Ability of synthetic peptides representing epitopes of outer membrane protein F of Pseudomonas aeruginosa to afford protection against P-aeruginosa infection in a murine acute pneumonia model

Three synthetic peptides (Nos 9, 10 and 18) representing surface-esposed, linear B-cell epitopes of outer membrane protein F of Pseudomonas aeruginosa were each conjugated to the carriers keyhole limpet hemocyanin (KLH) and bovine serum albumin (BSA), with the conjugates being used to immunize mice intranasally, Mice were also immunized intranasally with a KLH/BSA carrier control or with a peptide No. 8 conjugate as a negative control. An immunoglobulin G response reactive with P. aeruginosa whole cells was demonstrated by enzyme-linked immunosorbent assay (ELISA) of sera from mice immunized with peptide 9, 10 or 18, whereas no whole-cell reactivity by ELISA was detected in sera from mice immunized with peptide 8. Upon pulmonary challenge of immunized mice with a Fisher-Devlin immunotype 4 strain of P. aeruginosa, only those mice immunized with peptide 9 or peptide 10 had a significantly greater survival rate compared to control mice immunized with the carriers alone, Peptides 9 (TDAYNQKLSERRAN) and 10 (NATAEGRAINRRVE) have potential for further development as a protective vaccine against P, aeruginosa infections.