Engineered novel cytokine receptors IFNgR1, IL10Ra and IFNaR1/2 cis-dimers significantly enhance the binding of the relevant cytokines IFNg, IL-10 and IFNa 3033

Abstract Description Cytokines initiate signaling on target cells by engaging the ectodomains (ECDs) of cell surface receptors. Cytokine receptor dimeric forms are critical for cytokine ligand binding. To mimic the dimeric receptor conformation, we engineered novel cis-homodimers for human Type II interferon IFNg receptor 1 (IFNgR1) and interleukin 10 receptor alpha (IL10Ra), and the cis-heterodimer for human Type I interferon IFNa receptor 1/2 (IFNaR1/2). To generate IFNgR1 or IL10Ra homodimer, its ECD was fused with a homodimer motif at the C-terminus; to create IFNaR1/2 heterodimer, IFNaR1 and IFNaR2 ECDs were fused with a heterodimer motif at the C-terminus of each chain. These soluble dimeric receptor proteins were expressed/purified from HEK293 cells and could potently bind to the specific antibodies as measured by ELISA. We further investigated the dimeric or monomeric receptor proteins binding to the cytokine ligands. Notably, the dimeric forms of IFNgR1, IL10Ra or IFNaR1/2 dramatically enhanced the binding to the relevant cytokine IFNg, IL-10 or IFNa with >10-fold increases of binding potency based on determined EC50 values, compared to the monomeric receptor proteins. The findings imply that these engineered novel cis-homodimer and cis-heterodimer cytokine receptor proteins mimic the native conformation with better bioactivities. These innovative soluble cis-dimer cytokine receptor proteins can be very useful new molecules for basic immunology research and drug discovery. Topic Categories Cytokines and Chemokines and Their Receptors (CCR)