Junior Research Group "Sexually Transmitted Bacterial Pathogens" (NG 5), Robert Koch Institute, Berlin, Germany.
Organic and Bioorganic Chemistry, Department of Chemistry, Humboldt-Universität zu Berlin, Berlin, Germany.
Cell Microbiol. 2017 Oct;19(10). doi: 10.1111/cmi.12752. Epub 2017 Jun 15.
Chlamydiaceae are bacterial pathogens that cause diverse diseases in humans and animals. Despite their broad host and tissue tropism, all Chlamydia species share an obligate intracellular cycle of development and have evolved sophisticated mechanisms to interact with their eukaryotic host cells. Here, we have analysed interactions of the zoonotic pathogen Chlamydia psittaci with a human epithelial cell line. We found that C. psittaci recruits the ceramide transport protein (CERT) to its inclusion. Chemical inhibition and CRISPR/Cas9-mediated knockout of CERT showed that CERT is a crucial factor for C. psittaci infections thereby affecting different stages of the infection including inclusion growth and infectious progeny formation. Interestingly, the uptake of fluorescently labelled sphingolipids in bacteria inside the inclusion was accelerated in CERT-knockout cells indicating that C. psittaci can exploit CERT-independent sphingolipid uptake pathways. Moreover, the CERT-specific inhibitor HPA-12 strongly diminished sphingolipid transport to inclusions of infected CERT-knockout cells, suggesting that other HPA-12-sensitive factors are involved in sphingolipid trafficking to C. psittaci. Further analysis is required to decipher these interactions and to understand their contributions to bacterial development, host range, tissue tropism, and disease outcome.
衣原体科是一类引起人类和动物多种疾病的细菌病原体。尽管它们具有广泛的宿主和组织嗜性，但所有衣原体物种都具有严格的细胞内发育周期，并进化出了复杂的机制来与真核宿主细胞相互作用。在这里，我们分析了人畜共患病原体鹦鹉热衣原体与人类上皮细胞系的相互作用。我们发现，C. psittaci 将神经酰胺转运蛋白（CERT）募集到其包含体中。化学抑制和 CRISPR/Cas9 介导的 CERT 敲除表明，CERT 是 C. psittaci 感染的关键因素，从而影响感染的不同阶段，包括包含体生长和感染性后代的形成。有趣的是，在 CERT 敲除细胞中，包含体中细菌内荧光标记的神经酰胺的摄取被加速，表明 C. psittaci 可以利用 CERT 独立的神经酰胺摄取途径。此外，CERT 特异性抑制剂 HPA-12 强烈减少了感染 CERT 敲除细胞包含体中的神经酰胺转运，表明其他 HPA-12 敏感因子参与了神经酰胺向 C. psittaci 的转运。需要进一步分析这些相互作用，以了解它们对细菌发育、宿主范围、组织嗜性和疾病结局的贡献。
