Implication of antigenic conversion of Helicobacter pylori lipopolysaccharides that involve interaction with surfactant protein D
Implication of antigenic conversion of Helicobacter pylori lipopolysaccharides that involve interaction with surfactant protein D
复制标题
幽门螺杆菌脂多糖抗原转化涉及与表面活性蛋白 D 相互作用的意义
DOI：
10.1128/iai.00345-12
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发表时间：
2012
影响因子：
3.1
通讯作者：
Fujii N.
中科院分区：
文献类型：
--
作者：
Yokota S;Amano K;Nishitani C;Ariki S;Kuroki Y;Fujii N.
根据幽门螺杆菌脂多糖（Helicobacter pylori lipopolysaccharides，LPS）在人血清中的反应性，我们提出了两种抗原性类型：高抗原表位携带型LPS（highly antigenic epitope carrying LPS，HA-LPS）和弱抗原表位携带型LPS（weakly antigenic epitope carrying LPS，WA-LPS）。携带WA-LPS的菌株在来自胃癌患者的分离株中高度流行。与HA-LPS相比，WA-LPS表现出更有效的生物活性，即上调Toll样受体4（TLR 4）表达和诱导增强的上皮细胞增殖。利用单糖和甲基糖苷的竞争性结合试验以及利用糖苷酶处理的LPS的结合试验的结果表明，β-linkedN-乙酰基-d-葡萄糖胺和β-linkedd-半乳糖残基分别主要贡献于高抗原性表位和弱抗原性表位。WA-LPS与表面活性蛋白D（SP-D）的结合活性随Ca ~（2+）浓度的增加而增强，这种结合作用可被甲基-β-d-半乳糖苷抑制。加入SP-D后，WA-LPS的生物活性明显增强。一系列证据表明，去除包含高抗原性表位的β-N-乙酰基-d-葡糖胺残基导致弱抗原性表位暴露。弱抗原表位优先与SP-D相互作用，SP-D增强WA-LPS的生物活性。
We propose two antigenic types of Helicobacter pylori lipopolysaccharides (LPS): highly antigenic epitope-carrying LPS (HA-LPS) and weakly antigenic epitope-carrying LPS (WA-LPS) based on human serum reactivity. Strains carrying WA-LPS are highly prevalent in isolates from gastric cancer patients. WA-LPS exhibits more potent biological activities compared to HA-LPS, namely, upregulation of Toll-like receptor 4 (TLR4) expression and induction of enhanced epithelial cell proliferation. The results of competitive binding assays using monosaccharides and methylglycosides, as well as binding assays using glycosidase-treated LPS, suggested that β-linkedN-acetyl-d-glucosamine and β-linkedd-galactose residues largely contributed to the highly antigenic epitope and the weakly antigenic epitope, respectively. WA-LPS exhibited greater binding activity to surfactant protein D (SP-D) in a Ca2+-dependent manner, and this interaction was inhibited by methyl-β-d-galactoside. The biological activities of WA-LPS were markedly enhanced by the addition of SP-D. Lines of evidence suggested that removal of β-N-acetyl-d-glucosamine residue, which comprises the highly antigenic epitope, results in exposure of the weakly antigenic epitope. The weakly antigenic epitope interacted preferentially with SP-D, and SP-D enhanced the biological activity of WA-LPS.