Tannaes Tone, Bukholm Ida K, Bukholm Geir
Institute of Clinical Epidemiology and Molecular Biology, University of Oslo, Oslo, Norway.
FEMS Immunol Med Microbiol. 2005 Apr 1;44(1):17-23. doi: 10.1016/j.femsim.2004.10.003.
Helicobacter pylori phospholipase A (OMPLA) degrades bacterial membrane phospholipids to lysophospholipids. High levels of lysophospholipids are associated with higher hemolytic activity, increased release of urease and vacA and better adherence to epithelial cells in vitro. The phospholipase A gene (pldA) displays phase variation due to a slippage in a homopolymeric tract. The aim of this study was to determine if the relative amount of lysophospholipids in the cell wall is associated with ulcer disease, and to further investigate the significance of pldA phase variation. H. pylori isolates of 40 patients were examined. The relative lysophospholipid content of each isolate was determined and the pldA gene was sequenced. The study indicated that H. pylori can regulate its OMPLA activity by phase variation in the pldA gene or by protein level regulation among phase variants in the pldA 'ON' status. We found a significant difference between the relative amount of lysophospholipids of the ulcer group and the non-ulcer group (p=0.022). When the lysophospholipid/phospholipid ratios were compared with outcome, the OR for ulcer disease was 9.0 (95% CI 1.6-49.4; p=0.014). Isolates with a high OMPLA activity are significantly associated with patients with ulcer disease.
幽门螺杆菌磷脂酶A（OMPLA）可将细菌膜磷脂降解为溶血磷脂。高水平的溶血磷脂与更高的溶血活性、脲酶和空泡毒素A的释放增加以及体外对上皮细胞更好的黏附性相关。磷脂酶A基因（pldA）由于同聚物序列中的滑移而呈现相位变异。本研究的目的是确定细胞壁中溶血磷脂的相对含量是否与溃疡病相关，并进一步研究pldA相位变异的意义。对40例患者的幽门螺杆菌分离株进行了检测。测定了每个分离株的相对溶血磷脂含量，并对pldA基因进行了测序。研究表明，幽门螺杆菌可通过pldA基因的相位变异或通过pldA“开启”状态下相位变异体之间的蛋白质水平调节来调控其OMPLA活性。我们发现溃疡组和非溃疡组的溶血磷脂相对含量存在显著差异（p = 0.022）。当将溶血磷脂/磷脂比值与结果进行比较时，溃疡病的比值比为9.0（95%可信区间1.6 - 49.4；p = 0.014）。具有高OMPLA活性的分离株与溃疡病患者显著相关。
