Oh K O, Zhou Z, Kim K K, Samanta H, Fraser M, Kim Y J, Broxmeyer H E, Kwon B S
Department of Microbiology and Immunology, Walther Oncology Center, Indiana University School of Medicine, Indianapolis 46202.
J Immunol. 1991 Nov 1;147(9):2978-83.
We have produced recombinant proteins for a cytokine, L2G25BP (macrophage inflammatory protein-1 alpha) (MIP-1 alpha). By using the recombinant protein (rMIP-1 alpha), receptors for MIP-1 alpha were identified on Con A-stimulated and unstimulated CTLL-R8, a T cell line, and LPS-stimulated RAW 264.7, a macrophage cell line. The 125I-rMIP-1 alpha binds to the receptor in a specific and saturable manner. Scatchard analysis indicated a single class of high affinity receptor, with a Kd of approximately 1.5 x 10(-9) M and approximately 1200 binding sites/Con A-stimulated CTLL-R8 cell and a Kd of 0.9 x 10(-9) M and approximately 380 binding sites/RAW 264.7 cell. 125I-rMIP-1 alpha binding was inhibited by unlabeled rMIP-1 alpha in a dose-dependent manner, but not by IL-1 alpha or IL-2. rMIP-1 alpha inhibited the proliferation of unstimulated CTLL-R8 cells. Rabbit anti-rMIP-1 alpha antibodies blocked the growth-inhibitory effect of the rMIP-1 alpha on CTLL-R8 cells.
我们已经制备了一种细胞因子L2G25BP（巨噬细胞炎性蛋白-1α，即MIP-1α）的重组蛋白。通过使用重组蛋白（rMIP-1α），在刀豆蛋白A刺激的和未刺激的T细胞系CTLL-R8以及脂多糖刺激的巨噬细胞系RAW 264.7上鉴定出了MIP-1α的受体。125I-rMIP-1α以特异性和可饱和的方式与受体结合。Scatchard分析表明存在一类单一的高亲和力受体，在刀豆蛋白A刺激的CTLL-R8细胞上，解离常数（Kd）约为1.5×10^(-9) M，结合位点约为1200个/细胞；在RAW 264.7细胞上，Kd为0.9×10^(-9) M，结合位点约为380个/细胞。未标记的rMIP-1α以剂量依赖性方式抑制125I-rMIP-1α的结合，但IL-1α或IL-2则无此作用。rMIP-1α抑制未刺激的CTLL-R8细胞的增殖。兔抗rMIP-1α抗体可阻断rMIP-1α对CTLL-R8细胞的生长抑制作用。
