Evaluation Of The Immune Response Induced By Multiantigenic DNA Vaccine Encoding SAG1 And ROP2 Of Toxoplasma Gondii And The Adjuvant Properties Of Escherichia Coli Heat-Labile Enterotoxin B Subunit In BALB/c Mice

Infections by the intracellular protozoan parasite Toxoplasma gondii are widely prevalent in humans and other animals which can cause severe or lethal toxoplasmosis. In the present study, we constructed a multiantigenic DNA vaccine, eukaryotic plasmid pcDNA3.1-SAG1-ROP2, expressing surface protein SAG1 (main surface antigen 1) and ROP2 (rhoptry protein 2) of Toxoplasma gondii, eukaryotic plasmid pEASY-El-LTB and examined the expression ability of the DNA vaccine in Hela cells. Afterwards, we investigated the efficacy of pcDNA3.1-SAGl-ROP2 with or without co-administration of a plasmid encoding Escherichia coli Heat-Labile Enterotoxin B Subunit (pEASY-El-LTB) as genetic adjuvant to protect BALB/c mice against toxoplasmosis. The results show that mice immunized with pcDNA3.1-SAG1-ROP2 co-immunization with LTB genes elicited stronger humoral immune responses than others. Our study indicates that the introduction of multiantigenic DNA vaccine co-delivery of pEASY-El-LTB enhanced the potency of multiantigenic DNA vaccine.