Hepatitis: Diepolder HM

Diepolder HM. · No affiliation provided · J Infect Dis. · Pubmed #18544036 No free full text.

This publication has no abstract.

Diepolder HM. · No affiliation provided · J Hepatol. · Pubmed #15158347 No free full text.

This publication has no abstract.

Diepolder HM. · Medical Department II, University of Munich, Germany. · Antiviral Res. · Pubmed #19428600 No free full text.

Abstract: Despite the high propensity of hepatitis C virus to establish chronic viral persistence, immune-mediated viral clearance occurs in some patients, fostering hopes that therapeutic induction of specific antiviral immune responses might be able to contribute to viral clearance in chronically infected patients. Indeed, recent clinical trials of therapeutic vaccination have provided clear proof of concept that specific immunotherapy can reduce the viral load in some patients. Further improvement of these strategies will depend on a detailed analysis of the immunopathogenesis of chronic hepatitis C. Recent advances in our understanding of the mechanisms of down-regulation of virus-specific immune responses during chronic infection, including the role of regulatory T cells and inhibitory molecules such as programmed death receptor 1, may open up new avenues for second-generation immunotherapeutic interventions.

Diepolder HM, Kashiwagi N, Teuber G, Ulsenheimer A, Franz M, Yokoyama T, Zachoval R. · Institute for Immunology, University of Munich, Germany. · J Med Virol. · Pubmed #16121358 No free full text.

Abstract: The most important aim in controlling virus infections is to destroy infected cells. Impaired cellular immunity in HIV and HCV infection leads to chronic infection. This study examined the effect of cytapheresis on the subsequent response to interferon/ribavirin treatment in patients infected with HCV. Adacolumn cytapheresis was carried out once a day for 5 consecutive days in patients who relapsed or did not respond to previous peginterferon and ribavirin combination treatment (n = 14: relapsers = 3, non-responders = 11). Peginterferon and ribavirin combination treatment was started after cytapheresis. During combination treatment, the proliferative response of peripheral blood mononuclear cells to HCV proteins (core, NS3, NS4, and NS5), tetanus toxoid, and phytohemagglutinin was measured, and compared to the early virological response. After treatment by leucocytapheresis, the proliferative response of peripheral blood mononuclear cells to HCV-core and tetanus toxoid increased significantly over the baseline (P < 0.05). A marked increase in the phytohemagglutinin response was observed after peginterferon and ribavirin combination treatment was started (P < 0.01 at week 5 and P < 0.005 at week 13). There were, however, no clear changes in the proliferative response to other antigens. Among the 14 patients, 12 (85.7%) achieved an early virological response by week 13 (12 weeks after the start of combination treatment). After treatment, nine patients (64.3%) had a significant proliferative response to HCV core antigen. Among the nine patients, eight patients (88.9%) achieved early virological response. The results indicate that activation of cellular immunity by leucocytapheresis facilitates an early virological response rate in HCV patients. This new therapy may, therefore, become an additional therapeutic measure for HCV.

Gerlach JT, Diepolder HM, Zachoval R, Gruener NH, Jung MC, Ulsenheimer A, Schraut WW, Schirren CA, Waechtler M, Backmund M, Pape GR. · Medical Department II, Klinikum Grosshadern and Institute for Immunology, Schwabing, Munich, Germany. · Gastroenterology. · Pubmed #12851873 No free full text.

Abstract: BACKGROUND & AIMS: Acute hepatitis C virus infection accounts for approximately 20% of cases of acute hepatitis today. The aim of this study was to define the natural course of the disease and to contribute to the development of treatment strategies for acute hepatitis C virus. METHODS: The diagnosis of acute hepatitis C virus in 60 patients was based on seroconversion to anti-hepatitis C virus antibodies or clinical and biochemical criteria and on the presence of hepatitis C virus RNA in the first serum sample. RESULTS: Fifty-one of 60 (85%) patients presented with symptomatic acute hepatitis C virus. In the natural (untreated) course of acute symptomatic hepatitis C (n = 46), spontaneous clearance was observed in 24 patients (52%), usually within 12 weeks after the onset of symptoms, whereas all asymptomatic patients (n = 9) developed chronic hepatitis C. The start of antiviral therapy (interferon-alpha with or without ribavirin) beyond 3 months after the onset of acute hepatitis induced sustained viral clearance in 80% of treated patients. CONCLUSIONS: The management of acute hepatitis C has to take into account the high rate of spontaneous viral clearance within 12 weeks after the onset of symptomatic disease. Treatment of only those patients who remain hepatitis C virus RNA positive for more than 3 months after the onset of disease led to an overall viral clearance (self-limited and treatment induced) in 91% of patients, and unnecessary treatment was avoided in those with spontaneous viral clearance. Patients with asymptomatic acute hepatitis C virus infection are unlikely to clear the infection spontaneously and should be treated as early as possible.

