Schultz C, Izuhara K, Coffman R, Harada N
Department of Immunology, DNAX Research Institute, Palo Alto, CA 94304-1104, USA.
Immunol Lett. 1995 Jun;46(3):215-9. doi: 10.1016/0165-2478(95)00050-f.
To examine the region critical for differentiation in the human IL-4 receptor (hIL-4R), we transfected the Abelson murine leukemia virus (A-MuLV)-transformed murine pre-B cell line A20 with plasmid DNA encoding the hIL-4R. Transfectants expressed high affinity hIL-4Rs on the cell surface. Treatment with LPS and hIL-4 induced germline C epsilon transcripts in hIL-4R expressing A20 cells. Several hIL-4R mutant plasmids were then transfected into A20 cells and the transfectants were examined for hIL-4R expression and the ability to induce germline C epsilon transcripts upon stimulation with LPS and hIL-4. Although all A20 transfectants tested expressed the high-affinity hIL-4R, A20 transfectants expressing the mutant hIL-4R, which contains only 8 amino acids in the cytoplasmic domain, did not respond to LPS and hIL-4 with germline C epsilon transcripts. In addition, A20 transfectants expressing an internally deleted hIL-4R, in which the deleted region has been identified as the critical region for growth signal transduction in the previous study, failed to induce germline C epsilon transcripts with LPS and hIL-4. These results indicate that the critical region for the differentiation signal in the hIL-4R is identical to that for the growth signal, suggesting that IL-4 may share, at least partly, a common signal pathway for both growth and differentiation.
为了研究人白细胞介素-4受体（hIL-4R）中对分化至关重要的区域，我们用编码hIL-4R的质粒DNA转染了阿贝尔逊鼠白血病病毒（A-MuLV）转化的鼠前B细胞系A20。转染子在细胞表面表达高亲和力的hIL-4R。用脂多糖（LPS）和hIL-4处理可诱导表达hIL-4R的A20细胞中的胚系Cε转录本。然后将几种hIL-4R突变体质粒转染到A20细胞中，并检测转染子的hIL-4R表达以及在用LPS和hIL-4刺激后诱导胚系Cε转录本的能力。尽管所有测试的A20转染子都表达高亲和力的hIL-4R，但表达仅在胞质结构域含有8个氨基酸的突变型hIL-4R的A20转染子，在用LPS和hIL-4刺激时不会产生胚系Cε转录本。此外，表达内部缺失型hIL-4R的A20转染子（在先前的研究中已确定缺失区域是生长信号转导的关键区域），在用LPS和hIL-4刺激时也未能诱导胚系Cε转录本。这些结果表明，hIL-4R中分化信号的关键区域与生长信号的关键区域相同，这表明IL-4可能至少部分地共享生长和分化的共同信号通路。
