title: Dynamics of the splenic innate-like CD19⁺CD45Rlo cell population from adult mice in homeostatic and activated conditions.
abstract: In the adult spleen, CD19⁺CD45R(-/lo) (19⁺45R(lo)) lymphocytes of embryonic origin exist as a distinct population to that of the conventional B cell lineage. These cells display a plasmablast phenotype, and they spontaneously secrete IgG1 and IgA, whereas the bone marrow population of 19⁺45R(lo) cells contains B1 progenitors. In this study, we show that 19⁺45R(lo) cells are also present in Peyer's patches and in the spleen throughout the life span of wild-type mice, beginning at postnatal day 7. Although this population is heterogeneous, the surface phenotype of most of these cells distinguishes them from follicular, transitional, marginal zone, and B1 cells. In CBA/CaHN mice, few 19⁺45R(lo) cells were detected at postnatal day 7, and none was observed in the adult spleen. Splenic 19⁺45R(lo) cells exhibited homeostatic BrdU uptake in vivo and actively transcribed cell cycle genes. When transferred to immunodeficient RAG2⁻/⁻γchain⁻/⁻ recipient mice, 19⁺45R(lo) cells survived and differentiated into IgG1- and IgA-plasma cells. Moreover, in vitro stimulation of splenic 19⁺45R(lo) cells with LPS, CpG, BAFF/IL4, and CD40/IL4 induced cell proliferation, IgG1/IgA secretion and the release of IL-10, suggesting a potential immunoregulatory role for this subset of innate-like B cells.
authors: Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, 28220 Madrid, Spain. bdandres@isciii.es
authors: Belén
authors: B
authors: de Andrés
authors: Carmen
authors: C
authors: Prado
authors: Beatriz
authors: B
authors: Palacios
authors: Mario
authors: M
authors: Alía
authors: Sharmili
authors: S
authors: Jagtap
authors: Natalia
authors: N
authors: Serrano
authors: Isabel
authors: I
authors: Cortegano
authors: Miguel Angel R
authors: MA
authors: Marcos
authors: Maria Luisa
authors: ML
authors: Gaspar
mesh_terms: D000375:Aging / Q000276:immunology; D000818:Animals; D000831:Animals, Newborn; D018941:Antigens, CD19 / Q000096:biosynthesis*; D016175:B-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D006706:Homeostasis / Q000276:immunology*; D007113:Immunity, Innate; D007070:Immunoglobulin A / Q000378:metabolism; D007074:Immunoglobulin G / Q000378:metabolism; D016753:Interleukin-10 / Q000096:biosynthesis; D017493:Leukocyte Common Antigens / Q000378:metabolism*; D008213:Lymphocyte Activation / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D018345:Mice, Knockout; D056004:Molecular Dynamics Simulation; D013154:Spleen / Q000166:cytology / Q000276:immunology* / Q000378:metabolism
chemical_list: D018941:Antigens, CD19; C556062:IL10 protein, mouse; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D016753:Interleukin-10; D017493:Leukocyte Common Antigens