title: Identification of Immunoreactive Leishmania infantum Protein Antigens to Asymptomatic Dog Sera through Combined Immunoproteomics and Bioinformatics Analysis.
abstract: Leishmania infantum is the etiologic agent of zoonotic visceral leishmaniasis (VL) in countries in the Mediterranean basin, where dogs are the domestic reservoirs and represent important elements in the transmission of the disease. Since the major focal areas of human VL exhibit a high prevalence of seropositive dogs, the control of canine VL could reduce the infection rate in humans. Efforts toward this have focused on the improvement of diagnostic tools, as well as on vaccine development. The identification of parasite antigens including suitable major histocompatibility complex (MHC) class I- and/or II-restricted epitopes is very important since disease protection is characterized by strong and long-lasting CD8+ T and CD4+ Th1 cell-dominated immunity. In the present study, total protein extract from late-log phase L. infantum promastigotes was analyzed by two-dimensional western blots and probed with sera from asymptomatic and symptomatic dogs. A total of 42 protein spots were found to differentially react with IgG from asymptomatic dogs, while 17 of these identified by Coommasie stain were extracted and analyzed. Of these, 21 proteins were identified by mass spectrometry; they were mainly involved in metabolism and stress responses. An in silico analysis predicted that the chaperonin HSP60, dihydrolipoamide dehydrogenase, enolase, cyclophilin 2, cyclophilin 40, and one hypothetical protein contain promiscuous MHCI and/or MHCII epitopes. Our results suggest that the combination of immunoproteomics and bioinformatics analyses is a promising method for the identification of novel candidate antigens for vaccine development or with potential use in the development of sensitive diagnostic tests.
authors.affiliation: Laboratory of Cellular Immunology, Department of Microbiology, Hellenic Pasteur Institute, Athens, Greece.
authors.forename: Maria
authors.initials: M
authors.lastname: Agallou
authors.affiliation: Laboratory of Cellular Immunology, Department of Microbiology, Hellenic Pasteur Institute, Athens, Greece.|Chemical Engineering Laboratory, Department of Analysis, Design and Control of Chemical Processes, Department of Chemical Engineering, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: Evita
authors.initials: E
authors.lastname: Athanasiou
authors.affiliation: Biomedical Sciences Research Center "Alexander Fleming," Vari, Greece.
authors.forename: Martina
authors.initials: M
authors.lastname: Samiotaki
authors.affiliation: Biomedical Sciences Research Center "Alexander Fleming," Vari, Greece.
authors.forename: George
authors.initials: G
authors.lastname: Panayotou
authors.affiliation: Laboratory of Cellular Immunology, Department of Microbiology, Hellenic Pasteur Institute, Athens, Greece.
authors.forename: Evdokia
authors.initials: E
authors.lastname: Karagouni
mesh_terms: D000818:Animals; D000953:Antigens, Protozoan / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D019295:Computational Biology; D004285:Dogs; D015395:Histocompatibility Antigens Class I / Q000276:immunology; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D006801:Humans; D018314:Leishmania infantum / Q000276:immunology*; D040901:Proteomics; D015800:Protozoan Proteins / Q000276:immunology*
chemical_list: D000953:Antigens, Protozoan; D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II; D015800:Protozoan Proteins