Identification of bovine papillomavirus type 1 and 2 from bovine anogenital fibropapillomas

An investigation of bovine papillomaviruses from ocular squamous cell carcinomas in cattle

Background

Ocular squamous cell carcinomas (OSCCs) in cattle has been studied for many years, but no definite etiology has been established. Squamous cell carcinomas (SCCs) may occur in different body parts of cattle. Depending on the location, it can cause an economic loss of varying degrees.

Aims

The aim of this study was to investigate the causes of OSCCs in the eye region of cattle. Methods: Sixty tumoral masses taken form 60 cattle with proliferation in the eye region that were collected between the years 2012-2022 were used. These cases were admitted to our department for routine diagnosis. The tissues were diagnosed as OSCC using histopathological methods. The presence of bovine papillomavirus (BPV), one of the causative factors, was investigated using immunohistochemical and polymerase chain reaction (PCR).

Results

Macroscopically masses were nodular or cauliflower-like and fragile and had hemorrhagic surfaces. Considering the keratin pearls, tumoral islands, and squamous differentiation, 20 out of 60 cases were classified as well, 20 as moderately, and 20 as poorly-differentiated OSCCs. 47 of the 60 cases were BPV positive using immunohistochemical methods. However, BPV nucleic acid was detected in only two cases with PCR. Only one of the cases could be sequenced. After phylogenetic analysis, virus strain was identified as BPV-1.

Conclusion

Our results indicated that papillomaviruses can contribute to the development of OSCCs, in both precursor lesions and also advanced stage OSCCs. We found that BPV-1 has a possible causative role; however, more studies are needed to investigate the role of other viral agents and their interaction with secondary factors.

Full-genome characterization of a novel Felis catus papillomavirus 4 subtype identified in a cutaneous squamous cell carcinoma of a domestic cat

The present study describes two full-genome sequences of Felis catus papillomavirus type 4 (FcaPV4) identified in squamous cell carcinoma (SCC) of two domestic cats. Two full-genome sequences of FcaPV4 were detected and characterized by PCR and sequencing. The L1 nucleotide sequence homology of one case showed 95.70% sequence identity to the reference FcaPV4, suggesting that this isolate should be classified as a subtype. Reverse-transcriptase PCR (RT-PCR) of two oncogenes, E6 and E7 was performed to confirm mRNA expression. Expression of E6 and E7 mRNA was detected in both cases, suggesting that FcaPV4 contributes to the development of SCC. This is the first report of FcaPV4 subtype. The present study will update the genomic features of FcaPV4 and contribute to deepening our knowledge about the etiological roles of FcaPV4 in feline cutaneous SCC.

Genomic characterisation of bovine papillomavirus types 1 and 2 identified in equine sarcoids in Japan

BACKGROUND

Bovine papillomavirus types 1 and 2 (BPV1/2) infection in horses has been associated with the development of equine sarcoids. Previous findings revealed the presence of sarcoid-associated BPV sequence variants that have been proposed as a key factor of cross-species infection in horses. To verify this hypothesis, sarcoid-associated BPV variants should be identified regardless of geographic location.

OBJECTIVES

Sequence analyses of BPV1/2 derived from both horses and cattle were conducted to clarify the sarcoid-associated sequence variants. The aim of this study was to clarify the correlation between BPV phylogeny and the geographic origin/host species.

STUDY DESIGN

Cross-sectional study.

METHODS

Conventional PCR to detect BPV1/2 was performed with genomic DNA extracted from equine sarcoid (n = 10) and bovine papilloma (n = 10) samples collected in Japan. Direct sequencing results were compared between equine and bovine (equine/bovine)-derived BPV to identify sarcoid-associated variants of two early regions (E2, E5), one late region (L1) and the long control region (LCR). Phylogenetic and phylogeny-trait correlation were analysed using Bayesian Markov chain Monte Carlo (MCMC) method and Bayesian tip-association significance testing (BaTS).

RESULTS

Seven BPV1 and three BPV2 were identified from equine sarcoids using PCR and direct sequencing. Sequence analysis of equine/bovine-derived samples showed no sarcoid-associated variants in four regions (E2, E5, L1 and LCR) of either BPV1 or BPV2. The phylogenetic tree of BPV1 E2, L1 and LCR tended to cluster within its geographic origins. BaTS analysis demonstrated that BPV1 sequence variability may be due to the geographic origin rather than host species difference.

MAIN LIMITATIONS

There was a limitation in sample numbers.

CONCLUSIONS

This study supports the geographic-specific hypothesis of sequence variability, suggesting that BPV1 is shared between local equids and bovids. However, more extensively collected sequences worldwide and functional evaluations are needed to verify the geographic-specific sequence variability of BPV1/2 between equine- and bovine-derived sequence.

Anogenital-Associated Papillomaviruses in Animals: Focusing on Bos taurus Papillomaviruses

In contrast to the diverse studies on human papillomaviruses (HPVs), information on animal PVs associated with anogenital lesions is limited. In the animal kingdom, papillomas occur more commonly in cattle than in any other animals, and diverse types of Bos taurus papillomaviruses (BPVs) exist, including the very recently discovered BPV type 29 (BPV29). From this perspective, we will review previous studies describing PV types associated with anogenitals in animals, with a focus on BPVs. To date, two classical BPV types, classified into Deltapapillomavirus (BPV1 and BPV2) and Dyokappapapillomavirus (BPV22), and two novel Xipapillomaviruses (BPV28 and BPV29) have been identified from anogenital lesions and tissues of the domestic cow. Due to the limited reports describing anogenital-associated PVs in animals, the relationships between their phylogenetic and pathogenetic properties are still undiscovered. Animal studies are valuable not only for the veterinary field but also for human medicine, as animal diseases have been shown to mimic human diseases. Studies of anogenital-associated PVs in animals have a positive impact on various research fields.

Characterization of Bovine papillomavirus 28 (BPV28) and a novel genotype BPV29 associated with vulval papillomas in cattle

Papillomavirus (PV) infections are associated with the development of cutaneous and mucosal tumors in humans and various animal species. In humans, infection of high-risk human PVs (HPVs) causes anogenital cancers, while in animals, anogenital-associated PVs are not well understood. Among animal PVs, Bos taurus PVs (BPVs) have the most diverse genotypes, up to 28 of them. The present study will report two unique BPVs identified in vulval papilloma lesions from two Holstein Friesian cattle by conventional PCR and sequencing. In the first case, BPV28 harboring two L1 open reading frames (ORFs) due to a five-nucleotide deletion was identified. In the second case, histologically diagnosed as papilloma, an unclassified BPV genotype was detected. However, in both cases, the immunohistochemistry against PV antigen was negative. The full genome of the unclassified BPV was amplified by inverse PCR and analyzed by genome-walking sequencing. The L1 nucleotide sequence was most identical to BPV genotype 6 (BPV6), showing 78 % identity, indicating that this novel BPV should be classified as species Xipapillomavirus 1, genotype BPV29. The mRNA expression of three early genes (E1, E2, E10), but not L1, was confirmed in both BPV28- and BPV29-detected papilloma lesions. The present study suggests the involvement of novel types of BPV in vulval papilloma. The alteration of BPV28 pathogenicity due to the frameshift mutation of L1 needs to be elucidated in the future.