Abstract: Objective To detect the expression of CXCR2 on psoriatic lesional keratinocytes and to in-vestigate the mechanism of Vit D3 in the treatment of psoriasis.Methods The proliferative capacity of human keratinocyte cell line,HaCaT,treated with Vit D3 was detected by MTT assays.The expression of CXCR2 on HaCaT treated with Vit D3 was assayed by FACS calibur.Results The Vit D3 at proper concentrations could inhibit the proliferation of HaCaT and down-regulate the CXCR2 expression on the cells.Conclusion One of the mechanisms for Vit D3 in the treatment of psoriasis might be the inhibition of CXCR2 expression on keratinocytes,which con-tributes to inhibit the over-proliferation of keratinocytes in psoriasis.

Key words: Cholecalciferol, Keratinocytes, CXCR2