Abstract
Toxoplasma gondii can lead to congenital infections in human. Surface antigen protein 4 (SAG4) of T. gondii is a potential stimulator for humoral and cellular immune responses. In the present study, a DNA vaccine encoding SAG4 from T. gondii was constructed and used to immunize BALB/c mice with peptide to evaluate the protective efficacy of the vaccine. The productions of IgG antibodies and cytokines (gamma interferon) from the vaccine (pSAG4/peptide) group were significantly higher than pSAG4 or peptide groups. After a lethal challenge by 1 × 104 tachyzoites from the I strain (RH), the survival time of mice immunized by pSAG4/peptide was longer than that of pSAG4 or peptide immunized mice or control mice. Moreover, after challenging by 20 cysts of the II strain (PRU) of T. gondii, the number of brain cysts from pSAG4/peptide vaccinated mice was only 31% of the number in PBS injected mice. The findings suggested the SAG4 DNA vaccine with peptide led significant immune responses and improved the protection against T. gondii challenges.
Highlights
The obligate intracellular pathogen Toxoplasma gondii (T. gondii) can infect a broad range of warm-blooded hosts including human beings and livestock (Montoya and Liesenfeld, 2004)
The results showed that there were more antigenic index and surface probability regions of Surface antigen protein 4 (SAG4) than that of SAG1, which indicated that SAG4 protein had great potential to become an excellent B-cell antigen
The online Immune Epitope Database (IEDB) database had been used to predict T-cell epitopes on SAG4 protein, and several great potential T-cell epitopes on the protein were selected
Summary
The obligate intracellular pathogen Toxoplasma gondii (T. gondii) can infect a broad range of warm-blooded hosts including human beings and livestock (Montoya and Liesenfeld, 2004). T. gondii infection is the most common opportunistic infections and one of the main causes of death among AIDS patients. Toxoplasmosis is the most common cause of central nervous system symptoms (Dubey et al, 2014). Women who acquire toxoplasmosis during pregnancy may lead to miscarriage and mental alteration (Bamba et al, 2014). The collected results from epidemiologic survey indicated the high T. gondii prevalence can cause a large number of economic losses (Fajardo et al, 2013; Miao et al, 2013; Verin et al, 2013)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
