The Notch Signaling Pathway Regulates Basophil Responses During Helminth Infection

项目摘要 肠道蠕虫寄生虫感染全世界数百万人并导致显著的发病率。主持人- 保护性2型炎症的特征在于先天免疫细胞的激活，幼稚CD 4+细胞的极化， T细胞转化为2型辅助性T细胞，抗蠕虫上皮细胞反应和蠕虫排出。最近的研究 已经发现嗜碱性粒细胞，罕见的先天性粒细胞，促进2型炎症和蠕虫驱逐，但 蠕虫感染后控制嗜碱性粒细胞效应子功能的途径仍不完全确定。 然而，Notch信号通路作为一个关键的候选者，可以调节嗜碱性粒细胞的反应， 这个背景。配体与Notch受体结合导致Notch细胞内的核转位 结构域，其可以促进典型的2型炎症相关靶基因的转录激活 以及2型炎症反应的发展。然而，Notch如何塑造嗜碱性粒细胞的反应， 体内调节肠2型炎症和蠕虫排出是未知的。为了解决这个问题，在 初步研究，我们首次表明，小鼠嗜碱性粒细胞表达Notch 2感染后， 肠道蠕虫寄生虫鼠鞭虫使用Notch信号被基因阻断的小鼠 仅在嗜碱性粒细胞中，我们证明，虽然Notch信号传导不需要维持嗜碱性粒细胞 在稳定状态下，它确实有助于嗜碱性粒细胞的最佳种群扩张和蠕虫 T之后的间隙。小鼠感染。最后，我们发现Notch信号调节了精氨酸引起的 体外嗜碱性粒细胞活化。总的来说，这些数据使我们假设，在肠道蠕虫 寄生虫感染，嗜碱性粒细胞上调Notch并对Notch配体产生应答，介导最佳嗜碱性粒细胞 种群扩张和效应器功能以及有效的蠕虫驱逐。为了验证这一点，我们提出了三个 具体目标。目标1中的研究将测试Notch信号通路如何调节嗜碱性粒细胞群体 2型炎症过程中的扩增和分化，采用体外测定和体内方法 在T.小鼠感染。目标2中的研究将测试Notch信号传导如何促进嗜碱性粒细胞效应子功能 以及使用过继转移研究和T.穆里斯，与 一些研究集中在Notch 2在这一过程中的作用。目标3中的研究将测试Notch配体或 蠕虫蛋白酶可以激活嗜碱性粒细胞中的Notch信号，以促进效应器功能和2型 炎症，使用T.期间的体内实验。小鼠感染和体外测定。这些研究将剖析 Notch信号如何调节嗜碱性粒细胞反应，驱动肠道中的2型炎症， 蠕虫寄生虫感染我们的研究结果将扩大我们对肠道2型炎症的理解， 为靶向Notch治疗2型炎性疾病的疗法的开发和使用提供信息。

PROJECT SUMMARY Intestinal helminth parasites infect millions of people worldwide and cause significant morbidity. Host- protective type 2 inflammation is characterized by activation of innate immune cells, polarization of naïve CD4+ T cells to T helper type 2 cells, anti-helminth epithelial cell responses, and worm expulsion. Recent studies have revealed that basophils, rare innate granulocytes, promote type 2 inflammation and worm expulsion, but the pathways that control basophil effector function following helminth infection remain incompletely defined. However, the Notch signaling pathway stands out as a key candidate that could regulate basophil responses in this context. Ligand binding to a Notch receptor leads to nuclear translocation of the Notch intracellular domain, which can promote transcriptional activation of canonical type 2 inflammation-associated target genes and the development of type 2 inflammatory responses. However, how Notch shapes basophil responses that regulate intestinal type 2 inflammation and helminth expulsion in vivo is unknown. To address this, in preliminary studies, we show for the first time that murine basophils expressed Notch 2 following infection with the intestinal helminth parasite Trichuris muris. Using mice in which Notch signaling is genetically blocked solely in basophils, we demonstrate that while Notch signaling was not required to maintain the basophil population in the steady state, it does contribute to optimal basophil population expansion and helminth clearance following T. muris infection. Finally, we show that Notch signaling regulates cytokine-elicited basophil activation in vitro. Collectively, these data led us to hypothesize that during intestinal helminth parasite infection, basophils upregulate Notch and respond to Notch ligands, mediating optimal basophil population expansion and effector function and efficient helminth expulsion. To test this, we propose three specific aims. Studies in Aim 1 will test how the Notch signaling pathway regulates basophil population expansion and differentiation during type 2 inflammation, employing in vitro assays and in vivo approaches during T. muris infection. Studies in Aim 2 will test how Notch signaling promotes basophil effector function and contributions to type 2 inflammation in vivo using adoptive transfer studies and infection with T. muris, with some studies focusing on the role of Notch 2 in this process. Studies in Aim 3 will test how Notch ligands or helminth proteases could activate Notch signaling in basophils to promote effector function and type 2 inflammation, using in vivo experiments during T. muris infection and in vitro assays. These studies will dissect how Notch signaling regulates basophil responses that drive type 2 inflammation in the intestine following helminth parasite infection. Our results will expand our understanding of intestinal type 2 inflammation and inform the development and use of therapies that target Notch to treat type 2 inflammatory diseases.