TIGIT promotes CD8+T cells exhaustion and predicts poor prognosis of colorectal cancer

This study aimed at identifying the function of TIGIT in colorectal cancer. Patients with colorectal cancer showed significantly higher TIGIT+CD8+T cell infiltration in tumor tissues, metastases compared with paired PBMC and normal tissues through flow cytometry. TIGIT+CD8+T cells showed an exhausted phenotype and expressed low levels of killer cytokines IFN- γ, IL-2, TNF-α. In addition, more inhibitory receptors such as PD-1, LAG-3, and TIM-3 were expressed on the surface of TIGIT+CD8+T cells. TGF- β1 could promote the expression of TIGIT and inhibit CD8+T cell function in vitro. Moreover, the accumulation of TIGIT+T cells in tumors was associated with advanced disease, predicted early recurrence, and reduced survival rates in colorectal cancer patients. Our results indicate that TIGIT can be a biological marker for the prognosis of colorectal cancer, and TIGIT can be used as a potential target for treatment.
Source: Cancer Immunology, Immunotherapy - Category: Cancer & Oncology Source Type: research