Moore U M, Kaplow J M, Pleass R D, Castro S W, Naik K, Lynch C N, Daly S, Roach A G, Jaye M, Williams R J
Rhône-Poulenc Rorer Ltd., Dagenham Research Centre, Essex, United Kingdom.
J Leukoc Biol. 1997 Dec;62(6):911-5. doi: 10.1002/jlb.62.6.911.
The binding and functional activity of the CC chemokines monocyte chemoattractant protein-1 (MCP-1), MCP-2, and MCP-3 have been characterized using Chinese hamster ovary DXB-11 cells transfected with the chemokine receptor CCR2B. Receptor binding studies demonstrated that 125I-labeled MCP-1 bound to a single class of high-affinity receptors with a Kd of 0.14 (0.07-0.32) nM. In competition studies MCP-1, MCP-2, and MCP-3 completely inhibited 125I-labeled MCP-1 binding with Ki values of 0.3 (0.16-0.46), 8.8 (3.4-26), and 12.2 (0.6-22) nM, respectively. In calcium mobilization studies, MCP-1 and MCP-3 induced robust elevations in intracellular calcium concentrations, whereas MCP-2 was only weakly active. In contrast, using changes in extracellular acidification rate as a functional readout, all three chemokines were identified as potent agonists of CCR2B. These data demonstrate that MCP-2, in addition to MCP-1 and MCP-3, is a potent agonist of CCR2B and furthermore that MCP-2 activates either different or a subset of the signaling pathways activated by MCP-1 and MCP-3.
利用转染了趋化因子受体CCR2B的中国仓鼠卵巢DXB - 11细胞，对CC趋化因子单核细胞趋化蛋白 - 1（MCP - 1）、MCP - 2和MCP - 3的结合及功能活性进行了表征。受体结合研究表明，125I标记的MCP - 1与一类高亲和力受体结合，解离常数（Kd）为0.14（0.07 - 0.32）nM。在竞争研究中，MCP - 1、MCP - 2和MCP - 3分别以0.3（0.16 - 0.46）、8.8（3.4 - 26）和12.2（0.6 - 22）nM的Ki值完全抑制125I标记的MCP - 1结合。在钙动员研究中，MCP - 1和MCP - 3可显著提高细胞内钙浓度，而MCP - 2的活性较弱。相比之下，以细胞外酸化率变化作为功能读数，这三种趋化因子均被鉴定为CCR2B的有效激动剂。这些数据表明，除MCP - 1和MCP - 3外，MCP - 2也是CCR2B的有效激动剂，而且MCP - 2激活的信号通路要么与MCP - 1和MCP - 3激活的不同，要么是其一部分。
