IL-25 as a master regulator of extrafollicular benign IgE

项目摘要 我们最近发现，B1细胞在蠕虫感染后产生大量的IgE，并且B1细胞 IgE的作用与B2抗原(Ag)特异性的IgE相反。B1细胞IgE通过抑制肥大细胞脱颗粒 FCεRI的竞争。最近公布的数据还表明，这种“良性”的B1细胞IgE阻断了B2细胞的IgE- 介导性卵子抑制。这种B1细胞IgE的产生有助于蠕虫的免疫逃避和益处 生命和繁殖。此外，我们还表明，蠕虫诱导的警报蛋白IL-25负责 在体内诱导B1IgE的产生。为了实现以下三个目标，将进一步调查这些发现。 在目标1中，使用一种新开发的小鼠来制造标记有标志的分泌型IgE，我们将确定 蠕虫感染后B1细胞与B2细胞IgE的相对水平。将检查V(D)J区序列 蠕虫感染前后的B1细胞和B2细胞。将检测B1细胞IgE对其保护作用 蠕虫感染对过敏性呼吸道模型的影响。目标2将研究IL-25B1IgE的机制 增强功能。应用FLAG-IgE系统检测IL-25R-/-B1细胞重组时产生的IgE水平 将其与WT B2细胞进行比较。IL-25R在B1细胞室的表达分析将被评估。 我们将研究B1细胞中的IL-25信号，特别是关于STAT5和STAT3的诱导。目标3 将进入人类系统，初步数据显示部分产生IgE的B细胞上有IL-25R 对从扁桃体中分离的IL-25有反应。IL25R+B细胞的表面表型将更加完整 对已发表的“类B1”人类B细胞标记物进行了表征和比较。PBMC和脐带血B1细胞将 接受IL-25/IL-25R信号转导评估。我们还将检测过敏和非过敏患者PBMC中的B细胞。 过敏者确定两者的IL25R+B细胞水平是否有差异 人群，这可能表明对过敏敏感的偏向。加深对非特异性IgE的认识 诱导最终可能转化为更有效的过敏性疾病治疗。

Project Summary We have recently found that B1 cells make large amounts of IgE post-helminth infection and that the B1 cell IgE acts contrary to B2 antigen (Ag)-specific IgE. B1 cell IgE prevents mast cell degranulation through competition for the FcεRI. Recently published data also shows that this “benign” B1 cell IgE blocks B2 cell IgE- mediated egg suppression. This B1 cell IgE production assists the helminth in immune evasion and benefits life and reproduction. Further, we show that the helminth-induced alarmin, IL-25, is responsible for the induction of B1 IgE production in vivo. These findings will be further investigated with the following three aims. In Aim 1, using a newly developed mouse that makes FLAG-tagged secreted IgE, we will determine the relative levels of B1 cell vs B2 cell IgE seen post helminth infection. V(D)J region sequencing will be examined for B1 cells and B2 cells before and after helminth infection. B1 cell IgE will be examined for its protective effects after helminth infection in allergic airway models. Aim 2 will examine the mechanism of IL-25 B1 IgE enhancement. Using the FLAG-IgE system the levels of IgE made by IL-25R-/- B1 cells when reconstituting with WT B2 cells will be compared. IL-25R expression analysis on the B1 cell compartments will be assessed. IL-25 signaling in B1 cells will be examined, particularly with respect to STAT5 and STAT3 induction. Aim 3 will move into the human system where preliminary data shows IL-25R on a portion of B cells that produce IgE in response to IL-25 isolated from tonsil. The surface phenotype of the IL25R+ B cell will be more completely characterized and compared to published “B1-like” human B cell markers. PBMC and cord blood B1 cells will be assessed for IL-25/IL-25R signaling. We will additionally examine B cells in PBMC from allergic vs non- allergic individuals to determine if there are differences in the levels of the IL25R+ B cells in the two populations, which could indicate a bias towards allergic sensitivity. A better understanding of non-specific IgE induction could ultimately translate into more effective allergic disease treatments.