Enzootic bovine leukosis (EBL) is a contagious lymphoproliferative disease whose etiological agent is a retrovirus, the bovine leukemia virus (BLV). EBL is a complex disease. So on after infection a strong humoral antibody response develops and persists for the animal 's entire life. Such BLV-infected cattle can remain asymptomatic virus carriers for many years. They can also at a given time de...

Bovine buffy coat cells infected with the bovine leukemia virus (BLV) induce syncytia formation in human diploid embryonic lung cells as well as in monolayer cell cultures of bovine, simian, ovine, bat, and caprine origin, but not in mouse fibroblast cells, normall rat kidney cells, or RSV-transformed rat cells. Syncytia were not observed in diploid embryonic lung cells inoculated with bovine b...

We have detected elevated levels of c-myc gene expression in neoplastic cells from all seven bovine leukemia virus (BLV)-induced bovine tumors examined, but not in BLV-infected, nonneoplastic lymphoid cells. No rearrangement or amplification of the c-myc gene could be demonstrated in any of the BLV-induced tumors. Furthermore, BLV proviral DNA was found to have no preferred site of integration ...

The role of colostrum and milk in the transmission of the bovine leukemia virus (BLV) was examined by monitoring the development of BLV infection in calves that were fed since birth on colostrum and milk from their BLV-positive dams and then reared in complete or partial isolation from infected cattle. Twenty-one of the 25 calves raised in complete isolation remained negative for BLV until the ...

This study demonstrates that the bovine leukemia virus (BLV) can infect in vitro cells of human, simian, bovine, canine, caprine, ovine, and bat origin. Cultures of these cells, cocultivated with BLV-infected cells or inoculated with cell-free BLV preparations, continuoously showed the presence of cells with the internal BLV antigen as well as BLV-induced syncytia. Virus replication was abundan...

MicroRNAs (miRNAs) are small RNAs that play a regulatory role in numerous and diverse eukaryotic cellular processes. Virus-encoded miRNAs have garnered much interest, although the functions of most remain to be deciphered. To date, readily detectable, evolutionarily conserved natural miRNAs have only been identified from viruses with DNA genomes. Combined with the fact that most miRNAs are gene...

Background: Bovine leukaemia virus (BLV) is the primary cause of enzootic bovine leukaemia which belongs to the HTLV/BLV group of oncogenic retroviruses including Human T-cell leukaemia virus types 1, 2, and 3 and simian T-lymphotropic virus. Due to daily consumption of milk, meat and other dairy by-products, a possible role in appearing human cancers can be assumed for BLV. Materials and Metho...

Bovine leukemia virus (BLV) from either persistently infected bat cells or fetal lamb kidney cells induced rapid syncytium formation in F81 indicator cells. Distinct syncytia were seen within 2 h after inoculation of cells with highly concentrated (500-fold) cell-free BLV preparations and within 4 to 8 h when unconcentrated cell-free BLV preparations were used. Indicator cell densities of 1 x 1...

Introduction Bovine Leukosis Virus (BLV) is a retroviral infection that causes leukemia in cattle by targeting white blood cells and causing them to grow uncontrollably. Most BLV-infected cattle seldom present with outward clinical signs. Approximately 30% of infected animals, however, will have abnormally high white blood cell counts and up to 5% will develop malignant tumors or lymphosarcomas...

Thirteen bovine leukemia virus- (BLV-) negative and 22 BLV-positive Holstein cows were immunized with J5 Escherichia coli bacterin at dry off, three weeks before calving, during the second week after calving, and three weeks after the third immunization. Serum was collected before the initial immunization, immediately before the third and fourth immunizations, and 21 days after the fourth immun...