Trends in Adoptive Tumor Infiltrating Lymphocytes (TILs) Therapy

Adoptive T cell therapy based on tumor infiltrating lymphocytes (TILs) is the most effective treatment for malignant melanoma. The TILs therapy has demonstrated high overall response rates, resulting in tumor regression and prolonged survival in comparison to IL-2 and ipilimumab treatments. Expansion of TILs under exvivo conditions using patients’ own tumor tissue is a prerequisite for effective adoptive transfer immunotherapy. The process involves growing cells in the presence of IL-2, followed by identification of tumor reactive cells by immunoassays. The treatment itself is safe but preconditioning with chemo or radiotherapy prior to TILs infusion and IL-2 administration is associated with severe side effects. Chemotherapy depletes regulatory T cells and thus enhances efficacy of TILs. Studies have demonstrated that dendritic cell (DC) vaccine augments T cell activation and its infiltration to the primary tumor site. The combination of TILs and DC may circumvent the need for IL-2 injection. This hypothesis is still under investigation for further clinical evidences. This review focuses on the clinical developments of the TILs based adoptive T therapy and its possible combination with DC vaccine.