Zhang Yaling, Gong Shengwei, Xiong Kang, Yu Xiangtai, Mo Xinreng, Su Chang, Lu Yang
Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan, China.
Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China.
mSphere. 2024 Dec 19;9(12):e0091024. doi: 10.1128/msphere.00910-24. Epub 2024 Nov 27.
is an opportunistic human fungal pathogen that causes superficial mucosal and life-threatening bloodstream infections in immunocompromised individuals. Remodeling in cell wall components has been extensively exploited by fungal pathogens to adapt to host-derived stresses, as well as immune evasion. How this process contributes to pathogenicity is less understood. Here, we applied RNA sequencing and an invasive infection model to elucidate the prompt response of during infection. Fungal transcriptomes show a dramatic alteration in the expression of Srp1/Tip1-family cell wall structural proteins during systemic infection. Deletion of all six genes in this family ( and ) that are upregulated during infection leads to a significantly lower fungal burden in organs, as well as an attenuated virulence in the dextran sulfate sodium-induced colitis model. The sextuple mutant does not display any defect in response to host-derived stresses. Rather, deletion of all these six genes results in a lower cell surface exposure of an adhesin Epa1, which could contribute to its reduced adhesion to epithelial cells and cytotoxicity, as well as attenuated virulence. Our study reveals that cell wall remodeling triggered by the alteration in the expression of structural proteins is a key virulence attribute in that facilitates this fungus adhering to host cells and persisting in organs.IMPORTANCE is one of the most frequent causes of candidiasis after . While has been extensively studied, the mechanisms of infection and invasion of have not been fully elucidated. Using an infection model of systemic candidiasis and RNA sequencing, we show that there is a dramatic change in the expression of Srp1/Tip1-family genes during infection. Deletion of all six Srp1/Tip1-family genes that are upregulated during infection decreases the amount of cell wall-localized Epa1, probably reflecting the reduced adherence to epithelial cells and attenuated virulence in the sextuple mutant. These data suggest that alterations in the expression of Srp1/Tip1-family structural proteins trigger cell wall remodeling that increases the cell surface exposure of adhesins, such as Epa1, to promote virulence. Our study provides a pathogenic mechanism associated with in ensuring its sustenance and survival during infection.
是一种机会性人类真菌病原体,可在免疫功能低下的个体中引起浅表黏膜感染和危及生命的血流感染。真菌病原体广泛利用细胞壁成分的重塑来适应宿主来源的压力以及逃避免疫。这个过程如何导致致病性尚不太清楚。在这里,我们应用RNA测序和侵袭性感染模型来阐明感染期间的即时反应。真菌转录组显示,在全身感染期间,Srp1/Tip1家族细胞壁结构蛋白的表达发生了巨大变化。删除该家族中在感染期间上调的所有六个基因(和)会导致器官中的真菌负荷显著降低,以及在葡聚糖硫酸钠诱导的结肠炎模型中毒力减弱。六倍体突变体在对宿主来源的压力反应中没有表现出任何缺陷。相反,删除所有这六个基因会导致黏附素Epa1的细胞表面暴露减少,这可能导致其对上皮细胞的黏附减少、细胞毒性降低以及毒力减弱。我们的研究表明,由结构蛋白表达改变引发的细胞壁重塑是该真菌的一个关键毒力属性,有助于这种真菌黏附于宿主细胞并在器官中持续存在。重要性是念珠菌病发生后最常见的原因之一。虽然已经对进行了广泛研究,但其感染和侵袭机制尚未完全阐明。使用系统性念珠菌病感染模型和RNA测序,我们表明在感染期间Srp1/Tip1家族基因的表达有巨大变化。删除在感染期间上调的所有六个Srp1/Tip1家族基因会减少细胞壁定位的Epa1的量,这可能反映了六倍体突变体对上皮细胞的黏附减少和毒力减弱。这些数据表明,Srp1/Tip1家族结构蛋白表达的改变引发细胞壁重塑,增加了黏附素(如Epa1)的细胞表面暴露,从而促进毒力。我们的研究提供了一种与相关的致病机制,以确保其在感染期间的维持和存活。