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 Milk Macrophage Function in Bovine Leukemia Virus-Infected Dairy Cows

2021 ◽  
Vol 8 ◽  
Author(s):  
Ewerton de Souza Lima ◽  
Maiara Garcia Blagitz ◽  
Camila Freitas Batista ◽  
Alexandre José Alves ◽  
Artur Cezar de Carvalho Fernandes ◽  
...  
Keyword(s):  
Mammary Gland ◽  
Immune Responses ◽  
Dairy Cows ◽  
Bovine Leukemia Virus ◽  
Leukemia Virus ◽  
Persistent Lymphocytosis ◽  
Phagocytic Capacity ◽  
Adaptive Immune ◽  
Milk Samples ◽  
Viable Cells

The implications of bovine leukemia virus (BLV) on innate and adaptive immune responses have been widely investigated; however, the effects of BLV on mammary gland immunity require further investigation. The present study investigated the viability, phagocytic capacity, and intracellular production of reactive oxygen and nitrogen species (RONS) by macrophages in milk samples from dairy cows naturally infected with BLV with or without persistent lymphocytosis (PL). No effect of BLV infection in the overall number of macrophages per milliliter and in the percentage of viable macrophages among overall milk viable cells was found. Furthermore, BLV-infected dairy cows had a higher frequency of viable milk macrophages, while healthy animals had a tendency toward a higher percentage of apoptotic milk macrophages. The percentage of milk macrophages that phagocytosed Staphylococcus aureus in seronegative animals was higher than that in BLV-infected dairy cows. No effect of BLV infection on the intracellular RONS production and the intensity of phagocytosis by milk macrophages was observed. Thus, this study provides new insights into the implications of BLV infections in the bovine mammary gland.

scholarly journals Natural Infection of Dairy Cows with Bovine Leukemia Virus Affects Immunoglobulin Levels in Saliva and Serum but Not Milk

Pathogens ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 907
Author(s):  
Monika Dziuba ◽  
Vickie J. Ruggiero ◽  
Catherine Wilson ◽  
Paul C. Bartlett ◽  
Paul M. Coussens
Keyword(s):  
Pilot Study ◽  
Dairy Cows ◽  
Bovine Leukemia Virus ◽  
Leukemia Virus ◽  
Natural Infection ◽  
Total Serum ◽  
Serum Samples ◽  
Retroviral Infection ◽  
Serum Iga ◽  
The Impact

Bovine leukemia virus (BLV) is a retroviral infection that disrupts the immune function of infected animals. It is widespread among U.S. dairy cattle. In this pilot study, the average total IgA and IgM concentrations in milk, saliva, and serum samples from BLV ELISA-positive (ELISA+) dairy cows were compared against samples from BLV ELISA-negative (ELISA−) cows using the Kruskal–Wallis test (with ties). The results from ELISA+ cows were also stratified by lymphocyte count (LC) and proviral load (PVL). In milk and saliva from ELISA+ cows, the average total IgA and IgM concentrations were decreased compared to ELISA− cows, although this was only statistically significant for saliva IgM in cows with low PVL (p = 0.0424). Numerically, the average total IgA concentrations were 33.6% lower in milk and 23.7% lower in saliva, and the average total IgM concentrations were 42.4% lower in milk and 15.5% lower in saliva. No significant differences were observed in the total serum IgA concentrations, regardless of PVL and LC. The total serum IgM from ELISA+ cows was significantly decreased (p = 0.0223), with the largest decreases occurring in the highest PVL and LC subgroups. This pilot study is a first step in investigating the impact of BLV on mucosal immunity and will require further exploration in each of the various stages of disease progression.

