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Development of immunotherapy targeting neoplastic lymphocyte-specific antigen (2D7) against hematological malignancies

针对血液恶性肿瘤的肿瘤淋巴细胞特异性抗原（2D7）免疫疗法的开发

基本信息

批准号：
13557082
负责人：
MATSUMOTO Toshio
金额：
$ 6.85万
依托单位：
The University of Tokushima
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2003
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-13557082/
关键词：
hematoloeical malienanc monoclonal antibody immunotherary

项目摘要

We first examined the expression of 2D7 antigen among hematological malignancies. Flow cytometric analysis showed. that 2D7 was highly expressed on myeloma cells and B-cell lymphoblastic cells. These cells expressed 2D7 at significantly higher levels than normal hematopoietic cells. Molecular cloning of 2D7 revealed that the epitope protein was a part of human histocompatibility leukocyte antigen (HLA) class I complex, HLA-A. We next investigated the biological function of 2D7 by using, 2D7 antibody. The 2D7 antibody induced cell death in neoplastic myeloma cells in the presence of secondary antibody in a dose-dependent manner. In contrast, 2D7 antibody did not affect cell viability of normal blood cells. To establish HLA class I-targeting therapy, we generated a recombinant single-chain Fv diabody (2D7 diabody). We found that 2D7 diabody induced myeloma cell death more efficiently than 2D7 antibody without any effector-mediated mechanisms. In a severe combined immunodeficiency mouse model of human myeloma, administration of 2D7 diabody significantly reduced M-protein level and prolonged survival of these mice. Next, we analyzed the mechanism of cell death induced by 2D7 diabody using several signal transduction inhibitors. 2D7 diabody-mediated cell death was completely inhibited by actin polymerization inhibitors such as cytochalasin D and latrunculin A, suggesting the involvement of actin network. In fact, 2D7 diabody induced actin aggregation and this type of cell death was different from classical apoptosis. These findings demonstrate that 2D7 diabody specifically and potently induces cell death of neoplastic lymphoid cells expressing high levels of HLA-A, and suggest that HLA-A is a potential target for immunotherapy in patients with lymphoid malignancies.

我们首先检测了2D 7抗原在血液系统恶性肿瘤中的表达。流式细胞仪分析显示。2D 7在骨髓瘤细胞和B淋巴母细胞上高度表达。这些细胞以比正常造血细胞显著更高的水平表达2D 7。2D 7的分子克隆表明，该表位蛋白是人类组织相容性白细胞抗原（HLA）I类复合物HLA-A的一部分。接下来，我们通过使用2D 7抗体研究了2D 7的生物学功能。在存在二抗的情况下，2D 7抗体以剂量依赖性方式诱导肿瘤性骨髓瘤细胞的细胞死亡。相反，2D 7抗体不影响正常血细胞的细胞活力。为了建立HLA I类靶向治疗，我们产生了重组单链Fv双抗体（2D 7双抗体）。我们发现2D 7双抗体比2D 7抗体更有效地诱导骨髓瘤细胞死亡，而没有任何效应子介导的机制。在人骨髓瘤的严重联合免疫缺陷小鼠模型中，2D 7双抗体的施用显著降低了M蛋白水平并延长了这些小鼠的存活。接下来，我们使用几种信号转导抑制剂分析了2D 7双抗体诱导细胞死亡的机制。2D 7双抗体介导的细胞死亡被肌动蛋白聚合抑制剂如细胞松弛素D和latrunculin A完全抑制，表明肌动蛋白网络的参与。事实上，2D 7双抗体诱导肌动蛋白聚集，并且这种类型的细胞死亡不同于经典的细胞凋亡。这些发现表明，2D 7双抗体特异性地和有效地诱导表达高水平HLA-A的肿瘤淋巴细胞的细胞死亡，并表明HLA-A是淋巴恶性肿瘤患者免疫治疗的潜在靶点。