Sublingual papillomas of cheetahs in southern Africa

Nine distinct papillomaviruses (Lambdapapillomavirus) have been described in domestic and nondomestic cats, but not in cheetahs. These viruses have been associated with cutaneous papillomas or plaques, bowenoid in situ carcinomas, feline cutaneous squamous cell carcinomas (SCC), feline sarcoids, and oral (often sublingual) papillomas. Fourteen cheetahs from the AfriCat foundation (Namibia) and one from the Ann van Dyk Cheetah center (South Africa) presented with sublingual lesions reminiscent of sublingual papillomas. Two animals were biopsied and the histopathology revealed benign proliferative epithelial lesions with prominent thickening of the overlying squamous epithelium. Throughout the squamous epithelial layers were cells with nuclear enlargement, irregularity of the nuclear membranes and cell contours, focal hyperchromasia of the nuclei, and perinuclear halos, reminiscent of a virus-associated process as seen in papillomavirus infections. Thirteen more cheetahs were sampled and the tissue snap frozen for molecular characterization. Amplification and sequencing of the papillomavirus L1, E6, E7, and E1 gene regions was achieved with modified primers. Maximum likelihood phylogenetic analyses revealed all 15 cheetah papilloma samples were 99.99% genetically similar and closely related to, but genetically distinct from any known felinepapillomaviruses. All cheetahs were FIV and FeLV negative. The results suggest the samples identified in this study can be considered a previously undescribed or novel feline papillomavirus and the authors propose “Acinonyx jubatus papillomavirus type 1” (AjPV-1), within the Lambdapapillomavirus 1 genus (Family: Papillomaviridae).