Immune-Mediated Evasion of the Adaptive Immune Response by the Bordetellae
Open Access
- Author:
- Goebel, Elizabeth M.
- Graduate Program:
- Integrative Biosciences
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- June 25, 2008
- Committee Members:
- Eric Thomas Harvill, Committee Chair/Co-Chair
Bryan Grenfell, Committee Member
Avery August, Committee Member
Mary J Kennett, Committee Member
Michael Patrick Flanagan, Committee Member
Ottar N Bjornstad, Committee Member - Keywords:
- Bordetella pertussis
Bordetella parapertussis
Bordetella bronchiseptica
O-Antigen - Abstract:
- The Bordetella, a genus composed of nine species of gram negative bacteria, include B. bronchiseptica, B. pertussis, and B. parapertussis, three mammalian respiratory pathogens. B. bronchiseptica is frequently isolated from a wide range of non-human mammals, causing respiratory diseases such as kennel cough and atrophic rhinitis. B. pertussis and B. parapertussis are the causative agents of whooping cough, a disease that affects an estimated 50 million people annually worldwide. Interestingly, both B. pertussis and B. parapertussis evolved independently from a B. bronchiseptica-like progenitor, but do not induce reciprocal immunity due to the expression of O-antigen by B. parapertussis. Here we show that while B. bronchiseptica is susceptible to B. pertussis – induced immunity, B. parapertussis is able to avoid this immunity by requiring an antibody - mediated immune response against O-antigen for protection. In addition to being a protective antigen, O-antigen also facilitates B. parapertussis colonization of the respiratory tract via inhibiting complement component C3 binding and subsequent lysis. Together, these data offer an explanation for the apparent host tropism of B. bronchiseptica to non-human mammals and the circulation of two closely related pathogens B. pertussis and B. parapertussis in human populations.