Immunological evaluation of an alginate‐based conjugate as a vaccine candidate against Pseudomonas aeruginosa

Abstract

Pseudomonas aeruginosa is an opportunistic pathogen that causes serious infections, is usually resistant to antimicrobial agents, and is the leading cause of morbidity and premature mortality in patients with cystic fibrosis (CF). Mucoid strains of P. aeruginosa produce a virulence factor known as alginate. Developing a strategy to raise opsonic antibodies against alginate could be promising for the treatment of P. aeruginosa infection in CF patients. Conjugation of alginate to a carrier protein is a good method for increasing the immunogenicity of alginate. We conjugated alginate to the outer membrane vesicle (OMV) of Neisseria meningitidis serogroup B, which is a safe carrier protein, and evaluated its efficacy in mice. To evaluate the immune response, total IgG, IgG1, IgG2a, and IgG2b titers were analyzed. Immunization of mice with the alginate-OMV conjugate raised the levels of opsonic antibodies, and the vaccinated mice were protected when challenged intranasally with P. aeruginosa. Further studies showed that the conjugated vaccine could eliminate P. aeruginosa from the lungs of infected mice. This study supports the proposal that immunization of mice with an alginate-OMV conjugate vaccine could be safe and protective against P. aeruginosa infection.

Synthesis, Characterization, and Immunological Properties of LPS-Based Vaccines Composed of O-Polysaccharides Conjugated with Recombinant Exoprotein A from <i>Pseudomonas aeruginosa</i>

“…In these patients, P. aeruginosa is one of the most dangerous nosocomial pathogens, due to its production of several virulence factors such as exotoxin A, exoenzyme S, elastase, alginate and lipopolysaccharide (LPS) [3] [4]; emergence of multidrug resistant strains [5]; and absence of an efficient protective vaccine [2].…”

Comparative analysis of PIA and rSesC mixture, arisen antibodies against the biofilm forming Staphylococcus aureus.

“…Taking advantage of the previous procedure, the pyrogenicity and toxicity of the antigens were checked [23]. The amount of endotoxin in the prepared antigens was measured by a commercial Limulus amebocyte lysate kit (Thermo Scientific, Waltham, MA, USA) according to the manufacturer's recommendations.…”

Comparative analysis of PIA and rSesC mixture, as vaccine candidate against the biofilm forming Staphylococcus aureus.

“…Taking advantage of the previously procedure, the pyrogenicity and toxicity of the antigens were checked [15]. The amount of endotoxin in the prepared antigens was measured by a commercial Limulus amebocyte lysate kit (Thermo Scientific, Waltham, MA, USA) according to the manufacturer's recommendations.…”