title: Differential expression of Ixodes ricinus salivary gland proteins in the presence of the Borrelia burgdorferi sensu lato complex.
abstract: In Europe, Ixodes ricinus is the main vector of Lyme borreliosis. Their salivary glands play a critical role in the biological success of ticks. To better understand the cross-talk between Borrelia burgdorferi and tick salivary glands, we analyzed protein expression in the salivary glands of I. ricinus adult ticks that were infected by various strains of the B. burgdorferi sl complex. iTRAQ allowed the identification of more than 120 proteins, providing the first proteomic data pertaining to I. ricinus salivary glands. Among these proteins, only 12 were modulated in the presence of various Borrelia strains. Most of them are up-regulated and are involved in cell defense and protein synthesis and processing. Down-regulated proteins are mostly implicated in the cytoskeleton. The DIGE analysis allowed us to identify 35 proteins and showed the down-regulation of 4 proteins. All 15 proteins were not modulated by all strains. Overall, these observations showed that the presence of Borrelia in tick salivary glands is a factor of stress for the protein machinery, and also that some Borrelia strains produce a dysregulation of cytoskeletal proteins. Interestingly, a protein from Borrelia, OspA, was found in infected salivary glands. The consequence of its presence in salivary glands is discussed.
  
  
  CONCLUSIONS
  Lyme borreliosis is still the most prevalent arthropod-borne disease in the temperate regions of the northern hemisphere. The geographical distribution of Lyme borreliosis is expanding, especially towards higher altitudes and latitudes. Human pathogenic spirochetes causing Lyme borreliosis belong to the B. burgdorferi sensu lato complex. They are extracellular pathogens transmitted to humans through the bite of Ixodes spp. ticks. The bioactive molecules present in tick saliva not only promote tick feeding, but also create an advantageous microenvironment at the tick bite site for survival and replication of Borrelia bacteria. Investigation of the tick-host-pathogen interface would provide new strategies to control tick-borne infections. We chose to analyze the interaction of several strains of the B. burgdorferi sensu lato complex with I. ricinus salivary glands. We also investigated the presence of bacterial proteins in salivary glands. For these purposes, we undertook a proteomic study implying the complementary approaches of iTRAQ and DIGE. Our study allowed identifying several salivary markers of infection that were shown to vary according to the strain. Moreover, OspA, a bacterial protein was shown to be expressed in salivary glands and may be implied in the pathogenicity of some Borrelia strains.
authors.affiliation: CNR des Borrelia, Institut Pasteur, 28 rue du Dr Roux, 75724 Paris cedex 15, France.
authors.forename: Violaine
authors.initials: V
authors.lastname: Cotté
authors.affiliation: Laboratoire de Spectrométrie de Masse Bioorganique (LSMBO), Université de Strasbourg, CNRS-UMR7178, 25 rue Becquerel, 67087 Strasbourg Cedex 2, France.
authors.forename: Laurence
authors.initials: L
authors.lastname: Sabatier
authors.affiliation: Laboratoire de Spectrométrie de Masse Bioorganique (LSMBO), Université de Strasbourg, CNRS-UMR7178, 25 rue Becquerel, 67087 Strasbourg Cedex 2, France.
authors.forename: Gilles
authors.initials: G
authors.lastname: Schnell
authors.affiliation: CNR des Borrelia, Institut Pasteur, 28 rue du Dr Roux, 75724 Paris cedex 15, France.
authors.forename: Annick
authors.initials: A
authors.lastname: Carmi-Leroy
authors.affiliation: Plate-forme Protéomique, Institut Pasteur, 28 rue du Dr Roux, 75724 Paris cedex 15, France.
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Rousselle
authors.affiliation: Laboratoire de Génétique Moléculaire, Génomique et Microbiologie, Université de Strasbourg, CNRS-UMR7156, Equipe Ecophysiologie Moléculaire des Microorganismes 28, rue Goethe, 67083 Strasbourg Cedex, France.
authors.forename: Florence
authors.initials: F
authors.lastname: Arsène-Ploetze
authors.affiliation: INRA, UMR 1300 BioEpAR, ENVN, Atlanpole La Chantrerie, BP 40706, F 44307 Nantes Cedex 03, France.
authors.forename: Laurence
authors.initials: L
authors.lastname: Malandrin
authors.affiliation: CNR des Borrelia, Institut Pasteur, 28 rue du Dr Roux, 75724 Paris cedex 15, France.
authors.forename: Natacha
authors.initials: N
authors.lastname: Sertour
authors.affiliation: Plate-forme Protéomique, Institut Pasteur, 28 rue du Dr Roux, 75724 Paris cedex 15, France.
authors.forename: Abdelkader
authors.initials: A
authors.lastname: Namane
authors.affiliation: CNR des Borrelia, Institut Pasteur, 28 rue du Dr Roux, 75724 Paris cedex 15, France.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Ferquel
authors.affiliation: CNR des Borrelia, Institut Pasteur, 28 rue du Dr Roux, 75724 Paris cedex 15, France; Unité Interactions Moléculaires Flavivirus-Hôtes, 25 rue du Dr Roux, 75724 Paris cedex 15, France.
authors.forename: Valérie
authors.initials: V
authors.lastname: Choumet
mesh_terms: D000818:Animals; D001096:Arachnid Vectors / Q000378:metabolism* / Q000382:microbiology; D060829:Arthropod Proteins / Q000096:biosynthesis*; D015748:Borrelia burgdorferi Group; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D018884:Ixodes / Q000378:metabolism* / Q000382:microbiology; D008193:Lyme Disease / Q000378:metabolism / Q000635:transmission; D051379:Mice; D012469:Salivary Glands / Q000378:metabolism* / Q000382:microbiology; D012471:Salivary Proteins and Peptides / Q000096:biosynthesis*
chemical_list: D060829:Arthropod Proteins; D012471:Salivary Proteins and Peptides
keywords: Borrelia burgdorferi; DIGE; Ixodes ricinus; Salivary gland; iTRAQ