The immunological adjuvant activity of gypenosides liposome against Newcastle disease vaccine.

The adjuvant activity of gypenosides liposome (GPSL) encapsulated with liposome was investigated in vitro and in vivo. In vitro, different concentrations of GPSL were added into chicken's peripheral blood lymphocytes and splenic lymphocyte. The results showed that GPSL could significantly enhance T and B lymphocytes proliferation singly or synergistically with PHA and LPS and the efficacy were superior to those of gypenosides (GPS) and blank liposome (BL) at most of concentrations. In vivo, three hundred and fifty 14-day-old chickens were assigned to 7 groups randomly and vaccinated with Newcastle disease (ND) vaccine. Simultaneously, the chickens in experimental groups were, respectively, oral administration with the GPSL at three doses, GPS and BL. The results showed that GPSL could significantly enhance lymphocyte proliferation, increase antibody titer, and promote cytokine secretion in vitro and in vivo, moreover, the adjuvant activity of GPSL was better than those of GPS and BL. These indicated that formulations of GPS and liposome can further enhance the immune response against ND vaccine compared with the adjuvant alone.