Project description:The combination of peginterferon and ribavirin is the standard treatment for chronic hepatitis C. Our recent clinical study suggests that ribavirin augments the induction of interferon stimulated genes (ISGs) in patients treated for HCV infection [1]. In order to further characterize the mechanisms of action of ribavirin, we examined the effect of ribavirin treatment on ISG induction in cell culture. In addition, the effect of ribavirin on infectious HCV cell culture systems was also studied. Similar to interferon-alpha, ribavirin potently inhibits JFH-1 infection of Huh7.5.1 cells in a dose-dependent manner, which spans the physiological concentration of ribavirin in vivo. Microarray analysis and subsequent quantitative PCR assays demonstrated that ribavirin treatment resulted in the induction of a distinct set of ISGs. These ISGs, including IRF7 and IRF9 are known to play an important role in anti-HCV responses. When ribavirin is used in conjunction with interferon, induction of specific ISGs is synergistic when compared to either drug applied separately. Direct up-regulation of these antiviral genes by ribavirin is mediated by a novel mechanism different from those associated with interferon signaling and intracellular double stranded RNA sensing pathways such as RIG-I and MDA5. RNA interference studies excluded the activation of the Toll-like receptor and NF-KappaB pathways in the action of ribavirin. In conclusion, our study suggests that ribavirin, acting via a novel innate mechanism, potentiates the anti-HCV effect of interferon. Understanding the mechanism of action of ribavirin would be valuable in identifying novel antivirals.
Project description:The combination of peginterferon and ribavirin is the standard treatment for chronic hepatitis C. Our recent clinical study suggests that ribavirin augments the induction of interferon stimulated genes (ISGs) in patients treated for HCV infection [1]. In order to further characterize the mechanisms of action of ribavirin, we examined the effect of ribavirin treatment on ISG induction in cell culture. In addition, the effect of ribavirin on infectious HCV cell culture systems was also studied. Similar to interferon-alpha, ribavirin potently inhibits JFH-1 infection of Huh7.5.1 cells in a dose-dependent manner, which spans the physiological concentration of ribavirin in vivo. Microarray analysis and subsequent quantitative PCR assays demonstrated that ribavirin treatment resulted in the induction of a distinct set of ISGs. These ISGs, including IRF7 and IRF9 are known to play an important role in anti-HCV responses. When ribavirin is used in conjunction with interferon, induction of specific ISGs is synergistic when compared to either drug applied separately. Direct up-regulation of these antiviral genes by ribavirin is mediated by a novel mechanism different from those associated with interferon signaling and intracellular double stranded RNA sensing pathways such as RIG-I and MDA5. RNA interference studies excluded the activation of the Toll-like receptor and NF-KappaB pathways in the action of ribavirin. In conclusion, our study suggests that ribavirin, acting via a novel innate mechanism, potentiates the anti-HCV effect of interferon. Understanding the mechanism of action of ribavirin would be valuable in identifying novel antivirals. RNA from three samples were treated with Ribavirin and compared to three PBS treated samples
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
Project description:Transcriptional profiling of human mesenchymal stem cells comparing normoxic MSCs cells with hypoxic MSCs cells. Hypoxia may inhibit senescence of MSCs during expansion. Goal was to determine the effects of hypoxia on global MSCs gene expression.
Project description:Huh-7.5.1 cells were treated with 0.2% DMSO, 20 microM NeoB for 24 h. Treatment with 0.2% DMSO for 24h was prepared as non-treated Huh7.5.1 cells. Huh7.5.1 cells were kindly provided by Prof. Francis Chisari at The Scripps Research Institute.