Jaagsiekte Research Articles

Jaagsiekte sheep retrovirus infection of lung slice cultures.

BackgroundJaagsiekte sheep retrovirus (JSRV) is the causative agent of ovine pulmonary adenocarcinoma (OPA), a transmissible neoplastic disease of sheep. OPA is an economically important veterinary disease and is also a valuable naturally occurring animal model of human lung cancer, with which it shares a similar histological appearance and the activation of common cell signaling pathways. Interestingly, the JSRV Env protein is directly oncogenic and capable of driving cellular transformation in vivo and in vitro. Previous studies of JSRV infection in cell culture have been hindered by the lack of a permissive cell line for the virus. Here, we investigated the ability of JSRV to infect slices of ovine lung tissue cultured ex vivo.ResultsWe describe the use of precision cut lung slices from healthy sheep to study JSRV infection and transformation ex vivo. Following optimization of the culture system we characterized JSRV infection of lung slices and compared the phenotype of infected cells to natural field cases and to experimentally-induced OPA tumors from sheep. JSRV was able to infect cells within lung slices, to produce new infectious virions and induce cell proliferation. Immunohistochemical labeling revealed that infected lung slice cells express markers of type II pneumocytes and phosphorylated Akt and ERK1/2. These features closely resemble the phenotype of natural and experimentally-derived OPA in sheep, indicating that lung slice culture provides an authentic ex vivo model of OPA.ConclusionsWe conclude that we have established an ex vivo model of JSRV infection. This model will be valuable for future studies of JSRV replication and early events in oncogenesis and provides a novel platform for studies of JSRV-induced lung cancer.

Prevalence of ovine pulmonary adenocarcinoma (Jaagsiekte) in a UK slaughterhouse sheep study

Jaagsiekte sheep retrovirus (JSRV) causes ovine pulmonary adenocarcinoma (OPA or Jaagsiekte), a disease of increasing concern to sheep farmers. It is an infectious lung cancer caused by viral transformation of...

Histopathological and ultra structural studies of ovine pulmonary adenocarcinoma (Jaagsiekte)

The Ovine Pulmonary adenocarcinoma (OPA) is also known as Jaagsiekte, is a contagious transmissible lung tumor of sheep caused by Jaagsiekte Sheep Retrovirus (JSRV). In the present study, 3698 lungs collected from slaughtered sheep in and around Tirupati, AP, India and examined morphologically. 396 lungs were showed different pneumonic lesions. Among 396 lung lesions 39 (9.85%) were diagnosed as Pulmonary adenocarcinoma. Grossly, all the lungs congested, increase in size, weight and oedematous. Consistency varied from granular to meaty appearance and many of them revealed nodules ranging from very small to 2.5 cm in diameter and serous exudate on cut surface of lung. Histologically, Papillary projections of epithelium into either alveolar or bronchiolar lumen. Intra alveolar fibrosis was prominent in many cases. Alveolar macrophages were consistently found within alveolar spaces. OPA also associated with different types of pneumonias. Ultrastructurally, proliferation of type II pneumocytes (Type B cells) having microvilli and well developed junctional complexes. Non ciliated bronchiolar epithelial cells (Clara cells) with electron dense cytoplasmic granules without any surrounding membrane and microvilli and no virus particles were traced.

Detection of exogenous Jaagsiekte sheep retrovirus in Turkey

The aim of this study is to detect the exogenous Jaagsiekte sheep retrovirus (exJSRV) in suspected cases of ovine pulmonary adenocarcinoma (OPA) from the Eastern Anatolian region of Turkey. Pathological examination and PCR were carried out with the lung, lymph nodule, brain, heart and liver tissues of four sheep with suspected OPA. Histology of the lung sections indicated the well-circumscribed, multifocal and unencapsulated gray to white masses (arrows) on the parietal surface of medial and caudal lobes. exJSRV was detected in all tissue samples except for brain by nested polymerase chain reaction (nPCR). In addition to the nested-PCR results, the presence of exJSRV into the clinical samples was confirmed with sequencing of two PCR-positive products for OPAV. This report highlights the first presence of exJSRV in the sheep suspected with OPA in Turkey. Furthermore, the results provide supporting evidence for the metastasis of exJSRV in extra-thoracic tissues.

