Related Experiment Video
Updated: Mar 20, 2026
Non-Viral Engineering of Primary Human T Cells via Homology-Mediated End-Joining Targeted Integration of Large DNA Templates
Published on: May 9, 2025
Optimizing T-cell receptor gene therapy for hematologic malignancies
Emma C Morris1, Hans J Stauss1
1Institute of Immunity and Transplantation, University College London, London, United Kingdom.
Abstract:
Recent advances in genetic engineering have enabled the delivery of clinical trials using patient T cells redirected to recognize tumor-associated antigens. The most dramatic results have been seen with T cells engineered to express a chimeric antigen receptor (CAR) specific for CD19, a differentiation antigen expressed in B cells and B lineage malignancies. We propose that antigen expression in nonmalignant cells may contribute to the efficacy of T-cell therapy by maintaining effector function and promoting memory. Although CAR recognition is limited to cell surface structures, T-cell receptors (TCRs) can recognize intracellular proteins. This not only expands the range of tumor-associated self-antigens that are amenable for T-cell therapy, but also allows TCR targeting of the cancer mutagenome. We will highlight biological bottlenecks that potentially limit mutation-specific T-cell therapy and may require high-avidity TCRs that are capable of activating effector function when the concentrations of mutant peptides are low. Unexpectedly, modified TCRs with artificially high affinities function poorly in response to low concentration of cognate peptide but pose an increased safety risk as they may respond optimally to cross-reactive peptides. Recent gene-editing tools, such as transcription activator-like effector nucleases and clustered regularly interspaced short palindromic repeats, provide a platform to delete endogenous TCR and HLA genes, which removes alloreactivity and decreases immunogenicity of third-party T cells. This represents an important step toward generic off-the-shelf T-cell products that may be used in the future for the treatment of large numbers of patients.
Insights
Chimeric antigen receptor (CAR) T-cell therapy shows promise for cancer. T-cell receptors (TCRs) offer broader targeting, but challenges like affinity and safety require advanced gene-editing for off-the-shelf therapies.
Area of Science:
- Immunology
- Oncology
- Genetic Engineering
Background:
- Chimeric antigen receptor (CAR) T-cell therapy, particularly targeting CD19, has shown significant success in clinical trials for B cell malignancies.
- CARs recognize cell surface antigens, limiting their application to surface-expressed targets.
Purpose of the Study:
- To explore the potential of T-cell receptors (TCRs) for targeting intracellular tumor antigens, expanding therapeutic options beyond CARs.
- To address biological bottlenecks in mutation-specific T-cell therapy, including the need for high-avidity TCRs and potential safety concerns.
- To highlight the role of gene-editing technologies in developing universal, off-the-shelf T-cell therapies.
Main Methods:
- Review of recent advances in genetic engineering for T-cell therapy.
- Discussion of TCRs' ability to recognize intracellular antigens and target the cancer mutagenome.
- Analysis of challenges related to TCR affinity, peptide concentration, and potential cross-reactivity.
- Exploration of gene-editing tools like TALENs and CRISPR for TCR and HLA gene deletion.
Main Results:
- TCRs can target intracellular antigens, broadening the scope of T-cell therapy.
- High-avidity TCRs may be necessary for effective targeting of low-concentration mutant peptides.
- Artificially high-affinity TCRs may have suboptimal function at low peptide concentrations and pose safety risks due to cross-reactivity.
- Gene editing can remove endogenous TCR and HLA genes, reducing alloreactivity and immunogenicity.
Conclusions:
- TCR-based T-cell therapy offers expanded targeting capabilities for cancer treatment.
- Overcoming challenges in TCR affinity and specificity is crucial for effective and safe mutation-specific therapies.
- Gene editing advancements pave the way for developing "off-the-shelf" T-cell products for widespread patient use.
