- Email: [email protected]
342 INTRAHEPATIC IL-8 PRODUCING CD4+ REGULATORY T CELLS AND FIBROGENESIS IN CHRONIC HEPATITIS C
POSTERS 340 T CELLS REDIRECTED BY A CHIMERIC ANTIGEN RECEPTOR RECOGNIZING HBsAg EFFICIENTLY CONTROL HBV IN VIVO IN TRANSGENIC MICE 1 K. Krebs1 , N. Bottinger ¨ , L.-R. Huang2 , M. Chmielewski3 , 1 S. Arzberger , G. Gasteiger1 , E. Schmitt4 , F. Bohne1 , M. Aichler5 , 1 W. Uckert6 , H. Abken3 , M. Heikenwalder ¨ , P. Knolle2 , U. Protzer1 . 1 Institute of Virology, Technische Universit¨ at M¨ unchen, Helmholtz Zentrum M¨ unchen, Munich, 2 Institute of Molecular Medicine, University of Bonn, Bonn, 3 Department of Internal Medicine I, University Hospital Cologne, Cologne, 4 Institute of Immunology, University of Mainz, Mainz, 5 Institute of Pathology, Helmholtz Zentrum M¨ unchen, Munich, 6 Max Delbr¨ uck Center for Molecular Medicine, Berlin, Germany E-mail: [email protected] Background and Aims: Current antivirals suppress HBV but do not clear the infection. For virus clearance strong effector T cell responses are needed, which are sparse in chronically infected individuals. Cell therapy using T cells redirected by HBV-specific receptors may clear HBV and help to prevent and treat HBVassociated liver cancer. We designed a chimeric antigen receptor (CAR) that is composed of a single chain antibody fragment binding to HBsAg and CD28/CD3z signaling domains. This study aimed to proof feasibility of this approach in vivo addressing the following challenges: (i) T cell-depletion to generate space for cell engraftment in chronic virus carriers is too perilous, (ii) viral antigens circulating in high amounts may inactivate transferred T cells or (iii) trigger uncontrolled immune damage. Methods: Primary murine CD8+ T cells were isolated, stimulated using an optimized protocol and grafted with CARs by retroviral transduction. A CAR that binds HBV envelope proteins and transfers activation signals to the T cell was compared to a control CAR without a proper signaling domain and a CAR not binding HBV proteins. Results: CD8+ T cells engineered to express an HBV-specific CAR, which recognizes HBV envelope proteins of various subtypes on infected hepatocytes, were able to engraft and expand in immune competent HBV transgenic mice. Following adoptive transfer CARgrafted T cells targeted the liver, remained functional in vivo, rapidly and efficiently controlled HBV replication while causing only transient liver damage. The large amount of circulating viral antigens neither impaired nor over-activated the transferred T cells. Conclusion: HBV-specific cell therapy with CAR-engineered T cells bears the potential to treat chronic hepatitis B and HBV-associated hepatocellular carcinoma irrespective of the patient’s individual HLA-type. 341 CORTICOSTEROIDS AFFECT HEPATITIS C INFECTION BY MODULATING PLASMACYTOID DENDRITIC CELL FUNCTION J. Kwekkeboom1 , P.E. de Ruiter2 , P.P.C. Boor1 , Q. Pan1 , J. de Jonge2 , H.J. Metselaar1 , H.W. Tilanus2 , L.J.W. van der Laan2 . 1 Gastroenterology and Hepatology, 2 Surgery, Erasmus MC University Medical Center, Rotterdam, The Netherlands E-mail: [email protected] Introduction: Chronic hepatitis C virus (HCV) infection is one of the leading indications for liver transplantation (LTx), but outcomes are often compromised by re-infection of the graft. Several studies have indicated that the use of corticosteroid-based immunosuppression is a risk factor for severe HCV recurrence, but the mechanism for the steroid-mediated effect on HCV is unknown. Aim: To investigate the effect of steroids on HCV-replication, on the antiviral activity of IFN-a, and on the anti-viral effect of plasmacytoid dendritic cells (pDCs), which are the principal IFNa-producing cells. S142
