Synthesis of interferon in human leukocyte cells stimulated with influenza virus

Strains of influenza A virus were tested for their ability to induce interferon synthesis in suspension of human leukocytes. Both, active as well as UV-inactivated strains were shown to be weak interferon inducers as compared to Newcastle virus. It appeared that interferon synthesis in human leukocytes was conditioned not by infectivity of the virus but by the presence of its surface antigens--hemagglutinin and neuraminidase.