An siRNA-based microbicide to prevent HIV transmission

基于 siRNA 的杀菌剂可预防 HIV 传播

• 批准号: 7133772
• 负责人: Judy Lieberman
• 金额: $ 186.16万
• 依托单位: IMMUNE DISEASE INSTITUTE, INC.
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-30 至 2010-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7133772
• 关键词: AIDS education /prevention; RNA interference; antiAIDS agent; biotechnology; clinical research; cooperative study; small interfering RNA

DESCRIPTION (provided by applicant): A topical microbicide to prevent sexual transmission would contribute substantially to controlling the spread of HIV. RNA interference (RNAi) is an evolutionarily conserved, host defense against viruses and transposable elements, which uses small double-stranded RNAs, called small interfering RNAs (siRNA), to silence gene expression with exquisite specificity. siRNAs targeting viral coreceptors and/or HIV genes can prevent viral entry or suppress HIV replication, even in productively infected cells. By applying siRNAs mixed with a lipid carrier intravaginally in mice, siRNAs are delivered uniformly deep into the vagina and ectocervix and can silence an endogenous gene throughout the mucosa and submucosa. Silencing persists for at least 9 days without apparent toxicity, suggesting that an siRNA-based microbicide might have improved compliance, since it would not need to be used just before exposure. siRNAs targeting viral genes protected mice against intravaginal herpes simplex virus 2 (HSV-2), an important cofactor for HIV transmission. Based on these exciting preliminary data, this Integrated Preclinical/Clinical Program for Topical Microbicides will test the hypothesis that RNAi can form the basis of an anti-HIV microbicide. The siRNA complexes will be refined for improved delivery to cells important in HIV transmission to optimize protection from viral challenge without toxicity. The groundwork for performing a pilot study to test the safety of an siRNA-based microbicide will begin to be laid, but initiating pilot clinical studies is outside the scope of this proposal. Many steps are needed to develop an siRNA-based microbicide. Although mice were protected from vaginal HSV-2 challenge, the cell types targeted by HSV-2 (epithelial cells, neurons) are different than those important for HIV transmission. Moreover, although silencing was seen throughout the mouse genital tissue, some of the cells responsible for HIV transmission are rare in the normal uninflamed genital mucosa. The major first aim of this program is to determine which cells in the mucosa are efficiently targeted by siRNA-lipid complexes and, if necessary, to design alternate strategies to deliver siRNAs into the key cells believed to be important for HIV transmission - Langerhans cells and lamina propria T cells, dendritic cells and macrophages. Another key aim is to optimize the siRNAs for stability and efficiency of intracellular silencing and to develop a strategy for formulating the siRNA compounds into a gel suitable for vaginal application. Modifications will be tested iteratively in vitro in cell lines and primary cells, in human cervicovaginal explants and in mice. Lead candidates will then be tested in the macaque for protection against SHIV challenge.

描述（由申请人提供）：一种局部菌心预防性传播将极大地控制HIV的传播。 RNA干扰（RNAi）是一种进化保守的，宿主防御病毒和转座元素，它使用小的双链RNA，称为小型干扰RNA（siRNA），以精致的特异性沉默基因表达。靶向病毒感受器和/或艾滋病毒基因的siRNA可以防止病毒进入或抑制HIV复制，即使在有效感染的细胞中也是如此。通过将siRNA与脂质载体混合在小鼠的静脉内混合，将siRNA均匀地递送到阴道和骨膜内，并可以使整个粘膜和粘膜上的内源性基因保持沉默。沉默持续至少9天而没有明显的毒性，这表明基于siRNA的杀菌剂可能改善了依从性，因为它不需要在暴露前使用。靶向病毒基因的siRNA保护小鼠免受单纯疱疹病毒2（HSV-2）的影响，这是HIV传播的重要辅助因子。基于这些令人兴奋的初步数据，该综合临床前/临床局部微生物剂将测试RNAi可以构成抗HIV杀菌剂的基础的假设。 siRNA复合物将被改进，以改善对HIV传播中重要的细胞的递送，以优化没有毒性的病毒挑战的保护。进行试验研究以测试基于siRNA的杀菌剂的安全性的基础将开始奠定，但是启动试点临床研究不在该提案的范围之内。需要许多步骤来开发基于siRNA的菌心。尽管将小鼠免受阴道HSV-2挑战的保护，但HSV-2（上皮细胞，神经元）靶向的细胞类型与对HIV传播重要的细胞类型不同。此外，尽管在整个小鼠生殖器组织中都看到了沉默，但在正常的非发明生殖器粘膜中，某些负责HIV传播的细胞很少见。该程序的主要目的是确定粘膜中的哪些细胞有效地用siRNA -lipid复合物来靶向，并在必要时设计替代策略，以将siRNAs传递到关键细胞中，被认为对HIV传播至关重要 - Langerhans细胞和lamina Prespria T细胞，树突状细胞，树突状细胞和巨噬细胞。另一个关键目的是优化siRNA，以提高细胞内沉默的稳定性和效率，并制定一种将siRNA化合物制定成适合阴道施用的凝胶的策略。修饰将在细胞系和原代细胞，人宫颈阴道外植体和小鼠中进行迭代测试。然后，将在猕猴中测试主要候选人，以防止Shiv挑战。