Armillariella mellea induces maturation of human dendritic cells without induction of cytokine expression

Abstract

Ethnopharmacological relevance Armillariella mellea, an edible and medicinal mushroom possessing immuno-modulating potential, has been frequently used for the treatment of infectious diseases or cancers. Aim of the study In order to elucidate immune-regulatory mechanisms of Armillariella mellea, we investigated the effect of water-soluble components from Armillariella mellea (AME) on the regulation of human dendritic cell (DC) maturation and activation. Materials and Methods Immature DCs (iDCs) were prepared by differentiating human peripheral blood CD14-positive cells with GM-CSF and IL-4. Then, iDCs were treated with AME at 2–20 μg/ml for 48 h and subjected to flow cytometry to analyze the expression of DC markers. Dextran-FITC uptake assay and enzyme-linked immunosorbent assay were performed to examine the endocytic capacity of AME-stimulated DC and their production of cytokines, respectively. Results iDCs stimulated with AME showed representative features during DC maturation such as up-regulated expression of CD80, CD83, CD86, both MHC class I and II molecules, and CD205, with a simultaneous decrease in the expression of CD206 and the endocytic capacity. Interestingly, AME was not able to induce the production of TNF-α, IL-12p40, or IL-10, whereas lipopolysaccharides induced a substantial increase of all of the cytokines. Conclusion Armillariella mellea induces maturation of human DCs through a unique mechanism without inducing cytokine expression.