Pessanha de Carvalho Laís, Tenório de Melo Edésio José
Laboratory of Tissue and Cell Biology, State University of North Fluminense - Darcy Ribeiro, Campos dos Goytacazes, Rio de Janeiro 28013-602 Brazil.
J Parasit Dis. 2018 Sep;42(3):372-381. doi: 10.1007/s12639-018-1010-2. Epub 2018 May 29.
is transmitted to vertebrate hosts during the feeding of blood-sucking insects. After the invasion of host cells, the parasite resides within the parasitophorous vacuole until to escape to host cytoplasm and to proliferate, establishing an infection. Studies demonstrated that some intracellular parasites have to acquire all essential nutrients as well as transition metals from the host cell to be pathogenic, to maintain the homeostasis and to replicate. The present study investigated the progressive steps of the intracellular parasite development and establishment of infection in the presence of ZnCl, CdCl and HgCl. LLC-MK2 cells were infected with trypomastigotes during 6-84 h to investigate the steps of intracellular parasite development. After the host cells were infected during 12 h and treated with metals during 24 or 60 h or they were treated for 24 h and cultured for 72 h more to observe the reversibility. The results showed that the non-synchronous invasion of trypomastigotes resulted in an increasing number of intracellular parasites in intermediary forms (until 24 h post-infection), the appearance (from 36 h) and proliferation (84 h) of the amastigotes. The 24 h-treatments were not enough to impair parasite escape to the host cytoplasm and reproduction. However, 60 h of incubations led to a significant reduction in parasite numbers, as well as the reversibility assays. In conclusion, new insights about the intracellular development in the presence of metals were provided, and further studies should be performed to investigate the events involved in parasite death and elimination.
在吸血昆虫吸血过程中传播给脊椎动物宿主。侵入宿主细胞后，寄生虫驻留在寄生泡内，直到逃到宿主细胞质中增殖，从而建立感染。研究表明，一些细胞内寄生虫必须从宿主细胞获取所有必需营养物质以及过渡金属，才能致病、维持体内平衡并进行复制。本研究调查了在氯化锌、氯化镉和氯化汞存在的情况下细胞内寄生虫发育和感染建立的渐进步骤。用锥鞭毛体感染LLC-MK2细胞6至84小时，以研究细胞内寄生虫发育的步骤。宿主细胞感染12小时后，用金属处理24或60小时，或者处理24小时后再培养72小时以观察可逆性。结果表明，锥鞭毛体的非同步侵入导致中间形式的细胞内寄生虫数量增加（直到感染后24小时），无鞭毛体出现（从36小时开始）并增殖（84小时）。24小时的处理不足以损害寄生虫逃到宿主细胞质和繁殖的能力。然而，60小时的孵育导致寄生虫数量显著减少，以及可逆性分析。总之，本研究提供了关于金属存在下细胞内发育的新见解，应进一步开展研究以调查寄生虫死亡和清除所涉及的事件。
