Macromolecular synthesis during abortive infection of KB cells by influenza virus

When KB cells were infected either with the fowl plague (FPV) Rostock strain (Hav1N1) of influenza A virus the yield of cell-associated haemagglutinin and neuraminidase polypeptides was essentially comparable to the permissive cell system, but virus particles were not produced in the FPV-KB system. Biosynthesis and transport of RNP antigen from nucleus to cytoplasm of infected cells were traced by immunofluorescent staining at 4 and 8 hours after the beginning of infection. While the fluorescent-stained material was totally confined to the nuclei in FPV-infected KB cells, RNP antigen migrated out of the nucleus during the replicative cycle of an other strain of influenza virus assumed as positive contro,WSN virus, in the same host cell. Patterns of virus-specific protein synthesis were studied by pulse-labelling with 35S-methionine. The most significant feature concerned the amplification of synthesis of virus-induced matrix (M) protein which did not occur in FPV-infected cells at any times p.i. studied.