McNagny K M, Lim F, Grieser S, Graf T
Differentiation Programme, European Molecular Biology Laboratory, Heidelberg, Germany.
Leukemia. 1992 Oct;6(10):975-84.
E26 is an acute avian leukemia virus that contains two nuclear oncogenes, v-myb and v-ets, and that is capable of transforming early cells of the erythroid and myeloid lineages. In another study, we have found that TPA (phorbol 12,13-dibutyrate) treatment of E26-transformants displaying an 'early erythroid' phenotype results in the production of cells with either myeloid or eosinophil characteristics. To analyze this induction in greater detail we have produced a panel of four monoclonal antibodies against E26-transformants before and after TPA-induced differentiation. Two antibodies, MEP21 and MEP26, reacted with proteins of 150 and 47-60 kDa, respectively, which are expressed on the surface of E26 progenitor cells but whose expression is extinguished following TPA-induced differentiation. A third antibody, EOS47, recognizes a 100 kDa molecule that is expressed on the surface of TPA-induced peroxidase positive cells (an enzyme that in avian species is restricted to cells of the eosinophilic lineage). MEP21, MEP26, and EOS47 do not react with lymphoid, myeloid, or more mature erythroid lineage cell lines. The fourth antibody, MEP17, recognizes a heterodimer of 140 and 150 kDa chains which is expressed at high levels by E26-transformed progenitor cells and at lower levels by TPA-induced cells. Further biochemical characterization of the MEP17 antigen revealed a structure similar to that of the leukocyte adhesion molecule VLA-4; a member of the integrin family of adhesion proteins. All four antibodies react with subpopulations of cells in the bone marrow and spleens of 1-day-old chickens. Although the MEP21 and MEP26 antibodies do not appear to react with mature cells of most hematopoietic lineages they are expressed at high levels by mature thrombocytes. In addition, MEP17 is expressed at high levels by the majority of bursal B-cells, thrombocytes, and more weakly by thymocytes. The reagents described should be useful as markers for the study of development, migration, and differentiation of normal avian hematopoietic progenitor cells and eosinophilic precursors, and for the study of retrovirus-induced neoplasia.
E26是一种急性禽白血病病毒，它含有两个核癌基因，即v-myb和v-ets，能够转化红系和髓系谱系的早期细胞。在另一项研究中，我们发现用佛波酯12,13-二丁酸酯（TPA）处理表现出“早期红系”表型的E26转化细胞，会产生具有髓系或嗜酸性粒细胞特征的细胞。为了更详细地分析这种诱导作用，我们制备了一组针对TPA诱导分化前后的E26转化细胞的四种单克隆抗体。两种抗体MEP21和MEP26分别与150 kDa和47 - 60 kDa的蛋白质反应，这些蛋白质在E26祖细胞表面表达，但在TPA诱导分化后其表达消失。第三种抗体EOS47识别一种100 kDa的分子，该分子在TPA诱导的过氧化物酶阳性细胞（一种在禽类中仅限于嗜酸性粒细胞谱系细胞的酶）表面表达。MEP21、MEP26和EOS47不与淋巴系、髓系或更成熟的红系谱系细胞系反应。第四种抗体MEP17识别由140 kDa和150 kDa链组成的异二聚体，该异二聚体在E26转化的祖细胞中高水平表达，在TPA诱导的细胞中低水平表达。对MEP17抗原的进一步生化特性分析揭示了一种与白细胞黏附分子VLA-4类似的结构；VLA-4是黏附蛋白整合素家族成员。所有四种抗体都与1日龄鸡骨髓和脾脏中的细胞亚群反应。尽管MEP21和MEP26抗体似乎不与大多数造血谱系的成熟细胞反应，但它们在成熟血小板中高水平表达。此外，MEP17在大多数法氏囊B细胞、血小板中高水平表达，在胸腺细胞中表达较弱。所述试剂可用作研究正常禽类造血祖细胞和嗜酸性粒细胞前体的发育、迁移和分化以及逆转录病毒诱导的肿瘤形成的标志物。
