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The identification of sperm proteins involved in fertilization has been the subject of numerous investigations. Much interest has been dedicated to naturally occurring antisperm antibodies ( ASA) and their impact in fertility. Their presence in men and women has been associated with 2-50% of infertility cases. ASA may impair pre- and post-fertilization steps. Experimental models have been developed using sperm proteins as immunogens to evaluate their involvement in sperm function. Our team has pursued investigations to assess ASA presence in biological fluids from patients consulting for infertility and their effect on fertilization. We found ASA in follicular fluids with ability of inducing the acrosome reaction and blocking sperm- zona pellucida interaction and used them to identify sperm entities involved in these events. We generated and utilized antibodies against proacrosin/acrosin to characterize the sperm protease system. We implemented an ELISA to detect proacrosin/acrosin antibodies in human sera and evaluated their impact upon fertility by developing in vitro assays and a gene immunization model. This review presents a summary of ASA history, etiology, current approaches for detection and effects upon fertility. ASA (naturally occurring, generated by animal immunization and/or of commercial origin) are invaluable tools to understand the molecular basis of fertilization, better diagnose/treat immunoinfertility and develop immunocontraceptive methods. [ABSTRACT FROM AUTHOR]

Problem Evaluation of proacrosin/acrosin ability to induce an immune response in male mice after genetic immunization and assessment of animal fertility. Method of study Mice received 50 μg per animal of a plasmid containing the human proacrosin cDNA ( pSF2- Acro) (control: empty plasmid, pSF2). The humoral response was evaluated by ELISA and immunocytochemistry. In vivo fertility was assessed by mating immunized males with control females. The effect of antibodies upon Ca+2-ionophore-induced acrosomal exocytosis (AE) and in vitro sperm- zona pellucida (ZP) binding was also studied. Results pSF2- Acro-immunized mice developed high levels of specific antibodies ( P < 0.05) that recognized the sperm acrosomal cap. The number of fertile mice was lower ( P = 0.027) in pSF2- Acro-immunized animals than in controls. Litter size was smaller ( P < 0.05) in the pSF2- Acro group compared with controls. A negative correlation ( P < 0.05) between antibody levels and litter size was found. Antiproacrosin/acrosin antibodies inhibited sperm-ZP binding ( P < 0.0001) and Ca+2-ionophore-induced AE ( P < 0.05). Conclusion DNA immunization against proacrosin elicits an immune response in male mice associated with abnormal sperm functions and reduced fertility. [ABSTRACT FROM AUTHOR]

Problem The aim of this study was to determine if dietary fatty acids (FA) level or isomeric FA type may affect reproductive parameters in mice. Method of study Mice were fed for 1 month diets differing in cisFA ( cFA) content or type of isomeric FA. Resorption, number of fetuses and placental cytokine expression were determined and sperm acrosome reaction was evaluated after induction by calcium ionophore. Results Mice fed high fat diets showed increased fetal resorptions, a decrease in interleukin (IL)-4 placental expression in the first generation and an increase of tumor necrosis factor-α (TNF-α) in the second generation. In this generation, conjugated linoleic acid (CLA) returned TNF-α to normal levels and diminished IL-4 and transforming growth factor-β (TGF-β) expressions; males fed transFA ( tFA) and CLA showed a lower rate of induced acrosome reaction. Conclusion The amount and type of dietary FA may affect reproductive performance in mice by affecting sperm membrane functionality and placental cytokine production. [ABSTRACT FROM AUTHOR]