Abstract
T cell activation depends not only on the expression of a TCR, but also on that of accessory molecules that function in cell-cell adhesion and/or signal transduction. The subject of this report is the biochemical and functional characterization of what appears to be a novel murine lymphocyte cell surface antigen, provisionally termed sgp-60. Extensive, higher-order cross-linking of this glycoprotein with an anti-sgp-60 mAb and a second-step antibody reagent results in the activation of resting CD4+ T cells in the presence of a second signal. Monovalent or bivalent engagement of sgp-60 by the anti-sgp-60 antibody results in profound and direct inhibition of anti-CD3- or Con A-driven T cell activation, whereas alternative T cell activation via the phosphatidylinositol-linked proteins Thy-1 and TAP/Ly-6A is not affected. These findings raise the possibility that the sgp-60 molecule may be specifically involved in signal transduction through the TCR/CD3 complex and thus point to an important physiologic role for this protein in CD4+ T cells.
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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Antibodies, Monoclonal
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Antigen-Presenting Cells / immunology
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Antigens, Differentiation, T-Lymphocyte / analysis
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Antigens, Differentiation, T-Lymphocyte / physiology*
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Antigens, Ly / physiology
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Antigens, Surface / physiology*
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CD2 Antigens
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CD3 Complex
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Glycoproteins / analysis
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Glycoproteins / physiology*
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Glycosylation
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Interleukin-2 / pharmacology
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Lymphocyte Activation*
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Macromolecular Substances
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Mice
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Molecular Weight
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Phosphatidylinositols / physiology
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Precipitin Tests
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Receptors, Antigen, T-Cell / physiology*
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Receptors, Immunologic / analysis
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Receptors, Interleukin-2 / metabolism
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Signal Transduction
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T-Lymphocytes / physiology*
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Thy-1 Antigens
Substances
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Antibodies, Monoclonal
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Antigens, Differentiation, T-Lymphocyte
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Antigens, Ly
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Antigens, Surface
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CD2 Antigens
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CD3 Complex
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Glycoproteins
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Interleukin-2
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Macromolecular Substances
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Phosphatidylinositols
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Receptors, Antigen, T-Cell
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Receptors, Immunologic
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Receptors, Interleukin-2
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Thy-1 Antigens