Sperm functions influenced by immune reactions

Abstract

Antisperm antibodies (ASA) may interfere with the different steps of the fertilization process. The evolvement of the dysfunction depends on the cognate antigens of the ASA, which were usually identified using 2D-Western blot and MALDI protein analysis. A great variety of antigens are responsible for sperm agglutination, sperm apoptosis, and inhibition of sperm motility. Impairment of migration in the cervix mucus appears mostly to be independent of the cognate antigens of ASA, but it is a consequence of complement activation and cell lysis. Influences of ASA on acrosome reaction reveal a special problem as a large variety of cognate antigens are liberated only after acrosome reaction. The cognate antigens of ASA inhibiting zona binding and oolemma binding are the most promising structures for immune contraception. Also pronucleus formation may be influenced by ASA, but the clinical relevance of the antigens involved remains unclear. Identification of cognate antigens of ASA has a number of practical consequences: (i) ASA inhibiting the fertilization process may be identified by an ELISA or a RIA using specific proteins or peptides; (ii) the identification of functionally relevant antigens is a prerequisite for treatment options; (iii) the identification of immunogenic proteins facilitates studies on immune contraception. An overview of the sperm antigens involved in the different steps of the fertilization process, which were identified by immunological methods, is given in Table 1.4.1. They are further reviewed in the following sections. © 2009 Springer-Verlag Berlin Heidelberg.