Yi F C, Chua K Y, Cheong N, Shek L P, Lee B W
Department of Paediatrics, National University of Singapore, Singapore, Singapore.
Clin Exp Allergy. 2004 Nov;34(11):1762-7. doi: 10.1111/j.1365-2222.2004.02107.x.
Blo t 5 is a major allergen of Blomia tropicalis and its complementary DNA (cDNA) has been expressed in both prokaryotic and eukaryotic expression systems. Although the recombinant Blo t 5 has been well characterized, relatively less is known about its native counterparts and the allergenicity comparison of the native and recombinant Blo t 5 allergens has not been reported.
The aims of this study are to characterize the native counterpart of Blo t 5, and compare the allergenicity of native and recombinant Blo t 5 by in vivo and in vitro assays.
Native Blo t 5 were purified by immuno-affinity chromatography and characterized by proteomic means. The allergenicity of the allergen was evaluated by skin prick tests, human IgE ELISA, ELISA inhibition and histamine release assays.
Native Blo t 5 consists of at least five distinct isoforms, ranging from pI 3 to 5.5. Allergenicity assessment of recombinant and native Blo t 5 based on skin reaction, IgE-binding capacity and histamine release in allergic individuals indicated that there was a good correlation between both forms of Blo t 5 in general. However, data from IgE ELISA inhibition assay revealed the presence of additional unique IgE epitopes in native Blo t 5.
At least five distinct isoforms of Blo t 5 have been identified. Comparative assessment of native and recombinant Blo t 5 revealed that the allergenicity of these two forms was similar but not completely identical suggesting that the various isoforms of native Blo t 5 may exhibit additional unique IgE epitopes.
Blo t 5是热带无爪螨的一种主要变应原，其互补DNA（cDNA）已在原核和真核表达系统中表达。尽管重组Blo t 5已得到充分表征，但对其天然对应物的了解相对较少，且尚未报道天然和重组Blo t 5变应原的变应原性比较。
本研究旨在表征Blo t 5的天然对应物，并通过体内和体外试验比较天然和重组Blo t 5的变应原性。
通过免疫亲和色谱法纯化天然Blo t 5，并采用蛋白质组学方法进行表征。通过皮肤点刺试验、人IgE ELISA、ELISA抑制试验和组胺释放试验评估变应原变应原性。
天然Blo t 5由至少五种不同的亚型组成，pH值范围为3至5.5。基于过敏个体的皮肤反应、IgE结合能力和组胺释放对重组和天然Blo t 5进行的变应原性评估表明，两种形式的Blo t 5总体上具有良好的相关性。然而，IgE ELISA抑制试验的数据显示天然Blo t 5中存在额外的独特IgE表位。
已鉴定出至少五种不同的Blo t 5亚型。天然和重组Blo t 5的比较评估表明，这两种形式的变应原性相似但不完全相同，这表明天然Blo t 5的各种亚型可能表现出额外的独特IgE表位。
