Solving the complications of oncogenesis caused by retroviruses is a
challenging task for veterinary and biomedical scientists. Avian Leukosis viruses
(ALVs) are a group of avian oncogenic retroviruses that can cause neoplastic diseases
in chickens. The viral invasion starts due to the interaction between glycoproteins in
the viral envelop and receptor sites of host cells. The pathogenesis of ALVs could be
explained by three theories which include promoter insertion, enhancer activation, and
the presence of oncogenes in their genome. Additionally, these viruses show great
diversity due to the high mutational rate that enables them to escape from the action of
the host immune system and antiviral drugs. Therefore, due to the high mortality rate of
chickens, ALVs are responsible for huge economic losses in the poultry industry. Due
to horizontal & vertical transmission and genetic variations, there is no effective
vaccine to prevent infections of ALVs.
The aim of this chapter is to summarize various research aspects related to the
pathogenesis and transmission of ALVs. It is essential to understand these processes to
get further insight into the biology of ALV’s. Likewise, to design the control strategies
for ALV infections, it is invaluable to explore the interactions between ALVs and host
immunity.
Keywords: Avian Leukosis viruses, ALVs, Leukosis, Oncogenesis, Retroviruses, RNA tumor viruses.
