B. pertussis entry into respiratory epithelial cells and intracellular survival

LAMBERTI, YANINA; GORGOJO, JUAN; MASSILLO, CINTIA; RODRIGUEZ, MARIA EUGENIA

Dublin

Simposio; 10th International Symposium on Bordetella; 2013

Bordetella International Society

The reemergence of the whooping cough have led to consider the need of universal booster vaccination of adolescents and adults. However, the increasing incidence of pertussis despite high vaccination coverage together with the existence of circulating strains of B. pertussis not expressing two of the main vaccine antigens highlights the need to find new vaccine candidates. An effective way to improve pertussis control may comprise updating current vaccines by including antigens that are expected to be present in the infective phenotype. Antigenic proteins whose expression is induced under physiological conditions might be a good option. Several observations suggest that B. pertussis is iron-starved inside its natural human host and responds by expressing a number of vital iron uptake systems. With the aim of identifying protective antigens, we have focused on proteins that might be necessary for this nutrient acquisition during colonization. By mean of immunoproteomic analysis, we identified two antigenic proteins potentially involved in iron acquisition whose expression is induced during infection. We had previously demonstrated that one of them, namely IRP1-3, is protective against pertussis infection in mice. Herein, we showed that the other protein, named AfuA (BP1152), is a highly antigenic protein exposed on the bacterial surface, expressed during infection and highly conserved among clinical isolates. Immunization of mice with the recombinant AfuA induced opsonophagocytic antibodies, cellular immune response and protection against B. pertussis infection. Importantly, the addition of rAfuA and/or rIRP1-3 proteins to the commercial three pertussis components acellular vaccine significantly enhanced its protective activity.