Chemically Modified DNA Aptamers Bind Interleukin-6 with High Affinity and Inhibit Signaling by Blocking Its Interaction with Interleukin-6 Receptor

Abstract

Background: IL-6 signaling is a key component of inflammatory diseases.Results: Modified DNA aptamers that inhibit IL-6 signaling were discovered and optimized.Conclusion: Modified aptamers are stable in serum and block the interaction of IL-6 with its receptor IL-6Rα.Significance: Modified aptamers are a new class of antagonist with properties potentially suitable for clinical treatment of inflammation.

Non-helical DNA Triplex Forms a Unique Aptamer Scaffold for High Affinity Recognition of Nerve Growth Factor

“…Selections were performed in SB17T buffer (40 mM HEPES [pH 7.5], 102 mM NaCl, 5 mM KCl, 5 mM MgCl 2 , 1 mM EDTA, 0.05% TWEEN 20). Bn-dU SOMAmers were synthesized by solid phase synthesis using the phosphoramidite method (Beaucage and Caruthers, 1981), with modified deoxyuridine-5-carboxamide amidite reagents, as described previously (Davies et al, 2012;Gupta et al, 2014).…”

“…Such chemically modified aptamers are particularly well-suited to selection schemes that favor long-lived complexes; hence, we refer to this class of aptamers as SOMAmers (slow off-rate modified aptamers). SOMAmers have transformed the landscape of proteomics, leading to a sensitive and highly multiplexed platform with applications in biomarker discovery and early-stage disease detection (De Groote et al, 2013;Gold et al, 2010Gold et al, , 2012Loffredo et al, 2013;Lollo et al, 2014;Mehan et al, 2012Mehan et al, , 2013Ostroff et al, 2010Ostroff et al, , 2012, as well as sandwich-based single analyte detection assays (Ochsner et al, , 2014, rapid histochemistry tools (Gupta et al, 2011), and therapeutic applications (Gelinas et al, 2014;Gupta et al, 2014).…”

Towards applications of synthetic genetic polymers in diagnosis and therapy

“…Imaizumi et al show that a similar base modification may be used to select aptamers against a small molecule (Camptotecin, a quinolone alkaloid) [25]. Although large hydrophobic modifications may impart some resistance to nuclease degradation, a DNA backbone is used during selection, so post-SELEX screening for tolerated modifications (2 0 O-methyl-RNA and C3 spacers) must still be performed in order to achieve significant improvement in serum stability [21,24 ]. Kruspe and Hahn have recently shown that aptamer stability may not always be the goal, demonstrating that substitution of a DNA aptamer (also against IL-6) with 5-fluoro-dU yields a prodrug that is processed into cytotoxic nucleotides inside target cells [26].…”

“…a growth factor (PDGF) [21] and a proinflammatory cytokine (IL-6). In the latter case, the modified aptamers achieve high affinity through extensive hydrophobic contacts with their target, visible in a crystal structure of the complex [23 ], and can mediate promising biological effects, at least in vitro (inhibition of signalling by blocking IL-6 binding to its receptor in a cell culture proliferation assay) [24 ]. Imaizumi et al show that a similar base modification may be used to select aptamers against a small molecule (Camptotecin, a quinolone alkaloid) [25].…”

An affibody-adalimumab hybrid blocks combined IL-6 and TNF-triggered serum amyloid A secretion in vivo

“…2,27 Interestingly, a recently described, and also in vitro selected, nucleic acid aptamer to IL-6 has been shown to preferentially bind to the gp130 interacting surface characterized by this more rigid nature, although the aptamer structure also extends into the IL-6Ra/IL-6 interaction interface enough to affect that interaction. 28,29 However, from a library of antibody-like binders called "minibodies," binders to IL-6 have been selected that interfere with the IL-6Ra/IL-6 interaction, suggesting that the regions of IL-6 showing the increased mobility may indeed be addressed by in vitro selection. 30,31 The IL-6 signal generating complex involves the formation of a hexameric structure that can be obstructed also by other means.…”