Control of mucosal immunity by Gas- vs Gai-linked GPCR signaling in dendritic cells

树突状细胞中 Gas 与 Gai 连接的 GPCR 信号传导控制粘膜免疫

• 批准号: 9169832
• 负责人: Eyal Raz
• 金额: $ 46.11万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-06-06 至 2021-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9169832
• 关键词: Address; Adjuvant; Adoptive Transfer; Age; Antigens; CD4 Positive T Lymphocytes; CREB1 gene; Cell Differentiation process; Citrobacter rodentium; Colitis; Coupled; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; Dendritic Cells; Development; G Protein-Coupled Receptor Signaling; GTP-Binding Proteins; Gene Targeting; Genes; Host Defense; ITGAX gene; Immune; Immune response; Immunity; Immunization; Immunotherapeutic agent; In Vitro; Infection; Inflammation; Inflammatory disease of the intestine; Intestines; Knockout Mice; Link; Mediating; Mediator of activation protein; Medical; Microbe; Modeling; Mouse Strains; Mucosal Immune Responses; Mucosal Immunity; Mus; Organ; Pathology; Pathway interactions; Phenotype; Play; Production; Regulation; Research; Resistance; Role; Second Messenger Systems; Severities; Signal Transduction; Site; Stimulus; T-Lymphocyte; Testing; Trichuris; Wild Type Mouse; Work; antimicrobial; base; enteric pathogen; immunopathology; innovation; insight; knock-down; mouse model; mucosal site; pathogen; physiologic model; promoter; response; second messenger; small hairpin RNA

Project Summary We have uncovered a new pathway in CD11c+ dendritic cells (DC) that controls T helper cell differentiation into the Th17 and Th2 lineages. The pathway involves cyclic AMP (cAMP) and protein kinase A (PKA), and plays a key role in the differential induction of immune defense and immunopathology at mucosal sites. In this project, we will address the underlying mechanisms by focusing on signaling by the heterotrimeric (αβγ) GTP binding proteins, Gas (encoded by Gnas) and Gai (encode by Gnai2), which stimulate and inhibit cAMP synthesis, respectively. We have generated two powerful new physiologic models to explore cAMP functions in mucosal immune regulation, CD11c-specific conditional gene-targeted mice for Gnas (GnasCD11c, low cAMP) and Gai (Gnai2CD11c, high cAMP). We discovered that GnasCD11c mice are biased toward Th2, whereas Gnai2CD11c mice are prone to Th17, and that the two mouse strains display distinct mucosal immune abnormalities. These findings have led us to hypothesize that: I) Differential cAMP production in CD11c+ DC creates a pro-Th17 (high cAMP) or pro-Th2 (low cAMP) DC phenotypes; II) The imbalance of cAMP in the absence of Gas vs. Gai in DC results in differential immune reactivity in different mucosal organs; and III) Differential cAMP regulation in DC can be exploited pharmacologically as an innovative immune-modulatory strategy to treat Th17- and Th2-related pathologies and their related infections. We have assembled a multi- disciplinary team with complementary expertise to test these hypotheses in four Specific Aims. In Specific Aim 1 (SA1), we will assess the impact of Gas- and Gai-dependent signaling in DC on constitutive Th bias at different mucosal and systemic sites, and on spontaneous mucosal immunopathology. We will then evaluate the role of Gas and Gai on classical DC1 (cDC1) and cDC2 development and function. SA2 will explore the function of Gas and Gai in DC in controlling intestinal inflammation phenotypes in complementary models of colitis. SA3 will determine the importance of Gas and Gai in DC in antimicrobial host defense in the intestine, while SA4 will define Gas- and Gai- dependent mediators of DC-controlled Th17/Th2 polarization. Taken together, our discoveries in newly constructed Gnas∆CD11c and Gnai2CD11c mouse models have led to exciting and innovative hypotheses on the role of cAMP signaling in DC in orchestrating mucosal immune decisions, which will be systematically tested in this proposal. The results will yield new insight into the mechanisms of cAMP-dependent immune defense and immunopathology at mucosal sites. The findings will also form the basis for innovative immunotherapeutic strategies to target cAMP functions in DC. The project has a high likelihood of advancing basic immunological research, and addressing an unmet medical need in modulating destructive mucosal immune responses and in promoting protective responses against enteric pathogens.

项目摘要 我们已经发现了一个新的途径，在CD 11 c+树突状细胞（DC），控制T辅助细胞分化 Th 17和Th 2细胞系。该途径涉及环AMP（cAMP）和蛋白激酶A（PKA）， 在粘膜部位的免疫防御和免疫病理学的差异诱导中起关键作用。在这 项目，我们将通过关注异源三聚体（αβγ）GTP的信号转导来解决潜在的机制 结合蛋白，Gas（由Gnas编码）和Gai（由Gnai 2编码），其刺激和抑制cAMP 合成，分别。我们已经建立了两个强大的新的生理模型，以探索cAMP的功能， 粘膜免疫调节，CD 11 c特异性Gnas条件基因靶向小鼠（Gnas抑制CD 11 c，低cAMP） 和Gai（Gnai 2 → CD 11 c，高cAMP）。我们发现GnasCD 11 c小鼠偏向于Th 2，而 Gnai 2 + CD 11 c小鼠倾向于Th 17，并且两种小鼠品系显示出不同的粘膜免疫 异常这些发现使我们假设：I）CD 11 c + DC中的差异cAMP产生 产生pro-Th 17（高cAMP）或pro-Th 2（低cAMP）DC表型; DC中Gas与Gai的不存在导致不同粘膜器官中的不同免疫反应性;和III） DC中的差异cAMP调节可被用作一种创新的免疫调节剂。 治疗Th 17和Th 2相关病理及其相关感染的策略。我们已经建立了一个多- 学科团队与互补的专业知识，以测试这些假设在四个具体目标。具体目标 1（SA 1），我们将评估DC中Gas和Gai依赖性信号传导对组成性Th偏倚的影响， 不同的粘膜和全身部位，以及自发性粘膜免疫病理学。我们将评估 Gas和Gai在经典DC 1（cDC 1）和cDC 2发育和功能中的作用。SA 2将探索 DC中Gas和Gai在控制肠道炎症表型中的功能 结肠炎SA 3将确定DC中Gas和Gai在肠中抗微生物宿主防御中的重要性， 而SA 4将定义DC控制的Th 17/Th 2极化的Gas和Gai依赖性介质。采取 总之，我们在新构建的GnaI CD 11 c和GnaI 2 CD 11 c小鼠模型中的发现， 以及关于DC中cAMP信号传导在协调粘膜免疫决定中的作用的创新假设， 这将在本提案中进行系统测试。这些结果将为我们提供新的见解， cAMP依赖性免疫防御和粘膜部位的免疫病理学。调查结果还将构成 靶向DC中cAMP功能的创新免疫策略的基础。该项目具有很高的 推进基础免疫学研究的可能性，并解决调制中未满足的医疗需求， 破坏性粘膜免疫应答和促进针对肠道病原体的保护性应答。