Regulatory effect of Ganoderma lucidum polysaccharides on cytotoxic T-lymphocytes induced by dendritic cells in vitro

摘要

AIM: To study the regulatory effects of Ganoderma lucidum polysaccharides (G/-PS) on cytotoxicity and mechanism of specific cytotoxic T-lymphocytes (CTL) induced by dendritic cells (DC) in vitro during the stage of antigen presentation. METHODS: Cultured murine bone marrow-derived DC were pulsed with P815 tumor cell lysates and co-incubated with or without various concentrations of Gl-PS (0.8, 3.2, or 12.8 mg/L) at the same time. P815 specific CTL were induced by spleen lymphocytes stimulated with mature DC. Non-adherent cells and culture supernatants were harvested on d 5 for analysis of specific cytotoxicity with lactate dehydrogenase (LDH) activity assay, mRNA expression of IFN_γ, granzyme B with RT-PCR assay, and protein expression of IFN_γ, granzyme B with ELISA or Western blot assay, respectively. RESULTS: Three concentrations of Gl-PS promoted LDH activities released into culture supernatants (P<0.01). It also increased mRNA expression of IFNy in CTL (Gl-PS 12.8 mg/L vs RPMI medium 1640, P<0.05) and granzyme B in CTL (P<0.01). Protein production of IFN_γ in culture supernatants (P<0.05) and protein expression of granzyme B in CTL (Gl-PS 12.8 mg/L vs RPMI medium 1640, P<0.05) were also augmented by Gl-PS. CONCLUSION: Gl-PS is shown to promote the cytotoxicity of specific CTL induced by DC which were pulsed with P815 tumor antigen during the stage of antigen presentation, and the mechanism of cytotoxicity is believed to be going through IFN_γ and granzyme B pathways.