- Email: [email protected]
Hepatitis E virus-specific T cell responses against non-structural viral proteins in patients with ongoing and resolved hepatitis E
POSTER PRESENTATIONS Background and Aims: Since May 2015, 34 Prescribing Centers from the Lombardia Region HCV Network (Northern Italy) collected Real life data from DAA IFN-free treatments of older patients (>70 yrs old) with chronic Hepatitis C (HCV). Methods: We retrospectively/prospectively analyzed the data of 5,925 patients affected by HCV infection treated with DAA according to the EASL and AISF guidelines. The data were stratified for age. Results: At the time of the analysis, 3067 patients had completed the treatment, and 2987 could be evaluated for SVR 12; of these, 2.396 (78.12%) were younger than 70 yrs (group1) and 582 (21.87%) were older than 70 yrs (group 2). Baseline characteristics: in group 1, higher rates of both male and HIV co-infections were reported; the distribution of genotypes was significantly different among the two groups: Genotype 1b 68.6% vs. 38.5% and Genotype 2 28.4% vs. 9% respectively in Group 2 and 1. Only 2 pts with Genotype 3 were present in group 2. By ITT analysis, overall SVR12 was 95% (2834/ 2978) (the results are reported in Figure). Among the cirrhotic patients SVR12 was 94% and a MELD score improvement was observed (44.6% in group 1 vs 32.4% in group 2: p < 0.002); no differences in MELD variation emerged when pts ≥70 y.o. were stratified by 5-year blocks. SAEs were observed in 1.8% (n.56) during treatment or follow-up.
Conclusions: In our cohort, overall SVR12 was 95%. No significant differences in SVR were observed between patients with age greater or lower than 70 yrs (Figure 1). Among cirrhotic patients, a MELD score improvement was observed in 44,6% of younger patients vs. 33.5% of elder patients. Comorbidities, age-related metabolic events and/or longer disease duration might play a role in preventing liver function restoration after HCVRNA eradication in elder patients.
Viral Hepatitis: Immunological aspects FRI-284 Virus-specific coexpression of T-bet and Eomes defines highly functional CD8 and CD4 T cells in hepatitis B virus infection H. Karimzadeh1, P. Kurktschiev1, D. Scharafin1, W. Schraut1, N.H. Grüner1, M.-C. Jung2, M. Wächtler3, R. Zachoval1, M. Spannagl4, T. Böttler5, B. Raziorrouh1. 1Department of Medicine II, University Hospital Munich-Grosshadern; 2Leberzentrum München; 3Department of Medicine, Klinikum Schwabing; 4Laboratory of Immunogenetics and Molecular Diagnostics; 5Department of Medicine II, University Hospital Freiburg, Munich, Germany E-mail: [email protected] Background and Aims: Strong Th1-type T cell response is associated with successful clearance of hepatitis B virus (HBV) infection. Th1
master transcription factors are T-bet and Eomes which trigger IFN-g production and cytotoxic activity. Little is known about how the balance of these two factors influences the CD8 and CD4 T cell response during the course of HBV infection. Therefore, we aimed to investigate T-bet and Eomes coexpression in acute (n = 24) and chronic (n = 45) HBV infection to dissect the expression patterns which are associated with viral control. Methods: In this study, we analyzed the virus-specific CD8 and CD4 T cell response by using HLA-A02 and HLA-DRB01-restricted tetramers targeting immunodominant epitopes from the HBV core region. Enrichment-based Tetramer staining was combined with intracellular assessment of transcription factors. Intracellular cytokine staining (ICS) was performed after in vitro culturing of PBMCs with anti-CD3/ CD28, antigen with or without rhIL-2 and rhIL-12. Results: In the ex vivo studies we were able to show that antigenspecific CD8 and CD4 T cells from patients with acute HBV infection are associated with high coexpression of T-bet and Eomes, whereas chronically infected patients failed to express both markers. In order to induce T-bet and Eomes in chronic HBV as this phenotype is mentioned to be associated with viral control we first stimulated PBMC with anti-CD3/CD28 as a strong TCR stimulator. CD8 and CD4 T cells were characterized by upregulation of T-bet + Eomes– (CD8: 60%; CD4: 65%) and T-bet + Eomes + (CD8: 30.8%; CD4: 11%) T-cells. Notably, T-bet + Eomes + T cells are associated with improved IFN-g production (CD8: 13%; CD4: 14%) compared to T-bet + Eomes– (CD8: 1.9%; CD4: 2.2%), T-bet–Eomes– (CD8: 0.4%; CD4: 0.8%) and T-bet– Eomes+ (CD8: 4.5%; CD4: 4.9%) cells. Importantly, increasing MFI of Tbet and Eomes determines [T-bet + Eomes+]high expressing T cells as highly functional T cells characterized by strong IFN-g and Perforin production. Finally, we were able to selectively induce this [T-bet + Eomes+]high CD8 T cell subset in an antigen-specific manner by IL12. Conclusions: These findings represent a unique chance for prospective immuno-based antiviral treatment strategies by manipulation of transcriptional phenotypes of T cells. FRI-285 Hepatitis E virus-specific T cell responses against non-structural viral proteins in patients with ongoing and resolved hepatitis E J. Al-Ayoubi1, P. Behrendt1, B. Bremer1, A. Gisa1, F. Rinker1, M.P. Manns1,2, M. Cornberg1,2, H. Wedemeyer1,2, A.R.M. Kraft1,2. 