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A novel interaction between type IV pili of Neisseria gonorrhoeae and the human complement regulator C4B-binding protein

Blom, Anna M.; Rytkönen, Anne; Vasquez, Paola; Lindahl, Gunnar LU ; Dahlbäck, Björn LU and Jonsson, Ann-Beth (2001) In Journal of Immunology 166(11). p.6764-6770
Abstract
C4b-binding protein (C4BP) is an important plasma inhibitor of the classical pathway of complement activation. Several bacterial pathogens bind C4BP, which may contribute to their virulence. In the present report we demonstrate that isolated type IV pili from Neisseria gonorrhoeae bind human C4BP in a dose-dependent and saturable manner. C4BP consists of seven identical alpha-chains and one beta-chain linked together with disulfide bridges. We found that pili bind to the alpha-chain of C4BP, which is composed of eight homologous complement control protein (CCP) domains. From the results of an inhibition assay with C4b and a competition assay in which we tested mutants of C4BP lacking individual CCPs, we concluded that the binding area for... (More)
C4b-binding protein (C4BP) is an important plasma inhibitor of the classical pathway of complement activation. Several bacterial pathogens bind C4BP, which may contribute to their virulence. In the present report we demonstrate that isolated type IV pili from Neisseria gonorrhoeae bind human C4BP in a dose-dependent and saturable manner. C4BP consists of seven identical alpha-chains and one beta-chain linked together with disulfide bridges. We found that pili bind to the alpha-chain of C4BP, which is composed of eight homologous complement control protein (CCP) domains. From the results of an inhibition assay with C4b and a competition assay in which we tested mutants of C4BP lacking individual CCPs, we concluded that the binding area for pili is localized to CCP1 and CCP2 of the alpha-chain. The binding between pili and C4BP was abolished at 0.25 M NaCl, implying that it is based mostly on ionic interactions, similarly to what have been observed for C4b-C4BP binding. Furthermore, the N-terminal part of PilC, a structural component of pili, appeared to be responsible for binding of C4BP. Membrane cofactor protein, previously shown to be a receptor for pathogenic N. gonorrhoeae on the surface of epithelial cells, competed with C4BP for binding to pili only at high concentrations, suggesting that different parts of pili are involved in these two interactions. Accordingly, high concentrations of C4BP were required to inhibit binding of N. gonorrhoeae to Chang conjunctiva cells, and no inhibition of binding was observed with cervical epithelial cells. (Less)
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author
organization
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type
Contribution to journal
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published
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in
Journal of Immunology
volume
166
issue
11
pages
6764 - 6770
publisher
American Association of Immunologists
external identifiers
  • pmid:11359834
  • scopus:17544397196
ISSN
1550-6606
language
English
LU publication?
yes
id
5a8bcb0e-f616-4cb4-a803-6e1b93b4bbe8 (old id 1119862)
date added to LUP
2008-06-25 11:33:36
date last changed
2018-01-07 08:36:59
@article{5a8bcb0e-f616-4cb4-a803-6e1b93b4bbe8,
  abstract     = {C4b-binding protein (C4BP) is an important plasma inhibitor of the classical pathway of complement activation. Several bacterial pathogens bind C4BP, which may contribute to their virulence. In the present report we demonstrate that isolated type IV pili from Neisseria gonorrhoeae bind human C4BP in a dose-dependent and saturable manner. C4BP consists of seven identical alpha-chains and one beta-chain linked together with disulfide bridges. We found that pili bind to the alpha-chain of C4BP, which is composed of eight homologous complement control protein (CCP) domains. From the results of an inhibition assay with C4b and a competition assay in which we tested mutants of C4BP lacking individual CCPs, we concluded that the binding area for pili is localized to CCP1 and CCP2 of the alpha-chain. The binding between pili and C4BP was abolished at 0.25 M NaCl, implying that it is based mostly on ionic interactions, similarly to what have been observed for C4b-C4BP binding. Furthermore, the N-terminal part of PilC, a structural component of pili, appeared to be responsible for binding of C4BP. Membrane cofactor protein, previously shown to be a receptor for pathogenic N. gonorrhoeae on the surface of epithelial cells, competed with C4BP for binding to pili only at high concentrations, suggesting that different parts of pili are involved in these two interactions. Accordingly, high concentrations of C4BP were required to inhibit binding of N. gonorrhoeae to Chang conjunctiva cells, and no inhibition of binding was observed with cervical epithelial cells.},
  author       = {Blom, Anna M. and Rytkönen, Anne and Vasquez, Paola and Lindahl, Gunnar and Dahlbäck, Björn and Jonsson, Ann-Beth},
  issn         = {1550-6606},
  language     = {eng},
  number       = {11},
  pages        = {6764--6770},
  publisher    = {American Association of Immunologists},
  series       = {Journal of Immunology},
  title        = {A novel interaction between type IV pili of Neisseria gonorrhoeae and the human complement regulator C4B-binding protein},
  volume       = {166},
  year         = {2001},
}