Department of Respiratory Medicine, Children's Hospital of Nanjing Medical University, Nanjing, China.
Pediatric Department, Northern Jiangsu People's Hospital, Yangzhou, China.
Front Immunol. 2024 Mar 27;15:1325998. doi: 10.3389/fimmu.2024.1325998. eCollection 2024.
The house dust mite (HDM) is widely recognized as the most prevalent allergen in allergic diseases. Allergen-specific immunotherapy (AIT) has been successfully implemented in clinical treatment for HDM. Hypoallergenic B-cell epitope-based vaccine designed by artificial intelligence (AI) represents a significant progression of recombinant hypoallergenic allergen derivatives.
The three-dimensional protein structure of Der f 36 was constructed using Alphafold2. AI-based tools were employed to predict B-cell epitopes, which were subsequently verified through IgE-reaction testing. Hypoallergenic Der f 36 was then synthesized, expressed, and purified. The reduced allergenicity was assessed by enzyme-linked immunosorbent assay (ELISA), immunoblotting, and basophil activation test. T-cell response to hypoallergenic Der f 36 and Der f 36 was evaluated based on cytokine expression in the peripheral blood mononuclear cells (PBMCs) of patients. The immunogenicity was evaluated and compared through rabbit immunization with hypoallergenic Der f 36 and Der f 36, respectively. The inhibitory effect of the blocking IgG antibody on the specific IgE-binding activity and basophil activation of Der f 36 allergen was also examined.
The final selected non-allergic B-cell epitopes were 25-48, 57-67, 107-112, 142-151, and 176-184. Hypoallergenic Der f 36 showed significant reduction in IgE-binding activity. The competitive inhibition of IgE-binding to Der f 36 was investigated using the hypoallergenic Der f 36, and only 20% inhibition could be achieved, which is greatly reduced when compared with inhibition by Der f 36 (98%). The hypoallergenic Der f 36 exhibited a low basophil-stimulating ratio similar to that of the negative control, and it could induce an increasing level of IFN-γ but not Th2 cytokines IL-5 and IL-13 in PBMCs. The vaccine-specific rabbit blocking IgG antibodies could inhibit the patients' IgE binding and basophil stimulation activity of Derf 36.
This study represents the first application of an AI strategy to facilitate the development of a B-cell epitope-based hypoallergenic Der f 36 vaccine, which may become a promising immunotherapy for HDM-allergic patients due to its reduced allergenicity and its high immunogenicity in inducing blocking of IgG.
屋尘螨（HDM）被广泛认为是过敏性疾病中最普遍的过敏原。过敏原特异性免疫疗法（AIT）已成功应用于 HDM 的临床治疗。基于人工智能（AI）设计的低变应原性 B 细胞表位疫苗代表了重组低变应原过敏原衍生物的重大进展。
使用 Alphafold2 构建 Der f 36 的三维蛋白质结构。使用 AI 工具预测 B 细胞表位，并通过 IgE 反应测试进行验证。然后合成、表达和纯化低变应原性 Der f 36。通过酶联免疫吸附试验（ELISA）、免疫印迹和嗜碱性粒细胞活化试验评估其变应原性降低程度。根据患者外周血单核细胞（PBMC）中的细胞因子表达，评估低变应原性 Der f 36 和 Der f 36 对 T 细胞的反应。通过分别用低变应原性 Der f 36 和 Der f 36 对兔子进行免疫，评估其免疫原性并进行比较。还研究了阻断 IgG 抗体对 Der f 36 过敏原特异性 IgE 结合活性和嗜碱性粒细胞活化的抑制作用。
最终选择的非变应性 B 细胞表位为 25-48、57-67、107-112、142-151 和 176-184。低变应原性 Der f 36 显示出 IgE 结合活性的显著降低。使用低变应原性 Der f 36 研究了 IgE 结合的竞争抑制作用，仅能达到 20%的抑制率，与 Der f 36（98%）的抑制作用相比大大降低。低变应原性 Der f 36 诱导的嗜碱性粒细胞刺激比阴性对照低，并且能够在 PBMC 中诱导 IFN-γ水平升高，但不能诱导 Th2 细胞因子 IL-5 和 IL-13。疫苗特异性兔阻断 IgG 抗体可抑制患者 Derf 36 的 IgE 结合和嗜碱性粒细胞刺激活性。
本研究代表了首次应用 AI 策略来促进基于 B 细胞表位的低变应原性 Der f 36 疫苗的开发，由于其变应原性降低和诱导 IgG 阻断的高免疫原性，它可能成为 HDM 过敏患者的一种有前途的免疫疗法。
