HPV16 whole genome minority variants in persistent infections from young Dutch women

Abstract

Background: Chronic infections by one of the oncogenic human papillomaviruses (HPVs) are responsible for near 5% of the global cancer burden and HPV16 is the type most often found in cancers. HPV genomes displayunexpected levels of variation when deep-sequenced. Minor nucleotide variations (MNVs) may reveal HPVgenomic instability and HPV-related carcinogenic transformation of host cells. Objectives: The objective of this study was to investigate HPV16 genome variation at the minor variant level onpersisting HPV16 cervical infections from a population of young Dutch women. Study design:15 HPV16 infections were sequenced using a whole-HPV genome deep sequencing protocol (TaME-seq). One infection was followed over a three-year period, eight were followed over a two-year period, threewere followed over a one-year period and three infections had a single sampling point. Results and conclusions: Using a 1% variant frequency cutoff, we find on average 48 MNVs per HPV16 genomeand 1717 MNVs in total when sequencing coverage was > 100 × . Wefind the transition mutation T > C to be the most common, in contrast to other studies detecting APOBEC-related C > T mutation profiles in pre-cancerous and cancer samples. Our results suggest that the relative mutagenic footprint of HPV16 genomes may differ between the infections in this study and transforming lesions. In addition, we identify a number of MNVs that have previously been associated with higher incidence of high-grade lesions (CIN3+) in a population study. These findings may provide a starting point for future studies exploring causality between emerging HPV minorgenomic variants and cancer development.