title: Variant surface glycoproteins from Venezuelan trypanosome isolates are recognized by sera from animals infected with either Trypanosoma evansi or Trypanosoma vivax.
abstract: Salivarian trypanosomes sequentially express only one variant surface glycoprotein (VSG) on their cell surface from a large repertoire of VSG genes. Seven cryopreserved animal trypanosome isolates known as TeAp-ElFrio01, TEVA1 (or TeAp-N/D1), TeGu-N/D1, TeAp-Mantecal01, TeGu-TerecayTrino, TeGu-Terecay03 and TeGu-Terecay323, which had been isolated from different hosts identified in several geographical areas of Venezuela were expanded using adult albino rats. Soluble forms of predominant VSGs expressed during the early infection stages were purified and corresponded to concanavalin A-binding proteins with molecular masses of 48-67 kDa by sodium dodecyl sulfate-polyacrylamide gel electropohoresis, and pI values between 6.1 and 7.5. The biochemical characterization of all purified soluble VSGs revealed that they were dimers in their native form and represented different gene products. Sequencing of some of these proteins yielded peptides homologous to VSGs from Trypanosoma (Trypanozoon) brucei and Trypanosoma (Trypanozoon) evansi and established that they most likely are mosaics generated by homologous recombination. Western blot analysis showed that all purified VSGs were cross-reacting antigens that were recognized by sera from animals infected with either T. evansi or Trypanosoma (Dutonella) vivax. The VSG glycosyl-phosphatidylinositol cross-reacting determinant epitope was only partially responsible for the cross-reactivity of the purified proteins, and antibodies appeared to recognize cross-reacting conformational epitopes from the various soluble VSGs. ELISA experiments were performed using infected bovine sera collected from cattle in a Venezuelan trypanosome-endemic area. In particular, soluble VSGs from two trypanosome isolates, TeGu-N/D1 and TeGu-TeracayTrino, were recognized by 93.38% and 73.55% of naturally T. vivax-infected bovine sera, respectively. However, approximately 70% of the sera samples did not recognize all seven purified proteins. Hence, the use of a combination of various VSGs for the diagnosis of animal trypanosomosis is recommended.
authors.affiliation: Fundación Instituto de Estudios Avanzados IDEA, Caracas, Venezuela; Universidad Simón Bolívar, Departamento de Biología Celular, Caracas, Venezuela.
authors.forename: Rocío
authors.initials: R
authors.lastname: Camargo
authors.affiliation: Universidad Simón Bolívar, Departamento de Biología Celular, Caracas, Venezuela; Universidad Central de Venezuela, Instituto de Ciencia y Tecnología de Alimentos, Caracas, Venezuela.
authors.forename: Adriana
authors.initials: A
authors.lastname: Izquier
authors.affiliation: Fundación Instituto de Estudios Avanzados IDEA, Caracas, Venezuela.
authors.forename: Graciela L
authors.initials: GL
authors.lastname: Uzcanga
authors.affiliation: Instituto Venezolano de Investigaciones Científicas IVIC, Centro de Biofísica y Bioquímica, Caracas, Venezuela.
authors.forename: Trina
authors.initials: T
authors.lastname: Perrone
authors.affiliation: Parasitology Department, Liverpool School of Tropical Medicine, Liverpool, UK.
authors.forename: Alvaro
authors.initials: A
authors.lastname: Acosta-Serrano
authors.affiliation: Universidad Simón Bolívar, Departamento de Biología Celular, Caracas, Venezuela.
authors.forename: Liomary
authors.initials: L
authors.lastname: Carrasquel
authors.affiliation: Universidad Simón Bolívar, Departamento de Química, Caracas, Venezuela.
authors.forename: Laura P
authors.initials: LP
authors.lastname: Arias
authors.affiliation: Universidad Simón Bolívar, Departamento de Química, Caracas, Venezuela.
authors.forename: José L
authors.initials: JL
authors.lastname: Escalona
authors.affiliation: Universidad Simón Bolívar, Departamento de Biología Celular, Caracas, Venezuela.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Cardozo
authors.affiliation: Universidad Simón Bolívar, Departamento de Biología Celular, Caracas, Venezuela. Electronic address: jbubis@usb.ve.
authors.forename: José
authors.initials: J
authors.lastname: Bubis
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood*; D000953:Antigens, Protozoan / Q000276:immunology*; D002417:Cattle; D003429:Cross Reactions; D004591:Electrophoresis, Polyacrylamide Gel / Q000662:veterinary; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D008970:Molecular Weight; D051381:Rats; D017207:Rats, Sprague-Dawley; D020539:Sequence Analysis, Protein / Q000662:veterinary; D014345:Trypanosoma / Q000235:genetics / Q000276:immunology*; D016689:Trypanosoma vivax / Q000235:genetics / Q000276:immunology; D014352:Trypanosomiasis / Q000175:diagnosis / Q000276:immunology*; D014354:Trypanosomiasis, Bovine / Q000175:diagnosis / Q000276:immunology; D014643:Variant Surface Glycoproteins, Trypanosoma / Q000276:immunology*
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D014643:Variant Surface Glycoproteins, Trypanosoma
keywords: Animal trypanosomosis; Cross-reacting antigens; Diagnosis; Trypanosoma evansi; Trypanosoma vivax; Variant surface glycoproteins