The Department of Dermatology of the hospital, in collaboration with Professor Jun Yan’s group at the Center for Immunology, Oncology and Biomedicine of the University of Louisville School of Medicine, has made important progress in the study of psoriasis. The paper “Dermal γδ T cells are the main IL-17-producing cells in inflammatory skin diseases”, published in the latest issue of Immunity (impact factor 24.221), reveals the causative agent of psoriasis The “culprit” of psoriasis, γδ T lymphocytes in the dermis, was discovered. Psoriasis, commonly known as “psoriasis”, has a high incidence, with special types such as pustular and erythrodermic, which can be serious and even life-threatening; the arthritic type can cause deformities of the joints and is the most serious of all arthritic diseases in terms of disability. There is no effective treatment for arthritis, and it often relapses after symptoms have subsided, and the disease worsens when it relapses. In recent years, the disease itself and the complications caused by oral and injectable drugs for treatment have led to an increasing interest in the international medical community to study the pathogenesis of psoriasis and to develop new, targeted therapeutic agents accordingly. According to the corresponding author of the paper, the international medical community has focused on the results of this study because it has demonstrated for the first time that interleukin 17 (IL-17), which causes psoriasis, is not produced by Th17 cells in the blood circulation as long thought, but by γδ T cells in the dermis, which are stimulated by interleukin 23 (IL-23) to produce large amounts of IL-17 that cause psoriasis. IL-17, this research method and results have implications not only for psoriasis but also for the etiology of various other organ diseases. Prof. Zheng Jie said that the Department of Dermatology of Ruijin Hospital has long been devoted to the study of the pathogenesis of psoriasis, especially the role of streptococcal infection, and γδ T cells are the first lymphocytes to be activated after the pathogens come into contact with the body, and another important result in this study is that different ligands of Toll-like receptors (various pathogens, etc.) can synergize with IL-23 to varying degrees to make γδ T cells produce more IL-17. 17, this phenomenon provides a good entry point for deepening the study of how pathogenic infections such as streptococci cause the natural immune system to produce pathological immune responses; he said that the Department of Dermatology at Ruijin Hospital has long insisted on treating psoriasis with skin-specific treatments, i.e., phototherapy, topical medications, strengthening skin care and reducing the susceptibility of the organism to pathogens such as streptococci, without advocating excessive systemic medications, and this study The results of this study provide a theoretical basis for this treatment approach. The international medical community also values the results of this study because it may provide a “target” for the development of targeted therapeutic agents in the future.