Productive Infection of Bovine Papillomavirus Type 2 in the Urothelial Cells of Naturally Occurring Urinary Bladder Tumors in Cattle and Water Buffaloes

Abstract

BackgroundPapillomaviruses (PVs) are highly epitheliotropic as they usually establish productive infections within squamous epithelia of the skin, the anogenital tract and the oral cavity. In this study, early (E) and late (L) protein expression of bovine papillomavirus type 2 (BPV-2) in the urothelium of the urinary bladder is described in cows and water buffaloes suffering from naturally occurring papillomavirus-associated urothelial bladder tumors.Methods and FindingsE5 protein, the major oncoprotein of the BPV-2, was detected in all tumors. L1 DNA was amplified by PCR, cloned and sequenced and confirmed to be L1 DNA. The major capsid protein, L1, believed to be only expressed in productive papillomavirus infection was detected by Western blot analysis. Immunohistochemical investigations confirmed the presence of L1 protein both in the cytoplasm and nuclei of cells of the neoplastic urothelium. Finally, the early protein E2, required for viral DNA replication and known to be a pivotal factor for both productive and persistent infection, was detected by Western blot and immunohistochemically. Electron microscopic investigations detected electron dense particles, the shape and size of which are consistent with submicroscopic features of viral particles, in nuclei of neoplastic urothelium.ConclusionThis study shows that both active and productive infections by BPV-2 in the urothelium of the bovine and bubaline urinary bladder can occur in vivo.

Genetic characterization of Amazonian bovine papillomavirus reveals the existence of four new putative types

“…The histopathological findings of the samples are consistent with those lesions typically observed in papilloma lesions [17,24,25] but no fibroblast proliferation was observed, ergo clinical and histopathological findings confirmed the diagnosis of papillomatosis. The majority of the strains clustered within the Deltapapillomavirus genus that encompasses the BPV types considered to be etiological agents of papillomatosis in cattle [12,13,17,18], sarcoid disease in horses [4,5,26], as well as urinary bladder in cow [27]. BPVs 1 and 2 are the most common BPV types distributed worldwide and unusually, they have the ability to infect not only bovines but also other species such as equines [4,5,26], yaks [28], and buffalos [27,29].…”

“…The majority of the strains clustered within the Deltapapillomavirus genus that encompasses the BPV types considered to be etiological agents of papillomatosis in cattle [12,13,17,18], sarcoid disease in horses [4,5,26], as well as urinary bladder in cow [27]. BPVs 1 and 2 are the most common BPV types distributed worldwide and unusually, they have the ability to infect not only bovines but also other species such as equines [4,5,26], yaks [28], and buffalos [27,29]. In Brazil, these BPV types were already described in studies carried out in cattle herds from the Southern, South-East and North-East regions [13,18,30,31], and the present findings reveals that they are also present in the Amazon region of Brazil.…”

Bovine Papillomavirus Type 2 Infection and a Series of Mesenchymal Tumors of the Urinary Bladder in Cattle

“…It is well known that papillomavirus L1 protein plays a central role both in infection and immunogenicity [44]. It has just been shown that L1 protein is surprisingly expressed in high-grade bladder cancer of ruminants [45]. L1 protein expression may contribute to chronic inflammation of tumor stroma known to have an important role in the progression and metastasis of tumors.…”

Papillomaviruses in ruminants: An update

“…Bladder carcinomas are relatively common in cattle grazing on bracken fern in synergy with BPV1 and BPV2 (Roperto et al., ; Roperto, Russo, Ozkul, Corteggio, et al., ; Roperto, Russo, Sepici‐Dincel, et al., ; Wosiacki, Reis, Alfieri, & Alfieri, ). They were also detected in buffaloes and yaks, although sporadically (Roperto, Russo, Ozkul, Corteggio, et al., ; Roperto, Russo, Sepici‐Dincel, et al., ).…”