Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: DrugBank:EXPT01586 (G418)
 2,237 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The application of bone marrow gene therapy has been stalled by the inability to achieve stable high-level gene transfer and expression in the totipotent stem cells. We show that retroviral vectors can stably introduce genes into antigen-specific murine and human T lymphocytes in culture. Murine helper T cells were transduced with the retroviral vector SAX to express both neomycin-resistance and human adenosine deaminase genes. These cells were expanded in culture and selected for expression of neomycin resistance with G418. The gene insertion, selection, and culture expansion did not alter antigen specificity or growth characteristics of the T cells in vitro. To determine if cultured T cells might be used for gene therapy, their persistence and continued expression of the introduced genes was evaluated in nude mice transplanted with the SAX-transduced T cells. G418-resistant cells could be readily recovered from the spleens of recipients of transduced T cells for several months. In addition, recovered cells continued to produce human adenosine deaminase. Based on these observations, we studied cultured human tumor-infiltrating lymphocytes as a candidate cell for a trial of gene transfer in man. Exponential cultures of interleukin-2-stimulated tumor-infiltrating lymphocytes were efficiently transduced with the neomycin-resistance gene using the retroviral vector N2. Gene insertion and subsequent G418 selection did not substantially alter the growth characteristics, interleukin 2 dependence, membrane phenotype, or cytotoxicity profile of the transduced T cells. These studies provided a portion of the experimental evidence supporting the feasibility of the presently ongoing clinical trials of lymphocyte gene therapy in cancer as well as in patients with adenosine deaminase deficiency.
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PMID:Lymphocytes as cellular vehicles for gene therapy in mouse and man. 201 35

Tumor-infiltrating lymphocytes (TILs) are cells generated from tumor suspensions cultured in interleukin 2 that can mediate cancer regression when adoptively transferred into mice or humans. Since TILs proliferate rapidly in vitro, recirculate, and preferentially localize at the tumor site in vivo, they provide an attractive model for delivery of exogenous genetic material into man. To determine whether efficient gene transfer into TILs is feasible, we transduced human TILs with the bacterial gene for neomycin-resistance (NeoR) using the retroviral vector N2. The transduced TIL populations were stable and polyclonal with respect to the intact NeoR gene integration and expressed high levels of neomycin phosphotransferase activity. The NeoR gene insertion did not alter the in vitro growth pattern and interleukin 2 dependence of the transduced TILs. Analyses of T-cell receptor gene rearrangement for beta- and gamma-chain genes revealed the oligoclonal nature of the TIL populations with no major change in the DNA rearrangement patterns or the levels of mRNA expression of the beta and gamma chains following transduction and selection of TILs in the neomycin analog G418. Human TILs expressed mRNA for tumor necrosis factors (alpha and beta) and interleukin 2 receptor P55 but not for interleukin 1 beta, granulocyte/macrophage colony-stimulating factor, interleukin 6, and interferon gamma when grown with high-dose interleukin 2 without subsequent activation with mitogen or specific antigen. This pattern of cytokine-mRNA expression was not significantly altered following the transduction of TILs. The NeoR gene-transduced TILs could thus be used to follow the trafficking and survival of TILs in vivo, and clinical protocols using these transduced TILs in cancer patients have begun. The studies demonstrate the feasibility of TILs as suitable cellular vehicles for the introduction of therapeutic genes into patients receiving autologous TILs.
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PMID:Human gene transfer: characterization of human tumor-infiltrating lymphocytes as vehicles for retroviral-mediated gene transfer in man. 240 83

Two recombinant retroviral vectors encoding the cDNA of the human adenosine deaminase (ADA; EC 3.5.4.4) gene and the bacterial neomycin resistance (Neo) gene have been used to transduce bone marrow cells obtained from four patients affected by the ADA-deficient variant of severe combined immunodeficiency. By utilizing the long-term marrow culture system, freshly isolated bone marrow cells were subjected to multiple infection cycles with cell-free supernatants containing high titers of viral vector and then maintained in long-term marrow culture in the absence of any overt selection pressure. By using this experimental protocol, about 30-40% of the hematopoietic progenitors were productively transduced with the viral vector, as judged by the appearance of G418-resistant colonies derived from granulocyte/macrophage and multipotent hematopoietic progenitor cells. The vector-encoded human ADA gene was expressed efficiently in both the myeloid and lymphoid progeny of the cultured bone marrow cells, reaching levels between 15% and 100% as compared to the levels of ADA in normal bone marrow cells. The efficiency of gene transfer and ADA production was proportional to the number of infection cycles. Furthermore, transduction of the ADA vectors into the bone marrow cells derived from an ADA-deficient patient restored the capacity of the cells to respond to phytohemagglutinin and interleukin 2.
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PMID:Retroviral vector-mediated high-efficiency expression of adenosine deaminase (ADA) in hematopoietic long-term cultures of ADA-deficient marrow cells. 254 45

