Detection of new human papillomavirus sequences in skin lesions of a renal transplant recipient and characterization of one complete genome related to epidermodysplasia verruciformis-associated types.

Human papillomavirus (HPV) DNA, originally isolated from patients suffering from the skin disease epidermodysplasia verruciformis (EV), and a growing number of related sequences have recently been detected in a high percentage of benign and malignant skin lesions of both immunosuppressed and immunocompetent people. HPV L1 DNA fragments (374-389 bp long) from a solar keratosis and a squamous cell carcinoma (SCC) of a renal transplant recipient were amplified, cloned and sequenced. In 54 clones, six different HPV sequences were identified. One of these six corresponded to the known type HPV-8 and two (RTRX3 and RTRX7) have been described previously in cutaneous lesions of immunosuppressed patients. The remaining three sequences were different from all known HPV types: an HPV-9-related sequence (77.4% identity), an RTRX2-related sequence (82.6% identity), and an HPV-22-related sequence (83.7% identity). These three sequences, representing putatively new HPV types, were named RTRX8, RTRX9 and RTRX10, respectively. RTRX7 was found in the majority of clones from both lesions. The complete genome of RTRX7 (7731 bp) was cloned as six overlapping subgenomic fragments, generated by nested PCR with DNA extracts from the SCC. RTRX7 showed a genome organization typical of HPVs associated with EV. The L1 DNA sequence differed by 15% from the corresponding region of its closest known relative, HPV-12; thus, RTRX7 can be regarded as a new HPV type. RTRX7 DNA could not be detected by Southern blot hybridization with the homologous probe, indicating that the DNA concentration was below one copy per 10 cells in the investigated SCC.