PDF(Pubmed)
Abstract：
The increasing prevalence of invasive fungal pathogens is dramatically changing the clinical landscape of infectious diseases, posing an imminent threat to public health. Specifically, Cryptococcus neoformans, the human opportunistic pathogen, expresses elaborate virulence mechanisms and is equipped with sophisticated adaptation strategies to survive in harsh host environments. This study extensively characterizes Wos2, an Hsp90 co-chaperone homolog, featuring bilateral functioning for both cryptococcal adaptation and the resulting virulence response. In this study, we evaluated the proteome and secretome signatures associated with wos2 deletion in enriched and infection-mimicking conditions to reveal Wos2-dependent regulation of the oxidative stress response through global translational reprogramming. The wos2Δ strain demonstrates defective intracellular and extracellular antioxidant protection systems, measurable through a decreased abundance of critical antioxidant enzymes and reduced growth in the presence of peroxide stress. Additional Wos2-associated stress phenotypes were observed upon fungal challenge with heat shock, osmotic stress, and cell membrane stressors. We demonstrate the importance of Wos2 for intracellular lifestyle of C. neoformans during in vitro macrophage infection and provide evidence for reduced phagosomal replication levels associated with wos2Δ. Accordingly, wos2Δ featured significantly reduced virulence within impacting fungal burden in a murine model of cryptococcosis. Our study highlights a vulnerable point in the fungal chaperone network that offers a therapeutic opportunity to interfere with both fungal virulence and fitness.IMPORTANCEThe global impact of fungal pathogens, both emerging and emerged, is undeniable, and the alarming increase in antifungal resistance rates hampers our ability to protect the global population from deadly infections. For cryptococcal infections, a limited arsenal of antifungals and increasing rates of resistance demand alternative therapeutic strategies, including an anti-virulence approach, which disarms the pathogen of critical virulence factors, empowering the host to remove the pathogens and clear the infection. To this end, we apply state-of-the-art mass spectrometry-based proteomics to evaluate the impact of a recently defined novel co-chaperone, Wos2, toward cryptococcal virulence using in vitro and in vivo models of infection. We explore global proteome and secretome remodeling driven by the protein and uncover the novel role in modulating the fungal oxidative stress response. Complementation of proteome findings with in vitro infectivity assays demonstrated the protective role of Wos2 within the macrophage phagosome, influencing fungal replication and survival. These results underscore differential cryptococcal survivability and weakened patterns of dissemination in the absence of wos2. Overall, our study establishes Wos2 as an important contributor to fungal pathogenesis and warrants further research into critical proteins within global stress response networks as potential druggable targets to reduce fungal virulence and clear infection.
摘要：
侵袭性真菌病原体的日益流行正在极大地改变感染性疾病的临床格局,对公众健康构成迫在眉睫的威胁。具体来说,新生隐球菌,人类机会病原体，表达复杂的毒力机制，并配备了复杂的适应策略，可以在恶劣的宿主环境中生存。这项研究广泛地描述了Wos2，一种Hsp90共同伴侣同源物，具有隐球菌适应和由此产生的毒力反应的双侧功能。在这项研究中,我们评估了富集条件和感染模拟条件下与wos2缺失相关的蛋白质组和分泌组特征,以揭示Wos2依赖性通过全局翻译重编程调节氧化应激反应.wos2Δ菌株显示出细胞内和细胞外抗氧化保护系统的缺陷，可通过减少关键抗氧化酶的丰度和在过氧化物胁迫存在下减少的生长来衡量。在用热休克进行真菌攻击时，观察到了其他Wos2相关的应激表型，渗透胁迫,和细胞膜应激源。我们证明了Wos2在体外巨噬细胞感染期间对新生梭菌细胞内生活方式的重要性，并提供了与wos2Δ相关的吞噬体复制水平降低的证据。因此，wos2Δ在隐球菌病鼠模型中，在影响真菌负担的情况下，毒力显着降低。我们的研究强调了真菌伴侣网络中的一个脆弱点，该网络提供了干扰真菌毒力和适应性的治疗机会。重要性真菌病原体的全球影响，既新兴又新兴，不可否认，抗真菌药物耐药率的惊人增长阻碍了我们保护全球人口免受致命感染的能力。对于隐球菌感染，有限的抗真菌剂和不断增加的耐药率需要替代治疗策略，包括一种抗毒的方法,解除病原体的关键毒力因子，授权宿主去除病原体并清除感染。为此,我们应用最先进的基于质谱的蛋白质组学来评估最近定义的新型共伴侣的影响，Wos2，使用体外和体内感染模型对隐球菌毒力。我们探索了由蛋白质驱动的全球蛋白质组和分泌组重塑，并揭示了在调节真菌氧化应激反应中的新作用。蛋白质组发现与体外感染性测定的补充证明了Wos2在巨噬细胞吞噬体中的保护作用，影响真菌复制和存活。这些结果强调了在没有wos2的情况下隐球菌的生存能力差异和传播模式减弱。总的来说,我们的研究将Wos2确定为真菌发病机制的重要促成因素,并有必要进一步研究全球应激反应网络中的关键蛋白作为降低真菌毒力和清除感染的潜在药物靶标.
