Dataset Information

Advantages of a synthetic peptide immunogen over a protein immunogen in the development of an anti-pilus vaccine for Pseudomonas aeruginosa.

ABSTRACT: The type IV pilus is an important adhesin in the establishment of infection by Pseudomonas aeruginosa. We have previously reported on a synthetic peptide vaccine targeting the receptor-binding domain of the main structural subunit of the pilus, PilA. The receptor-binding domain is a 14-residue disulfide loop at the C-terminal end of the pilin protein. The objective of this study was to compare the immunogenicity of a peptide-conjugate to a protein subunit immunogen to determine which was superior for use in an anti-pilus vaccine. BALB/c mice were immunized with the native PAK strain pilin protein and a synthetic peptide of the receptor-binding domain conjugated to keyhole limpet haemocyanin. A novel pilin protein with a scrambled receptor-binding domain was used to characterize receptor-binding domain-specific antibodies. The titres against the native pilin of the animals immunized with the synthetic peptide-conjugate were higher than the titres of animals immunized with the pilin protein. In addition, the affinities of anti-peptide sera for the intact pilin receptor-binding domain were significantly higher than affinities of anti-pilin protein sera. These results have significant implications for vaccine design and show that there are significant advantages in using a synthetic peptide-conjugate over a subunit pilin protein for an anti-pilus vaccine.

SUBMITTER: Kao DJ

PROVIDER: S-EPMC2756486 | biostudies-literature | 2009 Jul

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Advantages of a synthetic peptide immunogen over a protein immunogen in the development of an anti-pilus vaccine for Pseudomonas aeruginosa.

Kao Daniel J DJ Hodges Robert S RS

Chemical biology & drug design 20090701 1

The type IV pilus is an important adhesin in the establishment of infection by Pseudomonas aeruginosa. We have previously reported on a synthetic peptide vaccine targeting the receptor-binding domain of the main structural subunit of the pilus, PilA. The receptor-binding domain is a 14-residue disulfide loop at the C-terminal end of the pilin protein. The objective of this study was to compare the immunogenicity of a peptide-conjugate to a protein subunit immunogen to determine which was superio ...[more]

PMID: 19519742

Similar Datasets

Project description:Antivirulence strategies aim to target pathogenicity factors while bypassing the pressure on the bacterium to develop resistance. The MgtC membrane protein has been proposed as an attractive target that is involved in the ability of several major bacterial pathogens, including Pseudomonas aeruginosa, to survive inside macrophages. In liquid culture, P. aeruginosa MgtC acts negatively on biofilm formation. However, a putative link between these two functions of MgtC in P. aeruginosa has not been experimentally addressed. In the present study, we first investigated the contribution of exopolysaccharides (EPS) in the intramacrophage survival defect and biofilm increase of mgtC mutant. Within infected macrophages, expression of EPS genes psl and alg was increased in a P. aeruginosa mgtC mutant strain comparatively to wild-type strain. However, the intramacrophage survival defect of mgtC mutant was not rescued upon introduction of psl or alg mutation, suggesting that MgtC intramacrophage role is unrelated to EPS production, whereas the increased biofilm formation of mgtC mutant was partially suppressed by introduction of psl mutation. We aimed to develop an antivirulence strategy targeting MgtC, by taking advantage of a natural antagonistic peptide, MgtR. Heterologous expression of mgtR in P. aeruginosa PAO1 was shown to reduce its ability to survive within macrophages. We investigated for the first time the biological effect of a synthetic MgtR peptide on P. aeruginosa. Exogenously added synthetic MgtR peptide lowered the intramacrophage survival of wild-type P. aeruginosa PAO1, thus mimicking the phenotype of an mgtC mutant as well as the effect of endogenously produced MgtR peptide. In correlation with this finding, addition of MgtR peptide to bacterial culture strongly reduced MgtC protein level, without reducing bacterial growth or viability, thus differing from classical antimicrobial peptides. On the other hand, the addition of exogenous MgtR peptide did not affect significantly biofilm formation, indicating an action toward EPS-independent phenotype rather than EPS-related phenotype. Cumulatively, our results show an antivirulence action of synthetic MgtR peptide, which may be more potent against acute infection, and provide a proof of concept for further exploitation of anti-Pseudomonas strategies.

Project description:Pseudomonas aeruginosa is a common bacterium in nosocomial infection. The biofilm-forming ability and antimicrobial resistance make P. aeruginosa biofilm infection refractory to patients requiring hospitalization, especially patients in the intensive care unit. Therefore, many alternative compounds have been developed. A newly synthesized peptide, RP557, derived from human cathelicidin LL-37, was evaluated for its antimicrobial and antibiofilm effect toward carbapenem-resistant P. aeruginosa (CRPA). The results showed that regardless of the resistance to carbapenems, the minimal inhibition concentrations of RP557 and LL-37 against P. aeruginosa were 32 µg/mL and 256 µg/mL, respectively. Both RP557 and LL-37 significantly reduced the P. aeruginosa biofilm mass at subMICs, while subMICs of carbapenems induced biofilm formation. RP557 could also remove approximately 50% of the mature biofilm at a concentration of 64 µg/mL, while 256 µg/mL LL-37 was needed to remove it. A quarter MIC of RP557 and LL-37 was used together with carbapenems (ertapenem, imipenem, and meropenem). The results show that both RP-557 and LL-37 might increase the susceptibility to CRPA by 4-16 times. Significant gene expression level changes were observed in RP557- or LL-37-treated CRPA. Confocal images showed that biofilm structures and biofilm cell viability were significantly reduced in the LL-37- or RP557-treated groups. Therefore, RP557 and its structural origin, LL-37, could be potential treatments for carbapenem-resistant P. aeruginosa infection, especially for chronic biofilm infection. IMPORTANCE Pseudomonas aeruginosa is one of the major pathogens of nosocomial infection. Combined its biofilm-forming ability with carbapenem-resistance, it is hard to handle P. aeruginosa infection, especially for patients requiring hospitalization. Antimicrobial peptide is a type of potential compound for bacterial infection treatment. Among these, RP557 was found effective in inhibiting biofilm previously. By assessing its effect on both carbapenem-resistant P. aeruginosa planktonic cells and biofilm, our results offered a potential treatment for carbapenem-resistant P. aeruginosa infection. It could be helpful to treat severe nosocomial infection related to carbapenem-resistant bacteria and increase the patients' survival rate.

Dataset Information

Advantages of a synthetic peptide immunogen over a protein immunogen in the development of an anti-pilus vaccine for Pseudomonas aeruginosa.

Publications

Advantages of a synthetic peptide immunogen over a protein immunogen in the development of an anti-pilus vaccine for Pseudomonas aeruginosa.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets