JNK pathway restricts DENV2, ZIKV and CHIKV infection by activating complement and apoptosis in mosquito salivary glands

PLoS Pathog. 2020 Aug 10;16(8):e1008754. doi: 10.1371/journal.ppat.1008754. eCollection 2020 Aug.

Abstract

Arbovirus infection of Aedes aegypti salivary glands (SGs) determines transmission. However, there is a dearth of knowledge on SG immunity. Here, we characterized SG immune response to dengue, Zika and chikungunya viruses using high-throughput transcriptomics. We also describe a transcriptomic response associated to apoptosis, blood-feeding and lipid metabolism. The three viruses differentially regulate components of Toll, Immune deficiency (IMD) and c-Jun N- terminal Kinase (JNK) pathways. However, silencing of the Toll and IMD pathway components showed variable effects on SG infection by each virus. In contrast, regulation of the JNK pathway produced consistent responses in both SGs and midgut. Infection by the three viruses increased with depletion of the activator Kayak and decreased with depletion of the negative regulator Puckered. Virus-induced JNK pathway regulates the complement factor, Thioester containing protein-20 (TEP20), and the apoptosis activator, Dronc, in SGs. Individual and co-silencing of these genes demonstrate their antiviral effects and that both may function together. Co-silencing either TEP20 or Dronc with Puckered annihilates JNK pathway antiviral effect. Upon infection in SGs, TEP20 induces antimicrobial peptides (AMPs), while Dronc is required for apoptosis independently of TEP20. In conclusion, we revealed the broad antiviral function of JNK pathway in SGs and showed that it is mediated by a TEP20 complement and Dronc-induced apoptosis response. These results expand our understanding of the immune arsenal that blocks arbovirus transmission.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aedes / immunology*
  • Aedes / virology
  • Animals
  • Apoptosis*
  • Chikungunya Fever / immunology*
  • Chikungunya Fever / metabolism
  • Chikungunya Fever / prevention & control
  • Chikungunya Fever / virology
  • Chikungunya virus / immunology
  • Complement System Proteins / immunology*
  • Complement System Proteins / metabolism
  • Dengue / immunology*
  • Dengue / metabolism
  • Dengue / prevention & control
  • Dengue / virology
  • Dengue Virus / immunology
  • Female
  • Host-Pathogen Interactions
  • Insect Proteins / genetics
  • Insect Proteins / metabolism
  • Insect Vectors / immunology
  • Insect Vectors / virology
  • MAP Kinase Signaling System*
  • Salivary Glands / immunology*
  • Salivary Glands / virology
  • Transcriptome
  • Virus Replication
  • Zika Virus / immunology
  • Zika Virus Infection / immunology*
  • Zika Virus Infection / metabolism
  • Zika Virus Infection / prevention & control
  • Zika Virus Infection / virology

Substances

  • Insect Proteins
  • Complement System Proteins

Grants and funding

This work was funded by the Tier-3 grant from the Ministry of Education, Singapore (MOE 2015-T3-1-003) and the Duke-NUS Signature Research Programme funded by the Agency for Science, Technology and Research (A*STAR), Singapore, and the Ministry of Health, Singapore. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.