title: Identification and characterization of a human CD5+ pre-naive B cell population.
abstract: We have identified a distinct pre-naive B cell population circulating in human peripheral blood that exhibits an intermediate phenotype between transitional and naive B cells. Like human transitional B cells, these cells express CD5 but have intermediate densities of CD38, CD10, CD9, and the ABCB1 transporter compared with transitional and naive B cells. These pre-naive B cells account for a majority of circulating human CD5(+) B cells. Importantly, CD5(+) pre-naive B cells could be induced to differentiate into cells with a naive phenotype in vitro. CD5(+) pre-naive B cells show only partial responses to BCR stimulation and CD40 ligation and undergo more spontaneous apoptosis and cell death than do naive B cells, whereas BAFF/BLyS (B cell-activating factor belonging to the TNF family) did not enhance their survival compared with naive B cells. In contrast, CD5(+) pre-naive B cells carry out certain functions comparable to naive B cells, including the capacity to differentiate into plasma cells and the ability to function as APCs. Notably, an increased proportion of CD5(+) pre-naive B cells were found in peripheral blood of patients with systemic lupus erythematosus. These results have identified a unique intermediate in human naive B cell development within the peripheral blood and derangements of its homeostasis in patients with systemic lupus erythematosus.
authors.affiliation: Department of Internal Medicine, Ewha Womans University School of Medicine, Seoul, Korea.
authors.forename: Jisoo
authors.initials: J
authors.lastname: Lee
authors.forename: Stefan
authors.initials: S
authors.lastname: Kuchen
authors.forename: Randy
authors.initials: R
authors.lastname: Fischer
authors.forename: Sooghee
authors.initials: S
authors.lastname: Chang
authors.forename: Peter E
authors.initials: PE
authors.lastname: Lipsky
mesh_terms: D000328:Adult; D000368:Aged; D016175:B-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology*; D018956:CD5 Antigens / Q000276:immunology* / Q000378:metabolism; D002454:Cell Differentiation / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D054448:Precursor Cells, B-Lymphoid / Q000166:cytology / Q000276:immunology* / Q000378:metabolism
chemical_list: D018956:CD5 Antigens