Submitted to: Workshop on Molecular Pathogenesis of Marek's Disease and Avian Immunology
Publication Type: Abstract Only
Publication Acceptance Date: 8/5/2006
Publication Date: 8/5/2006
Citation: Silva, R.F., Lee, L.F., Heidari, M., Gimeno, I.M., Spatz, S.J., Zelepsky, J. 2006. The role of UL13 in generating cell-free MDV [abstract]. 4th International Workshop on Molecular Pathogenesis of Marek's Disease Virus. p. 28.
Technical Abstract: MDV is an alpha-herpesvirus with a genomic organization that is very similar to HSV. However, the biology of MDV more closely approximates another alpha-herpesvirus, varicella-zoster virus (VZV). There are numerous similarities between the biology of VZV and MDV. VZV possesses no obvious gD homolog and like MDV apparently does not utilize any of the known herpesvirus entry mechanisms. MDV and VZV infections in cell culture are highly cell-associated and proceed via cell-to-cell spread with little to no infectious virus being released. In susceptible animals, MDV and VZV are initially taken up by macrophages or dendritic cells in the lungs, and quickly spread to CD4+ T-lymphocytes. Some of the VZV infected T lymphocytes migrate to epidermal cells where further viral replication occurs and large amounts of cell-free virus is released. The VZV ORF47 gene product, a serine/threonine kinase, was shown to be a critical virulence gene essential for T-cell and cell-free virus production. The MDV UL13 gene is a homolog of the VZV ORF47. We deleted UL13 from a vv MDV and found that the UL13 gene is nonessential for virus replication in cell culture. Susceptible chickens inoculated with the UL13 deletion mutant had typical MD lesions but at a significantly reduced frequency when compared with the parental, non-mutant MDV. We will report on the role of the UL13 gene product on cell fusion in culture and the generation of cell-free virus in the feather follicle epithelium.