Construction of Enterococcus faecium-mediated ExoU vaccine and its protective effect in mice challenged with
Fan Yang1, Shuhan Yang1, Xingkun Ou2
1Department of Infectious Diseases, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China.
Background:
Pseudomonas aeruginosa (Pa) is an opportunistic pathogen and an important cause of nosocomial infections, and its antimicrobial resistance is a major therapeutic challenge. DNA vaccination is an attractive antigen-specific immunotherapy approach.
Methods:
In this study, we used the most acutely cytotoxic effector exoenzyme U (ExoU) released by Pa as the specific antigen and the safe and reliable Enterococcus faecium (Ef) as the expression vector, to construct the recombinant Ef-ExoU vaccine. The immune protection and humoral and cellular immune responses of the DNA vaccine were evaluated in mice by oral gavage.
Results:
We found that the Ef-ExoU vaccine significantly reduced lung bacterial load and lung inflammatory cytokines (IL-6, TNF-α), probably by inducing higher levels of IgG and spleen CD4+ T cell proliferation, indicating the induction of a mixed Th1 and Th2 immune response.
Conclusions:
This study suggests that Ef-ExoU is a promising subunit vaccine candidate and provides a new strategy for the prevention and treatment of Pa infection.
Insights
A novel DNA vaccine using Enterococcus faecium (Ef) to deliver Pseudomonas aeruginosa (Pa) exoenzyme U (ExoU) shows promise. This Ef-ExoU vaccine effectively reduced lung bacterial load and inflammation in mice, indicating a potential new strategy against Pa infections.
Area of Science:
- Microbiology
- Immunology
- Vaccine Development
Background:
- Pseudomonas aeruginosa (Pa) is a significant cause of hospital-acquired infections.
- Antimicrobial resistance in Pa presents a major therapeutic challenge.
- DNA vaccination offers a potential immunotherapy approach for bacterial infections.
Purpose of the Study:
- To develop and evaluate a novel DNA vaccine against Pseudomonas aeruginosa.
- To assess the immunoprotective effects of a recombinant Enterococcus faecium-ExoU (Ef-ExoU) vaccine.
Main Methods:
- Constructed a recombinant Ef-ExoU vaccine using Enterococcus faecium as a safe expression vector.
- Administered the Ef-ExoU vaccine to mice via oral gavage.
- Evaluated immune protection, humoral, and cellular immune responses.
Main Results:
- The Ef-ExoU vaccine significantly reduced lung bacterial load in mice.
- Vaccination decreased lung inflammatory cytokines, including IL-6 and TNF-α.
- Induced elevated IgG levels and spleen CD4+ T cell proliferation, suggesting a mixed Th1/Th2 immune response.
Conclusions:
- The Ef-ExoU vaccine demonstrates potential as a subunit vaccine candidate against Pseudomonas aeruginosa.
- This study presents a novel strategy for preventing and treating Pa infections.
