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Background: Influenza is a contagious respiratory infectious disease out breaking in cold seasons of the year. The outbreak of the new influenza A (H1N1) virus in 2009 involved large populations of the world with considerable mortality. Hemagglutinin (HA) molecule, the main surface glycoprotein of the influenza virus, is one of the key factors for serological diagnostic kits and vaccine development. Thus establishment of HA gene bank of the circulating influenza viruses is essential in gaining quick access to large amounts of protein. Materials and Methods: The first step in providing such a bank is detection and isolation of HA full genome and its subunits by using specific primers and cloning them in proper vectors. For this purpose, using standard virus genome (A/New Caledonia/20/99(H1N1)) cultured on MDCK cell, HA coding gene was proliferated by RT-PCR using specific primers. Results: Isolation and cloning of the HA gene was verified by RT-PCR, enzyme digestion and determining nucleotide synonymy. Through the use of specific cloning primers, different HA gene constructs were propagated for expression of the gene in insect cells and E.coli bacteria. Conclusion: The results indicated the complete compatibility of the extracted HA gene with the influenza (A/New Caledonia/20/99(H1N1)) hemagglutinin. It makes it possible to use the gene as a source of cloning in a variety of eukaryotic and prokaryotic expression systems

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Background: Influenza A viruses are globally important respiratory pathogens which cause a high degree of morbidity and mortality during annual epidemics. M2 protein which expressed on the viral surface facilitates virus entry to the host cells. The extracellular domain of M2 protein (M2e) consists of N-terminal 24 residue which shows remarkable conservation among all subtypes of influenza A viruses. In this study, we evaluated the immunogenicity of three tandem repeats of M2e along with different adjuvants in BALB/C mice model.

Materials and Methods: Recombinant protein (3M2e) was expressed in Escherichia coli and purified. Six weeks old BALB/c mice were immunized interdermally with three doses of 3M2e alone or supplemented with Alum/CpG motif as adjuvant. Control group was injected with PBS. Two weeks after the last immunization, specific anti-M2 was measured using ELISA method and finally mice were challenged with one lethal dose (LD90) of PR8 virus.

Results: The results showed that 3M2e can induce specific antibody alone. However, 3M2e protein supplemented with Alum-CpG induced higher level of specific antibodies, so that, there was a significant difference with 3M2e group (p<0.05). Anti-M2 antibodies mostly consisted of IgG2a subclass which considered as activity index of TH1 Cells. Moreover, this group showed enhanced protection against wild-type virus (survival rate=60%).

Conclusion: Applying Alum-CpG as a complex adjuvant may play a crucial role in integrating innate and acquisitive immunity. We increased density of M2e in combination with complex adjuvant and showed that this vaccine induced power immune responses and semi-protected mice against lethal challenge.

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Background: Nef is one of the HIV-1 critical proteins, because it is essential for viral replication and AIDS disease progression and induction of immune response against it can partially inhibit viral infection. Moreover, a domain of the HIV-1 Trans-Activator of Transcription (Tat, 48-60 aa) could act as a cell penetrating peptide (CPP). In current study, cloning and expression of Tat-Nef fusion protein was performed in E. coli for the first time. The protein expression was confirmed by western blot analysis and was purified using reverse staining method.

Materials and Methods: In this experimental study, primarily, cloning of Tat-Nef fusion gene was done in pGEX6p2 expression vector. Then, the expression of Tat-Nef recombinat protein in E.coli BL21 (DE3) strain was performed by using IPTG inducer. The protein expression was confirmed by SDS-PAGE and western blotting using anti-Nef monoclonal antibody. Then, the recombinant fusion protein was purified from gel using reverse staining method.

Results: The results of PCR analysis and enzyme digestion showed a clear band of ~ 726 bp in agarose gel indicating the correct Tat-Nef fusion cloning in pGEX6p2 prokaryotic expression vector. In addition, a 54 kDa band of Tat-Nef on SDS-PAGE revealed Tat-Nef protein expression that western blot analysis using anti-Nef monoclonal antibody confirmed it.

Conclusion: The purified Tat-Nef recombinant fusion protein will be used as an antigen for protein vaccine design against HIV infection.