Modulation of IFN-γ, IL-4 and IL-17 Cytokines is Related to Parasitemia Control in Mice Infected by Trypanosoma cruzi and Treated with Biotherapy

Abstract

The study of biotherapies as an intervention in experimental models of infection is a possible means to understand the effects of these highly diluted medications. The present study evaluated the immunological and parasitological effects of biotherapies that were prepared from mouse serum that was uninfected (sarcode: BSNI_13cH group) and chronically infected with the Y strain of T. cruzi (nosode: BSI_13cH group), dynamization 13cH, in male Swiss mice at 28 days of age. On days 0 and 12 after infection (a.i.), the BSNI_13cH group exhibited a pronounced Th1 response that was attributable to a reduction of interleukin-4 (IL-4) concentrations, with no significant differences in interferon-γ (IFN-γ) concentrations and a decrease in IL-17A concentrations on day 0 a.i. compared with the control and BSI_13cH groups. However, this cytokine balance was not sufficient to alter blood parasitemia in treated animals, likely because of a decrease in IFN-γ concentrations on day 8 a.i., thus hindering a more effective Th1 response. In contrast, the BSI_13cH group presented a pronounced Th2 response that was attributable to an increase in IL-4 concentrations (on days 0 and 8 a.i.) and a decrease in IFN-γ concentration (on day 12 a.i.) compared with the control and BSNI_13cH groups. This cytokine balance suppressed the immune response to T. cruzi in murine infection, resulting in a significant increase in blood parasitemia, decrease in the patent period and subsequently a decrease in survival time. The results indicate that these highly diluted medications differentially modulate the immune system and represent a substantial contribution to the field of homeopathic medicine, providing evidence of the action of these medications.