Structural characterization and immune modulation activities of Chinese Angelica polysaccharide (CAP) and selenizing CAP (sCAP) on dendritic cells.

sCAP was obtained by the nitrate‑sodium selenite method. SEM, molecular weight evaluation, monosaccharide composition, FT-IR and NMR of sCAP were carried out. Compared with CAP, sCAP had a relatively smooth and lamellar sheet morphology with edge folds on the surface, presented molecular weights in range of 0.90-97.08 KDa, and was mainly composed of GalA, Ara and Gal. sCAP had both α and β configurations of the pyranose ring, the characteristic vibrational peak of Se-O-C and the signal of galacturonic acid residue. The phagocytic activity of immature BMDCs, the expression of CD40, CD80, CD86, and MHCII on BMDCs were detected by flow cytometry, the ability of sCAP-treated BMDCs to stimulate the proliferation of allogeneic lymphocytes, presentation of antigens, cytokines in the supernatants and the protein in MyD88/NF-κB signaling pathway were detected. The results showed that the phagocytic activity of immature BMDCs was significantly enhanced when sCAP was at 3.92-1.96 μg·mL. The levels of IL-6, TGF-β1, INF-γ, and TNF-α were significantly elevated, IL-1β and MIP-1α were significantly reduced. These results indicate that sCAP could be as a new immunopotentiator by increasing MyD88/NF-κB signaling pathway. This study provides a reference for the research and development of new dosage forms of polysaccharide.