title: Trypanosoma cruzi in the chicken model: Chagas-like heart disease in the absence of parasitism.
abstract: BACKGROUND
  The administration of anti-trypanosome nitroderivatives curtails Trypanosoma cruzi infection in Chagas disease patients, but does not prevent destructive lesions in the heart. This observation suggests that an effective treatment for the disease requires understanding its pathogenesis.
  
  
  RESULTS
  To understand the origin of clinical manifestations of the heart disease we used a chicken model system in which infection can be initiated in the egg, but parasite persistence is precluded. T. cruzi inoculation into the air chamber of embryonated chicken eggs generated chicks that retained only the parasite mitochondrial kinetoplast DNA minicircle in their genome after eight days of gestation. Crossbreeding showed that minicircles were transferred vertically via the germ line to chicken progeny. Minicircle integration in coding regions was shown by targeted-primer thermal asymmetric interlaced PCR, and detected by direct genomic analysis. The kDNA-mutated chickens died with arrhythmias, shortness of breath, cyanosis and heart failure. These chickens with cardiomyopathy had rupture of the dystrophin and other genes that regulate cell growth and differentiation. Tissue pathology revealed inflammatory dilated cardiomegaly whereby immune system mononuclear cells lyse parasite-free target heart fibers. The heart cell destruction implicated a thymus-dependent, autoimmune; self-tissue rejection carried out by CD45(+), CD8γδ(+), and CD8α lymphocytes.
  
  
  CONCLUSIONS
  These results suggest that genetic alterations resulting from kDNA integration in the host genome lead to autoimmune-mediated destruction of heart tissue in the absence of T. cruzi parasites.
authors.affiliation: Chagas Disease Multidisciplinary Research Laboratory, Faculty of Medicine, University of Brasilia, Brasilia, Federal District, Brazil. ateixeir@unb.br
authors.forename: Antonio R L
authors.initials: AR
authors.lastname: Teixeira
authors.forename: Clever
authors.initials: C
authors.lastname: Gomes
authors.forename: Nadjar
authors.initials: N
authors.lastname: Nitz
authors.forename: Alessandro O
authors.initials: AO
authors.lastname: Sousa
authors.forename: Rozeneide M
authors.initials: RM
authors.lastname: Alves
authors.forename: Maria C
authors.initials: MC
authors.lastname: Guimaro
authors.forename: Ciro
authors.initials: C
authors.lastname: Cordeiro
authors.forename: Francisco M
authors.initials: FM
authors.lastname: Bernal
authors.forename: Ana C
authors.initials: AC
authors.lastname: Rosa
authors.forename: Jiri
authors.initials: J
authors.lastname: Hejnar
authors.forename: Eduardo
authors.initials: E
authors.lastname: Leonardecz
authors.forename: Mariana M
authors.initials: MM
authors.lastname: Hecht
mesh_terms: D000818:Animals; D001327:Autoimmune Diseases / Q000473:pathology; D016827:CD8 Antigens / Q000032:analysis; D002598:Chagas Cardiomyopathy / Q000473:pathology*; D002645:Chickens; D004270:DNA, Circular / Q000235:genetics / Q000302:isolation & purification; D004272:DNA, Mitochondrial / Q000235:genetics / Q000302:isolation & purification; D016054:DNA, Protozoan / Q000235:genetics / Q000302:isolation & purification; D004195:Disease Models, Animal; D006333:Heart Failure; D006790:Host-Parasite Interactions; D017493:Leukocyte Common Antigens / Q000032:analysis; D016131:Lymphocyte Subsets / Q000737:chemistry / Q000276:immunology; D009205:Myocarditis / Q000473:pathology; D009206:Myocardium / Q000473:pathology; D016133:Polymerase Chain Reaction / Q000379:methods; D011201:Poultry Diseases / Q000473:pathology*; D014349:Trypanosoma cruzi / Q000235:genetics / Q000472:pathogenicity*
chemical_list: D016827:CD8 Antigens; D004270:DNA, Circular; D004272:DNA, Mitochondrial; D016054:DNA, Protozoan; D017493:Leukocyte Common Antigens