Shin Kwang Hyun, Jeong Kyoung Yong, Hong Chein-Soo, Yong Tai-Soon
Department of Environmental Medical Biology and Institute of Tropical Medicine, Arthropods of Medical Importance Resource Bank, Yonsei University College of Medicine, Seoul, Korea.
Korean J Parasitol. 2009 Mar;47(1):31-6. doi: 10.3347/kjp.2009.47.1.31. Epub 2009 Mar 12.
Cockroaches have been recognized as a major cause of asthma. Bla g 4 is one of the most important German cockroach allergens. The aim of this study is to investigate IgE reactivity to the recombinant Bla g 4 (rBla g 4) in the sera of allergic patients and identify linear IgE binding epitope. For protein expression, full-length Bla g 4 (EF202172) was divided into 5 overlapping peptide fragments (E1: aa 1-100, E2: aa 34-77, E3: aa 74-117, E4: aa 114-156, and E5: aa 153-182). The full-length and 5 peptide fragments of Bla g 4 was generated by PCR and over-expressed in E. coli BL21 (DE3). The IgE binding reactivities of the full-length and peptide fragments were measured by ELISA using 32 serum samples of cockroach allergy. The sera of 8 patients (25%) reacted with rBla g 4. Four sera (100%) showed IgE-binding reactivity to full-length and peptide fragment 4, and 2 sera (50%) reacted with peptide fragment 2. One (20%) serum reacted with peptide fragment 3. The results of ELISA using overlapping recombinant fragments indicated that the epitope region was located at amino acid sequences 34-73 and 78-113, and major IgE epitope of Bla g 4 was located at amino acid sequences 118-152 of C-terminal. B-cell epitope analysis of German cockroach allergen Bla g 4 could contribute to the strategic development of more specific and potentially efficacious immunotherapy.
蟑螂已被公认为是哮喘的主要诱因之一。Bla g 4是德国小蠊最重要的过敏原之一。本研究旨在调查过敏患者血清中针对重组Bla g 4（rBla g 4）的IgE反应性，并鉴定线性IgE结合表位。为进行蛋白表达，将全长Bla g 4（EF202172）分为5个重叠肽段（E1：氨基酸1 - 100，E2：氨基酸34 - 77，E3：氨基酸74 - 117，E4：氨基酸114 - 156，以及E5：氨基酸153 - 182）。通过PCR生成Bla g 4的全长及5个肽段，并在大肠杆菌BL21（DE3）中进行过表达。使用32份蟑螂过敏患者的血清样本，通过ELISA检测全长及肽段的IgE结合反应性。8例患者（25%）的血清与rBla g 4发生反应。4份血清（100%）对全长及肽段4显示出IgE结合反应性，2份血清（50%）与肽段2发生反应。1份血清（20%）与肽段3发生反应。使用重叠重组片段进行ELISA的结果表明，表位区域位于氨基酸序列34 - 73和78 - 113，Bla g 4的主要IgE表位位于C末端的氨基酸序列118 - 152。对德国小蠊过敏原Bla g 4的B细胞表位分析有助于制定更具特异性且可能有效的免疫治疗策略。
