Marek’s disease in chickens: a review with focus on immunology

Abstract

Marek’s disease (MD), caused by Marek’s disease virus (MDV), is a commercially important neoplastic disease of poultry which is only controlled by mass vaccination. Importantly, vaccines that can provide sterile immunity and inhibit virus transmission are lacking; such that vaccines are only capable of preventing neuropathy, oncogenic disease and immunosuppression, but are unable to prevent MDV transmission or infection, leading to emergence of increasingly virulent pathotypes. Hence, to address these issues, developing more efficacious vaccines that induce sterile immunity have become one of the important research goals for avian immunologists today. MDV shares very close genomic functional and structural characteristics to most mammalian herpes viruses such as herpes simplex virus (HSV). MD also provides an excellent T cell lymphoma model for gaining insights into other herpesvirus-induced oncogenesis in mammals and birds. For these reasons, we need to develop an in-depth knowledge and understanding of the host-viral interaction and host immunity against MD. Similarly, the underlying genetic variation within different chicken lines has a major impact on the outcome of infection. In this review article, we aim to investigate the pathogenesis of MDV infection, host immunity to MD and discuss areas of research that need to be further explored.

Galliformes and Columbiformes

“…Virus replicates in feather follicular epithelium and is shed in feather dander. Marek's disease pathogenesis has four phases (Boodhoo et al, 2016;Swayne et al, 2013). In the early phase, the inhalation of cell-free virus with feather dander infects the respiratory epithelial cell and local macrophages followed by viremia with cytolytic viral replication in lymphocytes.…”

UL36 Encoded by Marek’s Disease Virus Exhibits Linkage-Specific Deubiquitinase Activity

“…MDV is an avian alphaherpesvirus that can induce Marek's disease (MD) in susceptible chickens, which is characterized by multiple organ lymphoma, immunosuppression, and neurological disorders [17]. Although MD could be effectively controlled by vaccines, MD vaccines are incapable of preventing MDV infection, replication, and maturation in chicken cells [17]. With the introduction of MD vaccines in the 1970s, MDV evolved to be even more virulent and remains a threat to the poultry industry [18][19][20].…”

Targeted induction ofde novoFatty acid synthesis enhances MDV replication in a COX-2/PGE2αdependent mechanism through EP2 and EP4 receptors engagement

“…Upon infection of the host, the virus initially replicates in B and T cells. Subsequently, the virus establishes latency predominantly in CD4 + T cells, allowing the virus to persist in the host for life [5]. [5].…”

“…Subsequently, the virus establishes latency predominantly in CD4 + T cells, allowing the virus to persist in the host for life [5]. [5]. In addition, latently infected CD4 + T cell can undergo neoplastic transformation resulting in deadly lymphomas[5].…”

“…[5]. In addition, latently infected CD4 + T cell can undergo neoplastic transformation resulting in deadly lymphomas[5].…”