1Immunology Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
2Razi Vaccine and Serum Research Institute, Mashhad, Iran
3Department of Pathology, Imam Reza Hospital, Mashhad University of Medical Sciences, Mashhad, Iran
Background: DNA immunization with plasmid DNA encoding bacterial, viral, parasitic and tumor antigens has been reported to trigger protective immunity. Objective: To evaluate the use of a DNA immunization strategy for protection against anthrax, a plasmid was constructed. Methods: The partialsequence of protective antigen of Bacillus anthracis, amino acids 175-764, as a potent immunogenic target was selected. The DNA encoding this segment was utilized in the construction of pcDNA3.1+PA plasmid. After intramuscular injection of rats with pcDNA3.1+PA plasmid, the expression of PA was assessed by RT-PCR and immunohistochemistry at RNA and protein levels, respectively. We also evaluated the presence of anti-PA antibodies in sera of immunized mice with pcDNA3.1+PA construct using immunoblotting. Results: The integrity of pcDNA3.1+PA construct was confirmed with restriction analysis and sequencing. The expression of PA was detected at RNA and protein levels. The presence of anti-PA antibodies in immunized mice with pcDNA3.1+PA construct was also confirmed. Conclusion: Our results indicate that pcDNA3.1+PA eukaryotic expressing vector could express PA antigen, induce antibody response and may be used as a candidate for DNA vaccine against anthrax.