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目的 探讨γ干扰素 (IFN γ)对人NK细胞识别功能的负调节作用。方法 用MTT法测定人NK细胞系 (NK92 ,NKL)的细胞毒活性及细胞增殖能力 ;用RT PCR检测NK细胞受体 (NKG2D、NKG2A/B、KIR2DL1、KIR2DS1)及NKG2D的识别配体主要组织相容性复合体Ⅰ类链相关分子A(MICA)的表达。结果 NK细胞系 (NK92、NKL)对MICA表达阳性的肿瘤细胞杀伤活性明显高于对MICA表达阴性者 ;IFN γ 10 0 0U/ml以上可明显抑制NK细胞对MICA表达阳性肿瘤细胞的细胞毒活性 ,并轻度抑制NK细胞的增殖 ,而对MICA表达阴性肿瘤细胞的杀伤活性无明显抑制作用 ;IFN γ可抑制NK细胞系活化受体NKG2D的表达 ,增强抑制性受体NKG2A/B和KIR2DL1的表达。结论 IFN γ可能通过下调NK细胞活化受体的表达 ,上调抑制性受体的表达 ,使NK识别的信号平衡向抑制性方向倾斜 ,从而对NK细胞功能发挥负调节作用 ,这种作用可能是NK细胞自我调节功能的表现
Objective To investigate the negative regulatory effect of interferon gamma on human NK cell recognition. Methods The cytotoxicity and cell proliferation of human NK cell line (NK92, NKL) were measured by MTT assay. The main tissues of NK cell receptor (NKG2D, NKG2A / B, KIR2DL1, KIR2DS1) and NKG2D Expression of Class I Chain Related Molecule A (MICA) in Compatibility Complex. Results The cytotoxic activity of NK cell line (NK92, NKL) on MICA positive tumor cells was significantly higher than that on MICA negative ones. IFNγ above 10 0U / ml could obviously inhibit the cytotoxicity of NK cells to MICA positive tumor cells , And slightly inhibited the proliferation of NK cells, but had no obvious inhibitory effect on the killing activity of MICA-expressing negative tumor cells. IFNγ could inhibit the expression of NKG2D, an activator of NK cell line, and enhance the inhibitory activity of NKG2A / B and KIR2DL1 expression. Conclusions IFNγ may play a negative regulatory role on NK cell function by down-regulating the expression of NK cell-activating receptor, up-regulating the expression of inhibitory receptor and tilting the balance of NK-recognition signal to the inhibitory direction, which may be NK Cell self-regulating function of the performance