title: Anopheles gambiae salivary protein expression modulated by wild Plasmodium falciparum infection: highlighting of new antigenic peptides as candidates of An. gambiae bites.
abstract: BACKGROUND
  Malaria is the major parasitic disease worldwide caused by Plasmodium infection. The objective of integrated malaria control programs is to decrease malaria transmission, which needs specific tools to be accurately assessed. In areas where the transmission is low or has been substantially reduced, new complementary tools have to be developed to improve surveillance. A recent approach, based on the human antibody response to Anopheles salivary proteins, has been shown to be efficient in evaluating human exposure to Anopheles bites. The aim of the present study was to identify new An. gambiae salivary proteins as potential candidate biomarkers of human exposure to P. falciparum-infective bites.
  
  
  METHODS
  Experimental infections of An. gambiae by wild P. falciparum were carried out in semi-field conditions. Then a proteomic approach, combining 2D-DIGE and mass spectrometry, was used to identify the overexpressed salivary proteins in infected salivary glands compared to uninfected An. gambiae controls. Subsequently, a peptide design of each potential candidate was performed in silico and their antigenicity was tested by an epitope-mapping technique using blood from individuals exposed to Anopheles bites.
  
  
  RESULTS
  Five salivary proteins (gSG6, gSG1b, TRIO, SG5 and long form D7) were overexpressed in the infected salivary glands. Eighteen peptides were designed from these proteins and were found antigenic in children exposed to the Anopheles bites. Moreover, the results showed that the presence of wild P. falciparum in salivary glands modulates the expression of several salivary proteins and also appeared to induce post-translational modifications.
  
  
  CONCLUSIONS
  This study is, to our knowledge, the first that compares the sialome of An. gambiae both infected and not infected by wild P. falciparum, making it possible to mimic the natural conditions of infection. This is a first step toward a better understanding of the close interactions between the parasite and the salivary gland of mosquitoes. In addition, these results open the way to define biomarkers of infective bites of Anopheles, which could, in the future, improve the estimation of malaria transmission and the evaluation of malaria vector control tools.
authors.affiliation: MIVEGEC (UMR IRD224 CNRS 5290 UM1-UM2), Institut de Recherche pour le développement (IRD), 911 avenue Agropolis, Montpellier cedex 5, 34394, France. alexandra.marie@ird.fr.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Marie
authors.affiliation: CIRAD Département Systèmes Biologiques BIOS UMR 15 CMAEE "Contrôle des Maladies Exotiques et Emergentes", Campus International de Baillarguet, TA A-15/G, Montpellier cedex 5, 34398, France. philippe.holzmuller@cirad.fr.
authors.forename: Philippe
authors.initials: P
authors.lastname: Holzmuller
authors.affiliation: MIVEGEC (UMR IRD224 CNRS 5290 UM1-UM2), Institut de Recherche pour le développement (IRD), 911 avenue Agropolis, Montpellier cedex 5, 34394, France. majoline.tchioffo@ird.fr.
authors.forename: Majoline T
authors.initials: MT
authors.lastname: Tchioffo
authors.affiliation: MIVEGEC (UMR IRD224 CNRS 5290 UM1-UM2), Institut de Recherche pour le développement (IRD), 911 avenue Agropolis, Montpellier cedex 5, 34394, France. marie.rossignol@ird.fr.
authors.forename: Marie
authors.initials: M
authors.lastname: Rossignol
authors.affiliation: Institut de Génomique Fonctionnelle, CNRS UMR 5203, INSERM U661, UM1, UM2, Plate-forme de Protéomique Fonctionnelle CNRS UMS BioCampus 3426, Montpellier, 34094, France. Edith.Demettre@fpp.cnrs.fr.
authors.forename: Edith
authors.initials: E
authors.lastname: Demettre
authors.affiliation: Institut de Génomique Fonctionnelle, CNRS UMR 5203, INSERM U661, UM1, UM2, Plate-forme de Protéomique Fonctionnelle CNRS UMS BioCampus 3426, Montpellier, 34094, France. Martial.Seveno@fpp.cnrs.fr.
authors.forename: Martial
authors.initials: M
authors.lastname: Seveno
authors.affiliation: MIVEGEC (UMR IRD224 CNRS 5290 UM1-UM2), Institut de Recherche pour le développement (IRD), 911 avenue Agropolis, Montpellier cedex 5, 34394, France. vincent.corbel@ird.fr.|Department of Entomology, Faculty of Agriculture, Kasetsart University, 50 Ngam Wong Wan Rd, Ladyaow Chatuchak, Bangkok, 10900, Thailand. vincent.corbel@ird.fr.
authors.forename: Vincent
authors.initials: V
authors.lastname: Corbel
authors.affiliation: Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), Yaoundé, BP 288, Cameroun. hpaawono@yahoo.fr.
authors.forename: Parfait
authors.initials: P
authors.lastname: Awono-Ambéné
authors.affiliation: MIVEGEC (UMR IRD224 CNRS 5290 UM1-UM2), Institut de Recherche pour le développement (IRD), 911 avenue Agropolis, Montpellier cedex 5, 34394, France. isabelle.morlais@ird.fr.|Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), Yaoundé, BP 288, Cameroun. isabelle.morlais@ird.fr.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Morlais
authors.affiliation: MIVEGEC (UMR IRD224 CNRS 5290 UM1-UM2), Institut de Recherche pour le développement (IRD), 911 avenue Agropolis, Montpellier cedex 5, 34394, France. franck.remoue@ird.fr.
authors.forename: Franck
authors.initials: F
authors.lastname: Remoue
authors.affiliation: MIVEGEC (UMR IRD224 CNRS 5290 UM1-UM2), Institut de Recherche pour le développement (IRD), 911 avenue Agropolis, Montpellier cedex 5, 34394, France. sylvie.cornelie@ird.fr.|MIVEGEC- IRD- CREC, Cotonou, 01 BP4414 RP, Bénin. sylvie.cornelie@ird.fr.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Cornelie
mesh_terms: D000818:Animals; D000852:Anopheles / Q000469:parasitology* / Q000502:physiology; D015415:Biomarkers / Q000032:analysis; D005260:Female; D006801:Humans; D007299:Insect Bites and Stings / Q000276:immunology*; D019476:Insect Proteins / Q000276:immunology*; D016778:Malaria, Falciparum / Q000469:parasitology / Q000635:transmission*; D008297:Male; D010963:Plasmodium falciparum / Q000502:physiology*; D012469:Salivary Glands / Q000276:immunology; D012471:Salivary Proteins and Peptides / Q000276:immunology*
chemical_list: D015415:Biomarkers; D019476:Insect Proteins; D012471:Salivary Proteins and Peptides