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Sample records for adenoviral gene transfer

  1. Adenoviral Mediated Gene Transfer into the Dog Brain In Vivo

    Candolfi, Marianela; Kroeger, Kurt; Pluhar, Elizabeth; Liu, Chunyan; Barcia, Carlos; Bergeron, Josee; Puntel, Mariana; Curtin, James; McNiel, Elizabeth; Freese, Andrew; Ohlfest, John; Moore, Peter; Kuoy, William; Lowenstein, Pedro; Castro, Maria

    2007-01-01

    OBJECTIVE: Glioblastoma multiforme (GBM) is a devastating brain tumor for which there is no cure. Adenoviral-mediated transfer of conditional cytotoxic (herpes simplex virus [HSV] 1-derived thymidine kinase [TK]) and immunostimulatory (Fms-like tyrosine kinase 3 ligand [Flt3L]) transgenes elicited immune-mediated long-term survival in a syngeneic intracranial GBM model in rodents. However, the lack of a large GBM animal model makes it difficult to predict the outcome of therapies in humans. D...

  2. Adenoviral transfer of human interleukin-10 gene in lethal pancreatitis

    Zi-Qian Chen; Yao-Qing Tang; Yi Zhang; Zhi-Hong Jiang; En-Qiang Mao; Wei-Guo Zou; Ruo-Qing Lei; Tian-Quan Han; Sheng-Dao Zhang

    2004-01-01

    AIM: To evaluate the therapeutic effect of adenoviral-vectordelivered human interleukin-10 (hIL-10) gene on severe acute pancreatitis (SAP) rats.METHODS: Healthy Sprague-Dawley (SD) rats were intraperitoneally injected with adenoviral IL-10 gene (AdvhIL-10), empty vector (Adv0) or PBS solution. Blood,liver, pancreas and lung were harvested on the second day to examine hIL-10 level by ELISA and serum amylase by enzymatic assay. A SAP model was induced by retrograde injection of sodium taurocholate through pancreatic duct.SAP rats were then administered with AdvhIL-10, Adv0 and PBS solution by a single intraperitoneal injection 20 min after SAP induction. In addition to serum amylase assay,levels of hIL-10 and tumor necrosis factor-α (TNF-α) were detected by RT-PCR, ELISA and histological study. The mortality rate was studied and analyzed by Kaplan-Meier and log rank analysis.RESULTS: The levels of hIL-10 in the pancreas, liver and lung of healthy rats increased significantly after AdvhIL-10injection (1.42 ng/g in liver, 0.91 ng/g in pancreas); while there was no significant change of hIL-10 in the other two control groups. The concentration of hIL-10 was increased significantly in the SAP rats after AdvhIL-10 injection (1.68 ng/g in liver, 1.12 ng/g in pancreas) compared to the other two SAP groups with blank vector or PBS treatment (P<0.05). The serum amylase levels remained normal in the AdvhIL-10 transfected healthy rats. However,the serum amylase level was significantly elevated in the other two control SAP rats. In contrast, serum amylase was down-regulated in the AdvhIL-10 treated SAP groups.The TNF-α expression in the AdvhIL-10 treated SAP rats was significantly lower compared to the other two control SAP groups. The pathohistological changes in the AdvhIL-10 treated group were better than those in the other two control groups. Furthermore, the mortality of the AdvhIL-10 treated group was significantly reduced compared to the other two control groups (P

  3. Imaging expression of adenoviral HSV1-tk suicide gene transfer using the nucleoside analogue FIRU

    Substrates for monitoring HSV1-tk gene expression include uracil and acycloguanosine derivatives.The most commonly used uracil derivative to monitor HSV1-tk gene transfer is 1-(2-fluoro-2-deoxy-β-D-arabinofuranosyl)-5-[*I]iodouracil (fialuridine; I*-FIAU), where the asterisk denotes any of the radioactive iodine isotopes that can be used. We have previously studied other nucleosides with imaging properties as good as or better than FIAU, including 1-(2-fluoro-2-deoxy-β-D-ribofuranosyl)-5-[*I]iodouracil (FIRU). The first aim of this study was to extend the biodistribution data of 123I-labelled FIRU. Secondly, we assessed the feasibility of detecting differences in HSV1-tk gene expression levels following adenoviral gene transfer in vivo with 123I-FIRU. 9L rat gliosarcoma cells were stably transfected with the HSV1-tk gene (9L-tk+). 123I-FIRU was prepared by radioiodination of 1-(2-fluoro-2-deoxy-β-D-ribofuranosyl)-5-tributylstannyl uracil (FTMRSU; precursor compound) and purified using an activated Sep-Pak column. Incubation of 9L-tk+ cells and the parental 9L cells with 123I-FIRU resulted in a 100-fold higher accumulation of radioactivity in the 9L-tk+ cells after an optimum incubation time of 4 h. NIH-bg-nu-xid mice were then inoculated subcutaneously with HSV1-tk (-) 9L cells or HSV1-tk (+) 9L-tk+ cells into both flanks. Biodistribution studies and gamma camera imaging were performed at 15 min and 1, 2, 4 and 24 h p.i. At 15 min, the tumour/muscle, tumour/blood and tumour/brain ratios were 5.2, 1.0 and 30.3 respectively. Rapid renal clearance of the tracer from the body resulted in increasing tumour/muscle, tumour/blood and tumour/brain ratios, reaching values of 32.2, 12.5 and 171.6 at 4 h p.i. A maximum specific activity of 22%ID/g tissue was reached in the 9L-tk+ tumours 4 h after 123I-FIRU injection. Two Ad5-based adenoviral vectors containing the HSV1-tk gene were constructed: a replication-incompetent vector with the transgene in the former E1 region

  4. Dual-expressing adenoviral vectors encoding the sodium iodide symporter for use in noninvasive radiological imaging of therapeutic gene transfer

    Introduction: Noninvasive analysis of therapeutic transgene expression is important for the development of clinical translational gene therapy strategies against cancer. To image p53 and MnSOD gene transfer noninvasively, we used radiologically detectable dual-expressing adenoviral vectors with the human sodium iodide symporter (hNIS) as the reporter gene. Methods: Dual-expressing adenoviral vectors were constructed with hNIS cloned into E3 region and therapeutic genes, either MnSOD or p53, recombined into the E1 region. Steady-state mRNA levels of hNIS were evaluated by real-time polymerase chain reaction. hNIS function was determined by iodide uptake assay and MnSOD, and p53 protein levels were assessed by Western blots. Results: 125I- accumulation resulting from hNIS expression in both Ad-p53-hNIS- and Ad-MnSOD-hNIS-infected MDA-MB-435 cells could be visualized clearly on phosphorimaging autoradiograph. Iodide accumulation increased with increasing adenovirus titer, and there was a linear correlation between iodide uptake and dose. p53 and MnSOD protein levels increased as a function of adenovirus titer, and there was a direct positive correlation between p53 and MnSOD expression and hNIS function. P53 and MnSOD overexpression inhibited cell growth in the dual-expressing adenoviral vector-infected cells. Conclusions: Radiological detection of hNIS derived from dual-expressing adenoviral vectors is a highly effective method to monitor therapeutic gene transfer and expression in a noninvasive manner

  5. Targeted cancer gene therapy : the flexibility of adenoviral gene therapy vectors

    Rots, MG; Curiel, DT; Gerritsen, WR; Haisma, HJ

    2003-01-01

    Recombinant adenoviral vectors are promising reagents for therapeutic interventions in humans, including gene therapy for biologically complex diseases like cancer and cardiovascular diseases. In this regard, the major advantage of adenoviral vectors is their superior in vivo gene transfer efficienc

  6. Fetal muscle gene transfer is not enhanced by an RGD capsid modification to high-capacity adenoviral vectors.

    Bilbao, R; Reay, D P; Hughes, T; Biermann, V; Volpers, C; Goldberg, L; Bergelson, J; Kochanek, S; Clemens, P R

    2003-10-01

    High levels of alpha(v) integrin expression by fetal muscle suggested that vector re-targeting to integrins could enhance adenoviral vector-mediated transduction, thereby increasing safety and efficacy of muscle gene transfer in utero. High-capacity adenoviral (HC-Ad) vectors modified by an Arg-Gly-Asp (RGD) peptide motif in the HI loop of the adenoviral fiber (RGD-HC-Ad) have demonstrated efficient gene transfer through binding to alpha(v) integrins. To test integrin targeting of HC-Ad vectors for fetal muscle gene transfer, we compared unmodified and RGD-modified HC-Ad vectors. In vivo, unmodified HC-Ad vector transduced fetal mouse muscle with four-fold higher efficiency compared to RGD-HC-Ad vector. Confirming that the difference was due to muscle cell autonomous factors and not mechanical barriers, transduction of primary myogenic cells isolated from murine fetal muscle in vitro demonstrated a three-fold better transduction by HC-Ad vector than by RGD-HC-Ad vector. We hypothesized that the high expression level of coxsackievirus and adenovirus receptor (CAR), demonstrated in fetal muscle cells both in vitro and in vivo, was the crucial variable influencing the relative transduction efficiencies of HC-Ad and RGD-HC-Ad vectors. To explore this further, we studied transduction by HC-Ad and RGD-HC-Ad vectors in paired cell lines that expressed alpha(v) integrins and differed only by the presence or absence of CAR expression. The results increase our understanding of factors that will be important for retargeting HC-Ad vectors to enhance gene transfer to fetal muscle. PMID:12960972

  7. Vascular gene transfer from metallic stent surfaces using adenoviral vectors tethered through hydrolysable cross-linkers.

