Abstract
Core 2 beta-1,6-N-acetylglucosaminyltransferase, C2GnT, is a key enzyme in O-linked oligosaccharide (O-glycan) biosynthesis and the resultant core 2 branch serves as a backbone for additional glycosylation to form oligosaccharide ligands such as sialyl Le(x). Since the expression of C2GnT is highly regulated during T-cell development and increases in pathological conditions such as the Wiskott-Aldrich syndrome, we have generated transgenic mice overexpressing C2GnT in the T-cell lineage. Surprisingly, T lymphocytes in the transgenic mice develop normally, but they exhibit a reduced immune response when assayed by delayed-type hypersensitivity, proliferation upon stimulation and cytokine production. Moreover, T lymphocytes from the transgenic mice adhere much less efficiently to ICAM-1 and fibronectin than do T lymphocytes from non-transgenic mice. These results indicate that overexpression of the core 2 branched O-glycans in T lymphocytes results in reduced immune responses due to impaired cell-cell interaction. Such an impaired immune response may be one of the causes for immunodeficiency in the Wiskott-Aldrich syndrome.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Animals
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Antigens, CD*
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Carbohydrate Conformation
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Carbohydrate Sequence
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Cell Adhesion
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Fibronectins / metabolism
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Glycosylation
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Immune Tolerance / physiology*
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Intercellular Adhesion Molecule-1 / physiology
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Leukosialin
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Lymphocyte Activation
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Lymphocyte Specific Protein Tyrosine Kinase p56(lck) / genetics
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Mice
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Mice, Transgenic
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Molecular Sequence Data
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N-Acetylglucosaminyltransferases / genetics
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N-Acetylglucosaminyltransferases / metabolism*
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Oligosaccharides / chemistry*
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Organ Specificity
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Promoter Regions, Genetic
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Protein Processing, Post-Translational
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Recombinant Fusion Proteins / metabolism
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Sialoglycoproteins / chemistry
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Sialoglycoproteins / physiology
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T-Lymphocytes / cytology
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T-Lymphocytes / enzymology
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T-Lymphocytes / immunology*
Substances
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Antigens, CD
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Fibronectins
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Leukosialin
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Oligosaccharides
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Recombinant Fusion Proteins
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Sialoglycoproteins
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Spn protein, mouse
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Intercellular Adhesion Molecule-1
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N-Acetylglucosaminyltransferases
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beta-1,3-galactosyl-O-glycosyl-glycoprotein beta-1,6-acetylglucosaminyl transferase
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Lymphocyte Specific Protein Tyrosine Kinase p56(lck)