DETECTION OF GLYCOPROTEINS IMMUNOLOGICALLY RELATED TO RSV GP85 IN UNINFECTED AVIAN CELLS AND IN SERA FROM UNINFECTED BIRDS

The experiments described in this study deal with the detection of components immunologically related to oncornaviral glycoprotein (gp85) in uninfected cell extracts and sera. Cell extracts from chick helper factor- (chf) negative fibroblasts contain components detected by two of the three antisera used. Chf(+) chicken cell extracts contain in addition an antigenic determinant, presumably viral gp85, recognized by the third antiserum. The sera from uninfected chickens may contain two components immunologically related to gp85: One component recognized in a radioimmuno-precipitation assay (RIA) employing anti-AMV gp85 serum is present in high amounts in the sera of chf(+) and chf(-) birds, while a second component detected in a RIA employing anti-Prague B RSV serum is present only in the sera of chf(+) birds. Some biochemical studies dealing with the properties and size of the cross-reacting components are described. It is postulated that the components which immunologically cross-react with, but are not identical to, endogenous viral glycoprotein are products of genes related to the env gene of RAV-0 which, however, are nonfunctional as viral glycoprotein. © 1978.