Protective Immunity Induced In Mice By Multiantigenic DNA Vaccine With Genes Encoding ROP18and MIC2of Toxoplasma Gondii

The protozoan parasite Toxoplasma gondii invades and replicates within nucleated cells of warm-blooded animals and causes toxoplasmosis. Toxoplasma gondii is common more susceptible to infection for human. So far, there is no potent drugs of toxoplasma gondii disease. The vaccine against Toxoplasma gondii and the research of immune protective has gradually caused the attention. And that vaccination to prevent Toxoplasma gondii is the best strategy.Rhoptries are involved in T. gondii invasion and host cell interaction, and have been implicated as important virulence factors. The T. gondii ROP18protein is a highly polymorphic serine-threonine kinase that is secreted into the host cell during parasite invasion of the host cell, controlling the intracellular proliferation of T. gondii, and ROP18is considered one of the key virulence factors in the pathogenesis of T. gondii infection. The protein MIC2plays roles in gliding motility of T. gondii, transmigration of biological barriers, and attachment to the surface of host cell. The cytoplasmic tail of MIC2interacts with aldolase, which binds to parasite F-actin, bridging between cell surface adhesion and the parasite actinmyosin motor.In the present study, we constructed the multiantigenic ROP18-MIC2DNA vaccine against T. gondii infection and observed the protective immune responses induced in BALB/C mice. The sequences of genes encoding ROP18and MIC2protein were inserted into the eukaryotic expression vector pBudCE4.1and the multiantigenic recombinant plasmid pBudCE4.1-ROP18-MIC2was constructed. Mice were immunized intra-muscularly with the recombinant plasmid. The results show that the immune response elicited by multiantigenic DNA vaccination was stronger than the monovalent DNA vaccine.