1 Gastroenterology, Hepatology and Endocrinology, Hannover Medical School; 2German Center for Infection Research (DZIF), Hannover, Germany E-mail: [email protected] Background and Aims: Hepatitis E is an inflammatory liver disease caused by hepatitis E virus (HEV). HEV infection is generally selflimiting but can lead to persistent infection in immunocompromised individuals. Four different human pathogenic genotypes of HEV are known, which are geographically unequally distributed. Whereas the faecal-oral transmitted genotypes 1 and 2 are predominant in tropical regions, the zoonotic genotypes 3 and 4 occur more often in industrial nations. HEV-specific T cell responses are mainly studied against structural proteins of HEV, which are encoded by open-reading-frames (ORF) 2 and 3, while T cell responses against non-structural proteins encoded by ORF1 have not been investigated in detail so far. Our aim was to analyse HEV ORF 1-specific T cell responses in patients with acute, resolved and chronic hepatitis E in comparison to ORF 2 and 3-specific T cell responses. Methods: HEV genotype 3-specific CD8+ and CD4+ T cell responses, defined by proliferative (CFSE proliferation assay) and functional (intracellular cytokine staining) assays, were studied in patients with acute and chronic hepatitis E as well as in HEV seropositive and seronegative healthy individuals. Therefore, peripheral blood mononuclear cells (PBMCs) were stimulated with HEV-specific overlapping peptide pools spanning all three open reading frames.
Journal of Hepatology 2017 vol. 66 | S333–S542
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POSTER PRESENTATIONS Results: Broad and robust HEV-specific CD4+ and CD8+ T cell response were detectable against HEV non-structural proteins (ORF1), especially in patients with acute hepatitis E. Interestingly, there was no difference in terms of strength and frequency between T cell responses against non-structural and structural proteins. Even in long-term investigations no skewing in the HEV-specific T cell responses towards structural proteins were seen. HEV-antigen levels in the blood were inversely correlated with HEV-specific T cell responses. Conclusions: HEV genotype 3-specific T cell responses were detectable against the entire genome (ORF 1–3) in patients with hepatitis E. HEV-specific T cells are associated with control of HEV, these findings may have an impact for further vaccine development. Our data suggest that vaccine induced T cell responses against structural as well as non-structural HEV-proteins might be of importance. FRI-286 The impact of ERAP1 polymorphisms on virus-specific CD8+ T cell responses in an HLA*B27+ patient with acute hepatitis C virus infection J. Kemming1,2, E. Reeves*3, K. Nitschke1, V. Widmeier1, R. Thimme1, E. James*3, C. Neumann-Haefelin*1. 1Department of Medicine II, University Hospital Freiburg; 2University of Freiburg, Freiburg, Germany; 3 University of Southampton, Southampton, United Kingdom E-mail: [email protected] Background and Aims: In hepatitis C virus (HCV) infection, HLAB*27 is associated with spontaneous viral clearance of acute infection. However, some HLA-B*27+ patients develop chronic HCV infection due to an inefficient HCV-specific immune response. In order to determine factors influencing this course of infection we characterized an HLA*B27+ patient with acute infection, who controlled the virus to low titers but did not completely clear the virus for >12 months. Methods: We performed a comprehensive analysis of HCV-specific CD8+ T cell responses in this patient, using overlapping peptides, epitope fine trimming and HLA class I restriction experiments. In addition, we performed genetic analysis and functional testing of the endoplasmic reticulum aminopeptidase 1(ERAP1) genotype and phenotype of the patient. Results: We identified a total of 6 HCV-specific CD8+ T cell epitopes targeted in this patient. These epitopes were restricted by HLA-A*01, A*26, B*08, and B*27. Strikingly, some of these epitopes overlapped with previously described epitopes. However, most of the epitopes identified in the patient were longer than usually observed CD8+ T cell epitopes, e.g. consisting of 10–11 amino acids instead of 9 amino acids. This phenomenon was most obvious for a previously described HLA-B*27 restricted epitope. This epitope was described as a 9-mer, but targeted as an 11-mer in the patient. ERAP1 trims peptides in order to generate optimal ligands for HLA molecules. Polymorphisms in the ERAP1 gene are strongly associated