Expression of N-acetylglucosamine 6-O-sulfotransferases (GlcNAc6STs)-1 and -4 in human monocytes: GlcNAc6ST-1 is implicated in the generation of the 6-sulfo N-acetyllactosamine/Lewis x epitope on CD44 and is induced by TNF-alpha.
Sulfation at the 6-O position of N-acetylglucosamine (GlcNAc) in the context of sialyl 6-sulfo Lewis x occurs constitutively on specific glycoproteins present on high-walled endothelial venules (HEV) and is important for L-selectin dependent homing of lymphocytes. Here, the proinflammatory cytokine, TNF-alpha, induced the expression of 6-sulfo N-acetyllactosamine (LacNAc)/Lewis x on human peripheral blood monocytes (PBM). This epitope was detected by monoclonal antibody (mAb) AG107 after neuraminidase treatment suggesting a sialylated epitope, which was present on the cell adhesion molecule, CD44. Treatment of human PBM with TNF-alpha up-regulated the expression of N-acetylglucosamine 6-O-sulfotransferase-1 (GlcNAc6ST-1) and GlcNAc6ST-4, as determined by reverse transcriptase polymerase chain reaction (RT-PCR). However, only GlcNAc6ST-1 was induced by TNF-alpha in the human SR91 cell line, which also up-regulated the AG107 epitope. In ECV304 cells, the expression of GlcNAc6ST-4 alone was insufficient to generate the AG107 epitope. However, the transfection of GlcNAc6ST-1 resulted in significant sulfate incorporation into CD44 and generated the 6-sulfo LacNAc/Lewis x epitope on CD44, which was present largely on N-linked glycans. This demonstrates the induction of GlcNAc6STs in human monocytes in response to TNF-alpha and implicates GlcNAc6ST-1 in the generation of the 6-sulfo LacNAc/Lewis x epitope on CD44.
Tjew
Sie Lung
SL
Department of Microbiology and Immunology, University of British Columbia, 300-6174 University Boulevard, Vancouver, British Columbia, Canada V6T 1Z3.
Brown
Kelly L
KL
Kannagi
Reiji
R
Johnson
Pauline
P
D000606:Amino Sugars / Q000378:metabolism*; D001483:Base Sequence; D017931:DNA Primers; D000939:Epitopes / Q000378:metabolism*; D006801:Humans; D018960:Hyaluronan Receptors / Q000378:metabolism*; D016256:Lewis X Antigen / Q000378:metabolism*; D009000:Monocytes / Q000187:drug effects* / Q000201:enzymology / Q000276:immunology / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015238:Sulfotransferases / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D000097811:Carbohydrate Sulfotransferases
D000606:Amino Sugars; D017931:DNA Primers; D000939:Epitopes; D018960:Hyaluronan Receptors; D016256:Lewis X Antigen; D015238:Sulfotransferases; D014409:Tumor Necrosis Factor-alpha; D000097811:Carbohydrate Sulfotransferases; C000458:N-acetyllactosamine; C412374:N-acetylglucosamine-6-O--sulfotransferase-4