Enhancement of Astragalus polysaccharide on the immune responses in pigs inoculated with foot-and-mouth disease virus vaccine

摘要

The effects of Astragalus polysaccharides (APS) on the immune response in pigs immunized with foot-and-mouth disease virus (FMDV) vaccine were investigated. Fifteen pigs were randomly divided into five groups. Four groups were vaccinated with a FMDV inactivated vaccine. Pigs in three experimental groups were administered varying doses of APS (APS1, 5mg/kg; APS2, 10mg/kg; APS3, 20mg/kg). The influence of APS on the number of CD3~+CD4~-CD8~+ cytotoxic T cells, CD3~+CD4~+CD8~+ T helper memory cells, and CD3~-CD4~-CD8~+ natural killer cells among peripheral blood lymphocytes (PBL) in the three APS groups were significant compared to the vaccine group. In vitro stimulation of PBL by Con A and LPS in APS groups induced a stronger proliferative response at 2 and 6 weeks post-inoculation (PI). APS markedly increased the titer of FMDV-specific antibody in a dose-dependent manner, and up-regulated mRNA expression of IFN-γ and IL-6. APS could potentially be used as an immunomodulator for a FMDV vaccine and provide better protection against FMDV.