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Evaluation of PLGA nanoparticles containing outer membrane proteins of Acinetobacter baumannii bacterium in
Afshin Gholizadeh1, Reza Shapoury2, Parviz Pakzad1
1Department of Microbiology, Faculty of Sciences, North Tehran Branch, Islamic Azad University, Tehran, I.R. Iran.
Background And Purpose:
Acinetobacter baumannii (A. baumannii) is known as a pathogen with antibiotic resistance, causing respiratory infections. PLGA has been approved for use in vaccines as well as drug delivery. This study was performed to evaluate PLGA nanoparticles containing the outer membrane proteins (OMPs) of A. baumannii in stimulating the mice's immune system and improving pneumonia.
Experimental Approach:
Double emulsion solvent evaporation technique was used. The properties of the obtained nanospheres were determined using a zetasizer, FTIR, and AFM devices. Nanoparticles were administered to mice BALB/c by applying the intramuscular route. ELISA was used to measure the amounts of immunoglobulins produced; also, an opsonophagocytic killing assay was used to measure the effectiveness of immunoglobulins. Immunized mice were then challenged with live A. baumannii through the lungs; their internal organs were also removed for bacteriological studies.
Findings/Results:
The prepared particles were 550 nm in diameter with a negative surface charge. The production of the OMPs specific IgG was much higher in the group receiving nanoparticles containing antigen as compared to those getting pure antigen. The immunoglobulins produced against nanoparticles were superior to those developed against pure antigens. Mice that received the new nanovaccine were more resistant to pneumonia caused by this bacterium than those that received pure antigen.
Conclusion And Implication:
Overall, it can be said that PLGA nanoparticles could deliver their internal antigens (OMPs) well to the immune system of mice and stimulate humoral immunity in these animals, thus protecting them against pneumonia caused by A. baumannii.
Insights
Poly(lactic-co-glycolic) acid (PLGA) nanoparticles carrying Acinetobacter baumannii outer membrane proteins (OMPs) effectively stimulate an immune response. This nanovaccine protects mice against A. baumannii pneumonia, demonstrating potential for novel vaccines.
Area of Science:
- Nanotechnology
- Immunology
- Microbiology
Background:
- Acinetobacter baumannii is a significant antibiotic-resistant pathogen causing respiratory infections.
- Poly(lactic-co-glycolic) acid (PLGA) is an FDA-approved biodegradable polymer utilized in drug delivery and vaccines.
Purpose of the Study:
- To evaluate PLGA nanoparticles loaded with A. baumannii outer membrane proteins (OMPs) as a potential vaccine.
- To assess the immunogenicity and protective efficacy against A. baumannii-induced pneumonia in mice.
Main Methods:
- PLGA nanoparticles encapsulating A. baumannii OMPs were prepared using a double emulsion solvent evaporation technique.
- Nanoparticle characterization included size (550 nm) and surface charge determination.
- Immunogenicity was assessed via ELISA for immunoglobulin G (IgG) production and opsonophagocytic killing assays.
- Efficacy was evaluated by challenging immunized mice with live A. baumannii and performing bacteriological studies.
Main Results:
- PLGA nanoparticles exhibited a negative surface charge and a diameter of 550 nm.
- Significantly higher levels of OMP-specific IgG were produced in mice receiving nanoparticle-loaded antigen compared to pure antigen.
- The immunoglobulins generated against nanoparticles showed superior effectiveness.
- Mice vaccinated with the nanovaccine demonstrated enhanced resistance to A. baumannii pneumonia.
Conclusions:
- PLGA nanoparticles effectively deliver A. baumannii OMPs to the immune system.
- The nanovaccine formulation successfully stimulates a robust humoral immune response.
- This approach offers a promising strategy for developing a protective vaccine against A. baumannii infections.
