NEW MURINE MONOCLONAL-ANTIBODIES DIRECTED AGAINST GLYCOPHORIN-C AND GLYCOPHORIN-D, HAVE ANTI-GE2 SPECIFICITY

Background and Objectives: The Gerbich blood group system comprises th ree high-incidence antigens which have been localized on glycophorins C (GPC) and D (GPD) molecules. Murine monoclonal antibodies (mAbs) dir ected against Ge4 and Ge3 epitopes have already been obtained. We desc ribe two murine mAbs (ZI51.17 and J6) with Ge2 specificity. Materials and Methods: The mAbs were investigated by serological methods and imm unoblotting, with common, Ge-negative and enzyme-modified RBCs. Result s: Both mAbs behaved like anti-Ge2 in serological tests, but bound to GPC and GPD on immunoblots. ZI51.17 did not recognize the GPC(Yus) or GPC(Ge) variants, whereas J6 revealed a 25-kD component from Ge:-2,-3, 4 membranes, which is identical to the GPC(Ge) molecule. Conclusion: T hese two mAbs are directed to slightly different epitopes. The ZI51.17 and J6 epitopes are common to GPC and GPD, thus distinct from the Ge2 antigen defined by human alloantibodies.