ATTACHMENT OF NONTYPABLE HAEMOPHILUS-INFLUENZAE TO HUMAN PHARYNGEAL EPITHELIAL-CELLS MEDIATED BY A GANGLIOSIDE RECEPTOR

Nontypable Haemophilus influenzae (NTHI) is one of the major pathogens of human respiratory infections and has the ability to attach to phar yngeal epithelial cells, We characterized the epithelial cell receptor to which NTHI bind. Neuraminidase pretreatment of pharyngeal epitheli al cells resulted in a significant decrease in NTHI attachment, sugges ting sialic acid as an important component of the receptor, The attach ment was not decreased in NTHI pretreated with 1,000 mu g/ml of fucose , N-acetyl-neuraminic acid, N-acetyl-glucosamine, N-acetyl-galactosami ne, acetyl-salicylic acid and colominic acid. Only treatment with gang liosides D1a, D1b and D2 at a concentration of 12.5 mu g/ml significan tly decreased the attachment. On the other hand, treatment with gangli osides M1, M2, M3, D3, T1b and asialoganglioside M1 did not decrease t he attachment of NTHI, Only ganglioside D2 inhibited the attachment si gnificantly at a concentration of 12.5 ng/ml, Other isolates of NTHI s howed a decrease in attachment after treatment with ganglioside D2, Tr eatment of cells with anti-human GD2 monoclonal antibody also decrease d the attachment of NTHI in a dose-dependent manner, This study indica tes that sialic acid glycoconjugate, GD2, is one of the receptors of N THI on human pharyngeal epithelial cells.