Interactions of immunoliposomes with target cells.
Interactions of immunoliposomes with target cells.
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DOI：
10.1016/s0021-9258(17)44020-8
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发表时间：
1983-11
期刊：
影响因子：
--
通讯作者：
A. Huang;S. Kennel;L. Huang
中科院分区：
文献类型：
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作者：
A. Huang;S. Kennel;L. Huang
我们在脂质体表面共价贴附了一种针对小鼠主要组织相容性抗原H-2Kk的单克隆抗体（11-4.1）。研究了这些抗体包被脂质体（免疫脂质体）与靶细胞RDM-4淋巴瘤（H-2Kk）的相互作用。靶细胞在4℃时摄取的免疫脂质体中，约90%可以通过细胞的温和蛋白酶处理去除，而在37℃时摄取的免疫脂质体中，只有30%对相同的处理不稳定。此外，37℃时免疫脂质体的摄取被细胞松弛素B或2-脱氧葡萄糖和NaN3的组合所抑制。这些结果表明，免疫脂质体与靶细胞表面的结合是4℃时的主要摄取事件，而表面结合的脂质体在37℃时可能通过内吞途径被细胞迅速内化。用含羧基荧光素的免疫脂质体处理靶细胞的荧光显微镜研究也支持这一结论。如果内吞作用是免疫脂质体进入靶细胞的机制，那么包封的细胞毒性药物的有效性将取决于该药物对溶酶体失活的抗性及其从溶酶体系统逃逸的能力。与这一观点一致的是，我们观察到含有11-4.1抗体的脂体中包裹的甲氨蝶呤在相同剂量下特异性抑制RDM-4细胞中脱氧[6-3H]尿苷融入DNA，而在P3-X63-Ag8骨髓瘤细胞（H-2Kd）中则没有。所观察到的包膜甲氨蝶呤的细胞毒性作用可以通过溶酶性胺氯喹治疗细胞而逆转，氯喹已被证明可以增加哺乳动物细胞的溶酶体内pH值。另一方面，包裹在免疫脂质体中的胞嘧啶- β - d -阿拉伯糖醛酸苷没有表现出靶向特异性杀伤，这可能是因为该药物在溶酶体系统中很容易失活。这些结果在免疫脂质体的药物运载潜力方面进行了讨论。
We have covalently attached a monoclonal antibody (11-4.1) against the murine major histocompatibility antigen, H-2Kk, on the surface of liposomes. The interaction of these antibody-coated liposomes (immunoliposomes) with target cells, RDM-4 lymphoma (H-2Kk), was investigated. About 90% of the immunoliposomes taken up by target cells at 4 degrees C could be removed by a mild protease treatment of the cells, whereas only 30% of the uptake at 37 degrees C was labile to the same treatment. Furthermore, the uptake of immunoliposomes at 37 degrees C was inhibitable by cytochalasin B or by a combination of 2-deoxyglucose and NaN3. These results suggest that immunoliposome binding to the target cell surface is the primary uptake event at 4 degrees C and that the surface-bound liposomes are rapidly internalized by the cells at 37 degrees C, probably via an endocytic pathway. Studies with fluorescence microscopy of target cells treated with immunoliposomes containing carboxyfluorescein also supported this conclusion. If endocytosis is the mechanism by which immunoliposomes gain entry into target cells, the efficacy of a cytotoxic drug encapsulated would depend on the resistance of the drug to lysosomal inactivation and its ability to escape from the lysosomal system. Consistent with this notion, we observed that methotrexate encapsulated in liposomes bearing 11-4.1 antibody specifically inhibited deoxy[6-3H]uridine incorporation into DNA in target RDM-4 cells but not in P3-X63-Ag8 myeloma cells (H-2Kd) at the same doses. The observed cytotoxic effect of encapsulated methotrexate could be reversed by the treatment of cells with a lysosomotropic amine, chloroquine, which has been shown to increase the intralysosomal pH of mammalian cells. On the other hand, cytosine-beta-D-arabinofuranoside encapsulated in immunoliposomes showed no target-specific killing, probably because the drug is readily inactivated in the lysosomal system. These results are discussed in terms of the drug carrier potential of immunoliposomes.