T-cell immunoglobulin and mucin-domain containing-3 (TIM-3): Solving a key puzzle in autoimmune diseases.

• Comprehensive Analysis: The review provides a detailed exploration of the structure, signal transduction, and various ligands of T-cell immunoglobulin and mucin-domain containing-3 (TIM-3), an immune checkpoint molecule. • Clinical Implications: We delve into the role of TIM-3 in the pathogenesis of a range of autoimmune diseases and chronic inflammatory conditions, offering insights into potential therapeutic strategies. • Recent Findings: Our perspectives in the review are not only based on existing literature, but are also informed by our most recent research findings on TIM-3, bringing a fresh outlook to the field. • Bridging Basic Science with Clinical Practice: This review creates a comprehensive resource that merges foundational knowledge with cutting-edge research findings, offering valuable insights for a broad range of readers, including researchers, clinicians, and students. • Timely Contribution: Given the current interest in immune checkpoint molecules like TIM-3, this review makes a significant contribution to the literature, addressing a topic of high relevance in both research and clinical settings. Dysfunctional immune cells participate in the pathogenesis of a variety of autoimmune diseases, although the specific mechanisms remain elusive and effective clinical interventions are lacking. Recent research on immune checkpoint molecules has revealed significant expression of T cell immunoglobulin and mucin domain-containing protein 3 (TIM-3) on the surfaces of various immune cells. These include different subsets of T cells, macrophages, dendritic cells, natural killer cells, and mast cells. Further investigation into its protein structure, ligands, and intracellular signaling pathway activation mechanisms has found that TIM-3, by binding with different ligands, is involved in the regulation of crucial biological processes such as proliferation, apoptosis, phenotypic transformation, effector protein synthesis, and cellular interactions of various immune cells. The TIM-3-ligand axis plays a pivotal role in the pathogenesis of numerous conditions, including autoimmune diseases, infections, cancers, transplant rejection, and chronic inflammation. This article primarily focuses on the research findings of TIM-3 in the field of autoimmune diseases, with a special emphasis on the structure and signaling pathways of TIM-3, its types of ligands, and the potential mechanisms implicated in systemic lupus erythematosus, multiple sclerosis, rheumatoid arthritis, as well as other autoimmune diseases and chronic inflammation. The latest research results in the field of immunology suggest that TIM-3 dysfunction affects various immune cells and participates in the pathogenesis of diseases. Monitoring the activity of its receptor-ligand axis can serve as a novel biological marker for disease clinical diagnosis and prognosis evaluation. More importantly, the TIM-3-ligand axis and the downstream signaling pathway molecules may become key targets for targeted intervention treatment of autoimmune-related diseases. [ABSTRACT FROM AUTHOR]