In this study, the CAR-like multivalent aptamer nanoparticles (X-polymers) were assembled with the dimer of murine CD28 RNA aptamer (CD28Apt7), the tetramer of CTLA-4 (cytotoxic T-lymphocyte-associated protein 4) RNA aptamer (Del60), and a folic acid labeled ssDNA fragment in a stable nucleic acid three-way junction scaffold (3WJ). Results showed that the X-polymers could recognize both the mCD28 and mCTLA-4 molecules. Confocal imaging and flow cytometry assays showed that the X-polymers could target both T cells and B16 cells in vitro. With the first costimulatory signals provided by the CD3 antibodies, the X-polymers could increase T cell proliferation and reverse the inhibitory effect of interleukin-2 (IL-2) secreting caused by exogenous B7.1 molecules on T cells in vitro. Results of our study also showed that X-polymers could inhibit mouse melanoma B16 cell growth both in vitro and in vivo. Our study demonstrated for the first time that the multivalent aptamer nanoparticle-activated T cells could fulfill the function of CAR-T, which promised a novel approach to developing a multi-functional design of aptamer drugs with potential CAR-like characteristics to enhance the safety of CAR-T cell immunotherapy.

在这项研究中，CAR样多价适体纳米粒子（X聚合物）与鼠CD28 RNA适体（CD28Apt7）的二聚体，CTLA-4（细胞毒性T淋巴细胞相关蛋白4）RNA适体（Del60）的四聚体组装在一起。 ）和叶酸标记的ssDNA片段置于稳定的核酸三向连接支架（3WJ）中。结果表明，X聚合物可以识别mCD28和mCTLA-4分子。共聚焦成像和流式细胞仪检测表明，X聚合物可在体外靶向T细胞和B16细胞。借助CD3抗体提供的第一个共刺激信号，X聚合物可以增加T细胞增殖并逆转外源性B7.1分子对T细胞的分泌分泌的白介素2（IL-2）的抑制作用。我们的研究结果还表明，X-聚合物可以在体外和体内抑制小鼠黑色素瘤B16细胞的生长。我们的研究首次证明了多价适体纳米颗粒激活的T细胞可以履行CAR-T的功能，这为开发具有潜在CAR样特征的适体药物多功能设计以提高安全性提供了一种新方法-T细胞免疫疗法