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 El componente racial influencia la resistencia a la infección con el virus de la leucosis bovina

2018 ◽  
Vol 65 (2) ◽  
Author(s):  
Cristina Úsuga-Monroy ◽  
José Julian Echeverri ◽  
Albeiro López-Herrera
Keyword(s):  
Infection Rate ◽  
Vesicular Stomatitis Virus ◽  
Bovine Leukemia Virus ◽  
Leukemia Virus ◽  
Foot And Mouth Disease ◽  
Holstein Breed ◽  
Mouth Disease Virus ◽  
Significant Difference ◽  
Vesicular Stomatitis

The bovine leukemia virus (BLV) is a retrovirus that primarily affects dairy cattle, reducing milk production between 2.5 and 5%. The Colombian Blanco Orejinegro (BON) is a well-adapted, rustic, creole breed resistant to in vitro infections of Foot-and-mouth disease virus and vesicular stomatitis virus, as well as to Brucella abortus. This study aimed to determine if the crossing of BON and Holstein breeds is resistant to infection by BLV. Blood samples of 124 individuals (59 Holstein, 40 BON, and 25 BON x HOL) of the same herd were taken. The DNA was extracted, and a nested PCR was performed related to a region of the env gene of BLV. A fragment of 444 bp was obtained for positives animals. The molecular in-herd prevalence was 33% for BLV. A significant difference for BLV infection was found among the groups (p<0.05). The infection rate for the Holstein group was 55.9%, for BON cattle 5%, and for BON x HOL cattle 24%. The latter showed a reduction in the infection rate of 32% to the Holstein breed, which can be attributed to the presence of resistance genes in the BON breed. It was found that the level of infection is lower in BON x HOL cattle in contrast with Holstein dairy cows.

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 Antiviral Activity of Shiga Toxin 1: Suppression of Bovine Leukemia Virus-Related Spontaneous Lymphocyte Proliferation

2000 ◽  
Vol 68 (8) ◽  
pp. 4462-4469 ◽  
Author(s):  
Witold A. Ferens ◽  
Carolyn J. Hovde
Keyword(s):  
Antiviral Activity ◽  
Shiga Toxin ◽  
Bovine Leukemia Virus ◽  
Lymphocyte Proliferation ◽  
Mononuclear Cells ◽  
Leukemia Virus ◽  
Interleukin 2 ◽  
Pokeweed Mitogen ◽  
Potent Antiviral Activity ◽  
The Impact

ABSTRACT Human infections with Shiga toxin (Stx)-producing Escherichia coli (STEC) cause hemorrhagic colitis. The Stxs belong to a large family of ribosome-inactivating proteins (RIPs) that are found in a variety of higher plants and some bacteria. Many RIPs have potent antiviral activity for the plants that synthesize them. STEC strains, both virulent and nonvirulent to humans, are frequently isolated from healthy cattle. Interestingly, despite intensive investigations, it is not known why cattle carry STEC. We tested the hypothesis that Stx has antiviral properties for bovine viruses by assessing the impact of Stx type 1 (Stx1) on bovine peripheral blood mononuclear cells (PBMC) from cows infected with bovine leukemia virus (BLV). PBMC from BLV-positive animals invariably displayed spontaneous lymphocyte proliferation (SLP) in vitro. Stx1 or the toxin A subunit (Stx1A) strongly inhibited SLP. Toxin only weakly reduced the pokeweed mitogen- or interleukin-2-induced proliferation of PBMC from normal (BLV-negative) cows and had no effect on concanavalin A-induced proliferation. The toxin activity in PBMC from BLV-positive cattle was selective for viral SLP and did not abrogate cell response to pokeweed mitogen- or interleukin-2-induced proliferation. Antibody to virus or Stx1A was most effective at inhibiting SLP if administered at the start of cell culture, indicating that both reagents likely interfere with BLV-dependent initiation of SLP. Stx1A inhibited expression of BLV p24 protein by PBMC. A well-defined mutant Stx1A (E167D) that has decreased catalytic activity was not effective at inhibiting SLP, suggesting the inhibition of protein synthesis is likely the mechanism of toxin antiviral activity. Our data suggest that Stx has potent antiviral activity and may serve an important role in BLV-infected cattle by inhibiting BLV replication and thus slowing the progression of infection to its malignant end stage.

Sign in / Sign up

Export Citation Format

Share Document