INTERLEUKIN-6--A TRANSCRIPTION ACTIVATING CYTOKINE

白细胞介素-6（IL-6），一种20-26 kDa的磷酸化糖蛋白，其基因具有 已在多种异源系统中克隆和测序， 据报道，在活化的B细胞中诱导IG分泌，作为生长因子 和分化因子。 因为IG基因和它们的调控元件都被 详细表征，研究控制IG的分子机制 由IL-6诱导的分泌提供了理想的模型系统， 调查 最近，IL-6被报道转录激活 γ 1重链和λ轻链基因的亚克隆， 淋巴母细胞样细胞系CESS是根据高 密度IgGl表面表达。 本研究的目的是进一步研究分子水平 IL-6诱导IG产生的基础。 使用一组B细胞系 通过EBV永生化正常人B淋巴细胞获得，我们 证实IL-6刺激IG基因转录，引起显著的 每个细胞的mRNA数量增加。 我们进一步表明，IL-6 诱导生长应答基因c-myc和肌动蛋白的表达， 随后是DNA、RNA和蛋白质合成的增加， 号码 因此，IL-6不选择性激活IG转录， 作为B细胞刺激因子转录激活几种 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 lambda light chain genes in a subclone of the lymphoblastoid cell line CESS that was selected on the basis of high density IgGl 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.