with ankylosing spondylitis in HLA*B27+ patients and affect length, quality and quantity of peptides that are loaded onto HLA molecules and presented to CD8+ T cells. We thus speculated that ERAP1 polymorphisms might influence the epitope repertoire in our patient. Indeed, sequencing of the ERAP1 allotypes in this patient revealed polymorphisms in the ERAP1 gene which have been shown to affect trimming activity. Functional testing confirmed that the ERAP1 allotype of the patient displayed reduced peptide trimming activity in comparison to the wildtype ERAP1. Conclusions: Here we show for the first time that ERAP1 allotypes may have a strong impact on the HCV-specific CD8+ T cell response and may thus influence outcome of infection. These results further indicate that similar mechanisms may contribute to the protective role of HLA-B*27 in viral infections such as HCV and HIV infection on the one hand, and immunopathogenesis of HLA-B*27 associated rheumatologic disorders at the other hand.
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FRI-287 Regulation of hepatitis B immunopathology by hypoxia induced regulatory B cells J.-Y. Zhang1, S.-N. Zhou1, W.-X. Chang1, F.-S. Wang1. 1Treatment and Research Center for Infectious Diseases, Beijing 302 hospital, Beijing, China E-mail: [email protected] Background and Aims: B cells consistently represent abundant cellular components in livers of patients with chronic hepatitis, but the biological role of B cells in inflammatory liver are poor understood. Methods: Here we characterized peripheral and intrahepatic B cells in a cohort of HBV-infected patients. Results: We found B cells were largely accumulated in hypoxic portal area, paralleled by decreased CD39+CD73+ B cells in peripheral blood. These intrahepatic B cells positively correlated with histological activity index and experienced hypoxia as indicated by HIF-1alpha expression. Gene expression profiling of fresh ex vivo B cells and hypoxic B cells showed major differences. Hypoxic B cells acquired a higher glycolytic rate, reduced chemokine receptors expression, increased CD39/CD73 expression and peculiar adenosine production kinetics. Importantly, hypoxic B cells acquire a potent regulatory activity, at least in part through adenosine produced by CD39/CD73 pathway, to inhibit T-cell proliferation and cytokine production. Conclusions: These data demonstrate B cells in response to hypoxic environment take on a regulatory role and contribute to liver immunopathology. FRI-288 Comprehensive immune changes associated with HCV directacting antiviral cures D. Slauenwhite1, K. Arseneault1, C. Brisseau1, S. Oldford1, L. Barrett1,2. 1 Microbiology and Immunology, Dalhousie University; 2Infectious Diseases, Nova Scotia Health Authority, Halifax, Canada E-mail: [email protected] Background and Aims: T cells have been well studied in chronic viral infection, whereas the roles of B cells and NK cells remain less clear, particularly in HCV-infected individuals who achieve treatment-based viral cure. Moreover, studies often focus on one aspect of the immune system as opposed to considering cumulative immune function as a whole on a per-individual basis. This limits our ability to understand and predict what constitutes an effective immune response in HCV positive people on direct-acting antiviral (DAA) cure. It is important to determine immune cell phenotype and function in individuals with chronic HCV infection before and after HCV DAA-induced viral cure, and assess overall immunity per individual. Methods: HCV subjects were treated with DAA regimens for 12 weeks. Comprehensive peripheral blood mononuclear T cell, B cell, and NK cell immunophenotyping was performed in these individuals, as well as age and sex matched controls, at baseline, end of treatment (EOT), and post-treatment follow-up week 24. Polychromatic flow cytometry, in vitro Enzyme-Linked ImmunoSpot (ELISPOT), and cytotoxicity assays simultaneously assess phenotype and function in T cell subsets, B cells, and NK cells. The relative strength of T cell, B cell and NK cell responses were ranked and the cumulative strength of the immune response was determined for each individual. Results: All individuals had HCV viral suppression on DAA therapy. Markers of T cell immune exhaustion, including PD-1, Tim-3, and CTLA-4, decrease with viral suppression. The frequency of inhibitory receptor+ NK cells changed with therapy within an individual and across the study population. NK cells from some individuals had augmented cytotoxicity with viral suppression compared to before treatment. In contrast, abnormal frequencies of multiple B cell subpopulations at baseline persisted despite viral suppression. HCVspecific T cell responses were more frequent at EOT compared with those at baseline. Ranked cumulative measures of anti-HCV immunity per individual are described.
