Background & AimsThe function of cholinergic anti-inflammatory pathway (CAP) in acute liver failure (ALF) with inflammatory storm remains indefinite. The liver-gut-axis has been proved to be crucial for liver homeostasis. Investigation about CAP regulation on liver-gut-axis would enrich our understanding over cholinergic anti-inflammatory mechanism. MethodsCo-injection of Lipopolysaccharide and D-galactosamine were used to establish the model of ALF. PNU-282987 was used to activate the CAP. Histological staining, qRT-PCR, western blotting, RNA-Sequencing and flow cytometry were conducted. Liver biopsy specimens and patients’ serum from liver failure patients were also analyzed. ResultsWe confirmed that activating the CAP alleviated hepatocyte destruction, accompanied by a significant decrease in hepatocyte apoptosis, pro-inflammatory cytokines, and NLRP3 inflammasome activation. Moreover, hepatic MAdCAM1 and serum MAdCAM1 levels were induced in ALF and MAdCAM1 levels were positively correlated with the extent of liver damage and the expression of pro-inflammatory markers. Furthermore, Activating the CAP mainly downregulated ectopic expression of MAdCAM1 on endothelial cells, and inhibition of NF-κB p65 nuclear translocation was partly attributed to the decreased MAdCAM1. Notably, in ALF, the aberrant hepatic expression of MAdCAM1 subsequently recruited gut-derived α4β7+ CD4+T cells to the liver, which exhibited an augmented IFN-γ-secreting and IL-17-producing phenotype. Finally, we revealed that the levels of serum and hepatic MAdCAM1 were elevated in patients with liver failure and closely correlated with clinical course. Increasing hepatic infiltration of β7+ cells were also confirmed in patients. ConclusionsActivating the CAP attenuated liver injury by inhibiting MAdCAM1/α4β7 -mediated gut-derived proinflammatory lymphocytes infiltration, which provides a potential therapeutic target for ALF.