Characterization of in vivo immunoliposome targeting to pulmonary endothelium.
Characterization of in vivo immunoliposome targeting to pulmonary endothelium.
复制标题
靶向肺内皮的体内免疫脂质体的表征。
DOI：
10.1002/jps.2600791107
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发表时间：
1990
影响因子：
3.8
通讯作者：
Huang,L
中科院分区：
文献类型：
--
作者：
Maruyama,K;Holmberg,E;Kennel,SJ;Klibanov,A;Torchilin,VP;Huang,L
将两种特异性结合肺内皮细胞表面糖蛋白（gp112）的大鼠单克隆抗体34A和201B偶联到直径为0.25 μm的∽单层脂质体上。34A‐和201B‐脂质体（单克隆抗体分别为273‐34A和411‐201B），而非无抗体脂质体和与非特异性单克隆抗体14偶联的脂质体经尾静脉注射后，在小鼠肺内有效积累（注射剂量∽30%）。通过使用a125I标记的脂质标记物和包埋的水溶性标记物，证明了免疫脂质体对肺的靶向性。34A‐脂质体的肺积聚被游离抗体34A预孵育完全阻断，而不是抗体14，这表明免疫脂质体在靶部位的积聚是免疫特异性的。时间过程研究表明，34A‐脂质体在注射后1分钟内与肺抗原结合，表明靶结合发生在免疫脂质体通过肺毛细血管床的前几次通道中。未结合的免疫脂质体在注射后3-5分钟内被肝脏和脾脏吸收。随着免疫脂质体蛋白脂比的升高，肺蓄积水平显著增高。34A‐脂质体约有50%的注射剂量在肺中积累，平均每个脂质体有935个抗体分子。较大的免疫脂质体比较小的免疫脂质体在肺内积聚更明显。注射高剂量也会提高肺积聚水平。尽管这些免疫脂质体在肺中的积聚显然不是由于毛细血管栓塞，但有利于脂质体通过肺毛细血管的缓慢通道的条件（较大的脂质体尺寸和较高的注射剂量）导致高水平的肺结合。这些考虑与体外免疫脂质体与靶细胞的结合有很大不同。最后，每周向同一只小鼠重复注射（超过两次）免疫脂质体未能显示出明显的肺部积聚，这可能是由于小鼠产生了抗大鼠IgG抗体。
Two rat monoclonal antibodies, 34A and 201B, which specifically bind to a surface glycoprotein (gp112) of the pulmonary endothelial cell surface, have been coupled to unilamellar liposomes of ∽0.25 μm in diameter. The 34A‐ and 201B‐liposomes (monoclonal antibodies 273‐34A and 411‐201B, respectively), but not antibody‐free liposomes and liposomes coupled to 14, a nonspecific monoclonal antibody, accumulate efficiently (∽30% injected dose) in the lung of mice which have been injected via the tail vein. Immunoliposome targeting to lung is demonstrated both by using a125I‐labeled lipid marker and an entrapped water‐soluble marker. Lung accumulation of 34A‐liposomes is completely blocked by a preincubation of free antibody 34A, but not antibody 14, indicating that the immunoliposome accumulation at the target site is immunospecific. Time course studies have revealed that 34A‐liposomes bind to lung antigens within 1 min after injection, indicating that the target binding takes place during the first few passages of immunoliposomes through the lung capillary bed. Unbound immunoliposomes are taken up by liver and spleen within 3–5 min after injection. The level of lung accumulation increases significantly as the protein:lipid ratio of the immunoliposome increases. Approximately 50% of injected dose is accumulated in lung for 34A‐liposomes, with an average of 935 antibody molecules per liposome. Immunoliposomes of larger size accumulate in lung more significantly than those of smaller size. Injection with higher doses also enhances the level of lung accumulation. Although the lung accumulation of these immunmoliposomes is clearly not due to capillary embolism, conditions which favor slower passage of liposomes through the lung capillaries (larger liposome size and higher injection dose) result in high levels of lung binding. These considerations are quite different from immunoliposome binding to the target cells in vitro. Finally, repeated weekly injections (more than twice) of immunoliposomes into the same mouse have failed to show significant lung accumulation, probably due to the generation of anti‐rat IgG antibodies by the mouse.