The magnitude and breadth of hepatitis C virus–specific CD8+ T cells depend on absolute CD4+ T-cell count in individuals coinfected with HIV-1

Blood ◽  
2005 ◽  
Vol 105 (3) ◽  
pp. 1170-1178 ◽  
Author(s):  
Arthur Y. Kim ◽  
Georg M. Lauer ◽  
Kei Ouchi ◽  
Marylyn M. Addo ◽  
Michaela Lucas ◽  
...  
Keyword(s):  
T Cells ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
T Cell ◽  
Cd8 T Cells ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Cd4 T Cell ◽  
Cell Responses ◽  
Hiv 1

AbstractCD8+ T-cell responses are an essential antiviral host defense in persistent viral infections, and their sustained effectiveness is thought to be critically dependent on CD4+ T-helper cells. To determine the relationship between HIV-1–induced CD4+ T-cell depletion and hepatitis C virus (HCV)–specific CD8+ T-cell responses during viral persistence, we studied 103 persons positive for HCV, 74 coinfected with HIV-1. CD8+ T-cell responses to the entire HCV polyprotein were determined by using an interferon-γ enzyme-linked immunospot (ELISpot) assay. Although HIV-1 infection by itself was not associated with a diminished HCV-specific response, HIV-1–associated CD4+ depletion was associated with significantly lower HCV-specific CD8+ T cells (R = 0.48, P < .0001). In contrast, declining CD4+ counts over the same range were not associated with diminished Epstein-Barr virus (EBV)– (R = 0.19, P = .31) or HIV-1–specific (R = –0.13, P = .60) CD8+ T-cell responses in persons infected with all viruses. These data indicate that frequencies of circulating HCV-specific CD8+ T-cell responses are sensitive to absolute CD4+ T-cell counts and provide a possible explanation for the accelerated HCV disease course in persons coinfected with HIV-1 and HCV.

scholarly journals Differences in Hepatitis C Virus (HCV)-Specific CD8 T-Cell Phenotype during Pegylated Alpha Interferon and Ribavirin Treatment Are Related to Response to Antiviral Therapy in Patients Chronically Infected with HCV

2008 ◽  
Vol 82 (15) ◽  
pp. 7567-7577 ◽  
Author(s):  
Joana Caetano ◽  
António Martinho ◽  
Artur Paiva ◽  
Beatriz Pais ◽  
Cristina Valente ◽  
...  
Keyword(s):  
T Cells ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
T Cell ◽  
Cd8 T Cells ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Alpha Interferon ◽  
Response To Treatment ◽  
Cell Responses

ABSTRACT CD8 T cells play a major role in antiviral immune responses. Their importance for progression to chronic hepatitis C and response to treatment are still unclear. To address these issues, hepatitis C virus (HCV)-specific CD8 T-cell responses were monitored, at the single-cell level, using HLA class I pentamers specific for HCV core and HCV NS3 epitopes, in 23 chronically infected patients during treatment with pegylated alpha interferon and ribavirin. Patients who presented a sustained-response to therapy had stronger HCV-specific CD8 T-cell responses at all time points studied. Moreover, there were clear differences in the phenotypes of these cells during therapy: in responder patients, terminally differentiated effector cells increased more rapidly, and their frequency was always higher than in nonresponder patients. Sustained-responder patients also showed a higher frequency of HCV-specific CD8 T cells producing cytotoxic factors. Overall, a late and inefficient differentiation process of HCV-specific CD8 T cells might be associated with lack of response to treatment. A better knowledge of the mechanisms underlying this impairment may be important for the development of new therapeutic strategies to maintain, restore, or increase CD8 T-cell effectiveness in chronic HCV infection.

scholarly journals Single cell profiling of T and B cell repertoires following SARS-CoV-2 mRNA vaccine

