Bovine Papillomavirus Type Research Articles

Structure-based virtual screening and drug repurposing studies indicate potential inhibitors of bovine papillomavirus E6 oncoprotein.

Bovine papillomavirus type 1 (BPV1) is an oncogenic virus that causes lesions and cancer in infected cattle. Despite being one of the most studied genotypes in the family and occurring in herds worldwide, there are currently no vaccines or drugs for its control. The viral E6 oncoprotein plays a crucial role in infection by this virus, making it a promising target for the development of new therapies. In this regard, we integrated structure-based virtual screening approaches, drug repositioning, and molecular dynamics to identify approved drugs with the potential to inhibit BPV1 E6. Our results reveal that Lumacaftor and MK-3207 are promising candidates for controlling BPV1 infection. The findings of this study may contribute to the development of E6 oncoprotein blockers in an accelerated and cost-effective manner.

Molecular Detection by Rolling Circle Amplification Combined with Deep Sequencing of Mixed Infection by Bovine Papillomaviruses 2 and 4 in Carcinoma In Situ of the Bovine Esophageal Mucosa.

Papillomaviruses (PVs) are oncogenic and infect the skin and mucosa of various host species. Considering the recent advances in research on PVs using rolling circle amplification (RCA) followed by high-throughput sequencing (HTS), in this study, we aimed to investigate the bovine papillomavirus (BPV) types associated with proliferative lesions in the upper alimentary tract of an affected bull and characterize the viral strains through complete genome sequencing using this strategy. We analyzed the PV strains associated with two hyperplastic esophageal lesions through PCR using degenerate primer pairs and RCA, followed by HTS. HTS of the libraries generated using RCA products provided the whole genome sequence of BPV4 present in squamous papilloma, whereas the complete genome sequence of BPV2 and subgenomic fragments of BPV4 were identified in carcinoma in situ (CIS). For the first time, we have sequenced BPV2 identified from the CIS of the bovine upper alimentary canal. Additionally, RCA followed by HTS allowed characterization of the mixed infection by BPV2 and BPV4 in this lesion. These data reveal that BPV4 is not the only BPV type present in CIS of the esophageal mucous membrane; moreover, a mixed infection caused by BPV2 and BPV4 at the tested anatomical site was demonstrated.

Characterization of Bovine Papillomavirus Types Detected in Cattle Rumen Tissues from Amazon Region, Brazil.

The Bos Taurus Papillomavirus, commonly known as bovine papillomavirus (BPV), can cause lesions in the mucosa of the gastrointestinal tract (GIT) in cattle and induce the formation of papillomas in organs such as the pharynx, esophagus, rumen and reticulum. GIT papillomas can lead to feeding and breathing distress. Moreover, the sample collection is challenging, which reduces the BPV diagnosis in these organs. BPV can cause exophytic nodular, cauliflower-like, flat, filiform or atypical-shape papillomas at the epidermis. Histologically, the papillomas demonstrate orthokeratotic/parakeratotic hyperkeratosis and koilocytosis and, currently, BPV comprises 45 described types. The aim of this study was to carry out the genetic characterization of BPV present in rumen neoplastic lesions of cattle raised extensively in the Western Amazon region, Brazil. A total of 100 papillomatous ruminal samples were collected from animals slaughtered in Ji-Paraná and Urupá municipalities from the Rondônia state, Brazil. The samples were submitted to PCR using the primer pair FAP59/FAP64 and sequenced by the Sanger method. Histopathological analysis was performed on 24 samples, which had enough material for this purpose. As a result, samples were histologically classified as fibropapilloma and squamous papilloma. Among the samples analyzed, it was possible to identify the BPVs 2, 13 (Delta PVs) and 44, with one sample classified as a putative new subtype of BPV44. The present study could identify BPV13 and 44 types in cattle rumen tissues from the Brazilian Amazon region for the first time.

