Differential Distribution of Intercellular Adhesion Molecules (ICAM–1, ICAM–2, and ICAM–3) and THE MS–1 Antigen in Normal and Diseased Human Synovia

Abstract

ICAM-1, while found mainly on endothelial cells, is up-regulated on RA ST macrophages and lining cells, suggesting a role for these cells in the infiltration and tissue damage seen in the RA ST: ICAM-3, which is present mainly on normal resting leukocytes but not on normal endothelium, is expressed by some diseased ST leukocytes and endothelial cells. MS-1 is also found on the RA ST specialized, fenestrated endothelium, on macrophages, and in the lining layer. These results suggest that the differential expression of ICAMs and MS-1 in RA ST compared with normal ST might play a special role in the pathogenesis of RA.