A novel pathway of Th17/Th2 induction: The role of cAMP signaling in DC

摘要 Th 2和Th 17是适应性免疫的两个主要分支，涉及保护性和病理性免疫应答。 应答其免疫介导的病理学的范围包括过敏性疾病（Th 2）， 克罗恩病（Th 17）、多发性硬化（Th 17）和银屑病（Th 17）。尽管制定 生物制剂，如抗细胞因子抗体，更有效和低成本的治疗方法还没有 available.我们已经确定了一个新的途径，调节Th 2和Th 17分化， 树突状细胞（DC）中的cAMP水平。在标题为“一种新的代谢途径”的MPI RO 1申请中， Th 17/Th 2诱导-cAMP信号在DC中的作用”我们建议探索潜在的 通过G蛋白介导的机制和信号事件; Gαs（Gnas）和Gαi （Gnai 2）分别刺激和抑制cAMP合成，可以提供基础 对于这些新疗法。该途径的抑制（低cAMP）引起Th 2诱导DC （pro-Th 2 DC），并且其活化（高cAMP）诱导Th 17诱导DC（pro-Th 17 DC）。我们 产生了两种遗传小鼠模型：产生自发性Th 2偏倚的GnasΔ CD 11 c和 Gnai 2 Δ CD 11 c产生Th 17偏倚应答。我们最近发现不同的cAMP 诱导剂调节cDC 2细胞中转录因子的表达水平， Th 17/Th 2分化，如干扰素调节因子4（IRF 4）、IRF 5、Kruppel样因子4 （KLF 4）和Notch 2。在这里，我们发现不同的cAMP诱导剂调节表达水平， 这些因素和开关随后的Th偏见，这使我们提出，cDC 2 细胞代表了可塑性DC亚群，cAMP水平决定了cDC 2 Th 17和Th 2的倾向。因此，在本申请中，我们将探讨和剖析 以下主题：在SA 1-我们将分析是否增加cAMP的基因缺失Gnai 2 在DC中引起Th 17相关的免疫病理学超时，在SA 2中-我们将确定， 测试定义表型pro-Th 17或pro-Th 2 cDC 2的转录网络 亚群，在SA 3中-我们将测试GPCR激动剂（即，β2AR激动剂）， cAMP水平，引起Th 17驱动的嗜中性哮喘，在SA 4中，我们将鉴定和 功能性测试DC细胞产生的新的pro-Th 17或pro-Th 2介质。总结-我们的 cAMP调节cDC的pro-Th 2和pro-Th 17诱导特性的发现导致了 Th 2/Th 17调节新途径的鉴定。结果将提供新的见解 cDC 2的可塑性以及Th 2和Th 17的偏向性。它有可能推进基本的 免疫学研究，为新型和创新的免疫学奠定基础 战略布局

Abstract Th2 and Th17 are two major arms of adaptive immunity involved in protective and pathological responses. The range of their immune-mediated pathologies includes allergic diseases (Th2), Crohn’s disease (Th17), multiple sclerosis (Th17) and psoriasis (Th17). Despite the introduction of biologics such as anti-cytokines Abs, more effective and low-cost therapies are not yet available. We have identified a new pathway that regulates both Th2 and Th17 differentiation by cAMP levels in dendritic cells (DC). In this MPI RO1 application entitled: “A novel pathway of Th17/Th2 induction - the role of cAMP signaling in DC” we propose that exploring the underlying mechanisms and signaling events mediated through the G proteins; Gαs (Gnas) and Gαi (Gnai2), which stimulate and inhibit cAMP synthesis, respectively, can provide the foundation for such new therapies. The inhibition of this pathway (low cAMP) provokes Th2-inducing DC (pro-Th2 DC), and its activation (high cAMP) induces Th17-inducing DC (pro-Th17 DC). We generated two genetic mouse models; GnasΔCD11c that develop spontaneous Th2 bias and Gnai2ΔCD11c that develop a Th17 bias responses. We recently identified that different cAMP inducers regulate the expression levels of transcription factors in cDC2 cells that provoke Th17/Th2 differentiation such as interferon regulatory factor 4 (IRF4), IRF5, Kruppel-like factor 4 (KLF4) and Notch2. Here we shown that different cAMP inducers regulate the expression levels of these factors and switch the subsequent Th bias, which has led us to propose that the cDC2 cells represent a plastic DC subpopulation and that the cAMP levels dictate whether the cDC2 have a pro-Th17 and pro-Th2 bias. Hence, in this application we will explore and dissect the following topics: In SA1 - we will analyze whether increasing cAMP by genetic deletion of Gnai2 in DC causes a Th17-associated immunopathology overtime, in SA2 – we will determine and test the transcriptional network that defines the phenotypic pro-Th17 or pro-Th2 cDC2 subpopulations, in SA3 - we will test whether GPCR agonists (i.e., β2AR agonists) that increase cAMP levels, provoke Th17-driven neutrophilic asthma, and in SA4 - we will identify and functionally test novel pro-Th17 or pro-Th2 mediators produced by DC cells. In summary - our discovery that cAMP regulates the pro-Th2 and pro-Th17 inducing properties of cDCs has led to the identification of new pathway of Th2/Th17 regulation. The results will provide new insights into the plasticity of cDC2 and Th2- and Th17- biasing. It has the potential to advance basic immunological research and establish the basis for novel and innovative immunotherapeutic strategies.