Xiao Yu, Driedonks Tom, Witwer Kenneth W, Wang Qian, Yin Hang
Zhujiang Hospital, Laboratory of Medicine Center, Southern Medical University, Guangzhou, Guangdong, China.
Department of Molecular and Comparative Pathobiology, Baltimore, USA.
J Extracell Vesicles. 2020 Jul 15;9(1):1793515. doi: 10.1080/20013078.2020.1793515.
Innate immunity is a first line of defence against danger. Exogenous pathogen- or microbe-associated molecular patterns (PAMPs or MAMPs) trigger innate immune responses through well-understood cellular pathways. In contrast, endogenous damage-associated molecular patterns (DAMPs) convey "danger signals" via their (mis)localization or modification. Both MAMPs and DAMPs are often communicated on or within extracellular vesicles (EVs). Despite growing evidence for the importance of EVs and their cargo in modulating innate immune responses, in some cases, it is unclear how EV-transported molecules are sensed as abnormal. In particular, EVs constitutively carry RNA, which is also abundant in the cytoplasm. How, then, would RNA convey a danger signal as a cargo of EVs? In this Perspective, we offer some thoughts on how EV-associated RNAs might raise the alarm for innate immune responses - or silence them.
固有免疫是抵御危险的第一道防线。外源性病原体或微生物相关分子模式（PAMPs或MAMPs）通过广为人知的细胞途径触发固有免疫反应。相比之下，内源性损伤相关分子模式（DAMPs）通过其（错误）定位或修饰传递“危险信号”。MAMPs和DAMPs通常在细胞外囊泡（EVs）上或其内部传递。尽管越来越多的证据表明EVs及其货物在调节固有免疫反应中具有重要性，但在某些情况下，尚不清楚如何感知EVs运输的分子是异常的。特别是，EVs组成性携带RNA，而RNA在细胞质中也很丰富。那么，RNA作为EVs的货物如何传递危险信号呢？在这篇观点文章中，我们对EVs相关RNA如何引发固有免疫反应的警报——或使其沉默提出了一些想法。
