Binding of complement factor H (fH) to Neisseria meningitidis is specific for human fH and inhibits complement activation by rat and rabbit sera.
Infect Immun
; 77(2): 764-9, 2009 Feb.
Article
en En
| MEDLINE
| ID: mdl-19047406
ABSTRACT
Complement factor H (fH), a molecule that downregulates complement activation, binds to Neisseria meningitidis and increases resistance to serum bactericidal activity. We investigated the species specificity of fH binding and the effect of human fH on downregulating rat (relevant for animal models) and rabbit (relevant for vaccine evaluation) complement activation. Binding to N. meningitidis was specific for human fH (low for chimpanzee fH and not detected with fH from lower primates). The addition of human fH decreased rat and rabbit C3 deposition on the bacterial surface and decreased group C bactericidal titers measured with rabbit complement 10- to 60-fold in heat-inactivated sera from human vaccinees. Administration of human fH to infant rats challenged with group B strain H44/76 resulted in an fH dose-dependent increase in CFU/ml of bacteria in blood 8 h later (P < 0.02). At the highest fH dose, 50 microg/rat, the geometric mean number of CFU per ml was higher than that in control animals (1,050 versus 43 [P < 0.005]). The data underscore the importance of binding of human fH for survival of N. meningitidis in vitro and in vivo. The species specificity of binding of human fH adds another mechanism toward our understanding of why N. meningitidis is strictly a human pathogen.
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Complemento C3
/
Factor H de Complemento
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Activación de Complemento
/
Sueros Inmunes
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Infecciones Meningocócicas
/
Neisseria meningitidis
Tipo de estudio:
Prognostic_studies
Límite:
Animals
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Child, preschool
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Humans
Idioma:
En
Revista:
Infect Immun
Año:
2009
Tipo del documento:
Article
País de afiliación:
Estados Unidos