Journal of Hepatology 2017 vol. 66 | S333–S542
Conclusions: In our cohort, overall SVR12 was 95%. No significant differences in SVR were observed between patients with age greater or lower than 70 yrs (Figure 1). Among cirrhotic patients, a MELD score improvement was observed in 44,6% of younger patients vs. 33.5% of elder patients. Comorbidities, age-related metabolic events and/or longer disease duration might play a role in preventing liver function restoration after HCVRNA eradication in elder patients.
Viral Hepatitis: Immunological aspects FRI-284 Virus-specific coexpression of T-bet and Eomes defines highly functional CD8 and CD4 T cells in hepatitis B virus infection H. Karimzadeh1, P. Kurktschiev1, D. Scharafin1, W. Schraut1, N.H. Grüner1, M.-C. Jung2, M. Wächtler3, R. Zachoval1, M. Spannagl4, T. Böttler5, B. Raziorrouh1. 1Department of Medicine II, University Hospital Munich-Grosshadern; 2Leberzentrum München; 3Department of Medicine, Klinikum Schwabing; 4Laboratory of Immunogenetics and Molecular Diagnostics; 5Department of Medicine II, University Hospital Freiburg, Munich, Germany E-mail: [email protected] Background and Aims: Strong Th1-type T cell response is associated with successful clearance of hepatitis B virus (HBV) infection. Th1
master transcription factors are T-bet and Eomes which trigger IFN-g production and cytotoxic activity. Little is known about how the balance of these two factors influences the CD8 and CD4 T cell response during the course of HBV infection. Therefore, we aimed to investigate T-bet and Eomes coexpression in acute (n = 24) and chronic (n = 45) HBV infection to dissect the expression patterns which are associated with viral control. Methods: In this study, we analyzed the virus-specific CD8 and CD4 T cell response by using HLA-A02 and HLA-DRB01-restricted tetramers targeting immunodominant epitopes from the HBV core region. Enrichment-based Tetramer staining was combined with intracellular assessment of transcription factors. Intracellular cytokine staining (ICS) was performed after in vitro culturing of PBMCs with anti-CD3/ CD28, antigen with or without rhIL-2 and rhIL-12. Results: In the ex vivo studies we were able to show that antigenspecific CD8 and CD4 T cells from patients with acute HBV infection are associated with high coexpression of T-bet and Eomes, whereas chronically infected patients failed to express both markers. In order to induce T-bet and Eomes in chronic HBV as this phenotype is mentioned to be associated with viral control we first stimulated PBMC with anti-CD3/CD28 as a strong TCR stimulator. CD8 and CD4 T cells were characterized by upregulation of T-bet + Eomes– (CD8: 60%; CD4: 65%) and T-bet + Eomes + (CD8: 30.8%; CD4: 11%) T-cells. Notably, T-bet + Eomes + T cells are associated with improved IFN-g production (CD8: 13%; CD4: 14%) compared to T-bet + Eomes– (CD8: 1.9%; CD4: 2.2%), T-bet–Eomes– (CD8: 0.4%; CD4: 0.8%) and T-bet– Eomes+ (CD8: 4.5%; CD4: 4.9%) cells. Importantly, increasing MFI of Tbet and Eomes determines [T-bet + Eomes+]high expressing T cells as highly functional T cells characterized by strong IFN-g and Perforin production. Finally, we were able to selectively induce this [T-bet + Eomes+]high CD8 T cell subset in an antigen-specific manner by IL12. Conclusions: These findings represent a unique chance for prospective immuno-based antiviral treatment strategies by manipulation of transcriptional phenotypes of T cells. FRI-285 Hepatitis E virus-specific T cell responses against non-structural viral proteins in patients with ongoing and resolved hepatitis E J. Al-Ayoubi1, P. Behrendt1, B. Bremer1, A. Gisa1, F. Rinker1, M.P. Manns1,2, M. Cornberg1,2, H. Wedemeyer1,2, A.R.M. Kraft1,2. 1 Gastroenterology, Hepatology and Endocrinology, Hannover Medical School; 2German Center for Infection Research (DZIF), Hannover, Germany E-mail: [email protected] Background and Aims: Hepatitis E is an inflammatory liver disease caused by hepatitis E virus (HEV). HEV infection is generally selflimiting but can lead to persistent infection in immunocompromised individuals. Four different human pathogenic genotypes of HEV are known, which are geographically unequally distributed. Whereas the faecal-oral transmitted genotypes 1 and 2 are predominant in tropical regions, the zoonotic genotypes 3 and 4 occur more often in industrial nations. HEV-specific T cell responses are mainly studied against structural proteins of HEV, which are encoded by open-reading-frames (ORF) 2 and 3, while T cell responses against non-structural proteins encoded by ORF1 have not been investigated in detail so far. Our aim was to analyse HEV ORF 1-specific T cell responses in patients with acute, resolved and chronic hepatitis E in comparison to ORF 2 and 3-specific T cell responses. Methods: HEV genotype 3-specific CD8+ and CD4+ T cell responses, defined by proliferative (CFSE proliferation assay) and functional (intracellular cytokine staining) assays, were studied in patients with acute and chronic hepatitis E as well as in HEV seropositive and seronegative healthy individuals. Therefore, peripheral blood mononuclear cells (PBMCs) were stimulated with HEV-specific overlapping peptide pools spanning all three open reading frames.