Methods: As a model for HCV replication we used Huh7 hepatoma cells stably transfected with the non-structural coding sequence of HCV directly coupled to a luciferase reporter gene (Huh7-ET). A Huh7 cell line stably transfected with a luciferase gene under the control of an interferon response element (Huh7-ISRE-Luc) was used to investigate effects on IFN-a signal transduction. To study the effect of steroids on inhibition of HCV-replication by pDCs, human pDCs were stimulated with a Toll-Like Receptor (TLR)-7 ligand in the presence or absence of steroids, and conditioned media (pDCCM) from these cells were added to Huh7-ET cells. In addition, Huh7-ET cells were co-cultured with human pDCs in the presence or absence of steroids. Results: Dexamethasone and prednisolone did not affect HCV replication directly. IFN-a (10 IU/ml) completely inhibited HCV replication, but steroids did not interfere with the inhibition of HCV-replication by IFN-a. Moreover, steroids had no effect on IFN-a signal transduction as measured in Huh7-ISRE-Luc cells. pDC-CM from TLR-7 stimulated pDCs potently suppressed HCV replication. Interestingly, addition of steroids to PDC during TLR-7 stimulation inhibited IFN-a production and abrogated the antiviral capacity of pDC-CM. Addition of pDCs to Huh7-ET cells significantly reduced HCV replication, and this reduction was almost completely reversed by addition of steroids. Pre-incubation of the Huh7-ET cells with an IFN-a receptor blocking antibody inhibited the antiviral action of pDC-CM. Conclusion: Corticosteroids do not directly affect HCV-replication and neither interfere with the antiviral action of IFN-a, but inhibit the antiviral capacity of pDCs. Therefore, steroids may promote HCV-recurrence after LTx by suppressing IFN-a production by PDCs. 342 INTRAHEPATIC IL-8 PRODUCING CD4+ REGULATORY T CELLS AND FIBROGENESIS IN CHRONIC HEPATITIS C 1 B. Langhans1 , S. Arndt1 , I. Braunschweiger1 , B. Kramer ¨ , 1 R. Huneburg ¨ , S. Manekeller2 , T. Sauerbruch1 , U. Spengler1 . 1 Department of Internal Medicine I, 2 Department of Surgery, University of Bonn, Bonn, Germany E-mail: [email protected] Background and Aims: Regulatory CD4+ T cells (Tregs) can suppress T cell functions and thus are considered to potentially alter outcomes of HCV infection. Recently, we detected that Tregs clones from HCV-infected patients produce significant amounts of interleukin 8 (IL-8), which did not interfere with their immunosuppressive function. Here, we analyzed localization and frequency of IL-8+ Tregs in the blood and livers of patients with chronic hepatitis C and studied their effects on fibrogenesis. Methods: Biopsies and explant livers from 17 patients with chronic hepatitis C were studied by multiple colour immunofluorescence histology on cryostat sections. Numbers of IL-8+ Foxp3+ CD4+ Tregs were determined quantitatively using flow cytometry both in freshly isolated peripheral blood mononuclear cells and liver infiltrating lymphocytes obtained from unfixed parts of the liver samples. Finally, we analysed effects of Tregs from hepatitis C on activation of primary human hepatic stellate cells (HSC). Results: In liver tissue from chronic hepatitis C we detected IL-8+ CD4+ T cells in the lymphocytic infiltrates of fibrotic areas at low numbers (median 5 double-positive cells, range 3–15, per 200 mm2 visual field) and their position co-localized with that of Foxp3+ CD4+ T cells. Overall, percentage of Foxp3+ CD25+ CD127dim CD4+ Tregs in blood was increased in chronic hepatitis C (4.6±1.4% of CD4+ T cells) as compared to healthy controls (2.8±1.5%; p = 0.0087), but we did not find a significant difference in IL-8+ Foxp3+ CD4+ Tregs between chronic hepatitis C and controls. Of note, simultaneous comparison between blood and liver specimens of patients with chronic hepatitis C demonstrated that IL-8+ Foxp3+ CD4+ Tregs were markedly enriched in the livers
