What Causes Natural Suppression of Hepatitis C Virus?

A natural immune response can protect the liver from the hepatitis C virus (HCV), but researchers have been unclear as to how this occurs.

Investigators from the University of Adelaide in Australia recently discovered that a family of genes is responsible for causing this immune response that suppresses HCV infection in the liver.

"This improved understanding of the host response to HCV infection, and the HCV entry process, will provide new direction for the development of therapeutic treatments to either heighten this natural response, or generate mimics to target the virus specifically,” said Michael Beard, head of the Viral Pathogenesis Laboratory in the University of Adelaide School of Biological Science.

Untreated HCV infection typically leads to chronic disease and liver cancer, with these conditions increasing in frequency, the study noted. The Australian investigators are the first to show antiviral IFITM proteins produced through a natural immune response stop HCV from entering cells.

"We now have a good idea of what the IFITM proteins do in liver cells and how they act to suppress hepatitis C infection," Beard said.

Prior research found that the IFITM1, IFITM2, and IFITM3 proteins generate an antiviral response to several different viruses, including HCV. The role these proteins perform in HCV suppression remained unknown until the current study, however.

The researchers were able to show liver cells expressing high IFITM protein levels resist HCV infection by denying cell entry to the virus.

"Our research team demonstrated specific interactions between the proteins and the HCV entry process within the cells. It appears that the proteins act together in a specific way to target the virus,” Beard said. "This now points the way forward to develop ways of enhancing these mechanisms to prevent the virus from setting up infection."