Submerged cultivation of Ganoderma lucidum and the effects of its polysaccharides on the production of human cytokines TNF-α, IL-12, IFN-γ, IL-2, IL-4, IL-10 and IL-17

Abstract

An original strain of Ganoderma lucidum (W.Curt.:Fr.) Lloyd, MZKI G97 isolated from Slovenian habitats was grown by a submerged liquid substrate cultivation in a laboratory stirred tank reactor. Five fractions of extracellular and cell-wall polysaccharides were obtained by extraction, ethanol precipitation, and purification by ion-exchange, gel and affinity chromatography. The capacity of isolated polysaccharide fractions to induce innate inflammatory cytokines, and to modulate cytokine responses of activated lymphocytes was investigated. Human peripheral blood mononuclear cells (PBMC) were activated in vitro with polysaccharide fractions, in order to induce innate inflammatory cytokines: tumor necrosis factor alpha (TNF-α), interleukin (IL) 12 and interferon gamma (IFN-γ). For the immunomodulation capacity, polysaccharide fractions were cultured with ionomycine and phorbol myristate acetate (IONO+PMA) activated PBMC, and the concentrations of induced IL-2, IL-4, IFN-γ, IL-10 and IL-17 were measured. The results showed that polysaccharides from G. lucidum induced moderate to high amounts of innate inflammatory cytokines. Fungal cell-wall polysaccharides were stronger innate inflammatory cytokines inducers, while extracellular polysaccharides demonstrated a higher capacity to modulate cytokine responses of IONO+PMA induced production of IL-17. The results indicate that G. lucidum polysaccharides enhance Th1 response with high levels of IFN-γ and IL-2, and display low to no impact on IL-4 production. A similar pattern was observed at regulatory cytokine IL-10. All of the polysaccharide fractions tested induced IL-17 production at different concentration levels.