Abstract
CD19 and CD22 are B lymphocyte cell-surface molecules that positively and negatively regulate antigen receptor signal transduction, respectively. Biochemical studies with B cells from CD19-deficient and CD22-deficient mice indicated that these two regulatory molecules influenced each other's functions: CD22 expression negatively regulated CD19 tyrosine phosphorylation, while optimal CD22 function was dependent on CD19 expression. Functional CD19 and CD22 interactions were also assessed in vivo by generating CD19/CD22 double-deficient mice. Remarkably, the CD19 mutation was dominant to the CD22 mutation in most instances. B lymphocytes from CD19/CD22-deficient and CD19-deficient mice were functionally equivalent despite the negative influence normally provided by CD22 expression. These data collectively suggest that CD19 activates the CD22/SHP1 inhibitory pathway that then acts primarily on CD19.
Publication types
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Animals
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Antibody Formation
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Antigens, CD / physiology*
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Antigens, CD19 / physiology*
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Antigens, Differentiation, B-Lymphocyte / physiology*
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Calcium / metabolism
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Cell Adhesion Molecules*
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Immunoglobulin M / analysis
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Intracellular Signaling Peptides and Proteins
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Lectins*
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Mice
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Phosphorylation
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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 / metabolism
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Receptors, Antigen, B-Cell / analysis
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Receptors, Antigen, B-Cell / physiology*
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Sialic Acid Binding Ig-like Lectin 2
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Signal Transduction*
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Tyrosine / metabolism
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src-Family Kinases / metabolism
Substances
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Antigens, CD
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Antigens, CD19
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Antigens, Differentiation, B-Lymphocyte
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Cd22 protein, mouse
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Cell Adhesion Molecules
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Immunoglobulin M
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Intracellular Signaling Peptides and Proteins
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Lectins
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Receptors, Antigen, B-Cell
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Sialic Acid Binding Ig-like Lectin 2
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Tyrosine
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lyn protein-tyrosine kinase
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src-Family Kinases
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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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Calcium