pH-sensitive immunoliposomes mediate target-cell-specific delivery and controlled expression of a foreign gene in mouse.
pH-sensitive immunoliposomes mediate target-cell-specific delivery and controlled expression of a foreign gene in mouse.
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pH 敏感的免疫脂质体介导小鼠体内外源基因的靶细胞特异性递送和受控表达。
DOI：
10.1073/pnas.84.22.7851
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发表时间：
1987
影响因子：
11.1
通讯作者：
Huang,L
中科院分区：
文献类型：
--
作者：
Wang,CY;Huang,L
将含有哺乳动物cAMP启动子控制的大肠杆菌氯霉素乙酰转移酶(CAT)基因的质粒包裹在H-2Kk抗体包被的脂质体中，脂质体由二油酰磷脂酰乙醇胺、胆固醇和油酸组成(pH敏感免疫脂质体)。将包裹的或游离的DNA注射到免疫缺陷(裸鼠)BALB/c小鼠体内，荷瘤小鼠由H-2Kk阳性的RDM-4淋巴瘤细胞产生的腹水瘤。约20%的注射免疫脂质体被靶向RDM-4细胞摄取。当使用不含抗体的脂质体时，摄取较少。脂质体上靶向抗体的存在也显著降低了脾对脂质体的非特异性摄取。在pH敏感免疫脂质体包裹的DNA处理的小鼠RDM-4细胞中检测到显著的CAT酶活性。此外，RDM-4细胞中CAT的表达受cAMP的调控，因为只有注射8-溴-cAMP和3-异丁基-1-甲基黄嘌呤的小鼠细胞才有CAT活性。肝和脾的CAT活性(分别为RDM-4细胞的12倍和5倍)明显低于RDM-4细胞，而且这些网状内皮器的活性不受cAMP的调节。用pH不敏感的免疫脂质体(用磷脂酰胆碱代替磷脂酰乙醇胺)包裹DNA的小鼠RDM-4细胞的CAT活性约为注射pH敏感免疫脂质体的小鼠RDM-4细胞的四分之一，表明pH敏感的脂质体具有优越的递送效率。这些结果从免疫脂质体在癌症和遗传性疾病治疗中的DNA载体潜力的角度进行了讨论。
A plasmid containing the Escherichia coli chloramphenicol acetyltransferase (CAT) gene under the control of a mammalian cAMP-regulated promoter was entrapped in H-2Kk antibody-coated liposomes composed of dioleoyl phosphatidylethanolamine, cholesterol, and oleic acid (pH-sensitive immunoliposomes). The entrapped or free DNA was injected intraperitoneally into immunodeficient (nude) BALB/c mice bearing ascites tumor generated by H-2Kk-positive RDM-4 lymphoma cells. About 20% of the injected immunoliposomes were taken up by the target RDM-4 cells. Uptake was much less when liposomes without antibody were used. The presence of the targeting antibody on liposomes also significantly decreased the nonspecific uptake of liposomes by the spleen. Significant CAT enzyme activity was detected in RDM-4 cells from mice treated with DNA entrapped in the pH-sensitive immunoliposomes. Furthermore, CAT expression in RDM-4 cells was under the control of cAMP, as only the cells from mice injected with 8-bromo-cAMP and 3-isobutyl-1-methylxanthine showed CAT activity. CAT activity in liver and spleen was much lower (by factors of 12 and 5, respectively) than in the RDM-4 cells, and the activities in these reticuloendothelial organs were not regulated by cAMP. CAT activity in RDM-4 cells from mice injected with DNA entrapped in pH-insensitive immunoliposomes (containing phosphatidylcholine in place of phosphatidylethanolamine) was approximately one-fourth that in RDM-4 cells from mice injected with pH-sensitive immunoliposomes, indicating the superior delivery efficiency of the pH-sensitive liposomes. These results are discussed in terms of the DNA-carrier potential of immunoliposomes in therapy of cancer and genetic diseases.