W019 Marek's Disease Virus Infection Induces Differential Chromatin Marks and Tissue-specific effects in inbred chicken lines

Date: Tuesday, January 17, 2012
Time: 1:50 PM
Room: Pacific Salon 6-7 (2nd Floor)
Apratim Mitra , University of Maryland, College Park, MD
Huanmin Zhang , USDA-ARS, Avian Disease & Oncology Laboratory, East Lansing, MI
Juan Luo , University of Maryland, College Park, MD
Keji Zhao , National Heart, Lung and Blood Institute, National Institutes of Health
Jiuzhou Song , University of Maryland, College Park, MD
Marek’s disease (MD) is a viral neoplastic disease in chickens caused by the MD virus (MDV). Successful vaccination strategies have been used to battle against MD, but may have also resulted in a progressive increase in the virulence of MDV.  Therefore, the understanding of genetic resistance to MD is considered crucial for long-term control of the disease. Here we examined whether MDV infection induces changes in the epigenetic status of genes and whether this response is dependent of the host genotype. We generated genome-wide histone 3 lysine 4 (H3K4) and histone 3 lysine 27 (H3K27) trimethylation maps in thymus tissues from lines of chickens with varying resistance to MD. Differential chromatin marks were observed on several genes previously implicated in MD such as MX1, MMP2 and CTLA-4 and also on additional genes including EAF2, IGF2BP1 and GAL. We also detected bivalent domains on transcriptional regulators such as BCL6, CITED2 and EGR1 that have particular functions in immune response. Notably, novel putative roles for GAL and CITED2 in the mechanism of MD progression were uncovered. We also found tissue-specific effects of MDV infection with certain genes exhibiting differential marks only in spleen. Our results suggest widespread epigenetic changes are induced by MDV infection, the extent of which is determined by the level of MD resistance of the host.