Recent studies indicate that Th1 and Th2 cells differ in their
chemokine receptor expression and their responsiveness to various
chemokines. Therefore, selective Th2 cell recruitment in Th2-predominant inflammatory diseases such as
atopic dermatitis may be under the influence of some
chemokines. It is reported that
CC chemokine receptor (CCR) 4 is selectively expressed on Th2 cells whereas
CXC chemokine receptor (CXCR) 3 is selectively expressed on Th1 cells. In this study we examined CCR4 and CXCR3 expression on peripheral blood CD4+ and CD8+ T cells obtained from adult
atopic dermatitis subjects, and compared the results with those from patients with
psoriasis vulgaris and healthy controls. CCR4 was preferentially expressed on CD4+ T cells from
atopic dermatitis subjects and CXCR3 was preferentially expressed on CD4+ T cells from
psoriasis vulgaris subjects. This CCR4 expression was prominent especially in severe
atopic dermatitis subjects. CCR4 expression on CD4+ T cells in severe
atopic dermatitis subjects decreased on improvement of disease activity. CD25 was preferentially expressed on CCR4+CD4+ T cells but not on CXCR3+CD4+ T cells in
atopic dermatitis subjects.
Cutaneous lymphocyte-associated antigen was also preferentially expressed on CCR4+CD4+ T cells but not on CXCR3+CD4+ T cells in
atopic dermatitis subjects. CD4+ T cells in
atopic dermatitis skin lesions were predominantly CCR4+ cells. Taken together, this study strongly indicates that CCR4+CD4+ T cells reflect disease activity and suggests that CCR4 expression is important for T cell infiltration into
atopic dermatitis lesions. Thus, CCR4 may be a possible target for
therapy of
atopic dermatitis in the future.