Marek’s disease virus infection induced mitochondria changes in chickens

Authors: CHU, QIN - Beijing Academy Of Agricultural Sciences; DING, YI - University Of Maryland; CAI, WENTAO - China Agriculture University; LIU, LEI - China Agriculture University; Zhang, Huanmin; SONG, JIUZHOU - University Of Maryland

Submitted to: International Journal of Molecular Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/26/2019
Publication Date: 6/27/2019
Citation: Chu, Q., Ding, Y., Cai, W., Liu, L., Zhang, H., Song, J. 2019. Marek’s disease virus infection induced mitochondria changes in chickens. International Journal of Molecular Sciences. 20(13): 3150. https://doi.org/10.3390/ijms20133150.
DOI: https://doi.org/10.3390/ijms20133150

Interpretive Summary: Marek’s disease (MD) is an infectious disease of chicken caused by Marek’s disease virus (MDV). Commercial farms have MD under control by common use of MD vaccines and management measures. Many aspects of MD and MDV infection remain unclear, which include the detailed bioprocesses and genetic mechanisms underlying the resistance and susceptibility to the disease. This study was designed to investigate changes of mitochondria, a kind of rod-shaped organelles within cells and functionally responsible for many biochemical processes to take place in, and gene expression in two divergent genetic lines of chickens in response to MDV challenge. Intriguingly, data from this study shown that the mitochondrial DNA contents differed between the two genetic lines of chicken, and gene expressions were escalated significantly post MDV challenge. These findings provided important clues to advance the understanding on the bioprocesses in pathogenesis and tumorigenesis of viral infection, which would eventually benefit the poultry industry in control of the disease and the public for safe and quality chicken products.

Technical Abstract: Mitochondria are crucial cellular organelles in eukaryotes and participate in many cell processes including immune response, growth development, and tumorigenesis. Marek’s disease (MD), caused by an avian alpha-herpesvirus Marek’s disease virus (MDV), is characterized with lymphomas and immunosuppression. In this research, we hypothesize that mitochondria may play roles in response to MDV infection. To test it, mitochondrial DNA (mtDNA) abundance and gene expression in immune organs were examined in two well-defined and highly inbred lines of chickens, the MD-susceptible line 7(2) and the MD-resistant line 6(3). We found that mitochondrial DNA contents decreased significantly at the transformation phase in spleen of the MD-susceptible line 7(2) birds in contrast to the MD-resistant line 6(3). The mtDNA-genes and the nucleus-genes relevant to mtDNA maintenance and transcription, however, were significantly up-regulated. Interestingly, we found that POLG2 might play a potential role that led to the imbalance of mtDNA copy number and gene expression alteration. MDV infection induced imbalance of mitochondrial contents and gene expression, demonstrating the indispensability of mitochondria in virus-induced cell transformation and subsequent lymphoma formation, such as MD development in chicken. This is the first report on relationship between virus infection and mitochondria in chicken, which provides important insights into the understanding on pathogenesis and tumorigenesis due to viral infection.