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Binding of albumin promotes bacterial survival at the epithelial surface.

Egesten, Arne LU ; Frick, Inga-Maria LU ; Mörgelin, Matthias LU ; Olin, Anders LU and Björck, Lars LU (2011) In Journal of Biological Chemistry Dec. p.2469-2476
Abstract
Albumin (HSA) is the dominating protein in human plasma. Many bacterial species, especially streptococci, express surface proteins that bind HSA with high specificity and affinity, but the biological consequences of these protein-protein interactions are poorly understood. Group G streptococci (GGS), carrying the HSA-binding protein G, colonize the skin and the mucosa of the upper respiratory tract, mostly without causing disease. In case of bacterial invasion, pro-inflammatory cytokines are released that activate the epithelium to produce antibacterial peptides, in particular the chemokine MIG/CXCL9. In addition, the inflammation causes capillary leakage and extravasation of HSA and other plasma proteins; environmental changes at the... (More)
Albumin (HSA) is the dominating protein in human plasma. Many bacterial species, especially streptococci, express surface proteins that bind HSA with high specificity and affinity, but the biological consequences of these protein-protein interactions are poorly understood. Group G streptococci (GGS), carrying the HSA-binding protein G, colonize the skin and the mucosa of the upper respiratory tract, mostly without causing disease. In case of bacterial invasion, pro-inflammatory cytokines are released that activate the epithelium to produce antibacterial peptides, in particular the chemokine MIG/CXCL9. In addition, the inflammation causes capillary leakage and extravasation of HSA and other plasma proteins; environmental changes at the epithelial surface to which the bacteria need to respond. In this study, we find that GGS adsorb HSA from both saliva and plasma via binding to protein G, and that HSA bound to protein G binds and inactivates the antibacterial MIG/CXCL9 peptide. Another surface protein of GGS, FOG, was found to mediate adherence of the bacteria to pharyngeal epithelial cells through interaction with glycosaminoglycans. This adherence was not affected by the activation of the epithelium with a combination of IFN-γ and TNF-α, leading to the production of MIG/CXCL9. However, at the activated epithelial surface, adherent GGS were protected against killing by MIG/CXCL9 through protein G dependent HSA-coating. The findings identify a previously unknown bacterial survival strategy that help to explain the evolution of HSA-binding proteins among bacterial species of the normal human microbiota. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Biological Chemistry
volume
Dec
pages
2469 - 2476
publisher
ASBMB
external identifiers
  • wos:000286464300011
  • pmid:21098039
  • scopus:78951468815
ISSN
1083-351X
DOI
10.1074/jbc.M110.148171
language
English
LU publication?
yes
id
6a0b01e8-cd77-48a4-8e21-f21a18e3d125 (old id 1731663)
alternative location
http://www.ncbi.nlm.nih.gov/pubmed/21098039?dopt=Abstract
date added to LUP
2010-12-01 13:44:49
date last changed
2017-08-27 05:43:05
@article{6a0b01e8-cd77-48a4-8e21-f21a18e3d125,
  abstract     = {Albumin (HSA) is the dominating protein in human plasma. Many bacterial species, especially streptococci, express surface proteins that bind HSA with high specificity and affinity, but the biological consequences of these protein-protein interactions are poorly understood. Group G streptococci (GGS), carrying the HSA-binding protein G, colonize the skin and the mucosa of the upper respiratory tract, mostly without causing disease. In case of bacterial invasion, pro-inflammatory cytokines are released that activate the epithelium to produce antibacterial peptides, in particular the chemokine MIG/CXCL9. In addition, the inflammation causes capillary leakage and extravasation of HSA and other plasma proteins; environmental changes at the epithelial surface to which the bacteria need to respond. In this study, we find that GGS adsorb HSA from both saliva and plasma via binding to protein G, and that HSA bound to protein G binds and inactivates the antibacterial MIG/CXCL9 peptide. Another surface protein of GGS, FOG, was found to mediate adherence of the bacteria to pharyngeal epithelial cells through interaction with glycosaminoglycans. This adherence was not affected by the activation of the epithelium with a combination of IFN-γ and TNF-α, leading to the production of MIG/CXCL9. However, at the activated epithelial surface, adherent GGS were protected against killing by MIG/CXCL9 through protein G dependent HSA-coating. The findings identify a previously unknown bacterial survival strategy that help to explain the evolution of HSA-binding proteins among bacterial species of the normal human microbiota.},
  author       = {Egesten, Arne and Frick, Inga-Maria and Mörgelin, Matthias and Olin, Anders and Björck, Lars},
  issn         = {1083-351X},
  language     = {eng},
  pages        = {2469--2476},
  publisher    = {ASBMB},
  series       = {Journal of Biological Chemistry},
  title        = {Binding of albumin promotes bacterial survival at the epithelial surface.},
  url          = {http://dx.doi.org/10.1074/jbc.M110.148171},
  volume       = {Dec},
  year         = {2011},
}