Related Experiment Video
Updated: Jun 24, 2026
Visualisation and Quantification of Intracellular Interactions of Neisseria meningitidis and Human α-actinin by Confocal Imaging
Published on: October 24, 2010
Meningococcal factor H-binding protein variants expressed by epidemic capsular group A, W-135, and X strains from
P T Beernink1, D A Caugant, J A Welsch
1Center for Immunobiology and Vaccine Development, Children's Hospital Oakland Research Institute, Oakland, CA, USA.
Background:
Meningococcal epidemics in Africa are generally caused by capsular group A strains, but W-135 or X strains also cause epidemics in this region. Factor H-binding protein (fHbp) is a novel antigen being investigated for use in group B vaccines. Little is known about fHbp in strains from other capsular groups.
Methods:
We investigated fHbp in 35 group A, W-135, and X strains from Africa.
Results:
The 22 group A isolates, which included each of the sequence types (STs) responsible for epidemics since 1963, and 4 group X and 3 group W-135 isolates from recent epidemics had genes encoding fHbp in antigenic variant group 1. The remaining 6 W-135 isolates had fHbp variant 2. Within each fHbp variant group, there was 92%-100% amino acid identity, and the proteins expressed conserved epitopes recognized by bactericidal monoclonal antibodies. Serum samples obtained from mice vaccinated with native outer membrane vesicle vaccines from mutants engineered to express fHbp variants had broad bactericidal activity against group A, W-135, or X strains.
Conclusions:
Despite extensive natural exposure of the African population, fHbp is conserved among African strains. A native outer membrane vesicle vaccine that expresses fHbp variants can potentially elicit protective antibodies against strains from all capsular groups that cause epidemics in the region.
Insights
Factor H-binding protein (fHbp) is conserved across African meningococcal strains causing epidemics. Vaccines expressing fHbp variants show potential for broad protection against these diverse groups.
Area of Science:
- Microbiology
- Vaccinology
- Epidemiology
Background:
- Meningococcal epidemics in Africa are primarily driven by serogroup A strains, with W-135 and X also contributing.
- Factor H-binding protein (fHbp) is a key antigen for serogroup B vaccines, but its role in other serogroups is less understood.
Purpose of the Study:
- To investigate the presence and characteristics of fHbp in African strains of Neisseria meningitidis serogroups A, W-135, and X.
- To assess the potential of fHbp as a target for broad-spectrum meningococcal vaccines in Africa.
Main Methods:
- Analysis of fHbp genes and protein variants in 35 meningococcal isolates (22 group A, 10 group W-135, 3 group X) from African epidemics.
- Evaluation of amino acid identity and conserved epitopes within fHbp variants.
- Assessment of bactericidal activity of antibodies generated by fHbp-expressing vaccines in mouse models.
Main Results:
- All investigated African meningococcal strains (serogroups A, W-135, X) possessed fHbp genes, primarily encoding antigenic variant group 1, with high amino acid identity (92%-100%) within variants.
- Expressed fHbp proteins contained conserved epitopes recognized by bactericidal monoclonal antibodies.
- Vaccines based on native outer membrane vesicles expressing fHbp variants demonstrated broad bactericidal activity against epidemic strains.
Conclusions:
- Factor H-binding protein (fHbp) is a conserved antigen across diverse African meningococcal serogroups causing epidemics.
- A vaccine targeting fHbp variants has the potential to induce protective immunity against multiple epidemic-causing meningococcal strains in Africa.
