Effect of the Bovine Major Histocompatibility Complex on the Milk-borne Transmission of Bovine Leukemia Virus through Milk and iinfection control

Abstract

Bovine MHC, designated bovine leukocyte antigen (BoLA), maps to bovine autosomal chromosome 23, and BoLA-DRB3 is the most polymorphic of the BoLA class II gene cluster with 386 alleles reported to date. BoLA-DRB3 has been reported to be strongly associated with bovine leukemia virus (BLV) and several infectious diseases of cattle, including mastitis-causing bacteria and abortion-causing protozoa. In this review, we will outline the association that has been identified between horizontal and vertical infection of BLV and BoLA-DRB3. In particular, we review the effects of BoLA-DRB3 on BLV proviral load, anti-BLV antibody levels, and infectivity in bovine milk, which we were the first in the world to identify, and the combined effects between BoLA-DRB3 and BLV infection on economic traits related to milk. Finally, we devise an ideal method to control the transmission of BLV through milk based on BoLA-DRB3.