In vivo molecular imaging of cancer with a quenching near-infrared fluorescent probe using conjugates of monoclonal antibodies and indocyanine green.
In vivo molecular imaging of cancer with a quenching near-infrared fluorescent probe using conjugates of monoclonal antibodies and indocyanine green.
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DOI：
10.1158/0008-5472.can-08-3116
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发表时间：
2009-02-15
期刊：
影响因子：
11.2
通讯作者：
Kobayashi H
中科院分区：
文献类型：
--
作者：
Ogawa M;Kosaka N;Choyke PL;Kobayashi H
近红外（NIR）荧光团比可见荧光团有几个优点，包括更好的组织穿透性和更低的自身荧光，但只有吲哚菁绿（ICG）被临床批准。它在分子成像探针中的应用受到限制，因为它在蛋白质结合后会失去荧光。该特性可用于创建可激活的近红外探针。在细胞结合和内化后，ICG与靶向抗体分离，从而激活荧光。ICG与Daclizumab (Dac)，曲妥珠单抗（Tra）或panitumumab （Pan）抗体偶联。偶联物在PBS中几乎没有荧光，但经过SDS和2-ME后产生荧光，1:1偶联物的猝灭能力为10倍，1:5偶联物的猝灭能力为40 ~ 50倍。体外显微镜显示靶细胞内溶酶体的活化。在小鼠体内成像表明，用Dac-ICG可以特异性地显示表达cd -25的肿瘤。此外，使用Pan-ICG（1:5）和trai - icg（1:5）分别成功地在体内表征了过表达HER1和HER2的肿瘤。因此，我们开发了一种可激活的近红外光学探头，它只在目标细胞中“打开”。由于抗体和荧光团都是fda批准的，因此提高了临床转化的可能性。
Near-infrared (NIR) fluorophores have several advantages over visible fluorophores including improved tissue penetration and lower autofluorescence but only indocyanine Green (ICG) is clinically approved. Its use in molecular imaging probes is limited because it loses its fluorescence after protein binding. This property can be harnessed to create an activatable, NIR probe. After cell binding and internalization, ICG dissociates from the targeting antibody thus, activating fluorescence. ICG was conjugated to the antibodies Daclizumab (Dac), trastuzumab (Tra) or panitumumab (Pan). The conjugates had almost no fluorescence in PBS but became fluorescent after SDS and 2-ME, with a quenching capacity of 10-fold for 1:1 conjugates, and 40 to 50-fold for 1:5 conjugates. In vitro microscopy demonstrated activation within the endo-lysosomes in target cells. In vivo imaging in mice demonstrated that CD-25-expressing tumors were specifically visualized with Dac-ICG. Furthermore, tumors overexpressing HER1 and HER2 were successfully characterized in vivo using, Pan-ICG(1:5) and Tra-ICG(1:5), respectively. Thus, we have developed an activatable NIR optical probe which “switches on” only in target cells. Because both the antibody and the fluorophore, are FDA-approved, the likelihood of clinical translation is improved.