Bitter and sweet taste receptor physiology in airway ciliated cells

我们最近发现人鼻纤毛细胞表达T2R苦味受体。什么时候 纤毛中的T2Rs被分泌的细菌产物激活，刺激先天免疫信号级联反应，涉及 钙驱动的一氧化氮的产生增加了纤毛跳动，并直接杀死细菌。遗传 纤毛中的T2R基因之一TAS2R38基因的多态可能是感染易感性的基础 慢性鼻-鼻窦炎患者。我们假设呼吸道中T2R苦味受体反应的激活 纤毛细胞将激活先天免疫，在不使用常规抗生素的情况下帮助根除感染。 了解如何开发针对这些通路的局部疗法需要进一步 纤毛中其他纤毛定位的化学感觉受体的识别及其信号转导的知识 路径和下游效应。仍然迫切需要细胞生物学知识和 一般口外味觉感受器的生理学。我们假设鼻腔和支气管的活动纤毛 表达多种化学感觉受体，因为我们已经鉴定了多种T2Rs(4，14，16和38)和T1Rs 2 3(甜味感受器成分)定位于鼻腔纤毛。有趣的是，T2Rs和T1Rs 激活不同的通路，而舌头的细胞内信号是相似的。纤毛T2Rs 激活依赖于钙离子的NO的产生，可能还涉及到激酶AKT。纤毛T1R2/3的激活 激活调节呼吸道上皮葡萄糖转运蛋白的独特信号通路。了解纤毛 化学感觉和涉及的独特的信号通路将阐明如何利用这些受体 为了治疗的益处以及阐明非典型味觉受体信号的机制，可能 与舌头和/或表达它们的许多口外组织高度相关。 在目标1中，我们将结合活细胞成像进一步阐明纤毛T2Rs的信号转导。 空气-液体培养分化的原代人类细胞和细胞系的生化和分子方法 界面。在目标2中，我们将使用类似的技术来阐明T1R 受体调节原代人呼吸道葡萄糖转运及T1R受体对其的调节 和小鼠细胞。在目标3中，我们将使用一个 结合活细胞成像和生物化学，以及通过以下方式鉴定纤毛化学传感谱系 生化纤毛纯化与蛋白质组学。在一起，独立而又相互关联的目标将审查 呼吸道纤毛的重要化学感觉功能，揭示了利用化学感觉受体的新方法 呼吸道疾病的治疗靶点。同样重要的是，我们将揭示对细胞生物学的新见解 口外味觉感受器的功能，可能会在其他组织中翻译成T1Rs和T2Rs。而T2R的大部分 和T1R细胞生物学已经从异源系统中推断出来，我们独特的模型系统将使我们能够 研究内源性T1R和T2R功能在分化的原代人类细胞中的功能及其相互作用。

We recently discovered that human nasal ciliated cells express the T2R bitter taste receptors. When activated by secreted bacterial products, T2Rs in cilia stimulates an innate immune signaling cascade involving calcium-driven nitric oxide production that increases ciliary beating as well as directly kills bacteria. Genetic polymorphisms in the TAS2R38 gene, one of the T2Rs in cilia, may underlie susceptibility to infection in patients with chronic rhinosinusitis. We hypothesize that activation of T2R bitter receptor responses in airway ciliated cells will activate innate immune to help eradicate infections without the use of conventional antibiotics. Understanding how to develop topical therapeutics targeting these pathways requires further knowledge of the identity of other cilia-localized chemosensory receptors in cilia as well as their signaling pathways and downstream effects. There remains a critical need for knowledge of the cell biology and physiology of extraoral taste receptors in general. We hypothesize that sinonasal and bronchial motile cilia express multiple chemosensory receptors, as we have identified multiple T2Rs (4,14,16, and 38) and T1Rs 2 and 3 (components of the sweet taste receptor) localized to sinonasal cilia. Interestingly, T2Rs and T1Rs activate different pathways, in contrast to the tongue where their intracellular signaling is similar. Cilia T2Rs activate Ca2+-dependent NO production, possibly also involving the kinase AKT. Activation of cilia T1R2/3 activates a distinct signaling pathway that regulates airway epithelial glucose transporters. Understanding cilia chemosensation and the unique signaling pathways involved will shed light on how to leverage these receptors for therapeutic benefit as well as elucidate mechanisms of non-canonical taste receptor signaling that may be highly relevant to the tongue and/or the many extraoral tissues where they are expressed. In Aim 1, we will further elucidate the signaling of cilia T2Rs using a combination of live cell imaging, biochemical, and molecular approaches in differentiated primary human cells and cell lines cultured at air-liquid interface. In Aim 2, we will use similar techniques to elucidate the signaling mechanism by which T1R receptors regulate glucose transport in the airway as well as its regulation by T1R receptors in primary human and mouse cells. In Aim 3, we will examine the localization and interactions of T1Rs and T2Rs using a combination of live-cell imaging and biochemistry, as well as identify the cilia chemosensory repertoire by biochemical cilia purification and proteomics. Together, the independent yet inter-related aims will examine important chemosensory functions of airway cilia, revealing new ways to leverage chemosensory receptors as therapeutic targets for airway diseases. Equally importantly, we will reveal new insights into the cell biology of extraoral taste receptor function that will likely translate to T1Rs and T2Rs in other tissues. While much of T2R and T1R cell biology has been inferred from heterologous systems, our unique model system will allow us to study the function and interactions of endogenous T1R and T2R function in differentiated primary human cells.