银屑病在全球范围内具有高达2-3%的发病率，目前其确切病因和发病机制至今仍不清楚，且缺乏有效防治措施。中医药对银屑病的治疗作用已展示良好的应用前景。本课题组以往的研究发现髓系抑制性细胞在银屑病小鼠模型中显著性增多，国外最新研究发现银屑病患者的髓系抑制性细胞也有同样的现象。目前国内外研究对髓系抑制性细胞对银屑病的具体作用机理并不清楚。因此本研究在前期动物实验基础上进一步观察髓系抑制性细胞在银屑病患者外周血中是否也存在异常增多；然后分离出人髓系抑制性细胞，观察其对T细胞活化的抑制作用，以及对银屑病经典通路IL-17/Treg可能存在的调控作用；再通过动物实验及临床研究，体内观察中药复方PSORI-CM02在体内对髓系抑制性细胞的调控作用。本研究不仅有助于阐明髓系抑制性细胞对银屑病的免疫作用机理，而且能为中医药治疗银屑病的科学内涵提供新线索。

Psoriasis is a skin disease with worldwide prevalence rates range from 2 to 3%. The etiology and pathogenesis of psoriasis remain incompletely defined and It cannot be complete cleared by current treatments. Therapeutic effect of Chinese medicine on psoriasis has shown positive application prospect. We found a significant increase of myeloid-derived suppressor cells (MDSCs) in IMQ mouse model, as well as the results of psoriasis patients found by the latest research abroad. But the current research on the role of myeloid-derived suppressor cells in psoriasis is not clear. Based on the results of animal experiments, we investigate whether there is abnormal increase of MDSCs in the peripheral blood of patients with psoriasis; then we isolate MDSCs from peripheral blood, observe the inhibition function of MDSCs on T cells activation, as well as its regulation to psoriasis classical pathway of IL-17/Treg. We also design animal experiment and clinical research for investigating the regulation of Chinese herbal formula PSORI-CM02 on MDSCs in vivo. This study not only helps to elucidate the immune mechanism of MDSCs in psoriasis, but also to provide new evidence for the scientific connotation of Chinese medicine treatment on psoriasis.