Detection of vascular adhesion molecule-1 expression using a novel multimodal nanoparticle
Detection of vascular adhesion molecule-1 expression using a novel multimodal nanoparticle
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DOI：
10.1161/01.res.0000155722.17881.dd
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发表时间：
2005-02-18
影响因子：
20.1
通讯作者：
Weissleder, R
中科院分区：
文献类型：
--
作者：
Kelly, KA;Allport, JR;Weissleder, R
内皮血管粘附分子-1 (VCAM-1) 是白细胞-内皮粘附级联的关键组成部分，其严格的时间和空间调节使其成为成像和治疗的理想靶点。本研究的目标是开发新型 VCAM-1 靶向显像剂，可使用噬菌体展示衍生的肽序列和多峰纳米颗粒 (NP) 通过 MRI 和荧光成像进行检测。我们假设 VCAM-1 介导的噬菌体展示的细胞内化 - 选择的肽可以用作一种扩增策略，以陪伴和捕获表达 VCAM-1 的细胞内的显像剂，从而提高目标与背景的比率。为了实现我们的目标，在生理流动条件下对小鼠内皮进行迭代噬菌体展示，以鉴定 VCAM-1 介导的细胞内化肽家族。一个包含 VHSPNKK 基序的特定序列与极晚期抗原（VCAM-1 的一种已知配体）的 α 链具有同源性，显示可以结合 VCAM-1 并阻断白细胞-内皮相互作用。与 VCAM-1 单克隆抗体相比，该肽的目标与背景比高出 12 倍。 VHSPNKK 修饰的磁荧光 NP (VNP) 对表达 VCAM-1 的内皮细胞显示出高亲和力，但对巨噬细胞的亲和力却令人惊讶地低。相反，没有VCAM-1靶向序列的对照NP表现出对内皮细胞没有亲和力。在体内，VNP 成功地在小鼠肿瘤坏死因子-α 诱导的炎症模型中鉴定出表达 VCAM-1 的内皮细胞，并在胆固醇喂养的载脂蛋白 E apoE(-/-) 小鼠的动脉粥样硬化病变中与表达 VCAM-1 的细胞共定位。这些结果表明：（1）小肽序列可以显着改变纳米颗粒的靶向，（2）所使用的内化放大策略导致高目标与背景比率，以及（3）该技术可用于内皮标记物的体内成像。
Endothelial vascular adhesion molecule-1 (VCAM-1) is a critical component of the leukocyte-endothelial adhesion cascade, and its strict temporal and spatial regulation make it an ideal target for imaging and therapy. The goal of this study was to develop novel VCAM-1-targeted imaging agents detectable by MRI and fluorescence imaging using phage display-derived peptide sequences and multimodal nanoparticles (NPs). We hypothesized that VCAM-1 mediated cell internalization of phage display - selected peptides could be harnessed as an amplification strategy to chaperone and trap imaging agents inside VCAM-1-expressing cells, thus improving target-to-background ratios. To accomplish our goal, iterative phage display was performed on murine endothelium under physiological flow conditions to identify a family of VCAM-1-mediated cell-internalizing peptides. One specific sequence, containing the VHSPNKK motif that has homology to the alpha-chain of very late antigen (a known ligand for VCAM-1), was shown to bind VCAM-1 and block leukocyte-endothelial interactions. Compared with VCAM-1 monoclonal antibody, the peptide showed 12-fold higher target-to-background ratios. A VHSPNKK-modified magnetofluorescent NP (VNP) showed high affinity for endothelial cells expressing VCAM-1 but surprisingly low affinity for macrophages. In contrast, a control NP without VCAM-1 - targeting sequences showed no affinity for endothelial cells. In vivo, VNP successfully identified VCAM-1 - expressing endothelial cells in a murine tumor necrosis factor-alpha-induced inflammatory model and colocalized with VCAM-1 - expressing cells in atherosclerotic lesions present in cholesterol-fed apolipoprotein E apoE(-/-) mice. These results indicate that: (1) small peptide sequences can significantly alter targeting of NPs, (2) the used amplification strategy of internalization results in high target-to-background ratios, and (3) this technology is useful for in vivo imaging of endothelial markers.