Versatile carriers for cell-specific siRNA delivery in vivo

描述（由申请人提供）：基于rna干扰的抑制剂的主要障碍是将它们递送到对核酸摄取高度抵抗的原代细胞中。因此，抑制靶基因表达在这些细胞内的生物学和治疗目的一直是一个主要问题。近年来，siRNA载体设计取得了一些进展，使siRNA的高效和细胞特异性传递成为可能。然而，这些载体的配方是极其繁琐和成本高昂的初步实验室测试。我们建议开发一种新型的、具有成本效益的、易于制备的、非免疫原性的siRNA载体，用于siRNA在体内的细胞特异性递送。这些载体将由两种成分组成——(1)一种非免疫原性蛋白质/肽成分，与免疫球蛋白fc区结合，与siRNA结合域具有高亲和力；（ii）一种能够识别特定细胞表面受体并诱导内化的抗体成分。载体与抗体的简单混合或孵育将产生能够将siRNA递送到所需细胞类型的试剂。重要的是，通过简单的静脉注射，将药物输送到目标细胞类型/器官。我们将为每个人类免疫细胞亚型和定义的器官/组织生成siRNA载体，并评估siRNA在人类疾病相关小鼠模型中的治疗效果。我们的研究计划的成功完成有望导致易于翻译的递送平台的建立，用于潜在的siRNA候选治疗药物的临床前评估。

DESCRIPTION (provided by applicant): The main obstacle to RNA-interference-based inhibitors is delivering them into primary cells that are highly recalcitrant to nucleic acid uptake. As a result suppression of target gene expression within these cells for both biological and therapeutic purposes has been a major issue. In recent years there have been several advances in siRNA-carrier design that have enabled efficient and cell-specific siRNA delivery. However, formulation of these carriers is extremely cumbersome and cost-prohibitive for preliminary laboratory testing. We propose to develop novel, cost-effective, easy-to-formulate and non-immunogenic siRNA carriers for the cell-specific delivery of siRNA in vivo. These carriers will be formulated from two components- (1) a non-immunogenic protein/peptide component that binds the immunoglobulin Fc-region with a high affinity coupled to a siRNA binding domain and (ii) an antibody component capable of recognizing a specific cell-surface receptor and inducing internalization. Simple mixing or incubation of the carrier with the antibody will yield a reagent capable of siRNA delivery to the desired cell type. Importantly, delivery to the target cell type/organ will be achieved through simple intravenous injections. We will generate siRNA carriers to each of the human immune cell subtypes and defined organs/tissues and evaluate siRNA treatment efficacy in relevant murine models of human disease. The successful completion of our research plan is expected to lead to the establishment of easily translatable delivery platforms for the preclinical evaluation of potential siRNA therapeutic candidates. PUBLIC HEALTH RELEVANCE: siRNAs represent the most promising of RNA-based therapeutics advancing into clinical trials but efficient delivery is still an issue. The availability of 'user-friendly' siRNA carriers for delivery into practically any cell type of choice would tremendously expand the applicability of the RNAi technology. Here we propose to develop easy-to-formulate non-immunogenic reagents for the delivery of siRNA specifically into multiple human cells thereby increasing the range of siRNA- amenable cell types for in vivo applications to counter disease states.