Avaliação do perfil de citocinas produzidas em infecções de cepas brasileiras de Trypanosoma cruzi em macrófagos intraperitoneais

Abstract

Chagas disease (CD) is caused by the protozoan Trypanosoma cruzi and affects about 6 to 7 million people, mainly in Latin America and is still considered a neglected disease. T. cruzi has three parasitic forms, amastigote, epimastigote and trypomastigotes (blood – TCC and metacyclic – TMI), the latter being responsible for infecting humans. This parasite has a wide genetic variety and are grouped into Discrete Typing Units DTUs (TcI-TcVI) according to genetic similarities. This infection has an acute phase and a chronic phase, with the presence of severe clinical manifestations, such as the megas (gastric and / or cardiac). The induced immune response to the parasite is essential for defining these manifestations, as well as controlling their proliferation. However, this immune response may be influenced by several factors such as parasite strain, infective form and factors predisposed by the vertebrate host. Thus, this study aimed to evaluate the infection in peritoneal macrophages isolated from Balb/c and C57BL/6 mice with TCC and TMI forms obtained from T. cruzi strains AQ-4 and Hel. For this, Balb / c and C57BL/6 peritoneal macrophages were isolated and infected in vitro with TCC and TMI from strains AQ-4 and Hel. After 4 hours and 24 hours of infection, IL-10, IL-6, TNF-α productions were evaluated by ELISA and NO determined by Griess reaction. The determination of the DTU belonging to each strain was also performed by PCR-RFLP (Polymerase Chain Reaction-Restriction Fragments Length Polimorphims), targeting TcSC5D. Macrophages isolated from mice belonging to the Balb/c strain were higher inducers of IL-6, TNF-α and IL-10 when compared to C57BL/6, in contrast, macrophages from C57 showed higher NO levels. The AQ-4 strain presented higher levels of TNF-α and IL-10 production and the Hel strain for IL-6 and NO. CBT forms showed higher production of proinflammatory cytokines than metacyclic ones. This study allowed us to understand the onset of immune response to different strains of T. cruzi isolated in Brazil.