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Ovine pulmonary adenocarcinoma (OPA) is an important viral-induced neoplasia in sheep caused by exogenous Jaagsiekte sheep retrovirus (exJSRV). Coinfection of exJSRV and Maedi-Visna virus (MVV) is reported in OPA cases, but its worldwide distribution and significance on lung pathology is not yet completely understood. This study aimed to investigate the MVV coinfection rate in 82 exJSRV-related OPA cases, and their pathological effects on lung parenchyma in slaughtered sheep in Transylvania (Romania). On gross examination, classical form of OPA was identified in 92.7%; no changes consisting with MVV interstitial pneumonia were identified in the included cases. The most common histological type of OPA was acinar (58.5%) and the myxoid growths were found in 18 cases. The exJSRV and MMV coinfection rate in examined sheep was 47.6% (39/82). The assessment of perineoplastic areas from coinfected animals, revealed interstitial lymphoplasmacytic infiltrates in all cases, lymphoid hyperplasia in 60.6% cases (20/33) and fibromuscular hyperplasia in 63.7% (21/33). This is the first report providing new data on distribution of OPA coexisting with MVV infection in slaughtered sheep in Romania. We consider that the OPA and MVV coinfection may play an important role on the severity of ovine chronic pulmonary diseases and further studies are needed to confirm this hypothesis. [ABSTRACT FROM AUTHOR]

Simple Summary: In this study, a Common Objects in Context dataset of ovine pulmonary adenocarcinoma pathological images was constructed based on 7167 annotated typical lesions from 61,063 lung pathological images of ovine pulmonary adenocarcinoma. This study aimed to develop a mask regional convolutional neural network model for the localization and pathological diagnosis of ovine pulmonary adenocarcinoma lesions. The model achieved a mean average specificity of 0.573 and an average sensitivity of 0.745, with consistency rates of 100% for junior pathologists and 96.5% for senior pathologists in the diagnosis of ovine pulmonary adenocarcinoma. The successful development of this model not only facilitates the rapid diagnosis of ovine pulmonary adenocarcinoma by different personnel in practical applications but also lays a foundation for the transition from traditional pathology to digital pathology in the livestock industry. Ovine pulmonary adenocarcinoma (OPA) is a contagious lung tumour caused by the Jaagsiekte Sheep Retrovirus (JSRV). Histopathological diagnosis is the gold standard for OPA diagnosis. However, interpretation of traditional pathology images is complex and operator dependent. The mask regional convolutional neural network (Mask R-CNN) has emerged as a valuable tool in pathological diagnosis. This study utilized 54 typical OPA whole slide images (WSI) to extract 7167 typical lesion images containing OPA to construct a Common Objects in Context (COCO) dataset for OPA pathological images. The dataset was categorized into training and test sets (8:2 ratio) for model training and validation. Mean average specificity (mASp) and average sensitivity (ASe) were used to evaluate model performance. Six WSI-level pathological images (three OPA and three non-OPA images), not included in the dataset, were used for anti-peeking model validation. A random selection of 500 images, not included in the dataset establishment, was used to compare the performance of the model with assessment by pathologists. Accuracy, sensitivity, specificity, and concordance rate were evaluated. The model achieved a mASp of 0.573 and an ASe of 0.745, demonstrating effective lesion detection and alignment with expert annotation. In Anti-Peeking verification, the model showed good performance in locating OPA lesions and distinguished OPA from non-OPA pathological images. In the random 500-image diagnosis, the model achieved 92.8% accuracy, 100% sensitivity, and 88% specificity. The agreement rates between junior and senior pathologists were 100% and 96.5%, respectively. In conclusion, the Mask R-CNN-based OPA diagnostic model developed for OPA facilitates rapid and accurate diagnosis in practical applications. [ABSTRACT FROM AUTHOR]

Ovine pulmonary adenocarcinoma (OPA) is a contagious respiratory tumor of small ruminants, manifesting in chronic weight loss and respiratory failure. Infection with the betaretrovirus jaagsiekte sheep retrovirus (JSRV) is the cause of OPA. Here, we describe the gross and microscopic features of twenty-six sheep and one goat with naturally occurring JSRV-associated OPA. All the animals included in this study had pulmonary lesions morphologically consistent with OPA, but the majority of the observed lesions demonstrated features of both the classical and the atypical form of OPA, and were, therefore, classified grossly as mixed. The gross lesions were located mainly in the cranial pulmonary lobes, were multifocal to coalescing, variable in number and size, flat to slightly raised, firm, and white to grey. Histologically, the cases were classified according to the predominant architectural patterns as lepidic, papillary, acinar, or mixed; the mixed histological pattern was the most prevalent. The aim of this study was to describe the gross and microscopic spectrum of OPA in naturally infected small ruminants from Spain. The mixed form of OPA is less commonly reported, and can be confused with other concurrent pulmonary pathologies (such as BALT hyperplasia in SRLV-associated pneumonia or lungworm granulomas).

Ovine pulmonary adenocarcinoma (OPA) is an infectious, neoplastic lung disease of sheep that causes significant animal welfare and economic issues throughout the world. Understanding OPA pathogenesis is key to developing tools to control its impact. Central to this need is the availability of model systems that can monitor and track events after Jaagsiekte sheep retrovirus (JSRV) infection. Here, we report the development of an experimentally induced OPA model intended for this purpose. Using three different viral dose groups (low, intermediate and high), localised OPA tumour development was induced by bronchoscopic JSRV instillation into the segmental bronchus of the right cardiac lung lobe. Pre-clinical OPA diagnosis and tumour progression were monitored by monthly computed tomography (CT) imaging and trans-thoracic ultrasound scanning. Post mortem examination and immunohistochemistry confirmed OPA development in 89% of the JSRV-instilled animals. All three viral doses produced a range of OPA lesion types, including microscopic disease and gross tumours; however, larger lesions were more frequently identified in the low and intermediate viral groups. Overall, 31% of JSRV-infected sheep developed localised advanced lesions. Of the sheep that developed localised advanced lesions, tumour volume doubling times (calculated using thoracic CT 3D reconstructions) were 14.8 ± 2.1 days. The ability of ultrasound to track tumour development was compared against CT; the results indicated a strong significant association between paired CT and ultrasound measurements at each time point (R2 = 0.799, p < 0.0001). We believe that the range of OPA lesion types induced by this model replicates aspects of naturally occurring disease and will improve OPA research by providing novel insights into JSRV infectivity and OPA disease progression. [ABSTRACT FROM AUTHOR]

