Jump to Main Content
Differential host gene expression in cells infected with highly pathogenic H5N1 avian influenza viruses
- Sarmento, Luciana, Afonso, Claudio L., Estevez, Carlos, Wasilenko, Jamie, Pantin-Jackwood, Mary
- Veterinary immunology and immunopathology 2008 v.125 no.3-4 pp. 291
- bird diseases, avian influenza, Influenza A virus, strains, pathotypes, pathogenesis, host-pathogen relationships, immune system, immunity, immune response, gene expression, defense mechanisms, chickens, fibroblasts, cell physiology, major histocompatibility complex, interferons, interleukins, microbial growth, amino acid sequences, strain differences, microarray technology
- In order to understand the molecular mechanisms by which different strains of avian influenza viruses overcome host response in birds, we used a complete chicken genome microarray to compare early gene expression levels in chicken embryo fibroblasts (CEF) infected with two avian influenza viruses (AIV), A/CK/Hong Kong/220/97 and A/Egret/Hong Kong/757.2/02, with different replication characteristics. Gene ontology revealed that the genes with altered expression are involved in many vital functional classes including protein metabolism, translation, transcription, host defense/immune response, ubiquitination and the cell cycle. Among the immune-related genes, MEK2, MHC class I, PDCD10 and Bcl-3 were selected for further expression analysis at 24hpi using semi-quantitive RT-PCR. Infection of CEF with A/Egret/Hong Kong/757.2/02 resulted in a marked repression of MEK2 and MHC class I gene expression levels. Infection of CEF with A/CK/Hong Kong/220/97 induced an increase of MEK2 and a decrease in PDCD10 and Bcl-3 expression levels. The expression levels of alpha interferon (IFN-α), myxovirus resistance 1 (Mx1) and interleukin-8 (IL-8) were also analyzed at 24hpi, showing higher expression levels of all of these genes after infection with A/CK/Hong Kong/220/97 compared to A/Egret/Hong Kong/757.2/02. In addition, comparison of the NS1 sequences of the viruses revealed amino acid differences that may explain in part the differences in IFN-α expression observed. Microarray gene expression analysis has proven to be a useful tool on providing important insights into how different AIVs affect host gene expression and how AIVs may use different strategies to evade host response and replicate in host cells.