Analysis of the association between antibodies against bovine leukemia virus (BLV), BLV proviral load, and white blood cell (WBC) and lymphocyte counts was performed with 774 dairy cows. The average age, WBC counts and lymphoid cell counts tended to be higher in BLV antibody-positive cows than in antibody-negative cows. There was a similar trend in levels of proviral DNA. We analyzed age, WBC c...

This report describes the development of a 7-day infectivity assay for bovine leukemia virus (BLV) which is based on the induction of the major internal virion antigen (a protein with a molecular weight of 25,000) in susceptible indicator monolayer cell cultures. In this assay, the antigen is detected in the indicator cells by the immunoperoxidase antibody technique using a specific rabbit anti...

Bovine leukemia virus (BLV) is a valuable model system for understanding human T-lymphotropic virus 1 (HTLV-1); the availability of an infectious BLV clone, together with animal-model systems, will help to explore anti-HTLV-1 strategies. Nevertheless, the specificity and inhibitor sensitivity of the BLV protease (PR) have not been characterized in detail. To facilitate such studies, a molecular...

This review deals with the role of viruses in the aetiology of bovine mastitis. Bovine herpesvirus 1, bovine herpesvirus 4, foot-and-mouth disease virus, and parainfluenza 3 virus have been isolated from milk from cows with clinical mastitis. Intramammary inoculations of bovine herpesvirus 1 or parainfluenza 3 virus-induced clinical mastitis, while an intramammary inoculation of foot-and-mouth ...

This report describes the development of a 7-day infectivity assay for bovine leukemia virus (BLV) which is based on the induction of the major internal virion antigen (a protein with a molecular weight of 25,000) in susceptible indicator monolayer cell cultures. In this assay, the antigen is detected in the indicator cells by the immunoperoxidase antibody technique using a specific rabbit anti...

The nucleic acid-binding proteins of bovine leukemia virus (BLV) and feline leukemia virus (FeLV) were isolated in a high state of purity with chloroform-methanol extraction followed by reversed-phase liquid chromatography. Selective solubilization and purity of BLV p12 and FeLV p10 was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The compositions and molecular weight...

Blockade of immunoinhibitory molecules, such as programmed death-1 (PD-1)/PD-ligand 1 (PD-L1), is a promising strategy for reinvigorating exhausted T cells and preventing disease progression in a variety of chronic infections. Application of this therapeutic strategy to cattle requires bovinized chimeric antibody targeting immunoinhibitory molecules. In this study, anti-bovine PD-1 rat-bovine c...

Bovine leukemia virus latency is a viral strategy used to escape from the host immune system and contribute to tumor development. However, a highly expressed BLV micro-RNA cluster has been reported, suggesting that the BLV silencing is not complete. Here, we demonstrate the in vivo recruitment of RNA polymerase III to the BLV miRNA cluster both in BLV-latently infected cell lines and in ovine B...

Horizontal transmission is recognized as a major infection route for bovine leukemia virus (BLV), and cattle with high viral loads are considered to be a major infectious source in a herd. However, a correlation between viral loads and the risk of infection has been insufficient to use as a foundation for BLV control strategies. In this report, we examined the epidemiology of BLV infection and ...

Bovine leukemia virus (BLV) is a retrovirus that causes enzootic bovine leucosis. To investigate the presence and genetic variability of BLV in the Caribbean for the first time, we preformed fluorescence resonance energy transfer (FRET)-PCR for the pol of BLV on DNA from whole blood of cattle from Dominica, Montserrat, Nevis and St. Kitts. Standard PCRs with primers for the env were used for ph...