Identification of virus-encoded microRNAs in divergent Papillomaviruses

PLoS Pathog. 2018 Jul 26;14(7):e1007156. doi: 10.1371/journal.ppat.1007156. eCollection 2018 Jul.

Abstract

MicroRNAs (miRNAs) are small RNAs that regulate diverse biological processes including multiple aspects of the host-pathogen interface. Consequently, miRNAs are commonly encoded by viruses that undergo long-term persistent infection. Papillomaviruses (PVs) are capable of undergoing persistent infection, but as yet, no widely-accepted PV-encoded miRNAs have been described. The incomplete understanding of PV-encoded miRNAs is due in part to lack of tractable laboratory models for most PV types. To overcome this, we have developed miRNA Discovery by forced Genome Expression (miDGE), a new wet bench approach to miRNA identification that screens numerous pathogen genomes in parallel. Using miDGE, we screened over 73 different PV genomes for the ability to code for miRNAs. Our results show that most PVs are unlikely to code for miRNAs and we conclusively demonstrate a lack of PV miRNA expression in cancers associated with infections of several high risk HPVs. However, we identified five different high-confidence or highly probable miRNAs encoded by four different PVs (Human PVs 17, 37, 41 and a Fringilla coelebs PV (FcPV1)). Extensive in vitro assays confirm the validity of these miRNAs in cell culture and two FcPV1 miRNAs are further confirmed to be expressed in vivo in a natural host. We show that miRNAs from two PVs (HPV41 & FcPV1) are able to regulate viral transcripts corresponding to the early region of the PV genome. Combined, these findings identify the first canonical PV miRNAs and support that miRNAs of either host or viral origin are important regulators of the PV life cycle.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Gene Expression Profiling / methods*
  • Gene Expression Regulation, Viral / genetics*
  • HEK293 Cells
  • Humans
  • MicroRNAs / genetics*
  • Papillomaviridae / genetics*
  • Papillomavirus Infections / genetics
  • RNA, Viral / analysis*
  • RNA, Viral / genetics
  • Transcriptome

Substances

  • MicroRNAs
  • RNA, Viral

Grants and funding

This work was supported by a Burroughs Wellcome Investigators in Pathogenesis Award and a grant from the Cancer Prevention and Research Institute of Texas [RP140842] to CSS. AG is supported by the Free and Hanseatic City of Hamburg and the Federal Ministry of Health (BMG). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.