Evolutionary dynamics of endogenous Jaagsiekte sheep retroviruses proliferation in the domestic sheep, mouflon and Pyrenean chamois

The oncogenic exogenous Jaagsiekte sheep retrovirus (JSRV), responsible for ovine pulmonary adenocarcinoma, has several endogenous counterparts termed enJSRVs. Although many of these elements have been inactivated over time by the accumulation of deleterious mutations or internal recombination leading to solo long terminal repeat (LTR) formation, several members of enJSRVs have been identified as nearly intact and probably represent recent integration events. To determine the level of enJSRV polymorphism in the sheep population and related species, we have undertaken a study by characterizing enJSRVs copies and independent integration sites in six domestic sheep and two wild species of the sheep lineage. enJSRVs copies were detected by amplifying the env-LTR region by PCR, and for the detection of the insertion sites, we used two approaches: (1) an in silico approach based on the recently published Sheep Reference Genome Assembly (OARv3.0) and (2) an experimental approach based on PCR suppression and inverse PCR techniques. In total, 103 enJSRV sequences were generated across 10 individuals and enJSRV integrations were found on 11 of the 28 sheep chromosomes. These findings suggest that there are still uncharacterized enJSRVs, and that some of the integration sites are variable among the different species, breeds of the same species, subspecies and geographic locations.

Jaagsiekte sheep retrovirus detected in human lung cancer tissue arrays

BackgroundAdenocarcinoma is the most common type of non-small cell lung cancer and is frequently observed in non-smoking patients. Adenocarcinoma in-situ (formerly referred to as bronchioloalveolar carcinoma) is a subset of lung adenocarcinoma characterized by growth along alveolar septae without evidence of stromal, vascular, or pleural invasion, that disproportionately affects never-smokers, women, and Asians. Adenocarcinoma in-situ is morphologically and histologically similar to a contagious lung neoplasm of sheep called ovine pulmonary adenocarcinoma (OPA). OPA is caused by infection with the exogenous betaretrovirus, jaagsiekte sheep retrovirus (JSRV), whose envelope protein (Env) is a potent oncogene. Several studies have reported that a proportion of human lung adenocarcinomas are immunopositive for an antigen related to the Gag protein of JSRV, however other groups have been unable to verify these observations by PCR.MethodsHere we examine human lung cancer tissue arrays (TA) for evidence of JSRV Env protein and DNA by immunohistochemical staining and PCR, respectively.ResultsOur results reveal that a subset of human lung cancers express an antigen that reacts with a JSRV Env-specific monoclonal antibody in immunohistochemistry and that exogenous JSRV-like env and gag sequences can be amplified from TA tumor samples, albeit inefficiently.ConclusionsWhile a causative role has not been established, these data suggest that a JSRV-like virus might infect humans. With next generation sequencing approaches, a JSRV-like virus in human lung cancers may be identified which could have profound implications for prevention, diagnosis and therapy.

Natural ovine pulmonary adenocarcinoma in an Egyptian sheep farm

Ovine pulmonary adenocarcinoma is a naturally occurring retrovirus-induced contagious lung neoplasm in sheep. The current report aims to describe clinical and histopathological characteristics of the disease in an Egyptian sheep farm. In which, 4 dead and 5 sick young sheep were subjected to clinical, gross and histopathological examinations. For histopathological examination, tissue specimens were taken from lungs, mediastinal lymph nodes, liver, heart, kidneys and brain, fixed in 10% neutral buffered formalin and processed for light microscopy. Examined animals showed release of copious amount of mucoid fluid from their nostrils and marked loss of body weight. At necropsy, there were many solid grayish nodules exuding frothy fluid in the lungs and accumulation of mucoid fluid in the pleural cavity. Histopathological examination revealed presence of many nonencapsulated neoplastic foci originating from the alveolar epithelial lining. Neoplastic foci consisted of cuboidal and columnar cells that arranged in papillary and acinar forms. Proliferating cells appeared supported by loose connective tissue containing some fibroblasts and small blood vessels. Prominently, there was large number of swollen and ruffled macrophages in alveolar spaces adjacent to neoplastic foci. In conclusions, release of copious amount of mucoid fluid from nostrils and transformation of alveolar epithelial lining into cuboidal and columnar cells are pathognomonic for ovine pulmonary adenocarcinoma.

Ovine pulmonary adenocarcinoma in slaughtered sheep: a pathological and polymerase chain reaction study.

