CAR T-cells that target acute B-lineage leukemia irrespective of CD19 expression

Leukemia. 2021 Jan;35(1):75-89. doi: 10.1038/s41375-020-0792-2. Epub 2020 Mar 24.

Abstract

Chimeric antigen receptor (CAR) T-cells targeting CD19 demonstrate remarkable efficacy in treating B-lineage acute lymphoblastic leukemia (BL-ALL), yet up to 39% of treated patients relapse with CD19(-) disease. We report that CD19(-) escape is associated with downregulation, but preservation, of targetable expression of CD20 and CD22. Accordingly, we reasoned that broadening the spectrum of CD19CAR T-cells to include both CD20 and CD22 would enable them to target CD19(-) escape BL-ALL while preserving their upfront efficacy. We created a CD19/20/22-targeting CAR T-cell by coexpressing individual CAR molecules on a single T-cell using one tricistronic transgene. CD19/20/22CAR T-cells killed CD19(-) blasts from patients who relapsed after CD19CAR T-cell therapy and CRISPR/Cas9 CD19 knockout primary BL-ALL both in vitro and in an animal model, while CD19CAR T-cells were ineffective. At the subcellular level, CD19/20/22CAR T-cells formed dense immune synapses with target cells that mediated effective cytolytic complex formation, were efficient serial killers in single-cell tracking studies, and were as efficacious as CD19CAR T-cells against primary CD19(+) disease. In conclusion, independent of CD19 expression, CD19/20/22CAR T-cells could be used as salvage or front-line CAR therapy for patients with recalcitrant disease.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Antigens, CD19 / chemistry
  • Antigens, CD19 / immunology*
  • Antigens, Neoplasm
  • Biomarkers
  • Cell Line, Tumor
  • Cytokines / metabolism
  • Cytotoxicity, Immunologic
  • Disease Models, Animal
  • Gene Expression
  • Humans
  • Immunotherapy, Adoptive* / methods
  • Leukemia, B-Cell / genetics
  • Leukemia, B-Cell / immunology*
  • Leukemia, B-Cell / metabolism*
  • Leukemia, B-Cell / therapy
  • Mice, Transgenic
  • Protein Binding
  • Receptors, Antigen, T-Cell / immunology*
  • Receptors, Antigen, T-Cell / metabolism
  • Receptors, Chimeric Antigen / genetics
  • Receptors, Chimeric Antigen / immunology*
  • Receptors, Chimeric Antigen / metabolism
  • Structure-Activity Relationship
  • T-Lymphocytes / immunology*
  • T-Lymphocytes / metabolism*
  • Transduction, Genetic
  • Transgenes
  • Treatment Outcome
  • Xenograft Model Antitumor Assays

Substances

  • Antigens, CD19
  • Antigens, Neoplasm
  • Biomarkers
  • Cytokines
  • Receptors, Antigen, T-Cell
  • Receptors, Chimeric Antigen