Infection-derived lipids elicit an immune deficiency circuit in arthropods

Nat Commun. 2017 Feb 14:8:14401. doi: 10.1038/ncomms14401.

Abstract

The insect immune deficiency (IMD) pathway resembles the tumour necrosis factor receptor network in mammals and senses diaminopimelic-type peptidoglycans present in Gram-negative bacteria. Whether unidentified chemical moieties activate the IMD signalling cascade remains unknown. Here, we show that infection-derived lipids 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoglycerol (POPG) and 1-palmitoyl-2-oleoyl diacylglycerol (PODAG) stimulate the IMD pathway of ticks. The tick IMD network protects against colonization by three distinct bacteria, that is the Lyme disease spirochete Borrelia burgdorferi and the rickettsial agents Anaplasma phagocytophilum and A. marginale. Cell signalling ensues in the absence of transmembrane peptidoglycan recognition proteins and the adaptor molecules Fas-associated protein with a death domain (FADD) and IMD. Conversely, biochemical interactions occur between x-linked inhibitor of apoptosis protein (XIAP), an E3 ubiquitin ligase, and the E2 conjugating enzyme Bendless. We propose the existence of two functionally distinct IMD networks, one in insects and another in ticks.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / genetics
  • Adaptor Proteins, Signal Transducing / metabolism
  • Anaplasma marginale / immunology
  • Anaplasma marginale / pathogenicity
  • Anaplasma phagocytophilum / immunology
  • Anaplasma phagocytophilum / pathogenicity
  • Animals
  • Arthropods / immunology*
  • Arthropods / metabolism
  • Borrelia burgdorferi / immunology
  • Borrelia burgdorferi / pathogenicity
  • Carrier Proteins
  • Disease Models, Animal
  • Drosophila Proteins / genetics
  • Drosophila Proteins / metabolism
  • Drosophila melanogaster / metabolism
  • Escherichia coli / genetics
  • Fas-Associated Death Domain Protein
  • Gene Silencing
  • HEK293 Cells
  • Humans
  • Immunologic Deficiency Syndromes / immunology*
  • Immunologic Deficiency Syndromes / veterinary*
  • Ixodes / immunology*
  • Ixodes / metabolism
  • Lipids / adverse effects*
  • Lipids / immunology*
  • Lyme Disease / immunology
  • Phosphatidylglycerols / immunology
  • RNA, Small Interfering / metabolism
  • Recombinant Proteins
  • Signal Transduction
  • Transcription Factors / genetics
  • Transcription Factors / metabolism
  • Ubiquitin-Conjugating Enzymes / genetics
  • Ubiquitin-Conjugating Enzymes / metabolism
  • Ubiquitin-Protein Ligases / metabolism
  • X-Linked Inhibitor of Apoptosis Protein / metabolism

Substances

  • Adaptor Proteins, Signal Transducing
  • Carrier Proteins
  • Drosophila Proteins
  • Fas-Associated Death Domain Protein
  • Lipids
  • Phosphatidylglycerols
  • RNA, Small Interfering
  • Recombinant Proteins
  • Rel protein, Drosophila
  • Transcription Factors
  • X-Linked Inhibitor of Apoptosis Protein
  • casp protein, Drosophila
  • peptidoglycan recognition protein
  • 1-palmitoyl-2-oleoylglycero-3-phosphoglycerol
  • Ubiquitin-Conjugating Enzymes
  • Uev1a protein, Drosophila
  • ben protein, Drosophila
  • Ubiquitin-Protein Ligases

Supplementary concepts

  • Immune Deficiency Disease