Bovine papillomavirus clastogenic effect analyzed in comet assay

Identification of Genomic Instability in Cows Infected with BVD Virus

An important factor for dairy cattle farmers is the profitability of cattle rearing, which is influenced by the animals' health and reproductive parameters, as well as their genomic stability and integrity. Bovine viral diarrhea (BVD) negatively affects the health of dairy cattle and causes reproductive problems. The aim of the study was to identify genomic instability in cows with reproductive disorders following infection with the BVD virus. The material for analysis was peripheral blood from Holstein-Friesian cows with reproductive problems, which had tested positive for BVD, and from healthy cows with no reproductive problems, which had tested negative for BVD. Three cytogenetic tests were used: the sister chromatid exchange assay, fragile sites assay, and comet assay. Statistically significant differences were noted between the groups and between the individual cows in the average frequency of damage. The assays were good biomarkers of genomic stability and enabled the identification of individuals with an increased frequency of damage to genetic material that posed a negative impact on their health. The assays can be used to prevent disease during its course and evaluate the genetic resistance of animals. This is especially important for the breeder, both for economic and breeding reasons. Of the three assays, the comet assay proved to be the most sensitive for identifying DNA damage in the animals.

Unveiling Oxidative Stress-Induced Genotoxicity and Its Alleviation through Selenium and Vitamin E Therapy in Naturally Infected Cattle with Lumpy Skin Disease

Lumpy skin disease (LSD) is a contagious infection of cattle caused by a virus of the Poxviridae family, genus Capripoxvirus. In Pakistan, recent outbreaks have resulted in significant nationwide mortality and economic losses. A 20-day prospective cohort study was performed on sixty infected cattle with the aim to evaluate LSD-induced oxidative stress's genotoxic role and to determine the ameliorative effect of antioxidant therapy using principal component analysis (PCA) and a multivariable ordinal logistic regression model. LSDV was identified from scab samples and nodular lesions using RPO30-specific gene primers. The infected cattle were divided into control and treated groups. The animals were observed initially and finally on day 20 to evaluate the homeostatic, oxidative, and genotoxic changes. The animals in the treated group were administered a combination of selenium (Se) and vitamin E at the standard dose rate for five consecutive days. A substantial (p < 0.05) improvement in the hematological indices was observed in the treated group. The treated group also showed a significant (p < 0.05) reduction in levels of serum nitric oxide (NO) and malondialdehyde (MDA) post-therapy. The PCA at the final sampling data of the treated group showed that Principal Component (PC1 eigenvalue 1.429) was influenced by superoxide dismutase (SOD; 0.3632), catalase (CAT; 0.2906), and glutathione (GSH; 0.0816) and PC2 (eigenvalue 1.200) was influenced by CAT (0.4362), MDA (0.2056), and NO (0.0693). A significant correlation between serum NO (76%) and MDA levels (80%) was observed with genetic damage index (GDI) scores. The ordinal logistic regression model regarding the use of antioxidant therapy revealed 73.95-times (95%CI; 17.36-314.96) improvement in the GDI in treated animals. The multivariable ordinal logistic regression showed that each unit increase in NO and MDA resulted in a 13% increase in genotoxicity in infected individuals. In conclusion, our study revealed that LSD-induced oxidative stress and lipid peroxidation product causes genotoxicity in affected animals. Furthermore, the combined Se and vitamin E therapy significantly alleviated oxidative stress and genotoxicity in LSD-affected cattle.

Effect of Selected Micro- and Macroelements and Vitamins on the Genome Stability of Bovine Embryo Transfer Recipients following In Vitro Fertilization

Genome instability can lead to a wide variety of diseases. Many endogenous and exogenous factors influence the level of damage to genetic material. Genome integrity depends on factors such as the fidelity of DNA replication, normal DNA organization in the chromosomes, and repair mechanisms. Genome stability influences fertility, embryonic development, and the maintenance of pregnancy. In the case of in vitro fertilization, it can be an important factor determining the success of the procedure. The aim of the study was to assess the stability of the genomes of recipient cows following in vitro fertilization using cytogenetic tests and to analyze the effects of selected vitamins and micro- and macroelements on genome integrity. Genome stability was analyzed using the sister chromatid exchange, fragile site, and comet assays. The material for analysis was peripheral blood from 20 Holstein-Friesian heifers that were embryo transfer recipients. The effect of selected micro- and macroelements and vitamins on the genome stability of the cows was analyzed. Folic acid was shown to significantly influence the level of damage identified using the SCE, FS, and SCGE assays, while iron affected SCE and SCGE results, and zinc affected FS.

