scholarly journals Isolation of Bovine Leukemia Virus from Cows with Persistent Lymphocytosis in Iraq

2021 ◽  
pp. 100201
Author(s):  
Yahia Ismail Khudhair ◽  
Ahmed Majeed Al-Shammari ◽  
Saleem Amin Hasso ◽  
Nahi Yaseen
Keyword(s):  
Bovine Leukemia Virus ◽  
Leukemia Virus ◽  
Persistent Lymphocytosis

scholarly journals Influence of the Bovine Leukemia Virus on the Immunological Activity by the Neutrophilic Function

2020 ◽  
Vol 48 ◽  
Author(s):  
Vinícius Bigolin Narciso ◽  
Silvana Giacomini Collet ◽  
Lilian Kolling Girardini ◽  
Fernando Nogueira Souza ◽  
Alcione Santa Catarina ◽  
...  
Keyword(s):  
Oxidative Metabolism ◽  
Bovine Leukemia Virus ◽  
Leukemia Virus ◽  
Latency Period ◽  
Persistent Lymphocytosis ◽  
Phagocytic Capacity ◽  
Significant Difference ◽  
Zymosan Particle ◽  
The Impact ◽  
Hematological Alterations

Background: Bovine leukemia virus (VLB) is an oncogenic deltaretrovirus associated with the development of persistent lymphocytosis (LP) and lymphosarcomas in cattle. LP is characterized by chronic elevation of the number of circulating lymphocytes, in the case of B lymphocytes. Several studies have described functional changes in various leukocyte populations in both blood and milk in VLB-infected animals. The impact of some chronic diseases of low lethality is aggravated by the emergence of comorbidities.The objective of the present study was to evaluate the oxidative metabolism and neutrophil phagocytosis of bovines of the Holtein breed naturally infected with the bovine leukemia virus (VLB).Materials, Methods & Results: In this study, 20 cows were divided into three groups: (NG) seven non-seroreagent animals for VLB and without hematological alterations; (GAL) eight seroreagent animals for VLB and without hematological alterations; and (GLP) five seroreagent animals for VLB with persistent lymphocytosis (LP). The oxidative metabolism of neutrophils was determined by the tetrazolium nitroblast reduction test stimulated or not with Zymosan particles. The percentage of neutrophils that phagocytosed Zymosan particle (s) was also evaluated. The data were initially evaluated for normality and homoscedasticity by the Shapiro-Wilk test. Then the ANOVA test followed by the Student-Newman-Keuls test was applied for the comparison between the NG, GAL and GLP animals. Comparison between the NG animals and the seroreagent animals for the VLB (GVLB) was also performed through the unpaired Student's t-test. The value of P < 0.05 was considered significant. No significant differences were observed in oxidative neutrophil metabolism in stimulated and non-stimulated samples with Zymosan particles nor in the percentage of neutrophils that phagocytosed Zymosan particle (s) among the three experimental groups. However, as no differences were observed between the seroreagent animals for VLB with and without LP, we chose to divide the animals into only two experimental, non-seroreagent and seroreagent groups for VLB. Thus, when non-seroreagent animals for the VLB were compared with the seroreagent animals for the VLB, which corresponds to the GAL and GLP animals, a significant difference was observed in relation to the oxidative metabolism by neutrophils stimulated with Zymosan particles.Discussion: Some viral diseases are often associated with increased susceptibility to new infections and several studies have evaluated the role of peripheral blood mononuclear cells in VLB infection, but few studies have investigated neutrophil function. Some authors, when evaluating phagocytic capacity and oxidative metabolism, respectively, of blood leukocytes from VLB-infected animals, observed that VLB-infected animals displaying LP had lower phagocytic capacity and lower production of Reactive Oxygen Species (ROS). Some studies have shown that oxygen consumption by neutrophils was higher in experimentally infected sheep by VLB after 15 weeks of challenge, but this species is not a natural host of the virus, since transmission does not occur between sheep and cattle and the pathogenesis of infection by VLB is more acute in sheep, a result of the lower latency period for LP development. Other authors, when evaluating the interference of VLB in milk leukocytes, concluded that VLB-infected animals show lower intensity of intracellular ROS production by flow cytometry in VLB-infected animals, especially animals expressing LP, despite the fact that percentage of milk neutrophils that produced ROS did not differ between groups. It can be concluded that VLB interferes in neutrophilic function with possible implications for the health of VLB-infected animals and may favor secondary infections.

scholarly journals A hematologic key for bovine leukemia virus screening in Japanese black cattle

2019 ◽  
Vol 31 (4) ◽  
pp. 568-571
Author(s):  
Masataka Akagami ◽  
Shoko Oya ◽  
Yuki Kashima ◽  
Satoko Seki ◽  
Yoshinao Ouchi ◽  
...  
Keyword(s):  
Dairy Cattle ◽  
Bovine Leukemia Virus ◽  
Operating Characteristic ◽  
Leukemia Virus ◽  
Characteristic Curve ◽  
Persistent Lymphocytosis ◽  
Cutoff Values ◽  
Antibody Elisa ◽  
Hematologic Method ◽  
Virus Screening

