Infectious bronchitis is a highly contagious respiratory disease of chickens that can be fatal in young birds due to secondary bacterial infections, and sometimes kidney disease. Infection of egg-layers results in a drop in egg production. The disease, which has economic consequences to the poultry industry throughout the world, is caused by infectious bronchitis virus (IBV), a coronavirus. IBV has been reported to be the number one cause of infectious disease-related economic loss in the UK poultry industry and is a continual threat, in part due to the existence of a large number of IBV serotypes. There are numerous vaccines available for the control of IBV, although protection is short-lived and poorly cross-protective between serotypes.
In the Coronavirus Group we are investigating the potential for genetic manipulation of the IBV genome to rationally attenuate field strains predictably and specifically for vaccine production, including for in ovo vaccination. In order to do this we are identifying the IBV genes involved in virulence, as well as host factors involved in virus replication and viral replication machinery. We are presently modifying the IBV genome using a reverse genetics approach developed by us in order to achieve an optimum balance between attenuation of virulence and capacity to induce immunity. Establishing the virulence factors of IBV may allow the development of vaccines that could be administered in ovo without causing harm to the imminently hatching chicks.
We are focussed on the design of sustainable methods of controlling infectious diseases in chickens. To this end, we are evaluating the potential of the use of recombinant viruses as vaccines that can be grown in a cell line. Current IBV vaccines must be grown in embryonated eggs, a cumbersome and expensive process; the ability to grow vaccines on a cell line would be highly advantageous. We are investigating the possibility of utilizing IBV as a vector for the expression and delivery of foreign genes. The length of the IBV genome (27,600 nucleotides) suggests that it could accommodate large inserts from other pathogens, making possible the use of IBV as a vaccine vector against infectious bronchitis and other avian diseases.
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Coronavirus group
Publications
- Cottam, E. M., Maier, H. J., Manifava, M., Vaux, L. C., Priya, S., Gerner, W., Britton, P., Ktistakis, N. T. and Wileman, T. (2011). Coronavirus nsp6 proteins generate autophagosomes from the endoplasmic reticulum via an omegasome intermediate. Autophagy 7: (In Press).[Abstract]
- Armesto, M., Evans, S., Cavanagh, D., Abu-Median, A., Keep, S. and Britton, P. (2011). A Recombinant Avian Infectious Bronchitis Virus Expressing a Heterologous Spike Gene Belonging to the 4/91 Serotype. PLoS ONE 6(8): e24352. doi:10.1371/journal.pone.0024352.[Abstract]
- Li, Y., Reddy, K., Reid, S. M., Cox, W. J., Brown, I. H., Britton, P., Nair, V. and Iqbal, M. (2011). Recombinant herpesvirus of turkeys as a vector-based vaccine against highly pathogenic H7N1 avian influenza and Marek's disease. Vaccine (In Press).[Abstract]
- Armesto, M., Cavanagh, D. and Britton, P. (2009). The Replicase Gene of Avian Coronavirus Infectious Bronchitis Virus is a Determinant of Pathogenicity. PLoS ONE 4(10): e7384. doi:10.1371/journal.pone.0007384.[Abstract]
- Spencer, K.-A., Dee, M., Britton, P. and Hiscox, J.A. (2008). Role of phosphorylation clusters in the biology of the coronavirus infectious bronchitis virus nucleocapsid protein. Virology 370, 373-381. [Abstract]
- Tarpey, I., van Loon, A.A., de Haas, N., Davis, P.J., Orbell, S., Cavanagh, D., Britton, P., Casais, R., Sondermeijer, P. and Sundick, R. (2007). A recombinant turkey herpesvirus expressing chicken interleukin-2 increases the protection provided by in ovo vaccination with infectious bursal disease and infectious bronchitis virus. Vaccine 25, 8529-8535. [Abstract]