van Amsterdam Karin, van der Ende Arie
Academic Medical Center, Department of Medical Microbiology, PO Box 22660, 1100 DD Amsterdam, The Netherlands.
Helicobacter. 2004 Dec;9(6):614-21. doi: 10.1111/j.1083-4389.2004.00272.x.
Helicobacter pylori survives and proliferates in the human gastric mucosa. In this niche, H. pylori adheres to the gastric epithelial cells near the tight junctions. In vitro, H. pylori proliferated well in tissue-culture medium near gastric epithelial cells. However, in the absence of epithelial cells, growth of H. pylori could only be established in tissue-culture medium when, prior to the experiment, it was preincubated near gastric epithelial cells. Therefore, we aimed to determine whether diffusion of nutrients derived from epithelial cells was required for H. pylori growth in Dulbecco's modified Eagle's minimal essential medium (DMEM) cell culture medium.
Cell culture conditions essential for H. pylori growth in vitro were determined with gastric epithelial HM02 cells.
Deprivation of iron in cell-culture-conditioned DMEM resulted in a growth arrest of H. pylori. However, near gastric epithelial cells, growth of H. pylori was resistant to iron deprivation. Evidently, when residing close to epithelial cells, H. pylori was able to fulfil its iron requirements, even when the DMEM was deprived of iron. Nevertheless, supplementation with iron alone did not restore H. pylori growth in DMEM, hence other nutrients were deficient as well in the absence of epithelial cells. Growth of H. pylori in DMEM was restored when hypoxanthine, L-alanine and L-proline were added to the DMEM.
Diffusion of (precursors of) these nutrients from the gastric epithelial cells is essential for H. pylori growth in vitro. We hypothesize that in vivo, H. pylori favors colonization near the tight junctions, to gain maximal access to the nutrient(s) released by gastric epithelial cells.
幽门螺杆菌在人类胃黏膜中存活并增殖。在这个生态位中，幽门螺杆菌附着在紧密连接附近的胃上皮细胞上。在体外，幽门螺杆菌在胃上皮细胞附近的组织培养基中增殖良好。然而，在没有上皮细胞的情况下，只有在实验前将幽门螺杆菌预先在胃上皮细胞附近预孵育，它才能在组织培养基中生长。因此，我们旨在确定在杜尔贝科改良的伊格尔最低必需培养基（DMEM）细胞培养基中，幽门螺杆菌生长是否需要上皮细胞衍生营养物质的扩散。
用胃上皮HM02细胞确定幽门螺杆菌体外生长所需的细胞培养条件。
细胞培养条件下的DMEM中铁的缺乏导致幽门螺杆菌生长停滞。然而，在胃上皮细胞附近，幽门螺杆菌的生长对铁缺乏具有抗性。显然，当靠近上皮细胞时，即使DMEM中铁缺乏，幽门螺杆菌也能够满足其铁需求。然而，仅补充铁并不能恢复幽门螺杆菌在DMEM中的生长，因此在没有上皮细胞的情况下其他营养物质也不足。当向DMEM中添加次黄嘌呤、L-丙氨酸和L-脯氨酸时，幽门螺杆菌在DMEM中的生长得以恢复。
这些营养物质（或其前体）从胃上皮细胞的扩散对幽门螺杆菌的体外生长至关重要。我们推测，在体内，幽门螺杆菌倾向于在紧密连接附近定植，以最大限度地获取胃上皮细胞释放的营养物质。
