Department of Organic Chemistry, Lund University, 22100, Lund, Sweden.
Parasitol Res. 2009 Nov;105(6):1557-66. doi: 10.1007/s00436-009-1583-x. Epub 2009 Aug 20.
The var-gene encoding Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) is known to play a major role in the pathogenicity of the P. falciparum parasite. The protein enables the parasite to adhere to the endothelial linings of small blood vessels (cytoadherence) as well as to non-infected erythrocytes (rosetting), thus preventing clearance from the bloodstream. The development and spread of resistance towards most anti-malarial drugs used for treatment and prevention of the most severe form of malaria truly emphasise the importance of a continuous research and development of new drugs. In this study we use Systematic Evolution of Ligands by EXponential enrichment (SELEX) methodology to isolate high-affinity ligands (aptamers). To validate the results from the SELEX in vitro selection, different aptamers have been selected against PfEMP1 in a live cell assay of P. falciparum strain FCR3S1.2, a highly rosetting strain. We have been able to show the rosette disrupting capacity of these SELEX-aptamers at concentrations of 33 nM and with 100% disruption at 387 nM. The described results show that RNA aptamers are promising candidates for adjunct therapy in severe malaria.
疟原虫红细胞膜蛋白 1（PfEMP1）的 var 基因编码产物在疟原虫的致病性方面起着重要作用。该蛋白使寄生虫能够黏附在小血管的内皮衬里（细胞黏附）以及未感染的红细胞（成帽），从而阻止从血液中清除。针对大多数用于治疗和预防最严重形式疟疾的抗疟药物的耐药性的发展和传播，确实强调了持续研究和开发新药的重要性。在这项研究中，我们使用系统进化的配体通过指数富集（SELEX）方法来分离高亲和力的配体（适体）。为了验证 SELEX 体外选择的结果，我们针对 PfEMP1 在 FCR3S1.2 疟原虫菌株的活细胞测定中进行了不同适体的选择，该菌株是一种高度成帽的菌株。我们已经能够证明这些 SELEX-适体在 33 nM 的浓度下具有成帽破坏能力，并且在 387 nM 时具有 100%的破坏能力。所述结果表明，RNA 适体是严重疟疾辅助治疗的有前途的候选物。
