Immune response and protective effect against chronic Toxoplasma gondii infection induced by vaccination with a DNA vaccine encoding profilin

BMC Infectious Diseases

卷:18

Qi Gao¹  Xing-Quan Zhu¹  Ling-Ying Hu¹  Meng Wang¹  Nian-Zhang Zhang¹  Fu-Kai Zhang¹ 

[1] State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences;

关键词: Toxoplasma gondii;    Profilin;    Immunogenicity;    DNA vaccine;    Chronic toxoplasmosis;   

DOI  :  10.1186/s12879-018-3022-z

来源: DOAJ

【 摘 要 】

Abstract Background Toxoplasma gondii is an obligate intracellular parasite that can infect almost all warm-blooded animals. T. gondii profilin (TgPF) plays a crucial role in parasite motility and host cell invasion, and has shown promise against toxoplasmosis. DNA vaccine was considered to elicit effective humoral and cell-mediated immunity against T. gondii infection. The objective of the present study was to evaluate the immunogenicity of TgPF in mice using a DNA vaccination strategy. Methods A DNA vaccine (pVAX-PF) encoding TgPF gene was constructed and then was intramuscularly injected into mice with and without a plasmid encoding IL-15 (pVAX-IL-15). The immune responses in immunized Kunming mice including lymphocyte proliferation, levels of cytokines, antibody titers and T lymphocyte subclasses were analyzed. The protective efficacy against chronic T. gondii infection was observed at 4 weeks post-infection with the cyst-forming PRU strain of T. gondii (Genotype II). Results EitherpVAX-PF with or without pVAX-IL-15 could elicit higher level of IgG and IgG2a antibodies and produce strong cellular immune responses in the immunized mice. The brain cyst numbers in mice immunized with pVAX-PF + pVAX-IL-15 (1843 ± 215.7) and pVAX-PF (1897 ± 337.8) were reduced 40.82% and 39.08%, respectively, compared to that in mice received nothing (3114 ± 168.8), and the differences were statistically significant (P < 0.0001). However, the T. gondii cyst numbers in mice immunized with pVAX-PF + pVAX-IL-15 were not statistically significantly different compared to that in mice immunized with pVAX-PF alone [t(10) = 0.33, P > 0.05]. Conclusions The present study indicated that TgPF could be a promising vaccine candidate against chronic toxoplasmosis, which can be further used to develop multi-epitope vaccine formulations in food-producing animals against T. gondii infection.

【 授权许可】

Unknown