|Shea donohue, P|
Submitted to: Experimental Parasitology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 11/15/2004
Publication Date: 4/1/2005
Citation: Auyeung, K., Smith, A.D., Zhao, A., Madden, K., Elfrey, J., Sullivan, C., Levander, O.A., Urban Jr, J.F., Shea Donohue, P.T. 2005. Impact of vitamin E or selenium deficiency on nematode-induced alerations in murine intestinal function. Experimental Parasitology. 109:201-208. Interpretive Summary: Micronutrient deficiencies with selenium or vitamin E can go undetected until the stress of an infection demands an appropriate immune response. Both of these nutrients have been demonstrated to support optimal health of the immune response in order to respond to infectious agents. It had been shown that deficiencies in selenium and vitamin E make the host more susceptible to certain viruses that are able to exploit the limitations of an immune system that is dependent on adequate levels of selenium and vitamin E for proper function. The current study extends this observation to show that mice fed diets deficient in either selenium or vitamin E or both micronutrients respond less well to infections with worm parasites. This is important for two reasons, 1) worm parasites are a major health problem world wide, although most severe conditions are found in under developed countries, and 2) the response to worms is similar to that induced by food allergens because of the nature of the immune response that is stimulated by to both of these conditions. Further analysis revealed that although the net effect of either selenium or vitamin E deficiency was an inability to expel worm parasites, the mechanisms were different with vitamin E reducing the intensity of the intestinal tissue response while selenium had an unknown target. These results highlight the importance of adequate micronutrient intake in the diet to support robust immune function and show that there is a flushing response in the intestine that works against harmful agents and is dependent on adequate levels of vitamin E in the diet. Scientists interested in control of intestinal infections and responses to food allergens will benefit from the basic information from this work.
Technical Abstract: Nutrient status is an important component in the immune system and poor nutritional status is correlated with both the severity of and susceptibility to infection. The effects of deficiencies in the antioxidant nutrients, vitamin E (VE) and selenium (Se), on the host response to nematode infection are unknown. The aim of the study was to determine the effect of nutritional deficiencies on nematode-induced alterations in intestinal function in mice. BALB/c mice were fed control diets or diets deficient in selenium or vitamin E for a total of 12 weeks then inoculated with Heligmosomoides polygyrus. Egg and worm counts were assessed to determine host resistance. Section of jejunum were mounted in Ussing chambers to measure changes in permeability, absorption, and secretion or suspended in organ baths to determine smooth muscle contraction. Both Se and VE deficient diets reduced resistance to helminth infection. VE, but not Se, deficiency prevented nematode-induced decreases in glucose absorption and hyper contractility of smooth muscle contractility. Thus, nutritional status is an important factor in the functional response to enteric infection and deficiencies can supercede the effects of circulating Th2 cytokine up regulation.