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其递送到对核酸摄取高度不敏感的原代细胞中。因此，出于生物学和治疗目的，抑制这些细胞内的靶基因表达一直是一个主要问题。近年来，在siRNA载体设计方面取得了一些进展，这些进展已经实现了有效和细胞特异性的siRNA递送。然而，这些载体的配制对于初步的实验室测试来说极其麻烦且成本过高。我们建议开发新的，具有成本效益的，易于配制和非免疫原性的siRNA载体的细胞特异性交付的siRNA在体内。这些载体将由两种组分配制-（1）与siRNA结合结构域偶联的以高亲和力结合免疫球蛋白Fc区的非免疫原性蛋白/肽组分和（ii）能够识别特异性细胞表面受体并诱导内化的抗体组分。载体与抗体的简单混合或温育将产生能够将siRNA递送至所需细胞类型的试剂。重要的是，递送至靶细胞类型/器官将通过简单的静脉内注射实现。我们将为每种人类免疫细胞亚型和确定的器官/组织产生siRNA载体，并在人类疾病的相关鼠模型中评估siRNA治疗功效。我们的研究计划的成功完成有望建立易于翻译的递送平台，用于潜在siRNA治疗候选物的临床前评估。 公共卫生相关性：siRNA代表了进入临床试验的最有前途的基于RNA的治疗方法，但有效的递送仍然是一个问题。用于递送到几乎任何细胞类型的选择的“用户友好的”siRNA载体的可用性将极大地扩展RNAi技术的适用性。在这里，我们建议开发易于配制的非免疫原性试剂，用于将siRNA特异性递送到多个人类细胞中，从而增加适合体内应用的siRNA细胞类型范围，以对抗疾病状态。

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.