Transfer RNA Modifications in the Immune System Participate in Disease Pathogenesis.

The human immune system executes immune defense against foreign antigens, immune surveillance against mutant cells, and immune homeostasis to maintain bodily physiological equilibrium. Transfer RNA (tRNA) is an important part of gene expression regulation. Recent studies have found that aberrant tRNA modifications can disturb the function of the immune system by altering translation efficiency, including regulating immune recognition and signal transduction, as well as influencing apoptosis and autophagy. tRNA modifications are also closely related to the development and occurrence of immune-related disorders such as infections, tumors, and autoimmune diseases. By integrating current research on immune-related tRNA modifications, this review systematically summarizes the mechanisms of tRNA modifications involved in three major immune functions and their relationship with related diseases, encompassing the direct regulation of immune cells and the indirect immune effects mediated through tissue or tumor cells. In addition, some tRNA modifications can also modulate immune responses by affecting tRNA cleavage and the consequent generation of tRNA-derived small RNAs (tsRNAs). Accordingly, this review outlines promising intervention targets and unresolved research bottlenecks, facilitating follow-up investigations into tRNA modification-dependent immune regulation and translational therapeutic research.