TY - JOUR

T1 - Expression of ICAM-1 in colon epithelial cells

T2 - an ultrastructural study performed on in vivo and in vitro models

AU - Vainer, Ben

AU - Sørensen, Susanne

AU - Seidelin, Jakob

AU - Nielsen, Ole Haagen

AU - Horn, Thomas

PY - 2003/12

Y1 - 2003/12

N2 - BACKGROUND: Studies have suggested that in ulcerative colitis (UC), intercellular adhesion molecule-1 (ICAM-1) is involved in migration of leukocytes toward the colonic epithelium. A suitable in vitro model of chronic colonic inflammation does not exist, and the role of the epithelium is based on monolayers of cancer cells. Conflicting results exist on epithelial ICAM-1 expression, and the aim of this study was to compare the expression in various models of colonic epithelium.MATERIALS AND METHODS: Colonic biopsies from four UC patients and four controls were examined by cryoimmuno-electron microscopy using ICAM-1-antibodies. In four other controls, the epithelium was isolated from colonic biopsies, embedded in collagen, and evaluated similarly. Isolated crypts and cultured cancer cells were stimulated with interferon-gamma (IFN-gamma) or tumor necrosis factor-alpha (TNF-alpha).RESULTS: ICAM-1 was not expressed in the biopsies. In contrast, HT29 cells and the collagen-embedded crypts expressed ICAM-1 on the apical membranes proximal to the junctional complexes when stimulated with IFN-gamma or TNF-alpha in a dose-related manner.CONCLUSIONS: ICAM-1 is not expressed on colonic epithelium in vivo. However, both colonocytes and HT29 cells were capable of expressing ICAM-1 on their apical membranes in response to supraphysiologic cytokine concentrations. These observations question the justification of extrapolating observations from colon cancer cell lines to in vivo inflammatory conditions.

AB - BACKGROUND: Studies have suggested that in ulcerative colitis (UC), intercellular adhesion molecule-1 (ICAM-1) is involved in migration of leukocytes toward the colonic epithelium. A suitable in vitro model of chronic colonic inflammation does not exist, and the role of the epithelium is based on monolayers of cancer cells. Conflicting results exist on epithelial ICAM-1 expression, and the aim of this study was to compare the expression in various models of colonic epithelium.MATERIALS AND METHODS: Colonic biopsies from four UC patients and four controls were examined by cryoimmuno-electron microscopy using ICAM-1-antibodies. In four other controls, the epithelium was isolated from colonic biopsies, embedded in collagen, and evaluated similarly. Isolated crypts and cultured cancer cells were stimulated with interferon-gamma (IFN-gamma) or tumor necrosis factor-alpha (TNF-alpha).RESULTS: ICAM-1 was not expressed in the biopsies. In contrast, HT29 cells and the collagen-embedded crypts expressed ICAM-1 on the apical membranes proximal to the junctional complexes when stimulated with IFN-gamma or TNF-alpha in a dose-related manner.CONCLUSIONS: ICAM-1 is not expressed on colonic epithelium in vivo. However, both colonocytes and HT29 cells were capable of expressing ICAM-1 on their apical membranes in response to supraphysiologic cytokine concentrations. These observations question the justification of extrapolating observations from colon cancer cell lines to in vivo inflammatory conditions.

KW - Adult

KW - Colitis, Ulcerative

KW - Colon

KW - Colonic Neoplasms

KW - Female

KW - HT29 Cells

KW - Humans

KW - Intercellular Adhesion Molecule-1

KW - Interferon-gamma

KW - Intestinal Mucosa

KW - Male

KW - Microscopy, Electron

KW - Tumor Necrosis Factor-alpha

KW - Journal Article

KW - Research Support, Non-U.S. Gov't

U2 - 10.1007/s00428-003-0900-5

DO - 10.1007/s00428-003-0900-5

M3 - Journal article

C2 - 14564519

VL - 443

SP - 774

EP - 781

JO - Virchows Archiv

JF - Virchows Archiv

SN - 0945-6317

IS - 6

ER -