No abstract available.
Humans* ; Retroviridae*

Interleukin 12 (IL-12), a heterodimeric cytokine, promotes an effective antitumor response against tumors of various histological types when delivered systemically as a protein or locally by gene transfer. We investigated parameters that influenced the effectiveness of IL-12 retroviral-mediated gene therapy of cancer in animals using the murine breast cancer line TS/A. Syngeneic fibroblasts (TIB80), stably transduced with a retrovirus expressing murine IL-12, were used for peritumoral injection. Injection of fibroblasts into established tumors resulted in complete regression of tumor in 40 % of animals in a dose dependent manner when treated on day 4, and 20 % when treated on day 8. Significant inhibition of growth of day 21 and day 40 tumors was observed following peritumoral injection of IL-12-expressing fibroblasts in a dose-dependent manner. Delivery of IL-12 by syngeneic fibroblasts at a tumor site is effective in eradicating established, weakly immunogenic TS/A tumors.
Animals ; Breast Neoplasms ; Fibroblasts ; Genetic Therapy* ; Interleukin-12* ; Retroviridae

Background : Gene transfer with vectors derived from murine retroviruses is restricted to cells which are proliferating and synthesizing DNA at the time of infection. Accordingly, selective introduction of genes encoding for susceptibility to otherwise nontoxic drugs (suicide genes) into proliferating tumor may be used to treat cancer. We investigated the efficacy of in vitro transduction of neuroblastoma cell with the herpes simplex-thymidine kinase (HSV-tk) gene followed by administration of the antiviral drug ganciclovir. METHODS: The LNC/tK vector was transfered in vitro into mouse Neuro 2a cell lines (ATCC) and the transduced cell lines were selected in G-418, 500microgram/ml, for 14 days. Onex104 cells were cultured in 96 well culture plates in increasing concentrations of ganciclovir for 72 hours. The sesitivity to ganciclivir of these HSV-tk transduced, G-418 selected cells was measured with MTT assay RESULTS: The survival of HSV-tk transduced 1x104 neuro 2a cell lines is 103+/-3.5%, 68+/-4.2%, 54+/-3.8%, 17+/-2.6%, 13+/-3.1% at the concentration of 0, 0.1, 1.0, 10, 20microgram/ml ganciclovir, respectively. And the survival of HSV-tk not transduced 1x104 neuro 2a cell lines is 100+/-4.5%, 97+/-5.6%, 104+/-3.5%, 106+/-3.8%, 101+/-4.2%. CONCLUSION: We concluded that in vitro transduction of neuroblastoma cell with the herpes simplex-thymidine kinase gene followed by administration of the antiviral drug ganciclovir is very effective.
Animals ; Cell Line* ; DNA ; Ganciclovir ; Mice ; Neuroblastoma* ; Phosphotransferases ; Retroviridae ; Zidovudine*

Background : Gene transfer with vectors derived from murine retroviruses is restricted to cells which are proliferating and synthesizing DNA at the time of infection. Accordingly, selective introduction of genes encoding for susceptibility to otherwise nontoxic drugs (suicide genes) into proliferating tumor may be used to treat cancer. We investigated the efficacy of in vitro transduction of neuroblastoma cell with the herpes simplex-thymidine kinase (HSV-tk) gene followed by administration of the antiviral drug ganciclovir. METHODS: The LNC/tK vector was transfered in vitro into mouse Neuro 2a cell lines (ATCC) and the transduced cell lines were selected in G-418, 500microgram/ml, for 14 days. Onex104 cells were cultured in 96 well culture plates in increasing concentrations of ganciclovir for 72 hours. The sesitivity to ganciclivir of these HSV-tk transduced, G-418 selected cells was measured with MTT assay RESULTS: The survival of HSV-tk transduced 1x104 neuro 2a cell lines is 103+/-3.5%, 68+/-4.2%, 54+/-3.8%, 17+/-2.6%, 13+/-3.1% at the concentration of 0, 0.1, 1.0, 10, 20microgram/ml ganciclovir, respectively. And the survival of HSV-tk not transduced 1x104 neuro 2a cell lines is 100+/-4.5%, 97+/-5.6%, 104+/-3.5%, 106+/-3.8%, 101+/-4.2%. CONCLUSION: We concluded that in vitro transduction of neuroblastoma cell with the herpes simplex-thymidine kinase gene followed by administration of the antiviral drug ganciclovir is very effective.
Animals ; Cell Line* ; DNA ; Ganciclovir ; Mice ; Neuroblastoma* ; Phosphotransferases ; Retroviridae ; Zidovudine*

Human leukemia is closely associated with various genetic alterations such as chromosomal translocations and gene mutations. The use of retroviral transduction/bone marrow transplantation mouse model harboring these genetic abnormalities has been critical in understanding the molecular pathogenesis of leukemia and exploring new therapeutic target. Additional genetic events are verified to cooperate with fusion genes resulting from chromosomal translocations in acute myeloid leukemia (AML) to develop a leukemic phenotype in mice, such as C-KIT N822K with AML1-ETO, FLT3-ITD with PML-RARα, Meis1 with NUP98-HOX, and Cdx4 with MLL-AF9. Mouse model shows that BCR/ABL fusion gene induces chronic myeloid leukemia (CML), and suggests that GATA-2 L359V and high expression of Hes1 are key molecules in acute myeloid transformation of CML. Furthermore, combination therapy with Imatinib and arsenic sulfide for CML mice exerts more profound therapeutic effects than either drug as a single agent. This review focuses the recent progress and application of retroviral-mediated mouse models of myeloid leukemia, and discusses some factors influencing the mouse model establishment, including retroviral construction, retrovirus titer and hematopoietic microenvironment.
Animals ; Disease Models, Animal ; Leukemia, Myeloid ; genetics ; Mice ; Retroviridae ; genetics

