Allergy and Immunology Section, CSIR-Institute of Genomics and Integrative Biology, New Delhi 110007, India; Academy of Scientific and Innovative Research, Ghaziabad, U.P., 201002, India.
Allergy and Immunology Section, CSIR-Institute of Genomics and Integrative Biology, New Delhi 110007, India.
Immunobiology. 2021 Nov;226(6):152146. doi: 10.1016/j.imbio.2021.152146. Epub 2021 Oct 15.
Immune epitopes of allergens are pivotal for development of novel diagnostic and therapeutic modalities. Present study aims to identify antigenic determinants of Per a 5, a clinically relevant cross reactive cockroach allergen.
The three dimensional structure of Per a 5 was modelled using Modeller 9v11 software. A combination of sequence and structure based computational tools were employed for predicting B cell epitopes. Epitopes were synthesized and immunoreactivity was assessed by ELISA using cockroach hypersensitive patient's sera. Cross-reactivity potential of predicted epitopes was assessed with SDAP and ConSurf and validated by IgE ELISA with fungal and mite hypersensitive patient's sera.
Per a 5 structure exhibited good quality factor in ERRAT and high stereochemical stability. In silico analysis revealed six B cell epitopes (BC-P1 to P6). BC-P3 demonstrated significant IgE binding followed by BC-P2 and BC-P1 with cockroach hypersensitive patient's sera. Per a 5 epitopes demonstrate considerable similarity with broad spectrum of allergens from fungal, mites, helminths, fruits and nuts. Analysis of PD values indicate BC-P4 to be well conserved among dust mite and helminth GSTs (8.89, 10.63 and 10.69 with D. pteronyssinus, W. bancrofti and F. hepatica respectively). ConSurf analysis of Per a 5 revealed specific enrichment of evolutionarily similar amino acid residues in BC-P2 (with fungal and mite GSTs) and BC-P4 (with mite and helminth GSTs). Further, IgE binding analysis of epitopes demonstrate BC-P2, BC-P3 and BC-P5 as high IgE binders in fungal hypersensitive sera while BC-P1, BC-P2, BC-P4 and BC-P5 demonstrated significant IgE binding with mite hypersensitive sera.
Among the predicted epitopes, BC-P3 demonstrates maximal IgE binding ability. Computational analysis suggests strong evolutionary conservation and cross reactive potential of BC-P4 with allergens in dust mite and helminths. ELISA highlights predictive potential of analysing evolutionarily conserved residues for uncovering potentially cross reactive antigenic determinants.
Immune epitopes of Per a 5 were identified for aiding molecular diagnosis and potential cross reactivity.
过敏原的免疫表位是开发新型诊断和治疗方法的关键。本研究旨在鉴定 Per a 5（一种具有临床相关性的交叉反应性蟑螂过敏原）的抗原决定簇。
使用 Modeller 9v11 软件对 Per a 5 的三维结构进行建模。采用序列和结构相结合的计算工具预测 B 细胞表位。合成表位并使用蟑螂过敏患者的血清通过 ELISA 评估其免疫反应性。使用 SDAP 和 ConSurf 评估预测表位的交叉反应潜力，并使用真菌和螨虫过敏患者的血清通过 IgE ELISA 进行验证。
Per a 5 的结构在 ERRAT 中表现出良好的质量因子，并且具有较高的立体化学稳定性。计算机分析显示了六个 B 细胞表位（BC-P1 到 P6）。BC-P3 与蟑螂过敏患者的血清具有显著的 IgE 结合，其次是 BC-P2 和 BC-P1。Per a 5 表位与真菌、螨虫、蠕虫、水果和坚果的广谱过敏原具有相当大的相似性。PD 值分析表明，BC-P4 在尘螨和蠕虫 GST 中具有良好的保守性（与 D. pteronyssinus、W. bancrofti 和 F. hepatica 分别为 8.89、10.63 和 10.69）。Per a 5 的 ConSurf 分析显示，BC-P2（与真菌和螨虫 GSTs）和 BC-P4（与螨虫和蠕虫 GSTs）中特定的进化相似氨基酸残基丰富。此外，表位的 IgE 结合分析表明，BC-P2、BC-P3 和 BC-P5 是真菌过敏患者血清中的高 IgE 结合物，而 BC-P1、BC-P2、BC-P4 和 BC-P5 与螨虫过敏患者血清具有显著的 IgE 结合。
在预测的表位中，BC-P3 显示出最大的 IgE 结合能力。计算分析表明，BC-P4 与尘螨和蠕虫中的过敏原具有很强的进化保守性和交叉反应潜力。ELISA 强调了分析进化保守残基以揭示潜在的交叉反应性抗原决定簇的预测潜力。
鉴定了 Per a 5 的免疫表位，有助于分子诊断和潜在的交叉反应性。
