ANTI-ADHESIN ANTIBODIES THAT RECOGNIZE A RECEPTOR-BINDING MOTIF (ADHESINTOPE) INHIBIT PILUS FIMBRIAL-MEDIATED ADHERENCE OF PSEUDOMONAS-AERUGINOSA AND CANDIDA-ALBICANS TO ASIALO-GM(1) RECEPTORS AND HUMAN BUCCALEPITHELIAL-CELL SURFACE-RECEPTORS/

Pseudomonas aeruginosa and Candida albicans were reported to adhere to the glycosphingolipid asialo-GM(1) by means of pill and fimbriae, res pectively. These diverse adhesins have been previously reported to hav e an immunologically conserved antigenic epitope and the role of this cross-reactive epitope in adherence to asialo-GM1 was investigated in this study. Both the unbiotinylated PAK pilus and fimbrial adhesins in hibited biotinylated pill from P. aeruginosa PAK and biotinylated C. a lbicans fimbriae binding to asialo-GM(1) and receptors present on huma n buccal epithelial cells (BECs), which suggested that the same recept or sites were recognized by the two adhesins. Monoclonal antibodies PK 99H and Fm16 raised against the P. aeruginosa PAK pili and C. albicans fimbriae, respectively, recognized a conserved epitope present on the two adhesins. Both Fm16 and PK99H blocked fimbriae binding to asialo- GM(1) and BEC receptors and also inhibited P. aeruginosa and C. albica ns whole cell binding to BECs. These data suggested that the conserved epitope confers receptor-binding properties to the adhesins, demonstr ated that (i) asialo-GM(1)-like receptors present on epithelial cell s urfaces are utilized by the pilus and fimbrial adhesins and (ii) the b inding to these glycoreceptors is mediated by a conserved epitope that has receptor-binding properties.