title: B cell activation involves nanoscale receptor reorganizations and inside-out signaling by Syk.
abstract: Binding of antigen to the B cell antigen receptor (BCR) initiates a multitude of events resulting in B cell activation. How the BCR becomes signaling-competent upon antigen binding is still a matter of controversy. Using a high-resolution proximity ligation assay (PLA) to monitor the conformation of the BCR and its interactions with co-receptors at a 10-20 nm resolution, we provide direct evidence for the opening of BCR dimers during B cell activation. We also show that upon binding Syk opens the receptor by an inside-out signaling mechanism that amplifies BCR signaling. Furthermore, we found that on resting B cells, the coreceptor CD19 is in close proximity with the IgD-BCR and on activated B cells with the IgM-BCR, indicating nanoscale reorganization of receptor clusters during B cell activation.DOI: http://dx.doi.org/10.7554/eLife.02069.001.
authors: BIOSS Centre for Biological Signalling Studies, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany Department of Molecular Immunology, Biology III, Faculty of Biology, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany Max Planck Institute for Immunobiology and Epigenetics, Freiburg, Germany.
authors: Kathrin
authors: K
authors: Kläsener
authors: BIOSS Centre for Biological Signalling Studies, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany Department of Molecular Immunology, Biology III, Faculty of Biology, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany Max Planck Institute for Immunobiology and Epigenetics, Freiburg, Germany.
authors: Palash C
authors: PC
authors: Maity
authors: BIOSS Centre for Biological Signalling Studies, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany Department of Molecular Immunology, Biology III, Faculty of Biology, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany Max Planck Institute for Immunobiology and Epigenetics, Freiburg, Germany.
authors: Elias
authors: E
authors: Hobeika
authors: BIOSS Centre for Biological Signalling Studies, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany Department of Molecular Immunology, Biology III, Faculty of Biology, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany Max Planck Institute for Immunobiology and Epigenetics, Freiburg, Germany.
authors: Jianying
authors: J
authors: Yang
authors: BIOSS Centre for Biological Signalling Studies, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany Department of Molecular Immunology, Biology III, Faculty of Biology, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany Max Planck Institute for Immunobiology and Epigenetics, Freiburg, Germany michael.reth@bioss.uni-freiburg.de.
authors: Michael
authors: M
authors: Reth
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000378:metabolism*; D002460:Cell Line; D019281:Dimerization; D006801:Humans; D008213:Lymphocyte Activation; D051379:Mice; D011947:Receptors, Antigen, B-Cell / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D011947:Receptors, Antigen, B-Cell
keywords: B cell antigen receptor; inside-out signaling; nanoscale receptor organization