Influence of polysaccharides on neutrophil function: Specific antagonists suggest a model for cooperative saccharide‐associated inhibition of immune complex‐triggered superoxide production

Abstract

We have previously shown that certain monosaccharides (N-acetyl-D-glucosamine and mannose) could cooperatively inhibit the ability of neutrophils to release superoxide anions in response to immune complexes. To test the possible origins of the cooperative inhibition of superoxide release, we have examined the effect of a panel of polysaccharides on superoxide release in the presence or absence of immune complexes. Although exposure to particulate beta-glucan and hyaluronan triggered superoxide release from neutrophils, other polysaccharides including chitin and mannan were without effect. Both chitin and mannan, but not other polysaccharides, inhibited the immune complex-mediated stimulation of superoxide release in a dose-dependent fashion. In sharp contrast to the cooperative inhibition mediated by monosaccharides, chitin and mannan exhibited Hill coefficients of 1. This inhibition of superoxide production was not due to simple blockage of Fc receptors since fluorescent immune complexes bound equally well to neutrophils in the presence or absence of mannan or chitin as shown by epifluorescence microscopy and quantitative fluorometry. Furthermore, this inhibition of superoxide release was not observed when neutrophils were stimulated with phorbol myristate acetate and ionophore A23187 or hyaluronan. Therefore, the specific inhibition of superoxide production by mannan and chitin could not be explained by either receptor blockage or by some nonspecific effect on cells. We suggest that these molecules interfere with a step in transmembrane signaling, presumably involving the integrin CR3. The observed Hill coefficients suggest the possibility that one polysaccharide may simultaneously bind to two monosaccharide binding sites yielding a Hill coefficient of 1, whereas individual monosaccharides separately bind yielding a Hill coefficient of 2.

Effect of relative humidity on the aerosolization and total inflammatory potential of fungal particles from dust-inoculated gypsum boards

“…The β‐glucans have been shown to induce inflammation by activation of both neutrophils (Zhang and Petty, ) and macrophages (Lebron et al., ). In our study, β‐glucan per culturable fungal unit was significantly higher when aerosolized from high RH compared with low RH in both the inhalable and PM 1 fraction, and similarly to TIP, β‐glucan was high in the PM 1 fraction despite the low number of culturable fungal units.…”

β‐Glucan supplementation, allergy symptoms, and quality of life in self‐described ragweed allergy sufferers

“…1994; Lebron et al. 2003) and neutrophils (Zhang and Petty 1994) and are primarily responsible for stimulating the reticuloendothelial system (Di Carlo and Fiore 1958; Riggi and Di Luzio 1961; Wooles and Diluzio 1963). …”

Enzyme-Linked Immunosorbent Assay Specific for (1→6) Branched, (1→3)-β- d -Glucan Detection in Environmental Samples

“…The molecular weight, degree of (136)-linked side branching, helical conformation, and solubility are the most important factors which determine the biological activities of (133)-␤-D-glucans. The biological activities of (133)-␤-D-glucans include host-mediated antitumor activity (11), adjuvant effects (21), and activation of neutrophils (34), eosinophils (23), macrophages (15,27), and complement (26).…”