scholarly journals Systemic immune responses following infection with Jaagsiekte sheep retrovirus and in the terminal stages of ovine pulmonary adenocarcinoma

2002 ◽  
Vol 83 (7) ◽  
pp. 1753-1757 ◽  
Author(s):  
Christina Summers ◽  
William Neill ◽  
Patricia Dewar ◽  
Lorenzo Gonzalez ◽  
Renate van der Molen ◽  
...  
Keyword(s):  
Pulmonary Adenocarcinoma ◽  
Pokeweed Mitogen ◽  
Blood Leukocytes ◽  
Ovine Pulmonary Adenocarcinoma ◽  
Jaagsiekte Sheep Retrovirus ◽  
Adult Sheep ◽  
Specific Pathogen ◽  
Control Adult ◽  
Cellular Immune ◽  
And Control

Jaagsiekte sheep retrovirus (JSRV) is the aetiological agent of ovine pulmonary adenocarcinoma (OPA). To monitor changes in cellular immune function during JSRV infection, lymphoproliferation in response to various mitogens was measured in the blood of conventionally housed and specific-pathogen-free lambs experimentally infected with JSRV until the development of OPA and compared with uninfected control lambs. In addition, blood samples collected from adult field cases in the terminal stages of OPA and control adult sheep were compared. No difference in the proliferative response to phytohaemagglutinin and pokeweed mitogen between the animal groups was detected. In contrast, reduced responses to concanavalin A stimulation were demonstrated in the JSRV-inoculated lambs, prior to the onset of clinical disease, and also in the terminally ill adult sheep. Peripheral blood leukocytes were monitored to identify phenotypic frequency alterations. The CD4 lymphocytopaenia and neutrophilia reported previously in adult OPA cases were demonstrated but similar phenotypic changes were not identified during experimental infection.

scholarly journals Detection of Jaagsiekte sheep retrovirus in apparently healthy sheep by real-time TaqMan PCR in comparison with histopathological findings

2016 ◽  
Vol 60 (1) ◽  
pp. 7-12 ◽  
Author(s):  
Aliasghar Bahari ◽  
Masoud Sabouri Ghannad ◽  
Omid Dezfoulian ◽  
Fereydon Rezazadeh ◽  
Ali Sadeghi-Nasab
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Mediastinal Lymph Node ◽  
Pulmonary Adenocarcinoma ◽  
Ovine Pulmonary Adenocarcinoma ◽  
Jaagsiekte Sheep Retrovirus ◽  
Tissue Samples ◽  
Blood Samples ◽  
Proviral Dna ◽  
Healthy Sheep

Abstract Introduction: The aim of this study was to use TaqMan real-time PCR technique to investigate Jaagsiekte sheep retrovirus (JSRV) proviral DNA in whole blood samples of sheep, and compare the results to those of histopathological examinations. Material and Methods: Eighty blood samples from clinically healthy sheep were randomly collected before the animals were slaughtered. Ten tissue samples from each lung and associated caudal mediastinal lymph node were taken. Results: Fifteen (18.75%) blood samples were found to contain proviral DNA, and 11 (13.75%) corresponding lung samples showed microscopic changes consistent with ovine pulmonary adenocarcinoma. None of the samples displayed metastases to the caudal mediastinal lymph nodes. The prominent pattern of neoplastic nodules consisted of acinar (alveolar) form. Conclusion: The results indicated the higher sensitivity of real-time PCR compared to histopathological examinations in detection of ovine pulmonary adenocarcinoma.

scholarly journals The Diagnostic Challenges of Ovine Pulmonary Adenocarcinoma

Ruminants ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 58-71
Author(s):  
Hélder Quintas ◽  
Isabel Pires ◽  
Andreia Garcês ◽  
Justina Prada ◽  
Filipe Silva ◽  
...  
Keyword(s):  
Clinical Signs ◽  
Pulmonary Adenocarcinoma ◽  
Diagnostic Methods ◽  
Control Measures ◽  
Economic Losses ◽  
Ovine Pulmonary Adenocarcinoma ◽  
X Ray ◽  
Club Cells ◽  
Pulmonary Adenomatosis ◽  
And Control

Ovine pulmonary adenocarcinoma (OPA), also known as sheep pulmonary adenomatosis and jaagsiekte, is a contagious pulmonary tumor of sheep, characterized by neoplastic proliferation of type II pneumocyte and club cells. OPA is induced by the oncogenic activity of the envelope glycoprotein (Env) of exogenous jaagsiekte sheep retrovirus (JSRV). This disease is associated with significant economic losses in numerous sheep raising countries. The onset of suggestive clinical signs is often late, making difficult the early diagnosis of the disease and timely implementation of control measures on the affected farms. Further, the lack of diagnostic tests that can be performed routinely by veterinary clinicians to accurately assess infected animals (e.g., serological or others) means that the true prevalence at flock level is not known. Imaging diagnostic methods (e.g., ultrasound, X-ray and computed tomography) can be used to support the clinical diagnosis, even in pre-clinical stages in affected flocks. The diagnosis must be confirmed by PCR of nasal excretions or immunohistochemistry and PCR of tumor lesions. No vaccine for OPA has yet been developed. Thus, in this work, we review the main methods of diagnosis of OPA in order to support the clinician in the identification of the disease, avoid underdiagnosis and allow the implementation of suitable measures to prevent and control its spread.

