C-MALISA (cellular magnetic-linked immunosorbent assay), a new application of cellular ELISA for MRI
C-MALISA (cellular magnetic-linked immunosorbent assay), a new application of cellular ELISA for MRI
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DOI：
10.1016/j.jinorgbio.2005.02.009
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发表时间：
2005-05-01
影响因子：
3.9
通讯作者：
Muller, RN
中科院分区：
文献类型：
--
作者：
Burtea, C;Laurent, S;Muller, RN
一种改良的细胞ELISA（酶联免疫吸附试验），被称为细胞磁联免疫吸附试验（C-MALISA），已经发展成为磁共振成像（MRI）在体外临床诊断中的应用。为了验证该方法，通过接枝到USPIO（超小氧化铁颗粒）上合成了三种靶向整合素的造影剂：(a)纤维连接蛋白（FN）的CS1（连接段-1）片段（USPIO-g-FN）；(b)肽GRGD (USPIO-g-GRGD)；(c)非肽性RGD模拟物（USPIO-g-mimRGD）。刺激Jurkat细胞和大鼠单核细胞激活其整合素。将细胞固定在ELISA板上，用造影剂孵育，冲洗，用5n HCl消化后，进行MRI分析。在图像上测量顺磁弛豫率增强（R-2）。根据校准曲线将δ R-2转换为铁浓度值。3种造影剂的表观解离常数（K-d(*)）根据MRI测量的δ R-2估计。USPIO-g-FN、USPIO-g-GRGD和USPIO-g-mimGRG的K-d（*）分别为1.22 × 10(-7) M、7.00 × 10(-8) M和1.13 × 10-8 M。MRI证实，与对照组（即非刺激细胞和非特异性USPIO孵育的刺激细胞）相比，用整合素靶向化合物孵育的刺激细胞有统计学显著差异（p < 0.01, p < 0.05）。通过与GRGD（用于USPIO-g-mimRGD和USPIO-g-GRGD）或FN（用于USPIO-g-FN）的预孵育，证实了这三种化合物的整合素特异性。(c) 2005爱思唯尔公司版权所有。
A modified cellular ELISA (enzyme-linked immunosorbent assay), named cellular magnetic-linked immunosorbent assay (C-MALISA), has been developed as an application of magnetic resonance imaging (MRI) for in vitro clinical diagnosis. To validate the method, three contrast agents targeted to integrins were synthesized by grafting to USPIO (ultrasmall particles of iron oxide): (a) the CS1 (connecting segment-1) fragment of fibronectin (FN) (USPIO-g-FN); (b) the peptide GRGD (USPIO-g-GRGD); (c) a non-peptidic RGD mimetic (USPIO-g-mimRGD). Jurkat cells and rat mononuclear cells were stimulated to activate their integrins. After cell fixation on ELISA plates, incubation with the contrast agents, rinsing, and digestion in 5 N HCl, the samples were analyzed by MRI. Paramagnetic relaxation rate enhancements (Delta R-2) were measured on images. Delta R-2 was converted in values of iron concentration based on a calibration curve. The apparent dissociation constants (K-d(*)) of the three contrast agents were estimated based on the MRI measurement of Delta R-2. K-d(*) of 1.22 x 10(-7) M, of 7.00 x 10(-8) M, and of 1.13 x 10-8 M were found respectively for USPIO-g-FN, USPIO-g-GRGD, and USPIO-g-mimGRG. The MRI confirmed a statistically significant difference (p < 0.01, p < 0.05) between the stimulated cells incubated with integrin-targeted compounds with respect to the controls (i.e., non-stimulated cells and stimulated cells incubated with non-specific USPIO). The integrin specificity of the three compounds was confirmed by the pre-incubation with GRGD (for USPIO-g-mimRGD and USPIO-g-GRGD) or FN (for USPIO-g-FN). (c) 2005 Elsevier Inc. All rights reserved.