Rejuvenating Effector/Exhausted CAR T Cells to Stem Cell Memory-Like CAR T Cells By Resting Them in the Presence of CXCL12 and the NOTCH Ligand

• Published in: Cancer research communications 2021-10, Vol.1 (1), p.41-55
• Main Authors: Ando, Makoto, Kondo, Taisuke, Tomisato, Wataru, Ito, Minako, Shichino, Shigeyuki, Srirat, Tanakorn, Mise-Omata, Setsuko, Nakagawara, Kensuke, Yoshimura, Akihiko
• Format: Article
• Language: English
• Subjects: Hematological Cancers; Immunology; Immunotherapy
• ISSN: 2767-9764; 2767-9764
• DOI: 10.1158/2767-9764.CRC-21-0034

T cells with a stem cell memory (T ) phenotype provide long-term and potent antitumor effects for T-cell transfer therapies. Although various methods for the induction of T -like cells have been reported, few methods generate T -like cells from effector/exhausted T cells. We have reported that coculture with the Notch ligand-expressing OP9 stromal cells induces T -like (iT ) cells. Here, we established a feeder-free culture system to improve iT cell generation from expanded chimeric antigen receptor (CAR)-expressing T cells; culturing CAR T cells in the presence of IL7, CXCL12, IGF-I, and the Notch ligand, hDLL1. Feeder-free CAR-iT cells showed the expression of cell surface markers and genes similar to that of OP9-hDLL1 feeder cell-induced CAR-iT cells, including the elevated expression of SCM-associated genes, , , and , and reduced expression of exhaustion-associated genes like , , and . Feeder-free CAR-iT cells showed higher proliferative capacity depending on oxidative phosphorylation and exhibited higher IL2 production and stronger antitumor activity than feeder cell-induced CAR-iT cells. Our feeder-free culture system represents a way to rejuvenate effector/exhausted CAR T cells to SCM-like CAR T cells. Resting CAR T cells with our defined factors reprograms exhausted state to SCM-like state and enables development of improved CAR T-cell therapy.