Molecular Characterization and Developing a Point-of-Need Molecular Test for Diagnosis of Bovine Papillomavirus (BPV) Type 1 in Cattle from Egypt

Bovine papillomatosis is a viral disease of cattle causing cutaneous warts. A diagnosis of this viral infection is very mandatory for combating the resulting economic losses. Given the limited data available about bovine papillomavirus (BPV) in Egypt, the present study involved the molecular diagnosis of bovine papillomavirus type-1 (BPV-1), -2, -4, -5, and -10 in cattle presenting cutaneous warts on the head and neck from New Valley Province, Egypt. The phylogenetic analysis of the detected types of BPV was also performed, followed by developing a point-of-need molecular assay for the rapid identification of identified BPV types. In this regard, a total of 308 cattle from private farms in Egypt were clinically examined, of which 13 animals presented cutaneous warts due to suspected BPV infection. The symptomatic animals were treated surgically, and biopsies from skin lesions were collected for BPV-1, -2, -4, -5, and -10 molecular identification using polymerase chain reaction (PCR). The presence of BPV-1 DNA was confirmed in 11 collected samples (84.6%), while BPV-2, -4, -5, and -10 were not detected. Sequencing of the PCR products suggested the Egyptian virus is closely related to BPV found in India. An isothermal nucleic acid amplification test (NAAT) with labeled primers specific for the BPV-1 L1 gene sequence, and based on recombinase polymerase amplification (RPA), in combination with a lateral flow strip assay for the detection of RPA products, was developed and tested. The point-of-need molecular assay demonstrated a diagnostic utility comparable to PCR-based testing. Taken together, the present study provides interesting molecular data related to the occurrence of BPV-1 in Egypt and reveals the genetic relatedness of the Egyptian BPV-1 with BPV-1 found in buffalo in India. In addition, a simple, low-cost combined test was also validated for diagnosis of the infection. The present study suggests the necessity of future investigations about the circulating strains of the virus among the cattle in Egypt to assess their genetic relatedness and better understand the epidemiological pattern of the disease.

Evaluation of Hypoxia-Inducible Factor-1 Alpha (HIF-1α) in Equine Sarcoid: An Immunohistochemical and Biochemical Study

BACKGROUND

equine sarcoids are the most frequent skin tumors in equidae worldwide. It is well known that delta bovine papillomaviruses are their causative agents. We have recently shown the presence in equine sarcoids of abnormal vessel structures, which could cause a hypoxic condition. The aim of this study was to analyze the expression of hypoxia-inducible factor-1 alpha (HIF-1α) in a subset of BPV positive equine sarcoids and explore the relationship with vascular endothelial growth factor (VEGF) expression.

RESULTS

80% of equine sarcoids showed strong cytoplasmic staining in >60% of neoplastic fibroblasts, while 20% of samples showed a moderate cytoplasmic staining in 40-60% of neoplastic fibroblasts for HIF-1α. Results of Western blotting (WB) were consistent with immunohistochemistry (IHC). Moreover, a positive correlation between HIF-1α and VEGF expression (r = 0.60, p < 0.01) was observed.

CONCLUSION

we have shown that HIF-1α was strongly expressed in equine sarcoid. The upregulation of HIF-1α has been described in numerous tumors and can be modulated by many proteins encoded by transforming viruses. Thus, it is also possible that BPV could have a relevant role in HIF-1α pathway regulation, contributing to the development of equine sarcoids by promoting HIF-1α/VEGF mediated tumor angiogenesis.

Papillomaviruses: a systematic review

In the last decades, a group of viruses has received great attention due to its relationship with cancer development and its wide distribution throughout the vertebrates: the papillomaviruses. In this article, we aim to review some of the most relevant reports concerning the use of bovines as an experimental model for studies related to papillomaviruses. Moreover, the obtained data contributes to the development of strategies against the clinical consequences of bovine papillomaviruses (BPV) that have led to drastic hazards to the herds. To overcome the problem, the vaccines that we have been developing involve recombinant DNA technology, aiming at prophylactic and therapeutic procedures. It is important to point out that these strategies can be used as models for innovative procedures against HPV, as this virus is the main causal agent of cervical cancer, the second most fatal cancer in women.