scholarly journals Successful induction of ovine pulmonary adenocarcinoma in lambs of different ages and detection of viraemia during the preclinical period

2004 ◽  
Vol 85 (11) ◽  
pp. 3319-3324 ◽  
Author(s):  
Daniela Salvatori ◽  
Lorenzo González ◽  
Patricia Dewar ◽  
Christina Cousens ◽  
Marcelo de las Heras ◽  
...  
Keyword(s):  
Age Groups ◽  
Clinical Signs ◽  
Pulmonary Adenocarcinoma ◽  
Target Cells ◽  
Ovine Pulmonary Adenocarcinoma ◽  
Lung Fluid ◽  
Successful Induction ◽  
Neonatal Lambs ◽  
And Control ◽  
Intratracheal Injection

Ovine pulmonary adenocarcinoma (OPA) can be reproduced consistently in neonatal lambs by intratracheal injection of inocula containing jaagsiekte sheep retrovirus (JSRV). In this study, clinical disease, confirmed pathologically as OPA, was induced in a high proportion of lambs that had been inoculated intratracheally with infectious lung fluid at 1, 3 and 6 months of age. The incubation periods, however, were longer in these three age groups than in 1-week-old lambs that were used as controls. Viraemia was detected in all age groups before onset of clinical signs, but occurred later in older animals. These results suggest an age-dependent susceptibility to OPA that could be determined by the availability of JSRV target cells in the ovine lung. The feasibility of inducing OPA in older lambs and detecting JSRV viraemia in preclinical stages enables improved studies on the pathogenesis, assessment of vaccines, diagnosis and control of the disease.

scholarly journals Alveolar Type II Cells Expressing Jaagsiekte Sheep Retrovirus Capsid Protein and Surfactant Proteins Are the Predominant Neoplastic Cell Type in Ovine Pulmonary Adenocarcinoma

2002 ◽  
Vol 39 (3) ◽  
pp. 341-352 ◽  
Author(s):  
J. A. Platt ◽  
N. Kraipowich ◽  
F. A. Villafane ◽  
J. C. DeMartini
Keyword(s):  
Tumor Cells ◽  
Capsid Protein ◽  
Surfactant Protein ◽  
Neoplastic Cell ◽  
Pulmonary Adenocarcinoma ◽  
Clara Cell ◽  
Alveolar Type ◽  
Type Ii ◽  
Ovine Pulmonary Adenocarcinoma ◽  
Jaagsiekte Sheep Retrovirus

Ovine pulmonary adenocarcinoma is caused by jaagsiekte sheep retrovirus. To gain insight into the histogenesis and viral pathogenesis of this neoplasm, the tumor cell phenotypes and differentiation state were correlated with the distribution of jaagsiekte sheep retrovirus capsid protein in neoplastic and normal cells of the lung in nine naturally occurring and 12 experimentally induced cases of ovine pulmonary adenocarcinoma. Overall, 82% of tumor cells had ultrastructural features consistent with alveolar type II cells, 7% of tumor cells had features of Clara cells, and 11% of tumor cells were insufficiently differentiated to classify. The proportion of the neoplastic cell phenotypes varied within tumors, and no tumor consisted of a morphologically uniform cell population. To further characterize the neoplastic cell population, sections of tumors were immunostained with antibodies to surfactant protein A, surfactant protein C, and Clara cell 10-kd protein. Overall, surfactant proteins A and C were expressed in 70% and 80% of tumor cells, respectively, whereas Clara cell 10-kd protein was expressed in 17% of tumor cells. Jaagsiekte sheep retrovirus capsid protein was detected in 71% of tumor cells and in macrophages (5/21 tumors examined) and in nonneoplastic alveolar and bronchiolar cells (6/14 tumors). Expression of this viral protein in neoplastic cells, classified morphologically and by immunophenotyping primarily as of the alveolar type II lineage, implies an important role for specific virus–cell interactions in the pathogenesis of ovine pulmonary adenocarcinoma.

scholarly journals Ovine pulmonary adenocarcinoma diagnosis and control in practice

Livestock ◽  
2020 ◽  
Vol 25 (4) ◽  
pp. 191-195
Author(s):  
Davinia Hinde ◽  
Mike Evans ◽  
Phil Scott
Keyword(s):  
Economic Impact ◽  
Case Studies ◽  
Pulmonary Adenocarcinoma ◽  
Control Methods ◽  
Ovine Pulmonary Adenocarcinoma ◽  
Potential Control ◽  
Commercial Farms ◽  
And Control

This article discusses the diagnosis and control of ovine pulmonary adenocarcinoma (OPA), an ‘iceberg disease’ which can have both a large economic impact on flocks, and a damaging effect on the reputation of flocks supplying animals for breeding purposes. The potential control methods and their limitations are discussed, and two case studies illustrate how they have been applied by mixed practitioners working on commercial farms.

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