Characterization of human papillomavirus type 45, a new type 18-related virus of the genital tract.

DNA of human papillomavirus (HPV) type 45, a new HPV type 18-related papillomavirus of the genital tract, was cloned from a recurrent cervical lesion displaying mild to moderate dysplasia with koilocytosis. HPV-45 DNA was identified in paraffin sections of biopsies of both the initial and recurrent lesions of the patient, taken 7 months apart. HPV-45 DNA hybridized efficiently to that of many different HPV types under low and moderate stringency conditions (Tm - 37 degrees C to Tm - 25 degrees C) but with only HPV-18 DNA under high stringency conditions (Tm - 17 degrees C). HPV-45 DNA was distinguished from HPV-18 DNA by (i) differences in restriction enzyme digest patterns, (ii) lack of hybridization at Tm - 17 degrees C between HPV-18 and some fragments of HPV-45, (iii) a value of 25% in liquid reassociation kinetics between HPV-18 and HPV-45 and (iv) differences in intensities of hybridization with selected tissue DNAs. The prevalence of HPV-45 infection in the genital tract was low. In tests of over 600 tissue DNAs from female genital tract lesions, HPV-45 sequences were detected in three additional tissues, one each of invasive cervical carcinoma, condyloma, and normal cervical epithelium. HPV-45 is a newly recognized papillomavirus which rarely infects the genital tract and is associated with lesions across a wide histological spectrum.