Lymphocyte phenotypes were determined in sheep experimentally infected with bovine leukemia virus (BLV). BLV infection was detected by serological tests AGID and ELISA. Flow cytometry analysis with the use of specific monoclonal antibodies for CD markers and conjugates labeled with FITC or PE was performed. Proliferating cell nuclear antigen (PCNA) was estimated in lymphocytes of infected and h...

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...

169 Summary: Bovine leukemia virus (BLV) is the causative agent of enzootic bovine leukosis (EBL). After infection with BLV there is no detectable viremia but there is a strong and persistent humoral immune response to structural proteins, essentially the gp51 envelope glycoprotein and the major core protein p24. Polymerase chain reaction (PCR) with primers used to amplify part of env gene, aga...

Bovine leukemia virus (BLV), the causative agent of enzootic bovine leukosis, is an exogenous, B lymphotropic retrovirus belonging to the Retroviridae family that induces persistent lymphocytosis in cattle and sheep. PCR has proven to be particularly suitable for investigating herds of cattle with a very low incidence of BLV infection and for clarifying doubtful serological results obtain...

Bovine leukosis virus (BLV) is associated with the disease complex enzootic bovine leukosis. The infection may remain clinically silent in the form of an aleukaemic state or emerge as a persistent lymphocytosis and more rarely as lymphosarcroma. BLV has been considered classically to be a B lymphotropic virus, based upon the absolute increase in B lymphocytes in persistent lymphocytosis, the B ...

Data on the worldwide distribution of bovine immunodeficiency virus (BIV) and bovine leukemia virus (BLV) is limited. A prevalence study of antibodies to BIV and BLV was conducted in six different cattle herds in Brazil. Out of a total of 238 sera analyzed, 11.7% were found positive for anti-BIV p26 antibodies as determined by Western blot analysis, 2.1% were positive for anti-BLV gp51 antibodi...

The European Community's (EC) Key, which is also called Bendixen's Key, is a well-established bovine leukemia virus (BLV) diagnostic method that classifies cattle according to the absolute lymphocyte count and age. The EC Key was originally designed for dairy cattle and is not necessarily suitable for Japanese Black (JB) beef cattle. This study revealed the lymphocyte counts in the BLV-free and...

Bovine leukemia virus (BLV) expression is mostly silent in peripheral blood mononuclear cells (PBMCs) of infected animals. However, when infected cells are cultured, they are stimulated to produce virus. We studied viral transcription in PBMCs taken from BLV-infected sheep because the pattern of transcriptional activation in these cells should closely mimic activation of virus expression within...

Bovine leukemia virus (BLV), one of the most common infectious viruses of cattle, is endemic in many herds. Approximately 30-40% of adult cows in the United States are infected by this oncogenic C-type retrovirus and 1-5% of animals will eventually develop a malignant lymphoma. BLV, like the human and simian T cell leukemia viruses, is a deltaretrovirus but, in contrast with the latter, the BLV...

Programmed death-1 (PD-1), an immunoinhibitory receptor on T cells, is known to be involved in immune evasion through its binding to PD-ligand 1 (PD-L1) in many chronic diseases. We previously found that PD-L1 expression was upregulated in cattle infected with bovine leukemia virus (BLV) and that an antibody that blocked the PD-1/PD-L1 interaction reactivated T-cell function in vitro. Therefore...