Ovine pulmonary adenocarcinoma (OPA) is an important viral-induced neoplasia in sheep caused by exogenous Jaagsiekte sheep retrovirus (exJSRV). Coinfection of exJSRV and Maedi-Visna virus (MVV) is reported in OPA cases, but its worldwide distribution and significance on lung pathology is not yet completely understood. This study aimed to investigate the MVV coinfection rate in 82 exJSRV-related OPA cases, and their pathological effects on lung parenchyma in slaughtered sheep in Transylvania (Romania). On gross examination, classical form of OPA was identified in 92.7%; no changes consisting with MVV interstitial pneumonia were identified in the included cases. The most common histological type of OPA was acinar (58.5%) and the myxoid growths were found in 18 cases. The exJSRV and MMV coinfection rate in examined sheep was 47.6% (39/82). The assessment of perineoplastic areas from coinfected animals, revealed interstitial lymphoplasmacytic infiltrates in all cases, lymphoid hyperplasia in 60.6% cases (20/33) and fibromuscular hyperplasia in 63.7% (21/33). This is the first report providing new data on distribution of OPA coexisting with MVV infection in slaughtered sheep in Romania. We consider that the OPA and MVV coinfection may play an important role on the severity of ovine chronic pulmonary diseases and further studies are needed to confirm this hypothesis.

Ovine pulmonary adenocarcinoma (OPA) is a contagious neoplastic disease caused by jaagsiekte sheep retrovirus (JSRV) and is characterized by chronic respiratory clinical signs. In this study we describe intrathoracic and extrathoracic metastases in Pırlak ewes naturally infected with JSRV. Two Pırlak sheep flocks brought from two different provinces had progressive respiratory distress, nasal discharge, cough, and emaciation, and nine ewes from these two flocks were necropsied at the request of the owners. Gross findings revealed purple colored and consolidated cranioventral lung lobes with scattered white nodules of various sizes. One ewe had metastasis in the mediastinal lymph node, and another had metastasis in the left kidney. Histopathological examinations of the tumors in the lungs and metastases showed papillary and acinary growth patterns. Immunohistochemically, strong JSRV-Env expression was observed in neoplastic cells.

The study was conducted from 2017 to 2021 in sheep and goat population from Krishna, Guntur and Chittoor districts of Andhra Pradesh. A total of 1256 clinically unhealthy animals out of which 420 animals were manifested respiratory emaciated symptoms based on wheelbarrow test, all aged between 3 months to 4 years. Molecular diagnosis confirmed 38 samples out of 420 samples confirmed by wheelbarrow test. The prevalence rate of JSRV induced OPA is 3.02 % the less infection rate was observed in male as compared to females’ animals and this prevalence during the late winter seasons. The size of 7462 bp genome was sequenced from pathomorphological diversified animal lung sample. The genomic analysis reveals a total of 506 SNPs variants were recorded. The phylogenetic studies reveal, the isolated strain is very similar to South African strains but it diversified from UK and China strain. The structural and functional assessment studies based on derived amino acid sequence showed nonsignificant changes in 3D structures of proteins encoded by the JSRV genome. The substitution mutations both at Nucleotide and Amino acid sequence level suggest neutral evolution and they are under minimal evolutionary pressure.

Ovine pulmonary adenocarcinoma (OPA) is a contagious lung tumour caused by the Jaagsiekte Sheep Retrovirus (JSRV). Histopathological diagnosis is the gold standard for OPA diagnosis. However, interpretation of traditional pathology images is complex and operator dependent. The mask regional convolutional neural network (Mask R-CNN) has emerged as a valuable tool in pathological diagnosis. This study utilized 54 typical OPA whole slide images (WSI) to extract 7167 typical lesion images containing OPA to construct a Common Objects in Context (COCO) dataset for OPA pathological images. The dataset was categorized into training and test sets (8:2 ratio) for model training and validation. Mean average specificity (mASp) and average sensitivity (ASe) were used to evaluate model performance. Six WSI-level pathological images (three OPA and three non-OPA images), not included in the dataset, were used for anti-peeking model validation. A random selection of 500 images, not included in the dataset establishment, was used to compare the performance of the model with assessment by pathologists. Accuracy, sensitivity, specificity, and concordance rate were evaluated. The model achieved a mASp of 0.573 and an ASe of 0.745, demonstrating effective lesion detection and alignment with expert annotation. In Anti-Peeking verification, the model showed good performance in locating OPA lesions and distinguished OPA from non-OPA pathological images. In the random 500-image diagnosis, the model achieved 92.8% accuracy, 100% sensitivity, and 88% specificity. The agreement rates between junior and senior pathologists were 100% and 96.5%, respectively. In conclusion, the Mask R-CNN-based OPA diagnostic model developed for OPA facilitates rapid and accurate diagnosis in practical applications.

