Glycobiology Advance Access originally published online on April 9, 2008
Glycobiology 2008 18(7):494-501; doi:10.1093/glycob/cwn030
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Studies of Lewis antigens and H. pylori adhesion in CHO cell lines engineered to express Lewis b determinants
2 Division of Clinical Immunology and Transfusion Medicine, Karolinska Institute, SE 14186 Stockholm
3 Department of Surgery, Sahlgrenska University Hospital, SE 41345 Göteborg
4 Department of Medical Chemistry and Biophysics, Umeå University, SE 90187 Umeå, Sweden
1 To whom correspondence should be addressed: Division of Clinical Immunology and Transfusion Medicine, F79 Karolinska University Hospital, Huddinge S-141 86 Stockholm, Sweden. Tel: +46-8-585-81384; Fax: +46-8-585-81390; e-mail: jan.holgersson{at}ki.se
Received on February 15, 2008; revised on April 4, 2008; accepted on April 5, 2008
Many microbes bind and adhere via adhesins to host cell carbohydrates as an initial step for infection. Therefore, cell lines expressing Lewis b (Leb) determinants were generated as a potential model system for Helicobacter pylori colonization and infection, and their expression of blood group Lewis determinants was characterized. CHO-K1 cells were stably transfected with selected glycosyltransferase cDNAs, and two Leb positive clones, 1C5 and 2C2, were identified. Expression of Lewis (Lea, Leb, Lex, and Ley) determinants was analyzed by flow cytometry of intact cells, SDS–PAGE/Western blot of solubilized glycoproteins, and thin layer chromatography immunostaining of isolated glycolipids (GL). Binding of H. pylori to cells was examined by microscopy and quantified. Flow cytometry showed that 1C5 and 2C2 were Lea and Leb positive. 1C5 expressed Leb on O-linked, but not N-linked, glycans and only weakly on GLs. In contrast, 2C2 expressed Leb on N-, O-glycans, and GLs. Furthermore, both clones expressed Lea on N- and O-glycans but not on GLs. 2C2, but not 1C5, stained positively for Ley on N-linked glycans and GLs. Both clones, as well as the parental CHO-K1 cells, expressed Lex on GLs. A Leb-binding H. pylori strain bound to the 1C5 and 2C2 cells. In summary, two glycosyltransferase transfected CHO-K1 cell clones differed regarding Lewis antigen expression on N- and O-linked glycans as well as on GLs. Both clones examined supported adhesion of a Leb-binding H. pylori strain and may thus be a useful in vitro model system for H. pylori colonization/infection studies.
Key words: Bacterial adhesion / fucosyltransferase / Helicobacter pylori / Lewis antigens