Association between BoLA-DRB3.2 0902 allelomorphism and viral infection in cattle.

GOGORZA, L; RENSETTI, D; PEREZ, S. E; BECALUBA, M; JULIARENA, M

Praga

Congreso; 31st World Veterinary Congress; 2013

The gene from the major histocompatibility complex class II is associated with genetic resistance and susceptibility to a wide array of diseases. This gene encodes one of the most important proteins cellular and humoral immunity. The control and eradication of bovine leukemia virus (BLV) with genetic intervention is based on the selection of cattle carrying alleles of the bovine leukocyte antigen (BoLA) DRB3*0902, gene associated with BLV-infection resistance. A potential risk in expanding BoLA selected populations of cattle is that it might increase susceptibility to other infections. For this reason, we evaluated the activity of other infectious agents as bovine viral diarrhea virus (BVDV), bovine herpesvirus -4 (BoHV-4) and Neospora caninum (NC) in those animals. Samples of peripheral blood leucocytes (PBL) from 87 adult animals, with a unknown previous health status, were analyzed by viral isolation on MDBK cells for BVDV detection, nested PCR test for BoHV-4 detection and neutralization test for BVDV antibodies. Immunofluorescence assay was applied to NC antibodies detection. BoLA DRB3.2*0902 allele expression was analyzed by PCR-RFLP and specific allele - PCR. A high percentage of BVDV infection (11,5%) , BoHV-4 (63,4%), and N. caninum (49,5%) was detected. BVDV was isolated in cattle of 5 farms (55,5%). Cattle from 4 a farms were positive to BoHV-4 in leukocytes. All the groups showed seropositive records to NC. Only 21% of the animals were carriers of the BoLA DRB3.2*0902 allele. Further virological and epidemiological studies will be necessary to follow the consequences of the genetic selection on the herds