RNA aptamers specific for the Interleukin-6 receptor

Cindy Meyer¹, Katja Eydeler², Eileen Magbanua³, Tijana Zivkovic⁴, Nicolas Piganeau⁵, Inken Lorenzen⁶, Joachim Grötzinger⁷, Günter Mayer⁸, Stefan Rose-John⁹, Ulrich Hahn¹⁰

1 Institute for Biochemistry and Molecular Biology, Chemistry Department, MIN-Faculty, Hamburg University, Martin-Luther-King-Platz 6, 20146 Hamburg, Germany

2 Institute for Biochemistry and Molecular Biology, Chemistry Department, MIN-Faculty, Hamburg University, Martin-Luther-King-Platz 6, 20146 Hamburg, Germany

3 Institute for Biochemistry and Molecular Biology, Chemistry Department, MIN-Faculty, Hamburg University, Martin-Luther-King-Platz 6, 20146 Hamburg, Germany

4 Institute for Biochemistry and Molecular Biology, Chemistry Department, MIN-Faculty, Hamburg University, Martin-Luther-King-Platz 6, 20146 Hamburg, Germany

5 Institute for Biochemistry and Molecular Biology, Chemistry Department, MIN-Faculty, Hamburg University, Martin-Luther-King-Platz 6, 20146 Hamburg, Germany

6 Institute of Biochemistry, Medical Faculty, Christian-Albrechts-University, Olshausenstr. 40, 24098 Kiel, Germany

7 Institute of Biochemistry, Medical Faculty, Christian-Albrechts-University, Olshausenstr. 40, 24098 Kiel, Germany

8 Life and Medical Sciences Institute, University of Bonn, Gerhard-Domagk-Str. 1, 53121 Bonn, Germany

9 Institute of Biochemistry, Medical Faculty, Christian-Albrechts-University, Olshausenstr. 40, 24098 Kiel, Germany

10 Institute for Biochemistry and Molecular Biology, Chemistry Department, MIN-Faculty, Hamburg University, Martin-Luther-King-Platz 6, 20146 Hamburg, Germany

Abstract

Interleukin-6 (IL-6) is a multifunctional pro- and anti-inflammatory cytokine that regulates the growth and differentiation of various tissues (1). In various diseases, for example rheumatoid arthritis and colon cancer, elevated IL-6 levels were observed, promoting the progression and pathology of these diseases (2). Interfering with the IL-6 signaling pathway via the IL-6 receptor (IL-6R) system therefore seems to be a potentially useful therapeutic strategy.

One possible strategy could be the application of aptamers, small single-stranded nucleic

acids with a defined three-dimensional structure that are able to bind target molecules with high affinity and specificity (3,4).

In the present work we report on the development of RNA aptamers with high affinity for the IL-6R. The use of SELEX (Systematic Evolution of Ligands by EXponential enrichment) enabled the isolation of IL-6R specific ribonucleic acids (106 nt, K_d ~ 20 nM). Subsequently one aptamer could be shortened to a 19 nt short variant with same specificity. Flow cytometry experiments demonstrated that this shortened version was able to recognize the native IL-6R if presented on the surface of cells. If bound to IL-6R the aptamer becomes internalized into the cells in a receptor-mediated manner. The ability of the aptamer to interfere with IL-6R activities in vivo or to serve as delivery vehicle for drug molecules to or into the cells still needs to be determined.

References

1. Kallen, K.J., zum Buschenfelde, K.H. and Rose-John, S. (1997) The therapeutic potential of interleukin-6 hyperagonists and antagonists. Expert Opin Investig Drugs, 6, 237-266.

2. Febbraio, M.A., Rose-John, S. and Pedersen, B.K. (2010) Is interleukin-6 receptor blockade the Holy Grail for inflammatory diseases? Clin Pharmacol Ther, 87, 396-398.

3. Ellington, A.D. and Szostak, J.W. (1990) In vitro selection of RNA molecules that bind specific ligands. Nature, 346, 818-822.

4. Tuerk, C. and Gold, L. (1990) Systematic evolution of ligands by exponential enrichment: RNA ligands to bacteriophage T4 DNA polymerase. Science, 249, 505-510.

DOI^®: 10.3288/contoo.paper.1670