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1.
Nat Chem Biol ; 19(9): 1046-1047, 2023 Sep.
Article in English | MEDLINE | ID: mdl-36973441
2.
J Clin Invest ; 131(16)2021 08 16.
Article in English | MEDLINE | ID: mdl-34396987

ABSTRACT

Chimeric antigen receptor (CAR) T cells have induced remarkable antitumor responses in B cell malignancies. Some patients do not respond because of T cell deficiencies that hamper the expansion, persistence, and effector function of these cells. We used longitudinal immune profiling to identify phenotypic and pharmacodynamic changes in CD19-directed CAR T cells in patients with chronic lymphocytic leukemia (CLL). CAR expression maintenance was also investigated because this can affect response durability. CAR T cell failure was accompanied by preexisting T cell-intrinsic defects or dysfunction acquired after infusion. In a small subset of patients, CAR silencing was observed coincident with leukemia relapse. Using a small molecule inhibitor, we demonstrated that the bromodomain and extra-terminal (BET) family of chromatin adapters plays a role in downregulating CAR expression. BET protein blockade also ameliorated CAR T cell exhaustion as manifested by inhibitory receptor reduction, enhanced metabolic fitness, increased proliferative capacity, and enriched transcriptomic signatures of T cell reinvigoration. BET inhibition decreased levels of the TET2 methylcytosine dioxygenase, and forced expression of the TET2 catalytic domain eliminated the potency-enhancing effects of BET protein targeting in CAR T cells, providing a mechanism linking BET proteins and T cell dysfunction. Thus, modulating BET epigenetic readers may improve the efficacy of cell-based immunotherapies.


Subject(s)
Immunotherapy, Adoptive , Leukemia, Lymphocytic, Chronic, B-Cell/immunology , Leukemia, Lymphocytic, Chronic, B-Cell/therapy , Proteins/antagonists & inhibitors , Proteins/immunology , Receptors, Chimeric Antigen/immunology , T-Lymphocytes/immunology , Antigens, CD19/immunology , Azepines/pharmacology , Epigenesis, Genetic , Glycolysis/drug effects , Humans , Immune Tolerance , Immunologic Memory , Leukemia, Lymphocytic, Chronic, B-Cell/metabolism , Oxidative Phosphorylation/drug effects , Receptors, Chimeric Antigen/genetics , T-Lymphocytes/drug effects , T-Lymphocytes/metabolism , Triazoles/pharmacology
3.
Nat Med ; 24(10): 1499-1503, 2018 10.
Article in English | MEDLINE | ID: mdl-30275568

ABSTRACT

We report a patient relapsing 9 months after CD19-targeted CAR T cell (CTL019) infusion with CD19- leukemia that aberrantly expressed the anti-CD19 CAR. The CAR gene was unintentionally introduced into a single leukemic B cell during T cell manufacturing, and its product bound in cis to the CD19 epitope on the surface of leukemic cells, masking it from recognition by and conferring resistance to CTL019.


Subject(s)
Antigens, CD19/immunology , Drug Resistance, Neoplasm/immunology , Epitopes/immunology , Leukemia/drug therapy , Adult , Antigens, CD19/therapeutic use , B-Lymphocytes/immunology , Cell- and Tissue-Based Therapy , Humans , Leukemia/immunology , Leukemia/pathology , Male , Receptors, Antigen, T-Cell/immunology , Receptors, Antigen, T-Cell/therapeutic use , Receptors, Chimeric Antigen , T-Lymphocytes/immunology , Young Adult
4.
Nature ; 558(7709): 307-312, 2018 06.
Article in English | MEDLINE | ID: mdl-29849141

ABSTRACT

Cancer immunotherapy based on genetically redirecting T cells has been used successfully to treat B cell malignancies1-3. In this strategy, the T cell genome is modified by integration of viral vectors or transposons encoding chimaeric antigen receptors (CARs) that direct tumour cell killing. However, this approach is often limited by the extent of expansion and persistence of CAR T cells4,5. Here we report mechanistic insights from studies of a patient with chronic lymphocytic leukaemia treated with CAR T cells targeting the CD19 protein. Following infusion of CAR T cells, anti-tumour activity was evident in the peripheral blood, lymph nodes and bone marrow; this activity was accompanied by complete remission. Unexpectedly, at the peak of the response, 94% of CAR T cells originated from a single clone in which lentiviral vector-mediated insertion of the CAR transgene disrupted the methylcytosine dioxygenase TET2 gene. Further analysis revealed a hypomorphic mutation in this patient's second TET2 allele. TET2-disrupted CAR T cells exhibited an epigenetic profile consistent with altered T cell differentiation and, at the peak of expansion, displayed a central memory phenotype. Experimental knockdown of TET2 recapitulated the potency-enhancing effect of TET2 dysfunction in this patient's CAR T cells. These findings suggest that the progeny of a single CAR T cell induced leukaemia remission and that TET2 modification may be useful for improving immunotherapies.


Subject(s)
5-Methylcytosine/metabolism , Antigens, CD19/immunology , Dioxygenases/genetics , Immunotherapy/methods , Leukemia, Lymphocytic, Chronic, B-Cell/immunology , Leukemia, Lymphocytic, Chronic, B-Cell/therapy , T-Lymphocytes/immunology , T-Lymphocytes/transplantation , Adoptive Transfer , Aged , Alleles , Cell Differentiation , Clinical Trials as Topic , Clone Cells/cytology , Clone Cells/immunology , Dioxygenases/metabolism , Epigenesis, Genetic , HEK293 Cells , Humans , Leukemia, Lymphocytic, Chronic, B-Cell/genetics , Leukemia, Lymphocytic, Chronic, B-Cell/pathology , Male , Mutation , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolism , T-Lymphocytes/cytology , T-Lymphocytes/metabolism , Transgenes
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