Department of Microbiology, Immunology and Parasitology, Universidade Federal de São Paulo (UNIFESP), São Paulo 04023-062, Brazil.
Department of Pharmaceutical Sciences, Instituto de Ciências Ambientais, Químicas e Farmacêuticas (ICAQF), Universidade Federal de São Paulo (UNIFESP), Campus Diadema, Rua São Nicolau, 210, Diadema 09913-030, Brazil.
FEMS Yeast Res. 2018 Mar 1;18(2). doi: 10.1093/femsyr/foy007.
Paracoccidioides brasiliensis is the agent of paracoccidioidomycosis (PCM), a cause of disease in healthy and immunocompromised persons in Latin America. The infection begins after inhalation of the fungal propagules and their thermo-dimorphic shift to yeast form. The development of the disease depends on factors associated with the host immune response and the infectious agent's characteristics, especially virulence. The oxidative stress response is an important virulence attribute in several fungi. In this study, we assessed the enzymatic repertoire of responses to oxidative stress in the Pb18 isolate with different degrees of virulence. The virulence of attenuated Pb18 (aPb18) strain was recovered after several animal passages. Virulent strain (vPb18) showed an effective fungal oxidative stress response and several genes involved in response to oxidative stress were up-regulated in this isolate. These genes expressed the same profile when we recovered the phenotypic virulence in attenuated strain aPb18. Our study demonstrated that attenuated P. brasiliensis recovered their virulence after serial animal passages (vPb18), and this process positively modulated the fungus's antioxidant repertoire.
巴西副球孢子菌是副球孢子菌病（PCM）的病原体，在拉丁美洲，健康人和免疫功能低下者都会感染这种疾病。感染始于吸入真菌孢子及其向酵母形态的热二相转变。疾病的发展取决于与宿主免疫反应和感染因子特征相关的因素，特别是毒力。氧化应激反应是几种真菌中重要的毒力属性。在这项研究中，我们评估了不同毒力程度的 Pb18 分离株对氧化应激的酶反应谱。经过多次动物传代，减毒 Pb18（aPb18）菌株的毒力得以恢复。毒力株（vPb18）表现出有效的真菌氧化应激反应，并且该分离株中与氧化应激反应相关的几个基因被上调。当我们在减毒菌株 aPb18 中恢复表型毒力时，这些基因表达了相同的谱。我们的研究表明，经过连续的动物传代（vPb18），减毒巴西副球孢子菌恢复了其毒力，并且这个过程正向调节了真菌的抗氧化剂储备。
