Radiation-induced targeted extracellular vesicles -based gene delivery for glioma therapy

放射诱导的基于细胞外囊泡的基因递送用于神经胶质瘤治疗

• 批准号: 9902892
• 负责人: BAKHOS A TANNOUS
• 金额: $ 24.86万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-12-01 至 2021-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9902892
• 关键词: Adaptive Immune System; Affinity; Animals; Antibodies; Brain; Brain Neoplasms; CD47 gene; CD8-Positive T-Lymphocytes; Cells; Characteristics; Chemotherapy and/or radiation; Development; Eating; Excision; Exhibits; FDA approved; Gene Delivery; Glioblastoma; Glioma; Immune; Immune checkpoint inhibitor; Immune response; Immunosuppression; Immunotherapy; Injections; Innate Immune System; Integrin alphaVbeta3; Intravenous; Ligands; Malignant neoplasm of brain; Modification; Mus; Operative Surgical Procedures; Patients; Peptides; Property; RGD (sequence); Radiation; Radiation Dose Unit; Radiation therapy; Signal Transduction; Site; Small Interfering RNA; Surface; Survival Rate; System; Therapeutic; Tumor Antigens; Tumor-associated macrophages; Vascular Endothelial Cell; Vesicle; adaptive immune response; base; cancer type; checkpoint inhibition; clinical application; cytotoxic CD8 T cells; extracellular vesicles; immune checkpoint; immunogenicity; improved; intravenous administration; mouse model; nanotherapeutic; nerve stem cell; outcome forecast; programmed cell death ligand 1; radiation effect; recruit; targeted delivery; therapeutic transgene; tumor; tumor growth; tumor microenvironment; tumor-immune system interactions; uptake

Abstract Glioblastoma (GBM) is the most common primary malignant brain tumor with poor prognosis. Therapeutic suppression of immune checkpoint molecules elicits a tumor immune response and improves long-term survival in several types of cancers. GBM cells highly express immune checkpoint molecules including programmed death-ligand 1 (PD-L1) a critical “don’t find me” signal to the adaptive immune system, and CD47, a “don’t eat me” signal to the innate immune system as well as a regulator of the adaptive immune response. Although radiation therapy has been shown to counteracts the immunosuppressive GBM microenvironment by enhancing the presentation of normally suppressed tumor-associated antigens, promoting CD8+ T cell recruitment, radiation enhances even further the expression of PD-L1 on tumor and microenvironment. Unfortunately, little effect has been observed with checkpoint inhibitors against GBM. An effective GBM therapy requires a delivery system that reaches the tumor in the brain, with limited systemic effect. Endogenous small vesicles known as extracellular vesicles (EVs) hold a great promise as a delivery vehicle given their unique properties including low immunogenicity and innate stability. However, intravenous delivery of EVs to the brain remains a major challenge due to poor targeting of unmodified EVs, which can be improved by surface modification. Our preliminary results shows that The cyclo(Arg-Gly-Asp- D-Tyr-Lys) peptide, which exhibits high affinity to integrin αvβ3 on tumor vascular endothelial cells, could be conjugated on EVs surface (derived from FDA-approved normal neural progenitor cells), resulting in improved EV accumulation in brain tumors after intravenous administration. Furthermore, building on recent studies showing that short bursts of radiation therapy can prime tumors for enhanced accumulation and intratumoral distribution of nanotherapeutics in tumor-associated macrophages-dependent fashion, we showed that glioblastomas primed with radiation had an enhanced uptake of targeted EVs. In this proposal, we will take advantage of these unique characteristics of targeted EVs and load them with small interfering RNAs (siRNAs) against PD-L1 and CD47 to achieve enhanced immune response at the glioblastoma site, primed with radiation. We will evaluate whether radiation therapy will prime glioblastomas for enhanced uptake of these targeted EV across the BBB to deliver siRNAs to GBM, to increase CD8 T cells cytotoxic activity, thus halting tumor growth and prolonging animal survival in a syngeneic graft GBM mouse model.

摘要 胶质母细胞瘤（GBM）是最常见的原发性恶性脑肿瘤，预后差。治疗 免疫检查点分子的抑制可激发肿瘤免疫应答， 几种癌症的存活率。GBM细胞高度表达免疫检查点分子，包括 程序性死亡配体1（PD-L1）是适应性免疫系统的关键“不要找到我”信号， CD 47是先天免疫系统的“不要吃我”信号，也是适应性免疫的调节因子。 反应虽然放射治疗已被证明可以抵消免疫抑制GBM 通过增强正常抑制的肿瘤相关抗原的呈递来改善微环境， 促进CD 8 + T细胞募集，放射甚至进一步增强肿瘤上PD-L1的表达， 微环境。不幸的是，几乎没有观察到检查点抑制剂对GBM的作用。一个 有效的GBM治疗需要到达脑中肿瘤的递送系统， 效果被称为细胞外囊泡（EV）的内源性小囊泡作为递送具有很大的希望。 赋形剂，因为它们具有独特的性质，包括低免疫原性和先天稳定性。然而，在这方面， 由于未修饰的EV的靶向性差， 其可以通过表面改性来改善。我们的初步结果表明，环（Arg-Gly-Asp-） D-Tyr-Lys）肽对肿瘤血管内皮细胞上的整合素αvβ3表现出高亲和力， 缀合在EV表面上（源自FDA批准的正常神经祖细胞），导致 静脉内给药后改善EV在脑肿瘤中的蓄积。此外，在最近的基础上， 研究表明，短时间的放射治疗可以使肿瘤积累增加， 纳米治疗剂以肿瘤相关巨噬细胞依赖方式在肿瘤内分布，我们 显示，放射引发的胶质母细胞瘤对靶向EV的摄取增强。在这一提议中， 我们将利用目标电动汽车的这些独特特性， 针对PD-L1和CD 47的RNA（siRNA），以增强胶质母细胞瘤部位的免疫应答， 已经被辐射过了我们将评估放射治疗是否会引发胶质母细胞瘤， 这些靶向EV穿过BBB的摄取将siRNA递送至GBM，以增加CD 8 T细胞的细胞毒性 活性，从而阻止肿瘤生长并延长同基因移植GBM小鼠模型中的动物生存期。