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

Zinc Supplementation: Immune Balance of Pregnancy During the Chronic Phase of the Chagas Disease

BACKGROUND

Chagas disease or American trypanosomiasis is caused by the protozoan Trypanosoma cruzi and is endemic of the Americas. The control of the disease is restricted to toxic and potentially teratogenic drugs, which limit the use during pregnancy. The use of food supplementation offers a safe and low-cost form to alleviate Chagas disease symptoms, mostly in areas with alimentary risk. For example, zinc demonstrates positive effects in immune response, including in Chagas disease during pregnancy.

PURPOSE

This study describes the innate response in pregnant rats chronically infected with T. cruzi and supplemented with zinc.

METHODS

Pregnant female Wistar rats, infected with T. cruzi, were treated with 20 mg/kg/day zinc sulfate and euthanized on the 18th day. Samples (plasma, splenocytes, and peritoneal exudate) were collected and several immune parameters (nitric oxide, RT1B, CD80/CD86, MCP-1, CD11b/c, NK/NKT, IL-2, IL-10, INF-cc, and apoptosis) evaluated.

RESULTS

Under Zinc supplementation and/or T. cruzi infection, the gestation developed normally. Several innate immune parameters such as RT1B, CD80/CD86, MCP-1 expressing lymphocytes, IL-2, and IL-17 were positively altered, whereas nitric oxide, CD11b/c, NK/NKT, apoptosis, INF-γ, and corticosterone demonstrated a pro-pregnancy pattern.

CONCLUSION

Our results indicated that zinc has diverse effects on immune response during pregnancy. An anti-T. cruzi immunity, as well as a pro-gestation response, were observed after zinc supplementation. The complete comprehension of zinc supplementation in pregnancy will base an adequate strategy to alleviate Chagas disease symptoms and propagation, especially for populations from endemic areas.

The treatment with selenium increases placental parasitismin pregnant Wistar rats infected with the Y strain of Trypanosoma cruzi

Selenium (Se) is an essential micronutrient in the diet of mammals and has an important role in the immune function. Selenium is a key element in selenoproteins involved in the in the maintenance of the antioxidant defense. Diet with selenium is beneficial for the treatment of diseases correlated with high levels of oxidative stress, also observed in the Chagas disease. Chagas disease is a neglected disease caused by the protozoan Trypanosoma cruzi and several research groups are focused on the illness treatment. Immunomodulation of the infection using microelements is an important tool to avoid deleterious effects of the Chagas disease. Therefore, our objective was to evaluate the effects of selenium supplementation on pregnant Wistar rats infected with T. cruzi. Selenium treatment stimulated the weight and length of fetuses and placentas allied to the decrease of blood parasitemia. However, selenium demonstrated a low influence on T cells, diminishing the B cell population (CD45RA⁺). Moreover, the production of pro-inflammatory cytokines was downregulated under selenium administration. Low pro-inflammatory cytokines levels probably are related to the increase in the number of amastigote nests in infected and treated animals. Thus, selenium supplementation during pregnancy could impair the local placental immune response. Further studies are necessary to assess the interaction between selenium and the acute Chagas' disease during pregnancy, which will base future supplementation strategies.