GENETIC ASSOCIATION OF BOVINE LYMPHOCYTE ANTIGEN DRB3 ALLELES WITH IMMUNOLOGICAL TRAITS OF HOLSTEIN CATTLE

The associations between alleles at the BoLA (bovine lymphocyte antige n) DRB3 locus and 20 indicator traits of innate and adaptive immunity were investigated. Periparturient Holsteins (n = 127) were genotyped a t the BoLA DRB3 locus using polymerase chain reaction and restriction fragment length polymorphism. Twenty-two alleles were observed in the study population, and frequencies ranged from 21 to <1%. The same catt le were tested for a total of 20 innate and adaptive immunity traits, including lymphocyte response to mitogens (proliferative responses and Ig secretion), serum Ig, complement and conglutinin concentrations, t otal leukocyte count, and selected assays for neutrophil function. Mod els with gene substitution effects were used to investigate associatio ns between BoLA DRB3 alleles and each of the immunological variables. Significant associations were found with 13 of the leukocyte functions tested. The number of immune parameters with significant associations with any allele ranged from 0 (with alleles DRB3.223 and DRB3.2*27) to 7 (with DRB3.28). The immunological parameter that had the most as sociations with alleles was serum IgG(2) concentration with 6 alleles. One group of 4 alleles (representing 46% of the total allele frequenc y) was uniformly associated with increased IgM and complement and decr eased mononuclear cell numbers. Thus, we demonstrated that the BoLA DR B3 genotype can influence measures of innate and adaptive immunity.