Blom T, Huang R, Aveskogh M, Nilsson K, Hellman L
Department of Immunology, University of Uppsala, Sweden.
Eur J Immunol. 1992 Aug;22(8):2025-32. doi: 10.1002/eji.1830220811.
The knowledge about the differentiation of basophilic leukocytes is fragmentary. This report discusses a detailed phenotypic characterization of molecular markers for hematopoietic differentiation in a basophilic leukemia cell line, KU812. The expression of markers for lymphoid, erythroid, neutrophil, eosinophil, monocytic, megakaryocytic, mast cell and basophil differentiation was analyzed at the mRNA level by Northern blots in the KU812 cells, and for reference, in a panel of human cell lines representative of the different hematopoietic differentiation lineages. KU812 was found to express a number of mast cell and basophil-related proteins, i.e. mast cell tryptase, mast cell carboxypeptidase A, high-affinity immunoglobulin (IgE) receptor alpha and gamma chains and the core protein for heparin and chondroitin sulphate synthesis. We found no expression of a number of monocyte/-macrophage or neutrophil leukocyte markers except for lysozyme. From earlier studies, it has been shown that lysozyme is not expressed in murine mucosal mast cell lines. This finding, together with the expression of the mast cell carboxypeptidase in KU812 might distinguish the phenotype of this cell line from that typical of mucosal mast cell lines in rodents. We found a low level of expression of the eosinophil and basophil marker, major basic protein, which might indicate a relationship between basophils and eosinophils. No expression is, however, detected with the eosinophil-specific markers eosinophil cationic protein, eosinophil-derived neurotoxin or eosinophil peroxidase. We also report an extensive screening for inducers of basophilic differentiation of the KU812 cells. The most efficient protocol of induction included serum starvation which led to a dramatic increase in a number of markers specific for mast cells and basophils such as tryptase, carboxypeptidase A and the heparin core protein. Finally, diisopropylfluorophosphate analysis of total protein extracts from KU812 show four labeled protein bands with sodium dodecyl sulfate-polyacrylamide gel electrophoresis, indicating that this cell line expresses at least three previously undescribed serine proteases of which one or more could be a potential basophil-specific marker(s).
关于嗜碱性白细胞分化的知识尚不完整。本报告讨论了嗜碱性白血病细胞系KU812中造血分化分子标志物的详细表型特征。通过Northern印迹法在KU812细胞中以及作为参考在一组代表不同造血分化谱系的人类细胞系中，分析了淋巴细胞、红细胞、中性粒细胞、嗜酸性粒细胞、单核细胞、巨核细胞、肥大细胞和嗜碱性粒细胞分化标志物在mRNA水平的表达。发现KU812表达多种肥大细胞和嗜碱性粒细胞相关蛋白，即肥大细胞类胰蛋白酶、肥大细胞羧肽酶A、高亲和力免疫球蛋白（IgE）受体α和γ链以及肝素和硫酸软骨素合成的核心蛋白。除溶菌酶外，我们未发现多种单核细胞/巨噬细胞或中性粒细胞标志物的表达。早期研究表明，溶菌酶在小鼠黏膜肥大细胞系中不表达。这一发现，连同KU812中肥大细胞羧肽酶的表达，可能使该细胞系的表型与啮齿动物黏膜肥大细胞系的典型表型有所区别。我们发现嗜酸性粒细胞和嗜碱性粒细胞标志物主要碱性蛋白的表达水平较低，这可能表明嗜碱性粒细胞与嗜酸性粒细胞之间存在关联。然而，未检测到嗜酸性粒细胞特异性标志物嗜酸性粒细胞阳离子蛋白、嗜酸性粒细胞衍生神经毒素或嗜酸性粒细胞过氧化物酶的表达。我们还报告了对KU812细胞嗜碱性分化诱导剂的广泛筛选。最有效的诱导方案包括血清饥饿，这导致多种肥大细胞和嗜碱性粒细胞特异性标志物如类胰蛋白酶、羧肽酶A和肝素核心蛋白显著增加。最后，对KU812总蛋白提取物进行二异丙基氟磷酸分析，在十二烷基硫酸钠 - 聚丙烯酰胺凝胶电泳中显示出四条标记蛋白带，表明该细胞系表达至少三种先前未描述的丝氨酸蛋白酶，其中一种或多种可能是潜在的嗜碱性粒细胞特异性标志物。
