. 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

  2. Recovery of CD8+ T-cell function during systemic chemotherapy in advanced ovarian cancer.

    Science.gov (United States)

    Coleman, Sharon; Clayton, Aled; Mason, Malcolm D; Jasani, Bharat; Adams, Malcolm; Tabi, Zsuzsanna

    2005-08-01

    Immunologic approaches are emerging as new treatment options in several types of cancer. However, whereas the ability of patients to develop potent CD8+ T-cell responses is crucial for efficient antitumor responses, immunocompetence and T-cell function are not tested routinely in patients entering immunotherapy. The objective of our study was to monitor T-cell function in advanced cancer and during chemotherapy. CD8+ T-cell function of 21 patients with advanced ovarian cancer (stages III-IV) was assessed by cytokine flow cytometry following stimulation of 42 PBMC samples with a panel of synthetic viral peptides in vitro, consisting of pan-Caucasian epitopes. CD8+ T-cell responses were significantly lower in patients with high levels (>200 units/mL) of Ca125 (marker of tumor load and progression) than in those with low Ca125 levels (P = 0.0013). In longitudinal studies of nine patients, chemotherapy was associated with decreasing Ca125 levels in seven cases and also with improvement or maintenance of CD8+ T-cell function in seven cases. After the full course of chemotherapy, five of nine patients in remission displayed potent CD8+ T-cell responses, whereas four of nine patients in progression displayed low or decreasing T-cell responses, pointing toward a correlation between T-cell function and clinical response. Our results show for the first time that CD8+ T-cell function is not permanently suppressed in advanced cancer and successful chemotherapy is associated with improved antigen-specific T-cell reactivity. We suggest that functional assays determining T-cell immunocompetence can be valuable tools for optimizing cancer immunotherapy for improved clinical success. PMID:16061686

  3. Epitope selection from an uncensored peptide library displayed on avian leukosis virus

    International Nuclear Information System (INIS)

    Phage display libraries have provided an extraordinarily versatile technology to facilitate the isolation of peptides, growth factors, single chain antibodies, and enzymes with desired binding specificities or enzymatic activities. The overall diversity of peptides in phage display libraries can be significantly limited by Escherichia coli protein folding and processing machinery, which result in sequence censorship. To achieve an optimal diversity of displayed eukaryotic peptides, the library should be produced in the endoplasmic reticulum of eukaryotic cells using a eukaryotic display platform. In the accompanying article, we presented experiments that demonstrate that polypeptides of various sizes could be efficiently displayed on the envelope glycoproteins of a eukaryotic virus, avian leukosis virus (ALV), and the displayed polypeptides could efficiently attach to cognate receptors without interfering with viral attachment and entry into susceptible cells. In this study, methods were developed to construct a model library of randomized eight amino acid peptides using the ALV eukaryotic display platform and screen the library for specific epitopes using immobilized antibodies. A virus library with approximately 2 x 106 different members was generated from a plasmid library of approximately 5 x 106 diversity. The sequences of the randomized 24 nucleotide/eight amino acid regions of representatives of the plasmid and virus libraries were analyzed. No significant sequence censorship was observed in producing the virus display library from the plasmid library. Different populations of peptide epitopes were selected from the virus library when different monoclonal antibodies were used as the target. The results of these two studies clearly demonstrate the potential of ALV as a eukaryotic platform for the display and selection of eukaryotic polypeptides libraries

  4. Expression and immunological characterization of cardamom mosaic virus coat protein displaying HIV gp41 epitopes.

    Science.gov (United States)

    Damodharan, Subha; Gujar, Ravindra; Pattabiraman, Sathyamurthy; Nesakumar, Manohar; Hanna, Luke Elizabeth; Vadakkuppattu, Ramanathan D; Usha, Ramakrishnan

    2013-05-01

    The coat protein of cardamom mosaic virus (CdMV), a member of the genus Macluravirus, assembles into virus-like particles when expressed in an Escherichia coli expression system. The N and C-termini of the coat protein were engineered with the Kennedy peptide and the 2F5 and 4E10 epitopes of gp41 of HIV. The chimeric proteins reacted with sera from HIV positive persons and also stimulated secretion of cytokines by peripheral blood mononuclear cells from these persons. Thus, a system based on the coat protein of CdMV can be used to display HIV-1 antigens. PMID:23668610

  5. 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

  6. 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

  7. Tomato bushy stunt virus (TBSV), a versatile platform for polyvalent display of antigenic epitopes and vaccine design

    International Nuclear Information System (INIS)

    Viruses-like particles (VLPs) are frequently being used as platforms for polyvalent display of foreign epitopes of interest on their capsid surface to improve their presentation enhancing the antigenicity and host immune response. In the present study, we used the VLPs of Tomato bushy stunt virus (TBSV), an icosahedral plant virus, as a platform to display 180 copies of 16 amino acid epitopes of ricin toxin fused to the C-terminal end of a modified TBSV capsid protein (NΔ52). Expression of the chimeric recombinant protein in insect cells resulted in spontaneous assembly of VLPs displaying the ricin epitope. Cryo-electron microscopy and image reconstruction of the chimeric VLPs at 22 A resolution revealed the locations and orientation of the ricin epitope exposed on the TBSV capsid surface. Furthermore, injection of chimeric VLPs into mice generated antisera that detected the native ricin toxin. The ease of fusing of short peptides of 15-20 residues and their ability to form two kinds (T = 1, T = 3) of bio-nanoparticles that result in the display of 60 or 180 copies of less constrained and highly exposed antigenic epitopes makes TBSV an attractive and versatile display platform for vaccine design.

  8. 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

  9. The Crystal Structure of CD8alpha,Beta in Complex With YTS156.7.7 Fab And Interaction With Other CD8 Antibodies Define the Binding Mode of CD8alpha,Beta to MHC Class I

    Energy Technology Data Exchange (ETDEWEB)

    Shore, D.A.; Issafras, H.; Landais, E.; Teyton, L.; Wilson, I.A.

    2009-05-27

    The CD8{alpha}{beta} heterodimer interacts with class I pMHC on antigen-presenting cells as a co-receptor for TCR-mediated activation of cytotoxic T cells. To characterize this immunologically important interaction, we used monoclonal antibodies (mAbs) specific to either CD8{alpha} or CD8{beta} to probe the mechanism of CD8{alpha}{beta} binding to pMHCI. The YTS156.7 mAb inhibits this interaction and blocks T cell activation. To elucidate the molecular basis for this inhibition, the crystal structure of the CD8{alpha}{beta} immunoglobulin-like ectodomains were determined in complex with mAb YTS156.7 Fab at 2.7 {angstrom} resolution. The YTS156.7 epitope on CD8{beta} was identified and implies that residues in the CDR1 and CDR2-equivalent loops of CD8{beta} are occluded upon binding to class I pMHC. To further characterize the pMHCI/CD8{alpha}{beta} interaction, binding of class I tetramers to CD8{alpha}{beta} on the surface of T cells was assessed in the presence of anti-CD8 mAbs. In contrast to YTS156.7, mAb YTS105.18, which is specific for CD8{alpha}, does not inhibit binding of CD8{alpha}{beta} to class I tetramers, indicating the YTS105.18 epitope is not occluded in the pMHCI/CD8{alpha}{beta} complex. Together, these data indicate a model for the pMHCI/CD8{alpha}{beta} interaction similar to that observed for CD8{alpha}{alpha} in the CD8{alpha}{alpha}/pMHCI complex, but in which CD8{alpha} occupies the lower orientation (membrane proximal to the antigen presenting cell), and CD8{beta} occupies the upper position (membrane distal). The implication of this molecular assembly for the function of CD8{alpha}{beta} in T cell activation is discussed.

  10. Promiscuous Recognition of a Trypanosoma cruzi CD8+ T Cell Epitope among HLA-A2, HLA-A24 and HLA-A1 Supertypes in Chagasic Patients

    Science.gov (United States)

    Guzmán, Fanny; Rosas, Fernando; Thomas, M. Carmen; López, Manuel Carlos; González, John Mario; Cuéllar, Adriana; Puerta, Concepción J.

    2016-01-01

    Background TcTLE is a nonamer peptide from Trypanosoma cruzi KMP-11 protein that is conserved among different parasite strains and that is presented by different HLA-A molecules from the A2 supertype. Because peptides presented by several major histocompatibility complex (MHC) supertypes are potential targets for immunotherapy, the aim of this study was to determine whether MHC molecules other than the A2 supertype present the TcTLE peptide. Methodology/Principal Findings From 36 HLA-A2-negative chagasic patients, the HLA-A genotypes of twenty-eight patients with CD8+ T cells that recognized the TcTLE peptide using tetramer (twenty) or functional (eight) assays, were determined. SSP-PCR was used to identify the A locus and the allelic variants. Flow cytometry was used to analyze the frequency of TcTLE-specific CD8+ T cells, and their functional activity (IFN-γ, TNFα, IL-2, perforin, granzyme and CD107a/b production) was induced by exposure to the TcTLE peptide. All patients tested had TcTLE-specific CD8+ T cells with frequencies ranging from 0.07–0.37%. Interestingly, seven of the twenty-eight patients had HLA-A homozygous alleles: A*24 (5 patients), A*23 (1 patient) and A*01 (1 patient), which belong to the A24 and A1 supertypes. In the remaining 21 patients with HLA-A heterozygous alleles, the most prominent alleles were A24 and A68. The most common allele sub-type was A*2402 (sixteen patients), which belongs to the A24 supertype, followed by A*6802 (six patients) from the A2 supertype. Additionally, the A*3002/A*3201 alleles from the A1 supertype were detected in one patient. All patients presented CD8+ T cells producing at least one cytokine after TcTLE peptide stimulation. Conclusion/Significance These results show that TcTLE is a promiscuous peptide that is presented by the A24 and A1 supertypes, in addition to the A2 supertype, suggesting its potential as a target for immunotherapy. PMID:26974162

  11. 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

    -throughput sequencing. A bioinformatics approach was developed in order to identify peptide motifs of interest based on clustering and contrasting to control samples. Comparison of patient and control samples confirmed a major issue in phage display, namely the selection of unspecific peptides. The potential...... of the bioinformatic approach was demonstrated by identifying epitopes of a prominent peanut allergen, Ara h 1, in sera from patients with severe peanut allergy. The identified epitopes were confirmed by high-density peptide micro-arrays. The present study demonstrates that high-throughput sequencing can empower phage...

  12. 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...

  13. 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

  14. MimoPro: a more efficient Web-based tool for epitope prediction using phage display libraries

    Directory of Open Access Journals (Sweden)

    Guo William W

    2011-05-01

    Full Text Available Abstract Background A B-cell epitope is a group of residues on the surface of an antigen which stimulates humoral responses. Locating these epitopes on antigens is important for the purpose of effective vaccine design. In recent years, mapping affinity-selected peptides screened from a random phage display library to the native epitope has become popular in epitope prediction. These peptides, also known as mimotopes, share the similar structure and function with the corresponding native epitopes. Great effort has been made in using this similarity between such mimotopes and native epitopes in prediction, which has resulted in better outcomes than statistics-based methods can. However, it cannot maintain a high degree of satisfaction in various circumstances. Results In this study, we propose a new method that maps a group of mimotopes back to a source antigen so as to locate the interacting epitope on the antigen. The core of this method is a searching algorithm that is incorporated with both dynamic programming (DP and branch and bound (BB optimization and operated on a series of overlapping patches on the surface of a protein. These patches are then transformed to a number of graphs using an adaptable distance threshold (ADT regulated by an appropriate compactness factor (CF, a novel parameter proposed in this study. Compared with both Pep-3D-Search and PepSurf, two leading graph-based search tools, on average from the results of 18 test cases, MimoPro, the Web-based implementation of our proposed method, performed better in sensitivity, precision, and Matthews correlation coefficient (MCC than both did in epitope prediction. In addition, MimoPro is significantly faster than both Pep-3D-Search and PepSurf in processing. Conclusions Our search algorithm designed for processing well constructed graphs using an ADT regulated by CF is more sensitive and significantly faster than other graph-based approaches in epitope prediction. MimoPro is a

  15. Insert engineering and solubility screening improves recovery of virus-like particle subunits displaying hydrophobic epitopes.

    Science.gov (United States)

    Abidin, R S; Lua, L H L; Middelberg, A P J; Sainsbury, F

    2015-11-01

    The Polyomavirus coat protein, VP1 has been developed as an epitope presentation system able to provoke humoral immunity against a variety of pathogens, such as Influenza and Group A Streptococcus. The ability of the system to carry cytotoxic T cell epitopes on a surface-exposed loop and the impact on protein solubility has not been examined. Four variations of three selected epitopes were cloned into surface-exposed loops of VP1, and expressed in Escherichia coli. VP1 pentamers, also known as capsomeres, were purified via a glutathione-S-transferase tag. Size exclusion chromatography indicated severe aggregation of the recombinant VP1 during enzymatic tag removal resulting from the introduction the hydrophobic epitopes. Inserts were modified to possess double aspartic acid residues at each end of the hydrophobic epitopes and a high-throughput buffer condition screen was implemented with protein aggregation monitored during tag removal by spectrophotometry and dynamic light scattering. These analyses showed that the insertion of charged residues at the extremities of epitopes could improve solubility of capsomeres and revealed multiple windows of opportunity for further condition optimization. A combination of epitope design, pH optimization, and the additive l-arginine permitted the recovery of soluble VP1 pentamers presenting hydrophobic epitopes and their subsequent assembly into virus-like particles. PMID:26401641

  16. Globular Head-Displayed Conserved Influenza H1 Hemagglutinin Stalk Epitopes Confer Protection against Heterologous H1N1 Virus

    Science.gov (United States)

    Klausberger, Miriam; Tscheliessnig, Rupert; Neff, Silke; Nachbagauer, Raffael; Wohlbold, Teddy John; Wilde, Monika; Palmberger, Dieter; Krammer, Florian; Jungbauer, Alois; Grabherr, Reingard

    2016-01-01

    Significant genetic variability in the head region of the influenza A hemagglutinin, the main target of current vaccines, makes it challenging to develop a long-lived seasonal influenza prophylaxis. Vaccines based on the conserved hemagglutinin stalk domain might provide broader cross-reactive immunity. However, this region of the hemagglutinin is immunosubdominant to the head region. Peptide-based vaccines have gained much interest as they allow the immune system to focus on relevant but less immunogenic epitopes. We developed a novel influenza A hemagglutinin-based display platform for H1 hemagglutinin stalk peptides that we identified in an epitope mapping assay using human immune sera and synthetic HA peptides. Flow cytometry and competition assays suggest that the identified stalk sequences do not recapitulate the epitopes of already described broadly neutralizing stalk antibodies. Vaccine constructs displaying 25-mer stalk sequences provided up to 75% protection from lethal heterologous virus challenge in BALB/c mice and induced antibody responses against the H1 hemagglutinin. The developed platform based on a vaccine antigen has the potential to be either used as stand-alone or as prime-vaccine in combination with conventional seasonal or pandemic vaccines for the amplification of stalk-based cross-reactive immunity in humans or as platform to evaluate the relevance of viral peptides/epitopes for protection against influenza virus infection. PMID:27088239

  17. Molecular Anatomy and Number of Antigen Specific CD8 T Cells Required to Cause Type 1 Diabetes

    OpenAIRE

    Oldstone, Michael B.A.; Edelmann, Kurt H; McGavern, Dorian B.; Cruite, Justin T.; Welch, Megan J.

    2012-01-01

    We quantified CD8 T cells needed to cause type 1 diabetes and studied the anatomy of the CD8 T cell/beta (β) cell interaction at the immunologic synapse. We used a transgenic model, in situ tetramer staining to distinguish antigen specific CD8 T cells from total T cells infiltrating islets and a variety of viral mutants selected for functional deletion(s) of various CD8 T cell epitopes. Twenty percent of CD8 T cells in the spleen were specific for all immunodominant and subdominant viral glyc...

  18. 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...

  19. 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

  20. 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 < 0.001, respectively]. Furthermore, HCV mono-infected patients had increased frequencies of Tregs compared with...

  1. 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

  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. TIL therapy broadens the tumor-reactive CD8(+) T cell compartment in melanoma patients

    DEFF Research Database (Denmark)

    Kvistborg, Pia; Shu, Chengyi Jenny; Heemskerk, Bianca; Fankhauser, Manuel; Thrue, Charlotte Albæk; Toebes, Mireille; van Rooij, Nienke; Linnemann, Carsten; van Buuren, Marit M; Urbanus, Jos H M; Beltman, Joost B; thor Straten, Per; Li, Yong F; Robbins, Paul F; Besser, Michal J; Schachter, Jacob; Kenter, Gemma G; Dudley, Mark E; Rosenberg, Steven A; Haanen, John B A G; Hadrup, Sine Reker; Schumacher, Ton N M

    2012-01-01

    -induced T cell reactivity against a panel of 145 melanoma-associated CD8(+) T cell epitopes. Using this approach, we demonstrate that individual tumor-infiltrating lymphocyte cell products from melanoma patients contain unique patterns of reactivity against shared melanoma-associated antigens, and that the...

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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; Jensen, Benjamin Anderschou Holbech; Bartholdy, Christina; Buus, Anette Stryhn; Christensen, Jan Pravsgaard; Thomsen, Allan Randrup

    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...... infection with lymphocytic choriomeningitis virus. We found that localized immunization with intermediate doses of Ad vector induce a moderate number of functional CD8 T cells, which qualitatively match those found in LCMV-infected mice. Numbers of these cells may be efficiently increased by additional...... leads to the generation of a population of memory cells characterized by relatively low CD27 expression and high CD127 and KLRG1 expression. These memory CD8 T cells are capable of proliferating in response to viral challenge, and protect against infection with live virus. Furthermore, viral challenge...

  9. EBNA1 antigen-specific CD8+ T cells in cerebrospinal fluid of patients with multiple sclerosis.

    Science.gov (United States)

    Erdur, Hebun; Scholz, Veronika; Streitz, Mathias; Hammer, Markus; Meisel, Christian; Schönemann, Constanze; Wandinger, Klaus-Peter; Rosche, Berit

    2016-05-15

    Epidemiological data suggests that Epstein-Barr virus may be involved in the pathogenesis of Multiple Sclerosis (MS). We aimed to determine the frequency of CD8+ T cells specific for one EBNA1-derived epitope (HPVGEADYFEY) in cerebrospinal fluid (CSF) and blood of patients with MS and other inflammatory neurological diseases (OIND). The frequency of specific CD8+ T cells was assessed by HLA-class-I-binding pentamers restricted to HLA-B35. The frequency of HPVGEADYFEY-specific CD8+ T cells did neither differ significantly in blood nor CSF in MS compared to OIND, but was consistently higher in CSF compared to blood regardless of diagnosis. PMID:27138093

  10. The role of CD80/CD86 in generation and maintenance of functional virus-specific CD8+ T cells in mice infected with lymphocytic choriomeningitis virus

    DEFF Research Database (Denmark)

    Grujic, Mirjana; Bartholdy, Christina; Remy, Melissa; Pinschewer, Daniel D; Christensen, Jan P; Thomsen, Allan Randrup

    2010-01-01

    Lymphocytic choriomeningitis virus (LCMV)-specific CD8(+) T cell responses are considered to be independent of CD28-B7 costimulation. However, the LCMV-specific response has never been evaluated in B7.1/B7.2(-/-) mice. For this reason, we decided to study the T cell response in B7.1/B7.2(-/-) mice...... infection. Chronic infection was associated with a perturbed CD8(+) T cell epitope hierarchy, as well as with the accumulation of cells expressing markers of terminal differentiation and being unable to respond optimally to Ag restimulation. Examination of matched CD28(-/-) mice revealed a similar albeit...... less pronounced pattern of CD8(+) T cell dysfunction despite lack of virus persistence. Finally, analysis of B7.1/B7.2(-/-) mice infected with Armstrong virus revealed a scenario quite similar to that in Traub infected CD28(-/-) mice; that is, the mice displayed evidence of T cell dysfunction, but no...

  11. Cloning, protein expression and display of synthetic multi-epitope mycobacterial antigens on Salmonella typhi Ty21a cell surface.

    Science.gov (United States)

    Sarhan, Mohammed A A; Musa, Mustaffa; Zainuddin, Zainul F

    2011-09-01

    Expressing proteins of interest as fusion to proteins of bacterial envelope is a powerful technique for biotechnological and medical applications. The synthetic gene (VacII) encoding for T-cell epitopes of selected genes of Mycobacterium tuberculosis namely, ESAT6, MTP40, 38 kDa, and MPT64 was fused with N- terminus of Pseudomonas syringae ice nucleation protein (INP) outer membrane protein. The fused genes were cloned into a bacterial expression vector pKK223-3. The recombinant protein was purified by Ni-NAT column. VacII gene was displayed on the cell surface of Salmonella typhi Ty21a using N-terminal region of ice nucleation proteins (INP) as an anchoring motif. Glycine method confirmed that VacII was anchored on the cell surface. Western blot analysis further identified the synthesis of INP derivatives containing the N-terminal domain INP- VacII fusion protein of the expected size (52 kDa). PMID:21941936

  12. 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.

  13. 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

  14. 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.

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

    Science.gov (United States)

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

    2016-06-01

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

  16. A Gene Expression Signature That Correlates with CD8+ T Cell Expansion in Acute EBV Infection.

    Science.gov (United States)

    Greenough, Thomas C; Straubhaar, Juerg R; Kamga, Larisa; Weiss, Eric R; Brody, Robin M; McManus, Margaret M; Lambrecht, Linda K; Somasundaran, Mohan; Luzuriaga, Katherine F

    2015-11-01

    Virus-specific CD8(+) T cells expand dramatically during acute EBV infection, and their persistence is important for lifelong control of EBV-related disease. To better define the generation and maintenance of these effective CD8(+) T cell responses, we used microarrays to characterize gene expression in total and EBV-specific CD8(+) T cells isolated from the peripheral blood of 10 individuals followed from acute infectious mononucleosis (AIM) into convalescence (CONV). In total CD8(+) T cells, differential expression of genes in AIM and CONV was most pronounced among those encoding proteins important in T cell activation/differentiation, cell division/metabolism, chemokines/cytokines and receptors, signaling and transcription factors (TF), immune effector functions, and negative regulators. Within these categories, we identified 28 genes that correlated with CD8(+) T cell expansion in response to an acute EBV infection. In EBV-specific CD8(+) T cells, we identified 33 genes that were differentially expressed in AIM and CONV. Two important TF, T-bet and eomesodermin, were upregulated and maintained at similar levels in both AIM and CONV; in contrast, protein expression declined from AIM to CONV. Expression of these TF varied among cells with different epitope specificities. Collectively, gene and protein expression patterns suggest that a large proportion, if not a majority of CD8(+) T cells in AIM are virus specific, activated, dividing, and primed to exert effector activities. High expression of T-bet and eomesodermin may help to maintain effector mechanisms in activated cells and to enable proliferation and transition to earlier differentiation states in CONV. PMID:26416268

  17. Genome-Based In Silico Identification of New Mycobacterium tuberculosis Antigens Activating Polyfunctional CD8+ T Cells in Human Tuberculosis

    DEFF Research Database (Denmark)

    Tang, Sheila Tuyet; van Meijgaarden, Krista E.; Caccamo, Nadia;

    2011-01-01

    Although CD8(+) T cells help control Mycobacterium tuberculosis infection, their M. tuberculosis Ag repertoire, in vivo frequency, and functionality in human tuberculosis (TB) remains largely undefined. We have performed genome-based bioinformatics searches to identify new M. tuberculosis epitopes...... presented by major HLA class I supertypes A2, A3, and B7 (covering 80% of the human population). A total of 432 M. tuberculosis peptides predicted to bind to HLA-A*0201, HLA-A*0301, and HLA-B*0702 (representing the above supertypes) were synthesized and HLA-binding affinities determined. Peptide-specific CD......8(+) T cell proliferation assays (CFSE dilution) in 41 M. tuberculosis-responsive donors identified 70 new M. tuberculosis epitopes. Using HLA/peptide tetramers for the 18 most prominently recognized HLA-A*0201-binding M. tuberculosis peptides, recognition by cured TB patients' CD8(+) T cells was...

