To prevent undesirable differentiation during production of CAR- or TCR-engineered human T cells, Klebanoff et al. found that the addition of an AKT inhibitor preserved minimally differentiated CD62L-expressing populations and promoted favorable transcriptional and metabolic properties while being compatible with efficient viral transduction and expansion. CAR T cells prepared with AKT inhibitors improved survival in mice compared to conventionally engineered cells, prompting integration of this strategy into a clinical trial.

Adoptive immunotherapies using T cells genetically redirected with a chimeric antigen receptor (CAR) or T cell receptor (TCR) are entering mainstream clinical practice. Despite encouraging results, some patients do not respond to current therapies. In part, this phenomenon has been associated with infusion of reduced numbers of early memory T cells. Herein, we report that AKT signaling inhibition is compatible with CAR and TCR retroviral transduction of human T cells while promoting a CD62L-expressing central memory phenotype. Critically, this intervention did not compromise cell yield. Mechanistically, disruption of AKT signaling preserved MAPK activation and promoted the intranuclear localization of FOXO1, a transcriptional regulator of T cell memory. Consequently, AKT signaling inhibition synchronized the transcriptional profile for FOXO1-dependent target genes across multiple donors. Expression of an AKT-resistant FOXO1 mutant phenocopied the influence of AKT signaling inhibition, while addition of AKT signaling inhibition to T cells expressing mutant FOXO1 failed to further augment the frequency of CD62L-expressing cells. Finally, treatment of established B cell acute lymphoblastic leukemia was superior using anti-CD19 CAR-modified T cells transduced and expanded in the presence of an AKT inhibitor compared with conventionally grown T cells. Thus, inhibition of signaling along the PI3K/AKT axis represents a generalizable strategy to generate large numbers of receptor-modified T cells with an early memory phenotype and superior antitumor efficacy.

Author Info: (1) Center for Cell Engineering and Department of Medicine, Memorial Sloan Kettering Cancer Center (MSKCC), New York, New York, USA. Parker Institute for Cancer Immunotherapy

Author Info: (1) Center for Cell Engineering and Department of Medicine, Memorial Sloan Kettering Cancer Center (MSKCC), New York, New York, USA. Parker Institute for Cancer Immunotherapy, New York, New York, USA. Center for Cancer Research (CCR), National Cancer Institute (NCI), NIH, Bethesda, Maryland, USA. (2) Center for Cancer Research (CCR), National Cancer Institute (NCI), NIH, Bethesda, Maryland, USA. Department of Surgery, University of California Los Angeles, Los Angeles, California, USA. (3) Center for Cancer Research (CCR), National Cancer Institute (NCI), NIH, Bethesda, Maryland, USA. (4) Center for Cancer Research (CCR), National Cancer Institute (NCI), NIH, Bethesda, Maryland, USA. Immunology Graduate Group, University of Pennsylvania, Philadelphia, Pennsylvania, USA. (5) Center for Cell Engineering and Department of Medicine, Memorial Sloan Kettering Cancer Center (MSKCC), New York, New York, USA. Parker Institute for Cancer Immunotherapy, New York, New York, USA. (6) Center for Cancer Research (CCR), National Cancer Institute (NCI), NIH, Bethesda, Maryland, USA. (7) Center for Cancer Research (CCR), National Cancer Institute (NCI), NIH, Bethesda, Maryland, USA. (8) Center for Cancer Research (CCR), National Cancer Institute (NCI), NIH, Bethesda, Maryland, USA. (9) Center for Cancer Research (CCR), National Cancer Institute (NCI), NIH, Bethesda, Maryland, USA. Experimental Transplantation and Immunology Branch and. (10) Center for Cancer Research (CCR), National Cancer Institute (NCI), NIH, Bethesda, Maryland, USA. Experimental Transplantation and Immunology Branch and. (11) Center for Cancer Research (CCR), National Cancer Institute (NCI), NIH, Bethesda, Maryland, USA. (12) Center for Cancer Research (CCR), National Cancer Institute (NCI), NIH, Bethesda, Maryland, USA. (13) Center for Cancer Research (CCR), National Cancer Institute (NCI), NIH, Bethesda, Maryland, USA. (14) Experimental Immunology Branch, CCR, NCI, NIH, Bethesda, Maryland, USA. (15) Cell Processing Section, Department of Transfusion Medicine, Clinical Center, NIH, Bethesda, Maryland, USA. (16) Cell Processing Section, Department of Transfusion Medicine, Clinical Center, NIH, Bethesda, Maryland, USA. (17) Center for Cancer Research (CCR), National Cancer Institute (NCI), NIH, Bethesda, Maryland, USA. Experimental Transplantation and Immunology Branch and. (18) Center for Cancer Research (CCR), National Cancer Institute (NCI), NIH, Bethesda, Maryland, USA. (19) Center for Cancer Research (CCR), National Cancer Institute (NCI), NIH, Bethesda, Maryland, USA. Center for Cell-based Therapy, CCR, NCI, NIH, Bethesda, Maryland, USA.

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