Institute of Immunology and Infection Research and Centre for Immunity, Infection & Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom.
Unite Molecules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245), Sorbonne Universites, Museum national d'Histoire naturelle, CNRS, CP52, Paris, France.
PLoS Negl Trop Dis. 2019 Nov 26;13(11):e0007811. doi: 10.1371/journal.pntd.0007811. eCollection 2019 Nov.
The release of small non-coding RNAs (sRNAs) has been reported in parasitic nematodes, trematodes and cestodes of medical and veterinary importance. However, little is known regarding the diversity and composition of sRNAs released by different lifecycle stages and the portion of sRNAs that persist in host tissues during filarial infection. This information is relevant to understanding potential roles of sRNAs in parasite-to-host communication, as well as to inform on the location within the host and time point at which they can be detected.
We have used small RNA (sRNA) sequencing analysis to identify sRNAs in replicate samples of the excretory-secretory (ES) products of developmental stages of the filarial nematode Litomosoides sigmodontis in vitro and compare this to the parasite-derived sRNA detected in host tissues. We show that all L. sigmodontis developmental stages release RNAs in vitro, including ribosomal RNA fragments, 5'-derived tRNA fragments (5'-tRFs) and, to a lesser extent, microRNAs (miRNAs). The gravid adult females (gAF) produce the largest diversity and abundance of miRNAs in the ES compared to the adult males or microfilariae. Analysis of sRNAs detected in serum and macrophages from infected animals reveals that parasite miRNAs are preferentially detected in vivo, compared to their low levels in the ES products, and identifies miR-92-3p and miR-71-5p as L. sigmodontis miRNAs that are stably detected in host cells in vivo.
Our results suggest that gravid adult female worms secrete the largest diversity of extracellular sRNAs compared to adult males or microfilariae. We further show differences in the parasite sRNA biotype distribution detected in vitro versus in vivo. We identify macrophages as one reservoir for parasite sRNA during infection, and confirm the presence of parasite miRNAs and tRNAs in host serum during patent infection.
已报道在寄生线虫、吸虫和绦虫中有小非编码 RNA（sRNA）的释放。然而，对于不同生活史阶段释放的 sRNA 的多样性和组成以及在丝虫感染过程中在宿主组织中持续存在的 sRNA 部分知之甚少。这些信息对于理解 sRNA 在寄生虫与宿主之间的通讯中的潜在作用以及了解它们在宿主中的位置和可以检测到它们的时间点是相关的。
我们使用小 RNA（sRNA）测序分析来鉴定在体外发育阶段的丝状线虫利什曼原虫的排泄-分泌（ES）产物的重复样本中的 sRNA，并将其与在宿主组织中检测到的寄生虫衍生的 sRNA 进行比较。我们表明，所有利什曼原虫发育阶段都在体外释放 RNA，包括核糖体 RNA 片段、5'-衍生的 tRNA 片段（5'-tRFs），以及程度较小的 microRNAs（miRNAs）。与成年雄性或微丝蚴相比，雌性成虫（gAF）在 ES 中产生最多的 miRNA 多样性和丰度。对感染动物的血清和巨噬细胞中检测到的 sRNA 的分析表明，与 ES 产物中的低水平相比，寄生虫 miRNA 优先在体内被检测到，并确定 miR-92-3p 和 miR-71-5p 是利什曼原虫在体内稳定检测到的 miRNA。
我们的结果表明，与成年雄性或微丝蚴相比，雌性成虫释放的细胞外 sRNA 多样性最大。我们进一步显示了在体外和体内检测到的寄生虫 sRNA 生物型分布的差异。我们将巨噬细胞鉴定为感染期间寄生虫 sRNA 的一个储存库，并在有症状感染期间确认寄生虫 miRNA 和 tRNA 存在于宿主血清中。
