title: Isolation and characterization of 2'-amino-modified RNA aptamers for human TNFalpha.
abstract: Human tumor necrosis factor alpha (hTNFalpha), a pleiotropic cytokine with activities ranging from host defense mechanisms in infection and injury to severe toxicity in septic shock or other related diseases, is a promising target for drug screening. Using the SELEX (systematic evolution of ligands by exponential enrichment) process, we isolated oligonucleotide ligands (aptamers) with high affinities for hTNFalpha. Aptamers were selected from a starting pool of 40 randomized sequences composed of about 10(15) RNA molecules. Representative aptamers were truncated to the minimal length with high affinity for hTNFalpha and were further modified by replacement of 2'-OH with 2'-F and 2'-NH2 at all ribopurine positions. These modified RNA aptamers were resistant to nuclease. The specificity of these aptamers for hTNFalpha was confirmed, and their activity to inhibit the cytotoxicity of hTNFalpha on mouse L929 cells was determined. Results demonstrated that four 2'-NH2-modified aptamers bound to hTNFalpha with high affinity and blocked the binding of hTNFalpha to its receptor, thus protecting the L929 cells from the cytotoxicity of hTNFalpha. Oligonucleotide aptamers described here are potential therapeutics and diagnostics for hTNFalpha-related diseases.
authors.affiliation: State Key Laboratory for Molecular Virology and Genetic Engineering, Institute of Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 100052, China.
authors.forename: Xinrui
authors.initials: X
authors.lastname: Yan
authors.forename: Xuwen
authors.initials: X
authors.lastname: Gao
authors.forename: Zhiqing
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D000818:Animals; D020029:Base Pairing; D001483:Base Sequence; D001665:Binding Sites; D002478:Cells, Cultured; D006801:Humans; D008024:Ligands; D051379:Mice; D009841:Oligonucleotides / Q000235:genetics* / Q000494:pharmacology; D012313:RNA / Q000235:genetics* / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors / Q000235:genetics*
chemical_list: D008024:Ligands; D009841:Oligonucleotides; D014409:Tumor Necrosis Factor-alpha; D012313:RNA