Quantum dot/antibody conjugates for in vivo cytometric imaging in mice
Quantum dot/antibody conjugates for in vivo cytometric imaging in mice
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DOI：
10.1073/pnas.1421632111
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发表时间：
2015-02-03
影响因子：
11.1
通讯作者：
Duda, Dan G.
中科院分区：
文献类型：
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作者：
Han, Hee-Sun;Niemeyer, Elisabeth;Duda, Dan G.
多路、表型、活体细胞成像需要新颖的荧光基团偶联物，它们具有适合长周期循环和扩散的大小，并且与细胞/血清几乎没有非特异性结合，而与感兴趣的细胞具有高特异性结合。此外，这些缀合物必须在体内环境中稳定并保持高量子产率。在这里，我们证明这可以通过紧凑的（类似于15 nm的流体动力学直径）和生物相容性量子点(QD) -Ab共轭物来实现。我们通过四氮-降冰片烯环加成将整个单克隆抗体偶联到涂有降冰片烯的聚咪唑配体的量子点上，从而开发了这些偶联物。我们的QD免疫构建物用于骨髓体内单细胞标记。使用慢性颅骨骨窗的活体成像研究表明，我们的QD-Ab偶联物扩散到整个骨髓中，并有效地标记属于罕见的造血干细胞和祖细胞(Sca（1+) c-Kit（+）细胞）的单个细胞。这种体内细胞术技术可用于广泛的结构和功能成像，以研究完整和病变组织中细胞之间以及细胞与环境之间的相互作用。
Multiplexed, phenotypic, intravital cytometric imaging requires novel fluorophore conjugates that have an appropriate size for long circulation and diffusion and show virtually no nonspecific binding to cells/serum while binding to cells of interest with high specificity. In addition, these conjugates must be stable and maintain a high quantum yield in the in vivo environments. Here, we show that this can be achieved using compact (similar to 15 nm in hydrodynamic diameter) and biocompatible quantum dot (QD) -Ab conjugates. We developed these conjugates by coupling whole mAbs to QDs coated with norbornene-displaying polyimidazole ligands using tetrazine-norbornene cycloaddition. Our QD immunoconstructs were used for in vivo single-cell labeling in bone marrow. The intravital imaging studies using a chronic calvarial bone window showed that our QD-Ab conjugates diffuse into the entire bone marrow and efficiently label single cells belonging to rare populations of hematopoietic stem and progenitor cells (Sca(1+) c-Kit(+) cells). This in vivo cytometric technique may be useful in a wide range of structural and functional imaging to study the interactions between cells and between a cell and its environment in intact and diseased tissues.