Lee Robert J, Cohen Noam A
Department of Otorhinolaryngology, Perelman School of Medicine, University of Pennsylvania, Ravdin Building, 5th floor, Philadelphia, PA, 19104, USA.
J Mol Med (Berl). 2014 Dec;92(12):1235-44. doi: 10.1007/s00109-014-1222-6. Epub 2014 Nov 13.
Taste receptors on the tongue communicate information to the brain about the nutrient content or potential toxicity of ingested foods. However, recent research has now shown that taste receptors are also expressed far beyond the tongue, from the airway and gastrointestinal epithelia to the pancreas and brain. The functions of many of these so-called extraoral taste receptors remain unknown, but emerging basic science and clinical evidence suggests that bitter and sweet taste receptors in the airway are important in sensing bacteria and regulating innate immunity. This review focuses on the role of bitter and sweet taste receptors in human airway innate immunity and the potential clinical relevance to airway infections. The T2R38 bitter taste receptor in sinonasal cilia detects bitter bacterial quorum-sensing molecules and activates nitric oxide-dependent innate immune responses. Polymorphisms that underlie T2R38 functionality also appear to be involved in susceptibility to upper respiratory infection and chronic rhinosinusitis (CRS). Bitter and sweet receptors in specialized sinonasal solitary chemosensory cells control antimicrobial peptide secretion, which may have important implications for airway infections in CRS patients as well as patients with diabetes mellitus. Future research on taste receptors in the airway has tremendous potential to identify immune mechanisms involved in host-pathogen interactions and thus reveal novel therapeutic targets.
舌头上的味觉感受器会将摄入食物的营养成分或潜在毒性信息传递给大脑。然而,最近的研究表明,味觉感受器的表达范围远远超出舌头,从气道和胃肠道上皮到胰腺和大脑都有。许多这些所谓的口外味觉感受器的功能仍然未知,但新出现的基础科学和临床证据表明,气道中的苦味和甜味感受器在感知细菌和调节先天免疫方面很重要。这篇综述聚焦于苦味和甜味感受器在人类气道先天免疫中的作用以及与气道感染的潜在临床相关性。鼻窦纤毛中的T2R38苦味感受器能检测苦味细菌群体感应分子并激活依赖一氧化氮的先天免疫反应。构成T2R38功能基础的多态性似乎也与上呼吸道感染和慢性鼻窦炎(CRS)的易感性有关。鼻窦特化的孤立化学感受细胞中的苦味和甜味感受器控制抗菌肽的分泌,这可能对CRS患者以及糖尿病患者的气道感染具有重要意义。未来对气道味觉感受器的研究极有可能识别出参与宿主 - 病原体相互作用的免疫机制,从而揭示新的治疗靶点。