title: Expression of endothelial intercellular adhesion molecule-1 is determined by genotype: effects on efficiency of leukocyte adhesion to human endothelial cells.
abstract: Two biallelic polymorphisms, previously described in the human intercellular adhesion molecule (ICAM)-1 gene at codon 241 (glycine [G] to arginine [R] substitution) and codon 469 (glutamic acid [E] to lysine [K] substitution) have been associated with a number of diseases including myocardial infarction, transplant rejection, and diabetes. However, the functional significance of these polymorphisms has not been determined. ICAM-1 cell surface expression and ICAM-1-mediated leukocyte adhesion were investigated using Cos7 transfected with ICAM-1 polymorphic variants or human umbilical vein endothelial cells (HUVEC) of different ICAM-1 genotypes. There was significantly higher expression of surface ICAM-1 on Cos7 transfected with a plasmid encoding the GE (G241/E469) ICAM-1 variant or untreated HUVEC of GEGE (G241/E469 homozygous genotype). ICAM-1-mediated adhesion of peripheral blood mononuclear cells (PBMC) to GE-Cos7 cells or TNF-treated GEGE HUVEC was significantly increased. However, there was no significant difference in adhesion of PBMC to recombinant ICAM-1 of each polymorphic variant plated onto plastic wells. We conclude that the GE genotype of ICAM-1 is associated with greater cell surface expression of ICAM-1, which in turn leads to greater adhesion of leukocytes. This may explain the previously described associations of ICAM-1 polymorphisms with chronic inflammatory disease.
authors: Transplant Immunology Group (Imperial College London), Heart Science Centre, Harefield Hospital, Harefield, Middlesex UB9 6JH, United Kingdom.
authors: Angela L
authors: AL
authors: Holder
authors: Sabine
authors: S
authors: Wolf
authors: Claire
authors: C
authors: Walshe
authors: Priti
authors: P
authors: Pandya
authors: Rachel E
authors: RE
authors: Stanford
authors: John D
authors: JD
authors: Smith
authors: Marlene L
authors: ML
authors: Rose
authors: Charlotte
authors: C
authors: Lawson
mesh_terms: D019943:Amino Acid Substitution; D000818:Animals; D019556:COS Cells; D002448:Cell Adhesion / Q000235:genetics; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D042783:Endothelial Cells / Q000378:metabolism*; D005312:Fetal Blood / Q000166:cytology; D005786:Gene Expression Regulation; D005838:Genotype; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000096:biosynthesis / Q000235:genetics; D007963:Leukocytes, Mononuclear / Q000378:metabolism*; D011110:Polymorphism, Genetic; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D014471:Umbilical Veins / Q000166:cytology
chemical_list: D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D018799:Intercellular Adhesion Molecule-1