背景:已经报道了白细胞介素(IL)-36β介导的CD8+T细胞活化的抗肿瘤作用,但是分子机制在很大程度上是不确定的。
方法:采用实时定量PCR(qRT-PCR)和免疫组化染色检测胰腺癌组织中IL-36β的水平。进行细胞学和动物实验以研究IL-36β对胰腺癌细胞生长的影响。然后,我们通过流式细胞术检查了肿瘤中CD8T细胞和自然杀伤(NK)细胞的变化。通过微阵列分析确定微小RNA表达谱。
结果:结果显示胰腺癌组织中IL-36β水平降低。此外,IL-36β在肿瘤微环境(TME)中抑制肿瘤生长并促进CD8T和NK细胞增殖。此外,IL-36β刺激CD8+T细胞合成大量的干扰素-γ(IFN-γ)和IL-2。微阵列分析显示,IL-36β给予人和小鼠CD8+T细胞一致下调miRNA,let-7c-5p.let-7c-5p的下调导致CD8+T细胞中IFN-γ和IL-2上调,而它的上调却产生了相反的效果。进一步的实验证明IL-36β下调let-7c-5p+CD8+T细胞中的IFN-γ。
结论:这些发现表明IL-36β促进CD8+T细胞中IFN-γ和IL-2的产生,以及通过下调let-7c-5p在CD8+T细胞中的抗肿瘤作用。
BACKGROUND: The anti-tumor effect of interleukin (IL)-36β-mediated activation of CD8+ T cells has been reported, but the molecular mechanism is largely undefined.
METHODS: The levels of IL-36β in pancreatic cancer were examined by quantitative real-time PCR (qRT-PCR) and immunohistochemical staining. Cytology and animal experiments were performed to study the effects of IL-36β on the growth of pancreatic cancer cells. We then examined the changes of CD8+ T cells and natural killer (NK) cells in the tumor by flow cytometry. The microRNA expression profiles were determined by microarray analysis.
RESULTS: The results revealed decreased levels of IL-36β in pancreatic cancer tissues. In addition, IL-36β inhibited tumor growth and promoted CD8+ T and NK cell proliferation in the tumor microenvironment (TME). Moreover, IL-36β stimulated CD8+ T cells to synthesize high amounts of interferon-gamma (IFN-γ) and IL-2. Microarray analysis showed that IL-36β administration to human and mouse CD8+ T cells consistently downregulated the miRNA, let-7c-5p. Downregulation of let-7c-5p resulted in IFN-γ and IL-2 upregulation in CD8+ T cells, whereas its upregulation had the opposite effect. Further experiments demonstrated that IL-36β downregulated IFN-γ in let-7c-5p+ CD8+ T cells.
CONCLUSIONS: These findings suggest IL-36β promotes IFN-γ and IL-2 production in CD8+ T cells, as well as anti-tumor effects in CD8+ T cells by downregulating let-7c-5p.