Quantitative Analysis Of γδ T/Vγ9 T Lymphocytes And Expression Of IL-17A In Lesions Of Psoriasis Vulgaris

ObjectivePsoriasis is a common clinical chronic inflammatory skin disease induced by immune. The main pathological characteristics change are the proliferation of keratinocytes, a large number of white blood cells infiltration and neovascularization formed. Based on the clinical manifestations, there are four types of psoriasis:psoriasis vulgaris, arthropathic psoriasis, pustular psoriasis, erythrodermic psoriasis. Clinically, psoriasis vulgaris is the most common type of psoriasis, manifested as dry, red raised plaques with adherent silvery scales. The pathogenesis of psoriasis is not fully understood. Previous studies tend to think that psoriasis is an autoimmune skin disease associated with T lymphocytes. Interleukin-17 (IL-17) which is expressed by T helper 17 cells have the closely relationship with the incidence and development of psoriasis. But in some research, Th17 cells cannot explain the early immune responses regulated by IL-17. With the further of the research, it found that immune cells—γδ T cells is the important cells which can produce IL-17. The present study in relationship between psoriasis and gamma delta T cells are more concentrated in the study of mouse model of psoriasiss. A large clinical psoriasis patients’sample research has not been reported in China and abroad. In this paper, we plan to make a comparisons between the psoriasis lesional skin, non-lesional skin and the healthy people skin. For observe the expression difference of gamma delta T cells, Vy9 T cells and cytokine IL-17A and make correlation analysis of gamma delta T cells, Vy9 T cells and cytokine IL-17A functions in the pathogenesis of psoriasis vulgaris. In order to explore the pathogenesis of psoriasis and to provide a new direction for clinical treatment, not only has high academic value but also has a broad application prospect.MethodsThe experiment adapt immunofluorescence detection method to detect the expression of healthy skin, psoriasis vulgaris patients’lesional and non-lesional skin in T cells, Vy9 T cells and cytokines in IL-17A. We prepared healthy skin, psoriasis vulgaris patients’lesional and non-lesional skin lesions of paraffin and frozen sections, using PerCP/Cy5.5 anti-human CD3 and FITC anti-human TCR γ/δ, PerCP/Cy5.5 anti-human CD3 and PE anti-human TCR Vγ9, FITC anti-human TCR γ/δ and APC anti-human IL-17A antibody direct immunofluorescence double staining the target cells or cytokine. After taken photo by the fluorescence microscopy, the number of cells and the mean fluorescence intensity were analysis by Image-ProPlus and ImageJ software. Finally, added up data, the results were analyzed by statistical software SPSS 13.0.ResultsThrough the fluorescence microscope observation, skin lesions of psoriasis patients contain a large number of CD3+T cells, there were a high percentage γδ T cells and Vγ9 T cells distributed in the dermis. At the same time, a large number of IL-17A infiltration in the dermis. The expression numbers of γδ T cells were significantly higher in psoriatic lesion than that in non-lesional skin of psoriasis patients and normal skin of healthy people, p< 0.0001; the expression numbers of Vγ9 T cells were also higher in psoriatic lesion than that in non-lesional skin of psoriasis patients and and normal skin of healthy people,p< 0.0001, there had statistical significance. The percentage of Vγ9 T cells in CD3+ T cells in the lesional skin and non-lesional skin were higher than that in normal skin of healthy people, there had statistical significance, p< 0.0001; But, the percentage of Vγ9 T cells in CD3+ T cells in the lesional skin compared that in non-lesional skin of patients with psoriasis vulgaris had no statistical significance. p>0.05. The expression of γδ T cells and Vγ9 T cells between PASI score were positively correlated in the statistical results,p<0.05. The IL-17A mean fluorescence intensity in lesional skin of patients was significantly higher than that in non-lesional skin, the difference was statistically significant (p<0. 0001); the IL-17A mean fluorescence intensity in lesional skin of patients was significantly higher than that in healthy people, the difference was statistically significant (p< 0.0001); the IL-17A mean fluorescence intensity in non lesional skin of patients was significantly higher than that in healthy people, the difference was statistically significant (p< 0.0001). And the mean fluorescence intensity of IL-17A in psoriatic lesions and non lesional skin between PASI score were positive correlation, p<0.05.ConclusionThere were lots of proliferative γδT cells in the psoriatic dermis. The expression level was significantly higher than the healthy people. The Vγ9 T cells accounted for the largest proportion, expressed preferentially. And the expression of γδT cells and Vγ9 T cells were positively correlated with the severity of psoriasis vulgaris, especially Vγ9 T cells may play an important role in the pathogenesis of psoriasis vulgaris. At the same time, the γδT cells and Vγ9 T cells had closely relationship with expression of IL-17A, and the expression of IL-17A was positively correlated with the severity of psoriasis vulgaris. The γδT cells, especially Vγ9 T cells may be the major source of IL-17A in psoriasis vulgaris patients.