EVALUATION OF TESTICULAR SPERM CRISP2 AS A POTENTIAL TARGET FOR CONTRACEPTION

WEIGEL MUÑOZ MARIANA ; ERNESTO JUAN I. ; BLUGUERMANN CAROLINA; BUSSO DOLORES ; BATTISTONE MARÍA A.; COHEN DÉBORA J. ; CUASNICÚ PATRICIA S.

JOURNAL OF ANDROLOGY

AMER SOC ANDROLOGY, INC

Año: 2012 p. 1360 - 1370

0196-3635

CRISP2 (Cysteine Rich Secretory Protein 2) is a testicular sperm proposed to be involved in fertilization. With the aim of examining the relevance of CRISP2 for fertility and its potential use as a target for contraception, in the present work, male and female rats were immunized with recombinant CRISP2 coupled to Maltose Binding Protein (MBP) and evaluated for their subsequent fertility. As controls, animals were injected with either MBP or recombinant CRISP1. ELISA of sera collected at different intervals after immunization indicated that CRISP2 immunization raised specific antibodies in both sexes with levels that increased as a function of time. Western blot studies revealed that anti-CRISP2 sera were capable of recognizing CRISP2 in testicular, epididymal and sperm extracts while histological studies showed no evidence of autoimmune orchitis or epididymitis. Indirect immunofluorescence experiments revealed the ability of anti-CRISP2 sera to recognize the native sperm protein in fresh, capacitated and ionophore-induced acrosome reacted cells. Moreover, anti-CRISP2 sera significantly inhibited the sperm ability to penetrate zona-free eggs, confirming the role of CRISP2 in rat gamete fusion. In spite of the presence of circulating anti-CRISP2 antibodies capable of inhibiting the sperm fertilizing ability, mating studies revealed no effects of CRISP2 immunization on male or female fertility in contrast to the significant inhibition observed in both sexes in animals injected with CRISP1. Together, these observations indicated the immunogenic properties of testicular CRISP2 but do not support CRISP2 as a target for immunocontraception or as a molecule responsible for generating autoimmune orchitis or immunoinfertility.