A novel neutrophil-specific PET imaging agent: cFLFLFK-PEG-64Cu.
A novel neutrophil-specific PET imaging agent: cFLFLFK-PEG-64Cu.
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一种新型的中性粒细胞特异性宠物成像剂：CFLFLFK-PEG-64CU。
DOI：
10.2967/jnumed.108.056127
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发表时间：
2009-05
期刊：
影响因子：
--
通讯作者：
Pan D
中科院分区：
文献类型：
--
作者：
Locke LW;Chordia MD;Zhang Y;Kundu B;Kennedy D;Landseadel J;Xiao L;Fairchild KD;Berr SS;Linden J;Pan D
本文描述了一种新的高效64cu标记肽cFLFLFK-PEG-64Cu的合成和验证，该肽靶向白细胞上的甲酰肽受体（FPR）。肽配体是FPR的拮抗剂，设计不引起导致中性粒细胞减少的趋化反应。该合成配体选择性结合中性粒细胞的证据被提供。在小鼠肺炎症模型中评估了该化合物的PET成像特性。fpr特异性肽n -肉桂酰f -(D)L-F-(D)L-F (D)L-F （cFLFLF）在赖氨酸(K) ω-NH2处依次与双功能聚乙二醇片段（PEG, 3.4 kD）和2,2',2 ' ' -（1,4,7,10-四氮杂环十二烷-1,4,7,10-四基）四乙酸（DOTA）偶联，最后用[64Cu]CuCl2标记，形成cFLFLFK-PEG-64Cu。体外评价了该配体对人中性粒细胞的结合亲和力和刺激效能。研究了该肽在小鼠体内的血液动力学和器官分布特性。C57BL/6雄性小鼠10只；4只对照组小鼠和6只感染肺炎克雷伯菌的小鼠。示踪剂给药后18小时进行PET/CT扫描，评估标记肽在肺部的定位特性。通过髓过氧化物酶（MPO）测定，肺标准化摄取值（suv）与肺中性粒细胞活性相关。免疫组织化学（IHC）证实，中性粒细胞在克雷伯菌暴露24小时后肺组织中浸润的白细胞中占大多数。化合物cFLFLFK-PEG-64Cu与中性粒细胞FPR体外结合的Kd值为17.7 nM。功能性超氧化物刺激试验显示，对于中性粒细胞超氧化物的产生，配体的激动剂活性可以忽略不计。聚乙二醇化肽配体的血液清除半衰期为55±8分钟。示踪剂给药18小时后PET成像显示，克雷伯菌感染小鼠的平均肺部suv和肺部MPO活性分别比对照小鼠高5倍和6倍。免疫组化染色证实克雷伯氏菌感染小鼠肺部的细胞浸润在成像时几乎完全是中性粒细胞。这种新的靶向FPR的放射性标记肽在体外与中性粒细胞结合，并在体内炎症部位积累。这种修饰的肽可能被证明是探测炎症或损伤的有用工具。
The synthesis and validation of a new, highly potent 64Cu-labeled peptide, cFLFLFK-PEG-64Cu, that targets the formyl peptide receptor (FPR) on leukocytes is described. The peptide ligand is an antagonist of the FPR, designed not to elicit a chemotactic response resulting in neutropenia. Evidence for the selective binding of this synthesized ligand to neutrophils is provided. PET imaging properties of the compound was evaluated in a mouse model of lung inflammation. The FPR-specific peptide, N-cinnamoyl-F-(D)L-F-(D)L-F (cFLFLF), was sequentially conjugated at ω-NH2 of the lysine (K) with a bifunctional polyethylene glycol moiety (PEG, 3.4 kD) and a 2,2',2”,2'”-(1,4,7,10-tetraazacyclododecane-1,4,7,10-tetrayl) tetraacetic acid (DOTA), and finally labeled with [64Cu]CuCl2 to form cFLFLFK-PEG-64Cu. The binding affinity and stimulation potency of the ligand towards human neutrophils were assessed in vitro. Blood kinetic and organ biodistribution properties of the peptide were studied in the mouse. Ten male C57BL/6 mice were used for imaging; four control mice and six administered Klebsiella pneumonia. PET/CT scans were performed to assess the localization properties of the labeled peptide in lungs 18 hr after tracer administration. Lung standardized uptake values (SUVs) were correlated with lung neutrophil activity as measured by myeloperoxidase (MPO) assays. Immunohistochemistry (IHC) was performed to confirm that neutrophils constitute the majority of infiltrating leukocytes in lung tissue 24 hr post Klebsiella exposure. In vitro binding assays of the compound cFLFLFK-PEG-64Cu to the neutrophil FPR yielded a Kd of 17.7 nM. The functional superoxide stimulation assay exhibited negligible agonist activity of the ligand with respect to neutrophil superoxide production. The pegylated peptide ligand exhibited a blood clearance half-life of 55 ± 8 min. PET imaging 18 hr post tracer administration revealed mean lung SUVs and lung MPO activities for Klebsiella-infected mice that were 5- and 6-fold higher, respectively, compared with control mice. IHC staining confirmed that the cellular infiltrate in lungs of Klebsiella-infected mice was almost exclusively neutrophils at the time of imaging. This new radiolabeled peptide targeting the FPR binds to neutrophils in vitro and accumulates at sites of inflammation in vivo. This modified peptide may prove to be a useful tool to probe inflammation or injury.
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影响因子：
7.3
作者：
Sullivan, GW;Rieger, JM;Linden, J
通讯作者：
Linden, J
影响因子：
2.9
作者：
Derian, CK;Solomon, HF;Fischman, AJ
通讯作者：
Fischman, AJ
影响因子：
2.7
作者：
Zhang, Yi;Kundu, Bijoy;Pan, Dongfeng
通讯作者：
Pan, Dongfeng
影响因子：
2.2
作者：
FERRANTE, A;THONG, YH
通讯作者：
THONG, YH
DOI：
10.1152/ajplung.00146.2005
发表时间：
2005-11-01
影响因子：
4.9
作者：
Zhou, ZH;Kozlowski, J;Schuster, DP
通讯作者：
Schuster, DP