Journal of Hepatology 2013 vol. 58 | S63–S227
POSTERS (0.89±0.52%) versus blood (0.05±0.01%; p = 0.0005) and their numbers correlated with advanced stages of fibrosis (p = 0.022), but not to inflammation. Finally, in vitro supernatants of Tregs induced mRNA up-regulation of profibrogenic markers TIMP1, MMP2, TGFbeta1 and alpha-SMA in resting HSC (p < 0.05 each). Conclusion: Our data demonstrate that in chronic hepatitis C Foxp3+ CD4+ Tregs are enriched in areas of hepatic fibrosis, exhibit up-regulated IL-8 expression and can activate HSC. Thus, in addition to suppression of inflammation adaptive Tregs in hepatitis C play a dual role as regulators of fibrogenesis. 343 HUMAN HEPATOCYTE INDOLEAMINE-2,3-DIOXYGENASE CONTRIBUTES TO ANTIVIRAL DEFENSE AND IMMUNE REGULATION IN HEPATITIS C VIRUS INFECTION Q. Lepiller1,2,3 , E. Soulier1,2 , M. Lambotin1,2 , J. Barths1,2 , P. Bachellier4 , F. Stoll-Keller1,2,3 , T.F. Baumert1,2,5 , T.J. Liang6 , H. Barth1,2,3 . 1 Inserm U748, 2 Universit´e de Strasbourg, 3 Institut de Virologie, 4 Pˆ ole des Pathologies Digestives, H´epatiques et Transplantation, 5 Pˆ ole H´epato-digestif, Hˆ opitaux Universitaires de Strasbourg, Strasbourg, France; 6 Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD, USA E-mail: [email protected] Background and Aims: Chronic hepatitis C virus (HCV) infection is a major cause of liver disease and hepatocellular carcinoma. The mechanisms of viral pathogenesis are only partially understood. Indoleamine-2,3-dioxygenase (IDO) – an enzyme that catabolizes tryptophan – is a central regulator in negative feedback regulation of the immune system in clinically significant conditions, such as tumour-induced immunosuppression. An increased serum kynurenine to tryptophan ratio, which is an index of IDO activity, has been previously demonstrated in patients with chronic HCV infection when compared to patients with resolved HCV infection and healthy individuals. However, the molecular mechanism of IDO induction in HCV infection and its role in viral pathogenesis are unknown. Methods: Using primary human hepatocytes and cell-culture derived HCV JFH1 virus we investigated the effect of HCV infection on IDO expression. Real-time RT-PCR, gene transfection and silencing assays were performed to further identify the underlying molecular mechanisms of hepatic IDO induction. We evaluated the effect of IDO expression on HCV infectivity and the CD4+ T cell response using a hepatocyte co-culture system. Results: We show that HCV infection stimulates IDO expression in hepatocytes. IDO gene induction was transient and dependent on HCV replication and interferon-regulatory factor 1 (IRF1). Overexpression of hepatic IDO impaired HCV replication modestly. Moreover, IDO expression in hepatocytes significantly blocked CD4+ T cell effector function. Conclusions: Hepatic IDO plays a dual and opposing role during HCV infection by retarding viral replication and also regulating host immune responses. The dichotomous nature of IDO in HCV infection may favour HCV persistence within the host over viral eradication. Since IDO-inhibitor drugs have entered phase II clinical trials in cancer patients, the outcome of the ongoing clinical trials may provide valuable information regarding the potential efficacy of these drugs in chronic HCV infection and HCV-induced HCC.
