An antiviral state induced in HeLa cells by microinjected poly(rI).poly(rC).

The direct introduction with micropipettes of poly(rI).poly(rC) into the cytoplasm of several human cell lines inhibited the multiplication of vesicular stomatitis virus. This antiviral activity was at least partly due to interferon (IFN) production and secretion from the injected cells since it was species-specific, partly neutralized by IFN antibodies and was transmissible to non-adjacent cells. This suggests a mechanism of IFN induction involving the internalization of poly(rI).poly(rC) and its interaction with an intracellular target.