    Fishbein, Ilia; Forbes, Scott P; Adamo, Richard F; Chorny, Michael; Levy, Robert J; Alferiev, Ivan S

    2014-01-01

    In-stent restenosis presents a major complication of stent-based revascularization procedures widely used to re-establish blood flow through critically narrowed segments of coronary and peripheral arteries. Endovascular stents capable of tunable release of genes with anti-restenotic activity may present an alternative strategy to presently used drug-eluting stents. In order to attain clinical translation, gene-eluting stents must exhibit predictable kinetics of stent-immobilized gene vector release and site-specific transduction of vasculature, while avoiding an excessive inflammatory response typically associated with the polymer coatings used for physical entrapment of the vector. This paper describes a detailed methodology for coatless tethering of adenoviral gene vectors to stents based on a reversible binding of the adenoviral particles to polyallylamine bisphosphonate (PABT)-modified stainless steel surface via hydrolysable cross-linkers (HC). A family of bifunctional (amine- and thiol-reactive) HC with an average t1/2 of the in-chain ester hydrolysis ranging between 5 and 50 days were used to link the vector with the stent. The vector immobilization procedure is typically carried out within 9 hr and consists of several steps: 1) incubation of the metal samples in an aqueous solution of PABT (4 hr); 2) deprotection of thiol groups installed in PABT with tris(2-carboxyethyl) phosphine (20 min); 3) expansion of thiol reactive capacity of the metal surface by reacting the samples with polyethyleneimine derivatized with pyridyldithio (PDT) groups (2 hr); 4) conversion of PDT groups to thiols with dithiothreitol (10 min); 5) modification of adenoviruses with HC (1 hr); 6) purification of modified adenoviral particles by size-exclusion column chromatography (15 min) and 7) immobilization of thiol-reactive adenoviral particles on the thiolated steel surface (1 hr). This technique has wide potential applicability beyond stents, by facilitating surface engineering of

  8. Adenoviral p53 gene transfer and gemcitabine in three patients with liver metastases due to advanced pancreatic carcinoma

    Thiede, Christian; Fischer, Rainer; Ehninger, Gerhard; Haag, Cornelie

    2007-01-01

    Background. Current therapies for adenocarcinoma of the pancreas do not improve the life expectancy of patients. Methods. In a non-randomized pilot trail we tested whether a local therapy based upon an adenoviral gene transfer of wild type p53 in combination with gemcitabine administration would be safe in patients with liver metastases due to pancreatic carcinoma. We report on the clinical course of three patients with respect to safety, tolerability and tumor response. Results. Transient grade III toxicities occurred with fever, leucopenia, elevation of AP, ALT, AST, GGT, while grade IV toxicity occurred for bilirubin only. Laboratory tests suggested disseminated intravascular coagulation in all three patients, but fine needle biopsies of liver did not show any histological evidence of thrombus or clot formation. Progression of liver metastases was documented in one and stable disease in another patient two months after treatment. However, a major improvement with regression of the indexed lesion by 80% occurred in a third patient after a single administration of 7.5×1012 viral particles, and time to progression was extended to six months. Conclusion. The combination therapy of viral gene transfer and chemotherapy temporarily controls and diminishes tumor burden. Improvement of the toxicity profile is necessary. Further trials are warranted to improve treatment and life expectancy of patients suffering from fatal diseases such as pancreatic carcinoma. PMID:18333108

  9. Vascular Gene Transfer from Metallic Stent Surfaces Using Adenoviral Vectors Tethered through Hydrolysable Cross-linkers

    Fishbein, Ilia; Forbes, Scott P.; Adamo, Richard F.; Chorny, Michael; Levy, Robert J.; Alferiev, Ivan S.

    2014-01-01

    In-stent restenosis presents a major complication of stent-based revascularization procedures widely used to re-establish blood flow through critically narrowed segments of coronary and peripheral arteries. Endovascular stents capable of tunable release of genes with anti-restenotic activity may present an alternative strategy to presently used drug-eluting stents. In order to attain clinical translation, gene-eluting stents must exhibit predictable kinetics of stent-immobilized gene vector r...

  10. Adenoviral gene delivery to primary human cutaneous cells and burn wounds

    Hirsch, Stephan Tobias Florian; von Peter, Sebastian; Dubin, Grzegorz; Mittler, Dominik; Jacobsen, Frank; Lehnhardt, Marcus; Eriksson, Elof; Steinau, Hans-Ulrich; Steinsträßer, Lars

    2006-01-01

    The adenoviral transfer of therapeutic genes into epidermal and dermal cells is an interesting approach to treat skin diseases and to promote wound healing. The aim of this study was to assess the in vitro and in vivo transfection efficacy in skin and burn wounds after adenoviral gene delivery. Primary keratinocytes (HKC), fibroblasts (HFB), and HaCaT cells were transfected using different concentrations of an adenoviral construct (eGFP). Transfection efficiency and cytotoxicity was determine...

  11. Adenoviral gene transfer of endothelial nitric-oxide synthase (eNOS) partially restores normal pulmonary arterial pressure in eNOS-deficient mice

    Champion, Hunter C.; Bivalacqua, Trinity J.; Greenberg, Stanley S.; Giles, Thomas D.; Hyman, Albert L.; Kadowitz, Philip J.

    2002-01-01

    It has been shown that mice deficient in the gene coding for endothelial nitric-oxide synthase (eNOS) have increased pulmonary arterial pressure and pulmonary vascular resistance. In the present study, the effect of transfer to the lung of an adenoviral vector encoding the eNOS gene (AdCMVeNOS) on pulmonary arterial pressure and pulmonary vascular resistance was investigated in eNOS-deficient mice. One day after intratracheal administration of AdCMVeNOS to eNOS−/− mice, there was an increase in eNOS protein, cGMP levels, and calcium-dependent conversion of l-arginine to l-citrulline in the lung. The increase in eNOS protein and activity in eNOS−/− mice was associated with a reduction in mean pulmonary arterial pressure and pulmonary vascular resistance when compared with values in eNOS-deficient mice treated with vehicle or a control adenoviral vector coding for β-galactosidase, AdCMVβgal. These data suggest that in vivo gene transfer of eNOS to the lung in eNOS−/− mice can increase eNOS staining, eNOS protein, calcium-dependent NOS activity, and cGMP levels and partially restore pulmonary arterial pressure and pulmonary vascular resistance to near levels measured in eNOS+/+ mice. Thus, the major finding in this study is that in vivo gene transfer of eNOS to the lung in large part corrects a genetic deficiency resulting from eNOS deletion and may be a useful therapeutic intervention for the treatment of pulmonary hypertensive disorders in which eNOS activity is reduced. PMID:12237402

  12. Adenoviral Vectors for Hemophilia Gene Therapy

    Brunetti-Pierri, N; Ng, Philip

    2013-01-01

    Hemophilia is an inherited blood clotting disorder resulting from deficiency of blood coagulation factors. Current standard of care for hemophilia patients is frequent intravenous infusions of the missing coagulation factor. Gene therapy for hemophilia involves the introduction of a normal copy of the deficient coagulation factor gene thereby potentially offering a definitive cure for the bleeding disorder. A variety of approaches have been pursued for hemophilia gene therapy and this review article focuses on those that use adenoviral vectors. PMID:24883229

  13. Helper-dependent adenoviral vectors in experimental gene therapy*

    Józkowicz, Alicja; Dulak, Józef

    2005-01-01

    In the majority of potential applications gene therapy will require an effective transfer of a transgene in vivo resulting in high-level and long-term transgene expression, all in the absence of significant toxicity or inflammatory responses. The most efficient vehicles for delivery of foreign genes to the target tissues are modified adenoviruses. Adenoviral vectors of the first generation, despite the high infection efficacy, have an essential drawback: they induce strong immune response, wh...