Foamy virus can establish lifelong persistent infection in mammal hosts without inducing diseases. Such special characteristic stimulates the interests of researchers. As reported, the accessory protein Bet of foamy virus could regulate the gene expression and infection cycle of foamy virus and take part in the generation of chronic viral infection. And also, Bet might prevent the host cellular defense factor APO-BEC3 from interfering the replication of virus and play a role in maintaining viral persistent infection. In order to elucidate the roles of Bet in the foamy virus replication and infection, this review summarized the research progress of Bet protein reported in recent years.
Animals ; Gene Expression Regulation, Viral ; Humans ; Retroviridae Infections ; immunology ; virology ; Retroviridae Proteins ; genetics ; metabolism ; Spumavirus ; genetics ; metabolism

The study was conducted on 32 HIV positive patients (24 males and 8 females, over 15 years old, with CD4 T-cell counts <350 cell/mm3) who were treated with antiretrovirus therapy (Videx and Zerit) at Dong Da Hospital from Nov 2002 to Oct 2003. The results showed that ARV therapy is effective. The weight, Kanofsky scores, and T CD4 counts of patients were increased significantly after 6 months of treatment. Side effects included fatigue, headache, nausea, but only on first week. Enzyme amylase was increased slightly after 6 months of treatment
Anti-HIV Agents ; Anti-Retroviral Agents ; HIV ; Therapeutics ; Pharmaceutical Preparations ; Retroviridae

Retroviral vector provide a highly efficient method for gene transfer into eukaryotic cells. This vector system can be divided into two components; the retroviral vector itself and the retroviral packaging cell line. The key improvement in the design of these two components are. focused on two aspects; the reduction of helper virus production and high titer-virus. We used PA317 for retrovirus packaging cell line, for its high producibility of viral titer, To test the ability of the vectors to generate high titer-virus, we have chosen four different retroviral vectors; LN, LNSX, LNCX and LXSN. To test easily the viral titer, we have made recombinant construction with CD4 and CD8, checked their viral titer and stained their surface expression. LXSN which contain SV40 early promoter in front of leo gene showed best results in viral transient transfection assay, dot blot assay and surface expression. In addition, recombinant containing CD8 generally showed much higher viral titration and surface expression than CD4.
Cell Line ; Eukaryotic Cells ; Helper Viruses ; Product Packaging ; Retroviridae ; Transfection ; Zidovudine*

PURPOSE: We tried to assess the optimal conditions to improve low transduction efficiency and their effect on target cells. METHODS: Cultured NIH 3T3 cells were incubated with retroviral vectors bearing an enhanced green fluorescent protein (eGFP) gene. We varied the ratio of viral vectors to target cells (1:1-1:8) and the number of transfections (x1, x2), and compared transduction efficiencies. Also, the effects of polybrene on transduction efficiency and viability of target cells were assessed. Transduction of the eGFP gene was evaluated by observing NIH 3T3 cells under a fluorescence microscope and efficiencies were measured by the percentage of eGFP positive cells using FACscan. RESULTS: As the ratio of retroviral vectors to target cells increased, transduction efficiency was greatly improved, from 7% (1:1) to 38% (1:4). However, transduction efficiency did not increase any more when the ratio increased from 1:4 to 1:8. Cells transfected twice showed higher transduction efficiencies than cells transfected once, at a ratio of 1:8. The eGFP gene transduced to NIH 3T3 cells sustained its expression during repeated passages. However, after the third passage (day 9), the percentage of eGFP positive cells began to decline. The degree of this decline in eGFP expression was lower in cells transfected twice than in cells transfected once (P<0.05). The addition of polybrene did not have any toxic effect on NIH 3T3 cells and greatly increased transduction efficiency (P=0.007). In addition to vector component, transduction efficiency was very sensitive to culture confluence. Cells cultured and transfected in 24-well plate showed higher transduction efficiency, although cells cultured in 6- well plate proliferated more (P=0.024). CONCLUSION: Our data could be used as a basis for retrovirus-based gene therapy. Further study will follow using human cells as target cells.
Fluorescence ; Genetic Therapy ; Hexadimethrine Bromide ; Humans ; NIH 3T3 Cells* ; Retroviridae ; Transfection ; Zidovudine

BACKGROUND AND OBJECTIVES: Compared to other target cells examined for gene therapy, vascular smooth muscle cells (VSMCs) have the unique advantages including proximity to blood stream and relative abundance in vasculature. With an ultimate goal of developing VSMC-based therapies for cardiovascular disorders, we explored the utility of VSMC as a target cell for ex vivo gene therapy using a set of retroviral vectors. MATERIALS AND METHODS: Cultured VSMCs were transduced with replication-defective recombinant retroviruses harboring LacZ, nlsLacZ, mVEGF, mGM-CSF or bacterial CAT reporter. The VSMCs were examined for G418-selection, transduction efficiency, the level of transgene expression, and longevity of gene expression. ResultsVSMCs were readily transduced with different kinds of retroviral vectors. The bacterial neo r gene-transduced VSMCs were successfully selected with G418. The G418-selected VSMCs could express the transduced genes at a level comparable to NIH3T3. The level of transgene expression did not appear to be affected by the increasing number of passages. CONCLUSION: The results demonstrate an efficient transduction of VSMCs by retroviral vectors in vitro and an sustained expression of retrovirally transduced genes in VSMCs. VSMCs could be one of the ideal target cells for ex vivo cardiovascular gene therapy employing retroviral vector.
Animals ; Cats ; Gene Expression ; Genetic Therapy* ; Longevity ; Muscle, Smooth, Vascular* ; Retroviridae ; Rivers ; Transgenes ; Zidovudine