Multiplex Genome Editing to Generate Universal CAR T Cells Resistant to PD1 Inhibition

Abstract

<b>Purpose:</b> Using gene-disrupted allogeneic T cells as universal effector cells provides an alternative and potentially improves current chimeric antigen receptor (CAR) T-cell therapy against cancers and infectious diseases.<b>Experimental Design:</b> The CRISPR/Cas9 system has recently emerged as a simple and efficient way for multiplex genome engineering. By combining lentiviral delivery of CAR and electro-transfer of Cas9 mRNA and gRNAs targeting endogenous TCR, β-2 microglobulin (B2M) and PD1 simultaneously, to generate gene-disrupted allogeneic CAR T cells deficient of TCR, HLA class I molecule and PD1.<b>Results:</b> The CRISPR gene-edited CAR T cells showed potent antitumor activities, both <i>in vitro</i> and in animal models and were as potent as non-gene-edited CAR T cells. In addition, the TCR and HLA class I double deficient T cells had reduced alloreactivity and did not cause graft-versus-host disease. Finally, simultaneous triple genome editing by adding the disruption of PD1 led to enhanced <i>in vivo</i> antitumor activity of the gene-disrupted CAR T cells.<b>Conclusions:</b> Gene-disrupted allogeneic CAR and TCR T cells could provide an alternative as a universal donor to autologous T cells, which carry difficulties and high production costs. Gene-disrupted CAR and TCR T cells with disabled checkpoint molecules may be potent effector cells against cancers and infectious diseases. <i>Clin Cancer Res; 23(9); 2255-66. ©2016 AACR</i>.