Background: The purpose of the present study was to produce a pcDNA3.1(+)-ureA recombinant vector and evaluate the capacity of this vector to stimulate the immune response against H. pylori infection in infused BALB/c mice. 

Materials and methods: The pcDNA3.1(+)-ureA construct was prepared and transformed into E. coli, successfully. The animals we used in the study were allotted into three groups for infusion of 1) recombinant plasmid, 2) pcDNA3.1(+)-ureA + nanoparticles, and 3) pcDNA3.1(+). Blood and tissue specimens from each group of mice were collected at days 15, 30, and 45 after the last infusion and the expression levels of cytokines such as TGF-β1, IL-4, and IFNγ genes comparing to GAPDH as well as the expression of ureA in the mice’s thigh muscle were evaluated. 

Results: The genes expression analysis showed that the IL4 expression significantly decreased (p<0.001) but IFNγ and TGF-β1 expression increased in the blood of infused mice (p<0.001). Also, the urea expression level in pcDNA3.1(+)-urea and pcDNA3.1(+)-ureA+ nanoparticle 15, 30, and 45 days after the last infusion was significantly different (p<0.001) and its expressions at days 15 and 30 were significantly different (p<0.001), but 45 days after the last infusion it was not significantly different (p>0.05). 

Conclusion: The pcDNA3.1(+)-ureA recombinant vector with or without chitosan nanoparticles can stimulate the immune response in animal models against H. pylori infection. Also, after combining the recombinant vector with nanoparticles we observed a better immune response was observed. In future studies this recombinant construct can be used as a biomarker and therapeutic approaches in eukaryotic systems.