  18. Structure-Based Design of a Protein Immunogen that Displays an HIV-1 gp41 Neutralizing Epitope

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    Stanfield, Robyn L.; Julien, Jean-Philippe; Pejchal, Robert; Gach, Johannes S.; Zwick, Michael B.; Wilson, Ian A. (Scripps)

    2012-06-27

    Antibody Z13e1 is a relatively broadly neutralizing anti-human immunodeficiency virus type 1 antibody that recognizes the membrane-proximal external region (MPER) of the human immunodeficiency virus type 1 envelope glycoprotein gp41. Based on the crystal structure of an MPER epitope peptide in complex with Z13e1 Fab, we identified an unrelated protein, interleukin (IL)-22, with a surface-exposed region that is structurally homologous in its backbone to the gp41 Z13e1 epitope. By grafting the gp41 Z13e1 epitope sequence onto the structurally homologous region in IL-22, we engineered a novel protein (Z13-IL22-2) that contains the MPER epitope sequence for use as a potential immunogen and as a reagent for the detection of Z13e1-like antibodies. The Z13-IL22-2 protein binds Fab Z13e1 with a K{sub d} of 73 nM. The crystal structure of Z13-IL22-2 in complex with Fab Z13e1 shows that the epitope region is faithfully replicated in the Fab-bound scaffold protein; however, isothermal calorimetry studies indicate that Fab binding to Z13-IL22-2 is not a lock-and-key event, leaving open the question of whether conformational changes upon binding occur in the Fab, in Z13-IL-22, or in both.

  19. Targeting CD8 T-Cell Metabolism in Transplantation

    OpenAIRE

    Yap, Michelle; Brouard, Sophie; Pecqueur, Claire; Degauque, Nicolas

    2015-01-01

    Infiltration of effector CD8 T cells plays a major role in allograft rejection, and increases in memory and terminally differentiated effector memory CD8 T cells are associated with long-term allograft dysfunction. Alternatively, CD8 regulatory T cells suppress the inflammatory responses of effector lymphocytes and induce allograft tolerance in animal models. Recently, there has been a renewed interest in the field of immunometabolics and its important role in CD8 function and differentiation...

  20. 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

    The structure of epitopes recognised by anti-pectin monoclonal antibodies (mAbs) has been investigated using a series of model lime-pectin samples with defined degrees and patterns of methyl esterification, a range of defined oligogalacturonides and enzymatic degradation of pectic polysaccharides...

  1. 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.

  2. Comprehensive mapping of functional epitopes on dengue virus glycoprotein E DIII for binding to broadly neutralizing antibodies 4E11 and 4E5A by phage display.

    Science.gov (United States)

    Frei, Julia C; Kielian, Margaret; Lai, Jonathan R

    2015-11-01

    Here we investigated the binding of Dengue virus envelope glycoprotein domain III (DIII) by two broadly neutralizing antibodies (bNAbs), 4E11 and 4E5A. There are four serotypes of Dengue virus (DENV-1 to -4), whose DIII sequences vary by up to 49%. We used combinatorial alanine scanning mutagenesis, a phage display approach, to map functional epitopes (those residues that contribute most significantly to the energetics of antibody-antigen interaction) on these four serotypes. Our results showed that 4E11, which binds strongly to DENV-1, -2, and -3, and moderately to DENV-4, recognized a common conserved core functional epitope involving DIII residues K310, L/I387, L389, and W391. There were also unique recognition features for each serotype, suggesting that 4E11 has flexible recognition requirements. Similar scanning studies for the related bNAb 4E5A, which binds more tightly to DENV-4, identified broader functional epitopes on DENV-1. These results provide useful information for immunogen and therapeutic antibody design. PMID:26339794

  3. 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

  4. 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...... respective CD8(+) T-cell response. By comparing inhibitions of viral replication by CD8(+) T cells specific for the Gag KK10, Pol KY9, and Vpr VL9 HLA-B 2705-restricted epitopes, we observed a consistent hierarchy of antiviral efficacy (Gag KK10 > Pol KY9 > Vpr VL9). This hierarchy was associated with early...

  5. Furin-processed antigens targeted to the secretory route elicit functional TAP1-/-CD8+ T lymphocytes in vivo.

    Science.gov (United States)

    Medina, Francisco; Ramos, Manuel; Iborra, Salvador; de León, Patricia; Rodríguez-Castro, Marta; Del Val, Margarita

    2009-10-01

    Most pathogen-derived peptides recognized by CD8+ CTL are produced by proteasomes and delivered to the endoplasmic reticulum by the TAP transporters associated with Ag processing. Alternative proteases also produce antigenic peptides, but their actual relevance is unclear. There is a need to quantify the contribution of these supplementary pathways in vitro and in vivo. A well-defined TAP-independent secretory route of Ag processing involves the trans-Golgi network protease furin. Quantitation of this route by using OVA constructs encoded by vaccinia viruses indicates that it provides approximately one-third of all surface complexes of peptide and MHC class I molecules. Generation of the epitope carboxyl terminus is a dramatic rate-limiting step, since bypassing it increased efficiency by at least 1000-fold. Notably, the secretory construct activated a similar percentage of Ag-specific CD8+ T cells in wild type as in TAP1-deficient mice, which allow only secretory routes but which have a 10- to 20-fold smaller CD8 compartment. Moreover, these TAP1(-/-) OVA-specific CD8+ T lymphocytes accomplished elimination of epitope-bearing cells in vivo. The results obtained with this experimental system underscore the potential of secretory pathways of MHC class I Ag presentation to elicit functional CD8+ T lymphocytes in vivo and support the hypothesis that noncytosolic processing mechanisms may compensate in vivo for the lack of proteasome participation in Ag processing in persons genetically deficient in TAP and thus contribute to pathogen control. PMID:19752221

  6. CD8+ T cells in inflammatory demyelinating disease

    DEFF Research Database (Denmark)

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

    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...

  7. Phenotypic and functional characteristic of a newly identified CD8+Foxp3−CD103+ regulatory T cells

    OpenAIRE

    Liu, Ya; Lan, Qin; Lu, Ling; Chen, Maogen; Xia, Zanxian; Ma, Jilin; Wang, Julie; Fan, Huimin; Shen, Yi; Ryffel, Bernhard; Brand, David; Quismorio, Francisco; Liu, Zhongmin; Horwitz, David A.; Xu, Anping

    2013-01-01

    TGF-β and Foxp3 expressions are crucial for the induction and functional activity of CD4+Foxp3+ regulatory T (iTreg) cells. Here, we demonstrate that although TGF-β-primed CD8+ cells display much lower Foxp3 expression, their suppressive capacity is equivalent to that of CD4+ iTreg cells, and both Foxp3− and Foxp3+ CD8+ subsets have suppressive activities in vitro and in vivo. CD8+Foxp3− iTreg cells produce little IFN-γ but almost no IL-2, and display a typical anergic phenotype. Among phenot...

  8. 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.

  9. 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

  10. 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

  11. 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.

  12. Canine CD4(+)CD8(+) double-positive T cells can develop from CD4(+) and CD8(+) T cells.

    Science.gov (United States)

    Bismarck, Doris; Moore, Peter F; Alber, Gottfried; von Buttlar, Heiner

    2014-12-15

    For a long time the expression of the CD4 and CD8 receptor on peripheral blood T cells was thought to be mutually exclusive. However, in canine peripheral blood, similar to other species as swine or human for example, mature CD4(+)CD8(+) double-positive (dp) T cells exist which simultaneously express both surface receptors and have features of activated T cells. Canine CD4(+)CD8(+)dp T cells are heterogeneous and can be divided into three subpopulations by their intensity of CD4 and CD8α expression: CD4(bright)CD8α(bright), CD4(dim)CD8α(bright) and CD4(dim)CD8α(dim). The number of CD4(+)CD8α(+)dp T cells increases after in vitro stimulation of canine peripheral blood mononuclear cells (PBMC) raising the question of their progenitor(s). Thus, the aim of our study was to characterize the progenitor(s) of canine CD4(+)CD8α(+)dp T cells. By cell tracing experiments we identified both CD4(+) single-positive (sp) and also CD8α(+)sp T cells as progenitors of canine CD4(+)CD8α(+)dp T cells after in vitro stimulation. CD4(+)sp T cells almost exclusively upregulate a CD8αα homodimer, whereas CD8α(+)sp T cells can become CD4(+)CD8αβ(+) or CD4(+)CD8αα(+). Even in the absence of other cells, highly purified CD4(+)sp T cells can become double-positive upon in vitro stimulation, whereas highly purified CD8α(+)sp T cells fail to do so. However, CD8α(+)sp T cells can additionally express CD4 when stimulated in the presence of CD4(-)CD8α(-) double-negative (dn) cells or more efficiently when stimulated in the presence of CD4(+)sp T cells. Soluble factors secreted by CD4(+)sp T cells are sufficient for the upregulation of CD4 on CD8α(+)sp T cells, but direct cell-cell contact between CD4(+)sp and CD8α(+)sp T cells is more efficient. mRNA analysis shows that additional CD4 expression on CD8α(+)sp T cells results from de novo synthesis. Thus, uptake of soluble CD4 or trogocytosis is less likely as mechanism for generation of canine double-positive T cells. CD4(+)CD

  13. 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...

  14. 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

  15. Protective CD8+ T cell responses against the pre-erythrocytic stages of malaria parasites: an overview

    Directory of Open Access Journals (Sweden)

    Oliveira-Ferreira J

    2001-01-01

    Full Text Available CD8+ T cells have been implicated as critical effector cells in protection against the pre-erythrocytic stage of malaria in mice and humans following irradiated sporozoite immunization. Immunization experiments in animal models by several investigators have suggested different strategies for vaccination against malaria and many of the targets from liver stage malaria antigens have been shown to be immunogenic and to protect mice from the sporozoite challenge. Several prime/boost protocols with replicating vectors, such as vaccinia/influenza, with non-replicating vectors, such as recombinant particles derived from yeast transposon (Ty-particles and modified vaccinia virus Ankara, and DNA, significantly enhanced CD8+ T cell immunogenicity and also the protective efficacy against the circumsporosoite protein of Plasmodium berghei and P. yeti. Based on these experimental results the development of a CD8+ T cell inducing vaccine has moved forward from epitope identification to planning stages of safety and immunogenicity trials of candidate vaccines.

  16. Discovering neutralizing antibodies targeting the stem epitope of H1N1 influenza hemagglutinin with synthetic phage-displayed antibody libraries

    Science.gov (United States)

    Tung, Chao-Ping; Chen, Ing-Chien; Yu, Chung-Ming; Peng, Hung-Pin; Jian, Jhih-Wei; Ma, Shiou-Hwa; Lee, Yu-Ching; Jan, Jia-Tsrong; Yang, An-Suei

    2015-01-01

    Broadly neutralizing antibodies developed from the IGHV1–69 germline gene are known to bind to the stem region of hemagglutinin in diverse influenza viruses but the sequence determinants for the antigen recognition, including neutralization potency and binding affinity, are not clearly understood. Such understanding could inform designs of synthetic antibody libraries targeting the stem epitope on hemagglutinin, leading to artificially designed antibodies that are functionally advantageous over antibodies from natural antibody repertoires. In this work, the sequence space of the complementarity determining regions of a broadly neutralizing antibody (F10) targeting the stem epitope on the hemagglutinin of a strain of H1N1 influenza virus was systematically explored; the elucidated antibody-hemagglutinin recognition principles were used to design a phage-displayed antibody library, which was then used to discover neutralizing antibodies against another strain of H1N1 virus. More than 1000 functional antibody candidates were selected from the antibody library and were shown to neutralize the corresponding strain of influenza virus with up to 7 folds higher potency comparing with the parent F10 antibody. The antibody library could be used to discover functionally effective antibodies against other H1N1 influenza viruses, supporting the notion that target-specific antibody libraries can be designed and constructed with systematic sequence-function information. PMID:26456860

  17. 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

  18. 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...

  19. Recognition of breast cancer cells by CD8+ cytotoxic T-cell clones specific for NY-BR-1.

    Science.gov (United States)

    Wang, Wei; Epler, Jennifer; Salazar, Lupe G; Riddell, Stanley R

    2006-07-01

    Immunotherapy for breast cancer using cytotoxic T cells (CTL) is hindered by the lack of well-characterized breast cancer antigens that are expressed in most breast tumor cells and recognized by CD8+ CTL. A recently described breast tissue differentiation antigen, NY-BR-1, is expressed in >80% breast tumors and elicits a humoral response in a subset of breast cancer patients. To identify potential NY-BR-1 epitopes that are recognized by CTL, CD8+ T cells were stimulated in vitro with autologous dendritic cells pulsed with NY-BR-1 peptides that were predicted to bind to HLA-A2. In multiple normal female donors and breast cancer patients, specific CD8+ CTL responses were detected by enzyme-linked immunospot assay against several NY-BR-1 peptides after two cycles of stimulation. CD8+ CTL clones against three NY-BR-1 epitopes were isolated and recognized peptide-pulsed target cells with high avidity. T-cell clones specific for one of the NY-BR-1 epitopes (p904) also recognized breast tumor cells expressing NY-BR-1, NY-BR-1(-) cells transfected with a cDNA encoding the NY-BR-1 protein, and autologous dendritic cells pulsed with opsonized NY-BR-1+ breast tumor cells. Taken together, these results show that the p904 epitope derived from NY-BR-1 is efficiently processed and presented endogenously and identify NY-BR-1 as a promising target for T-cell-based immunotherapy for breast cancer. PMID:16818660

  20. Induction and maintenance of protective CD8+ T cells against malaria liver stages: implications for vaccine development

    Directory of Open Access Journals (Sweden)

    Sze-Wah Tse

    2011-08-01

    Full Text Available CD8+ T cells against malaria liver stages represent a major protective immune mechanism against infection. Following induction in the peripheral lymph nodes by dendritic cells (DCs, these CD8+ T cells migrate to the liver and eliminate parasite infected hepatocytes. The processing and presentation of sporozoite antigen requires TAP mediated transport of major histocompatibility complex class I epitopes to the endoplasmic reticulum. Importantly, in DCs this process is also dependent on endosome-mediated cross presentation while this mechanism is not required for epitope presentation on hepatocytes. Protective CD8+ T cell responses are strongly dependent on the presence of CD4+ T cells and the capacity of sporozoite antigen to persist for a prolonged period of time. While human trials with subunit vaccines capable of inducing antibodies and CD4+ T cell responses have yielded encouraging results, an effective anti-malaria vaccine will likely require vaccine constructs designed to induce protective CD8+ T cells against malaria liver stages.

  1. 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

  2. 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

  3. Prolonged antigen presentation by immune complex-binding dendritic cells programs the proliferative capacity of memory CD8 T cells.

    Science.gov (United States)

    León, Beatriz; Ballesteros-Tato, André; Randall, Troy D; Lund, Frances E

    2014-07-28

    The commitment of naive CD8 T cells to effector or memory cell fates can occur after a single day of antigenic stimulation even though virus-derived antigens (Ags) are still presented by DCs long after acute infection is resolved. However, the effects of extended Ag presentation on CD8 T cells are undefined and the mechanisms that regulate prolonged Ag presentation are unknown. We showed that the sustained presentation of two different epitopes from influenza virus by DCs prevented the premature contraction of the primary virus-specific CD8 T cell response. Although prolonged Ag presentation did not alter the number of memory CD8 T cells that developed, it was essential for programming the capacity of these cells to proliferate, produce cytokines, and protect the host after secondary challenge. Importantly, prolonged Ag presentation by DCs was dependent on virus-specific, isotype-switched antibodies (Abs) that facilitated the capture and cross-presentation of viral Ags by FcγR-expressing DCs. Collectively, our results demonstrate that B cells and Abs can regulate the quality and functionality of a subset of antiviral CD8 T cell memory responses and do so by promoting sustained Ag presentation by DCs during the contraction phase of the primary T cell response. PMID:25002751

  4. 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 the...

  5. 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.

  6. 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

  7. 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.

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    lymphoid tissues of numerous species, as well as in numerous disease settings, including cancer. The expression of CD4 and CD8 is regulated by a very strict transcriptional program involving the transcription factors Runx3 and ThPOK. Initially thought to be mutually exclusive within CD4(+) and CD8(+) T...... 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....

  9. 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.

  10. 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.

  11. 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...

  12. 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

  13. 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.

  14. Priming of Qualitatively Superior Human Effector CD8+ T Cells Using TLR8 Ligand Combined with FLT3 Ligand.

    Science.gov (United States)

    Lissina, Anna; Briceño, Olivia; Afonso, Georgia; Larsen, Martin; Gostick, Emma; Price, David A; Mallone, Roberto; Appay, Victor

    2016-01-01

    The quality of Ag-specific CD8(+) T cell responses is central to immune efficacy in infectious and malignant settings. Inducing effector CD8(+) T cells with potent functional properties is therefore a priority in the field of immunotherapy. However, the optimal assessment of new treatment strategies in humans is limited by currently available testing platforms. In this study, we introduce an original model of in vitro CD8(+) T cell priming, based on an accelerated dendritic cell coculture system, which uses unfractionated human PBMCs as the starting material. This approach enables the rapid evaluation of adjuvant effects on the functional properties of human CD8(+) T cells primed from Ag-specific naive precursors. We demonstrate that a selective TLR8 agonist, in combination with FLT3L, primes high-quality CD8(+) T cell responses. TLR8L/FLT3L-primed CD8(+) T cells displayed enhanced cytotoxic activity, polyfunctionality, and Ag sensitivity. The acquisition of this superior functional profile was associated with increased T-bet expression induced via an IL-12-dependent mechanism. Collectively, these data validate an expedited route to vaccine delivery or optimal T cell expansion for adoptive cell transfer. PMID:26608912

  15. 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.

  16. Probing the ability of the coat and vertex protein of the membrane-containing bacteriophage PRD1 to display a meningococcal epitope

    International Nuclear Information System (INIS)

    Bacteriophage PRD1 is an icosahedral dsDNA virus with a diameter of 740 A and an outer protein shell composed of 720 copies of major coat protein P3. Spike complexes at the vertices are composed of a pentameric base (protein P31) and a spike structure (proteins P5 and P2) where the N-terminal region of the trimeric P5 is associated with the base and the C-terminal region of P5 is associated with receptor-binding protein P2. The functionality of proteins P3 and P5 was investigated using insertions and deletions. It was observed that P3 did not tolerate changes whereas P5 tolerated changes much more freely. These properties support the hypothesis that viruses have core structures and functions, which remain stable over time, as well as other elements, responsible for host interactions, which are evolutionally more fluid. The insertional probe used was the apex of exposed loop 4 of group B meningococcal outer membrane protein PorA, a medically important subunit vaccine candidate. It was demonstrated that the epitope could be displayed on the virus surface as part of spike protein P5

  17. 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

  18. CD8 chemokine receptors in chronic obstructive pulmonary disease

    DEFF Research Database (Denmark)

    Smyth, L J C; Starkey, C; Gordon, F S; Vestbo, J; Singh, D

    2008-01-01

    study was to assess in COPD patients: (i) broncho-alveolar lavage (BAL) CD8 CCR3 and CCR4 expression in COPD patients; and (ii) airway levels of the CCR3 ligands, CCL11 and CCL5. Multi-parameter flow cytometric analysis was used to assess BAL CD3 and CD8-chemokine receptor expression in COPD patients......, 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 < 0...... was low level CCL11 production. CD8CCR3 and CCR5 expression appear to be regulated by cigarette smoke exposure. We show that COPD lung tissue released more CCL5, suggesting a role for CCL5-CCR3 signalling in pulmonary CD8 recruitment in COPD....

  19. 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*...

  20. 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.

  1. 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.

  2. Radiosensitivity of CD3-CD8+CD56+ NK cells

    Energy Technology Data Exchange (ETDEWEB)

    Vokurkova, Doris [Charles University in Prague, Faculty of Medicine in Hradec Kralove, Department of Medical Biochemistry, Simkova 870, 50038 Hradec Kralove 1 (Czech Republic); Vavrova, Jirina [University of Defence, Faculty of Military Health Sciences, Department of Radiobiology, Hradec Kralove (Czech Republic); Sinkora, Jiri [Becton Dickinson (Czech Republic); Stoklasova, Alena [Charles University in Prague, Faculty of Medicine in Hradec Kralove, Department of Medical Biochemistry, Simkova 870, 50038 Hradec Kralove 1 (Czech Republic); Blaha, Vaclav [University of Defence, Faculty of Military Health Sciences, Department of Radiobiology, Hradec Kralove (Czech Republic); Rezacova, Martina, E-mail: rezacovam@lfhk.cuni.c [Charles University in Prague, Faculty of Medicine in Hradec Kralove, Department of Medical Biochemistry, Simkova 870, 50038 Hradec Kralove 1 (Czech Republic)

    2010-10-15

    The effect of lower doses (0.5-3.0 Gy) of gamma radiation on radiosensitivity of CD3-/CD8+ NK cells subpopulation isolated from the peripheral blood of healthy volunteers was studied 48 h after the irradiation. Only a subtle increase in terms of induction of apoptosis (A+ cells), was observed in Annexin positive CD3-/CD8+ NK cells. The assessment of the relative presence of CD3{sup -}/CD8{sup +} NK cells in Annexin negative populations of lymphocytes considerably contributes to the elimination of individual variability and could be useful in biodosimetry. Living CD3-/CD8+; Annexin negative NK cells were analyzed using five-color flow cytometry 16 h after irradiation by the doses of 1-10 Gy. The study was carried out on NK cells subsets CD3-/CD8- CD16+, CD56 (dim) and CD56 (bright). NK cells characterized with their low-density expression of CD56 (dim) are more cytotoxic and express CD16. Those with high-density expression of CD56 (bright) are known for their capacity to produce cytokines following activation of monocytes but their natural cytotoxicity is low; they are classified as CD16- or CD16 (dim). A dose-depending decrease in the relative presence of CD3-/CD8+ NK cells was observed 16 h after ionizing radiation (1-10 Gy). The decrease was highly pronounced in CD56 (bright) subset of NK cells and this subpopulation was considered as the most radiosensitive one. Unfortunately, the most radiosensitive subpopulation of NK cells - CD56bright cannot be used as a biodosimetric marker due to its insufficient amount in peripheral blood.

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    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

  5. 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.

  6. Vaccination with Ad5 vectors expands Ad5-specific CD8 T cells without altering memory phenotype or functionality.

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    Natalie A Hutnick

    Full Text Available BACKGROUND: Adenoviral (Ad vaccine vectors represent both a vehicle to present a novel antigen to the immune system as well as restimulation of immune responses against the Ad vector itself. To what degree Ad-specific CD8(+ T cells are restimulated by Ad vector vaccination is unclear, although such knowledge would be important as vector-specific CD8(+ T cell expansion could potentially further limit Ad vaccine efficacy beyond Ad-specific neutralizing antibody alone. METHODOLOGY/PRINCIPAL FINDINGS: Here we addressed this issue by measuring human Adenovirus serotype 5 (Ad5-specific CD8(+ T cells in recipients of the Merck Ad5 HIV-1 vaccine vector before, during, and after vaccination by multicolor flow cytometry. Ad5-specific CD8(+ T-cells were detectable in 95% of subjects prior to vaccination, and displayed primarily an effector-type functional profile and phenotype. Peripheral blood Ad5-specific CD8(+ T-cell numbers expanded after Ad5-HIV vaccination in all subjects, but differential expansion kinetics were noted in some baseline Ad5-neutralizing antibody (Ad5 nAb seronegative subjects compared to baseline Ad5 nAb seropositive subjects. However, in neither group did vaccination alter polyfunctionality, mucosal targeting marker expression, or memory phenotype of Ad5-specific CD8(+ T-cells. CONCLUSIONS: These data indicate that repeat Ad5-vector administration in humans expands Ad5-specific CD8(+ T-cells without overtly affecting their functional capacity or phenotypic properties. This is a secondary analysis of samples collected during the 016 trial. Results of the Merck 016 trial safety and immunogenicity have been previously published in the journal of clinical infectious diseases [1]. TRIAL REGISTRATION: ClinicalTrials.gov NCT00849680[http://www.clinicaltrials.gov/show/NCT00849680].

  7. 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.

  8. 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; Riberdy, J M

    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 (<0.5 to >10%) by sequential priming with two different influenza A viruses (H3N2-->H1N1...

  9. 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.

  10. 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.

  11. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  13. 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...

  14. 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.

  15. 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.

  16. 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.

  17. 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...

  18. 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...

