新开发的 TGF-β 响应型 CAR-T 细胞用于增强增殖与细胞因子分泌

Chimeric antigen receptor (CAR) T cell therapy has emerged as a promising cancer treatment. Nevertheless, the tumor microenvironment (TME) of solid tumors provides substantial challenges to CAR T cell efficacy. Tumor growth factor-beta (TGF- ), a potent immunosuppressive cytokine in the TME, impedes T cell activation, proliferation, and cytotoxicity, diminishing the anti-tumor potency of CAR T cells. This study investigates whether TGF- RII CAR T cells can overcome these barriers and remain functional in TGF- -rich environments.

We developed a novel TGF- RII CAR T cell (TGF- RII-CD28CD3z) and a dominant-negative TGF- receptor (dnT RII) T cell utilizing Jurkat cells. Transduction efficiency and surface expression were confirmed using flow cytometry. T cell activation and proliferation were assessed by CD69 and Ki-67 expression, respectively. IL-2 and IFN- secretion were quantified using ELISA kits.

Flow cytometry confirmed the successful cell surface expression of the designed receptors: 62% and 24% for TGF- RII CAR and dnT RII, respectively. TGF- RII CAR T cells were markedly activated in a dose-dependent manner, with optimal responses at 10 ng/mL TGF- . The Ki-67 expression of CAR T cells, used as a proliferation marker, increased 1.21-fold (from 79.5% to 96%) upon exposure to 10 ng/mL TGF- . At 5 ng/mL TGF- , the cells' proliferation was maintained at a 1.04-fold increase. Cytokine analysis revealed a 1.9-fold increase in IL-2 (130 4 pg/mL) and a 2.7-fold increase in IFN- (146 21.9 pg/mL) secretion at 10 ng/mL TGF- . Additionally, at 5 ng/mL TGF- , IL-2 secretion increased 1.6-fold (110 10.7 pg/mL), and IFN- secretion increased 1.7-fold (94.3 10.2 pg/mL). In contrast, dnT RII T cells also produced IL-2 (95 pg/mL 22, 2.7-fold increase) but failed to sustain proliferation or IFN- production at 10 ng/mL TGF- .

Our findings demonstrate that the TGF- RII CAR T cells not only resist TGF- -mediated suppression but also promote activation, proliferation, and cytokine release in the presence of TGF- . This underscores their therapeutic potential as an innovative approach to overcome TGF- -driven immunosuppression and improve the CAR T cell therapy efficacy in solid tumors.