The HMW2 adhesin of non-typeable Haemophilus influenzae is a human-adapted lectin that mediates high-affinity binding to 2–6 linked N-acetylneuraminic acid glycans

• DOI: 10.1016/j.bbrc.2018.06.126
• Publication Date: 2018-06-27T22:23:16Z
• Authors: John M. Atack; Christopher J. Day; Jessica Poole; Kenneth L. Brockman; Lauren O. Bakaletz; Stephen J. Barenkamp; Michael P. Jennings
• Keywords: Phase variation; N-Acetylneuraminic acid; Glycoconjugate; Glycobiology

Non-typeable Haemophilus influenzae (NTHi) is a human-adapted bacterial pathogen, responsible for infections of the human respiratory tract. This pathogen expresses range adhesins that mediate binding to host cells. Most NTHi strains can express related HMW1 and HMW2. Expression HMW proteins phase-variable: changes in length simple-sequence repeats located encoding genes promoter regions results expression levels these adhesins. also controlled by epigenetic regulation. has been previously demonstrated bind α 2–3 sialyl-lactosamine, but affinity this interaction not investigated. The receptor(s) HMW2 currently unknown. We hypothesized glycans may act as receptors HMW2-mediated adherence. examined glycan-binding activity using glycan arrays Surface Plasmon Resonance (SPR). These studies demonstrate binds 2–6 linked N-acetylneuraminic acid with high affinity. did structures containing non-human form sialic acid, N-glycolylneuraminic acid. Thus, specificity have complementary lectin activities allow distinct niches host.