Ovine pulmonary adenocarcinoma is a transmissible pulmonary malignancy of sheep caused by a beta-retrovirus currently named Jaagsiekte sheep retrovirus (JSRV). Club cells (formerly Clara cells) in the bronchiole and type II pneumonocytes in the alveoli are the target oncogenic cells for this virus. Characterized clinically by intermittent cough, abundant nasal discharge, and progressive weight loss, the tumors randomly involve all lung lobes or have a cranioventral distribution mimicking bronchopneumonia. The definitive diagnosis of ovine pulmonary adenocarcinoma requires identifying Jaagsiekte sheep retrovirus or associated specific proteins in neoplastic cells such as JSRV-Env oncogenic protein. A two-year-old Male Pelibuey sheep with a history of chronic cough and progressive weight loss was treated unsuccessfully with antibiotics and died a few days later. Postmortem examination revealed lung edema and several nodular to locally extensive masses in the lungs. Microscopically the tumoral tissues were composed of clusters of neoplastic epithelial cells exhibiting a lepidic growth pattern typical of pulmonary carcinoma. Tumoral cells were immunopositive for Jaagsiekte sheep retrovirus-Env oncogenic protein. Based on these findings, the final diagnosis of ovine pulmonary adenocarcinoma was made. [ABSTRACT FROM AUTHOR]

Th is study aimed to evaluate the role of Matrix Metalloproteinase-9 in the metastasis of ovine pulmonary adenocarcinoma cases by immunohistochemical methods. Lung tissue samples were collected from 26 sheep brought to our department for routine histopathological diagnosis. Lung tissues were fixed in 10% neutral buff ered formalin, following routine procedures tissues were embedded in paraffin wax. Sections from tissues were cut into 5 μm thickness and stained with Hematoxylin & Eosin to detect histopathological changes. Th e sections were examined under a light microscope and photographs were taken. Avidin-Biotin Peroxidase method was used as immunohistochemical staining. Tumoral cells showed acinar, papillary or mixed type growths in ovine pulmonary adenocarcinomas. Only 2 of 20 cases had metastases to lymph nodes, and tumoral cell proliferation in these metastic areas was similar to primary cancer foci. All ovine pulmonary adenocarcinomas were positive for JSRV CA and Matrix Metalloproteinase-9 immunoreactivity. Any positive expression of JSRV CA and Matrix Metalloproteinase-9 were not detected in the control group. Th e number of JSRV CA and Matrix Metalloproteinase-9 immune positive cells was statistically increased in the ovine pulmonary adenocarcinoma group compared to the control group. In line with the data of this study, it is thought that Matrix Metalloproteinases play a serious role in tumor metastasis in ovine pulmonary adenocarcinomas, especially Matrix Metalloproteinase-9.

Ovine pulmonary adenocarcinoma (OPA) is a contagious respiratory tumor of small ruminants, manifesting in chronic weight loss and respiratory failure. Infection with the betaretrovirus jaagsiekte sheep retrovirus (JSRV) is the cause of OPA. Here, we describe the gross and microscopic features of twenty-six sheep and one goat with naturally occurring JSRV-associated OPA. All the animals included in this study had pulmonary lesions morphologically consistent with OPA, but the majority of the observed lesions demonstrated features of both the classical and the atypical form of OPA, and were, therefore, classified grossly as mixed. The gross lesions were located mainly in the cranial pulmonary lobes, were multifocal to coalescing, variable in number and size, flat to slightly raised, firm, and white to grey. Histologically, the cases were classified according to the predominant architectural patterns as lepidic, papillary, acinar, or mixed; the mixed histological pattern was the most prevalent. The aim of this study was to describe the gross and microscopic spectrum of OPA in naturally infected small ruminants from Spain. The mixed form of OPA is less commonly reported, and can be confused with other concurrent pulmonary pathologies (such as BALT hyperplasia in SRLV-associated pneumonia or lungworm granulomas).

Ovine pulmonary adenocarcinoma (OPA) is a model of human lung cancer and fatal viral disease that causes neoplasia in sheep respiratory cells. In the current study, 986 lung samples was inspected in the slaughterhouse, and finally twenty OPA lung organs were clinically diagnosed and five healthy lung organs were assigned as the control sample. Three SSCP patterns were detected for the affected lungs animals in comparison with the healthy lungs. In addition, sequencing results indicated three different single point mutations in exon 4 of TP53 within infected lungs, whereas no mutations were observed in exon 9 of this gene. Real-time PCR results showed up-regulation of the TP53 gene in all the infected lung cells compared to healthy cells. There was significant correlation between the mutations in exon 4 and OPAand can be used as a useful tool in determining the mechanism of lung cancer. [ABSTRACT FROM AUTHOR]

This study aimed to examine the tumor necrosis factor alpha and interferon gamma expressions in the tumor microenvironment of ovine pulmonary adenocarcinomas of different growth patterns and stages by immunohistochemistry and to investigate the effects of these cytokines on the tumor progression. The material of the present study consisted of lung tissue samples of 26 sheep. Lung tissues were fixed in 10% neutral buffered formalin, and later, routine procedures tissues were embedded in paraffin wax. To detect histopathological changes, 5-μm tissue sections were cut and stained with hematoxylin and eosin. Avidin-biotin peroxidase method was used for immunohistochemistry. Tumoral cells showed acinar, papillary, or mixed-type growths in ovine pulmonary adenocarcinomas. No expressions of tumor necrosis factor alpha and interferon gamma was observed in the control group, whereas all ovine pulmonary adenocarcinomas were immunohistochemically positive for tumor necrosis factor alpha and interferon gamma. In advanced-stage cases, the reactions were much more severe than in early-stage cases. The reactions were particularly concentrated in the cytoplasm of alveolar macrophages around the tumoral areas. Tumor necrosis factor alpha and interferon gamma can be remarkable markers to evaluate the severity of disease. [ABSTRACT FROM AUTHOR]

