Engineering Chimeric Antigen Receptor T-Cells against Immune Checkpoint Inhibitor Pd1 and Pd-L1 for Treating Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDA) is a dreadful and aggressive disease with 1-year survival rate of 20% and 5-year survival rate of 6%, the lowest of any tumor type routinely checked. Immune checkpoint inhibitor pathway PD1 (Programmed-Death-1) /PD-L1 (Programmed-Death-1 Ligand-1) axis is responsible for inhibitory T cell signaling that underpinning the mechanism of immune tolerance, and contributes to the maintenance of immune homeostasis. PD1/PD-L1 pathway also plays an essential role in immune suppression in the tumor microenvironment and blockade of PD1/PD-L1 by monoclonal antibodies has tremendous success in the treatment of several tumor types including lung cancer. However, even though PD-L1 is expressed on pancreatic cancer cells, current clinical trial using PD1/PD-L1 blockade failed to show any meaningful therapeutic effects. T cells engineered with chimeric antigen receptors (CARs) have been successfully applied in treating patients with advanced B cell malignancies and efforts for applying CAR-Ts in the treatment of solid tumors have been endeavored. CAR signaling is directly provided by intracellular and intramolecular CD3ζ and CD28 phosphorylation upon specific antigen interaction. Compared to “blockade of Inhibition” provided by Anti-PD1 or Anti-PDL1 antibodies, it is convincingly possible that a stronger effector T cells can be generated after CAR-mediated stimulation. Furthermore, since PD-L1 is expressed in various kinds of tumor cells, CAR-T generated in this way can be used to treat cancers of different cell types. In the current proposal, we proposed to generate PD-1 and PDL-1 based 4th generation CAR-T, elucidate the molecule mechanisms leading to the development of effector cells, and to test the in vitro cytotoxicity and in vivo function of these CAR-T cells. Specifically; Three specific aims: Aim1: Functional studies of the molecular mechanism on how the engineered immune checkpoint inhibitors PD1ACR (activating chimeric receptor)-T cell and PDL1CAR (chimeric antigen receptor)-T cell eliminate cancer cells that help the development of immunotherapies to treat pancreatic cancer. Xenograft tumor mouse model will be generated from NSG (NOD/SCID/IL-2Rγ-/-) mice and used to characterize the molecular mechanism of CARs and their effects on cancer elimination. Aim2: Investigation of both PD1ACR-T and PDL1CAR-T cells and their in-vitro functions as well as cytotoxic effects on PDL1-expressed pancreatic cancers. Aim3: Construction of the 4th generation CARs, T cells redirected for universal cytokine killing (TRUCKs), with a transgenic “payload” and investigation of the efficiency of elimination of total pancreatic cancers by the TRUCKs strategy.