Deciphering antigen-specific T cell navigation tactics and cancer immune evasion in co-cultures.

Insufficient infiltration of cytotoxic T cells into solid tumors remains a critical obstacle in cancer immunotherapy. Despite extensive efforts to comprehend the mechanisms governing this limited infiltration, few studies have focused on the evolution of T cell motility behavior after co-culture. In this study, we combined quantitative cell trajectory analysis, computational modeling, and bulk/single-cell RNA sequencing to systematically characterize the impact of cell interactions. We reveal that in a 2.5D co-culture system with multiple cancer-cell clusters, cancer-specific T cells exhibit increased directional persistence, which facilitates their efficient searching of cancer-cell clusters. Additionally, these T cells form prolonged interactions with cancer cells, which is the most crucial factor for their accumulation on cancer-cell clusters. Furthermore, post-interaction, a cancer-cell subpopulation displays immunosuppressive traits, reducing T cell attractant expression, and undergoing epithelial-to-mesenchymal transition. These findings offer valuable insights into improving immunotherapy efficacy and tackling T cell infiltration challenges in solid tumors.