Coleman J W, Buckley M G, Holliday M R, Morris A G
Department of Pharmacology and Therapeutics, University of Liverpool, GB.
Eur J Immunol. 1991 Oct;21(10):2559-64. doi: 10.1002/eji.1830211037.
Conditioned medium (CM) from concanavalin A-activated mouse spleen cells inhibits antigen-induced 5-hydroxytryptamine (5-HT) release from mouse peritoneal mast cells when added for 24 or 48 h to cell cultures containing monoclonal IgE sensitizing antibody. We present the following evidence that the spleen cell-derived inhibitory factor is interferon-gamma (IFN-gamma): (a) CM from Con A-activated spleen cells and from Chinese hamster ovary (CHO) cells transfected with the murine (Mu)IFN-gamma gene both produced a graded inhibition of 5-HT release when added to peritoneal cell cultures containing IgE and subsequently challenged with antigen; (b) the relative inhibitory potency of the two preparations corresponded to their relative IFN content as determined by antiviral bioassay; (c) the inhibitory activity of spleen cell CM and of CM from IFN-gamma gene-transfected CHO cells was abolished by treatment with a rat monoclonal MuIFN-gamma-neutralizing antibody, i.e. 5-HT release returned to control levels, and (d) a highly immunopurified preparation of recombinant MuIFN-gamma retained the inhibitory activity, and was active at concentrations as low as 2 U/ml. The inhibitory activity of IFN-gamma appeared to be a direct effect of the cytokine on mast cells, since CM generated for different time periods from unfractionated peritoneal cells treated with purified recombinant MuIFN-gamma contained no inhibitory activity other than IFN-gamma itself, as demonstrated by neutralization of the cytokine with monoclonal antibody. Furthermore, purified recombinant MuIFN-gamma was equally active on mast cells enriched by density centrifugation up to 95% purity as on unfractionated peritoneal cells (1%-2% mast cells). Purified recombinant MuIFN-gamma inhibited 5-HT release induced by a range of different cell activators, namely antigen, anti-IgE, compound 48/80 and calcium ionophore A23187. Hence inhibition is not specific to IgE-dependent activation of mast cells, but seems to be directed more generally at the secretory process of these cells.
刀豆球蛋白A激活的小鼠脾细胞产生的条件培养基（CM），当添加到含有单克隆IgE致敏抗体的细胞培养物中24或48小时时，可抑制抗原诱导的小鼠腹腔肥大细胞释放5-羟色胺（5-HT）。我们提供以下证据表明脾细胞衍生的抑制因子是干扰素-γ（IFN-γ）：（a）刀豆球蛋白A激活的脾细胞和转染了鼠（Mu）IFN-γ基因的中国仓鼠卵巢（CHO）细胞产生的CM，当添加到含有IgE的腹腔细胞培养物中并随后用抗原攻击时，均产生5-HT释放的分级抑制；（b）两种制剂的相对抑制效力与其通过抗病毒生物测定法测定的相对IFN含量相对应；（c）用大鼠单克隆MuIFN-γ中和抗体处理后，脾细胞CM和IFN-γ基因转染的CHO细胞的CM的抑制活性被消除，即5-HT释放恢复到对照水平，并且（d）高度免疫纯化的重组MuIFN-γ制剂保留了抑制活性，并且在低至2 U/ml的浓度下仍具有活性。IFN-γ的抑制活性似乎是细胞因子对肥大细胞的直接作用，因为用纯化的重组MuIFN-γ处理的未分级腹腔细胞在不同时间段产生的CM除了IFN-γ本身外没有其他抑制活性，这通过用单克隆抗体中和细胞因子来证明。此外，纯化的重组MuIFN-γ对通过密度离心富集至纯度达95%的肥大细胞的活性与对未分级腹腔细胞（1%-2%肥大细胞）的活性相同。纯化的重组MuIFN-γ抑制一系列不同细胞激活剂诱导的5-HT释放，这些激活剂包括抗原、抗IgE、化合物48/80和钙离子载体A23187。因此，抑制作用并非特异性针对肥大细胞的IgE依赖性激活，而是似乎更普遍地针对这些细胞的分泌过程。
