Cloning of tagD gene from Helicobacter pylori in PFLAG-CMV-3 eukaryotic vector to generate a DNA vaccine

Introduction: Helicobacter pylori is strongly associated with gastritis, stomach cancer, gastric lymphoma and peptic ulcer in human. Thiol peroxidase is encoded by tagD gene and plays a significant role in colonizing H. pylori in the stomach. The product of tagD gene stimulates the immune system in the host. This study aimed to isolate and clone tagD gene in the eukaryotic expression vector PFLAG-CMV-3 as a DNA vaccine candidate. Materials and methods: In this experimental research, tagD gene (537 bp) was amplified by PCR. The PCR products were cloned using cloning commercial kits (Thermo Fisher Co., COUNTRY) in pTZ vector. This gene was subcloned in the eukaryotic expression vector (PFLAG-CMV-3 vector), then transferred into CHO cells by electroporation method and was expressed. Results: The results indicate that amplification and cloning of tagD gene was successful, and the pTZ-tagD vector was formed. PFLAG-CMV-3 vector construction was confirmed by digestion and gene sequencing. The 19 kDa band was observed by gene expression analysis on SDS-PAGE. Conclusions: tagD gene in the PFLAG-CMV-3-tagD recombinant vector has the ability to produce specific protein in CHO cells. Therefore, this gene construct is useful to evaluate the immunogenicity as a DNA vaccine against H. pylori infection in animal models.