DEVELOPMENT OF AN IN VITRO MODEL FOR PREDICTING THE CONTACT SENSITIVITY TO OCCUPATIONAL CHEMICALS

接触致敏剂被认为是一种以Th1型辅助细胞激活为特征的免疫应答，而白细胞介素-2 （IL-2）是Th1细胞分泌的代表性细胞因子。本研究通过半抗原刺激DNCB接触致敏小鼠淋巴结细胞体外产生IL-2，评价DNCB对DNCB的接触敏感性和DNBS与DNCB的交叉敏感性。为了在体外诱导IL-2的产生，将致敏小鼠或对照小鼠的淋巴结细胞用指定浓度的半抗原培养。用MTT比色法测定培养48h上清液中IL-2的活性，以刺激IL-2依赖性CTLL-2细胞生长的能力，并以刺激指数表示。从我们的研究中得出以下事实。(1)以半抗原形式存在的DNCB可诱导DNCB致敏小鼠淋巴结细胞产生半抗原特异性IL-2。(2) dncb刺激的IL-2在体内接触致敏后第7天产生最大反应。(3) DNCB与DNBS在体外IL-2生成中存在交叉反应。(4)体外dncb特异性IL-2生成与DNBS交叉反应呈较强的量效关系。(5) dncb诱导的体外IL-2生成与dncb诱导的体内接触超敏反应、dnbs诱导的体外IL-2生成与dnbs诱导的体内接触超敏反应存在良好的相关性。因此，本研究提示半抗原诱导小鼠淋巴结细胞体外产生IL-2可能是预测化学物质接触敏感性及其交叉敏感性的一种新的体外模型。

Contact sensitizers are considered to lead to an immune response characteristic of Th1-type helper cells activation, and interleukin-2 (IL-2) is a representative cytokine secreted by Th1 cells. In this study, contact sensitivity to DNCB and the cross-sensitivity of DNBS with DNCB were evaluated using hapten-stimulated in vitro IL-2 production by the lymph node cells from mice contact sensitized with DNCB.For induction of in vitro IL-2 production, the lymph node cells from sensitized or control mice were cultured with the indicated concentrations of hapten. IL-2 activity in 48 hr culture supernatants was measured by its ability to stimulate IL-2-dependent CTLL-2 cell growths using MTT colorimetric assay and it was expressed as stimulation index. The following facts have emerged from our study.(1)DNCB in the form of hapten can induce hapten-specific in vitro IL-2 production by the lymph node cells from DNCB-sensitized mice.(2)DNCB-stimulated in vitro IL-2 production exhibited a maximal response on the 7th day after in vivo induction of contact sensitization.(3)There was a cross-reaction between DNCB and DNBS in in vitro IL-2 production.(4)DNCB-specific in vitro IL-2 production and the cross-reaction to DNBS showed the strong dose-response relationships.(5)There were goodcorrelations between DNCB-induced in vitro IL-2 production and DNCB-induced in vivo contact hypersensitivity as well as DNBS-induced in vitro IL-2 production and DNBS-elicited in vivo contact hypersensitivity. Thus, the present study suggests that hapten-induced in vitro IL-2 production by the murine lymph node cells may be a new in vitro model for predicting the contact sensitivity and their cross-sensitivity of chemicals.