Huang Xiaonan, Hu Zhen, Shang Weilong, Chen Juan, Hu Qiwen, Zhou Yumin, Ding Ruolan, Yin Jing, Li Mengyang, Liu He, Dou Jianxiong, Peng Huagang, Rao Yifan, Liu Lu, Wang Yuting, Tan Li, Yang Yuhua, Wu Jianghong, Xiao Chuan, Yang Yi, Rao Xiancai
Department of Microbiology, College of Basic Medical Sciences, Key Laboratory of Microbial Engineering under the Educational Committee in Chongqing, Army Medical University, Chongqing, China.
Department of Pharmacy, Xinqiao Hospital, Army Medical University, Chongqing, China.
J Extracell Vesicles. 2025 May;14(5):e70077. doi: 10.1002/jev2.70077.
Bacterial extracellular vesicles (EVs) are natural reservoirs of biological active substances. They exhibit promising application in developing bioproducts such as vaccine, drug-delivery system and anticancer agent. However, the low yield of naturally secreted EVs during bacterial growth is a bottleneck factor that restricts EV applications. In this study, we showed that sub-minimum inhibitory concentration (MIC) of β-lactams boosted EV production in various Staphylococcus aureus strains. The expression of penicillin-binding protein (PBP) genes increased after β-lactam treatment, and the inactivation of alternative PBPs promoted EV secretion of S. aureus. We also demonstrated that sub-MIC β-lactams promoted EV production via a reactive oxygen species (ROS)-dependent pathway. Deletion of redundant pbp genes enhanced oxacillin (OXA)-stimulated ROS levels. Transcriptomic and lipidomic analyses revealed that OXA-induced ROS triggered lipid metabolic reprogramming in S. aureus. Particularly, ROS promoted lipid peroxidation (LPO) and increased the biosynthesis of phosphatidic acid (PA) and lipoteichoic acid (LTA) that contributed to EV generation. Furthermore, OXA treatment altered the diversity of EV-loaded proteins. OXA-treated EVs induced stronger Dengue EDIII-specific antibodies in BALB/c mice than did EVs. Overall, this study provided mechanic insights into β-lactam-promoted EV production in S. aureus, and highlighted the potential strategies to prepare EVs for various applications.
细菌细胞外囊泡（EVs）是生物活性物质的天然储存库。它们在开发生物制品（如疫苗、药物递送系统和抗癌剂）方面具有广阔的应用前景。然而，细菌生长过程中天然分泌的EVs产量低是限制其应用的一个瓶颈因素。在本研究中，我们发现β-内酰胺类药物的亚最小抑菌浓度（MIC）可提高各种金黄色葡萄球菌菌株的EV产量。β-内酰胺类药物处理后，青霉素结合蛋白（PBP）基因的表达增加，替代PBP的失活促进了金黄色葡萄球菌的EV分泌。我们还证明，亚MIC的β-内酰胺类药物通过依赖活性氧（ROS）的途径促进EV产生。冗余pbp基因的缺失增强了苯唑西林（OXA）刺激的ROS水平。转录组学和脂质组学分析表明，OXA诱导的ROS触发了金黄色葡萄球菌的脂质代谢重编程。特别是，ROS促进了脂质过氧化（LPO），并增加了有助于EV生成的磷脂酸（PA）和脂磷壁酸（LTA）的生物合成。此外，OXA处理改变了EV负载蛋白的多样性。与未处理的EVs相比，OXA处理的EVs在BALB/c小鼠中诱导产生更强的登革热EDIII特异性抗体。总体而言，本研究为β-内酰胺类药物促进金黄色葡萄球菌EV产生提供了机制见解，并突出了制备用于各种应用的EVs的潜在策略。
