Major Histocompatibility Complex-Associated Resistance to Infectious Diseases: The Case of Bovine Leukemia Virus Infection

GUTIÉRREZ, SILVINA ELENA; ESTEBAN, EDUARDO; LUTZELSCHWAB, CLAUDIA; JULIARENA, MARCELA

Trends and Advances in Veterinary Genetics

InTechOpen

Año: 2017; p. 101 - 126

The major histocompatibility complex (MHC) is a polymorphic gene cluster of about150 genes, present in all vertebrates. Many of these genes contribute to immunity.Particularly, MHC‐encoded class I and class II molecules, which are typically highlypolymorphic and polygenic, are central in defining the specificity of the adaptive immuneresponse. Among the diversity of genes associated with disease resistance, MHC genesare particularly interesting as they are associated with resistance and susceptibility to awide range of diseases, some of which produce important economic losses in livestock.Enzootic bovine leukosis is an infectious disease caused by the retrovirus bovine leukemiavirus (BLV), with an important economic impact, mainly in dairy herds. In this chapter,MHC‐associated genetic resistance to BLV is revised. Certain alleles of the bovineMHC (BoLA) class II locus have been found strongly associated with resistance to viraldissemination. Genetic selection of resistant animals emerges as a natural strategy for thecontrol of infectious diseases, especially when there is no other alternative of control orprevention, as vaccines. Founded on this knowledge, a BLV control program based onselection of genetically resistant cattle was designed. The proof of concept indicates thatthis strategy is feasible to implement in dairy herds.