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Presence and Incidence of Izumo Antibodies in Sera of Immunoinfertile Women and Men
Author(s) -
Clark Sydney,
Naz Rajesh K.
Publication year - 2013
Publication title -
american journal of reproductive immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.071
H-Index - 97
eISSN - 1600-0897
pISSN - 1046-7408
DOI - 10.1111/aji.12060
Subject(s) - sperm , epitope , western blot , antibody , semen , antigen , incidence (geometry) , biology , andrology , immunology , medicine , genetics , gene , physics , optics
Problem Sperm antigens that are relevant to fertilization and fertility, and are involved in human immunoinfertility, are being investigated in several laboratories. Izumo is a sperm‐specific protein that has shown to be essential for sperm‐egg fusion. The present study was conducted to examine the expression of I zumo protein in human sperm. Also, the presence and incidence of I zumo antibodies in sera of immunoinfertile women and men were investigated. Method of study The expression of Izumo protein in human sperm was examined by the W estern blot procedure. Sera from immunoinfertile women ( n = 25) and fertile women ( n = 23), as well as sera from immunoinfertile men ( n = 20) and fertile men ( n = 15), were collected and analyzed for immunoreactivity with I zumo peptides in the enzyme‐linked immunosorbent assay ( ELISA ). Three epitopes of human I zumo, namely one epitope of I zumo1, and two epitopes of I zumo2 [ I zumo2 ( K ‐15), and I zumo2 ( T ‐17)], respectively, were selected for the present study. Results In the W estern blot procedure, the I zumo1 antibody recognized a specific protein band of ~39 kD a in human sperm extract. In ELISA , 56% of the immunoinfertile female sera reacted positively (≧3 S.D. units) with Izumo1, 40% with I zumo2 ( K ‐15), and 20% with I zumo2 ( T ‐17) peptide. None of the sera (0%) from fertile women reacted positively (≦3 S.D. units) with any of the three I zumo peptides. None of the sera from immunoinfertile (0%) or fertile men (0%) reacted positively with any of the three I zumo peptides. Conclusion Our findings indicate that human sperm expresses I zumo protein, and the immunoinfertile female sera have circulating isoantibodies against this protein. This is the first study to our knowledge, which examined the presence and incidence of I zumo antibodies in female and male immunoinfertility. These findings may find clinical applications in specific diagnosis and treatment of infertility, and contraceptive vaccine development.