Rowland T L, McHugh S M, Deighton J, Dearman R J, Ewan P W, Kimber I
Molecular Immunopathology Unit, Medical Research Council Centre, Cambridge, England, UK.
Immunopharmacology. 1998 Jul;40(1):11-20. doi: 10.1016/s0162-3109(98)00010-1.
Immunosuppressive drugs are used routinely to reduce the inappropriate production of cytokines in an immune response. Recent attention has focused on drugs that selectively inhibit specific cytokines. Both thalidomide and dexamethasone have been reported to exhibit immunomodulatory effects on cytokines in vitro. We wished to examine the effects of thalidomide and dexamethasone on the production of cytokines by peripheral blood mononuclear cells (PBMC), following mitogenic stimulation, at the level of both secreted product and mRNA production. PBMC from healthy human volunteers were stimulated optimally with phytohaemagglutinin (PHA) in the presence of varying concentrations of thalidomide and dexamethasone using dimethyl sulphoxide (DMSO) as the solvent. Analysis of supernatants by enzyme-linked immunosorbent assay (ELISA) showed that thalidomide caused a dose-dependent inhibition of the pro-inflammatory cytokines interleukin 6 (IL-6) and tumour necrosis factor alpha (TNF-alpha), maximally reducing production by 20 (P < 0.05) and 30% (P < 0.01), respectively, compared with controls. However, thalidomide did not affect either proliferation or the production of interleukin 2 (IL-2), interleukin 4 (IL-4) or interleukin 10 (IL-10). A slight bell shaped inhibition of interferon gamma (IFN-gamma) was seen which was statistically significant (P < 0.05). In contrast, dexamethasone inhibited markedly the expression of all cytokines tested (IL-2, IL-4, IL-6, IL-10, IFN-gamma and TNF-alpha) in dose-dependent fashion, reducing levels to near to background. Reverse transcription-polymerase chain reaction (RT-PCR) analyses showed that thalidomide inhibited selectively the expression of TNF-alpha and IL-6 mRNA, whereas dexamethasone inhibited mRNA levels of all cytokines examined. The data indicate that dexamethasone is a broad range immunosuppressant inhibiting all cytokines tested in a dose-dependent manner at the level of both secreted product and mRNA. Conversely, thalidomide selectively inhibits the production of IL-6 and TNF-alpha. Due to their markedly different effects on cytokine production, and the fact that both drugs act at the level of transcription, we believe they influence separate pathways involved in cytokine gene regulation.
免疫抑制药物通常用于减少免疫反应中细胞因子的不适当产生。最近的研究重点集中在选择性抑制特定细胞因子的药物上。据报道，沙利度胺和地塞米松在体外对细胞因子均表现出免疫调节作用。我们希望在分泌产物和mRNA产生水平上，研究沙利度胺和地塞米松对丝裂原刺激后外周血单个核细胞（PBMC）产生细胞因子的影响。以二甲基亚砜（DMSO）作为溶剂，在不同浓度的沙利度胺和地塞米松存在下，用植物血凝素（PHA）对健康人类志愿者的PBMC进行最佳刺激。通过酶联免疫吸附测定（ELISA）分析上清液表明，与对照组相比，沙利度胺对促炎细胞因子白细胞介素6（IL-6）和肿瘤坏死因子α（TNF-α）产生剂量依赖性抑制，最大程度分别降低20%（P<0.05）和30%（P<0.01）的产生。然而，沙利度胺对增殖或白细胞介素2（IL-2）、白细胞介素4（IL-4）或白细胞介素10（IL-10）的产生没有影响。观察到对干扰素γ（IFN-γ）有轻微的钟形抑制，具有统计学意义（P<0.05）。相比之下，地塞米松以剂量依赖性方式显著抑制所有测试细胞因子（IL-2、IL-4、IL-6、IL-10、IFN-γ和TNF-α）的表达，将水平降低至接近背景。逆转录-聚合酶链反应（RT-PCR）分析表明，沙利度胺选择性抑制TNF-α和IL-6 mRNA的表达，而地塞米松抑制所有检测细胞因子的mRNA水平。数据表明，地塞米松是一种广泛的免疫抑制剂，在分泌产物和mRNA水平上均以剂量依赖性方式抑制所有测试细胞因子。相反，沙利度胺选择性抑制IL-6和TNF-α的产生。由于它们对细胞因子产生的显著不同影响，以及两种药物均在转录水平起作用这一事实，我们认为它们影响细胞因子基因调控中不同的途径。
