Comparison of spleen transcriptomes of two wild rodent species reveals differences in the immune response against Borrelia afzelii

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 Borrelia afzelii, 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 B. afzelii-infected bank voles (Myodes glareolus) have about ten times higher bacterial load than infected yellow-necked mice (Apodemus flavicollis), indicating that these two species differ in resistance. In this study, we compared the immune response to B. afzelii 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 B. afzelii-infected yellow-necked mice, while IL6 signaling and the compleme...不同宿主物种对特定病原体的易感性往往存在显著差异，但此类差异的成因却鲜有阐明。蜱传细菌阿氏疏螺旋体（Borrelia afzelii）是人类莱姆疏螺旋体病的致病原之一，其自然宿主涵盖多种小型哺乳动物，包括田鼠与小鼠。既往研究表明，感染B. afzelii的林旅鼠（Myodes glareolus）的细菌载量约为感染该菌的黄喉姬鼠（Apodemus flavicollis）的10倍，提示这两个物种的抗病能力存在显著差异。本研究通过RNA测序（RNA-sequencing）量化脾脏组织的基因表达水平，对比了这两种宿主在感染B. afzelii后的免疫应答差异。基因集富集分析（Gene Set Enrichment Analysis, GSEA）结果显示，在受感染的林旅鼠与黄喉姬鼠体内，多条免疫通路均呈现下调表达趋势。此外，感染B. afzelii的黄喉姬鼠体内的干扰素α（IFNα）应答通路出现上调，而白细胞介素6（IL6）信号通路及补体...