title: Bystander B cells rapidly acquire antigen receptors from activated B cells by membrane transfer.
abstract: The B cell antigen receptor (BCR) efficiently facilitates the capture and processing of a specific antigen for presentation on MHC class II molecules to antigen-specific CD4(+) T cells (1). Despite this, the majority of B cells are thought to play only a limited role in CD4(+) T cell activation because BCRs are clonotypically expressed. Here, we show, however, that activated B cells can, both in vitro and in vivo, rapidly donate their BCR to bystander B cells, a process that is mediated by direct membrane transfer between adjacent B cells and is amplified by the interaction of the BCR with a specific antigen. This results in a dramatic expansion in the number of antigen-binding B cells in vivo, with the transferred BCR endowing recipient B cells with the ability to present a specific antigen to antigen-specific CD4(+) T cells.
authors.affiliation: Divisions of Immunology and Genetics and Molecular Bioscience, The John Curtin School of Medical Research, Australian National University, Canberra ACT 2601, Australia.
authors.forename: Ben J C
authors.initials: BJ
authors.lastname: Quah
authors.forename: Vaughan P
authors.initials: VP
authors.lastname: Barlow
authors.forename: Virginia
authors.initials: V
authors.lastname: McPhun
authors.forename: Klaus I
authors.initials: KI
authors.lastname: Matthaei
authors.forename: Mark D
authors.initials: MD
authors.lastname: Hulett
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Parish
mesh_terms: D001402:B-Lymphocytes / Q000276:immunology* / Q000378:metabolism*; D024201:Bystander Effect / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D002462:Cell Membrane / Q000276:immunology / Q000378:metabolism*; D002478:Cells, Cultured; D007136:Immunoglobulins / Q000276:immunology / Q000378:metabolism; D008213:Lymphocyte Activation / Q000276:immunology*; D011947:Receptors, Antigen, B-Cell / Q000276:immunology / Q000378:metabolism*; D012680:Sensitivity and Specificity; D013997:Time Factors
chemical_list: D007136:Immunoglobulins; D011947:Receptors, Antigen, B-Cell