Evaluating vaccine-elicited antibody activities againstNeisseria gonorrhoeae:cross-protective responses elicited by the 4CMenB meningococcal vaccine

Abstract

AbstractThe bacterial pathogenNeisseria gonorrhoeaeis an urgent global health problem due to increasing numbers of infections, coupled with rampant antibiotic resistance. Vaccines against gonorrhea are being prioritized to combat drug-resistantN. gonorrhoeae.Meningococcal serogroup B vaccines such as 4CMenB are predicted by epidemiology studies to cross-protect individuals from natural infection withN. gonorrhoeaeand elicit antibodies that cross-react withN. gonorrhoeae.Evaluation of vaccine candidates for gonorrhea requires a suite of assays for predicting efficacy in vitro and in animal models of infection, including the role of antibodies elicited by immunization. Here we present assays to evaluate antibody functionality after immunization: antibody binding to intactN. gonorrhoeae,serum bactericidal activity, and opsonophagocytic killing activity using primary human neutrophils (polymorphonuclear leukocytes). These assays were developed with purified antibodies againstN. gonorrhoeaeand used to evaluate serum from mice that were vaccinated with 4CMenB or given alum as a negative control. Results from these assays will help prioritize gonorrhea vaccine candidates for advanced preclinical to early clinical study and will contribute to identifying correlates and mechanisms of immune protection againstN. gonorrhoeae.