ABSTRACT
Revisões históricas aos avanços científicos para o controle da doença, o Simpósio Internacional Comemorativo do Centenário da Descoberta da Doença de Chagas (1909-2009).
Subject(s)
Humans , Conjunctivitis/diagnosis , Chagas Disease/diagnosis , Trypanosomiasis/diagnosis , Trypanosomiasis/pathology , Trypanosomiasis/transmission , Brazil/ethnology , History of Medicine , Trypanosomiasis/physiopathologyABSTRACT
Host resistance to Trypanosoma cruzi infection in dependent on both natural and acquired immune responses. During the early acute phase of infection in mice, natural killer (NK) cell-derived IFN-gamma is involved in controlling intracellular parasite replication, mainly through the induction of nitric oxide biosynthesis by activate macrophages. We have shown that IL-12, a powerful inducer of IFN-gamma production by NK cells, is synthesized soon after trypomastigote-macrophage interaction. The role of IL-12 in the control of T. cruzi infection in vivo was determined by treating infected mice with anti-IL-12 monoclonal antibody (mAb) and analyzing both parasitemia and mortality during the acute phase of infection. The anti-IL-12 mAb-treated mice had higher levels of parasitemia and mortality compared to control mice. Also, treatment of infected mice with mAb spectific for IFN-gamma or TNF-alpha inhibited the protective effect of exogenous IL-12. On the other hand, TGF-beta and IL-10 produced by infected macrophages inhibited the induction and effects of IL-12. Therefore, while IL-12, TNF-alpha and IFN-gamma correlate with resistance to T. cruzi infection, TGF-beta and IL-10 promote susceptibility. These results provide support for a role of innate immunity in the control of T. cruzi infection. In addition to its protective role, IL-12 may also be involved in the modulation of T. cruzi-induced myocarditis, since treatment of infected mice with IL-12 or anti-IL-12 mAb leads to an enhanced or decreased inflammatory infiltrate in the heart, respectively. Understanding the role of the cytokine produced during the acute phase of T. cruzi infection and their involvement in protection and pathogenesis would be essential to devise new vaccines or therapies.
Subject(s)
Mice , Animals , Disease Models, Animal , Interleukin-12/physiology , Trypanosoma cruzi/pathogenicity , Trypanosomiasis/immunology , Trypanosomiasis/physiopathology , Immunity, InnateABSTRACT
Reistance to Trypanosoma cruzi infections is critically dependent on cytokine-mediated activation of cell-mediated immune effector mechanisms. This review focuses on the role of IL-10, TNF-alpha, IFN-gamma and IL-12 in controlling T. cruzi replication by the innate and specific immune systems of the vertebrate host. A study performed on mice with disrupted recombinase-activating genes (RAG/KO), which lack T and B lymphocytes, revealed the importance of IL-12, IFN-gamma and TNF-alpha in the resistance against T. cruzi mediated by the innate immune system. In addition, data from experiments using IL-10 KO, RAG/KO and double RAG/IL-10 KO mice indicating an in vivo regulatory role of IL-10 in innate and T. cruzi-specific immunity are discussed.
Subject(s)
Mice , Animals , Cytokines/physiology , Immunity, Innate/physiology , Immunity/physiology , Trypanosoma cruzi/pathogenicity , Trypanosomiasis/immunology , Trypanosomiasis/physiopathology , Interferon-gamma , Interleukin-10 , Interleukin-12 , Mice, Knockout , Tumor Necrosis Factor-alphaABSTRACT
Se presenta un cado de adenitis cervical solitaria con fiebre prolongada, en la que en el estudio citolgico del material necrótico aspirado por punción con aguja fina ,se pudo identificar la presencia de amastigotes del Trypanosoma cruzi.El tratamiento con anfotericina B, permitió la remisión del cuadro y la negativización de las reacciones serológicas y parasitarias para enfermedad de Chagas.Se realiza una revisión del síndrome de fiebre prolongada de difícil diagnóstico clínico inmediato,acentuando en los aspectos prácticos del mismo