Tracing amino acid exchange during host-pathogen interaction by combined stable-isotope time-resolved Raman spectral imaging.
Tracing amino acid exchange during host-pathogen interaction by combined stable-isotope time-resolved Raman spectral imaging.
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DOI：
10.1038/srep20811
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发表时间：
2016-02-09
影响因子：
4.6
通讯作者：
Notingher I
中科院分区：
文献类型：
--
作者：
Naemat A;Elsheikha HM;Boitor RA;Notingher I
本研究探讨了芳香族氨基酸苯丙氨酸（Phe）在人视网膜色素上皮细胞株（ARPE-19）和弓形虫速殖子间的时空交换。弓形虫）。细胞培养物中氨基酸的稳定同位素标记（SILAC）与拉曼显微光谱相结合，以选择性地监测氘标记的苯丙氨酸掺入到单个活速殖子中的蛋白质中。我们的研究结果表明，非常快速的摄取l-Phe（D8）的细胞内生长的寄生虫。t.刚地速殖子一旦侵入宿主细胞就能够从宿主细胞中提取L-Phe（D8）。来自宿主细胞的l-Phe（D8）完全取代T内的l-Phe。弓形虫速殖子感染后7 - 9小时。基于拉曼光谱的定量模型允许估计Phe的交换速率为0.5 - 1.6 × 10 4分子/s。另一方面，细胞外速殖子在感染24小时后不能消耗l-Phe（D8）。这些发现进一步加深了我们对宿主细胞和这种严格的细胞内寄生虫之间氨基酸运输的理解。特别是，这项研究突出了新的方面的代谢的氨基酸苯丙氨酸操作期间的相互作用T。弓形虫及其宿主细胞。
This study investigates the temporal and spatial interchange of the aromatic amino acid phenylalanine (Phe) between human retinal pigment epithelial cell line (ARPE-19) and tachyzoites of the apicomplexan protozoan parasite Toxoplasma gondii (T. gondii). Stable isotope labelling by amino acids in cell culture (SILAC) is combined with Raman micro-spectroscopy to selectively monitor the incorporation of deuterium-labelled Phe into proteins in individual live tachyzoites. Our results show a very rapid uptake of l-Phe(D8) by the intracellular growing parasite. T. gondii tachyzoites are capable of extracting l-Phe(D8) from host cells as soon as it invades the cell. l-Phe(D8) from the host cell completely replaces the l-Phe within T. gondii tachyzoites 7–9 hours after infection. A quantitative model based on Raman spectra allowed an estimation of the exchange rate of Phe as 0.5–1.6 × 104 molecules/s. On the other hand, extracellular tachyzoites were not able to consume l-Phe(D8) after 24 hours of infection. These findings further our understanding of the amino acid trafficking between host cells and this strictly intracellular parasite. In particular, this study highlights new aspects of the metabolism of amino acid Phe operative during the interaction between T. gondii and its host cell.