Center for Translational Immunology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands.
Department of Dermatology/Allergology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands.
Allergy. 2021 Sep;76(9):2753-2764. doi: 10.1111/all.14897. Epub 2021 May 24.
Specific IgE against a peanut 2S albumin (Ara h 2 or 6) is the best predictor of clinically relevant peanut sensitization. However, sIgE levels of peanut allergic and those of peanut sensitized but tolerant patients partly overlap, highlighting the need for improved diagnostics to prevent incorrect diagnosis and consequently unnecessary food restrictions. Thus, we sought to explore differences in V(D)J gene transcripts coding for peanut 2S albumin-specific monoclonal antibodies (mAbs) from allergic and sensitized but tolerant donors.
2S albumin-binding B-cells were single-cell sorted from peripheral blood of peanut allergic (n=6) and tolerant (n=6) donors sensitized to Ara h2 and/or 6 (≥ 0.1 kU/l) and non-atopic controls (n=5). h 2 and/or 6 (≥ 0.1 kU/l). Corresponding h heavy and light chain gene transcripts were heterologously expressed as mAbs and tested for specificity to native Ara h2 and 6. HCDR3 sequence motifs were identified by Levenshtein distances and hierarchically clustering.
The frequency of 2S albumin-binding B cells was increased in allergic (median: 0.01%) compared to tolerant (median: 0.006%) and non-atopic donors (median: 0.0015%, p = 0.008). The majority of mAbs (74%, 29/39) bound specifically to Ara h 2 and/or 6. Non-specific mAbs (9/10) were mainly derived from non-atopic controls. In allergic donors, 89% of heavy chain gene transcripts consisted of VH3 family genes, compared with only 54% in sensitized but tolerant and 63% of non-atopic donors. Additionally, certain HCDR3 sequence motifs were associated with allergy (n = 4) or tolerance (n = 3) upon hierarchical clustering of their Levenshtein distances.
Peanut allergy is associated with dominant VH3 family gene usage and certain public antibody sequences (HCDR3 motifs).
针对花生 2S 白蛋白（Ara h 2 或 6）的特异性 IgE 是临床相关花生致敏的最佳预测因子。然而，花生过敏患者和花生致敏但耐受患者的 sIgE 水平部分重叠，这凸显了需要改进诊断方法以避免误诊，从而避免不必要的食物限制。因此，我们试图探索来自过敏和致敏但耐受供体的花生 2S 白蛋白特异性单克隆抗体（mAb）的 V(D)J 基因转录本之间的差异。
从花生过敏（n=6）和耐受（n=6）患者以及非过敏对照者（n=5）的外周血中，通过单细胞分选技术，从外周血中分离出 2S 白蛋白结合 B 细胞。致敏至 Ara h2 和/或 6（≥0.1 kU/l）。相应的 h 重链和轻链基因转录本被异源表达为 mAbs，并测试其对天然 Ara h2 和 6 的特异性。通过 Levenshtein 距离和层次聚类来确定 HCDR3 序列基序。
与耐受（中位数：0.006%）和非过敏对照者（中位数：0.0015%，p=0.008）相比，过敏者（中位数：0.01%）中 2S 白蛋白结合 B 细胞的频率增加。大多数 mAbs（74%，29/39）特异性结合 Ara h 2 和/或 6。非特异性 mAbs（9/10）主要来源于非过敏对照者。在过敏供体中，89%的重链基因转录本由 VH3 家族基因组成，而在致敏但耐受的供体中仅为 54%，在非过敏供体中为 63%。此外，通过对 Levenshtein 距离进行层次聚类，某些 HCDR3 序列基序与过敏（n=4）或耐受（n=3）相关。
花生过敏与优势 VH3 家族基因的使用和某些公共抗体序列（HCDR3 基序）相关。
