Immune response to Trichomonas vaginalis. IV. Immunochemical and immunobiological analyses of T. vaginalis antigen.

The immune response of patients with trichomoniasis vaginitis to Trichomonas vaginalis was examined by using passive hemagglutination assay and skin reactions. Trichomonas-specific immune responses could hardly be detected in the patients by these assay methods. In order to develop a simple and reliable assay for demonstration of T. vaginalis-specific immune responses in the patients, proliferation responses of peripheral mononuclear cells from the patients were examined. Lymphocytes obtained from the patients were shown to incorporate 3H-methyl-thymidine when stimulated with T. vaginalis antigen in vitro. Furthermore, immunochemical analysis of T. vaginalis antigen has been done by Sephadex chromatography and sodium dodecyl sulfate gel electrophoresis. The data revealed that the murine and human IgM antibodies specific to T. vaginalis recognize various antigens with a wide range of molecular weights (between 13,000 and 100,000 daltons), while human and murine IgG antibodies recognize molecules with a much narrower range of molecular weights (50,000-100,000 daltons).