Harnessing novel cell-penetrating antibodies for neuronal correction

描述（由申请人提供）：本提案的长期目标是开发用于治疗或预防神经系统疾病的重组细胞穿透抗体或“跨体”。在细胞内（体内）起作用的抗体显示出作为神经保护试剂的巨大潜力，可以减少几种人类神经退行性疾病（包括亨廷顿氏病、帕金森病、阿尔茨海默病和朊病毒疾病）中错误折叠蛋白的毒性积累。然而，由于缺乏强大的基因或蛋白质递送系统来有效地在体内施用这些重组治疗性蛋白质，目前阻碍了体内内的实际应用。该应用假设，某些自身抗体穿透细胞的新能力可以被利用来靶向重组治疗蛋白，如体内蛋白进入神经元，用于治疗应用。初步数据表明，通过ENT2/SLC29A2平衡核苷转运体穿透神经元的先导治疗性体内融合到良性抗dna转运体中，为这种实验方法提供了概念证明。使用亨廷顿氏病模型作为蛋白质聚集障碍的疾病范例，该提议的具体目标有三个方面：(i)优化穿透细胞的天然抗体的重组跨体结构域，（ii）在亨廷顿病细胞模型中测试抗亨廷顿蛋白先导体与优化的跨体融合的细胞穿透和功能功效，以及（iii）使用亨廷顿病转基因小鼠模型评估抗亨廷顿跨体在体内的治疗潜力。本提案中概述的实验最终解决了目前基因或蛋白质治疗的关键障碍，即实现重组治疗蛋白广泛有效地递送到神经元中，用于需要细胞内校正的神经系统疾病的子集。

DESCRIPTION (provided by applicant): The long-term goal of this proposal is to develop recombinant cell-penetrating antibodies or "transbodies" for the treatment or prevention of neurological disease. Antibodies that function intracellularly (intrabodies) show great potential as neuroprotective reagents for reducing the toxic accumulation of misfolded proteins underlying several human neurodegenerative disorders, including Huntington's, Parkinson's, Alzheimer's, and prion diseases. However, the practical application of intrabodies is currently hampered by a lack of robust gene or protein delivery systems for administering these recombinant therapeutic proteins effectively in vivo. This application hypothesizes that the novel ability of certain autoantibodies to penetrate cells can be harnessed to target recombinant therapeutic proteins such as intrabodies into neurons for therapeutic applications. Preliminary data using a lead therapeutic intrabody fused to a benign anti-DNA transbody that penetrates neurons through ENT2/SLC29A2 equilibrative nucleoside transporters offer proof of concept for this experimental approach. Using models of Huntington's disease as a disease paradigm for protein aggregation disorders, the specific aims of this proposal are three-fold: (i) to optimize recombinant transbody domains from naturally-occurring antibodies that penetrate cells, (ii) test a lead anti-huntingtin intrabody in fusion with optimized transbodies for cell penetration and functional efficacy in a cellular model of Huntington's disease, and (iii) evaluate anti-huntington transbodies for therapeutic potential in vivo using a transgenic mouse model of Huntington's disease. The experiments outlined in this proposal ultimately address what is currently a critical barrier for gene or protein therapies, namely achieving widespread and efficient delivery of recombinant therapeutic protein into neurons, for a subset of neurological conditions where intracellular correction is desired. PUBLIC HEALTH RELEVANCE: This application develops and tests cell-permeable antibodies or "transbodies" as specific agents for treating and preventing human neurological disease, using models of Huntington's disease, a lethal neurodegenerative disorder estimated to affect 1 in 10,000 Americans, as a disease paradigm. The methodologies tested in this proposal, if successful, may be directly applicable to other kinds of molecular therapies for which transport into diseased neurons is currently inefficient or unattainable.