Expression of adhesion molecules and their ligands in contact allergy

Sequential biopsies from skin lesions induced by nickel sulphate and sodium lauryl sulphate, respectively, were investigated with respect to expression of extracellular matrix proteins and adhesion molecules on lymphocytes, endothelial cells, and keratinocytes. The majority of the infiltrating lymphocytes expressed VLA-4, LFA-1, CD44 and ICAM-1, a variable fraction expressed Leu-8 and VLA-5, and few or no cells were positive for VLA-1, VLA-2 and VLA-6. Noteworthy, was that the infiltrating cells showed a substantial amount of fibronectin but relatively small or negligible presence of laminin, collagen type IV, IgG, IgA, IgM, and albumin. The fibronectin was associated with cell bodies as well as the area surrounding infiltrating cells. The number of infiltrating cells was larger in biopsies from nickel-sulphate induced lesions and the infiltrates contained more fibronectin than biopsies from lesions induced by sodium lauryl sulphate. However, at the single-cell level, the expression of VLA antigens, LFA-1, CD44 and ICAM-1 was similar in both groups. The endothelial cells of skin biopsies from nickel-sulphate-induced lesions showed a stronger expression of VCAM-1, ELAM-1 and ICAM-1 compared to biopsies from sodium lauryl sulphate-induced lesions. In the biopsies from nickel sulphate-induced lesions, the keratinocytes showed a tendency to less VLA-6 expression. These results suggest that fibronectin plays a role in lymphocyte extravasation or extravascular lymphocyte migration.