MODULATION OF CD3-DEPENDENT LYMPHOCYTE-PROLIFERATION BY EXTRACELLULAR-MATRIX PROTEINS IN ATOPIC-DERMATITIS

Patients with atopic dermatitis were found to have an about ir-fold in creased spontaneous proliferative response of peripheral blood lymphoc ytes and an about 4-fold elevation of CD3-dependent lymphocyte transfo rmation as compared to normal controls. The CD3-dependent lymphocyte r esponse in patients with severe atopic dermatitis lesions was increase d to a lower degree than in those with mild skin lesions. Despite a hi ghly increased CD3-dependent lymphocyte response, the ext acellular ma trix proteins could induce further co-stimulation of lymphocytes in pa tients with atopic dermatitis, similar to that in normal controls. How ever, co-activation by type IV collagen was markedly increased in pati ents with severe lesions, whereas co-stimulations by both type I colla gen and fibronectin mere decreased in patients with mild lesions. This finding reflects presumably the changes in lymphocyte subpopulations and their activities related to the recirculation of these cells throu gh the active skin lesions and to the contact of T cells with extracel lular matrix proteins. The percentage of CD26-positive lymphocytes was also significantly (p < 0.05) increased in patients with severe atopi c dermatitis. These data indicate that helper T cells are excessively activated in atopic dermatitis and that the function of beta-1-integri n receptors underlying the extracellular matrix protein-mediated co-ac tivation of CD3-dependent lymphocyte responses is modified by disease severity.