Marie Hlavnickova
Institute of Biotechnology CAS, v.v.i., Czech Republic
Title: Inhibitory binders derived from ABD-domain scaffold targeting human IL-17RA receptor as a non-immunoglobulin alternative for modulation of Th17-mediated pro-inflammatory axis
Biography
Biography: Marie Hlavnickova
Abstract
Interleukin 17 (IL-17) and its cognate receptor (IL-17RA) 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 keratinocytes. This work was aimed to generate novel protein binders of IL-17RA that will prevent from binding of IL-17A cytokine to this receptor expressed on the surface of keratinocytes. To this goal, we used a high-complex combinatorial library derived from scaffold of albumin-binding domain (ABD) of streptococcal protein G 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. The four variants exhibited high-affinity binding in nanomolar range to human keratinocyte HaCAT cells, as measured using Ligand Tracer Green Line system. Thus, we identified several ARS inhibitory variants with a blocking potential that will be further tested for their immunomodulatory function.