Characterization of Human Sperm Antigens Reacting with Sperm Antibodies from Autologous Serum and Seminal Plasma in an Infertile Population1

Abstract

Immunoblotting techniques were used to characterize the reactivity of human sperm antigens with sperm antibodies from an infertile population. Sperm antigens of each individual were tested with autologous sperm antibodies present in serum and seminal plasma in order to construct a preliminary map of the antigens of the infertile spermatozoon and to compare the qualitative differences in the antigenic profile between fertile and infertile subjects. A total of 61 infertile males, comprising 51 subjects having poor semen quality and 10 subjects with no abnormalities in semen analysis, entered the study; 55 subjects with proven fertility served as controls. Infertile subjects often showed specific immunoreactivity to 50-, 55-, 57-, 62-, and 72-kDa proteins in serum and to 57- and 62-kDa proteins in seminal plasma. As to comparison of immunoreactivities between fertile and infertile individuals, the sperm antigens may be divided into three groups. Group 1 antigens (50-, 69-, and 72-kDa proteins) were recognized by sperm antibodies present in both populations; group 2 antigens (57- and 62-kDa proteins), by sperm antibodies typical of the infertile population; group 3 antigens (45-, 55-, and 85-kDa proteins), by sperm antibodies typical of the fertile population. This classification shows that the infertile spermatozoon differs substantially at the immunogenic level from the fertile spermatozoon. The group 2 antigens seem to be involved in a relevant step in the reproductive process and hence have been termed "fertility-related antigens."

In vitro and in vivo studies evaluating antisemen antibodies as a potential spermicidal agent in hamsters

“…There are numerous antigens present on the surface and internally in sperm that are shared with somatic cells. Thus, immunization with the whole sperm can cause immunopathologic consequences in other tissues and organs (21). Nevertheless, it should immobilize sperm and not cause immunopathologic consequences if ASAs were placed into vagina directly.…”

Naturally-occurring antisperm antibodies in men: interference with fertility and implications for treatment

“…With this assumption, the study of clinical infertility due to ASA, regarded as "experiments of nature" in fertility reduction, has been approached to identify candidate sperm antigens for immunocontraceptive development (193,194). Numerous investigators have reported the identification of specific antigens using sera from WHO reference bank or from independent collections (106,(195)(196)(197)(198)(199)(200)(201)(202)(203)(204)(205)(206). However, characterization of sperm antigens was limited to SDS-Page in most studies, and results varied widely due to the methods and reagents employed.…”

Differential extraction and enrichment of human sperm surface proteins in a proteome: Identification of immunocontraceptive candidates

“…Studies of monoclonal and polyclonal antibodies which block sperm function have led to the identification of several candidate sperm immunogens [7][8][9]. Similarly, immunoblotting with sera from infertile men and women with antisperm antibodies has aided in the identification of sperm components, that are immunogenic in humans and associated with infertility [4,[10][11][12][13][14]. A comprehensive analysis of the full range of potential human sperm surface immunogens was initiated by Naaby-Hansen et al [15] utilizing 2-D gel electrophoresis to create a digitized sperm protein encyclopedia (proteome).…”