Recruitment of peripheral leukocytes to intestine is an essential process for intestinal inflammation. This study examined the localization of a novel molecule, 4C8 antigen, in inflammatory bowel disease; this molecule is involved in the transendothelial migration of T lymphocytes. Surgical specimens of human intestine were obtained from nine patients with ulcerative colitis, 13 with Crohn's disease, and eight controls. Immunohistological staining was performed using antibodies against 4C8 antigen, and CD3, CD4, CD8, CD20, CD68, CD45RA, CD45RO, CD11a, and CD62 (E- and P-selectin) by the peroxidase method. Immunological double staining was subsequently performed for the same specimens stained with anti-4C8 antibody using the alkaline phosphatase method. In normal controls, 4C8-positive cells were mainly found in lamina propria. 4C8-positive cells were increased in lamina propria and submucosa of specimens with Crohn's disease. Accumulation of 4C8-positive cells surrounding CD62-positive vessels was found in the submucosa of specimens with inflammatory bowel disease, but not in controls. Immunohistological double staining revealed that the major subsets of 4C8-positive cells were positive for CD3, CD4, CD45RO, and CD11a. 4C8-positive cells in human intestine belong to the subset of helper/inducer memory T cells newly recruited from the peripheral pool. Inhibition of the 4C8-ligand system could have potentially uses in the treatment of inflammatory bowel disease.
Copyright 2002 John Wiley & Sons, Ltd.