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

Singh, B; Su, YC; Al-Jubair, T; Mukherjee, O; Hallström, T; Mörgelin, M; Blom, AM; Riesbeck, K

HERO ID

2902766

Reference Type

Journal Article

Year

2014

Language

English

PMID

24664511

HERO ID 2902766
In Press No
Year 2014
Title A fine-tuned interaction between trimeric autotransporter haemophilus surface fibrils and vitronectin leads to serum resistance and adherence to respiratory epithelial cells
Authors Singh, B; Su, YC; Al-Jubair, T; Mukherjee, O; Hallström, T; Mörgelin, M; Blom, AM; Riesbeck, K
Journal Infection and Immunity
Volume 82
Issue 6
Page Numbers 2378-2389
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-depleted serum than in normal human serum (NHS), and increased MAC deposition was observed at the surface of an Hsf-deficient H. influenzae mutant. In parallel, Hsf-expressing Escherichia coli selectively acquired vitronectin from serum, resulting in significant inhibition of the MAC. Moreover, when vitronectin was bound to Hsf, increased bacterial adherence and internalization into epithelial cells were observed. Taking our findings together, we have defined a fine-tuned protein-protein interaction between Hsf and vitronectin that may contribute to increased Hib virulence.
Doi 10.1128/IAI.01636-13
Pmid 24664511
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English