344 PERIPHERAL HCV-SPECIFIC CYTOTOXIC RESPONSE DETECTION AT WEEK 12 OF PEGYLATED-INTERFERON alfa-2b PLUS RIBAVIRIN TREATMENT FOR CHRONIC HCV INFECTION CORRELATES WITH SUSTAINED VIROLOGIC RESPONSE DEVELOPMENT J.R. Larrubia, M.U. Lokhande, J. Miquel, S. Garc´ıa-Garzon, ´ A. Gonzalez-Praetorious, ´ E. Sanz-de-Villalobos. Translational Hepatology Unit, Guadalajara University Hospital, University of Alcal´ a, Guadalajara, Spain E-mail: [email protected] Background and Aims: The second phase of viral load (VL) decay, during Peg-interferon (IFN) plus rivabirin (RBV) treatment for hepatitis C virus (HCV) infection, is probably due to specific immune response. Low HCV VL decrease at week 12 (w12) of treatment has 100% negative predictive value of sustained virologic response (SVR), and this could be related with the absence of HCV-specific cytotoxic T lymphocytes (CTL). The development of SVR after PegIFNa2b plus RBV treatment according to the detection of HCVspecific CTL response at w12 was analysed. Methods: A longitudinal cohort study was carried out. 25 HLA-A2+ chronic HCV patients were recruited. Peripheral blood lymphocytes (PBL) were taken at weeks 0 and 12 of treatment. HCV-specific CTL response was tested directly ex-vivo and after specific in-vitro stimulation. HCV-specific CTLs were detected by PBL staining with anti-CD8-Cy5 mAb plus HLA-A2/peptide-PE multimers against two NS3 epitopes and subsequent flow-cytometric analysis. Samples were split into two groups according to the presence of detectable HCV-specific CTLs at w12 (Group 1: detection, Group 2: no detection). SVR rate was compared between both groups and ROC analysis of the ability of w12 HCV-specific CTL detection to predict SVR was carried out. Results: Both groups were similar according to sex, age, basal viral load, HCV-genotype and liver fibrosis. Group 1 and 2 consisted of 14 and 36 samples respectively. SVR was higher in group 1 (93%) than in group 2 (47%) (p = 0.003). In genotype-1 patients, an increase on HCV-specific CTL frequency between base line and w12 of treatment was observed (p = 0.011), but not in group 2. Also HCV-specific CTL proliferation was more frequent in group 1 than in group 2 during treatment (p = 0.025). Detection of HCV-specific CTLs at w12 correlated with the level of HCV viral load decrease between base line and w12 (p = 0.016, r = 0.389). The detection of HCV-specific CTLs at w12 among HCV genotype-1 patients with early virologic response (EVR) had a 100% PPV of SVR. Conclusion: Detection of HCV-specific CTLs at w12 of PegIFNa2b+RBV treatment correlates with the development of SVR. Interestingly, in EVR genotype-1 cases, this fact predicts accurately the development of SVR. 345 PERSISTENT HEPATITIS C VIRUS (HCV) INFECTION IMPAIRS HCV-SPECIFIC CYTOTOXIC T CELL REACTIVITY THROUGH Mcl-1/Bim IMBALANCE DUE TO CD127 DOWN-REGULATION ´ J. Miquel, J.R. Larrubia, M.U. Lokhande, S. Garc´ıa-Garzon, A. Gonzalez-Praetorious, ´ E. Sanz-de-Villalobos. Translational Hepatology Unit, Guadalajara University Hospital, University of Alcal´ a, Guadalajara, Spain E-mail: [email protected] Background and Aims: In persistent hepatitis C virus (HCV) infection, HCV-specific cytotoxic T lymphocyte (CTL) reactivity is impaired and this affects HCV control. Interleukin-7 receptor (CD127) expression on these cells could regulate CTL reactivity through Mcl-1/Bim balance modulation. Bim is a pro-apoptotic molecule blocked by the action of Mcl-1. Methods: Mcl-1/Bim expression and T cell reactivity on HCVspecific CTLs were compared according to CD127 phenotype. Peripheral blood lymphocytes (PBL) from HLA-A2+ HCV+ patients
