Monoclonal antibody specific for avian sarcoma virus structural protein p27

A hybridoma cell line which secretes antibody to the Rous sarcoma virus (RSV) structural protein p27 has been established. The hybrid resulted from the fusion of NS-1 myeloma cells with spleen cells from a Balb/c mouse which was immunized with RSV-transformed mouse cells. Antibodies produced by the hybrid clone immunoprecipitated p27 and gag precursor proteins (Pr180gag,pol, Pr76gag and Pr66gag) from [35S]methionine-labelled chicken embryo fibroblasts transformed by the Schmidt-Ruppin strain of RSV. When Schmidt-Ruppin virus was radioactively labelled with [35S]methionine, p27 was the only virus structural protein immunoprecipitated. Antibody production by the hybrid clone (designated 7-29-D6) has remained stable for longer than 12 months at a level of 50 micrograms IgG/ml medium. A highly sensitive method to determine the subclass specificity of monoclonal antibodies is described. In this procedure, the clone is incubated with [35S]-methionine, and radiolabelled antibody is precipitated with affinity-purified, subclass-specific rabbit anti-mouse serum and Staphylococcus aureus. The advantages of this procedure are discussed.