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...

Thirty colostrum-deprived calves from leukemia-free herds were foster nursed for 10 weeks on cows infected with bovine C-type virus (BLV) from multiple-case herds or on cows from leukemia-free herds. After weaning, the calves were raised in continuous contact with BLV-infected animals of approximately the same ages. Sera collected at 6 to 18 and 43 to 48 months of age were examined for the pres...

Peripheral blood lymphocytes from 14 cattle infected with the bovine leukemia virus (BLV) and 14 BLV-free cattle were examined by the membrane immunofluorescent antibody technique to detect surface immunoglobulin (S-Ig) and by the erythrocyte-antibody-complement (EAC) rosette test for the detection of complement receptors. Direct comparisons of the percentages of S-Ig-bearing cells and EAC rose...

Abstract Background Subclinical infection with bovine leukemia virus (BLV) in cows can cause economic losses milk and meat production many countries, as BLV-related negative effects. The volatile fatty acids (VFAs) microbiota present the digestive tracts of contribute to cow health. Here, we exploratorily investigated VFAs rumen gut respect subclinical BLV using housed at a single farm. Results...

Bovine leukemia virus (BLV) is highly endemic in many countries, including Iraq, and it impacts the beef and dairy industries. The current study sought to determine the percentage of BLV infection and persistent lymphocytosis (PL) in cattle in central Iraq. Hematological, serological, and molecular observations in cross breeds and local breeds of Iraqi cattle naturally infected with BLV were co...

Background: Bovine Leukemia Virus (BLV) is known by infections in bovine cattle and produce, in 30% of infected animals, persistent lymphocytosis significantly impacts the beef industry. It has been proposed that this virus could be transmitted to humans and be present in cases of breast cancer. Aim: to determine the presence of 380 bp of gag gene segment of BLV in paraffin-embedded breast tiss...

In a previous report, we had indicated that in a sheep model, the expression of tumor necrosis factor (TNF)-alpha was closely associated with disease progression in sheep experimentally infected with bovine leukemia virus (BLV). However, individual variabilities are observed in these responses in BLV-infected animals. To attempt to identify genetic factors promoting the progression to BLV-induc...

Modified bovine leukemia virus (BLV) glycoproteins were expressed by using vaccinia virus recombinants, and their fusogenic capacities were examined by a syncytia-formation assay. This analysis indicates that (i) both BLV envelope glycoproteins gp51 and gp30 are necessary for cell fusion; (ii) insertion of the N-terminal segment of gp30 (fusion peptide) into the lipid bilayer in an oblique orie...