Park HB, Kim KH, Kim JH, Kim SI, Oh YM, Kang M, Lee S, Hwang S, Lee H, Lee T, Park S, Lee JE, Jeong GR, Lee DH, Youn H, Choi EY, Son WC, Chung SJ, Chung J, Choi K (2024) Improved safety of chimeric antigen receptor T cells indirectly targeting antigens via switchable adapters. Nat Commun 15(1):9917. doi: 10.1038/s41467-024-53996-7 PMID: 39557825
Objective: To show that switchable CAR-T cells with a tumor targeting adaptor can mitigate on-target off-tumor toxicity against a low selectivity tumor antigen that cannot be targeted by conventional CAR-T cells, such as CD40.
Summary: The system is composed of anti-cotinine murine CAR-T cells and cotinine-labeled anti-CD40 single chain variable fragments (scFv), with which the authors show selective tumor killing while sparing CD40-expressing normal cells including macrophages in a mouse model of lymphoma. The authors evaluated whether Cot CAR-T cells could be depleted by Cot-saporin in vivo in an allogeneic CAR-T cell transfer model. When Balb/C mice transplanted with B6 bone marrow cells were injected with B6 Cot CAR-T cells, the transferred Cot CAR-T cells expanded in the peripheral blood in response to Balb/C alloantigen. However, when Cot-saporin was administered during this expansion phase, the Cot CAR-T cells failed to expand and were subsequently eliminated in the blood. Thus, Cot-saporin-mediated CotCAR-T cell suicide was confirmed in vitro and in vivo.
Usage: in vitro Cot CAR-T cell depletion by cotinine-drug conjugates: Peptides were incubated with saporin-labeled streptavidin (IT-27) at a molar ratio of 4:1 to generate cotinine-saporin conjugate (Cot-saporin). For Cot-saporin-dependent cytotoxicity assays on Cot CAR-T cells, a 1:1 mixed population (50,000 cells each) of Cot CAR-T cells (target cells) and control T cells (bystander non-CAR-T cells) were incubated with various doses of Cot-saporin for 48 h in medium containing human IL-2. Seven days after CAR-T cell transfer, Cot-saporin was administered intraperitoneally three times at 3-day intervals.
Related Products: Streptavidin-ZAP (Cat. #IT-27)