title: Most B cells in non-lymphoid tissues are naïve.
abstract: The current view of lymphocyte migration states that naïve lymphocytes re-circulate between the blood and the lymph via the lymph nodes, but are not able to access non-lymphoid tissues. We examined B lymphocytes in peripheral tissues and found that the majority were phenotypically similar to naïve B cells in lymphoid tissues and were located within the parenchyma, not associated with blood vessels. The mutation rate within the Vh region of these cells was substantially less than the rate attributed to somatic hypermutation and was identical to that observed in naïve B cells isolated from the lymph nodes, showing the presence of naïve B cells in the non-lymphoid organs. Further, using FTY720-treated mice, we showed that naïve B cells migrate through the peripheral tissues and, using pertussis toxin, that the entry of B cells was not controlled by chemokine-mediated signalling events. Overall, these results show that naïve B lymphocytes constitute the majority of the total B-cell population in non-lymphoid tissues and suggest that these cells may re-circulate through the periphery as part of their normal migration pathway. This has implications for the current view of the role of naïve B cells in priming and tolerance.
authors.affiliation: Division of Veterinary Pathology, Infection and Immunity, School of Clinical Veterinary Science, University of Bristol, North Somerset, UK.
authors.forename: Charlotte F
authors.initials: CF
authors.lastname: Inman
authors.forename: Tamsin Zangerle
authors.initials: TZ
authors.lastname: Murray
authors.forename: Mick
authors.initials: M
authors.lastname: Bailey
authors.forename: Stephen
authors.initials: S
authors.lastname: Cose
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D002460:Cell Line; D002465:Cell Movement; D018925:Chemokines / Q000378:metabolism; D005260:Female; D007135:Immunoglobulin Variable Region / Q000235:genetics; D007156:Immunologic Memory / Q000276:immunology*; D008099:Liver / Q000276:immunology*; D008168:Lung / Q000276:immunology*; D008198:Lymph Nodes / Q000276:immunology; D008221:Lymphoid Tissue / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D009092:Mucous Membrane / Q000276:immunology; D037342:Pertussis Toxin / Q000276:immunology; D010641:Phenotype; D054448:Precursor Cells, B-Lymphoid / Q000276:immunology* / Q000378:metabolism; D017422:Sequence Analysis, DNA; D013154:Spleen / Q000276:immunology
chemical_list: D018925:Chemokines; D007135:Immunoglobulin Variable Region; D037342:Pertussis Toxin