Abstract
Fc gamma RIIB1 (CD32) is a receptor that binds the Fc domain of Ag-complexed IgG. Coaggregation of B cell receptor (BCR) and Fc gamma RIIB1 generates a dominant negative signal that inhibits B cell activation. In Ag-specific Id-positive B cells, the co-cross-linking of BCR and Fc gamma RIIB1 by anti-Id Ab resulted in the association of both Src homology 2-containing protein tyrosine phosphatase (SHP-1) and Src homology 2-containing inositol phosphatase (SHIP) with the Fc gamma RIIB1; however, only SHIP activity was detected. "Superclustering" of the BCR and Fc gamma RIIB1 complex induced by stimulation with anti-Id Ab plus polyvalent Ag synergistically activated SHP-1. The degree of co-cross-linking between BCR and Fc gamma RIIB1 may determine the activation status of SHP-1 and SHIP.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Antibodies, Anti-Idiotypic / pharmacology
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Enzyme Activation / immunology
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Haptens / genetics
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Intracellular Signaling Peptides and Proteins
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Lymphoma, B-Cell / immunology
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Lymphoma, B-Cell / metabolism
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Mice
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Phosphorylation
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Protein Phosphatase 1
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Protein Tyrosine Phosphatase, Non-Receptor Type 11
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Protein Tyrosine Phosphatase, Non-Receptor Type 6
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Protein Tyrosine Phosphatases / antagonists & inhibitors
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Protein Tyrosine Phosphatases / metabolism*
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Receptor Aggregation / immunology*
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Receptors, Antigen, B-Cell / genetics
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Receptors, Antigen, B-Cell / metabolism*
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Receptors, Antigen, B-Cell / physiology
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Receptors, IgG / metabolism*
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Receptors, IgG / physiology
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SH2 Domain-Containing Protein Tyrosine Phosphatases
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Serum Albumin, Bovine / genetics
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Serum Albumin, Bovine / immunology
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Signal Transduction / immunology
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Transfection / immunology
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Trinitrobenzenes / immunology
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Tumor Cells, Cultured
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src Homology Domains / immunology*
Substances
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Antibodies, Anti-Idiotypic
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Haptens
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Intracellular Signaling Peptides and Proteins
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Receptors, Antigen, B-Cell
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Receptors, IgG
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Trinitrobenzenes
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trinitrophenyl-bovine serum albumin
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Serum Albumin, Bovine
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Protein Phosphatase 1
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Protein Tyrosine Phosphatase, Non-Receptor Type 11
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Protein Tyrosine Phosphatase, Non-Receptor Type 6
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Protein Tyrosine Phosphatases
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Ptpn11 protein, mouse
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Ptpn6 protein, mouse
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SH2 Domain-Containing Protein Tyrosine Phosphatases