Bovine serum albumin nanoparticle vaccine reduces lung pathology induced by live Pseudomonas aeruginosa infection in mice

Pseudomonas aeruginosa is an important opportunistic human pathogen that causes severe infections in immunocompromised patients and also in cystic fibrosis patients. The aim of this work was to study if a bovine serum albumin nanoparticles with entrapped antigens extracted from P. aeruginosa would be able to protect mice from nasal infection by this pathogen. Mice were immunized via the subcutaneous route using P. aeruginosa antigens, empty nanoparticles or nanoparticles with entrapped P. aeruginosa antigens on days 0, 7 and 14. The total IgG antibody production and specific IgG1 and IgG2a titer were measured by ELISA. Immunized mice were challenged with live P. aeruginosa and their lungs were collected for histopathology studies. Our data showed that NPPa-vaccinated mice presented a high anti-Pseudomonas IgG1 and a low IgG2a antibody titles and decreased inflammatory signs, with significant reduction in intensity and concentration of inflammatory cells, lower hemorrhagic, edema and hyperemia signs in the lungs of challenge mice with live P. aeruginosa if compared to the other groups. Therefore, this formulation is able to induce a functional response in an animal model of infection and thereby is a promising platform for P. aeruginosa vaccines.