Burkholderia thailandensis oacA Mutants Facilitate the Expression of Burkholderia mallei-Like O Polysaccharides
Burkholderia thailandensis oacA Mutants Facilitate the Expression of Burkholderia mallei-Like O Polysaccharides
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DOI：
10.1128/iai.01023-10
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发表时间：
2011-02-01
影响因子：
3.1
通讯作者：
Gherardini, Frank C.
中科院分区：
文献类型：
--
作者：
Brett, Paul J.;Burtnick, Mary N.;Gherardini, Frank C.
以往的研究表明，由鼻疽伯克霍尔德氏菌表达的O多糖（OPS）与由泰国伯克霍尔德氏菌产生的O多糖相似，除了它们在其6-脱氧-α-L-talopyranosyl残基上缺少4-O-乙酰基修饰。在本研究中，我们描述了一个开放的阅读框架，指定的oacA，由B表示的识别和表征。这就是造成这种现象的原因。利用B。thailandensis和B.免疫印迹分析表明，oacA突变体B表达的LPS抗原与oacA突变体B的LPS抗原相比，差异有显著性（P < 0. 05）。ThailandensisZT 0715与B产生的抗原相似。鼻疽ATCC 23344。此外，免疫印迹分析表明，当B.鼻疽菌ATCC 23344与oacA反式互补后，合成了B。类LPS抗原。为了阐明由ZT 0715表达的OPS部分的结构，通过核磁共振光谱分析纯化的样品。正如所预测的，这些研究表明，OacA活性的丧失影响了OPS部分的O乙酰化表型。然而，出乎意料的是，结果表明OPS抗原的O甲基化状态也受到OacA活性丧失的影响。尽管如此，揭示了由oacA突变体表达的LPS部分与B强烈反应。鼻疽LPS特异性保护性单克隆抗体9 C1 -2。基于这些发现，OacA似乎是B的4-O乙酰化和2-O甲基化所必需的。Thailandensis OPS抗原和ZT 0715可提供安全和成本有效B来源。鼻疽样OPS，以促进鼻疽亚单位疫苗候选物的合成。
Previous studies have shown that the O polysaccharides (OPS) expressed by Burkholderia mallei are similar to those produced by Burkholderia thailandensis except that they lack the 4-O-acetyl modifications on their 6-deoxy-alpha-L-talopyranosyl residues. In the present study, we describe the identification and characterization of an open reading frame, designated oacA, expressed by B. thailandensis that accounts for this phenomenon. Utilizing the B. thailandensis and B. mallei lipopolysaccharide (LPS)-specific monoclonal antibodies Pp-PS-W and 3D11, Western immunoblot analyses demonstrated that the LPS antigens expressed by the oacA mutant, B. thailandensis ZT0715, were antigenically similar to those produced by B. mallei ATCC 23344. In addition, immunoblot analyses demonstrated that when B. mallei ATCC 23344 was complemented in trans with oacA, it synthesized B. thailandensis-like LPS antigens. To elucidate the structure of the OPS moieties expressed by ZT0715, purified samples were analyzed via nuclear magnetic resonance spectroscopy. As predicted, these studies demonstrated that the loss of OacA activity influenced the O acetylation phenotype of the OPS moieties. Unexpectedly, however, the results indicated that the O methylation status of the OPS antigens was also affected by the loss of OacA activity. Nonetheless, it was revealed that the LPS moieties expressed by the oacA mutant reacted strongly with the B. mallei LPS-specific protective monoclonal antibody 9C1-2. Based on these findings, it appears that OacA is required for the 4-O acetylation and 2-O methylation of B. thailandensis OPS antigens and that ZT0715 may provide a safe and cost-effective source of B. mallei-like OPS to facilitate the synthesis of glanders subunit vaccine candidates.