IL-2、IL-15对NK细胞亚群表型和功能的调节作用

Immunoregulation of IL-2 and IL-15 on the phenotype and function of NK subsets in PBMC and mixed lymphocyte culture

目的 探讨IL 2和IL 15对NK细胞亚群表型和功能的调节作用。方法 采用双色免疫荧光染色和流式细胞仪分析 ,比较IL 2和IL 15对新鲜分离外周血单个核细胞 (PBMC)中NK细胞及经混合淋巴细胞培养 (MLC)活化的NK细胞表型的调节作用 ;用 4h51 Cr释放实验检测IL 2和IL 15对NK细胞杀伤水平的影响。结果 在PBMC培养中 ,当IL 2或IL 15最终为5 0U mL时 ,能明显上调PBMC中CD5 6 +NK细胞的比例 ,且IL 15对CD5 6 bright亚群增殖的促进作用强于IL 2 ;在MLC中 ,当IL 2或IL 15为 5 0U mL时 ,能够促进MLC活化的NK细胞比率的增加 ,NK细胞亚群由CD5 6 dim为主转变成CD5 6 bright为主 ,此诱导作用IL 2强于IL 15。IL 2和IL 15都能上调PBMC和MLC中NK细胞杀伤水平 ,并呈剂量依赖关系 ,在PBMC中 ,当IL 15为5 0U mL时 ,IL 15对NK细胞杀伤水平的促进作用强于IL 2 ;而在MLC中当IL 2为 5 0U mL时 ,对NK细胞杀伤水平的促进作用高于IL 15。在PBMC中 ,同时加入 5 0U mL的IL 15和IL 2 ,NK细胞杀伤率高于单独加入IL 15或IL 2。结论 IL 15促进PBMC中NK细胞向CD5 6 bright亚群分化和杀伤水平强于IL 2 ,而IL 2促进同种异体抗原诱导的活化NK细胞向CD5 6 bright亚群分化和杀伤水平则高于IL 15。这种反应格局的差别 。

Objective To investigate the immunoregulation of IL 2 and IL 15 on the phenotype and function of NK subsets in PBMC and mixed lymphocyte culture. Methods The phenotypic changes of NK cells in human peripheral mononuclear cell (PBMC) and mixed lymphocyte culture (MLC) in the presence of IL 2 or IL 15 were detected by double fluorescent staining and flow cytometry. 51 Cr release assay was employed to measure the specific lysis of NK cells killing target K562 cells. Results Both IL 2 and IL 15 could increase the ratios of NK cells in PBMC and MLC. In addition, IL 15 was more effective than IL 2 in improving the proliferation of CD56 bright NK subsets in PBMC while IL 2 was more effective than IL 15 in increasing the number of CD56 bright NK subsets in MLC when 50 U/mL IL 2 or IL 15 was added at the beginning of the culture. The cytotoxicity of NK cells in PBMC culture and MLC were greatly enhanced by the addition of IL 2 or IL 15 with a dose dependent manner. Furthermore, IL 15 was more powerful than IL 2 at 50 U/mL in enhancing the cytotoxicity of NK cells in PBMC, whereas IL 2 was more powerful than IL 15 in enhancing the cytotoxicity of NK cells in MLC at the same concentration. When 50 U/mL IL 15 and 50 U/mL IL 2 were added,the cytotoxicity of NK cells was higher than that of the cells cultured only with IL 15 or IL 2 at the same concentration. Conclusion IL 15 is more effective than IL 2 in upregulating the proliferation of CD56 bright NK subsets and cytotoxicity of resting NK cells at low concentration while IL 2 is more effective than IL 15 in improving the proliferation of CD56 bright NK subsets and cytotoxicity of MLC gene rated NK cells at certain concentration. The different pattern of immunomodulation by IL 2 or IL 15 on NK cells may be due to the different expression of IL 2R or/and IL 15R on NK cells in the given condition or other cytokines presented in the culture forming a cytokine net work.