Development Of An Animal Compound Immunopotentiator

For the past few years, breeding industry has developed rapidly in China. However, viral diseases have triggered a series of food safety issues, which not only greatly restricted the development of breeding industry, but also greatly threatened human health. We should focus more on how to control and prevent various diseases. At present, vaccination is the important measure to prevent diseases and the cooperation of vaccine with immunopotentiator can further improve immunization effect.The role of a certain or a kind of immunopotentiator was clear and it was reported that a certain immunopotentiator(especially Chinese herbal medicine) was used separately or different kinds were mixed together to enhance immune effect. Studies showed that, the immune effect of antigen when used alone or with just one kind of adjuvant would be restricted, while used with compound immunopotentiator could induce stronger immune effect than the former. Therefore, development of compound immunopotentiator with different types of adjuvants will be a new trend. Based on previous work, a novel,effective and multifunctional compound immunopotentiator was developed by mixing ingredients with immunological enhancement. According to the literature, three kinds of drugs, levamisole hydrochloride(LH), Concanavalin A(Con A), astragalus polysaccharide(APS), which were commonly used in clinic, were selected to compare the effect of their different injected dose on resisting Pseudorabies virus(PRV) and immune response of inactivated PRV vaccine in mice, in order to determine their optimal injected dose. The prescriptions which was composed of their optimal injected dose were chosen to compare their immune effect.First of all three injected dose levels of each drug were designed to be high, medium and low, LH with 30mg/kg,15mg/kg and 7.5mg/kg, Con A with 60mg/kg, 30mg/kg and 10mg/kg, APS with 80mg/kg, 40mg/kg and 20mg/kg.Mice of drug groups and only-vaccine group were vaccinated with 200?L inactivated PRV vaccine and mice of drug groups were injected with specific dose of drug(continuous injection for three days), while blank group with equal PBS. Secondary immunization at 14 d intervals. Blood samples were collected on day 14,day 21 and day 28 after primary immunizationfor measurement of IFN-?, IL-2,IL-4 and anti-PRV antibody. At 28 days after primary immunization, all the groups were challenged with 200?L 100 LD50 PRV(LD50= 10-5/0.1m L) and were under observation everyday. At the end of experiment, visceral organs of mice were obtained for the determination of the spleen index and pathogen detection. The results showed that LH, Con A and APS can enhance the secretion of cytokines(IL-2,IFN-? and IL-4) and specific antibody obviously when used with vaccine, but there were differences among injected doses. High doses of LH(H-LH) and low doses of APS(L-APS) improved higher secretion of cytokine and specific antibodies remarkably than other groups, while low and high doses of Con A(L-Con A, H-Con A) were better than M-Con A. Therefore, the optimal multicomponent drug,Group 1(H-LH+L-APS+L-Con A) and Group 2(H-LH+L-APS +H-Con A), were selected to the next experiment.Procedures of the second experiment with optimal prescriptions were the same as the prior. The results showed that: compared with single component drug, multicomponent drug could enhance the secretion of cytokines(IL-2, IFN-? and IL-4) and specific antibody remarkably instead of mutual antagonism, which indicated that they had better immune enhancement effect. This illustrated that the three drugs as components of the compound immunopotentiator used with vaccine can enhance immune function and promote the secretion of cytokines and specific antibodies. From the spleen index, the secretion of cytokines and antibodies into consideration, Group 1 was more effective than Group 2.And considering the cost, Group 1 has more application prospects than Group 2 obviously.