Journal of Hepatology 2013 vol. 58 | S63–S227
S143
Methods: As a model for HCV replication we used Huh7 hepatoma cells stably transfected with the non-structural coding sequence of HCV directly coupled to a luciferase reporter gene (Huh7-ET). A Huh7 cell line stably transfected with a luciferase gene under the control of an interferon response element (Huh7-ISRE-Luc) was used to investigate effects on IFN-a signal transduction. To study the effect of steroids on inhibition of HCV-replication by pDCs, human pDCs were stimulated with a Toll-Like Receptor (TLR)-7 ligand in the presence or absence of steroids, and conditioned media (pDCCM) from these cells were added to Huh7-ET cells. In addition, Huh7-ET cells were co-cultured with human pDCs in the presence or absence of steroids. Results: Dexamethasone and prednisolone did not affect HCV replication directly. IFN-a (10 IU/ml) completely inhibited HCV replication, but steroids did not interfere with the inhibition of HCV-replication by IFN-a. Moreover, steroids had no effect on IFN-a signal transduction as measured in Huh7-ISRE-Luc cells. pDC-CM from TLR-7 stimulated pDCs potently suppressed HCV replication. Interestingly, addition of steroids to PDC during TLR-7 stimulation inhibited IFN-a production and abrogated the antiviral capacity of pDC-CM. Addition of pDCs to Huh7-ET cells significantly reduced HCV replication, and this reduction was almost completely reversed by addition of steroids. Pre-incubation of the Huh7-ET cells with an IFN-a receptor blocking antibody inhibited the antiviral action of pDC-CM. Conclusion: Corticosteroids do not directly affect HCV-replication and neither interfere with the antiviral action of IFN-a, but inhibit the antiviral capacity of pDCs. Therefore, steroids may promote HCV-recurrence after LTx by suppressing IFN-a production by PDCs. 342 INTRAHEPATIC IL-8 PRODUCING CD4+ REGULATORY T CELLS AND FIBROGENESIS IN CHRONIC HEPATITIS C 1 B. Langhans1 , S. Arndt1 , I. Braunschweiger1 , B. Kramer ¨ , 1 R. Huneburg ¨ , S. Manekeller2 , T. Sauerbruch1 , U. Spengler1 . 1 Department of Internal Medicine I, 2 Department of Surgery, University of Bonn, Bonn, Germany E-mail: [email protected] Background and Aims: Regulatory CD4+ T cells (Tregs) can suppress T cell functions and thus are considered to potentially alter outcomes of HCV infection. Recently, we detected that Tregs clones from HCV-infected patients produce significant amounts of interleukin 8 (IL-8), which did not interfere with their immunosuppressive function. Here, we analyzed localization and frequency of IL-8+ Tregs in the blood and livers of patients with chronic hepatitis C and studied their effects on fibrogenesis. Methods: Biopsies and explant livers from 17 patients with chronic hepatitis C were studied by multiple colour immunofluorescence histology on cryostat sections. Numbers of IL-8+ Foxp3+ CD4+ Tregs were determined quantitatively using flow cytometry both in freshly isolated peripheral blood mononuclear cells and liver infiltrating lymphocytes obtained from unfixed parts of the liver samples. Finally, we analysed effects of Tregs from hepatitis C on activation of primary human hepatic stellate cells (HSC). Results: In liver tissue from chronic hepatitis C we detected IL-8+ CD4+ T cells in the lymphocytic infiltrates of fibrotic areas at low numbers (median 5 double-positive cells, range 3–15, per 200 mm2 visual field) and their position co-localized with that of Foxp3+ CD4+ T cells. Overall, percentage of Foxp3+ CD25+ CD127dim CD4+ Tregs in blood was increased in chronic hepatitis C (4.6±1.4% of CD4+ T cells) as compared to healthy controls (2.8±1.5%; p = 0.0087), but we did not find a significant difference in IL-8+ Foxp3+ CD4+ Tregs between chronic hepatitis C and controls. Of note, simultaneous comparison between blood and liver specimens of patients with chronic hepatitis C demonstrated that IL-8+ Foxp3+ CD4+ Tregs were markedly enriched in the livers
