Synopses from Theses of Recently Qualified PhD Students supported by BEMB Trust
| Student | Dr Laura Fyfe |
| Institution/Supervisor | IAH, Compton. Dr Colin Butter |
| Subject | The development of the immune structure and function of the avian lung |
| Submitted | November 2008 |
The development of the immune structure and function of the avian lung
The avian lung has been identified as an organ rich in lymphoid cells and is competent to actively participate in immune responses against respiratory pathogens. The administration of a vaccine against Marek's Disease via the in ovo route has been shown to lead to virus replication in the lung and subsequent protection from disease. Whilst the situation with other in ovo vaccines is unclear, the possibility exists that these too may utilise the lung in generation of protection. The mechanisms of how in ovo vaccination is effective are not clearly understood, and therefore knowledge of the development and function of both the embryonic and neonatal chicken will aid future development of vaccines. This thesis describes the functional and structural development of the embryonic and neonatal lung as a lymphoid organ. A requirement of microbial stimulus for the normal development of lymphoid tissue in the lung was demonstrated using germ-free and gnoto-biotic chicks, where restricted development of lymphoid tissue in the absence of microbial stimuli was observed, and could be restored by the addition of gut flora. The application of a viral vaccine, HVT, during the embryonic period resulted in an enhancement of lymphoid tissue in the lung, which may be mainained by viral persistence in the organ. This enhancement boosted a subsequent humoral response to a non-specific antigen, KLH. A long-lived humoral response in the lung compared to the spleen was demonstrated following vaccination in ovo with HVT, and also upon challenge with MDV. These findings may prove beneficial for the future development of in ovo vaccines and protection against respiratory pathogens in poultry.