Maïza H, Leca G, Mansur I G, Schiavon V, Boumsell L, Bensussan A
Laboratoire INSERM U93, Association Claude Bernard, Hopital Saint-Louis, Paris, France.
J Exp Med. 1993 Sep 1;178(3):1121-6. doi: 10.1084/jem.178.3.1121.
Human lymphocytes with natural killer (NK) activity, including most activated gamma/delta+ T lymphocytes, recognize and lyse tumor target cells without requiring recognition of major histocompatibility complex antigen. However, unlike gamma/delta+ T lymphocytes, NK cells do not express CD3/T cell receptor (TCR) molecules, and the receptors involved in cell-mediated cytotoxicity are unknown. To further delineate circulating NK cells, we developed monoclonal antibodies (mAbs) against the human NK leukemia YT2C2. We report the isolation of a mAb termed BY55, recognizing at the cell surface a novel 80-kD protein with restricted expression. In addition to the immunizing cell line, this mAb binds to circulating NK cells, gamma/delta+ cells, and a minor subset of alpha/beta+ T lymphocytes. Expression of the BY55 mAb-reactive epitope/molecule is regulated by activation, as short-term culture of peripheral blood lymphocytes (PBL) with phorbol ester induced its downmodulation. Furthermore, BY55 mAb reactivity was found neither with the NK nor with the TCR alpha/beta+ gamma/delta+ clones tested. Biochemical studies as well as phenotypic analysis revealed that this structure is different from all previously identified molecules on the lymphocyte cell surface. Interestingly, we found that BY55+ cells exert most NK activity obtained with fresh circulating lymphocytes. We report that within fresh E rosette-positive PBL only a subset of the CD16+, CD56+, and CD57+ cells coexpressed BY55 molecule, indicating that BY55 mAb defines a unique subset mediating NK activity of circulating PBL.
具有自然杀伤（NK）活性的人类淋巴细胞，包括大多数活化的γ/δ⁺ T淋巴细胞，无需识别主要组织相容性复合体抗原即可识别并裂解肿瘤靶细胞。然而，与γ/δ⁺ T淋巴细胞不同，NK细胞不表达CD3/T细胞受体（TCR）分子，且参与细胞介导细胞毒性的受体尚不清楚。为了进一步描述循环NK细胞，我们开发了针对人类NK白血病YT2C2的单克隆抗体（mAb）。我们报告分离出一种名为BY55的mAb，它在细胞表面识别一种表达受限的新型80-kD蛋白。除了免疫细胞系外，这种mAb还与循环NK细胞、γ/δ⁺细胞以及一小部分α/β⁺ T淋巴细胞结合。BY55 mAb反应性表位/分子的表达受激活调节，因为用佛波酯短期培养外周血淋巴细胞（PBL）可诱导其下调。此外，在所测试的NK细胞或TCR α/β⁺γ/δ⁺克隆中均未发现BY55 mAb反应性。生化研究以及表型分析表明，这种结构与淋巴细胞细胞表面所有先前鉴定的分子不同。有趣的是，我们发现BY55⁺细胞发挥了新鲜循环淋巴细胞所具有的大部分NK活性。我们报告，在新鲜的E花环阳性PBL中，只有一部分CD16⁺、CD56⁺和CD57⁺细胞共表达BY55分子，这表明BY55 mAb定义了一个介导循环PBL的NK活性的独特亚群。
