title: Immunologically relevant strain polymorphism in the Amastigote Surface Protein 2 of Trypanosoma cruzi.
abstract: Several evidences suggest that the Amastigote Surface Protein-2 (ASP-2) of Trypanosoma cruzi is an important target for immunity during infection. Based on this, we considered it important to evaluate its strain polymorphism. Initially, we observed the presence of conserved cross-reactive epitopes in amastigotes of all parasite strains tested. In addition, the predicted amino acid sequences of the genes isolated from the cDNA of amastigotes of CL-Brener, Tulahuen, Colombian and G strains displayed a high degree of identity (>80%) to the previously described genes of ASP-2. Unexpectedly, Sylvio X10/4 and G strains expressed a new isoform of ASP-2 with limited identity to the previously described genes, but with a high degree of identity when compared to each other. Immunological studies confirmed the presence of cross-reactive epitopes between recombinant proteins representing the different isoforms of ASP-2. However, the genetic vaccination of mice with the new isoform of asp-2 gene expressed by the G strain failed to provide the same degree of protective immunity to a challenge by parasites of the Y strain as did asp-2 genes of Y or CL-Brener strains. In summary, we found that few strains can express different isoforms of ASP-2 which may not share cross-protective epitopes.
authors.affiliation: Centro Interdisciplinar de Terapia Gênica (CINTERGEN), Universidade Federal de São Paulo-Escola Paulista de Medicina, Rua Mirassol, 207, São Paulo-SP 04044-010, Brazil.
authors.forename: Carla
authors.initials: C
authors.lastname: Claser
authors.forename: Noeli Maria
authors.initials: NM
authors.lastname: Espíndola
authors.forename: Gisela
authors.initials: G
authors.lastname: Sasso
authors.forename: Adelaide José
authors.initials: AJ
authors.lastname: Vaz
authors.forename: Silvia B
authors.initials: SB
authors.lastname: Boscardin
authors.forename: Mauricio M
authors.initials: MM
authors.lastname: Rodrigues
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000953:Antigens, Protozoan / Q000235:genetics / Q000276:immunology; D014355:Chagas Disease / Q000276:immunology / Q000469:parasitology / Q000517:prevention & control; D003429:Cross Reactions; D000939:Epitopes; D005260:Female; D014644:Genetic Variation; D006367:HeLa Cells; D006801:Humans; D007527:Isoenzymes / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D008018:Life Cycle Stages; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D009439:Neuraminidase / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D011110:Polymorphism, Genetic; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D014349:Trypanosoma cruzi / Q000145:classification* / Q000235:genetics / Q000254:growth & development / Q000276:immunology*; D014611:Vaccination
chemical_list: D000953:Antigens, Protozoan; D000939:Epitopes; D007527:Isoenzymes; D011994:Recombinant Proteins; C493236:ASP-2 protein, Trypanosoma cruzi; D009439:Neuraminidase