Ovine pulmonary adenocarcinoma (OPA) is a contagious tumour in sheep caused by jaagsiekte sheep retrovirus (JSRV). This tumour originates from the pneumocyte type II and Clara cells and grossly appears as hard, prominent nodules in different lobes. The clinical signs of the disease are similar to those of other chronic respiratory diseases and are not pathogonomic. Therefore, post mortem examinations and histopathological studies are the most reliable ways to diagnose OPA, particularly subclinical cases of this neoplasm. In this study, out of 1000 sheep lungs grossly inspected, 50 animals were suspected of OPA. The suspected lungs as well as 25 apparently normal lungs were examined by histopathological and PCR methods. The proviral DNA was detected in 1/25 apparently normal lungs and 8/50 of the suspected lungs and subsequently confirmed by histopathological studies. The PCR-positive lung samples from five sheep revealed lesions of 'atypical' OPA and those from three sheep showed the 'classic' form of the disease. The tumours were multifocal and the masses were distributed throughout the cranioventral and diaphragmatic lung lobes. The stroma of the tumours in the atypical cases was more severely affected with inflammatory cell infiltration and connective tissue proliferation. The histopathological characteristics of maedi including hyperplasia of the perivascular and peribronchiolar lymphoid cells, interstitial lymphoplasmacytic infiltration and smooth muscle hyperplasia were also associated with OPA, especially the atypical form of this adenocarcinoma. Atypical OPA was more prevalent than the classic form. Geographic and climatic conditions, duration of exposure to the virus and the immune status of individual animals might be responsible for the differences between the two pathological entities of OPA.

Nucleotide Sequencing and Phylogenetic Analysis Using PCR Amplicons of U3 Gene of Jaagsiekte Sheep Retrovirus (JSRV) Detected in Natural Cases of Ovine Pulmonary Adenocarcinoma in India

Ovine pulmonary adenocarcinoma (OPA) caused by an exogenous Jaagsiekte sheep retrovirus (JSRV) is prevalent in Indian sheep. In the present study, OPA was diagnosed in sheep by clinical signs, gross and histopathology and polymerase chain reaction (PCR). Proviral DNA of exogenous JSRV was detected in lung tumor tissues, mediastinal lymph nodes, blood and lung fluid samples from natural cases of OPA by using U3-hn PCR and the PCR amplicons were sequenced to analyze nucleotide divergence. In total, six isolates were sequenced that had 96% - 100% homology with a UK strain (AF105220.1) but more divergent from a South African strain (M80216) with 88% - 93% identity. The phylogenetic analysis revealed segregation of the six isolates into two clusters. In conclusion, this study is the first report on sequencing and phylogenetic analysis of JSRV in India and further studies are suggested to know the complete sequencing and genetic divergence of JSRV in Indian sheep.

Antibiotic Treatment Response of Chronic Lung Diseases of Adult Sheep in the United Kingdom Based upon Ultrasonographic Findings.

Examination of the lungs of adult sheep with chronic respiratory diseases was readily achieved using both 5 MHz linear and sector scanners. Superficial lung abscesses in eight sheep appeared as anechoic areas containing multiple hyperechoic dots bordered distally by a broad hyperechoic capsule. Unilateral fibrinous pleurisy (2 sheep) appeared as an anechoic area containing a hyperechoic latticework. Ovine pulmonary adenocarcinoma (OPA) lesions appeared as sharply demarcated hypoechoic areas in the lung parenchyma initially in the cranioventral lung lobes (21 sheep) with lesions also present in the caudodorsal diaphragmatic lobe (11 sheep); abscesses and areas of calcification within the OPA tumour mass were also identified. Daily treatment with procaine penicillin for 30 consecutive days was successful in both sheep with unilateral fibrinous pleurisy and six sheep identified with superficial lung abscesses measuring 2–8 cm in diameter; only one of two sheep with more extensive lesions recovered. Auscultation of the chest failed to detect adventitious sounds in any of the ten sheep with lung abscesses; normal breath sounds were reduced over the area of fibrinous pleurisy; no pleuritic rubs were heard. Wheezes and crackles auscultated in some OPA cases and did not correlate well with lesions detected ultrasonographically.

