title: Evaluation of the immunodiagnostic potential of a recombinant surface protein domain from Acanthamoeba castellanii.
abstract: Acanthamoeba spp. are free-living protists widely distributed in environment, able to cause keratitis, encephalitis and skin lesions in humans and animals. Acanthamoeba spp. exist in two forms: an infective trophozoite and a dormant cyst. Several factors contribute to the pathogenesis of Acanthamoeba spp. The parasite adhesion to the host cell is the primary step for infection and is mediated by a mannose binding-protein, expressed in the surface and considered the main pathogenicity factor in Acanthamoeba spp. So far, there was no evidence of another surface protein of Acanthamoeba spp. relevant for host invasion or infection by these organisms. The aims of this study were to identify and characterize an Acanthamoeba castellanii surface protein and to evaluate its diagnostic potential. In silico predictions of surface proteins allowed to identify the A. castellanii calreticulin as a possible surface antigen. The coding sequence of a predicted extracellular domain of A. castellanii calreticulin was cloned by in vivo homologous recombination and the recombinant polypeptide (AcCRT29-130) was produced. Its immunodiagnostic potential was assessed in a recombinant antigen-based ELISA with sera from experimentally infected rats that developed keratitis and encephalitis, and sera from patients with encephalitis. The AcCRT29-130 was significantly more recognized by sera from encephalitis infected rats in comparison with the non-infected controls. Human sera from encephalitis patients, however presented no significant response. These results showed the AcCRT29-130 potential for A. castellanii infection immunodiagnosis in animals, with further studies being required for assessment of its use for human infections.
authors.affiliation: Programa de Pós-graduação em Microbiologia Agrícola e do Ambiente,Instituto de Ciencias Básicas e da Saúde,UFRGS,Porto Alegre,RS,Brazil.
authors.forename: Alemao G Carpinteyro
authors.initials: AG
authors.lastname: Sánchez
authors.affiliation: Laboratório de Genômica Estrutural e Funcional,Centro de Biotecnologia,UFRGS,Porto Alegre,RS,Brazil.
authors.forename: Veridiana Gomes
authors.initials: VG
authors.lastname: Virginio
authors.affiliation: Programa de Pós-graduação em Microbiologia Agrícola e do Ambiente,Instituto de Ciencias Básicas e da Saúde,UFRGS,Porto Alegre,RS,Brazil.
authors.forename: Vinicius José
authors.initials: VJ
authors.lastname: Maschio
authors.affiliation: Laboratório de Genômica Estrutural e Funcional,Centro de Biotecnologia,UFRGS,Porto Alegre,RS,Brazil.
authors.forename: Henrique Bunselmeyer
authors.initials: HB
authors.lastname: Ferreira
authors.affiliation: Programa de Pós-graduação em Microbiologia Agrícola e do Ambiente,Instituto de Ciencias Básicas e da Saúde,UFRGS,Porto Alegre,RS,Brazil.
authors.forename: Marilise Brittes
authors.initials: MB
authors.lastname: Rott
mesh_terms: D048248:Acanthamoeba castellanii / Q000276:immunology*; D000562:Amebiasis / Q000175:diagnosis*; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood*; D000953:Antigens, Protozoan / Q000235:genetics / Q000276:immunology; D037282:Calreticulin / Q000235:genetics / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics / Q000276:immunology*; D051381:Rats; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D012698:Serologic Tests / Q000379:methods*
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D037282:Calreticulin; D008565:Membrane Proteins; D011994:Recombinant Proteins
keywords: Acanthamoeba castellanii; ELISA; calreticulin; immunodiagnostic; recombinant protein