Related Experiment Video
Updated: Jun 5, 2025

Non-Viral Engineering of Primary Human T Cells via Homology-Mediated End-Joining Targeted Integration of Large DNA Templates
Published on: May 9, 2025
T-Switch: A specificity-based engineering platform for developing safe and effective T cell therapeutics
Nouran S Abdelfattah1, Tomasz Kula1, Stephen J Elledge1
1Department of Genetics, Harvard Medical School, Division of Genetics, Brigham and Women's Hospital, Howard Hughes Medical Institute, 77 Avenue Louis Pasteur, Boston, MA 02115, USA.
Many promising targets for adoptive T cell therapy (ACT) are self-antigens, but self-reactive T cells are generally eliminated during thymic selection or diverted to regulatory phenotypes. To bypass T cell tolerance and obtain potent and safe T cell therapeutics, we developed T-Switch, an in vitro T cell receptor (TCR) engineering platform for the creation, modification, and comprehensive profiling of TCRs that can target self-antigens. T-Switch first expands T cells that recognize a "foreign" peptide closely related to a self-antigen. The fine specificity of the TCR is then modified by directed evolution of the peptide binding region to switch its specificity to the self-antigen of interest. We applied T-Switch to engineer synthetic TCRs reactive to a tumor-associated self-antigen, validated the safety and efficacy of this approach, and detected no off-target recognition as measured against the human proteome. Thus, T-Switch represents a resource for the creation of collections of highly sensitive synthetic TCRs for T cell-based immunotherapies.
Many promising targets for adoptive T cell therapy (ACT) are self-antigens, but self-reactive T cells are generally eliminated during thymic selection or diverted to regulatory phenotypes. To bypass T cell tolerance and obtain potent and safe T cell therapeutics, we developed T-Switch, an in vitro T cell receptor (TCR) engineering platform for the creation, modification, and comprehensive profiling of TCRs that can target self-antigens. T-Switch first expands T cells that recognize a "foreign" peptide closely related to a self-antigen. The fine specificity of the TCR is then modified by directed evolution of the peptide binding region to switch its specificity to the self-antigen of interest. We applied T-Switch to engineer synthetic TCRs reactive to a tumor-associated self-antigen, validated the safety and efficacy of this approach, and detected no off-target recognition as measured against the human proteome. Thus, T-Switch represents a resource for the creation of collections of highly sensitive synthetic TCRs for T cell-based immunotherapies.

