Vegh Peter, Magee David A, Nalpas Nicolas C, Bryan Kenneth, McCabe Matthew S, Browne John A, Conlon Kevin M, Gordon Stephen V, Bradley Daniel G, MacHugh David E, Lynn David J
Tuberculosis (Edinb). 2015 Jan;95(1):60-7. doi: 10.1016/j.tube.2014.10.011.
Mycobacterium bovis, the causative agent of bovine tuberculosis, a major problem for global agriculture, spreads via an airborne route and is taken up by alveolar macrophages (AM) in the lung. Here, we describe the first next-generation sequencing (RNA-seq) approach to temporally profile miRNA expression in primary bovine AMs post-infection with M. bovis. One, six, and forty miRNAs were identified as significantly differentially expressed at 2, 24 and 48 h post-infection, respectively. The differential expression of three miRNAs (bta-miR-142-5p, bta-miR-146a, and bta-miR-423-3p) was confirmed by RT-qPCR. Pathway analysis of the predicted mRNA targets of differentially expressed miRNAs suggests that these miRNAs preferentially target several pathways that are functionally relevant for mycobacterial pathogenesis, including endocytosis and lysosome trafficking, IL-1 signalling and the TGF-β pathway. Over-expression studies using a bovine macrophage cell-line (Bomac) reveal the targeting of two key genes in the innate immune response to M. bovis, IL-1 receptor-associated kinase 1 (IRAK1) and TGF-β receptor 2 (TGFBR2), by miR-146. Taken together, our study suggests that miRNAs play a key role in tuning the complex interplay between M. bovis survival strategies and the host immune response.
牛分枝杆菌是牛结核病的病原体，这是全球农业面临的一个主要问题，它通过空气传播途径传播，并被肺部的肺泡巨噬细胞（AM）摄取。在这里，我们描述了第一种下一代测序（RNA测序）方法，用于对牛分枝杆菌感染后原代牛肺泡巨噬细胞中miRNA表达进行时间分析。分别在感染后2、24和48小时，有1、6和40个miRNA被鉴定为显著差异表达。通过RT-qPCR证实了三种miRNA（bta-miR-142-5p、bta-miR-146a和bta-miR-423-3p）的差异表达。对差异表达miRNA的预测mRNA靶标的通路分析表明，这些miRNA优先靶向几个与分枝杆菌发病机制功能相关的通路，包括内吞作用和溶酶体运输、IL-1信号通路和TGF-β通路。使用牛巨噬细胞系（Bomac）进行的过表达研究揭示了miR-146对牛分枝杆菌固有免疫反应中两个关键基因白细胞介素-1受体相关激酶1（IRAK1）和转化生长因子-β受体2（TGFBR2）的靶向作用。综上所述，我们的研究表明，miRNA在调节牛分枝杆菌生存策略与宿主免疫反应之间的复杂相互作用中起关键作用。
