Cytokine receptor armored CAR-T cells enable robust T cell expansion and function in the absence of lymphodepletion Free

Chimeric antigen receptor (CAR) T cell therapy is emerging as a promising approach for oncology and autoimmune diseases. However, its broad clinical translation remains limited by the reliance on lymphodepleting chemotherapy (e.g., fludarabine/cyclophosphamide), which is particularly undesirable in non-malignant settings due to its associated toxicity. To overcome this barrier, we aimed to engineer CAR-T cells capable of robust in vivo expansion and persistence without lymphodepletion.

We systematically screened 19 underexplored immunomodulatory cytokines across the common γ-chain, β-chain, IL-6, and IL-10 families to identify candidates that enhance CAR-T function while minimizing systemic toxicity. This screen revealed IL27 with potent in vivo efficacy and favorable safety profiles in murine models.

To harness this cytokine signal in a cell-intrinsic manner, we engineered CAR T cells with constitutively active gp130 (cGP130)， a synthetic active receptor for IL27. This modification enhanced CAR T cell anti-tumor efficacy in vivo in the tumor bearing mice by 10X. In addition, CAR T cells with this receptor modification did not exhibit uncontrolled growth as confirmed by cytokine-independent growth assays and in vivo expansion kinetics.

To test whether this receptor-driven proliferation could eliminate the need for lymphodepletion, we constructed CD20-targeting CAR T cells from cynomolgus T cells armed with cGP130，so that the T cell could proliferate upon the stimulation of CD20 antigen. We infused multiple cells together into a single recipient without lymphodepletion and monitored the CART expansion via ddPCR. CART cells without modification had modest engraftment while CAR T cells expressing IL27 and cGP130 demonstrated robust expansion in non-human primates with a three-fold increase in Cmax. In addition, we did not observe toxicity or inflammatory reactions in the NHP.

These findings highlight IL27 and its receptor pathway as a promising strategy to optimize CAR T cell therapy. By eliminating the need for lymphodepletion, this approach could broaden the safe application of CAR T cells to autoimmune diseases and other non-malignant settings. Our results lay the groundwork for future clinical trials aimed at enhancing CAR T cell expansion, persistence, and therapeutic efficacy in the absence of lymphodepleting chemotherapy.