Analysis of leukocyte transepithelial migration using an in vivo murine colonic loop model
Analysis of leukocyte transepithelial migration using an in vivo murine colonic loop model
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DOI：
10.1172/jci.insight.99722
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发表时间：
2018-10-18
期刊：
影响因子：
8
通讯作者：
Parkos, Charles A.
中科院分区：
文献类型：
--
作者：
Flemming, Sven;Luissint, Anny-Claude;Parkos, Charles A.
控制白细胞跨血管内皮迁移（跨内皮迁移; TEdoM）的分子机制已在体内得到广泛表征，但由于缺乏合适的动物模型，白细胞跨上皮迁移（TEpM）及其失调（许多粘膜疾病的病理特征）的细节缺失。在这里，我们描述了一种小鼠模型，利用血管化的近端结肠段（pcLoop），并能够定量研究跨结肠上皮白细胞运输。与先前的体外研究一致，腔内注射抗整合素CD 11b/CD 18的抗体减少了多形核中性粒细胞（PMN）向pcLoops管腔中的募集，并增加了PMN的上皮下蓄积。我们使用pcLoop扩展了研究，以确定连接粘附分子-A（JAM-A或F11 R）在PMN TEpM中的作用，并证实JAM-A完全缺失或肠上皮选择性缺失JAM-A的小鼠结肠通透性增加。此外，在global-KO小鼠和肠上皮靶向JAM-A缺陷小鼠中，PMN向结肠腔的迁移减少，从而抑制了PMN的上皮下积聚。这些发现突出了JAM-A在体内调节PMN TEpM中的潜在新作用，并证明了该模型用于鉴定可在体内靶向以减少病理性肠道炎症的受体的实用性。
Molecular mechanisms that control leukocyte migration across the vascular endothelium (transendothelial migration; TEndoM) have been extensively characterized in vivo, but details of leukocyte transepithelial migration (TEpM) and its dysregulation (a pathologic feature of many mucosal diseases) are missing due to the lack of suitable animal models. Here, we describe a murine model that utilizes a vascularized proximal colonic segment (pcLoop) and enables quantitative studies of leukocyte trafficking across colonic epithelium. Consistent with previous in vitro studies, intraluminal injection of antibodies against integrin CD11b/CD18 reduced recruitment of polymorphonuclear neutrophils (PMN) into the lumen of pcLoops, and it increased subepithelial accumulation of PMN. We extended studies using the pcLoop to determine contributions of Junctional Adhesion Molecule-A (JAM-A, or F11R) in PMN TEpM and confirmed that mice with total loss of JAM-A or mice with intestinal epithelial selective loss of JAM-A had increased colonic permeability. Furthermore, there was reduced PMN migration into the colonic lumen that paralleled subepithelial accumulation of PMN in global-KO mice, as well as in intestinal epithelial-targeted JAM-A-deficient mice. These findings highlight a potentially novel role for JAM-A in regulating PMN TEpM in vivo and demonstrate utility of this model for identifying receptors that may be targeted in vivo to reduce pathologic intestinal inflammation.