Amoebal endosymbiont Parachlamydia acanthamoebae Bn9 can grow in immortal human epithelial HEp-2 cells at low temperature; an in vitro model system to study chlamydial evolution.
Amoebal endosymbiont Parachlamydia acanthamoebae Bn9 can grow in immortal human epithelial HEp-2 cells at low temperature; an in vitro model system to study chlamydial evolution.
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DOI：
10.1371/journal.pone.0116486
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发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
Yamaguchi H
中科院分区：
文献类型：
--
作者：
Yamane C;Yamazaki T;Nakamura S;Matsuo J;Ishida K;Yamazaki S;Oguri S;Shouji N;Hayashi Y;Yoshida M;Yimin;Yamaguchi H
古衣原体在7 - 14亿年前分化为致病性衣原体和环境性衣原体。然而，尽管环境衣原体已经在相对低温的恶劣生态位中进化为低等真核生物的内共生体，但致病性衣原体是如何适应在大约37°C下提供稳定生态位的哺乳动物细胞的，仍然未知。因此，我们评估了一种环境衣原体，副衣原体Bn9，是否可以在30°C的低温培养下在人HEp-2细胞中生长。定量RT-PCR对包涵体形成的评估显示，与37℃培养相比，30℃培养后细菌包涵体数量和16SrRNA转录水平显著增加。共聚焦显微镜显示，细菌位于HEp-2核附近，并具有活跃的复制能力。透射电镜也显示复制细菌由网状体组成，但有少数基本体。细胞松弛素D和利福平抑制包涵体的形成。Lactacystin能轻微抑制细菌包涵体的形成。使用细菌基因组序列草图的KEGG分析显示，它具有与致病性衣原体几乎相同的代谢途径。有趣的是，与致病性衣原体的基因组比较分析显示，副原体同样具有编码III型分泌系统的基因，但缺乏编码包涵体成熟所需的包涵膜蛋白（IncA至G）的基因。综上所述，我们得出结论，古代衣原体具有在人类细胞中生长的潜力，但克服热间隙是衣原体适应人类细胞的关键事件。
Ancient chlamydiae diverged into pathogenic and environmental chlamydiae 0.7–1.4 billion years ago. However, how pathogenic chlamydiae adapted to mammalian cells that provide a stable niche at approximately 37°C, remains unknown, although environmental chlamydiae have evolved as endosymbionts of lower eukaryotes in harsh niches of relatively low temperatures. Hence, we assessed whether an environmental chlamydia, Parachlamydia Bn9, could grow in human HEp-2 cells at a low culture temperature of 30°C. The assessment of inclusion formation by quantitative RT-PCR revealed that the numbers of bacterial inclusion bodies and the transcription level of 16SrRNA significantly increased after culture at 30°C compared to at 37°C. Confocal microscopy showed that the bacteria were located close to HEp-2 nuclei and were actively replicative. Transmission electron microscopy also revealed replicating bacteria consisting of reticular bodies, but with a few elementary bodies. Cytochalasin D and rifampicin inhibited inclusion formation. Lactacystin slightly inhibited bacterial inclusion formation. KEGG analysis using a draft genome sequence of the bacteria revealed that it possesses metabolic pathways almost identical to those of pathogenic chlamydia. Interestingly, comparative genomic analysis with pathogenic chlamydia revealed that the Parachlamydia similarly possess the genes encoding Type III secretion system, but lacking genes encoding inclusion membrane proteins (IncA to G) required for inclusion maturation. Taken together, we conclude that ancient chlamydiae had the potential to grow in human cells, but overcoming the thermal gap was a critical event for chlamydial adaptation to human cells.
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影响因子：
3.8
作者：
Kobayashi, Miho;Ishida, Kasumi;Yamaguchi, Hiroyuki
通讯作者：
Yamaguchi, Hiroyuki
影响因子：
4.4
作者：
Burillo, Almudena;Bouza, Emilio
通讯作者：
Bouza, Emilio
影响因子：
56.9
作者：
Horn, M;Collingro, A;Wagner, M
通讯作者：
Wagner, M
DOI：
10.1111/j.1365-3156.2010.02521.x
发表时间：
2010-06
期刊：
Tropical medicine & international health : TM & IH
影响因子：
--
作者：
Hu VH;Harding-Esch EM;Burton MJ;Bailey RL;Kadimpeul J;Mabey DC
通讯作者：
Mabey DC
影响因子：
4.4
作者：
Gimenez, Gregory;Bertelli, Claire;Greub, Gilbert
通讯作者：
Greub, Gilbert