Mechanisms by which selenium influences immune responses.

Selenium (Se) is an essential dietary trace element that influences immune responses through its incorporation into selenoproteins as the amino acid selenocysteine. This review summarizes data available to date regarding the mechanisms by which Se exerts its effects on inflammation and immune responses. This includes the effects of Se on phagocytes as well as effects on lymphocyte activation, proliferation, and differentiation. Also examined are the known functions of individual selenoproteins for regulating reactive oxygen species and redox potential in leukocytes. Overall, determining how Se contributes to optimal immune responses will depend on a better understanding of the mechanisms by which the selenoproteins, individually and collectively, shape inflammation and immune responses.