肝脏微环境变化是非酒精性脂肪性肝病(NAFLD)发病中的主要病理生理改变，其中关于免疫因素的研究主要集中在肝脏T细胞方面，而B淋巴细胞的研究鲜见。但研究表明B细胞在肥胖等与NAFLD常伴随的疾病中却发挥着重要作用。我们前期实验发现NAFLD小鼠肝脏内B细胞含量升高，提示肝脏B细胞参与了疾病发生；并且肠系膜淋巴结的B细胞回输后可向肝脏迁移，NAFLD小鼠肝脏匀浆上清对肠系膜淋巴结B细胞趋化能力更强，这些研究提示肠道B细胞也参与了NAFLD发生。因此本研究拟通过野生型NAFLD小鼠和B细胞缺陷型高脂喂养小鼠模型进行体内实验；并通过T细胞和B细胞共培养等体外实验，采用流式细胞术，RT-PCR及细胞回输实验等研究肝脏及肠道B细胞，尤其是表达CCR9、α4β7分子的B细胞在NAFLD发生中的变化情况及功能机制，进一步诠释NAFLD发生时肝肠轴的免疫机制。

Hepatic microenviornment variation is the major pathophysiological change during the progression of nonalcoholic fatty liver disease (NAFLD). Although many investigations about the immune factors in NAFLD had done, they were mainly focused on the function of T lymphocytes. Few studies were related with the influence of B lymphocytes in the pathogenesis of NAFLD. However, B lymphocytes play an important role in the pathogenesis of obesity and other diseases often associated with NAFLD. Our previous data showed the level of B lymphocytes was increased in the liver of NAFLD mice model, which indicated the hepatic B cells promoted this disease. Meanwhile, our previous study showed the B lymphocytes of mesenteric lymph node (MLN) could migrate to the liver. And the transwell assay showed the NAFLD liver homogenate attracted the mesenteric B lymphocytes more effectively than the control groups did. These facts provided clues that intestinal B cells were involved in the pathogenesis of NAFLD and could influence the liver of NAFLD as well. Therefore, this study aims to investigate the role of B lymphocytes in both the liver and the gut, especially the CCR9+ and α4β7+ B cells, during the progression of NAFLD by conducting experiments, such as flow cytometry analysis, Real-time PCR and cell reinfusion, both in vivo and in vitro. The former one includes the studies with wild-type NAFLD mice model and B cell-deficient mice model feeding with high fat diet, and the latter consists the coculture of B lymphocytes and T lymphocytes et al. To sum up, in this present study, we will investigate the alterations and the influences of hepatic and intestinal B lymphocytes and the CCR9+ α4β7+ B lymphocytes in the pathogenesis of NAFLD to shed light on the immune mechanisms of the liver-gut axis.