Cutaneous Human Papillomaviruses

University dissertation from Medical Microbiology, Lund University

Abstract: Human papillomaviruses (HPVs) exist as more than 100 distinct types. Variants of HPVs appear to be common findings while HPV subtypes have been considered rare. New information about subtypes has recently been reported by us. Our characterisation of subtype HPV38b[FA125] and the identification of several HPV isolates representing putative subtypes have considerably extended the knowledge about this taxon. Cutaneous HPVs are frequently found in healthy skin and some types have also been implicated in non-melanoma skin cancer in immunocompetent as well as in immunosuppressed individuals. However, data on whether these infections persist over time is limited. We recently reported that in a cohort of renal transplant recipients and matched healthy controls, 43% (19/44) of the cutaneous HPV infections persisted after 6.3 years. However, we did not detect any significant association between persistent infections and age, sex, immunosuppressive treatment, history of warts, or genus of HPV. The heterogeneity of cutaneous HPVs, especially in the genus Beta-papillomavirus, has been extended through our characterisation of three new types, HPV93, 96, and 107. The prevalence of these three types as well as HPV38 and its subtype HPV38b[FA125] and the recently described HPV92, was analysed in skin lesions and paired healthy skin. All types were only detected in low amounts and in low viral loads. However, the binding ability of the E7 protein of HPV92, 93 and 96 to the tumour suppressor protein Rb suggests a possible role for these types in the development of skin cancer.