李斯特菌侵染宿主细胞过程中磷脂酶D活性变化的初步研究

Activation of Phospholipases D in Vero cells During Infection by Listeria monocytogenes

摘要:

磷脂酶D(phospholipase，PLD)在感染和炎症反应中发挥重要作用，然而其在单核增生李斯特菌（简称李斯特菌）侵染非洲绿猴肾细胞(Vero)中是否被激活尚未见报道。对李斯特菌刺激下的Vero细胞内PLD的活性变化进行了初步研究。以李斯特菌、佛波醇PMA分别刺激正常细胞及高效表达PLD₂-K758R功能缺陷蛋白腺病毒预感染的Vero细胞，研究Vero细胞内PLD活性变化。结果发现，与对照组相比（不给予刺激），在李斯特菌和佛波醇PMA刺激正常Vero细胞过程中，胞内PLD活性增强非常显著。mPLD₂-K758R蛋白的过度表达对Vero细胞的PLD基础活性无影响，但对李斯特菌和PMA诱导的PLD激活有明显抑制作用。这初步表明，在李斯特菌诱导的Vero细胞对其吞噬过程中的确伴有PLD的激活，并且可能主要是PLD₂亚型被激活，但此吞噬过程中PLD的激活机制及激活后PLD的具体功能尚有待进一步研究。

Abstract:

Phospholipase D (PLD) may play an important role in the infection and inflammation process, but it is unknown whether cellular PLD was activated during the invasion of Listeria monocytogenes into Vero cells. Our study demonstrated that firstly the Vero cells either infected by Listeria monocytogenes or stimulated by PMA shows remarkable increase on PLD activity, compared to basal ones (no stimuli). Further, in the Vero cells with the overexpression of catalytically inactive PLD₂ (mPLD₂-K758R), PLD activition by both Listeria monocytogenes and PMA were dramatically inhibited, leaving basal PLD activity unaffected. These results indicated that the PLD activities may increase while Listeria monocytogenes invade the Vero cells and PLD₂ is likely to be activated. The important physiological role of PLD in this pathogen_host interaction process need to be further studied.