Analysis of chemokine receptor, and atypical chemokine receptor, expression is frequently hampered by the lack of availability of high-quality antibodies and the species specificity of those that are available. We have previously described methodology utilizing Alexa-Fluor-labeled chemokine ligands as versatile reagents to detect receptor expression. Previously this has been limited to hematopoietic cells and methodology for assessing expression of receptors on stromal cells has been lacking. Among chemokine receptors, the ones most frequently expressed on stromal cells belong to the atypical chemokine receptor subfamily. These receptors do not signal in the classic sense in response to ligand but scavenge their ligands and degrade them and thus sculpt in vivo chemokine gradients. Here, we demonstrate the ability to use either intratracheal or intravenous, Alexa-Fluor-labeled chemokine administration to detect stromal cell populations expressing the atypical chemokine receptor ACKR2. Using this methodology, we demonstrate, for the first time, expression of ACKR2 on blood endothelial cells. This observation sets the lung aside from other tissues in which ACKR2 is exclusively expressed on lymphatic endothelial cells and suggest unique roles for ACKR2 in the pulmonary environment.

中文翻译：

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非典型趋化因子受体 ACKR2 的肺基质表达分析揭示了小鼠血液内皮细胞中未预料到的表达。

趋化因子受体和非典型趋化因子受体的分析经常因缺乏高质量抗体和可用抗体的物种特异性而受到阻碍。我们之前已经描述了利用 Alexa-Fluor 标记的趋化因子配体作为通用试剂来检测受体表达的方法。以前，这仅限于造血细胞，并且缺乏评估基质细胞上受体表达的方法。在趋化因子受体中，最常在基质细胞上表达的属于非典型趋化因子受体亚家族。这些受体不会在经典意义上响应配体发出信号，而是清除它们的配体并降解它们，从而塑造体内趋化因子梯度。这里，我们展示了使用气管内或静脉内、Alexa-Fluor 标记的趋化因子给药来检测表达非典型趋化因子受体 ACKR2 的基质细胞群的能力。使用这种方法，我们首次证明了 ACKR2 在血液内皮细胞上的表达。这一观察结果将肺与其他组织除外，其中 ACKR2 仅在淋巴管内皮细胞上表达，并表明 ACKR2 在肺环境中的独特作用。