Tsutsui H, Nakanishi K, Matsui K, Higashino K, Okamura H, Miyazawa Y, Kaneda K
Section of Immunology, Toneyama Institute for Tuberculosis Research, Osaka, Japan.
J Immunol. 1996 Nov 1;157(9):3967-73.
NK cells, non-T non-B immune effector lymphocytes, are localized in many organs, including liver, as well as in the circulation. To investigate the regulatory mechanism of killing apparatus in hepatic NK cells, we established IL-2-dependent NK cell clones from liver lymphocytes of BALB/c nude mice. To generate the NK cell clones, we incubated liver lymphocytes with a high dose of IL-2 in the presence of irradiated Kupffer cells, as feeder cells and as the source of IL-12, originally identified as NK cell stimulatory factor. Unless liver lymphocytes were incubated with both IL-2 and Kupffer cells, no cell growth was observed. Hepatic NK cell clones were established from this cell line by limiting dilution. The surface phenotypes of cloned NK cells were IL-2R beta-chain+ CD16+ CD3- IgM-. The clones did not express NK2.1, which is expressed by a half of NK-enriched spleen cells of BALB/c mice. Although the cells contained dense granules reactive to mAb against perforin, they exerted no conventional cytolytic activity against YAC-1. They constitutively expressed Fas ligand (FasL) and specifically killed Fas-positive target cells by fragmenting DNA. This Fas-FasL-mediated killing activity was enhanced by IFN-gamma-inducing factor, a recently identified novel cytokine produced by activated Kupffer cells, but was not affected by other Kupffer cell-produced cytokines, such as IL-12, IL-1beta, and TNF-alpha. Taken together, these findings suggest that hepatic NK cells participate in the immune response as effector cells through the Fas-FasL system in collaboration with cytokines from Kupffer cells.
自然杀伤（NK）细胞作为非T非B免疫效应淋巴细胞，定位于包括肝脏在内的许多器官以及血液循环中。为了研究肝脏NK细胞杀伤机制的调控机理，我们从BALB/c裸鼠的肝脏淋巴细胞中建立了依赖白细胞介素-2（IL-2）的NK细胞克隆。为了获得NK细胞克隆，我们将肝脏淋巴细胞与高剂量的IL-2一起孵育，同时存在经辐照的库普弗细胞，作为饲养细胞以及IL-12的来源，IL-12最初被鉴定为NK细胞刺激因子。除非肝脏淋巴细胞与IL-2和库普弗细胞一起孵育，否则未观察到细胞生长。通过有限稀释法从该细胞系中建立了肝脏NK细胞克隆。克隆的NK细胞的表面表型为IL-2Rβ链阳性、CD16阳性、CD3阴性、IgM阴性。这些克隆不表达NK2.1，而BALB/c小鼠中一半富含NK细胞的脾细胞表达NK2.1。尽管这些细胞含有对穿孔素单克隆抗体有反应的致密颗粒，但它们对YAC-1没有传统的细胞溶解活性。它们组成性表达Fas配体（FasL），并通过DNA片段化特异性杀伤Fas阳性靶细胞。这种Fas-FasL介导的杀伤活性被IFN-γ诱导因子增强，IFN-γ诱导因子是最近鉴定出的一种由活化的库普弗细胞产生的新型细胞因子，但不受其他库普弗细胞产生的细胞因子如IL-12、IL-1β和TNF-α的影响。综上所述，这些发现表明肝脏NK细胞通过Fas-FasL系统与库普弗细胞产生的细胞因子协同作用，作为效应细胞参与免疫反应。
