Evidence for alpha v beta 3 and alpha v beta 5 integrin-like vitronectin (VN) receptors in Candida albicans and their involvement in yeast cell adhesion to VN

The expression of integrin vitronectin (VN) receptors on Candida albicans y easts and their involvement in the adhesion to VN were investigated. By; im munofluorescence and cytofluorimetric analysis, several antibodies directed against human alpha v, beta 3, beta 5, alpha v beta 3, or alpha v beta 5 i ntegrin positively stained C. albicans yeasts. Biochemical analysis on yeas t lysates with anti-human alpha v, beta 3, or beta 5 antibody revealed mole cular species of 130, 110, 100, and 84 kDa. The 130-kDa band was identified as Mr,whereas the doublet of 110/100 kDa and the 84-kDa band likely corres pond to the beta 3 and beta 5 subunits, respectively. Some 48%-54% of Candi da yeasts specifically adhered to VN, and this binding was strongly inhibit ed by anti-human alpha v, beta 3, alpha v beta 3, and alpha v beta 5 antibo dies and by RGD- but not RGE-containing peptides. In addition, VN inhibited C. albicans adherence to a human endothelial cell Une. Thus, C. albicans i n the yeast phase expresses VN receptors antigenically related to the verte brate alpha v beta 3 and alpha v beta 5 integrins, which mediate its adhesi on to VN.