Differences in interleukin-6 gene expression between cultured human corneal epithelial cells and keratocytes.
Differences in interleukin-6 gene expression between cultured human corneal epithelial cells and keratocytes.
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发表时间：
1995-02
影响因子：
4.4
通讯作者：
Christopher L. Cubitt;R. Lausch;J. Oakes
中科院分区：
文献类型：
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作者：
Christopher L. Cubitt;R. Lausch;J. Oakes
目的探讨人角膜上皮细胞和角膜基质细胞能否合成白细胞介素6（IL-6）。方法从同一供体角膜中分离上皮细胞和角膜基质细胞进行体外培养。2 - 3代后，将培养物暴露于不同浓度的重组人白细胞介素-1（IL-1 α）或肿瘤坏死因子（TNF-α）。随后对培养物上清液进行酶联免疫吸附测定以测定细胞因子含量。通过逆转录-聚合酶链反应监测细胞裂解物中细胞因子mRNA的水平。结果培养的人角膜基质细胞用100 U/ml IL-1 α刺激18 h，每10（6）个细胞产生超过160 ng IL-6。在相同条件下，500 U/ml TNF-α诱导约5 ng IL-6。暴露于任一细胞因子后3小时，IL-6 mRNA明显蓄积并持续至18小时。上皮细胞暴露于IL-1 α或TNF-α诱导IL-6 mRNA的最小和瞬时表达，每10（6）个细胞< 0.5 ng蛋白产物。IL-6的产生不足并不反映上皮细胞不能对IL-1 α和TNF-α产生应答，因为这两种细胞因子都诱导这些细胞产生大量的IL-8。结论IL-1 α和TNF-α均能诱导角膜基质细胞产生纳克级IL-6，但IL-1 α的诱导作用是TNF-α的30倍。相反，这两种细胞因子都不能刺激上皮细胞产生超过皮克量的IL-6。角膜基质细胞合成的大量IL-6可促进周围淋巴组织的多种活动，包括特异性免疫反应。
PURPOSE To determine whether interleukin-6 (IL-6) can be synthesized by human corneal keratocytes and epithelial cells. METHODS Epithelial cells and keratocytes isolated from the same donor corneas were grown in vitro. After 2 to 3 passages, the cultures were exposed to varying concentrations of recombinant human interleukin-1 (IL-1 alpha) or tumor necrosis factor (TNF-alpha). Culture supernatants subsequently underwent enzyme-linked immunosorbent assays for cytokine content. The levels of cytokine mRNA in cell lysates were monitored by the reverse transcription-polymerase chain reaction. RESULTS Cultured human keratocytes stimulated with 100 U/ml IL-1 alpha for 18 hours produced more than 160 ng IL-6 per 10(6) cells. Under the same conditions 500 U/ml TNF-alpha induced approximately 5 ng IL-6. IL-6 mRNA, evident by 3 hours after exposure to either cytokine, accumulated and persisted through 18 hours. Exposure of epithelial cells to IL-1 alpha or TNF-alpha induced minimal and transient expression of IL-6 mRNA and < 0.5 ng protein product per 10(6) cells. The poor production of IL-6 did not reflect an inability of epithelial cells to respond to IL-1 alpha and TNF-alpha because both cytokines induced these cells to make copious amounts of IL-8. CONCLUSIONS These results demonstrate that both IL-1 alpha and TNF-alpha could induce keratocytes to produce nanogram levels of IL-6 but IL-1 alpha was a 30-fold more effective inducer. In contrast, neither cytokine could stimulate epithelial cells to make more than picogram quantities of IL-6. The abundant IL-6 synthesized by keratocytes may promote various activities including specific immune responses in surrounding lymphoid tissues.