RNA aptamers as cell surface receptor agonists and siRNA delivery agents

针对包括少数细胞表面在内的多种蛋白质产生了RNA适配子 感受器。一般来说，这类适配子在体外和体内都是它们的目标蛋白的有效抑制剂。 此外，其中一些拮抗适体已经在临床试验中进行了评估，其中包括一项临床试验。 针对因子IXa开发，并已被FDA批准用于治疗老年性黄斑 退化。然而，直到去年，还没有一种适体被描述为激动剂。在这 建议我们探索适配子激活细胞表面受体的能力。在初步结果部分 我们描述了一系列研究，证明我们针对的适体的二聚体版本 T细胞上的两种不同的受体4-IBB和0X40能够激活小鼠原代T细胞上的这些受体 小鼠肿瘤中T细胞增殖、细胞因子释放和抗肿瘤疫苗活性增强的细胞 免疫治疗模式。据我们所知，这是最早发现的两个适配子 扮演激动者的角色。在这里，我们正在寻求支持来评估这两个激动型适配子的活性。 确定我们最近针对干细胞因子受体c-Kit制造的第三个适配子是否可以 也可以作为激动剂，激活干细胞因子受体和红细胞生成。对这些适配子的分析将 包括评估它们向原代1细胞以及T-Celi淋巴瘤和白血病细胞系递送siRNA的能力 (0X40和4-1 BB适配子)和红细胞前体及c-Kit阳性肿瘤细胞(cKit适配子)。 需要中介靶向传递小干扰RNA(SiRNAs)的技术来改善 基于siRNA的治疗剂的疗效、安全性和成本效益

RNA aptamers have been generated against a variety of proteins including a few cell surface receptors. In general such aptamer act as potent inhibitors of their target proteins both in vitro and in vivo. Moreover, a few of these antagonistic aptamers have been evaluated in clinical trials including one we developed against factor IXa and one that has been approved by the FDA for treating age related macular degeneration. However until last year, no aptamer has been described that can act as an agonist. In this proposal we explore the ability of aptamers to activate cell surface receptors. In the preliminary results section we describe a series of studies demonstrating that dimeric versions of aptamers that we have made against two different receptors on T-cells, 4-IBB and 0X40, are able to activate these receptors on primary murine T cells resulting in T-cell proliferation, cytokine release and enhanced antitumor vaccine activity in murine tumor immunotherapy models. To our knowledge these are the first two aptamers that have been identified that can act as agonists. Here we are seeking support to evaluate the activity of these two agonistic aptamers as well as determine whether a third aptamer that we have recently made against stem cell factor receptor, c-Kit, can also act as an agonist and activate stem cell factor receptor and erythropoiesis. Analysis of these aptamers will include assessing their ability to deliver siRNAs to primary 1-cells and T-celi lymphoma and leukemia cell lines (0X40 and 4-1 BB aptamers) and erythrocyte precursors and c-Kit positive tumor cells (cKit aptamer). Technologies that mediate targeted delivery of small interfering RNAs (siRNAs) are needed to improve the therapeutic efficacy, safety and cost effectiveness of siRNA-based therapeutic agents