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This study aimed to evaluate the role of Matrix Metalloproteinase-9 in the metastasis of ovine pulmonary adenocarcinoma cases by immunohistochemical methods. Lung tissue samples were collected from 26 sheep brought to our department for routine histopathological diagnosis. Lung tissues were fixed in 10% neutral buff ered formalin, following routine procedures tissues were embedded in paraffin wax. Sections from tissues were cut into 5 μm thickness and stained with Hematoxylin & Eosin to detect histopathological changes. Th e sections were examined under a light microscope and photographs were taken. Avidin-Biotin Peroxidase method was used as immunohistochemical staining. Tumoral cells showed acinar, papillary or mixed type growths in ovine pulmonary adenocarcinomas. Only 2 of 20 cases had metastases to lymph nodes, and tumoral cell proliferation in these metastic areas was similar to primary cancer foci. All ovine pulmonary adenocarcinomas were positive for JSRV CA and Matrix Metalloproteinase-9 immunoreactivity. Any positive expression of JSRV CA and Matrix Metalloproteinase-9 were not detected in the control group. Th e number of JSRV CA and Matrix Metalloproteinase-9 immune positive cells was statistically increased in the ovine pulmonary adenocarcinoma group compared to the control group. In line with the data of this study, it is thought that Matrix Metalloproteinases play a serious role in tumor metastasis in ovine pulmonary adenocarcinomas, especially Matrix Metalloproteinase-9. [ABSTRACT FROM AUTHOR]

Abstract Background Ovine pulmonary adenocarcinoma (OPA) is a neoplastic disease caused by exogenous Jaagsiekte Sheep Retrovirus (exJSRV). The prevalence of JSRV-related OPA in Eastern European countries, including Romania is unknown. We aimed to investigate: the prevalence and morphological features of OPA (classical and atypical forms) in the Transylvania region (Romania), the immunophenotype of the pulmonary tumors and their relationships with exJSRV infection. A total of 2693 adult ewes slaughtered between 2017 and 2019 in two private slaughterhouses from Transylvania region (Romania) was evaluated. Lung tumors were subsequently assessed by cytology, histology, immunocytochemistry, immunohistochemistry, electron microscopy and DNA testing. Results Out of 2693 examined sheep, 34 had OPA (1.26% prevalence). The diaphragmatic lobes were the most affected. Grossly, the classical OPA was identified in 88.24% of investigated cases and the atypical OPA in 11.76% that included solitary myxomatous nodules. Histopathology results confirmed the presence of OPA in all suspected cases, which were classified into acinar and papillary types. Myxoid growths (MGs) were diagnosed in 6 classical OPA cases and in 2 cases of atypical form. Lung adenocarcinoma was positive for MCK and TTF-1, and MGs showed immunoreaction for Vimentin, Desmin and SMA; Ki67 expression of classical OPA was higher than atypical OPA and MGs. JSRV-MA was identified by IHC (94.11%) in both epithelial and mesenchymal cells of OPA. Immunocytochemistry and electron microscopy also confirmed the JSRV within the neoplastic cells. ExJSRV was identified by PCR in 97.05% of analyzed samples. Phylogenetic analysis revealed the presence of the exJSRV type 2 (MT809678.1) in Romanian sheep affected by lung cancer and showed a high similarity with the UK strain (AF105220.1). Conclusions In this study, we confirmed for the first time in Romania the presence of exJSRV in naturally occurring OPA in sheep. Additionally, we described the first report of atypical OPA in Romania, and to the best of our knowledge, in Eastern Europe. Finally, we showed that MGs have a myofibroblastic origin.

Ovine pulmonary adenocarcinoma (OPA) is a neoplastic contagious chronic disease infecting sheep and goats. Jaagsiekte sheep retrovirus (JSRV) is an aetiological agent causing OPA in small ruminants. JSRV was first isolated and whole genome sequenced in South Africa. The OPA clinical manifestation shows overproduction of lung fluid, dyspnoea and pyrexia with cough resembling pneumonia. Pathologically infected lung tissue shows greyish white, moist, enlarged, heavy and oedematous characteristics. The total RNA from OPA infected sheep and goat samples were isolated by Trizol method and converted to cDNA using poly dTP primers. The JSRV U3 gene region was amplified by PCR. The PCR products were resolved in 2% Agarose gel, sequenced by Sanger method. The sequence analysis and phylogenetic studies were performed using Mega 6 software. The genetic analysis revealed that most of the presently isolated sequences showed homology with UK strain (AF105220) whereas one sequence (SVU01) obtained from infected goat sample showed homology with South African strain (M80216). The genetic analysis discloses that presently sequenced JSRV U3 gene sequences have genetically deviated from the previously reported U3 gene sequences. The SVU01 gene sequence revealed 97% homology to SA Strain (M80216), 93% homology with UK strain (AF105220) and 91% homology with GVM05 strain (AB915881). The remaining three gene sequences (SVU02, SVU03 and SVU04) isolated from sheep showed 97% homology to UK strain (AF105220). Further phylogenetics analysis revealed SVU02 and SVU03 closely cluster together along with GVM05 genotype, SVU04 clustered with UK strain (AF105220) whereas SVU01 branched separately clustering with SA strain (M80216) respectively. [ABSTRACT FROM AUTHOR]

Aim: This study aimed to conduct a clinical-histopathological and molecular evaluation of ovine pulmonary adenocarcinoma (OPA) in Awassi sheep in various regions of Al-Qadisiyah Province, Iraq. Materials and Methods: A total of 150 sheep were clinically evaluated, and the wheelbarrow test was performed. 100 samples (35 blood, 25 lung tissue, 20 lymph node, and 20 lung fluid samples) were randomly selected from living and slaughtered sheep. All samples were subjected to polymerase chain reaction (PCR). Histopathological examinations were performed for four lung tissue and two lymph node samples. Results: A diagnosis of OPA was made based on the results of the clinical examination and the clinical signs shown by the animals, such as dyspnea, polypnea, coughing, mucous nasal discharge, moist rales on auscultation of the affected lungs, and emaciation. Interestingly, the animals tested positive for the wheelbarrow test, with frothy nares accompanied by profuse and clear lung fluid. Histopathological examination showed various lesions such as glandular transformation in the lung tissues and emphysema. Moreover, lymph nodes showed marked follicular atrophy and necrosis-associated lymphocyte infiltration in the affected tissues. PCR revealed that 25% of the samples including eight (22.8%) blood, five (20%) lung tissue, five (25%) lymph node, and seven (35%) lung fluid samples were positive for Jaagsiekte sheep retrovirus; this result was highly significant. Conclusion: The results of our study indicated that in Iraq, OPA diagnosis should be based on pathological findings and results of advanced procedures such as PCR.

