Mpn491, a secreted nuclease of Mycoplasma pneumoniae, plays a critical role in evading killing by neutrophil extracellular traps
Mpn491, a secreted nuclease of Mycoplasma pneumoniae, plays a critical role in evading killing by neutrophil extracellular traps
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DOI：
10.1111/cmi.12666
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发表时间：
2017-03-01
影响因子：
3.4
通讯作者：
Kuwano，Koichi
中科院分区：
文献类型：
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作者：
Yamamoto，Takeshi;Kida，Yutaka;Kuwano，Koichi
中性粒细胞作为先天免疫系统的第一道防线，在抗菌防御中发挥着重要作用。近年来，中性粒细胞胞外陷阱(Nets)的释放被认为是中性粒细胞对入侵微生物的一种杀伤机制。肺炎支原体是呼吸道感染的病原体，已被证明对中性粒细胞的体外杀菌具有抵抗力，提示该细菌可能绕过了Net的杀菌活性。在本研究中，我们调查了M。肺炎杆菌对Nets介导的中性粒细胞杀伤具有抵抗机制，并发现该细菌降解Nets诱导的uPonM。肺炎感染。篮网的降级能力。肺炎杆菌需要产生一种分泌型核酸酶Mpn491，该核酸酶能够利用镁离子作为其水解性的辅因子。此外，核酸酶的失活导致了对FM易感性的增加。肺炎对Net介导的中性粒细胞杀伤作用。结果表明，M。肺炎采用Mpn491作为逃避中性粒细胞杀伤机制的手段。
Neutrophils play an important role in antimicrobial defense as the first line of innate immune system. Recently, the release of neutrophil extracellular traps (NETs) has been identified as a killing mechanism of neutrophils against invading microbes.Mycoplasma pneumoniae, a causative agent of respiratory infection, has been shown to be resistant toin vitrokilling by neutrophils, suggesting that the bacterium might circumvent bactericidal activity of NETs. In this study, we investigated whetherM. pneumoniaepossesses resistance mechanisms against the NETs‐mediated killing of neutrophils and found that the bacterium degrades the NETs induced uponM. pneumoniaeinfection. The NETs‐degrading ability ofM. pneumoniaerequired the production of a secreted nuclease, Mpn491, capable of using Mg2+as a cofactor for its hydrolytic activity. Moreover, the inactivation of the nuclease resulted in increased susceptibility ofM. pneumoniaeto the NETs‐mediated killing of neutrophils. The results suggest thatM. pneumoniaeemploys Mpn491 as a means for evading the killing mechanism of neutrophils.