Immunogenicity of meningococcal PBP2 during natural infection and protective activity of anti-PBP2 antibodies against meningococcal bacteraemia in mice.

OBJECTIVE

To evaluate the immunogenicity of the meningococcal penicillin-binding protein 2 (PBP2) and its potential as a vaccine candidate.

METHODS

The immunogenicity of meningococcal PBP2 was investigated using acute and convalescent sera from patients who recovered from meningococcal disease. Sera were tested against purified recombinant PBP2s corresponding to meningococcal isolates of different genetic lineages, of different serogroups and with various susceptibility levels to penicillin G. Mice were vaccinated with recombinant PBP2 and challenged with Neisseria meningitidis. A purified anti-PBP2 rabbit IgG was also used for passive protection experiments in mice.

RESULTS

Convalescent patients' sera recognized PBP2s from different strains, showing that this protein is immunogenic in meningococcal disease. Vaccination with purified recombinant PBP2 and purified anti-PBP2 rabbit IgG antibody conferred protection against experimental meningococcaemia in mice.

CONCLUSION

These data argue for considering meningococcal PBP2 as a vaccine candidate.