title: Recognition, survival and persistence of Staphylococcus aureus in the model host Tenebrio molitor.
abstract: The degree of specificity of any given immune response to a parasite is governed by the complexity and variation of interactions between host and pathogen derived molecules. Here, we assess the extent to which recognition and immuno-resistance of cell wall mutants of the pathogen Staphylococcus aureus may contribute to establishment and maintenance of persistent infection in the model insect host, Tenebrio molitor. The cell surface of S. aureus is decorated with various molecules, including glycopolymers such as wall teichoic acid (WTA). WTA is covalently bound to peptidoglycan (PGN) and its absence has been associated with increased recognition of PGN by host receptors (PGRPs). WTA is also further modified by other molecules such as D-alanine (D-alanylation). Both the level of WTA expression and its D-alanylation were found to be important in the mediation of the host-parasite interaction in this model system. Specifically, WTA itself was seen to influence immune recognition, while D-alanylation of WTA was found to increase immuno-resistance and was associated with prolonged persistence of S. aureus in T. molitor. These results implicate WTA and its D-alanylation as important factors in the establishment and maintenance of persistent infection, affecting different critical junctions in the immune response; through potential evasion of recognition by PGRPs and resistance to humoral immune effectors during prolonged exposure to the immune system. This highlights a mechanism by which specificity in this host-parasite interaction may arise.
authors.affiliation: Animal & Plant Sciences, University of Sheffield, Western Bank, Sheffield S10 2TN, UK; Fachbereich Biologie, Chemie, Pharmazie, Evolutionary Biology, Freie Universität Berlin, Königin-Luise-Straße 1-3, 14195 Berlin, Germany; Medical Sciences Doctoral Training Centre, University of Oxford, Oxford, UK.
authors.forename: Jack
authors.initials: J
authors.lastname: Dorling
authors.affiliation: Fachbereich Biologie, Chemie, Pharmazie, Evolutionary Biology, Freie Universität Berlin, Königin-Luise-Straße 1-3, 14195 Berlin, Germany; Oswaldo Cruz Institute, FIOCRUZ, Rio de Janeiro, Brazil; Centro Universitário Augusto Motta, Rio de Janeiro, Brazil.
authors.forename: Caroline
authors.initials: C
authors.lastname: Moraes
authors.affiliation: Fachbereich Biologie, Chemie, Pharmazie, Evolutionary Biology, Freie Universität Berlin, Königin-Luise-Straße 1-3, 14195 Berlin, Germany; Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB), Berlin, Germany. Electronic address: jens.rolff@fu-berlin.de.
authors.forename: Jens
authors.initials: J
authors.lastname: Rolff
mesh_terms: D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000276:immunology; D006458:Hemolymph / Q000276:immunology; D054884:Host-Pathogen Interactions; D057131:Immune Evasion; D019476:Insect Proteins / Q000276:immunology; D013211:Staphylococcus aureus / Q000502:physiology*; D013712:Tenebrio / Q000276:immunology* / Q000382:microbiology*
chemical_list: D023181:Antimicrobial Cationic Peptides; D019476:Insect Proteins
keywords: Antimicrobial peptides; Persistence; Wall teichoic acids