Valent P, Besemer J, Kishi K, Kaltenbrunner R, Kuhn B, Maurer D, Lechner K, Bettelheim P
I. Medical Department, University of Vienna, Austria.
J Immunol. 1990 Sep 15;145(6):1885-9.
The myeloid precursor cell line KU812 exhibits a constitutive potential to differentiate into basophilic cells. In the present study, the influence of recombinant human (rh)IL-2, rhIL-3, and recombinant human granulocyte-macrophage-CSF on basophilic differentiation of KU812-F cells was studied. Of all cytokines tested, rhIL-3 induced a significant increase in formation of metachromatically granulated cells (from 10% in control cultures up to 30% in cultures supplemented with 100 U/ml of rhIL-3) as well as dose-dependent (1.5- to 3 fold) increase in cellular histamine in KU812-F cell cultures. In addition, KU812-F cells exposed to rhIL-3 bound more IgE antibody than cells cultured in control medium with up to 3.3-fold increases in the mean fluorescence intensity on days 2 and/or 5 compared with control (p less than 0.001). RhIL-3 failed to induce significant changes in expression of the Tac-reactive subunit of the IL-2R (CD25), surface aminopeptidase N (CD13), ICAM-1 Ag (CD54), or CD40 Ag on KU812-F cells. To investigate the mechanism of IL-3 action on KU812-F cells, receptor analyses were performed by using 125I-radiolabeled rhIL-3. Quantitative binding studies and Scatchard plot analyses revealed the presence of a single class of 1910 to 2460 high affinity IL-3-binding sites per KU812-F cell with an apparent dissociation constant of 1.22 to 2.35 x 10(-9) M. Together, these results show that rhIL-3 promotes basophilic differentiation of KU812-F cells through a specific receptor.
髓系前体细胞系KU812具有分化为嗜碱性细胞的固有潜能。在本研究中，研究了重组人（rh）白细胞介素-2（IL-2）、rhIL-3和重组人粒细胞-巨噬细胞集落刺激因子对KU812-F细胞嗜碱性分化的影响。在所有测试的细胞因子中，rhIL-3可使异染性颗粒细胞的形成显著增加（从对照培养物中的10%增加到添加100 U/ml rhIL-3的培养物中的30%），并且使KU812-F细胞培养物中的细胞组胺呈剂量依赖性增加（1.5至3倍）。此外，与对照相比，暴露于rhIL-3的KU812-F细胞结合的IgE抗体更多，在第2天和/或第5天平均荧光强度增加高达3.3倍（p小于0.001）。rhIL-3未能诱导KU812-F细胞上IL-2受体（CD25）的Tac反应亚基、表面氨肽酶N（CD13）、细胞间黏附分子-1抗原（CD54）或CD40抗原的表达发生显著变化。为了研究IL-3对KU812-F细胞的作用机制，使用125I放射性标记的rhIL-3进行了受体分析。定量结合研究和Scatchard图分析显示，每个KU812-F细胞存在一类1910至2460个高亲和力IL-3结合位点，表观解离常数为1.22至2.35×10(-9)M。总之，这些结果表明rhIL-3通过特异性受体促进KU812-F细胞的嗜碱性分化。
