Repository logo

Temperature Sensitivity: A Potential Method for the Generation of Vaccines against the Avian Coronavirus Infectious Bronchitis Virus.

Published version

Change log


Keep, Sarah 
Stevenson-Leggett, Phoebe 
Steyn, Angela 
Oade, Michael S 
Webb, Isobel 


The Gammacoronavirus infectious bronchitis virus (IBV) is a highly contagious economically important respiratory pathogen of domestic fowl. Reverse genetics allows for the molecular study of pathogenic determinants to enable rational vaccine design. The recombinant IBV (rIBV) Beau-R, a molecular clone of the apathogenic Beaudette strain, has previously been investigated as a vaccine platform. To determine tissues in which Beau-R could effectively deliver antigenic genes, an in vivo study in chickens, the natural host, was used to compare the pattern of viral dissemination of Beau-R to the pathogenic strain M41-CK. Replication of Beau-R was found to be restricted to soft tissue within the beak, whereas M41-CK was detected in beak tissue, trachea and eyelid up to seven days post infection. In vitro assays further identified that, unlike M41-CK, Beau-R could not replicate at 41 °C, the core body temperature of a chicken, but is able to replicate a 37 °C, a temperature relatable to the very upper respiratory tract. Using a panel of rIBVs with defined mutations in the structural and accessory genes, viral replication at permissive and non-permissive temperatures was investigated, identifying that the Beau-R replicase gene was a determinant of temperature sensitivity and that sub-genomic mRNA synthesis had been affected. The identification of temperature sensitive allelic lesions within the Beau-R replicase gene opens up the possibility of using this method of attenuation in other IBV strains for future vaccine development as well as a method to investigate the functions of the IBV replicase proteins.



IBV, RNA synthesis, coronavirus, replicase, temperature sensitivity, Animals, Cell Line, Chick Embryo, Chickens, Coronavirus Infections, Infectious bronchitis virus, Poultry, Poultry Diseases, RNA, Viral, Temperature, Vaccination, Vaccines, Attenuated, Viral Vaccines, Virus Replication

Journal Title


Conference Name

Journal ISSN


Volume Title



Biotechnology and Biological Sciences Research Council (BB/M012794/1, BB/M012069/1, BBS/E/I/00007031, BBS/E/I/00007034, BBS/E/I/00007038)