AUTHOR=Her Zhisheng , Tan Joel Heng Loong , Lim Yee-Siang , Tan Sue Yee , Chan Xue Ying , Tan Wilson Wei Sheng , Liu Min , Yong Kylie Su Mei , Lai Fritz , Ceccarello Erica , Zheng Zhiqiang , Fan Yong , Chang Kenneth Tou En , Sun Lei , Chang Shih Chieh , Chin Chih-Liang , Lee Guan Huei , Dan Yock Young , Chan Yun-Shen , Lim Seng Gee , Chan Jerry Kok Yen , Chandy K. George , Chen Qingfeng TITLE=CD4+ T Cells Mediate the Development of Liver Fibrosis in High Fat Diet-Induced NAFLD in Humanized Mice JOURNAL=Frontiers in Immunology VOLUME=11 YEAR=2020 URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2020.580968 DOI=10.3389/fimmu.2020.580968 ISSN=1664-3224 ABSTRACT=

Non-alcoholic fatty liver disease (NAFLD) has been on a global rise. While animal models have rendered valuable insights to the pathogenesis of NAFLD, discrepancy with patient data still exists. Since non-alcoholic steatohepatitis (NASH) involves chronic inflammation, and CD4+ T cell infiltration of the liver is characteristic of NASH patients, we established and characterized a humanized mouse model to identify human-specific immune response(s) associated with NAFLD progression. Immunodeficient mice engrafted with human immune cells (HIL mice) were fed with high fat and high calorie (HFHC) or chow diet for 20 weeks. Liver histology and immune profile of HIL mice were analyzed and compared with patient data. HIL mice on HFHC diet developed steatosis, inflammation and fibrosis of the liver. Human CD4+ central and effector memory T cells increased within the liver and in the peripheral blood of our HIL mice, accompanied by marked up-regulation of pro-inflammatory cytokines (IL-17A and IFNγ). In vivo depletion of human CD4+ T cells in HIL mice reduced liver inflammation and fibrosis, but not steatosis. Our results highlight CD4+ memory T cell subsets as important drivers of NAFLD progression from steatosis to fibrosis and provides a humanized mouse model for pre-clinical evaluation of potential therapeutics.