Antiviral activities of cloned human leukocyte interferons against herpes simplex virus type 2 infections of mice.

Human alpha-interferons (IFN-alpha s) made in bacteria were examined for antiviral activity against herpes simplex virus type 2 (HSV-2) infections of mouse L-cells in vitro, and acute cervicovaginal and lethal systemic HSV-2 infections of BALB/c mice. The recombinant DNA-derived hybrid interferon IFN-alpha AD(Bgl) showed pronounced antiviral activity in vitro, exceeding the activity of either of the parental subtypes IFN-alpha A and IFN-alpha D and that of the other hybrids IFN-alpha AD(Pvu) and IFN-alpha DA(Bgl). A combination of topical and systemic treatments with IFN-alpha A and IFN-alpha AD(Bgl) failed to protect mice from subsequent challenge with an acute cervicovaginal infection of HSV-2. Protection from lethal systemic HSV-2 infection in mice was observed when IFN-alpha AD(Bgl) and IFN-alpha AD(Pvu) were administered systemically, whereas IFN-alpha A failed to confer protection. These results suggest that for protection against infection with HSV-2, the routes of introduction of the virus and of the interferon influence the host response to interferon therapy.