The Haemophilus influenzae Hap serine protease promotes adherence and microcolony formation, potentiated by a soluble host protein.


Journal Article

Haemophilus influenzae initiates infection by colonizing the upper respiratory mucosa. The process of colonization involves adherence to epithelium and evasion of host immunity. In this study, we examined the H. influenzae Hap adhesin, which has serine protease activity and undergoes autoproteolytic cleavage and extracellular release in broth. We found that the uncleaved cell-associated form of Hap mediates adherence to cultured epithelial cells and promotes bacterial aggregation and microcolony formation. Adherence and aggregation are augmented by secretory leukocyte protease inhibitor, a natural component of respiratory secretions that inhibits Hap autoproteolysis. These observations suggest a novel paradigm in host-pathogen relations, in which a soluble host protein whose primary function is to protect host epithelium potentiates properties that facilitate bacterial colonization.

Full Text

Cited Authors

  • Hendrixson, DR; St Geme, JW

Published Date

  • December 1998

Published In

Volume / Issue

  • 2 / 6

Start / End Page

  • 841 - 850

PubMed ID

  • 9885571

Pubmed Central ID

  • 9885571

Electronic International Standard Serial Number (EISSN)

  • 1097-4164

International Standard Serial Number (ISSN)

  • 1097-2765

Digital Object Identifier (DOI)

  • 10.1016/s1097-2765(00)80298-1


  • eng