Mechanisms of cetylpyridinium chloride inhibition of immune cell function

人们广泛接触高剂量（mM）的带正电荷的抗菌剂 十六烷基氯化吡啶（CPC）通过清洁和个人护理产品和食品处理， CPC，但很少有人知道它在人体内的毒理学，特别是低于临界胶束 浓度（~900 µM）。虽然应用的CPC保留在口腔粘膜中并释放到口腔粘膜中， 唾液中，低µM CPC持续浸泡口腔细胞，但缺乏关于 CPC对真核生物的影响。戈斯实验室发现，暴露于非- 细胞毒性，低μM CPC浓度有效抑制肥大细胞的信号传导，肥大细胞是 与T细胞和其它细胞共享核心信号元件免疫系统和神经系统 类型在肥大细胞中，在细胞表面受体的抗原交联后， 磷酸化级联增强，导致PLCγ1酶促裂解激活， 磷脂酰肌醇4，5-二磷酸（PIP 2）和随后的Ca 2+动员， 脱颗粒：微管将颗粒转运至细胞表面，导致细胞的胞吐作用。 生物活性物质，如组胺和血清素。T细胞的类似聚集 受体也导致酪氨酸磷酸化，Ca 2+动员，和下游T细胞 功能将确定CPC对肥大细胞和T细胞功能的影响。初步数据 已经导致CPC通过静电干扰抑制免疫细胞功能的假设 磷酸化和PIP 2，导致PIP 2结合蛋白的置换， PIP 2的纳米级聚集，Ca 2+从内质网（ER）储存中的温和释放， 从而抑制Ca 2+向胞质溶胶的流入并消除微管聚合。 将通过多种方法评估CPC对磷酸化的影响。共聚焦显微镜和 酶标仪实验将确定CPC对亚细胞定位和功能的影响， PLC γ1的PLCγ1产物肌醇1，4，5-三磷酸，启动ER Ca ~（2+）的释放; 内质网，线粒体，高尔基体和细胞质中的动态;以及Ca 2+下游的关键元件 包括蛋白激酶C、磷脂酶D和微管。CPC是否直接取代 将测量来自其伴侣蛋白的PIP 2。超分辨荧光光活化 定位显微镜将询问纳米级CPC对PIP 2簇和其他 对免疫功能至关重要的蛋白质相互作用，包括Git 1调节因子与 微管蛋白以及PIP 2与颗粒胞吐所需的机械。这项研究将 揭示CPC破坏免疫细胞功能的潜在机制，以实现 迫切需要深入了解CPC对环境人类健康的影响。

People are widely exposed to high (mM) doses of the positively-charged antibacterial agent cetylpyridinium chloride (CPC) via janitorial and personal care products and foods treated with CPC, yet little is known about its toxicology in humans, especially below the critical micelle concentration (~900 µM). While applied CPC is retained in the oral mucosa and is released into saliva such that low-µM CPC continuously bathes oral cells, there is a dearth of publications on the effects of CPC on eukaryotes. The Gosse lab has discovered that exposure to non- cytotoxic, low-µM CPC concentrations potently inhibits signaling of mast cells, key players in the immune and nervous systems that share core signaling elements with T cells and other cell types. In mast cells, upon antigen crosslinking of cell surface receptors, a tyrosine phosphorylation cascade ensues, leading to activation of PLCγ1 enzymatic cleavage of phosphatidylinositol 4,5-bisphosphate (PIP2) and subsequent Ca2+ mobilization and degranulation: microtubule transport of granules to the cell surface, leading to exocytosis of bioactive substances such as histamine and serotonin. Analogous aggregation of T cell receptors leads also to tyrosine phosphorylation, Ca2+ mobilization, and downstream T cell function. CPC effects on both mast and T cell function will be determined. Preliminary data have led to the hypothesis that CPC inhibits immune cell function by electrostatically interfering with phosphorylation and PIP2, leading to displacement of PIP2-binding proteins, disrupted nanoscale clustering of PIP2, muted release of Ca2+ from endoplasmic reticulum (ER) stores, and, thereby, inhibited inflow of Ca2+ to the cytosol and extinguished microtubule polymerization. CPC effects on phosphorylation will be assessed by multiple means. Confocal microscopy and plate reader experiments will define CPC effects on sub-cellular localization and function of PLCγ1; of PLCγ1 product inositol 1,4,5-trisphosphate which initiates release of ER Ca2+; of Ca2+ dynamics in ER, mitochondria, Golgi, and cytosol; and of key elements downstream of Ca2+ including protein kinase C, phospholipase D, and microtubules. Whether CPC directly displaces PIP2 from its partner proteins will be measured. Super-resolution fluorescence photoactivation localization microscopy will interrogate nanoscale CPC effects on PIP2 clusters and other protein interactions crucial to immune function, including co-localization of Git1 regulator with tubulin as well as PIP2 with machinery required for granule exocytosis. This research will uncover the mechanisms underlying CPC disruption of immune cell function in order to fulfill an urgent need by providing insights into CPC effects on environmental human health.