Cumberbatch M, Gould S J, Peters S W, Basketter D A, Dearman R J, Kimber I
Immunology Group, Zeneca Central Toxicology Laboratory, Macclesfield, Cheshire, UK.
J Clin Lab Immunol. 1992;37(2):65-81.
Chemical allergens differ with respect to the type of hypersensitivity reactions they preferentially elicit. Some chemicals, such as trimellitic anhydride (TMA), have the potential to induce both contact and respiratory hypersensitivity. Other chemicals cause only contact allergy. For example, 2,4-dinitrochlorobenzene (DNCB), a potent contact allergen, appears not to induce respiratory sensitization. In previous studies we have shown that topical exposure of mice to TMA and DNCB, under conditions of equivalent immunogenicity with respect to draining lymph node activation and contact sensitization, caused qualitatively different antibody responses. While the chemicals provoked IgG anti-hapten antibody responses of equivalent magnitude, only TMA induced an IgE response, and DNCB caused a significantly stronger IgG2a response. These data are consistent with the preferential activation by DNCB and TMA of Th1 and Th2 cells respectively. The purpose of the present study was to examine whether the qualitative differences in immune responses stimulated by these chemicals is reflected by variable affects on Langerhans cells (LC) in situ. Mice were exposed to concentrations of DNCB (1%) and TMA (50%) which caused equivalent levels of contact sensitization. Under these conditions topical exposure to DNCB, but not to TMA, or to vehicle alone, resulted in increased expression by LC of Ia antigen. Similar treatment with an irritant concentration (20%) of sodium dodecyl sulphate failed to influence Ia expression by LC. These data indicate that, at concentrations which induce similar levels of skin sensitization, not all contact allergens cause rapid changes in LC Ia expression, and that the qualitative differences in immune responses elicited by chemical allergens DNCB and TMA is associated with variable effects on LC.
化学过敏原在它们优先引发的超敏反应类型方面存在差异。一些化学物质，如偏苯三酸酐（TMA），有可能引发接触性和呼吸道超敏反应。其他化学物质仅引起接触性过敏。例如，强效接触性过敏原2,4-二硝基氯苯（DNCB）似乎不会引发呼吸道致敏。在先前的研究中，我们已经表明，在引流淋巴结活化和接触致敏方面具有同等免疫原性的条件下，将小鼠局部暴露于TMA和DNCB会导致性质不同的抗体反应。虽然这些化学物质引发了同等强度的IgG抗半抗原抗体反应，但只有TMA诱导了IgE反应，而DNCB则引发了明显更强的IgG2a反应。这些数据与DNCB和TMA分别优先激活Th1和Th2细胞一致。本研究的目的是检查这些化学物质刺激的免疫反应的定性差异是否通过对原位朗格汉斯细胞（LC）的不同影响而得以体现。将小鼠暴露于引起同等程度接触致敏的DNCB（1%）和TMA（50%）浓度下。在这些条件下，局部暴露于DNCB而非TMA或单独的赋形剂，会导致LC的Ia抗原表达增加。用刺激性浓度（20%）的十二烷基硫酸钠进行类似处理未能影响LC的Ia表达。这些数据表明，在诱导相似程度皮肤致敏的浓度下，并非所有接触性过敏原都会导致LC Ia表达迅速变化，并且化学过敏原DNCB和TMA引发的免疫反应的定性差异与对LC的不同影响有关。
