The Drosophila immune system detects bacteria through specific peptidoglycan recognition.
The Drosophila immune system discriminates between different classes of infectious microbes and responds with pathogen-specific defense reactions through selective activation of the Toll and the immune deficiency (Imd) signaling pathways. The Toll pathway mediates most defenses against Gram-positive bacteria and fungi, whereas the Imd pathway is required to resist infection by Gram-negative bacteria. The bacterial components recognized by these pathways remain to be defined. Here we report that Gram-negative diaminopimelic acid-type peptidoglycan is the most potent inducer of the Imd pathway and that the Toll pathway is predominantly activated by Gram-positive lysine-type peptidoglycan. Thus, the ability of Drosophila to discriminate between Gram-positive and Gram-negative bacteria relies on the recognition of specific forms of peptidoglycan.
Leulier
François
F
Centre de Génétique Moléculaire du CNRS, F-91198 Gif-sur-Yvette, France.
Parquet
Claudine
C
Pili-Floury
Sebastien
S
Ryu
Ji-Hwan
JH
Caroff
Martine
M
Lee
Won-Jae
WJ
Mengin-Lecreulx
Dominique
D
Lemaitre
Bruno
B
D000818:Animals; D030801:Animals, Genetically Modified; D001413:Bacillus thuringiensis / Q000276:immunology; D001483:Base Sequence; D004247:DNA / Q000235:genetics; D004330:Drosophila / Q000235:genetics / Q000276:immunology* / Q000382:microbiology; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000276:immunology; D015870:Gene Expression; D017344:Genes, Insect; D006090:Gram-Negative Bacteria / Q000276:immunology*; D006094:Gram-Positive Bacteria / Q000276:immunology*; D019476:Insect Proteins / Q000235:genetics; D007763:Lac Operon; D009113:Muramidase; D010457:Peptidoglycan / Q000276:immunology*; D011550:Pseudomonas aeruginosa / Q000276:immunology; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D051193:Toll-Like Receptors
C054756:DptA protein, Drosophila; D029721:Drosophila Proteins; D019476:Insect Proteins; D010457:Peptidoglycan; D011956:Receptors, Cell Surface; C068721:Tl protein, Drosophila; D051193:Toll-Like Receptors; C439909:imd protein, Drosophila; D004247:DNA; D009113:Muramidase