Structure, function and disease susceptibility of the bovine major histocompatibility complex

Abstract

The major histocompatibility complex (MHC) of cattle is known as the bovine leukocyte antigen (BoLA) and is located on chromosome 23. BoLA has been linked to variation in resistance to disease including bovine leukemia virus‐induced lymphoma and mastitis. Moreover, BoLA appears to influence other traits such as milk yield, growth and reproduction, which are not often measured in humans, and variations in individual immune response to antigen. The BoLA appears to be organized in a similar way to the MHC region in humans, but there are notable differences. A major rearrangement within the class II region has led to the division of the BoLA into two distinct subregions of chromosome 23 separated by about a third of the chromosome’s length. The class IIa subregion contains functionally expressed DR and DQ genes, while the class IIb subregion contains the genes of undefined status such as DYA, DYB, DMA, DMB, DOB, DOA, TAP1, TAP2, LAP2 and LMP7. In addition, one pair of human class II genes (DP) does not appear to have an equivalent in cattle, and there is one pair of DY genes that seem to be found only cattle, sheep and goats. In humans, three classical, polymorphic class I genes (HLA‐A, ‐B and ‐C ) are each present on all haplotypes. However, in cattle, none of the four (or more) classical class‐I genes identified are consistently expressed, and haplotypes differ from one to another in both the gene number and composition. These variations in both class I and II are likely to play an important role in cattle immune responses. This review summarizes current knowledge of the structural and functional features and disease association of BoLA genes.

Polymorphisms of BoLA-DRB3 gene and its association with resistance / susceptibility to Leucosis in Holstein cattle from La Pampa

“…Este polimorfismo tiene un profundo efecto en el reconocimiento de los antígenos por las células T y la combinación de poligenia y polimorfismo extiende ampliamente el rango de péptidos que pueden ser presentados a las células T por un individuo (Brown et al, 1993). El MHC de los mamíferos se divide comúnmente en tres regiones llamadas: MHC de clase I; clase II y de clase III, las cuales codifican para proteínas con diferentes funciones y distribución en los tejidos (Lewin et al, 1999;Takeshima y Aida, 2006). En bovinos, el MHC se denomina Antígeno Leucocítico Bovino (BoLA) y su descubrimiento es atribuido a Amorena y Stone (1978) y a Spooner et al (1978).…”

“…Diferentes autores han asociado los polimorfismos presentes en los genes del BoLA con enfermedades infecciosas (Xu et al, 1993;Dietz et al, 1997b;Mirsky et al, 1998;Aida et al, 2001, Martínez et al, 2005Martínez et al, 2006;Castro et al, 2006;Do Nascimiento et al, 2006;Juliarena et al, 2008;Panei et al, 2009, Baltian et al, 2012. Entre las enfermedades infecciosas estudiadas pueden mencionarse la brucelosis, mastitis, leucosis, dermatofilosis y ectoparasitosis, las que han sido asociadas principalmente a los polimorfismos presentes en el segundo exón del gen de clase II BoLA-DRB3 (Takeshima y Aida, 2006;Baltian et al, 2012;2014). También, estos polimorfismos han sido asociados con caracteres productivos como producción de leche, proteínas y grasa en leche, crecimiento (Machado et al, 2005;Do Nascimento et al, 2006;Zambrano et al, 2009b).…”

Asociación del locus BOLA-DRB3.2 con el virus de la leucosis bovina en el ganado criollo colombiano

“…El sistema BoLa es un conjuto de glicoproteínas que se ubican en la superficie celular y su función principal es la presentación de péptidos (TAKESHIMA y AIDA, 2006). Existen tres clases de genes BoLA.…”

“…Existen tres clases de genes BoLA. Los BoLA clase I codifican proteínas implicadas en el reconocimiento de las células del hospedero que han sido infectadas y en la presentación de péptidos endógenos a las células citotóxicas T o T CD8 + (LEWIN, 2009;TAKESHIMA y AIDA, 2006).…”

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“…Previously it was established that polymorphism in the BoLA-DRB3 exon 2 correlates with resistance to persistent lymphocytosis caused by bovine leukemia virus (Lewin and Bernoco, 1986;Xu et al, 1993;Zanotti et al, 1996;Takeshima and Aida, 2006;Behl et al, 2012). Genetic mechanisms of resistance and susceptibility to leukemia in Ayrshire and Black Pied cattle breeds were determined by allelic distribution of the BoLA-DRB3 gene.…”