Lipopolysaccharide interaction with cell surface Toll-like receptor 4-MD-2: higher affinity than that with MD-2 or CD14.
Lipopolysaccharide interaction with cell surface Toll-like receptor 4-MD-2: higher affinity than that with MD-2 or CD14.
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DOI：
10.1084/jem.20031076
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发表时间：
2003-10-06
期刊：
影响因子：
--
通讯作者：
Miyake K
中科院分区：
文献类型：
--
作者：
Akashi S;Saitoh S;Wakabayashi Y;Kikuchi T;Takamura N;Nagai Y;Kusumoto Y;Fukase K;Kusumoto S;Adachi Y;Kosugi A;Miyake K
Toll样受体是微生物产物的天然识别分子，但其与相应配体的直接相互作用尚不清楚。内毒素是革兰氏阴性细菌的一种膜成分，是研究最深入的TLR配体，可被TLR4和与TLR4胞外结构域相关的分子MD-2识别。尽管TLR4-MD-2识别内毒素，但对内毒素与TLR4-MD-2之间的物理相互作用知之甚少。在这里，我们展示了细胞表面的内毒素-TLR4-MD-2复合体。CD14能显著促进脂多糖-TLR4-MD-2复合体的形成，但不与脂多糖-TLR4-MD-2复合体共沉淀，提示CD14在脂多糖负载TLR4-MD-2中起作用，但不参与脂多糖与TLR4-MD-2之间的相互作用。内毒素-TLR4-MD-2复合物的解离常数(Kd)为∼3 nM，比已报道的LPSMD-2或LPSCD14的解离常数∼低10-20倍。洗涤剂的存在破坏了内毒素与CD14的相互作用，但不影响与TLR4-MD-2的相互作用。E5531是为治疗内毒素休克而开发的脂蛋白A拮抗剂，它在比阻断内毒素与CD14相互作用所需浓度低100倍的浓度下阻断内毒素与TLR4-MD-2的相互作用。这些结果揭示了内毒素与细胞表面TLR4-MD-2的直接相互作用不同于与MD-2或CD14的相互作用。
Toll-like receptors (TLRs) are innate recognition molecules for microbial products, but their direct interactions with corresponding ligands remain unclarified. LPS, a membrane constituent of gram-negative bacteria, is the best-studied TLR ligand and is recognized by TLR4 and MD-2, a molecule associated with the extracellular domain of TLR4. Although TLR4-MD-2 recognizes LPS, little is known about the physical interaction between LPS and TLR4-MD-2. Here, we demonstrate cell surface LPS–TLR4-MD-2 complexes. CD14 greatly enhances the formation of LPS–TLR4-MD-2 complexes, but is not coprecipitated with LPS–TLR4-MD-2 complexes, suggesting a role for CD14 in LPS loading onto TLR4-MD-2 but not in the interaction itself between LPS and TLR4-MD-2. A tentative dissociation constant (Kd) for LPS–TLR4-MD-2 complexes was ∼3 nM, which is ∼10–20 times lower than the reported Kd for LPS–MD-2 or LPS–CD14. The presence of detergent disrupts LPS interaction with CD14 but not with TLR4-MD-2. E5531, a lipid A antagonist developed for therapeutic intervention of endotoxin shock, blocks LPS interaction with TLR4-MD-2 at a concentration 100 times lower than that required for blocking LPS interaction with CD14. These results reveal direct LPS interaction with cell surface TLR4-MD-2 that is distinct from that with MD-2 or CD14.
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DOI：
10.1084/jem.189.11.1777
发表时间：
1999-06-07
期刊：
The Journal of experimental medicine
影响因子：
--
作者：
Shimazu R;Akashi S;Ogata H;Nagai Y;Fukudome K;Miyake K;Kimoto M
通讯作者：
Kimoto M
影响因子：
4.8
作者：
Correia, JD;Ulevitch, RJ
通讯作者：
Ulevitch, RJ
影响因子：
56.9
作者：
WRIGHT, SD;RAMOS, RA;MATHISON, JC
通讯作者：
MATHISON, JC
影响因子：
32.4
作者：
PUGIN, J;HEUMANN, D;ULEVITCH, RJ
通讯作者：
ULEVITCH, RJ
DOI：
10.1165/rcmb.2002-0132oc
发表时间：
2003-08-01
影响因子：
6.4
作者：
Tasaka, S;Ishizaka, A;Yamaguchi, K
通讯作者：
Yamaguchi, K