Eder Katalin, Vizler Csaba, Kusz Erzsebet, Karcagi Ildiko, Glavinas Hristos, Balogh Gabor E, Vigh Laszlo, Duda Erno, Gyorfy Zsuzsanna
Biological Research Center of Hungarian Academy of Sciences, Institute of Biochemistry, Temesvari krt. 62., Szeged H-6726, Hungary.
Biochem Biophys Res Commun. 2009 Nov 6;389(1):46-51. doi: 10.1016/j.bbrc.2009.08.082. Epub 2009 Aug 20.
Lipopolysaccharide (LPS) is the main component of Gram-negative bacteria that - upon infection - activates the host immune system and is crucial in fighting pathogens as well as in the induction of sepsis. In the present study we addressed the question whether the key structural components of LPS equally take part in the activation of different macrophage immune responses. By genomic modifications of Escherichia coli MG1655, we constructed a series of strains harboring complete and truncated forms of LPS in their cell wall. These strains were exposed to RAW 264.7 macrophages, after which phagocytosis, fast release of pre-synthesized TNF and activation of NF-kappaB signal transduction pathway were quantified. According to our results the core and lipid A moieties are involved in immune recognition. The most ancient part, lipid A is crucial in evoking immediate TNF release and activation of NF-kappaB. The O-antigen inhibits phagocytosis, leading to immune evasion.
脂多糖（LPS）是革兰氏阴性菌的主要成分，在感染时可激活宿主免疫系统，对抵抗病原体以及引发败血症至关重要。在本研究中，我们探讨了LPS的关键结构成分是否同样参与不同巨噬细胞免疫反应的激活。通过对大肠杆菌MG1655进行基因组改造，我们构建了一系列细胞壁中含有完整和截短形式LPS的菌株。将这些菌株暴露于RAW 264.7巨噬细胞后，对吞噬作用、预合成TNF的快速释放以及NF-κB信号转导通路的激活进行了量化。根据我们的结果，核心部分和脂质A部分参与免疫识别。脂质A是最古老的部分，在引发TNF的立即释放和NF-κB的激活中至关重要。O抗原抑制吞噬作用，导致免疫逃逸。