2021 ◽  
Author(s):  
Suhas Sureshchandra ◽  
Sloan A. Lewis ◽  
Brianna Doratt ◽  
Allen Jankeel ◽  
Izabela Ibraim ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
Single Cell ◽  
Cd8 T Cells ◽  
Natural Infection ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Cd4 T Cell ◽  
Cell Responses

mRNA based vaccines for SARS-CoV-2 have shown exceptional clinical efficacy providing robust protection against severe disease. However, our understanding of transcriptional and repertoire changes following full vaccination remains incomplete. We used single-cell RNA sequencing and functional assays to compare humoral and cellular responses to two doses of mRNA vaccine with responses observed in convalescent individuals with asymptomatic disease. Our analyses revealed enrichment of spike-specific B cells, activated CD4 T cells, and robust antigen-specific polyfunctional CD4 T cell responses in all vaccinees. On the other hand, CD8 T cell responses were both weak and variable. Interestingly, clonally expanded CD8 T cells were observed in every vaccinee, as observed following natural infection. TCR gene usage, however, was variable, reflecting the diversity of repertoires and MHC polymorphism in the human population. Natural infection induced expansion of larger CD8 T cell clones occupied distinct clusters, likely due to the recognition of a broader set of viral epitopes presented by the virus not seen in the mRNA vaccine. Our study highlights a coordinated adaptive immune response where early CD4 T cell responses facilitate the development of the B cell response and substantial expansion of effector CD8 T cells, together capable of contributing to future recall responses.

Spontaneous CD4 and CD8 Memory T Cell Responses Against MUC1 and Carcinoembryonic Antigen in Bone Marrow of Multiple Myeloma Patients.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 3533-3533
Author(s):  
Mathias Witzens-Harig ◽  
Dirk Hose ◽  
Michael Hundemer ◽  
Simone Juenger ◽  
Anthony D. Ho ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Bone Marrow ◽  
T Cells ◽  
T Cell ◽  
Carcinoembryonic Antigen ◽  
Cd8 T Cells ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Cd4 T Cell ◽  
Cell Responses

Abstract Introduction: The bone marrow (BM) is a site of induction of tumour antigen specific T cell responses in many malignancies. We have demonstrated in the BM of myeloma patients high frequencies of spontaneously generated CD8 memory T cells with specificity for the myeloma-associated antigen MUC1, which were not detectable in the peripheral blood (PB). Besides MUC1, carcinoembryonic antigen was recently identified as a tumour-associated antigen in a patient with multiple myeloma. Up to now, spontaneous CD4 T cell responses against myeloma-associated antigens have not been reported. We undertook this study to evaluate to what extent spontaneous CD4 T cell responses against myeloma antigens occur during myeloma progression and if MUC1 or carcinoembryonic antigen represent immunogenic targets of spontaneous CD4 and CD8 T cell responses. Methods: Altogether, 78 patients with multiple myeloma were included into the study. Presence of functionally competent antigen specific T cells was evaluated by ex vivo short term (40 h) IFN-γ Elispot analyses. CD4 T cell responses against MUC1 were assessed by stimulation of purified CD4 T cell fractions with antigen pulsed, autologous dendritic cells (DCs) pulsed with two synthetic 100 meric polypeptides (pp1-100ss and (137–157)5 tr) that can be processed and presented via multiple HLA-II alleles. CD4- or CD8 T cell reactivity against carcinoembryonic antigen was assessed on purified CD4- and CD8 T cell fractions by pulsing DCs with highly purified CEA derived from culture supernatants of an epithelial carcinoma cell line. CD8 responses against MUC1 were analyzed by stimulation of HLA-A2+ patients derived purified T cells with DCs loaded with HLA-A2 restricted MUC1-derived nonameric peptide LLLLTVLTV. As negative control antigen for MUC1 polypeptides and CEA human IgG was used for pulsing DCs at identical concentrations while HLA-A2-restricted peptide SLYNTVATL derived from HIV was used as control antigen for LLLLTVLTV. Test antigen specific reactivity was defined by significantly increased numbers of IFN-γ spots in triplicate test wells compared to control wells (p<0.05, students T test). Results: 8 out of 19 tested patients (42%) contained MUC1 specific CD8 T cells in their bone marrow, while MUC1 specific CD4 T cells were detected in the BM of 30% of the cases (3/10). Interestingly, in peripheral blood (PB) CD8 reactivity against MUC1 was detectable in only 1 out of 10 patients while CD4 reactivity in PB was not detectable at all (0/10). CEA was specifically recognized by BM CD8 T cells from 5 out of 30 patients (17%) and by BM CD4 T cells from 5 out of 18 patients (28%). CEA was not recognized by CD4 and CD8 T cells in the PB of the same patients (0/13). Conclusion: Spontaneous T helper responses against tumour-associated antigens occur in the BM at similar levels as antigen specific CD8 T cells responses while they are virtually undetectable in the PB. Compared to CEA, MUC1 induces CD8 T cell responses in a much higher proportion of myeloma patients. Nevertheless, our data suggest that CEA may trigger spontaneous T cell responses against multiple myeloma in a considerable number of patients. Thus, systematic functional analyses of this potential tumour antigen in multiple myeloma appears to be justified.

