CRISPR-based gene disruption and integration of high-avidity, WT1-specific T cell receptors improve antitumor T cell function

Sci Transl Med. 2022 Feb 9;14(631):eabg8027. doi: 10.1126/scitranslmed.abg8027. Epub 2022 Feb 9.

Abstract

T cell receptor (TCR)-based therapy has the potential to induce durable clinical responses in patients with cancer by targeting intracellular tumor antigens with high sensitivity and by promoting T cell survival. However, the need for TCRs specific for shared oncogenic antigens and the need for manufacturing protocols able to redirect T cell specificity while preserving T cell fitness remain limiting factors. By longitudinal monitoring of T cell functionality and dynamics in 15 healthy donors, we isolated 19 TCRs specific for Wilms' tumor antigen 1 (WT1), which is overexpressed by several tumor types. TCRs recognized several peptides restricted by common human leukocyte antigen (HLA) alleles and displayed a wide range of functional avidities. We selected five high-avidity HLA-A*02:01-restricted TCRs, three that were specific to the less explored immunodominant WT137-45 and two that were specific to the noncanonical WT1-78-64 epitopes, both naturally processed by primary acute myeloid leukemia (AML) blasts. With CRISPR-Cas9 genome editing tools, we combined TCR-targeted integration into the TCR α constant (TRAC) locus with TCR β constant (TRBC) knockout, thus avoiding TCRαβ mispairing and maximizing TCR expression and function. The engineered lymphocytes were enriched in memory stem T cells. A unique WT137-45-specific TCR showed antigen-specific responses and efficiently killed AML blasts, acute lymphoblastic leukemia blasts, and glioblastoma cells in vitro and in vivo in the absence of off-tumor toxicity. T cells engineered to express this receptor are being advanced into clinical development for AML immunotherapy and represent a candidate therapy for other WT1-expressing tumors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, Neoplasm
  • Humans
  • Leukemia, Myeloid, Acute* / genetics
  • Leukemia, Myeloid, Acute* / therapy
  • Receptors, Antigen, T-Cell / genetics
  • Receptors, Antigen, T-Cell, alpha-beta / genetics
  • T-Lymphocytes
  • WT1 Proteins* / genetics
  • WT1 Proteins* / metabolism

Substances

  • Antigens, Neoplasm
  • Receptors, Antigen, T-Cell
  • Receptors, Antigen, T-Cell, alpha-beta
  • WT1 Proteins
  • WT1 protein, human