A positive correlation between expression of β1-integrin cell adhesion molecules and fertilizing ability of human spermatozoa in vitro

The purpose of this study was to investigate firstly whether β1-integrin cell adhesion molecules are expressed by human spermatozoa, and secondly whether there is any relationship between the expression of β1-integrin cell adhesion molecules and the fertilizing ability of human spermatozoa in vitro. A total of 50 semen samples were examined. The samples were obtained from the male partners of couples undergoing in-vitro fertilization (IVF) for either unexplained, tubal or male factor infertility. A panel of six monoclonal antibodies against p1-integrin cell adhesion molecules and immunohistochemical techniques were used to identify the presence of these molecules on the spermatozoa. The percentage of spermatozoa showing strong immunolabelling with each monoclonal antibody was assessed in each sample. The relationship between these results and the aetiology of infertility and incidence of fertilization was examined. β1-lntegrins, and primarily the ones with α4-, α5- and α6-chains, were expressed by human spermatozoa. Compared with semen samples from unexplained or male factor infertility patients, samples from tubal infertility patients had a significantly higher (P < 0.05) percentage of spermatozoa expressing adhesion molecules. There was a positive correlation between the expression of α4, α5 and α6 adhesion molecules and the fertilizing ability of spermatozoa. The positive correlation between the presence of certain β1-integrin cell adhesion molecules and the fertilizing ability of human spermatozoa suggests that integrins may be putative determinants in egg—sperm recognition and interaction.