Incidence of ovine pulmonary adenocarcinoma in southern parts of India: A slaughter house based study

Ovine pulmonary adenocarcinoma (OPA) or ovine pulmonary carcinomatosis (previously known as ovine pulmonary adenomatosis) is a contagious tumour forming viral disease caused by the genus beta-retrovirus of retroviridae (jaagsiekte sheep retrovirus). This study was aimed to understand the prevalence of disease in the locality based on histopathological diagnosis and its correlation with age, sex and breed. Out of 903 sheep carcasses examined, OPA was recorded in 44 cases accounting to 4.87%. The gross lesions varied from multifocal greyish nodules to complete consolidation of the lung parenchyma. Histologically, there were single to multiple layers of cuboidal to columnar epithelial cells giving adenomatous appearance. The cuboidal or columnar tumour cells replaced the normal alveolar epithelia and in some cases it formed into papilliform growths that projected into the alveoli. The peribronchial and peribronchiolar lymphoid aggregates were consistent features in most of the cases studied. Argyrophilic nucleolar organizer regions (AgNORs) were counted in representative cases of nodular and consolidated forms of adenocarcinomatosis to assess the rate of cell proliferation. The average AgNOR counts per nucleus were 4.672 ± 0.68 and 3.086 ± 0.537 for nodular and consolidated forms respectively.

Overexpression of Cytokeratin 19, Aldolase A and Manganese Superoxide Dismutase in Ovine Pulmonary Adenocarcinoma

Overexpression of Cytokeratin 19, Aldolase A and Manganese Superoxide Dismutase in Ovine Pulmonary Adenocarcinoma

Solitary Tumours Associated with Jaagsiekte Retrovirus in Sheep are Heterogeneous and Contain Cells Expressing Markers Identifying Progenitor Cells in Lung Repair

Ovine pulmonary adenocarcinoma (OPA) is a naturally occurring lung cancer of sheep caused by jaagsiekte sheep retrovirus (JSRV). This study examines immunohistochemically solitary lung nodules considered as early OPA lesions from 11 sheep infected naturally by JSRV. All 11 neoplastic nodules exhibited features of adenocarcinoma and in four of them mesenchymal growth was also observed. Both types of lesion were labelled with antibody specific for JSRV-Env. In two cases infiltrating lymphoreticular cells also contained JSRV-Env. All tumours had a high Ki67 labelling index and variably contained cells expressing CC10 (a marker of Clara cells (CCs)), SPC (a marker of type II pneumocytes), p63 and keratin 14 (markers for stem/progenitor cells of the lung airway epithelia). Tumours with mesenchymal growth had intense expression of vimentin and desmin, weak expression of smooth muscle actin and did not express pancytokeratin and p63. Both epithelial and mesenchymal proliferations did not express the stem cell markers CD90 and CD117, but some tumour infiltrating cells expressed CD133. Solitary OPA tumours can therefore be adenocarcinomas or mixed tumours and have a heterogeneous cellular composition, containing groups of cells expressing markers that characterize local progenitor cells involved in lung repair.

Diagnosis and phylogenetic analysis of ovine pulmonary adenocarcinoma in China.

Ovine pulmonary adenocarcinoma (OPA) is a lung tumor of sheep caused by jaagsiekte sheep retrovirus (JSRV). OPA is common in sheep, and it is most commonly observed in China. Without preventative vaccines and serological diagnostic tools for assay of OPA, identification of JSRV based on reverse transcription polymerase chain reaction (RT-PCR) is very important for prevention and control measures for OPA in practice management. In this study, the diagnosis of OPA was made from analysis of clinical signs, pathological observations, JSRV-like particle discovery, and RT-PCR of the target env gene. The phylogenetic analysis showed that the China Shandong (SD) strain studied in this article belonged to exogenous JSRV, and it was very similar to 92k3, which was isolated from sheep in the Kenya (Y18305). The current study reported a severe outbreak of OPA in Shandong Province, China. The observations could offer a comparative view of the env gene of JSRV.

Host Species Barriers to Jaagsiekte Sheep Retrovirus Replication and Carcinogenesis

Understanding the factors governing host species barriers to virus transmission has added significantly to our appreciation of virus pathogenesis. Jaagsiekte sheep retrovirus (JSRV) is the causative agent of ovine pulmonary adenocarcinoma (OPA), a transmissible lung cancer of sheep that has rarely been found in goats. In this study, in order to further clarify the pathogenesis of OPA, we investigated whether goats are resistant to JSRV replication and carcinogenesis. We found that JSRV induces lung tumors in goats with macroscopic and histopathological features that dramatically differ from those in sheep. However, the origins of the tumor cells in the two species are identical. Interestingly, in experimentally infected lambs and goat kids, we revealed major differences in the number of virus-infected cells at early stages of infection. These differences were not related to the number of available target cells for virus infection and cell transformation or the presence of a host-specific immune response toward JSRV. Indeed, we also found that goats possess transcriptionally active endogenous retroviruses (enJSRVs) that likely influence the host immune response toward the exogenous JSRV. Overall, these results suggest that goat cells, or at least those cells targeted for viral carcinogenesis, are not permissive to virus replication but can be transformed by JSRV.

