title: Analysis of the Contribution of Hemocytes and Autophagy to Drosophila Antiviral Immunity.
abstract: Antiviral immunity in the model organism Drosophila melanogaster involves the broadly active intrinsic mechanism of RNA interference (RNAi) and virus-specific inducible responses. Here, using a panel of six viruses, we investigated the role of hemocytes and autophagy in the control of viral infections. Injection of latex beads to saturate phagocytosis, or genetic depletion of hemocytes, resulted in decreased survival and increased viral titers following infection with Cricket paralysis virus (CrPV), Flock House virus (FHV), and vesicular stomatitis virus (VSV) but had no impact on Drosophila C virus (DCV), Sindbis virus (SINV), and Invertebrate iridescent virus 6 (IIV6) infection. In the cases of CrPV and FHV, apoptosis was induced in infected cells, which were phagocytosed by hemocytes. In contrast, VSV did not trigger any significant apoptosis but we confirmed that the autophagy gene Atg7 was required for full virus resistance, suggesting that hemocytes use autophagy to recognize the virus. However, this recognition does not depend on the Toll-7 receptor. Autophagy had no impact on DCV, CrPV, SINV, or IIV6 infection and was required for replication of the sixth virus, FHV. Even in the case of VSV, the increases in titers were modest in Atg7 mutant flies, suggesting that autophagy does not play a major role in antiviral immunity in Drosophila Altogether, our results indicate that, while autophagy plays a minor role, phagocytosis contributes to virus-specific immune responses in insects.
  
  
  
  Phagocytosis and autophagy are two cellular processes that involve lysosomal degradation and participate in Drosophila immunity. Using a panel of RNA and DNA viruses, we have addressed the contribution of phagocytosis and autophagy in the control of viral infections in this model organism. We show that, while autophagy plays a minor role, phagocytosis contributes to virus-specific immune responses in Drosophila This work brings to the front a novel facet of antiviral host defense in insects, which may have relevance in the control of virus transmission by vector insects or in the resistance of beneficial insects to viral pathogens.
authors.affiliation: CNRS UPR9022, Institut de Biologie Moléculaire et Cellulaire, Strasbourg, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Lamiable
authors.affiliation: CNRS UPR9022, Institut de Biologie Moléculaire et Cellulaire, Strasbourg, France.
authors.forename: Johan
authors.initials: J
authors.lastname: Arnold
authors.affiliation: CNRS UPR9022, Institut de Biologie Moléculaire et Cellulaire, Strasbourg, France.|Department of Biochemistry and Immunology, Instituto de Ciências Biologicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Isaque Joao da Silva
authors.initials: IJDS
authors.lastname: de Faria
authors.affiliation: Department of Biochemistry and Immunology, Instituto de Ciências Biologicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Roenick Proveti
authors.initials: RP
authors.lastname: Olmo
authors.affiliation: CNRS UPR9022, Institut de Biologie Moléculaire et Cellulaire, Strasbourg, France.
authors.forename: Francesco
authors.initials: F
authors.lastname: Bergami
authors.affiliation: CNRS UPR9022, Institut de Biologie Moléculaire et Cellulaire, Strasbourg, France.|Faculté des Sciences de la Vie, Université de Strasbourg, Strasbourg, France.
authors.forename: Carine
authors.initials: C
authors.lastname: Meignin
authors.affiliation: CNRS UPR9022, Institut de Biologie Moléculaire et Cellulaire, Strasbourg, France.|University of Strasbourg Institute for Advanced Studies, Strasbourg, France.
authors.forename: Jules A
authors.initials: JA
authors.lastname: Hoffmann
authors.affiliation: CNRS UPR9022, Institut de Biologie Moléculaire et Cellulaire, Strasbourg, France.|Department of Biochemistry and Immunology, Instituto de Ciências Biologicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Joao Trindade
authors.initials: JT
authors.lastname: Marques
authors.affiliation: CNRS UPR9022, Institut de Biologie Moléculaire et Cellulaire, Strasbourg, France jl.imler@unistra.fr.|Faculté des Sciences de la Vie, Université de Strasbourg, Strasbourg, France.
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Imler
mesh_terms: D000818:Animals; D017209:Apoptosis; D001343:Autophagy; D000071193:Autophagy-Related Protein 7 / Q000235:genetics / Q000378:metabolism; D002460:Cell Line; D004267:DNA Viruses / Q000276:immunology*; D004330:Drosophila / Q000166:cytology / Q000235:genetics / Q000276:immunology* / Q000821:virology*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D006434:Hemocytes / Q000276:immunology*; D010587:Phagocytosis; D034622:RNA Interference; D012328:RNA Viruses / Q000276:immunology*; D012845:Sindbis Virus / Q000276:immunology; D014721:Vesicular stomatitis Indiana virus / Q000276:immunology; D014779:Virus Replication
chemical_list: C530193:Atg7 protein, Drosophila; D029721:Drosophila Proteins; D000071193:Autophagy-Related Protein 7