Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.1.21 (thymidine kinase)
 7,561 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Six murine L cell lines expressing five different human cell surface antigens have been prepared by DNA-mediated gene transfer. Ltk- cells were transfected with calcium phosphate co-precipitates of human genomic DNA and a plasmid containing the Herpes simplex thymidine kinase gene. After HAT selection, transfectants expressing specific cell surface antigens were identified by in situ immune rosetting using monoclonal antibodies. In this way, transfected cell lines expressing the CD9 antigen, the CD31 antigen (two lines), a unique platelet antigen, an X-linked antigen (R1), and a previously unreported monocyte antigen 11D1 were prepared. These cell lines have proved useful in the definitive assignment of monoclonal antibodies to specific CD groups. In addition, they provide a source of mRNA for use in expression cloning of the genes for these antigens.
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PMID:Transfection of genes for human cell surface antigens identified by monoclonal antibodies. 262 57

The herpes simplex virus thymidine kinase gene (HSV-TK) in combination with ganciclovir (GCV), is currently being used in gene therapy-based clinical trials for cancer treatment. Its therapeutic effect is based on a "bystander effect" whereby HSV-TK gene-modified tumor cells are toxic to nearby unmodified tumor cells when exposed to the antiviral drug GCV. We have recently hypothesized that the in vivo mechanism of this bystander effect is due to alterations in the tumor microenvironment in response to release of cytokines and an infiltration of leukocytes after treatment with HSV-TK gene-modified tumor cells and GCV, which results in tumor regression. Expression of B7, a recently identified costimulatory molecule that is important for T-cell stimulation, has been shown to be modulated by stimulatory cytokines interferon-gamma, tumor necrosis factor-alpha, and inhibited by interleukin-10. In the present study, we investigated whether the cytokines released after HSV-TK and GCV treatment could include the expression of the costimulatory molecules B7-1 and B7-2 and the adhesion molecule (ICAM)-1 in the tumor. Furthermore, we investigated whether this altered environment affected the antitumor properties of host lymphocytes. An in vitro model was developed to establish the effects of HSV-TK gene-modified tumor cells and GCV on tumor infiltrating cells. The murine macrophage cell line (IC21) was exposed to either supernatants or cell lysates collected from a mixture of HSV-TK-transduced (KBALB-STK) and non-transduced (KBALB) murine fibrosarcoma tumor cells previously exposed to GCV (experimental). Immunohistochemical analysis showed a significant expression (P < .0001) of B7-1 and B7-2 post exposure of IC21 cells to either supernatant or lysate. In contrast, the level of expression in IC21 cells exposed to the control lysate or supernatant remained unchanged for B7-1 and B7-2. In vivo analysis for B7-1 and B7-2 expression by immunohistochemistry in tumor tissues from experimental mice receiving HSV-TK gene-modified tumor cells and GCV treatment showed a significant expression of B7.1 (35%, P < .0001) and B7.2 (38.2%, P < .0001) on tumor-infiltrating mononuclear cells. In contrast, tumor-bearing control animals showed low levels of B7-2 expression (5.8%), whereas B7-1 was undetectable, as confirmed by reverse-transcriptase polymerase chain reaction. In addition, a significant up-regulation of ICAM expression (50%) on tumor tissues was observed in the experimental group (P = .0317) as compared with the control group (25%). Furthermore, T cells isolated from experimental mice showed a significant in vitro proliferative response (p = .0202) when exposed to syngeneic tumor cells as compared with the control group. These data demonstrated that the use of HSV-TK gene-modified tumor cells and GCV as a suicide gene in the treatment of an intraperitoneal tumor resulted in the expression of the B7 costimulatory molecules and ICAM-1 adhesion molecule and enhanced proliferative response of host T cells. These findings help to understand the mechanism of tumor cell killing in vivo using HSV-TK gene-modified tumor cells.
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PMID:Expression of costimulatory molecules: B7 and ICAM up-regulation after treatment with a suicide gene. 898 40