scholarly journals Enhancement of Antiviral CD8+ T-Cell Responses and Complete Remission of Metastatic Melanoma in an HIV-1-Infected Subject Treated with Pembrolizumab

2019 ◽  
Vol 8 (12) ◽  
pp. 2089 ◽  
Author(s):  
Oscar Blanch-Lombarte ◽  
Cristina Gálvez ◽  
Boris Revollo ◽  
Esther Jiménez-Moyano ◽  
Josep M. Llibre ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Metastatic Melanoma ◽  
Cd8 T Cells ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Viral Reactivation ◽  
Viral Reservoir ◽  
Cell Responses ◽  
Hiv 1

Background: Pembrolizumab is an immune checkpoint inhibitor against programmed cell death protein-1 (PD-1) approved for therapy in metastatic melanoma. PD-1 expression is associated with a diminished functionality in HIV-1 specific-CD8+ T cells. It is thought that PD-1 blockade could contribute to reinvigorate antiviral immunity and reduce the HIV-1 reservoir. Methods: Upon metastatic melanoma diagnosis, an HIV-1-infected individual on stable suppressive antiretroviral regimen was treated with pembrolizumab. A PET-CT was performed before and one year after pembrolizumab initiation. We monitored changes in the immunophenotype and HIV-1 specific-CD8+ T-cell responses during 36 weeks of treatment. Furthermore, we assessed changes in the viral reservoir by total HIV-1 DNA, cell-associated HIV-1 RNA, and ultrasensitive plasma viral load. Results: Complete metabolic response was achieved after pembrolizumab treatment of metastatic melanoma. Activated CD8+ T-cells expressing HLA-DR+/CD38+ transiently increased over the first nine weeks of treatment. Concomitantly, there was an augmented response of HIV-1 specific-CD8+ T cells with TNF production and poly-functionality, transitioning from TNF to an IL-2 profile. Furthermore, a transient reduction of 24% and 32% in total HIV-1 DNA was observed at weeks 3 and 27, respectively, without changes in other markers of viral persistence. Conclusions: These data demonstrate that pembrolizumab may enhance the HIV-1 specific-CD8+ T-cell response, marginally affecting the HIV-1 reservoir. A transient increase of CD8+ T-cell activation, TNF production, and poly-functionality resulted from PD-1 blockade. However, the lack of sustained changes in the viral reservoir suggests that viral reactivation is needed concomitantly with HIV-1-specific immune enhancement.

scholarly journals Preservation of Intrahepatic Hepatitis C Virus (HCV)–Specific CD4+T Cell Responses despite Global Loss of CD4+T Cells in HCV/HIV Coinfection

2007 ◽  
Vol 196 (4) ◽  
pp. 577-586 ◽  
Author(s):  
Chihiro Morishima ◽  
Margaret C. Shuhart ◽  
Christina S. Yoshihara ◽  
Denise M. Paschal ◽  
Melissa A. Silva ◽  
...  
Keyword(s):  
T Cells ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
T Cell ◽  
Cd4 T Cells ◽  
T Cell Responses ◽  
Cd4 T Cell ◽  
Cell Responses ◽  
Hiv Coinfection

scholarly journals Breadth of CD8 T-cell mediated inhibition of replication of diverse HIV-1 transmitted-founder isolates correlates with the breadth of recognition within a comprehensive HIV-1 Gag, Nef, Env and Pol potential T-cell epitope (PTE) peptide set