An epidemiological study was conducted along with pathological, immunohistochemistry (IHC) of capsid antigen and molecular detection of jaagsiekte sheep retrovirus (JSRV) causing ovine pulmonary adenocarcinoma (OPA) in sheep and goats population from three states of India viz. Delhi, Gannavaram (Andhra Pradesh), and Bareilly (Uttar Pradesh). A total of 1350 lungs samples were screened and out of which 31 (2.29%) animals were found to be positive [sheep (3.49%) and goats (0.00%)] for JSRV. The prevalence of infection was recorded Gannavarum (20.00%) followed by Delhi (2.10%) and no any positive cases found in Bareilly area. Age wise higher prevalence was recorded >3 year age groups followed by 1–3 years and 1 < year, respectively. Significantly, higher infection was observed in female sheep compared to male sex of sheep. Seasonally, the prevalence of JSRV infection was higher in monsoon (6.00%) followed winter season (3.34%) and summer season. The observations of the present study would provide basis for further an effective explorative surveillance and epidemiological studies to know real impact of JSRV infection circulating in sheep and goats population of India. [ABSTRACT FROM AUTHOR]

Abstract Background This ultrasonographic study monitored lesions involving the lung surface suspected to be the early stages of ovine pulmonary adenocarcinoma (OPA) tumours over 4 months in commercially farmed sheep. The enlargement of these lesions defined ultrasonographically, which likely represent the development of OPA tumours, have important implications for ultrasound screening schedules in veterinary management plans attempting to eliminate OPA by test-and-cull. Results The lungs of 58 adult Scottish Blackface sheep with ultrasonographic changes at the lung surface consistent with early OPA tumours were examined two to six times over 40 to 290 days. Lesion development, represented in early video recordings by 2–3 mm lesions involving the visceral pleural and comet tails, then a decreasing length of the hyperechoic line representing the normal visceral pleura and increasing depth of the sharply-demarcated and largely uniform hypoechoic areas into the lung parenchyma, was found in 26 of the 58 sheep. The rate at which the sonographic lesions progressed varied considerably and in 10 of 17 Group 1 sheep developed quickly from an estimated depth of 2–30 mm up to 70 mm between 60 and 120 days later. These sonographic lesions were confirmed as OPA at necropsy; histological changes of concurrent bacterial infection were detected in one of these 10 Group 1 sheep. Thirty-one sheep had sonographic changes ≤30 mm consistent with very early OPA at the first examination which had reduced or were not observed at subsequent examination. Five of these 31 sheep were necropsied, 3 had small OPA lesions while 2 had no significant pathology. Conclusion Lesions involving the visceral pleura, with sonographic changes consistent with previous published findings of early OPA, developed over 40–120 days to large masses in 10 of 17 Group 1 sheep with the provisional sonographic diagnosis confirmed histologically at necropsy. While it is possible that atalectic lung could have caused some of the minor sonographic changes there was no microscopic evidence of pathologies other than OPA in nine of 10 Group 1 sheep. We conclude that some small tumours progress to large tumours within 3 months questioning the assumption that OPA is a slow growing tumour in adult sheep taking several years to cause clinical disease. The findings that a proportion of small ultrasonographic lesions are not found again at subsequent scanning illustrates the challenges of interpreting small (

Abstract Background Ovine pulmonary adenocarcinoma (OPA), caused by Jaagsiekte sheep retrovirus (JSRV), is characterised by the development of invariably fatal lung tumours primarily in adult sheep. High infection rates and disease prevalence can develop during initial infection of flocks, leading to on-farm economic losses and animal welfare issues in sheep with advanced disease. The disease has been reported in Ireland and is notifiable, but the presence of JSRV has never been confirmed using molecular methods in this country. Additionally, due to the difficulties in ante-mortem diagnosis (especially of latently-infected animals, or those in the very early stages of disease), accurate information regarding national prevalence and distribution is unavailable. This study aimed to confirm the presence of JSRV in Ireland and to obtain estimates regarding prevalence and distribution by means of an abattoir survey utilising gross examination, histopathology, JSRV-specific reverse transcriptase polymerase chain reaction (RT-PCR) and SU protein specific immunohistochemistry (IHC) to examine the lungs of adult sheep. Results Lungs from 1911 adult sheep were examined macroscopically in the abattoir and 369 were removed for further testing due to the presence of gross lesions of any kind. All 369 were subject to histopathology and RT-PCR, and 46 to IHC. Thirty-one lungs (31/1911, 1.6%) were positive for JSRV by RT-PCR and/or IHC but only ten cases of OPA were confirmed (10/1911, 0.5%) Four lung tumours not associated with JSRV were also identified. JSRV-positive sheep tended to cluster within the same flocks, and JSRV-positive sheep were identified in the counties of Donegal, Kerry, Kilkenny, Offaly, Tipperary, Waterford and Wicklow. Conclusions The presence of JSRV has been confirmed in the Republic of Ireland for the first time using molecular methods (PCR) and IHC. In addition, an estimate of OPA prevalence in sheep at slaughter and information regarding distribution of JSRV infection has been obtained. The prevalence estimate appears similar to that of the United Kingdom (UK). Results also indicate that the virus has a diverse geographical distribution throughout Ireland. These data highlights the need for further research to establish national control and monitoring strategies.

