Effect of nutrient deficiencies on in vitro Th1 and Th2 cytokine response of peripheral blood mononuclear cells to Plasmodium falciparum infection

Peripheral blood mononuclear cells from Tanzanian preschool children were stimulated in vitro with Plasmodium falciparum-parasitized red blood cells to determine T-cell responses to malaria under different conditions of nutrient deficiencies and malaria status.The data obtained indicate that zinc deficiency is associated with an increase in TNF response by 37%; 95% CI: 14% to 118% and IFN-γ response by 74%; 95% CI: 24% to 297%. Magnesium deficiency, on the other hand, was associated with an increase in production of IL-13 by 80%; 95% CI: 31% to 371% and a reduction in IFN-γ production. These results reflect a shift in cytokine profile to a more type I cytokine profile and cell-cell mediated responses in zinc deficiency and a type II response in magnesium deficiency. The data also reveal a non-specific decrease in cytokine production in children due to iron deficiency anaemia that is largely associated with malaria infection status.The pathological sequels of malaria potentially depend more on the balance between type I and type II cytokine responses than on absolute suppression of these cytokines and this balance may be influenced by a combination of micronutrient deficiencies and malaria status.Frequent or chronic exposure to Plasmodium falciparum infection is thought to be a key element to immune protection against malaria in endemic areas [1]. Although the human immune system can kill parasites, it can also contribute to severe disease if not regulated and controlled to optimal levels [2,3]. In African countries, micronutrient deficiencies are common and may modulate immunity and predispose to infections. This is particularly relevant for young children who are most at risk of both malaria and micronutrient deficiencies.Deficiencies in mineral elements and vitamins can result in suppression of innate, T-cell mediated and humoral responses [4,5]. Coordinating these responses are the cytokines which are produced interactively by several types of immune cells [2,4].