Louisiana State University Health Sciences Center-Shreveport, Department of Microbiology & Immunology, 1501 Kings Highway, Shreveport, LA 71130, USA.
Infect Immun. 2010 May;78(5):1841-9. doi: 10.1128/IAI.01258-09. Epub 2010 Feb 22.
Helicobacter pylori chronically infects the gastric mucosa, where it can be found free in mucus, attached to cells, and intracellularly. H. pylori requires iron for growth, but the sources of iron used in vivo are unclear. In previous studies, the inability to culture H. pylori without serum made it difficult to determine which host iron sources might be used by H. pylori. Using iron-deficient, chemically defined medium, we determined that H. pylori can bind and extract iron from hemoglobin, transferrin, and lactoferrin. H. pylori can use both bovine and human versions of both lactoferrin and transferrin, contrary to previous reports. Unlike other pathogens, H. pylori preferentially binds the iron-free forms of transferrin and lactoferrin, which limits its ability to extract iron from normal serum, which is not iron saturated. This novel strategy may have evolved to permit limited growth in host tissue during persistent colonization while excessive injury or iron depletion is prevented.
幽门螺杆菌（Helicobacter pylori）会慢性感染胃黏膜，在胃黏膜中可在黏液中自由游离、黏附于细胞表面和细胞内。幽门螺杆菌的生长需要铁，但体内使用的铁源尚不清楚。在之前的研究中，由于无法在无血清的情况下培养幽门螺杆菌，因此很难确定幽门螺杆菌可能利用哪些宿主铁源。我们使用缺铁的化学定义培养基，确定了幽门螺杆菌可以结合并从血红蛋白、转铁蛋白和乳铁蛋白中提取铁。与之前的报道相反，幽门螺杆菌可以使用牛和人源的乳铁蛋白和转铁蛋白。与其他病原体不同，幽门螺杆菌优先结合无铁形式的转铁蛋白和乳铁蛋白，这限制了它从未饱和的正常血清中提取铁的能力。这种新的策略可能是为了在持续定植期间允许在宿主组织中有限生长，同时防止过度损伤或铁耗竭。