In vitro cell line and in vivo murine models have historically dominated pre-clinical cancer research. These models can be expensive and time consuming and lead to only a small percentage of anti-cancer drugs gaining a license for human use. Large animal models that reflect human disease have high translational value; these can be used to overcome current pre-clinical research limitations through the integration of drug development techniques with surgical procedures and anesthetic protocols, along with emerging fields such as implantable medical devices. Ovine pulmonary adenocarcinoma (OPA) is a naturally-occurring lung cancer that is caused by the jaagsiekte sheep retrovirus. The disease has similar histological classification and oncogenic pathway activation to that of human lung adenocarcinomas making it a valuable model for studying human lung cancer. Developing OPA models to include techniques used in the treatment of human lung cancer would enhance its translational potential, making it an excellent research tool in assessing cancer therapeutics. In this study we developed a novel OPA model to validate the ability of miniaturized implantable O2 and pH sensors to monitor the tumor microenvironment. Naturally-occurring pre-clinical OPA cases were obtained through an on-farm ultrasound screening programme. Sensors were implanted into OPA tumors of anesthetized sheep using a CT-guided trans-thoracic percutaneous implantation procedure. This study reports the findings from 9 sheep that received sensor implantations. Time taken from initial CT scans to the placement of a single sensor into an OPA tumor was 45 ± 5 min, with all implantations resulting in the successful delivery of sensors into tumors. Immediate post-implantation mild pneumothoraces occurred in 4 sheep, which was successfully managed in all cases. This is, to the best of our knowledge, the first description of the use of naturally-occurring OPA cases as a pre-clinical surgical model. Through the integration of techniques used in the treatment of human lung cancer patients, including ultrasound, general anesthesia, CT and surgery into the OPA model, we have demonstrated its translational potential. Although our research was tailored specifically for the implantation of sensors into lung tumors, we believe the model could also be developed for other pre-clinical applications.

Lung cancer represents a major worldwide health concern; although advances in patient management have improved outcomes for some patients, overall 5-year survival rates are only around 15%. In vitro studies and mouse models are commonly used to study lung cancer and their use has increased the molecular understanding of the disease. Unfortunately, mouse models are poor predictors of clinical outcome and seldom mimic advanced stages of the human disease. Animal models that more accurately reflect human disease are required for progress to be made in improving treatment outcomes and prognosis. Similarities in pulmonary anatomy and physiology potentially make sheep better models for studying human lung function and disease. Ovine pulmonary adenocarcinoma (OPA) is a naturally occurring lung cancer that is caused by the jaagsiekte sheep retrovirus. The disease is endemic in many countries throughout the world and has several features in common with human lung adenocarcinomas, including histological classification and activation of common cellular signaling pathways. Here we discuss the in vivo and in vitro OPA models that are currently available and describe the advantages of using pre-clinical naturally occurring OPA cases as a translational animal model for human lung adenocarcinoma. The challenges and options for obtaining these OPA cases for research purposes, along with their use in developing novel techniques for the evaluation of chemotherapeutic agents or for monitoring the tumor microenvironment in response to treatment, are also discussed.

Jaagsiekte sheep retrovirus (JSRV) is the etiologic agent of ovine pulmonary adenocarcinoma (OPA), a neoplastic lung disease of sheep. OPA is an important economic and welfare issue for sheep farmers and a valuable naturally occurring animal model for human lung adenocarcinoma. Here, we used RNA sequencing to study the transcriptional response of ovine lung tissue to infection by JSRV. We identified 1,971 ovine genes differentially expressed in JSRV-infected lung compared to noninfected lung, including many genes with roles in carcinogenesis and immunomodulation. The differential expression of selected genes was confirmed using immunohistochemistry and reverse transcription-quantitative PCR. A key finding was the activation of anterior gradient 2, yes-associated protein 1, and amphiregulin in OPA tumor cells, indicating a role for this oncogenic pathway in OPA. In addition, there was differential expression of genes related to innate immunity, including genes encoding cytokines, chemokines, and complement system proteins. In contrast, there was little evidence for the upregulation of genes involved in T-cell immunity. Many genes related to macrophage function were also differentially expressed, reflecting the increased abundance of these cells in OPA-affected lung tissue. Comparison of the genes differentially regulated in OPA with the transcriptional changes occurring in human lung cancer revealed important similarities and differences between OPA and human lung adenocarcinoma. This study provides valuable new information on the pathogenesis of OPA and strengthens the use of this naturally occurring animal model for human lung adenocarcinoma. [ABSTRACT FROM AUTHOR]

• Ovine pulmonary adenocarcinoma (OPA), a contagious lung cancer, is present in the major sheep rearing areas causing important economic losses. • There are no vaccines or treatment and death inevitably occurs in clinically affected animals. • Clinical OPA has a low prevalence in affected flocks under endemic conditions, but infected sheep may be present in a high proportion. • OPA has failed to be controlled due to the lack of tests, sensitive and specific enough, for identifying infected animals or preclinical stages. • Efforts have focussed on searching methods for early diagnosis but the identification of infected animals is essential for OPA eradication. Ovine pulmonary adenocarcinoma (OPA) is a contagious lung cancer of sheep caused by jaagsiekte sheep retrovirus (JSRV), which induces the transformation of secretory epithelial cells of the distal respiratory tract. The disease has been recorded in the major sheep rearing areas with the exceptions of Australia and New Zealand, and is clinically characterized by a chronic respiratory process that often involves the production of pulmonary fluid that is discharged from the nostrils in final stages of the disease while the "wheelbarrow" test is performed. The respiratory route has been accepted to be the most important natural mode of transmission for JSRV but colostrum and milk can transmit JSRV to lambs. In OPA affected flocks, under endemic conditions, JSRV infected sheep may be present in a high proportion but very few of them develop clinical signs. Such apparently healthy animals are responsible for the spread of the disease because is difficult to identify infected animals or preclinical stages. There are not serological diagnostic tests due to the lack of a detectable immune response in JSRV infected animals, and although blood molecular tests are available their sensitivity is low. For this reason the disease has failed to be controlled so far and continues to cause significant economic losses. Control strategies based on colostrum and milk management have been demonstrated to be effective but expensive for most commercial flocks. In the recent years efforts for controlling the disease have focussed on searching methods for early diagnosis and the next future seems to be the establishment of low risk status for OPA in the flocks. Nevertheless, working on improving the identification of infected animals is essential for the implementation of effective strategies for OPA eradication. [ABSTRACT FROM AUTHOR]

