Feline papillomas and papillomaviruses

Papillomaviruses (PVs) are highly species- and site-specific pathogens of s tratified squamous epithelium. Although PV infections in the various Felida e are rarely reported, we identified productive infections in six cat speci es. PV-induced proliferative skin or mucous membrane lesions were confirmed by immunohistochemical screening for papillomavirus-specific capsid antige ns. Seven monoclonal antibodies, each of which reacts with an immunodominan t antigenic determinant of the bovine papillomavirus L1 gene product, revea led that feline PV capsid epitopes were conserved to various degrees. This battery of monoclonal antibodies established differential expression patter ns among cutaneous and oral PVs of snow leopards and domestic cats, suggest ing that they represent distinct viruses. Clinically, the lesions in all sp ecies and anatomic sites were locally extensive and frequently multiple. Hi stologically, the areas of epidermal hyperplasia were flat with a similarit y to benign tumors induced by cutaneotropic, carcinogenic PVs in immunosupp ressed human patients. Limited restriction endonuclease analyses of viral g enomic DNA confirmed the variability among three viral genomes recovered fr om available frozen tissue. Because most previous PV isolates have been spe cies specific, these studies suggest that at least eight different cat papi llomaviruses infect the oral cavity (tentative designations: Asian lion, Pa nthera lee, P1PV; snow leopard, Panthera uncia, PuPV-1; bobcat, Felis rufus , FrPV; Florida panther, Felis concolor, FcPV; clouded leopard, Neofelis ne bulosa, NnPV; and domestic cat, Felis domesticus, FdPV-2) or skin (domestic cat, F. domesticus, FdPV-1; and snow leopard, P. uncia, PuPV-2).