ABSTRACT
This chapter considers how infections alter iron trafficking and the role of iron in immune responses. It describes the basic mechanisms that exist to maintain cellular and systemic iron homeostasis. The chapter provides a list of important proteins regulating iron trafficking in humans. If control of iron handling is important for defense against infection, one might expect there is evidence for positive selection at the genomic level for alterations in genes that control iron transport, and that genetic disorders of iron metabolism are associated with increased susceptibility to infections. Iron itself is a key regulator of hepcidin and appears to work in two ways. Firstly, increases in the amount of iron in the blood (transferrin saturation) are sensed by hepatocyte surface proteins and this information is signaled to increase hepcidin synthesis. Secondly, intracellular accumulation of iron in the liver is also sensed; this increases hepcidin synthesis.
