Isolation and immunogenicity of extracted outer membrane vesicles from Pseudomonas aeruginosa under antibiotics treatment conditions

Mehdi  Hadadi-Fishani; Shahin  Najar-Peerayeh; Seyed Davar Siadat; Mohammad Sekhavati; Ashraf Mohabati Mobarez

doi:10.18502/ijm.v13i6.8087

Mehdi Hadadi-Fishani Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
Shahin Najar-Peerayeh Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
Seyed Davar Siadat Department of Mycobacteriology and Pulmonary Research, Pasteur Institute, Tehran, Iran
Mohammad Sekhavati Department of Aerobic Bacterial Research and Vaccine Production, Razi Vaccine and Serum Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran
Ashraf Mohabati Mobarez Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran

DOI: https://doi.org/10.18502/ijm.v13i6.8087

Keywords: Outer membrane vesicle; Pseudomonas aeruginosa; Hypervesiculation; Immunization

Abstract

Background and Objectives: Different types of antibiotics have been indicated to enhance the secretion of OMVs from Pseudomonas aeruginosa. We aimed to investigate the effect of meropenem and amikacin antibiotics on inducing the secre- tion of OMVs and immunologic features in P. aeruginosa.

Materials and Methods: The OMVs were prepared from P. aeruginosa under hypervesiculation condition (treatment with amikacin and meropenem), and extraction was carried out by the sequential ultracentrifugation. Physicochemical features of extracted OMVs were evaluated by electron microscopy and SDS-PAGE. To quantify antibody synthesis and function after immunization with OMV, we used ELISA, serum bactericidal activity, and opsonophagocytosis. Production of cytokines from splenocytes of immunized mice was measured with ELISA.

Results: Specific-antibody IgG production, particularly IgG1 subclass, increased in mice primed with hypervesiculation-de- rived OMVs compared to normal condition-derived OMVs. Serum bactericidal activity and opsonophagocytosis of secreted antibody was enhanced in mice primed with hypervesiculation-derived OMVs. Investigation of cytokine production showed the upregulation of IL-8, IL-12, IL-17, and TNF-α and downregulation of IL-10.

Conclusion: Based on our findings, OMVs production can be increased by treating P. aeruginosa with amikacin and mero- penem antibiotics. Moreover, hypervesiculation-derived OMV scan possibly activate the humoral and cellular immune re- sponse more than normal OMVs.