Avian tumour virus interactions with chicken fibroblast membranes: partial characterization of initial attachment site activity.

Exposure of chicken embryo fibroblasts (CEF) to trypsin solubilizes cell surface components, including the initial attachment site for avian tumour viruses (ATV). The soluble attachment site activity appears to interact directly with the ATV in vitro thereby interfering with the binding of at least two ATV subgroups to both intact CEF and CEF plasma membranes. A result of this interaction in vitro is reduced ATV infectivity, demonstrated by reduced transforming capacity of RSV (RAV-I).