HeLa cells as a model to study the invasiveness and biology of Legionella pneumophila.
HeLa cells as a model to study the invasiveness and biology of Legionella pneumophila.
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DOI：
10.1139/w98-023
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发表时间：
1998-05
影响因子：
2.8
通讯作者：
R. Garduño;Frederick D. Quinn;Paul S. Hoffman
中科院分区：
文献类型：
--
作者：
R. Garduño;Frederick D. Quinn;Paul S. Hoffman
建立了HeLa细胞作为模型系统来研究嗜肺军团菌的侵袭性和生物学。在该模型中，可以区分入侵和粘附; pneumophila是粘附性和侵袭性的，而无毒力菌株是粘附性的，但侵袭性差。入侵是迅速的，并不需要从头细菌蛋白质的合成，这表明入侵因子是组成型表达的毒力菌株。进入HeLa细胞需要肌动蛋白聚合和一个完整的微管细胞骨架，只有适度抑制100 mM葡萄糖或半乳糖的存在下。毒力L.嗜肺细胞内毒素的释放发生在布满核糖体的复杂内体中，并导致可能从裂解的HeLa细胞释放的载有游离细菌的囊泡的形成。这些游离囊泡（称为成熟囊泡）在Percoll的连续密度梯度中分离。分离的成熟囊泡中所含的细菌具有独特的包膜结构，并且高度粘附于HeLa细胞，这些特征与Giménez染色后的鲜红色外观相关（Giménez阳性）。在复杂的内体中窝藏的平板生长的军团菌和复制的军团菌显示典型的革兰氏阴性包膜，并在Giménez染色后染色为绿色（Giménez阴性）。慢性感染培养的HeLa细胞也建立了可能是一个有用的工具，研究长期的相互作用之间的有毒L。嗜肺菌和哺乳动物细胞。HeLa细胞构成了一个有价值的模型系统，提供了独特的机会，研究寄生虫定向的内吞作用，以及阶段特异性寄生虫的相互作用。
HeLa cells were established as a model system to study the invasiveness and biology of Legionella pneumophila. In this model, invasion could be distinguished from adherence; virulent strains of L. pneumophila were adherent and invasive, whereas nonvirulent strains were adherent but poorly invasive. Invasion was rapid and did not require de novo bacterial protein synthesis, suggesting that the invasion factor is constitutively expressed by virulent strains. Entry into HeLa cells required actin polymerization and an intact microtubule cytoskeleton and was only moderately inhibited by the presence of 100 mM glucose or galactose. Intracellular replication of virulent L. pneumophila took place in ribosome-studded complex endosomes and led to the formation of free bacteria-laden vesicles presumably released from lysed HeLa cells. These free vesicles (referred to as mature vesicles) were isolated in continuous density gradients of Percoll. The bacteria contained in the isolated mature vesicles had a unique envelope structure and were highly adherent to HeLa cells, characteristics that correlated with a bright red appearance after the Giménez stain (Giménez positive). Plate-grown legionellae and replicating legionellae, harboured in complex endosomes, displayed a typical Gram-negative envelope and stained green after the Giménez stain (Giménez negative). Chronically infected cultures of HeLa cells were also established that may be a useful tool for studying long-term interactions between virulent L. pneumophila and mammalian cells. HeLa cells constitute a valuable model system that offers unique opportunities to study parasite-directed endocytosis, as well as stage specific-parasite interactions.