Identification of receptors for transcytotic delivery of therapeutic agents crossing the BBB

摘要 治疗药物跨细胞递送受体的鉴定 血脑屏障(BBB)是治疗和治疗疾病发展的根本障碍。 治疗脑胶质瘤或阿尔茨海默病等脑部疾病的诊断试剂/药物。当前 利用血管内皮细胞上的受体加强治疗药物对大脑的输送 以单抗(MAbbs)为靶点的脑毛细血管，以跨细胞递送mAb和 用于治疗的结合药物或融合蛋白。到目前为止研究最广泛的跨膜蛋白受体 血脑屏障是转铁蛋白受体(TFR)和人胰岛素受体(HIR)，两者都是由 构成血脑屏障的内皮细胞。在这种方法中，与治疗药物或蛋白质结合的单抗 从血液输送到脑实质达到疗效；但全身毒性低 运输效率阻碍了临床应用。仍然迫切需要确定 新的受体具有高转运效率和脑特异性表达，以提高治疗指数。 我们的方法将通过使用由以下组成的组合库来识别这些受体来解决这一障碍 工程复制能力慢病毒作为慢病毒递送的单链可变片段(ScFv) ScFv显示库。基于该平台的体内选择将提供具有结合特性的抗体 对跨细胞作用进行了优化，而这不能通过对人类细胞的体外选择来实现。 该项目的成功，这一多目标、跨细胞的平台，预计将加速 开发治疗脑部疾病的新疗法。我们将生成一个scFv面板，它可以针对 不同的受体能够跨细胞传递化疗药物、治疗性基因或融合的有效载荷 基于蛋白质的激动剂/拮抗剂，用于治疗胶质母细胞瘤或阿尔茨海默病等疾病。

Abstract Identification of receptors for transcytotic delivery of therapeutic agents The Blood-Brain-Barrier (BBB) is a fundamental obstacle for the development of therapeutic and diagnostic reagents/drugs for treating brain diseases such as glioma or Alzheimer’s Disease. Current approaches enhance the delivery of therapeutics to the brain utilizing receptors on the endothelial cells of the brain capillaries by targeting with monoclonal antibodies (mAbs) for transcytotic delivery of the mAb and conjugated drugs or fused proteins for therapy. The most widely studied receptors thus far for crossing the BBB are the transferrin receptor (TfR) and human insulin receptor (HIR), both of which are highly expressed by endothelial cells that make up the BBB. In this approach, mAbs conjugated to therapeutic drugs or proteins are transported from the blood into the brain parenchyma to achieve efficacy; however, systemic toxicity and low transport efficiency has hampered clinical applications. There is still a pressing need for the identification of new receptors with high transport efficiency and brain specific expression to enhance the therapeutic index. Our approach will address this barrier by identifying these receptors with a combinatorial library comprised of single-chain variable fragment (scFv) delivered by an engineered replication-competent lentivirus as a lentiviral scFv display library. In vivo selection based on this platform will provide antibodies with binding properties that are optimized for transcytosis, which cannot be achieved by in vitro selection on human cells. Success of the project, this multi-target, transcytotic platform, is anticipated to accelerate the development of new therapies for diseases of the brain. We will generate a panel of scFvs that can target different receptors capable of transcytosing a payload of chemotherapeutics, therapeutic genes, or fused protein-based agonists/antagonists to treat diseases such as glioblastoma or Alzheimer’s Disease.