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

Phosphorylation of viral polypeptides in cells infected with influenza virus

Abstract Experiments carried out in vivo with WSN (H0N1) and FPV (Hav1N1) strains of influenza virus have shown the presence of phosphorylated virus-induced polypeptides. Notably it was interesting the behaviour of the non-structural NS1, NP nucleoprotein and membrane M viral components whose phosphorylation was different among the cellular hosts tested. In in vitro experiments we were able to demonstrate a protein-kinase-activity in purified virions. The similarities and differences found in vivo and in vitro systems are discussed taking into consideration the fact that viral replicative cycle is closely dependent from the cellular host and the pattern of influenza virus infection is unique between different hosts. PMID: 7236359 [PubMed - indexed for MEDLINE