Barth H, Schnober EK, Neumann-Haefelin C, Thumann C, Zeisel MB, Diepolder HM, Hu Z, Liang TJ, Blum HE, Thimme R, Lambotin M, Baumert TF. · Department of Medicine II, University of Freiburg, Freiburg, Germany. · J Virol. · Pubmed #18216094 links to  free full text

Abstract: Class B scavenger receptors (SR-Bs) bind lipoproteins and play an important role in lipid metabolism. Most recently, SR-B type I (SR-BI) and its splicing variant SR-BII have been found to mediate bacterial adhesion and cytosolic bacterial invasion in mammalian cells. In this study, we demonstrate that SR-BI is a key host factor required for hepatitis C virus (HCV) uptake and cross-presentation by human dendritic cells (DCs). Whereas monocytes and T and B cells were characterized by very low or undetectable SR-BI expression levels, human DCs demonstrated a high level of cell surface expression of SR-BI similar to that of primary human hepatocytes. Antibodies targeting the extracellular loop of SR-BI efficiently inhibited HCV-like particle binding, uptake, and cross-presentation by human DCs. Moreover, human high-density lipoprotein specifically modulated HCV-like particle binding to DCs, indicating an interplay of HCV with the lipid transfer function of SR-BI in DCs. Finally, we demonstrate that anti-SR-BI antibodies inhibit the uptake of cell culture-derived HCV (HCVcc) in DCs. In conclusion, these findings identify a novel function of SR-BI for viral antigen uptake and recognition and may have an important impact on the design of HCV vaccines and immunotherapeutic approaches aiming at the induction of efficient antiviral immune responses.

Dambacher J, Beigel F, Zitzmann K, Heeg MH, Göke B, Diepolder HM, Auernhammer CJ, Brand S. · Department of Medicine II, University-Hospital Munich-Grosshadern, University of Munich, Marchioninistr. 15, 81377 Munich, Germany. · Cytokine. · Pubmed #18191408 No free full text.

Abstract: In this study, we analyzed if IL-22 displays, similar to other IL-10 like cytokines such as IL-28A, antiviral properties in hepatic cells. Using RT-PCR and immunoblotting, we demonstrated that hepatic cell lines and primary hepatocytes express the functional IL-22 receptor complex consisting of IL-22R1 and IL-10R2. Hepatic IL-22 mRNA expression as measured by quantitative PCR was up-regulated in autoimmune and viral hepatitis compared to cholestatic liver diseases, while IL-22 serum levels did not differ significantly between patients with viral hepatitis and normal controls. IL-22 did not significantly change the expression levels of IFN-alpha/-beta and of the antiviral proteins MxA and 2',5'-OAS. Consequently, it had in comparison to IFN-alpha no relevant antiviral activity in in vitro models of HCV replication and infection. Taken together, hepatic IL-22 expression is up-regulated in viral hepatitis but IL-22 does not directly regulate antiviral proteins and has, in contrast to IFN-alpha, no effect on HCV replication.

Lucas M, Ulsenheimer A, Pfafferot K, Heeg MH, Gaudieri S, Grüner N, Rauch A, Gerlach JT, Jung MC, Zachoval R, Pape GR, Schraut W, Santantonio T, Nitschko H, Obermeier M, Phillips R, Scriba TJ, Semmo N, Day C, Weber JN, Fidler S, Thimme R, Haberstroh A, Baumert TF, Klenerman P, Diepolder HM. · Peter Medawar Building for Pathogen Research, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom. · PLoS One. · Pubmed #17653276 links to  free full text

Abstract: BACKGROUND: CD4+ T cell help is critical in maintaining antiviral immune responses and such help has been shown to be sustained in acute resolving hepatitis C. In contrast, in evolving chronic hepatitis C CD4+ T cell helper responses appear to be absent or short-lived, using functional assays. METHODOLOGY/PRINCIPAL FINDINGS: Here we used a novel HLA-DR1 tetramer containing a highly targeted CD4+ T cell epitope from the hepatitis C virus non-structural protein 4 to track number and phenotype of hepatitis C virus specific CD4+ T cells in a cohort of seven HLA-DR1 positive patients with acute hepatitis C in comparison to patients with chronic or resolved hepatitis C. We observed peptide-specific T cells in all seven patients with acute hepatitis C regardless of outcome at frequencies up to 0.65% of CD4+ T cells. Among patients who transiently controlled virus replication we observed loss of function, and/or physical deletion of tetramer+ CD4+ T cells before viral recrudescence. In some patients with chronic hepatitis C very low numbers of tetramer+ cells were detectable in peripheral blood, compared to robust responses detected in spontaneous resolvers. Importantly we did not observe escape mutations in this key CD4+ T cell epitope in patients with evolving chronic hepatitis C. CONCLUSIONS/SIGNIFICANCE: During acute hepatitis C a CD4+ T cell response against this epitope is readily induced in most, if not all, HLA-DR1+ patients. This antiviral T cell population becomes functionally impaired or is deleted early in the course of disease in those where viremia persists.

