Our research is aimed at understanding virus-host interactions that regulate pathogenesis and outcome of RNA virus infections. Currently, work in the Li laboratory is centered on two main themes. The first one is to dissect innate immunity to infections by positive-strand RNA viruses such as hepatitis C virus and related viruses. We are studying how these viruses are detected by host innate immune sensors such as the Toll-like receptors and RIG-I-like receptors, leading to antiviral and inflammatory responses. The second focus area is to investigate how TRIM56, a tripartite motif protein, contributes to innate antiviral immunity. Studies are ongoing to delineate the molecular determinants by which TRIM56 restricts RNA virus infections and by which it promotes innate immune signaling. To study these themes, we employ virus-cell culture systems and various biochemical, cell biological and molecular approaches.