Specific genetic features of the Russian forms of bovine leukemia virus

Ruzina, M. N.; Andrianov, B. V.; Супрович, Т М; Sulimova, G. E.

doi:10.1134/s1022795413080139

Cited by 3 publications

(1 citation statement)

References 17 publications

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“…Following the Second World War, lymphoma in cattle was reported in all continents e.g. North America (Theilen et al, 1963), Australia (Clague and Granzien, 1966), Argentina (Sen et al, 1968), Japan and Russia (Ruzina et al, 2013). In most cases the spread has been linked with trade of dairy cattle for breeding.…”

Section: World-widementioning

confidence: 99%

Enzootic bovine leukosis

Sihvonen¹

2015

EFS2

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Enzootic bovine leukosis is a disease of cattle caused by bovine leukemia virus (BLV). The virus causes a persistent, life‐long infection in a subset of B cells. Malignant tumours (lymphomas) ultimately develop in 2–5% of infected animals, predominantly in adult cattle older than 3–5 years. Lymphomas invariably lead to death of the animal within months. Before 1960, BLV was endemic in dairy herds in Northern/Eastern Europe and North America. Since then it has spread to all continents. The disease has been successfully controlled and eliminated from many countries in Europe. There is no evidence to suggest that any significant reservoir of BLV exists among other species, nor for any role of BLV in human disease or cancers. BLV exhibits a slow, progressive spread within a herd and it is likely to persist if control measures are not applied. The main modes of transmission are perinatal from cow to calf, via colostrum and milk, and close contact that allows transfer of infected lymphocytes, such as dehorning and injections using non‐sterile utensils. Transfer between herds is almost entirely by movement of infected animals. Suitable methods have been developed for diagnosis of BLV infection in specimens of blood, milk and lymphomas. EBL has a negative impact on milk yield and leads to increased premature culling. The welfare consequences of lymphomas vary according to the location and magnitude of organ involvement. Criteria for maintaining country freedom from EBL differ substantially between OIE and EU. Surveillance for freedom should be based on a combination of serological testing of adult animals and identification of lymphomas at slaughter.

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Section: World-widementioning

confidence: 99%

Enzootic bovine leukosis

Sihvonen¹

2015

EFS2

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In vitro and in vivo antivirus activity of an anti-programmed death-ligand 1 (PD-L1) rat-bovine chimeric antibody against bovine leukemia virus infection

et al. 2017

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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, this study assessed its antivirus activities in vivo. First, we inoculated the anti-bovine PD-L1 rat monoclonal antibody 4G12 into a BLV-infected cow. However, this did not induce T-cell proliferation or reduction of BLV provirus loads during the test period, and only bound to circulating IgM+ B cells until one week post-inoculation. We hypothesized that this lack of in vivo effects was due to its lower stability in cattle and so established an anti-PD-L1 rat-bovine chimeric antibody (Boch4G12). Boch4G12 was able to bind specifically with bovine PD-L1, interrupt the PD-1/PD-L1 interaction, and activate the immune response in both healthy and BLV-infected cattle in vitro. Therefore, we experimentally infected a healthy calf with BLV and inoculated it intravenously with 1 mg/kg of Boch4G12 once it reached the aleukemic (AL) stage. Cultivation of peripheral blood mononuclear cells (PBMCs) isolated from the tested calf indicated that the proliferation of CD4+ T cells was increased by Boch4G12 inoculation, while BLV provirus loads were significantly reduced, clearly demonstrating that this treatment induced antivirus activities. Therefore, further studies using a large number of animals are required to support its efficacy for clinical application.

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Prostaglandin E2–Induced Immune Exhaustion and Enhancement of Antiviral Effects by Anti–PD-L1 Antibody Combined with COX-2 Inhibitor in Bovine Leukemia Virus Infection

Sajiki

Konnai

Okagawa

et al. 2019

The Journal of Immunology

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Bovine leukemia virus (BLV) infection is a chronic viral infection of cattle and endemic in many countries, including Japan. Our previous study demonstrated that PGE 2 , a product of cyclooxygenase (COX) 2, suppresses Th1 responses in cattle and contributes to the progression of Johne disease, a chronic bacterial infection in cattle. However, little information is available on the association of PGE 2 with chronic viral infection. Thus, we analyzed the changes in plasma PGE 2 concentration during BLV infection and its effects on proviral load, viral gene transcription, Th1 responses, and disease progression. Both COX2 expression by PBMCs and plasma PGE 2 concentration were higher in the infected cattle compared with uninfected cattle, and plasma PGE 2 concentration was positively correlated with the proviral load. BLV Ag exposure also directly enhanced PGE 2 production by PBMCs. Transcription of BLV genes was activated via PGE 2 receptors EP2 and EP4, further suggesting that PGE 2 contributes to disease progression. In contrast, inhibition of PGE 2 production using a COX-2 inhibitor activated BLV-specific Th1 responses in vitro, as evidenced by enhanced T cell proliferation and Th1 cytokine production, and reduced BLV proviral load in vivo. Combined treatment with the COX-2 inhibitor meloxicam and anti-programmed death-ligand 1 Ab significantly reduced the BLV proviral load, suggesting a potential as a novel control method against BLV infection. Further studies using a larger number of animals are required to support the efficacy of this treatment for clinical application.

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Specific genetic features of the Russian forms of bovine leukemia virus

Cited by 3 publications

References 17 publications

Enzootic bovine leukosis

Enzootic bovine leukosis

In vitro and in vivo antivirus activity of an anti-programmed death-ligand 1 (PD-L1) rat-bovine chimeric antibody against bovine leukemia virus infection

Prostaglandin E2–Induced Immune Exhaustion and Enhancement of Antiviral Effects by Anti–PD-L1 Antibody Combined with COX-2 Inhibitor in Bovine Leukemia Virus Infection

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