Sesión premio Novartis: Early immune response induced by different Trypanosoma cruzi infective stages

BRENDA GUTIERREZ; MARCEL RAMIREZ; ESTELA LAMMEL; GONZALEZ C; CAROLINA V. PONCINI

Congreso; LXVI Reunión Anual de la Sociedad Argentina de Inmunología. Reunión conjunta SAIC-SAI-SAFE, Mar del Plata, noviembre 2018; 2018

Trypanosoma cruzi is an intracellular protozoan parasite that affects millionsof people in Latin America. Infection commonly occurs by vectorialtransmission via skin and/or mucous membranes. Immunologic eventsoccurring immediately after the parasite entrance are poorly studied.Skin constitutes a complex network and includes several population ofantigen presenting cells (APCs). The phenotype, localization and functionalproperties dene cellular identity. Trypanosoma cruzi infective stages wouldcondition the repertoire of cells recruited into the site of infection.In the intradermic model, blood and in vitro cultured metacyclictrypomastigotes (bTp and mTp, respectively) not only displayed differences incell recruitment at the site of infection, but also the populations of APCs andtheir activation in draining lymph nodes and spleen. Animals inoculated withmTp exhibited 100% of survival with no parasite detection in blood, in contrastwith the ones injected with bTp that displayed 80% of mortality and highparasitemia. Infection after mTp inoculation was confirmed by qPCR, not onlyat the site of infection but also in spleen. Animals infected with mTp andchallenged with bTp 15 days later showed APCs with enhanced activation insecondary lymphoid organs compared to controls injected with bTp or notinfected mice. These animals also displayed a less number of amastigotenests in cardiac tissue than bTp infected ones. All the results suggest that bTpand mTp differently infect mice. In addition, both stages induce an unequalimmune response since the very beginning of the infection.