NEW VIRUS-SPECIFIC ANTIGENS IN CELLS INFECTED WITH INFLUENZA VIRUS

Hyperimmune peritoneal fluids were obtained from mice which were infected with the WSN strain of influenza A0 and subsequently inoculated intraperitoneally with infected mouse tissue. Up to 12 precipitin lines were obtained in agar immunodiffusion tests with extracts of chick embryo fibroblast cells infected with WSN. In similar tests using a hyperimmune peritoneal fluid which had been absorbed with purified virus until no antibody against haemagglutinin, neuraminidase, or internal antigen could be detected, up to five precipitin lines were observed. At least three precipitin lines were also detected in tests using this absorbed peritoneal fluid and extracts of cells infected with an influenza A1 or an A2 strain. Extracts from WSN-infected cells which had been pretreated with actinomycin D failed to give precipitin lines with the virus-absorbed peritoneal fluid. Nucleoli of infected cells which were reacted with fluorescent antibody against the internal antigen of the virion were not stained whereas the nucleoli of cells which were reacted with the virus particle-absorbed peritoneal fluid stained brilliantly. Faint staining was also present in the nucleus and the cytoplasm. The same distribution of fluorescence was observed in cells infected with an A1 or an A2 strain. No fluorescence was obtained with the virus-absorbed peritoneal fluid in WSN-infected cells which had been pretreated with actinomycin D. © 1969.