Abstract:
Mucus and its movements are essential to epithelial tissue immune defenses against pathogens, including fungal pathogens, which can infect respiratory, gastrointestinal or the genito-urinary tracts. Several epithelial cell types contribute to their immune defense. This review focuses on the respiratory tract because of its paramount importance, but the observations will apply to epithelial cell defenses of other mucosal tissue, including the gastrointestinal and genito-urinary tracts. Mucus and its movements can enhance or degrade the immune defenses of the respiratory tract, particularly the lungs. The enhancements include inhaled pathogen entrapments, including fungal pathogens, pollutants and particulates, for their removal. The detriments include smaller lung airway obstructions by mucus, impairing the physical removal of pathogens and impairing vital transfers of oxygen and carbon dioxide between the alveolar circulatory system and the pulmonary air. Inflammation, edema and/or alveolar cellular damage can also reduce vital transfers of oxygen and carbon dioxide between the lung alveolar circulatory system and the pulmonary air. Furthermore, respiratory tract defenses are affected by several fatty acid mediators which activate cellular receptors to manipulate neutrophils, macrophages, dendritic cells, various innate lymphoid cells including the natural killer cells, T cells, γδ T cells, mucosal-associated invariant T cells, NKT cells and mast cells. These mediators include the inflammatory and frequently immunosuppressive prostaglandins and leukotrienes, and the special pro-resolving mediators, which normally resolve inflammation and immunosuppression. The total effects on the various epithelial cell and immune cell types, after exposures to pathogens, pollutants or particulates, will determine respiratory tract health or disease.
摘要:
粘液及其运动对于抵抗病原体的上皮组织免疫防御至关重要,包括真菌病原体,可以感染呼吸道,胃肠道或生殖泌尿道。几种上皮细胞类型有助于其免疫防御。这篇综述的重点是呼吸道,因为它至关重要,但是这些观察结果将适用于其他粘膜组织的上皮细胞防御,包括胃肠道和生殖泌尿道。粘液及其运动可以增强或降低呼吸道的免疫防御能力,尤其是肺。增强包括吸入病原体截留,包括真菌病原体,污染物和颗粒物,为了他们的移除。损害包括粘液引起的较小的肺气道阻塞,损害病原体的物理清除,并损害肺泡循环系统和肺部空气之间的氧气和二氧化碳的重要转移。炎症,水肿和/或肺泡细胞损伤还可以减少肺泡循环系统和肺空气之间的氧气和二氧化碳的重要转移。此外,呼吸道防御受到几种脂肪酸介质的影响,这些介质激活细胞受体来操纵嗜中性粒细胞,巨噬细胞,树突状细胞,各种先天的淋巴细胞,包括自然杀伤细胞,T细胞,γδT细胞,粘膜相关的不变T细胞,NKT细胞和肥大细胞。这些介质包括炎症和经常免疫抑制的前列腺素和白三烯,和特别支持解决的调解员,通常可以解决炎症和免疫抑制。对各种上皮细胞和免疫细胞类型的总影响,暴露于病原体后,污染物或微粒,将决定呼吸道健康或疾病。