Albuquerque Priscila Costa, Nakayasu Ernesto S, Rodrigues Marcio L, Frases Susana, Casadevall Arturo, Zancope-Oliveira Rosely M, Almeida Igor C, Nosanchuk Joshua D
Instituto de Pesquisa Clinica Evandro Chagas, Fundação Oswaldo Cruz, RJ Brazil.
Cell Microbiol. 2008 Aug;10(8):1695-710. doi: 10.1111/j.1462-5822.2008.01160.x. Epub 2008 Apr 17.
Vesicular secretion of macromolecules has recently been described in the basidiomycete Cryptococcus neoformans, raising the question as to whether ascomycetes similarly utilize vesicles for transport. In the present study, we examine whether the clinically important ascomycete Histoplasma capsulatum produce vesicles and utilized these structures to secrete macromolecules. Transmission electron microscopy (TEM) shows transcellular secretion of vesicles by yeast cells. Proteomic and lipidomic analyses of vesicles isolated from culture supernatants reveal a rich collection of macromolecules involved in diverse processes, including metabolism, cell recycling, signalling and virulence. The results demonstrate that H. capsulatum can utilize a trans-cell wall vesicular transport secretory mechanism to promote virulence. Additionally, TEM of supernatants collected from Candida albicans, Candida parapsilosis, Sporothrix schenckii and Saccharomyces cerevisiae documents that vesicles are similarly produced by additional ascomycetes. The vesicles from H. capsulatum react with immune serum from patients with histoplasmosis, providing an association of the vesicular products with pathogenesis. The findings support the proposal that vesicular secretion is a general mechanism in fungi for the transport of macromolecules related to virulence and that this process could be a target for novel therapeutics.
最近在担子菌新生隐球菌中描述了大分子的囊泡分泌,这就提出了一个问题,即子囊菌是否同样利用囊泡进行运输。在本研究中,我们研究了临床上重要的子囊菌荚膜组织胞浆菌是否产生囊泡并利用这些结构分泌大分子。透射电子显微镜(TEM)显示酵母细胞通过跨细胞方式分泌囊泡。对从培养上清液中分离的囊泡进行蛋白质组学和脂质组学分析,发现了大量参与各种过程的大分子,包括代谢、细胞循环、信号传导和毒力。结果表明,荚膜组织胞浆菌可以利用跨细胞壁囊泡运输分泌机制来增强毒力。此外,对白色念珠菌、近平滑念珠菌、申克孢子丝菌和酿酒酵母培养上清液的TEM观察表明,其他子囊菌也同样产生囊泡。荚膜组织胞浆菌的囊泡与组织胞浆菌病患者的免疫血清发生反应,表明囊泡产物与发病机制有关。这些发现支持了囊泡分泌是真菌中运输与毒力相关大分子的一种普遍机制的观点,并且这一过程可能成为新型治疗方法的靶点。