Bacterial clearance in septic mice is modulated by MCP-1/CCL2 and nitric oxide.
Bacterial clearance in septic mice is modulated by MCP-1/CCL2 and nitric oxide.
复制标题
脓毒症小鼠的细菌清除受到 MCP-1/CCL2 和一氧化氮的调节。
DOI：
10.1097/shk.0b013e31827802b5
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发表时间：
2013-01
期刊：
影响因子：
--
通讯作者：
Castro-Faria-Neto HC
中科院分区：
文献类型：
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作者：
Gomes RN;Teixeira-Cunha MG;Figueiredo RT;Almeida PE;Alves SC;Bozza PT;Bozza FA;Bozza MT;Zimmerman GA;Castro-Faria-Neto HC
细菌清除是先天免疫应答最重要的有益结果之一。趋化因子是控制白细胞运输和活化的重要介质，而活性氧和活性氮是细菌杀伤的效应器。在本工作中，我们通过体内和体外感染模型研究单核细胞化学引诱蛋白1 (MCP-1)/CCL2和一氧化氮（NO）在脓毒症细菌清除中的作用。我们的研究结果显示，盲肠结扎穿刺致脓毒症后6 h小鼠腹腔MCP-1/CCL2和NO水平升高。抗mcp -1/CCL2单克隆抗体预处理可增加腹腔灌洗液中菌落形成单位（cfu）的数量。此外，经盲肠结扎和穿刺的CCR2 - / -小鼠腹膜液中CFU计数增加。用重组MCP-1/CCL2体外刺激腹腔巨噬细胞，可减少大肠杆菌攻击后上清中的CFU计数。相反，在相同的实验条件下，抗mcp -1/CCL2处理增加了CFU计数。MCP-1/CCL2和干扰素刺激培养的巨噬细胞对NO的产生具有协同作用。与野生型对照相比，LPS +干扰素刺激后，CCL2 - / -小鼠巨噬细胞的NO产量持续下降。最后，我们发现巨噬细胞与大肠杆菌孵育后，ERK抑制剂U0126增加了CFU数量，降低了细胞内NO水平。总之，我们首次证明MCP-1/CCL2在细菌清除中起关键作用，其机制涉及诱导NO合成酶的表达增加和ERK信号通路产生NO。
Bacterial clearance is one of the most important beneficial consequences of the innate immune response. Chemokines are important mediators controlling leukocyte trafficking and activation, whereas reactive oxygen and nitrogen species are effectors in bacterial killing. In the present work, we used in vivo and in vitro models of infections to study the role of monocyte chemoattractant protein 1 (MCP-1)/CCL2 and nitric oxide (NO) in the bacterial clearance in sepsis. Our results show that MCP-1/CCL2 and NO levels are increased in the peritoneal cavity of mice 6 h after sepsis induced by cecal ligation and puncture. Pretreatment with anti–MCP-1/CCL2 monoclonal antibodies increased the number of colony-forming units (CFUs) recovered in the peritoneal lavage fluid. Moreover, CFU counts were increased in the peritoneal fluid of CCR2−/− mice subjected to cecal ligation and puncture. In vitro stimulation of peritoneal macrophages with recombinant MCP-1/CCL2 reduced CFU counts in the supernatant after challenge with Escherichia coli. Conversely, treatment with anti–MCP-1/CCL2 increased CFU counts under the same experimental condition. Stimulation of cultured macrophages with MCP-1/CCL2 and interferon had a synergistic effect on NO production. Macrophages from CCL2−/− mice showed a consistent decrease in NO production when compared with wild-type controls after stimulation with LPS + interferon. Finally, we showed incubation of macrophages with E. coli, and the ERK inhibitor U0126 increased CFU numbers and decreased intracellular levels of NO. In conclusion, we demonstrated for the first time that MCP-1/CCL2 has a crucial role in the clearance of bacteria by mechanisms involving increased expression of inducible NO synthase and production of NO by ERK signaling pathways.