Journal of Hepatology 2013 vol. 58 | S63–S227
POSTERS (0.89±0.52%) versus blood (0.05±0.01%; p = 0.0005) and their numbers correlated with advanced stages of fibrosis (p = 0.022), but not to inflammation. Finally, in vitro supernatants of Tregs induced mRNA up-regulation of profibrogenic markers TIMP1, MMP2, TGFbeta1 and alpha-SMA in resting HSC (p < 0.05 each). Conclusion: Our data demonstrate that in chronic hepatitis C Foxp3+ CD4+ Tregs are enriched in areas of hepatic fibrosis, exhibit up-regulated IL-8 expression and can activate HSC. Thus, in addition to suppression of inflammation adaptive Tregs in hepatitis C play a dual role as regulators of fibrogenesis. 343 HUMAN HEPATOCYTE INDOLEAMINE-2,3-DIOXYGENASE CONTRIBUTES TO ANTIVIRAL DEFENSE AND IMMUNE REGULATION IN HEPATITIS C VIRUS INFECTION Q. Lepiller1,2,3 , E. Soulier1,2 , M. Lambotin1,2 , J. Barths1,2 , P. Bachellier4 , F. Stoll-Keller1,2,3 , T.F. Baumert1,2,5 , T.J. Liang6 , H. Barth1,2,3 . 1 Inserm U748, 2 Universit´e de Strasbourg, 3 Institut de Virologie, 4 Pˆ ole des Pathologies Digestives, H´epatiques et Transplantation, 5 Pˆ ole H´epato-digestif, Hˆ opitaux Universitaires de Strasbourg, Strasbourg, France; 6 Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD, USA E-mail: [email protected] Background and Aims: Chronic hepatitis C virus (HCV) infection is a major cause of liver disease and hepatocellular carcinoma. The mechanisms of viral pathogenesis are only partially understood. Indoleamine-2,3-dioxygenase (IDO) – an enzyme that catabolizes tryptophan – is a central regulator in negative feedback regulation of the immune system in clinically significant conditions, such as tumour-induced immunosuppression. An increased serum kynurenine to tryptophan ratio, which is an index of IDO activity, has been previously demonstrated in patients with chronic HCV infection when compared to patients with resolved HCV infection and healthy individuals. However, the molecular mechanism of IDO induction in HCV infection and its role in viral pathogenesis are unknown. Methods: Using primary human hepatocytes and cell-culture derived HCV JFH1 virus we investigated the effect of HCV infection on IDO expression. Real-time RT-PCR, gene transfection and silencing assays were performed to further identify the underlying molecular mechanisms of hepatic IDO induction. We evaluated the effect of IDO expression on HCV infectivity and the CD4+ T cell response using a hepatocyte co-culture system. Results: We show that HCV infection stimulates IDO expression in hepatocytes. IDO gene induction was transient and dependent on HCV replication and interferon-regulatory factor 1 (IRF1). Overexpression of hepatic IDO impaired HCV replication modestly. Moreover, IDO expression in hepatocytes significantly blocked CD4+ T cell effector function. Conclusions: Hepatic IDO plays a dual and opposing role during HCV infection by retarding viral replication and also regulating host immune responses. The dichotomous nature of IDO in HCV infection may favour HCV persistence within the host over viral eradication. Since IDO-inhibitor drugs have entered phase II clinical trials in cancer patients, the outcome of the ongoing clinical trials may provide valuable information regarding the potential efficacy of these drugs in chronic HCV infection and HCV-induced HCC.
