Synthetic IL-22 signaling revealed biological activity of homodimeric IL-10 receptor 2 and functional cross-talk with the IL-6 receptor gp130

Cytokine signaling is transmitted by cell surface receptors which function as natural biological switches to control among others mainly immune related processes. Recently, we have designed synthetic cytokine receptors (SyCyRs) consisting of GFP- and mCherry-nanobodies fused to trans-membrane and intracellular domains of cytokine receptors, which phenocopied cytokine signaling induced by non-physiological homo- and heterodimeric GFP-mCherry ligands. Interleukin 22 signals via IL-22Rα1 and the common IL-10R2, belongs to the IL-10 cytokine family and is critically involved in tissue regeneration. IL-22 SyCyRs phenocopied native IL-22 signal transduction as shown by induction of cytokine-dependent cellular proliferation, signal transduction and transcriptome analysis. Whereas homodimeric IL-22Rα1 SyCyRs failed to activate signaling, homodimerization of the second IL-22 signaling chain, SyCyR(IL-10R2), which was considered to not induce signal transduction, lead to induction of signal transduction. Interestingly, the SyCyR(IL-10R2) and SyCyR(IL-22Rα1) were able to form functional heterodimeric receptor signaling complexes with the synthetic IL-6 receptor chain SyCyR(gp130). In summary, we demonstrated that IL-22 signaling can be phenocopied by synthetic cytokine receptors. Further we identified a novel IL-10R2 homodimeric receptor complex and receptor cross-talk with gp130.

26

Mossner S, Kuchner M, Fazel Modares N, Knebel B, Al-Hasani H, Floss DM, Scheller J