Pseudotypes of vesicular stomatitis virus with coat antigen of bovine leukaemia virus--VSV (BLV): antigenic surface mosaic and the roles of precipitating antibodies and polycations.

The pseudotype particles vesicular stomatitis virus (bovine leukaemia virus) [VSV (BLV)] contain a surface antigenic mosaic, composed of both VSV- and BLV-specific antigens, as demonstrated by increased neutralization by anti-VSV serum after addition of complement or of "second antibody". All the pseudotype infectivity was precipitated by VSV-specific antibody: it could be pelleted by low-speed centrifugation and its infectivity recovered without any loss by sonication. Polycations present during adsorption had little effect on infectivity of the pseudotype for Vero cells, but markedly increased its titre for chicken fibroblasts.