Use of monoclonal antibodies to investigate immunologic cross-reactivity of histocompatibility antigens from various animal species

None of the anti-HLA-DR monoclonal antibodies tested inhibited MLRs between murine and human lymphocytes, although all of them inhibited the MLRs between allogeneic human lymphocytes, and specific HLA-DR polyclonal xenoantisera inhibited the MLRs between human and murine lymphocytes (unpublished results). The reasons for the different results obtained with monoclonal antibodies and polyclonal xenoantisera to HLA-DR antigens will be discussed elsewhere (Russo et al., in preparation). Monoclonal antibodies to histocompatibility antigens greatly facilitate investigations to determine cross-reactivity among these antigens from various animal species and to identify which portions of a histocompatibility antigen have been conserved through evolution and, therefore, are of probable importance to that molecule. This information will aid our understanding of the molecular basis on which histocompatibility antigens function immunologically.