A novel papillomavirus identified in multiple skin neoplasms in twin goats

Papillomaviruses (PV) have rarely been found in caprineneoplasms, and never in multiple coexisting tumours. We describe a novel papillomavirus in multiple neoplasticlesions in two adult twin goats. Anatomo-histopathological,immunohistochemical and ultrastructural investigationscharacterized the neoplasms as two ocular squamous cellcarcinomas, an ocular sarcoma, an ocular fibrosarcoma, acutaneous malignant melanoma, multiple cutaneousfibropapillomas and squamous cell carcinomas. No viralparticles were detected by ultrastructural investigations.Immunohistochemical staining was positive for papillomavirusantigen (L-1) only in the ocular squamous cell carcinomas.Immunohistochemistry for HSP 27 and HSP 73,involved in PV assembly, showed increased expression inthe tumoral cells. Polymerase chain reaction (PCR) withseveral sets of degenerate and consensus primers for PVindicated the presence of amplified product. Sequencesearching/alignment in the data bank showed homologiesto human, chimpanzee, and bovine PV. Our sequencesshowed also homology, but not identity, to a recentlysequenced papillomavirus found in healthy goat. New setsof primers were optimized to detect both goat PV. PCRwith these primers seems to indicate a low copy numberof PV in the samples. In situ hybridization showed nuclearpositivity exclusively in the neoplastic goat skin. Multiplyprimed rolling-circle amplification (RCA) demonstrated thepresence of circular DNA sequences referable to a DNApapillomavirus. This study indicates the existence of differentPV in caprine species, which may be implicated inthe development of some tumours in sibling animals.[...]