Ovine pulmonary adenocarcinoma (OPA), a transmissible lung tumor in sheep, caused by jaagsiekte sheep retrovirus (JSRV) can inflict fatality as high as 50% in the infected flock following initial detection of the disease. The routine diagnosis of OPA is entirely dependent on clinical signs that appear only at the terminal stages of the disease, followed by confirmation upon macroscopic and microscopic pathological investigations that requires sacrifice of the infected sheep. Serological tests are not available due to lack of JSRV specific antibodies. Polymerase Chain Reaction (PCR) is a useful tool for molecular diagnosis of OPA in sheep. This study aims to appraise the identification of OPA based on gross and histopathological lesions followed by molecular diagnosis of exogenous JSRV (ex- JSRV) by U3-hn PCR. A total of 150 lung samples of sheep suspected for OPA were collected from different slaughter houses and field mortalities in Andhra Pradesh for this investigation. Of these, 22 samples (14.7%) were positive for OPA based on gross histopathological findings and specific U3-hn PCR. Grossly, the affected lungs showed either consolidated areas or clearly demarcated tumor nodules in varying sizes. A few lungs revealed both. Histologically, papillary growth pattern was observed in 9 OPA lung samples. Acinar and bronchoalveolar growth patterns were observed in 7 and 4 lungs respectively. Two lungs showed more than one type of pattern in the same neoplastic tissue. Advanced lesions were characterized by dense fibrous tissue, thickened alveolar septa and infiltration of mononuclear cells in the interstitium. U3-hn PCR was conducted for molecular diagnosis and confirmation of OPA. An amplified product of 176bp was detected in positive samples. To improve the sensitivity, the product of the first round PCR was amplified by using a primer internal to the PCR product (P-VI) that was paired with primer P-I in the second round of hn PCR and a product of 133bp was detected. Electrophoretic analysis revealed the presence of bands of expected sizes in the PCR products in OPA positive animals. The study tends to conclude that U3-hn PCR may be used as a confirmatory inquest to detect the presence of ex-JSRV in OPA affected tissues in addition to gross and histopathological lesions and may be useful in epidemiological studies and disease control of OPA. [ABSTRACT FROM AUTHOR]

In vitro cell line and in vivo murine models have historically dominated pre-clinical cancer research. These models can be expensive and time consuming and lead to only a small percentage of anti-cancer drugs gaining a license for human use. Large animal models that reflect human disease have high translational value; these can be used to overcome current pre-clinical research limitations through the integration of drug development techniques with surgical procedures and anesthetic protocols, along with emerging fields such as implantable medical devices. Ovine pulmonary adenocarcinoma (OPA) is a naturally-occurring lung cancer that is caused by the jaagsiekte sheep retrovirus. The disease has similar histological classification and oncogenic pathway activation to that of human lung adenocarcinomas making it a valuable model for studying human lung cancer. Developing OPA models to include techniques used in the treatment of human lung cancer would enhance its translational potential, making it an excellent research tool in assessing cancer therapeutics. In this study we developed a novel OPA model to validate the ability of miniaturized implantable O2 and pH sensors to monitor the tumor microenvironment. Naturally-occurring pre-clinical OPA cases were obtained through an on-farm ultrasound screening programme. Sensors were implanted into OPA tumors of anesthetized sheep using a CT-guided trans-thoracic percutaneous implantation procedure. This study reports the findings from 9 sheep that received sensor implantations. Time taken from initial CT scans to the placement of a single sensor into an OPA tumor was 45 ± 5 min, with all implantations resulting in the successful delivery of sensors into tumors. Immediate post-implantation mild pneumothoraces occurred in 4 sheep, which was successfully managed in all cases. This is, to the best of our knowledge, the first description of the use of naturally-occurring OPA cases as a pre-clinical surgical model. Through the integration of techniques used in the treatment of human lung cancer patients, including ultrasound, general anesthesia, CT and surgery into the OPA model, we have demonstrated its translational potential. Although our research was tailored specifically for the implantation of sensors into lung tumors, we believe the model could also be developed for other pre-clinical applications. [ABSTRACT FROM AUTHOR]

We review three neoplastic wasting diseases affecting sheep generally recorded under common production cycles and with epidemiological and economic relevance in sheep-rearing countries: small intestinal adenocarcinoma (SIA), ovine pulmonary adenocarcinoma (OPA) and enzootic nasal adenocarcinoma (ENA). SIA is prevalent in Australia and New Zealand but present elsewhere in the world. This neoplasia is a tubular or signet-ring adenocarcinoma mainly located in the middle or distal term of the small intestine. Predisposing factors and aetiology are not known, but genetic factors or environmental carcinogens may be involved. OPA is a contagious lung cancer caused by jaagsiekte sheep retrovirus (JSRV) and has been reported in most sheep-rearing countries, resulting in significant economic losses. The disease is clinically characterized by a chronic respiratory process as a consequence of the development of lung adenocarcinoma. Diagnosis is based on the detection of JSRV in the tumour lesion by immunohistochemistry and PCR. In vivo diagnosis may be difficult, mainly in preclinical cases. ENA is a neoplasia of glands of the nasal mucosa and is associated with enzootic nasal tumour virus 1 (ENTV-1), which is similar to JSRV. ENA enzootically occurs in many countries of the world with the exception of Australia and New Zealand. The pathology associated with this neoplasia corresponds with a space occupying lesion histologically characterized as a low-grade adenocarcinoma. The combination of PCR and immunohistochemistry for diagnosis is advised.

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.

