Sequence- and Structure-Based Immunoreactive Epitope Discovery for Burkholderia pseudomallei Flagellin

Arnone Nithichanon; Darawan Rinchai; Alessandro Gori; Patricia Lassaux; Claudio Peri; Oscar Conchillio-Solé; Mario Ferrer-Navarro; Louise J Gourlay; Marco Nardini; Jordi Vila; Xavier Daura; Giorgio Colombo; Martino Bolognesi; Ganjana Lertmemonkolchai

doi:10.1371/journal.pntd.0003917

Sequence- and Structure-Based Immunoreactive Epitope Discovery for Burkholderia pseudomallei Flagellin

PLoS Negl Trop Dis. 2015 Jul 29;9(7):e0003917. doi: 10.1371/journal.pntd.0003917. eCollection 2015.

Affiliations

¹ The Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand.
² Istituto di Chimica del Riconoscimento Molecolare, Consiglio Nazionale delle Ricerche, Milan, Italy.
³ Department of Biosciences, CIMAINA and CNR Institute of Biophysics, University of Milan, Milan, Italy.
⁴ Institute of Biotechnology and Biomedicine, Universitat Autònoma de Barcelona, Bellaterra, Spain.
⁵ Department of Clinical Microbiology, Hospital Clinic, School of Medicine, University of Barcelona, Barcelona, Spain.
⁶ Institute of Biotechnology and Biomedicine, Universitat Autònoma de Barcelona, Bellaterra, Spain; Catalan Institution for Research and Advanced Studies, Barcelona, Spain.

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 (FliCBp). Here, we present the high resolution crystal structure of FliCBp and report the synthesis and characterization of three peptides predicted to be both B and T cell FliCBp 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.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Amino Acid Sequence
Bacterial Proteins / chemistry*
Bacterial Proteins / genetics
Bacterial Proteins / immunology*
Burkholderia pseudomallei / chemistry
Burkholderia pseudomallei / genetics
Burkholderia pseudomallei / immunology*
Epitope Mapping
Epitopes, B-Lymphocyte / chemistry
Epitopes, B-Lymphocyte / genetics
Epitopes, B-Lymphocyte / immunology
Epitopes, T-Lymphocyte / chemistry
Epitopes, T-Lymphocyte / genetics
Epitopes, T-Lymphocyte / immunology
Flagellin / chemistry*
Flagellin / genetics
Flagellin / immunology*
Humans
Leukocytes, Mononuclear / immunology
Melioidosis / immunology
Melioidosis / microbiology*
Molecular Sequence Data
Phagocytosis
X-Ray Diffraction

Substances

Bacterial Proteins
Epitopes, B-Lymphocyte
Epitopes, T-Lymphocyte
Flagellin

Grants and funding

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.