Interactions between Marek’s disease virus Rispens/CVI988 vaccine strain and adenovirus field strain in chicken embryo fibroblast (CEF) cultures

The aim of the study was to determine the influence of adenovirus infection on the replication of Marek’s disease virus vaccine strain Rispens/CVI988 during in vitro co-infection studies. Adenovirus field strain JN-5/10j was isolated from sick chickens. The study was conducted in chicken embryo fibroblast cultures (CEF). Monolayers of CEFs were infected with Rispens strain and field adenovirus strain JN-5/10j with different doses (101.0-103.0TCID50) in the following manner: a) simultaneously, b) first, infection with Rispens strain and after 24 h infection with adenovirus strain JN-5/10j and c) infection with adenovirus strain JN-5/10j 24 h before infection with Rispens strain. After 18, 24, 48, 72, and 96 h of incubation, the copy number of the pp38 gene of Rispens strain was determined using Real-time PCR. The results indicated that the Adenovirus infection before the infection with Rispens strain reduced the replication of the pp38 gene after 48 h by 2 log10.

The pp38 Gene of Marek's Disease Virus (MDV) Is Necessary for Cytolytic Infection of B Cells and Maintenance of the Transformed State but Not for Cytolytic Infection of the Feather Follicle Epithelium and Horizontal Spread of MDV

ABSTRACT Marek's disease virus has a unique phosphoprotein, pp38, which is suspected to play an important role in Marek's disease pathogenesis. The objective of the present study was to utilize a mutant virus lacking the pp38 gene (rMd5Δpp38) to better characterize the biological function of pp38. This work shows that the pp38 gene is necessary to establish cytolytic infection in B cells but not in feather follicle epithelium, to produce an adequate level of latently infected T cells, and to maintain the transformed status in vivo.