Large particulate allergens can elicit mast cell-mediated anaphylaxis without exit from blood vessels as efficiently as do small soluble allergens
Large particulate allergens can elicit mast cell-mediated anaphylaxis without exit from blood vessels as efficiently as do small soluble allergens
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大颗粒过敏原可以像小可溶性过敏原一样有效地引发肥大细胞介导的过敏反应，而无需从血管中排出
DOI：
10.1016/j.bbrc.2015.09.120
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Hajime Karasuyama.
中科院分区：
文献类型：
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作者：
LiHua Li;Takuya Ohta;Kayo Horiguchi;Yohei Kawano;Hiroshi Ohtsu;Yoshinori Yamanishi;MD.;Hajime Karasuyama.
过敏反应是一种快速发生、危及生命的过敏反应，通常涉及 IgE、肥大细胞和组胺。可以通过静脉注射相应的过敏原在IgE致敏的动物中进行实验诱导，过敏原激发后几分钟内即可检测到过敏反应的迹象。然而，考虑到过敏原被输送到血液循环中，而肥大细胞驻留在外周组织内而不是血液循环中，为什么过敏反应可以在体内快速引发仍然令人费解。为了解决这个问题，我们比较了同一过敏原的两种不同形式（小可溶性过敏原和大颗粒过敏原）在 IgE 致敏小鼠中诱导过敏反应的能力。与我们的预期相反，颗粒过敏原可以像可溶性过敏原一样快速有效地引起过敏反应，即使它们保留在血管内。体内成像分析表明血管内颗粒过敏原和血管周围肥大细胞穿过毛细血管壁直接相互作用。结合之前的报道，血管周围的肥大细胞可以通过将细胞突起延伸到血管壁来捕获血液循环中的IgE，我们的研究结果表明，血液循环的过敏原，无论其大小如何，都可以通过插入血管腔的肥大细胞突起上的交联IgE来刺激肥大细胞，而无需离开血管，从而如此迅速地引发过敏反应。
Anaphylaxis is a rapid-onset, life-threatening allergic reaction in that IgE, mast cells and histamine are commonly involved. It can be experimentally induced in IgE-sensitized animals by intravenous injection of corresponding allergens, and the sign of anaphylactic reaction can be detected within minutes after allergen challenge. However, it remains puzzling why the anaphylactic reaction can be initiatedin vivoso quickly, considering that allergens are delivered into the blood circulation while mast cells reside within peripheral tissues but not in the blood circulation. To address this issue, we compared two different forms of the same allergen, small soluble and large particulate ones, in their ability to induce anaphylaxis in IgE-sensitized mice. In contrast to our expectation, particulate allergens could induce anaphylaxis as quickly and efficiently as did soluble allergens, even though they remained inside of blood vessels. In vivo imaging analysis suggested the direct interaction of intravascular particulate allergens and perivascular mast cells across the capillary wall. Taken together with previous report that perivascular mast cells can capture IgE in the blood circulation by extending cell processes across the vessel wall, our findings imply that blood-circulating allergens, regardless of their size, can stimulate mast cells without exit from blood vessels, by means of cross-linking IgE on mast cell processes inserted into the vessel lumen, and hence initiate anaphylactic reaction so quickly.