Without a sufficient cell culture system, researchers have had little success designing and testing drugs for the treatment of the hepatitis C virus (HCV). Now, a recent paper describes an HCV genome that was isolated from a patient with fulminant hepatitis and supports both RNA replication and secretion of viral particles upon transfection in a human liver cell line (Huh7).
Lead author Takaji Wakita, of the Tokyo Metropolitan Institute for Neuroscience, notes that HCV infection only rarely causes fulminant-type hepatitis. Historically, he says, it has not been possible to isolate the virus from such patients because treatments can disrupt the balance between virus and immune response leading to liver infections that are difficult to distinguish from HCV. "However, [this] strain was isolated from a fulminant hepatitis patient who had no past history of liver disease or other viral infections," he says.
While previous researchers have been able to produce viral RNA replication, this is the first model to date to create infectious particles (see related story, page 29). Wakita's team showed that antibodies against CD81, HCV's presumed receptor, or serum from chronically infected HCV patients can neutralize the infection in Huh7 cells. Further, they demonstrated infection in a chimpanzee with particles isolated from culture. According to Charles Rice, an HCV researcher at the Rockefeller University in New York: "This opens up the ability to study HCV-binding and entry and receptor utilization."