功能化树突状细胞膜囊泡介导肝癌免疫治疗的机制研究

Hepatocellular carcinoma is one of the most predominant subjects of liver malignancies, which arouses global concern in the recent years. Current treatment options for patients with advanced hepatocellular carcinoma are limited, and there is an unmet need for novel therapeutic approaches. More importantly, hepatocellular carcinoma is an attractive target for immunomodulation therapy, since it arises in an inflammatory milieu due to hepatitis B/C infections and cirrhosis. However, major barriers to the development and success of immunotherapy in patients with hepatocellular carcinoma are the liver's inherent immunosuppressive function and unsatisfied drug carriers for immune-mediated therapies. In this project, we aim to develop a nanobiotechnology that can solve the challenges in the fabrication and engineering of cell plasma membrane derived vesicles for hepatocellular carcinoma immunotherapy. A proof-of-concept study will be performed with antigen peptide and imaging probe co-delivery with cell plasma membrane derived vesicles extracted from engineered dendritic cells. The nanoformula is prepared to study structure-activity relationship of effective immunomodulation pathway in antigen processing for immunotherapy. Furthermore, the magnetic resonance imaging and photoacoustic imaging provide an important method to monitor therapeutic response and analysis the signaling pathways to explore the potential immune modulation of HCC immunotherapy. We seek to determine and delineate the sophisticated functional nanotheranostics with optimized properties for arrange of immunotherapy applications: efficient antigen/epitope delivery, non-invasive quantitative analysis on the distribution of drug carriers and early therapy response in vivo. If successful, our study will provide a useful resource to explore new therapeutic targets and drug carriers for HCC immunotherapy.

原发性肝癌具有高侵袭性和高异质性的病理特点，外科手术为治疗首选但适应症有限且易出现手术残留，预后极差。以免疫治疗为代表的生物治疗技术是当前肝癌多学科协同综合治疗研究热点。发展安全高效的肝癌免疫治疗药物递送系统并阐明其作用机制是肝癌免疫治疗的关键问题。本项目旨在应用基因工程技术改造专职抗原提呈树突状细胞，将目的抗原定向表达锚定树突状细胞膜，进而采用自组装技术高效获得功能化细胞膜囊泡并同时装载分子影像探针，构建一类新型可视化肝癌免疫治疗药物递送系统。采用多模态分子影像方法无创动态实时监控疫苗递送载体的体内分布和治疗反应，进一步优化抗原导入策略、载体尺寸效应和理化特性，增强抗原递呈的靶向性和有效性，实现目的抗原可控递呈并深入揭示其免疫反应类型和免疫治疗作用机制，为研发具有临床应用价值的肝癌免疫治疗体系提供理论基础。

本课题采用纳米颗粒负载、质粒转染、病毒感染等多种研究策略将肿瘤抗原导入树突状细胞，探索了不同的肿瘤抗原导入方式致使MHC分子表达情况，比较了抗原导入策略对树突状细胞分化及抗原提呈能力的影响因素。进一步以树突状细胞膜囊泡为载体，成功构建了靶向淋巴结、可直接进行抗原递呈并高效刺激活化T细胞，并使T细胞向特定类型效应细胞分化的疫苗递呈系统。多模态影像监控下完成药物递送载体系统在小鼠肝癌动物模型体内的药物代谢动力学、生物组织分布、肝癌组织靶向效率分析以及病理组织学验证，为优化肝癌靶向免疫治疗方案提供了理论依据。本课题负责人多次参加本领域专业学术会议进行学术交流。通过本项目的开展，已在Biomaterials Science、Progress in Natural Science: Materials International以及Journal of Innovative Optical Health Sciences等学术期刊发表论文8篇。上述研究为我们在后续课题中进一步开展更加深入系统的肝癌免疫治疗顺利实施和拓展奠定了工作基础。