Lymphomagenesis in Marek's disease

Identification of the Neoplastically Transformed Cells in Marek's Disease Herpesvirus-Induced Lymphomas: Recognition by the Monoclonal Antibody AV37

“…The criteria are (i) hyperproliferation and yet (ii) protection from the default pathway of AICD in vivo (31), (iii) latent MDV infection (because herpesvirus replication in productive infections results in obligate cytolysis [17,82]), and (iv) ubiquity in MD lymphomas. Using only the MAb AV37, we were able to identify cells which fulfill the essential criteria for neoplastic transformation in vivo.…”

“…Finally, it would be greatly advantageous (but not critical to the definition of neoplastic transformation in vivo) if we could identify potential immune escape mechanisms of neoplastically transformed MD lymphoma cells. Such mechanisms would be essential in MD because MDV translates proteins in latency (62), and the neoplastically transformed cells must be latently MDV infected (17). Somehow, the neoplastically transformed cells must avoid inducing an immune response to such latent MDV antigens.…”

“…Second, despite this they must be protected from cell death in situ (31). Third, because herpesviruses have both productive and latent life cycles and because the productive herpesvirus life cycle is lytic, they must not be productively infected (17,82). Fourth, they must be present in all MD lymphomas.…”

Pathogenesis of Marek’s Disease Virus Infection

“…The various stages of infection with serotype-I virus in genetically susceptible chickens have been described in detail in a number of comprehensive reviews (BIGGS 1973;CALNEK 1980CALNEK , 1985bCALNEK , 1986CALNEK , 1998CALNEK and WITTER 1997;NAZERIAN 1979;PAYNE 1972;PURCHASE 1972;SCHAT 1987;SETTNES 1982). A fairly sharp line demarcates the first two stages, and latent infection in certain cell types is a prerequisite to transformation, but both transforming and latent infections may exist intermixed with cytolytic infections in different cell populations as lymphomas are developing in the later stages.…”

The effects of in ovo administration of encapsulated Toll-like receptor 21 ligand as an adjuvant with Marek’s disease vaccine

“…Chickens become infected by MDV following inhalation of infected dust via the respiratory route. MDV primarily infects macrophages, B and T cells and it mainly transforms CD4+ T cells although other T cell subtypes are susceptible to transformation 2 , 3 . Generally, MDV life cycle can be divided into the cytolytic phase (2–7 days post-infection - dpi), latent phase (7–10 dpi), late cytolytic phase, and transformation phase 2 .…”