Beyond tug-of-war: Iron metabolism in cooperative host–microbe interactions

摘要

Infections induce dramatic rearrangements in host macro- and micronutrient processes [1] and likely reflect host adaptive mechanisms to defend against infection. Traditional models to explain these adaptations suggest antagonistic host–pathogen coevolution. This is probably best exemplified by our current view of host iron metabolism during infection. Iron is an essential micronutrient for all living organisms. Within a host environment, pathogenic microorganisms require host iron to thrive and promote their fitness. In response, mammals have evolved a plethora of strategies that are believed to “starve” invading pathogens of iron, whereas pathogens have evolved ingenious countermeasures to bypass host iron sequestration. However, the role of iron metabolism during infection is far more complex than just a simple “tug-of-war” for nutrients. Here, we highlight recent discoveries demonstrating that iron can promote cooperation in host–microbe interactions, emphasizing alternative ways in which host iron metabolism influences disease outcomes.