Management of cutaneous bovine papillomatosis in cross bred Holstein Friesian cow – Case Report

Cutaneous bovine papillomatosis is caused by the bovine papillomavirus types (BPV-1 to -10). It is a contagious disease characterised by multiple skin lesions (tumours or growths) commonly in different body regions and is associated with huge economic losses. On 9th November, 2019 a client from the Gagi area of the Sokoto metropolis reported a case of pox-like-grown lesions on a one-year-old male crossed-bred Holstein-Friesian to the Aliyu Jodi Veterinary Clinic, Sokoto. There were ticks in the ear and beneath the tail on physical examination. The patient was diagnosed with cutaneous bovine papillomatosis. The condition was managed symptomatically, by excising the lesions and treatment using Ivermectin super® (Ivermectin 10 mg, Clorsulon 100 mg) subcutaneous (SC) injection, Pentstrep 20/25 inj.® (Procaine penicillin G 200 mg, Dihydrostreptomycin sulphate 250 mg) intramuscular (IM) injection, Flunixin (50 mg) intraveinous (IV) injection for 4 days and Multivitamin injection (x®). The cattle recovered with no history of recurrence or sign of skin damage. Symptomatic treatment is therefore recommended for cutaneous bovine papillomatosis and surgical excision should be carried out at mature (regressing stage) to avoid recurrence.

Bovine papillomavirus vertical transmission: BPV diversity and expression in maternal and fetal tissues.

Bovine Papillomaviruses (BPVs) constitute a diverse group within the Papillomaviridae family, playing a crucial role in bovine health and economic considerations. This study investigates the dynamics of vertical transmission of BPV in cattle, focusing on five cows and their reproductive tissues, as well as three gravid cows and their fetuses. DNA and RNA samples were extracted from the warts, fetal skin, placenta, uterus, ovary, and blood of cows, as well as the skin and blood of fetuses. Polymerase Chain Reaction (PCR) targeted BPV types 1-6 and 8-14, was assessed in both cows and fetuses. Additionally, Reverse Transcription PCR (RT-PCR) examined BPV-2 E5 oncogene expression in the skin and reproductive sites of mother cows and fetuses. Our findings unveil a rich diversity of BPV types, including BPV-2, 3, 9, 10, 12, and 14, present in both maternal and fetal tissues. Intriguingly, certain types, namely BPV-4, 6, 8, and 11, were exclusively identified in maternal tissues A higher diversity of BPVs was observed in cow warts, followed by cow blood, fetal blood, and fetal skin. Strikingly similar BPV types in gravid cow blood and fetuses suggest primary dissemination through the bloodstream and transmission via the placenta, though detected in lower numbers in cow uterus and ovary. Histopathological analysis revealed no abnormalities in the reproductive tissues despite the presence of BPV. However, in one bladder sample from a cow that did not consume bracken fern, urothelial neoplasia in situ was observed. The study extends beyond detection, exploring the expression of the BPV-2 E5 oncogene in fetal tissues, providing insights into potential cell implications. Comparative analyses with previous studies highlight the uniqueness of our investigation, encompassing a broader array of BPV types in the gravid cows and their fetuses. The findings not only establish a foundation for further investigations into the mechanisms of vertical transmission but also highlight the need for targeted interventions and surveillance strategies to mitigate potential health risks associated with specific BPV types.

Feline Facial Spindle Cell Tumors in 29 Cats: Histomorphological and Immunohistochemical Characterization.

