Iron at the host-microbe interface

Abstract

Iron is an essential micronutrient for nearly all living organisms. In addition to facilitating redox reactions, iron is bound by metalloproteins that participate in a variety of biological processes. As the bioavailability of free iron in host environments is extremely low, iron lies at the center of a battle for nutrients between microbes and their host. Mucosal surfaces such as the respiratory and gastrointestinal tracts are constantly exposed to commensal and pathogenic microorganisms. Whereas a key strategy of mammalian antimicrobial defense is to deprive microbes of iron, pathogens and some commensals have evolved effective strategies to circumvent iron limitation.Here we provide an overview of mechanisms underpinning the tug-of-war for iron between microbes and their host, with a particular focus on mucosal surfaces.

Baseline iron status and presence of anaemia determine the course of systemic Salmonella infection following oral iron supplementation in mice

“…Salmonella Typhimurium (S.Tm) is a facultative intracellular, Gram-negative pathogen replicating within macrophages and it is highly dependent on iron for achieving full virulence [ [17] , [18] , [19] ]. Because of the central role of iron in host-pathogen interaction, immune system driven restriction of iron from invading microbes has been identified as a central anti-microbial defence strategy for which the term nutritional immunity has been coined [ [20] , [21] , [22] ]. The idea is to reduce the accessibility of iron for microbes, and those specific processes may differ according to the localization and tissue specific preferences of different pathogens [ 23 , 24 ].…”

Siderophore-mediated zinc acquisition enhances enterobacterial colonization of the inflamed gut

“…Commensal and pathogenic Enterobacteriaceae exploit host inflammation to achieve high levels of colonization and outcompete obligate anaerobes; these mechanisms include the ability to utilize alternative electron acceptors that become available following the production of reactive oxygen and nitrogen species by activated host cells 5 , 7 , as well as new nutrient sources such as lactate 55 and acidic sugars 56 . In addition to taking advantage of new metabolic resources, Enterobacteriaceae must also overcome host-mediated mechanisms of nutritional immunity 13 , including metal ion starvation 57 .…”

Microbiome Analysis of Mucosal Ileoanal Pouch in Ulcerative Colitis Patients Revealed Impairment of the Pouches Immunometabolites

“…On the other hand, we found unknown species from the Enterobacteriaceae family in more abundance in IPAA UC patients. Noteworthy is that the enrichment of the iron-dependent pathogenic Enterobacteriaceae was detected in the stool of chronic pouchitis patients [53,54], highlighting an important role of the iron metabolism at the host-microbe interfaces since it presents a critical role in many aspects of the host's normal physiology and in maintaining immunity [55]. In animal models of IBD, it has been shown that a high concentration of luminal iron or heme iron alters gut microbial communities, further exacerbating the bloom of Enterobacteriaceae and worsening colitis [56].…”