Diaz-Ochoa Vladimir E, Jellbauer Stefan, Klaus Suzi, Raffatellu Manuela
Department of Microbiology and Molecular Genetics, University of California, Irvine Irvine, CA, USA ; Institute for Immunology, University of California, Irvine Irvine, CA, USA.
Front Cell Infect Microbiol. 2014 Jan 24;4:2. doi: 10.3389/fcimb.2014.00002. eCollection 2014.
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.
过渡金属离子是所有生物必需的微量营养素。在哺乳动物中，这些离子通常与蛋白质结合并被隔离在细胞内，从而限制了微生物对它们的获取。此外，在应对感染时，哺乳动物宿主通过激活上皮细胞和募集嗜中性粒细胞进一步降低金属营养素的可利用性，这两种细胞都会释放具有抗菌功能的金属结合蛋白。反过来，微生物已经进化出复杂的系统来克服这些限制并获取其生长所需的金属离子。在这里，我们综述了宿主和致病微生物用于竞争过渡金属离子的一些机制，并讨论了逃避“营养免疫”如何使病原体受益。此外，我们对黏膜尤其是炎症肠道中宿主与微生物竞争金属离子的机制提供了新的见解。
