Protective efficacy of two novel DNA vaccines expressing Toxoplasma gondii rhomboid 4 and rhomboid 5 proteins against acute and chronic toxoplasmosis in mice

• Published in: Expert review of vaccines Vol. 14; no. 9; p. 1289
• Main Authors: Zhang, Nian-Zhang, Xu, Ying, Wang, Meng, Petersen, Eskild, Chen, Jia, Huang, Si-Yang, Zhu, Xing-Quan
• Format: Journal Article
• Language: English
• Published: England 02.09.2015
• Subjects: Animals; Antibodies, Protozoan - blood; Brain - parasitology; Brain - pathology; CD4-Positive T-Lymphocytes - immunology; CD8-Positive T-Lymphocytes - immunology; Cytokines - secretion; Disease Models, Animal; Female; Immunoglobulin G - blood; Mice; Peptide Hydrolases - genetics; Peptide Hydrolases - immunology; Protozoan Proteins - genetics; Protozoan Proteins - immunology; Protozoan Vaccines - administration & dosage; Protozoan Vaccines - genetics; Protozoan Vaccines - immunology; Survival Analysis; Th1 Cells - immunology; Toxoplasma - genetics; Toxoplasma - immunology; Toxoplasmosis, Animal - prevention & control; Treatment Outcome; Vaccines, DNA - administration & dosage; Vaccines, DNA - genetics; Vaccines, DNA - immunology; DNA vaccine; ROM4; ROM5; Toxoplasma gondii; immune response; protective immunity
• ISSN: 1744-8395
• DOI: 10.1586/14760584.2015.1061938

To evaluate the protective efficacy of two novel DNA vaccines expressing Toxoplasma gondii rhomboid 4 (ROM4) and rhomboid 5 (ROM5) proteins against acute and chronic toxoplasmosis. DNA vaccines (pVAX-TgROM5 and pVAX-TgROM4) were constructed and their immunogenicity evaluated in Kunming mice. Mice vaccinated with pVAX-TgROM5 or pVAX-TgROM4 elicited strong Th1-type humoral and cellular responses, with higher level of IgG antibody titers (the predominance of IgG2a production), and increased levels of CD4(+) and CD8(+) T cells and cytokines IFN-γ, IL-2, IL-12 (p70) and IL-23. Mice vaccinated with pVAX-TgROM5 (11 days) showed a significantly longer survival time compared with controls (8 days) (p < 0.05) after lethal challenge. Brain cyst numbers of mice vaccinated with pVAX-TgROM5 and pVAX-TgROM4 reduced significantly (p < 0.05) (72.04 and 44.08%, respectively) compared with control groups after chronic challenge. The pVAX-TgROM5 showed a better protective efficacy against acute and chronic toxoplasmosis compared to pVAX-TgROM4.