title: Synthetic peptides mimic gp75 from Paracoccidioides brasiliensis in the diagnosis of paracoccidioidomycosis.
abstract: Paracoccidioidomycosis (PCM) is a systemic granulomatous disease, endemic in Latin America, caused by the thermal dimorphic fungus Paracoccidioides brasiliensis. Although some fungal antigens have already been characterized and used for serological diagnosis, cross-reactions have been frequently observed. Thus, the examination of fungal forms in clinical specimens or isolation of P. brasiliensis by culture is still the most frequent method for the diagnosis of this mycosis. In this study, a random peptide phage display library was used to select mimotopes of P. brasiliensis, which were employed as antigens in an indirect enzyme-linked immunosorbent assay. The protective monoclonal antibody against experimental PCM (anti-gp75) was used as molecular target to screen a phage display library. That approach led to a synthetic peptide named P2, which was synthesized and tested against PCM patients' sera to check whether it was recognized. There was significant recognition of P2 by sera of untreated PCM patients when compared with normal human sera. Sera from treated PCM group, patients with other mycosis or co-infected with HIV had much lower recognition of P2 than untreated patient group. The test showed a sensitivity of 100 and 94.59% of specificity in relation to human sera control. These data indicate a potential use of P2 as diagnostic tool in PCM. Its application for serological diagnosis of PCM may contribute to the development and standardization of simpler, faster and highly reproducible immunodiagnostic tests at low cost.
authors.affiliation: Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo-Escola Paulista de Medicina, Disciplina de Imunologia, Rua Botucatu, 862, 4º andar, São Paulo, 04023-900, Brazil.
authors.forename: Camila Pistelli
authors.initials: CP
authors.lastname: Caldini
authors.forename: Patricia
authors.initials: P
authors.lastname: Xander
authors.forename: Érika Seki
authors.initials: ÉS
authors.lastname: Kioshima
authors.forename: André Luis Lacerda
authors.initials: AL
authors.lastname: Bachi
authors.forename: Zoilo Pires
authors.initials: ZP
authors.lastname: de Camargo
authors.forename: Mário
authors.initials: M
authors.lastname: Mariano
authors.forename: José Daniel
authors.initials: JD
authors.lastname: Lopes
mesh_terms: D000818:Animals; D000908:Antibodies, Fungal / Q000097:blood*; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000302:isolation & purification; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D006801:Humans; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009172:Mycology / Q000379:methods*; D010229:Paracoccidioidomycosis / Q000175:diagnosis*; D019151:Peptide Library; D010455:Peptides / Q000302:isolation & purification; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000379:methods
chemical_list: D000908:Antibodies, Fungal; D000911:Antibodies, Monoclonal; D019151:Peptide Library; D010455:Peptides