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

摘要 用于治疗剂的胞吞转运的受体的鉴定 血脑屏障（BBB）是发展治疗和治疗性脑缺血的基本障碍。 用于治疗脑疾病如神经胶质瘤或阿尔茨海默病的诊断试剂/药物。电流 这些方法利用脑血管内皮细胞上的受体增强治疗剂向脑的递送， 通过用单克隆抗体（mAb）靶向脑毛细血管，用于mAb的胞吞转运， 用于治疗的缀合药物或融合蛋白。迄今为止，研究最广泛的受体是通过 BBB是转铁蛋白受体（TfR）和人胰岛素受体（HIR），这两者都是由BBB高表达的。 构成血脑屏障的内皮细胞。在该方法中，将与治疗药物或蛋白质缀合的mAb结合在一起。 从血液运输到脑实质中以实现功效;然而，全身毒性和低 运输效率阻碍了临床应用。仍然迫切需要查明 具有高转运效率和脑特异性表达以提高治疗指数的新受体。 我们的方法将通过用由以下组成的组合文库鉴定这些受体来解决这一障碍： 单链可变片段（scFv）由工程化的复制能力慢病毒作为慢病毒载体递送 scFv展示文库。基于该平台的体内选择将提供具有结合特性的抗体， 是针对转胞吞作用而优化的，这不能通过对人细胞的体外选择来实现。 该项目的成功，这一多靶点，转细胞平台，预计将加速 开发治疗脑部疾病的新疗法。我们将产生一组scFv， 能够转胞吞化学治疗剂、治疗基因的有效载荷的不同受体，或融合的 基于蛋白质的激动剂/拮抗剂以治疗诸如胶质母细胞瘤或阿尔茨海默病的疾病。

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.