CD226在NK细胞亚群上表达规律与功能关系的研究

Expression and function of CD226 with CD16 on NK subsets

目的 :观察CD2 2 6分子在NK细胞亚群上的分布和其他NK细胞活化性受体和抑制性受体的共存规律 ,及与NK细胞功能的关系。方法 :分别以IL 2或IL 15刺激PBMC和MLC细胞为模型 ,采用双重免疫荧光染色和流式细胞术分析 ,观察CD2 2 6分子在CD5 6 bright和CD5 6 dim NK细胞亚群上的表达 ,及与NK细胞活化性受体CD16和抑制性受体NKG2A的共存关系 ,同时用ELISA方法检测培养上清中IFN γ的水平。用 4小时51 Cr释放试实验检测NK细胞杀伤水平。结果 :在PBMC中 ,CD2 2 6主要分布于CD5 6 dim亚群 ,在IL 2作用下 ,CD2 2 6主要分布于CD5 6 bright亚群 ,而在IL 15作用下 ,NKG2A+ CD2 2 6 + 双阳性细胞明显增加。在MLC活化的NK细胞中 ,CD2 2 6主要分布于CD5 6 dim亚群 ,在IL 15作用下 ,CD2 2 6主要分布于CD5 6 bright亚群 ,IL 2和IL 15都能促进CD16 + CD2 2 6 + 和NKG2A+ CD2 2 6 + 双阳性细胞的增殖。IL 2和IL 15能明显提高PBMC培养上清中IFN γ的水平 ,并能促进PBMC和MLC中NK细胞的杀伤活性。结论 :CD2 2 6主要分布于活化NK细胞CD5 6 bright亚群上 ,其表达水平及与CD16及NKG2A共存关系可能受不同细胞因子调节并与NK细胞功能相关。

Objective:To investigate the expression and function of CD226 on NK s ubsets and its coexpression with other activation receptor and inhibition recept or on NK cells. Methods:The expression of CD226 on CD56 bright and CD56 dim NK subsets and coe xpress ion with CD16 and NKG2A in PBMC and MLC in the presence or absence of IL-2 or IL-15 were detected by double fluorescent staining and flow cytometry analysis. The level of IFN-γ in the supernatants of PBMC culture and MLC treated with o r without IL-2 or IL-15 were evaluated by ELISA. 51Cr release assay w as employed to measure the specific lysis of NK cells killing target K562 cells. Results:CD226 was mainly expressed on CD56 dim NK subsets in PBMC. When s imulated by IL-2, CD226 expression was shifted to CD56 bright NK subsets, while IL-15 increased the subpopulation of NKG2A+CD226+double positive cell s. In MLC-generated NK cells, CD226 was mainly expressed on CD56 dim NK su bsets, and also shifted to CD56 bright NK subsets in the addition of IL-15 . Furt hermore, the percentage of CD16+CD226+和NKG2A+CD226+ subsets were increa sed when stimulated by IL-2 or IL-15. There was great increase in IFN-γ lev el in the supernatants of PBMC culture in the presence of IL-2 or IL-15, but no difference in the supernatants of MLC treated with or without two cytokine s. Moreover, the cytotoxicity of NK cells in PBMC and MLC were greatly enhanced by IL-2 or IL-15. Conclusion:CD226 is mainly expressed on CD56 bright NK subsets in IL-2 or IL-1 5 activated NK cells, and is coexpressed with CD16 and NKG2A preferentiatly, whi ch maybe involve in the modulation of cytotoxicity of NK cells based on the balance of coexpressed activation and inhibition receptors. [