Gruener NH, Gerlach TJ, Ulsenheimer A, Diepolder HM, Wierenga E, Zachoval R, Heeg M, Pape GR, Jung MC. · Department of Internal Medicine II, Klinikum Grosshadern, University of Munich, Marchioninistrasse 15, 81377 Munich, Germany. · Vaccine. · Pubmed #17466417 No free full text.

Abstract: BACKGROUND/AIMS: In hepatitis B virus infection, viral elimination is dependent on an efficient antiviral T cell response which is not detectable in chronic hepatitis B. Therefore, new therapeutic concepts focus on T cell activation, such as epitope-based T cell-targeted vaccines. However, with the development of peptide-based vaccines in mind, viral mutations frequently described in hepatitis B within known immunodominant helper epitopes may have an influence on peptide selection. METHODS: Mutant peptides within immunodominant epitopes (aa 1-20, aa 91-105, and aa 143-157) at position 12, 14, 93, 97, 147, 151, 153, and 155 were tested with peripheral blood mononuclear and specific clone cells for their ability to induce proliferation, produce cytokines, induce T cell receptor down-regulation or antagonize wild-type activity of the hepatitis B core antigen-specific CD4+ T cell clones. RESULTS: Five variants could not induce T cell proliferation or cytokine production when the variants were presented alone. Coincubation with wild-type epitopes leads to T cell activation showing that the variants do not act as T cell receptor antagonists for hepatitis B virus-specific CD4+ T cells. In contrast, five other variants and wild-type peptides stimulated CD4+ T cell proliferation and production of Th1 cytokines. CONCLUSIONS: Our data demonstrate that frequently occurring mutations within immunodominant epitopes have rather a nonstimulatory than a strengthening effect and thus should not included in a vaccine.

Rollier CS, Paranhos-Baccala G, Verschoor EJ, Verstrepen BE, Drexhage JA, Fagrouch Z, Berland JL, Komurian-Pradel F, Duverger B, Himoudi N, Staib C, Meyr M, Whelan M, Whelan JA, Adams VC, Adams VA, Larrea E, Riezu JI, Lasarte JJ, Lasarte JJ, Bartosch B, Cosset FL, Spaan WJ, Diepolder HM, Pape GR, Sutter G, Inchauspe G, Heeney JL. · Department of Virology, Biomedical Primate Research Center, GH Rijswijk, The Netherlands. · Hepatology. · Pubmed #17326154 No free full text.

Abstract: Broad T cell and B cell responses to multiple HCV antigens are observed early in individuals who control or clear HCV infection. The prevailing hypothesis has been that similar immune responses induced by prophylactic immunization would reduce acute virus replication and protect exposed individuals from chronic infection. Here, we demonstrate that immunization of naïve chimpanzees with a multicomponent HCV vaccine induced robust HCV-specific immune responses, and that all vaccinees exposed to heterologous chimpanzee-adapted HCV 1b J4 significantly reduced viral RNA in serum by 84%, and in liver by 99% as compared to controls (P=0.024 and 0.028, respectively). However, despite control of HCV in plasma and liver in the acute period, in the chronic phase, 3 of 4 vaccinated animals developed persistent infection. Analysis of expression levels of proinflammatory cytokines in serial hepatic biopsies failed to reveal an association with vaccine outcome. However, expression of IDO, CTLA-4 [corrected] and PD-1 levels in liver correlated with clearance or chronicity. CONCLUSION: Despite early control of virus load, a virus-associated tolerogenic-like state can develop in certain individuals independent of vaccination history.

Ulsenheimer A, Lucas M, Seth NP, Tilman Gerlach J, Gruener NH, Loughry A, Pape GR, Wucherpfennig KW, Diepolder HM, Klenerman P. · Institute for Immunology, University of Munich, Munich, Germany. · J Viral Hepat. · Pubmed #16970603 No free full text.

Abstract: Hepatitis C virus (HCV) readily sets up persistence after acute infection. Cellular immune responses are thought to play a major role in control of the virus. Failure of CD4+ T-cell responses in acute disease is associated with viral persistence but the dynamics of this are poorly understood. We aimed to assess such responses using a novel set of Class II tetrameric complexes (tetramers) to study helper T-cells ex vivo in acute disease. We analysed the HCV-specific CD4+ T-cell response in a patient with acute hepatitis c infection. We were able to track the virus-specific CD4+ T-cells directly ex vivo with HLA DR4 tetramers. Proliferative responses were absent initially, recovered as viral load dropped and were lost again during relapse. Longitudinal tetramer analyses showed expanded populations of antiviral CD4+ T-cells throughout acute infection despite lack of proliferation. A pattern of transient CD4+ T-cell proliferative responses as HCV is partially controlled is observed. Failure to control virus is associated with emergence of 'dysfunctional' CD4+ T-cell populations. Failure to control HCV in acute disease may relate to the capacity to sustain efficient immune responses as virus attempts to 'bounce back' after partial control.

