Transition metal ions at the crossroads of mucosal immunity and microbial pathogenesis.
Transition metal ions are essential micronutrients for all living organisms. In mammals, these ions are often protein-bound and sequestered within cells, limiting their availability to microbes. Moreover, in response to infection, mammalian hosts further reduce the availability of metal nutrients by activating epithelial cells and recruiting neutrophils, both of which release metal-binding proteins with antimicrobial function. Microorganisms, in turn, have evolved sophisticated systems to overcome these limitations and acquire the metal ions essential for their growth. Here we review some of the mechanisms employed by the host and by pathogenic microorganisms to compete for transition metal ions, with a discussion of how evading "nutritional immunity" benefits pathogens. Furthermore, we provide new insights on the mechanisms of host-microbe competition for metal ions in the mucosa, particularly in the inflamed gut.
Department of Microbiology and Molecular Genetics, University of California, Irvine Irvine, CA, USA ; Institute for Immunology, University of California, Irvine Irvine, CA, USA.
Vladimir E
VE
Diaz-Ochoa
Department of Microbiology and Molecular Genetics, University of California, Irvine Irvine, CA, USA ; Institute for Immunology, University of California, Irvine Irvine, CA, USA.
Stefan
S
Jellbauer
Department of Microbiology and Molecular Genetics, University of California, Irvine Irvine, CA, USA ; Institute for Immunology, University of California, Irvine Irvine, CA, USA.
Suzi
S
Klaus
Department of Microbiology and Molecular Genetics, University of California, Irvine Irvine, CA, USA ; Institute for Immunology, University of California, Irvine Irvine, CA, USA.
Manuela
M
Raffatellu
D000818:Animals; D001419:Bacteria / Q000378:metabolism* / Q000472:pathogenicity*; D005658:Fungi / Q000378:metabolism* / Q000472:pathogenicity*; D054884:Host-Pathogen Interactions; D006801:Humans; D018928:Immunity, Mucosal; D007477:Ions / Q000378:metabolism; D008670:Metals / Q000378:metabolism*; D009092:Mucous Membrane / Q000276:immunology / Q000378:metabolism*; D014774:Virulence
D007477:Ions; D008670:Metals
S100 proteins; calprotectin; infection; iron; lipocalin-2; manganese; nutritional immunity; zinc