Journal of Hepatology 2017 vol. 66 | S333–S542
S537
POSTER PRESENTATIONS Results: Broad and robust HEV-specific CD4+ and CD8+ T cell response were detectable against HEV non-structural proteins (ORF1), especially in patients with acute hepatitis E. Interestingly, there was no difference in terms of strength and frequency between T cell responses against non-structural and structural proteins. Even in long-term investigations no skewing in the HEV-specific T cell responses towards structural proteins were seen. HEV-antigen levels in the blood were inversely correlated with HEV-specific T cell responses. Conclusions: HEV genotype 3-specific T cell responses were detectable against the entire genome (ORF 1–3) in patients with hepatitis E. HEV-specific T cells are associated with control of HEV, these findings may have an impact for further vaccine development. Our data suggest that vaccine induced T cell responses against structural as well as non-structural HEV-proteins might be of importance. FRI-286 The impact of ERAP1 polymorphisms on virus-specific CD8+ T cell responses in an HLA*B27+ patient with acute hepatitis C virus infection J. Kemming1,2, E. Reeves*3, K. Nitschke1, V. Widmeier1, R. Thimme1, E. James*3, C. Neumann-Haefelin*1. 1Department of Medicine II, University Hospital Freiburg; 2University of Freiburg, Freiburg, Germany; 3 University of Southampton, Southampton, United Kingdom E-mail: [email protected] Background and Aims: In hepatitis C virus (HCV) infection, HLAB*27 is associated with spontaneous viral clearance of acute infection. However, some HLA-B*27+ patients develop chronic HCV infection due to an inefficient HCV-specific immune response. In order to determine factors influencing this course of infection we characterized an HLA*B27+ patient with acute infection, who controlled the virus to low titers but did not completely clear the virus for >12 months. Methods: We performed a comprehensive analysis of HCV-specific CD8+ T cell responses in this patient, using overlapping peptides, epitope fine trimming and HLA class I restriction experiments. In addition, we performed genetic analysis and functional testing of the endoplasmic reticulum aminopeptidase 1(ERAP1) genotype and phenotype of the patient. Results: We identified a total of 6 HCV-specific CD8+ T cell epitopes targeted in this patient. These epitopes were restricted by HLA-A*01, A*26, B*08, and B*27. Strikingly, some of these epitopes overlapped with previously described epitopes. However, most of the epitopes identified in the patient were longer than usually observed CD8+ T cell epitopes, e.g. consisting of 10–11 amino acids instead of 9 amino acids. This phenomenon was most obvious for a previously described HLA-B*27 restricted epitope. This epitope was described as a 9-mer, but targeted as an 11-mer in the patient. ERAP1 trims peptides in order to generate optimal ligands for HLA molecules. Polymorphisms in the ERAP1 gene are strongly associated with ankylosing spondylitis in HLA*B27+ patients and affect length, quality and quantity of peptides that are loaded onto HLA molecules and presented to CD8+ T cells. We thus speculated that ERAP1 polymorphisms might influence the epitope repertoire in our patient. Indeed, sequencing of the ERAP1 allotypes in this patient revealed polymorphisms in the ERAP1 gene which have been shown to affect trimming activity. Functional testing confirmed that the ERAP1 allotype of the patient displayed reduced peptide trimming activity in comparison to the wildtype ERAP1. Conclusions: Here we show for the first time that ERAP1 allotypes may have a strong impact on the HCV-specific CD8+ T cell response and may thus influence outcome of infection. These results further indicate that similar mechanisms may contribute to the protective role of HLA-B*27 in viral infections such as HCV and HIV infection on the one hand, and immunopathogenesis of HLA-B*27 associated rheumatologic disorders at the other hand.
