The Haemophilus influenzae Hia autotransporter harbours two adhesive pockets that reside in the passenger domain and recognize the same host cell receptor.


Journal Article

Haemophilus influenzae is a human-specific pathogen and a major source of morbidity worldwide. Infection with this organism begins with colonization of the nasopharynx, a process that probably depends on adherence to respiratory epithelium. The Hia autotransporter protein is the major adhesin ex-pressed by a subset of non-typeable H. influenzae strains and promotes high-level adherence to a variety of human epithelial cell lines. In the current study, we discovered that the Hia passenger domain contains two distinct binding pockets, including one at the C-terminal end and a second at the N-terminal end. Competition assays revealed that the two binding pockets interact with the same host cell receptor structure, although with differing affinities. Additional experiments demonstrated that both binding domains are required for full-level bacterial adherence. These observations are reminiscent of eukaryotic cell adhesion molecules and highlight the first example of a bacterial adhesin with two domains that participate in a bivalent interaction with identical host cell receptors. Such an interaction increases avidity, thus stabilizing bacterial adherence to the epithelial surface, despite physical forces such as coughing, sneezing and mucociliary clearance.

Full Text

Cited Authors

  • Laarmann, S; Cutter, D; Juehne, T; Barenkamp, SJ; St Geme, JW

Published Date

  • November 2002

Published In

Volume / Issue

  • 46 / 3

Start / End Page

  • 731 - 743

PubMed ID

  • 12410830

Pubmed Central ID

  • 12410830

Electronic International Standard Serial Number (EISSN)

  • 1365-2958

International Standard Serial Number (ISSN)

  • 0950-382X

Digital Object Identifier (DOI)

  • 10.1046/j.1365-2958.2002.03189.x


  • eng