Imamura N, Mtasiwa D M, Inada T, Kuramoto A
Department of Internal Medicine, Hiroshima University, Japan.
Leukemia. 1990 Jul;4(7):525-8.
Peripheral blood leukemic cells from four patients with peroxidase negative acute leukemia, which expressed neither myeloid nor lymphoid cell surface antigens, were analyzed by using monoclonal antibodies (MoAb) capable of recognizing megakaryocyte-platelet-related antigens. Leukemic cells from one case reacted with 5F1 MoAb, whereas cells from all the tested cases reacted with OKM5 MoAb, which belongs to the same CD group as 5F1 (CD36). Also, culture cells from megakaryoblastic leukemia cell line, MEG-01, and human erythroleukemia cell line, HEL, showed a different pattern of expression for the CD36 antigen molecule detected by 5F1 and OKM5 MoAb, individually. Furthermore, we have demonstrated that the epitopes recognized by 5F1 and OKM5 MoAb appear on the same CD36 molecule on the surface of HEL cells by means of the two-color analysis using FACS-IV. On the basis of our experiments, we conclude that, CD36 molecule, a receptor for TSP, is synthesized and expressed in at least two ways, inside the cells and on the surface of megakaryocyte lineage leukemias and megakaryocytic leukemia cell lines MEG-01 and HEL. This is strongly suggestive that thrombospondin (TSP)-mediated adhesion represents an alternative pathway for cytoadherence, and that CD36 expression on various kinds of cells may lack some essential modifications or components necessary for the TSP receptor activity.
对4例过氧化物酶阴性的急性白血病患者的外周血白血病细胞进行了分析，这些细胞既不表达髓系也不表达淋巴系细胞表面抗原，采用能够识别巨核细胞 - 血小板相关抗原的单克隆抗体（MoAb）进行检测。1例患者的白血病细胞与5F1 MoAb反应，而所有检测病例的细胞均与OKM5 MoAb反应，OKM5 MoAb与5F1属于同一CD组（CD36）。此外，巨核母细胞白血病细胞系MEG - 01和人红白血病细胞系HEL的培养细胞，分别对5F1和OKM5 MoAb检测的CD36抗原分子呈现出不同的表达模式。此外，我们通过使用FACS - IV的双色分析证明，5F1和OKM5 MoAb识别的表位出现在HEL细胞表面的同一CD36分子上。基于我们的实验，我们得出结论，CD36分子作为血小板反应蛋白（TSP）的受体，至少以两种方式合成并表达，即在细胞内以及在巨核细胞系白血病细胞和巨核细胞白血病细胞系MEG - 01和HEL的表面。这强烈提示血小板反应蛋白（TSP）介导的黏附代表了细胞黏附的另一种途径，并且各种细胞上的CD36表达可能缺乏TSP受体活性所需的一些必要修饰或成分。
