Interleukin-6 Contributes To Immunity Against Bordetella Pertussis.
Open Access
- Author:
- Goel, Tania
- Graduate Program:
- Biochemistry, Microbiology, and Molecular Biology
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- June 12, 2008
- Committee Members:
- Eric Thomas Harvill, Thesis Advisor/Co-Advisor
- Keywords:
- Bordetella pertussis
Respiratory pathogen
Interleukin-6 - Abstract:
- Bordetella pertussis, an endemic human respiratory pathogen, causes whooping cough, a severe coughing illness. The number of cases of whooping cough is increasing despite high vaccination coverage. In the last decade, the function of leukocytes and cytokines during B. pertussis infection has been characterized. Here, we investigate the effect of a pro-inflammatory cytokine, interleukin (IL)-6, on clearance of this respiratory pathogen using a murine model of infection. B. pertussis cleared from the lungs of wild-type mice approximately 40 days postinoculation. However, in the absence of IL-6, B. pertussis grew to higher numbers and persisted more than 77 days. Also, IL-6 contributed to infection-induced immunity. B. pertussis specific serum antibody titers were decreased in the absence of IL-6, most of which were T cell dependent antibody subtype, IgG2b. Splenic T cell cytokine responses were dampened in helper T cell (TH) 1 and TH2 cytokine production in response to B. pertussis. CD4+ T cells and neutrophils, both required to clear B. pertussis infection, were found to be IL-6 dependent for recruitment to the lungs. Together, these results indicate that IL-6 contributes to clearance of B. pertussis in both naïve and previously infected hosts. Delay in clearance of this bacterium is likely caused by a defective T-cell response in the absence of IL-6.