Transcriptomic profiling of IDR CAR-T cells in the CD19 cancer model.

Chimeric antigen receptor (CAR)-T cell-based therapies demonstrated remarkable efficacies for treating otherwise intractable cancers, particularly B-cell malignancies. However, existing FDA-approved CAR-Ts were limited by low antigen sensitivity, rendering their insufficient targeting to low antigen-expressing cancers. To improve the antigen sensitivity of CAR-Ts, we engineered CARs targeting CD19, CD22, and HER2 by including intrinsically disordered regions (IDRs) that promote signaling condensation. The CARs fused with IDR from FUS, EWS, or TAF15 triggered enhanced membrane-proximal signaling in the CAR-T synapse, which led to an increased release of cytotoxic factors, a higher killing activity towards low antigen-expressing cancer cells in vitro. Moreover, the IDR CAR-Ts induced improved anti-tumor effects in vivo in both blood cancer and solid tumor models. No elevated tonic signaling was observed in IDR CAR-Ts. Together, we demonstrated IDRs as a new tool set to enhance CAR-T cytotoxicity and to broaden CAR-T’s application to low antigen-expressing cancers. PBMCs were isolated from mice blood. Human T cells were sorted for library preparation and single cell RNA sequence.