Ding Lin, Chen Tao, Wang Xiao-Jing, Zhou Li, Shi Ai-Chao, Ning Qin
Department and Institute of Infectious Diseases, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
J Huazhong Univ Sci Technolog Med Sci. 2013 Aug;33(4):505-510. doi: 10.1007/s11596-013-1150-7. Epub 2013 Aug 1.
The role of hepatic CD69+ natural killer (NK) cells in virus-induced severe liver injury and subsequent hepatic failure is not well defined. In this study, a mouse model of fulminant liver failure (FHF) induced by murine hepatitis virus strain 3 (MHV-3) was used to study the role of hepatic CD69+NK cells in the development of FHF. The CD69 expression in NK cells in the liver, spleen, bone marrow and peripheral blood was detected by using flow cytometry. The correlation between the CD69 level in hepatic NK cells and liver injury was studied. The functional marker (CD107a), and activating and inhibitory receptor (NKG2D and NKG2A) expressed on CD69+NK cells and CD69-NK cells were detected by using flow cytometry. Pro-inflammatory cytokines (IL-9, IFN-γ and TNF-α) were also examined by using intracellular staining. After MHV-3 infection, the number of CD69+NK cells in the liver of BALB/cJ mice was increased markedly and peaked at 72 h post-infection. Similar changes were also observed in the spleen, bone marrow and peripheral blood. Meanwhile, the CD69 expression in hepatic NK cells was highly correlated with the serum level of ALT and AST. The expression of CD107a and NKG2D, as well as the production of TNF-α, IFN-γ and IL-9 in hepatic CD69+NK cells was all significantly up-regulated during 48-72 h post-infection. In contrast, the NKG2A expression was increased in hepatic CD69-NK cells but not in CD69+NK cells. These results suggested that hepatic CD69+NK cells play a pivotal role in the pathogenesis of FHF by enhancing degranulation and cytotoxic ability of NK cells and increasing the production of pro-inflammatory cytokines.
肝内CD69⁺自然杀伤（NK）细胞在病毒诱导的严重肝损伤及随后的肝衰竭中所起的作用尚未明确。在本研究中，利用鼠肝炎病毒3型（MHV-3）诱导的暴发性肝衰竭（FHF）小鼠模型，研究肝内CD69⁺NK细胞在FHF发生发展中的作用。采用流式细胞术检测肝脏、脾脏、骨髓和外周血中NK细胞的CD69表达。研究肝内NK细胞中CD69水平与肝损伤之间的相关性。采用流式细胞术检测CD69⁺NK细胞和CD69⁻NK细胞上表达的功能标志物（CD107a）以及激活和抑制性受体（NKG2D和NKG2A）。还通过细胞内染色检测促炎细胞因子（IL-9、IFN-γ和TNF-α）。MHV-3感染后，BALB/cJ小鼠肝脏中CD69⁺NK细胞数量显著增加，并在感染后72小时达到峰值。在脾脏、骨髓和外周血中也观察到类似变化。同时，肝内NK细胞中的CD69表达与血清ALT和AST水平高度相关。感染后48 - 72小时内，肝内CD69⁺NK细胞中CD107a和NKG2D的表达以及TNF-α、IFN-γ和IL-9的产生均显著上调。相比之下，肝内CD69⁻NK细胞中NKG2A表达增加，而CD69⁺NK细胞中未增加。这些结果表明，肝内CD69⁺NK细胞通过增强NK细胞的脱颗粒和细胞毒能力以及增加促炎细胞因子的产生，在FHF的发病机制中起关键作用。
