title: Reciprocal immune benefit based on complementary production of antibiotics by the leech Hirudo verbana and its gut symbiont Aeromonas veronii.
abstract: The medicinal leech has established a long-term mutualistic association with Aeromonas veronii, a versatile bacterium which can also display free-living waterborne and fish- or human-pathogenic lifestyles. Here, we investigated the role of antibiotics in the dynamics of interaction between the leech and its gut symbiont Aeromonas. By combining biochemical and molecular approaches, we isolated and identified for the first time the antimicrobial peptides (AMPs) produced by the leech digestive tract and by its symbiont Aeromonas. Immunohistochemistry data and PCR analyses evidenced that leech AMP genes are induced in the gut epithelial cells when Aeromonas load is low (starved animals), while repressed when Aeromonas abundance is the highest (post blood feeding). The asynchronous production of AMPs by both partners suggests that these antibiotic substances (i) provide them with reciprocal protection against invasive bacteria and (ii) contribute to the unusual simplicity of the gut microflora of the leech. This immune benefit substantially reinforces the evidence of an evolutionarily stable association between H. verbana and A. veronii. Altogether these data may provide insights into the processes making the association with an Aeromonas species in the digestive tract either deleterious or beneficial.
authors.affiliation: Univ. Lille, Unité Evolution, Ecologie et Paléontologie (EEP), CNRS UMR 8198, F-59 000 Lille, France.
authors.forename: Aurélie
authors.initials: A
authors.lastname: Tasiemski
authors.affiliation: Univ. Lille, Unité Evolution, Ecologie et Paléontologie (EEP), CNRS UMR 8198, F-59 000 Lille, France.
authors.forename: François
authors.initials: F
authors.lastname: Massol
authors.affiliation: Univ. Lille, Unité Evolution, Ecologie et Paléontologie (EEP), CNRS UMR 8198, F-59 000 Lille, France.
authors.forename: Virginie
authors.initials: V
authors.lastname: Cuvillier-Hot
authors.affiliation: Univ. Lille, Unité Evolution, Ecologie et Paléontologie (EEP), CNRS UMR 8198, F-59 000 Lille, France.
authors.forename: Céline
authors.initials: C
authors.lastname: Boidin-Wichlacz
authors.affiliation: Univ. Lille, Centre d'infections et d'immunité de Lille, CNRS UMR 8204, INSERM U 1019, F-59 000 Lille, France.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Roger
authors.affiliation: Univ. Lille, Unité Protéomique, Réponse Inflammatoire, Spectrométrie de Masse (PRISM), INSERM U 1192, F-59 000 Lille, France.
authors.forename: Franck
authors.initials: F
authors.lastname: Rodet
authors.affiliation: Univ. Lille, Unité Protéomique, Réponse Inflammatoire, Spectrométrie de Masse (PRISM), INSERM U 1192, F-59 000 Lille, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Fournier
authors.affiliation: MIVEGEC, UMR IRD/CNRS/UM5290, 911 Avenue Agropolis, BP 64501, 34394 Montpellier Cedex 5, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Thomas
authors.affiliation: Univ. Lille, Unité Protéomique, Réponse Inflammatoire, Spectrométrie de Masse (PRISM), INSERM U 1192, F-59 000 Lille, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Salzet
mesh_terms: D000333:Aeromonas / Q000276:immunology / Q000378:metabolism*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000096:biosynthesis* / Q000276:immunology; D023181:Antimicrobial Cationic Peptides / Q000096:biosynthesis* / Q000276:immunology; D000069196:Gastrointestinal Microbiome / Q000276:immunology; D006801:Humans; D007865:Leeches / Q000276:immunology / Q000378:metabolism* / Q000382:microbiology; D013559:Symbiosis / Q000276:immunology
chemical_list: D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides