Inhibitory binders derived from ABD-domain scaffold targeting human IL-17RA receptor as an alternative for modulation of Th17-mediated pro-inflammatory axis

Marie Hlavničková¹, Milan Kuchař¹, Radim Osička², Lucie Marečková¹, Hana Petroková¹ and Petr Malý¹

¹Institute of Biotechnology AS CR, v. v. i. Průmyslová 595, Vestec, 252 42 Jesenice u Prahy,

²Institute of Microbiology AS CR, v. v. i. Vídeňská 1083, 142 20 Prague, Czech Republic

marie.hlavnickova@ibt.cas.cz, petr.maly@ibt.cas.cz

Interleukin 17 (IL-17) and its cognate receptor (IL-17RA)¹ play a crucial role in Th17 cells-mediated pro-inflammatory pathway and pathogenesis of several autoimmune disorders including psoriasis. Psoriasis is a chronic inflammatory skin disease with prevalence up to 3% worldwide it is characterized by hyperplasia of the epidermis, infiltration of leukocytes into both dermis and epidermis, and dilation and growth of blood vessels. IL-17 is mainly produced by Th-17 helper cells and, via binding to its receptor, mediates IL-17-driven  cell signaling in keratinocytes².

This work was aimed to generate a novel protein binders of IL-17RA that will prevent from binding of IL-17 to this receptor expressed on the surface of keratinocytes. To this goal, we used a high-complex combinatorial library derived from a scaffold of albumin-binding domain (ABD) of streptococcal protein G³, and ribosome display selection, to yield a collection of ABD-derived high-affinity ligands of human IL-17RA, called ARS binders. From 67 analysed ABD variants, 7 different sequence families were identified. Representatives of these groups competed with human IL-17A for binding to recombinant IL-17RA receptor as well as with IL-17RA-IgG chimera, as tested in ELISA. Five ARS variants bind to IL-17RA-expressing THP-1 and Raji cells, as tested by flow cytometry, and four variants exhibited high-affinity binding in nanomolar range to human keratinocyte HaCAT cells, as measured using LigandTracer Green Line system. Thus, we identified several ARS inhibitory variants with a blocking potential that will be further tested for their immunomodulatory function.

1.         Song X., Qian Y.: Cytokine 62 (2), 175-182. (2013).

2.         Garber K.: Nat. Biotechnol. 30, 475-477. (2012).

3.         Ahmad J.N., Li, J., Biedermannová L., Kuchař M., Šípová H., Semeradtová A., Černý J., Petroková H., Mikulecký P., Polínek J., Staněk O., Vondrášek J., Homola J., Malý J., Osička R., Šebo P., Malý P.: Proteins. 80(3), 774-789. (2012).

This study was supported by the Grant BIOCEV CZ.1.05/1.1.00/02.0109 from the ERDF fund and Institutional Research Concept No. RVO 86652036.