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

Abstract

Cancer immunotherapy using T cells redirected with chimeric antigen receptor (CAR) has shown a lot of promise. We have established a single-chain antibody (scFv) generation system in which scFv library-expressing CAR-T cells can be screened appropriately based on their antitumor functions. A variable region library containing the variable and J regions of the human immunoglobulin light or heavy chain was fused with the variable region of a heavy or light chain encoded by an existing tumor-specific antibody to generate a new scFv library. Then, scFv library-expressing CAR-T cells were generated and stimulated with target cells to concentrate the antigen-specific population. Using this system, target-specific recognition of CAR-T cells appeared to be finely tuned by selecting a new variable region. Importantly, we have demonstrated that the newly optimized scFv-expressing CAR-T cells had better proliferation capacity and durable phenotypes, enabling superior reactivity against advanced tumors in vivo in comparison with the original CAR-T cells. Therefore, the optimization of an scFv is needed to maximize the in vivo antitumor functions of CAR-T cells. This system may allow us to adjust an immunological synapse formed by an scFv expressed by CAR-T cells and a target antigen, representing an ideal form of CAR-T-cell immunotherapy.

• Authors: Toshiki Ochi, Masaki Maruta, Kazushi Tanimoto, Fumitake Kondo, Toshihiro Yamamoto, Mie Kurata, Hiroshi Fujiwara, Junya Masumoto, Katsuto Takenaka, Masaki Yasukawa
• Journal: Communications biology (Commun Biol) Vol. 4 Issue 1 Pg. 273 (03 02 2021) ISSN: 2399-3642 [Electronic] England
• PMID: 33654176 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Immunoglobulin Heavy Chains
• Immunoglobulin Light Chains
• Immunoglobulin Variable Region
• Receptors, Chimeric Antigen
• Single-Chain Antibodies

Topics

• Animals
• Female
• Humans
• Immunoglobulin Heavy Chains (genetics, metabolism)
• Immunoglobulin Light Chains (genetics, metabolism)
• Immunoglobulin Variable Region (genetics, metabolism)
• Immunological Synapses
• Immunotherapy, Adoptive
• Jurkat Cells
• K562 Cells
• Lymphoma (genetics, immunology, metabolism, therapy)
• Mice, Inbred NOD
• Mice, SCID
• Receptors, Chimeric Antigen (genetics, metabolism)
• Single-Chain Antibodies (genetics, metabolism)
• T-Lymphocytes (immunology, metabolism, transplantation)
• Tumor Burden
• Xenograft Model Antitumor Assays