Effects On The TNF-α Expression And Liver Egg Granuloma Formation In Mice Immunized By PcDNA3.0/SjRPS4·CB Vaccine Against Schistosoma Japonicum

Background:It has been proved that the vaccine is one of the most cost-effective measures to control the spread of infectious diseases.In recent years,we has established a number of vaccine-associated natural elements of the nucleic acid vaccine,including SIEA26-28kDa associated pcDNA3.0/SjRPS4,pcDNA3.0/SjCB associated Sj31/32kDa. In the preliminary experiments,Qinyonghua et al(2008) has constructed the multivalent vaccine pcDNA3.0/SjRPS4·CB and studied their immunoprotection against Schistosoma japonicum,they found that the pcDNA3.0/SjRPS4·CB group gained statistically significant effect on the reduction of rate of liver eggs,compared with the monovalent vaccine.The mise were immuned by pcDNA3.0/SjRPS4·CB so as to observe the pathological changes of egg granuloma in live and expression of TNF-α.Objective:The mise were immuned by pcDNA3.0/SjRPS4·CB to observe the effect on the egg granuloma and expression of TNF-αand explore the induction of protective immune mechanism.Methods: 1.The pathological changes of egg granuloma in the liver of immuned mice.The circumference and area of the egg granuloma were measured by using UVP gelimaging system.2.The expression of TNF-αmRNA,TNF-αprotein were detected by In situ hybridization(DNA-RNA) and immunohistochemistry(SP method) in immunized mice with liver egg granuloma.Result:1.The egg nodules of pcDNA3.0/SjRPS4·CB was grossly reduced compared with the other groups in liver.The perimeter and area of egg granuloma in the multivalent vaccine group(801.8±32.7,204919.3±16655.9) were significantly reduced than in the pcDNA3.0/SjCB (827.0±24.4,260076.1±14453.3),pcDNA3.0/SjRPS4(903.6±25.2, 217847.9±12770.1),pcDNA3.0(1099.1±23.3,495956.7±10847.8),and PBS(1351.8±25.9,581852.2±12264.0).2.The positive expression rates of TNF-αmRNA and protein of egg granuloma in liver of multivalent vaccine group pcDNA3.0/SjRPS4·CB (9.00±2.1718,9.13±2.326) were significantly higher than the pcDNA3.0/SjCB(6.33±3.063,9.13±2.326),pcDNA3.0/SjRPS4(6.00±3.229,6.53±2.503),pcDNA3.0(0.67±0.724,0.93±0.594),PBS (0.00±0.000,0.00±0.000),P＜0.05.Conclusion:1.The multivalent vaccine pcDNA3.0/SjRPS4·CB against Schistosoma japonicum has a good immune protection which is better than the immune protective effect of the monovalent vaccine in decrea -sing the egg granuloma and egg nodules.2.The expression of TNF-αwas significantly enhanced,it may be one of the mechanisms of the immune,the immune protection of multivalent vaccine was better than the monovalent vaccine.