Soft tissue tumors/sarcomas (STSs) in felines, encompassing a variety of mesenchymal tumors with similar histomorphological features, present diagnostic challenges due to their diverse cellular origins and the overlap with other tumor types such as feline sarcoid. This study aimed to delineate the clinical, histomorphological, and immunohistochemical characteristics of 34 feline facial spindle cell tumors affecting 29 cats, including testing for bovine papillomavirus type 14 (BPV14), the virus causing feline sarcoids. Only five out of 12 tumors previously diagnosed as feline sarcoids based on histomorphology were confirmed by PCR for BPV14, underscoring the importance of comprehensive diagnostic approaches to accurately distinguish between STSs and feline sarcoids. This study shows that most facial spindle cell tumors were compatible with peripheral nerve sheath tumors (PNSTs) based on positive immunohistochemical staining for Sox10 and other immunohistochemical markers such as GFAP, NSE, and S100. Some of these tumors displayed as multiple independent masses on the face or as erosive and ulcerative lesions without obvious mass formation, an atypical presentation and an important highlight for general practitioners, dermatologists, and oncologists. This study also describes periadnexal whorling of neoplastic cells as a novel histomorphologic finding in feline facial PNSTs and emphasizes Sox10 as a useful complementary immunohistochemical marker for the diagnosis of facial PNST in cats, providing valuable insights for veterinary pathologists.

Investigation of the Presence of Bovine Papillomavirus in Blood Leukocytes of Cattle in West Mediterranean of Turkey

One hundred Holstein cattle, varying in age from one to ten years, who had warts on different parts of its bodies and had previously had Bovine papillomavirus (BPV) typing had blood samples taken from them from various managements in Burdur-Center and its surroundings. DNA was extracted from leukocytes using the DNeasy Blood & Tissue Kit (Qiagen, Germany). RT-PCR test was performed using consensus and type-specific primers for the detection of BPV types. As a result of the study, RT-PCR test and consensus primers were not detected in blood leukocyte samples. Through the use of type-specific primers in an RT-PCR assay, the viral genome components of BPV-10 (56), BPV-11 (1), BPV-10+BPV-11 (2), BPV-10+BPV-12, and BPV-10+BPV-14 (2) were detected in these samples. BPV-12 was detected for the first time in blood leucocytes. In blood samples taken from animals classified according to the anatomical regions where the warts are located the highest BPV positivity (22,2%) was detected in animals with warts on the teats. Also, the most BPV-10 type was determined in the blood samples of animals with wart lesions on the teat and lobes. When the distribution of BPV PCR positive samples according to age groups was made, BPV PCR positive was found mostly in the between 1 and 47 month age group (71,4%). It was determined that the prevalence of BPV was high in the between 1 and 47 age group, while the rates of 48-83 months and later decreased with increasing age. In this investigation, it was found that BPV type 10 had been prevalent in blood leukocyte samples from cattle with warts in various areas of the body and with variable macroscopic appearance.

Molecular Detection and Quantification of Ovine Papillomavirus DNA in Equine Sarcoid

Equine sarcoids are caused by infection with bovine papillomavirus (BPV) types 1, 2, and possibly 13. However, a number of sarcoids lack BPV DNA, and new potential etiological agents for sarcoid diseases need to be considered. High-performance digital droplet polymerase chain reaction (ddPCR) was used for the quantitative detection of ovine papillomavirus (OaPV) types 1–4 DNA from 63 sarcoid DNA samples collected in Austria. All samples were comparatively evaluated for OaPV DNA loads by qPCR. Conventional PCR and amplicon sequencing were used to validate the data. Of the 63 sarcoid DNA isolates, ddPCR was able to detect 22 samples harboring OaPV DNA (34.92%), whereas only five of the OaPV-positive samples were revealed by qPCR (22.72%). The differences in detection by ddPCR and qPCR were statistically significant (p<0.05). The detected OaPV types were OaPV1, 3, and 4. Both methods failed to detect OaPV2 DNA, which could be due to the limited number of examined samples. Importantly, ddPCR detected multiple types of OaPV DNA in seven cases, whereas the qPCR failed to detect multiple infections. This study is the first to provide evidence of the presence of OaPV types 1, 3, and 4 DNA in a subset of equine sarcoids. The comparative detection approach underscores the superior sensitivity of ddPCR compared to that of qPCR.

Genetic Evaluation of Bovine Papillomavirus Types Associated with Teat Papillomatosis in Polish Dairy Cattle with the Report of a New Putative Type.

