LOCALIZATION OF ADHESION MOLECULES ON HUMAN SPERMATOZOA BY FLUORESCENCE MICROSCOPY

The expression of adhesion molecules on human spermatozoa of healthy p robands was analysed. The localization patterns of adhesion molecules (AM) on the spermatozoal surface were documented by fluorescence micro scopy. Spermatozoa were incubated with antibodies against alpha 1 (CD4 9a), alpha 2 (CD49b), alpha 3 (CD49c), alpha 4 (CD49d), alpha 5 (CD49e ), alpha 6 (CD49f) chains of beta 1 integrins, beta 1 (CD29), beta 2 ( CD18), alpha V (CD51), beta 3 (CD61) and beta 4 integrin chains, the L FA-3 (Lymphocyte function antigen, CD58) from the immunoglobulin super family and the extracellular matrix proteins laminin, fibronectin and collagen IV. For collagen IV, alpha 1 and alpha 2 chains no expression could be noticed. Laminin was detected at the acrosomal membrane, fib ronectin and beta 4 chain mainly at the equatorial membrane. The fibro nectin receptors alpha 3, alpha 4 and alpha 5 chains of the beta 1 int egrins were mainly located on acrosomal and equatorial membrane areas. Laminin receptor alpha 6 chain was located postacrosomal and less fre quently acrosomal. beta 2 chain and vitronectin receptors alpha V and beta 3 chains had a mainly postacrosomal localization pattern. LFA-3 w as found constantly on postacrosomal membrane areas. Double staining t echnique was used to prove the simultaneous occurrence of fibronectin and its integrin receptors alpha 3, alpha 4 and alpha 5 chains and of alpha V and beta 2 chains on spermatozoa. The localization patterns of integrins on double stained spermatozoa were similar to the patterns described for single stained spermatozoa. The localization of fibronec tin appeared to be influenced by the presence of integrins: the typica l equatorial fibronectin band disappeared in case of an equatorial loc alization of integrins.