N-glycosylated proteins are involved in efficient internalization of Klebsiella pneumoniae by cultured human epithelial cells
N-glycosylated proteins are involved in efficient internalization of Klebsiella pneumoniae by cultured human epithelial cells
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DOI：
10.1128/iai.65.11.4445-4451.1997
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发表时间：
1997-11-01
影响因子：
3.1
通讯作者：
Oelschlaeger, TA
中科院分区：
文献类型：
--
作者：
Fumagalli, O;Tall, BD;Oelschlaeger, TA
肺炎克雷伯菌能侵入培养的人上皮细胞，其内化过程依赖于微丝和微管。为了更好地理解这些侵入性细菌与宿主细胞受体的相互作用，在具有多种聚糖特异性的各种凝集素存在下用肺炎克雷伯氏菌感染膀胱、肺和回盲上皮细胞。发现N-乙酰葡糖胺（GlcNAc）特异性凝集素伴刀豆球蛋白A、曼陀罗凝集素和麦胚凝集素显著抑制肺炎克雷伯氏菌的侵入，pneumoniae感染进入这些细胞，但不干扰鼠伤寒沙门氏菌侵袭性菌株的内化。相反，K.在庆大霉素侵袭试验前，用葡萄糖或几丁质水解产物（一种葡萄糖或几丁质水解产物）预处理细菌，也能显著抑制肺炎克雷伯菌而非鼠伤寒沙门氏菌的摄取。其它碳水化合物如葡萄糖、半乳糖、甘露糖、岩藻糖和N-乙酰神经氨酸对肺炎克雷伯菌的摄取无抑制作用。当真核蛋白糖基化被衣霉素中断或宿主N-连接的表面聚糖被预处理去除时，利用N-糖苷酶F也显著抑制HCT 8细胞对鼠伤寒沙门氏菌的作用。这些研究表明，在体外培养的人上皮细胞中，肺炎克雷伯菌的内化过程中可能存在一种N-糖基化蛋白受体，其内部的GlcNAc残基可能是该受体的一种糖基成分。
Klebsiella pneumoniae obtained from patients with urinary tract infections is able to invade cultured human epithelial cells, The internalization process is dependent upon both microfilaments and microtubules. To better understand the interaction of these invasive bacteria with the host cell receptor(s), bladder, lung, and ileocecal epithelial cells were infected with K, pneumoniae in the presence of various lectins possessing multiple glycan specificities, It was found that the N-acetylglucosamine (GlcNAc)-specific lectins concanavalin A, Datura stramonium agglutinin, and wheat germ agglutinin significantly inhibited the invasion of K, pneumoniae into these cells but did not interfere with the internalization of an invasive strain of Salmonella typhimurium. Conversely, internalization of K. pneumoniae but not S, typhimurium was also significantly inhibited when the bacteria were pretreated with GlcNAc or chitin hydrolysate, a GlcNAc polymer, prior to the gentamicin invasion assay, Other carbohydrates such as glucose, galactose, mannose, fucose, and N-acetylneuraminic acid had no inhibitory effects an K, pneumoniae uptake, Furthermore, internalization of K, pneumoniae but not S. typhimurium by HCT8 cells was also significantly inhibited when eukaryotic protein glycosylation was interrupted by tunicamycin or when host N-linked surface glycans were removed by pretreatment,vith N-glycosidase F. These studies suggest that a N-glycosylated protein receptor is involved in the internalization of K, pneumoniae by human epithelial cells in vitro, The results also indicate that internal GlcNAc residues might be a carbohydrate component of the receptor.