Nanocage-based systemic delivery of TGFβ trap for immunomodulation of brain neoplasms

项目摘要 大多数恶性脑癌或胶质母细胞瘤（GBM）患者的寿命不超过20个月， 高度积极的治疗，以及那些有很高的肿瘤复发概率的人。国家 指导和/或帮助我们身体的免疫系统对抗恶性癌症的治疗策略 最近已经引入，并且在针对非脑的临床研究中的成功提供了希望 癌的然而，这种所谓的免疫疗法，特别是检查点抑制， 在最近的一些临床试验中，脑癌患者中的可测量的益处。这个令人失望 现实在很大程度上归因于脑癌抵抗免疫疗法或抑制我们的免疫反应的独特能力。 防御性免疫系统具体而言，转化生长因子β（TGFβ）高度上调， 在GBM中以多管齐下的方式促进免疫抑制肿瘤微环境中的关键作用。 因此，我们假设TGFβ阻断剂会掩盖肿瘤免疫抑制，从而挽救肿瘤。 检查点抑制作为GBM的可行且有效的治疗。事实上，这种做法的有效性和潜在影响 联合入路已在多种非脑恶性实体瘤中得到临床前证实。然而，在这方面， 由于不能实现TGFβ的均匀和稳定递送，其在GBM中的实现尚未完成 抑制剂在整个脑肿瘤组织中，包括特别是免疫抑制性缺氧肿瘤区域。 紧密密封的血脑屏障（BBB）防止全身施用的治疗外渗到脑内。 脑组织一旦越过血脑屏障，治疗必须渗透高密度和粘附性肿瘤 细胞外基质扩散到整个肿瘤组织并到达远离血液的缺氧肿瘤区域 船舶.为此，我们建议开发和评估创新的基于纳米笼的人铁蛋白蛋白 能够克服这些具有挑战性的生物屏障以广泛阻断TGFβ的递送平台 在全身给药后遍及脑肿瘤组织。我们最近展示了我们的原型 纳米笼提供稳定的体循环、有效的外渗和肿瘤摄取、肿瘤组织穿透 以及在缺氧肿瘤区域中的积累。此外，我们的初步研究表明， 设计为携带TGFβ陷阱，可显著增强阻断免疫抑制性TGFβ信号传导的能力 与临床相关的抗TGF β抗体相比。我们还提供了一个概念验证的证据 这表明该纳米笼增强了临床上使用的检查点抑制剂在小鼠中的治疗功效 GBM模型因此，我们预计，TGFβ拮抗纳米笼将在本提案中得到进一步发展， 消除了GBM臭名昭著的免疫抑制性质，从而使其他难治性免疫 检查点抑制在从脑中根除恶性肿瘤组织方面非常有效。拟议 这种方法如果成功，将为治疗GBM和其他可能难以治愈的癌症提供突破 也

Project Summary Most of the patients with malignant brain cancer or glioblastoma (GBM) do not live more than 20 months despite highly aggressive treatments, and those who do have a very high probability of tumor recurrence. State-of-the- art therapeutic strategies that instruct and/or help our body's immune system to fight against malignant cancers have been recently introduced and hope has been provided by success in clinical studies targeting non-brain cancers. However, this so-called immunotherapy, particularly checkpoint inhibition, has failed to show measurable benefits among patients with brain cancers in a number of recent clinical trials. This disappointing reality is largely attributed to the unique ability of brain cancers to resist immunotherapy or to suppress our defensive immune system. Specifically, transforming growth factor β (TGFβ) is highly upregulated and plays pivotal roles in promoting the immunosuppressive tumor microenvironment in a multi-pronged manner in GBM. Thus, we hypothesize that TGFβ blockade would mask the tumor immuno-suppression, thereby rescuing checkpoint inhibition as a viable and potent treatment for GBM. Indeed, the validity and potential impacts of this combined approach have been preclinically demonstrated in multiple non-brain malignant solid tumors. However, its realization in GBM is yet to be accomplished due to inability to achieve uniform and robust delivery of TGFβ inhibitors throughout the brain tumor tissue, including the particularly immunosuppressive hypoxic tumor areas. The tightly sealed blood-brain barrier (BBB) precludes extravasation of systemically-administered therapy into the brain tissue. Once beyond the BBB, therapy must percolate the highly dense and adhesive tumor extracellular matrix to spread throughout the tumor tissue and reach hypoxic tumor regions distanced from blood vessels. To this end, we propose to develop and evaluate innovative human ferritin protein nanocage-based delivery platform capable of overcoming these challenging biological barriers for widespread TGFβ blockade throughout the brain tumor tissue following systemic administration. We recently demonstrated that our prototype nanocage provides stable systemic circulation, efficient extravasation and tumor uptake, tumor tissue penetration as well as accumulation in hypoxic tumor regions. In addition, our pilot study shows that the nanocage specifically designed to carry TGFβ trap provides markedly enhanced ability to block the immunosuppressive TGFβ signaling in vitro compared to the clinically-relevant anti-TGFβ antibody. We also provide a proof-of-concept evidence suggesting that this nanocage enhances therapeutic efficacy of a clinically used checkpoint inhibitor in a mouse model of GBM. We thus expect that TGFβ-antagonizing nanocages to be further developed in this proposal will dismantle the notoriously immunosuppressive nature of GBM and thus make the otherwise refractory immune checkpoint inhibition highly efficacious in eradicating malignant tumor tissues from the brain. The proposed approach, if successful, will provide a breakthrough in treating GBM and potentially other hard-to-cure cancers as well.