A Mitogenic Action for Fibrinogen Mediated through Intercellular Adhesion Molecule-1

• Published in: The Journal of biological chemistry 1997-06, Vol.272 (24), p.15474-15480
• Main Authors: Gardiner, Elizabeth E., D'Souza, Stanley E.
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Cell Line; Fibrinogen - metabolism; Humans; Immunoglobulins - chemistry; Intercellular Adhesion Molecule-1 - chemistry; Intercellular Adhesion Molecule-1 - immunology; Intercellular Adhesion Molecule-1 - metabolism; Mitogens - metabolism; Molecular Sequence Data; Transfection
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.272.24.15474

Intercellular adhesion molecule-1 (ICAM-1) is a cell surface ligand for αLβ2 and αMβ2 integrins and has a key role in leukocyte adhesion to the vascular endothelium. The plasma protein fibrinogen has also been shown to interact with ICAM-1. We have investigated the effect of fibrinogen binding to ICAM-1-expressing cells on cell proliferation. The inclusion of 200–800 nmfibrinogen but not fibronectin to the culture medium of Raji induced a 2–4-fold increase in [3H]thymidine incorporation after 8 h. Cell proliferation in cultures containing fibrinogen was also confirmed by direct cell counting. The proliferative response in Raji was abrogated by an anti-ICAM-1 mAb 84H10 which maps to the first Ig domain of ICAM-1. A purified truncated form of ICAM-1 containing the first two Ig-like domains and a peptide with amino acid sequence corresponding to ICAM-1 (8–22) was also able to block the proliferative action of fibrinogen on Raji. 200 nmfibrinogen induced a 3-fold increase in [3H]thymidine incorporation by 293 cells transfected with ICAM-1 cDNA but not control non-transfected 293 cells. Comparable mitogenic effects were achieved with fibrinogen fragments X and D100, and with a synthetic peptide with an amino acid sequence matching fibrinogen γ chain (117–133). These results indicate that interaction between discrete sequences within ICAM-1 and fibrinogen result in cellular proliferation.