FLAG-tagged CD19-specific CAR-T cells eliminate CD19-bearing solid tumor cells in vitro and in vivo

Front Biosci (Landmark Ed). 2017 Jun 1;22:1644-1654. doi: 10.2741/4563.

Abstract

Autologous T cells expressing chimeric antigen receptors (CARs) specific for CD19 have demonstrated remarkable efficacy as therapeutics for B cell malignancies. In the present study, we generated FLAG-tagged CD19-specific CAR-T cells (CD19-FLAG) and compared them to their non-tagged counterparts for their effects on solid and hematological cancer cells in vitro and in vivo. For solid tumors, we used HeLa cervical carcinoma cells engineered to overexpress CD19 (HeLa-CD19), and for hematological cancer we used Raji Burkitt's lymphoma cells, which endogenously express CD19. Like non-tagged CD19 CAR-T cells, CD19-FLAG CAR-T cells expanded in culture >100-fold and exhibited potent cytolytic activity against both HeLa-CD19 and Raji cells in vitro. CD19-FLAG CAR-T cells also secreted significantly more IFN-gamma and IL-2 than the control T cells. In vivo, CD19-FLAG CAR-T cells significantly blocked the growth of HeLa-CD19 solid tumors, increased tumor cleaved caspase-3 levels, and expanded systemically. CD19-FLAG CAR-T cells also significantly reduced Raji tumor burden and extended mouse survival. These results demonstrate the strong efficacy of FLAG-tagged CD19 CAR-T cells in solid and hematological cancer models.

MeSH terms

  • Animals
  • Antigens, CD19 / genetics
  • Antigens, CD19 / immunology*
  • Antigens, CD19 / metabolism
  • Cell Line, Tumor
  • Cells, Cultured
  • Cytokines / immunology
  • Cytokines / metabolism
  • Cytotoxicity, Immunologic / immunology
  • HeLa Cells
  • Hematologic Neoplasms / genetics
  • Hematologic Neoplasms / immunology
  • Hematologic Neoplasms / metabolism
  • Humans
  • Interleukin Receptor Common gamma Subunit / deficiency
  • Interleukin Receptor Common gamma Subunit / genetics
  • Male
  • Mice, Inbred NOD
  • Mice, Knockout
  • Mice, SCID
  • Neoplasms / genetics
  • Neoplasms / immunology*
  • Neoplasms / metabolism
  • Oligopeptides / genetics
  • Oligopeptides / immunology*
  • Oligopeptides / metabolism
  • Receptors, Antigen, T-Cell / genetics
  • Receptors, Antigen, T-Cell / immunology
  • Receptors, Antigen, T-Cell / metabolism
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / immunology
  • Recombinant Fusion Proteins / metabolism
  • T-Lymphocytes / immunology*
  • T-Lymphocytes / metabolism
  • Treatment Outcome
  • Xenograft Model Antitumor Assays / methods*

Substances

  • Antigens, CD19
  • Cytokines
  • Il2rg protein, mouse
  • Interleukin Receptor Common gamma Subunit
  • Oligopeptides
  • Receptors, Antigen, T-Cell
  • Recombinant Fusion Proteins
  • FLAG peptide