Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica.
Departamento de Bioquímica, Escuela de Medicina, Universidad de Costa Rica, San José, Costa Rica.
Front Cell Infect Microbiol. 2023 Oct 27;13:1278718. doi: 10.3389/fcimb.2023.1278718. eCollection 2023.
Neutrophil extracellular traps (NETs) are networks of DNA and various microbicidal proteins released to kill invading microorganisms and prevent their dissemination. However, a NETs excess is detrimental to the host and involved in the pathogenesis of various inflammatory and immunothrombotic diseases. is a widely distributed pathogen associated with several animal and human diseases, that produces many exotoxins, including the phospholipase C (CpPLC), the main virulence factor in gas gangrene. During this disease, CpPLC generates the formation of neutrophil/platelet aggregates within the vasculature, favoring an anaerobic environment for growth. This work demonstrates that CpPLC induces NETosis in human neutrophils. Antibodies against CpPLC completely abrogate the NETosis-inducing activity of recombinant CpPLC and secretome. CpPLC induces suicidal NETosis through a mechanism that requires calcium release from inositol trisphosphate receptor (IP) sensitive stores, activation of protein kinase C (PKC), and the mitogen-activated protein kinase/extracellular signal-regulated kinase (MEK/ERK) pathways, as well as the production of reactive oxygen species (ROS) by the metabolism of arachidonic acid. Proteomic analysis of the secretome identified 40 proteins, including a DNAse and two 5´-nucleotidases homologous to virulence factors that could be relevant in evading NETs. We suggested that in gas gangrene this pathogen benefits from having access to the metabolic resources of the tissue injured by a dysregulated intravascular NETosis and then escapes and spreads to deeper tissues. Understanding the role of NETs in gas gangrene could help develop novel therapeutic strategies to reduce mortality, improve muscle regeneration, and prevent deleterious patient outcomes.
中性粒细胞胞外诱捕网（NETs）是一种由 DNA 和各种杀菌蛋白组成的网络，用于杀死入侵的微生物并防止其传播。然而，NETs 的过度产生对宿主有害，并与各种炎症和免疫血栓性疾病的发病机制有关。 是一种广泛分布的病原体，与多种动物和人类疾病有关，它产生许多外毒素，包括磷脂酶 C（CpPLC），这是气性坏疽的主要毒力因子。在这种疾病中，CpPLC 导致中性粒细胞/血小板在血管内聚集，有利于 生长的厌氧环境。这项工作表明，CpPLC 诱导人中性粒细胞发生 NETosis。针对 CpPLC 的抗体完全消除了重组 CpPLC 和 分泌组的诱导 NETosis 活性。CpPLC 通过一种需要肌醇三磷酸受体（IP）敏感储存钙离子释放、蛋白激酶 C（PKC）和丝裂原激活蛋白激酶/细胞外信号调节激酶（MEK/ERK）途径激活以及花生四烯酸代谢产生活性氧（ROS）的机制诱导自杀性 NETosis。对 分泌组的蛋白质组学分析鉴定了 40 种蛋白质，包括一种 DNA 酶和两种与可能逃避 NETs 的毒力因子同源的 5´-核苷酸酶。我们认为，在气性坏疽中，这种病原体受益于能够获得由血管内 NETosis 失调引起的组织损伤的代谢资源，然后逃脱并传播到更深的组织。了解 NETs 在气性坏疽中的作用可能有助于开发新的治疗策略，以降低死亡率、促进肌肉再生并防止患者出现不良后果。
