INTERLEUKIN-6: A TRANSCRIPTION ACTIVATING CYTOKINE

白介素6(IL-6)，一个20-26 kDa的磷酸糖蛋白，其基因已被 在各种异源系统中克隆和测序，已经被 据报道，在激活的B细胞中诱导Ig分泌，作为一种生长 以及这些细胞的分化因子。 因为免疫球蛋白基因和它们的调控元件 详细表征，研究免疫球蛋白的分子调控机制 IL-6诱导的细胞分泌提供了一种理想的模型系统 调查。最近，IL-6被报道转录激活 亚克隆中的Gamma1重链和Gamma轻链基因 淋巴母细胞系CESS是根据高表达的 免疫球蛋白1表面密度表达。 本研究的目的是进一步研究分子水平。 IL-6诱导免疫球蛋白产生的基础。使用一组B细胞系 通过EBV永生化正常人B淋巴细胞，我们获得了 证实IL-6刺激Ig基因转录，导致显著 每个细胞的信使核糖核酸的数量增加。我们进一步表明，IL-6 诱导生长反应基因c-myc和肌动蛋白的表达， 其次是DNA，RNA和蛋白质合成以及细胞的增加 数字。因此，IL-6并不选择性地激活Ig转录，而是 作为B细胞刺激因子转录激活几个 生长反应基因。

Interleukin-6 (IL-6), a 20-26 kDa phospho-glycoprotein whose gene has been cloned and sequenced in a variety of heterologous systems, has been reported to induce Ig secretion in activated B cells, acting as a growth and differentiation factor for these cells. Because both the Ig genes and their regulatory elements have been characterized in detail, study of the molecular mechanisms governing Ig secretion induced by IL-6 provides an ideal model system for investigation. Recently, IL-6 was reported to transcriptionally activate gamma1 heavy chain and gamma light chain genes in a subclone of the lymphoblastoid cell line CESS that was selected on the basis of high density IgG1 surface expression. The purpose of the present study was to investigate further the molecular basis for Ig production induced by IL-6. Using a panel of B cell lines obtained by EBV immortalization of normal human B lymphocytes, we confirmed that IL-6 stimulates Ig gene transcription, causing significant increases in the amounts of mRNA per cell. We further showed that IL-6 induces expression of the growth responsive genes c-myc and actin, followed by increases in DNA, RNA and protein synthesis as well as cell numbers. Thus, IL-6 does not selectively activate Ig transcription but acts as a B cell stimulatory factor transcriptionally activating several growth responsive genes.