Open AccessFc-mediated binding of IgG to vimentin-type intermediate filaments in vascular endothelial cells.
Author(s) -
Göran K. Hansson,
Gordon Starkebaum,
Earl P. Benditt,
Stephen M. Schwartz
Publication year - 1984
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.81.10.3103
Subject(s) - vimentin , intermediate filament , cytoskeleton , binding site , microbiology and biotechnology , intracellular , chemistry , plasma protein binding , monoclonal antibody , antibody , endothelial stem cell , biology , biophysics , cell , biochemistry , in vitro , immunology , immunohistochemistry
Prior studies have shown that vascular endothelial cells bind circulating IgG intracellularly during cell death. We now demonstrate that all endothelial cells have intracellular binding sites for IgG and that these binding sites are exposed to circulating IgG only if the plasma membrane is damaged. The binding sites are located on the cytoskeletal intermediate filaments and can be detected also in other cells containing vimentin-type intermediate filaments. Monoclonal human IgG1 exhibited saturable, high-affinity binding to vimentin-enriched cytoskeletons. Binding was inhibited by Fc fragments but not by Fab, F(ab')2, or pFc' fragments, suggesting that the binding site on IgG is located in the C gamma 2 domain of the Fc fragment. Binding of IgG to intermediate filaments may be important for the destruction and removal of damaged cells.