Monoclonal rat anti-mouse brain antibody detects Abelson murine leukemia virus target cells in mouse bone marrow

We report the characterization of a monoclonal antibody which detects a surface antigen expressed by the bone marrow target cell of A-MuLV. Treatment of bone marrow cells with this antibody and complement results in >95% loss of the A-MuLV-derived in vitro transformed foci. The surface antigen detected by this antibody is also expressed on A-MuLV-transformed lymphoid cell lines, thymocytes, and some peripheral lymphocytes. This antigen is not expressed, however, by the pluripotent hematopoietic stem cell defined by the spleen colony-forming assay. We present evidence that the antigen detected is neither a virally encoded product, nor exclusively associated with the BALB/c genome.