Expression of cutaneous lymphocyte-associated antigen on human CD4(+) and CD8(+) Th2 cells

The cutaneous lymphocyte-associated antigen (CLA) represents the homing rec eptor involved in selective migration of memory/effector T cells to the ski n. Numerous reports demonstrated distinct CLA expression on Th1 cells. Howe ver, T cells isolated from skin lesions and CLA(+) T cells circulating in p eripheral blood of atopic dermatitis patients expressed high IL-5 and IL-13 . Accordingly, we investigated the regulation of CLA on human type 1 and ty pe 2 T cells. CLA was induced on freshly generated Th1 and Tc1 cells only, but not on those of type 2. Anti-CD3 stimulation was sufficient to induce C LA on Th2 cells in the absence of serum in the culture medium. In serum con taining medium, IL-4 inhibited CLA and related alpha -fucosyltransferase mR NA expression. IL-12 and/or staphylococcal enterotoxin B (SEB) stimulation up-regulated CLA expression on either Th2 and Tc2 cells. On stimulation wit h IL-12, CLA was expressed on the surface of bee venom phospholipase A,spec ific Th1, Th2, Th0 and T regulatory 1 clones, representing non-skin-related antigen-specific T cells. In addition, CLA could be re-induced on T cells that had lost CLA expression upon resting. These results suggest that skin- selective homing is not restricted to functional and phenotypic T cell subs ets.