目的:探讨骨髓瘤细胞RPMI 8266逃逸NK细胞免疫杀伤的机制。方法:流式细胞仪检测K562和8266细胞表面MICA/B、ULBP1～3和HLA-Ⅰ类分子的表达。4hLDH释放法测定效靶比20∶1时阻断前后NK细胞对2种细胞杀伤活性变化。观察效靶比20∶1时NK细胞对药物处理后RPMI 8226细胞杀伤活性变化、RPMI 8226细胞表面NKG2D配体和HLA-Ⅰ类分子的表达及NK细胞对RPMI 8266细胞的克隆形成率的影响。结果:K562细胞高表达MICA/B和ULBP 1～3分子;RPMI 8266细胞表达HLA-Ⅰ类分子,2株细胞NKG2D配体表达差异有统计学意义,P<0.001。单抗分别阻断MICA/B、ULBP 1～3分子后,效靶比为20∶1时NK细胞对K562细胞的杀伤活性明显降低,P值均<0.05;对RPMI 8266细胞的杀伤活性基本无变化,P值均>0.05。抗W6/32单抗封闭8266细胞表面HLA-Ⅰ类分子后,NK细胞对K562细胞的杀伤活性无上升(P=0.721),而对RPMI 8266细胞的杀伤活性上升,P=0.000。1/2IC50的三氧化二砷处理后RPMI8226细胞ULBP2、3配体升高(P=0.000),NK细胞对8266细胞的杀伤活性与对照组相比差异有统计学意义,P=0.001;1/2IC50硼替佐米处理后RPMI 8226细胞表面各NKG2D配体无变化,P>0.05。NK细胞对K562细胞克隆形成抑制率为(63.48±6.78)%,对RPMI 8226细胞为(23.71±2.39)%,P=0.000。结论:RPMI8266细胞逃逸NK细胞免疫杀伤机制可能与该细胞高表达HLA-Ⅰ类分子,低表达NKG2D的配体MICA/B和ULBP1～3分子有关。 OBJECTIVE: To investigate the mechanism of RPMI 8266 escape NK cell immune killing in myeloma cells. Methods: Flow cytometry was used to detect the expression of MICA / B, ULBP1 ~ 3 and HLA-Ⅰ on the surface of K562 and 8266 cells. 4hLDH release assay to determine the effective target ratio of 20: 1 before and after blocking NK cells on the two kinds of cell activity changes. The cytotoxicity of NK cells to RPMI 8226 cells treated with NK cells was observed at 20: 1. The expression of NKG2D ligand and HLA class I molecules on RPMI 8226 cells and the effect of NK cells on the clonogenicity of RPMI 8266 cells were observed. Results: MICA / B and ULBP 1 ~ 3 molecules were highly expressed in K562 cells. HLA-Ⅰ molecules were expressed in RPMI 8266 cells. There was significant difference in NKG2D ligand expression between the two cells (P <0.001). After the MICA / B and ULBP 1 ~ 3 molecules were blocked by the McAbs, the cytotoxic activity of NK cells on K562 cells was significantly decreased at 20: 1, both P <0.05. The killing activity of RPMI 8266 cells was almost no Changes, P values ​​were> 0.05. Anti-W6 / 32 monoclonal antibody blocked the HLA class I molecules on 8266 cell surface, NK cell killing activity of K562 cells was not increased (P = 0.721), while the cytotoxic activity of RPMI 8266 cells increased, P = 0.000.1 / 2IC50 After treatment with arsenic trioxide, the ULBP2 and 3 ligands in RPMI8226 cells were increased (P = 0.000), and the cytotoxicity of NK cells to 8266 cells was significantly different from that in the control group (P = 0.001). After treatment with 1 / 2IC50 bortezomib There was no change in each NKG2D ligand on RPMI 8226 cell surface, P> 0.05. The inhibitory rate of NK cell cloning to K562 cells was (63.48 ± 6.78)% and that of RPMI 8226 cells was (23.71 ± 2.39)%, P = 0.000. CONCLUSION: The mechanism of NK cell immunostaining of RPMI8266 cells may be related to the high expression of HLA class Ⅰ molecules and low expression of NKG2D ligand MICA / B and ULBP1 ~ 3 molecules.