title: Defining a protective epitope on factor H binding protein, a key meningococcal virulence factor and vaccine antigen.
abstract: Mapping of epitopes recognized by functional monoclonal antibodies (mAbs) is essential for understanding the nature of immune responses and designing improved vaccines, therapeutics, and diagnostics. In recent years, identification of B-cell epitopes targeted by neutralizing antibodies has facilitated the design of peptide-based vaccines against highly variable pathogens like HIV, respiratory syncytial virus, and Helicobacter pylori; however, none of these products has yet progressed into clinical stages. Linear epitopes identified by conventional mapping techniques only partially reflect the immunogenic properties of the epitope in its natural conformation, thus limiting the success of this approach. To investigate antigen-antibody interactions and assess the potential of the most common epitope mapping techniques, we generated a series of mAbs against factor H binding protein (fHbp), a key virulence factor and vaccine antigen of Neisseria meningitidis. The interaction of fHbp with the bactericidal mAb 12C1 was studied by various epitope mapping methods. Although a 12-residue epitope in the C terminus of fHbp was identified by both Peptide Scanning and Phage Display Library screening, other approaches, such as hydrogen/deuterium exchange mass spectrometry (MS) and X-ray crystallography, showed that mAb 12C1 occupies an area of ∼1,000 Å(2) on fHbp, including >20 fHbp residues distributed on both N- and C-terminal domains. Collectively, these data show that linear epitope mapping techniques provide useful but incomplete descriptions of B-cell epitopes, indicating that increased efforts to fully characterize antigen-antibody interfaces are required to understand and design effective immunogens.
authors: Research Center, Novartis Vaccines and Diagnostics srl, 53100 Siena,  Italy.
authors: Enrico
authors: E
authors: Malito
authors: Agnese
authors: A
authors: Faleri
authors: Paola
authors: P
authors: Lo Surdo
authors: Daniele
authors: D
authors: Veggi
authors: Giulietta
authors: G
authors: Maruggi
authors: Eva
authors: E
authors: Grassi
authors: Elena
authors: E
authors: Cartocci
authors: Isabella
authors: I
authors: Bertoldi
authors: Alessia
authors: A
authors: Genovese
authors: Laura
authors: L
authors: Santini
authors: Giacomo
authors: G
authors: Romagnoli
authors: Erica
authors: E
authors: Borgogni
authors: Sébastien
authors: S
authors: Brier
authors: Carla
authors: C
authors: Lo Passo
authors: Maria
authors: M
authors: Domina
authors: Flora
authors: F
authors: Castellino
authors: Franco
authors: F
authors: Felici
authors: Stijn
authors: S
authors: van der Veen
authors: Steven
authors: S
authors: Johnson
authors: Susan M
authors: SM
authors: Lea
authors: Christoph M
authors: CM
authors: Tang
authors: Mariagrazia
authors: M
authors: Pizza
authors: Silvana
authors: S
authors: Savino
authors: Nathalie
authors: N
authors: Norais
authors: Rino
authors: R
authors: Rappuoli
authors: Matthew J
authors: MJ
authors: Bottomley
authors: Vega
authors: V
authors: Masignani
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D000918:Antibody Specificity / Q000276:immunology; D000942:Antigens, Bacterial / Q000737:chemistry / Q000276:immunology*; D001426:Bacterial Proteins / Q000737:chemistry / Q000276:immunology*; D061505:Cell Surface Display Techniques; D018360:Crystallography, X-Ray; D041961:Deuterium Exchange Measurement; D018604:Epitope Mapping; D000939:Epitopes / Q000737:chemistry / Q000276:immunology*; D013058:Mass Spectrometry; D008589:Meningococcal Infections / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control; D022401:Meningococcal Vaccines / Q000276:immunology*; D008958:Models, Molecular; D009345:Neisseria meningitidis / Q000276:immunology* / Q000472:pathogenicity*; D010455:Peptides / Q000737:chemistry / Q000276:immunology; D011485:Protein Binding / Q000276:immunology; D020349:Surface Plasmon Resonance; D037521:Virulence Factors / Q000737:chemistry / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D000939:Epitopes; D022401:Meningococcal Vaccines; D010455:Peptides; D037521:Virulence Factors; C484699:factor H-binding protein, Neisseria meningitidis
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