title: Promotion of IL-4- and IL-5-dependent differentiation of anti-mu-primed B cells by ascorbic acid 2-glucoside.
abstract: The stable ascorbic acid derivative 2-O-alpha-D-glucopyranosyl-L-ascorbic acid (AA-2G) was used to investigate the role of ascorbic acid (AA) in B cell differentiation in vitro. AA-2G is stable in a solution unlike AA but is hydrolyzed by cellular alpha-glucosidase to release AA. Mouse spleen B cells were primed for 2 days with an anti-mu antibody in the presence of interleukin (IL)-4 and IL-5 and then washed and recultured with AA-2G in the presence of IL-4 and IL-5. AA-2G, but not AA, dose-dependently increased IgM production, the greatest enhancement being 150% at concentrations of more than 0.5mM. In the absence of IL-4 and IL-5, primed B cells produced a negligible amount of IgM, and AA-2G had no effect. AA-2G-induced IgM production in the presence of IL-4 and IL-5 was inhibited by the alpha-glucosidase inhibitor castanospermine. Intracellular AA content, depleted during the priming period, increased by adding AA-2G at the start of reculture. Treatment of B cells with AA-2G resulted in an increase in the number of IgM-secreting cells, CD138-positive cells and CD45R/B220-negative cells. The number of viable cells in untreated cultures decreased gradually, but the decrease was significantly attenuated by AA-2G, resulting in about 70% more viable cells in AA-2G-treated cultures. AA-2G caused a slight but reproducible enhancement of DNA synthesis and a slight decrease in the number of cells with a sub-G1 DNA content. These results demonstrated that AA released from AA-2G enhanced cytokine-dependent IgM production in anti-mu-primed B cells and suggest that its effect is caused through promoting the differentiation of B cells to plasma cells and attenuating the gradual decrease in the number of viable cells.
authors.affiliation: Department of Immunochemistry, Division of Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Ichiyama
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Mitsuzumi
authors.forename: Ming
authors.initials: M
authors.lastname: Zhong
authors.forename: Akihiro
authors.initials: A
authors.lastname: Tai
authors.forename: Akihiro
authors.initials: A
authors.lastname: Tsuchioka
authors.forename: Saeko
authors.initials: S
authors.lastname: Kawai
authors.forename: Itaru
authors.initials: I
authors.lastname: Yamamoto
authors.forename: Eiichi
authors.initials: E
authors.lastname: Gohda
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000378:metabolism; D000917:Antibody Formation / Q000187:drug effects* / Q000276:immunology; D001205:Ascorbic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D002454:Cell Differentiation / Q000187:drug effects* / Q000276:immunology; D002478:Cells, Cultured; D005260:Female; D007148:Immunoglobulin mu-Chains / Q000276:immunology; D018189:Immunomagnetic Separation; D015847:Interleukin-4 / Q000378:metabolism*; D015848:Interleukin-5 / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D013154:Spleen / Q000166:cytology
chemical_list: D000911:Antibodies, Monoclonal; D007148:Immunoglobulin mu-Chains; D015848:Interleukin-5; D015847:Interleukin-4; C065378:ascorbic acid 2-O-glucoside; D001205:Ascorbic Acid