  19. Number of CD4+ and CD8+ T-cell CDR3 clonotypes expanding during acute infection of macaques with simian immunodeficiency virus

    International Nuclear Information System (INIS)

    The total number of circulating CD4+ and CD8+ T-cells undergoing clonal expansions following SIVmac251 infection was determined using a T-cell receptor Vβ chain (TRBV) third complementarity-determining region (CDR3) DNA heteroduplex tracking assay (HTA). This assay measures the number of newly expanding T-cell clones but not their antigenic specificity. Fewer expanding CD4+ (3-23 per animal) than CD8+ (18-37 per animal) clonotypes were observed during the acute phase of SIV infection. CD8+ T-cell expansions peaked at 4 weeks postinfection (wpi) concomitant with early reductions in viremia. Expanding clone TRBV transcripts ranged in frequency from the limit of detection of 2% to 40% of their TRBV subfamily's transcripts. The number of expanding CD4+ or CD8+ clones correlated with neither peak, subsequent slope, nor steady-state viremia. CDR3 repertoires in CD8-expressing cells in different anatomical compartments were also analyzed. Repertoires were polyclonal in the thymus, oligoclonal in mesenteric lymph nodes, peripheral blood mononuclear cells (PBMC), and spleen, and extremely oligoclonal in intra-epithelial lymphocytes (IEL) and lamina propria lymphocytes (LPL). The lack of correlation between the number of expanding T-cell clonotypes and viremia levels may reflect the highly variable selection pressure imposed on SIV by T-cell responses targeting different epitopes in outbred macaques

  20. 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

  1. 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

  2. Identification of murine T-cell epitopes in Ebola virus nucleoprotein

    International Nuclear Information System (INIS)

    CD8 T cells play an important role in controlling Ebola infection and in mediating vaccine-induced protective immunity, yet little is known about antigenic targets in Ebola that are recognized by CD8 T cells. Overlapping peptides were used to identify major histocompatibility complex class I-restricted epitopes in mice immunized with vectors encoding Ebola nucleoprotein (NP). CD8 T-cell responses were mapped to a H-2d-restricted epitope (NP279-288) and two H-2b-restricted epitopes (NP44-52 and NP288-296). The identification of these epitopes will facilitate studies of immune correlates of protection and the evaluation of vaccine strategies in murine models of Ebola infection

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

    Directory of Open Access Journals (Sweden)

    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.

  4. 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

    The cartography of β-cell epitopes targeted by CD8(+) T cells in type 1 diabetic (T1D) patients remains largely confined to the common HLA-A2 restriction. We aimed to identify β-cell epitopes restricted by the HLA-B7 (B*07:02) molecule, which is associated with mild T1D protection. Using DNA...... immunization on HLA-B7-transgenic mice and prediction algorithms, we identified GAD and preproinsulin candidate epitopes. Interferon-γ (IFN-γ) enzyme-linked immunospot assays on peripheral blood mononuclear cells showed that most candidates were recognized by new-onset T1D patients, but not by type 2 diabetic...... 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...

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

    Directory of Open Access Journals (Sweden)

    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.

  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. Peptide pool immunization and CD8+ T cell reactivity

    DEFF Research Database (Denmark)

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

    2013-01-01

    peptide in the Elispot culture. Immunization with a mixture of the VSV-peptide and a "normal" peptide also resulted in IFNγ spot formation without addition of peptide to the assay culture. Peptide-tetramer staining of CD8(+) T cells from mice immunized with a mixture of VSV-peptide and "normal" peptide......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...... peptides induced normal peptide immunity i.e. the specific T cell reactivity in the Elispot culture was strictly dependent on exposure to the immunizing peptide ex vivo. However, immunization with two of the peptides, a VSV- and a Mycobacterium-derived peptide, resulted in IFNγ spot formation without...

  8. Vitamin D receptor expression controls proliferation of naïve CD8+ T cells and development of CD8 mediated gastrointestinal inflammation

    OpenAIRE

    Chen, Jing; Bruce, Danny; Cantorna, Margherita T.

    2014-01-01

    Background Vitamin D receptor (VDR) deficiency contributes to the development of experimental inflammatory bowel disease (IBD) in several different models. T cells have been shown to express the VDR, and T cells are targets of vitamin D. In this article we determined the effects of VDR expression on CD8+ T cells. Results VDR KO CD8+ T cells, but not WT CD8+ T cells, induced colitis in Rag KO recipients. In addition, co-transfer of VDR KO CD8+ T cells with naïve CD4+ T cells accelerated coliti...

  9. 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...

  10. Characterization of the CD8+ T cell responses directed against respiratory syncytial virus during primary and secondary infection in C57BL/6 mice

    International Nuclear Information System (INIS)

    The BALB/c mouse model for human respiratory syncytial virus infection has contributed significantly to our understanding of the relative role for CD4+ and CD8+ T cells to immune protection and pathogenic immune responses. To enable comparison of RSV-specific T cell responses in different mouse strains and allow dissection of immune mechanisms by using transgenic and knockout mice that are mostly available on a C57BL/6 background, we characterized the specificity, level and functional capabilities of CD8+ T cells during primary and secondary responses in lung parenchyma, airways and spleens of C57BL/6 mice. During the primary response, epitopes were recognized originating from the matrix, fusion, nucleo- and attachment proteins, whereas the secondary response focused predominantly on the matrix epitope. C57BL/6 mice are less permissive for hRSV infection than BALB/c mice, yet we found CD8+ T cell responses in the lungs and bronchoalveolar lavage, comparable to the responses described for BALB/c mice

  11. 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

  12. 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

  13. Defects in the acquisition of tumor-killing capability of CD8+ cytotoxic T cells in streptozotocin-induced diabetic mice.

    Directory of Open Access Journals (Sweden)

    Shu-Ching Chen

    Full Text Available Emerging evidences have shown that diabetes mellitus not only raises risk but also heightens mortality rate of cancer. It is not clear, however, whether antitumor CD8+ cytotoxic T lymphocyte (CTL response is down-modulated in diabetic hosts. We investigated the impact of hyperglycemia on CTLs' acquisition of tumor-killing capability by utilizing streptozotocin-induced diabetic (STZ-diabetic mice. Murine diabetes was induced by intraperitoneal injection of STZ (200 mg/kg in C57BL/6 mice, 2C-T cell receptor (TCR transgenic and P14-TCR transgenic mice. The study found that, despite harboring intact proliferative capacity measured with CFSE labeling and MTT assay, STZ-diabetic CD8+ CTLs displayed impaired effector functions. After stimulation, STZ-diabetic CD8+ CTLs produced less perforin and TNFα assessed by intracellular staining, as well as expressed less CD103 protein. Furthermore, adoptive transfer of STZ-diabetic P14 CD8+ effector cells showed an insufficient recruitment to the B16.gp33 melanoma and inadequate production of perforin, granzyme B and TNFα determined by immunohistochemistry in the tumor milieu. As a result, STZ-diabetic CD8+ effector cells were neither able to eliminate tumor nor to improve survival of tumor-bearing mice. Taken together, our data suggest that CD8+ CTLs are crippled to infiltrate into tumors and thus fail to acquire tumor-killing capability in STZ-diabetic hosts.

  14. Expansion of CD8+ cells in autoimmune hemolytic anemia.

    Science.gov (United States)

    Smirnova, S Ju; Sidorova, Ju V; Tsvetaeva, N V; Nikulina, O F; Biderman, B V; Nikulina, E E; Kulikov, S M; Sudarikov, A B

    2016-05-01

    Autoimmune hemolytic anemia (AIHA) is a rare blood disease associated with the production of auto-antibodies and autoimmune hemolysis. A critical role of B-cells in the development of AIHA has been demonstrated before. Here, we present the analysis of the clonal T-cell populations in patients with AIHA. Thirty-three patients with AIHA were included in this study. Thirteen patients with other anemias, 14 patients with other autoimmune conditions (SLE - 6, RA - 8) and 20 healthy donors were included in the study as a control group. The clonality of T-cell was evaluated by the assessment of the T-cell receptor gamma and beta chain gene rearrangements (TCRG and TCRB). The incidence of T-cell monoclonality detected in patients with AIHA was significantly higher compared to the control group. The persistence of T-cell clones did not correlate with the level of hemoglobin and other signs of remission or relapse and did not disappear after the therapy and clinical improvement (observation period was between 1 and 10 years). There was no correlation between the T-cell clonality and the gender, age, splenectomy, duration or severity of the disease. Fractionation of T-lymphocytes (CD4+, CD8+, CD4+25+) revealed that the monoclonal T-cells belonged to the CD8+ sub-population. We assume that besides a possible causative role of the T-cell clones in AIHA to autoimmune process, these clones do not directly participate in the development and maintenance of hemolysis. Most of the AIHA patients (48.5%) demonstrated a T-cell monoclonality, which requires monitoring and should be distinguished from T-cell tumors. PMID:26829107

  15. 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.

  16. 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.

  17. 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

  18. 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.

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    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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-01-01

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

  20. 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

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

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    Shaniya H Khan

    2015-10-01

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

  2. ELISPOTs Produced by CD8 and CD4 Cells Follow Log Normal Size Distribution Permitting Objective Counting

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    Alexey Y. Karulin

    2015-01-01

    Full Text Available Each positive well in ELISPOT assays contains spots of variable sizes that can range from tens of micrometers up to a millimeter in diameter. Therefore, when it comes to counting these spots the decision on setting the lower and the upper spot size thresholds to discriminate between non-specific background noise, spots produced by individual T cells, and spots formed by T cell clusters is critical. If the spot sizes follow a known statistical distribution, precise predictions on minimal and maximal spot sizes, belonging to a given T cell population, can be made. We studied the size distributional properties of IFN-γ, IL-2, IL-4, IL-5 and IL-17 spots elicited in ELISPOT assays with PBMC from 172 healthy donors, upon stimulation with 32 individual viral peptides representing defined HLA Class I-restricted epitopes for CD8 cells, and with protein antigens of CMV and EBV activating CD4 cells. A total of 334 CD8 and 80 CD4 positive T cell responses were analyzed. In 99.7% of the test cases, spot size distributions followed Log Normal function. These data formally demonstrate that it is possible to establish objective, statistically validated parameters for counting T cell ELISPOTs.

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

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    Babs E Verstrepen

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

  4. 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...

  5. 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

  6. 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

  7. 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...

  8. 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+...

  9. 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.

  10. 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%

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

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    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.

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

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    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.

  13. Polymicrobial sepsis alters Ag-dependent and -independent memory CD8 T cell functions1

    OpenAIRE

    Duong, Sean; Condotta, Stephanie A.; Rai, Deepa; Martin, Matthew D.; Griffith, Thomas S.; Vladimir P. Badovinac

    2014-01-01

    Mortality from sepsis frequently results from secondary infections, and the extent to which sepsis affects pathogen-specific memory CD8 T cell responses remains unknown. Using the cecal-ligation and puncture (CLP) model of polymicrobial sepsis, we observed rapid apoptosis of pre-existing memory CD8 T cells after sepsis induction that led to a loss in CD8 T cell-mediated protection. Ag-sensitivity (functional avidity) and Ag-driven secondary expansion of memory CD8 T cells were decreased after...

  14. 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...

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

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    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.

  16. 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

  17. 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

  18. Nevirapine Inhibits the Anti-HIV Activity of CD8+ Cells

    OpenAIRE

    Liu, Lianxing; Wang, Lin; Huang, Liusheng; Siu, Vincent; Teque, Fernando; Aweeka, Francesca T.; Levy, Jay A.

    2013-01-01

    Antiretroviral therapy (ART) significantly reduced the CD8+ cell non-cytotoxic anti-HIV response (CNAR) in twelve HIV-1-infected subjects (p < 0.0001). In separate experiments, CD8+ cells from long term survivors (LTS) were co-cultured with HIV-infected CD4+ cells using varying concentrations of anti-HIV drugs. The antiviral function of CD8+ cells from four of fourteen LTS was reduced with exposure to 10µM nevirapine (p < 0.05). The antiviral activity of CD8+ cells from two LTS was inhibited ...

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

    Directory of Open Access Journals (Sweden)

    Diana Fleissner

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

  20. 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...

  1. 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...

  2. 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

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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.

  8. 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.

  9. 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...

  10. 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

  11. 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

  12. Differential gene expression in CD8+ cells exhibiting noncytotoxic anti-HIV activity

    International Nuclear Information System (INIS)

    Suppressive subtractive hybridization with polymerase chain reaction was used to identify the gene(s) associated with the CD8+ cell noncytotoxic anti-HIV response. The differences in gene expression profiles of CD8+ cells from a pair of discordant HIV-positive identical twins were studied. Forty-nine genes were identified as expressed at higher levels in the CD8+ cells from the infected twin that inhibited viral replication. The differential expression of these genes was then evaluated using Q-PCR to determine if this gene expression pattern is evident in CD8+ cells from other HIV-positive subjects showing this antiviral activity. Three genes, including one unknown, were found to have significantly increased expression in antiviral CD8+ cells

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

    DEFF Research Database (Denmark)

    Labuda, Tord; Christensen, Jan Pravsgaard; Rasmussen, Susanne; Bonnesen, Barbara; Karin, Michael; Thomsen, Allan Randrup; Ødum, Niels

    2006-01-01

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

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    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...... can still induce some antiviral protection, and in vivo depletion of CD8(+) T cells from these animals revealed a pivotal role for CD8(+) T cells in controlling virus replication in the absence of a humoral response. Finally, we demonstrated that effector CD8(+) T cells also contribute to viral...... control in the presence of circulating YF-specific Abs. To our knowledge, this is the first time that YF-specific CD8(+) T cells have been demonstrated to possess antiviral activity in vivo....

  15. Induction of cytotoxic CD8+CD56+ T cells from human thymocytes by interleukin-15

    DEFF Research Database (Denmark)

    Thulesen, S; Nissen, Mogens Holst; Ødum, N; Röpke, C

    2001-01-01

    CD8(+) CD56(+) cells isolated from human peripheral blood lymphocytes have been shown recently to represent a population of cytotoxic active T cells. However, it is not known if these cells are intrathymically or extrathymically developed or how these cells are influenced by growth factors. In the...... present study, we investigated the effects of interleukin-2 (IL-2) and IL-15 on human thymocytes with respect to development of CD8(+) CD56(+) T cells. Freshly isolated thymocytes contain few CD8(+) CD56(+) cells, but the number of these cells increases significantly when thymocytes are grown in the...... presence of IL-15 or IL-2. However, IL-15 induced a significantly higher fraction of CD8(+) CD56(+) cells compared with IL-2. Thus, although IL-2 and IL-15 are known to have a number of redundant functions, we here demonstrate that IL-15 is superior to IL-2 in inducing CD8(+) CD56(+) T cells from cultures...

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

    Science.gov (United States)

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

    2012-06-01

    Besides the classically described subsets of memory CD8 T cells generated under infectious conditions, are T inflammatory memory cells generated under sterile priming conditions, such as sensitization to allergens. Although not fully differentiated as pathogen-induced memory cells, they display memory properties that distinguish them from naive CD8 T cells. Given these memory cells are generated in an antigen-specific context that is devoid of pathogen-derived danger signals and CD4 T cell help, we herein questioned whether they maintained their activation and differentiation potential, could be recruited in an immune response directed against a pathogen expressing their cognate antigen and further differentiate in fully competent secondary memory cells. We show that T inflammatory memory cells can indeed take part to the immune response triggered by a viral infection, differentiate into secondary effectors and further generate typical central memory CD8 T cells and effector memory CD8 T cells. Furthermore, the secondary memory cells they generate display a functional advantage over primary memory cells in their capacity to produce TNF-α and the XCL1 chemokine. These results suggest that cross-reactive stimulations and differentiation of cells directed against allergens or self into fully competent pathogen-induced memory cells might have incidences in inflammatory immuno-pathologies. PMID:22528127

  17. 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.

  18. Activated human γδ T cells induce peptide-specific CD8+ T-cell responses to tumor-associated self-antigens.

    Science.gov (United States)

    Altvater, Bianca; Pscherer, Sibylle; Landmeier, Silke; Kailayangiri, Sareetha; Savoldo, Barbara; Juergens, Heribert; Rossig, Claudia

    2012-03-01

    Specific cellular immunotherapy of cancer requires efficient generation and expansion of cytotoxic T lymphocytes (CTLs) that recognize tumor-associated self-antigens. Here, we investigated the capacity of human γδ T cells to induce expansion of CD8+ T cells specific for peptides derived from the weakly immunogenic tumor-associated self-antigens PRAME and STEAP1. Coincubation of aminobisphosphonate-stimulated human peripheral blood-derived γδ T cells (Vγ9+Vδ2+), loaded with HLA-A*02-restricted epitopes of PRAME, with autologous peripheral blood CD8+ T cells stimulated the expansion of peptide-specific cytolytic effector memory T cells. Moreover, peptide-loaded γδ T cells efficiently primed antigen-naive CD45RA+ CD8+ T cells against PRAME peptides. Direct comparisons with mature DCs revealed equal potency of γδ T cells and DCs in inducing primary T-cell responses and peptide-specific T-cell activation and expansion. Antigen presentation by γδ T-APCs was not able to overcome the limited capacity of peptide-specific T cells to interact with targets expressing full-length antigen. Importantly, T cells with regulatory phenotype (CD4+ CD25hiFoxP3+) were lower in cocultures with γδ T cells compared to DCs. In summary, bisphosphonate-activated γδ T cells permit generation of CTLs specific for weakly immunogenic tumor-associated epitopes. Exploiting this strategy for effective immunotherapy of cancer requires strategies that enhance the avidity of CTL responses to allow for efficient targeting of cancer. PMID:21928126

  19. 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

  20. 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...

  1. 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.

  2. Regulation of maturation and activating potential in CD8+ versus CD8- dendritic cells following in vivo infection with vaccinia virus.

    Science.gov (United States)

    Yammani, Rama D; Pejawar-Gaddy, Sharmila; Gurley, Thaddeus C; Weimer, Eric T; Hiltbold, Elizabeth M; Alexander-Miller, Martha A

    2008-08-15

    DC maturation is known to be a necessary step in the generation of an effective immune response. We have used vaccinia virus (VACV) as a model to investigate the regulation of DC subsets in vivo following infection. While a number of in vitro studies have shown that DC infected with VACV fail to undergo maturation, the effect of VACV infection on the maturation of and cytokine production by DC subsets in vivo remains less defined. We have found that following systemic infection with vaccinia virus, both CD8+ and CD8- dendritic cells are infected. The number of infected DC peaked at 6 h and was highly decreased by 24 h post-infection. In both subsets, there was evidence of generalized upregulation of costimulatory molecules. Surprisingly, this included vaccinia infected DC, suggesting the regulation of DC maturation in vivo is much more complex and likely influenced by DC extrinsic signals. However, while we observed generalized upregulation of costimulatory molecules, IL-12 production was restricted to a subset of non-infected cells in both the CD8+ and CD8- DC populations. Importantly, the control of IL-12 production was differentially dependent on MyD88 signaling. IL-12 production was ablated in the absence of MyD88 in CD8- DC, while it was unchanged in CD8+ DC. These findings provide new insights into the control of DC maturation in vivo and demonstrate that the regulation of maturation in vivo following virus infection can be differentially controlled in distinct types of DC. PMID:18586296

  3. Establishment of antitumor memory in humans using in vitro-educated CD8+ T cells.

    Science.gov (United States)

    Butler, Marcus O; Friedlander, Philip; Milstein, Matthew I; Mooney, Mary M; Metzler, Genita; Murray, Andrew P; Tanaka, Makito; Berezovskaya, Alla; Imataki, Osamu; Drury, Linda; Brennan, Lisa; Flavin, Marisa; Neuberg, Donna; Stevenson, Kristen; Lawrence, Donald; Hodi, F Stephen; Velazquez, Elsa F; Jaklitsch, Michael T; Russell, Sara E; Mihm, Martin; Nadler, Lee M; Hirano, Naoto

    2011-04-27

    Although advanced-stage melanoma patients have a median survival of less than a year, adoptive T cell therapy can induce durable clinical responses in some patients. Successful adoptive T cell therapy to treat cancer requires engraftment of antitumor T lymphocytes that not only retain specificity and function in vivo but also display an intrinsic capacity to survive. To date, adoptively transferred antitumor CD8(+) T lymphocytes (CTLs) have had limited life spans unless the host has been manipulated. To generate CTLs that have an intrinsic capacity to persist in vivo, we developed a human artificial antigen-presenting cell system that can educate antitumor CTLs to acquire both a central memory and an effector memory phenotype as well as the capacity to survive in culture for prolonged periods of time. We examined whether antitumor CTLs generated using this system could function and persist in patients. We showed that MART1-specific CTLs, educated and expanded using our artificial antigen-presenting cell system, could survive for prolonged periods in advanced-stage melanoma patients without previous conditioning or cytokine treatment. Moreover, these CTLs trafficked to the tumor, mediated biological and clinical responses, and established antitumor immunologic memory. Therefore, this approach may broaden the availability of adoptive cell therapy to patients both alone and in combination with other therapeutic modalities. PMID:21525398

  4. 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, ...

  5. 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.

  6. 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

  7. CD8alpha/alpha+ T-cells and Immune Memory

    OpenAIRE

    Magalhaes, Isabelle

    2009-01-01

    A better understanding of T-cell memory formation is crucial for rationale vaccine design and the identification of correlates of immune protection. The CD8alphaalpha homodimer expressed on CD8+ T-cells is not anymore considered to represent a TCR co-receptor, it may rather represent a mechanism to modulate T-cell avidity and identify a subset of memory T-cells. The aim of the work presented in this thesis was to characterize the CD8alphaalpha+ T-cell compartment in the cont...

  8. 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.

  9. 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....

  10. 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

  11. 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...

  12. 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...

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

    International Nuclear Information System (INIS)

    Intracerebral infection of susceptible mice with Theiler's murine encephalomyelitis virus (TMEV) induces immune-mediated demyelinating disease and this system serves as a relevant infectious model for human multiple sclerosis. It was previously shown that β2M-deficient C57BL/6 mice lacking functional CD8+ T cells display increased viral persistence and enhanced susceptibility to TMEV-induced demyelination, and yet the majority of mice are free of clinical signs. To understand the mechanisms involved in this general resistance of C57BL/6 mice in the absence of CTL responses, mice (μMT) deficient in the B-cell compartment lacking membrane IgM molecules were treated with anti-CD8 antibody and then infected with TMEV. Although little difference in the proliferative responses of peripheral T cells to UV-inactivated TMEV and the resistance to demyelinating disease was observed between virus-infected μMT and control B6 mice, the levels of CD4+ T cells were higher in the CNS of μMT mice. However, after treatment with anti-CD8 antibody, 100% of the mice displayed clinical gray matter disease and prolonged viral persistence in μMT mice, while only 10% of B6 mice showed clinical symptoms and very low viral persistence. Transfusion of sera from TMEV-infected B6 mice into anti-CD8 antibody-treated μMT mice partially restored resistance to virus-induced encephalitis. These results indicate that the early anti-viral antibody response is also important in the protection from TMEV-induced encephalitis particularly in the absence of CD8+ T cells

  14. 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.

  15. 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

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

    Directory of Open Access Journals (Sweden)

    Jang Eun Lee

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

  17. Perforin-deficient CD8+ T cells mediate fatal lymphocytic choriomeningitis despite impaired cytokine production

    DEFF Research Database (Denmark)

    Storm, Pernille; Bartholdy, Christina; Sørensen, Maria Rathmann; Christensen, Jan Pravsgaard; Thomsen, Allan Randrup

    2006-01-01

    the outcome of i.c. infection with LCMV. We confirmed that the expansion of virus-specific CD8(+) T cells is unimpaired in perforin-deficient mice. However, despite the fact that the virus-specific CD8(+) effector T cells in perforin-deficient mice are broadly impaired in their effector function......, these mice invariably succumb to i.c. infection with LCMV strain Armstrong, although a few days later than matched wild-type mice. Upon further investigation, we found that this delay correlates with the delayed recruitment of inflammatory cells to the central nervous system (CNS). However, CD8...... the main explanation for the delayed onset of fatal disease in perforin-deficient mice. However, once accumulated in the CNS, virus-specific CD8(+) T cells can induce fatal CNS pathology despite the absence of perforin-mediated lysis and reduced capacity to produce several key cytokines....

