Antigenic regions defined by monoclonal antibodies on tumor-associated antigens of bovine leukemia virus-induced lymphosarcoma cells.

Tumor-associated antigens (TAAs) expressed on enzootic bovine leukosis tumors were divided previously into three types by use of 13 monoclonal antibodies (MAbs): common TAA, partially common TAA and individually distinct TAA. Since MAb-defined epitopes on the common TAA were conserved on both soluble TAA prepared from bovine B-lymphoma cells and untreated viable same cells, all the MAbs that bound to the soluble TAA also bound to untreated viable cells. By contrast, MAb-defined epitopes on the partially common and individually distinct TAAs varied according to the test systems used. Two of seven MAbs were found to bind to both the soluble TAA and viable cells and one MAb bound to the soluble TAA but not to the viable cells.