PURPOSE: Atherosclerosis is classically defined as an immune-mediated disease characterized by accumulation of low-density lipoprotein cholesterol over intima in medium sized and large arteries. Recent studies have demonstrated that both innate and adaptive immune responses are involved in atherosclerosis. In addition, experimental and human models have recognized many autoantigens in pathophysiology of this disease. Oxidized low-density lipoproteins, beta2 glycoprotein I (beta-2-GPI), and heat shock protein 60 (HSP60) are the best studied of them which can represent promising approach to design worthwhile vaccines for modulation of atherosclerosis. MATERIALS AND METHODS: In silico approaches are the best tools for design and evaluation of the vaccines before initiating the experimental study. In this study, we identified immunogenic epitopes of HSP60, ApoB-100, and beta-2-GPI as major antigens to construct a chimeric protein through bioinformatics tools. Additionally, we have evaluated physico-chemical properties, structures, stability, MHC binding properties, humoral and cellular immune responses, and allergenicity of this chimeric protein by means of bioinformatics tools and servers. RESULTS: Validation results indicated that 89.1% residues locate in favorite or additional allowed region of Ramachandran plot. Also, based on Ramachandran plot analysis this protein could be classified as a stable fusion protein. In addition, the epitopes in the chimeric protein had strong potential to induce both the B-cell and T-cell mediated immune responses. CONCLUSION: Our results supported that this chimeric vaccine could be effectively utilized as a multivalent vaccine for prevention and modulation of atherosclerosis.
Apolipoprotein B-100 ; Arteries ; Atherosclerosis* ; Autoantigens ; B-Lymphocytes ; beta 2-Glycoprotein I ; Chaperonin 60 ; Cholesterol ; Computational Biology ; Computer Simulation* ; Epitopes ; Humans ; Immune System* ; Immunity, Cellular ; Lipoproteins ; Lipoproteins, LDL ; T-Lymphocytes ; Vaccines

PURPOSE: Staphylococcus aureus is one of the most important causes of nosocomial and community-acquired infections. The increasing incidence of multiple antibiotic-resistant S. aureus strains and the emergence of vancomycin resistant S. aureus strains have placed renewed interest on alternative means of prevention and control of infection. S. aureus produces a variety of virulence factors, so a multi-subunit vaccine will be more successful for preventing S. aureus infections than a mono-subunit vaccine. MATERIALS AND METHODS: We selected three important virulence factors of S. aureus, clumping factor A (ClfA), iron-regulated surface determinant (IsdB), and gamma hemolysin (Hlg) that are potential candidates for vaccine development. We designed synthetic genes encoding the clfA, isdB, and hlg and used bioinformatics tools to predict structure of the synthetic construct and its stabilities. VaxiJen analysis of the protein showed a high antigenicity. Linear and conformational B-cell epitopes were identified. RESULTS: The proteins encoded by these genes were useful as vaccine candidates against S. aureus infections. CONCLUSION: In silico tools are highly suited to study, design, and evaluate vaccine strategies.
Community-Acquired Infections ; Computational Biology ; Computer Simulation* ; Epitopes, B-Lymphocyte ; Genes, Synthetic ; Incidence ; Staphylococcus aureus* ; Vaccines ; Vancomycin ; Virulence Factors

PURPOSE: Escherichia coli O157:H7 is one of the most important pathogens which create hemorrhagic colitis and hemolytic uremic syndrome in human. It is one of the most prevalent causes of diarrhea leading to death of many people every year. The first diagnosed gene in the locus of enterocyte effacement pathogenicity island is eae gene. The product of this gene is a binding protein called intimin belonging to the group of external membrane proteins regarded as a good stimulants of the immune system. Chitosan with its lipophilic property is an environmentally friendly agent able to return to the environment. MATERIALS AND METHODS: Intimin recombinant protein was expressed in pET28a vector with eae gene and purification was performed using Ni-NTA and finally the recombinant protein was approved through western blotting. This protein was encapsulated using chitosan nanoparticles and the size of nanoparticles was measured by Zetasizer. Intimin encapsulated was prescribed for three sessions among three groups of oral, injection, and oral-injection using Chitosan nanoparticles. Challenge was performed for all three groups with 108 E. coli O157:H7 bacteria. RESULTS: Intimin produced by chitosan nanoparticles improves immunological responses through the adjuvant nature of chitosan nanoparticles. Chitosan may be used as a carrier for transportation of the prescribed vaccine. Among the mice, encapsulated intimin could be able to provide suitable titers of IgG and IgA by the aid of chitosan nanoparticles. Results of mice challenge showed that decreased the bacterial shedding significantly. CONCLUSION: Results showed that the chitosan nanovaccine with intimin protein may be used as a suitable candidate vaccine against E. coli O157:H7.
Animals ; Bacteria ; Bacterial Shedding ; Blotting, Western ; Carrier Proteins ; Chitosan ; Colitis ; Diarrhea ; Enterocytes ; Escherichia coli ; Genomic Islands ; Hemolytic-Uremic Syndrome ; Humans ; Immune System ; Immunoglobulin A ; Immunoglobulin G ; Membrane Proteins ; Mice ; Nanoparticles ; Transportation