Trypanosoma cruzi: do different sylvatic strains trigger distinct immune responses?
Strains of Trypanosoma cruzi are multiclonal populations that can be classified in groups or genotypes, differing in pathogenicity, virulence, and histotropism. In this experiment the distinct behavior of two strains of T. cruzi, MORC-1 and MORC-2, was documented. Blood parasitemia, spleen proliferation, nitric oxide, histopathology of the spleen and heart were used as tools to evaluate parasite persistence. Groups of male mice were separated and divided in three groups: Control (C), Infected (IM-1) and Infected (IM-2). The peak of parasitemia occurred on 10days post infection for both strains. LPS stimulated animals, infected MORC-2 group displayed significant higher concentrations of NO when compared to infected MORC-1 group (P<0.05). For ConA stimulated lymphoproliferation, infected MORC-1 group displayed higher proliferation index as compared to infected MORC-2 group. An opposite behavior for IL-4 and TNF-alpha was observed according to the strain. For MORC-1 enhanced concentrations of IL-4 were present with concomitant reduced levels of TNF-alpha, while for MORC-2 enhanced concentrations of TNF-alpha and reduced levels of IL-4 were found. The histopathology of heart and spleen showed important differences in which MORC-1 displayed statistically enhanced number of amastigote in the heart and spleen as compared to MORC-2. Concluding, each strain triggered a distinct immune response with enhanced cytokine TH-1 profile for MORC-2 and TH-2 for MORC-1.
Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Brazil. leony@fcfrp.usp.br
Leony Cristina
LC
Caetano
José Clóvis
JC
do Prado
Miriam Paula Alonso
MP
Toldo
Ana Amélia Carraro
AA
Abrahão
D000818:Animals; D001938:Brazil; D014355:Chagas Disease / Q000276:immunology* / Q000469:parasitology / Q000473:pathology; D002685:Chiroptera; D006321:Heart / Q000469:parasitology; D015847:Interleukin-4 / Q000097:blood; D008213:Lymphocyte Activation; D008264:Macrophages / Q000378:metabolism; D008297:Male; D051379:Mice; D009206:Myocardium / Q000473:pathology; D009569:Nitric Oxide / Q000032:analysis; D018512:Parasitemia / Q000276:immunology / Q000469:parasitology; D013154:Spleen / Q000166:cytology / Q000276:immunology / Q000469:parasitology / Q000473:pathology; D014349:Trypanosoma cruzi / Q000145:classification / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
D014409:Tumor Necrosis Factor-alpha; D015847:Interleukin-4; D009569:Nitric Oxide