  14. Treatment of colorectal and hepatocellular carcinomas by adenoviral mediated gene transfer of endostatin and angiostatin-like molecule in mice

    Schmitz, V; Wang, L.; Barajas, M. (Miguel); Gomar, C.; Prieto, J.; Qian, C

    2004-01-01

    Aim and method: In this study, we explored the responsiveness of different tumour entities (colorectal carcinoma (CRC), hepatocellular carcinoma (HCC), and the murine Lewis lung carcinoma (LLC)) to angiostatic antitumour treatment with two recombinant adenoviral vectors encoding angiostatin-like molecule (AdK1-3) and endostatin (Adendo).

  15. Adenoviral gene transfer into the normal and injured spinal cord: enhanced transgene stability by combined administration of temperature-sensitive virus and transient immune blockade.

    Romero, M I; Smith, G M

    1998-12-01

    This study characterized gene transfer into both normal and injured adult rat dorsal spinal cord using first (E1-/E3-) or second (E1-/E2A125/E3-, temperature-sensitive; ts) generation of replication-defective adenoviral (Ad) vectors. A novel immunosuppressive regimen aimed at blocking CD4/CD45 lymphocytic receptors was tested for improving transgene persistence. In addition, the effect of gene transfer on nociception was also evaluated. Seven days after treatment, numerous LacZ-positive cells were observed after transfection with either viral vector. By 21 days after transfection, beta-galactosidase staining was reduced and suggestive of ongoing cytopathology in both Ad-treated groups, despite the fact that the immunogenicity of LacZ/Adts appeared less when compared with that elicited by the LacZ/Ad vector. In contrast, immunosuppressed animals showed a significant (P < or = 0.05) increase in the number of LacZ-positive cells not displaying cytopathology. In these animals, a concomitant reduction in numbers of macrophages/microglia and CD4 and CD8 lymphocytes was observed. Only animals that received LacZ/Adts and immunosuppression showed transgene expression after 60 days. Similar results were observed in animals in which the L4-L5 dorsal roots were lesioned before transfection. Gene transfer into the dorsal spinal cord did not affect nociception, independent of the adenovirus vector. These results indicate that immune blockade of the CD4/CD45 lymphocytic receptors enhanced transgene stability in adult animals with normal or injured spinal cords and that persistent transgene expression in the spinal cord does not interfere with normal neural function. PMID:10023440

  16. Adenoviral gene transfer corrects the ion transport defect in the sinus epithelia of a porcine CF model.

    Potash, Andrea E; Wallen, Tanner J; Karp, Philip H; Ernst, Sarah; Moninger, Thomas O; Gansemer, Nicholas D; Stoltz, David A; Zabner, Joseph; Chang, Eugene H

    2013-05-01

    Cystic fibrosis (CF) pigs spontaneously develop sinus and lung disease resembling human CF. The CF pig presents a unique opportunity to use gene transfer to test hypotheses to further understand the pathogenesis of CF sinus disease. In this study, we investigated the ion transport defect in the CF sinus and found that CF porcine sinus epithelia lack cyclic AMP (cAMP)-stimulated anion transport. We asked whether we could restore CF transmembrane conductance regulator gene (CFTR) current in the porcine CF sinus epithelia by gene transfer. We quantified CFTR transduction using an adenovirus expressing CFTR and green fluorescent protein (GFP). We found that as little as 7% of transduced cells restored 6% of CFTR current with 17-28% of transduced cells increasing CFTR current to 50% of non-CF levels. We also found that we could overcorrect cAMP-mediated current in non-CF epithelia. Our findings indicate that CF porcine sinus epithelia lack anion transport, and a relatively small number of cells expressing CFTR are required to rescue the ion transport phenotype. These studies support the use of the CF pig as a preclinical model for future gene therapy trials in CF sinusitis. PMID:23511247

  17. Effects of adenoviral gene transfer of mutated IкBα, a novel inhibitor of NF-кb, on human monocyte-derived dendritic cells

    Lin-fu ZHOU; Ming-shun ZHANG; Kai-sheng YIN; Yong JI; Wei-ping XIE; Xue-fan GUI; Xiao-hui JI

    2006-01-01

    Aim: To investigate the effects of adenoviral gene transfer of IкBα mutant (IкBαM), a novel inhibitor of nuclear factor кB (NF- кB), on apoptosis, phenotype and function of human monocyte-derived dendritic cells (DC). Methods: Monocytes, cocultured with granulocyte/macrophage colony-stimulating factor (GM-CSF; 900 ng/mL) and interleukin (IL)-4 (300 ng/mL) for 5 d, followed by stimulation with lipopolysaccharide (LPS; 100 ng/mL) for 2 d differentiated into mature DC. Monocytes were either left untransfected or were transfected with Ad IкBαM or AdLacZ. The transcription and expression of the IкBαM gene, and the inhibitory effect of IкBαM on tumor necrosis factor (TNF)-α-induced NF-кB activation in mature DC were detected by polymerase chain reaction (PCR), reverse transcription-polymerase chain reaction (RT-PCR), Western blot analysis, and electrophoretic mobility shift assays, respectively. The phenotype, apoptosis, IL-12 secretion level of DC, and ability to stimulate the proliferation of T cells were determined by flow cytometry, enzyme-linked immunosorbent assay and mixed leukocyte reaction. Results: PCR and RT-PCR were used to detect a unique 801 bp band in Ad IкBαM-transfected mature DC, and also a dose- and time-dependent expression of the IкBαM gene, which peaked at a multiplicity of infection of 100 pfu/cell and at 48 h. Furthermore, Ad IкBαM significantly suppressed the TNF-α-induced NF- кB activation, augmented apoptosis, downregulated CD80, CD83, and CD86 surface molecules, IL-12 secretion levels and the ability to stimulate the proliferation of T cells in mature DC. Conclusion: Ad IкBαM effectively transfected and potently inhibited NF-кB activation in monocyte-derived mature DC. Overexpression of the IкBαM gene in mature DC may contribute to T-cell immunosuppression through induction of DC apoptosis and downregulation of B7 molecules, providing a potential strategy for future DC-based immunotherapy of asthma.

  18. Prevention of beta cell dysfunction and apoptosis by adenoviral gene transfer of rat insulin-like growth factor 1

    CHEN Zhi-hong; LI Tang; CHEN Zong-bo; LUO Bing; SUN Ruo-peng

    2009-01-01

    Background Islet β-cells are almost completely destroyed when patients with type 1 diabete are diagnosed. To date, insulin substitute therapy is still one of the main treatments. The cure of type 1 diabetes requires β-cell regeneration from islet cell precursors and prevention of recurring autoimmunity, Therefore, β-cell regeneration and proliferation emerge as a new research focus on therapy for type 1 diabetes. Islet β-cell regeneration and development are controlled by many growth factors, especially insulin-like growth factor-1 (IGF-1).Methods Recombinant adenovirus encoding rat IGF-1 (rlGF-1) was constructed and transduced into rat β-cells, RINm5F cells. Western blotting analysis and ELISA were used to detect rlGF-1 protein. Streptozotocin (STZ) was used to induce RINm5F cell destruction. The level of nitric oxide (NO) was detected in cell culture supernatants by the Griess reaction. Islet cell function was evaluated by glucose-stimulated insulin production. Flow cytometry analysis was further used to investigate the apoptosis of RINm5F cells. Thiaoollyl blue viability assay was applied to determine cell viability.Results The recombined adenovirus-rlGF-1 was successfully constructed and the titer was 4.0×108pfu/ml. The rlGF-1 protein was effectively expressed in the RINm5F cells and cell culture supernatants, rlGF-1 expression remarkably inhibited STZ-induced islet cell apoptosis and significantly decreased the level of NO. Furthermore, IGF-1 expression also significantly protected insulin secretion and cell proliferation in a time-dependent manner.Conclusions Our study suggests that locally produced rlGF-1 from RINm5F cells may be beneficial in maintaining β-cell function, protecting β-cells from the destruction of apoptosis factors and promoting β-cell survival and proliferation. IGF-1 might be considered as a candidate gene in gene therapy for type 1 diabetes. In addition, it appears that the apoptosis induced by STZ may be NO-dependent.

  19. Adenoviral gene therapy in gastric cancer: A review

    Nima Khalighinejad; Hesammodin Hariri; Omid Behnamfar; Arash Yousefi; Amir Momeni

    2008-01-01

    Gastric cancer is one of the most common malignancies worldwide. With current therapeutic approaches the prognosis of gastric cancer is very poor, as gastric cancer accounts for the second most common cause of death in cancer related deaths. Gastric cancer like almost all other cancers has a molecular genetic basis which relies on disruption in normal cellular regulatory mechanisms regarding cell growth, apoptosis and cell division. Thus novel therapeutic approaches such as gene therapy promise to become the alternative choice of treatment in gastric cancer. In gene therapy, suicide genes, tumor suppressor genes and anti-angiogenesis genes among many others are introduced to cancer cells via vectors.Some of the vectors widely used in gene therapy are Adenoviral vectors. This review provides an update of the new developments in adenoviral cancer gene therapy including strategies for inducing apoptosis, inhibiting metastasis and targeting the cancer cells.

