RESUMO
Our previous study has demonstrated that Ganoderma atrum polysaccharide (PSG-1) has immunomodulatory activity on spleen lymphocytes. However, how PSG-1 exerts its effect on purified lymphocytes is still obscure. Thus, this study aimed to investigate the immunomodulatory activity of PSG-1 on purified T lymphocytes and further elucidate the underlying mechanism based on RNA sequencing (RNA-seq). Our results showed that PSG-1 promoted T lymphocytes proliferation and increased the production of IL-2, IFN-γ, and IL-12. Meanwhile, RNA-seq analysis found 394 differentially expressed genes. KEGG pathway analysis identified 20 significant canonical pathways and seven biological functions. Furthermore, PSG-1 elevated intracellular Ca2+ concentration and calcineurin (CaN) activity and raised the p-ERK, p-JNK, and p-p38 expression levels. T lymphocytes proliferation and the production of IL-2, IFN-γ, and IL-12 were decreased by the inhibitors of calcium channel and mitogen-activated protein kinases (MAPKs). These results indicated that PSG-1 possesses immunomodulatory activity on purified T lymphocytes, in which Ca2+/CaN and MAPK pathways play essential roles.
Assuntos
Calcineurina/imunologia , Cálcio/imunologia , Ganoderma/química , Fatores Imunológicos/farmacologia , Extratos Vegetais/farmacologia , Polissacarídeos/farmacologia , Linfócitos T/efeitos dos fármacos , Verduras/química , Calcineurina/genética , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Interleucina-12/genética , Interleucina-12/imunologia , Interleucina-2/genética , Interleucina-2/imunologia , Proteína Quinase 3 Ativada por Mitógeno/genética , Proteína Quinase 3 Ativada por Mitógeno/imunologia , Análise de Sequência de RNA , Linfócitos T/imunologia , Proteínas Quinases p38 Ativadas por Mitógeno/genética , Proteínas Quinases p38 Ativadas por Mitógeno/imunologiaRESUMO
Ganoderma atrum (G. atrum), a member of the genus Ganoderma, is an edible and medicinal fungus. In this study, we investigated the direct and indirect effects of G. atrum polysaccharide (PSG-1) on dendritic cells (DCs). Firstly, flow cytometric and ELISA analysis showed that PSG-1 increased cell surface molecule expression of MHC-II, CD80 and CD86, and enhanced the production of IL-12 p70, IL-6, IL-10, RANTES, MIP-1α and MCP-1 in DCs. PSG-1-treated DCs promoted the proliferation of splenic T lymphocyte of mouse in mixed lymphocyte reaction. The above results demonstrated that PSG-1 induced the maturation of DCs. Secondly, PSG-1 increased the phosphorylation of p38, ERK and JNK determined by western blot. Inhibitors of p38, ERK and JNK decreased PSG-1-induced expression of MHC-II, CD80 and CD86 and production of IL-6 and IL-10 by DCs. These results suggested that PSG-1 induced mitogen-activated protein kinase (MAPK) activation was involved in the regulation of maturation markers and cytokines expression in DCs. Finally, PSG-1 increased expression of MHC-II of DCs in a DCs-Caco-2 co-culture model, suggesting that PSG-1 could indirectly influence DCs. In summary, our data suggested that PSG-1 directly induced DCs maturation via activating MAPK pathways, and indirectly stimulated DCs separated by intestinal epithelial cells.