Sauvonnet Nathalie, Pradet-Balade Bérengère, Garcia-Sanz Jose A, Cornelis Guy R
Microbial Pathogenesis Unit, Christian de Duve Institute of Cellular Pathology and Université Catholique de Louvain, B-1200 Brussels, Belgium.
J Biol Chem. 2002 Jul 12;277(28):25133-42. doi: 10.1074/jbc.M203239200. Epub 2002 May 2.
The Yop virulon, which comprises a complete type III secretion system and secreted proteins, allows bacteria from the genus Yersinia to resist the nonspecific immune response of the host. This virulon, which is encoded by a plasmid called pYV in Yersinia enterocolitica, enables extracellular bacteria to inject six Yop effectors (YopE, -H, -T, -O, -P, -M) into the host cell. To investigate the role of YopP, YopM, and the other pYV-encoded factors on the expression of the host cell genes, we characterized the transcriptome alterations in infected mouse macrophages using the microarray technique. PU5-1.8 macrophages were infected either with an avirulent (pYV(-)), a wild type (pYV(+)), or two knockout (yopP(-) and yopM(-)) mutants of Y. enterocolitica. Expression alterations in response to Y. enterocolitica infection were monitored for 6657 genes. Among those, 857 genes were affected, 339 of which were specifically regulated by the action of the Yop virulon. Further analysis of those 339 genes allowed identification of specific targets of YopP, YopM, or the other pYV-encoded factors. According to these results, the main action of the Yop virulon is to counteract the host cell pro-inflammatory response to the infection. YopP participates to this inhibition, whereas another pYV-encoded factor appears to also be involved in this down-regulation. Besides, YopM was found to induce the regulation of genes involved in cell cycle and cell growth, revealing for the first time an in vitro effect for YopM. In addition to YopM, other pYV factors distinct from YopP affected the expression of genes involved in cycling. In conclusion, these results provide new insight into the mechanisms of Yersinia pathogenicity by identifying the changes in host genes expression after infection and highlight the concerted actions of the different Yop effectors.
Yop毒力蛋白复合物由一个完整的III型分泌系统和分泌蛋白组成，它使耶尔森氏菌属的细菌能够抵抗宿主的非特异性免疫反应。这种毒力蛋白复合物由小肠结肠炎耶尔森氏菌中一种名为pYV的质粒编码，能使胞外细菌将六种Yop效应蛋白（YopE、-H、-T、-O、-P、-M）注入宿主细胞。为了研究YopP、YopM以及其他pYV编码因子在宿主细胞基因表达中的作用，我们使用微阵列技术对感染的小鼠巨噬细胞中的转录组变化进行了表征。用无毒力（pYV(-)）、野生型（pYV(+)）或小肠结肠炎耶尔森氏菌的两个基因敲除突变体（yopP(-)和yopM(-)）感染PU5-1.8巨噬细胞。监测了6657个基因对小肠结肠炎耶尔森氏菌感染的表达变化。其中，857个基因受到影响，其中339个基因受到Yop毒力蛋白复合物作用的特异性调控。对这339个基因的进一步分析确定了YopP、YopM或其他pYV编码因子的特异性靶点。根据这些结果，Yop毒力蛋白复合物的主要作用是对抗宿主细胞对感染的促炎反应。YopP参与了这种抑制作用，而另一个pYV编码因子似乎也参与了这种下调过程。此外，发现YopM可诱导参与细胞周期和细胞生长的基因的调控，首次揭示了YopM的体外效应。除YopM外，其他不同于YopP的pYV因子也影响了参与细胞周期的基因的表达。总之，这些结果通过确定感染后宿主基因表达的变化，为耶尔森氏菌致病性机制提供了新的见解，并突出了不同Yop效应蛋白的协同作用。
