Flow Cytometry-Based Isolation and Therapeutic Evaluation of Tumor-Infiltrating Lymphocytes in a Mouse Model of Pancreatic Cancer

Pancreatic cancer is an aggressive malignancy with a dismal prognosis and limited therapeutic options. Adoptive cell therapy, which involves isolating and activating a patient's own immune cells, such as tumor-infiltrating lymphocytes (TILs), before re- infusing them, represents a promising experimental approach. However, techniques for adoptive cell transfer in preclinical pancreatic cancer models are not well established. Here, we describe a detailed protocol for adoptive cell therapy using TILs from a syngeneic pancreatic cancer mouse model. The procedure involves implanting live or irradiated mouse pancreatic cancer cells in fluorescence-labeled reporter mice to initiate immune cell influx, then isolating lymphocytes from primary tumors via flow cytometry sorting and/or activating and expanding tumor-reactive T cells ex vivo, and adoptively transferring these activated T cells intraperitoneally into tumor- bearing mice, followed by interleukin-2 administration. Bioluminescent tumor imaging allows for longitudinal monitoring of orthotopic tumor growth and response to therapy, especially evaluating the tumor-specific cytotoxic effects. This approach recapitulates the logistics involved in developing adoptive cell transfer therapies for pancreatic cancer patients. The results demonstrate enhanced antitumor efficacy of adoptively transferred tumor-reactive T cells compared to irrelevant lymphocyte controls. This versatile methodology enables the in vivo study of adoptive immunotherapy in pancreatic cancer as well as the optimization of cell processing parameters and combination treatment regimens.