Zhong Xiuqin, Lundberg Max, Råberg Lars
Department of Biology Lund University Lund Sweden.
Ecol Evol. 2020 May 25;10(13):6421-6434. doi: 10.1002/ece3.6377. eCollection 2020 Jul.
Different host species often differ considerably in susceptibility to a given pathogen, but the causes of such differences are rarely known. The natural hosts of the tick-transmitted bacterium , which is one of causative agents of Lyme borreliosis in humans, include a variety of small mammals like voles and mice. Previous studies have shown that infected bank voles () have about ten times higher bacterial load than infected yellow-necked mice (), indicating that these two species differ in resistance. In this study, we compared the immune response to infection in these host species by using RNA sequencing to quantify gene expression in spleen. Gene set enrichment analysis (GSEA) showed that several immune pathways were down-regulated in infected animals in both bank voles and yellow-necked mice. Moreover, IFNα response was up-regulated in -infected yellow-necked mice, while IL6 signaling and the complement pathway were down-regulated in infected bank voles; differences in regulation of these three pathways between bank voles and yellow-necked mice could thus contribute to the difference in resistance to between the species. This study provides knowledge of gene expression induced by a zoonotic pathogen in its natural host, and possible species-specific regulation of immune responses associated with resistance.
不同宿主物种对特定病原体的易感性往往有很大差异，但这种差异的原因却鲜为人知。蜱传播细菌是人类莱姆病的病原体之一，其天然宿主包括田鼠和小鼠等多种小型哺乳动物。先前的研究表明，受感染的普通田鼠体内的细菌载量比受感染的黄颈鼠高出约十倍，这表明这两个物种在抵抗力方面存在差异。在本研究中，我们通过RNA测序对脾脏中的基因表达进行定量，比较了这些宿主物种对感染的免疫反应。基因集富集分析（GSEA）表明，普通田鼠和黄颈鼠受感染动物的几种免疫途径均下调。此外，在受感染的黄颈鼠中，IFNα反应上调，而在受感染的普通田鼠中，IL6信号传导和补体途径下调；因此，普通田鼠和黄颈鼠在这三种途径调节上的差异可能导致了物种间对抵抗力的差异。本研究提供了关于人畜共患病原体在其天然宿主中诱导的基因表达的知识，以及与抵抗力相关的免疫反应可能存在的物种特异性调节。