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0260118
Author(s):  
Peter Hayes ◽  
Natalia Fernandez ◽  
Christina Ochsenbauer ◽  
Jama Dalel ◽  
Jonathan Hare ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cell Epitope ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
T Cell Epitope ◽  
Cell Numbers ◽  
Cell Responses ◽  
Hiv 1

Full characterisation of functional HIV-1-specific T-cell responses, including identification of recognised epitopes linked with functional antiviral responses, would aid development of effective vaccines but is hampered by HIV-1 sequence diversity. Typical approaches to identify T-cell epitopes utilising extensive peptide sets require subjects’ cell numbers that exceed feasible sample volumes. To address this, CD8 T-cells were polyclonally expanded from PBMC from 13 anti-retroviral naïve subjects living with HIV using CD3/CD4 bi-specific antibody. Assessment of recognition of individual peptides within a set of 1408 HIV-1 Gag, Nef, Pol and Env potential T-cell epitope peptides was achieved by sequential IFNγ ELISpot assays using peptides pooled in 3-D matrices followed by confirmation with single peptides. A Renilla reniformis luciferase viral inhibition assay assessed CD8 T-cell-mediated inhibition of replication of a cross-clade panel of 10 HIV-1 isolates, including 9 transmitted-founder isolates. Polyclonal expansion from one frozen PBMC vial provided sufficient CD8 T-cells for both ELISpot steps in 12 of 13 subjects. A median of 33 peptides in 16 epitope regions were recognised including peptides located in previously characterised HIV-1 epitope-rich regions. There was no significant difference between ELISpot magnitudes for in vitro expanded CD8 T-cells and CD8 T-cells directly isolated from PBMCs. CD8 T-cells from all subjects inhibited a median of 7 HIV-1 isolates (range 4 to 10). The breadth of CD8 T-cell mediated HIV-1 inhibition was significantly positively correlated with CD8 T-cell breadth of peptide recognition. Polyclonal CD8 T-cell expansion allowed identification of HIV-1 isolates inhibited and peptides recognised within a large peptide set spanning the major HIV-1 proteins. This approach overcomes limitations associated with obtaining sufficient cell numbers to fully characterise HIV-1-specific CD8 T-cell responses by different functional readouts within the context of extreme HIV-1 diversity. Such an approach will have useful applications in clinical development for HIV-1 and other diseases.

scholarly journals Specificity of CD8+ T-Cell Responses Following Vaccination with Conserved Regions of HIV-1 in Nairobi, Kenya

Vaccines ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 260
Author(s):  
Yehia S. Mohamed ◽  
Nicola J. Borthwick ◽  
Nathifa Moyo ◽  
Hayato Murakoshi ◽  
Tomohiro Akahoshi ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Lines ◽  
Cd8 T Cells ◽  
Cell Epitope ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
T Cell Epitope ◽  
Cell Responses ◽  
Hiv 1

Sub-Saharan Africa carries the biggest burden of the human immunodeficiency virus type 1 (HIV-1)/AIDS epidemic and is in an urgent need of an effective vaccine. CD8+ T cells are an important component of the host immune response to HIV-1 and may need to be harnessed if a vaccine is to be effective. CD8+ T cells recognize human leukocyte antigen (HLA)-associated viral epitopes and the HLA alleles vary significantly among different ethnic groups. It follows that definition of HIV-1-derived peptides recognized by CD8+ T cells in the geographically relevant regions will critically guide vaccine development. Here, we study fine details of CD8+ T-cell responses elicited in HIV-1/2-uninfected individuals in Nairobi, Kenya, who received a candidate vaccine delivering conserved regions of HIV-1 proteins called HIVconsv. Using 10-day cell lines established by in vitro peptide restimulation of cryopreserved PBMC and stably HLA-transfected 721.221/C1R cell lines, we confirm experimentally many already defined epitopes, for a number of epitopes we define the restricting HLA molecule(s) and describe four novel HLA-epitope pairs. We also identify specific dominance patterns, a promiscuous T-cell epitope and a rescue of suboptimal T-cell epitope induction in vivo by its functional variant, which all together inform vaccine design.

