Exploring potential virulence regulators in Paracoccidioides brasiliensis isolates of varying virulence through quantitative proteomics

Paracoccidioides brasiliensis is the agent of paracoccidioidomycosis, an important systemic mycosis in Latin America. Few virulence factors have been identified for this pathogen. In this study, we quantitatively evaluated the protein composition of P. brasiliensis in the yeast phase using minimal and rich media to obtain a better understanding of its virulence and to gain new insights into pathogen adaptation strategies. This analysis was performed on two isolates of the Pb18 strain showing distinct infection profiles in B10.A mice. Using liquid chromatography/tandem mass spectrometry (LC-MS/MS) analysis, we identified and quantified 317 proteins in minimal medium, 29 of which were overexpressed in virulent Pb18. In rich medium, 29 out of 214 identified proteins were over-expressed in the virulent fungus. Alcohol dehydrogenase, mitochondrial peroxiredoxin PRX1 and protein vacuolar ATP synthase catalytic subunit A were up-regulated in virulent Pb18 in both media, suggesting potential roles of these proteins in virulence regulation in P. brasiliensis. Proteins up-regulated in both isolates were grouped according to their functional categories. Virulent Pb18 undergoes metabolic reorganization and increased expression of proteins involved in fermentative respiration. This approach allowed us to identify potential virulence regulators and to understand how Paracoccidioides modulates the host-pathogen interaction to its advantage. Data are available via ProteomeXchange Consortium with identifier PXD000804.

巴西副球孢子菌（Paracoccidioides brasiliensis）是副球孢子菌病（paracoccidioidomycosis）的致病菌，该病是拉丁美洲地区一种重要的系统性真菌病。迄今针对该病原菌鉴定得到的毒力因子寥寥无几。本研究采用基础培养基与富营养培养基，对酵母相巴西副球孢子菌的蛋白质组成进行定量分析，以期深入解析其毒力机制，并为病原菌适应策略研究提供新视角。本次分析针对两株在B10.A小鼠中表现出显著感染表型差异的Pb18菌株展开。本研究采用液相色谱-串联质谱（liquid chromatography/tandem mass spectrometry，LC-MS/MS）技术，在基础培养基中鉴定并定量了317种蛋白质，其中29种在强毒力Pb18菌株中呈过表达状态；在富营养培养基中，214种被鉴定蛋白质里有29种在强毒力真菌中过表达。乙醇脱氢酶、线粒体过氧化物酶PRX1以及液泡ATP合酶催化亚基A蛋白在两种培养基的强毒力Pb18菌株中均呈现上调表达，提示这些蛋白质可能参与巴西副球孢子菌的毒力调控过程。研究人员按照功能类别对两株菌株中均上调表达的蛋白质进行了归类分析。结果显示，强毒力Pb18菌株发生了代谢重编程，且参与发酵呼吸过程的蛋白质表达水平显著升高。本研究方法成功鉴定出潜在的毒力调控因子，并阐明了巴西副球孢子菌如何调控宿主-病原菌互作以利于自身定植。相关数据集已通过蛋白质组交换联盟（ProteomeXchange Consortium）公开，数据集标识符为PXD000804。