Effects of the disruption of the HSP70-II gene on the growth, morphology, and virulence of Leishmania infantum promastigotes
Effects of the disruption of the HSP70-II gene on the growth, morphology, and virulence of Leishmania infantum promastigotes
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DOI：
10.2436/20.1501.01.47
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发表时间：
2008-06-01
影响因子：
3.1
通讯作者：
Requena, Jose M.
中科院分区：
文献类型：
--
作者：
Folgueira, Cristina;Carrion, Javier;Requena, Jose M.
70 kDa热休克蛋白(HSP70)在原核生物和真核生物中高度保守，不仅在应激条件下，而且在正常条件下，在多种细胞功能中都发挥着重要作用。在原生动物婴儿利什曼原虫中，内脏利什曼病的病原体HSP70由两个HSP70基因编码。在这里，我们描述了缺乏HSP70-II(Delta HSP70-II)的前鞭毛体的表型变化。当前鞭毛体进入稳定期时，HSP70-HSP70的缺失引起了生长的重大变化。此外，在Delta HSP70-II突变培养物中经常观察到异常形式。用流式细胞仪检测Delta HSP70-II突变体细胞在G(2)/M期的积聚。此外，Delta HSP70-II前鞭毛体在巨噬细胞内的增殖能力有限，尽管与野生型细胞的附着和摄取没有显著差异。此外，HSP70-II在BALB/c小鼠实验性感染中高度减弱。在重新表达HSP70-II的突变体中，生长速度恢复，正常形态恢复，与巨噬细胞的相互作用增加。然而，重新表达HSP70-II的前鞭毛体并没有恢复其毒力。总体而言，这些数据强调了HSP70-II表达在利什曼原虫毒力中所起的重要作用，表明该基因是治疗干预的有希望的靶点。
The 70-kDa heat shock protein (HSP70) is highly conserved among both prokaryotes and eukaryotes and plays essential roles in diverse cellular functions not only under stress but also under normal conditions. In the protozoan Leishmania infantum, the causative agent of visceral leishmaniasis, HSP70 is encoded by two HSP70 genes. Here, we describe the phenotypic alterations of HSP70-II-deficient (Delta hsp70-II) promastigotes. The absence of HSP70-Hcaused a major alteration in growth as the promastigotes reached stationary phase. In addition, aberrant forms were frequently observed in Delta hsp70-II mutant cultures. An accumulation of cells in the G(2)/M phase in cultures of the Delta hsp70-II mutant was determined by flow cytometry. Furthermore, Delta hsp70-II promastigotes showed a limited capacity of multiplication within macrophages, even though attachment to and uptake by macrophages did not differ significantly from the wild-type. Moreover, HSP70-II was highly attenuated in BALB/c mouse experimental infections. In mutants re-expressing HSP70-II, the growth rate was restored, the normal morphology was recovered, and interactions with macrophages increased. However, promastigotes reexpressing HSP70-II did not recover their virulence. Overall, these data highlight the essential role played by HSP70-II expression in Leishmania virulence, pointing to this gene as a promising target for therapeutic interventions.