E-selectin and vascular cell adhesion molecule-1 as critical adhesion molecules for infiltration of T lymphocytes and eosinophils in atopic dermatitis.

Abstract

To study the temporal and spatial relationship between infiltrating T-cell subsets or eosinophils and cell adhesion molecules on endothelial cells in skin lesions of atopic dermatitis (AD), we undertook immunohistochemical analysis using monoclonal antibodies against surface markers of T cells, eosinophil granule proteins and cell adhesion molecules. Predominant mononuclear cells in acute and chronic skin lesions were CD3, CD4 and CD45RO positive helper-inducer/memory T cells. Their number was significantly and strongly correlated with the intensity of E-selectin expression. Eosinophils and deposition of eosinophil-derived granule proteins such as eosinophil cationic protein (ECP), major basic protein (MBP) and eosinophil peroxidase (EPO) were found constantly in acute lesions and only occasionally in chronic lesions. The total number of immunoreactive eosinophils and deposits of MBP, EPO and ECP were significantly and strongly correlated with the staining intensity of VCAM-1. In chronic lesions significant reduction of VCAM-1 expression paralleled occasional infiltration of eosinophils. Our results demonstrate the possibility that E-selectin and VCAM-1 are the critical adhesion molecules for trafficking of memory T cells and eosinophils, respectively, into skin lesion of AD. Persistent expression of the adhesion molecules may be related to prolongation of the skin lesion in AD.