Gerlach JT, Ulsenheimer A, Grüner NH, Jung MC, Schraut W, Schirren CA, Heeg M, Scholz S, Witter K, Zahn R, Vogler A, Zachoval R, Pape GR, Diepolder HM. · Department of Gastroenterology and Hepatology, University Hospital Zurich, Rämistrasse 100, 8091 Zurich, Switzerland. · J Virol. · Pubmed #16160170 links to  free full text

Abstract: The hepatitis C virus (HCV)-specific CD4+ T-cell response against nonstructural proteins is strongly associated with successful viral clearance during acute hepatitis C. To further develop these observations into peptide-based vaccines and clinical immunomonitoring tools like HLA class II tetramers, a detailed characterization of immunodominant CD4+ T-cell epitopes is required. We studied peripheral blood mononuclear cells from 20 patients with acute hepatitis C using 83 overlapping 20-mer peptides covering the NS3 helicase and NS4. Eight peptides were recognized by > or = 40% of patients, and specific CD4+ T-cell clones were obtained for seven of these and three additional, subdominant epitopes. Mapping of minimal stimulatory sequences defined epitopes of 8 to 13 amino acids in length, but optimal T-cell stimulation was observed with 10- to 15-mers. While some epitopes were presented by different HLA molecules, others were presented by only a single HLA class II molecule, which has implications for patient selection in clinical trials of peptide-based immunotherapies. In conclusion, using two different approaches we identified and characterized a set of CD4+ T-cell epitopes in the HCV NS3-NS4 region which are immunodominant in patients achieving transient or persistent viral control. This information allows the construction of a valuable panel of HCV-specific HLA class II tetramers for further study of CD4+ T-cell responses in chronic hepatitis C. The finding of immunodominant epitopes with very constrained HLA restriction has implications for patient selection in clinical trials of peptide-based immunotherapies.

Ulsenheimer A, Gerlach JT, Jung MC, Gruener N, Wächtler M, Backmund M, Santantonio T, Schraut W, Heeg MH, Schirren CA, Zachoval R, Pape GR, Diepolder HM. · Institute for Immunology, Klinikum Grosshadern, University of Munich, Munich, Germany. · Hepatology. · Pubmed #15726647 No free full text.

Abstract: Chronic evolution of acute hepatitis C (aHC) occurs in more than 80% of patients but can frequently be prevented by early treatment with interferon (IFN)-alpha. Plasmacytoid dendritic cells (pDCs) are the major endogenous IFN-alpha producers, but their role in aHC is unknown. In this study, frequency, phenotype, and pDC function were analyzed in 13 patients with aHC and 32 patients with chronic hepatitis C (cHC) compared with 20 healthy controls, 33 sustained responders to antiviral treatment, 14 patients with acute hepatitis B (aHB), and 21 patients with nonviral inflammatory disease. In aHC, pDCs in the peripheral blood were significantly reduced compared with healthy controls (median, 0.1% vs. 0.36%, P < .0005) and were inversely correlated to alanine aminotransferase levels (r = -0.823; P < .005). Circulating pDCs in aHC were immature, as determined via reduced expression of HLA-DR and CCR7, and produced little amounts of IFN-alpha (median, 3.5 pg/50,000 peripheral blood mononuclear cells [PBMCs] vs. 498.4 pg/50,000 PBMCs in healthy controls; P < .0005). Less pronounced changes were present in cHC (median, 0.17%, 28.0 pg/50,000 PBMCs IFN-alpha, respectively). However, a significantly reduced frequency and IFN-alpha production was also found in self-limited aHB (median 0.1%, 8.6 pg/50,000 PBMCs) and in patients with nonviral inflammatory disease (median 0.19%, 7.5 pg/50,000 PBMCs). In conclusion, in aHC frequency and IFN-alpha-producing capacity of peripheral blood pDCs are dramatically reduced and inversely correlated with the degree of liver inflammation. In cHC there is incomplete recovery of pDC function, which, however, could be solely due to the chronic inflammatory state.

Barth H, Ulsenheimer A, Pape GR, Diepolder HM, Hoffmann M, Neumann-Haefelin C, Thimme R, Henneke P, Klein R, Paranhos-Baccalà G, Depla E, Liang TJ, Blum HE, Baumert TF. · Department of Medicine II, University of Freiburg, Hugstetter Strasse 55, D-79106 Freiburg, Germany. · Blood. · Pubmed #15657184 links to  free full text