  18. 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; Marker, O; Thomsen, Allan Randrup

    1995-01-01

    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...... infection results in the appearance of activated CD8+ cells with an increased expression of VLA-4. In this study we have compared various T cell high and low responder situations, and these experiments revealed that acute inflammation correlates directly with VLA-4 expression on splenic CD8+ cells. This...... ability to transfer virus-specific, delayed-type hypersensitivity when the donor cells were given i.v., but not when the cells were injected directly into the test site. Co-transfer of CD8-depleted cells with anti-VLA-4-blocked cells did not reveal any cooperation. Taken together, these results indicate...

  19. 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.

  20. An assessment on epitope prediction methods for protozoa genomes

    Directory of Open Access Journals (Sweden)

    Resende Daniela M

    2012-11-01

    Full Text Available Abstract Background Epitope prediction using computational methods represents one of the most promising approaches to vaccine development. Reduction of time, cost, and the availability of completely sequenced genomes are key points and highly motivating regarding the use of reverse vaccinology. Parasites of genus Leishmania are widely spread and they are the etiologic agents of leishmaniasis. Currently, there is no efficient vaccine against this pathogen and the drug treatment is highly toxic. The lack of sufficiently large datasets of experimentally validated parasites epitopes represents a serious limitation, especially for trypanomatids genomes. In this work we highlight the predictive performances of several algorithms that were evaluated through the development of a MySQL database built with the purpose of: a evaluating individual algorithms prediction performances and their combination for CD8+ T cell epitopes, B-cell epitopes and subcellular localization by means of AUC (Area Under Curve performance and a threshold dependent method that employs a confusion matrix; b integrating data from experimentally validated and in silico predicted epitopes; and c integrating the subcellular localization predictions and experimental data. NetCTL, NetMHC, BepiPred, BCPred12, and AAP12 algorithms were used for in silico epitope prediction and WoLF PSORT, Sigcleave and TargetP for in silico subcellular localization prediction against trypanosomatid genomes. Results A database-driven epitope prediction method was developed with built-in functions that were capable of: a removing experimental data redundancy; b parsing algorithms predictions and storage experimental validated and predict data; and c evaluating algorithm performances. Results show that a better performance is achieved when the combined prediction is considered. This is particularly true for B cell epitope predictors, where the combined prediction of AAP12 and BCPred12 reached an AUC value

  1. Temporary, but Essential Requirement of CD8+ T Cells Early in the Pathogenesis of Diabetes in BB Rats as Revealed by Thymectomy and CD8 Depletion

    Directory of Open Access Journals (Sweden)

    Jan Rozing

    2003-01-01

    Full Text Available Autoimmunity-prone BB rats demonstrate a T lymphocytopenia and abnormal T cell subset distribution. To test whether the life span of all T cells or only of certain subsets is reduced in BB rats, we thymectomised 8-week-old BB and PVG rats and subsequently assessed size and composition of the T cell population over a 6-week-period. In both strains, thymectomy (Tx was followed by a decrease in peripheral T cell numbers, which was proportionally larger in BB rats. The decline of the Thy-1+ recent thymic migrant (RTM T cell phenotype was similar in both strains. BB rats showed a rapid preferential loss of CD8+ and CD45RC+ T cells, whereas the relative loss of RT6+ T cells was proportional to that of all T cells and not significantly different from that in PVG rats. Tx at 8-week did not prevent diabetes. Tx of 4-week-old BB rats revealed essentially the same changes in peripheral T cell subset distribution as in 8-week-old animals. However, Tx at week 4 did prevent diabetes. Since this raised the possibility of a temporary requirement of CD8+ T cells for the development of diabetes, we performed CD8 depletions during different pre-diabetic intervals. We found that CD8 depletion from 4 to 8 and 4 to 14 weeks, but not from 8 to 14 weeks of age prevented diabetes. We conclude that the protective effect of early adult Tx is, at least in part, due to the rapid loss of CD8+ T cells, and that these cells are only required between 4 and 8 weeks of age for diabetes to develop in BB rats.

  2. 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.

  3. 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 ...

  4. Protective CD8+ T lymphocytes in Primates Immunized with Malaria Sporozoites

    OpenAIRE

    Weiss, Walter R.; Jiang, Chengyong George

    2012-01-01

    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 atten...

  5. 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...

  6. Biopolymer encapsulated live influenza virus as a universal CD8+ T cell vaccine against influenza virus

    OpenAIRE

    Boesteanu, Alina C.; Babu, Nadarajan S.; Wheatley, Margaret; Papazoglou, Elisabeth S.; Katsikis, Peter D.

    2010-01-01

    Current influenza virus vaccines primarily elicit antibodies and can be rendered ineffective by antigenic drift and shift. Vaccines that elicit CD8+ T cell responses targeting less variable proteins may function as universal vaccines that have broad reactivity against different influenza virus strains. To generate such a universal vaccine, we encapsulated live influenza virus in a biopolymer and delivered it to mice subcutaneously. This vaccine was safe, induced potent CD8+ T cell immunity an...

  7. 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 ...

  8. Immunodominant Tuberculosis CD8 Antigens Preferentially Restricted by HLA-B

    OpenAIRE

    Lewinsohn, Deborah A.; Winata, Ervina; Swarbrick, Gwendolyn M; Tanner, Katie E; Cook, Matthew S.; Null, Megan D.; Cansler, Meghan E; Sette, Alessandro; Sidney, John; Lewinsohn, David M

    2007-01-01

    CD8+ T cells are essential for host defense to intracellular bacterial pathogens such as Mycobacterium tuberculosis (Mtb), Salmonella species, and Listeria monocytogenes, yet the repertoire and dominance pattern of human CD8 antigens for these pathogens remains poorly characterized. Tuberculosis (TB), the disease caused by Mtb infection, remains one of the leading causes of infectious morbidity and mortality worldwide and is the most frequent opportunistic infection in individuals with HIV/AI...

  9. 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.

  10. 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

  11. 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

  12. 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.

  13. 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

  14. 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.

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

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    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.

  16. 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

  17. 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.

  18. 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

  19. 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

  20. 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...

  1. 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

  2. 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.

  3. 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.

  4. 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

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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...

  10. CD8+ T lymphocytes in lung tissue from patients with idiopathic pulmonary fibrosis

    Directory of Open Access Journals (Sweden)

    Roussos Charis

    2005-07-01

    Full Text Available Abstract Background Several studies have implicated a role of inflammation in the pathogenesis of lung damage in idiopathic pulmonary fibrosis (IPF. Parenchymal lung damage leads to defects in mechanics and gas exchange and clinically manifests with exertional dyspnea. Investigations of inflammatory cells in IPF have shown that eosinophils, neutrophils and CD8+ TLs may be associated with worse prognosis. We wished to investigate by quantitative immunohistochemistry infiltrating macrophages, neutrophils and T lymphocytes (TLs subpopulations (CD3+, CD4+ and CD8+ in lung tissue of patients with IPF and their correlation with lung function indices and grade of dyspnoea. Methods Surgical biopsies of 12 patients with IPF were immunohistochemically stained with mouse monoclonal antibodies (anti-CD68 for macrophages, anti-elastase for neutrophils, and anti-CD3, anti-CD4, anti-CD8 for CD3+TLs, CD4+TLs, and CD8+TLs respectively. The number of positively stained cells was determined by observer-interactive computerized image analysis (SAMBA microscopic image processor. Cell numbers were expressed in percentage of immunopositive nuclear surface in relation to the total nuclear surface of infiltrative cells within the tissue (labeling Index. Correlations were performed between cell numbers and physiological indices [FEV1, FVC, TLC, DLCO, PaO2, PaCO2 and P(A-aO2] as well as dyspnoea scores assessed by the Medical Research Council (MRC scale. Results Elastase positive cells accounted for the 7.04% ± 1.1 of total cells, CD68+ cells for the 16.6% ± 2, CD3+ TLs for the 28.8% ± 7, CD4+ TLs for the 14.5 ± 4 and CD8+ TLs for the 13.8 ± 4. CD8+TLs correlated inversely with FVC % predicted (rs = -0.67, p = 0.01, TLC % predicted (rs = -0.68, p = 0.01, DLCO % predicted (rs = -0.61, p = 0.04, and PaO2 (rs = -0.60, p = 0.04. Positive correlations were found between CD8+TLs and P(A-aO2 (rs = 0.65, p = 0.02 and CD8+TLs and MRC score (rs = 0.63, p = 0.02. Additionally

  11. 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

  12. 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.

  13. Differential sensitivity of naive and memory CD8+ T cells to apoptosis in vivo.

    Science.gov (United States)

    Grayson, Jason M; Harrington, Laurie E; Lanier, J Gibson; Wherry, E John; Ahmed, Rafi

    2002-10-01

    Apoptosis is a critical regulator of homeostasis in the immune system. In this study we demonstrate that memory CD8(+) T cells are more resistant to apoptosis than naive cells. After whole body irradiation of mice, both naive and memory CD8(+) T cells decreased in number, but the reduction in the number of naive cells was 8-fold greater than that in memory CD8(+) T cells. In addition to examining radiation-induced apoptosis, we analyzed the expansion and contraction of naive and memory CD8(+) T cells in vivo following exposure to Ag. We found that memory CD8(+) T cells not only responded more quickly than naive cells after viral infection, but that secondary effector cells generated from memory cells underwent much less contraction compared with primary effectors generated from naive cells (3- to 5-fold vs 10- to 20-fold decrease). Increased numbers of secondary memory cells were observed in both lymphoid and non-lymphoid tissues. When naive and memory cells were transferred into the same animal, secondary effectors underwent less contraction than primary effector cells. These experiments analyzing apoptosis of primary and secondary effectors in the same animal show unequivocally that decreased downsizing of the secondary response reflects an intrinsic property of the memory T cells and is not simply due to environmental effects. These findings have implications for designing prime/boost vaccine strategies and also for optimizing immunotherapeutic regimens for treatment of chronic infections. PMID:12244170

  14. 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.

  15. 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.

  16. Functional classification of memory CD8(+) T cells by CX3CR1 expression.

    Science.gov (United States)

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

    2015-01-01

    Localization of memory CD8(+) T cells to lymphoid or peripheral tissues is believed to correlate with proliferative capacity or effector function. Here we demonstrate that the fractalkine-receptor/CX3CR1 distinguishes memory CD8(+) T cells with cytotoxic effector function from those with proliferative capacity, independent of tissue-homing properties. CX3CR1-based transcriptome and proteome-profiling defines a core signature of memory CD8(+) T cells with effector function. We find CD62L(hi)CX3CR1(+) memory T cells that reside within lymph nodes. This population shows distinct migration patterns and positioning in proximity to pathogen entry sites. Virus-specific CX3CR1(+) memory CD8(+) T cells are scarce during chronic infection in humans and mice but increase when infection is controlled spontaneously or by therapeutic intervention. This CX3CR1-based functional classification will help to resolve the principles of protective CD8(+) T-cell memory. PMID:26404698

  17. 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

  18. 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

  19. CD8+ T lymphocyte expansion, proliferation and activation in dengue fever.

    Science.gov (United States)

    de Matos, Andréia Manso; Carvalho, Karina Inacio; Rosa, Daniela Santoro; Villas-Boas, Lucy Santos; da Silva, Wanessa Cardoso; Rodrigues, Célia Luiza de Lima; Oliveira, Olímpia Massae Nakasone Peel Furtado; Levi, José Eduardo; Araújo, Evaldo Stanislau Affonso; Pannuti, Claudio Sergio; Luna, Expedito José Albuquerque; Kallas, Esper George

    2015-02-01

    Dengue fever induces a robust immune response, including massive T cell activation. The level of T cell activation may, however, be associated with more severe disease. In this study, we explored the level of CD8+ T lymphocyte activation in the first six days after onset of symptoms during a DENV2 outbreak in early 2010 on the coast of São Paulo State, Brazil. Using flow cytometry we detected a progressive increase in the percentage of CD8+ T cells in 74 dengue fever cases. Peripheral blood mononuclear cells from 30 cases were thawed and evaluated using expanded phenotyping. The expansion of the CD8+ T cells was coupled with increased Ki67 expression. Cell activation was observed later in the course of disease, as determined by the expression of the activation markers CD38 and HLA-DR. This increased CD8+ T lymphocyte activation was observed in all memory subsets, but was more pronounced in the effector memory subset, as defined by higher CD38 expression. Our results show that most CD8+ T cell subsets are expanded during DENV2 infection and that the effector memory subset is the predominantly affected sub population. PMID:25675375

  20. 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

  1. 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

  2. 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.

  3. 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.

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

    Science.gov (United States)

    Sullivan, Lucy C.; Westall, Glen P.; Widjaja, Jacqueline M. L.; Mifsud, Nicole A.; Nguyen, Thi H. O.; Meehan, Aislin C.; Kotsimbos, Tom C.; Brooks, Andrew G.

    2015-01-01

    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. PMID:26302084

  5. Rabies virus-based vaccines elicit neutralizing antibodies, poly-functional CD8+ T cell, and protect rhesus macaques from AIDS-like disease after SIVmac251 challenge

    Science.gov (United States)

    Faul, Elizabeth J.; Aye, Pyone P.; Papaneri, Amy B.; Pahar, Bapi; McGettigan, James P.; Schiro, Faith; Chervoneva, Inna; Montefiori, David C.; Lackner, Andrew A.; Schnell, Matthias J.

    2010-01-01

    Highly attenuated rabies virus (RV) vaccine vectors were evaluated for their ability to protect against highly pathogenic SIVmac251 challenge. Mamu-A*01 negative rhesus macaques were immunized in groups of four with either: RV expressing SIVmac239-GagPol, a combination of RV expressing SIVmac239-Env and RV expressing SIVmac239-GagPol, or with empty RV vectors. Eight weeks later animals received a booster immunization with a heterologous RV expressing the same antigens. At twelve weeks post-boost, all animals were challenged intravenously with 100 TCID50 of pathogenic SIVmac251-CX. Immunized macaques in both vaccine groups had 1.3–1.6-log fold decrease in viral set point compared to control animals. The GagPol/Env immunized animals also had a significantly lower peak viral load. When compared to control animals following challenge, vaccinated macaques had a more rapid induction of SIVmac251 neutralizing antibodies and of CD8+ T cell responses to various SIV epitopes. Moreover, vaccinated macaques better-maintained peripheral memory CD4+ T cells and were able to mount a poly-functional CD8+ T cell response in the mucosa. These findings indicate promise for RV-based vectors and have important implications for the development of an efficacious HIV vaccine. PMID:19879223

  6. 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

  7. 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; Hammer, J; Nielsen, H

    1994-01-01

    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...... 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...... 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...

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

    DEFF Research Database (Denmark)

    Marquez, M.-E.; Ellmeier, W.; Sanchez-Guajardo, Vanesa Maria; Freitas, A.A.; Acuto, O.; Di Bartolo, V.

    2005-01-01

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

  9. 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

  10. Suppression of HIV Replication by CD8+ Regulatory T-Cells in Elite Controllers

    Science.gov (United States)

    Lu, Wei; Chen, Song; Lai, Chunhui; Lai, Mingyue; Fang, Hua; Dao, Hong; Kang, Jun; Fan, Jianhua; Guo, Weizhong; Fu, Linchun; Andrieu, Jean-Marie

    2016-01-01

    We previously demonstrated in the Chinese macaque model that an oral vaccine made of inactivated SIV and Lactobacillus plantarum induced CD8+ regulatory T-cells, which suppressed the activation of SIV+CD4+ T-cells, prevented SIV replication, and protected macaques from SIV challenges. Here, we sought whether a similar population of CD8+ T-regs would induce the suppression of HIV replication in elite controllers (ECs), a small population (3‰) of HIV-infected patients with undetectable HIV replication. For that purpose, we investigated the in vitro antiviral activity of fresh CD8+ T-cells on HIV-infected CD4+ T-cells taken from 10 ECs. The 10 ECs had a classical genomic profile: all of them carried the KIR3DL1 gene and 9 carried at least 1 allele of HLA-B:Bw4-80Ile (i.e., with an isoleucine residue at position 80). In the nine HLA-B:Bw4-80Ile-positive patients, we demonstrated a strong viral suppression by KIR3DL1-expressing CD8+ T-cells that required cell-to-cell contact to switch off the activation signals in infected CD4+ T-cells. KIR3DL1-expressing CD8+ T-cells withdrawal and KIR3DL1 neutralization by a specific anti-killer cell immunoglobulin-like receptor (KIR) antibody inhibited the suppression of viral replication. Our findings provide the first evidence for an instrumental role of KIR-expressing CD8+ regulatory T-cells in the natural control of HIV-1 infection. PMID:27148256

  11. Intrasinusoidal cytotoxic CD8+ T cells in nodular regenerative hyperplasia of the liver.

    Science.gov (United States)

    Ziol, Marianne; Poirel, Helene; Kountchou, Gisele N; Boyer, Olivier; Mohand, Djamila; Mouthon, Luc; Tepper, Maryline; Guillet, Jean-Gerard; Guettier, Catherine; Raphael, Martine; Beaugrand, Michel

    2004-10-01

    Diffuse nodular regenerative hyperplasia (NRH) of the liver is an acquired architectural disturbance that can lead to portal hypertension. Although frequently associated with autoimmune or hematologic malignancies, its exact pathogenesis remains largely unknown. We observed CD8+ cytotoxic T cells in the liver sinusoids of 14 of 44 NRH patients and explored possible relationships between these lymphocytes and vascular damage. The immunophenotype of intrahepatic lymphocytes was determined using immunohistochemical analysis and endothelial injury using the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling method for apoptosis combined with endothelial cell labeling. Controls for the quantitative analysis of liver-infiltrating lymphocytes consisted of patients with chronic hepatitis C or normal liver (n = 13 and n = 6, respectively). Liver specimens from the 14 patients dislayed intrasinusoidal infiltrate composed of CD3+ and CD8+ lymphocytes, located near atrophic liver cell plates. Significantly more granzyme B+ and CD57+ lymphocytes were observed in NRH than chronic hepatitis C samples with quantitatively similar CD8+ infiltrates. Double-labeling revealed apoptotic endothelial sinusoidal cells in CD8+ T-cell-infiltrated areas in all NRH samples but never in chronic hepatitis C or normal livers. T-cell receptor rearrangement or immunoscope analysis suggested liver-specific polyclonal or oligoclonal T-cell expansions. Clinical and biological characteristics of the 14 patients were similar to those observed in the 30 patients with NRH devoid of lymphocytic infiltration. We report here that CD8+ cytotoxic T cells infiltrated the liver sinusoids of a high percentage (32%) of NRH patients and suggest that some NRH cases might result from chronic, cytotoxic CD8+ T-lymphocyte targeting of sinusoidal endothelial cells. PMID:15492992

  12. CD8+ CD205+ splenic dendritic cells are specialized to induce Foxp3+ regulatory T cells.

    Science.gov (United States)

    Yamazaki, Sayuri; Dudziak, Diana; Heidkamp, Gordon F; Fiorese, Christopher; Bonito, Anthony J; Inaba, Kayo; Nussenzweig, Michel C; Steinman, Ralph M

    2008-11-15

    Foxp3(+)CD25(+)CD4(+) regulatory T cells (Treg) mediate immunological self-tolerance and suppress immune responses. A subset of dendritic cells (DCs) in the intestine is specialized to induce Treg in a TGF-beta- and retinoic acid-dependent manner to allow for oral tolerance. In this study we compare two major DC subsets from mouse spleen. We find that CD8(+) DEC-205/CD205(+) DCs, but not the major fraction of CD8(-) DC inhibitory receptor-2 (DCIR2)(+) DCs, induce functional Foxp3(+) Treg from Foxp3(-) precursors in the presence of low doses of Ag but without added TGF-beta. CD8(+)CD205(+) DCs preferentially express TGF-beta, and the induction of Treg by these DCs in vitro is blocked by neutralizing Ab to TGF-beta. In contrast, CD8(-)DCIR2(+) DCs better induce Foxp3(+) Treg when exogenous TGF-beta is supplied. In vivo, CD8(+)CD205(+) DCs likewise preferentially induce Treg from adoptively transferred, Ag-specific DO11.10 RAG(-/-) Foxp3(-)CD4(+) T cells, whereas the CD8(-)DCIR2(+) DCs better stimulate natural Foxp3(+) Treg. These results indicate that a subset of DCs in spleen, a systemic lymphoid organ, is specialized to differentiate peripheral Foxp3(+) Treg, in part through the endogenous formation of TGF-beta. Targeting of Ag to these DCs might be useful for inducing Ag-specific Foxp3(+) Treg for treatment of autoimmune diseases, transplant rejection, and allergy. PMID:18981112

  13. 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.

  14. The localization of naive and memory CD8+ T cells following infection

    OpenAIRE

    Yang, Edward

    2009-01-01

    Different subsets of memory CD8⁺ T cells populate the T cell compartment. Antigen-experienced memory (true-memory) cells are formed in a classic immune response against an invading pathogen, but memory-like (HP-memory) cells can also be generated through antigen-independent homeostatic proliferation resulting from lymphopenia. HP-memory cells subsequently acquire the same effector functions and surface marker expression as true-memory cells. When HP- and true-memory CD8⁺ cells of the same spe...

  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. Separate Roles for Antigen Recognition and Lymph Node Inflammation in CD8+ Memory T Cell Formation

    OpenAIRE

    Fransen, Marieke F.; van Stipdonk, Marianne J.; Sluijter, Marjolein; Schoenberger, Stephen P.; Melief, Cornelis J; Offringa, Rienk

    2010-01-01

    Priming of naive CD8+ T cells by pathogens or vaccines generally involves their interaction with Ag-loaded dendritic cells (DCs) in the context of an inflamed lymph node. Lymph node activation fosters DC and T cell encounters and subsequently provides newly primed T cells with nurturing conditions. We dissected these two aspects by infusing in vitro primed CD8+ T cells into naive recipient mice harboring a single activated lymph node and comparing the fate of these T cells with those infused ...

  17. Immunological control of a murine gammaherpesvirus independent of CD8+ T cells

    DEFF Research Database (Denmark)

    Stevenson, P G; Cardin, R D; Christensen, Jan Pravsgaard; Doherty, P C

    Adult thymectomized C57 BL/6J mice were depleted of T cell subsets by MAb treatment either prior to, or after, respiratory challenge with murine gammaherpesvirus-68. Protection against acute infection was maintained when either the CD4+ or the CD8+ T cell population was greatly diminished, whereas...... the concurrent removal of both T cell subsets proved invariably fatal. The same depletions had little effect on mice with established infection. The results indicate firstly that both CD4+ and CD8+ T cells play a significant part in dealing with the acute infection, and secondly that virus...

  18. 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

    : 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...... 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...

  19. Effect of ageing on CMV-specific CD8 T cells from CMV seropositive healthy donors

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    Alonso Corona

    2009-08-01

    Full Text Available Abstract Background Ageing is associated with changes in the immune system with substantial alterations in T-lymphocyte subsets. Cytomegalovirus (CMV is one of the factors that affect functionality of T cells and the differentiation and large expansions of CMV pp65-specific T cells have been associated with impaired responses to other immune challenges. Moreover, the presence of clonal expansions of CMV-specific T cells may shrink the available repertoire for other antigens and contribute to the increased incidence of infectious diseases in the elderly. In this study, we analyse the effect of ageing on the phenotype and frequency of CMV pp65-specific CD8 T cell subsets according to the expression of CCR7, CD45RA, CD27, CD28, CD244 and CD85j. Results Peripheral blood from HLA-A2 healthy young, middle-aged and elderly donors was analysed by multiparametric flow cytometry using the HLA-A*0201/CMV pp65495–504 (NLVPMVATV pentamer and mAbs specific for the molecules analysed. The frequency of CMV pp65-specific CD8 T cells was increased in the elderly compared with young and middle-aged donors. The proportion of naïve cells was reduced in the elderly, whereas an age-associated increase of the CCR7null effector-memory subset, in particular those with a CD45RAdim phenotype, was observed, both in the pentamer-positive and pentamer-negative CD8 T cells. The results also showed that most CMV pp65-specific CD8 T cells in elderly individuals were CD27/CD28 negative and expressed CD85j and CD244. Conclusion The finding that the phenotype of CMV pp65-specific CD8 T cells in elderly individuals is similar to the predominant phenotype of CD8 T cells as a whole, suggests that CMV persistent infections contributes to the age-related changes observed in the CD8 T cell compartment, and that chronic stimulation by other persistent antigens also play a role in T cell immunosenescence. Differences in subset distribution in elderly individuals showing a decrease in

  20. 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...