Teat papillomatosis is reported to be one of the factors causing mastitis and milk losses in dairy cattle. Little is known about bovine papillomavirus (BPV) circulation in the European cattle population, and no reports can yet be found about its prevalence in Polish herds. In this study, 177 BPV-like lesions were collected from teats of 109 slaughtered cows. BPV was identified in 39 of the examined animals, using PCR amplification and Sanger dideoxy sequencing. In total, 10 BPV types were isolated, among which the most common were infections caused by types 8 and 7. Macroscopically, "rice-grain" type lesions dominated (76%) and were mainly found on one teat (57.4%). The diversity of BPV types causing teat papillomatosis in Polish cows seems to be large, with nine already known types isolated and a new putative type found. The spread of new types among the worldwide cattle population can be seen for the first time, as type 25 and so called isolates BPV42 and BPV43 were found in the European cattle population.

L1 Gene based Molecular Characterization of Bovine Papillomavirus Type 1 (BPV1) Isolated from Cutaneous Warts of Cattle, Maharashtra

Background: Bovine papillomatosis (BP) is distributed worldwide among cattle but is relatively less common in buffaloes. Prevalence of this disease is established in buffaloes from India and Italy caused by bovine papilloma virus (BPV). The current study aimed to study the detection of bovine papilloma virus from cutaneous warts by polymerase chain reaction and confirmed by nucleotide sequencing and phylogenetic analysis. Methods: In this study a total of 10 wart samples from affected cattle were aseptically collected. Grossly, most of cutaneous warts were of variable sizes, rough or coarse in texture, grayish/blackish/flesh colored, irregular in shape (dome or button) or resembling cauliflower-like masses and elevated from skin surface by broad base. Molecular characterization of viral DNA from wart samples and partial gene sequencing, its analysis were carried out by using bioinformatics tools to establish the phylogenetic relationship. Result: In our investigation it revealed that out of total 10 cutaneous wart tissue samples, only six cattle were positive for BPV-1 while all the samples were found negative for BPV-2. The phylogenetic analysis of BPV-1gene of papilloma virus of cattle showed 100% homology with already reported sequence from china. The BPV-1 partial sequences generated in present study revealed close homology as well as with the earlier published BPV-1 sequences on NCBI.

A different treatment approach for Bovine papillomavirus in an Arabian horse

A wart lesion was observed near the anus of a female Arabian horse housed in a private equine facility in Bucak District of Burdur Province. During the histopathological examination of the mass, revealed equine sarcoid was revealed. Polymerase chain reaction (PCR) revealed the presence of bovine papillomavirus (BPV) type 10 and type 12 viral genomes in the tissue. It was observed that the combined treatment approach of PAPILEND™® cream + Zylexis™ + AlquermoldTM premix powder was beneficial in treating the sarcoid associated with BPV type 10 and type 12 on the anal region. No recurrence of the lesion was observed during the 6-month follow-up period. In conclusion, it is recommended to diagnose the presence of BPV in horses with warts and to investigate the efficacy of this combined treatment approach in larger populations.

Complete genomic characterization of bovine papillomavirus type 1 and 2 strains infers ongoing cross-species transmission between cattle and horses

Infection with bovine papillomavirus (BPV) types 1 and 2 results in the most common skin tumor of horses, termed equine sarcoid. The persistent and recurrent nature of this tumor stands in contrast to the regressive nature of BPV-1/− 2 induced cutaneous papillomas in cattle. The circulation of horse-specific BPV-1/− 2 variants within equine populations has been suggested as a possible explanation for the difference in clinical presentation of BPV-1/− 2 infection between horses and cattle. In order to investigate this hypothesis, we identified 98 complete BPV-1/− 2 genomes using a Nanopore sequencing approach. Separate BPV-1/− 2 alignments were used to infer Bayesian phylogenetic trees. Phylogeny-trait association concerning host species was investigated using Bayesian Tip-association Significance software (BaTS) Overall, 179 unique BPV-1 and 128 BPV-2 substitutions were found. The E2 coding region in the viral genome exhibited an exceptionally high rate of non-synonymous mutations (81 %, n = 13/16). Interestingly, extensive deletions in the L1/L2 region (up to 1.5 kb) were found exclusively in horse-derived samples. Nevertheless, the most frequently detected single nucleotide polymorphisms were shared between equine and bovine hosts, which is in agreement with BaTS results indicating no phylogeny-host correlation. We found indications that horse-specific mutations might exist in subpopulations of equine derived BPV-1/− 2, but these did not result in horse-adapted genetic variants. Based on these observations, cross-species transmission from cattle to horses seems to be an ongoing process, rather than an ancient occurrence that has been followed by the circulation of horse-adapted BPV variants in the horse population..

