Protection against infection with Neisseria gonorrhoeae by immunization with outer membrane protein complex and purified pili.

Some of the antigens that are capable of producing strain-related immunity to gonococcal infection in the guinea pig are located on the outer membrane of Neisseria gonorrhoeae. This finding has been demonstrated by immunization of guinea pigs with isolated outer membranes from two different strains of N. gonorrhoeae prior to challenged. Isolated principal outer membrane protein complex proved a better protective immunogen than purified pili from the same strain of N. gonorrhoeae. Principal outer membrane protein appears to react in antibody-complement-mediated killing of gonococci, whereas antibodies to pili are only weakly bactericidal. Pili-mediated attachment of N. gonorrhoeae to human cells is inhibited by antibodies to pili, and maximal inhibition occurs when antibodies are directed at pili antigenically identical to the pili mediating the attachment.