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FRI-287 Regulation of hepatitis B immunopathology by hypoxia induced regulatory B cells J.-Y. Zhang1, S.-N. Zhou1, W.-X. Chang1, F.-S. Wang1. 1Treatment and Research Center for Infectious Diseases, Beijing 302 hospital, Beijing, China E-mail: [email protected] Background and Aims: B cells consistently represent abundant cellular components in livers of patients with chronic hepatitis, but the biological role of B cells in inflammatory liver are poor understood. Methods: Here we characterized peripheral and intrahepatic B cells in a cohort of HBV-infected patients. Results: We found B cells were largely accumulated in hypoxic portal area, paralleled by decreased CD39+CD73+ B cells in peripheral blood. These intrahepatic B cells positively correlated with histological activity index and experienced hypoxia as indicated by HIF-1alpha expression. Gene expression profiling of fresh ex vivo B cells and hypoxic B cells showed major differences. Hypoxic B cells acquired a higher glycolytic rate, reduced chemokine receptors expression, increased CD39/CD73 expression and peculiar adenosine production kinetics. Importantly, hypoxic B cells acquire a potent regulatory activity, at least in part through adenosine produced by CD39/CD73 pathway, to inhibit T-cell proliferation and cytokine production. Conclusions: These data demonstrate B cells in response to hypoxic environment take on a regulatory role and contribute to liver immunopathology. FRI-288 Comprehensive immune changes associated with HCV directacting antiviral cures D. Slauenwhite1, K. Arseneault1, C. Brisseau1, S. Oldford1, L. Barrett1,2. 1 Microbiology and Immunology, Dalhousie University; 2Infectious Diseases, Nova Scotia Health Authority, Halifax, Canada E-mail: [email protected] Background and Aims: T cells have been well studied in chronic viral infection, whereas the roles of B cells and NK cells remain less clear, particularly in HCV-infected individuals who achieve treatment-based viral cure. Moreover, studies often focus on one aspect of the immune system as opposed to considering cumulative immune function as a whole on a per-individual basis. This limits our ability to understand and predict what constitutes an effective immune response in HCV positive people on direct-acting antiviral (DAA) cure. It is important to determine immune cell phenotype and function in individuals with chronic HCV infection before and after HCV DAA-induced viral cure, and assess overall immunity per individual. Methods: HCV subjects were treated with DAA regimens for 12 weeks. Comprehensive peripheral blood mononuclear T cell, B cell, and NK cell immunophenotyping was performed in these individuals, as well as age and sex matched controls, at baseline, end of treatment (EOT), and post-treatment follow-up week 24. Polychromatic flow cytometry, in vitro Enzyme-Linked ImmunoSpot (ELISPOT), and cytotoxicity assays simultaneously assess phenotype and function in T cell subsets, B cells, and NK cells. The relative strength of T cell, B cell and NK cell responses were ranked and the cumulative strength of the immune response was determined for each individual. Results: All individuals had HCV viral suppression on DAA therapy. Markers of T cell immune exhaustion, including PD-1, Tim-3, and CTLA-4, decrease with viral suppression. The frequency of inhibitory receptor+ NK cells changed with therapy within an individual and across the study population. NK cells from some individuals had augmented cytotoxicity with viral suppression compared to before treatment. In contrast, abnormal frequencies of multiple B cell subpopulations at baseline persisted despite viral suppression. HCVspecific T cell responses were more frequent at EOT compared with those at baseline. Ranked cumulative measures of anti-HCV immunity per individual are described.
Journal of Hepatology 2017 vol. 66 | S333–S542