Borghi Sara, Antunes Ana, Haag Andreas F, Spinsanti Marco, Brignoli Tarcisio, Ndoni Enea, Scarlato Vincenzo, Delany Isabel
Immune Monitoring Laboratory, NYU Langone Health, 550 First Avenue, New York, NY 10016, USA.
Department of Pathology, NYU Grossman School of Medicine, 550 First Avenue, New York, NY 10016, USA.
Microorganisms. 2022 Apr 18;10(4):834. doi: 10.3390/microorganisms10040834.
Neisseria meningitidis colonizes the nasopharynx of humans, and pathogenic strains can disseminate into the bloodstream, causing septicemia and meningitis. NHBA is a surface-exposed lipoprotein expressed by all N. meningitidis strains in different isoforms. Diverse roles have been reported for NHBA in heparin-mediated serum resistance, biofilm formation, and adherence to host tissues. We determined that temperature controls the expression of NHBA in all strains tested, with increased levels at 30−32 °C compared to 37 °C. Higher NHBA expression at lower temperatures was measurable both at mRNA and protein levels, resulting in higher surface exposure. Detailed molecular analysis indicated that multiple molecular mechanisms are responsible for the thermoregulated NHBA expression. The comparison of mRNA steady-state levels and half-lives at 30 °C and 37 °C demonstrated an increased mRNA stability/translatability at lower temperatures. Protein stability was also impacted, resulting in higher NHBA stability at lower temperatures. Ultimately, increased NHBA expression resulted in higher susceptibility to complement-mediated killing. We propose that NHBA regulation in response to temperature downshift might be physiologically relevant during transmission and the initial step(s) of interaction within the host nasopharynx. Together these data describe the importance of NHBA both as a virulence factor and as a vaccine antigen during neisserial colonization and invasion.
脑膜炎奈瑟菌定殖于人类鼻咽部,致病菌株可扩散至血液中,引发败血症和脑膜炎。NHBA是一种表面暴露脂蛋白,所有脑膜炎奈瑟菌菌株均以不同的同种型表达。NHBA在肝素介导的血清抗性、生物膜形成以及对宿主组织的黏附中发挥着多种作用。我们确定温度可控制所有测试菌株中NHBA的表达,与37°C相比,在30 - 32°C时表达水平更高。在较低温度下,无论是mRNA水平还是蛋白质水平,均可检测到更高的NHBA表达,从而导致更高的表面暴露。详细的分子分析表明,多种分子机制负责NHBA的温度调节表达。对30°C和37°C时mRNA稳态水平和半衰期的比较表明,在较低温度下mRNA稳定性/可翻译性增加。蛋白质稳定性也受到影响,导致在较低温度下NHBA稳定性更高。最终,NHBA表达增加导致对补体介导杀伤的敏感性更高。我们认为,在传播过程以及宿主鼻咽部相互作用的初始步骤中,NHBA对温度下降的调节可能具有生理相关性。这些数据共同描述了NHBA作为毒力因子以及在奈瑟菌定殖和侵袭过程中作为疫苗抗原的重要性。