Activation of macrophages by linear (1right-arrow3)-beta-D-glucans. Impliations for the recognition of fungi by innate immunity

J Biol Chem. 2002 Sep 27;277(39):36825-31. doi: 10.1074/jbc.M206756200. Epub 2002 Jul 24.


Although (1-->3)-beta-d-glucans, which are one of major fungal cell wall components, are known to activate invertebrate innate immune systems, their activities on mammalian cells remain elusive. Here, we report their activities on mouse macrophages. Among the various (1-->3)-beta-d-glucans, curdlan, a linear (1-->3)-beta-d-glucan, although not branched beta-glucans, exhibits significant activity to stimulate nuclear factor-kappaB in macrophages. The activity of curdlan is dramatically enhanced by pretreatment with sodium hydroxide or dimethyl sulfoxide, which disrupts multiple-stranded helices of (1-->3)-beta-d-glucans, and is dose-dependently inhibited by a (1-->3)-beta-d-glucan-binding protein and by laminarioligosaccharides with (1-->3)-beta-d-glucosidic linkages. Intriguingly, the activity of curdlan is also augmented by incubation with zymolyase, which releases (1-->3)-beta-d-glucans with a single helical structure from the glucan-networks assembled by multiple-stranded helices. The activation of macrophages culminates in the production of inducible nitric-oxide synthase, tumor necrosis factor-alpha, and macrophage inflammatory protein-2. Furthermore, a dominant-negative mutant of MyD88, an adaptor protein mediating signaling through the Toll-like receptor/inerleukin-1 receptor-like (TIR) domain, inhibits the activation of macrophages by curdlan. These results strongly suggest that macrophages respond to linear (1-->3)-beta-d-glucans, possibly released from fungal cell walls, via a receptor(s) harboring the TIR domain, such as a Toll-like receptor, to induce inflammatory reactions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing
  • Animals
  • Antigens, Differentiation / metabolism*
  • Blotting, Northern
  • Blotting, Western
  • Cell Line
  • Chemokine CXCL2
  • Dimethyl Sulfoxide / pharmacology
  • Dose-Response Relationship, Drug
  • Escherichia coli / metabolism
  • Fungal Proteins / metabolism*
  • Genes, Dominant
  • Genes, Reporter
  • Glucans / metabolism*
  • Hydrolases / metabolism
  • Immunity*
  • Macrophage Activation*
  • Macrophages / metabolism
  • Mice
  • Monokines / metabolism
  • Myeloid Differentiation Factor 88
  • NF-kappa B / metabolism
  • Nitric Oxide Synthase / metabolism
  • Nitric Oxide Synthase Type II
  • Oligosaccharides / metabolism
  • Protein Binding
  • Protein Structure, Tertiary
  • RNA, Messenger / metabolism
  • Receptors, Immunologic / metabolism*
  • Signal Transduction
  • Sodium Hydroxide / pharmacology
  • Temperature
  • Time Factors
  • Tumor Necrosis Factor-alpha / metabolism
  • beta-Glucans*


  • Adaptor Proteins, Signal Transducing
  • Antigens, Differentiation
  • Chemokine CXCL2
  • Fungal Proteins
  • Glucans
  • Monokines
  • Myd88 protein, mouse
  • Myeloid Differentiation Factor 88
  • NF-kappa B
  • Oligosaccharides
  • RNA, Messenger
  • Receptors, Immunologic
  • Tumor Necrosis Factor-alpha
  • beta-Glucans
  • zymolyase
  • Sodium Hydroxide
  • curdlan
  • Nitric Oxide Synthase
  • Nitric Oxide Synthase Type II
  • Nos2 protein, mouse
  • Hydrolases
  • Dimethyl Sulfoxide