Redirected Antitumor Activity of Primary Human Lymphocytes Transduced With a Fully Human Anti-Mesothelin Chimeric Receptor

Mol Ther. 2012 Mar;20(3):633-43. doi: 10.1038/mt.2011.256. Epub 2011 Nov 29.

Abstract

Cancer regression by gene-modified T cells bearing a chimeric antigen receptor (CAR) exodomain of mouse origin can be limited by the induction of transgene immunogenicity resulting in poor persistence and function in vivo. The development of functionally-active CAR of human origin can address this issue. Here, we constructed and evaluated fully human anti-mesothelin CARs comprised of a human mesothelin-specific single-chain antibody variable fragment (P4 scFv) coupled to T cell signaling domains. Primary human T cells expressing P4 CAR specifically produced proinflammatory cytokines, degranulated and exerted potent cytolytic functions when cultured with mesothelin-expressing tumors in vitro. P4 CAR T cells also mediated bystander killing of mesothelin-negative cancer cells during coculture. CAR reactivity was not abrogated by soluble tumor-secreted or recombinant mesothelin protein even at supraphysiological levels. Importantly, adoptive transfer of P4 CAR-expressing T cells mediated the regression of large, established tumor in the presence of soluble mesothelin in a xenogenic model of human ovarian cancer. Thus, primary human T cells expressing fully human anti-mesothelin CAR efficiently kill mesothelin-expressing tumors in vitro and in vivo and have the potential to overcome the issue of transgene immunogenicity that may limit CAR T cell trials that utilize scFvs of mouse origin.

Publication types

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

MeSH terms

  • Animals
  • Bystander Effect / immunology
  • Cell Line
  • Cytotoxicity, Immunologic
  • Epitopes / immunology
  • Female
  • GPI-Linked Proteins / immunology*
  • GPI-Linked Proteins / metabolism
  • Gene Order
  • Genetic Vectors / genetics
  • Humans
  • Lentivirus / genetics
  • Mice
  • Ovarian Neoplasms / immunology*
  • Ovarian Neoplasms / metabolism
  • Ovarian Neoplasms / therapy
  • Receptors, Antigen, T-Cell / genetics*
  • Receptors, Antigen, T-Cell / immunology
  • Single-Chain Antibodies / genetics*
  • Single-Chain Antibodies / immunology
  • T-Lymphocytes / immunology*
  • T-Lymphocytes / metabolism
  • Transduction, Genetic
  • Xenograft Model Antitumor Assays

Substances

  • Epitopes
  • GPI-Linked Proteins
  • Receptors, Antigen, T-Cell
  • Single-Chain Antibodies
  • mesothelin