title: In contrast to conventional inactivated influenza vaccines, 4xM2e.HSP70c fusion protein fully protected mice against lethal dose of H1, H3 and H9 influenza A isolates circulating in Iran.
abstract: Ideal vaccines against influenza viruses should elicit not only a humoral response, but also a cellular response. Mycobacterium tuberculosis HSP70 (mHSP70) have been found to promote immunogenic APCs function, elicit a strong cytotoxic T lymphocyte (CTL) response, and prevent the induction of tolerance. Moreover, it showed linkage of antigens to the C-terminus of mHSP70 (mHSP70c) can represent them as vaccines resulted in more potent, protective antigen specific responses in the absence of adjuvants or complex formulations. Hence, recombinant fusion protein comprising C-terminus of mHSP70 genetically fused to four tandem repeats of the ectodomain of the conserved influenza matrix protein M2 (M2e) was expressed in Escherichia coli, purified under denaturing condition, refolding, and then confirmed by SDS-PAGE, respectively. The recombinant fusion protein, 4xM2e.HSP70c, retained its immunogenicity and displayed the protective epitope of M2e by ELISA and FITC assays. A prime-boost administration of 4xM2e.HSP70c formulated in F105 buffer by intramuscular route in mice (Balb/C) provided full protection against lethal dose of mouse-adapted H1N1, H3N2, or H9N2 influenza A isolates from Iran compared to 0-33.34% survival rate of challenged unimmunized and immunized mice with the currently in use conventional vaccines designated as control groups. However, protection induced by immunization with 4xM2e.HSP70c failed to prevent weight loss in challenged mice; they experienced significantly lower weight loss, clinical symptoms and higher lung viral clearance in comparison with protective effects of conventional influenza vaccines in challenged mice. These data demonstrate that C-terminal domain of mHSP70 can be a superior candidate to deliver the adjuvant function in M2e-based influenza A vaccine in order to provide significant protection against multiple influenza A virus strains.
authors.affiliation: Applied Biotechnology Research Center, Baqiyatallah University of Medical Sciences, P.O. Box 14155-3651,Tehran, Iran. smebrahimi@shirazu.ac.ir
authors.forename: Seyyed Mahmoud
authors.initials: SM
authors.lastname: Ebrahimi
authors.forename: Mehran
authors.initials: M
authors.lastname: Dabaghian
authors.forename: Majid
authors.initials: M
authors.lastname: Tebianian
authors.forename: Mohammad Hossein Zabeh
authors.initials: MH
authors.lastname: Jazi
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology*; D001835:Body Weight; D004195:Disease Models, Animal; D004926:Escherichia coli / Q000235:genetics; D005260:Female; D015870:Gene Expression; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000276:immunology*; D006801:Humans; D009980:Influenza A virus / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification; D007252:Influenza Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D007251:Influenza, Human / Q000821:virology*; D007273:Injections, Intramuscular; D007492:Iran; D051379:Mice; D008807:Mice, Inbred BALB C; D009976:Orthomyxoviridae Infections / Q000276:immunology / Q000401:mortality / Q000517:prevention & control*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology; D020449:Repetitive Sequences, Amino Acid; D016019:Survival Analysis; D014611:Vaccination / Q000379:methods; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D014763:Viral Matrix Proteins / Q000235:genetics / Q000276:immunology*; D000086082:Viroporin Proteins
chemical_list: D001426:Bacterial Proteins; D018840:HSP70 Heat-Shock Proteins; D007252:Influenza Vaccines; D011993:Recombinant Fusion Proteins; D014614:Vaccines, Synthetic; D014763:Viral Matrix Proteins; C444642:HSP70 protein, Mycobacterium tuberculosis; C488937:M2 protein, Influenza A virus; D000086082:Viroporin Proteins