DNA prime followed by protein boost enhances the protective efficacy against Schistosoma japonicum infection in mice / 生物工程学报

Schistosomiasis japonica is an endemic, zoonotic disease of major public health importance in China. Vaccination is needed as a complementary approach to the ongoing control programs. In the present study, we determined if the efficacies of DNA vaccine encoding the SjGST and Sj32 asparaginyl endopeptidase protein could be enhanced by boosting with SjGST-32 protein vaccines. Mice were inoculated with a VR1012-SjGST-32 DNA vaccine followed by boosting with rSjGST-32 at 0, 14 and 28 d. Two weeks after the final boost, mice were challenged percutaneously with cercariae. On day 45 following the challenge, all mice were sacrificed and the numbers of recovered worms and hepatic eggs were counted. Moreover, we analyzed the immune response among various vaccination groups. The results showed that DNA vaccine efficacy was enhanced when mice were boosted with protein vaccine. Adult worm and liver egg burdens were reduced 42.3% and 59.6%, respectively. We further found that DNA vaccine followed by boosting with protein significantly increased the IgG titer and T cell proliferation over those seen in mice vaccinated solely with DNA vaccines. Furthermore, the higher level of IFN-gamma expression in the splenetic CD4+ T cell showed that DNA prime-Protein boosting vaccine induced CD4+ Th1-type responses. Thus, DNA vaccine efficacy was significantly enhanced via boosting protein vaccine which might provide a basis for rational application of the Schistosoma vaccine.

A Study on the Recombinant 26 kDa Glutathione-S-Transferase as a Vaccine Candidate:Dynamics of Antibodies in Immunized Buffaloes and Protection against Schistosoma japonicum Infections / 中国寄生虫学与寄生虫病杂志

ObjectiveTo observe the dynamics of antibodies and protection against Schistosoma japonicum infections in buffaloes after immunized with recombinant 26 kDa glutathione S transferase (reSjc26GST). Methods Buffaloes in 2 villages endemic for schistosomiasis japonica were selected as test and control groups, respectively.In test group initially 96 buffaloes were vaccinated with reSjc26GST, and 90 buffaloes in the control group did not experience vaccination. The indicators included levels of antibodies to reSjc26GST in buffaloes before and after infection with S japonicum and changes in infection rate. Results Specific antibodies, which showed a trend of trapezoid increase, were induced in buffaloes after immunized with reSjc26GST. Twenty months after immunization, the infection rate of the test group was decreased by 62 2% when compared with that before vaccination,and by 67 7% when compared with that of the control in the corresponding period.Conclusion Specific antibodies and a certain extent of protection were induced in buffaloes after immunized with reSjc26GST, which played an significant role in ameliorating morbidity.

Epidemiological study of schistosomiasis japonica on liver and spleen with ultrasonographical assessment among inhabitants in Dongting Lake endemic areas / 中国血吸虫病防治杂志

Objective To understand the morbidity of schistosomiasis japonica and health status of the liver and spleen of residents in a village and to evaluate the application of ultrasound on schistosomiasis epidemiology. Methods A total of 454 residents aged 5-65 years were examined by methods of Kato-Katz and ultrasound as well as disease history inquiry. Results The positive rate was 9.38% by stool examination, with no significant difference between males and females. The intensity of the infection among population was 5.70 eggs per gram of stool (EPG), with significant difference between males and females. The stool positive rate and EPG in farmers and students were the highest. Among 10.66% of the males and 8.10% of the females, as well as in 23.81% of the stool positive and 8.31% of the stool negative, the parenchyma of the liver was abnormal(≥GradeⅡ),with significant difference between males and females and between the stool positive and the stool negative. The abnormal rate of liver parenchyma went up with the age. Conclusion Ultrasound can evaluate the health status of inhabitants with schistosomiasis japonica and improve the compliance rate of residents to praziquantel chemotherapy.

STUDY ON ERYTHROCYTE IMMUNE FUNCTION OF RABBITS WITH SCHISTOSOMA JAPONICUM INFECTION / 中国血吸虫病防治杂志

0.05), and the all had significant differences in 2 to 4 months post-infection compared with the normal controls (P