CD8~+T细胞对白癜风患者黑素细胞的杀伤机制

目的:明确CD8~+T细胞对白癜风患者黑素细胞的杀伤机制。方法:分选白癜风患者及正常人外周血CD8~+T细胞,分别与原代黑素细胞及永生化正常黑素细胞系PIG1及永生化白癜风黑素细胞系PIG3V建立共孵育杀伤模型,采用流式细胞术检测靶细胞被杀伤情况,酶联免疫吸附法(ELISA)检测杀伤环境中IFN-γ、TNF-α、颗粒酶B及穿孔素的分泌水平。结果:白癜风患者外周血CD8~+T细胞杀伤原代黑素细胞及PIG3V能力,分泌IFN-γ、颗粒酶B及穿孔素水平均高于健康对照,而杀伤PIG1能力和TNF-α水平并无显著差异;白癜风患者CD8~+T细胞IFN-γ分泌水平与细胞杀伤率呈明显正相关。结论:白癜风患者CD8~+T细胞杀伤黑素细胞是白癜风发病的重要机制,且该杀伤作用可能依赖IFN-γ、颗粒酶B及穿孔素分泌水平的上调。

Mechanism of CD8+T cells killing melanocytes in the patients with vitiligo

Objective: To determine the killing mechanism of CD8+T cells to melanocytes in the patients with vitiligo.Methods: CD8+T cells were obtained from peripheral blood in 8 patients with vitiligo and 8 healthy controls.The primary melanocyte, immortalized normal melanocyte cell line PIG1 and immortalized vitiligo melanocyte cell line PIG3V were co-cultivated with selected CD8+T cells respectively.The number of the death of melanocytes killed by CD8+T cells was assessed by Flow cytometry.The expression levels of IFN-γ, TNF-α, granzyme B and perforin were measured by ELISA.Results: The number of died primary melanocytes and PIG3V killed by CD8+T cells, the expression level of IFN-γ, granzyme B and perforin in the patients with vitiligo was higher than those in controls.There was no significant difference in the number of died PIG1 and the expression level of TNF-α between the patients and healthy controls.There was an obviously positive correlation between the level of IFN-γ secreted by CD8+ T cells and the number of died melanocytes killed by CD8+T cells.Conclusion: The killing of melanocytes by CD8+T cells plays an important role in the development of vitiligo, which probably depends on the increased expression of IFN-γ, granzyme B and perforin.