NK细胞功能亚群：“NKh1和NKh2”的初步验证

目的 证实NK细胞存在与T细胞类似的Th1/Th2两类亚群。方法 从健康人外周血分离纯化NK细胞,利用促漂移和RT－PCR的技术,检测外周血静止的NK细胞及在不同极化条件下培养的NK细胞表达I和II类细胞因子的情况。结果 采用补体裂解法＋单抗铺皿法分离纯化15例人外周血NK细胞,TR－PCR方法检测NK细胞表达的两类因子,发现外周血静止NK细胞因子的表达较强,主要是IFNγ,Ⅱ类细胞因子中主要是IL－10、IL－13、IL－13。在促Th1极化条件下,NK细胞中表达的I类细胞因子I类细胞因子IFNγ明显增强,Ⅱ类细胞因子表达减强,而在促Th2极化状态下,NK细胞表达的IFNγ水平下降,Ⅱ类细胞因子的表达水平升高。静止和Ⅱ类细胞因子状态下NK细胞均表达极低水平或不表达IL－4。结论 NK细胞根据其产生的细胞因子可以分化为两个亚群。暂命名为NKh1和NKh2。外周血静止的NK细胞主要以NKh1表型为主,两个亚群均表达较高水平的IFNγ,这与NK细胞的杀伤功能是密切相关的。

Differentiation of natural killer cells into two functional subsets: NKh1 and NKh2

OBJECTIVE: To verify the presence of functional subsets of natural killer cells based on the cytokine production. METHODS: NK cells were purified and cultured in complete RPMI1640 medium in the presence of either IFN gamma + anti-IL-4(classical Th1 polarization) or IL-4 + anti-IFN gamma (classical Th2 polarization) for three days, and then were collected and detected for type I/type II cytokines by RT-PCR method. RESULTS: NK cells were purified from 15 healthy donors, over 70% purity of NK cells were determined by flow cytometry. NK cells in peripheral blood expressed high level of type I cytokines, mainly IFN gamma, but low level of type II cytokines such as IL-10 and IL-13, IL-4 was not produced by NK cells. Cells cultured in IFN gamma + anti-IL-4 condition exhibited significantly increased level of IFN gamma, unchanged IL-2, and decreased type II cytokines. Cells grew in IL-4 + anti-IFN gamma condition exhibited increased IL-10 and IL-13, and decreased IFN gamma expressions. CONCLUSIONS: Based on the cytokine production, NK cells may be divided into two functional subsets in the same manner as that of T lymphocytes(e.g. Th1/Th2): NKh1 and NKh2. The biological characterization and phenotypic marker are under investigate.