title: Absolute quantification of a very virulent Marek's disease virus dynamic quantity and distributions in different tissues.
abstract: Chickens infected with Marek's disease virus (MDV) carry the virus consistently for a long time, which increases the incidence and rate of virus-induced multi-organ tumors and increases its potential for horizontal transmission. There is a positive correlation between very virulent (vv) MDV quantity and the pathology. The purpose of this study was to determine the vvMDV loads dynamics in different phases, and the correlation between the viral quantity and tumor development. We used a SYBR Green duplex real-time quantitative PCR (q-PCR) assay to detect and quantify MDV loads and distributions in different tissues, targeting the Eco-Q protein gene (meq) of the virus and the house-keeping ovotransferrin (ovo) gene of chickens. The q-PCR was performed using different tissue DNA preparations derived from chickens which were infected with 1,000 pfu of the SDWJ1302 strain and tissue samples were collected from control and MDV-infected birds on 7, 10, 15, 21, 28, 40, 60, and 90 d post-infection (DPI). The data indicated that the MDV genome was almost quantifiable in immune organs of infected chickens as early as 7 DPI, and the number of MDV genome copies in the blood and different organs peaked by 28 DPI, but then gradually decreased by 40 DPI. The levels of viral quantity in the lymphocytes, liver, and spleen were all higher than those in other organs, and that in the feather follicles was the highest among different phases of MDV infection. The vvMDV could still be detected in peripheral blood and tissues by 90 DPI, and the vast existence of virus will stimulate tissue destruction. The data provided further evidence of viral infection involving multi-organ distribution and mainly involving immune organ proliferation, resulting in immunosuppression.
authors.affiliation: Collaborative Innovation Center for the Origin and Control of Emerging Infectious Diseases, Taishan Medical College, Taian 271000, China.
authors.forename: Zhenjie
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: College of Veterinary Medicine, Shandong Agricultural University, Taian 271018, China.
authors.forename: Shaoqiong
authors.initials: S
authors.lastname: Liu
authors.affiliation: College of Veterinary Medicine, Shandong Agricultural University, Taian 271018, China.
authors.forename: Chengtai
authors.initials: C
authors.lastname: Ma
authors.affiliation: College of Veterinary Medicine, Shandong Agricultural University, Taian 271018, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Zhao
authors.affiliation: College of Veterinary Medicine, Shandong Agricultural University, Taian 271018, China zzcui@sdau.edu.cn.
authors.forename: Zhizhong
authors.initials: Z
authors.lastname: Cui
mesh_terms: D000818:Animals; D030161:Avian Proteins / Q000235:genetics* / Q000378:metabolism; D052160:Benzothiazoles; D002645:Chickens; D003207:Conalbumin / Q000235:genetics* / Q000378:metabolism; D003959:Diamines; D008381:Herpesvirus 2, Gallid / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D008380:Marek Disease / Q000821:virology*; D009856:Oncogene Proteins, Viral / Q000235:genetics* / Q000378:metabolism; D009928:Organ Specificity; D009930:Organic Chemicals; D011201:Poultry Diseases / Q000821:virology*; D011804:Quinolines; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013047:Specific Pathogen-Free Organisms; D014018:Tissue Distribution; D014774:Virulence
chemical_list: D030161:Avian Proteins; D052160:Benzothiazoles; D003959:Diamines; C100369:Eco-Q protein, Gallid herpesvirus 2; D009856:Oncogene Proteins, Viral; D009930:Organic Chemicals; D011804:Quinolines; D003207:Conalbumin; C098022:SYBR Green I
keywords: Marek's disease virus; absolute quantitation; duplex real-time quantitative PCR; genome copy number; viral quantity and distribution