Diagnosis and phylogenetic analysis of bovine papillomaviruses in cattle papillomatosis cases by different methods

Papillomaviruses, known as epitheliotropic, cause proliferation in the skin, mucosa, and different visceral organs. In this study, it was aimed to diagnose bovine papillomavirus (BPV) by using different methods in the lesion taken from twenty cattle with papillomas in different areas of the body and to reveal its molecular characterization. In our study, molecular, immunohistochemistry, and transmission electron microscopy (TEM) methods were used for virus identification. Additionally, sequencing analysis was used to ascertain the phylogenetic relationship between the obtained field strains and other isolates submitted to GenBank. Histopathological analyses of the collected samples were done in addition to diagnostic procedures. Intranuclear virus particles were detected when the papillomas were investigated with TEM. In PCR analyses using degenerate and type-specific primer sets, the presence of BPV nucleic acid was determined in 70% (14/20) and 90% (18/20) of the samples, respectively. No virus could be detected in PCR applications using MY 09/11 degenerate primer sets. Twenty animals of different ages, races, and genders included in the study by random sampling method from different herds were divided into 4 groups according to the body regions where the lesions were located. Sequence analysis was performed on a sample from each group that showed strong positivity in the PCR technique using FAP 59/64 degenerate primer set and type-specific primer set. Sequence analyses were performed using FAP 59/64 degenerate primers of amplicons for phylogenetic research. In these analyses, three of the isolated strains were identified as BPV-1, which is in the Deltapapillomavirus 4 genus, and one as BPV-2. As a result of the study, it was concluded that molecular and phylogenetic studies using type-specific primers are more beneficial in order to fully reveal the etiology of papillomatosis in cattle and it would be correct to determine BPV types before prophylactic (vaccine, etc.) applications.

Performance of fine-needle aspirate testing compared with superficial swab testing for quantification of BPV-1/−2 viral load in equine sarcoids

Bovine papillomavirus (BPV) types 1 and 2 are causally associated with equine sarcoid, the most common mesenchymal neoplasm of horses, but the viral load (VL) differs between lesions. Sensitive and accurate BPV detection and quantification is essential for clinicians to confirm clinical suspicion, as well as in research settings for stratifying these skin lesions. Due to the limitations of histopathology in sarcoid diagnosis, PCR screening of superficial swabs constitutes the principal sampling method for BPV detection. This study aimed to investigate the ability of superficial swabs and fine-needle aspirates (FNA) to accurately detect the VL in equine sarcoids, considering the main clinical types: occult, nodular, verrucous and fibroblastic. Superficial swabs and FNAs from a series of sarcoid-affected horses were tested in parallel for BPV DNA quantification. Quantitative real-time PCR screening of postoperative tissue biopsies served as reference standard for the accuracy assessment of the viral titters. Our results indicate that VL is not a predictor of the clinical type. Student's t-test results gave evidence of a significant difference between both sample methods (P < 0.001) with FNA giving the best approximation of the actual VL (P < 0.01). In contrast to superficial swabs, the reference standard correlated moderately with FNA in general (P < 0.05; r = 0.39) and strongly with FNA results within the occult sarcoid group (P < 0.05; r = 0.59). In conclusion, the correlation of FNA with the reference standard was strong enough to suggest this is the preferred method for quantifying VL in sarcoids.