  20. Gene Therapy with Helper-Dependent Adenoviral Vectors: Current Advances and Future Perspectives

    Philip Ng

    2010-09-01

    Full Text Available Recombinant Adenoviral vectors represent one of the best gene transfer platforms due to their ability to efficiently transduce a wide range of quiescent and proliferating cell types from various tissues and species. The activation of an adaptive immune response against the transduced cells is one of the major drawbacks of first generation Adenovirus vectors and has been overcome by the latest generation of recombinant Adenovirus, the Helper-Dependent Adenoviral (HDAd vectors. HDAds have innovative features including the complete absence of viral coding sequences and the ability to mediate high level transgene expression with negligible chronic toxicity. This review summarizes the many aspects of HDAd biology and structure with a major focus on in vivo gene therapy application and with an emphasis on the unsolved issues that these vectors still presents toward clinical application.

  1. Adenoviral Vectors for Hemophilia Gene Therapy

    Brunetti-Pierri, N.; Ng, Philip

    2013-01-01

    Hemophilia is an inherited blood clotting disorder resulting from deficiency of blood coagulation factors. Current standard of care for hemophilia patients is frequent intravenous infusions of the missing coagulation factor. Gene therapy for hemophilia involves the introduction of a normal copy of the deficient coagulation factor gene thereby potentially offering a definitive cure for the bleeding disorder. A variety of approaches have been pursued for hemophilia gene therapy and this review ...

  2. Clinical adenoviral gene therapy for prostate cancer

    Schenk, E.; Essand, M.; Bangma, Ch. H.; Barber, Ch.; Behr, J.-P.; Briggs, S.; Carlisle, R.; Cheng, W.-S.; Danielsson, A.; Dautzenberg, I. J. C.; Dzojic, H.; Erbacher, P.; Fisher, K.; Frazier, A.; Georgopoulos, L. J.; Hoeben, R.; Kochanek, S.; Koppers-Lalic, D.; Kraaij, R.; Kreppel, F.; Lindholm, L.; Magnusson, M.; Maitland, N.; Neuberg, P.; Nilsson, B.; Ogris, M.; Remy, J.-S.; Scaife, M.; Schooten, E.; Seymour, L.; Totterman, T.; Uil, T. G.; Ulbrich, Karel; Veldhoven-Zweistra, J. L. M.; de Vrij, J.; van Weerden, W.; Wagner, E.; Willemsen, R.

    2010-01-01

    Roč. 21, č. 7 (2010), s. 807-813. ISSN 1043-0342 EU Projects: European Commission(XE) 512087 - GIANT Keywords : adenovirus * gene delivery * prostate cancer Subject RIV: CD - Macromolecular Chemistry Impact factor: 4.829, year: 2010

  3. Anti-Inflammatory Effects of Modified Adenoviral Vectors for Gene Therapy: A View through Animal Models Tested.

    Castañeda-Lopez, M E; Garza-Veloz, I; Lopez-Hernandez, Y; Barbosa-Cisneros, O Y; Martinez-Fierro, M L

    2016-07-01

    The central dogma of gene therapy relies on the application of novel therapeutic genes to treat or prevent diseases. The main types of vectors used for gene transfer are adenovirus, retrovirus, lentivirus, liposome, and adeno-associated virus vectors. Gene therapy has emerged as a promising alternative for the treatment of inflammatory diseases. The main targets are cytokines, co-stimulatory molecules, and different types of cells from hematological and mesenchymal sources. In this review, we focus on molecules with anti-inflammatory effects used for in vivo gene therapy mediated by adenoviral gene transfer in the treatment of immune-mediated inflammatory diseases, with particular emphasis on autoinflammatory and autoimmune diseases. PMID:27245510

  4. Evaluation of signal transduction pathways after transient cutaneous adenoviral gene delivery

    Steinau Hans-Ulrich

    2011-01-01

    Full Text Available Abstract Background Adenoviral vectors have provided effective methods for in vivo gene delivery in therapeutic applications. However, these vectors can induce immune responses that may severely affect the ability of vector re-application. There is limited information about the mechanisms and signal transduction pathways involved in adenoviral recognition. For optimization of cutaneous gene therapy it is necessary to investigate molecular mechanisms of virus recognition in epidermal cells. The aim of this study was to investigate the signal transduction of the innate immunity after adenoviral DNA internalization in keratinocytes. Methods In vitro, keratinocytes were transfected with DNA, in the presence and absence of inhibitors for signalling molecules. In vivo, immunocompetent and athymic mice (n = 3 per group were twice transduced with an Ad-vector. Results The results show an acute induction of type-I-interferon after in vitro transfection. Inhibition of PI3K, p38 MAPK, JNK and NFkappaB resulted in a decreased expression of type-I-interferon. In contrast to immunocompetent mice, athymic mice demonstrated a constant transgene expression and reduced inflammatory response in vivo. Conclusion The results suggest an induction of the innate immunity triggered by cytoplasm localised DNA which is mediated by PI3K-, p38 MAPK-, JNK-, NFkappaB-, JAK/STAT- and ERK1/2-dependent pathways. A stable transgene expression and a reduced inflammatory response in immunodeficient mice have been observed. These results provide potential for an effective adenoviral gene delivery into immunosupressed skin.

  5. Tropism-modification strategies for targeted gene delivery using adenoviral vectors

    Baker, Andrew H; Parker, Alan L.; Bradshaw, Angela C.; Nicklin, Stuart A.; McNeish, Iain A; Raul Alba; Lynda Coughlan

    2010-01-01

    Achieving high efficiency, targeted gene delivery with adenoviral vectors is a long-standing goal in the field of clinical gene therapy. To achieve this, platform vectors must combine efficient retargeting strategies with detargeting modifications to ablate native receptor binding (i.e. CAR/integrins/heparan sulfate proteoglycans) and “bridging” interactions. “Bridging” interactions refer to coagulation factor binding, namely coagulation factor X (FX), which bridges hepatocyte transduction in...

  6. Helper-dependent adenoviral vectors for liver-directed gene therapy

    Brunetti-Pierri, Nicola; Ng, Philip

    2011-01-01

    Helper-dependent adenoviral (HDAd) vectors devoid of all viral-coding sequences are promising non-integrating vectors for liver-directed gene therapy because they have a large cloning capacity, can efficiently transduce a wide variety of cell types from various species independent of the cell cycle and can result in long-term transgene expression without chronic toxicity. The main obstacle preventing clinical applications of HDAd for liver-directed gene therapy is the host innate inflammatory...

  7. Adenoviral-mediated localized CTLA-4Ig gene expression induces long-term allograft pancreas survival and donor-specific immune tolerance in rats

    2008-01-01

    T cell activation following alloantigen recognition plays a critical role in the development of the rejection in all solid organ, tissue and cell transplantation. A recombinant molecule, cytotoxic T lymphocyte antigen 4 antibody (CTLA-4Ig), is known to induce to T-cell into "anergy" by blocking the costimulatory B7-CD28 interaction. Either systemic or localized administration of CTLA-Ig has been shown to prolong allograft survival and induce donor-specific tolerance in some transplant models. In this study, we characterized the expression and immunosuppressive effectiveness of adenoviral-mediated CTLA-4Ig gene transfer. We demonstrated transduction of the allografts with AdCTLA-41g resulted in localized expression, permanent graft survival and stable donor-specific tolerance. In addition, by performing simultaneous dual-organ transplantation, we targeted on immunosuppression through a local expression of CTLA-4Ig via adenoviral-mediated gene transfer into pancreatic allografts.

  8. Challenges and Prospects for Helper-Dependent Adenoviral Vector-Mediated Gene Therapy

    Pasquale Piccolo; Nicola Brunetti-Pierri

    2014-01-01

    Helper-dependent adenoviral (HDAd) vectors that are devoid of all viral coding sequences are promising non-integrating vectors for gene therapy because they efficiently transduce a variety of cell types in vivo, have a large cloning capacity, and drive long-term transgene expression without chronic toxicity. The main obstacle preventing clinical applications of HDAd vectors is the host innate inflammatory response against the vector capsid proteins that occurs shortly after intravascular vect...

  9. Challenges and Prospects for Helper-Dependent Adenoviral Vector-Mediated Gene Therapy

    Pasquale Piccolo

    2014-04-01

    Full Text Available Helper-dependent adenoviral (HDAd vectors that are devoid of all viral coding sequences are promising non-integrating vectors for gene therapy because they efficiently transduce a variety of cell types in vivo, have a large cloning capacity, and drive long-term transgene expression without chronic toxicity. The main obstacle preventing clinical applications of HDAd vectors is the host innate inflammatory response against the vector capsid proteins that occurs shortly after intravascular vector administration and result in acute toxicity, the severity of which is dose dependent. Intense efforts have been focused on elucidating adenoviral vector–host interactions and the factors involved in the acute toxicity. This review focuses on the recent acquisition of data on such interactions and on strategies investigated to improve the therapeutic index of HDAd vectors.

