Sugita K, Mori T, Yokota S, Kuroki M, Koyama T O, Inukai T, Iijima K, Goi K, Tezuka T, Kojika S, Shiraishi K, Nakamura M, Miyamoto N, Karakida N, Kagami K, Nakazawa S
Department of Pediatrics, Yamanashi Medical University, Japan.
Leukemia. 1999 May;13(5):779-85. doi: 10.1038/sj.leu.2401408.
We previously reported a novel monoclonal antibody KOR-SA3544 which predominantly reacted with a surface antigen (sSA3544) expressed on Philadelphia chromosome (Ph1)-positive acute lymphoblastic leukemia (ALL). In the present study, we demonstrate that the antibody specifically recognized nonspecific cross-reacting antigen (NCA)-50/90 (CD66c), one of the carcinoembryonic antigen (CEA)-related glycoproteins encoded by a member of the CEA gene family. In addition, we show that the SA3544 antigen (NCA-50/90) was invariably expressed in cytoplasm of all of the human leukemic cell lines examined (sSA3544-positive B-lymphoid two, sSA3544-negative T or B-lymphoid and non-lymphoid 24) regardless of the presence or absence of surface expression of this antigen. Immunoelectromicroscopic examination revealed that the cytoplasmic antigen was mainly present in granules in sSA3544-positive leukemia cells, whereas it was diffusely present in cytosol in sSA3544-negative leukemia cells. Thus, among members of the CEA family, NCA-50/90 was first demonstrated to be expressed not only on the surface of some leukemia cells, but also in cytoplasm of various types of leukemia cells.
我们之前报道了一种新型单克隆抗体KOR-SA3544，它主要与费城染色体（Ph1）阳性急性淋巴细胞白血病（ALL）上表达的一种表面抗原（sSA3544）发生反应。在本研究中，我们证明该抗体特异性识别非特异性交叉反应抗原（NCA）-50/90（CD66c），它是癌胚抗原（CEA）相关糖蛋白之一，由CEA基因家族的一个成员编码。此外，我们发现SA3544抗原（NCA-50/90）在所检测的所有人类白血病细胞系（sSA3544阳性B淋巴细胞系2个，sSA3544阴性T或B淋巴细胞系以及非淋巴细胞系24个）的细胞质中均有表达，无论该抗原在细胞表面是否表达。免疫电镜检查显示，细胞质抗原在sSA3544阳性白血病细胞中主要存在于颗粒中，而在sSA3544阴性白血病细胞中则弥漫存在于胞质溶胶中。因此，在CEA家族成员中，首次证明NCA-50/90不仅在某些白血病细胞表面表达，而且在各种类型白血病细胞的细胞质中也有表达。
