Abstract
The B cell receptor is required for the emigration of newly generated B lymphocytes and for their maintenance in the periphery. A specific maintenance defect was noted in fraction I (IgDhighIgMlow) B cells in Xid mice (which harbor a mutation in Btk). Although Bcl-2 levels in fractions I and II (IgDhighIgMhigh) are equivalent in normal and Xid B cells, a novel peak of Bcl-2low fraction III (IgDlowIgMhigh) B cells was noted in the Xid mouse. Since this B cell population resembled bone marrow immature B cells, we examined the emigration of newly formed B cells in normal and Xid mice. These studies revealed the accelerated emigration of newly formed Xid B cells. We conclude that distinct Btk-independent and Btk-dependent signals mediate emigration and maintenance events during peripheral B cell maturation.
Publication types
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Agammaglobulinaemia Tyrosine Kinase
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Animals
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Apoptosis / genetics
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Apoptosis / immunology
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B-Lymphocytes / enzymology
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B-Lymphocytes / metabolism
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B-Lymphocytes / pathology*
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Cell Differentiation / genetics
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Cell Differentiation / immunology
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Cell Movement / genetics*
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Cell Movement / immunology*
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Cell Separation
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Disease Models, Animal
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Immunologic Deficiency Syndromes / enzymology
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Immunologic Deficiency Syndromes / genetics*
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Immunologic Deficiency Syndromes / pathology*
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Mice
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Mice, Inbred CBA
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Mice, Mutant Strains
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Protein-Tyrosine Kinases / deficiency
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Protein-Tyrosine Kinases / genetics
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Proto-Oncogene Proteins c-bcl-2 / deficiency
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Proto-Oncogene Proteins c-bcl-2 / genetics
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Proto-Oncogene Proteins c-bcl-2 / metabolism
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Stem Cells / enzymology
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Stem Cells / metabolism
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Stem Cells / pathology
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X Chromosome / immunology
Substances
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Proto-Oncogene Proteins c-bcl-2
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Protein-Tyrosine Kinases
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Agammaglobulinaemia Tyrosine Kinase
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Btk protein, mouse