De novo developed protein binders mimicking Interferon lambda signaling

Abstract

We hereby describe the process of design and selection of nonantibody protein binders mimicking cytokine signaling. We chose to mimic signaling of IFN‐λ1, type 3 interferon (also known as IL‐29) for its novelty and the importance of its biological functions. All four known interferons λ signal through binding to the extracellular domains of IL‐28 receptor 1 (IL‐28R1) and IL‐10 receptor 2 (IL‐10R2). Our binders were therefore trained to bind both receptors simultaneously. The bifunctional binder molecules were developed by yeast display, a method of directed evolution. The signaling capacity of the bivalent binders was tested by measuring phosphorylation of the JAK/STAT signaling pathway and production of mRNA of six selected genes naturally induced by IFN‐ λ1 in human cell lines. The newly developed bivalent binders offer opportunities to study cytokine‐related biological functions and modulation of the cell behavior by receptor activation on the cell surfaces alternative to the use of natural IFN‐λ.

Combined in vitro and cell‐based selection display method producing specific binders against IL‐9 receptor in high yields

“…For our display selection experiments, we used two scaffold molecules developed in our laboratory [12]. The first scaffold called 57aBi has already been successfully trained to bind human IL-10 [12] and to function as interferon-lambda 1 surrogate [13]. The second scaffold called 57bBi is used here for the first time.…”