Tat-functionalized near-infrared emissive polymersomes for dendritic cell labeling
Tat-functionalized near-infrared emissive polymersomes for dendritic cell labeling
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DOI：
10.1021/bc0601267
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发表时间：
2007-01-01
影响因子：
4.7
通讯作者：
Hammer, Daniel A.
中科院分区：
文献类型：
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作者：
Christian, Natalie A.;Milone, Michael C.;Hammer, Daniel A.
树突状细胞（DC）在免疫耐受和免疫反应的启动中发挥着关键作用。体内追踪 DC 的能力对于开发基于 DC 的细胞疗法以及增进我们对 DC 功能和病理生理学的理解至关重要。在这里，我们将细胞渗透性肽 Tat 与近红外 (NIR) 发射聚合物囊泡结合，以便能够有效地进行细胞内递送，以便将来使用这些光学探针进行 DC 跟踪。近红外成像可以在厘米组织深度对充满荧光团的细胞进行定量、重复的体内检测，而不会干扰细胞功能。流式细胞术和共聚焦显微镜结果表明，Tat 介导的聚合物囊泡向 DC 的递送具有浓度和时间依赖性，从而导致点状细胞内定位。此外，用 Tat NIR 发射聚合物囊泡加载细胞不会干扰细胞因子诱导的 DC 成熟，并且对 DC 活力影响不大，但对成熟 DC 诱导的初始 T 细胞的激活有显着影响。当与肽缀合时，我们观察到近红外发射聚合物囊泡的显着吸收，检测下限为 5000 个标记的 DC。聚合物囊泡递送的程度估计为 70 000 +/- 10 000 个囊泡/细胞，相当于 0.7 +/- 0.1 fmol 的 NIR 荧光团。我们的研究将使未来能够通过基于近红外荧光的成像对离体标记的 DC 进行体内跟踪。
Dendritic cells (DCs) play a pivotal role in both immune tolerance and the initiation of immunological responses. The ability to track DCs in vivo is imperative for the development of DC-based cellular therapies and to advance our understanding of DC function and pathophysiology. Here, we conjugate a cell permeable peptide, Tat, to near-infrared (NIR) emissive polymersomes in order to enable efficient intracellular delivery for future DC tracking with these optical probes. NIR imaging allows quantitative, repetitive, in vivo detection of fluorophore-laden cells, at centimeter tissue depths without disturbing cellular function. Flow cytometry and confocal microscopy results indicate that Tat-mediated polymersome delivery to DCs is concentration and time dependent, resulting in punctate intracellular localization. Further, loading cells with Tat NIR emissive polymersomes does not interfere with cytokine-induced DC maturation and has modest effects on DC viability, but has a significant effect on mature DC-induced activation of naive T cells. We observe significant uptake of NIR emissive polymersomes when conjugated to the peptide, with a lower detection limit of 5000 labeled DCs. The extent of polymersome delivery is estimated as 70 000 +/- 10 000 vesicles/cell, equivalent to 0.7 +/- 0.1 fmol of NIR fluorophore. Our studies will enable future in vivo tracking of ex vivo labeled DCs by NIR fluorescence based imaging.