Bensimon C, Wakasugi H, Wakasugi N, Jitsukawa S, Tursz T
Laboratoire d'Immuno-Biologie Cellulaire, UA1156 CNRS, Villejuif, France.
J Immunol. 1989 Apr 1;142(7):2290-8.
We produced an IgM mAb termed 4.9 against an EBV-containing lymphoblastoid cell line, termed 3B6. This mAb reacted with both various B and T cell lines such as HSB2 cells, with an NK-like cell line YT-C3 cells, and with human fibroblast MCR-5 cells. It also reacted with normal resting peripheral B lymphocytes, monocytes, and anti-CD2- or anti-CD3-activated T lymphocytes. The 4.9 mAb immunoprecipitated two bands estimated to be of Mr 68 and 75 kDa from iodinated 3B6 cells. The 4.9 mAb inhibited the proliferation of peripheral T lymphocytes induced either by anti-CD3 mAb or anti-CD2 mAb. The 4.9 mAb inhibited also the proliferation of murine thymocytes both in the presence of PHA and IL-1 and the proliferation of human fibroblasts in the presence of IL-1. Radiolabeled IL-1 binding on 3B6 cells revealed two types of IL-1 binding sites with high and low affinity for IL-1 (300 sites/cell with a Kd of 6 x 10(-11)M and 6000 sites/cell with a Kd of 3 x 10(-9)M). On both 3B6 and YT-C3 cells, mAb 4.9 inhibited specifically the binding of 125I-labeled rIL-1, alpha or beta, whereas the irrelevant IgM mAb did not. Conversely, rIL-1, alpha or beta, could inhibit specifically the binding of radioiodinated 4.9 mAb to 3B6 or YT-C3 cells, whereas rIL-2, rIFN, or the irrelevant IgM mAb were ineffective. 125I-4.9 mAb bound 3B6 cells with an association constant (Ka) of 2 x 10(8)/M and demonstrated 6000 binding sites/cell. We thus conclude that mAb 4.9 recognizes a protein complex (68 to 75 kDa) closely associated with the IL-1R.
我们制备了一种针对含EBV的淋巴母细胞系3B6的IgM单克隆抗体，命名为4.9。该单克隆抗体可与多种B细胞和T细胞系（如HSB2细胞）、一种NK样细胞系YT - C3细胞以及人成纤维细胞MCR - 5细胞发生反应。它还能与正常静息外周B淋巴细胞、单核细胞以及抗CD2或抗CD3激活的T淋巴细胞发生反应。4.9单克隆抗体从碘化的3B6细胞中免疫沉淀出两条估计分子量分别为68 kDa和75 kDa的条带。4.9单克隆抗体可抑制抗CD3单克隆抗体或抗CD2单克隆抗体诱导的外周T淋巴细胞增殖。4.9单克隆抗体在PHA和IL - 1存在的情况下也可抑制小鼠胸腺细胞增殖，在IL - 1存在的情况下可抑制人成纤维细胞增殖。3B6细胞上的放射性标记IL - 1结合显示出两种对IL - 1具有高亲和力和低亲和力的IL - 1结合位点（分别为300个位点/细胞，Kd为6×10⁻¹¹M和6000个位点/细胞，Kd为3×10⁻⁹M）。在3B6和YT - C3细胞上，单克隆抗体4.9特异性抑制¹²⁵I标记的rIL - 1α或β的结合，而无关的IgM单克隆抗体则无此作用。相反，rIL - 1α或β可特异性抑制放射性碘化的4.9单克隆抗体与3B6或YT - C3细胞的结合，而rIL - 2、rIFN或无关的IgM单克隆抗体则无效。¹²⁵I - 4.9单克隆抗体以2×10⁸/M的缔合常数（Ka）结合3B6细胞，显示出6000个结合位点/细胞。因此我们得出结论，单克隆抗体4.9识别一种与IL - 1受体紧密相关的蛋白质复合物（68至75 kDa）。
