A single-chain antibody generation system yielding CAR-T cells with superior antitumor function.

Area of Science:

• Immunology
• Oncology
• Biotechnology

Background:

• Chimeric antigen receptor (CAR)-T cell therapy is a promising cancer immunotherapy approach.
• The efficacy of CAR-T cells relies on the specific recognition of tumor antigens by the CAR's single-chain variable fragment (scFv).

Purpose of the Study:

• To develop a system for generating and screening scFv libraries to optimize CAR-T cell antitumor functions.
• To improve the in vivo efficacy of CAR-T cells through scFv optimization.

Main Methods:

• Established a system for generating scFv libraries by fusing variable and J regions of human immunoglobulin chains with tumor-specific antibody variable regions.
• Generated scFv library-expressing CAR-T cells and stimulated them with target cells to enrich antigen-specific populations.
• Selected and evaluated newly optimized scFv-expressing CAR-T cells for their functional properties.

Main Results:

• Demonstrated that target-specific recognition by CAR-T cells can be finely tuned through variable region selection.
• Newly optimized scFv-expressing CAR-T cells exhibited enhanced proliferation capacity and durable phenotypes.
• These optimized CAR-T cells showed superior in vivo reactivity against advanced tumors compared to original CAR-T cells.

Conclusions:

• Optimization of scFvs is crucial for maximizing the in vivo antitumor functions of CAR-T cells.
• The developed system allows for the fine-tuning of the immunological synapse between scFv and target antigen.
• This approach represents an advanced strategy for CAR-T cell immunotherapy.