Immunotherapy of Equine Sarcoids-From Early Approaches to Innovative Vaccines.

Horses and other equid species are frequently affected by bovine papillomavirus type 1 and/or 2 (BPV1, BPV2)-induced skin tumors termed sarcoids. Although sarcoids do not metastasize, they constitute a serious health problem due to their BPV1/2-mediated resistance to treatment and propensity to recrudesce in a more severe, multiple form following accidental or iatrogenic trauma. This review provides an overview on BPV1/2 infection and associated immune escape in the equid host and presents early and recent immunotherapeutic approaches in sarcoid management.

Development of modern immunization agent against bovine papillomavirus type 1 infection based on BPV1 L1 recombinant protein.

Bovine papillomavirus type 1 L1 protein was produced in a baculovirus expression system and purified as virus-like particles (VLPs) by affinity chromatography using lectins. The morphological integrity of VLPs was confirmed by electron microscopy. Differences between the two detected variants were deciphered by mass spectrometry of peptides (MALDI-TOF). Mice were immunized with purified VLPs in doses of 10, 25, or 50 μg in combination with 1% saponin and 15% alhydrogel per dose as adjuvants. Analysis of the humoral immune response revealed increased levels of specific antibodies detected 3 weeks after the first immunization in all groups of animals. This was further significantly increased by the booster applied 3 weeks after the first dose, with the best immune response in a group of mice immunized by the largest dose of antigen. BPV1 L1 VLPs purified by affinity chromatography using lectins could be used for prophylactic immunization in veterinary medicine.

Expression of collagenases (matrix metalloproteinase-1, -8, -13) and tissue inhibitor of metalloproteinase-3 (TIMP-3) in naturally occurring bovine cutaneous fibropapillomas.

Bovine cutaneous fibropapillomas are among the most common skin tumors in cattle; their etiology is associated with infection by bovine papillomavirus (BPV) types-1/-2 which are considered oncogenic. Degradation of the extracellular matrix (ECM), especially collagenolysis, is a key event during a series of relevant physiological processes, including tissue remodeling and repair. Various types of proteins are implicated in the regulation of ECM degradation: among these, matrix metalloproteinases (MMPs), a group of zinc-dependent endoenzymes, and tissue inhibitors of matrix metalloproteinases (TIMPs) are known to play a major role. Previous studies reported that aberrant expression of collagenolytic MMPs (MMP-1/-8/-13) and unbalancing between MMPs and TIMPs represent a critical step in tumor growth and invasion; however, studies regarding this topic in bovine cutaneous fibropapillomas are lacking. The aim of this study was to investigate the expression of the collagenases MMP-1/-8/-13 and TIMP-3 in naturally occurring fibropapillomas harboring BPV-2 DNA and normal skin samples. Here, by immunohistochemistry and western blotting analysis, we demonstrated overexpression of MMP-8/-13 along with a down-regulation of MMP-1, associated with a decrease in TIMP-3 levels in tumor compared with normal skin samples. This is the first study describing MMP-1/-8/-13 and TIMP-3 expression in bovine cutaneous fibropapillomas and our results suggest that an impaired expression of collagenases along with an imbalance between MMPs/TIMPs may contribute to an increased collagenolytic activity, which in turn could be important in ECM changes and tumors development.

Phylogeny and amino acid analysis in single and mixed bovine papillomavirus infections in Southern Brazil, 2016-2020.

