A novel association of BoLA DRB3 alleles in BLV infected cattle with different proviral loads.

NIETO FARIAS VICTORIA; CAFFARO MARIA EUGENIA; LENDEZ PAMELA ANAHI; PASSUCCI JUAN ANTONIO; POLI MARIO ANDRES; CERIANI MARIA CAROLINA; DOLCINI GUILLERMINA LAURA

BRAZILIAN JOURNAL OF VETERINARY RESEARCH AND ANIMAL SCIENCE

Fundacao Medicina Veterinaria

Lugar: San Pablo; Año: 2017 vol. 54 p. 215 - 224

1413-9596

Bovine leukemia virus (BLV) is associated with the most common neoplastic disease of cattle. BLV has a silent dissemination in the herd due to infected cell exchange, thus the concentration of BLV-infected cells in blood should play a major role in the success of viral transmission. Genes from Bovine leukocyte antigen (BoLA), the MHC system of cattle, are associated with genetic resistance and susceptibility to a wide range of diseases, and also with production traits. Some BoLA DRB3.2 allele polymorphisms in Holstein cattle have been associated with resistance or susceptibility to BLV-disease development, or with proviral load (PVL). We studied 107 BLV-infected Argentinean Holstein dairy cows belonging to a unique herd. PVL was analyzed by qPCR and animals were classified as high proviral load (HPVL, N=88) and low proviral load (LPVL, N=19), and BoLA DRB3.2 alleles were genotyped. Alleles BoLA DRB3.2*1501 and *1201 were significantly associated with HPVL (p=0.0230 and p=0.0111 respectively), while allele BoLA DRB3.2*0201 was significantly associated with LPVL (p=0.0030). Our study aims to contribute to the knowledge of the association between BoLA polymorphism and development of a BLV infection profile. Genes that best explains the PVL in this population resulted BoLA DRB3.2*0201 (as a protection factor) and *1501 (as a risk factor). Allelic differences may play an important role in the development of effective immune responses. A better understanding how BoLA polymorphism contributes to these responses and the establishment of a BLV status is desirable to schedule and evaluate control measures.