口腔味蕾细胞中的味觉受体有助于机体鉴别营养物质和有害物质,对哺乳动物的生存具有重要意义。近年来发现,味觉受体及其下游信号转导通路还在呼吸道、大脑、胃肠道等多种组织细胞中表达。表达味觉受体的细胞统称为化学感官细胞,在抵抗微生物感染、调节营养吸收、维持内环境稳态中发挥重要作用。目前已发现多种组织细胞中的味觉受体可识别细菌等微生物,介导宿主免疫应答反应,在感染性疾病发生发展过程中起到重要作用。本文就味觉受体的信号转导机制及其对微生物的调控作用进行综述。
Taste receptors guide individuals to consume nutrients while avoiding potentially noxious substances. Interes- tingly, recent studies have shown that taste receptors are also expressed beyond the taste buds, including brain, respiratory system, and digestive system, etc. These extragustatory taste receptors play important roles in microbial infection, nutrient uptake and host homeostasis. Many extragustatory taste receptors have been proposed to sense microorganisms and regulate host innate defense. More importantly, polymorphisms of genes encoding taste receptor, particularly bitter taste receptor, are linked to different innate defensive responses. This review introduces the molecular basis of taste signal transduction, and the role of taste receptors in the regulation of innate immunity during microbial infection were further discussed in detail.