期刊
CARBOHYDRATE RESEARCH
卷 343, 期 12, 页码 1952-1965出版社
ELSEVIER SCI LTD
DOI: 10.1016/j.carres.2007.12.012
关键词
Helicobacter pylori; Lewis antigens; fucosylation; Fucosyltransferases; molecular mimicry; bacterial pathogenesis
Helicobacter pylori is a prevalent bacterial, gastroduodenal pathogen of humans that can express Lewis (Le) and related antigens in the O-chains of its surface lipopolysaccharide. The O-chains of H. pylori are commonly composed of internal Le(x) units with terminal Le(x) or Le units or, in some strains, with additional units of Le(a), Le(b), Le(c), sialyl-Le(x) and H-I antigens, as well as blood groups A and B, thereby producing a mosaicism of antigenic units expressed. The genetic determination of the Le antigen biosynthetic pathways in H. pylori has been studied, and despite striking functional similarity, low sequence homology occurs between the bacterial and mammalian alpha(1,3/4)- and alpha(1,2)-fucosyltransferases. Factors affecting Le antigen expression in H. pylori, that can influence the biological impact of this molecular mimicry, include regulation of fucosyltransferase genes through slipped-strand mispairing, the activity and expression levels of the functional enzymes, the preferences of the expressed enzyme for distinctive acceptor molecules and the availability of activated sugar intermediates. Le mimicry was initially implicated in immune evasion and gastric adaptation by the bacterium, but more recent studies show a role in gastric colonization and bacterial adhesion with galectin-3 identified as the gastric receptor for polymeric Le(x) on the bacterium. From the host defence aspect, innate immune recognition of H. pylori by surfactant protein D is influenced by the extent of LPS fucosylation. Furthermore, Le antigen expression affects both the inflammatory response and T-cell polarization that develops after infection. Although controversial, evidence suggests that long-term H. pylori infection can induce autoreactive anti-Le antibodies cross-reacting with the gastric mucosa, in part leading to the development of gastric atrophy. Thus, Le antigen expression and fucosylation in H. pylori have multiple biological effects on pathogenesis and disease outcome. (C) 2007 Elsevier Ltd. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据