Inhibition of mouse acrosome reaction and sperm-zona pellucida binding by anti-human sperm membrane protein 1 antibody

Aim： To investigate the possible functions of human sperm membrane protein （hSMP-1） in the process of fertilization. Methods： A 576-bp cDNA fragment of HSD-1 gene coding for the extracellular domain of hSMP-1 was cloned and expressed. The localization of this protein on human and mouse sperm was determined by indirect immunofluorescent staining by using anti-recombinant hSMP-1 （anti-rhSMP-1） antibodies. Sperm acrosome reaction and spermzona pellucida （ZP） binding assay were carried out in 10-week-old BALB/c mice. Results： Recombinant hSMP-1 was successfully cloned and expressed. The expression of the native protein was limited on the acrosome of human and mouse sperm. Treatment of anti-rhSMP-1 antibodies significantly decreased the average number of sperms bound to each egg. Meanwhile, the percentage of acrosome reaction was decreased in comparison to pre-immune control after treatment with anti-rhSMP-1 （P 〈 0.05）. Conclusion： The results suggest that anti-rhSMP-1 antibody inhibited mouse acrosome reaction and sperm-ZP binding.

The antibody against a nuclear autoantigenic sperm protein can result in reproductive failure

To study whether the antibody against the testis form of the nuclear autoantigenic sperm protein(tNASP)could result in reproductive failure,we successfully cloned and expressed a 339-bp cDNA fragment of mouse tNASP(mtNASP).Using mouse as a model,recombinant mtNASP(rmtNASP)and a synthetic peptide,human tNASP393-408(htNASP393-408),were investigated for their antifertility effect.Active immunization with rmtNASP or the synthesized peptide raised high antibody titers in the immunized mice.Sperm-egg binding and fusion assay were carried out in 8-10-week-old BALB/c mice.Sperm-egg binding and in vitro fertilization of mouse oocytes were inhibited by co-incubation of zona-free mouse oocytes with capacitated mouse spermatozoa in the presence of varying concentrations of the antisera against rmtNASP.There was a significant antifertility effect in animals immunized with rmtNASP or the synthesized peptide.The effect on fertility in the mice immunized with the synthesized peptide was reversible.Our data indicate that active immunization with rmtNASP antigen may induce a strong antibody response that causes an inhibition of fertility.

Corrigendum to ＂The antibody against a nuclear autoantigenic sperm protein can result in reproductive failure＂ by M. Wang et al.

In published paper by M. Wang et al [1], the Table 2 in page 186 was inadvertently misrepresented. The correct statistical method of the average litter size and standard error should count all animals （including non-pregnant which were considered to have zero pups） whereas we had included only mice that had been pregnant previously. Now, the correct representation of Table 2 should be：