Bovine papillomaviruses (BPVs) exhibit a high degree of genetic variability, and several viral types have been identified based on analysis of the L1 gene. The L1 is the main capsid protein and the main target for neutralizing antibodies. We performed a retrospective study onBPVscirculating in Rio Grande do Sul state, Southern Brazil, in 2016-2020. DNA from 43 bovine papilloma samples were amplified using two degenerate primer sets - FAP59/64 and MY09/11 - targeting the L1 region, and analyzed for phylogeny, mixed BPV infections(coinfections) and amino acid (aa) sequences. We also performed an in silico analysis with 114 BPV L1 sequences from the GenBank database to assess the agreement between the phylogeny obtained based on complete L1 sequences versus that based on the region amplified using the FAP59/64 and MY09/11 primer sets. Considering single and coinfections, we identified 31 BPV-1 (31/43; 72.1%), 27 BPV-2 (27/43; 62.8%) and 4 BPV-6 (4/43; 9.3%). Coinfections with BPV-1 and BPV-2 were observed in 61.3% of the samples. Our results are supported by in silico analyses that demonstrate that the classification usingFAP59/64 or MY09/11 matches the complete L1 results, except for BPV-17 and -18, which may be mistakenly classified depending on the primers used. Furthermore, we found unique or rare amino acids in at least one L1 sequence of each BPV type identified in our study, some of which have been identified previously in papillomavirus epitopes, suggesting immune-mediated selection. Finally,our study provides an overview of BPVscirculatingin Southern Brazil over the last five years and point to the combined use of primers FAP59/64 and MY09/11 for analysis of BPV coinfections and putative epitopes.

Searching bovine papillomavirus presence in lesions seen on teats of cows

The samples were taken from 106 cows with various-looking lesions on their teats and ranged in age from 2 to 8 years. Enzyme-linked immunosorbent assay (ELISA) antigen (Ag) positive for the bovine papillomavirus (BPV) was found in 59 (55.7%) blood serum samples. PCR using FAP59/64 primers was positive for 24 (22.6%) samples. BPV-2 (40, 37.7%), BPV-6 (28, 26.4%), BPV-8 (30, 28.3%), BPV-9 (36, 34%), BPV-10 (32, 30.3%), and BPV-12 (22, 20.8%) were found in a PCR type-specific analysis of single and mixed type teat warts. The highest positivity was observed in BPV-2, BPV-9 and BPV-10 in flat and round forms, BPV-6, BPV-10, BPV-12, and mixed types in rice grain-cauliflower forms, BPV-9 and mixed types in filiform in the distribution of types based on the macroscopic appearance of teat lesions. As for the distribution of BPV types according to age, the most BPV-2 types were found in the age group of two years, the most BPV-10 types in the age group of three years, the most BPV-9 types in the age group of four years, the most BPV-8+BPV-12 types in the age group of five years, and the most mixed types between the ages of six and eight years. The existence of the virus was then checked using electron microscopy on the chosen samples (at least one investigation was conducted), and it was positively identified using BPV type-specific primers. The authors concluded that BPV detection using an ELISA (Ag) test from blood serum samples was shown to be less sensitive than BPV type-specific PCR from wart samples.

Bovine Papillomavirus Type 1 or 2 Virion-Infected Primary Fibroblasts Constitute a Near-Natural Equine Sarcoid Model.

Equine sarcoids are common, locally aggressive skin tumors induced by bovine papillomavirus types 1, 2, and possibly 13 (BPV1, BPV2, BPV13). Current in vitro models do not mimic de novo infection. We established primary fibroblasts from horse skin and succeeded in infecting these cells with native BPV1 and BPV2 virions. Subsequent cell characterization was carried out by cell culture, immunological, and molecular biological techniques. Infection of fibroblasts with serial 10-fold virion dilutions (2 × 106-20 virions) uniformly led to DNA loads settling at around 150 copies/cell after four passages. Infected cells displayed typical features of equine sarcoid cells, including hyperproliferation, and loss of contact inhibition. Neither multiple passaging nor storage negatively affected cell hyperproliferation, viral DNA replication, and gene transcription, suggestive for infection-mediated cell immortalization. Intriguingly, extracellular vesicles released by BPV1-infected fibroblasts contained viral DNA that was most abundant in the fractions enriched for apoptotic bodies and exosomes. This viral DNA is likely taken up by non-infected fibroblasts. We conclude that equine primary fibroblasts stably infected with BPV1 and BPV2 virions constitute a valuable near-natural model for the study of yet unexplored mechanisms underlying the pathobiology of BPV1/2-induced sarcoids.