The Notch Signaling Pathway Regulates Basophil Responses During Helminth Infection

项目总结 肠道蠕虫寄生虫感染全世界数百万人，并造成重大发病率。主机- 保护性2型炎症的特征是天然免疫细胞的激活，幼稚的CD4+的极化 T细胞转化为辅助性T细胞2型，抗蠕虫上皮细胞反应，以及驱虫。最新研究 已经发现嗜碱性粒细胞，一种罕见的天然粒细胞，促进2型炎症和蠕虫排出，但 在蠕虫感染后控制嗜碱粒细胞效应器功能的途径仍未完全确定。 然而，Notch信号通路是调节嗜碱性细胞反应的关键候选信号通路。 这一背景。与Notch受体结合的配体导致Notch细胞内的核转位 结构域，可促进规范的2型炎症相关靶基因的转录激活 和2型炎症反应的发展。然而，诺奇如何塑造嗜碱粒细胞的反应 体内对肠道2型炎症和蠕虫排出的调节尚不清楚。为了解决这一问题，请在 初步研究表明，我们首次发现小鼠嗜碱性粒细胞表达Notch 2。 肠道寄生虫--鞭毛虫。使用Notch信号被基因阻断的小鼠 仅在嗜碱性细胞中，我们证明了虽然Notch信号不是维持嗜碱性细胞所必需的 在稳定状态下，它确实有助于嗜碱性粒细胞种群的最佳扩张和蠕虫 梅毒螺旋体感染后的清除。最后，我们证明了Notch信号调节细胞因子的诱导 体外激活嗜碱粒细胞。总而言之，这些数据让我们假设在肠道蠕虫期间 寄生虫感染，嗜碱性粒细胞上调Notch并对Notch配体产生反应，介导最佳嗜碱性细胞 种群扩张和效应器功能及有效驱除蠕虫。为了测试这一点，我们提出了三个 明确的目标。目标1的研究将测试Notch信号通路如何调节嗜碱性细胞数量 用体外和体内方法研究2型炎症的扩增和分化 在毛滴虫感染期间。Aim 2的研究将测试Notch信号如何促进嗜碱性粒细胞效应器功能 以及通过过继转移研究和感染毛滴虫对体内II型炎症的贡献， 一些研究集中在Notch 2在这一过程中的作用。AIM 3的研究将测试Notch配体或 蠕虫蛋白水解酶可激活嗜碱性粒细胞中的Notch信号以促进效应器功能和2型 感染毛滴虫期间的体内实验和体外检测。这些研究将剖析 Notch信号如何调节嗜碱性细胞反应，从而驱动肠道中的2型炎症 蠕虫寄生虫感染。我们的结果将扩大我们对肠道2型炎症和 告知针对Notch治疗2型炎症性疾病的治疗方法的开发和使用。

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.