Characterization of two novel cutaneous human papillomaviruses, HPV93 and HPV96.

Two novel human papillomaviruses (HPVs), HPV93 and HPV96, with genomes of 7450 and 7438 bp, respectively, are described. The L1 open reading frame of HPV93 showed highest identity to HPV24 (79%) and that of HPV96 had highest identity to HPV92 (71%). Real-time PCR for HPV92, 93 and 96 on stripped biopsies from tumours and healthy skin from 269 immunocompetent patients found HPV DNA in 2.6% of tumours and in 0.4% of healthy skin samples. Double infections were observed in two tumours. HPV92 was detected in four, HPV93 in two and HPV96 in three tumours. The range of viral loads spanned from one copy per 45 cells to one copy per 10,000 cells. The E7 proteins of HPV92, 93 and 96 were found to bind the retinoblastoma protein (pRb). These results suggest a possible role for these HPV types in skin carcinogenesis that deserves further study.