Project description:Studying hepatitis delta virus (HDV) and developing new treatments is hampered by the absence limited availability of small animal models. Here a description of a robust mouse model of HDV infection that mimics several important characteristics of the human disease is presented. HDV- and HBV-replication competent genomes were delivered to the mouse liver using adeno-associated viruses (AAV) (AAV-HDV and AAV-HBV). Viral load, antigen expression and genomes were quantified at different time points after AAV injection. Furthermore, liver pathology, genome editing, and the activation of the innate immune response were evaluated. AAV-HDV infection initiated HDV replication in mouse hepatocytes. Genome-editing was confirmed by the presence of small and large-HDV-antigens and sequencing. Viral replication was detected for 45 days, even after the AAV-HDV vector had almost disappeared. In the presence of HBV, HDV infectious particles were detected in serum. Furthermore, as observed in patients, co-infection was associated with the reduction of HBV antigen expression and the onset of liver damage that included the up/down-regulation of genes involved in the development of liver pathologies. HDV replication induced a sustained type-I IFN response, which was significantly reduced in immunodeficient mice and almost absent in MAVS-deficient mice. The animal model described here reproduces important characteristics of human HDV infection and provides a valuable tool for characterizing the viral infection and for developing new treatments. Furthermore, MAVS was identified as a main player in HDV detection and adaptive immunity was found to be involved in the amplification of the innate immune response.
Project description:MK: MK-801. Young male C57BL/6J mice received an injection of MK-801 (300 micro-g per g body weight). RNA from control mice were extracted 1hr, 2hr, 4hr, and 6hr after MK experimental mice received their last shock treatment. MK C+S: MK-801 & Context + Shock: Young male C57BL/6J mice received an injection of MK-801 (300 micro-g per g body weight) 1 h prior to contextual fear conditioning that consisted of: Placement into a novel spatial context for 2 min. After 2 min, a 1 sec (0.5 mA) shock was administered through a floor grid. The 2 min-1 sec shock paradigm was repeated for a total of 3 shocks. 1 min after the last shock, animals were removed to their homecage. RNA was extracted 1hr, 2hr, 4hr, and 6hr after the last shock treatment. Keywords: time-course
Project description:MK: MK-801. Young male C57BL/6J mice received an injection of MK-801 (300 micro-g per g body weight). RNA from control mice were extracted 1hr, 2hr, 4hr, and 6hr after MK experimental mice received their last shock treatment. MK C+S: MK-801 & Context + Shock: Young male C57BL/6J mice received an injection of MK-801 (300 micro-g per g body weight) 1 h prior to contextual fear conditioning that consisted of: Placement into a novel spatial context for 2 min. After 2 min, a 1 sec (0.5 mA) shock was administered through a floor grid. The 2 min-1 sec shock paradigm was repeated for a total of 3 shocks. 1 min after the last shock, animals were removed to their homecage. RNA was extracted 1hr, 2hr, 4hr, and 6hr after the last shock treatment. Keywords: time-course
Project description:Humanized Liver Chimeric Mice (HLCM)-derived human hepatocytes (HLCM-HH) were challenged with HBV or HDV as monoinfection or HBV-HDV coinfection, followed by the extraction of total cellular RNA for the subsequent poly-A based mRNA sequencing analysis.
Project description:The same entry pathway is shared by HBV and HDV. Both viruses attach to hepatocytes via heparansulfate proteoglycan and utilize sodium taurocholate co-transporting polypeptide (NTCP) for a specifc entry. This specific entry step is inhibited by Myrcludex B, a 47-aa lipopeptide myristoylated at the N-terminus. Here we compared the cellular response in the gene expression level triggerred by both viruses. The microarray data shows that HBV infection leads to a silent response but HDV infection triggers high level of innate response such as inteferon-stimulated genes (ISG) expression. Moreover, the response depends on the hepatic cell lines used for infection. Compared to HepG2 cells, HuH7 can not induce ISG even infected by HDV. Abstract of manuscript: Background & aims: Hepatitis B virus (HBV) and D virus (HDV) co-infections cause the most severe form of viral hepatitis. HDV induces an innate immune response, but it is unknown how the host cell senses HDV and if this defense affects HDV replication. We aim to characterize interferon (IFN) activation by HDV, identify the responsible sensor and evaluate the effect of IFN on HDV replication. Methods: HDV and HBV susceptible hepatoma cell lines and primary human hepatocytes (PHH) were used for infection studies. Viral markers and cellular gene expression were analyzed at different time points after infection. Pattern recognition receptors (PRRs) required for HDV-mediated IFN activation and the impact on HDV replication were studied using stable knock-down or overexpression of the PRRs. Results: Microarray analysis revealed that HDV but not HBV infection activated a broad range of interferon stimulated genes (ISGs) in HepG2NTCP cells. HDV strongly activated IFN-β and IFN-λ in cell lines and PHH. HDV induced IFN levels remained unaltered upon RIG-I or TLR3 knock-down, but were almost completely abolished upon MDA5 depletion. Conversely, overexpression of MDA5 but not RIG-I and TLR3 in Huh7.5NTCP cells partially restored ISG induction. During long-term infection, IFN levels gradually diminished in both HepG2NTCP and HepaRGNTCP cell lines. MDA5 depletion had little effect on HDV replication despite dampening HDV-induced IFN response. Moreover, treatment with type I or type III IFNs did not abolish HDV replication. Conclusions: Active replication of HDV induces an IFN-β/λ response, which is predominantly mediated by MDA5. This IFN response and exogenous IFN treatment have only a moderate effect on HDV replication in vitro indicating the adaption of HDV replication to an IFN activated state.
Project description:Chronic co-infection with HBV and HDV leads to the most aggressive form of chronic viral hepatitis. In this study, we aimed at elucidating the molecular mechanisms leading to the interference on HBV observed in most of patients co-infected with HDV. We performed transcriptomic analyses of in vitro samples in order to compare the HBV and HDV-induced modulations in viral transcription, immune response, and pathway regulation.This is of importance because beside providing basic knowledge on the interplay between a satellite virus and its helper virus, the data will help the identification of new antiviral target that may affect both viruses.
Project description:Sal: Saline. Young male C57BL/6J mice received an injection of saline (5 microL per g body weight). RNA from control mice were extracted 1hr, 2hr, 4hr, and 6hr after MK experimental mice received their last shock treatment. MK: MK-801. Young male C57BL/6J mice received an injection of MK-801 (300 micro-g per g body weight). RNA from control mice were extracted 1hr, 2hr, 4hr, and 6hr after MK experimental mice received their last shock treatment. Keywords: time-course
Project description:Sal: Saline. Young male C57BL/6J mice received an injection of saline (5 microL per g body weight). RNA from control mice were extracted 1hr, 2hr, 4hr, and 6hr after MK experimental mice received their last shock treatment. MK: MK-801. Young male C57BL/6J mice received an injection of MK-801 (300 micro-g per g body weight). RNA from control mice were extracted 1hr, 2hr, 4hr, and 6hr after MK experimental mice received their last shock treatment. Keywords: time-course