Synthetic IL-22 signaling revealed biological activity of homodimeric IL-10 receptor 2 and functional cross-talk with the IL-6 receptor gp130. 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. Overall design: We used microarrays to detail the overall influence of the constructs to confirm background free action of the receptor constructs.

细胞因子信号转导由细胞表面受体介导，这类受体作为天然生物开关，主要调控包括免疫相关过程在内的诸多生命活动。本研究团队此前设计了一类合成细胞因子受体（synthetic cytokine receptors, SyCyRs），其由GFP、mCherry纳米抗体分别融合至细胞因子受体的跨膜结构域与胞内结构域构成，可重现由非生理性同源、异源二聚体GFP-mCherry配体诱导的细胞因子信号转导。白细胞介素22（interleukin 22, IL-22）通过IL-22Rα1与共用受体IL-10R2进行信号转导，隶属于IL-10细胞因子家族，在组织再生过程中发挥关键调控作用。IL-22型SyCyRs可重现天然IL-22的信号转导过程，该结论通过细胞因子依赖的细胞增殖诱导、信号转导检测及转录组分析得以验证。尽管同源二聚化的IL-22Rα1型SyCyRs无法激活信号转导，但此前被认为不能诱导信号转导的第二条IL-22信号链——SyCyR(IL-10R2)的同源二聚化，却可触发信号转导。有趣的是，SyCyR(IL-10R2)与SyCyR(IL-22Rα1)可与合成IL-6受体链SyCyR(gp130)形成具有功能活性的异源二聚体受体信号复合物。综上，本研究证实合成细胞因子受体可重现IL-22的信号转导过程；此外本研究还发现了一种新型IL-10R2同源二聚体受体复合物，并揭示了其与gp130的受体交叉对话。实验整体设计：本研究使用基因芯片（microarrays）详细分析了各重组构建体的整体影响，以验证该受体构建体无背景信号的作用特性。