title: Regulation of B1 cell migration by signals through Toll-like receptors.
abstract: Peritoneal B1 cells are known to generate large amounts of antibodies outside their residential site. These antibodies play an important role in the early defense against bacteria and viruses, before the establishment of adaptive immune responses. Although many stimuli, including antigen, lipopolysaccharide, or cytokines, have been shown to activate B1 cells and induce their differentiation into plasma cells, the molecular signals required for their egress from the peritoneal cavity are not understood. We demonstrate here that direct signals through Toll-like receptors (TLRs) induce specific, rapid, and transient down-regulation of integrins and CD9 on B1 cells, which is required for detachment from local matrix and a high velocity movement of cells in response to chemokines. Thus, we revealed an unexpected role for TLRs in governing the interplay between integrins, tetraspanins, and chemokine receptors required for B1 cell egress and, as such, in facilitating appropriate transition from innate to adaptive immune responses.
authors.affiliation: Laboratory for Mucosal Immunity, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan.
authors.forename: Seon-ah
authors.initials: SA
authors.lastname: Ha
authors.forename: Masayuki
authors.initials: M
authors.lastname: Tsuji
authors.forename: Keiichiro
authors.initials: K
authors.lastname: Suzuki
authors.forename: Bob
authors.initials: B
authors.lastname: Meek
authors.forename: Nobutaka
authors.initials: N
authors.lastname: Yasuda
authors.forename: Tsuneyasu
authors.initials: T
authors.lastname: Kaisho
authors.forename: Sidonia
authors.initials: S
authors.lastname: Fagarasan
mesh_terms: D000818:Animals; D016175:B-Lymphocyte Subsets / Q000166:cytology* / Q000276:immunology* / Q000382:microbiology; D002465:Cell Movement / Q000276:immunology*; D002478:Cells, Cultured; D007778:Lactobacillus / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010537:Peritoneum / Q000166:cytology / Q000276:immunology / Q000382:microbiology; D015398:Signal Transduction / Q000276:immunology*; D051197:Toll-Like Receptor 4 / Q000172:deficiency / Q000235:genetics / Q000502:physiology; D051193:Toll-Like Receptors / Q000502:physiology*
chemical_list: C493487:Tlr4 protein, mouse; D051197:Toll-Like Receptor 4; D051193:Toll-Like Receptors