RESUMO
Dictyophora indusiata, an edible mushroom, is widely used not only as health foods but also as traditional Chinese medicine. This study aimed to investigate the molecular mechanism involved in the immunostimulatory activity of a polysaccharide from Dictyophora indusiata (DIP) in RAW264.7 cells. Results indicated that DIP induced the up-regulation of nitric oxide (NO), interleukin-1ß (IL-1ß), interleukin-6 (IL-6) and tumour necrosis factor (TNF-α) production as well as the mRNA expression levels of iNOS, IL-1ß, IL-6 and TNF-α in macrophages. Furthermore, the functional blocking antibodies against TLR4 could markedly suppress DIP-mediated NO, IL-1ß, IL-6 and TNF-α production. Flow cytometry and confocal laser-scanning microscopy analyses confirmed that DIP could bind specifically to target cells, and the binding could be inhibited by anti-TLR4 monoclonal antibodies. The expression of nuclear factor kappa B (NF-κB) p65 was significantly induced by DIP. Therefore, the DIP-induced macrophage activation may be mediated via the TLR4/NF-κB signalling pathway.
Assuntos
Adjuvantes Imunológicos/farmacologia , Agaricales/química , Polissacarídeos Fúngicos/farmacologia , Macrófagos/metabolismo , Transdução de Sinais/efeitos dos fármacos , Adjuvantes Imunológicos/química , Animais , Linhagem Celular , Polissacarídeos Fúngicos/química , Camundongos , Monocinas/metabolismo , NF-kappa B/metabolismo , Óxido Nítrico/metabolismo , Receptor 4 Toll-Like/metabolismoRESUMO
A water-soluble polysaccharide named DI was extracted from the fruiting bodies of gastroid mushroom Dictyophora indusiata with boiling water. The chemical and physical characteristics of DI were investigated by a combination of chemical and instrumental analysis methods. The immunomodulatory activities on RAW 264.7 macrophage of DI in vitro were also studied. The results showed that DI is a ß-(1â3)-glucan with side branches of ß-(1â6)-glucosyl units, and it has triple-helical structure. DI has no toxic effect on cells, but can promote macrophage multiplication. DI significantly affects the immune function by promoting the production of nitric oxide and cytokines, such as tumor necrosis factor-α, interleukin-1, -6, and -12, showing an obvious dose-effect relationship. This work extends the application scope of the polysaccharide from D. indusiata in the biomedical field.