Characterization of the Burkholderia cenocepacia J2315 Surface-Exposed Immunoproteome

Abstract

Infections by the Burkholderia cepacia complex (Bcc) remain seriously life threatening to cystic fibrosis (CF) patients, and no effective eradication is available. A vaccine to protect patients against Bcc infections is a highly attractive therapeutic option, but none is available. A strategy combining the bioinformatics identification of putative surface-exposed proteins with an experimental approach encompassing the “shaving” of surface-exposed proteins with trypsin followed by peptide identification by liquid chromatography and mass spectrometry is here reported. The methodology allowed the bioinformatics identification of 263 potentially surface-exposed proteins, 16 of them also experimentally identified by the “shaving” approach. Of the proteins identified, 143 have a high probability of containing B-cell epitopes that are surface-exposed. The immunogenicity of three of these proteins was demonstrated using serum samples from Bcc-infected CF patients and Western blotting, validating the usefulness of this methodology in identifying potentially immunogenic surface-exposed proteins that might be used for the development of Bcc-protective vaccines.

Immunization and Immunotherapy Approaches against Pseudomonas aeruginosa and Burkholderia cepacia Complex Infections

“…Recently, Sousa et al used a surface shaving approach to identify the surface exposed immunoproteome of B . cenocepacia J2315 [ 111 ]. Bioinformatic identification of putative surface-exposed proteins was combined with an experimental approach that consisted of the incubation of the live intact cells with trypsin, allowing the “shaving” of the surface proteins that were identified by liquid chromatography and mass spectrometry.…”

“…The shaving approach was able to identify only 16 of the 143 potentially immunogenic proteins. The difference observed emphasize the importance of combined bioinformatics and experimental approaches [ 111 ]. The immunogenicity of three proteins identified in this work (BCAL2958, BCAL2645, BCAL2022) was demonstrated using sera samples from CF patients with previous history of Bcc infection, validating the approach for the detection of potential immunogenic proteins.…”

A Polyclonal Antibody Raised against the Burkholderia cenocepacia OmpA-like Protein BCAL2645 Impairs the Bacterium Adhesion and Invasion of Human Epithelial Cells In Vitro

“…The discovery of possible new targets for the development of immunoprotective strategies against Bcc prompted us to uncover surface exposed proteins from the highly transmissible epidemic Bcc strain B. cenocepacia J2315 [ 22 ]. A surfomics approach allowed the isolation and identification of the surface exposed moieties of proteins expressed in B. cenocepacia J2315 [ 23 ]. Sixteen of these surface exposed proteins were predicted to be immunogenic, and among them the BCAL2645 protein was chosen for further studies.…”

Omics and Bioinformatics Approaches to Identify Novel Antigens for Vaccine Investigation and Development

“…Despite the remarkable advances in CF therapy, Bcc respiratory infections remain difficult, and often impossible, to eradicate using clinically available antibiotics, and no protective vaccines are available [ 4 ]. Aiming at the identification of surface-exposed proteins of potential use as components for the development of vaccines protective against Bcc infections, Sousa et al used a strategy combining bioinformatics to identify putative immunogenic surface-exposed proteins with the experimental identification of surface proteins by “shaving” live bacteria with trypsin, followed by liquid chromatography and mass spectrometry [ 5 ]. The “shaving” methodology was developed by Rodríguez-Ortega et al to identify surface-exposed streptococcal proteins as potential candidates for vaccine development [ 6 ].…”

“…The “shaving” methodology was developed by Rodríguez-Ortega et al to identify surface-exposed streptococcal proteins as potential candidates for vaccine development [ 6 ]. Sousa et al validated the results by demonstrating the immunoreactivity of three surface-exposed proteins with serum samples from CF patients with a clinical record of infection by Bcc [ 5 ]. Since Bcc bacteria share with other pathogens of the Burkholderia genus, such as B. pseudomalllei and B. mallei , a large number of conserved proteins, the authors foresee that the exploitation of Bcc immunogenic proteins might lead to the development of a broad-spectrum vaccine protective against infections by pathogens of the Burkholderia genus [ 5 ].…”