[23, 24] Recently, studies in B cells have shown that antibody engagement of CD81, a key receptor for HCV infection, induces spleen tyrosine kinase (SYK) phosphorylation of ezrin that recruits F-actin to facilitate cytoskeletal reorganization.[25] In addition, recent studies have found that inhibition of actin and/or microtubule

functions markedly reduced HCV infection in vitro.[10, 26] Taken together, these studies implicate host cytoskeletal proteins in the pathophysiology of HCV infection. Ezrin-moesin-radixin Smad inhibitor (EMR) represents a group of human cytoskeletal proteins that regulate lentiviral infection by modulating stable and dynamic microtubule formation.[8, 9] EMR also function as linkers between the actin cytoskeleton and plasma membrane proteins and as signal transducers in numerous signaling pathways.[27, 28] This family of proteins show >70% sequence homology among members and display a high degree of functional redundancy.[29] Given that EMR proteins regulate human immunodeficiency virus (HIV) infection,[8, 9] it remains unknown Selleck EMD 1214063 if these proteins can regulate other positive sense RNA virus infections including HCV. In the present study we performed a comprehensive molecular analysis to characterize the role of human EMR in HCV infection and replication. Using HCV J6/JFH-1 virus infection

and the HCV Con1 replicon system we demonstrate that HCV infection and replication can be modulated by proteins of the EMR family. We found that chronic HCV infection resulted in a significant decrease in moesin and radixin expression in Huh7.5 cells and HCV-infected patients compared to controls. The significant decrease in moesin and radixin in HCV J6/JFH-1-infected Huh7.5 cells was associated with increased stable microtubule aggregate formation. Overexpression or transient knockdown

of EMR proteins differentially modulated target cell susceptibility to HCV infection and replication. 上海皓元医药股份有限公司 These experiments provided mechanistic insights into modulation of HCV infection by the EMR family of proteins and identified targets for development of new therapies against HCV infection. Huh7.5 and Con1 HCV FL replicon cells were cultured as described[30] Infectious and replication competent HCV J6/JFH-1 virions were generated using pFL-J6/JFH-1 plasmid as described.[31] Detailed protocols are described in the Supporting Materials and Methods. Liver biopsy specimens were obtained from the National Institutes of Health (NIH) liver tissue cell distribution system (LTCDS; Minneapolis, MN; Pittsburgh, PA; Richmond, VA), which was funded by NIH contract # N01-DK-7-004/HHSN26700700004C. Patient samples represented genotypes 1a and 3. Additional methods are included in the Supporting Materials.