Abstract：
Legionella pneumophila is an opportunistic pathogen responsible for Legionnaires\' disease or Legionellosis. This bacterium is found in the environment interacting with free-living amoebae such as Acanthamoeba castellanii. Until now, proteomic analyses have been done in amoebae infected with L. pneumophila but focused on the Legionella-containing vacuole. In this study, we propose a global proteomic analysis of the A. castellanii proteome following infection with L. pneumophila wild-type (WT) or with an isogenic ΔdotA mutant strain, which is unable to replicate intracellularly. We found that infection with L. pneumophila WT leads to reduced levels of A. castellanii proteins associated with lipid homeostasis/metabolism, GTPase regulation, and kinase. The levels of organelle-associated proteins were also decreased during infection. Legionellapneumophila WT infection leads to increased levels of proteins associated with polyubiquitination, folding or degradation, and antioxidant activities. This study reinforces our knowledge of this too little explored but so fundamental interaction between L. pneumophila and A. castellanii, to understand how the bacterium could resist amoeba digestion.
摘要：
嗜肺军团菌是导致军团菌病或军团菌病的机会性病原体。这种细菌存在于与自由生活的变形虫相互作用的环境中，例如castellanii。直到现在,已经在感染了嗜肺乳杆菌的变形虫中进行了蛋白质组学分析，但重点是含军团菌的液泡。在这项研究中,我们提出了一个全面的蛋白质组学分析后感染嗜肺乳杆菌野生型（WT）或等基因ΔdotA突变株，无法在细胞内复制。我们发现感染嗜肺乳杆菌WT会导致与脂质稳态/代谢相关的A.castellanii蛋白水平降低，GTP酶调节和激酶。感染期间细胞器相关蛋白的水平也降低。嗜肺支原体WT感染导致与蛋白质多泛素化相关的蛋白质水平增加，折叠或降解和抗氧化活性。这项研究加强了我们对肺炎克雷伯氏菌和卡斯特兰氏杆菌之间这种很少探索但如此基本的相互作用的认识，了解细菌如何抵抗变形虫的消化。
