Identification of sperm proteins involved in fertilization using immunological approaches

VAZQUEZ LEVIN, M.H.

Pittsburgh area, PA, EEUU.

Congreso; 30th Annual Meeting American Society of Reproductive Immunology. The Nemacolin Resort,; 2010

American Society of Reproductive Immunology

Speaker Mónica H. Vazquez-Levin, PhD National Research Council of Argentina Instituto de Biología y Medicina Experimental Title Identification of Sperm Proteins Involved in Fertilization Using Immunological Approaches Abstract Fertilization results from successful gamete interaction. Testicular spermatozoa undergo maturation during their epididymal transit. Once deposited in the female tract, sperm cells undergo capacitation, by means of their interaction with the oviductal epithelium and its secretions. Upon arrival to the fertilization site, capacitated spermatozoa traverse the cumulus mass and interact with the zona pellucida (ZP). This interaction triggers the acrosomal exocytosis, a process that allows sperm penetration through the ZP. Spermatozoa that reach the perivitelline space bind and fuse to the oolemma. Using classical immunological approaches we have developed projects aimed at identifying sperm proteins involved in fertilization. Studies have been done in human, murine and bovine models. Our investigations have contributed to the knowledge of the sperm proacrosin/acrosin system, by studying its trypsin-like proteinase and ZP-binding activities. Moreover, antibodies towards proacrosin/acrosin have been detected in women consulting for infertility, and their effects have been studied using in vitro assays and a gene immunization model. In recent years, our interest has been extended to the assessment of cell-cell adhesion molecules in the male reproductive tract and gametes and their involvement in sperm-oocyte interaction. Our reports have described the expression of Neural cadherin in the male gonad and its presence and localization in testicular as well as in ejaculated, capacitated and acrosome reacted cells; in addition, studies have shown evidence on its participation in sperm-oolemma adhesion events. Using a similar approach, localization of Epithelial cadherin in spermatozoa has been evaluated, and evidence has been presented on sperm acquisition of the adhesion protein during epididymal transit, as well as its involvement in sperm interaction with the ZP and the oolemma. The identification of sperm proteins involved in gamete interaction will help in the understanding of the molecular basis of fertilization and may contribute to the diagnosis and treatment of male infertility.