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A Toxoplasma gondii vaccine encoding multistage antigens in conjunction with ubiquitin confers protective immunity to BALB/c mice against parasite infection.

Yin H, Zhao L, Wang T, Zhou H, He S, Cong H - Parasit Vectors (2015)

Bottom Line: DNA vaccines have proved effective in the protection against parasites.Our results indicated that the DNA vaccine had the advantage of inducing a stronger humoral response, whereas the adenovirus-vectored vaccine effectively improved the cellular immune response.Priming vaccination with DNA vaccine and boosting with the recombinant adenovirus vaccine encoding ubiquitin conjugated multi-stage antigens of T. gondii was proved to be a potential strategy against the infection of type I and type II parasite.

View Article: PubMed Central - PubMed

Affiliation: Department of Human Parasitology, Shandong University, School of Medicine, No. 44 Wenhuaxi Road, Jinan, Shandong, 250012, PR China. yinhuiquan521@126.com.

ABSTRACT

Background: Toxoplasma gondii is a widely prevalent intracellular parasite which infects almost all warm-blooded animals including humans and causes serious zoonotic toxoplasmosis. DNA vaccines have proved effective in the protection against parasites. However, the problems of weak immunity and inefficient delivery of DNA vaccine remain major issues. Therefore, comprehensive antigens derived from all stages of the parasite, effective adjuvants and delivery systems should be considered in the vaccine construction.

Methods: SAG3101-144,ROP18347-396, MIC6288-347, GRA7182-224, MAG158-125, BAG1156-211 and SPA142-200, derived from antigens in tachyzoite, bradyzoite and sporozoite stages of T. gondii were screened based on CD8(+) T cell epitope binding affinity to HLA and H-2. We constructed a recombinant DNA vaccine and an adenovirus vaccine encoding multi-stage antigen of T. gondii linked to ubiquitin molecules and vaccinated BALB/c mice with different strategies. Antibodies, cytokines, splenocytes proliferation, as well as the percentage of CD4(+) and CD8(+) T cells in immunized mouse were analyzed by the Enzyme-Linked Immunosorbent Assays (ELISA), Flow Cytometry (FCM). Protective efficacy was evaluated by challenging immunized mice with type I and type II parasite.

Results: Our results indicated that the DNA vaccine had the advantage of inducing a stronger humoral response, whereas the adenovirus-vectored vaccine effectively improved the cellular immune response. Priming with DNA vaccine and boosting with adenovirus-vectored vaccine induced Th1-type immune responses with highest levels of IgG2a and secretion of cytokines IL-2 and IFN-γ. Effective protection against type I and type II parasite with an increase in survival rate and a decrease in brain cyst burden was achieved in immunized mice.

Conclusions: Priming vaccination with DNA vaccine and boosting with the recombinant adenovirus vaccine encoding ubiquitin conjugated multi-stage antigens of T. gondii was proved to be a potential strategy against the infection of type I and type II parasite.

No MeSH data available.


Related in: MedlinePlus

Challenge study of immunized mice against type I and type II parasite infection 4 weeks after the immunization. a shows the survival curves of vaccinated mice challenged against the type II parasite challenging. b shows the efficiency against the type II parasite challenge by counting the cysts in the brains of immunized mice.*indicates statistically significant differences between the marked group
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Fig6: Challenge study of immunized mice against type I and type II parasite infection 4 weeks after the immunization. a shows the survival curves of vaccinated mice challenged against the type II parasite challenging. b shows the efficiency against the type II parasite challenge by counting the cysts in the brains of immunized mice.*indicates statistically significant differences between the marked group

Mentions: Figure 6a shows the survival curves of vaccinated mice challenged with 1 × 103 tachyzoites of T. gondii RH strain and monitored for 28 days after infection. All the mice in the control groups (PBS, pVAX1, Ad-GFP) died within 10 days. Of the mice vaccinated with the p-MAS DNA vaccine, 33 % survived. The survival rate increased by 17 % when ubiquitin was introduced to the vaccine construction. The highest survival rate, 67 %, was achieved in mice vaccinated with p-UMASprime and Ad-UMASboost .Fig. 6


A Toxoplasma gondii vaccine encoding multistage antigens in conjunction with ubiquitin confers protective immunity to BALB/c mice against parasite infection.

