TIGIT/CD226 Axis Regulates Anti-Tumor Immunity

Area of Science:

• Immunology
• Oncology
• Molecular Biology

Background:

• Tumors evade immune surveillance through immunosuppressive pathways, notably inhibitory receptors on T cells.
• Current immune checkpoint inhibitors like anti-PD-1/PD-L1 and anti-CTLA-4 benefit only a subset of cancer patients.
• There is a critical need for novel therapeutic targets in cancer immunotherapy.

Purpose of the Study:

• To review recent findings on T cell immunoreceptor with Ig and immunoreceptor tyrosine-based inhibitory motif (ITIM) domains (TIGIT) and CD226 in cancer immunotherapy.
• To explore the potential of TIGIT and CD226 as targets for novel cancer treatments.
• To discuss the role of TIGIT in combination therapy with PD-1/PD-L1 blockade.

Main Methods:

• Literature review of recent discoveries on TIGIT and CD226.
• Analysis of TIGIT's role as an inhibitory checkpoint receptor on T and natural killer cells.
• Discussion of CD226's opposing stimulatory function and shared ligands with TIGIT.

Main Results:

• TIGIT acts as an inhibitory receptor, dampening adaptive and innate immunity.
• CD226 competes with TIGIT for ligand binding, providing a stimulatory signal.
• Anti-TIGIT monoclonal antibody (tiragolumab) combined with anti-PD-L1 shows clinical efficacy in non-small cell lung cancer.

Conclusions:

• TIGIT represents a promising target for cancer immunotherapy, potentially overcoming limitations of current treatments.
• Combination strategies involving TIGIT blockade, such as with anti-PD-L1, are advancing to clinical trials.
• Understanding the interplay between TIGIT and CD226 is crucial for developing effective immunotherapies.