Transcriptome analysis of Neisseria meningitidis in human whole blood and mutagenesis studies identify virulence factors involved in blood survival.
Transcriptome analysis of Neisseria meningitidis in human whole blood and mutagenesis studies identify virulence factors involved in blood survival.
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人类全血和诱变研究中脑膜炎的转录组分析确定了与血液存活有关的毒力因子。
DOI：
10.1371/journal.ppat.1002027
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发表时间：
2011-05
期刊：
影响因子：
6.7
通讯作者：
Serruto D
中科院分区：
文献类型：
--
作者：
Echenique-Rivera H;Muzzi A;Del Tordello E;Seib KL;Francois P;Rappuoli R;Pizza M;Serruto D
脑膜炎奈瑟氏菌（Nm）在感染过程中会遇到宿主体内的多种环境，这使得快速适应成为脑膜炎球菌生存的关键因素。尽管侵入血流在脑膜炎球菌疾病过程中很重要，但人们对 Nm 如何适应以允许在血液中存活和生长知之甚少。为了解决这个问题，我们使用人类全血感染的离体模型进行了时程转录组分析。我们观察到 Nm 改变了基因组约 30% 的 ORF 的表达，并且在转录调节因子、转运和结合蛋白、能量代谢和表面暴露的毒力因子的表达中观察到了主要的动态变化。特别是，我们发现编码调节因子 Fur 的基因以及编码铁吸收系统的所有基因均显着上调。对编码参与 Nm 发病机制的表面暴露蛋白的调控基因的分析使我们能够更好地了解用于规避宿主防御的机制。在血液感染期间，Nm 激活编码 H 因子结合蛋白、fHbp 和 NspA 的基因，编码 SodC、Kat 和 AniA 等解毒酶的基因，以及一些可能在血液存活中发挥作用的特征较少的表面暴露蛋白。通过对上调基因子集的诱变研究，我们能够识别出对人类血液中生存至关重要的新蛋白质，并确定先前已知的毒力因子在帮助血液中生存方面的其他作用。缺乏编码假设蛋白 NMB1483 和表面暴露蛋白 NalP、Mip 和 NspA、Fur 调节剂、转铁蛋白结合蛋白 TbpB 和 L-乳酸渗透酶 LctP 的基因的 Nm 突变株对人血杀伤敏感。增加对 Nm 如何响应血液适应的知识也可能有助于制定诊断和治疗策略，以控制由这种微生物引起的破坏性疾病。 脑膜炎奈瑟菌 (Nm) 是一种人类独有的病原体，也是全世界细菌性脑膜炎和败血症的主要原因。宿主与病原体相互作用期间细菌转录组的表征是了解细菌病原体感染过程的基本步骤。尽管脑膜炎球菌败血症很严重，但人们对 Nm 如何适应以使其在人类血液中存活和生长知之甚少。在这项工作中，我们报告了 Nm 在人全血中孵育后的转录反应。基因表达结果表明，基因组的很大一部分ORF（约30%）在人血液中孵育后出现差异表达，其中涉及Nm代谢对血液的适应以及毒力和破坏宿主免疫系统的基因被上调。将转录分析与缺失突变体和补充菌株的产生和表征相结合，我们确定了对人类血液中生存重要的新因素。对血液中 Nm 的首次基因表达分析显着增加了我们对这种细菌如何响应人类血液并导致败血症的了解。我们的结果还提供了有关基因功能的新信息，并可能最终有助于制定控制这种毁灭性疾病的诊断和治疗策略。
During infection Neisseria meningitidis (Nm) encounters multiple environments within the host, which makes rapid adaptation a crucial factor for meningococcal survival. Despite the importance of invasion into the bloodstream in the meningococcal disease process, little is known about how Nm adapts to permit survival and growth in blood. To address this, we performed a time-course transcriptome analysis using an ex vivo model of human whole blood infection. We observed that Nm alters the expression of ≈30% of ORFs of the genome and major dynamic changes were observed in the expression of transcriptional regulators, transport and binding proteins, energy metabolism, and surface-exposed virulence factors. In particular, we found that the gene encoding the regulator Fur, as well as all genes encoding iron uptake systems, were significantly up-regulated. Analysis of regulated genes encoding for surface-exposed proteins involved in Nm pathogenesis allowed us to better understand mechanisms used to circumvent host defenses. During blood infection, Nm activates genes encoding for the factor H binding proteins, fHbp and NspA, genes encoding for detoxifying enzymes such as SodC, Kat and AniA, as well as several less characterized surface-exposed proteins that might have a role in blood survival. Through mutagenesis studies of a subset of up-regulated genes we were able to identify new proteins important for survival in human blood and also to identify additional roles of previously known virulence factors in aiding survival in blood. Nm mutant strains lacking the genes encoding the hypothetical protein NMB1483 and the surface-exposed proteins NalP, Mip and NspA, the Fur regulator, the transferrin binding protein TbpB, and the L-lactate permease LctP were sensitive to killing by human blood. This increased knowledge of how Nm responds to adaptation in blood could also be helpful to develop diagnostic and therapeutic strategies to control the devastating disease cause by this microorganism. Neisseria meningitidis (Nm) is an exclusively human pathogen and a leading cause of bacterial meningitis and septicemia worldwide. Characterization of the bacterial transcriptome during host-pathogen interactions is a fundamental step for understanding the infectious processes of bacterial pathogens. Despite the severity of meningococcal sepsis, little is known about how Nm adapts to permit survival and growth in human blood. In this work we report the transcriptional response of Nm after incubation in human whole blood. The gene expression results indicate that a significant part of the ORFs of the genome (≈30%) is differentially expressed after incubation in human blood, with genes involved in adaptation of Nm metabolism to blood and in virulence and subversion of the host immune system being up-regulated. Combining transcriptional analysis with the generation and characterization of deletion mutants and complementing strains, we identify new factors important for survival in human blood. This first gene expression analysis of Nm in blood significantly increases our knowledge of how this bacterium responds to human blood and causes septicemia. Our results also provide new information on gene function and may ultimately help in the development of diagnostic and therapeutic strategies to control this devastating disease.
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影响因子：
3.1
作者：
Exley, RM;Goodwin, L;Tang, CM
通讯作者：
Tang, CM
DOI：
10.1073/pnas.0603940103
发表时间：
2006-07-18
影响因子：
11.1
作者：
Giuliani, Marzia M.;Adu-Bobie, Jeannette;Pizza, Mariagrazia
通讯作者：
Pizza, Mariagrazia
影响因子：
6
作者：
Graham, MR;Virtaneva, K;Musser, JM
通讯作者：
Musser, JM
影响因子：
14.9
作者：
Haft, DH;Loftus, BJ;White, O
通讯作者：
White, O
影响因子：
3.1
作者：
Dunn, KLR;Farrant, JL;Kroll, JS
通讯作者：
Kroll, JS