Deleting DNMT3A in CAR T cells prevents exhaustion and enhances antitumor activity

Abstract

DNMT3A deletion preserves CAR T cell functionality during prolonged stimulation.

Adoptive Cell Therapy in Pediatric and Young Adult Solid Tumors: Current Status and Future Directions

“…Additional modifications include creation of ACT which is resistant to exhaustion [e.g. DNA methyltransferase 3 alpha knock-out ( 95 ) or PD-1 deletion ( 96 )] or tuning ACT to be effective despite low antigen density [e.g. c-Jun overexpression ( 97 , 98 )].…”

CD19-CAR T cells undergo exhaustion DNA methylation programming in patients with acute lymphoblastic leukemia

“…A more targeted approach involves deletion of the de novo methyltransferase DNMT3A in CAR T cells, which directly inhibits the acquisition of exhaustion-associated DNA methylation. Indeed, we have shown that DNMT3A KO CAR T cells exhibit enhanced proliferation with sustained antitumor ability as compared to their control counterparts (Prinzing et al, 2021). By characterizing the DNA methylation programs acquired during 10 Cell Reports 37, 110079, November 30, 2021…”

“…Building upon our findings from the murine LCMV model system, we recently identified loci targeted by DNMT3A in human CAR T cells undergoing exhaustion in preclinical model systems (Prinzing et al, 2021). Using the DNMT3A targeted genes conserved in both murine and human model systems, we assessed these loci for enrichment of DNA methylation during the post-infusion CAR T cell response.…”

“…Many time points at which CD19-CAR T cells were isolated from patients did not yield high enough cell numbers to perform analysis. Further, given that DNA methylation has now been established as reinforcing T cell differentiation, specifically exhaustion (Ghoneim et al, 2017;Prinzing et al, 2021), our efforts were focused on demonstrating the changes in DNA methylation that occur during an in vivo CAR T cell response. By using patient samples, we are able to use clinical response to validate our studies and focused here on both antigen-positive leukemia and endogenous B cell reconstitution as metrics of CD8 + CD19-CAR T cell function.…”

CAR T Cell Immunotherapy Beyond Haematological Malignancy

“…Further, even after repeated exposure to antigens in vitro , these CAR T cells showed sustained expression of T cell proliferation and memory-related genes, but reduced expression of exhaustion-related genes, resulting in enhanced anti-tumor activity in mouse leukemia and lymphoma models. To achieve sustained blocking of de novo DNA methylation, Prinzing et al ( 71 ) employed CRISPR-Cas9-mediated knockout of Dnmt3a in CAR T cells targeting various tumor-associated antigens and showed that these cells retain proliferative capacity and effector function during repeated antigen stimulation in vitro . The enhanced proliferation of these cells was coupled to decreased methylation of promoter regions of TCF7 and LEF1, TFs that are associated with the stem-like phenotype of T cells, as well as to the increased expression of IL-10.…”