Temporal gene expression analysis of the Brucella melitensis-infected bovine Peyer's patch

In a time course study, we characterized global gene expression profile of B. melitensis-infected bovine Peyer patches in the first 4 h p.i. Microarray analysis revealed that 2,916 bovine genes were detected as differentially expressed (z-score p < 0.025) in loops inoculated with virulent B. melitensis 16M compared with controls between 15 min and 4 h post-infection. From these genes, 2,286 (78%) were up- and 630 (22%) were down-regulated. Specific genes and biological processes identified in this study will further help elucidate how both host and Brucella interact during the early infectious process to the eventual benefit of the pathogen and to the detriment of the naïve host. Microarrays were used to examine the transcriptional profiles of bovine intestinal Peyer patches infected with wild type Brucella melitensis 16M across five time points (15 min, 30 min, 1, 2 and 4 hours). Intestinal loops inoculated with cell culture medium were used as a control. Experiments were performed in quadruplicate (bovine ligated ileal loops surgeries were performed with four calves), generating a total of 40 arrays.

本研究开展时间进程实验，对感染马尔他布鲁氏菌（Brucella melitensis）的牛派尔集合淋巴结（Peyer patches）在感染后最初4小时内的全局基因表达谱进行了表征。基因芯片（Microarray）分析显示，在感染后15分钟至4小时期间，与对照组相比，接种强毒马尔他布鲁氏菌16M的肠袢样本中，共有2916个牛基因被鉴定为差异表达基因（z分数p<0.025）。其中2286个（78%）基因呈上调表达，630个（22%）呈下调表达。本研究鉴定得到的特异性基因及生物学过程，将有助于进一步阐明宿主与布鲁氏菌在感染早期的互作机制，揭示病原体如何在初始感染阶段获得生存优势，而初次感染宿主如何受到损害。本研究采用基因芯片技术，针对5个时间点（15分钟、30分钟、1小时、2小时及4小时）的牛肠道派尔集合淋巴结样本，检测感染野生型马尔他布鲁氏菌16M后的转录组表达谱。以接种细胞培养基的肠袢作为空白对照组。实验设置4次生物学重复（通过4头犊牛实施牛结扎回肠肠袢手术），最终共获得40张基因芯片数据。