Multimodal cell tracking from systemic administration to tumour growth by combining gold nanorods and reporter genes.
Multimodal cell tracking from systemic administration to tumour growth by combining gold nanorods and reporter genes.
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DOI：
10.7554/elife.33140
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发表时间：
2018-06-27
期刊：
影响因子：
7.7
通讯作者：
Plagge A
中科院分区：
文献类型：
--
作者：
Comenge J;Sharkey J;Fragueiro O;Wilm B;Brust M;Murray P;Levy R;Plagge A
了解外源性细胞植入后的命运对于临床应用非常重要。临床前研究允许对细胞位置和存活进行成像。用纳米颗粒标记可以实现高灵敏度检测，但细胞分裂和细胞死亡会导致信号稀释和假阳性。相比之下，遗传报告信号通过细胞分裂被放大。在这里，我们将基于慢病毒的双顺反子报告基因载体和二氧化硅包覆的金纳米棒（GNRs）作为细胞标记和跟踪的协同工具。生物发光报告基因荧光素酶和光声报告基因近红外荧光蛋白iRFP 720的共表达使得能够在小鼠中随时间跟踪细胞。多光谱光声断层扫描（MSOT）显示心脏内注射后GNR标记细胞的立即生物分布和高分辨率GNR的连续清除（第1-15天），而光声iRFP 720检测表明肿瘤生长（第10-40天）。这种多模式细胞跟踪方法可以广泛应用于癌症和再生医学研究，以监测短期和长期的生物分布，肿瘤形成和转移。许多科学家正在研究利用人体细胞治疗疾病的可能性。例如，使用干细胞再生受损的身体部位或基因工程免疫细胞摧毁癌症。科学家们需要新的工具来跟踪这些细胞一旦被注射到实验室动物身上会发生什么。这将帮助他们了解他们是如何工作的，并确保这些潜在的治疗是安全的。使用细胞作为治疗的一个问题是它们可能形成癌性肿瘤。为了在实验室动物中追踪这些细胞，科学家需要两样东西：一种将治疗细胞与动物正常细胞区分开来的方法，以及一种成像工具，使他们能够看到细胞在活体动物中的位置。区分治疗细胞和正常细胞的一种方法是对它们进行基因工程改造，使其产生一种名为iRFP 720的荧光蛋白。另一种方法是用金纳米棒填充细胞。荧光蛋白和金纳米棒都吸收红外范围内的光。科学家们可以使用一种称为多光谱光声断层扫描的技术，将红外光转换为超声信号来创建图像，以查看这些标记在体内的位置。现在，Comenge等人表明，金纳米棒和多光谱光声断层扫描在注入小鼠血流后立即跟踪细胞。大多数注射的细胞在几天内死亡，纳米棒通过肝脏逐渐从体内消除。但是一些注射的细胞在一个月内存活、繁殖并形成肿瘤。这是意料之中的，因为他们使用的细胞是根据它们有时形成肿瘤的能力选择的。使用多光谱光声断层扫描来跟踪制造iRFP 720的细胞，Comenge等人能够准确地看到肿瘤在体内深处的位置。金纳米棒和iRFP 720可以让科学家们在短期和长期内追踪癌症或其他疾病的细胞疗法。这可能有助于他们证明这些治疗方法是否有效，以及它们是否有有害影响。Comenge等人正在帮助其他科学家使用这些技术，分发他们的工具来制造iRFP 720生产细胞。
Understanding the fate of exogenous cells after implantation is important for clinical applications. Preclinical studies allow imaging of cell location and survival. Labelling with nanoparticles enables high sensitivity detection, but cell division and cell death cause signal dilution and false positives. By contrast, genetic reporter signals are amplified by cell division. Here, we characterise lentivirus-based bi-cistronic reporter gene vectors and silica-coated gold nanorods (GNRs) as synergistic tools for cell labelling and tracking. Co-expression of the bioluminescence reporter luciferase and the optoacoustic reporter near-infrared fluorescent protein iRFP720 enabled cell tracking over time in mice. Multispectral optoacoustic tomography (MSOT) showed immediate biodistribution of GNR-labelled cells after intracardiac injection and successive clearance of GNRs (day 1–15) with high resolution, while optoacoustic iRFP720 detection indicated tumour growth (day 10–40). This multimodal cell tracking approach could be applied widely for cancer and regenerative medicine research to monitor short- and long-term biodistribution, tumour formation and metastasis. Many scientists are studying the possibility of using human cells to treat diseases. For example, using stem cells to regenerate damaged body parts or genetically engineered immune cells to destroy cancer. Scientists need new tools to track what happens to these cells once they have been injected into a laboratory animal. This will help them understand how they work and make sure these potential treatments are safe. One concern with using cells as a treatment is that they might form cancerous tumors. To track these cells in a laboratory animal, scientists need two things: a way to distinguish the treatment cells from the animal’s normal cells and an imaging tool that allows them to see where the cells are in a living animal. One way to differentiate treatment cells from normal cells is to genetically engineer them to make a fluorescent protein called iRFP720. Another way is to fill the cells with gold nanorods. Both, the fluorescent protein and the gold nanorods, absorb light in the infrared range. Scientists can use a technique called multispectral optoacoustic tomography, which transforms infrared light into ultrasound signals to create an image, to see where these markers are in the body. Now, Comenge et al. showed that the gold nanorods and multispectral optoacoustic tomography track the cells immediately after injection into the blood stream of a mouse. Most of the injected cells die within a few days, and the nanorods are progressively eliminated from the body through the liver. But some of the injected cells live on, multiply, and form tumors within a month. This was expected because the cells they used were chosen for their ability to sometimes form tumors. Using multispectral optoacoustic tomography to track the cells making iRFP720, Comenge et al. were able to see exactly where the tumors are deep inside the body. Together, gold nanorods and iRFP720 could allow scientists to track where the cell-based therapies for cancer or other diseases go in the short and long term. This may help them prove whether these treatments work, and whether they have harmful effects. Comenge et al. are helping other scientists to use these techniques by distributing their tool for making iRFP720-producing cells.