Hepatic cholinergic T cell signaling mediates an adaptive response to alcohol-induced liver stress

Abstract

Alcohol-associated liver disease (ALD) is a major cause of liver-related morbidity and mortality, yet no targeted, disease-modifying therapy exists and the immune mechanisms driving disease progression remain poorly defined. Acetylcholine-producing cholinergic immune cells have emerged as regulators of homeostasis across tissues and in disease, but their role in alcohol-induced hepatic stress is unknown. Here, we characterized the hepatic cholinergic immune landscape during alcohol-induced stress using flow cytometry and single-cell RNA-sequencing of ChAT-eGFP reporter mice. Alcohol feeding expanded hepatic cholinergic immune cells, with T cells constituting a substantial and dynamic fraction of this population that showed a broad increase in acetylcholine signaling and shifted towards a repressed, anergy-like transcriptional state. CD4 T cells underwent coordinated suppression of cholesterol biosynthesis, while CD8 T cells instead adopted a cytotoxic activation program. Together, these findings identify cholinergic T cell signaling, and cholesterol metabolism within CD4 T cells specifically, as a previously unrecognized adaptive response to alcohol-induced liver stress, nominating candidate therapeutic targets for a disease that is marred by critically limited treatment options.