Human keratinocytes are a source for tumor necrosis factor alpha: evidence for synthesis and release upon stimulation with endotoxin or ultraviolet light.
Human keratinocytes are a source for tumor necrosis factor alpha: evidence for synthesis and release upon stimulation with endotoxin or ultraviolet light.
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DOI：
10.1084/jem.172.6.1609
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发表时间：
1990-12-01
期刊：
影响因子：
--
通讯作者：
Luger TA
中科院分区：
文献类型：
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作者：
Köck A;Schwarz T;Kirnbauer R;Urbanski A;Perry P;Ansel JC;Luger TA
肿瘤坏死因子α（TNF-α）除了对某些肿瘤细胞具有细胞毒性外，还被证明是参与免疫和炎症调节的多功能细胞因子。由于已经证明人角质形成细胞是各种细胞因子的有效来源，因此研究了表皮细胞是否合成和释放TNF-α。在TNF-α-特异性ELISA和生物测定中测试源自正常人角质形成细胞（HNK）和人表皮样癌细胞系（KB，A431）的上清液。在未处理的表皮细胞的上清液中，没有发现或发现最小的TNF-α活性，而在用脂多糖（LPS）或紫外线（UV）光刺激后，检测到显著量的TNF-α活性。使用针对人TNF-α的抗体的蛋白质印迹分析揭示了角质形成细胞衍生的TNF-α的分子量为17 kD。这些生物学和生物化学数据也通过北方印迹分析证实，该分析揭示了LPS或紫外线B（UVB）处理的HNK和KB细胞中TNF-α特异性的mRNA。此外，在单次全身UVB暴露后12和24小时，在从人类志愿者获得的血清中检测到增加的TNF-α水平，这导致严重的晒伤反应。这些发现表明，角质形成细胞在刺激时能够合成和释放TNF-α，其可以进入循环。因此，TNF-α与其他表皮细胞衍生的细胞因子一起可在宿主防御由微生物剂或UV照射引起的损伤事件期间介导局部和全身炎症反应。
Tumor necrosis factor alpha (TNF-alpha), in addition to being cytotoxic for certain tumor cells, has turned out as a multifunctional cytokine that is involved in the regulation of immunity and inflammation. Since human keratinocytes have been demonstrated to be a potent source of various cytokines, it was investigated whether epidermal cells synthesize and release TNF-alpha. Supernatants derived from normal human keratinocytes (HNK) and human epidermoid carcinoma cell lines (KB, A431) were tested both in a TNF-alpha-specific ELISA and a bioassay. In supernatants of untreated epidermal cells, no or minimal TNF-alpha activity was found, while after stimulation with lipopolysaccharide (LPS) or ultraviolet (UV) light, significant amounts were detected. Western blot analysis using an antibody directed against human TNF-alpha revealed a molecular mass of 17 kD for keratinocyte- derived TNF-alpha. These biological and biochemical data were also confirmed by Northern blot analysis revealing mRNA specific for TNF- alpha in LPS- or ultraviolet B (UVB)-treated HNK and KB cells. In addition, increased TNF-alpha levels were detected in the serum obtained from human volunteers 12 and 24 h after a single total body UVB exposure, which caused a severe sunburn reaction. These findings indicate that keratinocytes upon stimulation are able to synthesize and release TNF-alpha, which may gain access to the circulation. Thus, TNF- alpha in concert with other epidermal cell-derived cytokines may mediate local and systemic inflammatory reactions during host defense against injurious events caused by microbial agents or UV irradiation.