Abstract: Hepatitis C virus (HCV) is a major cause of chronic hepatitis worldwide. Interaction of dendritic cells (DCs) with viral particles may play an important role in the immunopathogenesis of HCV infection. Since the synthesis or purification of infectious virions is limited, we used HCV-like particles (HCV-LPs) to study the interaction of HCV with human DCs. Immature DCs exhibited an envelope-specific and saturable binding of HCV-LPs, indicating receptor-mediated DC-HCV-LP interaction. Confocal microscopy revealed that HCV-LPs were rapidly taken up by DCs in a temperature-dependent manner. Competition experiments demonstrated that C-type lectins such as mannose receptor or DC-SIGN (DC-specific intercellular adhesion molecule 3-grabbing nonintegrin) were not sufficient for mediating HCV-LP binding. HCV-LP uptake was followed by DC activation. DCs pulsed with HCV-LPs stimulated HCV core-specific CD4(+) T cells, indicating that uptake of HCV-LPs by DCs leads to antigen processing and presentation on major histocompatibility complex (MHC) class II molecules. Finally, HCV-LP-derived antigens were efficiently cross-presented to HCV core-specific CD8(+) T cells. These findings demonstrate that HCV-LPs represent a novel model system to study HCV-DC interaction allowing definition of the molecular mechanisms of HCV uptake, DC activation, and antigen presentation to T cells. Furthermore, HCV-LP-mediated DC activation and efficient antigen presentation may explain the marked immunogenicity of HCV-LPs in vivo.

Gruener NH, Jung MC, Ulsenheimer A, Gerlach JT, Zachoval R, Diepolder HM, Baretton G, Schauer R, Pape GR, Schirren CA. · Department of Medicine II, Klinikum Grosshadern, University of Munich, Munich, Germany. · Liver Transpl. · Pubmed #15558593 links to  free full text

Abstract: Virus-specific CD8+ T cells play a major role in antiviral immune defenses; their significance in the transplant setting, however, is unclear. In the present study, we asked whether hepatitis C virus (HCV)-specific CD8+ T cells were detectable in the presence of an immunosuppressive treatment and whether the HCV-specific CD8+ T cell response correlates with treatment outcome in patients who receive interferon (IFN)-alpha / ribavirin therapy after orthotopic liver transplantation (OLTx). Liver- and blood-derived T cell lines of 21 patients after OLTx were studied before, at the end of, and after antiviral treatment. Virus-specific IFN-gamma production in response to a panel of previously identified HCV-specific epitopes restricted by the human leukocyte antigen (HLA) class I molecules A2, A3, B7, B35, and B44 of structural and nonstructural HCV protein was determined by enzyme-linked immunospot (ELISPOT) assay. Before treatment, only low numbers of HCV-specific CD8+ T cells were detectable. In 6 patients with a sustained virological response, a significant, multispecific, and sustained CD8+ T cell response was detectable, which was mainly found in the peripheral blood. Nonresponders and transient responders showed undetectable, weak, or transient HCV-specific CD8+ T cell responses. (Sustained responders vs. transient and nonresponders: Wilcoxon rank-signed test; P < .01). In conclusion, our data indicate that despite immunosuppression, HCV-specific CD8+ T cells are detectable in patients with recurrent HCV infection after OLTx and that a significant, multispecific, and long-lasting HCV-specific CD8+ T cell response contributes to viral elimination.

Diepolder HM. · Medizinische Klinik und Poliklinik II, Ludwig-Maximilians-Universität München, Klinikum Grosshadern. · Internist (Berl). · Pubmed #14991162 No free full text.

Abstract: The hepatitis viruses A to E are biologically and clinically heterogeneous: hepatitis A and E are transmitted faecal-orally and never lead to chronic infection. In contrast, the other viruses-B, C, D-are transmitted parenterally and are the leading causes of chronic viral infections in humans worldwide. Highly efficient vaccines are available against hepatitis A and B. The therapeutic armamentarium for chronic hepatitis B and C has significantly expanded during the last several years. Two nucleoside analogues, lamivudine and adefovir, have been licensed for the treatment of chronic hepatitis B and can be used for patients in whom interferon would be contra-indicated such as decompensated cirrhotics. Standard therapy for chronic hepatitis C is a combination of a pegylated interferon-alpha and ribavirin, which can lead to sustained viral clearance in more than 50% of treatable patients. Patients with decompensated cirrhosis can be treated by liver transplantation which offers a 5-year-survival of greater than 80%.

Schirren CA, Zachoval R, Gerlach JT, Ulsenheimer A, Gruener NH, Diepolder HM, Baretton G, Schraut W, Rau HG, Nitschko H, Pape GR, Jung MC. · Department of Medicine II, Klinikum Grosshadern, University of Munich, Marchioninistrasse 15, D-81377 Munich, Germany. · J Hepatol. · Pubmed #12927926 No free full text.

