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Background: Anthrax is a common disease among human and livestock which is caused by Bacillus anthracis. Bacillus anthracis has two strong immunogenic proteins: Protective antigen (PA) and lethal factor domain I (LFD1) that have always been considered as vaccine candidates against Bacillus anthracis. The aim of this study is to express and purify the lethal factor domain I (LFD1) in Escherichia coli and produce polyclonal antibody against it in mice. Materials and Methods: In this experimental study, LFD1 gene was amplified with BamH I and Xho I restriction site by PCR. After isolation, the gene was cloned to the expression vector pET28a (+). This vector was transformed to E. coli-BL21 (DE3) PLysSto to express LFD1 gene. The expression of LFD1 gene was induced by IPTG. After protein purification by affinity chromatography, the produced antigen was injected into mice for four times. Then the produced polyclonal antibody in mice serum was evaluated. Results: The cloned LFD1 gene in pET28a (+) vector was confirmed by PCR, enzymatic analysis, and sequencing. The expressed and purified recombinant protein was confirmed by SDS-PAGE and Western blotting. Finally, the isolated polyclonal antibody from mice serum was evaluated and confirmed by ELISA test. Conclusion: Noticing the appropriate expression, easy purification of LFD1, and the titer of produced polyclonal antibody against LFD1 in mice due to its immunogenicity, it can be considered as a good vaccine candidate against anthrax.

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Background: The emergence of antibiotic resistance, particularly resistance to methicillin in Staphylococcus aureus has made the treatment process more difficult. Therefore, producing of an effective vaccine seems to be necessary to prevent infections with methicillin-resistant Staphylococcus aureus (MRSA). In this study, a mixture of naloxone and alum has been used to improve the efficacy of a vaccine against MRSA.

Materials and Methods: MRSA 834 strain was grown on TSB medium and the grown cells were harvested and killed by sonication and were used as a vaccine model. Balb/c mice were divided into six groups and the vaccines were either injected alone, with naloxone, alum, or a mixture of naloxone - alum and control group received naloxone and PBS buffer. Total IgG antibody level was measured by ELISA method and finally, the challenge test of this bacterium was performed and the mice were examined regarding the degree of bacteria growth in their kidneys.

Results: The serum level of Total IgG antibody in the mixture of naloxone – alum with MRSA group was shown to be significantly increased (p<0.05). Furthermore, the lowest bacterial load was observed in this group.

Conclusion: It seems that a mixture of naloxone and alum as an adjuvant with the killed methicillin-resistant Staphylococcus aureus enhances the humoral immunity leading to a high level of protection against MRSA infections. Therefore, this seems to be a good option for improving the performance of this vaccine.

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Background and Aim: The human coronavirus is a member of the Coronaviridae family and causes upper respiratory tract infections. Despite repeated severe epidemics and the lack of appropriate antiviral drugs, not much progress has been made on the epitope-based vaccine designed for HCoV. 
Methods & Materials: The method of this study was to select the spike corona virus protein sequence from NCBI, retrieve the protein sequence and determine the T, B epitopes required to produce the chimer vaccine, evaluate the antigenicity and allergenicity and toxicity of the selected epitopes, respectively. Different servers were designed to configure the primary chimer composition of the epitope vaccine. Then, the chimer vaccine was evaluated in terms of structure and connectivity to B cells and MHCI and II compounds, and the two-dimensional structure and position of amino acids and bonds in the immunogenic model were studied, as well as the physicochemical and stability of the model vaccine by some other servers. Finally, it was tested for binding against HLA molecules using silico docking techniques to investigate the interaction with the epitope.
Ethical Considerations: All ethical principles are considered in this article. Participants were informed about the research objective and its implementation stages. They also made sure their information was confidential. The principles of the Helsinki Convention were also observed.
Results: The results showed that the immunogenic construct created in terms of two-dimensional and three-dimensional structure and the position of amino acids and bonds in the model of immunogenic structure, toxicity and allergenicity and antigenicity were in good condition. And had stability (instability index 33.93) and favorable half-life and suitable physicochemical conditions.
Conclusion: In general, the immunogenic structure that was prepared in this research process could have a favorable interaction with some components of the immune system (HLA) in the docking process, which indicates the optimal identification of this structure by the humoral and cellular immune system and stimulation in In order to produce immunity in the body of the host, of course, more reliable proof of it requires clinical phase processes.