The adaptive potential of a survival artist: characterization of the in vitro interactions of Toxoplasma gondii tachyzoites with di-cationic compounds in human fibroblast cell cultures
The adaptive potential of a survival artist: characterization of the in vitro interactions of Toxoplasma gondii tachyzoites with di-cationic compounds in human fibroblast cell cultures
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DOI：
10.1017/s0031182011001776
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发表时间：
2012-02-01
期刊：
影响因子：
2.4
通讯作者：
Hemphill, Andrew
中科院分区：
文献类型：
--
作者：
Kropf, Christian;Debache, Karim;Hemphill, Andrew
研究了二阳离子戊烷脒类似物对刚地弓形虫（RH和Me49背景）的影响。72小时生长试验表明，芳基脒DB750抑制刚地弓形虫RH和刚地弓形虫Me49速殖子的增殖，半数抑制浓度（IC50）分别为0.11和0.13μM。将成纤维细胞单层用1μM DB750预孵育12小时，然后在无药物的情况下培养，也导致寄生虫增殖受到显著抑制。然而，在药物暴露5 - 6天后，刚地弓形虫速殖子适应了该化合物，并在浓度高达1.2μM时恢复增殖。在一组针对刚地弓形虫体外活性进行筛选的32种二阳离子化合物中，选择了芳基脒DB745（其IC50为0.03μM且具有良好的选择性毒性）进行进一步研究。DB745还抑制了适应DB750的刚地弓形虫的增殖（IC50 = 0.07μM）。与DB750相反，DB745对细胞外未适应的刚地弓形虫速殖子也有显著的负面影响，但对适应DB750的刚地弓形虫没有影响。刚地弓形虫对DB745的适应（浓度高达0.46μM）要困难得多，且仅在110天的时间内才可行。在感染适应DB750的刚地弓形虫的培养物中，偶尔可以通过透射电子显微镜（TEM）检测到看似完整的寄生虫。这说明了刚地弓形虫速殖子适应环境变化的惊人能力，至少在体外条件下是如此，并表明DB745可能是一个有趣的药物候选物，可在适当的体内模型中进行进一步评估。
The impact of di-cationic pentamidine-analogues against Toxoplama gondii (Rh-and Me49-background) was investigated. The 72 h-growth assays showed that the arylimidamide DB750 inhibited the proliferation of tachyzoites of T. gondii Rh and T. gondii Me49 with an IC50 of 0.11 and 0.13 mu M, respectively. Pre-incubation of fibroblast monolayers with 1 mu M DB750 for 12 h and subsequent culture in the absence of the drug also resulted in a pronounced inhibiton of parasite proliferation. However, upon 5-6 days of drug exposure, T. gondii tachyzoites adapted to the compound and resumed proliferation up to a concentration of 1.2 mu M. Out of a set of 32 di-cationic compounds screened for in vitro activity against T. gondii, the arylimidamide DB745, exhibiting an IC50 of 0.03 mu M and favourable selective toxicity was chosen for further studies. DB745 also inhibited the proliferation of DB750-adapted T. gondii (IC50 = 0.07 mu M). In contrast to DB750, DB745 also had a profound negative impact on extracellular non-adapted T. gondii tachyzoites, but not on DB750-adapted T. gondii. Adaptation of T. gondii to DB745 (up to a concentration of 0.46 mu M) was much more difficult to achieve and feasible only over a period of 110 days. In cultures infected with DB750-adapted T. gondii seemingly intact parasites could occasionally be detected by TEM. This illustrates the astonishing capacity of T. gondii tachyzoites to adapt to environmental changes, at least under in vitro conditions, and suggests that DB745 could be an interesting drug candidate for further assessments in appropriate in vivo models.