Interaction between endotoxin and human monocytes: characteristics of the binding of 3H-labeled lipopolysaccharide and 51Cr-labeled lipid A before and after the induction of endotoxin tolerance.
Interaction between endotoxin and human monocytes: characteristics of the binding of 3H-labeled lipopolysaccharide and 51Cr-labeled lipid A before and after the induction of endotoxin tolerance.
复制标题
内毒素与人单核细胞的相互作用：诱导内毒素耐受前后3H标记脂多糖与51Cr标记脂质A的结合特征。
DOI：
10.1073/pnas.81.11.3491
复制
发表时间：
1984
影响因子：
11.1
通讯作者：
Sullivan,R
中科院分区：
文献类型：
--
作者：
Larsen,NE;Sullivan,R
用氚标记伤寒杆菌内毒素（脂多糖，LPS），并通过凝胶过滤纯化。使用这种制剂，我们发现，结合3 H-标记的LPS（3 H-LPS）分离的人单核细胞组成的快速（t1/2小于5分钟），可逆的，温度无关的表面吸附相，其次是一个较慢的（t1/2大于20分钟）的结合期，是不可逆的和温度依赖性的。3 H-LPS与单核细胞之间的相互作用依赖于LPS的浓度和细胞数量。我们观察到用LPS初始处理细胞后3 H-LPS表面结合明显减少，这很可能是由于单核细胞膜上可用于结合LPS的位点数量获得性减少。根据表面结合数据的双倒数图（1/结合vs. 1/游离）计算3 H-LPS结合参数的估计值，表明用LPS预处理单核细胞后，3 H-LPS的相对结合亲和力（Kd）不变;然而，LPS结合位点的总数似乎通过这种操作减少。竞争结合实验的结果还表明，与LPS孵育前后的细胞对3 H-LPS的结合亲和力是相同的。脂质A，我们从LPS中提取和标记的铬-51，表现出类似的结合亲和力的3 H-LPS和，像3 H-LPS，可以从细胞中置换的竞争浓度的未分级的LPS，但是，两个标记的配体的结合动力学有很大的不同。我们的研究结果表明，单核细胞暴露于LPS可能会改变这些细胞的能力，相互作用，从而响应，LPS。
Salmonella typhi endotoxin (lipopolysaccharide, LPS) was labeled with tritium and purified by gel filtration. Using this preparation, we found that binding of 3H-labeled LPS (3H-LPS) to isolated human monocytes consisted of a rapid (t1/2 less than 5 min), reversible, temperature-independent phase of surface adsorption that was followed by a slower (t1/2 greater than 20 min) period of binding that was irreversible and temperature-dependent. The interactions between 3H-LPS and monocytes that we measured were dependent both on the concentration of LPS and the cell number. We observed an apparent decrease in 3H-LPS surface binding after initial treatment of the cells with LPS, which was most likely due to an acquired reduction in the number of sites on the monocyte membrane available for the binding of LPS. Estimates of the parameters of the binding of 3H-LPS were calculated from a double-reciprocal plot (1/bound vs. 1/free) of the surface binding data and suggest that the relative binding affinity (Kd) for 3H-LPS was unchanged after pretreatment of the monocytes with LPS; however, the total number of LPS binding sites appeared to be reduced by this manipulation. The results of competition binding experiments also suggest that the binding affinity for 3H-LPS was the same before and after incubation of the cells with LPS. Lipid A, which we extracted from LPS and labeled with chromium-51, exhibited a binding affinity similar to that of 3H-LPS and, like 3H-LPS, could be displaced from the cells by competing concentrations of unfractionated LPS; however, the kinetics of binding of the two labeled ligands differed considerably. Our results suggest that exposure of monocytes to LPS may alter the ability of these cells to interact with, and consequently respond to, LPS.