Effect Of Fuzheng Jiedu Granule On The Immune Response To Swine Fever Vaccine

Classical swine fever(CSF) is one of the major infectious disease causing great economic losses in pig industries. Until now, using of swine fever vaccine(CSFV) is the only way to control the desiseases caused by CSF in China. However, because of the low quality vaccine or the compromised immunocompetence of the host, immune failures are frequent, causing huge economic losses. A line of studies has reported that many of the traditional Chinese medicine(TCM) have antiviral and immuno-enhancement abilities, and they are safe. TCM were also combined with vaccine to increase the immune effects of the hosts. This research was design to study the effect of Fuzheng Jiedu Granule, which was mainly composed with astragalus, radix isatidis and herba epimedii, on the immune response of pigs to swine fever vaccine.There were six groups: Control, CSFV-only, CSFV-astragalus(CSFV-AST)(0.5g/Kg.b.w), CSFV-low(CSFV-L)(0.2g/Kg.b.w)-medium(CSFV-M)(0.4g/Kg.b.w) and-high(CSFV-H)(0.8g/Kg.b.w) doses of Fuzheng Jiedu Granule. Firstly, blood routine(RBC and Hb) and biochemistry(AST and ALT) examination was performed on day 0, 10, 20, 30, 40 after vaccinating of CFS vaccine. Secondly, CFS antibody levels in peripheral bloodstream of pigs in 6 groups were detected on day 0, 7, 14, 24, 34, 44, 54, 69, 79 after vaccinating of CFS vaccine; the levels of IgG and IgM antibodies were detected on day 0, 10, 20, 30, 40; neutrophil phagocytosis rates were detected by flow cytometry method(FCM), in order to evaluate the influence of Fuzheng Jiedu Granule on the humoral immune response to CSFV. Thirdly, fluorescent-labeled CD3~+, CD4~+, CD8~+-antibodies were used to detect the levels of CD3~+, CD4~+, CD8~+ T cells in bloodstream on day 10, 20, 30, 40 after vaccinating of CFS vaccine using FCM and CD4~+/CD8~+ ratios were also evaluated; then, proliferation rates of lymphocytes stimulated by ConA were detected through Cell Counting Kit-8(CCK-8) method, in order to evaluate the influences of Fuzheng Jiedu Granule on the cellular immune response to CSF vaccine. Finally, activities of superoxide dismutase(SOD) in peripheral blood of pigs were tested on day 10, 20, 30, 40 after vaccinating of CFS vaccine, in order to evaluate the influences of the drug on the SOD activity.The results of blood routine and biochemical examination showed that RBC, Hb, AST and ALT tested on day 0, 10, 20, 30, 40 of all tested groups had no significant differences, which indicated that the application of tested doses of Fuzheng Jiedu Granule had no adverse influence on health of the swine.According to the results of CSFV antibody detection, all group reached to the peak CSFV antibody level on Day 54, except Control; CSFV antibody levels were increased in pigs of CSFV-L,M and H group; Noteblely, CFSV antibody blocking rate of CSFV-M group reached to more than 50% on Day 14, with significant difference compared to that of CSFV-only group(p<0.05); CSFV-L, H and CSFV-AST could also increase the CFSV antibody blocking rates, but no significant differences were seen except on Day 54. With regard to IgG and IgM, the results showed that increases of IgM were detected on Day 20, which was earlier than IgG that detected on Day 40; All CSFV-L, M and H could increase the level of IgG and IgM; Among them, the effect of CSFV-H group was higher than that of CSFV-AST group, but had no significant difference(p > 0.05). CSFV-L, M and H doses of Fuzheng Jiedu Granule could not enhance the effect of neutrophil phagocytosis.The results of T lymphocyte subgroup detection showed that percentages of tested T cell subgroups had no significant changes from Day 10 to Day 20(p>0.05); From Day 30 to Day 40, levels of CD3~+, CD4~+, CD8~+ cell increased significantly, and CD4~+ / CD8~+ ratios were stable; according to the results of lymphocyte proliferation tests, it showed that low, medium and high dose of Fuzheng Jiedu Granule could improve the proliferation of lymphocytes stimulated by ConA, and the effect is directly proportional to the concentration of the Fuzheng Jiedu Granule.The results of superoxide dismutase(SOD) activity tests showed that both medium and high dose of Fuzheng Jiedu Granule could significantly increase the SOD activity, and there was no significant difference between CSFV-M and H group(p > 0.05).The results showed that Fuzheng Jiedu Granule can significantly enhance the effect of swine fever vaccine by increased the humoral immune response, cellular immune response, as well as the activity of SOD in peripheral blood of pig herds. Medium and High dose of Fuzheng Jiedu Granule have no significant differences on those effects, so medium dose was recommended. The results of this study will provide basis of combination use of Fuzheng Jiedu Granule with swine fever vaccine in animal husbandry.