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Modification and Functionalization of the Guanidine Group by Tailor-made Precursors
Published on: April 27, 2017
Guanine modification of inhibitory oligonucleotides potentiates their suppressive function
Franziska Römmler1, Marion Jurk, Eugen Uhlmann
1Institut für Medizinische Mikrobiologie, Immunologie, und Hygiene, Technische Universität München, 81675 Munich, Germany.
Journal of Immunology (Baltimore, Md. : 1950)
|August 23, 2013
Summary
Modifying guanine in inhibitory oligonucleotides (INH-ODNs) prevents higher-order structures, enhancing their potential to block TLR7 and TLR9. This G-modification improves INH-ODN efficacy for treating inflammatory diseases like lupus.
Area of Science:
- Immunology
- Molecular Biology
- Pharmacology
Background:
- Inhibitory oligonucleotides (INH-ODNs) targeting Toll-like receptors 7 and 9 (TLR7/9) are crucial for modulating immune responses.
- The prototypic INH-ODN 2088 forms G-quadruple structures, complicating prediction of its pharmacological and immunological behavior.
- These higher-order structures can hinder the development of effective INH-ODN-based therapeutics.
Purpose of the Study:
- To investigate the impact of G-modification within the G-quadruple of INH-ODNs on their structure and inhibitory potential.
- To compare the efficacy of G-modified INH-ODNs with the prototypic INH-ODN 2088 in vitro and in vivo.
- To assess the therapeutic potential of G-modified INH-ODNs for inflammatory conditions, including systemic lupus erythematosus.
Main Methods:
- Synthesis and characterization of G-modified INH-ODNs using 7-deaza-guanine or 7-deaza-2'-O-methyl-guanine.
- In vitro assays measuring TNF-α and IL-12p40 secretion from bone marrow-derived macrophages, conventional dendritic cells, and B cells.
- In vivo studies evaluating the efficacy of G-modified INH-ODNs in wild-type and autoimmune MRL/Mp-lpr/lpr mice.
Main Results:
- G-modification successfully prevented higher-order structures in INH-ODNs, improving their inhibitory capacity.
- G-modified INH-ODNs showed enhanced inhibition of TLR7-induced TNF-α and TLR7/9-induced IL-12p40 release compared to INH-ODN 2088.
- G-modified INH-ODNs were more effective in inhibiting IL-6 release from B cells and demonstrated superior in vivo efficacy in mouse models of autoimmune disease.
Conclusions:
- G-modification of INH-ODNs is a viable strategy to overcome structural limitations and enhance inhibitory potency.
- G-modified INH-ODNs represent a promising class of therapeutics with improved efficacy for inflammatory diseases, such as systemic lupus erythematosus.
- These findings support the development of novel INH-ODN-based therapies for autoimmune and inflammatory conditions with significant unmet medical needs.
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