Osawa H, Diamantstein T
Institut für Immunologie, Klinikum Steglitz, Freie Universität Berlin, Federal Republic of Germany.
Immunol Lett. 1989 Feb;20(3):205-12. doi: 10.1016/0165-2478(89)90081-3.
The monoclonal antibody (mAb) AHT-107 recognized a determinant distal to the interleukin 2 (IL-2) binding site on the p55 subunit of the IL-2 receptor (IL-2R) (the Tac antigen, CD25) of human T lymphoblasts, while the mAb AHT-54 recognized a determinant close to the IL-2 binding site as did the anti-Tac. The AHT-107 inhibited IL-2 dependent proliferation of human T lymphoblasts equally as well as did the AHT-54. Both mAbs inhibited the high-affinity binding and crosslinking of IL-2 to the p55 + p75 heterodimeric complex on forskolin-treated YT cells. Remarkably, the AHT-107 did not inhibit the low-affinity binding and cross-linking of IL-2 to the p55 molecule on human p55 cDNA-transfected cells, while the AHT-54 as well as anti-Tac did so. In contrast, the mAb PC61, that was previously reported to recognize a determinant distal to the IL-2 binding site on the mouse p55 subunit of IL-2R and to dissociate IL-2 from the high-affinity IL-2R complex by altering the conformation of the p55 molecule itself, inhibited the low-affinity binding and cross-linking of IL-2 to the p55 molecule on mouse p55 cDNA-transfected cells. Further, we showed that the AHT-107 did not dissociate IL-2 from the high-affinity IL-2R complex once formed on human T lymphoblasts.(ABSTRACT TRUNCATED AT 250 WORDS)
单克隆抗体（mAb）AHT - 107识别位于人T淋巴母细胞白细胞介素2（IL - 2）受体（IL - 2R）p55亚基（Tac抗原，CD25）上IL - 2结合位点远端的一个决定簇，而mAb AHT - 54识别的决定簇靠近IL - 2结合位点，抗Tac抗体也是如此。AHT - 107抑制人T淋巴母细胞依赖IL - 2的增殖的效果与AHT - 54相同。两种单克隆抗体均抑制IL - 2与经福司可林处理的YT细胞上p55 + p75异二聚体复合物的高亲和力结合和交联。值得注意的是，AHT - 107不抑制IL - 2与人p55 cDNA转染细胞上p55分子的低亲和力结合和交联，而AHT - 54以及抗Tac抗体则会抑制。相反，先前报道的单克隆抗体PC61识别位于小鼠IL - 2R p55亚基上IL - 2结合位点远端的一个决定簇，并通过改变p55分子自身构象使IL - 2从高亲和力IL - 2R复合物上解离，它能抑制IL - 2与小鼠p55 cDNA转染细胞上p55分子的低亲和力结合和交联。此外，我们发现AHT - 107一旦在人T淋巴母细胞上形成高亲和力IL - 2R复合物后，不会使IL - 2从该复合物上解离。（摘要截短于250字）
