Differences in Transcriptional Activity of Human Papillomavirus Type 6 Molecular Variants in Recurrent Respiratory Papillomatosis

PLoS One. 2015 Jul 7;10(7):e0132325. doi: 10.1371/journal.pone.0132325. eCollection 2015.

Abstract

A significant proportion of recurrent respiratory papillomatosis (RRP) is caused by human papillomavirus type 6 (HPV-6). The long control region (LCR) contains cis-elements for regulation of transcription. Our aim was to characterize LCR HPV-6 variants in RRP cases, compare promoter activity of these isolates and search for cellular transcription factors (TFs) that could explain the differences observed. The complete LCR from 13 RRP was analyzed. Transcriptional activity of 5 variants was compared using luciferase assays. Differences in putative TFs binding sites among variants were revealed using the TRANSFAC database. Chromatin immunoprecipation (CHIP) and luciferase assays were used to evaluate TF binding and impact upon transcription, respectively. Juvenile-onset RRP cases harbored exclusively HPV-6vc related variants, whereas among adult-onset cases HPV-6a variants were more prevalent. The HPV-6vc reference was more transcriptionally active than the HPV-6a reference. Active FOXA1, ELF1 and GATA1 binding sites overlap variable nucleotide positions among isolates and influenced LCR activity. Furthermore, our results support a crucial role for ELF1 on transcriptional downregulation. We identified TFs implicated in the regulation of HPV-6 early gene expression. Many of these factors are mutated in cancer or are putative cancer biomarkers, and must be further studied.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Cell Line
  • Genetic Variation*
  • Human papillomavirus 6 / genetics*
  • Humans
  • Molecular Sequence Data
  • Papillomavirus Infections / genetics*
  • Papillomavirus Infections / virology*
  • Promoter Regions, Genetic
  • Protein Binding
  • Respiratory Tract Infections / genetics*
  • Respiratory Tract Infections / virology*
  • Transcription Factors / metabolism
  • Transcription, Genetic*

Substances

  • Transcription Factors

Supplementary concepts

  • Recurrent respiratory papillomatosis

Associated data

  • GENBANK/KF436496
  • GENBANK/KF436497
  • GENBANK/KF436498
  • GENBANK/KF436499
  • GENBANK/KF436500
  • GENBANK/KF436501
  • GENBANK/KF436502
  • GENBANK/KF436503
  • GENBANK/KF436504
  • GENBANK/KF436505
  • GENBANK/KF436506
  • GENBANK/KF436507
  • GENBANK/KF436508
  • GENBANK/KF436509

Grants and funding

This work was supported by Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) (grant numbers 10/00029-0 to CMB and 08/57889-1 to LLV); Conselho Nacional de Desenvolvimento Científico e Tencnológico (CNPq) (grant number 573799/2008-3 to LLV); and Ludwig Institute for Cancer Research. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.