Accurate control of dual-receptor-engineered T cell activity through a bifunctional anti-angiogenic peptide

Abstract

BackgroundChimeric antigen receptors (CARs) presented on T cell surfaces enable redirection of T cell specificity, which has enormous promise in antitumor therapy. However, excessive activity and poor control over such engineered T cells cause significant safety challenges, such as cytokine release syndrome and organ toxicities. To enhance the specificity and controllable activity of CAR-T cells, we report a novel switchable dual-receptor CAR-engineered T (sdCAR-T) cell and a new switch molecule of FITC-HM-3 bifunctional molecule (FHBM) in this study.MethodsWe designed a fusion molecule comprising FITC and HM-3. HM-3, an antitumor peptide including an Arg-Gly-Asp sequence, can specifically target integrin αvβ3 that is presented on some tumor cells. Moreover, to improve the specificity of CAR-T cells, we also generated the sdCAR-T cell line against cognate tumor cells expressing human mesothelin (MSLN) and integrin αvβ3. Finally, the activity of sdCAR-T cell and FHBM is verified via in vitro and in vivo experiments.ResultsIn the presence of FHBM, the designed sdCAR-T cells exerted high activity including activation and proliferation and had specific cytotoxicity in a time- and dose-dependent manner in vitro. Furthermore, using a combination of FHBM in nude mice, sdCAR-T cells significantly inhibited the growth of MSLN+ K562 cells and released lower levels of the cytokines (e.g., interleukin-2, interferon γ, interleukin-6, and tumor necrosis factor α) relative to conventional CAR-T cells, obtaining specific, controllable, and enhanced cytotoxicity.ConclusionsOur data indicate that FHBM can accurately control timing and dose of injected CAR-T cells, and sdCAR-T cells exert significant antitumor activity while releasing lower levels of cytokines for the cognate tumor cells expressing both MSLN and integrin αvβ3. Therefore, combination therapies using sdCAR-T cells and the switch molecule FHBM have significant potential to treat malignancies.Electronic supplementary materialThe online version of this article (10.1186/s13045-018-0591-7) contains supplementary material, which is available to authorized users.

Recombination of a dual-CAR-modified T lymphocyte to accurately eliminate pancreatic malignancy

“…To further improve the safety of dCAR-T cell therapy, we envision that the CD3ζ signaling pathway of dCAR structure could be characterized to a novel model that can be precisely regulated. With the advance of a CAR diagram and a switch molecule, the dCAR model could be regulated via the first signaling pathway (CD3ζ) in the presence or absence of the exogenous factors, achieving the precise control of injected dCAR-T cells [ 32 – 34 ] (Fig. 4c ).…”

Advances on chimeric antigen receptor-modified T-cell therapy for oncotherapy

“…The CRS is not common in solid tumors treated by CAR-T cells; however, on target/off-tumor toxicity has become common due to unavoidable expression, to some extent, of target antigens in normal tissues [ 60 ]. This phenomenon could be solved by manufacturing CAR-T cells with dual antigen specificity or switchable dual-receptor [ 76 , 77 ] or by transfecting T cells with mRNA encoding CAR to reduce their half-life; these CAR-T cells can be repeated administered, and the toxicity to normal tissues can be mitigated [ 78 ]. Moreover, the hostile immunosuppressive microenvironment is one of the major challenges in CAR-T-cell treatment of solid tumors.…”

Recent Advances in Allogeneic CAR-T Cells

“…Because each CAR has a CD247 and TNFRSF9 domain as a signaling inducer inside the cell, both CARs should be activated. So, one CAR should bind to TAA and another CAR should bind to FITC of FHBM for CAR-T cell activation [84]. This dual activation system with a switch molecule could efficiently control CAR-T cells' activity.…”