Yin H, Zhao L, Wang T, Zhou H, He S, Cong H - Parasit Vectors (2015)

Challenge study of immunized mice against type I and type II parasite infection 4 weeks after the immunization. a shows the survival curves of vaccinated mice challenged against the type II parasite challenging. b shows the efficiency against the type II parasite challenge by counting the cysts in the brains of immunized mice.*indicates statistically significant differences between the marked group
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4588682&req=5

Fig6: Challenge study of immunized mice against type I and type II parasite infection 4 weeks after the immunization. a shows the survival curves of vaccinated mice challenged against the type II parasite challenging. b shows the efficiency against the type II parasite challenge by counting the cysts in the brains of immunized mice.*indicates statistically significant differences between the marked group
Mentions: Figure 6a shows the survival curves of vaccinated mice challenged with 1 × 103 tachyzoites of T. gondii RH strain and monitored for 28 days after infection. All the mice in the control groups (PBS, pVAX1, Ad-GFP) died within 10 days. Of the mice vaccinated with the p-MAS DNA vaccine, 33 % survived. The survival rate increased by 17 % when ubiquitin was introduced to the vaccine construction. The highest survival rate, 67 %, was achieved in mice vaccinated with p-UMASprime and Ad-UMASboost .Fig. 6

Bottom Line: DNA vaccines have proved effective in the protection against parasites.Our results indicated that the DNA vaccine had the advantage of inducing a stronger humoral response, whereas the adenovirus-vectored vaccine effectively improved the cellular immune response.Priming vaccination with DNA vaccine and boosting with the recombinant adenovirus vaccine encoding ubiquitin conjugated multi-stage antigens of T. gondii was proved to be a potential strategy against the infection of type I and type II parasite.

View Article: PubMed Central - PubMed

Affiliation: Department of Human Parasitology, Shandong University, School of Medicine, No. 44 Wenhuaxi Road, Jinan, Shandong, 250012, PR China. yinhuiquan521@126.com.

ABSTRACT

Background: Toxoplasma gondii is a widely prevalent intracellular parasite which infects almost all warm-blooded animals including humans and causes serious zoonotic toxoplasmosis. DNA vaccines have proved effective in the protection against parasites. However, the problems of weak immunity and inefficient delivery of DNA vaccine remain major issues. Therefore, comprehensive antigens derived from all stages of the parasite, effective adjuvants and delivery systems should be considered in the vaccine construction.

Methods: SAG3101-144,ROP18347-396, MIC6288-347, GRA7182-224, MAG158-125, BAG1156-211 and SPA142-200, derived from antigens in tachyzoite, bradyzoite and sporozoite stages of T. gondii were screened based on CD8(+) T cell epitope binding affinity to HLA and H-2. We constructed a recombinant DNA vaccine and an adenovirus vaccine encoding multi-stage antigen of T. gondii linked to ubiquitin molecules and vaccinated BALB/c mice with different strategies. Antibodies, cytokines, splenocytes proliferation, as well as the percentage of CD4(+) and CD8(+) T cells in immunized mouse were analyzed by the Enzyme-Linked Immunosorbent Assays (ELISA), Flow Cytometry (FCM). Protective efficacy was evaluated by challenging immunized mice with type I and type II parasite.

Results: Our results indicated that the DNA vaccine had the advantage of inducing a stronger humoral response, whereas the adenovirus-vectored vaccine effectively improved the cellular immune response. Priming with DNA vaccine and boosting with adenovirus-vectored vaccine induced Th1-type immune responses with highest levels of IgG2a and secretion of cytokines IL-2 and IFN-γ. Effective protection against type I and type II parasite with an increase in survival rate and a decrease in brain cyst burden was achieved in immunized mice.

Conclusions: Priming vaccination with DNA vaccine and boosting with the recombinant adenovirus vaccine encoding ubiquitin conjugated multi-stage antigens of T. gondii was proved to be a potential strategy against the infection of type I and type II parasite.

No MeSH data available.


Related in: MedlinePlus