Phagocytosis by human neutrophils is stimulated by a unique fungal cell wall component

Cell Host Microbe. 2007 Jul 12;2(1):55-67. doi: 10.1016/j.chom.2007.06.002.

Abstract

Innate immunity depends upon recognition of surface features common to broad groups of pathogens. The glucose polymer beta-glucan has been implicated in fungal immune recognition. Fungal walls have two kinds of beta-glucan: beta-1,3-glucan and beta-1,6-glucan. Predominance of beta-1,3-glucan has led to the presumption that it is the key immunological determinant for neutrophils. Examining various beta-glucans for their ability to stimulate human neutrophils, we find that the minor cell wall component beta-1,6-glucan mediates neutrophil activity more efficiently than beta-1,3-glucan, as measured by engulfment, production of reactive oxygen species, and expression of heat shock proteins. Neutrophils rapidly ingest beads coated with beta-1,6-glucan while ignoring those coated with beta-1,3-glucan. Complement factors C3b/C3d are deposited on beta-1,6-glucan more readily than on beta-1,3-glucan. Beta-1,6-glucan is also important for efficient engulfment of the human pathogen Candida albicans. These unique stimulatory effects offer potential for directed stimulation of neutrophils in a therapeutic context.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Candida / physiology*
  • Cell Wall / physiology*
  • Gene Expression Regulation
  • Heat-Shock Proteins / genetics
  • Heat-Shock Proteins / physiology
  • Humans
  • Neutrophils / microbiology
  • Neutrophils / physiology*
  • Oligonucleotide Array Sequence Analysis
  • Phagocytosis / physiology*
  • Polymerase Chain Reaction
  • beta-Glucans / pharmacology

Substances

  • Heat-Shock Proteins
  • beta-Glucans