title: Eosinophils are required for the maintenance of plasma cells in the bone marrow.
abstract: Plasma cells are of crucial importance for long-term immune protection. It is thought that long-lived plasma cells survive in specialized niches in the bone marrow. Here we demonstrate that bone marrow eosinophils localized together with plasma cells and were the key providers of plasma cell survival factors. In vitro, eosinophils supported the survival of plasma cells by secreting the proliferation-inducing ligand APRIL and interleukin-6 (IL-6). In eosinophil-deficient mice, plasma cell numbers were much lower in the bone marrow both at steady state and after immunization. Reconstitution experiments showed that eosinophils were crucial for the retention of plasma cells in the bone marrow. Moreover, depletion of eosinophils induced apoptosis in long-lived bone marrow plasma cells. Our findings demonstrate that the long-term maintenance of plasma cells in the bone marrow requires eosinophils.
authors.affiliation: Deutsches Rheuma-Forschungszentrum, Institut der Leibniz-Gemeinschaft, Berlin, Germany.
authors.forename: Van Trung
authors.initials: VT
authors.lastname: Chu
authors.forename: Anja
authors.initials: A
authors.lastname: Fröhlich
authors.forename: Gudrun
authors.initials: G
authors.lastname: Steinhauser
authors.forename: Tobias
authors.initials: T
authors.lastname: Scheel
authors.forename: Toralf
authors.initials: T
authors.lastname: Roch
authors.forename: Simon
authors.initials: S
authors.lastname: Fillatreau
authors.forename: James J
authors.initials: JJ
authors.lastname: Lee
authors.forename: Max
authors.initials: M
authors.lastname: Löhning
authors.forename: Claudia
authors.initials: C
authors.lastname: Berek
mesh_terms: D019264:Adoptive Transfer; D000818:Animals; D000943:Antigens, Differentiation / Q000096:biosynthesis; D017209:Apoptosis / Q000276:immunology; D001781:Blood Component Removal; D001853:Bone Marrow / Q000276:immunology / Q000473:pathology*; D002470:Cell Survival / Q000276:immunology; D002478:Cells, Cultured; D004804:Eosinophils / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D007156:Immunologic Memory; D015850:Interleukin-6 / Q000276:immunology / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D010950:Plasma Cells / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D053300:Tumor Necrosis Factor Ligand Superfamily Member 13 / Q000276:immunology / Q000378:metabolism*
chemical_list: D000943:Antigens, Differentiation; D015850:Interleukin-6; D053300:Tumor Necrosis Factor Ligand Superfamily Member 13; C036763:monocyte-macrophage differentiation antigen