Temporal Appearance of Antisperm Antibodies during Sexual Maturation of Rats after Obstruction of the Vas Deferens

Sperm protein autoantigens recognized by serum antisperm autoantibodies during development following vas deferens obstruction were studied using western blot analysis. At age 10 days, rats in an obstructed group underwent bilateral ligation and division of the vas deferens, whereas animals assigned to a sham group received a sham operation. At ages 14, 21, 35, 56, 91, and 128 days, rats were sacrificed and blood samples were obtained. Sperm antigens were recognized infrequently and with low intensity by most sera obtained at ages 14 through 56 days. Subsequently, the incidence as well as the intensity of staining of antigens in blots increased at 91‐and 128‐day intervals in obstructed animals. The increase in antisperm antibodies correlated with the appearance of sperm throughout the epididymis at approximately 56 days postnatally. A set of autoantigens including proteins migrating at 82‐78, 76‐73, 68, 57, 54, 48, 44, 42, 38–42, 36, and 22 kDa were recognized with the highest frequency and intensity after puberty. A 42‐kDa protein appeared to be one of the first autoantigens recognized when obstructed animals underwent sexual maturation. Although individual animals recognized different patterns of sperm autoantigens, a repertoire of 10–12 autoantigens dominated the antisperm antibody response when obstructed animals underwent sexual maturation.

Sperm Autoantigens Recognized by Autoantibodies in Developing Rats Following Prepubertal Obstruction of the Vas Deferens

FLICKINGER,

BARAN,

HOWARDS

et al. 1996

Morphometric and Immunocytochemical Study of the Fetal, Infant, and Adult Human Vas Deferens

REGADERA,

ESPAÑA,

ROIAS

et al. 1997

The human vas deferens (VD) is often considered simply as a conduit to transfer mature sperm from the epididymis to the ejaculatory duct. The cells that make up the epithelium of the VD, however, exhibit many characteristics of cells found in more complex epithelia, which are involved in absorption and/or secretion. In the present investigation, morphometry was utilized to characterize in detail the changes incurred by the human VD during its development, growth, and aging and to determine if these changes correlate with testicular maturation. In addition, the specific types of keratins present in the epithelial cells were defined, as well as desmin distribution in the muscular layers, during the various phases of the development, growth, and involution of the human VD. Results of the morphometric study are consistent with the interpretation that the development, growth, and aging of the VD are delayed, but parallel to, the identical phases exhibited by the human testis. Further, a differential expression of distinct keratin types was observed in the VD during the various phases examined in this study. Taken together, these two correlations may suggest that the VD is unlikely to function solely as a conduit for sperm. The rationale for this interpretation is as follows: 1) the complex developmental and maturational changes measured in the present investigation in the human VD are common to other absorptive and/or secretory epithelia; and 2) these changes parallel developmental changes observed in other androgen‐dependent epithelia of the male reproductive tract, which also function to contribute components to seminal fluid as well as to provide a conduit for sperm.

Epididymal Obstruction During Development Results in Antisperm Autoantibodies at Puberty in Rats

FLICKINGER,

BARAN,

HOWARDS

et al. 1998

An autoimmune response to sperm occurs after vasectomy, but there is little information on whether similar reactions occur after obstruction of the male reproductive tract at other points. Male Lewis rats received bilateral ligation of the corpus epididymidis or a sham operation at age 10 days, and the subsequent systemic antisperm autoantibody responses were compared to those observed following obstruction of the vas deferens. After sexual maturation, rats with epididymal ligations had antisperm antibodies on an enzyme‐linked immunosorbent assay that were significantly higher than those of sham‐operated animals and did not differ from antibody levels in vasectomized rats at the same ages. Western blot analysis showed that certain sperm proteins were recognized by antisperm antibodies after both epididymal ligation and vasectomy, including the previously identified “dominant” autoantigens at 73–83, 68–72, 48, 42, and 22 kDa. On the other hand, sera from rats with epididymal ligations recognized 60 and 52 kDa proteins that were not bound by most postvasectomy sera. Conversely, 42–48 and 38–42 kDa bands were more strongly and frequently stained after vasectomy than after epididymal ligation. The results demonstrate that antisperm antibodies are produced after obstruction of the epididymis and that the magnitude of the response is comparable to that after vasal obstruction. Differences in autoantigens recognized after epididymal and vasal obstructions may reflect maturational changes in sperm components that take place during the passage of spermatozoa through the epididymis.