Characterization and Functional Analysis of scFv-based Chimeric Antigen Receptors to Redirect T Cells to IL13Rα2-positive Glioma

Mol Ther. 2016 Feb;24(2):354-363. doi: 10.1038/mt.2015.199. Epub 2015 Oct 30.

Abstract

Immunotherapy with T cells expressing chimeric antigen receptors (CARs) is an attractive approach to improve outcomes for patients with glioblastoma (GBM). IL13Rα2 is expressed at a high frequency in GBM but not in normal brain, making it a promising CAR T-cell therapy target. IL13Rα2-specific CARs generated up to date contain mutated forms of IL13 as an antigen-binding domain. While these CARs target IL13Rα2, they also recognize IL13Rα1, which is broadly expressed. To overcome this limitation, we constructed a panel of IL13Rα2-specific CARs that contain the IL13Rα2-specific single-chain variable fragment (scFv) 47 as an antigen binding domain, short or long spacer regions, a transmembrane domain, and endodomains derived from costimulatory molecules and CD3.ζ (IL13Rα2-CARs). IL13Rα2-CAR T cells recognized IL13Rα2-positive target cells in coculture and cytotoxicity assays with no cross-reactivity to IL13Rα1. However, only IL13Rα2-CAR T cells with a short spacer region produced IL2 in an antigen-dependent fashion. In vivo, T cells expressing IL13Rα2-CARs with short spacer regions and CD28.ζ, 41BB.ζ, and CD28.OX40.ζ endodomains had potent anti-glioma activity conferring a significant survival advantage in comparison to mice that received control T cells. Thus, IL13Rα2-CAR T cells hold the promise to improve current IL13Rα2-targeted immunotherapy approaches for GBM and other IL13Rα2-positive malignancies.

Publication types

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

MeSH terms

  • Animals
  • Brain Neoplasms / immunology
  • Brain Neoplasms / therapy*
  • Cell Line, Tumor
  • Coculture Techniques
  • Glioblastoma / immunology
  • Glioblastoma / therapy*
  • Humans
  • Interleukin-13 Receptor alpha2 Subunit / immunology*
  • Interleukin-13 Receptor alpha2 Subunit / metabolism
  • Mice
  • Single-Chain Antibodies / immunology*
  • Single-Chain Antibodies / therapeutic use
  • Survival Analysis
  • T-Lymphocytes / immunology*
  • Xenograft Model Antitumor Assays

Substances

  • Interleukin-13 Receptor alpha2 Subunit
  • Single-Chain Antibodies