Antisense oligonucleotides (ASOs) are promising therapeutics for treating various neurological disorders. However, ASOs are unable to readily cross the mammalian blood-brain barrier (BBB) and therefore need to be delivered intrathecally to the central nervous system (CNS). Here, we engineered a human transferrin receptor 1 (TfR1) binding molecule, the oligonucleotide transport vehicle (OTV), to transport a tool ASO across the BBB in human TfR knockin (TfR mu/hu KI) mice and nonhuman primates. Intravenous injection and systemic delivery of OTV to TfR mu/hu KI mice resulted in sustained knockdown of the ASO target RNA, Malat1 , across multiple mouse CNS regions and cell types, including endothelial cells, neurons, astrocytes, microglia, and oligodendrocytes. In addition, systemic delivery of OTV enabled Malat1 RNA knockdown in mouse quadriceps and cardiac muscles, which are difficult to target with oligonucleotides alone. Systemically delivered OTV enabled a more uniform ASO biodistribution profile in the CNS of TfR mu/hu KI mice and greater knockdown of Malat1 RNA compared with a bivalent, high-affinity TfR antibody. In cynomolgus macaques, an OTV directed against MALAT1 displayed robust ASO delivery to the primate CNS and enabled more uniform biodistribution and RNA target knockdown compared with intrathecal dosing of the same unconjugated ASO. Our data support systemically delivered OTV as a potential platform for delivering therapeutic ASOs across the BBB.

中文翻译：

---

靶向转铁蛋白受体以跨哺乳动物血脑屏障转运反义寡核苷酸


反义寡核苷酸（ASO）是治疗各种神经系统疾病的有前景的疗法。然而，ASO 无法轻易穿过哺乳动物血脑屏障 (BBB)，因此需要通过鞘内递送至中枢神经系统 (CNS)。在这里，我们设计了一种人转铁蛋白受体 1 (TfR1) 结合分子，即寡核苷酸转运载体 (OTV)，在人 TfR 敲入 (TfR mu/hu KI) 小鼠和非人灵长类动物中将工具 ASO 转运穿过 BBB。向 TfR mu/hu KI 小鼠静脉注射和全身递送 OTV 导致多个小鼠 CNS 区域和细胞类型（包括内皮细胞、神经元、星形胶质细胞、小胶质细胞和少突胶质细胞）持续敲低 ASO 靶标 RNA Malat1。此外，OTV 的全身递送能够在小鼠股四头肌和心肌中敲低 Malat1 RNA，而仅用寡核苷酸很难靶向这些肌肉。与二价高亲和力 TfR 抗体相比，系统递送的 OTV 能够在 TfR mu/hu KI 小鼠的 CNS 中实现更均匀的 ASO 生物分布，并更大程度地敲低 Malat1 RNA。在食蟹猴中，针对 MALAT1 的 OTV 表现出强大的 ASO 递送至灵长类中枢神经系统，与鞘内给药相同的未缀合 ASO 相比，能够实现更均匀的生物分布和 RNA 靶点敲低。我们的数据支持系统地将 OTV 作为跨 BBB 提供治疗性 ASO 的潜在平台。