EVIDENCE FOR INCOMPLETE REPLICATION OF A PENGUIN POXVIRUS IN CELLS OFMAMMALIAN ORIGIN

The recent discovery of a novel poxvirus [penguin-pox virus (PPV)] fro m Jackass penguins offers the potential of a unique candidate vaccine vector for use in mammals. Infectivity studies were therefore undertak en using a number of mammalian cell lines and chick embryo fibroblasts (CEF). It was shown that the simian CV-1 cell line was able to suppor t replication of the PPV DNA, but no infectious progeny virus could be recovered from the infected cells. Electron microscopy was used to es tablish the extent of virus morphogenesis in CV-1 cells as compared to that in both chorio-allantoic membranes (CAMs) of hens' eggs and CEF cells. it appears that CV-1 cells are able to support partial maturati on of PPV, but that morphogenesis does not proceed to the stage of mat ure infectious particles. Vaccinia virus promoters were successful in achieving transient gene expression in PPV-infected cells.