  1. 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...

  2. 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...

  3. Lung CD8+ T cells in COPD have increased expression of bacterial TLRs

    Directory of Open Access Journals (Sweden)

    Freeman Christine M

    2013-02-01

    Full Text Available Abstract Background Toll-like receptors (TLRs on T cells can modulate their responses, however, the extent and significance of TLR expression by lung T cells, NK cells, or NKT cells in chronic obstructive pulmonary disease (COPD is unknown. Methods Lung tissue collected from clinically-indicated resections (n = 34 was used either: (a to compare the expression of TLR1, TLR2, TLR2/1, TLR3, TLR4, TLR5, TLR6 and TLR9 on lung CD8+ T cells, CD4+ T cells, NK cells and NKT cells from smokers with or without COPD; or (b to isolate CD8+ T cells for culture with anti-CD3ε without or with various TLR ligands. We measured protein expression of IFN-γ, TNF-α, IL-13, perforin, granzyme A, granzyme B, soluble FasL, CCL2, CCL3, CCL4, CCL5, CCL11, and CXCL9 in supernatants. Results All the lung subsets analyzed demonstrated low levels of specific TLR expression, but the percentage of CD8+ T cells expressing TLR1, TLR2, TLR4, TLR6 and TLR2/1 was significantly increased in COPD subjects relative to those without COPD. In contrast, from the same subjects, only TLR2/1 and TLR2 on lung CD4+ T cells and CD8+ NKT cells, respectively, showed a significant increase in COPD and there was no difference in TLR expression on lung CD56+ NK cells. Production of the Tc1 cytokines IFN-γ and TNF-α by lung CD8+ T cells were significantly increased via co-stimulation by Pam3CSK4, a specific TLR2/1 ligand, but not by other agonists. Furthermore, this increase in cytokine production was specific to lung CD8+ T cells from patients with COPD as compared to lung CD8+ T cells from smokers without COPD. Conclusions These data suggest that as lung function worsens in COPD, the auto-aggressive behavior of lung CD8+ T cells could increase in response to microbial TLR ligands, specifically ligands against TLR2/1.

  4. GATA-3 regulates the homeostasis and activation of CD8+ T cells1

    OpenAIRE

    Tai, Tzong-Shyuan; Pai, Sung-Yun; Ho, I-Cheng

    2012-01-01

    GATA-3, a C2C2 type zinc finger transcription factor, regulates many steps of T cell development and differentiation. It is also required for optimal production of type 2 cytokines by CD8+ T cells. However, its role in the development and function of this subset of T cells is still poorly characterized. Here we report that GATA-3 is required for MHC-mediated positive selection and final maturation of CD8 single positive thymocytes. Deficiency of GATA-3 mediated by a CD4cre transgene led to ag...

  5. 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

  6. Canine CD4+CD8+ double positive T cells in peripheral blood have features of activated T cells.

    Science.gov (United States)

    Bismarck, Doris; Schütze, Nicole; Moore, Peter; Büttner, Mathias; Alber, Gottfried; Buttlar, Heiner v

    2012-10-15

    In dogs a CD4(+)CD8(+) double positive T cell subpopulation exists that has not been phenotypically defined yet. We demonstrate that canine CD4(+)CD8(+) T cells are mature CD1a(-) and TCRαβ(+) T cells. To analyse the activation potential of CD4(+)CD8(+) T cells, PBMC from dogs vaccinated against canine distemper virus (CDV) were re-stimulated with CDV. Upon antigen-specific stimulation, the CD4(+)CD8(+) T cell fraction increases and consists nearly exclusively of proliferated cells. Similarly, other features of activated effector/memory T cells such as up-regulation of CD25 and MHC-II as well as down-regulation of CD62L (L-selectin) were observed in CD4(+)CD8(+) T cells after stimulation. Canine CD4(+)CD8(+) T cells are less abundant, but more heterogeneous than porcine ones, comprising a small proportion expressing the β chain of CD8 in addition to the CD8α chain, like human CD4(+)CD8(+) T cells. In summary, this analysis provides the basis for functional characterisation of the in vivo relevance of CD4(+)CD8(+) T cells in T-cell mediated immunity. PMID:22789871

  7. A subset of human plasmacytoid dendritic cells expresses CD8α upon exposure to herpes simplex virus type 1.

    Science.gov (United States)

    Schuster, Philipp; Thomann, Sabrina; Werner, Maren; Vollmer, Jörg; Schmidt, Barbara

    2015-01-01

    Classical and plasmacytoid dendritic cells (DC) play important roles in the defense against murine and human infections with herpes simplex virus (HSV). So far, CD8α expression has only been reported for murine DC. CD8α(+) DC have prominent cross-presenting activities, which are enhanced by murine CD8α(+) PDC. The human orthologue of murine CD8α(+) DC, the CD141 (BDCA3)(+) DC, mainly cross-present after TLR3 ligation. We report here the serendipitous finding that a subset of human PDC upregulates CD8α upon HSV-1 stimulation, as shown by gene array and flow cytometry analyses. CD8α, not CD8ß, was expressed upon exposure. Markers of activation, migration, and costimulation were upregulated on CD8α-expressing human PDC. In these cells, increased cytokine and chemokine levels were detected that enhance development and function of T, B, and NK cells, and recruit immature DC, monocytes, and Th1 cells, respectively. Altogether, human CD8α(+) PDC exhibit a highly activated phenotype and appear to recruit other immune cells to the site of inflammation. Further studies will show whether CD8α-expressing PDC contribute to antigen cross-presentation, which may be important for immune defenses against HSV infections in vitro and in vivo. PMID:26082771

  8. 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.

  9. 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

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    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

  10. Migration of CD8+ T Cells into the Central Nervous System Gives Rise to Highly Potent Anti-HIV CD4dimCD8bright T Cells in a Wnt Signaling-Dependent Manner.

    Science.gov (United States)

    Richards, Maureen H; Narasipura, Srinivas D; Seaton, Melanie S; Lutgen, Victoria; Al-Harthi, Lena

    2016-01-01

    The role of CD8(+) T cells in HIV control in the brain and the consequences of such control are unclear. Approximately 3% of peripheral CD8(+) T cells dimly express CD4 on their surface. This population is known as CD4(dim)CD8(bright) T cells. We evaluated the role of CD4(dim)CD8(bright) and CD8 single positive T cells in HIV-infected brain using NOD/SCID/IL-2rcγ(-/-) mice reconstituted with human PBMCs (NSG-huPBMC). All three T cell populations (CD4 single positive, CD8 single positive, and CD4(dim)CD8(bright)) were found in NSG-huPBMC mouse brain within 2 wk of infection. Wnts secreted from astrocytes induced CD4(dim)CD8(bright) T cells by 2-fold in vitro. Injection of highly purified CD8 single positive T cells into mouse brain induced CD4(dim)CD8(bright) T cells by 10-fold, which were proliferative and exhibited a terminally differentiated effector memory phenotype. Brain CD4(dim)CD8(bright) T cells from HIV-infected mice exhibited anti-HIV-specific responses, as demonstrated by induction of CD107ab post exposure to HIV peptide-loaded targets. Further, higher frequency of CD4(dim)CD8(bright) T cells (R = -0.62; p ≤ 0.001), but not CD8 single positive T cells (R = -0.24; p ≤ 0.27), negatively correlated with HIV gag mRNA transcripts in HIV-infected NSG-huPBMC brain. Together, these studies indicate that single positive CD8(+) T cells entering the CNS during HIV infection can give rise to CD4(dim)CD8(bright) T cells, likely through a Wnt signaling-dependent manner, and that these cells are associated with potent anti-HIV control in the CNS. Thus, CD4(dim)CD8(bright) T cells are capable of HIV control in the CNS and may offer protection against HIV-associated neurocognitive disorders. PMID:26582945

  11. 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.

  12. 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

  13. 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

  14. 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...

  15. 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

  16. 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

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

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    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.

  18. 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; Thomsen, Allan Randrup

    1996-01-01

    killing. An enhanced cytotoxic potential as well as an increased capacity to produce IFN-gamma is observed for at least 2 months after infection and cell sorting analysis revealed that this could be ascribed to a long-standing increase in the frequency of CD8+ Pgp-1hi cells. Therefore, these results...

  19. Phenotyping of circulating CD8(+) T cell subsets in human cutaneous leishmaniasis

    Czech Academy of Sciences Publication Activity Database

    Khamesipour, A.; Rostami, M.N.; Tasbihi, M.; Mohammadi, A.M.; Shahrestani, T.; Sarrafnejad, A.; Sohrabi, Yahya; Eskandari, S.E.; Valian, H.K.

    2012-01-01

    Roč. 14, č. 9 (2012), s. 702-711. ISSN 1286-4579 Institutional research plan: CEZ:AV0Z50520514 Institutional support: RVO:68378050 Keywords : CD8(+) T cells * memory T cells * cutaneous leishmaniasis * IFN-gamma Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.920, year: 2012

  20. Varicella-zoster virus reactivation during acute enterovirus infection is associated with CD8 lymphocytopenia

    OpenAIRE

    Chia, John K; Chia, Andrew A

    2009-01-01

    The trigger or triggers for reactivation of varicella-zoster virus have not been well defined in the medical literature. We investigated the role of enterovirus infections in triggering herpes zoster in five patients and correlated the reactivation with transient CD8 T lymphocyte depletion during the acute enterovirus infection.

  1. 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...

  2. Interleukin 15 is a growth factor for human thymocytes with preferential effect on CD8(+)cells

    DEFF Research Database (Denmark)

    Thulesen, S; Nielsen, M; Petersen, T R; Holst Nissen, M; Ødum, Niels; Röpke, C

    2000-01-01

    The effects of IL-15, as compared to IL-2, on growth of human thymocytes has been evaluated. Expression of comparable amounts of receptor chains was found on IL-2 and IL-15 cultured thymocytes, as well as comparable receptor signalling. However, IL-15 was superior to IL-2 in promoting CD8...

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

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    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.

  4. The effect of vitamin A on CD4+ and CD8+ cells irradiated by 60Co γ-ray

    International Nuclear Information System (INIS)

    The monocyte-depleted peripheral blood mononuclear cells were separated into CD4+ and CD8+ subpopulations by panning technique with McAb CD4 and CD8. The purity of CD4+ and CD8+ cells was 89.2% and 85.8% respectively, which was estimated by an indirect immunofluorescence technique. The radiosensitivities of CD4+ and CD8+ cells and the effect of DNA synthesis in both cells' subpopulations influenced by Vit A were assessed by 3H-TdR incorporation. The experimental result showed that after γ-radiation in different doses on CD4+ and CD8+ cells, the 3H-TdR incorporation was significantly decreased. The 3H-TdR incorporation rate in CD8+ cells irradiated with addition of 5 μg/ml Vit A increased significantly (p<0.05)

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

    DEFF Research Database (Denmark)

    Andreasen, Susanne; Christensen, Jeanette Erbo; Marker, O; Thomsen, Allan Randrup

    2000-01-01

    and extensively, whereas vesicular stomatitis virus (VSV) spreads poorly. We found that the primary response of CD40L-/- mice toward VSV is significantly impaired; proliferation of both CD4+ and CD8+ cells is reduced 2- to 3-fold, few CD8+ cells acquire an activated phenotype, and little functional...... activity is induced. Very similar results were obtained in VSV-infected, CD28-deficient mice. In contrast, neither CD40L nor CD28 was required for induction of a primary CD8+ response toward LCMV. Surprisingly, lack of CD4+ T cells had no impact on the primary immune response toward any of the viruses......-specific CD8+ T cells on day 6 postinfection. Finally, despite the fact that the primary LCMV-specific CD8+ response is virtually unimpaired in CD40L-/- mice, their capacity to maintain CD8+ effector activity and to permanently control the infection is significantly reduced. Thus, our results demonstrate that...

  6. 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.

  7. 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. PMID:22496155

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

    Directory of Open Access Journals (Sweden)

    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.

  10. Natural killer cells promote early CD8 T cell responses against cytomegalovirus.

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    Scott H Robbins

    2007-08-01

    Full Text Available Understanding the mechanisms that help promote protective immune responses to pathogens is a major challenge in biomedical research and an important goal for the design of innovative therapeutic or vaccination strategies. While natural killer (NK cells can directly contribute to the control of viral replication, whether, and how, they may help orchestrate global antiviral defense is largely unknown. To address this question, we took advantage of the well-defined molecular interactions involved in the recognition of mouse cytomegalovirus (MCMV by NK cells. By using congenic or mutant mice and wild-type versus genetically engineered viruses, we examined the consequences on antiviral CD8 T cell responses of specific defects in the ability of the NK cells to control MCMV. This system allowed us to demonstrate, to our knowledge for the first time, that NK cells accelerate CD8 T cell responses against a viral infection in vivo. Moreover, we identify the underlying mechanism as the ability of NK cells to limit IFN-alpha/beta production to levels not immunosuppressive to the host. This is achieved through the early control of cytomegalovirus, which dramatically reduces the activation of plasmacytoid dendritic cells (pDCs for cytokine production, preserves the conventional dendritic cell (cDC compartment, and accelerates antiviral CD8 T cell responses. Conversely, exogenous IFN-alpha administration in resistant animals ablates cDCs and delays CD8 T cell activation in the face of NK cell control of viral replication. Collectively, our data demonstrate that the ability of NK cells to respond very early to cytomegalovirus infection critically contributes to balance the intensity of other innate immune responses, which dampens early immunopathology and promotes optimal initiation of antiviral CD8 T cell responses. Thus, the extent to which NK cell responses benefit the host goes beyond their direct antiviral effects and extends to the prevention of innate

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

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    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.

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

    International Nuclear Information System (INIS)

    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 μmol/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.)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.).

  14. Memory Stem T Cells in Autoimmune Disease: High Frequency of Circulating CD8+ Memory Stem Cells in Acquired Aplastic Anemia.

    Science.gov (United States)

    Hosokawa, Kohei; Muranski, Pawel; Feng, Xingmin; Townsley, Danielle M; Liu, Baoying; Knickelbein, Jared; Keyvanfar, Keyvan; Dumitriu, Bogdan; Ito, Sawa; Kajigaya, Sachiko; Taylor, James G; Kaplan, Mariana J; Nussenblatt, Robert B; Barrett, A John; O'Shea, John; Young, Neal S

    2016-02-15

    Memory stem T cells (TSCMs) constitute a long-lived, self-renewing lymphocyte population essential for the maintenance of functional immunity. Hallmarks of autoimmune disease pathogenesis are abnormal CD4(+) and CD8(+) T cell activation. We investigated the TSCM subset in 55, 34, 43, and 5 patients with acquired aplastic anemia (AA), autoimmune uveitis, systemic lupus erythematosus, and sickle cell disease, respectively, as well as in 41 age-matched healthy controls. CD8(+) TSCM frequency was significantly increased in AA compared with healthy controls. An increased CD8(+) TSCM frequency at diagnosis was associated with responsiveness to immunosuppressive therapy, and an elevated CD8(+) TSCM population after immunosuppressive therapy correlated with treatment failure or relapse in AA patients. IFN-γ and IL-2 production was significantly increased in various CD8(+) and CD4(+) T cell subsets in AA patients, including CD8(+) and CD4(+) TSCMs. CD8(+) TSCM frequency was also increased in patients with autoimmune uveitis or sickle cell disease. A positive correlation between CD4(+) and CD8(+) TSCM frequencies was found in AA, autoimmune uveitis, and systemic lupus erythematosus. Evaluation of PD-1, CD160, and CD244 expression revealed that TSCMs were less exhausted compared with other types of memory T cells. Our results suggest that the CD8(+) TSCM subset is a novel biomarker and a potential therapeutic target for AA. PMID:26764034

  15. 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.

  16. Further progress on defining highly conserved immunogenic epitopes for a global HIV vaccine

    DEFF Research Database (Denmark)

    De Groot, Anne S; Levitz, Lauren; Ardito, Matthew T;

    2012-01-01

    Two major obstacles confronting HIV vaccine design have been the extensive viral diversity of HIV-1 globally and viral evolution driven by escape from CD8(+) cytotoxic T-cell lymphocyte (CTL)-mediated immune pressure. Regions of the viral genome that are not able to escape immune response and that...... context of global HIV evolution. Twenty-seven HLA-A3 epitopes were chosen from an analysis performed in 2003 on 10,803 HIV-1 sequences, and additional sequences were selected in 2009 based on an expanded set of 43,822 sequences. These epitopes were tested in vitro for HLA binding and for immunogenicity...... with PBMCs of HIV-infected donors from Providence, Rhode Island. Validation of these HLA-A3 epitopes conserved across time, clades, and geography supports the hypothesis that epitopes such as these would be candidates for inclusion in our globally relevant GAIA HIV vaccine constructs....

  17. Nasal vaccination stimulates CD8(+) T cells for potent protection against mucosal Brucella melitensis challenge.

    Science.gov (United States)

    Clapp, Beata; Yang, Xinghong; Thornburg, Theresa; Walters, Nancy; Pascual, David W

    2016-05-01

    Brucellosis remains a significant zoonotic threat worldwide. Humans and animals acquire infection via their oropharynx and upper respiratory tract following oral or aerosol exposure. After mucosal infection, brucellosis develops into a systemic disease. Mucosal vaccination could offer a viable alternative to conventional injection practices to deter disease. Using a nasal vaccination approach, the ΔznuA B. melitensis was found to confer potent protection against pulmonary Brucella challenge, and reduce colonization of spleens and lungs by more than 2500-fold, with >50% of vaccinated mice showing no detectable brucellae. Furthermore, 10-fold more brucellae-specific, interferon-γ (IFN-γ)-producing CD8(+) T cells than CD4(+) T cells were induced in the spleen and respiratory lymph nodes. Evaluation of pulmonary and splenic CD8(+) T cells from mice vaccinated with ΔznuA B. melitensis revealed that these expressed an activated effector memory (CD44(hi)CD62L(lo)CCR7(lo)) T cells producing elevated levels of IFN-γ, tumor necrosis factor-α, perforin and granzyme B. To assess the relative importance of these increased numbers of CD8(+) T cells, CD8(-/-) mice were challenged with virulent B. melitensis, and they showed markedly increased bacterial loads in organs in contrast to similarly challenged CD4(-/-) mice. Only ΔznuA B. melitensis- and Rev-1-vaccinated CD4(-/-) and wild-type mice, not CD8(-/-) mice, were completely protected against Brucella challenge. Determination of cytokines responsible for conferring protection showed the relative importance of IFN-γ, but not interleukin-17 (IL-17). Unlike wild-type (wt) mice, IL-17 was greatly induced in IFN-γ(-/-) mice, but IL-17 could not substitute for IFN-γ's protection, although an increase in brucellae dissemination was observed upon in vivo IL-17 neutralization. These results show that nasal ΔznuA B. melitensis vaccination represents an attractive means to stimulate systemic and mucosal immune protection via CD

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

    Directory of Open Access Journals (Sweden)

    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

  19. 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...

  20. 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.

  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. 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.

  4. 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

  5. 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...

  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. CD8+ T Cells Maintain Suppression of Simian Immunodeficiency Virus in the Central Nervous System

    OpenAIRE

    Marcondes, Maria Cecilia G.; Morsey, Brenda; Emanuel, Katy; Lamberty, Benjamin G.; Flynn, Claudia T.; Fox, Howard S.

    2014-01-01

    Human immunodeficiency virus (HIV) accesses the brain early in infection and can lead to neurocognitive disorders. The brain can also serve as a viral reservoir, but how virus is controlled in the brain is unknown. To examine this, CD8-depleting monoclonal antibody was injected into the cerebrospinal fluid of rhesus monkeys with chronic simian immunodeficiency virus (SIV) infection. This treatment led to the rapid increase of SIV in the brain. Virus in the brain is maintained by active suppre...

  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. 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

  10. 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...

  11. 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...

  12. 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

  13. The Secreted Protein Rv1860 of Mycobacterium tuberculosis Stimulates Human Polyfunctional CD8+ T Cells.

    Science.gov (United States)

    Satchidanandam, Vijaya; Kumar, Naveen; Biswas, Sunetra; Jumani, Rajiv S; Jain, Chandni; Rani, Rajni; Aggarwal, Bharti; Singh, Jaya; Kotnur, Mohan Rao; Sridharan, Anand

    2016-04-01

    We previously reported that Rv1860 protein fromMycobacterium tuberculosisstimulated CD4(+)and CD8(+)T cells secreting gamma interferon (IFN-γ) in healthy purified protein derivative (PPD)-positive individuals and protected guinea pigs immunized with a DNA vaccine and a recombinant poxvirus expressing Rv1860 from a challenge with virulentM. tuberculosis We now show Rv1860-specific polyfunctional T (PFT) cell responses in the blood of healthy latentlyM. tuberculosis-infected individuals dominated by CD8(+)T cells, using a panel of 32 overlapping peptides spanning the length of Rv1860. Multiple subsets of CD8(+)PFT cells were significantly more numerous in healthy latently infected volunteers (HV) than in tuberculosis (TB) patients (PAT). The responses of peripheral blood mononuclear cells (PBMC) from PAT to the peptides of Rv1860 were dominated by tumor necrosis factor alpha (TNF-α) and interleukin-10 (IL-10) secretions, the former coming predominantly from non-T cell sources. Notably, the pattern of the T cell response to Rv1860 was distinctly different from those of the widely studiedM. tuberculosisantigens ESAT-6, CFP-10, Ag85A, and Ag85B, which elicited CD4(+)T cell-dominated responses as previously reported in other cohorts. We further identified a peptide spanning amino acids 21 to 39 of the Rv1860 protein with the potential to distinguish latent TB infection from disease due to its ability to stimulate differential cytokine signatures in HV and PAT. We suggest that a TB vaccine carrying these and other CD8(+)T-cell-stimulating antigens has the potential to prevent progression of latentM. tuberculosisinfection to TB disease. PMID:26843486

  14. Induction of CD8+ Regulatory T Cells Protects Macaques against SIV Challenge

    Directory of Open Access Journals (Sweden)

    Wei Lu

    2012-12-01

    Full Text Available Efforts to develop a vaccine against HIV have so far met with limited success. Given that CD4+ T cell activation drives the initial burst of viral replication, we explored in macaques whether an oral vaccine comprised of Lactobacillus plantarum, a commensal bacterium that favors immune tolerance, and inactivated simian immunodeficiency virus mac239 (SIVmac239 would induce CD4+ T cell unresponsiveness/tolerance toward SIV antigens and thereby prevent the establishment of SIV infection. The tolerogenic vaccine induced MHC-Ib/E-restricted CD8+ regulatory T cells (Tregs that suppressed SIV-harboring CD4+ T cell activation and ex vivo SIV replication in 15 of 16 animals without inducing SIV-specific antibodies or cytotoxic T lymphocytes. Of 16 macaques that were intrarectally challenged with SIVmac239 or heterologous strain SIVB670, 15 were sterilely protected. In four macaques that were rechallenged intravenously, plasma SIV levels peaked slightly and then dropped to undetectable levels, although the animals subsequently harbored intracellular SIV DNA. Infusion of CD8 antibodies confirmed the role of CD8+ Tregs in preventing/suppressing SIV in vivo. These findings suggest a new avenue of research toward developing an HIV-1 vaccine.

  15. 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.

  16. 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.

  17. CD8+ T cell activation predominate early immune responses to hypercholesterolemia in Apoe-/- mice

    Directory of Open Access Journals (Sweden)

    Björkbacka Harry

    2010-12-01

    Full Text Available Abstract Background It is well established that adaptive immune responses induced by hypercholesterolemia play an important role in the development of atherosclerosis, but the pathways involved remain to be fully characterized. In the present study we assessed immune responses to hypercholesterolemia induced by feeding Apoe-/- mice a high-fat diet for 4 or 8 weeks. Results The primary immune response in lymph nodes draining the aortic root was an increased expression of interferon (IFN-γ in CD8+CD28+ T cells, while an activation of IFN-γ expression in CD4+ T cells was observed only after 8 weeks of high-fat diet. Contrarily, spleen CD4+ T cells responded with a higher expression of IL-10. Spleen CD8+ T cells expressed both IFN-γ and IL-10 and showed enhanced proliferation when exposed to Concanavalin A. Plasma levels of IgG and IgM against oxidized LDL did not change, but the level of apolipoprotein B/IgM immune complexes was increased. Conclusion Hypercholesterolemia leads to unopposed activation of Th1 immune responses in lymph nodes draining atherosclerotic lesions, whereas Th1 activation in the spleen is balanced by a concomitant activation of Th2 cells. The activation of CD8+ T cells implies that hypercholesterolemia is associated with formation of cell autoantigens.