  10. Adenoviral delivery of the EMX2 gene suppresses growth in human gastric cancer.

    Jie Li

    Full Text Available BACKGROUND: EMX2 is a human orthologue of the Drosophila empty spiracles homeobox gene that has been implicated in embryogenesis. Recent studies suggest possible involvement of EMX2 in human cancers; however, the role of EMX2 in carcinogenesis needs further exploration. RESULTS: In this study, we reported that down-regulation of EMX2 expression was significantly correlated with EMX2 promoter hypermethylation in gastric cancer. Restoring EMX2 expression using an adenovirus delivery system in gastric cancer cell lines lacking endogenous EMX2 expression led to inhibition of cell proliferation and Wnt signaling pathway both in vitro and in a gastric cancer xenograft model in vivo. In addition, we observed that animals treated with the adenoviral EMX2 expression vector had significantly better survival than those treated with empty adenoviral vector. CONCLUSION: Our study suggests that EMX2 is a putative tumor suppressor in human gastric cancer. The adenoviral-EMX2 may have potential as a novel gene therapy for the treatment of patients with gastric cancer.

  11. Adenoviral Delivery of the EMX2 Gene Suppresses Growth in Human Gastric Cancer

    Li, Jie; Mo, Minli; Chen, Zhao; Chen, Zhe; Sheng, Qing; Mu, Hang; Zhang, Fang; Zhang, Yi; Zhi, Xiu-Yi; Li, Hui; He, Biao; Zhou, Hai-Meng

    2012-01-01

    Background EMX2 is a human orthologue of the Drosophila empty spiracles homeobox gene that has been implicated in embryogenesis. Recent studies suggest possible involvement of EMX2 in human cancers; however, the role of EMX2 in carcinogenesis needs further exploration. Results In this study, we reported that down-regulation of EMX2 expression was significantly correlated with EMX2 promoter hypermethylation in gastric cancer. Restoring EMX2 expression using an adenovirus delivery system in gastric cancer cell lines lacking endogenous EMX2 expression led to inhibition of cell proliferation and Wnt signaling pathway both in vitro and in a gastric cancer xenograft model in vivo. In addition, we observed that animals treated with the adenoviral EMX2 expression vector had significantly better survival than those treated with empty adenoviral vector. Conclusion Our study suggests that EMX2 is a putative tumor suppressor in human gastric cancer. The adenoviral-EMX2 may have potential as a novel gene therapy for the treatment of patients with gastric cancer. PMID:23029345

  12. Radiation-Induced Upregulation of Gene Expression From Adenoviral Vectors Mediated by DNA Damage Repair and Regulation

    Purpose: In the present study, we evaluated the combination of replication-deficient adenoviruses and radiotherapy in vitro. The purpose of the present study was to analyze the mechanism of radiation-mediated upregulation of adenoviral transgene expression. Methods and Materials: Adenoviral transgene expression (luciferase or green fluorescent protein) was studied with and without radiation in three cell lines: breast cancer M4A4-LM3, prostate cancer PC-3MM2, and lung cancer LNM35/enhanced green fluorescent protein. The effect of the radiation dose, modification of the viral capsid, and five different transgene promoters were studied. The cellular responses were studied using mass spectrometry and immunofluorescence analysis. Double strand break repair was modulated by inhibitors of heat shock protein 90, topoisomerase-I, and DNA protein kinase, and transgene expression was measured. Results: We found that a wide range of radiation doses increased adenoviral transgene expression regardless of the cell line, transgene, promoter, or viral capsid modification. Treatment with adenovirus, radiation, and double strand break repair inhibitors resulted in persistence of double strand breaks and subsequent increases in adenovirus transgene expression. Conclusions: Radiation-induced enhancement of adenoviral transgene expression is linked to DNA damage recognition and repair. Radiation induces a global cellular response that results in increased production of RNA and proteins, including adenoviral transgene products. This study provides a mechanistic rationale for combining radiation with adenoviral gene delivery.

  13. Radiation-Induced Upregulation of Gene Expression From Adenoviral Vectors Mediated by DNA Damage Repair and Regulation

    Nokisalmi, Petri; Rajecki, Maria; Pesonen, Sari; Escutenaire, Sophie [Cancer Gene Therapy Group, Molecular Cancer Biology Program, Transplantation Laboratory, Haartman Institute, and Finnish Institute for Molecular Medicine, University of Helsinki, Helsinki (Finland); Helsinki and Uusimaa Hospital District Laboratory, Helsinki University Central Hospital, Helsinki (Finland); Soliymani, Rabah [Protein Chemistry Unit, Department of Anatomy, Institute of Biomedicine, Biomedicum Helsinki (Finland); Tenhunen, Mikko [Department of Radiation and Oncology, Helsinki University Central Hospital, Helsinki (Finland); Ahtiainen, Laura [Cancer Gene Therapy Group, Molecular Cancer Biology Program, Transplantation Laboratory, Haartman Institute, and Finnish Institute for Molecular Medicine, University of Helsinki, Helsinki (Finland); Helsinki and Uusimaa Hospital District Laboratory, Helsinki University Central Hospital, Helsinki (Finland); Hemminki, Akseli, E-mail: akseli.hemminki@helsinki.fi [Cancer Gene Therapy Group, Molecular Cancer Biology Program, Transplantation Laboratory, Haartman Institute, and Finnish Institute for Molecular Medicine, University of Helsinki, Helsinki (Finland); Helsinki and Uusimaa Hospital District Laboratory, Helsinki University Central Hospital, Helsinki (Finland)

    2012-05-01

    Purpose: In the present study, we evaluated the combination of replication-deficient adenoviruses and radiotherapy in vitro. The purpose of the present study was to analyze the mechanism of radiation-mediated upregulation of adenoviral transgene expression. Methods and Materials: Adenoviral transgene expression (luciferase or green fluorescent protein) was studied with and without radiation in three cell lines: breast cancer M4A4-LM3, prostate cancer PC-3MM2, and lung cancer LNM35/enhanced green fluorescent protein. The effect of the radiation dose, modification of the viral capsid, and five different transgene promoters were studied. The cellular responses were studied using mass spectrometry and immunofluorescence analysis. Double strand break repair was modulated by inhibitors of heat shock protein 90, topoisomerase-I, and DNA protein kinase, and transgene expression was measured. Results: We found that a wide range of radiation doses increased adenoviral transgene expression regardless of the cell line, transgene, promoter, or viral capsid modification. Treatment with adenovirus, radiation, and double strand break repair inhibitors resulted in persistence of double strand breaks and subsequent increases in adenovirus transgene expression. Conclusions: Radiation-induced enhancement of adenoviral transgene expression is linked to DNA damage recognition and repair. Radiation induces a global cellular response that results in increased production of RNA and proteins, including adenoviral transgene products. This study provides a mechanistic rationale for combining radiation with adenoviral gene delivery.

  14. Adenoviral gene therapy in gastric cancer: A review

    Khalighinejad, Nima; Hariri, Hesammodin; Behnamfar, Omid; Yousefi, Arash; Momeni, Amir

    2008-01-01

    Gastric cancer is one of the most common malignancies worldwide. With current therapeutic approaches the prognosis of gastric cancer is very poor, as gastric cancer accounts for the second most common cause of death in cancer related deaths. Gastric cancer like almost all other cancers has a molecular genetic basis which relies on disruption in normal cellular regulatory mechanisms regarding cell growth, apoptosis and cell division. Thus novel therapeutic approaches such as gene therapy promi...

  15. Intra-arterial adenoviral mediated tumor transfection in a novel model of cancer gene therapy

    Siemionow Maria

    2006-08-01

    Full Text Available Abstract Background The aim of the present study was to develop and characterize a novel in vivo cancer gene therapy model in which intra-arterial adenoviral gene delivery can be characterized. In this model, the rat cremaster muscle serves as the site for tumor growth and provides convenient and isolated access to the tumor parenchyma with discrete control of arterial and venous access for delivery of agents. Results Utilizing adenovirus encoding the green fluorescent protein we demonstrated broad tumor transfection. We also observed a dose dependant increment in luciferase activity at the tumor site using an adenovirus encoding the luciferase reporter gene. Finally, we tested the intra-arterial adenovirus dwelling time required to achieve optimal tumor transfection and observed a minimum time of 30 minutes. Conclusion We conclude that adenovirus mediated tumor transfection grown in the cremaster muscle of athymic nude rats via an intra-arterial route could be achieved. This model allows definition of the variables that affect intra-arterial tumor transfection. This particular study suggests that allowing a defined intra-tumor dwelling time by controlling the blood flow of the affected organ during vector infusion can optimize intra-arterial adenoviral delivery.

