ABSTRACT
@#The T-cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain (TIGIT) is an inhibitory receptor mainly expressed on active T-cells, or natural killer cells (NK cells) that activate negative stimulus signals in immune cells by combining with multiple ligands on the surface of target cells including tumor cells and infected cells. TIGIT plays an important regulatory role in the immune pathogenesis of tumors, viral infections and various autoimmune diseases by inhibiting the over activation of cells and the over secretion of proinflammatory cytokines. Recent researches show that TIGIT is highly expressed in T cells and NK cells of cancer patients, and is related to disease progression and poor clinical prognosis. Researchers try to enhance the activity of T cells or NK cells by blocking the binding of TIGIT and its ligand for therapeutic intervention. At present, there have been many reports about the use of anti-TIGIT monoclonal antibody treatment in different mouse tumor models leading to tumor regression, TIGIT has received extensive attention in cancer immunotherapy as a promising target for next generation cancer immunotherapy. Several clinical trials are currently evaluating the efficacy of anti-TIGIT monoclonal antibodies (mAbs) in patients with several cancers. The most advanced candidate, tiragolumab, has exhibited remarkable efficacy in programmed cell death ligand 1 (PD-L1)-positive non-small cell lung carcinoma (NSCLC) patients in phase Ⅱ clinical trials, in combination with PD-L1 blockade. However, the specific mechanism of TIGIT blockade remains to be fully elucidated.