IMMUNOGENICITY AND EVOLUTIONARY VARIABILITY OF EPITOPES WITHIN IGA1 PROTEASE FROM SEROGROUP A NEISSERIA-MENINGITIDIS

Five murine epitopes were defined and mapped within IgA1 protease prod uced by Neisseria meningitidis. Epitopes 1 and 2 were present in IgA1 protease from all strains, and from Neisseria gonorrhoeae. Epitopes 3 through to 5 varied between subgroups of serogroup A meningococci, but have remained constant over decades within the subgroups, except for epitope 4, which changed between 1983 and 1987 during the spread of su bgroup III meningococci from Asia to Africa. Binding of monoclonal ant ibodies to epitopes 1, 4 and 5 neutralized enzymatic function. Human s era containing antibodies to IgA1 protease as a result of natural infe ction inhibited binding of monoclonal antibodies to epitope 4 but not to the other epitopes.