SECRETORY MONOCLONAL IGA ANTIBODY TO HUMAN SPERM PRODUCED BY GASTROINTESTINAL IMMUNIZATION INHIBITS HUMAN SPERM ACTIVITY AND MOUSE INVITRO FERTILIZATION

BALB/c mice were immunized intragastrically with human sperm. Cells from the Peyer's patches and spleens of the immunized mice were for the preparation of hybridomas secreting antisperm monoclonal IgA (mcIgA). The specific ratio of IgA-secreting cells in Peyer's patches was much higher than that in spleen. The binding site on human sperm of 9 of 19 mcIgA was in the post-acrosomal region using an immunofluorescent assay. Two of eight selected mcIgA caused strong human sperm agglutination and three of them produced significant inhibition of mouse in vitro fertilization. No mcIgA tested caused obvious human sperm immobilization or inhibited mouse in vivo fertilization. In vitro assembly of selected mcIgA in ascites with mouse secretory component (SC) caused no significant changes in effects on sperm function and in vitro fertilization. By use of Western blotting, dimer or higher polymers were demonstrated in all selected mcIgAs and corresponding protein antigens in 6 of 8 selected mcIgAs. These results suggest that human sperm function may be inhibited and fertilization rate reduced by specific secretory IgA to human sperm and that secretory immunity to protein antigens of human sperm could be induced by intragastrointestinal immunization.

Detection of cutaneous antibodies in excised skin explants from grass carp, Ctenopharyngodon idella (Valenciennes), immune to Scophthalmus maximus rhabdovirus

This study determined whether cutaneous antibodies were present in excised skin explants of grass carp, Ctenopharyngodon idella, immune to Scophthalmus maximus rhabdovirus (SMRV). Culture fluid from immune skin explants were assayed by indirect enzyme-linked immunosorbent assay (iELISA), Western blot, indirect immunofluorescent assay (IFA) and flow cytometry (FCM). iELISA showed that cutaneous antibody titres were much lower (1:12) than antiserum titres (1:1458) from intraperitoneally immunized grass carp. The phosphoprotein and matrix protein antigens of purified SMRV proteins were recognized by cutaneous antibodies from skin culture fluid using Western blot. The skin culture fluid produced staining signals in viral assembly sites and cytoplasm of SMRV-infected epithelioma papulosum cyprini (EPC) cells by IFA. FCM showed that 4.39% SMRV-infected EPC cells were detected, while non-specific reaction was seen in 2% of control cells. This is the first description of cutaneous antibodies against SMRV in grass carp.