Diagnosis and control of ovine pulmonary adenocarcinoma (Jaagsiekte)

Ovine pulmonary adenocarcinoma (OPA) is a contagious tumour of the lungs of sheep. It is also commonly known as Jaagsiekte, ovine pulmonary carcinoma or sheep pulmonary adenomatosis. OPA is generally...

Long-term study of ovine pulmonary adenocarcinogenesis in sheep with marginal vs. sufficient nutritional selenium supply: Results from computed tomography, pathology, immunohistochemistry, JSRV-PCR and lung biochemistry

The impact of selenium (Se) in carcinogenesis is still debatable due to inconsistent results of observational studies, recent suspicion of diabetic side effects and e.g. dual roles of glutathione peroxidases (GPx). Previously, our group introduced long-term studies on lung carcinogenesis using the jaagtsiekte sheep retrovirus (JSRV) induced ovine pulmonary adenocarcinoma (OPA) as an innovative animal model. The present report describes the results of sufficient (0.2mg Se/kg dry weight (dw)) vs. marginal (<0.05mg Se/kg dw) nutritional Se supply on cancer progression over a two-year period in 16 animals. Computed tomography (CT) evaluation of lung cancer progression, final pathological examination, evidence of pro-viral JSRV-DNA in lung, lymph nodes and broncho-alveolar lavage cells as well as biochemical analysis of Se, GPx1 and thioredoxin reductase (TrxR) activity in lung tissue were recorded. Additionally, immunohistochemical determination of GPx1 expression in unaffected and neoplastic lung cells was implemented.The feeding regime caused significant differences in Se concentration and GPx1 activity in lung tissue between groups, whereas TrxR activity remained unaffected. JSRV was evident in broncho-alveolar lavage cells, lung tissue and lung lymph nodes. Quarterly executed CT could not demonstrate differences in lung cancer proliferation intensity. Necropsy and histopathology substantiated CT findings. Immunohistochemical analysis of GPx1 in lung tissue suggested a coherency of GPx1 immunolabelling intensity in dependence of tumour size.It was concluded that the model proved to be suitable for long-term studies of lung cancer proliferation including the impact of modifiable nutritional factors. Proliferation of OPA was unaffected by marginal vs. sufficient nutritional Se supply.

Precision-cut Lung Slices to Study the Pathogenesis of Ovine Pulmonary Adenocarcinoma

Precision-cut Lung Slices to Study the Pathogenesis of Ovine Pulmonary Adenocarcinoma

Histopathological study of naturally occurring ovine pulmonary adenocarcinoma in native goat in Khuzestan, Iran

Histopathological study of naturally occurring ovine pulmonary adenocarcinoma in native goat in Khuzestan, Iran

Adeno-Associated Virus Vector Mediated Expression of an Oncogenic Retroviral Envelope Protein Induces Lung Adenocarcinomas in Immunocompetent Mice

Lung cancer is the most common cause of cancer-related death worldwide. A poor overall survival rate of 16% necessitates the need for novel treatment strategies. Mouse models of lung cancer are important tools for analyzing the significance of somatic mutations in the initiation and progression of lung cancer. Of additional importance, however, are animal models of virally induced cancers. JSRV is a simple betaretrovirus that causes contagious lung cancer in sheep known as ovine pulmonary adenocarcinoma and closely resembles human lung adenocarcinoma. Previously we showed that expression of the JSRV envelope (Env) from an AAV vector induced lung tumors in immunodeficient mice, but not in immunocompetent mice. Because of the importance of studying lung cancer in the context of an intact immune system we sought to improve our mouse model. In this report, we employed the use of a strong JSRV enhancer-promoter combination to express Env at high levels and demonstrate for the first time, lung tumor induction in immunocompetent mice. This occurred despite a robust Env-specific antibody-mediated immune response. The PI3K/Akt and MAPK pathways were activated in both immunocompetent and immunodeficient mice, however, differential activation of PTEN, GSKα, p70S6K, p38MAPK, ATF2 and STAT5 was observed. A JSRV Env lung tumor-derived cell line was shown to have a similar signal transduction activation profile as Env-induced lung tumors in C57BL/6 mice. Given the similarities between our model and pulmonary adenocarcinomas in humans, and the ease with which tumors can be induced in any transgenic mouse, this system can be used to uncover novel mechanisms involved lung tumorigenesis.