Marziali Giacomo, Marangoni Antonella, Foschi Claudio, Re Maria Carla, Calonghi Natalia
FaBiT Department, University of Bologna, Via Irnerio 42, 40126 Bologna, Italy.
Microbiology, DIMES, University of Bologna, St. Orsola Hospital, Via Massarenti, 9, 40138 Bologna, Italy.
Pathogens. 2020 Apr 17;9(4):298. doi: 10.3390/pathogens9040298.
Previous works suggest that sugars can have a beneficial effect on (CT) survival and virulence. In this study, we investigated the effect of different sugars on CT infectivity, elucidating some of the molecular mechanisms behind CT-sugar interaction. CT infectivity was investigated on HeLa cells after 2 hour-incubation of elementary bodies (EBs) with glucose, sucrose, or mannitol solutions (0.5, 2.5, 5.0 mM). The effect of sugars on EB membrane fluidity was investigated by fluorescence anisotropy measurement, whereas the changes in lipopolysaccharide (LPS) exposure were examined by cytofluorimetric analysis. By means of a Western blot, we explored the phosphorylation state of Focal Adhesion Kinase (FAK) in HeLa cells infected with EBs pre-incubated with sugars. All sugar solutions significantly increased CT infectivity on epithelial cells, acting directly on the EB structure. Sugars induced a significant increase of EB membrane fluidity, leading to changes in LPS membrane exposure. Especially after incubation with sucrose and mannitol, EBs led to a higher FAK phosphorylation, enhancing the activation of anti-apoptotic and proliferative signals in the host cells. Sugars can increase CT infectivity and virulence, by modulating the expression/exposure of chlamydial membrane ligands. Further in-depth studies are needed to better understand the molecular mechanisms involved.
先前的研究表明，糖类可对沙眼衣原体（CT）的存活和毒力产生有益影响。在本研究中，我们调查了不同糖类对CT感染性的影响，阐明了CT与糖类相互作用背后的一些分子机制。在用葡萄糖、蔗糖或甘露醇溶液（0.5、2.5、5.0 mM）对原体（EB）进行2小时孵育后，在HeLa细胞上研究了CT感染性。通过荧光各向异性测量研究了糖类对EB膜流动性的影响，而通过细胞荧光分析检测了脂多糖（LPS）暴露的变化。通过蛋白质印迹法，我们探究了用糖类预孵育的EB感染的HeLa细胞中粘着斑激酶（FAK）的磷酸化状态。所有糖类溶液均显著增加了CT对上皮细胞的感染性，直接作用于EB结构。糖类导致EB膜流动性显著增加，导致LPS膜暴露发生变化。特别是在与蔗糖和甘露醇孵育后，EB导致更高的FAK磷酸化，增强了宿主细胞中抗凋亡和增殖信号的激活。糖类可通过调节衣原体膜配体的表达/暴露来增加CT感染性和毒力。需要进一步深入研究以更好地理解其中涉及的分子机制。
