Designing and construction a DNA vaccine encoding the fusion fragment of cfp10 and ag85a immunodominant genes of Mycobacterium tuberculosis

Abstract

Background: Pathogenic mycobacteria are one of major causes of human morbidity and mortality. Mycobacterium tuberculosis (M. tuberculosis) is an etiological agent of human tuberculosis. Designing new vaccines including DNA vaccines may be considered as new approaches for preventing of TB. Materials and Methods: M. tuberculosis H37Rv was grown on Lowenstein Jensen medium for 4 weeks at 37oC and then DNA was extracted. The cfp10 gene was amplified by PCR. After digesting the PCR product and the plasmid, cfp10 fragment was ligated into the vector using T4 DNA ligase. Then, Ag85A was subcloned into pcDNA/cfp10. Escherichia coli strain JM109 bacteria were transformed by the desired construct. Clone confirmations were performed by colony PCR, restriction enzyme digestion and DNA sequencing. Recombinant vector was transfected into HeLa cells and total RNA was extracted, then cDNA was synthesized using oligo-dT. Finally PCR was performed by cfp10 primers. Results: The cfp10 was amplified by PCR method and the PCR products were visualized by agarose gel electrophoresis. The cfp10 fragments showed 303 bp in length. The cfp10 cloned into pcDNA. Then, Ag85Awas ligated into pcDNA/cfp10 after digestion correctly. Colony-PCR and restriction enzyme digestion and sequencing confirmed the cloning the fusion Ag85A/cfp10 fragment. Finally, after cDNA synthesis, expression of vector was confirmed in eukaryotic system. Conclusion: Cloning of Ag85A/cfp10 genes of M. tuberculosis were performed correctly. It can use as a DNA vaccine for investigation the immune responses in animal models in future studies. K e y w o r ds: DNA vaccine, cfp10 , A g85A , Mycobacterium tuberculosis