Immunolocalization of intercellular adhesion molecule‐1 and leukocyte functional associated antigen‐1 in schistosomal soluble egg antigen‐induced granulomatous hyporesponsivenessNote

In this work, the changes in expression of the adhesion molecules ICAM-1/LFA-1 on inflammatory cells of the liver were studied by immunohistochemistry. Mice sensitized with SEA and infected with S. mansoni and S. mansoni-infected controls were examined from day 35 to day 56 postinfection. A significant upregulation of ICAM-1 and LFA-1 in both the SEA group and the infected control group started shortly after egg deposition at day 35 and persisted up to day 56 p.i. Notably, both ICAM-1 and LFA-1 expression peaks were shifted earlier to day 38 p.i. in the SEA group compared to day 40 in the infected control group. The distribution of ICAM- 1 and LFA- 1 in both groups was comparable. At the early phase of infection before granuloma formation, both ICAM-1 and LFA-1 were detected along the sinusoidal wall of small blood vessels. At the acute cellular granuloma phase, they were homogeneously distributed all over the inflammatory cells, while at the chronic fibrocellular stage a non-homogeneous staining of granuloma cells at the periphery of the granuloma was apparent. The present data suggest that adhesion molecules play a role in the initiation and maintenance of granuloma formation. Thus, the granulomatous hyporesponsiveness induced by sensitization with SEA was associated with reduced expression of adhesion molecules.