Diverse immunological roles of liver‐resident immune cells in liver diseases

Abstract The liver immune microenvironment is a complex system regulated by the interaction between circulating immune cells and resident immune cell populations. In recent years, liver resident immune cells (LRICs) have received increasing attention as an important cell population for regulating liver pathology. These types of non‐circulating liver cells have unique adaptability, not only meeting the metabolic needs of the liver but also maintaining its immune homeostasis. The advancement of high‐throughput technology has enabled in‐depth research on the unique origin, developmental pathways, and functional plasticity of LRICs. LRICs can initiate rapid, strong, and long‐lasting tissue‐specific immune responses to effectively curb disease progression. However, these powerful abilities may translate into pathogenic factors in specific situations: triggering tissue damage in the autoimmune environment and mediating graft rejection after liver transplantation. This article systematically reviews the current understanding of these key resident immune cell populations, details their multidimensional and often paradoxical mechanisms of action in a variety of major liver pathologies, and discusses the prospects of emerging therapeutic strategies for these key cell players.