Gastrointestinal eosinophils
Gastrointestinal eosinophils
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胃肠道嗜酸性粒细胞
DOI：
10.1034/j.1398-9995.2001.00905.x
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发表时间：
2001
期刊：
影响因子：
12.4
通讯作者：
M. Rothenberg
中科院分区：
文献类型：
--
作者：
M. Rothenberg
嗜酸性粒细胞被广泛认为是一种促炎症的白细胞，它只占循环血细胞的一小部分。虽然大多数嗜酸性粒细胞在健康状态下驻留在胃肠道中，但我们最近开始阐明这一群体的嗜酸性粒细胞的调节和功能(图1)。在基线(健康)条件下，胃肠道嗜酸性粒细胞主要存在于胃和肠道的固有层。有趣的是，嗜酸性粒细胞在胚胎发育期间迁移到胃肠道，其在围产期小鼠中的浓度与成年小鼠相当，表明嗜酸性粒细胞归巢独立于肠道菌群发生。嗜酸性粒细胞趋化因子是一种嗜酸性粒细胞选择性趋化因子，在胃肠道的所有节段都有结构性表达，是嗜酸性粒细胞归巢至固有层所必需的。在Th2相关的炎症状态下(如白介素5过度表达或口服变应原激发)，固有层中的嗜酸性粒细胞水平以嗜酸性粒细胞依赖的方式升高。此外，变应原激发促进嗜酸性粒细胞向Peyer‘s斑块的外皮质和滤泡间区迁移，这一过程受IL-5的严格调控，而受嗜酸性粒细胞趋化因子的影响较小，提示其他嗜酸性粒细胞趋化因子参与了这一淋巴室。此外，在黏膜变应原攻击后，在IL-5的调节下，嗜酸性粒细胞在食道内积聚，而食道是一个在基线时通常没有嗜酸性粒细胞的器官。初步研究表明，胃肠道嗜酸性粒细胞表达a4b7整合素，该分子在一定程度上是嗜酸性粒细胞归巢的原因。最后，最近的分析表明，在实验性胃肠道过敏模型中诱导的胃肠道病理在很大程度上依赖于嗜酸性粒细胞。综上所述，嗜酸性粒细胞是胃肠道免疫系统的驻留细胞，在Th2相关的条件下，它们的水平因抗原暴露而增加，而嗜酸性粒细胞趋化因子和IL-5以组织特异性的方式不同地调节它们的运输。我们认为，嗜酸性粒细胞是胃肠道免疫系统中不可或缺的成员，可能在先天性、调节性和炎症性免疫反应中发挥重要作用。过敏2001：56：Suppl。67：21-22英国印刷。保留所有权利#Munksgaard 2001
Eosinophils are widely accepted to be proinflammatory leukocytes that account for a small subset of circulating blood cells. While most eosinophils reside in the gastrointestinal tract under healthy states, we have recently started to elucidate the regulation and function of this population of eosinophils (Fig. 1). Under baseline (healthy) conditions, gastrointestinal eosinophils predominantly reside in the lamina propria in the stomach and intestine. Interestingly, eosinophils migrate to the gastrointestinal tract during embryonic development and their concentrations in perinatal mice are comparable to those in adults, indicating that eosinophil homing occurs independently of intestinal flora. The chemokine eotaxin, an eosinophil selective chemoattractant that is constitutively expressed throughout all segments of the gastrointestinal tract, is required for eosinophil homing to the lamina propria. During Th2 associated inflammatory conditions (e.g. interleukin (IL)-5 overexpression or oral allergen challenge), elevated levels of eosinophils occur in the lamina propria in an eotaxin-dependent manner. In addition, allergen challenge promotes eosinophil migration to the outer cortex and interfollicular regions of Peyer’s patches, and this process is critically regulated by IL-5 and less significantly by eotaxin, suggesting the involvement of other eosinophil chemokines in this lymphoid compartment. Furthermore, following mucosal allergen challenge, eosinophils under the regulation of IL-5 accumulate in the esophagus, an organ normally devoid of eosinophils at baseline. Preliminary investigations have shown that gastrointestinal eosinophils express the a4b7 integrin and that this molecule is responsible, in part, for eosinophil homing. Finally, recent analysis has shown that the gastrointestinal pathology induced during experimental gastrointestinal allergy models is largely dependent upon eosinophils. In summary, eosinophils are resident cells of the gastrointestinal immune system, their levels are increased by antigen exposure under Th2-associated conditions, and eotaxin and IL-5 differentially regulate their trafficking in a tissue specific manner. We propose that eosinophils are integral members of the gastrointestinal immune system and are likely to be important in innate, regulatory and inflammatory immune responses. Allergy 2001: 56: Suppl. 67: 21–22 Printed in UK. All rights reserved Copyright # Munksgaard 2001