Evaluation of the Immune Response Against Helicobacter pylori in Infused BALB/c Mice by pcDNA3.1(+)-ureA 

Abstract

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.

In Peripheral Blood Mononuclear Cells Helicobacter pylori Induces the Secretion of Soluble and Exosomal Cytokines Related to Carcinogenesis

“…Moreover, H. pylori CagA reduces the secretion of IL-12p40, and increases the expression of IL-10, which shows pro- and anti-inflammatory effects, promoted by this oncoprotein [ 37 ]. In mice that were treated with the recombinant proteins rUreB, rCagA, or pcDNA3.1(+)-ureA plasmid from H. pylori , it was found that these molecules increase the secretion of IFN-γ, IL-17A, and TGF-β1 with a concomitant IL-4 diminished production and that CD4+ T-cells preferentially differentiated into Th1 and Th17 lymphocyte subpopulations; these events are characteristic of gastric inflammation [ 38 , 39 , 40 ]. In patients with non-ulcer dyspepsia, gastritis or peptic ulcers that were infected by H. pylori , a high secretion of IL-17, IFN-γ, IL-23, IL-6, IL-10, TNF-α, IL-21, IL-8, and IL-37 was reported [ 41 , 42 , 43 , 44 , 45 , 46 , 47 ].…”

How Long Will It Take to Launch an Effective Helicobacter pylori Vaccine for Humans?

“… 34 Most studies have used urease as a candidate antigen, such as Nasr-Esfahani et al, who showed that injecting the recombinant plasmid pcDNA3.1 (+)- ureA into mice can stimulate an immunoresponse in an animal model infected with H. pylori . 35 Intranasal immunization with recombinant UreB vaccine with plant polysaccharides as adjuvants protected mice from H. pylori infection, which may be related to increased gastrointestinal specific SIgA and Th1/Th17 CD4 + T-cell response. 36 Most of the vaccines that have entered the clinical research stage contain urease antigen.…”