Coddens Annelies, Diswall Mette, Angström Jonas, Breimer Michael E, Goddeeris Bruno, Cox Eric, Teneberg Susann
Laboratory of Veterinary Immunology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke 9820, Belgium.
J Biol Chem. 2009 Apr 10;284(15):9713-26. doi: 10.1074/jbc.M807866200. Epub 2009 Feb 10.
F18-fimbriated Escherichia coli are associated with porcine postweaning diarrhea and edema disease. Adhesion of F18-fimbriated bacteria to the small intestine of susceptible pigs is mediated by the minor fimbrial subunit FedF. However, the target cell receptor for FedF has remained unidentified. Here we report that F18-fimbriated E. coli selectively interact with glycosphingolipids having blood group ABH determinants on type 1 core, and blood group A type 4 heptaglycosylceramide. The minimal binding epitope was identified as the blood group H type 1 determinant (Fucalpha2Galbeta3GlcNAc), while an optimal binding epitope was created by addition of the terminal alpha3-linked galactose or N-acetylgalactosamine of the blood group B type 1 determinant (Galalpha3(Fucalpha2)Galbeta3GlcNAc) and the blood group A type 1 determinant (GalNAcalpha3(Fucalpha2)-Galbeta3GlcNAc). To assess the role of glycosphingolipid recognition by F18-fimbriated E. coli in target tissue adherence, F18-binding glycosphingolipids were isolated from the small intestinal epithelium of blood group O and A pigs and characterized by mass spectrometry and proton NMR. The only glycosphingolipid with F18-binding activity of the blood group O pig was an H type 1 pentaglycosylceramide (Fucalpha2Galbeta3GlcNAc-beta3Galbeta4Glcbeta1Cer). In contrast, the blood group A pig had a number of F18-binding glycosphingolipids, characterized as A type 1 hexaglycosylceramide (GalNAcalpha3(Fucalpha2)Galbeta3GlcNAcbeta3Galbeta4Glcbeta1Cer), A type 4 heptaglycosylceramide (GalNAcalpha3(Fucalpha2)Galbeta3GalNAcbeta3Galalpha4Galbeta4Glcbeta1Cer), A type 1 octaglycosylceramide (GalNAcalpha3(Fucalpha2)Galbeta3GlcNAcbeta3Galbeta3GlcNAcbeta3Galbeta4Glcbeta1Cer), and repetitive A type 1 nonaglycosylceramide (GalNAcalpha3(Fucalpha2)Galbeta3GalNAcalpha3-(Fucalpha2)Galbeta3GlcNAcbeta3Galbeta4Glcbeta1Cer). No blood group antigen-carrying glycosphingolipids were recognized by a mutant E. coli strain with deletion of the FedF adhesin, demonstrating that FedF is the structural element mediating binding of F18-fimbriated bacteria to blood group ABH determinants.
F18菌毛化大肠杆菌与猪断奶后腹泻及水肿病有关。F18菌毛化细菌与易感猪小肠的黏附由次要菌毛亚基FedF介导。然而，FedF的靶细胞受体仍未明确。在此我们报告，F18菌毛化大肠杆菌与1型核心上具有ABH血型决定簇的糖鞘脂以及A型4七糖神经酰胺选择性相互作用。最小结合表位被鉴定为H1型血型决定簇（Fucα2Galβ3GlcNAc），而通过添加B1型血型决定簇（Galα3(Fucα2)Galβ3GlcNAc）和A1型血型决定簇（GalNAcα3(Fucα2)-Galβ3GlcNAc）的末端α3连接的半乳糖或N-乙酰半乳糖胺可形成最佳结合表位。为评估F18菌毛化大肠杆菌对糖鞘脂的识别在靶组织黏附中的作用，从O型和A型血猪的小肠上皮中分离出F18结合糖鞘脂，并通过质谱和质子核磁共振进行表征。O型血猪中唯一具有F18结合活性的糖鞘脂是H1型五糖神经酰胺（Fucα2Galβ3GlcNAc-β3Galβ4Glcβ1Cer）。相比之下，A型血猪有多种F18结合糖鞘脂，其特征为A1型六糖神经酰胺（GalNAcα3(Fucα2)Galβ3GlcNAcβ3Galβ4Glcβ1Cer）、A4型七糖神经酰胺（GalNAcα3(Fucα2)Galβ3GalNAcβ3Galα4Galβ4Glcβ1Cer）、A1型八糖神经酰胺（GalNAcα3(Fucα2)Galβ3GlcNAcβ3Galβ3GlcNAcβ3Galβ4Glcβ1Cer）以及重复A1型九糖神经酰胺（GalNAcα3(Fucα2)Galβ3GalNAcα3-(Fucα2)Galβ3GlcNAcβ3Galβ4Glcβ1Cer）。缺失FedF黏附素的突变大肠杆菌菌株未识别出携带血型抗原的糖鞘脂，这表明FedF是介导F18菌毛化细菌与ABH血型决定簇结合的结构元件。
