RNAi vector deilvery to inhibit JE/WN encephalitis

RNAi 载体递送抑制乙型脑炎/西伯利亚脑炎

• 批准号: 7678720
• 负责人: MANJUNATH NARASIMHA SWAMY
• 金额: $ 18.21万
• 依托单位: TEXAS TECH UNIVERSITY HEALTH SCIS CENTER
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-01-15 至 2009-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7678720
• 关键词: Acute; Antibodies; Antiviral Agents; Bioterrorism; Blood - brain barrier anatomy; Brain; Categories; Cerebrospinal Fluid; Clinical; Code; Complex; Conserved Sequence; Culicidae; Development; Diffuse; Drug Delivery Systems; E protein; Encapsulated; Encephalitis; Ensure; Exhibits; Flavivirus; Genomics; Geographic Locations; Human; Immunoliposome; Infection; Intervention; Intravenous; Invasive; Japanese Encephalitis; Japanese encephalitis virus; Lipids; Mediating; Membrane; Messenger RNA; Methods; Mus; National Institute of Allergy and Infectious Disease; Nature; Neurologic; Numbers; RNA; RNA Interference; Role; Route; Site; Small Interfering RNA; Survivors; Testing; Therapeutic; Time; Transferrin; Transferrin Receptor; Viral; Viral Envelope Gene; Virus; West Nile virus; Work; base; brain cell; disability; mortality; nanoparticle; prevent; small hairpin RNA; targeted delivery; tool; uptake; vector

DESCRIPTION: West Nile (WN) and Japanese encephalitis (JE) viruses are mosquito-borne flaviviruses that cause a devastating acute neurological illness with up to 30% mortality and permanent neurological disabilities in the survivors. These are also potential category B bioterrorism agents and there is no effective treatment for these viruses. Recently RNA interference, where short RNA molecules (siRNA) mediate the destruction of corresponding mRNA molecules in a sequence-specific manner, has emerged as a tool for potential antiviral therapeutics. After testing several genomic sequences as targets, we have found that a siRNA targeting a highly conserved sequence in the viral envelope gene can protect mice from fatal encephalitis induced by either WNV or JEV. Because many strains of viruses exist in nature that may exhibit small differences even within the conserved sequence, in Aim 1, we will identify an additional 2-3 conserved target sequences that can effectively suppress both JEV and WNV. We will also test if treatment with a combination of siRNAs will increase the magnitude and/or breadth of protection. Additionally to enhance confidence, we will also test the siRNAs for their ability to inhibit multiple viral strains isolated from different geographic locations. In preliminary studies, a single treatment with either lentivirally expressed shRNA or synthetic siRNA was sufficient to provide protection from an infection induced 6 or 18 h earlier. However the currently used method involves administration of siRNA intracranially at the same site as viral challenge and thus, the siRNA is unlikely to diffuse enough to protect all brain cells, which would be required for treatment to be effective after the virus has extensively spread at later time points after infection. Thus in order to realize the siRNA treatment potential in a clinical setting, in Aim 2, we will develop methods for better delivery of siRNA across the brain. Because it will provide the most practical form of treatment, we will develop non- invasive methods for siRNA delivery. To enable uptake by brain cells following intravenous delivery, we will develop pegylated immunoliposomes coated with transferrin receptor antibody as well as use polymeric nanoparticles coated with transferrin. Alternatively, we will try siRNA delivery into the cerebrospinal fluid. If these methods do not work, we will also test delivery efficacy using methods that disrupt the blood-brain barrier transiently. Efficacy will be determined by testing the siRNA's ability to prevent as well as to cure an established infection.

描述：西尼罗河病毒(WN)和日本脑炎(JE)病毒是由蚊子传播的黄病毒，会导致一种毁灭性的急性神经疾病，幸存者的死亡率高达30%，并导致永久性神经残疾。这些也是潜在的B类生物恐怖主义制剂，这些病毒还没有有效的治疗方法。最近，RNA干扰，其中短RNA分子(SiRNA)以序列特异性的方式介导相应的mRNA分子的破坏，已经成为潜在的抗病毒治疗的工具。在测试了几个基因组序列作为靶点后，我们发现针对病毒包膜基因中高度保守序列的siRNA可以保护小鼠免受WNV或JEV诱导的致死性脑炎。由于自然界中存在许多病毒株，即使在保守序列内也可能表现出微小的差异，在目标1中，我们将额外识别2-3个保守的靶序列，可以有效地抑制JEV和WNV。我们还将测试联合使用siRNAs是否会增加保护的幅度和/或广度。此外，为了增强信心，我们还将测试siRNAs对来自不同地理位置的多种病毒株的抑制能力。在初步研究中，用慢病毒表达的shRNA或合成的siRNA单独处理足以提供对6或18小时前诱导的感染的保护。然而，目前使用的方法涉及在病毒挑战的同一部位对siRNA进行脑内注射，因此，siRNA不太可能扩散到足以保护所有脑细胞，这将是病毒在感染后的稍后时间点广泛传播后才能有效治疗所需的。因此，为了在临床环境中实现siRNA的治疗潜力，在目标2中，我们将开发更好地在大脑中传递siRNA的方法。因为它将提供最实用的治疗形式，我们将开发非侵入性的siRNA传递方法。为了能够在静脉注射后被脑细胞摄取，我们将开发包被转铁蛋白受体抗体的聚乙二醇化免疫脂质体，以及使用包被转铁蛋白的聚合物纳米颗粒。或者，我们将尝试将siRNA输送到脑脊液中。如果这些方法不起作用，我们还将使用瞬时破坏血脑屏障的方法来测试递送效果。疗效将通过测试siRNA预防和治愈既定感染的能力来确定。