CRISPR-Cas9 mediated efficient PD-1 disruption on human primary T cells from cancer patients

Authors:
Su S, Hu B, Shao J, Shen B, Du J, Du Y, Zhou J, Yu L, Zhang L, Chen F, Sha H, Cheng L, Meng F, Zou Z, Huang X, Liu B
In:
Source: Scientific Reports
Publication Date: (2016)
Issue: 6(20070): 10.1038/srep20070
Research Area:
Cancer Research/Cell Biology
Gene Expression
Cells used in publication:
T cell, human peripheral blood unstim.
Species: human
Tissue Origin: blood
Platform:
Nucleofector® I/II/2b
Experiment
A mixture of 5?µg of pST1374-Cas9-GFP and 10?µg of pGL3-U6-hPD-1-sgRNA plasmids was used, and different programs (Y-001, T-007, T-023, X-001, U-014, V-024) were applied. GFP expression was determined 24?h later by fluorescence microscope or flow cytometry. We found that higher transfection efficacy was obtained with program U-014 than with V-024 and T-007. Notably, during the following days, significant improved cell viability was observed with program T-007 than with U-014 and V-024 shown by Trypan blue exclusion assay. Therefore, T-007 was used as the optimal program for the following experiments.
Abstract
Strategies that enhance the function of T cells are critical for immunotherapy. One negative regulator of T-cell activity is ligand PD-L1, which is expressed on dentritic cells (DCs) or some tumor cells, and functions through binding of programmed death-1 (PD-1) receptor on activated T cells. Here we described for the first time a non-viral mediated approach to reprogram primary human T cells by disruption of PD-1. We showed that the gene knockout of PD-1 by electroporation of plasmids encoding sgRNA and Cas9 was technically feasible. The disruption of inhibitory checkpoint gene PD-1 resulted in significant reduction of PD-1 expression but didn't affect the viability of primary human T cells during the prolonged in vitro culture. Cellular immune response of the gene modified T cells was characterized by up-regulated IFN-? production and enhanced cytotoxicity. These results suggest that we have demonstrated an approach for efficient checkpoint inhibitor disruption in T cells, providing a new strategy for targeting checkpoint inhibitors, which could potentially be useful to improve the efficacy of T-cell based adoptive therapies.