Department of Allergy and Clinical Immunology, National Research Institute for Child Health and Development, Tokyo, Japan; Department of Pediatrics, Jikei University School of Medicine, Tokyo, Japan.
Department of Allergy and Clinical Immunology, National Research Institute for Child Health and Development, Tokyo, Japan; First Department of Medicine, Tokyo Women's Medical University, Tokyo, Japan.
Allergol Int. 2018 Jul;67(3):380-387. doi: 10.1016/j.alit.2018.01.003. Epub 2018 Feb 10.
Direct contact of food proteins with eczematous lesions is thought to be the main cause of epicutaneous sensitization. To further investigate the development and pathogenesis of food allergy in vivo, a good mouse model of epicutaneous sensitization is needed. However, a fundamental problem in that regard is that the optimal age for epicutaneous sensitization of mice is unknown. In this study, we attempted to elucidate that optimal age.
Dorsal skin of wild-type BALB/c female mice (1, 3, 8 and 24 weeks old) was shaved, depilated and tape-stripped. A Finn chamber containing a 20-μl-aliquot of 20-mg/ml (OVA) was applied to the tape-stripped skin on 3 consecutive days/week, for 3 weeks. The body temperature was measured after intraperitoneal OVA challenge. Serum OVA-specific IgE titers and OVA-induced cytokine production by spleen cells were measured by ELISA. Dendritic cells (DCs) that migrated to the draining lymph nodes were quantified by FITC-labeled OVA and flow cytometry. The mRNA expression levels in the dorsal skin were measured by qPCR.
A significant age-dependent body temperature decline was observed after OVA challenge. The serum OVA-specific IgE titer, OVA-induced cytokine production (i.e., IL-4, IL-5 and IL-13) by spleen cells, and number of FITC-OVA-engulfing DCs increased with age. In addition, mRNA for IL-33, but not TSLP or IL-25, was significantly induced in the skin by tape-stripping and increased with age.
Twenty-four-week-old mice showed the greatest DC migration, Th2 polarization, IgE production and body temperature decline. Skin-derived IL-33 is likely to play key roles in those changes.
人们认为食物蛋白与湿疹样病变的直接接触是导致表皮致敏的主要原因。为了进一步研究食物过敏的发展和发病机制，需要建立一个良好的表皮致敏的小鼠模型。然而，在这方面存在一个根本问题，即未知表皮致敏的最佳小鼠年龄。在这项研究中，我们试图阐明这一最佳年龄。
将野生型 BALB/c 雌性小鼠（1、3、8 和 24 周龄）的背部皮肤剃毛、脱毛和胶带撕脱。将含有 20-μl-20-mg/ml（OVA）的 Finn 室应用于连续 3 天/周、共 3 周的胶带撕脱皮肤。在腹腔内 OVA 挑战后测量体温。通过 ELISA 测量血清 OVA 特异性 IgE 滴度和脾细胞产生的 OVA 诱导细胞因子。通过 FITC 标记的 OVA 和流式细胞术定量迁移到引流淋巴结的树突状细胞（DC）。通过 qPCR 测量背部皮肤的 mRNA 表达水平。
OVA 挑战后，体温显著呈年龄依赖性下降。血清 OVA 特异性 IgE 滴度、OVA 诱导的脾细胞细胞因子产生（即 IL-4、IL-5 和 IL-13）以及 FITC-OVA 吞噬的 DC 数量随年龄增加而增加。此外，皮肤中 IL-33 的 mRNA 表达在胶带撕脱后显著增加，且随年龄增加而增加，但 TSLP 和 IL-25 的 mRNA 表达未增加。
24 周龄的小鼠显示出最大的 DC 迁移、Th2 极化、IgE 产生和体温下降。皮肤衍生的 IL-33 可能在这些变化中起关键作用。
