Limits...
Vaccination with Toxoplasma gondii calcium-dependent protein kinase 6 and rhoptry protein 18 encapsulated in poly(lactide-co-glycolide) microspheres induces long-term protective immunity in mice.

Zhang NZ, Xu Y, Wang M, Chen J, Huang SY, Gao Q, Zhu XQ - BMC Infect. Dis. (2016)

Bottom Line: However, no effective vaccine is yet available.Poly(lactide-co-glycolide) polymers can reduce protein degradation and sustain the release of antigens over a long period, which could generate a long-lasting immune response in vivo.Further comparison of the immune responses to the proteins adjuvanted with PLG or Montanide™ ISA 206 VG 6 weeks after the last immunization revealed that antigens encapsulated in PLG conferred greater protective immunity against challenge.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, 730046, PR China.

ABSTRACT

Background: Toxoplasmosis is a worldwide zoonosis caused by the intracellular parasite Toxoplasma gondii. However, no effective vaccine is yet available. Poly(lactide-co-glycolide) polymers can reduce protein degradation and sustain the release of antigens over a long period, which could generate a long-lasting immune response in vivo. Using a mouse model of toxoplasmosis, we evaluated the protective efficacy of vaccination with two recombinant proteins, which are formulated in biodegradable polymers.

Methods: Two recombinant proteins, rCDPK6 and rROP18, were encapsulated in poly(D,L-lactide-co-glycolide) (PLG), and then injected subcutaneously into Kunming mice. The mice immune responses were evaluated in terms of lympho-proliferation, cytokine expression, and antibodies. The survival of infected mice and brain cyst formation were also evaluated at 6 weeks after challenge with T. gondii RH strain (genotype I) or PRU strain (genotype II).

Results: Both protein vaccines induced Th1-biased immune responses, with increased specific antibodies and T cells, high levels of interferon-γ and interleukin 2, and strong lymphocyte proliferative responses. The mice immunized with the various protein vaccines survived slightly longer time than the control groups (P > 0.05) after injection with T. gondii RH strain. There were fewer brain cysts in the mice in all the immunized groups than that in the control groups, and the brain cysts were significantly reduced in mice immunized with proteins + 206, rCDPK6 + PLG and rCDPK6 + rROP18 + PLG (P < 0.05) compared controls. Further comparison of the immune responses to the proteins adjuvanted with PLG or Montanide™ ISA 206 VG 6 weeks after the last immunization revealed that antigens encapsulated in PLG conferred greater protective immunity against challenge.

Conclusions: These findings suggest that the two recombinant T. gondii proteins encapsulated in PLG conferred immunity to T. gondii for an extended period, providing the foundation for the further development of a commercial vaccine against toxoplasmosis.

No MeSH data available.


Related in: MedlinePlus

Survival rates of mice immunized with various protein vaccines after challenge with Toxoplasma gondii. Kunming mice were challenged with 1 × 103 tachyzoites of Toxoplasma gondii RH strain, 6 weeks after the second immunization
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4836102&req=5

Fig5: Survival rates of mice immunized with various protein vaccines after challenge with Toxoplasma gondii. Kunming mice were challenged with 1 × 103 tachyzoites of Toxoplasma gondii RH strain, 6 weeks after the second immunization

Mentions: At 6 weeks after vaccination, 10 mice from each group were challenged with 103 tachyzoites of the T. gondii RH strain and 10 cysts of the PRU strain. The average survival time of the mice immunized with the various protein vaccines (8.56 days) was slightly longer than that in the controls (8 days) (Fig. 5). Immunization with rROP18 + PLG (10.9 days ± 2.58), rROP18 (10.1 days ± 1.52), and rCDPK6 + PLG (9.1 days ± 0.24) was showed to significantly prolong the average survival time in mice compared with that of the controls after challenged with RH strain (P < 0.05).Fig. 5


Vaccination with Toxoplasma gondii calcium-dependent protein kinase 6 and rhoptry protein 18 encapsulated in poly(lactide-co-glycolide) microspheres induces long-term protective immunity in mice.

Zhang NZ, Xu Y, Wang M, Chen J, Huang SY, Gao Q, Zhu XQ - BMC Infect. Dis. (2016)

Survival rates of mice immunized with various protein vaccines after challenge with Toxoplasma gondii. Kunming mice were challenged with 1 × 103 tachyzoites of Toxoplasma gondii RH strain, 6 weeks after the second immunization
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4836102&req=5

Fig5: Survival rates of mice immunized with various protein vaccines after challenge with Toxoplasma gondii. Kunming mice were challenged with 1 × 103 tachyzoites of Toxoplasma gondii RH strain, 6 weeks after the second immunization
Mentions: At 6 weeks after vaccination, 10 mice from each group were challenged with 103 tachyzoites of the T. gondii RH strain and 10 cysts of the PRU strain. The average survival time of the mice immunized with the various protein vaccines (8.56 days) was slightly longer than that in the controls (8 days) (Fig. 5). Immunization with rROP18 + PLG (10.9 days ± 2.58), rROP18 (10.1 days ± 1.52), and rCDPK6 + PLG (9.1 days ± 0.24) was showed to significantly prolong the average survival time in mice compared with that of the controls after challenged with RH strain (P < 0.05).Fig. 5

Bottom Line: However, no effective vaccine is yet available.Poly(lactide-co-glycolide) polymers can reduce protein degradation and sustain the release of antigens over a long period, which could generate a long-lasting immune response in vivo.Further comparison of the immune responses to the proteins adjuvanted with PLG or Montanide™ ISA 206 VG 6 weeks after the last immunization revealed that antigens encapsulated in PLG conferred greater protective immunity against challenge.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, 730046, PR China.

ABSTRACT

Background: Toxoplasmosis is a worldwide zoonosis caused by the intracellular parasite Toxoplasma gondii. However, no effective vaccine is yet available. Poly(lactide-co-glycolide) polymers can reduce protein degradation and sustain the release of antigens over a long period, which could generate a long-lasting immune response in vivo. Using a mouse model of toxoplasmosis, we evaluated the protective efficacy of vaccination with two recombinant proteins, which are formulated in biodegradable polymers.

Methods: Two recombinant proteins, rCDPK6 and rROP18, were encapsulated in poly(D,L-lactide-co-glycolide) (PLG), and then injected subcutaneously into Kunming mice. The mice immune responses were evaluated in terms of lympho-proliferation, cytokine expression, and antibodies. The survival of infected mice and brain cyst formation were also evaluated at 6 weeks after challenge with T. gondii RH strain (genotype I) or PRU strain (genotype II).

Results: Both protein vaccines induced Th1-biased immune responses, with increased specific antibodies and T cells, high levels of interferon-γ and interleukin 2, and strong lymphocyte proliferative responses. The mice immunized with the various protein vaccines survived slightly longer time than the control groups (P > 0.05) after injection with T. gondii RH strain. There were fewer brain cysts in the mice in all the immunized groups than that in the control groups, and the brain cysts were significantly reduced in mice immunized with proteins + 206, rCDPK6 + PLG and rCDPK6 + rROP18 + PLG (P < 0.05) compared controls. Further comparison of the immune responses to the proteins adjuvanted with PLG or Montanide™ ISA 206 VG 6 weeks after the last immunization revealed that antigens encapsulated in PLG conferred greater protective immunity against challenge.

Conclusions: These findings suggest that the two recombinant T. gondii proteins encapsulated in PLG conferred immunity to T. gondii for an extended period, providing the foundation for the further development of a commercial vaccine against toxoplasmosis.

No MeSH data available.


Related in: MedlinePlus