  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. 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...

  20. Vaccine Design for H5N1 Based on B- and T-cell Epitope Predictions

    Science.gov (United States)

    Tambunan, Usman Sumo Friend; Sipahutar, Feimmy Ruth Pratiwi; Parikesit, Arli Aditya; Kerami, Djati

    2016-01-01

    From 2003 to 2013, Indonesia had the highest number of avian influenza A cases in humans, with 192 cases and 160 fatalities. Avian influenza is caused by influenza virus type A, such as subtype H5N1. This virus has two glycoproteins: hemagglutinin and neuraminidase, which will become the primary target to be neutralized by vaccine. Vaccine is the most effective immunologic intervention. In this study, we use the epitope-based vaccine design from hemagglutinin and neuraminidase of H5N1 Indonesian strain virus by using immunoinformatics approach in order to predict the binding of B-cell and T-cell epitopes (class I and class II human leukocyte antigen [HLA]). BCPREDS was used to predict the B-cell epitope. Propred, Propred I, netMHCpan, and netMHCIIpan were used to predict the T-cell epitope. Two B-cell epitopes of hemagglutinin candidates and one B-cell epitope of neuraminidase candidates were obtained to bind T-cell CD4+ (class II HLA), and also five T-cell epitope hemagglutinin and four T-cell epitope neuraminidase were obtained to bind T-cell CD8+ (class I HLA). The visualization of epitopes was done using MOE 2008.10. It shows that the binding affinity of epitope–HLA was based on minimum binding free energy (ΔGbinding). Based on this result, visualization, and dynamic simulation, four hemagglutinin epitopes (MEKIVLLLA, CPYLGSPSF, KCQTPMGAI, and IGTSTLNQR) and two neuraminidase epitopes (NPNQKIITI and CYPDAGEIT) were computed as having the best binding affinity from HLA ligand. The results mentioned above are from in silico experiments and need to be validated using wet experiment. PMID:27147821

  1. 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

  2. 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

  3. 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

  4. 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

  5. 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...

  6. 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.

  7. 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

  8. 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.

  9. B cells pulsed with Helicobacter pylori antigen efficiently activate memory CD8+ T cells from H. pylori-infected individuals.

    Science.gov (United States)

    Azem, Josef; Svennerholm, Ann-Mari; Lundin, B Samuel

    2006-01-01

    Helicobacter pylori infection causes chronic gastritis that may progress to peptic ulcers or gastric adenocarcinoma and thereby cause major world-wide health problems. Previous studies have shown that CD4+ T cells are important in the immune response to H. pylori in humans, but the role of CD8+ T cells is less clear. In order to study the CD8+ T cell response to H. pylori in greater detail, we have evaluated efficient conditions for activation of CD8+ T cells in vitro. We show that H. pylori-reactive CD8+ T cells can be activated most efficiently by B cells or dendritic cells pulsed with H. pylori antigens. We further show that the majority of CD8+ T cells in H. pylori-infected gastric mucosa are memory cells, and that memory CD8+ T cells sorted from peripheral blood of H. pylori-infected individuals respond 15-fold more to H. pylori urease compared to memory cells from uninfected subjects. We conclude that CD8+ T cells do participate in the immune response to H. pylori, and this may have implications for the development of more severe disease outcomes in H. pylori-infected subjects. PMID:16324887

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

    DEFF Research Database (Denmark)

    Grujic, Mirjana; Christensen, Jan P; Sørensen, Maria R; Abrink, Magnus; Pejler, Gunnar; Thomsen, Allan R

    2008-01-01

    (-/-)) mice with lymphocytic choriomeningitis virus (LCMV). Wt and SG(-/-) mice cleared 10(3) PFU of highly invasive LCMV with the same kinetics, and the CD8(+) T lymphocytes from wt and SG(-/-) animals did not differ in GrB, perforin, IFN-gamma, or TNF-alpha content. However, when a less invasive LCMV strain...... was used, SG(-/-) GrB(+) CD8(+) T cells contained approximately 30% less GrB than wt GrB(+) CD8(+) T cells. Interestingly, the contraction of the antiviral CD8(+) T cell response to highly invasive LCMV was markedly delayed in SG(-/-) mice, and a delayed contraction of the virus-specific CD8(+) T cell...... response was also seen after infection with vesicular stomatitis virus. BrdU labeling of cells in vivo revealed that the delayed contraction was associated with sustained proliferation of Ag-specific CD8(+) T cells in SG(-/-) mice. Moreover, wt LCMV-specific CD8(+) T cells from TCR318 transgenic mice...

  11. 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

  12. 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...

  13. 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...

  14. IL-15 induces unspecific effector functions in human peptide-specific CD8+ T-cell cultures

    DEFF Research Database (Denmark)

    Lyngstrand, S T; Würtzen, P A; Ødum, N; Nissen, Mogens Holst; Röpke, C

    2002-01-01

    Antigen (Ag)-specific CD8+ T cells are a major host defence against viral infections. In the present study, we generated human CD8+ T-cell lines specific towards influenza matrix peptide (IMP)-pulsed Ag-presenting cells. We compared the effect of interleukin-2 (IL-2) and IL-15 on the proliferation...... cultures. Secondary IMP-specific CD8+ T cells were generated by the addition of IL-2 during two cycles of restimulation. From the third restimulation, identical CTL cultures were expanded with either IL-2 or IL-15 in parallel. Cell expansion as well as Ag specificity was considerably reduced after a 5 day...

  15. CD8 apoptosis may be a predictor of T cell number normalization after immune reconstitution in HIV

    Directory of Open Access Journals (Sweden)

    Martinez Maria L

    2007-01-01

    Full Text Available Abstract Background As part of the Houston Vanguard study, a subset of 10 patients randomized to receive IL-2 therapy were compared to 4 patients randomized to not receive IL-2, for markers of T cell activation and death during the first three cycles of IL-2. All patients were treated with combination antiretroviral therapy (ART and were virally suppressed. The purpose of the study was to examine the role of CD8+ T cell death in responses to ART and IL-2 therapy. Methods Lymphocytes were examined at Day 0, 5 and 30 days during three cycles of IL-2 therapy. CD25, CD38, HLA-DR expression and annexin (cell death were examined on CD4 and CD8 subpopulations. Follow up studies examined CD4 levels and CD4:CD8 reconstitution after 6 years using both univariant and multivariate analyses. Results Human lymphocytes responded to IL-2 therapy by upregulation of CD25 on CD4+ T cells, leading to an increase in CD4 cell counts. CD8+ T cells did not increase CD25 expression, but upregulated activation antigens (CD38 and DR and had increased death. At baseline, 7 of the 14 patients had high CD8+ T cell apoptosis (mean 17.0% ± 6.0. We did an exploratory analysis of immune status after six years, and found that baseline CD8+ T cell apoptosis was correlated with CD4 cell count gain beginning two years post enrollment. Patients with low levels of CD8+ T cell apoptosis at baseline (mean 2.2% ± 2.1 had significantly higher CD4 cell counts and more normalized CD4:CD8 ratios than patients with high CD8+ T cell apoptosis (mean CD4 cell counts 1,209 ± 164 vs 754 ± 320 cells/mm3; CD4:CD8 ratios 1.55 vs. 0.70, respectively. Conclusion We postulate that CD8+ T cell apoptosis may reflect inherent activation status, which continues in some patients even though viral replication is suppressed which influences the ability of CD4+ T cells to rebound. Levels of CD8+ T cell apoptosis may therefore be an independent predictor of immune status, which should be shown in a

  16. 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

  17. 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.

  18. 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

  19. Antigen and Memory CD8 T Cells: Were They Both Right?

    Directory of Open Access Journals (Sweden)

    Epelman Slava

    2007-06-01

    Full Text Available Picture yourself as a researcher in immunology. To begin your project, you ask a question: Do CD8 T cells require antigen to maintain a memory response? This question is of prime importance to numerous medical fields. In chronologic order, you digest the literature, but unfortunately, you hit a major stumbling block in the 1990s. The crux of the problem is that which so often happens in science: two well-recognized, capable groups emerge with diametrically opposed conclusions, leaving you pondering which set of wellcontrolled data to believe. Fortunately, years later, a surprising group of articles sheds light on this mystery and subtly reconciles these two positions.

  20. Tracking antigen-specific CD8+ T cells in the rat using MHC class I multimers.

    OpenAIRE

    Duplan, Valérie; Suberbielle, Elsa; Napper, Catherine,; Joly, Etienne; Saoudi, Abdelhadi; Gonzalez-Dunia, Daniel

    2007-01-01

    Studies of the quantitative and qualitative aspects of anti-microbial, anti-tumoral or autoreactive immune responses have been greatly facilitated by the possibility to stain antigen-specific CD8(+) T cells using fluorescently labeled multimeric major histocompatibility complex (MHC) class I/peptide complexes. So far, this technology has been developed for human and mouse, but not yet in the rat. Here, we describe the generation of the first rat MHC multimer. We produced a rat RT1(l) Pro5 MHC...

  1. Role of CD4+ and CD8+ T cells in murine resistance to street rabies virus.

    OpenAIRE

    Perry, L. L.; Lodmell, D L

    1991-01-01

    Mice of the SJL/J and BALB/cByJ inbred strains are naturally resistant to street rabies virus (SRV) injected via the intraperitoneal route. To determine the cellular mechanism of resistance, monoclonal antibodies specific for CD4+ or CD8+ subsets of T cells were used to deplete the respective cell population in SRV-infected animals. Elimination of CD4+ T-helper cells abrogated the production of immunoglobulin G (IgG) neutralizing antibodies in response to rabies virus infection and reversed t...

  2. 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...

  3. 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...

  4. Highly conserved antigenic epitope regions of hemagglutinin and neuraminidase genes between 2009 H1N1 and seasonal H1N1 influenza: vaccine considerations

    OpenAIRE

    Huang, Ping; Yu, Shouyi; Wu, Changyou; Liang, Lijun

    2013-01-01

    An immunoinformatics study was conducted to determine the highly conserved antigenic epitope regions of hemagglutinin (HA) and neuraminidase (NA) genes in the humoral immunity and CD4+ and CD8+ T cellular immunity between 2009 pandemic H1N1 (pH1N1) and seasonal H1N1 (sH1N1) viruses. It was found that in sH1N1 viruses, 29 epitope regions of HA genes and 8 epitope regions of NA genes which had been experimentally identified, were highly conserved (97.1-100.0%) in the corresponding genes and pre...

  5. HLA-B7–Restricted Islet Epitopes Are Differentially Recognized in Type 1 Diabetic Children and Adults and Form Weak Peptide-HLA Complexes

    OpenAIRE

    Scotto, Matthieu; Afonso, Georgia; Østerbye, Thomas; Larger, Etienne; Luce, Sandrine; Raverdy, Cécile; Novelli, Giulia; Bruno, Graziella; Gonfroy-Leymarie, Céline; Launay, Odile; Lemonnier, François A.; Buus, Søren; Carel, Jean-Claude; Boitard, Christian; Mallone, Roberto

    2012-01-01

    The cartography of β-cell epitopes targeted by CD8+ T cells in type 1 diabetic (T1D) patients remains largely confined to the common HLA-A2 restriction. We aimed to identify β-cell epitopes restricted by the HLA-B7 (B*07:02) molecule, which is associated with mild T1D protection. Using DNA immunization on HLA-B7–transgenic mice and prediction algorithms, we identified GAD and preproinsulin candidate epitopes. Interferon-γ (IFN-γ) enzyme-linked immunospot assays on peripheral blood mononuclear...

  6. Priming of CD8 T Cells by Adenoviral Vectors Is Critically Dependent on B7 and Dendritic Cells but Only Partially Dependent on CD28 Ligation on CD8 T Cells

    DEFF Research Database (Denmark)

    Nielsen, Karen N; Steffensen, Maria A; Christensen, Jan P;

    2014-01-01

    Adenoviral vectors have long been forerunners in the development of effective CD8 T cell-based vaccines; therefore, it is imperative that we understand the factors controlling the induction of robust and long-lasting transgene-specific immune responses by these vectors. In this study, we investig......Adenoviral vectors have long been forerunners in the development of effective CD8 T cell-based vaccines; therefore, it is imperative that we understand the factors controlling the induction of robust and long-lasting transgene-specific immune responses by these vectors. In this study, we...... investigated the organ sites, molecules, and cell subsets that play a critical role in the priming of transgene-specific CD8 T cells after vaccination with a replication-deficient adenoviral vector. Using a human adenovirus serotype 5 (Ad5) vector and genetically engineered mice, we found that CD8(+) and/or CD......103(+) dendritic cells in the draining lymph node played a critical role in the priming of Ad5-induced CD8 T cell responses. Moreover, we found that CD80/86, but not CD28, was essential for efficient generation of both primary effectors and memory CD8 T cells. Interestingly, the lack of CD28...

  7. 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.

  8. Lymphocytic choriomeningitis virus infection is associated with long-standing perturbation of LFA-1 expression on CD8+ T cells

    DEFF Research Database (Denmark)

    Andersson, E C; Christensen, Jan Pravsgaard; Scheynius, A; Marker, O; Thomsen, Allan Randrup

    1995-01-01

    Flow cytometric analysis of splenocytes from mice infected with lymphocytic choriomeningitis virus revealed marked and long-standing up-regulation of LFA-1 expression on CD8+, but not on CD4+ T cells. Appearance of CD8+ T cells with a changed expression of adhesion molecules reflected polyclonal...... activation and expansion which was demonstrated not to depend on CD4+ T cells or their products. Cell sorting experiments defined virus-specific CTL to be included in this population (LFA-1hiMEL-14lo), but since about 80% of splenic CD8+ T cells have a changed phenotype, extensive bystander activation must...... take place; this is indicated also by the finding that CD8+LFA-1hi cells transiently express several markers of cellular activation, e.g. transferrin receptor, IL-2R alpha and beta. Analysis of cells from the cerebrospinal fluid of mice infected intracerebrally showed that virtually all T cells present...

  9. 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; Doherty, P C

    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...

  10. Tcf1 and Lef1 transcription factors establish CD8(+) T cell identity through intrinsic HDAC activity.

    Science.gov (United States)

    Xing, Shaojun; Li, Fengyin; Zeng, Zhouhao; Zhao, Yunjie; Yu, Shuyang; Shan, Qiang; Li, Yalan; Phillips, Farrah C; Maina, Peterson K; Qi, Hank H; Liu, Chengyu; Zhu, Jun; Pope, R Marshall; Musselman, Catherine A; Zeng, Chen; Peng, Weiqun; Xue, Hai-Hui

    2016-06-01

    The CD4(+) and CD8(+) T cell dichotomy is essential for effective cellular immunity. How individual T cell identity is established remains poorly understood. Here we show that the high-mobility group (HMG) transcription factors Tcf1 and Lef1 are essential for repressing CD4(+) lineage-associated genes including Cd4, Foxp3 and Rorc in CD8(+) T cells. Tcf1- and Lef1-deficient CD8(+) T cells exhibit histone hyperacetylation, which can be ascribed to intrinsic histone deacetylase (HDAC) activity in Tcf1 and Lef1. Mutation of five conserved amino acids in the Tcf1 HDAC domain diminishes HDAC activity and the ability to suppress CD4(+) lineage genes in CD8(+) T cells. These findings reveal that sequence-specific transcription factors can utilize intrinsic HDAC activity to guard cell identity by repressing lineage-inappropriate genes. PMID:27111144

  11. 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.

  12. 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

  13. 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.

  14. Integration of B cells and CD8+ T in the protective regulation of systemic epithelial inflammation

    Science.gov (United States)

    Wei, Bo; McPherson, Michael; Turovskaya, Olga; Velazquez, Peter; Fujiwara, Daisuke; Brewer, Sarah; Braun, Jonathan

    2008-01-01

    Mechanisms that control abnormal CD4+ T cell-mediated tissue damage are a significant factor in averting and resolving chronic inflammatory epithelial diseases. B cells can promote such immunoregulation, and this is thought to involve interaction with MHC II- or CD1-restricted regulatory T cells. The purpose of this study is to genetically define the interacting cells targeted by protective B cells, and to elucidate their regulatory mechanisms in CD4+ T cell inflammation. Transfer of Gαi2−/− CD3+ T cells into lymphopenic mice causes a dose-dependent multi-organ inflammatory disease including the skin, intestine, and lungs. Disease activity is associated with elevated levels of serum TNF-α and IFN-γ and an activated IL-17 producing CD4+ T cell population. Mesenteric node B cells from wild type mice suppress disease activity, serum cytokine expression, and levels of CD4+ T cells producing TNF-α, IFN-γ, and IL-17. The protective function of B cells requires genetic sufficiency of IL-10, MHC I and TAP1. Regulatory B cells induce the expansion and activation of CD8+ T cells, which is correlated with disease protection. These results demonstrate that CD8+ T cells can ameliorate lymphopenic systemic inflammatory disease, through peptide/MHC I-dependent B cell interaction. PMID:18282744

  15. 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

  16. 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.

  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. 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.

  20. 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...

  1. 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...

  2. 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.

  3. 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 ...

  4. Akt1 and -2 inhibition diminishes terminal differentiation and enhances central memory CD8+ T-cell proliferation and survival

    OpenAIRE

    Abu Eid, Rasha; Friedman, Kevin M; Mkrtichyan, Mikayel; Walens, Andrea; King, William; Janik, John; Khleif, Samir N

    2015-01-01

    The CD8 + T-cell response comprises terminally differentiated effector cells and antigen-experienced memory T cells. The latter encompass central (TCM) and effector (TEM) memory cells. TCM cells are superior in their protection against viral and bacterial challenges and mediation of antitumor immunity due to their higher proliferative ability upon antigen re-encounter. Defining a mechanism to enhance TCM cells and delay terminal differentiation of CD8 + T cells is crucial for cancer immune th...

  5. The effect of aging and caloric restriction on murine CD8+ T cell chemokine receptor gene expression

    Directory of Open Access Journals (Sweden)

    Mo RuRan

    2007-11-01

    Full Text Available Abstract Background The mechanism explaining the increased disease susceptibility in aging is not well understood. CD8+ T cells are crucial in anti-viral and anti-tumor responses. Although the chemokine system plays a critical role in CD8+ T cell function, very little is known about the relationship between aging and the T cell chemokine system. Results In this study we have examined the effect of aging on murine CD8+ T cell chemokine receptor gene expression. Freshly isolated splenic CD8+ T cells from old C57BL/6 mice were found to have higher CCR1, CCR2, CCR4, CCR5 and CXCR5, and lower CCR7 gene expression compared to their younger cohort. Anti-CD3/anti-CD28 stimulation elicited a similar robust chemokine receptor response from young and old CD8+ T cells. Western blot analyses confirmed elevated protein level of CCR4 and CCR5 in aged CD8+ T cells. Increases in T cell CCR1 and CCR5 expression also correlate to increased in vitro chemotaxis response to macrophage-inflammatory protein-1 α(MIP-1α. Finally, caloric restriction selectively prevents the loss of CD8+ T cell CCR7 gene expression in aging to the level that is seen in young CD8+ T cells. Conclusion These findings are consistent with the notion that aging exists in a state of low grade pro-inflammatory environment. In addition, our results provide a potential mechanism for the reported aging-associated impaired T cell lymphoid homing and allograft response, and reduced survival in sepsis.

  6. 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 CD8 T cells have been identified as a key factor in mediating protection against challenge with infectious Plasmodium sporozoites. Liver CD3 + CD8 T cells can further be divided into subsets based on the expression of specific surface molecules and the increase of CD8 effector memory (TEM) cells (identified by the phenotype CD44(+)CD62L(-)) has been shown to mediate protection by releasing of IFN-γ while CD8 central memory (TCM) cells (CD44(+)CD62L(+)) are important for maintaining long-term protection.Identification of multiple CD8 T cell subsets present in the liver relies on the ability to detect multiple surface markers simultaneously. Polychromatic flow cytometry affords the user with the ability to distinguish multiple lymphocyte populations as well as subsets defined within each population. In this chapter we present a basic 9-color surface staining panel that can be used to identify CD8 TEM, CD8 TCM, short-lived effector cells (SLECs), and memory precursor cells (MPECs) as well as identify those cells which have recently undergone degranulation (surface expression of CD107a). This panel has been designed to allow for the addition of intracellular staining for IFN-γ on other available channels (such as PE) as is discussed in another chapter for analysis of functional CD8 T cell responses. PMID:26450377

  7. Change of paradigm: CD8+ T cells as important helper for CD4+ T cells during asthma and autoimmune encephalomyelitis

    OpenAIRE

    Huber, Magdalena; Lohoff, Michael

    2015-01-01

    Summary The activation of naive CD4+ and CD8+ T cells in response to antigen and their subsequent proliferation and differentiation into effectors are important features of a cell-mediated immune response. CD4+ T cells (also known as T helper cells, Th) differentiate into several subpopulations including Th1, Th2, Th9, Th17, Tfh and Treg cells, characterized by specific cytokine profiles and effector functions. However, recent evidence indicates that CD8+ T cells (termed cytotoxic T lymphocyt...

  8. Contribution of Herpesvirus Specific CD8 T Cells to Anti-Viral T Cell Response in Humans

    OpenAIRE

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

    2010-01-01

    Herpesviruses infect most humans. Their infections can be associated with pathological conditions and significant changes in T cell repertoire but evidences of symbiotic effects of herpesvirus latency have never been demonstrated. We tested the hypothesis that HCMV and EBV-specific CD8 T cells contribute to the heterologous anti-viral immune response. Volume of activated/proliferating virus-specific and total CD8 T cells was evaluated in 50 patients with acute viral infections: 20 with HBV, 1...

  9. Association of Hepatitis C Virus Infection With CD4/CD8 Ratio in HIV-Positive Women

    Science.gov (United States)

    O'Brien, Thomas R.; Prokunina-Olsson, Ludmila; Augenbraun, Michael; Plankey, Michael; Karim, Roksana; Sarkar, Monika; French, Audrey L.; Pierce, Chris; Strickler, Howard D.; Anastos, Kathryn

    2016-01-01

    Background: Recent studies reported that the CD4/CD8 T-cell ratio is inversely associated with biomarkers traditionally used to measure immune activation and systemic inflammation in highly active antiretroviral therapy–treated HIV-infected (HIV+) patients. The relation of hepatitis C virus (HCV) coinfection with the CD4/CD8 ratio in HIV+ patients is unknown. Methods: We examined 50,201 CD4/CD8 ratios measured over 20 years in 3 groups of HIV+ women enrolled in the Women's Interagency HIV Study: HCV antibody negative (n = 1734), cleared HCV (n = 231), and chronic HCV (n = 751) in multivariate models. IFNL4-ΔG genotype and HCV viral load were also considered. Results: Compared with HCV antibody negative status, chronic HCV infection was associated with lower CD4/CD8 ratios when HIV viral load was suppressed to the lower limit of quantification (β = −0.08; P = 0.002). Cleared HCV (β = −0.10; P = 0.0009), but not IFNL4-ΔG genotype or HCV viral load, was also associated with lower CD4/CD8 ratios when HIV viral load was suppressed to the lower limit of quantification. Conclusions: The association of HCV coinfection with CD4/CD8 ratio is consistent with previously observed associations of HCV coinfection with biomarkers traditionally used to measure immune activation and systemic inflammation in HIV+ patients. These data provide additional support for the use of CD4/CD8 ratio for routine monitoring of immune activation and inflammation in HIV+ patients, including those with HIV/HCV coinfection; however, the unexpected association between cleared HCV and lower CD4/CD8 ratio requires additional study. PMID:27183178

  10. Immediate dysfunction of vaccine-elicited CD8+ T cells primed in the absence of CD4+ T cells

    Science.gov (United States)

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

    2016-01-01

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

  11. CD8α− Dendritic Cells Induce Antigen-Specific T Follicular Helper Cells Generating Efficient Humoral Immune Responses

    Directory of Open Access Journals (Sweden)

    Changsik Shin

    2015-06-01

    Full Text Available Recent studies on T follicular helper (Tfh cells have significantly advanced our understanding of T cell-dependent B cell responses. However, little is known about the early stage of Tfh cell commitment by dendritic cells (DCs, particularly by the conventional CD8α+ and CD8α− DC subsets. We show that CD8α− DCs localized at the interfollicular zone play a pivotal role in the induction of antigen-specific Tfh cells by upregulating the expression of Icosl and Ox40l through the non-canonical NF-κB signaling pathway. Tfh cells induced by CD8α− DCs function as true B cell helpers, resulting in significantly increased humoral immune responses against various human pathogenic antigens, including Yersinia pestis LcrV, HIV Gag, and hepatitis B surface antigen. Our findings uncover a mechanistic role of CD8α− DCs in the initiation of Tfh cell differentiation and thereby provide a rationale for investigating CD8α− DCs in enhancing antigen-specific humoral immune responses for improving vaccines and therapeutics.

