Related Experiment Video
Updated: Jan 20, 2026
Production of Human CRISPR-Engineered CAR-T Cells
Published on: March 15, 2021
Anti-CAR-engineered T cells for epitope-based elimination of autologous CAR T cells
Stefanie Koristka1, Pauline Ziller-Walter2, Ralf Bergmann1
1Department of Radioimmunology, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Bautzner Landstraße 400, 01328, Dresden, Germany.
Abstract:
Although CAR T-cell therapy has demonstrated tremendous clinical efficacy especially in hematological malignancies, severe treatment-associated toxicities still compromise the widespread application of this innovative technology. Therefore, developing novel approaches to abrogate CAR T-cell-mediated side effects is of great relevance. Several promising strategies pursue the selective antibody-based depletion of adoptively transferred T cells via elimination markers. However, given the limited half-life and tissue penetration, dependence on the patients' immune system and on-target/off-side effects of proposed monoclonal antibodies, we sought to exploit αCAR-engineered T cells to efficiently eliminate CAR T cells. For comprehensive and specific recognition, a small peptide epitope (E-tag) was incorporated into the extracellular spacer region of CAR constructs. We provide first proof-of-concept for targeting this epitope by αE-tag CAR T cells, allowing an effective killing of autologous E-tagged CAR T cells both in vitro and in vivo whilst sparing cells lacking the E-tag. In addition to CAR T-cell cytotoxicity, the αE-tag-specific T cells can be empowered with cancer-fighting ability in case of relapse, hence, have versatile utility. Our proposed methodology can most probably be implemented in CAR T-cell therapies regardless of the targeted tumor antigen aiding in improving overall safety and survival control of highly potent gene-modified cells.
Insights
Researchers developed a novel method using engineered T-cells to eliminate CAR T-cells, enhancing safety for cancer therapy. This approach targets a specific tag on CAR T-cells, effectively removing them while sparing healthy cells.
Area of Science:
- Immunology
- Cell Therapy
- Cancer Research
Background:
- Chimeric antigen receptor (CAR) T-cell therapy shows high efficacy in hematological cancers but is limited by severe toxicities.
- Current strategies for mitigating CAR T-cell side effects, such as antibody-based depletion, have limitations including short half-life and potential off-target effects.
Purpose of the Study:
- To develop a novel, self-contained method for eliminating CAR T-cells to improve treatment safety.
- To engineer T-cells capable of specifically targeting and eliminating CAR T-cells expressing a defined epitope.
Main Methods:
- Incorporated a small peptide epitope (E-tag) into the CAR construct's extracellular spacer region.
- Engineered a second set of T-cells (αE-tag CAR T-cells) to recognize and eliminate E-tagged CAR T-cells.
- Evaluated the efficacy of αE-tag CAR T-cells in vitro and in vivo for selective CAR T-cell depletion.
Main Results:
- Demonstrated effective in vitro and in vivo killing of autologous E-tagged CAR T-cells by αE-tag CAR T-cells.
- Confirmed that αE-tag CAR T-cells specifically target E-tagged cells, sparing those without the tag.
- Showcased the potential for αE-tag CAR T-cells to retain anti-cancer activity for relapse scenarios.
Conclusions:
- This study presents the first proof-of-concept for using αCAR-engineered T-cells to eliminate CAR T-cells.
- The proposed methodology offers a versatile strategy to enhance the safety of CAR T-cell therapies across various cancer types.
- This approach has the potential to improve patient safety and survival outcomes in gene-modified cell therapies.
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