Impact of Bovine Major Histocompatibility Complex on Infection, Symptom Onset and Prevention of Enzootic Bovine Leukosis

Enzootic bovine leukosis (EBL) is a malignant B-lymphoma caused by bovine leukemia virus (BLV) and causes serious problems for the cattle industry. EBL is a typical multifactorial disease in cattle, and host, viral, and environmental factors are thought to determine susceptibility. One of the most important host factors is the polymorphism of the major histocompatibility complex (MHC) (BoLA). Several studies have identified genetic variations in BoLA-DRB3, a functionally important locus and the most highly polymorphic BoLA class II locus in cattle. To date, 386 BoLA-DRB3 alleles have been registered in the Immuno Polymorphism Database- MHC database. Importantly, the BoLA-DRB3 polymorphism influences susceptibility to BLV-induced lymphoma, and to proviral load (PVL) which is an important risk factor of virus-associated disease prediction.