ABSTRACT
Cationic PLG nanoparticles and liposome were prepared and used as package molecules to pack up pUC18-CpG. The effects of the packed pUC18-CpG on the cellular and humoral immune responses were detected in the mice that were inoculated with pig paratyphoid vaccine. The results showed that compared with the control, the amount of IgG and the titre of specific antibody were significantly increased in the sera of mice immunized with the CpG plasmid entrapped by cationic PLG nanoparticles; the proliferation and induced IL-2 bioactivity of lymphocytes were significantly enhanced in the spleen of the immunized mice; the stimulatory effect of cationic PLG nanoparticles was similar to or stronger than that of cationic liposome. These indicated that cationic PLG nanoparticle could be employed as an effective package molecule to promote the immunostimulatory effect of pUC18-CpG.