Monitoring C3aR Expression Using a Floxed tdTomato-C3aR Reporter Knock-in Mouse
Monitoring C3aR Expression Using a Floxed tdTomato-C3aR Reporter Knock-in Mouse
复制标题
用Floxed tdTomato-C3 aR报告基因敲入小鼠监测C3 aR表达
DOI：
10.4049/jimmunol.1700318
复制
发表时间：
2017-07-15
影响因子：
4.4
通讯作者：
Koehl, Joerg
中科院分区：
文献类型：
--
作者：
Quell, Katharina M.;Karsten, Christian M.;Koehl, Joerg
C3 a通过激活其同源C3 a受体发挥多种生物学功能。C3 2/2和C3 aR（-/-）小鼠在确定C3 a/C3 aR轴在急性和慢性炎性疾病（包括缺血/再灌注损伤、过敏性哮喘、自身免疫性肾炎和类风湿性关节炎）的调节中的重要作用方面起着重要作用。令人惊讶的是，很少有人知道C3 aR在免疫和基质细胞中的表达和功能。为了缩小这一差距，我们产生了一个floxed串联染料番茄（tdTomato）-C3 aR报告基因敲入小鼠，我们用它来监测C3 aR的表达细胞驻留在肺，气道，固有层（LP）的小肠，脑，内脏脂肪组织，骨髓（BM），脾，和循环。我们发现tdTomato-C3 aR在脑、肺、LP和内脏脂肪组织中的强表达，而在脾、血液、BM和气道中的表达较小。大多数巨噬细胞和嗜酸性粒细胞群体是tdTomato-C3 aR（+）。有趣的是，大多数组织嗜酸性粒细胞和一些巨噬细胞群体表达C3 aR细胞内。骨髓来源的树突状细胞（DC）、肺源性分化簇（CD）11b（+）常规DC（cDC）和单核细胞来源的DC、LP CD 103（+）和CD 11b（+）cDC均为tdTomato-C3 aR+，但肺CD 103（+）cDC和脾DC均为tdTomato-C3 aR+。令人惊讶的是，BM、血液、肺嗜中性粒细胞和肥大细胞均不表达C3 aR。同样，所有淋巴衍生的细胞都是tdTomato-C3 aR（-），除了一些LP衍生的3型先天淋巴细胞。肺和脂蛋白衍生的上皮细胞表达最好的C3 aR的次要水平。总之，我们提供了新的见解C3 aR在小鼠中的表达模式。floxed C3 aR敲入小鼠将有助于可靠地跟踪和有条件地删除炎症实验模型中的C3 aR表达。
C3a exerts multiple biologic functions through activation of its cognate C3a receptor. C3 2/2 and C3aR(-/-) mice have been instrumental in defining important roles of the C3a/C3aR axis in the regulation of acute and chronic inflammatory diseases, including ischemia/reperfusion injury, allergic asthma, autoimmune nephritis, and rheumatoid arthritis. Surprisingly little is known about C3aR expression and function in immune and stromal cells. To close this gap, we generated a floxed tandem-dye Tomato (tdTomato)-C3aR reporter knock-in mouse, which we used to monitor C3aR expression in cells residing in the lung, airways, lamina propria (LP) of the small intestine, brain, visceral adipose tissue, bone marrow (BM), spleen, and the circulation. We found a strong expression of tdTomato-C3aR in the brain, lung, LP, and visceral adipose tissue, whereas it was minor in the spleen, blood, BM, and the airways. Most macrophage and eosinophil populations were tdTomato-C3aR(+). Interestingly, most tissue eosinophils and some macrophage populations expressed C3aR intracellularly. BM-derived dendritic cells (DCs), lungresident cluster of differentiation (CD) 11b(+) conventional DCs (cDCs) and monocyte-derived DCs, LP CD103(+), and CD11b(+) cDCs but not pulmonary CD103 (+) cDCs and splenic DCs were tdTomato-C3aR +. Surprisingly, neither BM, blood, lung neutrophils, nor mast cells expressed C3aR. Similarly, all lymphoid-derived cells were tdTomato-C3aR(-), except some LP-derived type 3 innate lymphoid cells. Pulmonary and LP-derived epithelial cells expressed at best minor levels of C3aR. In summary, we provide novel insights into the expression pattern of C3aR in mice. The floxed C3aR knock-in mouse will help to reliably track and conditionally delete C3aR expression in experimental models of inflammation.