Neisserial antigen H.8 is immunogenic in patients with disseminated gonococcal and meningococcal infections.

Antigenic diversity among and within strains of Neisseria gonorrhoeae and Neisseria meningitidis has complicated studies of the pathogenesis of these strains and obstructed vaccine development. We previously described a distinct surface antigen (H.8) common to pathogenic Neisseria. We have now demonstrated in vivo expression of the H.8 antigen by detecting antibody responses to the antigen in 13 patients with disseminated neisserial infections. Each serum sample from a convalescent patient blocked the binding between the infecting meningococcal or gonococcal strain and a monoclonal antibody directed to the H.8 antigen, as demonstrated by binding-inhibition studies in enzyme-linked immunosorbent assays (P less than .005). Testing by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and western blotting demonstrated an IgG response in each convalescent serum to an antigen co-migrating with the H.8 antigen. Specificity of this antibody response was confirmed by probing recombinant bacteriophage that expressed the H.8 antigen. The commonality and the immunogenicity of the H.8 antigen indicate its possible role in the pathogenesis of, and its potential as a vaccine component for, gonococcal and meningococcal diseases.