Sequence- and structure-based immunoreactive epitope discovery for Burkholderia pseudomallei flagellin
Nithichanon, Arnone (Khon Kaen University. Centre for Research and Development of Medical Diagnostic Laboratories)
Rinchai, Darawan (Khon Kaen University. Centre for Research and Development of Medical Diagnostic Laboratories)
Gori, Alessandro (Consiglio Nazionale delle Ricerche. Istituto di Chimica del Riconoscimento Molecolare)
Lassaux, Patricia (Università degli Studi di Milano. Centro di Eccellenza Interdisciplinare Materiali e Interfacce Nanostrutturati)
Peri, Claudio (Consiglio Nazionale delle Ricerche. Istituto di Chimica del Riconoscimento Molecolare)
Conchillo-Solé, Oscar (Universitat Autònoma de Barcelona. Institut de Biotecnologia i de Biomedicina "Vicent Villar Palasí")
Ferrer-Navarro, Mario (Universitat de Barcelona. Departament de Microbiologia Clínica)
Gourlay, Louise J. (Università degli Studi di Milano. Centro di Eccellenza Interdisciplinare Materiali e Interfacce Nanostrutturati)
Nardini, Marco (Università degli Studi di Milano. Centro di Eccellenza Interdisciplinare Materiali e Interfacce Nanostrutturati)
Vila Estapé, Jordi (Universitat de Barcelona. Departament de Microbiologia Clínica)
Daura i Ribera, Xavier (Universitat Autònoma de Barcelona. Institut de Biotecnologia i de Biomedicina "Vicent Villar Palasí")
Colombo, Giorgio (Consiglio Nazionale delle Ricerche. Istituto di Chimica del Riconoscimento Molecolare)
Bolognesi, Martino (Università degli Studi di Milano. Centro di Eccellenza Interdisciplinare Materiali e Interfacce Nanostrutturati)
Lertmemonkolchai, Ganjana (Khon Kaen University. Centre for Research and Development of Medical Diagnostic Laboratories)

Date:	2015
Abstract:	Burkholderia pseudomallei is a Gram-negative bacterium responsible for melioidosis, a serious and often fatal infectious disease that is poorly controlled by existing treatments. Due to its inherent resistance to the major antibiotic classes and its facultative intracellular pathogenicity, an effective vaccine would be extremely desirable, along with appropriate prevention and therapeutic management. One of the main subunit vaccine candidates is flagellin of Burkholderia pseudomallei (FliC). Here, we present the high resolution crystal structure of FliC and report the synthesis and characterization of three peptides predicted to be both B and T cell FliC epitopes, by both structure-based in silico methods, and sequence-based epitope prediction tools. All three epitopes were shown to be immunoreactive against human IgG antibodies and to elicit cytokine production from human peripheral blood mononuclear cells. Furthermore, two of the peptides (F51-69 and F270-288) were found to be dominant immunoreactive epitopes, and their antibodies enhanced the bactericidal activities of purified human neutrophils. The epitopes derived from this study may represent potential melioidosis vaccine components. Melioidosis is an infectious disease caused by Burkolderia pseudomallei that poses a major public health problem in Southeast Asia and northern Australia. This bacterium is difficult to treat due to its intrinsic resistance to antibiotics, poor diagnosis, and the lack of a licensed vaccine. Vaccine safety is a prime concern, therefore recombinant protein subunit and/or peptide vaccine components, may represent safer alternatives. In this context, we targeted one of the main subunit vaccine candidates tested to date, flagellin from B. pseudomallei (FliC) that comprises the flagellar filament that mediates bacterial motility. Based on the knowledge that activation of both cell-mediated and antibody-mediated responses must be addressed in a melioidosis vaccine, we identified B and T cell immunoreactive peptides from FliC, using both sequence-based and structure-based computational prediction programs, for further in vitro immunological testing. Our data confirm the accuracy of sequence-based epitope prediction tools, and two structure-based methods applied to the FliC crystal structure (here-described), in predicting both T- and B-cell epitopes. Moreover, we identified two epitope peptides with significant joint T-cell and B-cell activities for further development as melioidosis vaccine components.
Note:	Ajuts: Financial support from the Thailand Research Fund through the Royal Golden Jubilee Ph.D. Program (Grant No. PHD/0167/2553 to AN and GL) is acknowledged. The structural work was funded by Fondazione CARIPLO (Progetto Vaccini, contract number 2009-3577) and joint funding between the Fondazione CARIPLO and the Regione Lombardia (Progetto PROVA, contract number 42666248). LJG is a recipient of Assegno di Ricerca (2012) from the University of Milan. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Published in:	PLoS neglected tropical diseases, Vol. 9, Issue 7 (July 2015) , e0003917, ISSN 1935-2735

DOI: 10.1371/journal.pntd.0003917
PMID: 26222657

20 p, 2.1 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Health sciences and biosciences > Institut de Biotecnologia i de Biomedicina (IBB)
Articles > Research articles
Articles > Published articles