Effects of Alpha Interferon Treatment on Intrinsic Anti-HIV-1 Immunity In Vivo

Alpha interferon (IFN-alpha) suppresses human immunodeficiency virus type 1 (HIV-1) replication in vitro by inducing cell-intrinsic retroviral restriction mechanisms. We investigated the effects of IFN-alpha/ribavirin (IFN-alpha/riba) treatment on 34 anti-HIV-1 restriction factors in vivo. Expression of several anti-HIV-1 restriction factors was significantly induced by IFN-alpha/riba in HIV/ hepatitis C virus (HCV)-coinfected individuals. Fold induction of cumulative restriction factor expression in CD4+ T cells was significantly correlated with viral load reduction during IFN-alpha/riba treatment (r(2) = 0.649; P < 0.016). Exogenous IFN-alpha induces supraphysiologic restriction factor expression associated with a pronounced decrease in HIV-1 viremia.