Beta 1 -integrins of spermatozoa: a flow cytophotometric analysis

The expression of adhesion molecules on human ejaculated spermatozoa was investigated by means of flow cytophotometry using monoclonal antibodies against eight different adhesion molcules. Spermatozoa from infertility patients who exhibited normal semen parameters showed specific fluorescence after incubation with antibodies against very late antigens VLAα4, VLAα 5, VLAα 6, and corresponding matrix proteins laminin and fibronectin. Semen samples from men with teratozoospermia or oligoasthenoteratozoospermia were characterized by reduced expression of adhesion molecules. Normal and pathological semen samples differed mostly in the expression of VLAα5. After artificial induction of the acrosome reaction by a cold shock method and incubation with 2 mM Ca²⁺, a changed pattern of adhesion molecules on the sperm surface was found for VLAα6 as the most prominent molecule. After treatment of spermatozoa with 0.10% Triton X-100, the number of cells with adhesion molecules increased significantly. This result suggests that adhesion molecules are an integral part of sperm structure.