Sulfated Radix Cyathulae officinalis Polysaccharides Act as Adjuvant via Promoting the Dendritic Cell Maturation and Suppressing Treg Frequency

This study was conducted to evaluate the adjuvant potential of sulfated Radix Cyathulae officinalis Kuan polysaccharides (sRCPS) and their effects on specific cellular and humoral immune responses to hepatitis B subunit vaccine in mice. Our data demonstrated that sRCPS significantly promoted the rHBsAg-specific IgG, IgG1, IgG2a, and IgG2b antibody titers, the activities of natural killer cells (NK) and cytotoxic T lymphocytes (CTL), T cells proliferation, and phagocytic capacity of peritoneal macrophages. Furthermore, sRCPS increased the levels of IL-4, IL-2, and IFN-gamma in CD4(+)T cells and the level of IFN-gamma in CD8(+)T cells. In addition, sRCPS enhanced the expression of CD40(+), CD80(+), CD86(+), MHC I and MHC II in dendritic cells (DCs) and upregulated the mRNA levels of MHC I, MHC II. sRCPS downregulated the frequency of CD4(+) CD25(+) Foxp3(+) Treg cells. sRCPS increased both cellular and humoral immune responses by upregulating DC maturation, and suppressing the frequency of Treg cells.