2 NKT cells are abundant in the liver. They recognize lipid antigens presented by CD1d and had different roles in liver diseases. NKT cells produce a wide range of cytokines promptly after activation.23 It is well accepted that Th1 cytokines suppress fibrosis, whereas Th2 cytokines promote fibrosis.24 In wildtype (WT) mice, it was reported that NKT cells can suppress the activation of HSC.22 But in different animal models and in human patients the conclusions were controversial.25, 26 Although the acceleration of HBV infection to liver fibrosis BYL719 have been extensively observed in clinical settings,

the immune response during this process is not clear, especially in the condition of the HBV carriers with no obvious symptoms. In this study, by using HBV transgenic mice (HBV-tg) that mimic human HBV healthy carriers,27 we found liver fibrosis spontaneously occurred in old age of HBV-tg mice, and, importantly, 5-Fluoracil ic50 HBV-tg mice were much more sensitive to the hepatotoxin CCl4-induced liver injury and liver fibrosis with the accompanied overactivation of HSCs. Further study demonstrated

that hepatic NKT cells from HBV-tg mice could directly activate HSCs and thereafter induce liver fibrosis in the experiments of cellular depletion and adoptive transfer, and IL-4 and IL-13 secreted by NKT cells were considered a crucial step for the activation of HSCs. α-SMA: α smooth muscle actin; CCl4: carbon tetrachloride; ECM: extracellular matrix; HBV: hepatitis B virus; HBV-tg: HBV transgenic mice; HSC: hepatic stellate cells; IFN-γ, interferon gamma; IL: interleukin; MMP: matrix metalloproteinase; MNC: mononuclear cell; mRNA: messenger RNA; NKT, natural killer T; qPCR: quantitative polymerase chain reaction; TIMP: tissue inhibitor of metalloproteinase. selleck chemicals HBV transgenic mice C57BL/6J-TgN (AlblHBV) 44Bri, which contains HBV genome S, pre-S, and X domains, were purchased from VITALRIVER experiment animal company (Beijing, China), who obtained the animals from Jackson Laboratory

(Bar Harbor, ME). C57BL/6 mice were also purchased from VITALRIVER experiment animal company. Rag1−/− mice were purchased from Model Animal Research Center (Nanjing, China), who obtained the mice from Jackson Laboratory. Mice were housed in a specific pathogen-free facility and used according to the regulations of animal care of University of Science and Technology of China. For chronic liver injury and fibrosis, male 7 to 10-week-old C57BL/6 and HBV-tg mice (weighing about 20-25 g) were injected (intraperitoneally, i.p., 2 times a week) with 0.5 μL per gram of body weight of pure CCl4 diluted with olive oil (Sigma). After several weeks’ injections (2, 4, 10, and 14 weeks, respectively), mice were sacrificed 72 hours following the last CCl4 injection, and liver tissues and serum were collected. For acute liver injury, both mice were injected CCl4 once and then killed and analyzed at different timepoints.