Abstract: BACKGROUND/AIMS: Patients with recurrent hepatitis C virus (HCV)-infection after liver transplantation (OLTx) could develop an early, multispecific, preferentially intrahepatic CD4+ T cell response. We asked now whether there is a correlation between the HCV-specific CD4+ T cell response and treatment outcome in patients who receive interferon (IFN)-alpha/ribavirin. METHODS: Liver- and blood-derived T cell lines of 20 patients were studied in parallel before, under, at the end and after antiviral treatment. Virus-specific IFN-gamma production at a single cell level to HCV-proteins (core, non-structural protein (NS)3/4, NS5) was determined by enzyme-linked immunospot assay. RESULTS: In 6/7 non-responders a weak HCV-specific CD4+ T cell response was detectable. All six sustained responders developed a strong, at NS3/4 and NS5 directed and long-lasting CD4+ T cell response which was mainly detected in peripheral blood mononuclear cells. This reaction was significantly stronger: (1) in the responders than in the non-responders; and (2) within the responders at the end of treatment than before (P<0.03). Seven transient-responders showed a weak and/or transient HCV-specific CD4+ T cell response. CONCLUSIONS: In patients with recurrent HCV-infection after OLTx, who receive antiviral treatment, a strong, at NS3/4 and NS5 directed and long-lasting CD4+ T cell response is associated with HCV-elimination whereas no or a weak/transient response is associated with treatment failure.

Ulsenheimer A, Gerlach JT, Gruener NH, Jung MC, Schirren CA, Schraut W, Zachoval R, Pape GR, Diepolder HM. · Institute for Immunology, University of Munich, Germany. · Hepatology. · Pubmed #12717401 No free full text.

Abstract: Chronic hepatitis C is characterized by a weak or absent hepatitis C virus (HCV)-specific CD4(+) T-cell response in terms of antigen-specific proliferation or interferon gamma (IFN-gamma) secretion. To clarify whether this is due to the absence or functional impairment of antigen-specific CD4(+) T cells we developed an assay that relies on the induced expression of the T-cell activation marker CD25 and is therefore independent from cytokine secretion or proliferation. In 10 of 20 patients with chronic hepatitis C, a significant number of antigen-specific activated CD4(+) T cells (mean 1.06%/patient; range, 0% to 5.2% of CD4(+) T cells) could be shown, whereas antigen-specific proliferation was present in only 1 of 20 patients. IFN-gamma secretion was absent in all 13 patients tested. However, significant antigen-specific interleukin 10 (IL-10) and transforming growth factor beta (TGF-beta) secretion was present in 6 of 10 and 3 of 10 patients, respectively. In 8 patients with acute hepatitis C, irrespective of disease outcome, HCV-specific CD4(+) T cells were detected in all patients and at a significantly higher frequency (mean 3.7%/patient; range, 1.16% to 7.17%) in the first weeks of disease. A chronic course of disease was associated either with a loss of both IFN-gamma secretion and proliferation, resembling an anergic state, or a loss of T-cell proliferation followed by a rapid decline in IFN-gamma-producing cells, corresponding to exhaustion of the specific immune response. In conclusion, functional changes of HCV-specific CD4(+) T cells or failure to develop a long-lasting T-helper response may contribute to chronic hepatitis C viral persistence.

Gruener NH, Jung MC, Ulsenheimer A, Gerlach TJ, Diepolder HM, Schirren CA, Hoffmann R, Wächtler M, Backmund M, Pape GR. · Institute for Immunology, University of Munich, Goethestrasse 31, D-80336 Munich, Germany. · J Hepatol. · Pubmed #12445431 No free full text.

Abstract: BACKGROUND/AIMS: Specific T cell responses during acute hepatitis B and during chronic hepatitis C have been described in detail. However, the T cell responses during the rare setting of acute hepatitis B virus (HBV) infection in the course of chronic hepatitis C that eventually lead to clearance of both viruses are completely unknown. METHODS: We analyzed the virus specific CD4+ and CD8+ T cell response during an acute HBV superinfection in a patient with chronic hepatitis C. RESULTS: The patient eliminated hepatitis C virus (HCV)-RNA and HBV-DNA from serum soon after the clinical onset of acute hepatitis B. The HBV specific T cell response found in this patient corresponds to the typical response that has been described in acute hepatitis B without chronic HCV infection. In contrast the hepatitis C specific immune response was similar to that generally found in chronic hepatitis C despite the fact that the patient also eliminated HCV-RNA. CONCLUSIONS: We hypothesize that the acute HBV infection induced a HBV specific T cell response which was associated with elimination HBV DNA and HCV-RNA, the latter possibly by bystander mechanisms, e.g. via secretion of cytokines. If such a non-specific bystander mechanism which has proven to be effective in the experimental setting and which is formally described here for a single patient can be shown to be a more general phenomenon, it may support the approach with new antiviral strategies, e.g. the induction of non-specific defense mechanisms against HCV.

Isaguliants MG, Widell A, Zhang SM, Sidorchuk A, Levi M, Smirnov VD, Santantonio T, Diepolder HM, Pape GR, Nordenfelt E. · Department of Virology, Swedish Institute for Infectious Disease Control, Stockholm, Sweden. · J Med Virol. · Pubmed #11782929 No free full text.

