The aim of the work carried out in this thesis was to investigate the effects of GM-CSF and IL-3 after gene-gun vaccination. Initial studies focused on the histological effects of GM-CSF and IL-3 in ovine skin. GM-CSF induced a linear increase in IL-1β transcripts from 1-24 hours concomitant with pronounced neutrophilic infiltration and micro-abscess formation by 24 hours. Maximal GM-CSF and IL-3 mRNA expression was evident at approx. 4 hours, whereas IL-1β and TNF-α transcripts remained highly elevated up to 96 hours. Infiltration of DC, co-ordinately with a rise in MHC class II DRα expression in perivascular regions, was observed 72-96 hours after administration of IL-3, whereas infiltates of B cells and DC were observed at 24 and 72 hours, respectively. Subsequent work characterised DC draining skin before and after GM-CSF administration by means of cannulation of the pseudoafferent lymphatics. Two sub-populations of afferent lymph DC (ALDC) were isolated based on differential expression of SIRPα as described in both cattle and rats, Ovine SIRPα<sup>+</sup> ALDC constitutively express high levels of IL-1β, IL-18 and IL-10 mRNA. Conversely, SIRPα<sup>-</sup> ALDC does not express IL-10 but express high levels of IL-12p40. SIRPα<sup>+</sup> ALDC may contain Langerhans’ cells since both ATPase and langerin were detected. Both subpopulations express Toll-like receptor 3 (TLR3) and TLR9, whereas SIRPα<sup>+</sup> ALDC uniquely express TLR4 (+/- CD14). Vaccination with pGM-CSF resulted in increased cytokine production by ALDC subpopulations and upregulation of MHC class IIα, CD1b, CD40, CD86 and CD11c. These studies have extended the knowledge of GM-CSF and IL-3 as adjuvants and highlight the use of the cannulation model to further decipher the immune mechanisms of adjuvants. This work has demonstrated that GM-CSF not only recruits DC into skin but also activates DC, possibly as a result of increased expression of “danger signals” including IL-1β and TNF-α.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:657449 |
| Date | January 2006 |
| Creators | Matthews, Katie |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/29874 |
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