Orf virus (ORFV) infection in a three-dimensional human skin model: Characteristic cellular alterations and interference with keratinocyte differentiation

PLoS One. 2019 Jan 30;14(1):e0210504. doi: 10.1371/journal.pone.0210504. eCollection 2019.

Abstract

ORF virus (ORFV) is the causative agent of contagious ecthyma, a pustular dermatitis of small ruminants and humans. Even though the development of lesions caused by ORFV was extensively studied in animals, only limited knowledge exists about the lesion development in human skin. The aim of the present study was to evaluate a three-dimensional (3D) organotypic culture (OTC) as a human skin model for ORFV infection considering lesion development, replication of the virus, viral gene transcription and modulation of differentiation of human keratinocytes by ORFV. ORFV infection of OTC was performed using the ORFV isolate B029 derived from a human patient. The OTC sections showed a similar structure of stratified epidermal keratinocytes as human foreskin and a similar expression profile of the differentiation markers keratin 1 (K1), K10, and loricrin. Upon ORFV infection, OTCs exhibited histological cytopathic changes including hyperkeratosis and ballooning degeneration of the keratinocytes. ORFV persisted for 10 days and was located in keratinocytes of the outer epidermal layers. ORFV-specific early, intermediate and late genes were transcribed, but limited viral spread and restricted cell infection were noticed. ORFV infection resulted in downregulation of K1, K10, and loricrin at the transcriptional level without affecting proliferation as shown by PCNA or Ki-67 expression. In conclusion, OTC provides a suitable model to study the interaction of virus with human keratinocytes in a similar structural setting as human skin and reveals that ORFV infection downregulates several differentiation markers in the epidermis of the human skin, a hitherto unknown feature of dermal ORFV infection in man.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Differentiation*
  • Cell Line
  • Cells, Cultured
  • Ecthyma, Contagious / genetics
  • Ecthyma, Contagious / metabolism
  • Ecthyma, Contagious / virology*
  • Foreskin / growth & development
  • Foreskin / metabolism
  • Foreskin / virology*
  • Gene Expression Profiling
  • Humans
  • Keratinocytes / metabolism
  • Keratinocytes / pathology
  • Keratinocytes / virology*
  • Keratins / genetics
  • Keratins / metabolism
  • Male
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism
  • Mice
  • Orf virus / physiology*
  • Organ Culture Techniques / methods*
  • Organogenesis
  • Sheep

Substances

  • Membrane Proteins
  • loricrin
  • Keratins

Grants and funding

This study was supported by Leipzig University. LS was funded by the PhD program from the Hanns Seidel Foundation, Germany (no grant number is available) (URL: https://www.hss.de/stipendium/auswahlverfahren/promotionsfoerderung/). MM received a fellowship from the Philipp Schwartz Initiative, which was launched by the Alexander von Humboldt Foundation together with the German Federal Foreign Office (no grant number is available). URL://www.humboldt-foundation.de/web/philipp-schwartz-initiative.html. The commercial affiliation of GK (Klinikum Fulda gAG) and SS (IDT Biologika GmbH) did not play a role in the study. Both commercial companies did not have a role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ‘author contribution’ section.