HPV Type 16 Infection Switches Keratinocytes from Apoptotic to Proliferative Fate under TWEAK/Fn14 Interaction

J Invest Dermatol. 2015 Oct;135(10):2427-2436. doi: 10.1038/jid.2015.201. Epub 2015 May 27.

Abstract

Previously, tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK) had been known to be an inducer of apoptosis of keratinocytes by engaging the Fn14 receptor. However, the high-risk human papillomavirus (HPV) infection confers a proliferation advantage on keratinocytes that may consequently harbor tumorigenicity. This study was designed to investigate the cross-talk in keratinocytes between TWEAK/Fn14 signaling and HPV type 16 infection, which may cooperate in regulating cell-cycle progression. TWEAK and Fn14 expression was determined in anogenital warts and normal skin. Both primary keratinocytes and HaCaT cells were transfected with HPV16 E6/E7 genes. The results showed that Fn14 is highly expressed upon HPV16 transfection and accompanied by an increase in Ras GTPase activity and TNF-receptor-associated factor 2 (TRAF2) expression. Moreover, the E6/E7-transfected keratinocytes exhibit a shift of TNF receptor profile from type 1 to type 2 and weakened apoptotic response to TNF-α stimuli, when compared with the normal control. Surprisingly, significant increase in proliferation but not apoptosis was seen in E6/E7-positive keratinocytes, as TWEAK was additionally supplemented. In conclusion, the HPV16 infection in keratinocytes causes a switch of apoptotic to proliferative fate under TWEAK/Fn14 interaction, possibly by favoring Ras and TRAF2 activation and modulating TNF receptor expression.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis / genetics*
  • Apoptosis / physiology
  • Biopsy, Needle
  • Blotting, Western
  • Cell Proliferation
  • Cells, Cultured
  • Flow Cytometry
  • Human papillomavirus 16 / isolation & purification*
  • Humans
  • Immunohistochemistry
  • Keratinocytes / cytology
  • Keratinocytes / metabolism
  • Papillomavirus Infections / pathology*
  • Real-Time Polymerase Chain Reaction / methods
  • Receptors, Tumor Necrosis Factor / genetics*
  • Sensitivity and Specificity
  • TWEAK Receptor
  • Tissue Culture Techniques
  • Transfection

Substances

  • Receptors, Tumor Necrosis Factor
  • TNFRSF12A protein, human
  • TWEAK Receptor