The promising clinical outcomes of tumor-infiltrating lymphocytes (TIL) therapy, a type of adoptive cellular therapy using infiltrated lymphocytes from resected tumor samples, have spurred interest in generating personalized, patient-specific TIL to recognize and target diverse cancer cells. Accurate antigen transfer to dendritic cells, which then reinvigorates a patient’s TIL with superior tumor-homing ability and low off-target toxicity in treating solid tumor malignancies, is the crucial step of successful immunotherapies and cancer vaccines. Presently, the central antigen-loading system in TIL therapy uses a coculture of tumor lysates and dendritic cells. However, due to the insufficient loaded antigens into dendritic cells or the low quality of ex vivo differentiated dendritic cells, and the lack of effective examining methods to evaluate the immune response induced by tumor antigens, the responsiveness of conventional TIL immunotherapy treatment is not satisfied. We are pioneering a transformational approach to improve tumor antigen loading and let dendritic cells select and detect proper tumor antigens for triggering strong TIL responses. This in vivo and ex vivo antigen-specific T cell response assessment platform has implications for improving T cell- based immunotherapies and cancer vaccines. With this cutting-edge platform, a series of TIL therapy pipelines have been established and are scheduled to enter the clinical stage in the coming future.