Institute for Biochemistry and Molecular Biology, Chemistry Department, MIN-Faculty, Hamburg University, Hamburg, Germany.
RNA Biol. 2012 Jan;9(1):67-80. doi: 10.4161/rna.9.1.18062. Epub 2012 Jan 1.
Aptamers represent an emerging strategy to deliver cargo molecules, including dyes, drugs, proteins or even genes, into specific target cells. Upon binding to specific cell surface receptors aptamers can be internalized, for example by macropinocytosis or receptor mediated endocytosis. Here we report the in vitro selection and characterization of RNA aptamers with high affinity (Kd = 20 nM) and specificity for the human IL-6 receptor (IL-6R). Importantly, these aptamers trigger uptake without compromising the interaction of IL-6R with its natural ligands the cytokine IL-6 and glycoprotein 130 (gp130). We further optimized the aptamers to obtain a shortened, only 19-nt RNA oligonucleotide retaining all necessary characteristics for high affinity and selective recognition of IL-6R on cell surfaces. Upon incubation with IL-6R presenting cells this aptamer was rapidly internalized. Importantly, we could use our aptamer, to deliver bulky cargos, exemplified by fluorescently labeled streptavidin, into IL-6R presenting cells, thereby setting the stage for an aptamer-mediated escort of drug molecules to diseased cell populations or tissues.
适配体代表了一种将货物分子（包括染料、药物、蛋白质甚至基因）递送到特定靶细胞的新兴策略。与特定的细胞表面受体结合后，适配体可以被内化，例如通过巨胞饮作用或受体介导的内吞作用。在这里，我们报告了对人类白细胞介素 6 受体（IL-6R）具有高亲和力（Kd = 20 nM）和特异性的 RNA 适配体的体外选择和特性。重要的是，这些适配体在不影响 IL-6R 与其天然配体细胞因子白细胞介素 6（IL-6）和糖蛋白 130（gp130）相互作用的情况下触发摄取。我们进一步优化了适配体，获得了一个缩短的、只有 19 个核苷酸的 RNA 寡核苷酸，保留了高亲和力和选择性识别细胞表面 IL-6R 的所有必要特征。与表达 IL-6R 的细胞孵育后，该适配体迅速被内化。重要的是，我们可以使用我们的适配体将大体积的货物，例如荧光标记的链霉亲和素，递送到表达 IL-6R 的细胞中，从而为药物分子通过适配体介导递送到疾病细胞群或组织奠定了基础。
