Human immunodeficiency virus-1 Rev protein activates hepatitis C virus gene expression by directly targeting the HCV 5'-untranslated region.

Coinfection with human immunodeficiency virus-1 (HIV-1) and hepatitis C virus (HCV) accelerates hepatitis C disease progression; however, the mechanism underlying this effect is unknown. Here, we investigated the role of HIV-1 in HCV gene expression and the mechanism involved in this regulation. We discovered that HIV-1 Rev protein activates HCV gene expression. We further revealed that Rev binds to the internal loop of the HCV 5'-untranslated region (5'-UTR) to stimulate HCV IRES-mediated translation.