title: Mapping B-cell epitopes for the peroxidoxin of Leishmania (Viannia) braziliensis and its potential for the clinical diagnosis of tegumentary and visceral leishmaniasis.
abstract: The search toward the establishment of novel serological tests for the diagnosis of leishmaniasis and proper differential diagnosis may represent one alternative to the invasive parasitological methods currently used to identify infected individuals. In the present work, we investigated the potential use of recombinant peroxidoxin (rPeroxidoxin) of Leishmania (Viannia) braziliensis as a potential antigen for the immunodiagnosis of human tegumentary (TL) and visceral leishmaniasis (VL) and canine visceral leishmaniasis (CVL). Linear B-cell epitope mapping was performed to identify polymorphic epitopes when comparing orthologous sequences present in Trypanosoma cruzi, the agent for Chagas disease (CD), and the Homo sapiens and Canis familiaris hosts. The serological assay (ELISA) demonstrated that TL, VL and CVL individuals showed high levels of antibodies against rPeroxidoxin, allowing identification of infected ones with considerable sensitivity and great ability to discriminate (specificity) between non-infected and CD individuals (98.46% and 100%; 98.18% and 95.71%; 95.79% and 100%, respectively). An rPeroxidoxin ELISA also showed a greater ability to discriminate between vaccinated and infected animals, which is an important requirement for the public campaign control of CVL. A depletion ELISA assay using soluble peptides of this B-cell epitope confirmed the recognition of these sites only by Leishmania-infected individuals. Moreover, this work identifies two antigenic polymorphic linear B-cell epitopes of L. braziliensis. Specific recognition of TL and VL patients was confirmed by significantly decreased IgG reactivity against rPeroxidoxin after depletion of peptide-1- and peptide-2-specific antibodies (peptide 1: reduced by 32%, 42% and 5% for CL, ML and VL, respectively; peptide-2: reduced by 24%, 22% and 13% for CL, ML and VL, respectively) and only peptide-2 for CVL (reduced 9%). Overall, rPeroxidoxin may be a potential antigen for the immunodiagnosis of TL, VL or CVL, as it has a higher agreement with parasitological assays and is better than other reference tests that use soluble Leishmania antigens for diagnosing CVL in Brazil (EIE-LVC, Bio-manguinhos, FIOCRUZ).
authors.affiliation: Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Daniel
authors.initials: D
authors.lastname: Menezes-Souza
authors.affiliation: Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Tiago Antônio de Oliveira
authors.initials: TA
authors.lastname: Mendes
authors.affiliation: Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Ronaldo Alves Pinto
authors.initials: RA
authors.lastname: Nagem
authors.affiliation: Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Thaís Teodoro de Oliveira
authors.initials: TT
authors.lastname: Santos
authors.affiliation: Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Ana Luíza Teixeira
authors.initials: AL
authors.lastname: Silva
authors.affiliation: Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Marcelo Matos
authors.initials: MM
authors.lastname: Santoro
authors.affiliation: Centro de Ciências Biológicas e da Saúde, Universidade Estadual de Montes Claros, Montes Claros, Brazil.
authors.forename: Silvio Fernando Guimarães
authors.initials: SF
authors.lastname: de Carvalho
authors.affiliation: Programa de Pós-Graduação em Ciências da Saúde. Infectologia e Medicina Tropical, Faculdade de Medicina and Departamento de Patologia Clínica, COLTEC, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Eduardo Antônio Ferraz
authors.initials: EA
authors.lastname: Coelho
authors.affiliation: Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Daniella Castanheira
authors.initials: DC
authors.lastname: Bartholomeu
authors.affiliation: Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Ricardo Toshio
authors.initials: RT
authors.lastname: Fujiwara
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000953:Antigens, Protozoan / Q000276:immunology; D003429:Cross Reactions / Q000276:immunology; D004285:Dogs; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D018604:Epitope Mapping; D018985:Epitopes, B-Lymphocyte / Q000276:immunology*; D005260:Female; D006801:Humans; D007114:Immunization; D007074:Immunoglobulin G / Q000276:immunology; D007892:Leishmania braziliensis / Q000276:immunology*; D007898:Leishmaniasis, Visceral / Q000097:blood / Q000175:diagnosis* / Q000276:immunology* / Q000469:parasitology; D008297:Male; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry; D054464:Peroxiredoxins / Q000737:chemistry / Q000276:immunology*; D016052:Protozoan Vaccines / Q000276:immunology; D012372:ROC Curve; D011933:Reagent Kits, Diagnostic; D011994:Recombinant Proteins / Q000302:isolation & purification; D015203:Reproducibility of Results; D012995:Solubility
chemical_list: D000953:Antigens, Protozoan; D018985:Epitopes, B-Lymphocyte; D007074:Immunoglobulin G; D010455:Peptides; D016052:Protozoan Vaccines; D011933:Reagent Kits, Diagnostic; D011994:Recombinant Proteins; D054464:Peroxiredoxins