|WANG, DAN - Shandong Agricultural University|
|DELEKTA, PHILLIP - Orise Fellow|
|SUN, SHUHONG - Shandong Agricultural University|
Submitted to: Virology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/31/2016
Publication Date: N/A
Interpretive Summary: Marek’s disease (MD) causes enormous economical losses to the poultry industry. Marek’s disease virus (MDV), the etiological agent of MD, is a herpes virus that causes immunosuppression in the infected chickens. Although vaccination prevents tumor development, it does not induce sterile immunity and infectious viruses are produced in the feather follicle epithelial (FFE) cells and disseminated into the environment to infect contact birds. The goal of this study was to investigate immunological response in the skin of MDV-infected chickens and possible mechanism of immune evasion in the FFE cells. Although the overall gene expression pattern revealed a strong antiviral type of immunity, down regulation of some critical immune-related genes was suggestive of immunosuppression and viral-induced immune evasion. Replication of a massive number of virus particles and the lack of a significant number of cytotoxic killer T cell was apparent. This study provides further insight into the pathogenesis of MDV and the need for development of recombinant vaccines to block replication of MDV in the FFE cells and spread of the virus particles into the environment.
Technical Abstract: Marek’s disease (MD) is a highly contagious lymphoproliferative and neuropathic disease of chickens. The feather follicle epithelium (FFE) is the only anatomical site within the host where infectious enveloped cell-free MD virus (MDV) particles are produced and disseminated into the environment. MD vaccine prevents oncogenesis but does not provide protection against super-infection and viral replication. This study investigated the immunological responses and mechanism of viral immune evasion in the FFE. Strong viral replication and lack of a significant number of cytotoxic T lymphocytes (CTL) in the infected tissues was prominent. Although the overall gene expression pattern was suggestive of a Th1 type immune response, the expression levels of several key immune genes were down regulated in the infected tissues. The mechanism of MDV-induced immunosuppression appears to be through the inhibition of CTL function due to down regulation of CD8 and decrease CTL migration due to decrease expression of cell adhesion molecules.