摘要

beta-Glucans (BGs) are the major cell wall components of fungi and yeasts. BGs are not found in animals. They are considered to be pathogen-associated molecular patterns (PAMPs), which are recognized by the innate immune system. Although immunomodulating activities have been demonstrated by various BGs prepared from fungi and yeasts, their molecular mechanisms are not fully characterized yet. Recent studies have begun to shed some light on their cellular receptors, such as dectin-1, and their molecular mechanisms of action. We have extensively investigated the response of leukocytes to BG, focusing on cytokine induction by SCG, which is a major 6-branched 1,3-beta-D-glucan in the higher Basidiomycetes mushroom Sparassis crispa. There are strain-related differences in the reactivity of mice to SCG, and DBA/1 and DBA/2 mice are highly sensitive strains. GM-CSF plays a key biological role in this activity, and cytokine induction was completely abolished in dendritic cells from dectin-1 knockout mice. In addition, exogenous as well as endogenous GM-CSF strongly modulated leucocyte reactivity to SCG. In this review, molecular mechanisms of BGs activity are summarized and discussed from the viewpoint of cytokines and receptors.

  • 出版日期2008