Antigenicity, cross-reactivity and surface exposure of the Neisseria meningitidis 37 kDa protein (Fbp).
The 37 kDa iron-repressible protein, Fbp, was purified from two Neisseria meningitidis strains by metal-affinity chromatography and used to obtain mouse monospecific polyclonal immune sera. Dot-blot, immunoblotting and whole cell ELISA results demonstrate that the Fbp is present in all 16 N. meningitidis and four commensal Neisseria species tested, is highly antigenic in mouse when injected in pure form, and shows intra- and inter-species antigenic homogeneity, anti-Fbp antibodies being fully cross-reactive using the techniques mentioned. We also found that Fbp molecules (or parts of them) are surface exposed, in disagreement with the proposed exclusively periplasmic localization, although anti-Fbp antibodies seem unable to block iron uptake or to induce complement-mediated killing of the meningococci. Taken along with the high immunogenicity of the purified protein and the complete cross-reactivity of the antibodies elicited, this suggests that the protective effect of the purified Fbp must be further studied to evaluate its inclusion in future vaccine trials.
Gómez
J A
JA
Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad de Santiago de Compostela, Spain.
Agra
C
C
Ferrón
L
L
Powell
N
N
Pintor
M
M
Criado
M T
MT
Ferreirós
C M
CM
D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D000942:Antigens, Bacterial / Q000276:immunology*; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins / Q000276:immunology*; D015153:Blotting, Western; D003429:Cross Reactions; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D033862:Iron-Binding Proteins; D051379:Mice; D008807:Mice, Inbred BALB C; D016253:Microscopy, Immunoelectron; D009345:Neisseria meningitidis / Q000276:immunology*; D033902:Periplasmic Binding Proteins
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D033862:Iron-Binding Proteins; D033902:Periplasmic Binding Proteins