Human papillomavirus (HPV) types 101 and 103 isolated from cervicovaginal cells lack an E6 open reading frame (ORF) and are related to gamma-papillomaviruses

Complete genomes of HPV101 and HPV103 were PCR amplified and cloned from cervicovaginal cells of a 34-year-old female with cervical intraepithelial neoplasia grade 3 (CIN 3) and a 30-year-old female with a normal Pap test, respectively. HPV101 and HPV103 contain 4 early genes (E7, E1, E2, and E4) and 2 late genes (L2 and L1), but both lack the canonical E6 ORF. Pairwise alignment similarity of the L1 ORF nucleotide sequences of HPV101 and HPV103 indicated that they are at least 30% dissimilar to each other and all known PVs. However, similarities of the other ORFs (E7, E1, E2, and L2) indicated that HPV101 and HPV103 are most related to each other. Phylogenetic analyses revealed that these two types form a monophyletic clade, clustering together with the gamma- and pi-PV groups. These data demonstrated that HPV genomes closely related to papillomaviruses identified from cutaneous epithelia can be isolated from the genital mucosal region. Moreover, this is the first report of HPVs lacking an E6 ORF and phylogenetic evidence suggests this occurred subsequent to their emergence from the gamma-/pi-PVs.