Passive enhancement of rat renal allografts using mouse monoclonal xenoantibodies.

These studies test the effectiveness for passive enhancement of rat renal allografts of mouse monoclonal xenoantibodies to rat major histocompatibility complex (MHC) antigens. Two fully characterized, noncytotoxic monoclonal antibodies, both of which show some allospecificity, were tested in several different MHC-incompatible strain combinations chosen such that the monoclonal antibodies reacted with the donor but not the recipient strain. The antibody F21-105-1, directed at RT1-A (class I) antigens, interacts with all strains tested except the PVG/c strain and was tested in the LEW to PVG/c and WAG to PVG/c combinations. The antibody F17-23-2, directed to RT1-B (class II or Ia) antigens, interacts with all strains tested except the PVG/c, AUG, and WAG strains and was tested in the LEW to PVG/c and LEW to WAG combinations. Our results demonstrate that noncytotoxic monoclonal xenoantibodies are effective for passive enchancement but that in strong donor-recipient combinations they might not be quite as effective as conventional allosera. Nevertheless, they are likely to be useful reagents for testing the efficacy of passive enhancement in the clinical situation.