Abstract
We hereby describe the process of design and selection of nonantibody protein binders mimicking cytokine signaling. We chose to mimic signaling of IFN-lambda 1, type 3 interferon (also known as IL-29) for its novelty and the importance of its biological functions.
All four known interferons lambda 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- lambda 1 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-lambda.