PROTECTIVE EFFECT OF PORPHYROMONAS-GINGIVALIS OUTER-MEMBRANE VESICLES AGAINST BACTERICIDAL ACTIVITY OF HUMAN SERUM
PROTECTIVE EFFECT OF PORPHYROMONAS-GINGIVALIS OUTER-MEMBRANE VESICLES AGAINST BACTERICIDAL ACTIVITY OF HUMAN SERUM
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DOI：
10.1128/iai.59.9.3004-3008.1991
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发表时间：
1991-09-01
影响因子：
3.1
通讯作者：
BELANGER, M
中科院分区：
文献类型：
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作者：
GRENIER, D;BELANGER, M
本研究旨在评价牙龈卟啉单胞菌外膜囊泡对人血清杀菌活性的影响。用胞外囊泡对人血清进行处理，然后将其与赭绿微囊藻细胞悬液孵育。在37℃下培养2 h后，用血琼脂平板培养法测定其存活率。在终浓度为0.3 mg/ml时，外膜囊泡完全抑制血清杀菌活性。沸腾的小泡阻止了这种抑制。然而，当使用较高浓度(1.5 mg/ml)的煮熟小泡时，血清致死作用被部分抑制，这表明与小泡相关的热不稳定和热稳定成分都参与了这一过程。将次适浓度(0.1 mg/ml)的囊泡与还原剂结合，可使杀菌活性恢复抑制，而将最适浓度(0.3 mg/ml)的囊泡与硫醇封闭剂结合，可恢复杀菌活性。当用纯化的牙龈假单胞菌脂多糖制剂代替囊泡时，也观察到杀菌活性被抑制。这些结果表明，与牙龈假单胞菌外膜囊泡相关的脂多糖和蛋白水解酶(S)可能分别代表热稳定组分和不稳定组分。牙龈假单胞菌释放的外膜囊泡可能保护其他细菌不受补体作用，从而有利于牙周病的发病过程。
The present study was undertaken to evaluate the effect of Porphyromonas gingivalis outer membrane vesicles on the bactericidal activity of human serum. Human serum was pretreated with extracellular vesicles and then incubated with a cell suspension of Capnocytophaga ochracea. After 2 h at 37-degrees-C, the percent viability of C. ochracea was determined by cultivation on blood agar plates. At a final concentration of 0.3 mg/ml, outer membrane vesicles completely inhibited the serum bactericidal activity against C. ochracea. Boiling the vesicles prevented this inhibition. However, partial inhibition of the serum lethal action was obtained when a higher concentration (1.5 mg/ml) of boiled vesicles was used, which indicates the involvement of both heat-labile and heat-stable components associated with vesicles. Combining vesicles at a suboptimal concentration (0.1 mg/ml) with a reducing agent brought back inhibition of the bactericidal activity, whereas combining vesicles at an optimal concentration (0.3 mg/ml) with a thiol-blocking reagent caused a restoration of the bactericidal activity. When a purified preparation of P. gingivalis lipopolysaccharides was used instead of vesicles, inhibition of the bactericidal activity was also observed. These results indicate that the lipopolysaccharides and the proteolytic enzyme(s) associated with P. gingivalis outer membrane vesicles are likely to represent the heat-stable and the heat-labile components, respectively. It is possible that outer membrane vesicles released by P. gingivalis protect other bacterial species from complement action, thus favoring the pathogenic process of periodontal disease.