ALLOANTIBODY RESPONSES TO ANTIGENS RECOGNIZED BY RABBIT ANTITROPHOBLAST ANTISERA IN TROPHOBLAST AND MONONUCLEAR CELL (MNC) MEMBRANES BY PRIMARY ABORTING WOMEN BEFORE AND AFTER PATERNAL LEUKOCYTE IMMUNIZATION

PROBLEM: Because shared allogeneic antigens are expressed on periphera l blood lymphocytes, as well as trophoblasts, it has been proposed tha t lymphocyte transfusions may appropriately sensitize recurrent sponta neous aborters (RSA) to trophoblast and lead to pregnancy conservation . The degree to which these responses are affected by this treatment, however, has not been defined. METHOD: SDS-polyacrylamide gel electrop horesis (SDS-PAGE) and Western blot analyses were used to study the al loantibody responses in RSA patients both before and after immunizatio n with paternal leukocytes (MNC) against membrane proteins isolated fr om peripheral blood mononuclear cells (MNC), first trimester and full term chorionic villi (CV). RESULTS: A distinct set of antigens with ap parent molecular weights of 32, 36, 41, 63, 65, and 85 kDa was identif ied in both MNC and trophoblast membranes by rabbit anti-trophoblast a ntisera. In addition, a 55 kDa protein was recognized by MNC membranes . Thirty-eight percent of primary RSA sera recognized this 55 kDa prot ein. After paternal MNC immunization, all primary RSA samples displaye d increased reactivity or produced antibodies to this 55 kDa protein w hen compared with preimmunization sera. The protein was identified as MCP using a rabbit polyclonal anti-MCP antisera. In contrast, reactivi ty to the other antigens present in the membrane preparations decrease d after paternal MNC immunization. CONCLUSION: Changes in immune react ivity in RSA patients after paternal MNC immunization suggest that imm unization alters serum immune reactivity to MNC and trophoblast shared antigens.