Adjuvanted bacteriophage vaccine targeting Pseudomonas aeruginosa

Abstract

Pseudomonas aeruginosa (Pa) is a Gram-negative bacterium which is associated with chronic diabetic wounds as well as potentially deadly lung infections in cystic fibrosis patients. Approximately 51,000 cases of Pa infections occur annually; of these cases, 13% are resistant to antibiotics which results in the deaths of ~400 individuals every year. Diversity between Pa strains presents a challenge in developing a vaccine or therapeutic capable of resolving infections caused by different strains. Pf phage (a filamentous bacteriophage) has been found in Pa from chronic diabetic wound isolates and has been show to increase virulence of Pa. Recent findings by our team indicate that a Pf phage-targeted vaccine or monoclonal antibody provide protection from the establishment of Pa infection in mice. To further improve this innovative new vaccine targeting Pa, adjuvant systems were used to enhance humoral response to the vaccine. A consensus peptide from Pf Phage coat protein was conjugated to the carrier protein CRM197 and combined with novel adjuvants and delivery systems. Selected adjuvants significantly enhanced humoral immunity to the Pf Phage peptide in a dose-dependent manner. Combination adjuvant systems were also used to further enhance antigen-specific immunity to Pf Phage and cell-mediated immunity to the carrier protein. The development of an adjuvanted Pf phage vaccine to protect against Pa infections is a new and innovative strategy with the potential to protect patients at risk for opportunistic bacterial infections.