Barluzzi R, Brozzetti A, Delfino D, Bistoni F, Blasi E
Department of Experimental Medicine and Biochemical Sciences, Microbiology Section, University of Perugia, Perugia, Italy.
Med Mycol. 1998 Aug;36(4):189-97.
Using two isogenic strains of Cryptococcus neoformans, we studied the influence of the capsule in C. neoformans microglial-cell interaction. We demonstrate that the acapsular mutant yeasts (CAP67) are more susceptible to phagocytosis and killing than encapsulated yeasts (B3501) by the murine microglial cells, BV-2. RT-PCR analysis showed that the pattern of gene transcripts for tumour necrosis factor alpha (TNF-a), interleukin (IL)-1beta, IL-6, IL-12p40 and granulocyte macrophage colony stimulating factor remains unchanged following BV-2 cell infection with CAP67 or B3501 yeasts. Moreover, no induction of TNF-alpha secretion occurs in BV-2 cells infected with either B3501 or CAP67 yeasts or exposed to glucuronoxylomannan (GXM) or galactoxylomannan (GalXM). Nevertheless, lipopolysaccharide-induced TNF-alpha secretion is downregulated by cell infection with B3501 or CAP67 yeasts or exposure to GXM or GalXM. Overall, by means of a continuous cell line, it appears that the C. neoformans capsule is detrimental to microglial cell antifungal activity, while no effect can be attributed to the capsule as trend of cytokine gene expression and TNF-alpha secretion.
我们使用两种新型隐球菌同基因菌株，研究了荚膜在新型隐球菌与小胶质细胞相互作用中的影响。我们证明，无荚膜突变酵母（CAP67）比有荚膜酵母（B3501）更容易被小鼠小胶质细胞BV-2吞噬和杀灭。逆转录聚合酶链反应（RT-PCR）分析表明，在用CAP67或B3501酵母感染BV-2细胞后，肿瘤坏死因子α（TNF-α）、白细胞介素（IL）-1β、IL-6、IL-12p40和粒细胞巨噬细胞集落刺激因子的基因转录模式保持不变。此外，在用B3501或CAP67酵母感染或暴露于葡糖醛酸木聚糖甘露糖（GXM）或半乳糖木聚糖甘露糖（GalXM）的BV-2细胞中，未发生TNF-α分泌的诱导。然而，脂多糖诱导的TNF-α分泌在被B3501或CAP67酵母感染或暴露于GXM或GalXM的细胞中被下调。总体而言，通过连续细胞系研究发现，新型隐球菌荚膜对小胶质细胞的抗真菌活性具有不利影响，而在细胞因子基因表达趋势和TNF-α分泌方面，荚膜没有影响。
