Karrow N A, Leffel E K, Guo T L, Zhang L X, McCay J A, Germolec D R, White K L
Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA 23298-6013, USA.
Am J Contact Dermat. 2001 Mar;12(1):6-17. doi: 10.1053/ajcd.2001.0120006.
Although the Murine Local Lymph Node Assay (LLNA) is efficient in identifying chemicals with sensitizing potential, there is increasing need for alternative end points. Cinnamaldehyde (CIN) was chosen for evaluation based on its moderate potency and extensive use in fragrance materials.
The purpose of the present studies is to incorporate some alternative end points, such as phenotypic analysis and cytokine production, into a modified LLNA/irritancy assay (IA) to evaluate the sensitization of female B6C3F1 mice to CIN.
Several nontraditional end points, including the analysis of lymphocyte subpopulations, B7 costimulatory molecule and cytokine messenger RNA (mRNA) expression, and intracellular interferon-gamma (IFN-gamma) levels, were incorporated into a modified murine local lymph node (LLNA)/irritancy assay (IA) to evaluate the sensitization of female B6C3F1 mice to cinnamaldehyde (CIN).
The alternate end points used in these studies support the classification of CIN as a moderately potent sensitizer. Dermal treatment with CIN resulted in an increase in the percentage of B cells in the auricular lymph nodes (ALNs) and expression of the costimulatory molecule, B7-2, on B cells. Lymph node cells also showed increased transforming growth factor-beta1, migration-inhibition factor, and mild increases in IFN-gamma and interleukin-2 cytokine mRNA expression. Although the increase in IFN-gamma mRNA expression did not translate into increased intracellular IFN-gamma levels, the absolute number of T cells producing IFN-gamma in the ALNs increased. Conversely, the MEST did not classify CIN as a contact allergen.
The nontraditional end points used in the LLNA/IA were not as sensitive as the traditional radioisotope method used to assess cell proliferation. However, they may help identify compounds inappropriately classified as sensitizers or nonsensitizers by the LLNA and MEST.
尽管小鼠局部淋巴结试验（LLNA）在识别具有致敏潜力的化学物质方面很有效，但对替代终点的需求日益增加。肉桂醛（CIN）因其中等效力和在香料材料中的广泛应用而被选作评估对象。
本研究的目的是将一些替代终点，如表型分析和细胞因子产生，纳入改良的LLNA/刺激性试验（IA）中，以评估雌性B6C3F1小鼠对CIN的致敏作用。
将几个非传统终点，包括淋巴细胞亚群分析、B7共刺激分子和细胞因子信使核糖核酸（mRNA）表达，以及细胞内干扰素-γ（IFN-γ）水平，纳入改良的小鼠局部淋巴结（LLNA）/刺激性试验（IA）中，以评估雌性B6C3F1小鼠对肉桂醛（CIN）的致敏作用。
这些研究中使用的替代终点支持将CIN归类为中等效力的致敏剂。用CIN进行皮肤处理导致耳淋巴结（ALN）中B细胞百分比增加，以及B细胞上共刺激分子B7-2的表达增加。淋巴结细胞还显示转化生长因子-β1、迁移抑制因子增加，以及IFN-γ和白细胞介素-2细胞因子mRNA表达轻度增加。尽管IFN-γ mRNA表达的增加并未转化为细胞内IFN-γ水平的增加，但ALN中产生IFN-γ的T细胞绝对数量增加。相反，MEST未将CIN归类为接触性变应原。
LLNA/IA中使用的非传统终点不如用于评估细胞增殖的传统放射性同位素方法敏感。然而，它们可能有助于识别被LLNA和MEST不恰当地归类为致敏剂或非致敏剂的化合物。
