Baculovirus stimulates antiviral effects in mammalian cells

Herein, we report that Autographa californica nucleopolyhedrovirus, a membe r of the Baculoviridae family, is capable of stimulating antiviral activity in mammalian cells. Baculoviruses are not pathogenic to mammalian cells. N evertheless, live baculovirus is shown here to induce interferons (IFN) fro m murine and human cell lines and induces in vivo protection of mice from e ncephalomyocarditis virus infection. Monoclonal antibodies specific for the baculovirus envelope gp67 neutralize baculovirus-dependent IFN production. Moreover, UV treatment of baculovirus eliminates both infectivity and IFN- inducing activity. In contrast, the IFN-inducing activity of the baculoviru s was unaffected by DNase or RNase treatment. These data demonstrate that I FN production can be induced in mammalian cells by baculovirus even though the cells fail to serve as a natural host for an active viral infection. Ba culoviruses, therefore, provide a novel model in which to study at least on e alternative mechanism for IFN induction in mammalian cells.