TIGIT Emerges as a Breakthrough Second-Generation Immune Checkpoint Target to Overcome Cancer Immunotherapy Resistance
核心洞察
TIGIT (搜索) is broadly expressed on T cells, NK cells, and regulatory T cells, exerting immunosuppressive effects by competitively binding CD155 (搜索) and CD112 (搜索) ligands to block CD226 (搜索) co-stimulatory signaling.
Elevated TIGIT (搜索) expression correlates with poor prognosis across multiple cancers including breast, colorectal, and pancreatic malignancies, and outperforms PD-1 (搜索) in defining exhausted CD8+ T-cell phenotypes.
The phase II CITYSCAPE trial demonstrated that combining anti-TIGIT (搜索) antibody tiragolumab with anti-PD-1 (搜索) agent atezolizumab significantly improved objective response rates and progression-free survival in NSCLC patients.
Despite significant advances in conventional cancer treatments and the introduction of first-generation immune checkpoint inhibitors, malignant tumors continue to pose formidable challenges due to therapeutic resistance and modest response rates. Now, a comprehensive review published in the Journal of Pancreatology on March 30, 2026, positions T-cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain (TIGIT (搜索)) as a compelling second-generation target poised to reshape the immunotherapy landscape.
The review, authored by researchers from Qilu Hospital of Shandong University, synthesizes the growing body of evidence supporting TIGIT (搜索)'s central role in tumor immune evasion and its therapeutic potential across a range of malignancies.
TIGIT (搜索)'s Multifaceted Immunosuppressive Mechanisms
TIGIT (搜索) distinguishes itself from other emerging checkpoints such as LAG-3 and TIM-3 through its broad expression across immune cells integral to anti-tumor immunity, notably T cells, natural killer (NK) cells, and regulatory T cells (Tregs). Mechanistically, TIGIT exerts immunosuppressive influence primarily through competitive engagement with ligands CD155 (搜索) and CD112 (搜索), interrupting the activating signals mediated by CD226 (搜索), a co-stimulatory receptor imperative for robust T and NK cell cytotoxic activity.
Beyond ligand competition, TIGIT (搜索) interferes with the cis-dimerization of CD226 (搜索), further dampening cytotoxic signaling pathways. The molecule also directly binds CD155 (搜索) expressed on dendritic cells, hindering their maturation and function — an effect compounded by TIGIT-mediated induction of the anti-inflammatory cytokine interleukin-10 (IL-10). This cytokine milieu skews the immune response away from effective tumor eradication while simultaneously fostering Treg maturation and elevated expression of the transcription factor Foxp3.
Prognostic Significance Across Cancer Types
Clinical evidence links elevated TIGIT (搜索) expression to poor prognosis in multiple cancers. Comprehensive analyses of The Cancer Genome Atlas (TCGA) data reveal that heightened TIGIT expression in breast cancer (搜索) tissues significantly associates with diminished overall survival rates and reduced progression-free intervals. Similar correlations have been substantiated in colorectal and pancreatic cancers.
Notably, TIGIT (搜索) outperforms PD-1 (搜索) in defining tumor CD8+ T-cell phenotypes, underscoring its utility beyond a therapeutic target and extending into realms of prognostication and personalized medicine. Its superior specificity in delineating exhausted CD8+ T-cell phenotypes compared to PD-1 enhances its potential as a biomarker with sensitivity that, in some cases, surpasses that of the well-characterized PD-1 checkpoint.
Clinical Translation and Combinatorial Strategies
While TIGIT (搜索) monotherapy has exhibited limited efficacy in clinical settings, dual blockade of TIGIT and PD-1 (搜索) pathways has demonstrated profound immunologic synergy. The phase II CITYSCAPE trial exemplifies this approach: the anti-TIGIT antibody tiragolumab, in combination with the anti-PD-1 agent atezolizumab, markedly improved objective response rates and progression-free survival in non-small cell lung cancer (搜索) (NSCLC) patients compared to PD-1 inhibition alone, with manageable safety profiles.
This synergy is attributed to TIGIT (搜索) blockade's capacity to reverse T-cell exhaustion and mitigate NK cell depletion, effectively overcoming mechanisms of PD-1 (搜索) resistance.
Pipeline Advances and Next-Generation Agents
Several TIGIT (搜索) inhibitors are currently advancing through late-phase clinical trials. Agents such as vibostolimab, tiragolumab, and ociperlimab are in phase III trials, demonstrating promising profiles in solid tumors. Concurrently, innovative platforms are developing dual-target antibodies — exemplified by candonilimab, which concurrently targets TIGIT and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4 (搜索)) — aiming to amplify immunostimulatory effects while curtailing toxicity.
Future Directions
Future research directives are poised to refine this therapeutic landscape by identifying robust biomarkers predictive of response to TIGIT (搜索)-targeted treatment, optimizing dosing regimens, and exploring combinatorial frameworks with metabolic or epigenetic modulators. The integration of these approaches promises to enhance the durability and breadth of clinical responses, potentially transforming current paradigms of cancer management.
By intricately modulating multiple axes of immune regulation, TIGIT (搜索) inhibition offers a strategic lever to recalibrate antitumor immunity, surmounting the resistance that plagues existing immunotherapeutic regimens. As the scientific and clinical communities continue to harness the intricate biology of TIGIT and integrate it into multi-modal treatment regimens, the field stands on the cusp of a paradigm shift toward achieving durable, robust antitumor immunity.