title: Kinetics of B cell receptor signaling in human B cell subsets mapped by phosphospecific flow cytometry.
abstract: Differences in BCR signaling may govern outcomes as diverse as proliferation and cell death. We profiled BCR signaling kinetics in subsets of primary human B cells using flow cytometry. In the predominant population expressing IgM, BCR cross-linking led to a quick burst of Syk, ERK1/2, and p38 signaling. In contrast, IgG B cells sustained higher per-cell ERK1/2 phosphorylation over time. This dichotomy suggested a mechanism for dampening signals transmitted by IgM. Regulatory phosphatase activity in IgM B cells was BCR-mediated and initiated more slowly than kinase activity. This BCR-mediated phosphatase activity was sensitive to inhibition by H(2)O(2) and required to attenuate IgM BCR signaling. These results provide the first kinetic maps of BCR signaling in primary human B cell subsets and enable new studies of signaling in B cell disorders, such as autoimmunity and cancer.
authors.affiliation: Department of Medicine, Oncology Division, Stanford University, Stanford, CA 94305, USA.
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Irish
authors.forename: Debra K
authors.initials: DK
authors.lastname: Czerwinski
authors.forename: Garry P
authors.initials: GP
authors.lastname: Nolan
authors.forename: Ronald
authors.initials: R
authors.lastname: Levy
mesh_terms: D000077329:Agammaglobulinaemia Tyrosine Kinase; D016175:B-Lymphocyte Subsets / Q000201:enzymology / Q000276:immunology* / Q000378:metabolism*; D005434:Flow Cytometry / Q000379:methods*; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry; D007074:Immunoglobulin G / Q000096:biosynthesis / Q000378:metabolism; D007075:Immunoglobulin M / Q000096:biosynthesis / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D007700:Kinetics; D020935:MAP Kinase Signaling System / Q000276:immunology*; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism / Q000502:physiology; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism / Q000502:physiology; D010449:Peptide Mapping / Q000379:methods; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D011947:Receptors, Antigen, B-Cell / Q000378:metabolism / Q000502:physiology*; D000072377:Syk Kinase
chemical_list: D007074:Immunoglobulin G; D007075:Immunoglobulin M; D047908:Intracellular Signaling Peptides and Proteins; D011947:Receptors, Antigen, B-Cell; D006861:Hydrogen Peroxide; D011505:Protein-Tyrosine Kinases; D000077329:Agammaglobulinaemia Tyrosine Kinase; C000606896:SYK protein, human; D000072377:Syk Kinase; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3