Avian sarcoma virus envelope glycoprotein (gp85) specifically binds chick embryo fibroblasts

Highly purified Prague (Pr) strain Rous sarcoma virus (RSV) subgroup C envelope glycoprotein (gp85) is shown to bind cellular receptor sites present on C/E, and to a much lesser extent C/C, chicken embryo fibroblasts. The specificity of this binding activity is indicated by the fact that neither C/E nor C/C chicken embryo fibroblasts exhibit detectable binding of Rauscher murine leukemia virus envelope glycoprotein (gp70). Moreover, of the avian viruses tested, only those with subgroup C host range inhibit binding of ¹²⁵I-labeled PrRSV-C gp85 by C/E chicken embryo fibroblasts. These findings provide a potential approach for quantitation and characterization of avian type C viral cellular receptor sites.