Characterization and immunoenhancement activities of Eucommia ulmoides polysaccharides.

•Chemical properties, monosaccharide composition, scanning electron microscopy (SEM) analyses, and immunoenhancement activities of EUPS were firstly characterized.•EUPS significantly stimulated proliferation of splenic lymphocyte in vitro.•EUPS significantly promoted IL-4 and IFN-γ production of T lymphocyte in vitro.•EUPS could activate DCs and induce them to the maturation in vitro.•EUPS as an adjuvant significantly improved the humoral and cellular immune response in vivo.