title: Versatile biosynthetic engineering of sialic acid in living cells using synthetic sialic acid analogues.
abstract: Sialic acids are critical components of many glycoconjugates involved in biologically important ligand-receptor interactions. Quantitative and structural variations of sialic acid residues can profoundly affect specific cell-cell, pathogen-cell, or drug-cell interactions, but manipulation of sialic acids in mammalian cells has been technically limited. We describe the finding of a previously unrecognized and efficient uptake and incorporation of sialic acid analogues in mammalian cells. We added 16 synthetic sialic acid analogues carrying distinct C-1, C-5, or C-9 substitutions individually to cell cultures of which 10 were readily taken up and incorporated. Uptake of C-5- and C-9-substituted sialic acids resulted in the structural modification of up to 95% of sialic acids on the cell surface. Functionally, binding of murine sialic acid-binding immunoglobulin-like lectin-2 (Siglec-2, CD22) to cells increased after N-glycolylneuraminic acid treatment, whereas 9-iodo-N-acetylneuraminic acid abolished binding. Furthermore, susceptibility to infection by the B-lymphotropic papovavirus via a sialylated receptor was markedly enhanced following pretreatment of host cells with selected sialic acid analogues including 9-iodo-N-acetylneuraminic acid. This novel experimental strategy allows for an efficient biosynthetic engineering of surface sialylation in living cells. It is versatile, extending the repertoire of modification sites at least to C-9 and enables detailed structure-function studies of sialic acid-dependent ligand-receptor interactions in their native context.
authors.affiliation: Angewandte Tumorvirologie, Deutsches Krebsforschungszentrum, Im Neuenheimer Feld 280, D-69120 Heidelberg, Germany.
authors.forename: Cornelia
authors.initials: C
authors.lastname: Oetke
authors.forename: Reinhard
authors.initials: R
authors.lastname: Brossmer
authors.forename: Lars R
authors.initials: LR
authors.lastname: Mantey
authors.forename: Stephan
authors.initials: S
authors.lastname: Hinderlich
authors.forename: Rainer
authors.initials: R
authors.lastname: Isecke
authors.forename: Werner
authors.initials: W
authors.lastname: Reutter
authors.forename: Oliver T
authors.initials: OT
authors.lastname: Keppler
authors.forename: Michael
authors.initials: M
authors.lastname: Pawlita
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000096:biosynthesis / Q000378:metabolism; D000944:Antigens, Differentiation, B-Lymphocyte / Q000378:metabolism; D002051:Burkitt Lymphoma; D015815:Cell Adhesion Molecules; D002999:Clone Cells; D016895:Culture Media, Serum-Free; D018922:HL-60 Cells; D006801:Humans; D037102:Lectins; D051379:Mice; D019158:N-Acetylneuraminic Acid / Q000031:analogs & derivatives* / Q000096:biosynthesis*; D051918:Sialic Acid Binding Ig-like Lectin 2; D012799:Sialyltransferases; D013379:Substrate Specificity; D014407:Tumor Cells, Cultured; D000094802:beta-D-Galactoside alpha 2-6-Sialyltransferase
chemical_list: D015703:Antigens, CD; D000944:Antigens, Differentiation, B-Lymphocyte; D015815:Cell Adhesion Molecules; D016895:Culture Media, Serum-Free; D037102:Lectins; D019158:N-Acetylneuraminic Acid; D051918:Sialic Acid Binding Ig-like Lectin 2; D012799:Sialyltransferases; C497867:CD22 protein, human; C497868:Cd22 protein, mouse; C093493:ST6GAL1 protein, human; D000094802:beta-D-Galactoside alpha 2-6-Sialyltransferase