• M2e-HSP70 chimeric protein as an influenza vaccine candidate
  • Tina Hassan Panah,1 Fataneh Fatemi,2,* Omid Ranaee Siyadat,3
    1. Protein Research Center, Shahid Beheshti University, Tehran, Iran
    2. Protein Research Center, Shahid Beheshti University, Tehran, Iran
    3. Protein Research Center, Shahid Beheshti University, Tehran, Iran


  • Introduction: Influenza virus is the cause of annual epidemics and causes the death of thousands of people in the world. This virus is transmitted from one person to another by respiratory droplets in the air or contact with contaminated surfaces and causes destruction and disruption of the respiratory tract. This disease is dangerous for the elderly, young children and people who suffer from underlying diseases such as lung, kidney, heart, etc. It is very necessary to prevent it through effective and universal vaccines. There is always a serious need to improve the vaccines produced against the influenza virus in order to create a broader immunity with long-term stability. By comparing the types of vaccines designed against the influenza virus, one of the necessities that is now felt is to separate the stages of vaccine production from the embryonated egg system and to be on the path of producing new vaccines based on biotechnology. One of the best production routes for seasonal vaccines, as well as for modern and universal vaccines, is the route of recombinant protein vaccines. So far, a lot of work has been done on recombinant influenza protein vaccines and its various genes have been investigated. One of these proteins is the M2e protein, which is highly conserved in different influenza virus strains. M2e is a type 3 non-glycosylated protein that is abundantly expressed in the plasma membrane of virus-infected cells.
  • Methods: In the present study, the recombinant production of this protein in Escherichia coli bacteria and the purification of the produced product were carried out with the aim of using it as a component of the influenza vaccine set. In this study, the recombinant influenza virus M2e protein was expressed and purified in a chimeric form with HSP70, in order to be used in the production of a subunit vaccine set in the prokaryotic host E.coli.
  • Results: For this purpose, the 4xM2e.HSP70 gene fragment was expressed in the expression host E.coli strain M-15, using the isopropyl beta-di1-thiogalactopyranoside (IPTG) inducer. And it was confirmed by performing SDS-PAGE and western blot with Anti-His-tag antibody. The expression was carried out in optimized conditions with 0.5 mM amount of IPTG inducer at 25°C temperature and after protein extraction with urea and its purification in optimized conditions with urea by Ni-NTA affinity chromatography column, protein 4xM2e.HSP70 was recovered and deureated by dialysis method in 2 phosphate buffer and saline buffer. Finally, its production efficiency was about 165 μg/ml protein. In this method, a suitable amount of M2e protein was obtained in the shortest time and at a low cost, for the following purposes, which indicates the efficient production of recombinant protein in the prokaryotic system in order to be used in the influenza vaccine.
  • Conclusion: According to the results obtained from this research, it is suggested that the expression of the desired gene construct be investigated in order to optimize production in other hosts such as eukaryotic hosts, as well as the protein function and immunogenicity of the desired construct alone, together with adjuvant or by adding other protected proteins of influenza virus to be evaluated.
  • Keywords: Influenza A virus, M2e, HSP70, Protein expression, E.coli