SUPRAMOLECULAR PEPTIDE CO-ASSEMBLIES FOR CYTOSOLIC PROTEIN DELIVERY

项目摘要。将重组蛋白输送到胞浆中将提供进入治疗靶点的途径 在细胞外环境中不能获得的药物，具有比所提供的更快的药代动力学 通过需要转录和翻译的基因传递方法。能够运送活性蛋白质的交通工具 需要穿过细胞膜进入细胞质，以绕过有限的被动内化 蛋白质由于其大的尺寸、电荷和亲水性。一辆理想的交通工具应该是快速高效的 无论蛋白质的物理性质如何，将任何蛋白质运送到胞浆中，都可以在温和的条件下制造。 保持蛋白质活性，保护蛋白质在运输过程中不被降解，并且不诱导 副作用，如细胞死亡或抗蛋白免疫原性。为此，拟议的研究 该计划将开发一种创新的新载体，用于胞浆蛋白的传递，其基础是成对的相反- 带电的合成肽，Catch()和Catch(-)，在水中共同组装成b-折叠纳米纤维。 任一捕获肽与蛋白质末端的重组融合提供了一种可溶前体(即 在存在互补捕获物的情况下，被结合到纳米纤维中形成的纳米纤维 多肽伙伴。我们未发表的数据表明，聚山梨酸酯辅料(例如吐温-20和-80)推动 从互补的Catch()肽和稀释物(即，微米)混合物中快速形成纳米颗粒 捕获蛋白对。这些捕获的蛋白质颗粒进入胞浆，在那里蛋白质表现出来 生化活动。Catch-Protein颗粒不具有细胞毒性，也不会诱导针对该蛋白质的抗体。 在老鼠身上。总而言之，这些观察表明，捕获蛋白颗粒是一种理想的候选载体。 用于胞浆蛋白的输送。根据这些观察，我们假设：(1)捕获蛋白颗粒 通过内吞作用内化，其中胞浆递送是通过阴离子Catch-Protein的质子化实现的 在内体酸化过程中，产生阳离子纳米结构，导致内体囊泡破裂；以及 (2)Catch-Protein颗粒可以通过胞浆递送在体外产生耐受树突状细胞。 免疫抑制酶吲哚-2，3-双加氧酶。为了检验这些假设，特定目标1将 使用体外细胞模型表征通过Catch-Protein颗粒的胞浆蛋白输送，并建立 光谱学、流式细胞术和显微镜方法，以及已有的内吞作用抑制剂。特定的 AIM 2将使用OTI和OTI来评估细胞内递送Catch-IDO用于细胞介导的免疫调节 OTII抗原特异性免疫反应模型。这一计划的成功将提供量化和 对Catch-Protein颗粒内化的机制理解将对未来的翻译具有重要意义 努力，同时也建立捕捉蛋白质颗粒作为免疫工程的一种有前途的策略。

Project Summary. Delivery of recombinant proteins into the cytosol would provide access to therapeutic targets that are not accessible within the extracellular environment, with faster pharmacokinetics than what are afforded by gene delivery approaches requiring transcription and translation. Vehicles that can shuttle active proteins across the cell membrane and into the cytosol are needed to circumvent the limited passive internalization of proteins due to their large size, charge, and hydrophilicity. An ideal vehicle would mediate rapid and efficient delivery of any protein cargo into the cytosol, regardless of protein physical properties, be fabricated under mild conditions that maintain protein activity, protect the protein from degradation during transport, and not induce adverse side-effects, such as cell death or anti-protein immunogenicity. Toward this end, the proposed research program will develop an innovative new vehicle for cytosolic protein delivery based on pairs of oppositely- charged synthetic peptides, CATCH(+) and CATCH(-), that co-assemble into b-sheet nanofibers in water. Recombinant fusion of either CATCH peptide onto the terminus of a protein provides a soluble precursor (i.e., a “CATCH-Protein”) that is incorporated into the nanofibers that form in the presence of a complementary CATCH peptide partner. Our unpublished data demonstrate that polysorbate excipients (e.g. Tween-20 and -80) drive the rapid formation of nanoparticles from dilute (i.e., µM) mixtures of a complementary CATCH(+) peptide and CATCH-Protein pair. These CATCH-Protein particles traffic into the cytosol, where the protein then exhibits biochemical activity. CATCH-Protein particles are not cytotoxic and do not induce antibodies against the protein in mice. Collectively, these observations suggest that CATCH-Protein particles are an ideal candidate vehicle for cytosolic protein delivery. Informed by these observations, we hypothesize that: (1) CATCH-Protein particles are internalized by endocytosis, where cytosolic delivery is enabled by protonation of the anionic CATCH-Protein during endosome acidification, which yields cationic nanostructures that induce endosomal vesicle rupture; and (2) CATCH-Protein particles can be employed to generate tolerogenic dendritic cells ex vivo via cytosolic delivery of the immunosuppressive enzyme indoleamine-2,3-dioxygenase. To test these hypotheses, Specific Aim 1 will characterize cytosolic protein delivery via CATCH-Protein particles using in vitro cell models and established spectroscopy, flow cytometry, and microscopy methods, alongside established endocytosis inhibitors. Specific Aim 2 will evaluate cytosolic delivery of CATCH-IDO for cell-mediated immunomodulation using the OTI and OTII antigen-specific immune response models. Success of this program will provide quantitative and mechanistic understanding of CATCH-Protein particle internalization that will be important for future translational efforts, while also establishing CATCH-Protein particles as a promising strategy for immune engineering.