中文摘要：

目的 探讨人CD56^＋NK细胞亚群、表型和生物学特征。方法 分离正常人外周血单个核细胞，利用多种抗体进行细胞表面和细胞内细胞毒效应分子（颗粒酶B和穿孔素）染色，通过流式细胞仪，在单个细胞水平上分析CD56^＋NK细胞亚群的表型及其生物学特征。结果 根据CD56分子表达密度的不同，将人外周血中NK细胞分为CD56^bright出和CD56^dim两大亚群。CD56^bright和CD56^dim细胞均表达CD95，CD56^bright细胞亚群中，CD95^bright和CD95^dim表达百分率分别为21．4％和77．0％；CD56^dim细胞亚群中，CD95^bright和CD95^dim表达百分率分别为23．1％和75．6％。与CD56^bright出细胞亚群相比，CD56^bright细胞表达CD8、颗粒酶B和穿孔素细胞的阳性率较高，分别为9．1％、6．2％和8．O％。在CD56^bright和CD56^bright亚群中，CD95^brightCD8^＋亚群高表达颗粒酶B和穿孔素。结论 人外周血CD56^＋NK细胞由不同表型和生物学特征的细胞亚群组成，CD56^dim”和CD56^dimCD8^＋NK细胞亚群在杀伤破坏靶细胞中发挥重要作用。

英文摘要：

Objective To characterize the phenotypic and biological properties of CD56^＋ natural killer cells from human peripheral blood mononuclear cells （PBMCs）. Methods Surface markers and intracellular cytotoxic molecules were stained with multi-color-labeled monoclonal antibodies and analyzed at the single cell level the relation between NK subsets and biological characteristics by flow cytometry. Results NK cells in PBMCs could be divided into two major populations, CD56bright and CD56^dim, based upon the expression of CD56 molecules. Both CD56^brigt and CD56^dim expressed CD95 （Fas） with CD95^bright and CD95^dim subsets. CD56^dim subsets had higher percentage of CD8, granzyme B and perforin expression compared to those of CD56^bright subsets. In CD56^bright and CD56^dim subpepulations, CD95^bright and CD8^＋ subsets had higher percentage of granzyme B and perforin expression. Conclusion CD56^＋ NK cells in PBMCs are composed of distinct subpepulations, CD56^dim and CD56^diam CD8^＋ NK subsets have higher percentage of ganzyme B and perforin and may play an important role in the killing of target cells.