Bitter and sweet taste receptor physiology in airway ciliated cells

我们最近发现人鼻纤毛细胞表达T2 R苦味受体。当 被分泌的细菌产物激活，纤毛中的T2 R刺激先天免疫信号级联反应， 钙驱动的一氧化氮产生，增加纤毛跳动以及直接杀死细菌。遗传 TAS 2 R38基因的多态性，纤毛中的T2 R之一，可能是感染易感性的基础， 慢性鼻窦炎患者。我们假设气道中T2 R苦味受体反应的激活 纤毛细胞将激活先天免疫，帮助消除感染，而无需使用传统的抗生素。 了解如何开发针对这些途径的局部治疗需要进一步的研究。 了解纤毛中其他纤毛定位的化学感受受体的身份以及它们的信号传导 路径和下游效应。仍然迫切需要细胞生物学知识， 口腔外味觉感受器的生理学。我们假设鼻窦和支气管运动纤毛 表达多种化学感受受体，因为我们已经鉴定了多种T2 R（4、14、16和38）和T1 R 2， 3（甜味感受器的成分）定位于鼻窦纤毛。有趣的是，T2 R和T1 R 激活不同的途径，与舌相反，它们的细胞内信号相似。纤毛T2 Rs 激活Ca 2+依赖的NO产生，可能还涉及激酶AKT。纤毛T1 R2/3的激活 激活调节气道上皮葡萄糖转运蛋白的独特信号通路。了解纤毛 化学感受和所涉及的独特信号通路将阐明如何利用这些受体 以及阐明非典型味觉受体信号传导的机制， 与舌头和/或表达它们的许多口腔外组织高度相关。 在目标1中，我们将使用活细胞成像， 在空气-液体环境中培养的分化的原代人类细胞和细胞系中的生物化学和分子方法 接口.在目标2中，我们将使用类似的技术来阐明T1 R 受体调节气道中的葡萄糖转运，以及T1 R受体在原代人中的调节 和小鼠细胞。在目标3中，我们将使用一种新的方法来研究T1 R和T2 R的定位和相互作用。 活细胞成像和生物化学的组合，以及通过以下方式识别纤毛化学感受库： 生物化学纤毛纯化和蛋白质组学。这些独立而又相互关联的目标将共同审查 重要的化学感受功能的气道纤毛，揭示了新的方法来利用化学感受受体， 气道疾病的治疗靶点。同样重要的是，我们将揭示新的见解，细胞生物学， 口外味觉感受器的功能，可能会转化为T1 R和T2 R在其他组织。虽然大部分T2 R 和T1 R细胞生物学已经从异源系统推断，我们独特的模型系统将使我们能够 研究分化的原代人类细胞中内源性T1 R和T2 R功能的功能和相互作用。

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.