Zinc and Health: Workshop Summary

Session III

Session III, Immune System, Antioxidant and Defense Functions of Zinc illustrated the role of the immune system in zinc physiology.  The immune system is very adversely and rapidly affected by even modest degrees of zinc deficiency, and can alter immune system function and host defense mechanisms. The classic effects of zinc deficiency on the immune system are thymic atrophy and lymphopenia.  The effect of zinc nutriture on Th2 immunity has been under-appreciated. Zinc is required for the development of Th2 immune responses that help protect against infection   resulting from gastrointestinal helminth parasites. The gut is an excellent site for studying zinc's putative role in Thl/Th2 balance.  Zinc has also been shown to have a role in the modulation of cytokine production.  If proper parameters are chosen, the immune system could be used as a good bellwether of how effective zinc supplementation is in a number of clinical areas, such as GI mucosal immunology and pulmonary immunology.  Data were presented to show that the status of zinc in the cell affects and modulates cell death or apoptosis. The ability of nitric oxide to release zinc from metallothionein is really an interesting and important discovery suggesting that  an antioxidant role exists for cellular zinc.