Muhanna N, Horani A, Doron S, Safadi R
Liver/Gastroenterology Units, Division of Medicine, Hadassah University Hospital, Jerusalem, Israel.
Clin Exp Immunol. 2007 May;148(2):338-47. doi: 10.1111/j.1365-2249.2007.03353.x.
Recent functional research studies suggest an anti-fibrotic role for natural killer (NK) cells coupled with a profibrotic role for CD8 cells. However, the morphological cellular interplay between the different cell types is less clear. To investigate lymphocyte/hepatic stellate cell (HSC) interactions, hepatic fibrosis was induced by administering carbon tetrachloride (CCl4) intraperitoneally (i.p.) for 4 weeks in C57Bl/6 mice. Animals were killed at 0, 1, 2, 3 and 4 weeks. Liver sections were stained for Sirius red. Confocal microscopy was used to evaluate alpha smooth-muscle actin (alphaSMA) and lymphocyte subsets in liver sections. At weeks 0 and 4, liver protein extracts were assessed for alphaSMA by Western blotting and isolated liver lymphocytes as well as HSC were analysed by fluorescence activated cell sorter (FACS). Similar to the results obtained from classical Sirius red staining and alphaSMA blotting, analysis of liver sections by confocal microscopy revealed a marked and continuous accumulation of alphaSMA staining along sequential experimental check-points after administering CCl4. Although the number of all liver lymphocyte subsets increased following fibrosis induction, FACS analysis revealed an increase in the distribution of liver CD8 subsets and a decrease of CD4 T cells. Confocal microscopy showed a significant early appearance of CD8 and NK cells, and to a lesser extent CD4 T cells, appearing only from week 2. Lymphocytes were seen in proximity only to HSC, mainly in the periportal area and along fibrotic septa, suggesting a direct interaction. Notably, lymphocyte subsets were undetectable in naive liver sections. Freshly isolated HCS show high expression of major histocompatibility complex (MHC) class II and CD11c. In the animal model of hepatic fibrosis, lymphocytes infiltrate into the liver parenchyma and it is thought that they attach directly to activated HSC. Because HSCs express CD11c/class II molecules, interactions involving them might reflect that HSCs have an antigen-presenting capacity.
最近的功能研究表明，自然杀伤（NK）细胞具有抗纤维化作用，而CD8细胞则具有促纤维化作用。然而，不同细胞类型之间的形态学细胞相互作用尚不清楚。为了研究淋巴细胞/肝星状细胞（HSC）的相互作用，通过在C57Bl/6小鼠腹腔内（i.p.）注射四氯化碳（CCl4）4周来诱导肝纤维化。在0、1、2、3和4周时处死动物。肝切片用天狼星红染色。共聚焦显微镜用于评估肝切片中的α平滑肌肌动蛋白（αSMA）和淋巴细胞亚群。在第0周和第4周，通过蛋白质免疫印迹法评估肝蛋白提取物中的αSMA，并通过荧光激活细胞分选仪（FACS）分析分离的肝淋巴细胞以及HSC。与经典天狼星红染色和αSMA印迹法得到的结果相似，共聚焦显微镜对肝切片的分析显示，在注射CCl4后的连续实验检查点，αSMA染色有明显且持续的积累。尽管纤维化诱导后所有肝淋巴细胞亚群的数量都增加了，但FACS分析显示肝CD8亚群的分布增加，而CD4 T细胞减少。共聚焦显微镜显示CD8和NK细胞在早期显著出现，而CD4 T细胞出现较晚，仅从第2周开始出现。淋巴细胞仅在靠近HSC的位置可见，主要在门静脉周围区域和纤维化间隔处，提示存在直接相互作用。值得注意的是，在未处理的肝切片中未检测到淋巴细胞亚群。新鲜分离的HCS显示主要组织相容性复合体（MHC）II类和CD11c的高表达。在肝纤维化动物模型中，淋巴细胞浸润到肝实质中，并且认为它们直接附着于活化的HSC。由于HSC表达CD11c/II类分子，涉及它们的相互作用可能反映出HSC具有抗原呈递能力。
