Department of Radiology, Mount Sinai School of Medicine, New York, New York 10029-6574, USA.
Magn Reson Med. 2010 Nov;64(5):1510-9. doi: 10.1002/mrm.22519.
Ex vivo generated dendritic cells are currently used to induce therapeutic immunity in solid tumors. Effective immune response requires dendritic cells to home and remain in lymphoid organs to allow for adequate interaction with T lymphocytes. The aim of the current study was to detect and track Feridex labeled human dendritic cells in murine models using magnetic resonance imaging. Human dendritic cells were incubated with Feridex and the effect of labeling on dendritic cells immune function was evaluated. Ex vivo dendritic cell phantoms were used to estimate sensitivity of the magnetic resonance methods and in vivo homing was evaluated after intravenous or subcutaneous injection. R2*-maps of liver, spleen, and draining lymph nodes were obtained and inductively coupled plasma mass spectrometry or relaxometry methods were used to quantify the Feridex tissue concentrations. Correlations between in vivo R2* values and iron content were then determined. Feridex labeling did not affect dendritic cell maturation or function. Phantom results indicated that it was possible to detect 125 dendritic cells within a given slice. Strong correlation between in vivo R2* values and iron deposition was observed. Importantly, Feridex-labeled dendritic cells were detected in the spleen for up to 2 weeks postintravenous injection. This study suggests that magnetic resonance imaging may be used to longitudinally track Feridex-labeled human dendritic cells for up to 2 weeks after injection.
目前，体外生成的树突状细胞被用于诱导实体瘤中的治疗性免疫。有效的免疫反应需要树突状细胞归巢并留在淋巴器官中，以便与 T 淋巴细胞充分相互作用。本研究的目的是使用磁共振成像检测和追踪 Feridex 标记的人类树突状细胞在小鼠模型中的情况。将人类树突状细胞与 Feridex 孵育，并评估标记对树突状细胞免疫功能的影响。使用体外树突状细胞模型来估计磁共振方法的灵敏度，并在静脉内或皮下注射后评估体内归巢情况。获得肝脏、脾脏和引流淋巴结的 R2*-图谱，并使用电感耦合等离子体质谱或弛豫率方法来定量 Feridex 的组织浓度。然后确定体内 R2值与铁含量之间的相关性。Feridex 标记不会影响树突状细胞的成熟或功能。体模结果表明，有可能在给定切片中检测到 125 个树突状细胞。体内 R2值与铁沉积之间存在很强的相关性。重要的是，在静脉内注射后长达 2 周的时间内，在脾脏中检测到 Feridex 标记的树突状细胞。这项研究表明，磁共振成像可能用于在注射后长达 2 周的时间内对 Feridex 标记的人类树突状细胞进行纵向追踪。
