Effects of Yersinia pseudotuberculosis outer membrane vesicles on Pseudomonas aeruginosa antigens immune response

Area of Science:

• Bacteriology
• Immunology
• Vaccine Development

Background:

• Outer membrane vesicles (OMVs) are self-adjuvanting, immunogenic nanoparticles produced by Gram-negative bacteria.
• The immunomodulatory effects of OMVs when combined with specific antigens require further investigation.
• Pseudomonas aeruginosa is an opportunistic pathogen causing severe infections, necessitating novel vaccine strategies.

Purpose of the Study:

• To evaluate the immune response and protective efficacy of recombinant OMVs (rOMVs) derived from Yersinia pseudotuberculosis expressing Pseudomonas aeruginosa antigens.
• To compare the efficacy of rOMVs carrying PcrV (rOMVyp2P) versus OprF/I (rOMVyp2F) against P. aeruginosa infection.

Main Methods:

• Construction of a recombinant Yersinia pseudotuberculosis ΔlpxL strain expressing PcrV or OprF/I antigens.
• Purification of ΔlpxL rOMVPcrV (rOMVyp2P) and ΔlpxL rOMVOprF/I (rOMVyp2F).
• Analysis of humoral and cellular immune responses, and survival rates in a mouse model of P. aeruginosa PAO1 pulmonary infection.

Main Results:

• Both rOMVyp2P and rOMVyp2F facilitated humoral immune responses against PcrV and OprF/I antigens, respectively.
• rOMVs induced a balanced Th1/Th2 immune response, with elevated IgM and IgA antibody levels.
• ΔlpxL rOMVPcrV demonstrated significantly better protection against P. aeruginosa pulmonary infection, with a 20% survival rate compared to the ΔlpxL rOMVOprF/I group.

Conclusions:

• Recombinant Yersinia pseudotuberculosis OMVs can effectively present Pseudomonas aeruginosa antigens and elicit robust immune responses.
• ΔlpxL rOMVPcrV shows enhanced efficacy in conferring pulmonary immune protection against Pseudomonas aeruginosa infection.
• These findings suggest potential for developing OMV-based vaccines against P. aeruginosa.