Nejat Düzgüneş: 0000-0001-6159-1391


Biomedical Sciences

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Biochimica et Biophysica Acta - Biomembranes









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Cationic liposome-mediated intracellular delivery of a fluorescein-labeled chimeric DNA-RNA ribozyme targeted to the HIV-1 5' LTR was investigated, using THP-1, THP-1/HIV-1(IIIB) or HeLa/LAV cells. Different fluorescence patterns were observed when the cells were exposed to Lipofectamine, Lipofectin or DMRIE:DOPE (1:1) complexed to the ribozyme. With Lipofectamine intense cell-associated fluorescence was found. Incubation with Lipofectin resulted in less intense diffuse fluorescence, while with DMRIE an intense but sporadic fluorescence was observed. Differentiated THP-1/HIV-1(IIIB) cells were more susceptible to killing by liposome-ribozyme complexes than THP-1 cells. Under non-cytotoxic conditions (a 4-h treatment) complexes of 5, 10 or 15 μM Lipofectin or DOTAP:DOPE (1:1) and ribozyme, at lipid:ribozyme ratios of 8:1 or 4:1, did not affect p24 production in THP-1/HIV-1(IIIB) cells in spite of the intracellular accumulation of the ribozyme. A 24-h exposure of THP-1/HIV-1(IIIB) cells to 5 μM Lipofectin or DOTAP:DOPE (1:1) complexed with either the functional or a modified control ribozyme reduced virus production by approximately 30%. Thus, the antiviral effect of the liposome-complexed ribozyme was not sequence-specific. In contrast, the free ribozyme at a relatively high concentration inhibited virus production by 30%, while the control ribozyme was ineffective, indicating a sequence-specific effect. Both Lipofectin and DOTAP complexed with ribozyme were toxic at 10 and 15 μM after a 24-h treatment. A 4-h treatment of HeLa/LAV cells with Lipofectin at 5, 10 or 15 μM was not toxic to the cells, but also did not inhibit p24 production. In contrast, treatment of HeLa CD4+ cells immediately after infection with HIV-1(IIIB) at the same lipid concentrations and lipid:ribozyme ratios was cytotoxic. Our results indicate that the delivery of functional ribozyme into cells by cationic liposomes is an inefficient process and needs extensive improvement before it can be used in ex vivo and in vivo applications. Copyright (C) 1998 Elsevier Science B.V.

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Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

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