Constructing novel chimeric DNA vaccine against Salmonella enterica based on SopB and GroEL proteins: an in silico approach

Salmonella enterica is an important enteric pathogen that causes intestinal and systemic infections in warm-blooded animals. Due to different problems caused by administration of live attenuated vaccines, a DNA vaccine that is protective against S. enterica is desirable. By combining conserved antigenic determinant into a single vaccine, cross-protective immunity against many different immunogenic serovars can be achieved. This study proposed an in silico approach by assembling antigenic and conserved regions of SopB and GroEL proteins of S. enterica to induce multi-epitopic responses against the pathogen. In total, two unique and reliable antigenic regions of each protein were found and assembled in a chimeric DNA construct fused using appropriate linkers. Epitope predictions showed that the hypothetical synthetic construct could induce B and T-cell epitopes that yield a high immune response. Most regions of the chimeric construct were predicted to have high antigenic propensity and surface accessibility. The three-dimensional structure of the construct was generated and validated as a proper model which may define reliability, structural quality and conformation. DNA vaccine could cause concentration and increasing immune responses to critical epitopes and decrease adverse effects of vaccination. Successful in silico modeling has shown to be a promising approach to design robust vaccine targeting SopB and GroEL proteins of S. enterica. © 2017, The Korean Society of Pharmaceutical Sciences and Technology.