Cross-reactivity of sperm and T lymphocyte antigens.

Evidence is presented for cross-reactivity between antigens on human sperm and T lymphocytes. In 25 infertile couples in which both the males and females had significant antisperm immunity, antibody (Ab) titers to thymocytes (mean +/- S.E.M. 159 +/- 4 and 72 +/- 14, respectively, in males and females), T cell lines CCRF-CEM (69 +/- 5 and 48 +/- 8) and HSB-2 (56 +/- 15) and 41 +/- 8), suppressor-enriched (TG) cells (26 +/- 6 and 66 +/- 28) and helper-enriched (TG-) cells (26 +/- 4 and 46 +/- 14) were significantly elevated, as compared with Ab titers in 45 normal males and 45 normal females without antisperm immunity. Antibody titers to adult B cells, B cell line RAJI, and granulocytes were similar in the two groups. Antisperm Ab titers in sera, sperm extracts, and seminal plasma of the infertile subjects were significantly reduced after absorption with sperm, thymocytes, or T cell line CCRF-CEM but not with the B cell line RAJI. Antithymocyte Ab titers in the sera were significantly reduced (p less than 0.001) after absorption with thymocytes, CCRF-CEM, or sperm, but not RAJI. Lymphocytes from the infertile patients, when stimulated with pokeweed mitogen in vitro, produced antisperm and anti-T-lymphocyte antibodies at significantly higher titers than normal controls.