Zinc deficiency is very common. It is estimated that around two billion people worldwide are affected by zinc deficiency.
Clinical manifestations of zinc deficiency include weight loss, growth retardation, stunting, immune dysfunction, lymphopenia, decreased ratio of T helper (Th) cells to cytotoxic T cells, decreased activity of natural killer cells ( NK) and increased monocyte cytotoxicity as well as increased oxidative stress and increased inflammatory immune response.
Dietary insufficiency and/or compromised absorption may lead to disturbance of zinc homeostasis essential for immune system function by regulating intracellular signaling pathways in innate and adaptive immune cells.
Zinc homeostasis is essential for multiple aspects of the immune system, including hematopoiesis, cell maturation, cell differentiation, cell cycle progression for proper immune cell function.
Regarding Innate Immunity, zinc deficiency negatively influences critical functions of neutrophils, such as phagocytosis, oxidative burst, degranulation, cytokine production, chemotaxis, and neutrophil extracellular trap (NET) formation.
Regarding Adaptive Immunity, zinc deficiency also negatively affects the maturation and function of T and B cells, which occurs through the deregulation of basic biological functions at the cellular level. For T cells, a perturbed ratio of Th1 and Th2 cells favors Th2-driven allergic reactions.
- Zinc flux signals as well as its normal homeostasis control the proper function of innate and adaptive immunity.
- Zinc deficiency causes severe impairment of immune function, involving both the adaptive and innate immune systems.
- A balanced zinc homeostasis is crucial to defend against invading pathogens or to protect the human body against a reactive immune system that causes autoimmune diseases, chronic inflammation or allergies.
- Therefore, zinc can be seen as a potential therapeutic for clinical use that beneficially influences the well-being of the patient suffering from immunity.
- In this regard, zinc can be expected as a guardian of the immune system, since the proper function of virtually all immune cells is highly dependent on zinc.