Park Dayoung, Arabyan Narine, Williams Cynthia C, Song Ting, Mitra Anupam, Weimer Bart C, Maverakis Emanual, Lebrilla Carlito B
From the ‡Department of Chemistry, University of California, Davis, CA, 95616.
§Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, CA, 95616.
Mol Cell Proteomics. 2016 Dec;15(12):3653-3664. doi: 10.1074/mcp.M116.063206. Epub 2016 Oct 17.
Although gut host-pathogen interactions are glycan-mediated processes, few details are known about the participating structures. Here we employ high-resolution mass spectrometric profiling to comprehensively identify and quantitatively measure the exact modifications of native intestinal epithelial cell surface N-glycans induced by S. typhimurium infection. Sixty minutes postinfection, select sialylated structures showed decreases in terms of total number and abundances. To assess the effect of cell surface mannosylation, we selectively rerouted glycan expression on the host using the alpha-mannosidase inhibitor, kifunensine, toward overexpression of high mannose. Under these conditions, internalization of S. typhimurium significantly increased, demonstrating that bacteria show preference for particular structures. Finally, we developed a novel assay to measure membrane glycoprotein turnover rates, which revealed that glycan modifications occur by bacterial enzyme activity rather than by host-derived restructuring strategies. This study is the first to provide precise structural information on how host N-glycans are altered to support S. typhimurium invasion.
尽管肠道宿主与病原体的相互作用是由聚糖介导的过程，但关于参与其中的结构的细节却知之甚少。在此，我们采用高分辨率质谱分析来全面鉴定和定量测量鼠伤寒沙门氏菌感染诱导的天然肠上皮细胞表面N-聚糖的确切修饰。感染60分钟后，选定的唾液酸化结构在总数和丰度方面均有所下降。为了评估细胞表面甘露糖基化的影响，我们使用α-甘露糖苷酶抑制剂 kifunensine 选择性地改变宿主上的聚糖表达，使其向高甘露糖的过表达方向转变。在这些条件下，鼠伤寒沙门氏菌的内化显著增加，表明细菌对特定结构表现出偏好。最后，我们开发了一种新颖的测定方法来测量膜糖蛋白的周转率，结果表明聚糖修饰是由细菌酶活性而非宿主衍生的重组策略引起的。这项研究首次提供了关于宿主N-聚糖如何被改变以支持鼠伤寒沙门氏菌入侵的精确结构信息。
