Subfamily: Firstpapillomavirinae

Genus: Betapapillomavirus

Distinguishing features

Members of this genus typically cause latent infections. However, in patients with specific (immune) disorders, members of this genus can cause warts or progress to cutaneous squamous cell carcinomas (SCC). Patients suffering from the rare disease epidermodysplasia verruciformis (EV) are at a higher risk of developing SCC, and certain members of the genus Betapapillomavirus have been implicated (Arnold and Hofbauer 2012). Recent evidence suggests that, in the general population, certain betapapillomavirus types may be a co-factor in the development of SCC. Remarkably, these betapapillomavirus types are not detected in most SSC, suggesting that viral proteins may not be required to maintain the malignant SCC lesions. Members of the genus Betapapillomavirus are also the most common human papillomavirus (HPV) types found in the human oral cavity and some have been prospectively associated with oropharyngeal cancer development (Agalliu et al., 2016). 

Virion

See discussion under family description. 

Genome organization and replication

See discussion under family description. 

Biology

See discussion under family description. 

Species demarcation criteria

Putative novel papillomavirus genome with complete genome sequence data available and that is <70% related to papillomaviruses within the genus (Figure 1. Betapapillomavirus). 

Figure 1. . Betapapillomavirus. Phylogenetic tree of members of the genus Betapapillomavirus. The E1, E2, L2, and L1 nucleotide sequences of 343 papillomavirus isolates including representatives of all species and genera within the Papillomaviridae family were aligned as amino acid sequences using MUSCLE v7.221 (Edgar 2004). JModeltest2 (Darriba et al., 2012) was used to determine the optimal model of evolution (GTR + I + G) for the concatenated nucleotide sequences. Maximum likelihood (ML) trees were constructed using RAxML MPI v8.2.9 (Stamatakis 2006) implementing the GTR substitution model. ML bootstrap analysis used the autoMRE-based stopping criterion in RAxML. Following tree construction (tree available in the Resources section of the Papillomaviridae Report), the subtree corresponding to the genus Betapapillomavirus was isolated. Tips are labelled with virus names and accession numbers; nodes are labelled with bootstrap support values.

Related, unclassified viruses

Virus names and virus abbreviations are not official ICTV designations.