Protection of chickens against infectious bronchitis virus with a multivalent DNA vaccine and boosting with an inactivated vaccine

The protective efficacy of DNA plasmids encoding avian infectious bronchitis virus (IBV) S1, N, or M protein was investigated in chickens. Chickens were inoculated monovalently (with plasmid pVAX1-16S1, pVAX1-16M, or pVAX1-16N alone) or multivalently (combination of the three different plasmids, pVAX1-16S1/M/N). A prime-boost immunization protocol against IBV was developed. Chickens were immunized with the multivalent DNA vaccine twice and then boosted with an inactivated vaccine once. Antibody titers of the chickens immunized with pVAX1-16S1/M/N were much higher than those of the monovalent groups (p < 0.01). A protective rate up to 90% was observed in the pVAX1-16S1/M/N group. The serum antibody titers in the prime-boost birds were significantly higher than those of the multivalent DNA vaccine group (p < 0.01) but not significantly different compared to the inactivated vaccine group at 49 days of age. Additionally, the prime-boost group also showed the highest level of IBV-specific cellular proliferation compared to the monovalent groups (p < 0.01) but no significant difference was found compared to the multivalent DNA vaccine group, and the prime-boost group completely protected from followed viral challenge.

Protective immunity effect of Schistosoma japonicum multivalent DNA vaccine in infected BALB/c mice / 中国血吸虫病防治杂志

Objective To test the protective effect of multivalent DNA vaccine against Schistosoma japonicum infection. Methods Sixty-five female BALB/c mice of 5-6 weeks old were randomly divided into 5 groups: pcDNA3.1 group (control group), pcDNA3.1-TPI group (TPI), pcDNA3.1-(CDR3)_6 group [(CDR3)_6], pcDNA3.1-TPI-linker-(CDR3)_6 group (TLC) and pcDNA3.1-(CDR3)_6-linker-TPI group (CLT). Each mouse was immunized with 100 ?g of pcDNA3.1 , pcDNA3.1-TPI,pcDNA3.1-(CDR3)_6 ,pcDNA3.1-TPI-linker-(CDR3)_6 or pcDNA3.1-(CDR3)_6-linker-TPI plasmid DNA by intramuscular injection, respectively. All animals were boosted at week 2 and week 4 with the same dosage and same method. Four weeks after the 3rd immunization, all mice were challenged with (45?1) cercariae of Schistosoma japonicum by abdominal skin penetration. Forty-five days post-challenge, the mice were sacrificed and perfused, and the numbers of recoveredworms and hepatic eggs were counted. The blood was collected from the tail veins of all mice 2 days before the 1st immunization and challenge, respectively. Serum was prepared for detection of IgG, IgG_1 and IgG_ 2a . Two weeks after the 3rd immunization, the spleen cells of 2 mice from each group were cultured and stimulated with ConA and rSjCTPI peptide, and the supernatant was collected for detection of IL-2, IL-4 and IFN-?. Results The worm reduction rates in TPI group, (CDR3)_6 group, TLC group and CLT group were 26.25%, 24.10%, 37.30% and 39.09%, the hepatic egg reduction rates were 32.64%, 32.27%, 41.61% and 49.54% respectively compared with the control group. The levels of protection in TLC group and CLT group both were higher than those in TPI group and (CDR3)_6 group(P

Construction of Multivalent DNA Vaccine against Schistosoma japonicum / 中国寄生虫学与寄生虫病杂志

Objective To construct a multivalent DNA vaccine.\ Methods\ The multivalent DNA vaccine candidates pBK Sj26 Sj23,pBK Sj32 Sj23 were constructed based on the plasmids pBluescript Sj26,pBluescript Sj32 and pBluescript Sj23 with three pairs of specific primers using DNA recombinant technique. In the primers, a synthetic linker sequence encoding a peptide was designed,and the antigen genes Sj26 and Sj23,Sj32 and Sj23 were then ligated. After identification, the quadriceps muscle of mice were immunized with the multivalent antigen genes. Four weeks after immunization, the multivalent antigen genes were present in the muscular tissue of mice by PCR.\ Results\ The eukaryotic plasmids including multivalent antigens of S.japonicum were constructed successfully, and the plasmids including multivalent antigen gene could be stably existing in the muscle tissue of mice and the multivalent antigens could be expressed in the muscle tissue cells of mice.\ Conclusion\ A multivalent S.japonicum DNA vaccine has been established.