GENOMIC AND FUNCTIONAL ANALYSIS OF THE MUCOSAL IMMUNE RESPONSE AND ITS ROLE IN PROTECTION AGAINST RESPIRATORY PATHOGENS IN POULTRY
Location: Exotic and Emerging Avian Viral Diseases Research Unit
Title: Microarray analysis following infection with highly pathogenic avian influenza H5N1 virus in naive and vaccinated SPF chickens
Submitted to: Avian Immunology Research Group Abstract
Publication Type: Abstract Only
Publication Acceptance Date: April 16, 2008
Publication Date: June 24, 2008
Citation: Kapczynski, D.R., Afonso, C.L., Pantin Jackwood, M.J., Liljebjelke, K.A., Sarmento, L., Suarez, D.L., Swayne, D.E. 2008. Microarray analysis following infection with highly pathogenic avian influenza H5N1 virus in naive and vaccinated SPF chickens [abstract]. In: Proceedings of Avian Immunology Research Group Conference, June 24-27, 2008, Queensland, Australia. p. 22.
Avian influenza (AI) is a viral disease of poultry that remains a constant threat to commercial poultry throughout the world. Within the last few years, outbreaks of highly pathogenic avian influenza (HPAI) H5N1 have originated in Southeast Asia and spread to several European, Middle Eastern, and African countries, where they continue to cause significant economic losses. Because infection of poultry with HPAI usually results in death within 2-6 days, the adaptive immune response contributes little to protection from disease. Instead, it is the early innate immune response which is critical for cytokine and interferon production, required for survival of the host. In these studies, microarray analysis was employed to examine the early host response to HPAI in poultry using a commercial whole genome (44K genes) chicken microarray. Naïve and vaccinated chickens were infected via natural route of exposure with the A/Egret/Hong Kong/757.2/02 isolate of H5N1, with RNA expression levels compared in spleen, lung, and bursa. Gene normalization and statistical analysis were analyzed using GeneSpring 7.0 computer software (Agilent). A marked increase in cytokine, interferon, and transcription factor genes was identified in naïve-infected birds, whereas mock and vaccinated birds displayed low to moderate increases in similar gene expression levels. Using a >2.0 fold increase cut off for analysis, the spleen displayed the highest number of upregulated genes, followed by the lung and bursa. Semi-quantitative RRT-PCR was used to confirm increased gene expression levels in select cytokine and interferon genes. Overall, these results provide insights into the molecular interactions and signaling pathways in naïve and vaccinated birds following HPAI H5N1 infection.