A fine-tuned interaction between trimeric autotransporter haemophilus surface fibrils and vitronectin leads to serum resistance and adherence to respiratory epithelial cells.

ABSTRACT: Haemophilus influenzae type b (Hib) escapes the host immune system by recruitment of the complement regulator vitronectin, which inhibits the formation of the membrane attack complex (MAC) by inhibiting C5b-C7 complex formation and C9 polymerization. We reported previously that Hib acquires vitronectin at the surface by using Haemophilus surface fibrils (Hsf). Here we studied in detail the interaction between Hsf and vitronectin and its role in the inhibition of MAC formation and the invasion of lung epithelial cells. The vitronectin-binding region of Hsf was defined at the N-terminal region comprising Hsf amino acids 429 to 652. Moreover, the Hsf recognition site on vitronectin consisted of the C-terminal amino acids 352 to 374. H. influenzae was killed more rapidly in vitronectin-deplete

SUBMITTER: Singh B 

PROVIDER: S-EPMC4019195 | biostudies-literature | 2014 Jun

REPOSITORIES: biostudies-literature