Laboratório de Estudos Integrados em Bioquímica Microbiana, Instituto de Microbiologia Professor Paulo de Góes, Cidade Universitária, Rio de Janeiro, Brazil.
Infect Immun. 2010 Apr;78(4):1601-9. doi: 10.1128/IAI.01171-09. Epub 2010 Feb 9.
Cryptococcus neoformans and distantly related fungal species release extracellular vesicles that traverse the cell wall and contain a varied assortment of components, some of which have been associated with virulence. Previous studies have suggested that these extracellular vesicles are produced in vitro and during animal infection, but the role of vesicular secretion during the interaction of fungi with host cells remains unknown. In this report, we demonstrate by fluorescence microscopy that mammalian macrophages can incorporate extracellular vesicles produced by C. neoformans. Incubation of cryptococcal vesicles with murine macrophages resulted in increased levels of extracellular tumor necrosis factor alpha (TNF-alpha), interleukin-10 (IL-10), and transforming growth factor beta (TGF-beta). Vesicle preparations also resulted in a dose-dependent stimulation of nitric oxide production by phagocytes, suggesting that vesicle components stimulate macrophages to produce antimicrobial compounds. Treated macrophages were more effective at killing C. neoformans yeast. Our results indicate that the extracellular vesicles of C. neoformans can stimulate macrophage function, apparently activating these phagocytic cells to enhance their antimicrobial activity. These results establish that cryptococcal vesicles are biologically active.
新型隐球菌和远缘真菌物种释放的细胞外囊泡可穿透细胞壁，其中包含各种成分，其中一些与毒力有关。先前的研究表明，这些细胞外囊泡在体外和动物感染期间产生，但真菌与宿主细胞相互作用过程中囊泡分泌的作用尚不清楚。在本报告中，我们通过荧光显微镜证明哺乳动物巨噬细胞可以摄取新型隐球菌产生的细胞外囊泡。隐球菌囊泡与鼠巨噬细胞孵育会导致细胞外肿瘤坏死因子-α（TNF-α）、白细胞介素-10（IL-10）和转化生长因子-β（TGF-β）水平升高。囊泡制剂也会导致吞噬细胞产生一氧化氮的剂量依赖性刺激，表明囊泡成分刺激巨噬细胞产生抗菌化合物。经处理的巨噬细胞对新型隐球菌酵母的杀伤作用更强。我们的结果表明，新型隐球菌的细胞外囊泡可以刺激巨噬细胞功能，显然激活这些吞噬细胞以增强其抗菌活性。这些结果表明隐球菌囊泡具有生物活性。
