中文摘要：

目的：自然杀伤细胞（ NK）不表达HLA-G抗原，将其与K562-G1细胞共培养，可检测到NK细胞表面表达HLA-G1蛋白，研究NK细胞表面获取HLA-G1抗原的机制。方法建立稳定表达HLA-G1抗原的K562细胞株；分别将K562-G1、K562、脱落的HLA-G1与NK-92MI细胞共培养，以及将HLA-G1与NK-92MI细胞上的HLA-G受体进行阻断后进行共培养，通过流式细胞术及荧光显微镜技术检测NK-92MI细胞对HLA-G1蛋白的获取情况。通过基于CD107a标记的流式细胞术，检测K562细胞表达HLA-G1前后对NK-92MI细胞杀伤活性的影响。结果 NK-92MI细胞能通过细胞间的相互接触转移快速获取K562-G1细胞表面的HLA-G1蛋白。 HLA-G特异性抗体87G阻断或其受体KIR2DL4特异性抗体＃33和ILT2受体特异性抗体阻断后，均不影响NK-92MI细胞对HLA-G1的获取。功能研究显示，HLA-G1能显著抑制NK细胞对K562细胞的杀伤活性（P＜0．01）。结论 NK细胞通过胞啃机制快速获取HLA-G1蛋白，其转移机制与受体配体间的亲和力、HLA-G1分子胞外结构域及非特异性的被动黏附作用无关。

英文摘要：

Objective To investigate the mechanism of acquisition of HLA-G1 antigen by NK cells.Methods K562 cells stably expressing HLA-G1 antigen （K562-G1） were constructed.K562-G1 cells, K562 cells and shed HLA-G1 were respectively co-cultured with NK-92MI cells to observe the acquisi-tion of HLA-G by NK cells.To further investigate the mechanism , NK-92MI cells with blockage HLA-G re-ceptors were further co-cultured with K562-G1 cells and HLA-G1 proteins expressing on K 562-G1 cells were blocked and then co-cultured with NK-92MI cells. Acquisition of HLA-G 1 by NK-92MI cells was analyzed by flow cytometry and fluorescence microscopy .The effects of HLA-G1 expression on the cytotoxicity of NK-92MI cell were evaluated by flow cytometry analysis based on CD 107a labeling.R esults NK-92MI cells could quickly acquire HLA-G1 from K562-G1 cells in co-culture experiments .Blockade of HLA-G1 or its re-ceptors KIR2DL4 and ILT2 with specific mAbs did not affect the acquisition of HLA-G1 by NK-92MI cells. Moreover, HLA-G1 could significantly inhibit the cytotoxicity of NK cell （ P〈0.01）.Conclu sion NK-92MI cells acquire HLA-G1 from K562-G1 cells via trogocytosis , which is not associated with affinity be-tween receptor and ligand , extracellular domain of HLA-G1 or passive adhesion .