title: Immunoproteomic identification of antigenic salivary biomarkers detected by Ixodes ricinus-exposed rabbit sera.
abstract: Ixodes ricinus, the primary vector of tick-borne disease in Europe, is currently expanding its distribution area and its activity in many countries. Antibody responses to tick salivary antigens have been proposed as an alternative marker of exposure to tick bites. However, the identification of the I. ricinus corresponding antigens remains elusive. Using rabbits artificially exposed to I. ricinus and 2 other European tick species (Rhipicephalus sanguineus and Dermacentor reticulatus) as controls, a cross-comparison of IgG profiles was performed against protein salivary gland extracts (pSGE) from these 3 tick species using immunoblots. Immunoblot analysis highlighted a singularity in the immune patterns according to tick species exposure and pSGE antigen source. Two protein bands were detected against I. ricinus pSGE only in rabbits exposed to I. ricinus bites. An immunoproteomic approach based on a fluorescence detection method was developed to unambiguously identify corresponding antigenic spots on 2-D gels. Among the unique I. ricinus salivary antigenic proteins detected by sera from rabbits exposed to this tick species, I. ricinus calreticulin was identified. Although tick calreticulin was previously proposed as a potential antigenic marker following exposure to ticks (particularly in North American tick species), the present study suggested that Ixodes calreticulin does not appear to be cross-recognized by the 2 other tick genera tested. Additional experiments are needed to confirm the use of I. ricinus calreticulin salivary protein as a potential discriminant antigenic biomarker to Ixodes tick exposure.
authors.affiliation: Aix Marseille Université, Unité de Recherche en Maladies Infectieuses et Tropicales Emergentes (URMITE), UM 63, CNRS 7278, IRD 198, Inserm 1095, WHO Collaborative Center for Rickettsioses and Other Arthropod-Borne Bacterial Diseases, Faculté de Médecine, 27 Boulevard Jean Moulin, 13385 Marseille Cedex 5, France. vinhvuhai@gmail.com
authors.forename: Vinh
authors.initials: V
authors.lastname: Vu Hai
authors.forename: Frédéric
authors.initials: F
authors.lastname: Pages
authors.forename: Nathalie
authors.initials: N
authors.lastname: Boulanger
authors.forename: Stéphane
authors.initials: S
authors.lastname: Audebert
authors.forename: Philippe
authors.initials: P
authors.lastname: Parola
authors.forename: Lionel
authors.initials: L
authors.lastname: Almeras
mesh_terms: D000818:Animals; D000918:Antibody Specificity; D015415:Biomarkers; D037282:Calreticulin / Q000276:immunology / Q000302:isolation & purification; D003870:Dermacentor / Q000276:immunology / Q000378:metabolism; D015180:Electrophoresis, Gel, Two-Dimensional; D005260:Female; D007074:Immunoglobulin G / Q000276:immunology*; D018884:Ixodes / Q000276:immunology* / Q000378:metabolism; D013058:Mass Spectrometry; D023421:Models, Animal; D040901:Proteomics / Q000379:methods*; D011817:Rabbits; D048508:Rhipicephalus sanguineus / Q000276:immunology / Q000378:metabolism; D012469:Salivary Glands / Q000276:immunology; D012471:Salivary Proteins and Peptides / Q000276:immunology* / Q000302:isolation & purification; D013047:Specific Pathogen-Free Organisms; D064927:Tick Bites; D013984:Tick Infestations / Q000276:immunology* / Q000469:parasitology
chemical_list: D015415:Biomarkers; D037282:Calreticulin; D007074:Immunoglobulin G; D012471:Salivary Proteins and Peptides
keywords: Exposure markers; Ixodes ricinus; Salivary antigens; Tick-borne diseases; Vaccine candidates