  16. Clinical utility of recombinant adenoviral human p53 gene therapy: current perspectives

    Chen GX

    2014-10-01

    Full Text Available Guang-xia Chen,1,* Shu Zhang,2–4,* Xiao-hua He,1 Shi-yu Liu,1 Chao Ma,2–4 Xiao-Ping Zou2–4 1Department of Gastroenterology, First People’s Hospital of Xuzhou, Xuzhou, Jiangsu Province, People’s Republic of China; 2Department of Gastroenterology, Drum Tower Hospital, 3Medical School of Nanjing University, 4Jiangsu Clinical Medical Center of Digestive Disease, Nanjing, People’s Republic of China *These authors have contributed equally to the paperAbstract: Gene therapy has promised to be a highly effective antitumor treatment by introducing a tumor suppressor gene or the abrogation of an oncogene. Among the potential therapeutic transgenes, the tumor suppressor gene p53 serves as an attractive target. Restoration of wild-type p53 function in tumors can be achieved by introduction of an intact complementary deoxyribonucleic acid copy of the p53 gene using a suitable viral vector, in most cases an adenoviral vector (Adp53. Preclinical in vitro and in vivo studies have shown that Adp53 triggers a dramatic tumor regression response in various cancers. These viruses are engineered to lack certain early proteins and are thus replication defective, including Gendicine, SCH-58500, and Advexin. Several types of tumor-specific p53-expressing conditionally replicating adenovirus vectors (known as replication-competent CRAdp53 vectors have been developed, such as ONYX 015, AdDelta24-p53, SG600-p53, OBP-702, and H101. Various clinical trials have been conducted to investigate the safety and efficiency of these adenoviral vectors. In this review we will talk about the biological mechanisms, clinical utility, and therapeutic potentials of the replication-deficient Adp53-based and replication-competent CRAdp53-based gene therapy.Keywords: adenovirus, Adp53, CRAdp53

  17. Loss of Endothelial Barrier in Marfan Mice (mgR/mgR Results in Severe Inflammation after Adenoviral Gene Therapy.

    Philipp Christian Seppelt

    Full Text Available Marfan syndrome is an autosomal dominant inherited disorder of connective tissue. The vascular complications of Marfan syndrome have the biggest impact on life expectancy. The aorta of Marfan patients reveals degradation of elastin layers caused by increased proteolytic activity of matrix metalloproteinases (MMPs. In this study we performed adenoviral gene transfer of human tissue inhibitor of matrix metalloproteinases-1 (hTIMP-1 in aortic grafts of fibrillin-1 deficient Marfan mice (mgR/mgR in order to reduce elastolysis.We performed heterotopic infrarenal transplantation of the thoracic aorta in female mice (n = 7 per group. Before implantation, mgR/mgR and wild-type aortas (WT, C57BL/6 were transduced ex vivo with an adenoviral vector coding for human TIMP-1 (Ad.hTIMP-1 or β-galactosidase (Ad.β-Gal. As control mgR/mgR and wild-type aortas received no gene therapy. Thirty days after surgery, overexpression of the transgene was assessed by immunohistochemistry (IHC and collagen in situ zymography. Histologic staining was performed to investigate inflammation, the neointimal index (NI, and elastin breaks. Endothelial barrier function of native not virus-exposed aortas was evaluated by perfusion of fluorescent albumin and examinations of virus-exposed tissue were performed by transmission electron microscopy (TEM.IHC and ISZ revealed sufficient expression of the transgene. Severe cellular inflammation and intima hyperplasia were seen only in adenovirus treated mgR/mgR aortas (Ad.β-Gal, Ad.hTIMP-1 NI: 0.23; 0.43, but not in native and Ad.hTIMP-1 treated WT (NI: 0.01; 0.00. Compared to native mgR/mgR and Ad.hTIMP-1 treated WT aorta, the NI is highly significant greater in Ad.hTIMP-1 transduced mgR/mgR aorta (p = 0.001; p = 0.001. As expected, untreated Marfan grafts showed significant more elastolysis compared to WT (p = 0.001. However, elastolysis in Marfan aortas was not reduced by adenoviral overexpression of hTIMP-1 (compared to untreated

  18. Helper-dependent adenoviral vectors for liver-directed gene therapy of primary hyperoxaluria type 1

    Castello, Raffaele; Borzone, Roberta; D’Aria, Stefania; Annunziata, Patrizia; Piccolo, Pasquale; Brunetti-Pierri, Nicola

    2015-01-01

    Primary hyperoxaluria type 1 (PH1) is an inborn error of liver metabolism due to deficiency of the peroxisomal enzyme alanine:glyoxylate aminotransferase (AGT) which catalyzes conversion of glyoxylate into glycine. AGT deficiency results in overproduction of oxalate which ultimately leads to end-stage renal disease and death. Organ transplantation as either preemptive liver transplantation or combined liver/kidney transplantation is the only available therapy to prevent disease progression. Gene therapy is an attractive option to provide an alternative treatment for PH1. Towards this goal, we investigated helper-dependent adenoviral (HDAd) vectors for liver-directed gene therapy of PH1. Compared to saline controls, AGT-deficient mice injected with an HDAd encoding the AGT under the control of a liver-specific promoter showed a significant reduction of hyperoxaluria and less increase of urinary oxalate following challenge with Ethylene Glycol (EG), a precursor of glyoxylate. These studies may thus pave the way to clinical application of HDAd for PH1 gene therapy. PMID:26609667

  19. Comparison of osteogenic potentials of human rat BMP4 and BMP6 gene therapy using [E1-] and [E1-,E2b-] adenoviral vectors

    Hongwei Li, Jin Zhong Li, Debra D. Pittman, Andy Amalfitano, Gerald R. Hankins, Gregory A. Helm

    2006-01-01

    Full Text Available Osteogenic potentials of some recombinant human bone morphogenetic protein (BMP first-generation adenoviral vectors (ADhBMPs are significantly limited in immunocompetent animals. It is unclear what role expression of viral proteins and foreign proteins transduced by adenoviral vectors play in the host immune response and in ectopic bone formation. In this study two sets of experiments were designed and performed. First, rat BMP6 cDNA were amplified, sequenced, and recombined in first-generation adenoviral vector (ADrBMP6. A comparison of human and rat BMP6 adenoviral vectors demonstrated identical osteogenic activities in both immunodeficient and immunocompetent rats. Second, the activities of recombinant human BMP6 in E1- (ADhBMP6 and [E1-,E2b-] ( [E1-,E2b-]ADGFP&hBMP6, and [E1-,E2b-]ADhBMP6 adenoviral vectors were compared in both in vitro and in vivo models. Similar activities of these two generations of BMP adenoviral vectors were found in all models. These results indicate that the amount of viral gene expression and the source of the BMP cDNA are not major factors in the interruption of osteogenic potentials of recombinant BMP6 adenoviral vectors in immunocompetent animals.

  20. Effects of recombinant adenoviral vector containing IRE1α gene on proliferation and apoptosis of ATDC5 stem cells

    Xiang-zhu LI

    2013-09-01

    Full Text Available Objective To construct the recombinant adenoviral vector containing human IRE1α (type I transmembrane protein kinase/endoribonucleasegene, and investigate its effects on proliferation and apoptosis of ATDC5 stem cells. Methods  By using pAdEasyTM adenovirus vector system, the recombinant shuttle vectors of IRE1α full-length gene(pAdTrack-IRE1αand RNase+Kinasedomain(pAdTrack-R+Kwere constructed, and then transferred with pAdEasy-1 to generate recombinant adenovirus plasmid pAd-IRE1α and pAd-R+K by electroporation method. Subsequently, the plasmids were transfected into HEK-293 cells to pack and amplify the recombinant adenovirus Ad-IRE1α and Ad-R+K. The expression of recombinant adenovirus was detected by PCR. The ATDC5 cells wereinfected in vitro by recombinant adenovirus Ad-IRE1α and Ad-R+K, the infection efficiency of green fluorescent protein(GFPwas observed, and the influence of Ad-IRE1α and Ad-R+K on the proliferation and apoptosis of ATDC5 cells under endoplasmic reticulum stress(ERS or non-ERS was detected by flow cytometry(FCM. Results Restriction endonuclease digestion analysis and PCR indicated that the recombinant adenovirus vector Ad-IRE1α andAd-R+K was successfully constructed. FCM detection showed that under ERS conditions, the G1 phasedcreased and S phase increased in ATDC5 cells after transfected by Ad-IRE1α and Ad-R+K, meanwhile the apoptosis rate increased significantly(P<0.05. Conclusion Infection of recombinant adenovirus containing IRE1α gene may promote the proliferation and apoptosis of ATDC5cells.

