CD8-like molecules on human spermatozoa

The object of the present study was to investigate whether there were differences in the presence of CD8-like molecules on human ejaculated spermatozoa from fertile donors and subfertile patients (with leucocytospermia). In our previous report we defined CD4-like molecule heterogeneity on normozoospermic and globozoospermic human spermatozoa. In this investigation the results from indirect and absorption ELISA, as well as the indirect IEM and IIF findings, demonstrated the presence of CD8 immunopositive spermatozoa in all samples studied. The ELISA data showed that anti-human MoAb CD8 recognized an epitope common to the human spermatozoa with normal morphology and foetal thymocytes. During absorption experiments MoAb CD8 was preincubated with spermatozoa and allowed to react with thymocytes. A significant decrease of the reactivity was obtained for MoAb CD8 by ELISA. Localization of the antigenic determinants, identified by MoAb CD8, in the acrosomal region, in the neck and on the sperm-tail plasma membrane was defined in normozoospermic samples. Similar in localization but different in intensity, CD8-like sperm immunoreactivity was found in leucocytospermic samples in comparison to normozoospermic samples. The obtained results proved the heterogeneity in the presence, localization and expression of CD-like antigen determinants on human spermatozoa and enlarged the information about CD8-like antigen characteristics of the spermatozoa from fertile donors and subfertile patients.