No abstract

Background: Topical glucocorticoid (GC) is still the first choice in the treatment of psoriasis. Although psoriasis can be controlled rapidly by topical GC, the relapse occurs very soon. Till now, the mechanism of it has not been well known. Objective: Study the mechanism of psoriasis relapse associated with topical GC. Methods: Mice ear skin was treated with IMQ once daily for 21d, from day 6 additional halometasone cream (topical GC) was used once daily with Vaseline control for 16d (treatment group). Then, both treatments were withdrawed and the mice recovered for 2W (withdrawal group). Thereafter, IMQ was reapplied once daily for 1W (relapse group). At the indicated time points, mice were sacrificed and analyzed by FACES and Real-time PCR. Results: At treatment group, the psoriatic phenotype in topical GC applied mice almost disappeared. However, the expression of IL-7R on Vg4+T and gdT were upregulated in skin, and the expression of IL-7, CCL20 and CCL2 were enhanced in skin. Moreover, there was increased ratio of Vg4+T among gdT in skin and draining lymph node. At withdrawal and relapse group, the expression of CCR6 on Vg4+T and gdT were increased in