title: Identification of lipoteichoic acid as a ligand for draper in the phagocytosis of Staphylococcus aureus by Drosophila hemocytes.
abstract: Phagocytosis is central to cellular immunity against bacterial infections. As in mammals, both opsonin-dependent and -independent mechanisms of phagocytosis seemingly exist in Drosophila. Although candidate Drosophila receptors for phagocytosis have been reported, how they recognize bacteria, either directly or indirectly, remains to be elucidated. We searched for the Staphylococcus aureus genes required for phagocytosis by Drosophila hemocytes in a screening of mutant strains with defects in the structure of the cell wall. The genes identified included ltaS, which encodes an enzyme responsible for the synthesis of lipoteichoic acid. ltaS-dependent phagocytosis of S. aureus required the receptor Draper but not Eater or Nimrod C1, and Draper-lacking flies showed reduced resistance to a septic infection of S. aureus without a change in a humoral immune response. Finally, lipoteichoic acid bound to the extracellular region of Draper. We propose that lipoteichoic acid serves as a ligand for Draper in the phagocytosis of S. aureus by Drosophila hemocytes and that the phagocytic elimination of invading bacteria is required for flies to survive the infection.
authors.affiliation: Graduate School of Medical Science, Kanazawa University, Kanazawa, Ishikawa, Japan.
authors.forename: Yumi
authors.initials: Y
authors.lastname: Hashimoto
authors.forename: Yukichika
authors.initials: Y
authors.lastname: Tabuchi
authors.forename: Kenji
authors.initials: K
authors.lastname: Sakurai
authors.forename: Mayumi
authors.initials: M
authors.lastname: Kutsuna
authors.forename: Kenji
authors.initials: K
authors.lastname: Kurokawa
authors.forename: Takeshi
authors.initials: T
authors.lastname: Awasaki
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Sekimizu
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Nakanishi
authors.forename: Akiko
authors.initials: A
authors.lastname: Shiratsuchi
mesh_terms: D000818:Animals; D004330:Drosophila / Q000276:immunology* / Q000382:microbiology; D029721:Drosophila Proteins / Q000276:immunology* / Q000378:metabolism; D006434:Hemocytes / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology; D008024:Ligands; D008070:Lipopolysaccharides / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D008565:Membrane Proteins / Q000276:immunology* / Q000378:metabolism; D010587:Phagocytosis / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013203:Staphylococcal Infections / Q000276:immunology* / Q000378:metabolism; D013211:Staphylococcus aureus / Q000235:genetics / Q000276:immunology; D013682:Teichoic Acids / Q000235:genetics / Q000276:immunology / Q000378:metabolism*
chemical_list: D029721:Drosophila Proteins; D008024:Ligands; D008070:Lipopolysaccharides; D008565:Membrane Proteins; D013682:Teichoic Acids; C495322:drpr protein, Drosophila; C009900:lipoteichoic acid