Immunotargeting of antioxidant enzymes to the pulmonary endothelium
Immunotargeting of antioxidant enzymes to the pulmonary endothelium
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DOI：
10.1073/pnas.93.11.5213
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发表时间：
1996-05-28
影响因子：
11.1
通讯作者：
Fisher, AB
中科院分区：
文献类型：
--
作者：
Muzykantov, VR;Atochina, EN;Fisher, AB
肺内皮的氧化损伤对一系列疾病具有病理学意义。已提出施用抗氧化酶，超氧化物歧化酶（SOD）和过氧化氢酶（Cat）作为保护内皮的方法。然而，这些酶及其衍生物都不具有对内皮的特异性亲和力，并且不会在肺中积累。以前，我们已经描述了血管紧张素转换酶（ACE）的单克隆抗体，在大鼠，仓鼠，猫，猴和人类全身注射后，选择性地在肺中积累。在目前的工作中，我们描述了一个系统，用于选择性肺内输送CuZn-SOD和Cat与生物素标记的抗ACE抗体mAb 9 B 9（b-mAb 9 B 9）通过链霉亲和素（SA）-生物素桥。在生物素/酶比20下用生物素酯生物素化的两种酶保留酶活性并结合SA而不损失活性。我们构建了由b-mAb 9 B 9、SA和生物素化SOD或生物素化Cat组成的三分子杂聚物复合物，并研究了静脉注射后这些复合物在大鼠体内的生物分布和肺摄取。生物素化酶的生物分布与未修饰的酶相似。SA的结合显著延长了循环中生物素化酶的寿命。与结合非特异性IgG的酶、其他酶衍生物和未修饰的酶相反，结合b-mAb 9 B 9的生物素化酶在大鼠肺中特异性蓄积（9%注射SOD/g肺组织和7.5%注射Cat/g肺组织）。非修饰酶或具有非特异性IgG的衍生物的肺摄取不超过注射剂量的0.5%/g。与b-mAb 9 B 9偶联的SOD和Cat均在大鼠肺中保留至少数小时。三氯乙酸沉淀的放射性标记猫与肺组织匀浆的微粒体和质膜组分相关。因此，用生物素修饰抗氧化酶和SA介导的与b-mAb 9 B 9的偶联抑制了酶的循环，导致在肺中的选择性蓄积和酶向肺内皮的细胞内递送。这些结果提供了一种保护肺内皮免受氧化损伤的方法的背景。
Oxidative injury to the pulmonary endothelium has pathological significance for a spectrum of diseases. Administration of antioxidant enzymes, superoxide dismutase (SOD) and catalase (Cat), has been proposed as a method to protect endothelium. However, neither these enzymes nor their derivatives possess specific affinity to endothelium and do not accumulate in the lung. Previously we have described a monoclonal antibody to angiotensin-converting enzyme (ACE) that accumulates selectively in the lung after systemic injection in rats, hamsters, cats, monkeys, and humans. In the present work we describe a system for selective intrapulmonary delivery of CuZn-SOD and Cat conjugated with biotinylated anti-ACE antibody mAb 9B9 (b-mAb 9B9) by a streptavidin (SA)-biotin bridge. Both enzymes biotinylated with biotin ester at biotin/enzyme ratio 20 retain enzymatic activity and bind SA without loss of activity. We have constructed tri-molecular heteropolymer complexes consisting of b-mAb 9B9, SA, and biotinylated SOD or biotinylated Cat and have studied biodistribution and pulmonary uptake of these complexes in the rat after i.v. injection. Biodistribution of biotinylated enzymes was similar to that of nonmodified enzymes. Binding of SA markedly prolonged lifetime of biotinylated enzymes in the circulation. In contrast to enzymes conjugated with nonspecific IgG, other enzyme derivatives, and nonmodified enzymes, biotinylated enzymes conjugated with b-mAb 9B9 accumulated specifically in the rat lung (9% of injected SOD/g of lung tissue and 7.5% of injected Cat/g of lung tissue). Pulmonary uptake of nonmodified enzymes or derivatives with nonspecific IgG did not exceed 0.5% of injected dose/g. Both SOD and Cat conjugated with b-mAb 9B9 were retained in the rat lung for at least several hours. Trichloracetic acid-precipitable radiolabeled Cat was associated with microsomal and plasma membrane fractions of the lung tissue homogenate. Thus, modification of antioxidant enzymes with biotin and SA-mediated conjugation with b-mAb 9B9 prolongs the circulation of enzymes resulting in selective accumulation in the lung and intracellular delivery of enzymes to the pulmonary endothelium. These results provide the background for an approach to provide protection of pulmonary endothelium against oxidative insults.