Adhesion molecules in intestinal Schistosoma mansoni infection

Abstract

Adhesion molecules constitute essential elements in inflammation, mediating various cellular interactions. We investigated the expression of adhesion molecules mediating cell-cell [intercellular adhesion molecule-1 (ICAM-1) and lymphocyte function-associated antigen-1 (LFA-1)] and cell-matrix interactions [very late antigen-4 (VLA-4), VLA-6, and syndecan-1] in intestinal granulomas of mice infected with the parasite Schistosoma mansoni. Up-regulation of ICAM-1, LFA-1, and VLA-4 was seen in ileal and colonic granulomas, at both the acute (8 weeks postinfection) and the chronic stage (13–16 weeks postinfection). Up-regulation of VLA-6 was absent in all intestinal granulomas. Syndecan-1 immunoreactive (antigen-driven) B-lymphocytes were seen in the proximity of egg-antigen-laden macrophages in the inner part of ileal and colonic granulomas, although B-cells are considered to be absent in ileal granulomas. Estimation of intestinal granuloma volumes demonstrated the lack of down-modulation observed in ileal granulomas. From our results we infer that adhesion molecules constitute important elements in schistosomal intestinal granuloma formation. Organ-related differences between hepatic and intestinal granulomas exist (e.g., granuloma volume), but these differences are not morphologically reflected in a differential expression of the adhesion molecules ICAM-1, LFA-1, and VLA-4. Syndecan-1 immunoreactive B-lymphocytes also appear to be involved in ileal granuloma formation.