Abstract: A rare collection of serum samples from patients with hepatitis C virus (HCV) infection followed up from the onset of clinical symptoms was acquired. RNA corresponding to the hypervariable region 1 (HVR1) of E2 protein of HCV isolated from nine patients was reverse-transcribed, amplified, sequenced, and HVR1 amino acid sequences were deduced. These sequences and a selection of HVR1 amino acid sequences of matching HCV genotypes from protein and translated DNA sequence databanks were used to create the HVR1 amino acid consensus. The degenerated peptides mimicking N- and C-termini of the consensus were synthesized. Most (76%) of 17 patients followed up for the period from 1 week to a minimum of 7 months from the onset of acute symptoms developed antibodies reacting with peptides representing N- and/or C- termini of HVR1. Antibody recognition of the consensus HVR1 peptides indicates that the variability of HVR1 sequence on the protein level is limited with certain conserved structure(s) being untouched. A tendency was observed for a slower development of anti-HVR1 antibody response in patients developing chronic HCV, as compared to those with self-limiting HCV infection.

Diepolder HM, Gruener NH, Gerlach JT, Jung MC, Wierenga EA, Pape GR. · Institute for Immunology, University of Munich, 80336 Munich, Germany. · J Virol. · Pubmed #11483723 links to  free full text

Abstract: CD4(+) T cells play a major role in the host defense against viruses and intracellular microbes. During the natural course of such an infection, specific CD4(+) T cells are exposed to a wide range of antigen concentrations depending on the body compartment and the stage of disease. While epitope variants trigger only subsets of T-cell effector functions, the response of virus-specific CD4(+) T cells to various concentrations of the wild-type antigen has not been systematically studied. We stimulated hepatitis B virus core- and hepatitis C virus NS3-specific CD4(+) T-cell clones which had been isolated from patients with acute hepatitis during viral clearance with a wide range of specific antigen concentrations and determined the phenotypic changes and the induction of T-cell effector functions in relation to T-cell receptor internalization. A low antigen concentration induced the expression of T-cell activation markers and adhesion molecules in CD4(+) T-cell clones in the absence of cytokine secretion and proliferation. The expression of CD25, HLA-DR, CD69, and intercellular cell adhesion molecule 1 increased as soon as T-cell receptor internalization became detectable. A 30- to 100-fold-higher antigen concentration, corresponding to the internalization of 20 to 30% of T-cell receptor molecules, however, was required for the induction of proliferation as well as for gamma interferon and interleukin-4 secretion. These data indicate that virus-specific CD4(+) T cells can respond to specific antigen in a graded manner depending on the antigen concentration, which may have implications for a coordinate regulation of specific CD4(+) T-cell responses.

Cucchiarini M, Kammer AR, Grabscheid B, Diepolder HM, Gerlach TJ, Grüner N, Santantonio T, Reichen J, Pape GR, Cerny A. · Department of Clinical Research, Institute of Clinical Pharmacology, Bern, Switzerland. · Cell Immunol. · Pubmed #11006009 No free full text.

Abstract: After infection by hepatitis C virus (HCV), a minority of patients develop acute symptomatic disease and some of them are able to clear the virus. In this study, we analyzed peripheral blood mononuclear cells from nine patients with acute symptomatic disease with respect to their cytotoxic T lymphocyte (CTL) response using a panel of HCV-derived peptides in a semiquantitative secondary in vitro culture system. We could detect early CTL responses in 67% of these patients. The CTL responses were directed against multiple viral epitopes, in particular within the structural (core 2-9, core 35-44, core 131-140, and core 178-187) and nonstructural regions of the virus (NS3 1073-1081, NS3 1406-1415, NS4 1807-1816, NS5 2252-2260, and NS5B 2794-2802). We compared the CTL responses displayed by recently and chronically infected HLA-A2-positive patients. Virus-specific CTLs were detectable in chronic carriers but the percentage of positive peptide-specific CTL responses was significantly higher in recently infected patients (P = 0.002). Follow-up of recently infected patients during subsequent disease development showed a significant decrease in the values and proportions of positive peptide-specific CTL responses (P = 0.002 and 0.013, respectively). Patients with limited viral replication exhibited significantly more vigorous early responses (P = 0.024). These data suggest a protective role for the early antiviral CTL response in HCV infection.

Grüner NH, Gerlach TJ, Jung MC, Diepolder HM, Schirren CA, Schraut WW, Hoffmann R, Zachoval R, Santantonio T, Cucchiarini M, Cerny A, Pape GR. · Institute for Immunology, D-80336 Munich, Germany. uni-muenchen.de. · J Infect Dis. · Pubmed #10823750 No free full text.

Abstract: CD8+ T lymphocytes play a major role in antiviral immune defense. Their significance for acute hepatitis C is unclear. Our aim was to correlate the CD8+ T cell response with the outcome of infection. Eighteen patients with acute hepatitis C and 19 normal donors were studied. Hepatitis C virus (HCV)-specific CD8+ T cells were identified in the enzyme-linked immunospot assay by their interferon-gamma (IFN-gamma) production after specific stimulation. The highest numbers of IFN-gamma-producing HCV-specific CD8+ T cells were found in patients with acute hepatitis C and a self-limited course of disease during the first 6 months after onset of disease, but these numbers dropped thereafter to undetectable levels. The differences in responsiveness between patients with self-limited disease versus patients with a chronic course were statistically significant (P<.001). Our data show that the number of IFN-gamma-producing HCV-specific CD8+ T cells during the first 6 months after onset of disease is associated with eradication of the HCV infection.

