Studies on human spermatozoa autoantigens. I. Fractionation of sperm membrane antigens: evidence of three antigenic systems.
In order to identify human spermatozoal surface autoantigens, suspensions of previously frozen washed sperm were ground and ultracentrifuged (170,000 g for 60 min). The antigenicity of the fast supernatant (FS) and the fast pellet (FP) were defined by specific inhibition of spermotoxic and various sperm-agglutinating activities of autoimmune human sera (WHO Reference Bank). The FS and the urea-soluble extract of FP were fractionated on Sephadex G-200 columns, and the antigenicity of these fractions was similarly defined. Both FS and FP inhibited, to variable extents, the anti-sperm activities. Inhibition of head-to-head (H-H) agglutination by FS was twice as strong as by FP. The reverse was observed with tail-to-tail (T-T) agglutination. Ten times more FS than FP was necessary to inhibit the spermotoxicity of all tested sera. Four fractions were collected after FS filtration on Sephadex G-200. F1, a homogeneous protein, inhibited spermotoxicity and H-H agglutination F2 inhibited all activities (including T-T agglutination). F3, a low molecular weight fraction, selectively inhibited H-H agglutination. F4 was inactive. Treatment by 8 M urea allowed a partial solubilization of FP antigenicity. Urea-soluble fractions inhibited spermotoxicity and H-H but not T-T agglutination. The antigen(s) involved in T-T agglutination is (are) destroyed by urea since the urea-treated FP was no longer able significantly to decrease T-T agglutination. These results suggest that at least three different autoantigens are responsible for H-H sperm agglutination, T-T sperm agglutination and spermotoxicity respectively.
D000372:Agglutination Tests; D000941:Antigens / Q000302:isolation & purification*; D000954:Antigens, Surface / Q000302:isolation & purification*; D001324:Autoantigens / Q000302:isolation & purification*; D002850:Chromatography, Gel; D003602:Cytotoxicity, Immunologic; D006801:Humans; D007531:Isoflurophate / Q000494:pharmacology; D008297:Male; D013077:Sperm Head / Q000276:immunology; D013082:Sperm Tail / Q000276:immunology; D013094:Spermatozoa / Q000276:immunology*; D014508:Urea / Q000494:pharmacology
D000941:Antigens; D000954:Antigens, Surface; D001324:Autoantigens; D007531:Isoflurophate; D014508:Urea