The European Community’s leukosis key (EC key) is a well-known hematologic method for detecting bovine leukemia virus (BLV) infection in dairy cattle. The key identifies infected cattle with persistent lymphocytosis via a combination of lymphocyte count (LC) and age. Using the EC key to identify BLV-infected Japanese black (JB) cattle is problematic, however, given the inherently lower LCs of JB cattle compared to dairy cattle. We analyzed the LC in BLV-positive and -negative JB cattle and estimated LC cutoff values by age using receiver operating characteristic curve analysis. Among the 716 JB blood samples collected, 452 (63%) JB cattle were confirmed as BLV-positive by an antibody ELISA for ≥1-y-old cattle and by real-time PCR for <1-y-old cattle. The cutoff values for the LC in each age group were calculated as 6.3 × 109/L for <1 y, 5.9 × 109/L for 1 to <2 y, 5.5 × 109/L for 2 to <3 y, 4.5 × 109/L for 3 to <6 y, 4.3 × 109/L for 6 to ≤10 y, and 3.7 × 109/L for >10 y. The sensitivity and specificity of the estimated cutoff values were 0.49 (95% confidence interval: 0.44–0.53) and 0.81 (0.75–0.85), whereas those of the EC key were 0.20 (0.16–0.24) and 0.99 (0.97–1.00). Our LC cutoff values for screening JB cattle for BLV infection appear to be preferable to those of the EC key.

scholarly journals IFN-γ mRNA expression is lower in Holstein cows infected with bovine leukemia virus with high proviral load and persistent lymphocytosis

2020 ◽  
Vol 64 (04) ◽  
pp. 451-456
Author(s):  
C. Úsuga-Monroy ◽  
L. G. González Herrera ◽  
J. J. Echeverri Zuluaga ◽  
F. J. Díaz ◽  
A. López-Herrera
Keyword(s):  
Mrna Expression ◽  
Bovine Leukemia Virus ◽  
Proviral Load ◽  
Leukemia Virus ◽  
Holstein Cows ◽  
Persistent Lymphocytosis ◽  
High Proviral Load ◽  
Ifn Γ

scholarly journals Bovine Leukemia Virus-Induced Persistent Lymphocytosis in Cattle Does Not Correlate with Increased Ex Vivo Survival of B Lymphocytes

1999 ◽  
Vol 73 (2) ◽  
pp. 1127-1137 ◽  
Author(s):  
Franck Dequiedt ◽  
Glenn H. Cantor ◽  
Valerie T. Hamilton ◽  
Suzanne M. Pritchard ◽  
William C. Davis ◽  
...  
Keyword(s):  
Cell Death ◽  
Cell Survival ◽  
Bovine Leukemia Virus ◽  
Mononuclear Cells ◽  
Ex Vivo ◽  
Leukemia Virus ◽  
Spontaneous Apoptosis ◽  
Persistent Lymphocytosis ◽  
Peripheral Blood Mononuclear

ABSTRACT Bovine leukemia virus (BLV) is an oncogenic retrovirus associated with B-cell lymphocytosis, leukemia, and lymphosarcoma in the ovine and bovine species. We have recently reported that in sheep, BLV protects the total population of peripheral blood mononuclear cells (PBMCs) from ex vivo spontaneous apoptosis. This global decrease in the apoptosis rates resulted from both direct and indirect mechanisms which allow extension of cell survival. Although sheep are not natural hosts for BLV, these animals are prone to develop virus-induced leukemia at very high frequencies. Most infected cattle, however, remain clinically healthy. This difference in the susceptibilities to development of leukemia in these two species might be related to alterations of the apoptotic processes. Therefore, we designed this study to unravel the mechanisms of programmed cell death in cattle. We have observed that PBMCs from persistently lymphocytotic BLV-infected cows were more susceptible to spontaneous ex vivo apoptosis than cells from uninfected or aleukemic animals. These higher apoptosis rates were the consequence of an increased proportion of B cells exhibiting lower survival abilities. About one-third of the BLV-expressing cells did not survive the ex vivo culture conditions, demonstrating that viral expression is not strictly associated with cell survival in cattle. Surprisingly, culture supernatants from persistently lymphocytotic cows exhibited efficient antiapoptotic properties on both uninfected bovine and uninfected ovine cells. It thus appears that indirect inhibition of cell death can occur even in the presence of high apoptosis rates. Together, these results demonstrate that the protection against spontaneous apoptosis associated with BLV is different in cattle and in sheep. The higher levels of ex vivo apoptosis occurring in cattle might indicate a decreased susceptibility to development of leukemia in vivo.

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