  12. Intrinsic features of the CD8α(-) dendritic cell subset in inducing functional T follicular helper cells.

    Science.gov (United States)

    Shin, Changsik; Han, Jae-A; Choi, Bongseo; Cho, Yoon-Kyoung; Do, Yoonkyung; Ryu, Seongho

    2016-04-01

    T follicular helper (Tfh) cells, a true B cell helper, have a critical role in enhancing humoral immune responses. However, the initial differentiation of Tfh cells by dendritic cells (DCs), the most potent antigen presenting cells, has not been clearly understood, particularly in the knowledge of the two major conventional dendritic cell subsets, CD8α(+) DCs or CD8α(-) DCs. Here we demonstrated that the localization of CD8α(-) DCs in the marginal zone (MZ) bridging channels is closely associated with the induction of CXCR5(+)CCR7(low) Tfh cells. We also showed that the major source of IL-6 for inducing Tfh cells is provided from the activated CD4(+) T cells induced by CD8α(-) DCs, and IL-6 directly secreted from the DC subsets seems minor. CD8α(-) DCs were superior in inducing functional Tfh cells over other antigen presenting cells including B cells. We here observed the unknown intrinsic features of the DC subsets, suggesting the potential of utilizing the CD8α(-) DC subset as therapeutic vaccine for the regulation of humoral immune responses. PMID:26850563

  13. Blimp-1-mediated CD4 T cell exhaustion causes CD8 T cell dysfunction during chronic toxoplasmosis.

    Science.gov (United States)

    Hwang, SuJin; Cobb, Dustin A; Bhadra, Rajarshi; Youngblood, Ben; Khan, Imtiaz A

    2016-08-22

    CD8, but not CD4, T cells are considered critical for control of chronic toxoplasmosis. Although CD8 exhaustion has been previously reported in Toxoplasma encephalitis (TE)-susceptible model, our current work demonstrates that CD4 not only become exhausted during chronic toxoplasmosis but this dysfunction is more pronounced than CD8 T cells. Exhausted CD4 population expressed elevated levels of multiple inhibitory receptors concomitant with the reduced functionality and up-regulation of Blimp-1, a transcription factor. Our data demonstrates for the first time that Blimp-1 is a critical regulator for CD4 T cell exhaustion especially in the CD4 central memory cell subset. Using a tamoxifen-dependent conditional Blimp-1 knockout mixed bone marrow chimera as well as an adoptive transfer approach, we show that CD4 T cell-intrinsic deletion of Blimp-1 reversed CD8 T cell dysfunction and resulted in improved pathogen control. To the best of our knowledge, this is a novel finding, which demonstrates the role of Blimp-1 as a critical regulator of CD4 dysfunction and links it to the CD8 T cell dysfunctionality observed in infected mice. The critical role of CD4-intrinsic Blimp-1 expression in mediating CD4 and CD8 T cell exhaustion may provide a rational basis for designing novel therapeutic approaches. PMID:27481131

  14. T-bet and Eomes Are Differentially Linked to the Exhausted Phenotype of CD8+T Cells in HIV Infection

    DEFF Research Database (Denmark)

    Buggert, Marcus; Tauriainen, Johanna; Yamamoto, Takuya;

    2014-01-01

    CD8+ T cell exhaustion represents a major hallmark of chronic HIV infection. Two key transcription factors governing CD8+ T cell differentiation, T-bet and Eomesodermin (Eomes), have previously been shown in mice to differentially regulate T cell exhaustion in part through direct modulation of PD...... to an inverse expression balance between T-bet and Eomes, which is not reversed despite long-term viral control through ART. These results aid to explain the inability of HIV-specific CD8+ T cells to control the viral replication post-ART cessation.......CD8+ T cell exhaustion represents a major hallmark of chronic HIV infection. Two key transcription factors governing CD8+ T cell differentiation, T-bet and Eomesodermin (Eomes), have previously been shown in mice to differentially regulate T cell exhaustion in part through direct modulation of PD-1....... Here, we examined the relationship between these transcription factors and the expression of several inhibitory receptors (PD-1, CD160, and 2B4), functional characteristics and memory differentiation of CD8+ T cells in chronic and treated HIV infection. The expression of PD-1, CD160, and 2B4 on total...

  15. Lung function decline in asthma patients with elevated bronchial CD8, CD4 and CD3 cells.

    Science.gov (United States)

    den Otter, Irene; Willems, Luuk N A; van Schadewijk, Annemarie; van Wijngaarden, Simone; Janssen, Kirsten; de Jeu, Ronald C; Sont, Jacob K; Sterk, Peter J; Hiemstra, Pieter S

    2016-08-01

    Which inflammatory markers in the bronchial mucosa of asthma patients are associated with decline of lung function during 14 years of prospective follow-up?To address this question, 19 mild-to-moderate, atopic asthmatic patients underwent spirometry and bronchoscopy at baseline and after 14 years of follow-up (t=14). Baseline bronchial biopsies were analysed for reticular layer thickness, eosinophil cationic protein (EG2), mast cell tryptase (AA1), CD3, CD4 and CD8. Follow-up biopsies were stained for EG2, AA1, neutrophil elastase, CD3, CD4, CD8, CD20, granzyme B, CD68, DC-SIGN, Ki67 and mucins.Decline in forced expiratory volume in 1 s (FEV1) % predicted was highest in patients with high CD8 (p=0.01, both pre- and post-bronchodilator) or high CD4 counts at baseline (p=0.04 pre-bronchodilator, p=0.03 post-bronchodilator). Patients with high CD8, CD3 or granzyme B counts at t=14 also exhibited faster decline in FEV1 (p=0.00 CD8 pre-bronchodilator, p=0.04 CD8 post-bronchodilator, p=0.01 granzyme B pre-bronchodilator, and pgroups can be identified on the basis of inflammatory phenotypes. PMID:27230446

  16. MicroRNA-155 is required for effector CD8+ T cell responses to virus infection and cancer

    Science.gov (United States)

    DUDDA, Jan C.; SALAUN, Bruno; JI, Yun; PALMER, Douglas C.; Monnot, Gwennaelle C.; MERCK, Estelle; BOUDOUSQUIE, Caroline; UTZSCHNEIDER, Daniel T.; ESCOBAR, Thelma M.; PERRET, Rachel; MULJO, Stefan A.; HEBEISEN, Michael; RUFER, Nathalie; ZEHN, Dietmar; DONDA, Alena; RESTIFO, Nicholas P.; HELD, Werner; GATTINONI, Luca; ROMERO, Pedro

    2013-01-01

    SUMMARY MicroRNAs regulate the function of several immune cells but their role in promoting CD8+ T-cell immunity remains unknown. Here we report that miR-155 is required for CD8+ T-cell responses to both virus and cancer. In the absence of miR-155, accumulation of effector CD8+ T cells was severely reduced during acute and chronic viral infections and control of virus replication was impaired. Similarly, Mir155-/- CD8+ T cells were in effective at controlling tumor growth, whereas miR-155 overexpression enhanced the antitumor response. miR-155 deficiency resulted in accumulation of SOCS-1 causing defective cytokine signaling through STAT5. Consistently, enforced expression of SOCS-1 in CD8+ T cells phenocopied the miR-155 deficiency, whereas SOCS-1 silencing augmented tumor destruction. These findings identify miR-155 and its target SOCS-1 as key regulators of effector CD8+ T cells that can be modulated to potentiate immunotherapies for infectious diseases and cancer. PMID:23601686

  17. IL-12 and IL-4 activate a CD39-dependent intrinsic peripheral tolerance mechanism in CD8(+) T cells.

    Science.gov (United States)

    Noble, Alistair; Mehta, Hema; Lovell, Andrew; Papaioannou, Eleftheria; Fairbanks, Lynette

    2016-06-01

    Immune responses to protein antigens involve CD4(+) and CD8(+) T cells, which follow distinct programs of differentiation. Naïve CD8 T cells rapidly develop cytotoxic T-cell (CTL) activity after T-cell receptor stimulation, and we have previously shown that this is accompanied by suppressive activity in the presence of specific cytokines, i.e. IL-12 and IL-4. Cytokine-induced CD8(+) regulatory T (Treg) cells are one of several Treg-cell phenotypes and are Foxp3(-) IL-10(+) with contact-dependent suppressive capacity. Here, we show they also express high level CD39, an ecto-nucleotidase that degrades extracellular ATP, and this contributes to their suppressive activity. CD39 expression was found to be upregulated on CD8(+) T cells during peripheral tolerance induction in vivo, accompanied by release of IL-12 and IL-10. CD39 was also upregulated during respiratory tolerance induction to inhaled allergen and on tumor-infiltrating CD8(+) T cells. Production of IL-10 and expression of CD39 by CD8(+) T cells was independently regulated, being respectively blocked by extracellular ATP and enhanced by an A2A adenosine receptor agonist. Our results suggest that any CTL can develop suppressive activity when exposed to specific cytokines in the absence of alarmins. Thus negative feedback controls CTL expansion under regulation from both nucleotide and cytokine environment within tissues. PMID:26990545

  18. A Distinct Lung-Interstitium-Resident Memory CD8+ T Cell Subset Confers Enhanced Protection to Lower Respiratory Tract Infection

    Directory of Open Access Journals (Sweden)

    Pavlo Gilchuk

    2016-08-01

    Full Text Available The nature and anatomic location of the protective memory CD8+ T cell subset induced by intranasal vaccination remain poorly understood. We developed a vaccination model to assess the anatomic location of protective memory CD8+ T cells and their role in lower airway infections. Memory CD8+ T cells elicited by local intranasal, but not systemic, vaccination with an engineered non-replicative CD8+ T cell-targeted antigen confer enhanced protection to a lethal respiratory viral challenge. This protection depends on a distinct CXCR3LO resident memory CD8+ T (Trm cell population that preferentially localizes to the pulmonary interstitium. Because they are positioned close to the mucosa, where infection occurs, interstitial Trm cells act before inflammation can recruit circulating memory CD8+ T cells into the lung tissue. This results in a local protective immune response as early as 1 day post-infection. Hence, vaccine strategies that induce lung interstitial Trm cells may confer better protection against respiratory pathogens.

  19. IL-17-expressing CD4⁺ and CD8⁺ T lymphocytes in human toxoplasmosis.

    Science.gov (United States)

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

    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 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. PMID:25214715

  20. CD8(+) T cells mediate RAS-induced psoriasis-like skin inflammation through IFN-γ.

    Science.gov (United States)

    Gunderson, Andrew J; Mohammed, Javed; Horvath, Frank J; Podolsky, Michael A; Anderson, Cherie R; Glick, Adam B

    2013-04-01

    The RAS signaling pathway is constitutively activated in psoriatic keratinocytes. We expressed activated H-RAS(V12G) in suprabasal keratinocytes of adult mice and observed rapid development of a psoriasis-like skin phenotype characterized by basal keratinocyte hyperproliferation, acanthosis, hyperkeratosis, intraepidermal neutrophil microabscesses, and increased T helper type 1 (Th1)/Th17 and T cell type 1 (Tc1)/Tc17 skin infiltration. The majority of skin-infiltrating CD8(+) T cells coexpressed IFN-γ and IL-17A. When RAS was expressed on a Rag1-/- background, microabscess formation, inducible nitric oxide synthase expression, and keratinocyte hyperproliferation were suppressed. Depletion of CD8(+), but not CD4(+), T cells reduced cutaneous and systemic inflammation, the RAS-induced increase in cutaneous Th17 and IL-17(+) γδ T cells, and epidermal hyperproliferation to levels similar to a Rag1-/- background. Reconstitution of Rag1-/- inducible RAS mice with purified CD8(+) T cells restored microabscess formation and epidermal hyperproliferation. Neutralization of IFN-γ, but not of IL-17A, in CD8(+) T-cell-reconstituted Rag1-/- mice expressing RAS blocked CD8-mediated skin inflammation, inducible nitric oxide synthase expression, and keratinocyte hyperproliferation. These results show that CD8(+) T cells can orchestrate skin inflammation with psoriasis-like pathology in response to constitutive RAS activation in keratinocytes, and this is primarily mediated through IFN-γ. PMID:23151849

  1. Functional simian immunodeficiency virus Gag-specific CD8+ intraepithelial lymphocytes in the mucosae of SIVmac251- or simian-human immunodeficiency virus KU2-infected macaques

    International Nuclear Information System (INIS)

    The vaginal and rectal mucosae are the first line of cellular immune defense to sexually transmitted human immunodeficiency virus type 1 (HIV-1) entry. Thus, intraepithelial lymphocytes (IELs) may be important in the immune response to HIV infection. Here we investigated whether functional IELs in mucosal compartments could be visualized by direct staining with a tetrameric complex specific for the simian immunodeficiency virus (SIV) immunodominant Gag epitope in either separated IEL cells or tissues of macaques infected with SIVmac251. Of the 15 Mamu-A*01-positive macaques studied here, eight were chronically infected with either SIVmac251 or simian-human immunodeficiency virus (SHIV) KU2 and the remaining seven were exposed mucosally to SIVmac251 and sacrificed within 48 h to assess the local immune response. Gag-specific CD8+ T-cells were found in separated IELs from the rectum, colon, jejunum, and vagina of most infected animals. Direct staining of tetramers also revealed their presence in intact tissue. These Gag-specific IELs expressed the activation marker CD69 and produced IFN-γ, suggesting an active immune response in this locale

  2. TGF-β-induced CD4+Foxp3+ T cells attenuate acute graft-versus-host disease by suppressing expansion and killing of effector CD8+ cells.

    Science.gov (United States)

    Gu, Jian; Lu, Ling; Chen, Maogen; Xu, Lili; Lan, Qin; Li, Qiang; Liu, Zhongmin; Chen, Guihua; Wang, Ping; Wang, Xuehao; Brand, David; Olsen, Nancy; Zheng, Song Guo

    2014-10-01

    The use of TGF-β-induced CD4(+)Foxp3(+) T cells (induced regulatory T cells [iTregs]) is an important prevention and treatment strategy in autoimmune diseases and other disorders. However, the potential use of iTregs as a treatment modality for acute graft-versus-host disease (aGVHD) has not been realized because they may be unstable and less suppressive in this disease. We restudied the ability of iTregs to prevent and treat aGVHD in two mouse models. Our results showed that, as long as an appropriate iTreg-generation protocol is used, these iTregs consistently displayed a potent ability to control aGVHD development and reduce mortality in the aGVHD animal models. iTreg infusion markedly suppressed the engraftment of donor CD8(+) cells and CD4(+) cells, the expression of granzyme A and B, the cytotoxic effect of donor CD8(+) cells, and the production of T cell cytokines in aGVHD. Therefore, we conclude that as long as the correct methods for generating iTregs are used, they can prevent and even treat aGVHD. PMID:25156367

  3. In vitro activation of CMV-specific human CD8ţ T cells by adenylate

    Czech Academy of Sciences Publication Activity Database

    Jelínek, J.; Adkins, Irena; Mikulková, Z.; Jagosová, J.; Pacasová, R.; Michličková, S.; Šebo, Peter; Michálek, J.

    2012-01-01

    Roč. 47, č. 2 (2012), s. 243-250. ISSN 0268-3369 R&D Projects: GA MŠk 2B06161; GA ČR GP310/09/P582 Institutional research plan: CEZ:AV0Z50200510 Keywords : T cells * antigenic peptide epitopes * CyaA toxoid Subject RIV: EE - Microbiology, Virology Impact factor: 3.541, year: 2012

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    Lifescience Database Archive (English)

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  9. Optimal in vitro culture conditions for murine predominant immature CD8a+ dendritic cells

    Institute of Scientific and Technical Information of China (English)

    NA Ning; XU Lin; CAO Kai-yuan; LUO Yun; YUAN Guang-qing; XIANG Peng; HONG Liang-qing; LI Shu-nong

    2009-01-01

    Background The prospects of using immature CD8a+ dendritic cells (DC2) to establish transplant immunologic tolerance and treatments for autoimmune diseases in the future are promising. However, the methods for inducing DC2 are still being explored. The present study was aimed to investigate the optimal in vitro conditions for preparing large numbers f predominant DC2 from murine bone marrow cells.Methods Three groups of bone marrow cells cultured under different conditions were examined, namely a cytokine-induced experimental group (cytokine group), a control group with a low concentration of granulocyte-macrophage colony stimulating factor (GM-CSF, low GM-CSF group) and a control group without ndogenous cytokines. The cytokine group was cultured with 5 ng/ml GM-CSF, 25 ng/ml Fit3 ligand (Flt3L), 20 ng/ml interleukin 4 (IL-4) and 100 ng/ml stem cell factor (SCF). The low GM-CSF control group was cultured with 0.4 ng/ml GM-CSF, 25 ng/ml FIt3L and 100 ng/ml SCF, without IL-4. The control group without exogenous cytokines was cultured without dditional cytokines. All cells were cultured at 37℃ under 5% CO2. On days 3, 7 and 16, 4-color flow cytometry was carried out to analyze the cell phenotypes, and the total cell numbers were counted to analyze the cell yields. Phase-contrast microscopy was used to observe the cell morphologies.Results The cytokine group exhibited higher proportions f typical immature CD8a+ DC, especially on day 3, but the total cell number and DC2 proportion decreased during prolonged culture. The low GM-CSF control group showed the same tendencies as the cytokine group on days 16 and 22, but produced higher total cell numbers (P <0.05) with lower DC2 proportions and cell numbers. The control group without exogenous cytokines spontaneously generated a certain proportion of DC2, but with low total cell and DC2 numbers that decreased rapidly, especially during prolonged culture (days 7 and 16, P <0.05).Conclusions Culture in the presence of 5 ng

  10. Endoplasmic reticulum targeting sequence enhances HBV-specific cytotoxic T lymphocytes induced by a CTL epitope-based DNA vaccine

    International Nuclear Information System (INIS)

    CD8+ T cells play a critical role in protective immunity against Hepatitis B Virus (HBV). Epitope-based DNA vaccines expressing HBV-dominant CTL epitopes can be used as candidate vaccines capable of inducing cytotoxic T Lymphocytes (CTL) responses. A plasmid DNA encoding a CTL epitope of HBV core antigen, HBc18-27, was constructed. Intramuscular immunization of C57BL/6 mice with this DNA vaccine resulted in successful induction of HBV-specific CTL responses. In order to promote transportation of the peptide into endoplasmic reticulum (ER) to bind to MHC class I molecules for optimal class I antigen presentation, an ER targeting sequence (ERTS) was fused with the C18-27 encoding gene. ERTS fusion significantly enhanced specific CD8+ T cell responses in terms of CTL cytolysis as well as IFN-γ secretion. This enhancement was correlated with promoted epitope presentation on target cell surface. We report here an enhanced immunogenicity of an epitope-based DNA vaccine using an ER targeting signal sequence, which has significant implications for future design of therapeutic HBV vaccine

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

    DEFF Research Database (Denmark)

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

    2009-01-01

    in vitro T cell stimulation was investigated. By use of an antigenic peptide derived from the cytomegalovirus (CMVp) we tested the stimulatory efficacy of recombinant plate bound MHC molecules (PB-MHC), being immobilized in culture plates. A single stimulation of non-adherent peripheral blood...... effect of new stimulatory cocktails, e.g. cytokines and co-stimulatory molecules, by use of the present rapid and easy-to-use method of expanding peptide specific T cells.......Development of methods for efficient in vitro stimulation and expansion of peptide specific CD8(+) T cells is compelling not only with respect to adoptive T cell therapy but also regarding analysis of T cell responses and search for new immunogenic peptides. In the present study, a new approach to...

  12. 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

    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...... intravenous ranitidine 100 mg twice daily for 4 days from skin incision, followed by oral ranitidine 150 mg twice daily for a further 5 days; 13 control patients received no ranitidine. Routine blood analysis, clinical data, duration of surgery, anaesthesia, antibiotic prophylaxis and perioperative blood...... IL-2 receptor increased from day 0 to day 9 (P < 0.01); in control patients it decreased from day 0 to day 1, did not change significantly by day 3 and increased by day 9. The change from day 0 to day 1 was significantly different between the two groups (P < 0.01). Five of the 13 control patients...

  13. Peripheral blood TIM-3 positive NK and CD8+ T cells throughout pregnancy

    DEFF Research Database (Denmark)

    Meggyes, Matyas; Miko, Eva; Polgar, Beata;

    2014-01-01

    negative regulator of Th1 immunity and tolerance induction. Data about the TIM-3/Gal-9 pathway in the pathogenesis of human diseases is emerging, but their possible role during human pregnancy is not precisely known. The aim of our study was to investigate the number, phenotype and functional activity of...... TIM-3+ peripheral blood mononuclear cells during healthy human pregnancy. METHODS OF STUDY: 57 healthy pregnant women [first trimester (n = 16); second trimester (n = 19); third trimester (n = 22)] and 30 non-pregnant controls were enrolled in the study. We measured the surface expression of TIM-3 by...... cytotoxic T cells, NK cells and NK cell subsets as well as Galectin-9 expression by regulatory T cells by flow cytometry. We analyzed the cytokine production and cytotoxicity of TIM3+ and TIM3- CD8 T and NK cells obtained from non-pregnant and healthy pregnant women at different stages of pregnancy by flow...

  14. 4-1BB signaling breaks the tolerance of maternal CD8+ T cells that are reactive with alloantigens.

    Directory of Open Access Journals (Sweden)

    Kwang H Kim

    Full Text Available 4-1BB (CD137, TNFRSF9, a member of the activation-induced tumor necrosis factor receptor family, is a powerful T-cell costimulatory molecule. It generally enhances CD8(+ T responses and even breaks the tolerance of CD8(+ T cells in an antigen-specific manner. In the present study we found that it was expressed in the placentas of pregnant mice and that its expression coincided with that of the immunesuppressive enzyme indoleamine 2,3-dioxygenase (IDO. Therefore, we investigated whether 4-1BB signaling is involved in fetal rejection using agonistic anti-4-1BB mAb and 4-1BB-deficient mice. Treatment with agonistic anti-4-1BB mAb markedly increased the rate of rejection of allogeneic but not syngeneic fetuses, and this was primarily dependent on CD8(+ T cells. Complement component 3 (C3 seemed to be the effector molecule because 4-1BB triggering resulting in accumulation of C3 in the placenta, and this accumulation was also reversed by anti-CD8 mAb treatment. These findings demonstrate that 4-1BB triggering breaks the tolerance of CD8(+ T cells to alloantigens in the placenta. Moreover, triggering 4-1BB protected the pregnant mice from Listeria monocytogenes (LM infection, but led to rejection of semi-allogeneic fetuses. Therefore, given the cross-recognition of alloantigen by pathogen-reactive CD8(+ T cells, the true function of 4-1BB may be to reverse the hypo-responsiveness of pathogen-reactive CD8(+ T cells in the placenta in cases of infection, even if that risks losing the fetus.

  15. CD8+ T-Cells Count in Acute Myocardial Infarction in HIV Disease in a Predominantly Male Cohort

    Directory of Open Access Journals (Sweden)

    Oluwatosin A. Badejo

    2015-01-01

    Full Text Available Human Immunodeficiency Virus- (HIV- infected persons have a higher risk for acute myocardial infarction (AMI than HIV-uninfected persons. Earlier studies suggest that HIV viral load, CD4+ T-cell count, and antiretroviral therapy are associated with cardiovascular disease (CVD risk. Whether CD8+ T-cell count is associated with CVD risk is not clear. We investigated the association between CD8+ T-cell count and incident AMI in a cohort of 73,398 people (of which 97.3% were men enrolled in the U.S. Veterans Aging Cohort Study-Virtual Cohort (VACS-VC. Compared to uninfected people, HIV-infected people with high baseline CD8+ T-cell counts (>1065 cells/mm3 had increased AMI risk (adjusted HR=1.82, P<0.001, 95% CI: 1.46 to 2.28. There was evidence that the effect of CD8+ T-cell tertiles on AMI risk differed by CD4+ T-cell level: compared to uninfected people, HIV-infected people with CD4+ T-cell counts ≥200 cells/mm3 had increased AMI risk with high CD8+ T-cell count, while those with CD4+ T-cell counts <200 cells/mm3 had increased AMI risk with low CD8+ T-cell count. CD8+ T-cell counts may add additional AMI risk stratification information beyond that provided by CD4+ T-cell counts alone.

