In vitro and in vivo immunomodulatory activity of acetylated polysaccharides from Cyclocarya paliurus leaves

In this study, we aimed to investigate the immunomodulatory effects of polysaccharides from Cyclocarya paliurus leaves after acetylation modification (Ac-CPP0.1) on dendritic cells (DCs) and immunosuppressed mice. In vitro, Ac-CPP0.1 promoted phenotypic and functional maturation of DCs. Specifically, it increased the expression of costimulatory molecules (CD80, CD86, and MHC II) and the secretion of cytokines (TNF-α, IL-6, IL-1β, IL-10, IL-12p70) of DCs. In vivo, Ac-CPP0.1 significantly improved immunosuppression of mice, which was manifested by increased body weight and immune organ index, up-regulated cytokines (IL-4, IL-17, TGF-β3, and TNF-α), and restored short-chain fatty acid (SCFAs) levels of intestinal. The immunoactivation of Ac-CPP0.1 in DCs and in mice is linked to the activation of the TLR4/NF-κB signaling pathway. Furthermore, Ac-CPP0.1 reversed intestinal flora imbalance caused by cyclophosphamide. At the species level, Ac-CPP0.1 increased the abundance of unclassified_Muribaculaceae, unclassified_Desulfovibrio, Bacteroides_acidifaciens and Faecalibaculum_rodentium, decreased the level of Lactobacillus_johnsonii, unclassified_g_Staphylococcus and Staphylococcus_nepalensis. In summary, Ac-CPP0.1 has considerable immunomodulatory potential, which is beneficial to the future utilization and development of Cyclocarya paliurus.