Purpose To predict the course of immune recovery (IR) in HIV-1-infected patients after initiation of combined antiretroviral therapy (cART) by determination of the plasma concentration of Torque Teno Virus (TTV). TTV has been identified as marker for risk assessment in immunosuppressed patients after transplantation procedures. Here, TTV was analyzed in HIV-1-infected therapy-naïve patients to evaluate its use as predictor of the course of IR for guidance of individualized treatment. Methods TTV DNA was quantified in plasma samples of 301 therapy-naïve HIV-1-infected patients and correlated to CD4 + cell count, HIV viral load, presence of the herpes viruses CMV, EBV and HHV-8, age and sex. Patients were classified according to their initial CD4 + cell count and to the extent of CD4 + T-cell increase within the first year of cART. Results TTV DNA was detectable in 96% of the patients’ plasma samples with a median TTV plasma concentration of 5.37 log 10 cop/ml. The baseline CD4 + cell count was negatively correlated with TTV plasma concentration ( p = 0.003). In patients with a CD4 + cell recovery < 50 cells/µl, the median TTV plasma concentration was significantly higher compared to patients with a CD4 + cell recovery of > 200 CD4 + cells/µl (5.68 log 10 cop/ml versus 4.99 log 10 cop/ml; p = 0.011). TTV plasma concentration in combination with baseline CD4 + cell count were significantly correlated to CD4 + cell recovery ( p = 0.004). For all other parameters considered, no significant correlation for CD4 + cell recovery was found. Conclusion Within the cohort, the significantly elevated TTV plasma concentration in patients with diminished CD4 + cell recovery indicates a more profound immune defect. Baseline TTV plasma concentrations and CD4 + cell count are predictive for the course of immune recovery in HIV-1-infected patients with severe immunodeficiency.

Die Hepatitis C Virus (HCV) assoziierte Leberzirrhose ist eine der häufigsten Indikationen zur Lebertransplantation (LT). Es kommt fast immer zu einer HCV-Reinfektion des Transplantats. Mit Zulassung der direkt antiviral wirkenden Therapeutika (DAAs) konnte der Therapieerfolg erheblich verbessert werden. Aber im Kontext einer HCV-Therapie nach LT ist der Einfluss der immunsuppressiven Therapie (IS) auf die Wirksamkeit der DAAs nicht bekannt.

The CD8 T cell response plays a central role for spontaneous immune control of acute Hepatitis B Virus (HBV) infection. In turn, patients with chronic infection typically have a weak and often exhausted T cell response. Accordingly, rescue of such dysfunctional T cell responses by therapeutic vaccination or transfer of adaptive cytotoxic T cells has been suggested as potential treatment strategies of patients with chronic infection. Importantly, these therapies rely on presentation of viral epitopes in the context of HLA class I molecules. Although selection of viral escape mutations has been well defined in chronic infections with HCV or HIV, the influence of viral sequence variants on the T cell response in HBV is less clear. Here, we studied viral sequence diversity in the HLA-A*02-restricted immunodominant HBV CTL epitope core18 – 27 (FLPSDFFPSV) and its impact on the CD8 T cell response in detail.

Gegenwärtig ist die Hepatitis C Virus (HCV)-Infektion noch eine häufige Ursache für eine Lebertransplantation (LT). Um nach erfolgreicher LT eine Organabstoßung zu vermeiden, ist eine Behandlung mit immunsuppressiven Substanzen (IS) unumgänglich. Vorarbeiten konnten zeigen, dass mTor-Inhibitoren (Everolimus (EVR), Sirolimus (SRL)) die HCV-Replikationsaktivität, in Abhängigkeit vom HCV-Genotyp, unterschiedlich beeinflussen und dass virale Proteine mit dem Tumorsuppressorprotein PML interagieren. Darüber hinaus ist ein Zusammenhang von PML mit der mTor-vermittelten Signaltransduktion bekannt.