  16. Ex vivo restimulation of human PBMC expands a CD3+CD4-CD8- γδ+ T cell population that can confound the evaluation of CD4 and CD8 T cell responses to vaccination.

    Science.gov (United States)

    Sedgmen, B J; Papalia, L; Wang, L; Dyson, A R; McCallum, H A; Simson, C M; Pearse, M J; Maraskovsky, E; Hung, D; Eomois, P P; Hartel, G; Barnden, M J; Rockman, S P

    2013-01-01

    The measurement of vaccine-induced humoral and CD4(+) and CD8(+) cellular immune responses represents an important correlate of vaccine efficacy. Accurate and reliable assays evaluating such responses are therefore critical during the clinical development phase of vaccines. T cells play a pivotal role both in coordinating the adaptive and innate immune responses and as effectors. During the assessment of cell-mediated immunity (CMI) in subjects participating in a large-scale influenza vaccine trial, we identified the expansion of an IFN-γ-producing CD3(+)CD4(-)CD8(-) γδ (+) T cell population in the peripheral blood of 90/610 (15%) healthy subjects. The appearance of CD3(+)CD4(-)CD8(-) γδ (+) T cells in the blood of subjects was transient and found to be independent of the study cohort, vaccine group, subject gender and ethnicity, and ex vivo restimulation conditions. Although the function of this population and relevance to vaccination are unclear, their inclusion in the total vaccine-specific T-cell response has the potential to confound data interpretation. It is thus recommended that when evaluating the induction of IFN-γ-producing CD4(+) and CD8(+) immune responses following vaccination, the CD3(+)CD4(-)CD8(-) γδ (+) T cells are either excluded or separately enumerated from the overall frequency determination. PMID:24066003

  17. Ex Vivo Restimulation of Human PBMC Expands a CD3+CD4−CD8−γδ+ T Cell Population That Can Confound the Evaluation of CD4 and CD8 T Cell Responses to Vaccination

    Science.gov (United States)

    Sedgmen, B. J.; Papalia, L.; Wang, L.; Dyson, A. R.; McCallum, H. A.; Simson, C. M.; Pearse, M. J.; Maraskovsky, E.; Hung, D.; Eomois, P. P.; Hartel, G.; Barnden, M. J.; Rockman, S. P.

    2013-01-01

    The measurement of vaccine-induced humoral and CD4+ and CD8+ cellular immune responses represents an important correlate of vaccine efficacy. Accurate and reliable assays evaluating such responses are therefore critical during the clinical development phase of vaccines. T cells play a pivotal role both in coordinating the adaptive and innate immune responses and as effectors. During the assessment of cell-mediated immunity (CMI) in subjects participating in a large-scale influenza vaccine trial, we identified the expansion of an IFN-γ-producing CD3+CD4−CD8−γδ+ T cell population in the peripheral blood of 90/610 (15%) healthy subjects. The appearance of CD3+CD4−CD8−γδ+ T cells in the blood of subjects was transient and found to be independent of the study cohort, vaccine group, subject gender and ethnicity, and ex vivo restimulation conditions. Although the function of this population and relevance to vaccination are unclear, their inclusion in the total vaccine-specific T-cell response has the potential to confound data interpretation. It is thus recommended that when evaluating the induction of IFN-γ-producing CD4+ and CD8+ immune responses following vaccination, the CD3+CD4−CD8−γδ+ T cells are either excluded or separately enumerated from the overall frequency determination. PMID:24066003

  18. Ex Vivo Restimulation of Human PBMC Expands a CD3+CD4-CD8-γδ+ T Cell Population That Can Confound the Evaluation of CD4 and CD8 T Cell Responses to Vaccination

    Directory of Open Access Journals (Sweden)

    B. J. Sedgmen

    2013-01-01

    Full Text Available The measurement of vaccine-induced humoral and CD4+ and CD8+ cellular immune responses represents an important correlate of vaccine efficacy. Accurate and reliable assays evaluating such responses are therefore critical during the clinical development phase of vaccines. T cells play a pivotal role both in coordinating the adaptive and innate immune responses and as effectors. During the assessment of cell-mediated immunity (CMI in subjects participating in a large-scale influenza vaccine trial, we identified the expansion of an IFN-γ-producing CD3+CD4-CD8-γδ+ T cell population in the peripheral blood of 90/610 (15% healthy subjects. The appearance of CD3+CD4-CD8-γδ+ T cells in the blood of subjects was transient and found to be independent of the study cohort, vaccine group, subject gender and ethnicity, and ex vivo restimulation conditions. Although the function of this population and relevance to vaccination are unclear, their inclusion in the total vaccine-specific T-cell response has the potential to confound data interpretation. It is thus recommended that when evaluating the induction of IFN-γ-producing CD4+ and CD8+ immune responses following vaccination, the CD3+CD4-CD8-γδ+ T cells are either excluded or separately enumerated from the overall frequency determination.

  19. CD8+ cell noncytotoxic antiviral response (CNAR) to HIV in nosocomial HIV-infected individuals%医源性HIV感染者CD8+细胞非细胞毒性HIV抑制作用的研究

    Institute of Scientific and Technical Information of China (English)

    袁霖; 马丽英; 臧希卉; 孟向东; 彭虹; 赵全壁; 邢辉; 邵一鸣

    2008-01-01

    Objective To study the CD8+ cell noncytotoxic antiviral response (CNAR) to HIV in nosocomial HIV infected individuals, and reveal the relationship between the CNAR and CD4 cell count. MethodCD8+ cells from HIV-1 sero-positive individuals were separated by immunomagnetic beads and mixed withCD4+ cells at different CD8 CD4 cell input ratios (2:1,1:1,0.5:1 and 0.25:1). Reverse transcriptase (RT) activity of cocultured supernatant was tested and compared with negative control and the suppression rate of HIV-1 replication was measured. Result The average CD8 : CD4 cell input ratios to reach 80% suppression of HIV replication in the group with CD4300/μl were 2.4:1 and 1.3:1, respectively (P cell count. The ability to suppress HIV replication in subjects with CD4>300 is stronger than those with CD4300个/μl组的平均CD8与CD4比例为1.3:1,两组间比较差异有统计学意义(P300的个体较CD4<300的个体有着更显著的抑制HIV复制的能力.

  20. Airway CD8(+) T Cells Are Associated with Lung Injury during Infant Viral Respiratory Tract Infection.

    Science.gov (United States)

    Connors, Thomas J; Ravindranath, Thyyar M; Bickham, Kara L; Gordon, Claire L; Zhang, Feifan; Levin, Bruce; Baird, John S; Farber, Donna L

    2016-06-01

    Infants and young children are disproportionately susceptible to severe complications from respiratory viruses, although the underlying mechanisms remain unknown. Recent studies show that the T cell response in the lung is important for protective responses to respiratory infections, although details on the infant/pediatric respiratory immune response remain sparse. The objectives of the present study were to characterize the local versus systemic immune response in infants and young children with respiratory failure from viral respiratory tract infections and its association to disease severity. Daily airway secretions were sampled from infants and children 4 years of age and younger receiving mechanical ventilation owing to respiratory failure from viral infection or noninfectious causes. Samples were examined for immune cell composition and markers of T cell activation. These parameters were then correlated with clinical disease severity. Innate immune cells and total CD3(+) T cells were present in similar proportions in airway aspirates derived from infected and uninfected groups; however, the CD8:CD4 T cell ratio was markedly increased in the airways of patients with viral infection compared with uninfected patients, and specifically in infected infants with acute lung injury. T cells in the airways were phenotypically and functionally distinct from those in blood with activated/memory phenotypes and increased cytotoxic capacity. We identified a significant increase in airway cytotoxic CD8(+) T cells in infants with lung injury from viral respiratory tract infection that was distinct from the T cell profile in circulation and associated with increasing disease severity. Airway sampling could therefore be diagnostically informative for assessing immune responses and lung damage. PMID:26618559

  1. Epitope prediction methods

    OpenAIRE

    Karosiene, Edita; Nielsen, Morten; Lund, Ole

    2013-01-01

    Major histocompatibility complex (MHC molekyler spiller en afgørende rolle i adaptiv immunitet, ved at udvælge peptider fra egne og ikke-egne proteiner til genkendelse af immunsystemet. MHC molekyler præsenterer peptider på celleoverfladen, som så genkendes af CD8+ og CD4+ T lymfocytter, som er i stand til at initiere et immunrespons. Det er derfor yderst vigtigt at kunne identificere peptider, som binder til MHC molekyler, for derved at kunne forstå arten af immunresponset, samt at opdage T ...

  2. IL-2 and IL-15 Each Mediate De Novo Induction of FOXP3 Expression in Human Tumor Antigen-specific CD8 T Cells

    OpenAIRE

    Ahmadzadeh, Mojgan; Antony, Paul A.; Rosenberg, Steven A

    2007-01-01

    Although FOXP3 is primarily expressed by regulatory CD4 T cells (Treg) in vivo, polyclonal activation of human CD8 T cells can result in the expression of FOXP3 in a fraction of CD8 T cells. However, the cellular lineage and mechanism of FOXP3 induction in CD8 T cells remain unclear. Here, we demonstrate that interleukin-2 (IL-2) induces FOXP3 expression in OKT3-stimulated or antigen-stimulated CD8 T cells, indicating that FOXP3 expression is neither limited to a unique subset of CD8 T cells ...

  3. Further progress on defining highly conserved immunogenic epitopes for a global HIV vaccine: HLA-A3-restricted GAIA vaccine epitopes.

    Science.gov (United States)

    De Groot, Anne S; Levitz, Lauren; Ardito, Matthew T; Skowron, Gail; Mayer, Kenneth H; Buus, Soren; Boyle, Christine M; Martin, William D

    2012-07-01

    Two major obstacles confronting HIV vaccine design have been the extensive viral diversity of HIV-1 globally and viral evolution driven by escape from CD8(+) cytotoxic T-cell lymphocyte (CTL)-mediated immune pressure. Regions of the viral genome that are not able to escape immune response and that are conserved in sequence and across time may represent the "Achilles' heel" of HIV and would be excellent candidates for vaccine development. In this study, T-cell epitopes were selected using immunoinformatics tools, combining HLA-A3 binding predictions with relative sequence conservation in the context of global HIV evolution. Twenty-seven HLA-A3 epitopes were chosen from an analysis performed in 2003 on 10,803 HIV-1 sequences, and additional sequences were selected in 2009 based on an expanded set of 43,822 sequences. These epitopes were tested in vitro for HLA binding and for immunogenicity with PBMCs of HIV-infected donors from Providence, Rhode Island. Validation of these HLA-A3 epitopes conserved across time, clades, and geography supports the hypothesis that epitopes such as these would be candidates for inclusion in our globally relevant GAIA HIV vaccine constructs. PMID:22777092

  4. Vaccination with an adenoviral vector encoding the tumor antigen directly linked to invariant chain induces potent CD4(+) T-cell-independent CD8(+) T-cell-mediated tumor control

    DEFF Research Database (Denmark)

    Sorensen, Maria R; Holst, Peter J; Pircher, Hanspeter;

    2009-01-01

    Antigen-specific immunotherapy is an attractive strategy for cancer control. In the context of antiviral vaccines, adenoviral vectors have emerged as a favorable means for immunization. Therefore, we chose a strategy combining use of these vectors with another successful approach, namely linkage of...... the vaccine antigen to invariant chain (Ii). To evaluate this strategy we used a mouse model, in which an immunodominant epitope (GP33) of the LCMV glycoprotein (GP) represents the tumor-associated neoantigen. Prophylactic vaccination of C57BL/6 mice with a replication-deficient human adenovirus 5...... than vaccination with adenovirus expressing GP alone (Ad-GP), or GP and Ii unlinked (Ad-GP+Ii). Ad-Ii-GP- induced tumor control depended on an improved generation of the tumor-associated neoantigen-specific CD8(+) T-cell response and was independent of CD4(+) T cells. IFN-gamma was shown to be a key...

  5. Radiosensitivity of CD4 and CD8 positive human T lymphocytes by an in vitro colony formation assay

    International Nuclear Information System (INIS)

    The recent development of an in vitro lymphocyte colony assay provides a new opportunity to examine possible variations in human radiosensitivity using peripheral blood lymphocytes (PBL) in place of the hitherto used skin fibroblast assay. Our recent study showed that most of the colonies consisted of lymphocytes bearing CD4 or CD8 antigens. Since the fraction of CD4+ and CD8+ cells in PBL differs among individuals, it was suspected that individual radiosensitivity might be biased by the different subset frequencies if the dose-survival curves of the CD4+ and CD8+ cells differed. In the present study, CD4+ lymphocytes (helper/inducer T cells) and CD8+ lymphocytes (suppressor/cytotoxic T cells) were isolated from PBL and their dose-survival curves were determined. The results showed that the D10 (the dose required to reduce the surviving fraction to 10 %) was quite similar for these two types of cells (3.13 ± 0.10 Gy [mean ±SD] for CD4+, 3.34 ± 0.50 Gy for CD8+ and 3.07 ± 0.05 Gy for the unsorted cells), supporting the use of a whole PBL population for screening of individuals with altered radiosensitivity. (author)

  6. Engagement of NKG2D on bystander memory CD8 T cells promotes increased immunopathology following Leishmania major infection.

    Directory of Open Access Journals (Sweden)

    Erika J Crosby

    2014-02-01

    Full Text Available One of the hallmarks of adaptive immunity is the development of a long-term pathogen specific memory response. While persistent memory T cells certainly impact the immune response during a secondary challenge, their role in unrelated infections is less clear. To address this issue, we utilized lymphocytic choriomeningitis virus (LCMV and Listeria monocytogenes immune mice to investigate whether bystander memory T cells influence Leishmania major infection. Despite similar parasite burdens, LCMV and Listeria immune mice exhibited a significant increase in leishmanial lesion size compared to mice infected with L. major alone. This increased lesion size was due to a severe inflammatory response, consisting not only of monocytes and neutrophils, but also significantly more CD8 T cells. Many of the CD8 T cells were LCMV specific and expressed gzmB and NKG2D, but unexpectedly expressed very little IFN-γ. Moreover, if CD8 T cells were depleted in LCMV immune mice prior to challenge with L. major, the increase in lesion size was lost. Strikingly, treating with NKG2D blocking antibodies abrogated the increased immunopathology observed in LCMV immune mice, showing that NKG2D engagement on LCMV specific memory CD8 T cells was required for the observed phenotype. These results indicate that bystander memory CD8 T cells can participate in an unrelated immune response and induce immunopathology through an NKG2D dependent mechanism without providing increased protection.

  7. PD-L1 Expression on Retrovirus-Infected Cells Mediates Immune Escape from CD8+ T Cell Killing.

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    Ilseyar Akhmetzyanova

    2015-10-01

    Full Text Available Cytotoxic CD8+ T Lymphocytes (CTL efficiently control acute virus infections but can become exhausted when a chronic infection develops. Signaling of the inhibitory receptor PD-1 is an important mechanism for the development of virus-specific CD8+ T cell dysfunction. However, it has recently been shown that during the initial phase of infection virus-specific CD8+ T cells express high levels of PD-1, but are fully competent in producing cytokines and killing virus-infected target cells. To better understand the role of the PD-1 signaling pathway in CD8+ T cell cytotoxicity during acute viral infections we analyzed the expression of the ligand on retrovirus-infected cells targeted by CTLs. We observed increased levels of PD-L1 expression after infection of cells with the murine Friend retrovirus (FV or with HIV. In FV infected mice, virus-specific CTLs efficiently eliminated infected target cells that expressed low levels of PD-L1 or that were deficient for PD-L1 but the population of PD-L1high cells escaped elimination and formed a reservoir for chronic FV replication. Infected cells with high PD-L1 expression mediated a negative feedback on CD8+ T cells and inhibited their expansion and cytotoxic functions. These findings provide evidence for a novel immune escape mechanism during acute retroviral infection based on PD-L1 expression levels on virus infected target cells.

  8. Evidence of a pathogenic role for CD8+ T cells in anti-GABAB receptor limbic encephalitis

    Science.gov (United States)

    Golombeck, Kristin S.; Bönte, Kathrin; Mönig, Constanze; van Loo, Karen M.; Hartwig, Marvin; Schwindt, Wolfram; Widman, Guido; Lindenau, Matthias; Becker, Albert J.; Glatzel, Markus; Elger, Christian E.; Wiendl, Heinz; Meuth, Sven G.; Lohmann, Hubertus; Gross, Catharina C.

    2016-01-01

    Objectives: To characterize the cellular autoimmune response in patients with γ-aminobutyric acid (GABA)B receptor antibody–associated limbic encephalitis (GABAB-R LE). Methods: Patients underwent MRI, extensive neuropsychological assessment, and multiparameter flow cytometry of peripheral blood and CSF. Results: We identified a series of 3 cases of nonparaneoplastic GABAB-R LE and one case of paraneoplastic GABAB-R LE associated with small cell lung cancer. All patients exhibited temporal lobe epilepsy, neuropsychological deficits, and MRI findings typical of LE. Absolute numbers of CD19+ B cells, CD138+ CD19+ plasma cells, CD4+ T cells, activated HLADR+ CD4+ T cells, as well as CD8+ T cells and HLADR+ CD8+ T cells did not differ in peripheral blood but were elevated in CSF of patients with GABAB-R LE compared to controls. Augmented absolute numbers of CD138+ CD19+ plasma cells and activated HLADR+ CD8+ T cells in CSF corresponded to higher overall neuropsychological and memory deficits in patients with GABAB-R LE. A histologic specimen of one patient following selective amygdalohippocampectomy revealed perivascular infiltrates of CD138+ plasma cells and CD4+ T cells, whereas cytotoxic CD8+ T cells were detected within the brain parenchyma in close contact to neurons. Conclusion: Our data suggest a pathogenic role for CD8+ T cells in addition to the established role of plasma cell–derived autoantibodies in GABAB-R LE. PMID:27213174

  9. Investigation of biochemical property changes in activation-induced CD 8 + T cell apoptosis using Raman spectroscopy

    Science.gov (United States)

    Lee, Young Ju; Ahn, Hyung Joon; Lee, Gi-Ja; Jung, Gyeong Bok; Lee, Gihyun; Kim, Dohyun; Shin, Jae-Ho; Jin, Kyung-Hyun; Park, Hun-Kuk

    2015-07-01

    The study was to investigate the changes in biochemical properties of activated mature CD8+ T cells related to apoptosis at a molecular level. We confirmed the activation and apoptosis of CD8+ T cells by fluorescence-activated cell sorting and atomic force microscopy and then performed Raman spectral measurements on activated mature CD8+ T cells and cellular deoxyribose nucleic acid (DNA). In the activated mature CD8+ T cells, there were increases in protein spectra at 1002 and 1234 cm-1. In particular, to assess the apoptosis-related DNA spectral signatures, we investigated the spectra of the cellular DNA isolated from resting and activated mature CD8+ T cells. Raman spectra at 765 to 786 cm-1 and 1053 to 1087 cm-1 were decreased in activated mature DNA. In addition, we analyzed Raman spectrum using the multivariate statistical method including principal component analysis. Raman spectra of activated mature DNA are especially well-discriminated from those of resting DNA. Our findings regarding the biochemical and structural changes associated with apoptosis in activated mature T cells and cellular DNA according to Raman spectroscopy provide important insights into allospecific immune responses generated after organ transplantation, and may be useful for therapeutic manipulation of the immune response.

  10. Enumeration of CD4 and CD8 T-cells in HIV infection in Zimbabwe using a manual immunocytochemical method

    DEFF Research Database (Denmark)

    Gomo, E; Ndhlovu, P; Vennervald, B J; Nyazema, N; Friis, Henrik

    2001-01-01

    OBJECTIVES: To enumerate CD4 and CD8 T-cells using the simple and cheap immuno-alkaline phosphatase (IA) method and to compare it with flow cytometry (FC); and to study the effects of duration of sample storage on the IA method results. DESIGN: Method comparison study. SETTING: Blair Research...... Laboratory, Harare, Zimbabwe. SUBJECTS: 41 HIV positive and 11 HIV negative men and women from Harare participating in HIV studies at Blair Research Laboratory, Zimbabwe. MAIN OUTCOME MEASURES: CD4 and CD8 T-cell counts by FC and the IA method. RESULTS: The IA method and FC were highly correlated for CD4...... counts (Spearman rs = 0.91), CD4 percentage (rs = 0.84), CD8 count (rs = 0.83), CD8 percentage (rs = 0.96) and CD4/CD8 ratio (rs = 0.89). However, CD4 cell counts and percentage measured by the IA method were (mean difference +/- SE) 133 +/- 24 cells/microL [corrected] and 6.7 +/- 1.1% higher than those...

  11. Long-term treatment of pigs with low doses of monoclonal antibodies against porcine CD4 and CD8 antigens

    DEFF Research Database (Denmark)

    Lohse, Louise; Nielsen, Jens; Eriksen, Lis

    2006-01-01

    In vivo depletion of lymphocyte subsets allows investigation of the role of specific subsets in protective immunity. In the present study we evaluated the effects of long-term, low-dose treatment with murine monoclonal antibodies (mAbs) against porcine CD4 and CD8 surface antigens on lymphocyte....... Treatment with the anti-CD4 mAb almost completely eliminated the CD4(+) T-cell subset from the circulation after 2 weeks of therapy. This depletion persisted until the end of the experimental period 5 weeks after initiated therapy. Treatment with the anti-CD8 mAb was less effective, reducing the CD8(+) T......-cell subset in peripheral blood by approximately 50% of the initial level after 3 weeks of therapy. Further, the anti-CD8 mAb-treated pigs showed a parallel increase in the CD4(+) T-cell subset from day 7. Two-colour FCM analysis indicated that a shift in phenotype from single-positive CD4(+)/CD8(-) to double...

  12. Is an increase in CD4/CD8 T-cell ratio in lymph node fine needle aspiration helpful for diagnosing Hodgkin lymphoma? A study of 85 lymph node FNAs with increased CD4/CD8 ratio

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    Hernandez Osvaldo

    2005-01-01

    Full Text Available Abstract Background An elevated CD4/CD8 T-cell ratio on flow cytometry (FCM analysis has been reported in the literature to be associated with Hodgkin lymphoma (HL. The purpose of our study was to determine the diagnostic significance of an elevated CD4/CD8 ratio in lymph node fine needle aspiration (FNA specimens. Design Between 1996 and 2002, out of 837 lymph node FNAs submitted for flow cytometry analysis, 85 cases showed an elevated CD4/CD8 ratio, defined as greater than or equal to 4, without definitive evidence of a lymphoproliferative disorder. The cytologic diagnoses of these 85 cases were grouped into four categories: reactive, atypical, Hodgkin lymphoma (HL, and non-Hodgkin lymphoma (NHL. Histologic follow-up was available in 17/85 (20% of the cases. Results 5 of the 64 cases in which FCM and cytology did not reveal evidence of a lymphoproliferative disease had tissue follow-up because of persistent lymphadenopathy and high clinical suspicion. 3/5 (60% confirmed the diagnosis of reactive lymphadenopathy. The two remaining cases (40% were positive for lymphoma (1HL, 1NHL. 8/15 cases called atypical on cytology had histologic follow-up. 7/8 (87.5% cases were positive for lymphoma (3HL, 4NHL. 3/4 cases called HL on cytology had tissue follow-up and all 3 (100% confirmed the diagnosis of HL. One case diagnosed as NHL on cytology was found to be a diffuse large B-cell lymphoma. In summary, out of 17 cases with histologic follow-up 4/17 (24% were reactive with CD4/CD8 T-cell ratio of 4.1–29, 7/17 (41% were HLs with CD4/CD8 T-cell ratio of 5.3