title: Antigenic cross-reactivity of sperm and T lymphocytes.
abstract: Since seminal components can mediate immunosuppression in vitro, it is possible that some antigen(s) may be common to both the reproductive and immunologic systems. In a group of 70 couples with unexplained infertility, 50 "autoimmune" males and 40 "isoimmune" females had lower than normal percentages of total T cells (mean values +/- standard error of the mean 63 +/- 2% and 60 +/- 2% for immune males and females, respectively, versus 77 +/- 2% and 78 +/- 5% for 50 normal males and females, respectively; P < 0.001). Sheep red blood cell (SRBC) rosetting of lymphocytes was significantly reduced when SRBC were preincubated with sperm extracts (61 +/- 4% versus 9 +/- 2%; P < 0.001) but not when SRBC were incubated with normal serum or when lymphocytes were preincubated with sperm extracts. Antisperm antibody titers in the patients' sera (48 +/- 13) were correlated with their antithymocyte antibody titers (18 +/- 3) (P < 0.01). Moreover, antithymocyte antiserum (titer 1024) cross-reacted with sperm extract (titer 128), and vice versa. This cross-reactivity was significantly reduced by absorption of the sera with sperm cells (P < 0.001), thymocytes (P < 0.001), or white blood cells (P < 0.005). Absorption of autoimmune sperm extracts and seminal plasmas with thymocytes or sperm cells reduced the Coombs' titers, especially immunglobulin G (P < 0.01) and immunoglobulin A (P < 0.025). Similar results were obtained in passive hemagglutiation, immunofluorescence, and cytotoxicity assays. We conclude that sperm and T cells share a common antigen(s).
mesh_terms: D000042:Absorption; D000818:Animals; D000906:Antibodies; D000941:Antigens; D003429:Cross Reactions; D003602:Cytotoxicity, Immunologic; D005260:Female; D005455:Fluorescent Antibody Technique; D006386:Hemagglutination Tests; D006801:Humans; D007106:Immune Sera / Q000494:pharmacology; D007248:Infertility, Male / Q000276:immunology; D007962:Leukocytes / Q000276:immunology; D008297:Male; D011817:Rabbits; D012397:Rosette Formation; D013094:Spermatozoa / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000906:Antibodies; D000941:Antigens; D007106:Immune Sera