Design and evaluation of a recombinant fluorescent reporter virus for identifying cells latently infected by Marek's Disease Virus

Marek's Disease Virus (MDV) is an alphaherpesvirus that causes Marek's Disease (MD) in chickens. Live vaccines provide non-sterilizing immunity that protects chickens from char- acteristic lymphomas which emerge from latently infected T cells. Evidence suggests that vaccine-mediated protection from MD is conferred primarily by mechanisms other than conventional adaptive immunity. Studying MDV latency is difficult due to the lack of con- venient markers such as viral antigen expression. Therefore, I generated a recombinant Marek's Disease Virus (rMDV) encoding a fluorescently labelled histone protein to label latently infected cells. The rMDV replicated in vitro to produce fluorescent plaques but, unexpectedly, the signal was not nuclear-localized. The rMDV, despite the virulence of its parental virus, did not replicate efficiently in vivo or cause disease. Although this strategy did not generate a rMDV suitable for detecting latently infected cells, these findings provide valuable insights for future development of tools to study MDV latency and tumorigenesis.