Weghofer M, Dall'Antonia Y, Grote M, Stöcklinger A, Kneidinger M, Balic N, Krauth M-T, Fernández-Caldas E, Thomas W R, van Hage M, Vieths S, Spitzauer S, Horak F, Svergun D I, Konarev P V, Valent P, Thalhamer J, Keller W, Valenta R, Vrtala S
Division of Immunopathology, Department of Pathophysiology, Center for Physiology and Pathophysiology, Medical University of Vienna, Vienna, Austria.
Allergy. 2008 Jun;63(6):758-67. doi: 10.1111/j.1398-9995.2008.01647.x.
The house dust mite (HDM) Dermatophagoides pteronyssinus is a major allergen source eliciting allergic asthma. The aim of the study was to identify new important HDM allergens associated with allergic asthma.
A cDNA coding for a new mite allergen, designated Der p 21, was isolated using immunoglobulin E (IgE) antibodies from patients with allergic asthma out of a D. pteronyssinus expression cDNA library and expressed in Escherichia coli.
Circular dichroism analysis of the purified allergen showed that rDer p 21 (14 726 Da) is one of the few mite allergens with an alpha-helical secondary structure. The protein exhibited high thermal stability and refolding capacity, and, as determined by small angle X-ray scattering, formed a dimer consisting of two flat triangles. rDer p 21 bound high levels of patients' IgE antibodies and showed high allergenic activity in basophil activation experiments. Rabbit anti-Der p 21 IgG antibodies inhibited mite-allergic patients' IgE binding and allowed the ultrastructural localization of the allergen in the midgut (epithelium, lumen and faeces) of D. pteronyssinus by immunogold electron microscopy. Der p 21 revealed sequence homology with group 5 mite allergens, but IgE and IgG reactivity data and cross-inhibition studies identified it as a new mite allergen.
Der p 21 is a new important mite allergen which is liberated into the environment via faecal particles and hence may be associated with allergic asthma.
屋尘螨（HDM）粉尘螨是引发过敏性哮喘的主要过敏原来源。本研究的目的是鉴定与过敏性哮喘相关的新的重要屋尘螨过敏原。
使用来自过敏性哮喘患者的免疫球蛋白E（IgE）抗体，从粉尘螨表达cDNA文库中分离出编码一种新的螨过敏原（命名为Der p 21）的cDNA，并在大肠杆菌中表达。
对纯化过敏原的圆二色性分析表明，重组Der p 21（14 726道尔顿）是少数具有α-螺旋二级结构的螨过敏原之一。该蛋白表现出高热稳定性和重折叠能力，并且通过小角X射线散射测定，形成了由两个扁平三角形组成的二聚体。重组Der p 21结合了高水平的患者IgE抗体，并在嗜碱性粒细胞活化实验中显示出高致敏活性。兔抗Der p 21 IgG抗体抑制螨过敏患者的IgE结合，并通过免疫金电子显微镜使过敏原在粉尘螨中肠（上皮、管腔和粪便）中的超微结构定位。Der p 21与第5组螨过敏原显示出序列同源性，但IgE和IgG反应性数据以及交叉抑制研究将其鉴定为一种新的螨过敏原。
Der p 21是一种新的重要螨过敏原，它通过粪便颗粒释放到环境中，因此可能与过敏性哮喘有关。
