Involvement of alpha v beta 3 integrin-like receptor and glycosaminoglycans in Candida albicans germ tube adhesion to vitronectin and to a human endothelial cell line

The present study was undertaken to investigate the expression of alphav be ta3 and alphav beta5 integrin-like vitronectin receptors (VNRs) on Candida albicans germ tube and their involvement in its adhesion to vitronectin (VN ) and human endothelial cells. By immunofluorescence and FACS analysis, sev eral monoclonal antibodies directed against human alphav or beta3 integrin subunit or alphav beta3 and alphav beta5 heterodimers, positively stained C . albicans germ tubes. C. albicans germ tubes specifically adhered (45-50%) to VN and this adhesion was markedly inhibited by RGD-, but not RGE-contai ning peptides. Adhesion of C. albicans germ tubes to VN was strongly inhibi ted by anti-alphav, anti-beta3 or anti-alphav beta3, but not by alphav beta 5 monoclonal antibody. C. albicans germ tube adhesion to VN was also inhibi ted by glycosaminoglycans (GAGs) such as heparin or chondroitin sulphate. F inally, we show that C. albicans germ tubes adhere to the human EA.hy 926 e ndothelial cell line. This adhesion is markedly blocked by anti-beta3 monoc lonal antibody, GRGDSP peptide or heparin, and is completely abolished by t heir combination. Overall these results indicate that C. albicans germ tube adherence to VN and to a human endothelial cell line is mediated by alphav beta3, but not by alphav beta5-like integrin, and depends on GAGs which ma y act by regulating alphav beta3 integrin-like/VN adhesive interaction. (C) 2001 Academic Press.