Modern portable ultrasonography machines provide veterinary clinicians with an inexpensive and non-invasive method to further examine the respiratory system of sheep on farm. The procedure would take no more than 2–5 min, with results immediately available. Repeated, regular ultrasonographic examination allows lung and pleural pathologies to be monitored over time, permitting accurate evaluation of various treatments regimens. Critically, ultrasonographic examination informs the clinician regarding the development/regression of lesions, rather than relying upon extrapolation of post-mortem findings regarding aetiology and progression of disease. Ultrasonographic examination presents no human health and safety restrictions. Lesion as small as 2–3 cm in diametre, involving the visceral pleura can be readily identified ultrasonographically. The distribution of lung pathology caused by ovine pulmonary adenocarcinoma can be accurately outlined during ultrasonographic examination of the chest, but the operator must be aware that secondary abscessation of the tumour mass and associated fibrinous pleurisy may prove misleading. Repeated 6- to 12-monthly ultrasonographic examination of the lungs of all adult sheep in a flock is an exciting development that may reduce, and potentially eliminate, pulmonary adenocarcinoma from closed sheep flocks, with effective biosecurity measures. With appropriate handling facilities, an experienced operator can examine both sides of the chest of 50–80 sheep per hour, making such screening affordable even to commercial farmers. Resolution of extensive unilateral fibrinous pleurisy over several months has been recorded and in some cases it has proven difficult to differentiate such resolving lesions from abscesses involving the lungs/pleurae. [ABSTRACT FROM AUTHOR]

The envelope (Env) of Jaagsiekte sheep retrovirus (JSRV) is an oncoprotein of ovine pulmonary adenocarcinoma (OPA). Autophagy is involved in different cancers, but how it is carcinogenic in JSRV Env is unclear. Modulation of autophagy in exJSRV-env-NM-transfected cells through the Akt/mTOR and MAPK signaling pathway was studied, and we observed strong positive labeling of p-Akt, p-mTOR, p-MEK1/2, p-ERK1/2, p-p38 and p-JNK in tumor cells and typical type II pneumocytes in naturally infected OPA lung tissues, which was co-aligned with JSRV-Env positive cells as shown by immunohistochemical and microscopic analysis. Akt/mTOR and MAPK pathways were activated in OPA lung and JSRV-Env transfected NIH 3T3 cells. Decreased Beclin1 and LC3 II/I suggested that autophagy was inhibited in OPA lung and JSRV-Env transfected NIH 3T3 cells. Beclin1 and LC3 II/I increased in JSRV-Env transfected NIH3T3 cells treated with mTOR inhibitor (rapamycin), ERK1/2 inhibitor (PD 98059), p38 inhibitor (SB 203580) and JNK inhibitor (SP 600125), suggesting that Akt/mTOR and MAPK pathways were responsible for JSRV-Env decreased autophagy. In conclusion, JSRV Env decreased autophagy in JSRV-Env transfected NIH3T3 cells through Akt/mTOR and MAPK pathways, in particular, JNK and p38 pathways. [ABSTRACT FROM AUTHOR]

Background: Jaagsiekte sheep retrovirus (JSRV) causes a contagious lung cancer in sheep and goats that can be transmitted by aerosols produced by infected animals. Virus entry into cells is initiated by binding of the viral envelope (Env) protein to a specific cell-surface receptor, Hyal2. Unlike almost all other retroviruses, the JSRV Env protein is also a potent oncoprotein and is responsible for lung cancer in animals. Of concern, Hyal2 is a functional receptor for JSRV in humans. Results: We show here that JSRV is fully capable of infecting human cells, as measured by its reverse transcription and persistence in the DNA of cultured human cells. Several studies have indicated a role for JSRV in human lung cancer while other studies dispute these results. To further investigate the role of JSRV in human lung cancer, we used highly-specific mouse monoclonal antibodies and a rabbit polyclonal antiserum against JSRV Env to test for JSRV expression in human lung cancer. JSRV Env expression was undetectable in lung cancers from 128 human subjects, including 73 cases of bronchioalveolar carcinoma (BAC; currently reclassified as lung invasive adenocarcinoma with a predominant lepidic component), a lung cancer with histology similar to that found in JSRV-infected sheep. The BAC samples included 8 JSRV DNA-positive samples from subjects residing in Sardinia, Italy, where sheep farming is prevalent and JSRV is present. We also tested for neutralizing antibodies in sera from 138 Peruvians living in an area where sheep farming is prevalent and JSRV is present, 24 of whom were directly exposed to sheep, and found none. Conclusions: We conclude that while JSRV can infect human cells, JSRV plays little if any role in human lung cancer. [ABSTRACT FROM AUTHOR]

Jaagsiekte sheep retrovirus (JSRV) is the causative agent of a lung cancer in sheep known as ovine pulmonary adenocarcinoma (OPA). The disease has been identified around the world in several breeds of sheep and goats, and JSRV infection typically has a serious impact on affected flocks. In addition, studies on OPA are an excellent model for human lung carcinogenesis. A unique feature of JSRV is that its envelope (Env) protein functions as an oncogene. The JSRV Env-induced transformation or oncogenesis has been studied in a variety of cell systems and in animal models. Moreover, JSRV studies have provided insights into retroviral genomic RNA export/expression mechanisms. JSRV encodes a trans-acting factor (Rej) within the env gene necessary for the synthesis of Gag protein from unspliced viral RNA. This review summarizes research pertaining to JSRV‑induced pathogenesis, Env transformation, and other aspects of JSRV biology.

Ovine pulmonary adenocarcinoma ( OPA) is a contagious lung cancer in sheep caused by Jaagsiekte sheep retrovirus ( JSRV). OPA is present in many sheep-rearing countries causing economic and welfare issues, as currently no efficient vaccines or treatments are available. Breed differences suggest a host genetic component may influence the pathogenesis of OPA, but so far few genes have been identified. In this work, a genetic association study was carried out in Latxa dairy sheep which were classified as cases/controls based on the presence/absence of OPA lung tumours. Candidate genes included cytokines and a receptor and innate immunity genes. After SNPs in the candidate genes were identified, the distribution of alleles in cases and controls was compared by means of logistic regression analyses at the allelic, genotypic and haplotypic levels. The association analysis showed that several candidate genes were significantly associated with resistance or susceptibility to OPA; two of the candidates, CCR5 and MX1, remained significantly associated with resistance and susceptibility respectively, even after Bonferroni correction. [ABSTRACT FROM AUTHOR]

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Background: Jaagsiekte 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. Results: We 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. Conclusions: We 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. [ABSTRACT FROM AUTHOR]