Trypanosoma cruzi high infectivity in vitro is related to cardiac lesions during long-term infection in Beagle dogs.
Trypanosoma cruzi is a hemoflagelate parasite associated with heart dysfunctions causing serious problems in Central and South America. Beagle dogs develop the symptoms of Chagas disease in humans, and could be an important experimental model for better understanding the immunopathogenic mechanisms involved in the chagasic infection. In the present study we investigated the relation among biological factors inherent to the parasite (trypomastigote polymorphism and in vitro infectivity) and immunoglobulin production, inflammation, and fibrosis in the heart of Beagle dogs infected with either T. cruzi Y or Berenice-78 strains. In vitro infectivity of Vero cells as well as the extension of cardiac lesions in infected Beagle was higher for Y strain when compared to Berenice-78 strain. These data suggested that in vitro infectivity assays may correlate with pathogenicity in vivo. In fact, animals infected with Y strain, which shows prevalence of slender forms and high infectivity in vitro, presented cardiomegaly, inflammation, and fibrosis in heart area. Concerning the immunoglobulin production, no statistically significant difference was observed for IgA, IgM or IgG levels among T. cruzi infected animals. However, IgA together IgM levels have shown to be a good marker for the acute phase of Chagas disease.
Guedes
Paulo M M
PM
Departamento de Patologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brasil. guedespm@nupeb.ufop.br
Veloso
Vanja M
VM
Caliari
Marcelo V
MV
Carneiro
Cláudia M
CM
Souza
Sheler M
SM
de Lana
Marta
M
Chiari
Egler
E
Bahia
Maria T
MT
Galvão
Lúcia M C
LM
D000208:Acute Disease; D000818:Animals; D015415:Biomarkers; D002598:Chagas Cardiomyopathy / Q000276:immunology / Q000469:parasitology* / Q000473:pathology; D002908:Chronic Disease; D004195:Disease Models, Animal; D004285:Dogs; D005355:Fibrosis / Q000469:parasitology / Q000473:pathology; D006801:Humans; D007136:Immunoglobulins / Q000096:biosynthesis*; D007249:Inflammation / Q000469:parasitology / Q000473:pathology; D018512:Parasitemia; D013997:Time Factors; D014349:Trypanosoma cruzi / Q000145:classification / Q000472:pathogenicity*; D014774:Virulence
D015415:Biomarkers; D007136:Immunoglobulins