Versatile biosynthetic engineering of sialic acid in living cells using synthetic sialic acid analogues.
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.
Oetke
Cornelia
C
Angewandte Tumorvirologie, Deutsches Krebsforschungszentrum, Im Neuenheimer Feld 280, D-69120 Heidelberg, Germany.
Brossmer
Reinhard
R
Mantey
Lars R
LR
Hinderlich
Stephan
S
Isecke
Rainer
R
Reutter
Werner
W
Keppler
Oliver T
OT
Pawlita
Michael
M
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
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