初次变应性接触性皮炎小鼠模型的建立与评价

Establishment and evaluation of primary allergic contact dermatitis mouse model

目的建立并评价初次变应性接触性皮炎（ACD）小鼠模型。方法用1-氟-2，4二硝基苯（DNFB）分别制作经典ACD小鼠模型及初次ACD模型，在以下3方面对二者进行比较：以激发前后耳肿度为临床观察指标；以ELISA与实时RT—PCR方法检测耳组织中IL-2、INF-γ与IL-4的表达水平；进行局部淋巴结分析（LLNA），以流式细胞术检测耳引流淋巴结中淋巴细胞增殖与活化的情况。结果初次ACD小鼠模型耳背部单次用药6天后出现较明显的耳肿度变化，这与经典ACD模型自诱导至炎症出现的时间相同；与经典ACD小鼠模型相似，初次ACD小鼠模型的耳肿度亦呈现出随时间变化的趋势；二者组织浸润细胞均以单-核细胞为主；与正常小鼠相比，二者组织中Th1型细胞因子IL-2与IFN-γ表达均增加，Th2型因子IL-4均未增加，耳引流淋巴结中T淋巴细胞均出现明显增殖与活化。结论初次ACD模型与经典模型机制相似，均为Th1型变态反应，二者可以互用。

Objective To establish and evaluate a new mouse model of allergic contact dermatitis （ACD）-primary ACD mouse model. Methods To establish classical ACD mouse model, mice were sensitized with 1-fluoro-2,4-dinitrobenzene （DNFB） on day 1 and elicited with DNFB on day 6, and primary ACD mouse model was built by painting of 10uL 0.2% DNFB once on the ear. Mice were killed 24 hours after the elicitation in classical model group and 6 days after the sensitization in primary model group; skin specimens were obtained from the right ear of these mice. Ear swelling after painting was used as clinical index. ELISA and real time RT-PCR were performed to measure the expression of IL-2, IFN-γ and IL-4 in these specimens. Local lymph node assay was carried out and flow cytometry was used to detect the proliferation and activation of T lymphocytes in local lymph nodes. Results Ear swelling response was observed 6 days after ear challenge with DNFB in primary ACD, which was the same as the time interval from back elicitation to occurrence of ear inflammation in classical ACD. Kinetics of the inflammatory response to DNFB during primary ACD was similar to that during classical ACD. In both models,the ear tissues were mainly infiltrated by mononuclear cells; a significant increase was observed in the tissue levels of IL-2 and INF-γ as well as in the proliferation and activation of T lymphocytes in local lymph nodes; while there were no significant changes in the level of IL-4, compared with the normal control mice. Conclusions Similar to classical ACD, Thl type cell-mediated immune responses were reproduced in primary ACD mouse model, and each model can take the place of the other in comparative research.