Hepatitis C virus (HCV) infection causes chronic liver diseases and is a global public health problem. Detailed analyses of HCV have been hampered by the lack of viral culture systems. Subgenomic replicons of the JFH1 genotype 2a strain cloned from an individual with fulminant hepatitis replicate efficiently in cell culture. Here we show that the JFH1 genome replicates efficiently and supports secretion of viral particles after transfection into a human hepatoma cell line (Huh7). Particles have a density of about 1.15-1.17 g/ml and a spherical morphology with an average diameter of about 55 nm. Secreted virus is infectious for Huh7 cells and infectivity can be neutralized by CD81-specific antibodies and by immunoglobulins from chronically infected individuals. The cell culture-generated HCV is infectious for chimpanzee. This system provides a powerful tool for studying the viral life cycle and developing antiviral strategies.

April 2020 Nsp3 abcam ab181620 Nucleocapsid Sino Biological 40143-MM05 Validation Commercial antibodies validated as per manufacturers website: Beta actin Sigma A5441 Immunoblot on chicken fibroblast cell extracts Spike Abcam Ab252690 Validated by ELISA on free peptide from SARS-CoV-1 Nsp3 abcam ab181620 Validated by western blot on SARS-CoV-1 infected cells Nucleocapsid Sino Biological 40143-MM05 Validated by western blot with corresponding viruses Eukaryotic cell lines Policy information about cell lines Cell line source(s) VeroE6 cells were obtained from ATCC, Calu-3 cells were obtained from Manfred Frey, originally from ATCC. Authentication Cells were not further authenticated Mycoplasma contamination Cells have been tested and are free of mycoplasma.

HIV release requires TSG101, a cellular factor that sorts proteins into vesicles that bud into multivesicular bodies (MVB). To test whether other proteins involved in MVB biogenesis (the class E proteins) also participate in HIV release, we identified 22 candidate human class E proteins. These proteins were connected into a coherent network by 43 different protein-protein interactions, with AIP1 playing a key role in linking complexes that act early (TSG101/ESCRT-I) and late (CHMP4/ESCRT-III) in the pathway. AIP1 also binds the HIV-1 p6(Gag) and EIAV p9(Gag) proteins, indicating that it can function directly in virus budding. Human class E proteins were found in HIV-1 particles, and dominant-negative mutants of late-acting human class E proteins arrested HIV-1 budding through plasmal and endosomal membranes. These studies define a protein network required for human MVB biogenesis and indicate that the entire network participates in the release of HIV and probably many other viruses.