Role of the metalloprotease ADAM10 in Interleukin-11 signaling

细胞因子白介素-11 （IL-11）以其抗炎和再生功能而闻名，尤其是在心脏和结肠中。然而，最近的数据指出IL-11在骨癌和胃癌形成中的促炎和促癌作用。到目前为止，仅描述了通过膜结合IL-11受体（IL-11R）的经典信号通路。然而，我们最近的数据显示，膜结合的IL-11R可以被金属蛋白酶ADAM10而不是ADAM17切割，从而产生可溶性IL-11R （sIL-11R）。IL-11R和IL-6R嵌合受体的实验表明，IL-11R的柄区负责ADAM10和ADAM17的选择性。IL-11R能够结合IL-11，这种复合物可以通过反式信号通路激活不表达IL-11R的细胞。此外，我们首次发现sIL-11R可以在健康人的血清中检测到。因此，本提案的目的是确定哪些诱导剂激活了ADAM10对IL-11R的有限蛋白水解，以及小鼠和人类之间是否存在差异。此外，我们将通过蛋白质组学方法和几个IL-11R突变体绘制ADAM10使用的IL-11R的确切切割位点，并研究IL-11R是否随后被其他蛋白酶（如γ分泌酶）切割。我们还将从人和小鼠血清中分离IL-11R，以确定它是来自膜结合前体的有限蛋白水解还是IL-11R mRNA的选择性剪接。具有拮抗功能和抑制性抗体的IL-11突变体将被开发并表征为抑制IL-11促炎特性的工具。最后，为了进一步研究IL-11经典和反式信号，我们将构建表达IL-11R的转基因小鼠和IL-11R报告小鼠，并对其进行初步表征。

The cytokine Interleukin-11 (IL-11) is best known for its anti-inflammatory and regenerative functions, especially in the heart and the colon. Recent data however point to a pro-inflammatory and pro-cancerogenetic role of IL-11 in bone and gastric cancer formation. Until now, only a classic signaling pathway through the membrane-bound IL-11 receptor (IL-11R) has been described. Our recent data show, however, that the membrane-bound IL-11R can be cleaved off by the metalloprotease ADAM10, but not ADAM17, resulting in a soluble IL-11R (sIL-11R). Experiments with chimeric receptors of IL-11R and IL-6R revealed that the so-called stalk region of the IL-11R is responsible for the selectivity of ADAM10 and ADAM17. The sIL-11R is able to bind IL-11, and this complex can activate cells that do not express IL-11R through a trans-signaling pathway. Furthermore, we found for the first time that sIL-11R can be detected in the serum of healthy humans.Aim of this proposal is therefore to determine which inductors activate the limited proteolysis of the IL-11R by ADAM10, and whether there are differences between mice and humans. Furthermore, we will map the exact cleavage site of the IL-11R used by ADAM10 via a proteomics approach and several IL-11R mutants, and investigate if the IL-11R is subsequently cleaved by other proteases, e. g. the gamma-secretase. We will also isolate sIL-11R out of human and murine serum to determine whether it derives from limited proteolysis of the membrane-bound precursor or alternative splicing of the IL-11R mRNA. IL-11 mutants with antagonizing functions as well as inhibitory antibodies will be developed and characterized as tools to inhibit the pro-inflammatory properties of IL-11. Finally, to further investigate IL-11 classic and trans-signaling, a transgenic mouse expressing sIL-11R and an IL-11R reporter mouse will be generated and initially characterized.