Monoclonal antibodies against antigens expressed by human sperm

Latheef S, Sharun K, Khurana SK, K. A, Tiwari R, Bhatt P, K. V, Chaicumpa W. Role of Antisperm Antibodies in Infertility, Pregnancy, and Potential forContraceptive and Antifertility Vaccine Designs: Research Progress and Pioneering Vision

Sperm of humans, non-human primates, and other mammalian subjects is considered to be antigenic. The effect of changes in autoimmunity on reproductive cells such as spermatozoa and oocytes play a critical but indistinct role in fertility. Antisperm antibodies (ASAs) are invariably present in both females and males. However, the degree of ASA occurrence may vary according to individual and gender. Although the extent of infertility due to ASAs alone is yet to be determined, it has been found in almost 9-12% of patients who are infertile due to different causes. Postcoital presence of spermatozoa in the reproductive tract of women is not a contributory factor in ASA generation. However, ASA generation may be induced by trauma to the vaginal mucosa, or by anal or oral sex resulting in the deposition of sperm inside the digestive tract. It is strongly believed that, in humans and other species, at least some antibodies may bind to sperm antigens, causing infertility. This form of infertility is termed as immunological infertility, which may be accompanied by impairment of fertility, even in individuals with normozoospermia. Researchers target ASAs for two major reasons: (i) to elucidate the association between ASAs and infertility, the reason ASAs causes infertility, and the mechanism underlying ASA-mediated infertility; and (ii) to assess the potential of ASAs as a contraceptive in humans in case ASAs influences infertility. Therefore, this review explores the potential application of ASAs in the development of anti-spermatozoa vaccines for contraceptive purposes. The usefulness of ASAs for diagnosing obstructive azoospermia, salpingitis, and oligoasthenoteratozoospermia has been reviewed extensively. Important patents pertaining to potential candidates for spermatozoa-derived vaccines that may be utilized as contraceptives are discussed in depth. Antifertility vaccines, as well as treatments for ASA-related infertility, are also highlighted. This review will address many unresolved issues regarding mechanisms involving ASAs in the diagnosis, as well as prognoses, of male infertility. More documented scientific reports are cited to support the mechanisms underlying the potential role of ASA in infertility. The usefulness of sperm antigens or ASAs (recombinant) in human and wild or captive animal contraceptive vaccines has been revealed through research but is yet to be validated via clinical testing.

Evaluation of the acrosome reaction using monoclonal antibodies against different acrosomal antigens--comparison with the triple stain technique

The acrosome reaction of human sperm was evaluated in vitro with the aid of there monoclonal antibodies TüS-1, TüS-19 and TüS-20, which react with antigens in the anterior part of the acrosome. Data were compared with results obtained using the triple stain technique. Seminal smears were performed prior to, and following incubation for 5 and 24 h in Hams-F10 containing 3% human serum albumin. Using the triple stain technique, 15.2 +/- 7.1% of sperm exhibited acrosome activation after 5 h and 16.8 +/- 8.4% after incubation for 24 h. The corresponding values obtained using antibody TüS-1 were 12.9 +/- 5.8 and 13.2 +/- 2.2%, with TüS-19 10.1 +/- 3.8 and 10.8 +/- 1.4% and with TüS-20, 9.0 +/- 3.4 and 10.4 +/- 2.9%. When the same sperm smears were stained firstly with rose Bengal, and secondly with TüS-1 both methods stained the same cells and the same region of the cells, thus indicating that both methods stain the same substrate. Staining of the acrosome with monoclonal antibodies gives clearer results than the triple stain technique, and could be used in preference in future studies dealing with diagnosis of the acrosome reaction in vitro.