Toggle Main Menu Toggle Search

Open Access padlockePrints

The binding of factor H to a complex of physiological polyanions and C3b on cells is impaired in atypical hemolytic uremic syndrome

Lookup NU author(s): Professor David KavanaghORCiD

Downloads

Full text for this publication is not currently held within this repository. Alternative links are provided below where available.


Abstract

Factor H (fH) is essential for complement homeostasis in fluid-phase and on surfaces. Its two C-terminal domains (CCP 19-20) anchor fH to self-surfaces where it prevents C3b amplification in a process requiring its N-terminal four domains. In atypical hemolytic uremic syndrome (aHUS), mutations clustering toward the C terminus of fH may disrupt interactions with surface-associated C3b or polyanions and thereby diminish the ability of fH to regulate complement. To test this, we compared a recombinant protein encompassing CCP 19-20 with 16 mutants. The mutations had only very limited and localized effects on protein structure. Although we found four aHUS-linked fH mutations that decreased binding to C3b and/or to heparin (a model compound for cell surface polyanionic carbohydrates), we identified five aHUS-associated mutants with increased affinity for either or both ligands. Strikingly, these variable affinities for the individual ligands did not correlate with the extent to which all the aHUS-associated mutants were found to be impaired in a more physiological assay that measured their ability to inhibit cell surface complement functions of full-length fH. Taken together, our data suggest that disruption of a complex fH-self-surface recognition process, involving a balance of affinities for protein and physiological carbohydrate ligands, predisposes to aHUS.


Publication metadata

Author(s): Ferreira VP, Herbert AP, Cortés C, McKee KA, Blaum BS, Esswein ST, Uhrín D, Barlow PN, Pangburn MK, Kavanagh D

Publication type: Article

Publication status: Published

Journal: Journal of Immunology

Year: 2009

Volume: 182

Issue: 11

Pages: 7009-7018

ISSN (print): 0022-1767

ISSN (electronic): 1550-6606

Publisher: American Association of Immunologists

URL: http://dx.doi.org/10.4049/jimmunol.0804031

DOI: 10.4049/jimmunol.0804031

Notes: 078780/Z/05/Z/Wellcome Trust/United Kingdom DK-35081/DK/NIDDK NIH HHS/United States Journal Article Research Support, N.I.H., Extramural Research Support, Non-U.S. Gov't United States 1950)


Altmetrics

Altmetrics provided by Altmetric


Share