In Silico Analysis and Expression of Influenza Virus 3M2e-HA2 Chimer Protein Fused to C-Terminal Domain of Leishmania major HSP70

Abstract

Background: Design and construction of a universal vaccine based on conserved influenza antigens is the best way to protect populations from unforeseen influenza outbreaks. The ectodomain of matrix protein 2 (M2e) and hemagglutinin stalk domain (HA2) are considered as conserved influenza antigens. Genetic linkage of adjuvant HSP70 to these antigens can improve the efficacy of the vaccine. Objectives: The aim of this study was to produce a chimer protein to confer cross-protection against different subtypes of influenza A virus. Methods: The chimer form was subjected to in silico modeling and Immunoinformatics prediction analysis. The heat shock protein 70 (HSP70c) gene was cloned into the pET28a vector downstream of 3M2e-HA2 and expressed in Escherichia coli host. The desired chimer protein was purified with the Ni-TED column. Results: Validation analysis of the tertiary structure model showed that the model is in the range of native conformations. High score epitopes by Immunoinformatics tools were predicted. The expression of purified 3M2e-HA2-HSP70c was confirmed by the western-blotting assay. Conclusions: The genetic fusion of adjuvant HSP70 to the target antigen may improve the stimulation of immune responses. In silico analysis revealed the appropriate epitopes characterization of conserved antigens. Hence, the constructed chimer protein could be considered as a potential universal vaccine candidate to protect against influenza infection.