Department of Molecular Parasitology, Humboldt-University Berlin, Berlin, Germany.
Clin Exp Allergy. 2009 Oct;39(10):1585-96. doi: 10.1111/j.1365-2222.2009.03290.x. Epub 2009 Jun 8.
Some helminth infections are negatively associated with the prevalence of allergic disorders, arguing for a modulation of allergic reactions by the parasites, depending on the worm species, intensity and phase of infection and the type of disease.
The aim of this study was to analyse the influence of a chronic infection with the gastrointestinal nematode Heligmosomoides polygyrus, in a murine model of allergic airway disease and of atopic dermatitis (AD), respectively.
Mice were infected with H. polygyrus and systemically sensitized with the model allergen ovalbumin. Subsequently, the animals were challenged with the allergen either via the airways for induction of airway disease, or via skin patches for induction of dermatitis.
Mice concomitantly infected with H. polygyrus showed diminished eosinophil and lymphocyte recruitment into the lungs and decreased allergen-specific IgE levels when compared with sensitized and airway challenged controls. In addition, animals showed a trend towards reduced airway hyper-reactivity. In contrast, no significant differences in the severity of eczematous skin lesions were observed between infected and control animals in the AD model. Although H. polygyrus infection reduced CD8+ and CD4+ T-cell infiltration into the skin and production of allergen-specific IgE, mast cell recruitment was significantly increased in worm-infected mice in the dermatitis model. The worm infection was associated with significantly elevated numbers of Foxp3+ regulatory T cells (Treg) in peribronchial lymph nodes in H. polygyrus-infected sensitized and airway challenged mice. In contrast, Treg cells were basically absent in eczematous skin and their number was not increased in skin-draining lymph nodes of mice with experimental dermatitis.
Infection with the gastrointestinal nematode used in our study leads to significant inhibition of mucosa-associated but not cutaneous allergic reactions, pointing to a site specificity of the immunomodulation exerted by helminths. This finding might be an important aspect for future considerations of helminths for treatment of allergic diseases.
一些寄生虫感染与过敏疾病的患病率呈负相关，这表明寄生虫会根据蠕虫种类、感染强度和阶段以及疾病类型来调节过敏反应。
本研究旨在分析慢性感染胃肠道线虫 Heligmosomoides polygyrus 对过敏性气道疾病和特应性皮炎（AD）的影响。
将小鼠感染 H. polygyrus 并用模型过敏原卵清蛋白进行系统致敏。随后，通过气道对动物进行过敏原攻击以诱导气道疾病，或通过皮肤贴片诱导皮炎。
与致敏和气道攻击对照组相比，同时感染 H. polygyrus 的小鼠肺部嗜酸性粒细胞和淋巴细胞募集减少，过敏原特异性 IgE 水平降低。此外，动物表现出气道高反应性降低的趋势。相比之下，在 AD 模型中，感染组和对照组之间在湿疹样皮肤病变的严重程度上没有观察到显著差异。尽管 H. polygyrus 感染减少了 CD8+和 CD4+T 细胞浸润到皮肤和过敏原特异性 IgE 的产生，但在皮炎模型中，蠕虫感染的小鼠中肥大细胞募集显著增加。在 H. polygyrus 感染的致敏和气道攻击的小鼠中，蠕虫感染与支气管周围淋巴结中显著增加的 Foxp3+调节性 T 细胞（Treg）数量相关。相比之下，在特应性皮炎小鼠的湿疹皮肤中基本上没有 Treg 细胞，并且在皮肤引流淋巴结中它们的数量也没有增加。
本研究中使用的胃肠道线虫感染导致黏膜相关的过敏反应显著抑制，但不影响皮肤过敏反应，这表明寄生虫的免疫调节具有部位特异性。这一发现可能是未来考虑寄生虫治疗过敏疾病的一个重要方面。
