An animal model of respiratory infection was used to determine the effect of
various factors, thought to influence the ability of the host to clear bacteria, on
the host?s innate response to an NTHi lung infection.
Mucosal immunisation with NTHi has previously been shown to enhance the
clearance of NTHi from the lung in an animal model of infection through the
increased recruitment of phagocytes. Comparisons of cytokine and chemokine
kinetic profiles were made in order to determine differences between innate and
acquired immune response and the way in which mucosal immunisation
controls the innate immune response to NTHi. Increased production of proinflammatory
cytokines and chemokines in the early stages of NTHi lung
infection enhanced the ability to clear bacteria from the rat lung in the immune
animals through the increased recruitment of phagocytes to the site. Mucosal
immunisation was found to alter the cytokine and chemokine mRNA profiles of
CD4+ and CD8+ cells, with increased levels of MCP-1 protein being detected in
both types of immune cells.
An antecedent viral infection has been shown to increase the chance of
developing a respiratory bacterial infection. The NTHi model of respiratory
infection was used to characterise the effect that a viral infection had on the
host response to the host?s innate response to a bacterial infection and the
ability to clear the bacteria. The host?s ability to clear NTHi from the rat lung
was enhanced by an antecedent viral infection through alterations to the innate
immune response and the cytokine and chemokine kinetic profiles.
The use of a mutant strain of NTHi deficient in a component of
Lipooligosaccharide (LOS), Phosphorylcholine (ChoP), was utilised as a tool to
characterise the innate immune response to LOS. Animals challenged with the
LOS mutant strain had a reduced inflammatory response to NTHi through the
decreased production of pro-inflammatory cytokines and chemokines and the
reduced recruitment of phagocytes to the site of infection.
This thesis has contributed valuable information to enable a better
understanding of the host?s innate immune response to respiratory infection.
This study has identified the role of cytokines and chemokines in the innate
response to a respiratory bacterial infection and the enhanced ability of the host
to clear NTHi from the lung.
| Identifer | oai:union.ndltd.org:ADTP/202624 |
| Date | January 2008 |
| Creators | Clarke, Jodie Louise, n/a |
| Publisher | University of Canberra. n/a |
| Source Sets | Australiasian Digital Theses Program |
| Language | English |
| Detected Language | English |
| Rights | ), Copyright Jodie Louise Clarke |
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