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Induction of intercellular adhesion molecule‐1 by monocyte adhesion to endothelial cells in human culture system
Author(s) -
Combe Christian,
Duplàa Cecile,
Couffinhal Thierry,
Moreau Catherine,
Bonnet Jacques
Publication year - 1995
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.1041640210
Subject(s) - monocyte , adhesion , intercellular adhesion molecule 1 , icam 1 , cell adhesion molecule , microbiology and biotechnology , intercellular adhesion molecule , cell adhesion , cytokine , intracellular , chemistry , biology , immunology , organic chemistry
Abstract Increased monocyte adhesion to the endothelial lining of blood vessels by cytokine‐inducible adhesion proteins is a crucial event in inflammatory processes. Moreover, adherence is known to induce cytokine gene expression, suggesting a possible positive feedback mechanism. Therefore, we determined whether monocyte adhesion to endothelial cells (ECs) amplifies their adhesion by inducing intercellular adhesion molecule 1 (ICAM‐1), and whether such positive feedback mechanism could be mediated by secretion of interleukin‐1 (IL‐1). Using monocyte‐EC couples obtained after monocyte adhesion to ECs, and methods of quantitative polymerase chain reaction and immunofluorescence flow cytometry, we showed a biphasic increase of ICAM‐1 mRNA content (2 and 16 hours) and a time‐dependent increase of cell surface expression of ICAM‐1, mainly on ECs, and couple adhesiveness, after monocyte adhesion to ECs. Anti‐ICAM‐1 monoclonal antibody inhibited 63% of the enhancement of adhesiveness induced on monocyte‐EC couples by previous monocyte adhesion, suggesting that monocyte adhesion to ECs induces an increase of couple adhesiveness which is partially dependent on the ICAM‐1 pathway. The early ICAM‐1 mRNA induction was associated with a fast induction of IL‐1b̃ mRNA and a 7.7‐fold increase in IL‐1b̃ protein in supernatant. However, 30% of this 2‐hour ICAM‐1 mRNA peak was abolished by recombinant soluble human IL‐1 receptor, suggesting that the early ICAM‐1 overexpression was partially mediated by IL‐1b̃, and could be induced directly by adherence. The second ICAM‐1 mRNA peak was accompanied by a marked increase in IL‐1b̃ mRNA and protein secretion (2.6 ng/ml). The binding to ICAM‐1 did not appear to directly stimulate IL‐1b̃ synthesis. These results indicate that monocyte adhesion to endothelial cells appears to stimulate their own recruitment via induction of ICAM‐1 thereby constituting a self‐perpetuating positive feedback system. © 1995 Wiley‐Liss, Inc.