Clinical Laboratory, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China.
Pediatric Gastroenterology Department, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China.
Clin Exp Allergy. 2019 Dec;49(12):1605-1614. doi: 10.1111/cea.13489. Epub 2019 Sep 12.
Helicobacter pylori neutrophil-activating protein (NAP) is an immune modulator with anti-Th2 inflammation activity that can be used to prevent IgE-mediated allergic reactions. Cholera toxin B (CTB) is a mucosal adjuvant that can induce antigen tolerance. Bacillus subtilis spores are an ideal vehicle for the oral delivery of heterologous antigens.
We investigated the therapeutic effect of recombinant NAP B subtilis spores on peanut allergies in a mouse model.
Female C3H/HeJ mice were sensitized and challenged with peanut extract by oral administration. Before challenge, recombinant NAP and CTB-NAP (CNAP) spores were orally administered to sensitized mice for 4 weeks. Faecal peanut-specific IgA and serum-specific IgE, IgG1, and IgG2a levels were measured, and the intestinal microbiota was analysed. Mice were intraperitoneally injected with anti-CD25 antibodies for regulatory T cell (Treg) depletion to evaluate the efficacy of Tregs in preventing peanut allergy. After challenge, anaphylactic reactions, plasma histamine, Tregs, and splenocyte interleukin (IL)-10, IL-4, IL-5 and interferon-γ (IFN-γ) levels were evaluated.
After 4 weeks of recombinant spore treatment, faecal IgA levels and serum IgG2a levels were increased, while serum IgG1 and IgE levels were reduced. Intestinal microbiota analysis revealed that CNAP spores increased the taxonomic abundance of Firmicutes at the phylum level and Clostridia at the class level. After challenge, the administration of NAP or CNAP spores to mice was found to ameliorate anaphylactic reactions and decrease plasma histamine levels. Administration of NAP or CNAP spores also enhanced IL-10 and IFN-γ secretion, and suppressed IL-4 and IL-5 secretion. The protective effect of CNAP spores was more pronounced than that of NAP spores; this therapeutic effect was lost after Treg depletion.
Recombinant NAP spores successfully suppressed Th2 inflammation via the up-regulation of Tregs; this may serve as a novel therapeutic approach for treating food allergies.
幽门螺杆菌中性粒细胞激活蛋白（NAP）是一种具有抗 Th2 炎症活性的免疫调节剂，可用于预防 IgE 介导的过敏反应。霍乱毒素 B（CTB）是一种黏膜佐剂，可诱导抗原耐受。枯草芽孢杆菌孢子是递呈异源抗原的口服载体的理想选择。
我们在花生过敏的小鼠模型中研究了重组 NAP 枯草芽孢杆菌孢子的治疗效果。
雌性 C3H/HeJ 小鼠经口给予花生提取物致敏和激发。激发前，用重组 NAP 和 CTB-NAP（CNAP）孢子对致敏小鼠进行 4 周口服治疗。检测粪便花生特异性 IgA 和血清特异性 IgE、IgG1 和 IgG2a 水平，并分析肠道菌群。用抗 CD25 抗体腹腔注射以耗尽调节性 T 细胞（Treg），评估 Treg 对预防花生过敏的疗效。激发后，评估过敏反应、血浆组胺、Treg 以及脾细胞白细胞介素（IL）-10、IL-4、IL-5 和干扰素-γ（IFN-γ）水平。
重组孢子治疗 4 周后，粪便 IgA 水平和血清 IgG2a 水平升高，而血清 IgG1 和 IgE 水平降低。肠道菌群分析显示，CNAP 孢子增加了门水平厚壁菌门和纲水平梭菌属的分类丰度。激发后，NAP 或 CNAP 孢子给药可改善过敏反应并降低血浆组胺水平。NAP 或 CNAP 孢子给药还增强了 IL-10 和 IFN-γ的分泌，抑制了 IL-4 和 IL-5 的分泌。CNAP 孢子的保护作用比 NAP 孢子更明显；Treg 耗尽后，这种治疗效果丧失。
重组 NAP 孢子通过上调 Treg 成功抑制了 Th2 炎症；这可能成为治疗食物过敏的一种新的治疗方法。
