Scientific Publications by FDA Staff

Infect Immun 2008 Apr;76(4):1774-80

O antigen Protects Bordetella parapertussis from Complement.

Goebel EM, Wolfe DN, Elder K, Stibitz S, Harvill ET

Harvill, ET (reprint author), Penn State Univ, Dept Vet & Biomed Sci, 115 Henning Bldg,Univ Pk, University Pk, PA 16802 USA Penn State Univ, Dept Vet & Biomed Sci, University Pk, PA 16802 USA US FDA, Grad Program Immunol & Infect Dis, Bethesda, MD 20892 USA US FDA, Grad Program Pathobiol, Bethesda, MD 20892 USA US FDA, Ctr Biol Evaluat & Res, Bethesda, MD 20892 USA

Bordetella pertussis, a causative agent of whooping cough, expresses BrkA which confers serum resistance, but the closely related human pathogen that also causes whooping cough, B. parapertussis, does not. Interestingly, B. parapertussis, but not B. pertussis, produces an O-antigen, a factor shown in other models to confer serum resistance. Using a murine model of infection, we determined that O-antigen contributes to the ability of B. parapertussis to colonize the respiratory tract during the first week of infection, but not thereafter. Interestingly, an O-antigen deficient strain of B. parapertussis was not defective in colonizing mice lacking the complement cascade. O-antigen prevented both complement component C3 deposition on the surface, and complement mediated killing of B. parapertussis. In addition, O-antigen was required for B. parapertussis to systemically spread in complement-sufficient mice, but not complement-deficient mice. These data indicate that O-antigen enables B. parapertussis to efficiently colonize the lower respiratory tract by protecting against complement-mediated control and clearance.