ISG15/USP18/STAT2 is a molecular hub regulating IFN I-mediated control of Dengue and Zika virus replication

Front Immunol. 2024 Feb 7:15:1331731. doi: 10.3389/fimmu.2024.1331731. eCollection 2024.

Abstract

The establishment of a virus infection is the result of the pathogen's ability to replicate in a hostile environment generated by the host's immune system. Here, we found that ISG15 restricts Dengue and Zika viruses' replication through the stabilization of its binding partner USP18. ISG15 expression was necessary to control DV replication driven by both autocrine and paracrine type one interferon (IFN-I) signaling. Moreover, USP18 competes with NS5-mediated STAT2 degradation, a major mechanism for establishment of flavivirus infection. Strikingly, reconstitution of USP18 in ISG15-deficient cells was sufficient to restore the STAT2's stability and restrict virus growth, suggesting that the IFNAR-mediated ISG15 activity is also antiviral. Our results add a novel layer of complexity in the virus/host interaction interface and suggest that NS5 has a narrow window of opportunity to degrade STAT2, therefore suppressing host's IFN-I mediated response and promoting virus replication.

Keywords: Dengue virus; ISG15; ISGylation; USP18; Zika virus; antiviral response; immune evasion; type one interferon.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cytokines / metabolism
  • Dengue* / genetics
  • Humans
  • Interferon Type I* / metabolism
  • STAT2 Transcription Factor / genetics
  • STAT2 Transcription Factor / metabolism
  • Ubiquitin Thiolesterase / metabolism
  • Ubiquitins / metabolism
  • Virus Replication
  • Zika Virus Infection* / genetics
  • Zika Virus*

Substances

  • Interferon Type I
  • ISG15 protein, human
  • Ubiquitins
  • Cytokines
  • USP18 protein, human
  • Ubiquitin Thiolesterase
  • STAT2 protein, human
  • STAT2 Transcription Factor