title: Immunoproteomic analysis of Brucella melitensis and identification of a new immunogenic candidate protein for the development of brucellosis subunit vaccine.
abstract: In order to screen immunogenic candidate antigens for the development of a brucellosis subunit vaccine, an immunoproteomic assay was used to identify immunogenic proteins from Brucella melitensis 16 M soluble proteins. In this study, a total of 56 immunodominant proteins were identified from the two-dimensional electrophoresis immunoblot profiles by liquid chromatography tandem mass spectrometry (LC-MS/MS). Two proteins of interest, riboflavin synthase alpha chain (RS-α) and Loraine synthase (LS-2), which are both involved in riboflavin synthesis, were detected by two-dimensional immunoblots using antisera obtained from Brucella-infected human and goats. LS-2, however, is an already well-known vaccine candidate. Therefore, we focussed our studies on the novel vaccine candidate RS-α. B. melitensis RS-α and LS-2 were then expressed in Escherichia coli as fusion proteins with His tag. The humoral and cellular immune responses to the recombinant (r)RS-α was characterized. In response to in vitro stimulation by rRS-α, splenocytes from mice vaccinated with rRS-α were able to produce γ-interferon (IFN-γ) and interleukin (IL)-2 but not interleukin (IL)-4 and interleukin (IL)-10. Furthermore, rRS-α or rLS-2-vaccinated mice were partially protected against B. melitensis infection. Our results suggested that we have developed a high-throughout, accurate, rapid and highly efficient method for the identification of candidate antigens by a combination of immunoproteomics with immunisation and bacterial challenge and rRs-α could be a useful candidate for the development of subunit vaccines against B. melitensis.
authors.affiliation: The Eleventh Institute of the Academy of Military Medical Sciences of PLA, Changchun 130122, China. yangyanling12280@sina.com
authors.forename: Yanling
authors.initials: Y
authors.lastname: Yang
authors.forename: Lin
authors.initials: L
authors.lastname: Wang
authors.forename: Jigang
authors.initials: J
authors.lastname: Yin
authors.forename: Xinglong
authors.initials: X
authors.lastname: Wang
authors.forename: Shipeng
authors.initials: S
authors.lastname: Cheng
authors.forename: Xulong
authors.initials: X
authors.lastname: Lang
authors.forename: Xiuran
authors.initials: X
authors.lastname: Wang
authors.forename: Hailong
authors.initials: H
authors.lastname: Qu
authors.forename: Chunhui
authors.initials: C
authors.lastname: Sun
authors.forename: Jinglong
authors.initials: J
authors.lastname: Wang
authors.forename: Rui
authors.initials: R
authors.lastname: Zhang
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000276:immunology; D001426:Bacterial Proteins / Q000276:immunology*; D002004:Brucella Vaccine / Q000276:immunology*; D017347:Brucella melitensis; D002006:Brucellosis / Q000517:prevention & control; D002469:Cell Separation; D015180:Electrophoresis, Gel, Two-Dimensional; D005260:Female; D005434:Flow Cytometry; D006041:Goats; D006801:Humans; D015151:Immunoblotting; D016056:Immunodominant Epitopes / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D040901:Proteomics; D011994:Recombinant Proteins / Q000276:immunology; D012258:Riboflavin Synthase / Q000276:immunology*; D053719:Tandem Mass Spectrometry; D022223:Vaccines, Subunit / Q000276:immunology
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D002004:Brucella Vaccine; D016056:Immunodominant Epitopes; D011994:Recombinant Proteins; D022223:Vaccines, Subunit; D012258:Riboflavin Synthase