Different Infective Forms Trigger Distinct Immune Response in Experimental Chagas Disease

Abstract

Although metacyclic and blood trypomastigotes are completely functional in relation to parasite-host interaction and/or target cell invasion, they differ in the molecules present on the surface. Thus, aspects related to the variability that the forms of T. cruzi interacts with host cells may lead to fundamental implications on the immune response against this parasite and, consequently, the clinical evolution of Chagas disease. We have shown that BT infected mice presented higher levels of parasitemia during all the acute phase of infection. Moreover, the infection with either MT or BT forms resulted in increased levels of total leukocytes, monocytes and lymphocytes, specifically later for MT and earlier for BT. The infection with BT forms presented earlier production of proinflammatory cytokine TNF-α and later of IFN-γ by both T cells subpopulations. This event was accompanied by an early cardiac inflammation with an exacerbation of this process at the end of the acute phase. On the other hand, infection with MT forms result in an early production of IFN-γ, with subsequent control in the production of this cytokine by IL-10, which provided to these animals an immunomodulatory profile in the end of the acute phase. These results are in agreement with what was found for cardiac inflammation where animals infected with MT forms showed intense cardiac inflammation later at infection, with a decrease in the same at the end of this phase. In summary, our findings emphasize the importance of taking into account the inoculums source of T. cruzi, since vectorial or transfusional routes of T. cruzi infection may trigger distinct parasite-host interactions during the acute phase that may influence relevant biological aspects of chronic Chagas disease.

The TcI and TcII Trypanosoma cruzi experimental infections induce distinct immune responses and cardiac fibrosis in dogs

“…However, this same strain favours IL-4 production, which can help control the tissue lesion. Similar observations were made during murine infection with Be-78 (TcII), which favours early production of IFN-γ and coincides with cardiac inflammation ( Vieira et al 2012 ). Petray et al (1993) studied the influence of anti-IFN-γ and anti-IL-4 treatment on the course of experimental murine infection with two reticulotropic strains and the Col strain, a myotropic strain.…”

Natural sesquiterpene lactones induce programmed cell death in Trypanosoma cruzi: A new therapeutic target?

“…In chronic chagasic myocarditis the maintenance of a pro-inflammatory response is the cause of an excessive or uncontrolled heart inflammation (Rosenberg et al 2010;Vieira et al 2012). Therefore inducing apoptosis-like cell death in the parasite not only allows killing the pathogen but also could contribute to the modulation of the inflammatory response, with beneficial effects on the infected host tissues.…”

Mixed Formulation of Conventional and Pegylated Meglumine Antimoniate-Containing Liposomes Reduces Inflammatory Process and Parasite Burden in Leishmania infantum-Infected BALB/c Mice

“…After euthanasia, the spleens of the animals (n ϭ 12 per experimental group) were removed, and cell suspensions were prepared as described by Taylor et al (39). The protocol used for dosing intracytoplasmic cytokines in spleen was previously described by Vieira et al (40), with some modifications.…”