scholarly journals Viral Immune Evasion Due to Persistence of Activated T Cells Without Effector Function

1998 ◽  
Vol 188 (12) ◽  
pp. 2205-2213 ◽  
Author(s):  
Allan J. Zajac ◽  
Joseph N. Blattman ◽  
Kaja Murali-Krishna ◽  
David J.D. Sourdive ◽  
M. Suresh ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Effector Function ◽  
Cd4 T Cell ◽  
Activation Markers ◽  
Cell Responses ◽  
Cell Immunity

We examined the regulation of virus-specific CD8 T cell responses during chronic lymphocytic choriomeningitis virus (LCMV) infection of mice. Our study shows that within the same persistently infected host, different mechanisms can operate to silence antiviral T cell responses; CD8 T cells specific to one dominant viral epitope were deleted, whereas CD8 T cells responding to another dominant epitope persisted indefinitely. These virus-specific CD8 T cells expressed activation markers (CD69hi, CD44hi, CD62Llo) and proliferated in vivo but were unable to elaborate any antiviral effector functions. This unresponsive phenotype was more pronounced under conditions of CD4 T cell deficiency, highlighting the importance of CD8– CD4 T cell collaboration in controlling persistent infections. Importantly, in the presence of CD4 T cell help, adequate CD8 effector activity was maintained and the chronic viral infection eventually resolved. The persistence of activated virus-specific CD8 T cells without effector function reveals a novel mechanism for silencing antiviral immune responses and also offers new possibilities for enhancing CD8 T cell immunity in chronically infected hosts.

scholarly journals Strain-Specific T-Cell Suppression and Protective Immunity in Patients with Chronic Hepatitis C Virus Infection

2005 ◽  
Vol 79 (11) ◽  
pp. 6976-6983 ◽  
Author(s):  
Kazushi Sugimoto ◽  
David E. Kaplan ◽  
Fusao Ikeda ◽  
Jin Ding ◽  
Jonathan Schwartz ◽  
...  
Keyword(s):  
T Cells ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
T Cell ◽  
Cell Response ◽  
T Cell Responses ◽  
T Cell Response ◽  
Cd4 T Cell ◽  
Cell Responses ◽  
Genotype 2

ABSTRACT Hepatitis C virus (HCV) frequently persists with an apparently ineffective antiviral T-cell response. We hypothesized that some patients may be exposed to multiple HCV subtypes and that strain-specific T cells could contribute to the viral dynamics in this setting. To test this hypothesis, CD4 T-cell responses to three genotype 1a-derived HCV antigens and HCV antibody serotype were examined in chronically HCV infected (genotypes 1a, 1b, 2, 3, and 4) and spontaneously HCV recovered subjects. Consistent with multiple HCV exposure, 63% of patients infected with genotypes 2 to 4 (genotypes 2-4) and 36% of those infected with genotype 1b displayed CD4 T-cell responses to 1a-derived HCV antigens, while 29% of genotype 2-4-infected patients showed serotype responses to genotype 1. Detection of 1a-specific T cells in patients without active 1a infection suggested prior self-limited 1a infection with T-cell-mediated protection from 1a but not from non-1a viruses. Remarkably, CD4 T-cell responses to 1a-derived HCV antigens were weakest in patients with homologous 1a infection and greater in non-1a-infected patients: proportions of patients responding were 19% (1a), 36% (1b), and 63% (2-4) (P = 0.0006). Increased 1a-specific CD4 T-cell responsiveness in non-1a-infected patients was not due to increased immunogenicity or cross-reactivity of non-1a viruses but directly related to sequence divergence. We conclude that the T-cell response to the circulating virus is either suppressed or not induced in a strain-specific manner in chronically HCV infected patients and that, despite their ability to clear one HCV strain, patients may be reinfected with a heterologous strain that can then persist. These findings provide new insights into host-virus interactions in HCV infection that have implications for vaccine development.

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