3.4. The stimulation index highlights the variances in the impact of alcohol on both adaptive and innate immunity in animals infected with T. cruzi.
The stimulation index (SI) is an important metric in experimental designs assessing functional parameters in leukocytes following stimulation with specific antigens. It estimates the degree to which cytokine production varies, either increasing or decreasing, compared to unstimulated control cultures. The results reiterate that ethanol pre-administration in T. cruzi infected mice, appears to amplify the adaptive immunity response, especially mediated by CD8+ T lymphocytes, reflecting a mixed profile of activation compared to other groups, due to the high production of IL-4, IL-10 and IFN-γ (Figure 6B). In turn, for CD4+ T lymphocytes (Figure 6A) the most prominent results are selective for IFN-γ and B lymphocytes (Figure 6C) for the increase in IL-10. Regarding innate immune cells, the SI confirms the apparent suppression of the cytokine response in ethanol-pre-exposed mice infected with T. cruzi compared to all other groups, mainly NK (Figure 6D) and dendritic cells (Figure 6F). In turn, IL-10 production by macrophages (Figure 6E) is elevated in ethanol-pre-exposed mice (infected or not) compared to control-infected mice. The main results are observed in this study were summarized in Figure 7.