Inhibition of human immunodeficiency virus type 1-induced cell fusion by recombinant human interferons.

Pretreatment of HeLa T4 cells with recombinant alpha, beta, or gamma interferon (IFN) was found to significantly inhibit syncytium formation induced by the human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein. All three IFNs were found to be potent inhibitors of fusion in a system in which Spodoptera frugiperda cells, infected with a baculovirus recombinant expressing the HIV-1 envelope protein, were cocultivated with HeLa T4 cells. In addition, these IFNs were also found to block HeLa T4 cell fusion induced by the HIV-1 envelope proteins expressed from a vaccinia virus recombinant. Furthermore, the IFNs inhibited cell fusion between HIV-1 envelope glycoprotein-expressing cells and either immortalized or fresh CD4+ lymphocytes pretreated with the IFNs. These results suggest that further testing of human IFNs for therapy of HIV-1 infection will be of interest.