  1. Tropism-Modification Strategies for Targeted Gene Delivery Using Adenoviral Vectors

    Andrew H. Baker

    2010-10-01

    Full Text Available Achieving high efficiency, targeted gene delivery with adenoviral vectors is a long-standing goal in the field of clinical gene therapy. To achieve this, platform vectors must combine efficient retargeting strategies with detargeting modifications to ablate native receptor binding (i.e. CAR/integrins/heparan sulfate proteoglycans and “bridging” interactions. “Bridging” interactions refer to coagulation factor binding, namely coagulation factor X (FX, which bridges hepatocyte transduction in vivo through engagement with surface expressed heparan sulfate proteoglycans (HSPGs. These interactions can contribute to the off-target sequestration of Ad5 in the liver and its characteristic dose-limiting hepatotoxicity, thereby significantly limiting the in vivo targeting efficiency and clinical potential of Ad5-based therapeutics. To date, various approaches to retargeting adenoviruses (Ad have been described. These include genetic modification strategies to incorporate peptide ligands (within fiber knob domain, fiber shaft, penton base, pIX or hexon, pseudotyping of capsid proteins to include whole fiber substitutions or fiber knob chimeras, pseudotyping with non-human Ad species or with capsid proteins derived from other viral families, hexon hypervariable region (HVR substitutions and adapter-based conjugation/crosslinking of scFv, growth factors or monoclonal antibodies directed against surface-expressed target antigens. In order to maximize retargeting, strategies which permit detargeting from undesirable interactions between the Ad capsid and components of the circulatory system (e.g. coagulation factors, erythrocytes, pre-existing neutralizing antibodies, can be employed simultaneously. Detargeting can be achieved by genetic ablation of native receptor-binding determinants, ablation of “bridging interactions” such as those which occur between the hexon of Ad5 and coagulation factor X (FX, or alternatively, through the use of polymer

  2. Radiosensitization effect of recombinant adenoviral-mediated PUMA gene on pancreatic carcinoma cells

    Objective: To study the effect of PUMA gene mediated by recombinant adenovirus vector combined with radiation on the pancreatic carcinoma. Methods: The PANC-1 cells were infected with Ad- PUMA (MOI=10, 50 and 100, respectively) for 48 h. The expression of PUMA mRNA and protein was detected by RT-PCR and Western blot, respectively. PANC-1 cells were divided into 4 groups: control group, transfection group, irradiation group and combined treatment group. The cell growth inhibition rate and apoptotic rate of PANC-1 cells were assessed by MTT assay and flow cytometry. Human pancreatic carcinomas were transplanted subcutaneously in nude mice, which were randomized into 4 groups: control group, transfection group, irradiation group and combined treatment group. Tumor growth rate and apoptotic index at different time points were recorded in 35 days. Results: The expression of PUMA mRNA and protein was increased with the increase of MOI of Ad-PUMA, which was does-dependant (MOI=10, mRNA=0.46± 0.02, protein=0.75± 0.09; MOI=50, mRNA=1.12±0.09, protein=1.01±0.18; MOI=100, mRNA=1.50±0.08, protein= 1.80±0.15; P3, (39.5±9.23)mm3, (33.6±10.3)mm3 and (52.0±11.43)mm3, respectively, P<0.05]. And the apoptotic index was increased in the same manner (AI=0.43±0.05, 0.29±0.10, 0.24±0.05 and 0.00±0.00, respectively, P<0.05). Conclusions: Recombinant adenoviral-mediated PUMA gene combined with irradiation could increase the cell-killing effect on pancreatic carcinoma. It is better than that of either one kind of therapy. (authors)

  3. Generation and characterization of novel adenoviral vectors for hybrid nuclease-mediated gene targeting

    Henriques, Sara Filipa Dias

    2013-01-01

    Tese de mestrado [versão pública]. Biologia (Biologia Humana e Ambiente). Universidade de Lisboa, Faculdade de Ciências, 2013 Adenovirus-based vectors are among the most efficient and disseminated gene transfer vehicles currently in use in a broad range of basic and applied research applications including the testing of gene therapy. As a gene therapy modality, gene targeting relies on the site-specific genome modification based on “integrases” or on the error-free homologous recombination...

  4. Comparison of [18F]FHBG and [14C]FIAU for imaging of HSV1-tk reporter gene expression: adenoviral infection vs stable transfection

    Earlier studies involving comparison of different reporter probes have shown conflicting results between pyrimidine nucleosides [e.g., 2'-fluoro-2'-deoxy-1-β-d-arabinofuranosyl-5-iodouracil (FIAU)] and acycloguanosine derivatives [e.g., penciclovir (PCV), 9-(4-fluoro-3-hydroxymethylbutyl)guanine (FHBG)]. We hypothesized that this reported discrepancy may be related to how the reporter gene is delivered to the cells - stably transfected vs adenoviral infection. We directly compared the uptake characteristics of [18F]FHBG, [3H]PCV, and [14C]FIAU in cell culture and in vivo using an adenoviral mediated gene transfer model and stably transfected cells. We further compared the uptake of three reporter probes using both HSV1-tk and a mutant HSV1-sr39tk expressing cells to assess the optimal reporter probe/reporter gene combination. [14C]FIAU accumulation was greater than that of [3H]PCV and [18F]FHBG in control cells and in HSV1-tk stably transfected cells (P8 pfu), [18F]FHBG and [3H]PCV accumulation was significantly greater than that of [14C]FIAU (P18F]FHBG and [3H]PCV accumulated to a significantly greater extent than [14C]FIAU in C6-stb-sr39tk+ and AdCMV-HSV1-sr39tk infected C6 cells (P14C]FIAU led to significantly higher %ID/g in C6-stb-tk+ xenografts than [18F]FHBG (P14C]FIAU, [18F]FHBG led to as high %ID/g in HSV1-tk expressing hepatocytes and to significantly greater %ID/g in C6-stb-sr39tk+ xenografts and HSV1-sr39tk expressing hepatocytes. Dynamic sequential images showed that [18F]FHBG was well retained in HSV1-sr39tk expressing cells (C6-stb-sr39tk+) for at least 4 h after injection, while it was rapidly cleared from HSV1-tk expressing cells (MH3924A-stb-tk+). [14C]FIAU accumulated in HSV1-tk stably expressing cells to a greater extent than either [3H]PCV or [18F]FHBG. However, the accumulation of [3H]PCV and [18F]FHBG in adenoviral infected C6 cells or hepatocytes was equivalent to or greater than that of [14C]FIAU. These results may be due to intracellular

  5. Novel approach to abuse the hyperactive K-Ras pathway for adenoviral gene therapy of colorectal cancer

    Background: Functional activation of oncogenic K-Ras signaling pathway plays an important role in the early events of colorectal carcinogenesis (CRC). K-Ras proto-oncogene is involved in 35–40% of CRC cases. Mutations in the Ras gene trigger the transduction of proliferative and anti-apoptotic signals, even in the absence of extra cellular stimuli. The objective of the current study was to use a gene-targeting approach to kill human CRC cells selectively harboring mutated K-Ras. Results: A recombinant adenovirus that carries a lethal gene, PUMA, under the control of a Ras responsive promoter (Ad-Py4-SV40-PUMA) was used selectively to target CRC cells (HCT116, SW480, DLD1 and RIE-Ras) that possess a hyperactive Ras pathway while using HT29 and RIE cells as a control that harbors wild type Ras and exhibit very low Ras activity. Control vector, without the Ras responsive promoter elements was used to assess the specificity of our “gene therapy” approach. Both adenoviral vectors were assed in vitro and in xenograft model in vivo. Ad-Py4-SV40-PUMA showed high potency to induce ∼ 50% apoptosis in vitro, to abolish completely tumor formation by infecting cells with the Ad-Py4-SV40-PUMA prior xenografting them in nude mice and high ability to suppress by ∼ 35% tumor progression in vivo in already established tumors. Conclusions: Selective targeting of CRC cells with the activated Ras pathway may be a novel and effective therapy in CRC. The high potency of this adenoviral vector may help to overcome an undetectable micro metastasis that is the major hurdle in challenging with CRC.

