Iron overload and immunity.
Progress in the characterization of genes involved in the control of iron homeostasis in humans and in mice has improved the definition of iron overload and of the cells affected by it. The cell involved in iron overload with the greatest effect on immunity is the macrophage. Intriguing evidence has emerged, however, in the last 12 years indicating that parenchymal iron overload is linked to genes classically associated with the immune system. This review offers an update of the genes and proteins relevant to iron metabolism expressed in cells of the innate immune system, and addresses the question of how this system is affected in clinical situations of iron overload. The relationship between iron and the major cells of adaptive immunity, the T lymphocytes, will also be reviewed. Most studies addressing this last question in humans were performed in the clinical model of Hereditary Hemochromatosis. Data will also be reviewed demonstrating how the disruption of molecules essentially involved in adaptive immune responses result in the spontaneous development of iron overload and how they act as modifiers of iron overload.
Porto
Graça
G
Institute of Molecular and Cellular Biology, Rua do Campo Alegre, Porto 8234150, Portugal. gporto@ibmc.up.pt
De Sousa
Maria
M
D000818:Animals; D005805:Genes, MHC Class I / Q000502:physiology; D000071020:Hemochromatosis Protein; D015395:Histocompatibility Antigens Class I / Q000235:genetics; D006706:Homeostasis / Q000502:physiology; D006801:Humans; D007113:Immunity, Innate / Q000502:physiology; D007501:Iron / Q000378:metabolism*; D019190:Iron Overload / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics; D051379:Mice
C103673:HFE protein, human; D000071020:Hemochromatosis Protein; D015395:Histocompatibility Antigens Class I; D008565:Membrane Proteins; D007501:Iron