How many papillomavirus species can go undetected in papilloma lesions?

A co-infection comprising to at least seven papillomavirus (PV) types was detected by next generation sequencing (NGS) of randomly primed rolling circle amplification (RCA) products of a bovine (Bos taurus) papilloma lesion from the Brazilian Amazon region. Six putative new PV types that could not be detected by commonly used PCR protocols were identified. Their overall L1 nucleotide identities were less than 90% compared to described PV species and types. L1 nucleotide BLAST sequence hits showed that each new type was related to Beta, Gamma, Dyokappa, Dyoeta, and Xipapillomavirus, as well as two likely new unclassified genera. Our results show that the employment of NGS is relevant to the detection and characterization of distantly related PV and is of major importance in co-infection studies. This knowledge will help us understand the biology and pathogenesis of PV, as well as contribute to disease control. Moreover, we can also conclude that there are many unknown circulating PVs.

Mutagenic Potential ofBos taurus Papillomavirus Type 1 E6 Recombinant Protein: First Description

Bovine papillomavirus (BPV) is considered a useful model to study HPV oncogenic process. BPV interacts with the host chromatin, resulting in DNA damage, which is attributed to E5, E6, and E7 viral oncoproteins activity. However, the oncogenic mechanisms of BPV E6 oncoprotein per se remain unknown. This study aimed to evaluate the mutagenic potential of Bos taurus papillomavirus type 1 (BPV-1) E6 recombinant oncoprotein by the cytokinesis-block micronucleus assay (CBMNA) and comet assay (CA). Peripheral blood samples of five calves were collected. Samples were subjected to molecular diagnosis, which did not reveal presence of BPV sequences. Samples were treated with 1 μg/mL of BPV-1 E6 oncoprotein and 50 μg/mL of cyclophosphamide (positive control). Negative controls were not submitted to any treatment. The samples were submitted to the CBMNA and CA. The results showed that BPV E6 oncoprotein induces clastogenesis per se, which is indicative of genomic instability. These results allowed better understanding the mechanism of cancer promotion associated with the BPV E6 oncoprotein and revealed that this oncoprotein can induce carcinogenesis per se. E6 recombinant oncoprotein has been suggested as a possible vaccine candidate. Results pointed out that BPV E6 recombinant oncoprotein modifications are required to use it as vaccine.

Bovine papillomavirus isolation by ultracentrifugation

The bovine papillomavirus (BPV) is the etiological agent of bovine papillomatosis, which causes significant economic losses to livestock, characterized by the presence of papillomas that regress spontaneously or persist and progress to malignancy. Currently, there are 13 types of BPVs described in the literature as well as 32 putative new types. This study aimed to isolate viral particles of BPV from skin papillomas, using a novel viral isolation method. The virus types were previously identified with new primers designed. 77 cutaneous papilloma samples of 27 animals, Simmental breed, were surgically removed. The DNA was extracted and subjected to PCR using Delta-Epsilon and Xi primers. The bands were purified and sequenced. The sequences were analyzed using software and compared to the GenBank database, by BLAST tool. The viral typing showed a prevalence of BPV-2 in 81.81% of samples. It was also detected the presence of the putative new virus type BR/UEL2 in one sample. Virus isolation was performed by ultracentrifugation in a single density of cesium chloride. The method of virus isolation is less laborious than those previously described, allowing the isolation of complete virus particles of BPV-2.

Bovine and Human Papillomaviruses

Fifty years ago, inoculation with bovine papillomavirus (BPV) was found to cause mesenchymal tumors of the skin in cattle and horses, as well as tumors of the bladder in cattle. Subsequent to these studies of BPVs, human papillomaviruses (HPVs) were found to cause cervical cancer resulting in intense research into papillomaviruses. During the past 50 years, the ways that HPVs and BPVs cause disease have been investigated, and both HPVs and BPVs have been associated with an increasingly diverse range of diseases. Herein, the biology, oncogenic mechanisms, and diseases associated with BPVs are compared with those of HPVs. As reviewed, there are currently significant differences between BPVs and HPVs. However, research 50 years ago into BPVs formed a prologue for the recognition that papillomaviruses have a significant role in human disease, and it is possible that future research may similarly reveal that BPVs are less different from HPVs than is currently recognized.