OVIDUCTAL ANTIBODY-RESPONSE TO A DEFINED RECOMBINANT SPERM ANTIGEN INMACAQUES

Macaque oviductal fluids were assayed for specific antibodies to the i ntra-acrosomal sperm protein SP-10 after immunizations with recombinan t macaque SP-10 (re-mqSP-10), a candidate contraceptive vaccinogen. Ac cess ports, consisting of a subcutaneous collecting reservoir and a ca theter to cannulate the oviduct, were implanted into monkeys for repea ted aspiration of oviductal fluid. Monkeys were inoculated i.m. once a month with an emulsion consisting of 2 mg re-mqSP-10 in a vehicle of squalene and mannin monooleate. Oviductal fluids and serum were collec ted during the periovulatory period for six menstrual cycles, and IgG and IgA antigen-specific antibodies in preimmune and immune fluids wer e compared by ELISA. Both relative and absolute concentrations of SP-I O-specific immunoglobulins (Ig) were determined. Oviductal fluids from immunized animals showed significant increases in anti-SP-10 IgG at c ycle 2 and at all subsequent intervals. Anti-SP-10 IgA significantly i ncreased in oviductal fluid at cycles 4, 5, and 6. Serum anti-SP-10 Ig C increased at cycle 2 and remained significantly elevated through cyc le 6, while serum anti-SP-10 IgA was higher than in preimmune samples at cycle 4. Serum antibodies generated to the recombinant SP-10 recogn ized SP-10 extracted from macaque sperm on Western blots. Immunocytoch emical staining of macaque and human sperm showed acrosomal immunofluo rescence with both immune oviductal fluids and serum using both anti-I gG and anti-IgA secondary antibodies. This study demonstrates for the first time 1) IgC and IgA antibodies to a defined recombinant sperm-sp ecific antigen in primate oviductal fluids after systemic immunization and 2) the recognition by primate oviductal fluid IgG and IgA of the endogenous contraceptive target on both human and macaque sperm.