Mohammad Hadi Fakoor; Parviz Owlia; Seyed Latif Mousavi gargari; Azar Sabokbar
Abstract
Background: Pseudomonas aeruginosa is considered as the most severe cause of infections in burn patients and pneumonia infections. Objective: To study the protective effects of recombinant protein vaccine harboring the PcrV of P. aeruginosa in the mouse model of burn and respiratory infections. Methods: ...
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Background: Pseudomonas aeruginosa is considered as the most severe cause of infections in burn patients and pneumonia infections. Objective: To study the protective effects of recombinant protein vaccine harboring the PcrV of P. aeruginosa in the mouse model of burn and respiratory infections. Methods: Recombinant protein vaccine harboring the PcrV was expressed in the E. coli BL-21 strain. Mice were immunized with the purified recombinant protein, and the antibody titer was measured in the sera obtained from the immunized mice. Immunized and control mice werechallenged by active and passive immunization. The microbial counts in the lung, skin, liver, spleen, and kidney were compared with the control mice. Results: Bioinformatics analysis indicated that the PcrV protein was conserved in 1552 clinical and environmental isolates. Also, the isoelectric point (pI), molecular weight, and Grand Average of Hydropathy (GRAVY) score were analyzed. Mice were injected with recombinant protein, and serum from immunized mice reacted strongly with recombinant antigen at a dilution of 1:64000. The survival rate of mice infected with 5xLD50 of the P. aeruginosa increased significantly up to 75% in the standard strains (PAO1 and PAK), and the number of bacteria, especially in the internal organs (kidney, spleen, and liver) significantly reduced compared to the mice immunized with placebo. Conclusions: Our results demonstrated that the PcrV protein could be an effective candidate vaccine for the generation of antibody response against P. aeruginosa infection.
Atina Vakili; Seyed Latif Mousavi Gargari; Shahram Nazarian; Jafar Amani
Abstract
Background: Cholera disease caused by Vibrio cholerae remains a major cause of morbidity and mortality throughout the world. Various strategies with different proteins as immunogens have been tried for vaccine development, none of which have been sufficiently effective to preclude cholera. Chimeric proteins, ...
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Background: Cholera disease caused by Vibrio cholerae remains a major cause of morbidity and mortality throughout the world. Various strategies with different proteins as immunogens have been tried for vaccine development, none of which have been sufficiently effective to preclude cholera. Chimeric proteins, with their ability to present multiple antigens at the same time, can play important roles in immunization. Objective: To evaluate the immunogenicity of a chimeric construct, comprised of OmpW and CtxB as immunogenic proteins of Vibrio cholera, in BALB/c mice. Methods: The construct was designed after bioinformatics assessments and then expressed in E.coli. Chimeric protein, OmpW, and CtxB were purified with Ni-NTA chromatography and confirmed by Western blotting. Mice were immunized with purified recombinant proteins. The antibody titers and specificity of the immune sera were then analyzed by ELISA and challenged on the pups of immunized mice with 1, 5 and 10 LD50. Mice ileal loop assay was also performed. Results: Significant differences were observed in antibody titers in immunized mice compared to the control groups. Infant mouse challenge was performed so as to compare the protective efficacies of the selected immunogen regimens. Of the Pups from dams immunized with chimeric protein which received 1 LD50, 75% survived. Pups belonging to PBS-immunized dams, experienced 100% mortality. The serum raised toward immunogenic construct, inhibited cholera toxin activity in ileal loop test up to 68%. Conclusion: Chimeric construct is able to induce the immune system and provide up to 75% inhibition of toxin activity against 1 LD50 of Vibrio cholerae.
