Expression of the LFA‐1 β2 Integrin (CD11a/CD18) and ICAM‐1 (CD54) in Normal and Coeliac Small Bowel Mucosa

Abstract

The leucocyte adhesion molecules (beta 2 integrins) comprise CD11 alpha-chains and a common beta-chain (CD18). CD11a (leucocyte function-associated antigen 1, LFA-1) is expressed by most T cells, and is involved in antigen presentation by macrophages via its counter-receptor, intercellular adhesion molecule (ICAM-1, CD54). By criteria of double-label immunofluorescence of cryostat tissue sections, virtually all lamina propria T cells of the normal small bowel were found to express LFA-1 strongly. By contrast, only 30-60% of intra-epithelial lymphocytes (IEL) expressed detectable LFA-1, most of which were LFA-1 weak and CD18-. ICAM-1 was expressed strongly only by vascular endothelium. In coeliac disease, there was a modest increase of diffuse ICAM-1 expression in the lamina propria, mainly in the subepithelial zone, where ICAM-1+ macrophages were occasionally seen. There was also a slight overall increase in CD11a expression by IEL, seen predominantly in surface epithelium and mainly by the CD4+ minority subset, but not by CD4-CD8- (TcR gamma delta +) cells. These data suggest that the LFA-1/ICAM-1-dependent antigen presentation pathway is of minor importance to IEL in the normal small bowel, and does not assume a major role in coeliac disease.

The Neonatal Development of Intraepithelial and LaminaPropria Lymphocytes in the Murine Small Intestine

“…In contrast to IEL, we found a much higher expression on murine LPL, similar to what has been reported in humans (Jarry et al, 1990;Smart et al, 1991). CD54 expression on IEL was about 20% and increased around weaning in parallel with an increase in the number of IEL, probably indicating IEL activation.…”

Adulthood-Onset Celiac Disease Is Associated with Intercellular Adhesion Molecule-1 (ICAM-1) Gene Polymorphism

“…ICAM-1 is expressed by vascular endothelium in normal intestine, and is over-expressed in the lamina propria of CD patients, mainly in the subepithelial zone [29]. Gliadin induces expression of ICAM-1 in explant cultures of CD biopsies [30], and increased levels of soluble ICAM-1 levels have been found in the serum of CD patients [31,32].…”

The mucosal T cell integrin αM290β7 recognizes a ligand on mucosal epithelial cell lines

“…ICAM-1 has not, however, been seen on gut epithelium in tissue sections, even in inflammatory disorders [28]. Neither is ICAM-2 nor ICAM-3 (ICAM-R) present in gut epithelium [29,301.…”