title: Proteomic profiling and identification of immunodominant spore antigens of Bacillus anthracis, Bacillus cereus, and Bacillus thuringiensis.
abstract: Differentially expressed and immunogenic spore proteins of the Bacillus cereus group of bacteria, which includes Bacillus anthracis, Bacillus cereus, and Bacillus thuringiensis, were identified. Comparative proteomic profiling of their spore proteins distinguished the three species from each other as well as the virulent from the avirulent strains. A total of 458 proteins encoded by 232 open reading frames were identified by matrix-assisted laser desorption ionization-time-of-flight mass spectrometry analysis for all the species. A number of highly expressed proteins, including elongation factor Tu (EF-Tu), elongation factor G, 60-kDa chaperonin, enolase, pyruvate dehydrogenase complex, and others exist as charge variants on two-dimensional gels. These charge variants have similar masses but different isoelectric points. The majority of identified proteins have cellular roles associated with energy production, carbohydrate transport and metabolism, amino acid transport and metabolism, posttranslational modifications, and translation. Novel vaccine candidate proteins were identified using B. anthracis polyclonal antisera from humans postinfected with cutaneous anthrax. Fifteen immunoreactive proteins were identified in B. anthracis spores, whereas 7, 14, and 7 immunoreactive proteins were identified for B. cereus and in the virulent and avirulent strains of B. thuringiensis spores, respectively. Some of the immunodominant antigens include charge variants of EF-Tu, glyceraldehyde-3-phosphate dehydrogenase, dihydrolipoamide acetyltransferase, Delta-1-pyrroline-5-carboxylate dehydrogenase, and a dihydrolipoamide dehydrogenase. Alanine racemase and neutral protease were uniquely immunogenic to B. anthracis. Comparative analysis of the spore immunome will be of significance for further nucleic acid- and immuno-based detection systems as well as next-generation vaccine development.
authors.affiliation: Vital Probes, Inc., 1300 Old Plank Road, Mayfield, PA 18433, USA.
authors.forename: Vito G
authors.initials: VG
authors.lastname: Delvecchio
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Connolly
authors.forename: Timothy G
authors.initials: TG
authors.lastname: Alefantis
authors.forename: Alexander
authors.initials: A
authors.lastname: Walz
authors.forename: Marian A
authors.initials: MA
authors.lastname: Quan
authors.forename: Guy
authors.initials: G
authors.lastname: Patra
authors.forename: John M
authors.initials: JM
authors.lastname: Ashton
authors.forename: Jessica T
authors.initials: JT
authors.lastname: Whittington
authors.forename: Ryan D
authors.initials: RD
authors.lastname: Chafin
authors.forename: Xudong
authors.initials: X
authors.lastname: Liang
authors.forename: Paul
authors.initials: P
authors.lastname: Grewal
authors.forename: Akbar S
authors.initials: AS
authors.lastname: Khan
authors.forename: Cesar V
authors.initials: CV
authors.lastname: Mujer
mesh_terms: D000942:Antigens, Bacterial / Q000235:genetics / Q000302:isolation & purification*; D001408:Bacillus anthracis / Q000737:chemistry* / Q000235:genetics / Q000276:immunology*; D001409:Bacillus cereus / Q000737:chemistry* / Q000235:genetics / Q000276:immunology*; D001413:Bacillus thuringiensis / Q000737:chemistry* / Q000235:genetics / Q000276:immunology*; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification; D015180:Electrophoresis, Gel, Two-Dimensional; D005798:Genes, Bacterial; D016056:Immunodominant Epitopes / Q000235:genetics / Q000302:isolation & purification; D016366:Open Reading Frames; D040901:Proteomics; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013171:Spores, Bacterial / Q000737:chemistry* / Q000235:genetics / Q000276:immunology*; D014774:Virulence / Q000276:immunology
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D016056:Immunodominant Epitopes