A murine retroviral vector, LSNLsrc, has been constructed and examined for its ability to induce growth factor independence in cells normally dependent on interleukin 2 (IL-2) or interleukin 3 (IL-3) for growth. The LSNLsrc vector coexpressed the v-src gene of Rous sarcoma virus and the neo gene from transposon Tn5, allowing infected cells to be selected on the basis of G418 resistance. The murine cell lines CTLL-2 and FD.C/1, which are dependent for growth on IL-2 and IL-3, respectively, were both readily infected with the LSNLsrc virus. LSNLsrc-infected, G418-resistant cultures of FD.C/1 cells were able to give rise to IL-3-independent progeny, but all G418-resistant CTLL-2 cells retained normal IL-2 dependence. The induction of IL-3 independence by v-src was not a direct event, since limiting dilution analysis of the LSNLsrc-infected FD.C/1 cells showed that most of them were IL-3 dependent, despite expression of v-src mRNA and active pp60v-src kinase. However, clones selected from this population in the presence of IL-3 were able to undergo a subsequent progression event and generate IL-3-independent progeny. The generation of factor-independent variants in the clonal cultures was a rare event, as witnessed by the death of most of the cells in each clone when IL-3 was withdrawn. Together, these data indicate that a secondary event, in addition to v-src expression, was required to generate IL-3-independent growth. No evidence was found for an autocrine mechanism of transformation involving IL-2, IL-3, interleukin 4, or granulocyte-macrophage colony-stimulating factor.
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PMID:Nature and specificity of lymphokine independence induced by a selectable retroviral vector expressing v-src. 311 87

A recombinant retroviral vector with an inserted bacterial neomycin resistance (neo) gene was used to transfer in vitro neomycin resistance (neoR) into murine cytotoxic lymphocyte precursors (CLP). The infection protocol involved co-cultivation of mitogen-activated splenic T-blasts with irradiated cells that produced either the recombinant retrovirus plus a helper virus, or exclusively the recombinant retrovirus. Infected T-blasts were subsequently cultured under limiting dilution (LD) conditions that supported clonal in vitro development of a large fraction of murine CLP. In infected T-blast populations, frequency estimates were obtained for CLP that developed into functional cytotoxic T-lymphocyte (CTL) populations under G418-selected or non-selected conditions; from these frequency estimates, an efficiency of transduction of the neoR phenotype into murine CLP of 2-8% was calculated. Some conditions were defined that influenced transduction efficiency, i.e., the density of the infecting monolayer cells; the presence of interleukin 2-containing conditioned medium and mitogenic lectins during the co-culture period; a delayed onset of G418 selection after infection. It was demonstrated that the neoR phenotype of functional CTL populations derived from infected CLP resulted from expressed recombinant retrovirus.
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PMID:Introduction of a selectable gene into murine T-lymphoblasts by a retroviral vector. 348 30

We examined the ability of recombinant adeno-associated virus (rAAV) to transfer regulated gene expression into T cell lines. An AAV-based vector containing the neomycin resistance gene and expressing the firefly luciferase (luc) gene under the regulatory control of the interleukin 2 promoter (pAAV-luc) was generated and adenovirus-free rAAV (rAAV-luc) was produced from this vector. Transfection of pAAV-luc into the human T cell line Jurkat resulted in luciferase expression while infection of Jurkat T cells with rAAV-luc resulted in significant luciferase expression only after selection for neomycin-resistant cells. Long-term growth of transduced Jurkat T cells showed that there was no detectable constitutive expression of luciferase and that luciferase gene expression remained inducible for at least 180 days. Luciferase expression was activated by PMA and ionomycin and by anti-CD3 antibodies and was inhibited by cyclosporin A. Examination of G418-resistant clones showed that rAAV-luc had integrated into the host chromosomes but that some of the clones lost some of the transferred DNA or lost expression from the transferred DNA. These results indicate that rAAV can transfer and integrate regulated gene expression into T cell lines but that the transferred genetic material may be lost or its expression may be silenced over time.
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PMID:Transfer of activation-dependent gene expression into T cell lines by recombinant adeno-associated virus. 1043 2