Inhibition of bacterial and boar epididymal sperm immunogenicity by boar seminal immunosuppressive component in mice.

Intravenous deposition of the immunosuppressive component, isolated from boar seminal vesicle secretion, led to suppression of primary and secondary antibody response to boar epididymal spermatozoa and to bacterial antigens. The most effective suppression of the immune response was achieved in female mice treated with immunosuppressive component 3 days before the immunization with antigen. The treatment with immunosuppressor 3 days after the immunization resulted in less effective immunosuppression. After the primary immunization, male mice displayed low sensitivity to epididymal spermatozoa. The production of IgG and IgM antibodies to spermatozoa was depressed for a relatively long period in female mice treated with immunosuppressor. The immunosuppressive components of the reproductive gland secretions may protect sperm cells from the adverse effect of the immune system cells and enhance the chance of conception. However, seminal immunosuppressive components may play an unfavourable role by producing a predisposition in the reproductive tract to bacterial or viral infections.