CRISPR-mediated TCR replacement generates superior anticancer transgenic T cells

Area of Science:

• Immunology
• Genetics
• Oncology

Background:

• Adoptive T cell therapy using cancer-specific T-cell receptors (TCRs) shows promise for cancer treatment.
• Endogenous TCRs in recipient cells compete with transgenic TCRs, leading to mixed dimers and potential autoreactivity.
• This competition limits the efficacy and surface expression of engineered TCRs.

Purpose of the Study:

• To develop a TCR replacement strategy to enhance T cell-based cancer immunotherapy.
• To improve the surface expression and functionality of transgenic TCRs in engineered T cells.
• To increase the sensitivity and efficacy of T cells against various cancer types.

Main Methods:

• Utilized clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein-9 (Cas9) technology to knock out endogenous TCR-β chains.
• Simultaneously transduced T cells with a cancer-reactive TCR of choice.
• Evaluated the surface expression, polyfunctionality, and antigen sensitivity of engineered T cells.

Main Results:

• The TCR replacement strategy significantly increased surface expression of transgenic αβ and γδ TCRs.
• Engineered T cells exhibited enhanced and more polyfunctional responses against target cancer cell lines.
• TCR-plus-CRISPR-modified T cells demonstrated up to a thousandfold greater antigen sensitivity compared to standard methods.
• In blood cancers, particularly B-cell acute lymphoblastic leukemia, CRISPR/Cas9 combined with TCR transfer showed superior redirection of CD4+ and CD8+ T cells.

Conclusions:

• TCR replacement using CRISPR/Cas9 technology is a viable strategy to overcome limitations of standard TCR transfer.
• This approach enhances T cell potency, specificity, and sensitivity for improved cancer immunotherapy.
• Combining genome editing with TCR transfer represents a promising avenue for developing next-generation cancer immunotherapies.