Background. The influence of immunosuppressants on hepatitis C virus (HCV) re-infection after liver transplantation, particularly mammalian target of rapamycin inhibitors, remains unclear. The aim of our study was to analyze the influence of everolimus (EVR) on HCV replication activity in the context of underlying molecular mechanisms, with focus on the pro-myelocytic leukemia protein (PML). Methods. HCV viral load was recorded in 40 patients with post-transplant HCV reinfection before and 8 weeks after introduction of EVR. An HCV cell culture replicon system for genotype (GT) lb, GT2b, and GT3a was used to compare the influence of EVR on HCV replication for the respective genotypes in vitro. Fluorescence-activated cell-sorting analysis was used to test for effects on cell proliferation. PML expression was silenced with the use of small hairpin RNA constructs, and PML expression was quantified by means of quantitative real-time polymerase chain reaction. Results. In patients with HCV, the viral load of GT1a and GT1b was hardly affected by EVR, whereas the viral load was reduced in patients with GT2a (P <= .0001) or GT3 infection (P <= .05). In vitro EVR impairs HCV replication activity of GT2a and GT3a up to 60% (P <= .0005), whereas in GT1b cells, HCV replication activity is increased by 50% (P <= .005). Replicon cell viability was not impaired. HCV replication activity is impaired in the absence of PML, which can be reversed by overexpression of PML isoforms. Furthermore, in the absence of PML, the effect of EVR on HCV replication activity is nearly abrogated. Conclusions. The mammalian target of rapamycin inhibitor EVR influences HCV replication via PML. The herein presented results suggest a genotype-dependent benefit for an EVR-based immunosuppressive regimen in patients with GT2a or GT3 reinfection after liver transplantation.

Einleitung: Die Hepatitis C Virus (HCV) assoziierte Leberzirrhose ist eine der häufigsten Ursachen für Lebertransplantationen (LT). In annähernd allen Fällen erfolgt eine HCV-Reinfektion des Transplantats. Neue Behandlungsmöglichkeiten durch direkt antiviral wirkende Therapeutika (DAAs), konnte die HCV-Therapie erheblich verbessern. Der Einfluss der nach LT notwendigen immunsuppressiven Therapie auf die Wirksamkeit der DAA-basierten HCV-Therapie ist bisher nicht bekannt.

Hintergrund: Die neuen direkt antiviral wirkenden Therapeutika (DAAs) ermöglichen eine Verlaufsverbesserung der bisher schlechten Langzeitprognose und hohen Hepatitis C Virus (HCV)-Reinfektionsraten nach Lebertransplantation (LT). In diesem Zusammenhang wurde der Einfluss der immunsuppressiven Therapie (IS) auf die Wirkung der DAAs nicht untersucht. Mit unseren Untersuchungen wollen wir den Einfluss der verschiedenen IS (Calcineurin (CNI)- und mTor-Inhibitoren) auf die Wirkung der verschiedenen DAAs in vitro aufklären.

Interferon-inducible cholesterol-25-hydroxylase restricts hepatitis C virus replication via blockage of membranous web formation A Kusuma, I Romero-Brey, C Berger, CC Colpitts, T Boldanova, D Todt, PM Perin, P Behrendt, FWR Vondran, S Xu, C Goffinet, LM Schang, MH Heim, R Bartenschlager, T Pietschmann and E Steinmann Twincore, Institute of Experimental Virology, Hannover, Germany, Heidelberg University, Heidelberg, Germany, University of Alberta, Edmonton, AB, Canada, University of Basel, Basel, Switzerland, Medical School Hannover, Hannover, Germany

Background: Chronic infections with the hepatitis B virus (HBV) are worldwide an enormous public health problem. Effective suppression of viral replication can be achieved with inhibitors of the viral polymerase, however, in most cases lifelong treatment is required to avoid recurrence of viremia. Activation of HBV-specific CD8 T cells by therapeutic vaccination may promote sustained control of viral replication by clearance of cccDNA from infected hepatocytes. Importantly, little is known about the exact targets of the CD8 T cell response and the extent of selection pressure on the virus. Here, it was hypothesized that CD8 T cell responses associated with strong selection pressure on the virus can be identified by viral sequence analysis.

Interferon-inducible cholesterol-25-hydroxylase restricts hepatitis C virus replication via blockage of membranous web formation A Kusuma, I Romero-Brey, C Berger, CC Colpitts, T Boldanova, D Todt, PM Perin, P Behrendt, FWR Vondran, S Xu, C Goffinet, LM Schang, MH Heim, R Bartenschlager, T Pietschmann and E Steinmann Twincore, Institute of Experimental Virology, Hannover, Germany, Heidelberg University, Heidelberg, Germany, University of Alberta, Edmonton, AB, Canada, University of Basel, Basel, Switzerland, Medical School Hannover, Hannover, Germany

Die Hepatitis C Virus (HCV) -Reinfektion nach Lebertransplantation (LT) ist ein gravierendes medizinsches Probleme aufgrund einer hohen Mortalität und schlechten Langzeitprognose der Patienten. Neue antivirale Behandlungsmöglichkeiten geben derzeit eine Perspektive auf eine Verbesserung des Verlaufs. Allerdings ist der Einfluss verschiedener immunsuppressiver Subtanzen, insbesondere der mTor-Inhibitoren, auf den Verlauf der HCV- Reinfektion nach LT nicht abschließend geklärt.