Is the adaptive immune response in murine Trypanosoma cruzi infection influenced by zinc supplementation?

Chagas disease afflicts 7 to 8 million people worldwide and congenital Chagas' disease usually leads to changes in the maternal environment, culminating in fetal adaptations. Several articles have described the importance of micronutrients on pregnancy, which is sensitive to infections. In Trypanosoma cruzi endemic regions, the Chagas disease is aggravated by the lack of micronutrients in an average diet, to which pregnant women are more susceptible. The aim of this study was to evaluate distinct T cells phenotypes and intracellular cytokines by flow cytometry in pregnant Wistar rats under zinc therapy during experimental Chagas' disease. Twenty female Wistar rats were infected with 1 x 10(5) blood trypomastigotes (Y strain) and 30 days after infection the animals were mated and grouped: pregnant infected (PI-n = 5), pregnant infected/zinc supplied (PIZ-n = 5), pregnant control (PC-n = 5), control/zinc supplied (PCZ-n = 5). Zinc supplementation: 20 mg of zinc/Kg/day (gavage) for 18 days followed by euthanasia. The immune parameters showed: decreased percentages of CD62(Low)CD44(high) surface marker for infected and treated group (PIZ) when compared to PI (p < 0.05). Concerning to T regulatory cells (Treg cells), a significantly lower percentage of splenic Treg cells was found in the infected and treated group (PIZ) as compared to the PI group (p < 0.05). The expression of the co-stimulatory molecule CD28 displayed a significant reduced percentage in TCD8(+) for infected and zinc treated group (PIZ) as compared to (PI). The percentages of CD4(+)/CD11a(+) T cells subsets were lower on PIZ as compared to PI. Concerning to CD45RA(+) (B lymphocytes) analysis, infected pregnant and treated group (PIZ) showed a significant decrease in CD45RA percentage when compared to (PI) (p < 0.05). The intracellular cytokine profiles for TCD4(+) and TCD8(+) producing IL-4 and IFN-gamma revealed that zinc treated and untreated infected pregnant group (PI and PIZ) displayed increased cytokines concentrations as compared to zinc treated and untreated pregnant controls (PC and PCZ). Our data revealed the involvement of zinc as a signaling molecule in the modulation of the inflammatory process and immune response which occurs during pregnancy of T. cruzi infected rats. Zinc acted in a dual fashion, modulating the host's immune response in a way to protect the organism against the deleterious effects of the infection and an overwhelming pro -inflammatory response during pregnancy. (AU)