Pape GR, Gerlach TJ, Diepolder HM, Grüner N, Jung M, Santantonio T. · Med. Clinic II, Klinikum Grosshadern and; Institute for Immunology, Ludwig-Maximilians-University of Munich, Germany. · J Viral Hepat. · Pubmed #10760033 No free full text.

Abstract: T cells are believed to be the main players in antiviral defence. To investigate the role of the specific CD4+ T cell response for clearance and control of the hepatitis C virus we studied patients with acute hepatitis C (AHC) during the phase of spontaneous viral clearance and during follow up after elimination of the virus and resolution of disease. Symptomatic AHC has a self-limited course in 50% of patients, whereas the other half show virus persistence and develop chronic course of disease. Patients who were able to mount a vigorous, polyclonal, multispecific, TH1 lymphokine dominated CD4+ T-cell response showed viral clearance and a self-limited course of disease. In contrast, absence of this T-cell response in patients with AHC invariably led to viral persistence and chronic hepatitis. The characteristics of the T-cell response were as follows: it was mainly directed against nonstructural proteins of the virus, it was multispecific and demonstrated immunodominant epitopes, and the majority of T-cell clones established from our patients responded to a single peptide (NS3 amino acid 1248-1261) within the helicase region of HCV. Presentation of the peptide was HLA DR specific, the peptide showed promiscuous binding, and it had high binding affinity to 10 of the most common 13 HLA DR alleles, thus patients with diverse HLA DR backgrounds could mount an immune response. Furthermore, the epitope was conserved in 100% of 33 HCV strains published in databases. This strong initial CD4+ T-cell response is not sufficient for a definitive recovery from AHC, it has to be maintained to control the hepatitis C virus. Loss of the response after initial resolution of disease is followed by relapse. Even 20 years after an episode of self-limited AHC with elimination of HCV, we have observed a significant virus-specific CD4+ T-cell response. Our data indicate the decisive role of the virus-specific CD4+ T-cell response for clearance and control of HCV, and contribute to our understanding of immune mechanisms by which the host defends the HCV virus. This is a prerequisite for the development of new strategies to efficiently defend the virus by manipulating or modulating the immune response.

Schirren CA, Jung M, Worzfeld T, Mamin M, Baretton GB, Gruener NH, Gerlach JT, Diepolder HM, Zachoval R, Pape GR. · Department of Medicine II, Klinikum Grosshadern, Munich, Germany. · Liver Transpl. · Pubmed #10719024 links to  free full text

Abstract: Orthotopic liver transplantation (OLT) is a successful treatment in patients with hepatitis C virus (HCV)-associated end-stage liver disease worldwide. T lymphocytes and their cytokines are believed to have a pivotal role in the defense against HCV and in allograft rejection. An immunosuppressive drug regimen may cause a cytokine imbalance toward a T helper (TH) cell type 2 profile that is associated with the persistence of infection and acceptance of the graft. The aim of this study is to assess whether cytokine imbalances toward a TH1- or TH2-type response may have a role in recurrent HCV infection and rejection after OLT. Twenty-one intrahepatic T-cell lines of 15 patients with recurrent HCV infection after OLT (group A) and 15 lines of 11 patients with rejection (group B) were studied. Both patient groups had received liver allografts because of HCV-associated end-stage liver disease. Patients with HCV-induced liver disease who did not undergo OLT served as controls: 17 patients with chronic hepatitis C (CH-C) and 8 patients with cirrhosis. At the time of liver biopsy, 14 blood-derived T-cell lines of 12 patients with recurrent HCV infection, 7 of 10 patients with rejection, and 18 of 18 control patients were also investigated. Regardless of the underlying disease (recurrent HCV infection, rejection, HCV-induced hepatitis, and cirrhosis), all liver tissue-derived T-cell lines produced interferon-gamma; some additionally produced interleukin-4 (IL-4), but none produced IL-10, indicating that the TH0/1 cytokine profile dominates. T-cell lines showing a TH1 cytokine profile derived from intrahepatic T cells could be established significantly more often in recurrent HCV infection and rejection than in controls with CH-C (Fisher's exact test, P <.05). The cytokine profile of intrahepatic T cells did not differ from that obtained in peripheral blood. TH0/1 cytokine profile dominates the intrahepatic and blood-derived immune response in recurrent HCV infection and rejection after OLT regardless of the mode of immunosuppression. The lymphokine profile of immunocompromised patients with recurrent HCV infection or rejection does not differ principally from that of patients with HCV-induced hepatitis and cirrhosis, but seems to show a TH1 profile significantly more often.