Immunological Host Defense Mechanism and Applications of Fungal β-Glucans by Employing Dectin-1 Receptor in the Innate Immunity
Mushrooms have been considered as highly valuable sources for the treatment of various diseases with their unique biological and medicinal efficacies.Traditionally some of the medicinal mushrooms have been used to treat cancer,fungal infection,hypertension,diabetes,inflammation and kidney malfunction.Many of the medicinal mushrooms have high-molecular weight β-glucans which have antitumor and antifungal activities by stimulating innate immunity.Innate immune cells have pattern recognition receptors (PRRs) such as Dectin-1,toll-like receptors (TLR),mannose receptors (MRs) and RNA helicases on their surfaces of the cell.These PRRs recognize pathogens by binding with highly conserved pathogen-associated molecular patterns (PAMPs) such as β-glucan,mannan and LPS.The immunomodulating activities of the innate immune cells are augmented by binding to the Dectin-1 receptor of β-glucan on the macrophage or dendritic cells.Upon binding with β-glucan,those innate immunity cells activate adaptive immune cells such as B,T lymphocytes or natural killer cells,by secreting various cytokines of IL-4,IL-6 and TNF-α.Among the β-glucans,water-insoluble β-glucans have stronger immunostimulating activities than those of the water-soluble counterparts.In addition to the anticancer activity,β-glucans have antifungal response by binding to the Dectin-1 in a similar manner which remains to be further understood concerning their anticancer mechanism.The fungal protection responses of the β-glucan occur mainly on the mucosal surface or in the systemic circulating system.Under the situations of immunocompromization,organ-transplantation,consumption of immunosuppresing drug or HIV-infection,patients are susceptible to Candida albicans,Aspergillus fumigatus,Pneumocystis carinii and Cryptococcus neoformans.Even fungal or bacterial infections of aquarium fishes can be prevented by feeding them with β-glucans in their diet.In the defense by β-glucan,these various hosts are believed to utilize Dectin-1 signal transduction.During the elimination of the fungal pathogens by the phagocytes in the host,Dectin-1 recognizes and binds with funga1β-glucan.The recognition and binding by Dectin-1 results in numerous immune responses:mannose receptor shedding,phagosomal maturation,increasing major histocompatibility complex (MHC) recruitment to the phagosome,and secretion of inflammatory cytokines.In this review,recent progresses will be discussed on the antifungal mechanisms of the funga1β-glucan as well as its anticancer functions.
Dectin-1 β-glucan anti-tumor pattern recognition receptor (PRR) pathogen-associated molecular pattern (PAMP)
D.H.LEE H.W.KIM
Department of Life Sciences, University of Seoul, Seoul 130-743, Korea
国际会议
The 7th International Medicinal Mushroom Congerence(第七届国际药用菌大会(IMMC7)
北京
英文
244-258
2013-08-26（万方平台首次上网日期，不代表论文的发表时间）