新生隐球菌是导致致命感染的人类真菌病原体,尤其是免疫系统低下的患者。由于长期的治疗方案和结构相似的农业应用而过度暴露于抗真菌药物削弱了目前抗真菌药物在临床上的功效。抗真菌耐药性的快速进化促使人们发现抑制真菌毒力决定子的新化合物,而不是直接杀死病原体,作为克服疾病和减少抵抗的选择性压力的替代策略。这里,我们评估了淡水贻贝提取物(原油和澄清)对产生明确定义的毒力决定子(即,耐热性,黑色素,胶囊,和生物膜)和氟康唑耐药性。我们证明了提取物对真菌耐热性的影响,胶囊生产,和生物膜的形成,以及在巨噬细胞存在下对氟康唑的敏感性。此外,我们测量了提取物对与真菌毒力决定子和氟康唑耐药性相关的商业肽酶(隐球菌直系同源物的家族代表)的抑制活性,并将这些表型发现与定量蛋白质组学分析相结合。我们的方法定义了每种治疗的不同特征,并验证了分级分离后从选定的提取物中对多糖胶囊的抗毒力作用的新机制。通过了解推动贻贝抗真菌活性的机制,我们可能会开发创新的治疗方案,以克服真菌感染,并提高耐药菌株对氟康唑的敏感性。重要的是,全球真菌感染的患病率和严重程度上升,随着抗真菌耐药性的增加,迫切需要新的策略来对抗真菌病原体和克服耐药性。严重的,我们目前克服真菌感染的方法是有限的,并推动了耐药性的发展;然而,解除病原体的毒力因子并促进宿主细胞清除的抗毒力方法是有希望的。这里,我们探索了来自淡水贻贝的天然化合物对经典真菌毒力决定子的功效,包括耐热性,胶囊生产,应激反应,和生物膜的形成。我们将我们的表型发现与最先进的基于质谱的蛋白质组学相结合,以确定这些抗真菌特性的机械驱动因素,并提出减少感染和支持耐药菌株治疗的创新途径。
Cryptococcus neoformans is a human fungal pathogen responsible for fatal infections, especially in patients with a depressed immune system. Overexposure to antifungal drugs due to prolonged treatment regimens and structure-similar applications in agriculture have weakened the efficacy of current antifungals in the clinic. The rapid evolution of antifungal resistance urges the discovery of new compounds that inhibit fungal virulence determinants, rather than directly killing the pathogen, as alternative strategies to overcome disease and reduce selective pressure toward resistance. Here, we evaluated the efficacy of freshwater mussel extracts (crude and clarified) against the production of well-defined virulence determinants (i.e., thermotolerance, melanin, capsule, and biofilm) and fluconazole resistance in C. neoformans. We demonstrated the extracts\' influence on fungal thermotolerance, capsule production, and biofilm formation, as well as susceptibility to fluconazole in the presence of macrophages. Additionally, we measured the inhibitory activity of extracts against commercial peptidases (family representatives of cryptococcal orthologs) related to fungal virulence determinants and fluconazole resistance, and integrated these phenotypic findings with quantitative proteomics profiling. Our approach defined distinct signatures of each treatment and validated a new mechanism of anti-virulence action toward the polysaccharide capsule from a selected extract following fractionation. By understanding the mechanisms driving the antifungal activity of
mussels, we may develop innovative treatment options to overcome fungal infections and promote susceptibility to fluconazole in resistant strains.
OBJECTIVE: As the prevalence and severity of global fungal infections rise, along with an increasing incidence of antifungal resistance, new strategies to combat fungal pathogens and overcome resistance are urgently needed. Critically, our current methods to overcome fungal infections are limited and drive the evolution of resistance forward; however, an anti-virulence approach to disarm virulence factors of the pathogen and promote host cell clearance is promising. Here, we explore the efficacy of natural compounds derived from freshwater
mussels against classical fungal virulence determinants, including thermotolerance, capsule production, stress response, and biofilm formation. We integrate our phenotypic discoveries with state-of-the-art mass spectrometry-based proteomics to identify mechanistic drivers of these antifungal properties and propose innovative avenues to reduce infection and support the treatment of resistant strains.