TIGIT+ CD4+ T Cell Enrichment in Colorectal Liver Metastases Is Associated with Shorter Survival

Abstract

Simple Summary Colorectal cancer frequently spreads to the liver, where the local immune environment may limit the effectiveness of immunotherapy. We examined immune cells from blood, non-tumor liver tissue, and colorectal cancer liver metastases. Freshly isolated immune cells from 17 patients were analyzed, and a separate cohort of 19 patients was studied after ex vivo expansion of tumor-infiltrating lymphocytes. Higher TIGIT expression on CRCLM-infiltrating CD4+ T cells was associated with shorter survival in optimized cut-off analyses, whereas PD-1 expression was not. Continuous Cox estimates showed the same direction of association, and a similar survival pattern was observed in the separate expanded-cell cohort. Together, these findings identify TIGIT+ CD4+ T cell enrichment as a promising candidate marker in CRCLM and provide a rationale for prospective biomarker and functional investigation.