DNA motifs that encode for specific transcriptional regulatory sequences (TRS) when engineered adjacent to the structural protein coding domain of a suicide enzyme can provide cell-lineage specific protein expression. The disparate up-regulation of several genes in adult T-cell leukemia (ATL) versus HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP), seropositive carriers (SPC) and uninfected normals may reflect events at the molecular level related to leukemogenesis or to processes maintaining the heme-oncologic phenotype. Further, the genetic transduction of cytokine and receptor genes uniquely associated with ATL may provide targets for the development of leukemia-specific gene therapies aimed at exploiting differences in the production of certain growth factors and growth factor receptors. Comparisons of the transcriptional and translational levels of interleukin-2 receptor alpha chain (IL-2R alpha), transforming growth factor-beta 1 (TGF-beta 1) and intracellular adhesion molecule-1 (ICAM-1) in ATL, HAM/TSP, and SPC and in several control populations revealed selectively up-regulated expression in ATL. We evaluated the feasibility of using lymphoid-specific TRS to activate herpes simplex virus thymidine kinase (HSVtk) to achieve selective cytotoxicity in leukemias expressing terminal deoxynucleotidyl transferase (TdT). Selective and efficient leukemic cell killing was produced and suggests that similar chimeric gene constructs containing TRS elements for IL-2R alpha, TGF-beta 1, or ICAM-1 may prove useful in designing gene therapies to treat ATL.
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PMID:Pleiotropic expression of heterologous cytokine/receptor genes in HTLV-1 associated diseases: candidate TRS for chimeric gene therapy. 920 5

Antigen transport from the airway mucosa to the thoracic lymph nodes (TLNs) was studied in vivo by intratracheal instillation of fluorescein isothiocyanate (FITC)-conjugated macromolecules. After instillation, FITC(+) cells with stellate morphology were found deep in the TLN T cell area. Using flow cytometry, an FITC signal was exclusively detected in CD11c(med-hi)/major histocompatibility complex class II (MHCII)(hi) cells, representing migratory airway-derived lymph node dendritic cells (AW-LNDCs). No FITC signal accumulated in lymphocytes and in a CD11c(hi)MHCII(med) DC group containing a CD8 alpha(hi) subset (non-airway-derived [NAW]-LNDCs). Sorted AW-LNDCs showed long MHCII(bright) cytoplasmic processes and intracytoplasmatic FITC(+) granules. The fraction of FITC(+) AW-LNDCs peaked after 24 h and had reached baseline by day 7. AW-LNDCs were depleted by 7 d of ganciclovir treatment in thymidine kinase transgenic mice, resulting in a strong reduction of FITC-macromolecule transport into the TLNs. Compared with intrapulmonary DCs, AW-LNDCs had a mature phenotype and upregulated levels of MHCII, B7-2, CD40, and intracellular adhesion molecule (ICAM)-1. In addition, sorted AW-LNDCs from FITC-ovalbumin (OVA)-instilled animals strongly presented OVA to OVA-TCR transgenic T cells. These results validate the unique sentinel role of airway DCs, picking up antigen in the airways and delivering it in an immunogenic form to the T cells in the TLNs.
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PMID:Specific migratory dendritic cells rapidly transport antigen from the airways to the thoracic lymph nodes. 1113 20

The goal of this study was to delineate the transcriptional mechanisms underlying thrombin-mediated induction of vascular adhesion molecule-1 (VCAM-1). Treatment of human umbilical vein endothelial cells with thrombin resulted in a 3.3-fold increase in VCAM-1 promoter activity. The upstream promoter region of VCAM-1 contains a thrombin response element, two nuclear factor kappaB (NF-kappaB) motifs, and a tandem GATA motif. In transient transfection assays, mutation of the thrombin response element had no effect on thrombin induction. In contrast, mutation of either NF-kappaB site resulted in a complete loss of induction, whereas a mutation of the two GATA motifs resulted in a significant reduction in thrombin stimulation. In electrophoretic mobility shift assays, nuclear extracts from thrombin-treated endothelial cells displayed markedly increased binding to the tandem NF-kappaB and GATA motifs. The NF-kappaB complex was supershifted with anti-p65 antibodies, but not with antibodies to RelB, c-Rel, p50, or p52. The GATA complex was supershifted with antibodies to GATA-2, but not GATA-3 or GATA-6. A construct containing tandem copies of the VCAM-1 GATA motifs linked to a minimal thymidine kinase promoter was induced 2.4-fold by thrombin. Taken together, these results suggest that thrombin stimulation of VCAM-1 in endothelial cells is mediated by the coordinate action of NF-kappaB and GATA transcription factors.
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PMID:Thrombin stimulation of the vascular cell adhesion molecule-1 promoter in endothelial cells is mediated by tandem nuclear factor-kappa B and GATA motifs. 1159 Jan 77