Evaluation of immunotoxicity of occupational chemicals based on cytokine analysis

在这项研究中，我们通过分析各种细胞因子活性及其基因表达来评估职业化学品，特别是职业致敏剂的免疫毒性。首先，我们使用定量RT-PCR检测了DNCB、恶唑酮和吡咯酰氯等强接触致敏剂致敏小鼠引流淋巴结中的9种细胞因子mrna。我们观察到，接触敏感后6天引流淋巴结中Th1 （IL-2、IL-12和ifn - γ）和Th2细胞因子mrna （IL-4、IL-10和IL-13）均显著升高，表明接触敏感剂诱导了Th1和Th2细胞因子基因。同时，在接触性变应性皮炎小鼠皮肤损伤中进一步证实了IL-2、IL-4、IL-12和ifn - γ mrna在DNCB、恶唑酮和吡咯酰氯的上调表达。此外，为了证实上述发现是否适用于所有接触致敏剂，我们检查了福尔马林致敏小鼠引流淋巴结和炎症皮肤中的细胞因子mrna。我们发现，在最后一次使用福尔马林3天后，淋巴结中IL-2、IL-4、IL-12、IL-13和ifn - γ mrna的表达明显增强。在皮肤病变的情况下，IL-4和ifn - γ mrna均显著高于对照组小鼠。通过小鼠耳肿胀反应测量皮肤部位的细胞因子mrna与接触性过敏呈正相关。此外，我们还测试了重组IL-12是否可以作为预测试验的佐剂。结果表明，IL-12在体内通过促进Th1细胞因子和抑制Th2细胞因子显著增强接触超敏反应。综上所述，本研究表明细胞因子分析在职业性化学品免疫毒性评价中的有用性。

In this study, we have evaluated the immunotoxicity of occupational chemicals, in particular occupational sensitizers by analyzing various cytokine activities and their gene expression. Firstly, using quantitative RT-PCR we have detected nine cytokine mRNAs in the draining lymph nodes of mice sensitized with strong contact sensitizers such as DNCB,oxazolone and picryl chloride. It was observed that both Th1 (IL-2, IL-12 and IFN-gamma) and Th2 cytokine mRNAs (IL-4, IL-10 and IL-13) were significantly elevated in the draining lymph nodes 6 days following contact sensitivity, indicating the induction of both Th1 and Th2 cytokine genes by contact sensitizers. Meanwhile, the up-regulated expression of IL-2, IL-4, IL-12 and IFN-gamma mRNAs was further demonstrated in the skin lesions of mice with contact allergic dermatitis to DNCB,oxazolone and picryl chloride. Moreover, to confirm wether the above findings are common to all contact sensitizers we have examined the cytokine mRNAs in the draining lymph nodes and inflammatory skin in formalin-sensitized mice. We found that the expression of IL-2, IL-4, IL-12, IL-13 and IFN-gamma mRNAs was markedly enhanced in the lymph nodes three days after the last application of formalin. In the case of the skin lesions, both IL-4 and IFN-gamma mRNAs were significantly higher than those in control mice. The cytokine mRNAs at the skin sites were positively correlated with contact hypersensitivity as measured by mouse ear swelling response. Furthermore, we have tested if recombinant IL-12 could be used as adjuvant in the predicting tests. As results, we have demonstrated that IL-12 significantly enhanced contact hypersensitivity by promoting Th1 cytokines and suppressing Th2 cytokines in vivo. Taken together, this study indicates the usefulness of cytokine analysis in the evaluation of immunotoxicity from occupational chemicals.