ANTIGENICITY OF GONOCOCCAL PILUS OLIGOMERS

THE DEVELOPMENT OF A SAFE AND EFFICACIOUS VACCINE FOR GONORRHEA BASED ON OLIGOMERS FROM PILI IS A MAJOR GOAL OF IMMUNOMED CORPORATION. EARLY ATTEMPTS TO DEVELOP GONORRHEA VACCINES USING INTACT PILI FAILED BECAUSE OF ANTIGENIC DIVERSITY AMONG THE BACTERIAL STRAINS IN THE POPULATION. A PRELIMINARY STUDY OF OLIGOMERS FROM THE TYPE 2 COLONIAL FORM OF NEISSERIA GONORRHOEAE HAS SHOWN THAT THEY WERE BETTER THAN INTACT PILI FOR ELICITING ANTIBODIES THAT CROSS-REACT WITH PILI FROM HETEROLOGOUS STRAINS. THIS RESULT SUGGESTS THAT A VACCINE CONTAINING OLIGOMERS SHOULD PROVIDE BETTER CROSS-PROTECTION THAN ONE CONTAINING INTACT PILI. IN THIS PROPOSAL, ANTIBODIES ELICITED BY OLIGOMERS FROM UP TO 10 STRAINS OF NEISERRIA GONORRHOEAE WILL BE EXAMINED TO (1) CONFIRM THEIR CAPACITY FOR CROSS-REACTIVITY WITH INTACT PILI FROM HETEROLOGOUS STRAINS, AND (2) DETERMINE THEIR CAPACITY FOR PREVENTING BACTERIAL ADHESION TO HUMAN CELLS. IF A SIGNIFICANT ADVANTAGE FOR THE USE OF OLIGOMERS IS INDICATED, A PHASE II APPLICATION WOULD BE MADE FOR THE DEVELOPMENT OF A PROTOTYPE GONORRHEA VACCINE BASED ON THOSE STRAINS YIELDING OLIGOMERS WITH THE GREATEST DEGREE OF CROSS-REACTIVITY.