Investigation on the agonistic and antagonistic biological activities of synthetic Chlamydia lipid A and its use in in vitro enzymatic assays
Investigation on the agonistic and antagonistic biological activities of synthetic Chlamydia lipid A and its use in in vitro enzymatic assays
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DOI：
10.1177/0968051907079122
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发表时间：
2007-01-01
期刊：
影响因子：
--
通讯作者：
Brade, Helmut
中科院分区：
文献类型：
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作者：
Heine, Holger;Gronow, Sabine;Brade, Helmut
用表达toll样受体（TLR） 2或TLR4的人胚胎肾（HEK） 293细胞释放白介素-8的方法，检测了代表天然衣原体脂质A主要分子种类的合成1,4'-双磷酸化五酰基和四酰基脂质A结构的内毒活性。这两种化合物都不能瞬时激活转染TLR2的HEK293细胞。五酰基脂质A是表达TLR4/MD-2/CD14的HEK293细胞的弱激活剂，而四酰基脂质A即使在高浓度下也无活性。大肠杆菌脂质A的四酰基衍生物（化合物406）或抗cd14单克隆抗体MEM-18可拮抗五酰基脂质A的弱活性。四酰基脂质A和五酰基脂质A均不能拮抗大肠杆菌型脂质A（化合物506）或肠道沙门氏菌血清型平滑脂多糖的活性。四酰脂质A和五酰脂质A可作为大肠杆菌、沙眼衣原体和鼻灰衣原体Kdo转移酶的受体，并通过薄层色谱法和单克隆抗体免疫染色对产物进行检测。
The synthetic 1,4'-bisphosphorylated penta-acyl and tetra-acyl lipid A structures representing the major molecular species of natural chlamydial lipid A were tested for their endotoxic activities as measured by interleukin-8 release from human embryonic kidney (HEK) 293 cells expressing Toll-like receptor (TLR) 2 or TLR4. Both compounds were unable to activate HEK293 cells transiently transfected with TLR2. The penta-acyl lipid A was a weak activator of HEK293 cells expressing TLR4/MD-2/CD14 whereas tetra-acyl lipid A was inactive even at high concentrations. The weak activity of the penta-acyl lipid A could be antagonized by the tetra-acyl derivative of Escherichia coli lipid A (compound 406) or the anti-CD 14 monoclonal antibody MEM-18. Both, tetra- and pentaacyl lipid A were unable to antagonize the activity of synthetic E. coli-type lipid A (compound 506) or smooth lipopolysaccharide of Salmonella enterica serovar Friedenau. Tetra- and penta-acyl lipid A served as acceptors for Kdo transferases from E. coli, Chlamydia trachomatis and Chlamydophila psittaci as shown by in vitro assays and detection of the products by thin layer chromatography and immune staining with monoclonal antibody.