Development of immunodiagnostic tools for in situ investigation of Ovis aries papillomavirus 3 (OaPV3)

Cutaneous squamous cell carcinoma (cSCC) is a malignant lesion characterized by proliferation and transformation of keratinocytes in the epidermis and infiltrating derma. cSCC is reported in domestic and wild animal species, worldwide. The occurrence and development of cSCC rely on synergic multifactorial conditions, most importantly sunlight exposure and Papillomavirus (PV) infection. In sheep, the development of such lesions represents a threat both to animal welfare and milk production. Ovis aries papillomavirus 3 (OaPV3) is the main cSCC viral determinant and oncogenic properties of viral E6 and E7 proteins were preliminarily investigated. However, E6 and E7 role and mechanisms resulting in cSCC have not been fully clarified, mainly due to the lack specific immunological tools, such as antibodies for in situ detection of ovine papillomavirus. This paper reports the development of specific serological tools for the investigation of OaPV3 pathogenicity, and their preliminary use to screen 4 ovine cSSC formalin-fixed paraffin embedded tissues. Relevance of immunological tools to investigation of viral biological properties and diagnosis are also discussed.