Viral sequences related to a human skin papillomavirus in genital warts

Abstract

GENITAL WARTS (condylomata acuminata) are benign tumours which are mostly venereally transmitted¹; their malignant conversion has been observed only rarely (see refs 2, 3 for reviews). Typical viral particles, long believed to be those of the human papillomavirus (HPV) found in skin warts⁴, were observed irregularly in these lesions^5–7. Epidemiological¹ and serological⁶ data, as well as molecular hybridisation experiments showing the absence of DNA sequences homologous to skin HPV DNA in condylomas^8,9, have raised the possibility that these lesions are due to a distinct HPV. However, the demonstration of at least four distinct HPV types in skin lesions^10–13 requires a reexamination of this problem. We have identified four types of HPV showing little, if any, DNA sequence homology and distinct serological properties: HPV type 1 (HPV-1) associated with deep plantar warts¹², HPV type 2 (HPV-2) isolated from common warts¹², HPV type 3 (HPV-3) found in flat warts and in flat wart-like lesions of patients suffering from epidermodysplasia verruciformis (EV)¹³ and HPV type 4 (HPV-4) isolated from morphologically distinct EV lesions (reddish or pityriasis versicolor-like plaques)¹³. HPV-4 is found more frequently than HPV-3 in patients with EV showing a malignant conversion of some lesions^13,22. We report here RNA–DNA hybridisation data indicating that genital warts are associated with an HPV showing little, if any, DNA sequence homology with HPV-1, HPV-2 and HPV-3 and a low extent of homology with an HPV-4 isolate taken as prototype in previous studies¹³.