O-antigen is a Critical Antigen for the Development of a Protective Immune Response to Bordetella parapertussis

ZHANG, XUQING; GOEBEL, ELIZABETH; RODRIGUEZ, MARIA EUGENIA; PRESTON; ANDREW; HARVILL, ERIC

INFECTION AND IMMUNITY

AMER SOC MICROBIOLOGY

Año: 2009 vol. 77 p. 5050 - 5058

0019-9567

Despite excellent vaccine coverage in developed countries, whooping cough is a re-emerging disease that can be caused by two closely related pathogens, B. pertussis or B. parapertussis.  The two are antigenically distinct and current vaccines, containing only B. pertussis-derived antigens, confer protection against B. pertussis but not against B. parapertussis.  B. pertussis does not express O-antigen while B. parapertussis retains it as a dominant surface antigen.  Since O-antigen is a protective antigen for many pathogenic bacteria, we examined whether this factor is a potential protective antigen for B. parapertussis.  In a mouse model of infection, immunization with wild-type B. parapertussis elicited a strong antibody response to O-antigen and conferred efficient protection against a subsequent B. parapertussis challenge.  However, immunization with the isogenic mutant lacking O-antigen, B. parapertussis∆wbm, induced antibodies that recognized other antigens but did not efficiently mediate opsonophagocytosis of B. parapertusis.  The passive transfer of sera raised against B. parapertussis, but not B. parapertussis∆wbm, reduced B. parapertussis load in the lower respiratory tract of mice.  The addition of 10µg of purified B. parapertussis lipopolysaccharide (LPS), which contains the O-antigen, but not B. parapertussis∆wbm LPS, drastically improved the efficacy of the acellular vaccine, Adacel®, against this pathogen.  These data suggest that O-antigen is a critical protective antigen of B. parapertussis and its inclusion can substantially improve whooping cough vaccine efficacy against this pathogen