Nutritional Science Institute, Morinaga Milk Industry Co., Ltd. Zama, Kanagawa, 252-8583, Japan.
Immun Inflamm Dis. 2015 Sep;3(3):280-8. doi: 10.1002/iid3.67. Epub 2015 Jun 16.
IgE-mediated mast cell activation is the trigger of anaphylaxis in humans, whereas it is known that not only IgE but also IgG can induce anaphylaxis in mice. In our preliminary experiments, the expression of a murine basophil identification marker, CD200R3, on antigen-sensitized basophils decreased following specific antigen challenge. Interestingly, this decrease did not always correspond with increased expression of the IgE-mediated basophil activation marker CD200R1. Since IgG as well as IgE plays a role in mouse anaphylaxis, we hypothesized that the observed decrease in CD200R3 on basophils was caused by IgG-mediated cell activation. We attempted to establish whether CD200R3 is a marker of IgG-mediated basophil activation and if its expression is correlated with anaphylaxis in a mouse model. Mouse basophils were stimulated via Fc∊Rs and/or FcγRs, and levels of CD200R1 and CD200R3 were analyzed by flow cytometry. Basophils derived from naive mice were challenged with a natural antigen, β-lactoglobulin, after passive sensitization with anti-β-LG serum or IgG/IgG subclass-depleted antiserum. Systemic anaphylaxis was induced by i.v. injection of anti-FcγRIII/II monoclonal antibody, and CD200R3 expression on peripheral basophils was assessed. Stimulation via Fc∊Rs induced a significant increase in CD200R1 expression but had only a small effect on that of CD200R3. However, anti-FcγRIII/II stimulation reduced CD200R3 expression markedly. In passive sensitization experiments, down-regulation of CD200R3 induced by antigen challenge was strongly negated by the depletion of IgG or IgG1 from antiserum. Intravenous injection of anti-FcγRIII/II induced CD200R3 down-regulation on peripheral basophils, together with a drop in rectal temperature. Lowered CD200R3 expression on basophils is induced by IgG-mediated stimulation via FcγRs. Use of CD200R1 and CD200R3 as activation markers enables the evaluation of murine basophil activation mediated by IgE and IgG, respectively.
IgE 介导的肥大细胞活化是人类过敏反应的触发因素，而已知不仅 IgE，而且 IgG 也可以在小鼠中诱导过敏反应。在我们的初步实验中，在抗原致敏的肥大细胞上，抗原刺激后 CD200R3 的表达减少。有趣的是，这种减少并不总是与 IgE 介导的肥大细胞活化标志物 CD200R1 的表达增加相对应。由于 IgG 和 IgE 在小鼠过敏反应中都起作用，我们假设观察到的肥大细胞上 CD200R3 的减少是由 IgG 介导的细胞活化引起的。我们试图确定 CD200R3 是否是 IgG 介导的肥大细胞活化的标志物，以及其表达是否与小鼠模型中的过敏反应相关。通过 Fc∊Rs 和/或 FcγRs 刺激小鼠肥大细胞，并通过流式细胞术分析 CD200R1 和 CD200R3 的水平。通过被动敏化抗β-LG 血清或 IgG/IgG 亚类耗尽抗血清，用天然抗原β-乳球蛋白刺激来自幼稚小鼠的肥大细胞。通过静脉内注射抗 FcγRIII/II 单克隆抗体诱导全身性过敏反应，并评估外周肥大细胞上 CD200R3 的表达。通过 Fc∊Rs 刺激诱导 CD200R1 表达显著增加，但对 CD200R3 的影响很小。然而，抗 FcγRIII/II 刺激显著降低 CD200R3 的表达。在被动敏化实验中，抗血清中 IgG 或 IgG1 的耗竭强烈否定了抗原挑战引起的 CD200R3 下调。静脉内注射抗 FcγRIII/II 诱导外周肥大细胞上 CD200R3 下调，同时直肠温度下降。FcγRs 介导的 IgG 介导的刺激诱导肥大细胞上 CD200R3 的下调。使用 CD200R1 和 CD200R3 作为激活标志物，可以分别评估 IgE 和 IgG 介导的小鼠肥大细胞活化。
