CCL17/CCL22-CCR4轴增强CAR-M杀伤复发难治性经典霍奇金淋巴瘤的作用与潜在机制

得益于免疫治疗为主的多种治疗手段的出现，cHL的治疗有效率得到了大幅度提高，但仍有部分患者复发难治，故需探索新的治疗手段。申请人前期发现cHL中肿瘤细胞高表达CCL17/CCL22以募集CCR4+免疫细胞(如Treg等)，而这些CCR4+细胞分泌CCL17/CCL22形成趋化因子轴的正反馈,加速免疫抑制微环境形成。基于申请人在细胞免疫治疗方面的研究，提出假说，在巨噬细胞中表达CCR4和CD30-CAR可引导CAR-M高效进入瘤体，对CD30+肿瘤细胞和Treg进行选择性杀伤。本研究拟通过基因工程修饰与M1巨噬细胞诱导以制备表达CCR4和CD30-CAR的CAR-M，利用细胞系模型和动物模型，评估其体内外趋化、吞噬和肿瘤杀伤的能力，结合单细胞转录组测序分析，阐明CCL17/CCL22-CCR4轴增强CAR-M杀伤CD30+肿瘤细胞和Treg细胞的机制，为探索cHL治疗手段提供新的思路。

Benefiting from the emergence of multiple treatments based on immunotherapy, the effectiveness of treatment of cHL has been greatly improved. But there are still some patients who are relapsed and refractory, so it is necessary to explore new treatments. In our preliminary work, we found that HRS tumor cells in cHL highly express CCL17/CCL22 to recruit CCR4+ immune cells, such as Treg cells. And these CCR4+ cells also secrete CCL17/CCL22 to form positive feedback of CCL17/CCL22-CCR4 axis, which accelerates the formation of immunosuppressive microenvironment. Based on the applicant’s research on immune cell therapy, we proposed a novel hypothesis that the expression of CCR4 and CD30-specific CAR in macrophages may efficiently guide macrophages into tumors and selectively kill CD30+ HRS cells and Treg cells. To identify our hypothesis, we try to express both exogenous CCR4 and artificial CD30-specific CAR in macrophages through genetic engineering and M1 culture condition. And then we will use cell line models and animal models to evaluate the chemotaxis, phagocytosis and tumor-killing abilities of engineered CAR-M in vitro and in vivo. Combined with single-cell transcriptome analysis, the mechanism of CCL17/CCL22-CCR4 axis enhancing CAR-M to kill CD30+ tumor cells and Treg cells was explored, which provides a new idea for exploring the treatment of cHL.