Human antibody response to the 70-Kd common neisserial antigen in patients and carriers of meningococci or non-pathogenic Neisseria.

A surface antigen of 70 Kd, common to most Neisseria species, was previously described. This antigen is expressed and immunogenic in vivo in humans since 70-Kd-specific antibodies were detected in 22/26 patients with meningococcal meningitis and 12/17 healthy meningococcal carriers. Sera from convalescent patients and from carriers blocked the binding between mouse 70-Kd-specific serum and a strain of N. gonorrhoeae. The correspondence between inhibition-ELISA, using whole gonococci as solid phase, and detection of anti-70-Kd antibodies by Western blotting confirmed the specificity of the mouse serum. Non-pathogenic Neisseria species although possessing the 70-Kd structure elicited less frequently an antibody response in children. The immunogenicity of the 70-Kd antigen in humans supports its potential use as a vaccine component.