Proliferation of T lymphocytes from atopic dermatitis skin is enhanced upon anti-CD3, reduced upon mitogen and superantigen, and negligible upon tuberculin stimulation.

Knowledge about the nature of lymphocytes infiltrating atopic dermatitis skin is restricted to allergen-specific T cells. We investigated the proliferative capacities of T lymphocytes cultured in an antigen-independent way from biopsies of atopic dermatitis skin. When compared with peripheral blood mononuclear cells (PBMC) from healthy donors or atopic dermatitis patients, the skin-homing lymphocytes proliferated more vigorously in response to stimulation with anti-CD3 antibodies (1 microglml), reflecting their high response capacity. When stimulated with phytohemagglutinin (10 microg/ml) or staphylococcal enterotoxin A (0.1 microg/ml) the skin-homing lymphocytes achieved significantly lower proliferation levels than PBMC. In contrast to normal and atopic PBMC the skin-homing lymphocytes did not respond to tuberculin purified protein derivative (10 microg/ml). In the mixed lymphocyte reaction the skin-homing lymphocytes did not stimulate autologous PBMC to proliferate. We conclude that skin-homing lymphocytes have more pronounced immune deviations than PBMC in patients with atopic dermatitis. They represent a valuable approach for further investigating the pathogenesis of the disease.