Edin Expression in the Fat Body Is Required in the Defense Against Parasitic Wasps in Drosophila melanogaster

PLoS Pathog. 2015 May 12;11(5):e1004895. doi: 10.1371/journal.ppat.1004895. eCollection 2015 May.

Abstract

The cellular immune response against parasitoid wasps in Drosophila involves the activation, mobilization, proliferation and differentiation of different blood cell types. Here, we have assessed the role of Edin (elevated during infection) in the immune response against the parasitoid wasp Leptopilina boulardi in Drosophila melanogaster larvae. The expression of edin was induced within hours after a wasp infection in larval fat bodies. Using tissue-specific RNAi, we show that Edin is an important determinant of the encapsulation response. Although edin expression in the fat body was required for the larvae to mount a normal encapsulation response, it was dispensable in hemocytes. Edin expression in the fat body was not required for lamellocyte differentiation, but it was needed for the increase in plasmatocyte numbers and for the release of sessile hemocytes into the hemolymph. We conclude that edin expression in the fat body affects the outcome of a wasp infection by regulating the increase of plasmatocyte numbers and the mobilization of sessile hemocytes in Drosophila larvae.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Genetically Modified
  • Biomarkers / metabolism
  • Crosses, Genetic
  • Drosophila Proteins / antagonists & inhibitors
  • Drosophila Proteins / genetics
  • Drosophila Proteins / metabolism*
  • Drosophila melanogaster / cytology
  • Drosophila melanogaster / immunology
  • Drosophila melanogaster / metabolism*
  • Drosophila melanogaster / parasitology
  • Fat Body / cytology
  • Fat Body / immunology
  • Fat Body / metabolism*
  • Gene Knockdown Techniques
  • Genes, Reporter
  • Hematopoiesis, Extramedullary
  • Hemocytes / cytology
  • Hemocytes / immunology
  • Hemocytes / metabolism
  • Hemolymph / cytology
  • Hemolymph / immunology
  • Hemolymph / metabolism
  • Host-Parasite Interactions*
  • Immunity, Innate
  • Kinetics
  • Larva / cytology
  • Larva / immunology
  • Larva / metabolism
  • Larva / parasitology
  • Ovum / immunology
  • Ovum / physiology
  • Parasite Egg Count
  • RNA Interference
  • Recombinant Fusion Proteins / metabolism
  • Up-Regulation*
  • Wasps / immunology*
  • Wasps / physiology

Substances

  • Biomarkers
  • Drosophila Proteins
  • Edin protein, Drosophila
  • Recombinant Fusion Proteins

Grant support

The study was financially supported by the Academy of Finland (MR, DH and LV), the Jane and Aatos Erkko Foundation (MR), the Sigrid Juselius Foundation (MR, DH), the Swedish Cancer Society (DH), the Tampere Tuberculosis Foundation (MR), the Tampere Graduate Program in Biotechnology and Biomedicine (LMV), the Competitive State Research Financing of the Tampere University Hospital (MR) and the Competitive State Research Financing of the Oulu University Hospital (MR). The Drosophila work was carried out at the University of Tampere Drosophila core facility supported by Biocenter Finland. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.