title: Association of BoLA class II haplotypes with subclinical progression of bovine leukaemia virus infection in Holstein-Friesian cattle.
abstract: The influence of bovine lymphocyte antigen (BoLA) complex polymorphism on subclinical progression of bovine leukaemia virus (BLV) infection was investigated in 41 Holstein-Friesian cows from two herds in Italy. All cows were seropositive for BLV and 22 had persistent lymphocytosis (PL). BoLA-A specificities were defined by serology, and class II haplotypes were defined based on restriction fragment length polymorphism (RFLP) and polymerase chain reaction (PCR)-RFLP analysis of DQ and DR genes. Chi-square analysis revealed a significant and absolute association of haplotype DQA*3A-DQB*3A-DRB2*2A-DRB3.2*11 with resistance to PL (P chi 2 = 0.028, relative risk (RR) = 0.061). Consistent with this observation, multiple regression analysis revealed that animals carrying this haplotype had lower lymphocyte counts (P = 0.0057). By contrast, haplotype DQA*12-DQB*12-DRB2*3A-DRB3.2*8 was associated with susceptibility to PL (P chi 2 = 0.043, RR = 9.625) and increased lymphocyte counts (P = 0.0537). These results confirm the association of haplotype DQA*3A-DQB*3A-DRB2*2A-DRB3.2*11 with resistance to PL, and substantiate earlier findings of haplotype DQA*12-DQB*12-DRB2*3A-DRB3.2*8 as a risk factor for subclinical progression to PL in BLV-infected Holstein-Friesian cattle.
authors.affiliation: Institute of Zootechnics, Faculty of Veterinary Medicine, University of Milan, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Zanotti
authors.forename: G
authors.initials: G
authors.lastname: Poli
authors.forename: W
authors.initials: W
authors.lastname: Ponti
authors.forename: M
authors.initials: M
authors.lastname: Polli
authors.forename: M
authors.initials: M
authors.lastname: Rocchi
authors.forename: E
authors.initials: E
authors.lastname: Bolzani
authors.forename: M
authors.initials: M
authors.lastname: Longeri
authors.forename: S
authors.initials: S
authors.lastname: Russo
authors.forename: H A
authors.initials: HA
authors.lastname: Lewin
authors.forename: M J
authors.initials: MJ
authors.lastname: van Eijk
mesh_terms: D000818:Animals; D002417:Cattle; D018450:Disease Progression; D016583:Enzootic Bovine Leukosis / Q000235:genetics / Q000276:immunology*; D005260:Female; D006683:HLA-DQ Antigens / Q000235:genetics*; D059848:HLA-DQ alpha-Chains; D059866:HLA-DQ beta-Chains; D006684:HLA-DR Antigens / Q000235:genetics*; D006239:Haplotypes; D007558:Italy; D001909:Leukemia Virus, Bovine; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D012150:Polymorphism, Restriction Fragment Length
chemical_list: D006683:HLA-DQ Antigens; D059848:HLA-DQ alpha-Chains; D059866:HLA-DQ beta-Chains; C069050:HLA-DQA1 antigen; C057615:HLA-DQbeta antigen; D006684:HLA-DR Antigens