Application of monoclonal antibodies in the avian leukosis virus GS-antigen ELISA.

Five hybridoma cell lines which secrete antibodies to avian leukosis/ sarcoma (ALV) group-specific (gs) antigens (gag gene products) have been established. The hybrid cells resulted from fusion of P3/X63-Ag8.653 myeloma cells with splenocytes of BALB/c mice which had been immunised with purified avian myeloblastosis virus (AMV). Screening of supernatant fluids was performed by an indirect double antibody sandwich enzyme-linked immunosorbent assay (IDAS-ELISA) and the immunoelectroblotting technique. Three hybrid clones secrete monoclonal antibodies (MCA) to 27,000 dalton polypeptides (p27) and two hybridomas produce monoclonal antibody directed to 19,000 dalton phosphoprotein (pp19). All five monoclonal antibodies belong to mouse immunoglobulin isotype IgG(1). MCAs directed to different ALV-p27 epitopes can replace polyclonal rabbit or hamster anti-gs sera in the DAS-ELISA in use for the detection of congenitally ALV-shedding hens. In albumen samples a 16- to 32-fold increase of sensitivity of ALV gs-antigen detection was obtained as compared to the DAS-ELISA employing polyclonal sera. Gs-antigens of a purified AMV preparation were detectable up to minimal concentrations of 13 pg/ml.