Bovine papillomavirus E2 and E5 gene expression in sperm cells of healthy bulls

Abstract

Papillomaviruses are found in epithelial lesions and are linked to different carcinogenic processes in humans and other animals. Although BPV has been characterized as epitheliotropic, the presence of viral DNA has been detected in other tissues and fluids, such as fresh semen. The aim of this study was to evaluate the presence and expression of BPV in sperm cells of bulls (Bos taurus) asymptomatic for papillomatosis. A PCR assay was carried out with specific primers to test BPV2 in 26 semen samples. The presence of BPV transcripts was assessed by RT-PCR to E2 and E5 genes. BPV2 DNA was detected in nine out of 26 samples and the expression of E2 and E5 were detected in five out of nine BPV positive samples. This is the first record of BPV2 expression in bull sperm cells.Keywords Bovine papillomavirus Á Semen Á Viral gene expression Papillomaviruses (PVs) are double-stranded DNA tumour viruses identified in a broad range of animal species that belongs to the amniotes, including human being [1]. So far, 13 genotypes of Bovine papillomavirus (BPV1-13) have been characterized [21] and classified in three different genera: Deltapapillomaviruses (BPV1 and 2), Epsilonpapillomaviruses (BPV5 and 8) and Xipapillomaviruses (BPV3, 4, 6, 9, 10 and 11). BPV7 is classified as an unassigned PV genus [12,14]. BPVs from Delta-PVs and BPV5 can infect epithelial and subepithelial fibroblasts inducing fibro-epithelial tumours in cattle, known as fibropapillomas while BPVs from another genus can induce true papillomas [22]. Normally, papillomas regress as a result of cellmediate immune response [17]. However, occasionally papillomas may develop in squamous cell carcinoma as a result of involvement of environmental and genetic cofactors [3,5]. Recently, the co-infection among BPVs in skin lesions (warts) has been described, but the real significance of this finding need to be clarified [7,25,31].PVs are described as epitheliotropic viruses, although their presence has been detected in different tissues and cells [11,20,36]. Few studies have contributed to improved understanding of PV transmission, however, its spread through non-epithelial, however, its spreading of through non-epithelial tissues and fluids has been suggested [6,11].In humans, infected sperm are able to penetrate the oocyte, to deliver HPV genome in the oocyte and HPV genes can be actively transcribed by the fertilized oocyte [10]. There are few reports focusing on the study of BPV in reproductive tract and its cells [13,35] although the BPV-1 were described in the prepuce and penis [16] and BPV-2 were found infecting placenta and actively expressed in equine semen [30,34]. In an early study, we demonstrate the high incidence of BPV2 in commercial doses of bull semen from national and multinational companies [33]. However, studies are needed to understand the biological significance of BPV presence in semen. The present study aimed to evaluate the presence of BPV in sperm cells of healthy bull, as well as the viral gene expression. The semen was collected fro...

Design, synthesis, and evaluation of peptides derived from L1 protein against bovine papillomavirus-1/2 identified along Mexico’s cattle export route

“…In contrast, we targeted L1 and L2 genes, genotype-specific sequences, and performed another sequencing for double-checking. These proteins are expressed only in keratinocytes or permissive cells in which the virus is assembled ( 24 , 26 ), which highlights the importance of the sampling methodology. Bovine papillomaviruses 1 and 2 were identified in samples from Nuevo León, Veracruz, Chiapas and Tabasco, which corroborates what Rojas et al .…”