EVIDENCE FOR MULTIPLE BINDING SITES FOR SEVERAL SPECIES OF HU IFN ALPHA

几种纯品的抗增殖和竞争结合活性 人淋巴母细胞干扰素α的种类与人淋巴母细胞干扰素的比较 重组干扰素α-2b对Daudi和AU937细胞的作用我们发现， 每个细胞系上干扰素种类的抗增殖活性 Daudi细胞比AU937细胞更敏感。这是 对细胞生长的50%抑制作用从0.003 ng/ml到大于10 对Daudi细胞为1.2 ng/ml，对AU937细胞大于100 ng/ml Scatchard分析表明，干扰素-α2b结合位点数 在Daudi细胞上(12,700个结合位点/细胞)大于AU937细胞 (3,300个结合位点/细胞)；然而，它们的受体亲和力相似 有趣的是，似乎有三个物种(n，o，p)表现出 在两种细胞系上都有最高的抗增殖活性，但不存在竞争 干扰素α-2b结合位点。这些数据表明，可能存在 多个受体或多个受体组件参与 这些分子的生物学行为。克隆的研究正在进行中 并检测其受体结合特性。

The antiproliferative and competitive binding activities of several purifie species of human lymphoblastoid interferon alpha were compared to that of recombinant interferon alpha-2b on Daudi and AU937 cells. We found that the antiproliferative activity of the interferon species on each cell line has a broad range and that Daudi cells were more sensitive than AU937 cells. Th 50% inhibition of cell growth ranged from .003 ng/ml to greater than 10 ng/ml on Daudi cells and 1.2 ng/ml to greater than 100 ng/ml on AU937 cells Scatchard analyses demonstrated that the IFN-alpha 2b binding site number is greater on Daudi cells (12,700 binding sites/cell) than AU937 cells (3,300 binding sites/cell); however, their receptor affinities were similar Interestingly, there appears to be three species (n,o,p) which exhibit the highest antiproliferative activities on both cell lines but do not compete for the interferon alpha-2b binding site. These data suggest that there may be more than one receptor or multiple receptor components involved in the biological actions of these molecules. Studies are in progress to clone species o and to examine its receptor binding properties.