Uptake and intracellular transport of RNA aptamers in African trypanosomes suggest therapeutic "piggy-back" approach
Uptake and intracellular transport of RNA aptamers in African trypanosomes suggest therapeutic "piggy-back" approach
复制标题
DOI：
10.1016/s0968-0896(01)00032-3
复制
发表时间：
2001-10-01
影响因子：
3.5
通讯作者：
Göringer, HU
中科院分区：
文献类型：
--
作者：
Homann, M;Göringer, HU
非洲锥虫是原生动物，作为细胞外寄生虫在人类和其他哺乳动物的血液中繁殖。寄生虫通过周期性地改变其糖蛋白表面外壳来逃避宿主免疫系统的破坏。这种现象被称为抗原变异，并且是受感染宿主无法清除感染的原因。以前，我们报道了选择RNA适体结合到布氏锥虫的42 kDa的表面蛋白。该多肽位于寄生虫表面的特定亚结构内，即所谓的鞭毛口袋。在这里，我们分析的命运结合到鞭毛口袋的适体。在升高的温度下，RNA的两个末端被降解以形成约50个核苷酸的稳定核心结构。RNA通过内吞作用迅速内化，并通过囊泡转运转运至溶酶体。内吞过程是序列特异性的，并且不发生随机化的RNA序列或显著缩短的适体片段。与转铁蛋白的共定位实验表明受体介导的摄取。所鉴定的内化和转运途径用于将适体偶联的生物素分子靶向至溶酶体。这表明RNA可以用作“背负式”分子以将适体偶联的化合物/毒素靶向寄生虫的溶酶体区室。(C)2001年由Elsevier Science Ltd.出版
African trypanosomes are protozoan organisms that multiply as extracellular parasites in the blood of humans and other mammals. The parasites escape destruction by the host immune system by periodically changing their glycoprotein surface coat. This phenomenon is known as antigenic variation and is responsible for the inability of the infected host to clear the infection. Previously we reported the selection of RNA aptamers that bind to a 42 kDa surface protein of Trypanosoma brucei. The polypeptide is localised within a specific substructure on the parasite surface, the so-called flagellar pocket. Here we analyse the fate of the aptamers upon binding to the flagellar pocket. At elevated temperatures, both terminal ends of the RNAs are degraded to form a stable core structure of approximately 50 nucleotides. The RNAs become rapidly internalised by endocytosis and are transported to the lysosome by vesicular transport. The endocytotic process is sequence specific and does not occur with randomised RNA sequences or significantly shortened aptamer fragments. Co-localisation experiments with transferrin suggest a receptor-mediated uptake. The identified internalisation and transport pathway was used to target aptamer-coupled biotin molecules to the lysosome. This demonstrates that the RNAs can be used as 'piggy-back' molecules to target aptamer-coupled compounds/toxins to the lysosomal compartment of the parasite. (C) 2001 Published by Elsevier Science Ltd.