Transcriptome analysis reveals an activation of major histocompatibility complex 1 and 2 pathways in chicken trachea immunized with infectious laryngotracheitis virus vaccine.

Infectious laryngotracheitis is an acute, contagious, upper respiratory disease of chickens caused by gallid herpes virus 1. Due to mortality rates that can reach up to 70% depending on the virulence of the virus, the disease is of great economic importance to the poultry industry. In this study, 15-d-old specific pathogen-free White Leghorn chickens were used to perform transcriptome analysis of chicken trachea immunized with infectious laryngotracheitis virus vaccine. Myosin and several collagen-related genes were downregulated in the immunized group, suggesting that normal function and structure may be compromised. In addition, we identified some cytokine receptors and several immune genes, such as Granzyme A (GZMA), CD4 molecule (CD4), CD8a molecule (CD8A), and CD8b molecule (CD8B), that were upregulated upon vaccination. The gene ontology analysis shows that genes included in the biological process cluster were related to antigen processing and presentation, positive regulation of immune system processes, T cell selection, and positive regulation of T cell activation. In conclusion, chicken embryo origin vaccine activation of the major histocompatibility complex 1 and 2 pathways provides insight for evaluation and design of infectious laryngotracheitis vaccines.