Chemically modified DNA aptamers bind interleukin-6 with high affinity and inhibit signaling by blocking its interaction with interleukin-6 receptor.
Interleukin-6 (IL-6) is a pleiotropic cytokine that regulates immune and inflammatory responses, and its overproduction is a hallmark of inflammatory diseases. Inhibition of IL-6 signaling with the anti-IL-6 receptor antibody tocilizumab has provided some clinical benefit to patients; however, direct cytokine inhibition may be a more effective option. We used the systematic evolution of ligands by exponential enrichment (SELEX) process to discover slow off-rate modified aptamers (SOMAmers) with hydrophobic base modifications that inhibit IL-6 signaling in vitro. Two classes of IL-6 SOMAmers were isolated from modified DNA libraries containing 40 random positions and either 5-(N-benzylcarboxamide)-2'-deoxyuridine (Bn-dU) or 5-[N-(1-naphthylmethyl)carboxamide]-2'-deoxyuridine (Nap-dU) replacing dT. These modifications facilitate the high affinity binding interaction with IL-6 and provide resistance against degradation by serum endonucleases. Post-SELEX optimization of one Bn-dU and one Nap-dU SOMAmer led to improvements in IL-6 binding (10-fold) and inhibition activity (greater than 20-fold), resulting in lead SOMAmers with sub-nanomolar affinity (Kd = 0.2 nm) and potency (IC50 = 0.2 nm). Although similar in inhibition properties, the two SOMAmers have unique sequences and different ortholog specificities. Furthermore, these SOMAmers were stable in human serum in vitro for more than 48 h. Both SOMAmers prevented IL-6 signaling by blocking the interaction of IL-6 with its receptor and inhibited the proliferation of tumor cells in vitro as effectively as tocilizumab. This new class of IL-6 inhibitor may be an effective therapeutic alternative for patients suffering from inflammatory diseases.
['Gupta|Shashi|S|', 'Hirota|Masao|M|', 'Waugh|Sheela M|SM|', 'Murakami|Ikuo|I|', 'Suzuki|Tomoki|T|', 'Muraguchi|Masahiro|M|', 'Shibamori|Masafumi|M|', 'Ishikawa|Yuichi|Y|', 'Jarvis|Thale C|TC|', 'Carter|Jeffrey D|JD|', 'Zhang|Chi|C|', 'Gawande|Bharat|B|', 'Vrkljan|Michael|M|', 'Janjic|Nebojsa|N|', 'Schneider|Daniel J|DJ|']
D000595:Amino Acid Sequence D000818:Animals D000893:Anti-Inflammatory Agents D052157:Aptamers, Nucleotide D001483:Base Sequence D016466:CHO Cells D003412:Cricetulus D055808:Drug Discovery D006801:Humans D015850:Interleukin-6 D008252:Macaca fascicularis D051379:Mice D008969:Molecular Sequence Data D051381:Rats D019947:Receptors, Interleukin-6 D052156:SELEX Aptamer Technique D044967:Serum
Aptamers SELEX SOMAmer Cell Signaling Drug Discovery Interleukin Molecular Evolution Nuclease Stability Nucleic Acid Chemistry Protein-DNA Interaction