344 PERIPHERAL HCV-SPECIFIC CYTOTOXIC RESPONSE DETECTION AT WEEK 12 OF PEGYLATED-INTERFERON alfa-2b PLUS RIBAVIRIN TREATMENT FOR CHRONIC HCV INFECTION CORRELATES WITH SUSTAINED VIROLOGIC RESPONSE DEVELOPMENT J.R. Larrubia, M.U. Lokhande, J. Miquel, S. Garc´ıa-Garzon, ´ A. Gonzalez-Praetorious, ´ E. Sanz-de-Villalobos. Translational Hepatology Unit, Guadalajara University Hospital, University of Alcal´ a, Guadalajara, Spain E-mail: [email protected] Background and Aims: The second phase of viral load (VL) decay, during Peg-interferon (IFN) plus rivabirin (RBV) treatment for hepatitis C virus (HCV) infection, is probably due to specific immune response. Low HCV VL decrease at week 12 (w12) of treatment has 100% negative predictive value of sustained virologic response (SVR), and this could be related with the absence of HCV-specific cytotoxic T lymphocytes (CTL). The development of SVR after PegIFNa2b plus RBV treatment according to the detection of HCVspecific CTL response at w12 was analysed. Methods: A longitudinal cohort study was carried out. 25 HLA-A2+ chronic HCV patients were recruited. Peripheral blood lymphocytes (PBL) were taken at weeks 0 and 12 of treatment. HCV-specific CTL response was tested directly ex-vivo and after specific in-vitro stimulation. HCV-specific CTLs were detected by PBL staining with anti-CD8-Cy5 mAb plus HLA-A2/peptide-PE multimers against two NS3 epitopes and subsequent flow-cytometric analysis. Samples were split into two groups according to the presence of detectable HCV-specific CTLs at w12 (Group 1: detection, Group 2: no detection). SVR rate was compared between both groups and ROC analysis of the ability of w12 HCV-specific CTL detection to predict SVR was carried out. Results: Both groups were similar according to sex, age, basal viral load, HCV-genotype and liver fibrosis. Group 1 and 2 consisted of 14 and 36 samples respectively. SVR was higher in group 1 (93%) than in group 2 (47%) (p = 0.003). In genotype-1 patients, an increase on HCV-specific CTL frequency between base line and w12 of treatment was observed (p = 0.011), but not in group 2. Also HCV-specific CTL proliferation was more frequent in group 1 than in group 2 during treatment (p = 0.025). Detection of HCV-specific CTLs at w12 correlated with the level of HCV viral load decrease between base line and w12 (p = 0.016, r = 0.389). The detection of HCV-specific CTLs at w12 among HCV genotype-1 patients with early virologic response (EVR) had a 100% PPV of SVR. Conclusion: Detection of HCV-specific CTLs at w12 of PegIFNa2b+RBV treatment correlates with the development of SVR. Interestingly, in EVR genotype-1 cases, this fact predicts accurately the development of SVR. 345 PERSISTENT HEPATITIS C VIRUS (HCV) INFECTION IMPAIRS HCV-SPECIFIC CYTOTOXIC T CELL REACTIVITY THROUGH Mcl-1/Bim IMBALANCE DUE TO CD127 DOWN-REGULATION ´ J. Miquel, J.R. Larrubia, M.U. Lokhande, S. Garc´ıa-Garzon, A. Gonzalez-Praetorious, ´ E. Sanz-de-Villalobos. Translational Hepatology Unit, Guadalajara University Hospital, University of Alcal´ a, Guadalajara, Spain E-mail: [email protected] Background and Aims: In persistent hepatitis C virus (HCV) infection, HCV-specific cytotoxic T lymphocyte (CTL) reactivity is impaired and this affects HCV control. Interleukin-7 receptor (CD127) expression on these cells could regulate CTL reactivity through Mcl-1/Bim balance modulation. Bim is a pro-apoptotic molecule blocked by the action of Mcl-1. Methods: Mcl-1/Bim expression and T cell reactivity on HCVspecific CTLs were compared according to CD127 phenotype. Peripheral blood lymphocytes (PBL) from HLA-A2+ HCV+ patients
Journal of Hepatology 2013 vol. 58 | S63–S227
S143