Evaluation of Testicular Sperm CRISP2 as a Potential Target for Contraception.

WEIGEL MUÑOZ, M; ERNESTO JI,; BLUGUERMANN C; BUSSO, D; AGUSTINA BATTISTONE; COHEN DJ; CUASNICÚ PS

JOURNAL OF ANDROLOGY

AMER SOC ANDROLOGY, INC

Año: 2012 vol. 33 p. 1360 - 1370

0196-3635

CRISP2 (Cysteine Rich Secretory Protein 2) is a testicular sperm proposed to be involved in 23 fertilization. With the aim of examining the relevance of CRISP2 for fertility and its potential use 24 as a target for contraception, in the present work, male and female rats were immunized with 25 recombinant CRISP2 coupled to Maltose Binding Protein (MBP) and evaluated for their 26 subsequent fertility. As controls, animals were injected with either MBP or recombinant 27 CRISP1. ELISA of sera collected at different intervals after immunization indicated that CRISP2 28 immunization raised specific antibodies in both sexes with levels that increased as a function of 29 time. Western blot studies revealed that anti-CRISP2 sera were capable of recognizing CRISP2 30 in testicular, epididymal and sperm extracts while histological studies showed no evidence of 31 autoimmune orchitis or epididymitis. Indirect immunofluorescence experiments revealed the 32 ability of anti-CRISP2 sera to recognize the native sperm protein in fresh, capacitated and 33 ionophore-induced acrosome reacted cells. Moreover, anti-CRISP2 sera significantly inhibited 34 the sperm ability to penetrate zona-free eggs, confirming the role of CRISP2 in rat gamete 35 fusion. In spite of the presence of circulating anti-CRISP2 antibodies capable of inhibiting the 36 sperm fertilizing ability, mating studies revealed no effects of CRISP2 immunization on male or 37 female fertility in contrast to the significant inhibition observed in both sexes in animals injected 38 with CRISP1. Together, these observations indicated the immunogenic properties of testicular 39 CRISP2 but do not support CRISP2 as a target for immunocontraception or as a molecule 40 responsible for generating autoimmune orchitis or immunoinfertility.