Transglutaminase-Catalyzed Crosslinking of an Immunosuppressive and Anti-Inflammatory Protein Secreted from the Rat Seminal Vesicles

Abstract

It is well known that the mammalian reproduction system is potentially hazardous because of male gamete immunogenicity. In fact, it has been demonstrated by a variety of immunological techniques that the epididymal sperm cells possess non-self specific, highly immunogenic autoantigens and alloantigens on their surface. Therefore, sperm antigens should be able to elicit a dangerous immunological response in the female genital tract where the sperm cells should be rejected. However, even though spermatozoa possess components which are antigenically foreign to the female mammal, the deposition of sperm cells at natural mating does not cause sterilizing anti-sperm immunity. The surface antigenic characteristics of the epididymal sperm cells change following their mixing in the ejaculate with the secretions of the male accessory sexual glands; in fact, the male gametes lose their immunological reactivity in the seminal plasma, adapting themselves to avoid rejecton by the immunocompetent elements normally occurring in the female genital tract.²