Progress on chicken T cell immunity to viruses
CELLULAR AND MOLECULAR LIFE SCIENCES
Authors: Dai, Manman; Xu, Chenggang; Chen, Weisan; Liao, Ming
Avian virus infection remains one of the most important threats to the poultry industry. Pathogens such as avian influenza virus (AIV), avian infectious bronchitis virus (IBV), and infectious bursal disease virus (IBDV) are normally controlled by antibodies specific for surface proteins and cellular immune responses. However, standard vaccines aimed at inducing neutralizing antibodies must be administered annually and can be rendered ineffective because immune-selective pressure results in the continuous mutation of viral surface proteins of different strains circulating from year to year. Chicken T cells have been shown to play a crucial role in fighting virus infection, offering lasting and cross-strain protection, and offer the potential for developing universal vaccines. This review provides an overview of our current knowledge of chicken T cell immunity to viruses. More importantly, we point out the limitations and barriers of current research and a potential direction for future studies.
Identification of IBV QX vaccine markers : Should vaccine acceptance by authorities require similar identifications for all live IBV vaccines?
Authors: Listorti, Valeria; Laconi, Andrea; Catelli, Elena; Cecchinato, Mattia; Lupini, Caterina; Naylor, Clive J.
IBV genotype QX causes sufficient disease in Europe for several commercial companies to have started developing live attenuated vaccines. Here, one of those vaccines (L1148) was fully consensus sequenced alongside its progenitor field strain (1148-A) to determine vaccine markers, thereby enabling detection on farms. Twenty-eight single nucleotide substitutions were associated with the 1148-A attenuation, of which any combination can identify vaccine L1148 in the field. Sixteen substitutions resulted in amino acid coding changes of which half were in spike. One change in the 1b gene altered the normally highly conserved final 5 nucleotides of the transcription regulatory sequence of the S gene, common to all IBV QX genes. No mutations can currently be associated with the attenuation process. Field vaccination strategies would greatly benefit by such comparative sequence data being mandatorily submitted to regulators prior to vaccine release following a successful registration process. (C) 2017 Published by Elsevier Ltd.