Cell-death-inducing monoclonal antibodies raised against DT40 tumor cells: Identification of chicken transferrin receptor as a novel cell-death receptor
Cell-death-inducing monoclonal antibodies raised against DT40 tumor cells: Identification of chicken transferrin receptor as a novel cell-death receptor
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DOI：
10.1111/j.1349-7006.2008.00753.x
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发表时间：
2008-05-01
期刊：
影响因子：
5.7
通讯作者：
Masuko, Takashi
中科院分区：
文献类型：
--
作者：
Ohno, Yoshiya;Yagi, Hideki;Masuko, Takashi
我们获得了特异性诱导细胞死亡的单克隆抗体D18和D19。D18和D19可引起细胞表面磷脂酰丝氨酸暴露、亚G（0）/G（1）峰和DNA断裂等凋亡现象，并抑制DT 40细胞的增殖。各种正常鸡组织的流式细胞术和免疫组织学分析显示，这些单克隆抗体识别的抗原的表达被限制在淋巴器官，包括骨髓和腔上囊的细胞，并在一些上皮组织中的细胞。mAb诱导的细胞死亡通过线粒体途径进行，线粒体膜电位丧失。细胞凋亡通常以细胞收缩为特征;然而，D18和D19引起肿胀，其先于细胞死亡。我们分析了单克隆抗体免疫沉淀的抗原，并确定了一个90至100 kDa的细胞表面糖蛋白作为鸡转铁蛋白受体（TfR）。结合抑制试验证实两种mAb识别的表位不同。过量的鸡血清不抑制mAb对DT 40细胞的反应性，表明D18和D19诱导的细胞死亡不是由于抑制转铁蛋白（Tf）与鸡TfR的结合而引起的。由于D18和D19诱导细胞死亡的全长鸡TfR的cDNA转染的人胚肾细胞，我们预计人TfR是一个有前途的目标抗体治疗各种人类恶性肿瘤。
We obtained unique cell-death-inducing monoclonal antibodies (mAbs) named D18 and D19 against chicken DT40 cells. D18 and D19 caused several signs of apoptosis, such as exposed phosphatidyl serine on the cell surface, a sub G(0)/G(1) peak, and DNA fragmentation, and inhibited the proliferation of DT40 cells. Flow cytometric and immunohistological analyses of various normal chicken tissues revealed the expression of the antigen recognized by these mAbs to be restricted to cells in lymphoid organs including bone marrow and bursa of fabricius, and to cells in some epithelial tissues. The cell death induced by the mAbs progressed through a mitochondrial pathway with loss of mitochondrial membrane potential. Apoptosis is generally characterized by cell shrinking; however, D18 and D19 elicited swelling, which preceded the cell death. We analyzed the antigen immunoprecipitated by the mAbs, and identified a 90- to 100-kDa cell-surface glycoprotein as the chicken transferrin receptor (TfR). Epitopes recognized by the two mAbs were confirmed to be different by the binding inhibition assay. The reactivity of the mAbs against DT40 cells was not inhibited by excess chicken serum, suggesting that the cell death induced by D18 and D19 was not caused by inhibition of the binding of transferrin (Tf) to chicken TfR. Since D18 and D19 have induced cell death in human embryonic kidney cells transfected with cDNA of the full-length chicken TfR, we expect human TfR to be a promising target in antibody therapy for various human malignancies.