title: Isolation and characterization of baker's yeast capable of strongly activating a macrophage.
abstract: A physiological function of the β-glucans which constitute the cell wall of Saccharomyces cerevisiae is to activate immune cells. Here, we focused on the immunostimulation ability of S. cerevisiae itself to give this ability to fermented foods including yeast. Previously, we found that in S. cerevisiae the deletion of MCD4 gene causes exposure of β-glucans on the cell surface and that the mcd4 deletion mutant strongly enhances immunity in vitro and in vivo. However, this is not a practical strain but a genetically modified strain with an antibiotic resistance gene, and growth was very slow. The aim of this study was to acquire a practical strain capable of strongly activating a macrophage. The parental strain y-21 was mutated with ethyl methanesulfonate, and the resulting strain was screened. Two mutants (AP-57 and AQ-37) were obtained. AQ-37 had the same fermentation capacity as y-21. In addition, a mutation point of AQ-37 was identified, suggesting that the mutation of NDD1 gene affects the cell wall structure and confers a high ability for macrophage stimulation. The obtained yeast may activate immune cells in materials to which the yeast is added.
authors.affiliation: Department of Applied Chemistry and Bioengineering, Graduate School of Engineering, Osaka City University, Osaka, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Takada
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Nishino
authors.forename: Chinatsu
authors.initials: C
authors.lastname: Ito
authors.forename: Hajime
authors.initials: H
authors.lastname: Watanabe
authors.forename: Ken
authors.initials: K
authors.lastname: Kanzaki
authors.forename: Taro
authors.initials: T
authors.lastname: Tachibana
authors.forename: Masayuki
authors.initials: M
authors.lastname: Azuma
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D002473:Cell Wall / Q000378:metabolism; D005285:Fermentation; D005800:Genes, Fungal; D008262:Macrophage Activation / Q000276:immunology*; D008264:Macrophages / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology*; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development / Q000276:immunology* / Q000302:isolation & purification*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
chemical_list: D014409:Tumor Necrosis Factor-alpha
keywords: NDD1 gene; Saccharomyces cerevisiae; cell wall mutant; macrophage activation; β-glucan