Research Project
10377182
Project Summary/Abstract In this Administrative Supplement, the candidate, Mr. Vaughn Rogers will generate a checkpoint ligand PD-L2 conditional knockout mouse strain. During the first funding periods of the parent grant, using single cell RNA seq, we discovered that both PD-L1 and PD-L2 are predominantly expressed on immune cells rather than on GBM cancer cells and that our mouse GBM tumors are resistant to anti PD-1 checkpoint blockade treatment. The hypothesis is that resistance to anti PD-1 immunotherapy is related to the high levels of PD-L1 and PD-L2 expression in tumor immune cells. PD-L1 and PD-L2 are ligands of PD-1 and studies in many cancers have shown that high expression of these ligands confers resistance to anti PD-1 immunotherapy. Here Mr. Rogers is interested in studying the effects of genetic ablation of PD-L1 and PD-L2. In collaboration with the Boussiotis lab, the Charest lab already obtained and characterized a conditional PD-L1 knockout strain. Here, Mr. Rogers? project is to generate a PD- L2 conditional knockout mouse to study the consequences of inactivating PD-L1 and PD-L2 in innate intratumoral immune cells on efficacy of anti-PD-1 immunotherapy. In doing so, he will learn the basics of molecular biology and genome manipulation by generating a Cre/lox conditional knockout mouse strain for the PD-L2 checkpoint ligand. He will used his knowledge of molecular techniques and learn new ones to construct a targeting vector, introduce it into mouse embryonic stem (mES) cells, select, isolate clones, screen clones and generate chimeric animals and germline transmitted knockout stain. This mouse will then be used in conjunction with immune cell-specific Cre transgenics to selectively ablate expression of PD- L2 and PD-L1 in specific immune cells and ascertain the consequences on GBM tumor growth and its response to anti PD-1 checkpoint blockade therapy.
