Monteiro M A, Chan K H, Rasko D A, Taylor D E, Zheng P Y, Appelmelk B J, Wirth H P, Yang M, Blaser M J, Hynes S O, Moran A P, Perry M B
Canadian Bacterial Diseases Network, National Research Council, Ottawa, K1A 0R6 Ontario, Canada.
J Biol Chem. 1998 May 8;273(19):11533-43. doi: 10.1074/jbc.273.19.11533.
Previous structural investigations performed on the lipopolysaccharides (LPSs) from the human gastric pathogen Helicobacter pylori have revealed that these cell surface glycan molecules express type 2 partially fucosylated, glucosylated, or galactosylated N-acetyllactosamine O antigen chains (O-chains) of various lengths, which may or may not be terminated at the nonreducing end by Lewis X (Lex) and/or Ley blood group epitopes in mimicry of human cell surface glycoconjugates and glycolipids. Subsequently, serological experiments with commercially available Lewis-specific monoclonal antibodies also have recognized the presence of Lex and Ley blood group antigens in H. pylori but, in addition, have indicated the presence of type 1 chain Lea, Leb, and Led (H-type 1) blood group epitopes in some H. pylori strains. To confirm their presence, structural studies and additional serological experiments were undertaken on H. pylori strains suspected of carrying type 1 chain epitopes. These investigations revealed that the O-chain region of H. pylori strain UA948 carried both Lea (type 1) and Lex (type 2) blood group determinants. The O-chain from H. pylori UA955 LPS expressed the terminal Lewis disaccharide (type 1 chain) and Lex and Ley antigens (type 2). The O-chain of H. pylori J223 LPS carried the type 1 chain precursor Lec, the H-1 epitope (Led, type 1 chain) and an elongated nonfucosylated type 2 N-acetyllactosamine chain (i antigen). Thus, O-chains from H. pylori LPSs can also express fucosylated type 1 sequences, and the LPS from a single H. pylori strain may carry O-chains with type 1 and 2 Lewis blood groups simultaneously. That monoclonal antibodies putatively specific for the Leb determinant can detect glycan substructures (Le disaccharide, Lec, and Led) of Leb indicates their nonspecificity. The expression of both type 1 and 2 Lewis antigens by H. pylori LPSs mimics the cell surface glycomolecules present in both the gastric superficial (which expresses mainly type 1 determinants) and the superficial and glandular epithelium regions (both of which express predominantly type 2 determinants). Therefore, each H. pylori strain may have a different niche within the gastric mucosa, and each individual LPS blood group antigen may have a dissimilar role in H. pylori adaptation.
先前对人类胃部病原体幽门螺杆菌的脂多糖（LPS）进行的结构研究表明，这些细胞表面聚糖分子表达了不同长度的2型部分岩藻糖基化、葡萄糖基化或半乳糖基化的N-乙酰乳糖胺O抗原链（O链），其在非还原端可能被Lewis X（Lex）和/或Ley血型抗原表位终止，以模仿人类细胞表面糖缀合物和糖脂。随后，使用市售的Lewis特异性单克隆抗体进行的血清学实验也证实了幽门螺杆菌中Lex和Ley血型抗原的存在，但此外，还表明在一些幽门螺杆菌菌株中存在1型链Lea、Leb和Led（H-1型）血型抗原表位。为了证实它们的存在，对怀疑携带1型链抗原表位的幽门螺杆菌菌株进行了结构研究和额外的血清学实验。这些研究表明，幽门螺杆菌菌株UA948的O链区域同时携带Lea（1型）和Lex（2型）血型决定簇。来自幽门螺杆菌UA955 LPS的O链表达了末端Lewis二糖（1型链）以及Lex和Ley抗原（2型）。幽门螺杆菌J223 LPS的O链携带1型链前体Lec、H-1抗原表位（Led，1型链）和一条延长的非岩藻糖基化2型N-乙酰乳糖胺链（i抗原）。因此，幽门螺杆菌LPS的O链也可以表达岩藻糖基化的1型序列，并且来自单个幽门螺杆菌菌株的LPS可能同时携带具有1型和2型Lewis血型的O链。推测对Leb决定簇具有特异性的单克隆抗体能够检测Leb的聚糖亚结构（Le二糖、Lec和Led），这表明了它们的非特异性。幽门螺杆菌LPS同时表达1型和2型Lewis抗原，模仿了胃表层（主要表达1型决定簇）以及表层和腺上皮区域（两者均主要表达2型决定簇）中存在的细胞表面糖分子。因此，每个幽门螺杆菌菌株在胃黏膜内可能具有不同的生态位，并且每个单独的LPS血型抗原在幽门螺杆菌的适应性中可能具有不同的作用。