  6. Novel approach to abuse the hyperactive K-Ras pathway for adenoviral gene therapy of colorectal cancer

    Naumov, Inna [Integrated Cancer Prevention Center, Tel Aviv (Israel); Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv (Israel); Kazanov, Dina [Integrated Cancer Prevention Center, Tel Aviv (Israel); Lisiansky, Victoria [Integrated Cancer Prevention Center, Tel Aviv (Israel); Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv (Israel); Starr, Alex [Lung and Allergy Institute, Tel Aviv Sourasky Medical Center, Tel Aviv (Israel); Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv (Israel); Aroch, Ilan; Shapira, Shiran; Kraus, Sarah [Integrated Cancer Prevention Center, Tel Aviv (Israel); Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv (Israel); Arber, Nadir, E-mail: narber@post.tau.ac.il [Integrated Cancer Prevention Center, Tel Aviv (Israel); Department of Gastroenterology, Tel Aviv Sourasky Medical Center, Tel Aviv (Israel); Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv (Israel)

    2012-01-15

    Background: Functional activation of oncogenic K-Ras signaling pathway plays an important role in the early events of colorectal carcinogenesis (CRC). K-Ras proto-oncogene is involved in 35-40% of CRC cases. Mutations in the Ras gene trigger the transduction of proliferative and anti-apoptotic signals, even in the absence of extra cellular stimuli. The objective of the current study was to use a gene-targeting approach to kill human CRC cells selectively harboring mutated K-Ras. Results: A recombinant adenovirus that carries a lethal gene, PUMA, under the control of a Ras responsive promoter (Ad-Py4-SV40-PUMA) was used selectively to target CRC cells (HCT116, SW480, DLD1 and RIE-Ras) that possess a hyperactive Ras pathway while using HT29 and RIE cells as a control that harbors wild type Ras and exhibit very low Ras activity. Control vector, without the Ras responsive promoter elements was used to assess the specificity of our 'gene therapy' approach. Both adenoviral vectors were assed in vitro and in xenograft model in vivo. Ad-Py4-SV40-PUMA showed high potency to induce {approx} 50% apoptosis in vitro, to abolish completely tumor formation by infecting cells with the Ad-Py4-SV40-PUMA prior xenografting them in nude mice and high ability to suppress by {approx} 35% tumor progression in vivo in already established tumors. Conclusions: Selective targeting of CRC cells with the activated Ras pathway may be a novel and effective therapy in CRC. The high potency of this adenoviral vector may help to overcome an undetectable micro metastasis that is the major hurdle in challenging with CRC.

  7. Adenoviral Producer Cells

    Imre Kovesdi

    2010-08-01

    Full Text Available Adenovirus (Ad vectors, in particular those of the serotype 5, are highly attractive for a wide range of gene therapy, vaccine and virotherapy applications (as discussed in further detail in this issue. Wild type Ad5 virus can replicate in numerous tissue types but to use Ad vectors for therapeutic purposes the viral genome requires modification. In particular, if the viral genome is modified in such a way that the viral life cycle is interfered with, a specific producer cell line is required to provide trans-complementation to overcome the modification and allow viral production. This can occur in two ways; use of a producer cell line that contains specific adenoviral sequences incorporated into the cell genome to trans-complement, or use of a producer cell line that naturally complements for the modified Ad vector genome. This review concentrates on producer cell lines that complement non-replicating adenoviral vectors, starting with the historical HEK293 cell line developed in 1977 for first generation Ad vectors. In addition the problem of replication-competent adenovirus (RCA contamination in viral preparations from HEK293 cells is addressed leading to the development of alternate cell lines. Furthermore novel cell lines for more complex Ad vectors and alternate serotype Ad vectors are discussed.

  8. Inferring horizontal gene transfer.

    Matt Ravenhall

    2015-05-01

    Full Text Available Horizontal or Lateral Gene Transfer (HGT or LGT is the transmission of portions of genomic DNA between organisms through a process decoupled from vertical inheritance. In the presence of HGT events, different fragments of the genome are the result of different evolutionary histories. This can therefore complicate the investigations of evolutionary relatedness of lineages and species. Also, as HGT can bring into genomes radically different genotypes from distant lineages, or even new genes bearing new functions, it is a major source of phenotypic innovation and a mechanism of niche adaptation. For example, of particular relevance to human health is the lateral transfer of antibiotic resistance and pathogenicity determinants, leading to the emergence of pathogenic lineages. Computational identification of HGT events relies upon the investigation of sequence composition or evolutionary history of genes. Sequence composition-based ("parametric" methods search for deviations from the genomic average, whereas evolutionary history-based ("phylogenetic" approaches identify genes whose evolutionary history significantly differs from that of the host species. The evaluation and benchmarking of HGT inference methods typically rely upon simulated genomes, for which the true history is known. On real data, different methods tend to infer different HGT events, and as a result it can be difficult to ascertain all but simple and clear-cut HGT events.

  9. [Construction of recombinant adenoviral vector expressing genes of the conservative influenza proteins M2 and nucleoprotein].

    Esmagambetov, I B; Sedova, E S; Shcherbinin, D N; Lysenko, A A; Garas, M N; Shmarov, M M; Logunov, D Iu

    2014-01-01

    Influenza is a highly contagious and one of the most massive infection diseases. General epidemiological significance has a strain, which belongs to subtype A. A high degree of genetic variety leads to the permanent changes in the antigenic structure of the influenza virus. Therefore, the current influenza vaccines require periodic updating of the composition of strains. Presently, it is important to develop a universal vaccine that can protect against different strains of influenza A virus at the same time and is based on the conserved antigens of the influenza virus. The recombinant adenovirus vectors expressing genes of conserved viral antigenes may be a promising candidate vaccine against influenza A. Using the method of the homologous recombination, we developed in this study recombinant adenovirus of fifth serotype that expresses genes of the ion channel M2 and nucleoprotein NP of the influenza virus A. Genes of the consensus protein M2 and NP of human influenza A virus were included into the structure of the viral genome. The expression of the antigens M2 and NP using recombinant adenovirus vector was detected by a Western blot assay. The immunogenicity of the developed recombinant adenovirus vector was demonstrated by the intranasal immunization of laboratory mice. PMID:25080815

  10. Preparation of a recombinant adenoviral encoding human NIS gene and its specific expression in cardiomyocytes

    Objective: To construct a recombinant adenovirus vector containing the human NIS gene with the myosin light chain-2(MLC-2v) gene as the promoter and evaluate its specific expression and feasibility as a reporter gene in cardiomyocytes. Methods: MLC-2v promoter and NIS were subcloned into an adenovirus shuttle vector, and forwarded by homologous recombination in the bacteria BJ5183 containing AdEasy-1 plasmid. Positive recombinant adenovirus vector was selected, packaged and amplified in the HEK293 cells to obtain recombinant adenovirus Ad-MLC-NIS. Ad-cytomegalovirus (CMV)-NIS with cytomegalovirus as the promoter, Ad-MLC without NIS and Ad-NIS without promoter were constructed as the controls. Cardiomyocytes and non-cardiomyocytes were then infected by the adenovirus. The protein expression was tested by Western blot analysis. The function and features of NIS protein were evaluated by dynamic iodide uptake and NaClO4 iodine uptake inhibition test in vitro. The viability and proliferation of cardiomyocytes after adenovirus transfection and radioiodine incubation were checked by trypan blue staining. Results: Recombinant NIS adenovirus was successfully constructed. Western blot analysis showed that the NIS protein was highly expressed in cardiomyocytes transfected with Ad-MLC-NIS, and all cells transfected with Ad-CMV-NIS. However, in non-cardiomyocytes transfected with Ad-MLC-NIS, little NIS protein was detected. Dynamic iodine uptake tests showed that the peaks of iodide uptake of the three different cell lines (H9C2, A549, U87 cell) transfected with Ad-MLC-NIS were 5844.0, 833.6 and 846.0 counts · min-1, respectively. The iodide uptake function of H9C2 was inhibited by NaClO4. There was almost no change in cell viability and proliferation when the MOI was 100. Conclusions: Ad-MLC-NIS allows myocardial specific expression of an external gene, and the cardiomyocytes with NIS expression are capable of iodine uptake. Further research of NIS as a reporter gene in

  11. Peri- and Postnatal Effects of Prenatal Adenoviral VEGF Gene Therapy in Growth-Restricted Sheep.

    Carr, David J; Wallace, Jacqueline M; Aitken, Raymond P; Milne, John S; Martin, John F; Zachary, Ian C; Peebles, Donald M; David, Anna L

    2016-06-01

    Uterine artery (UtA) adenovirus (Ad) vector-mediated overexpression of vascular endothelial growth factor (VEGF) enhances uterine blood flow in normal sheep pregnancy and increases fetal growth in the overnourished adolescent sheep model of fetal growth restriction (FGR). Herein, we examined its impact on gestation length, neonatal survival, early postnatal growth and metabolism. Singleton-bearing ewes were evenly allocated to receive Ad.VEGF-A165 (5 × 10(10) particles/ml, 10 ml, n = 17) or saline (10 ml, n = 16) injected into each UtA at laparotomy (0.6 gestation). Fetal growth was serially monitored (blind) by ultrasound until delivery. Lambs were weighed and blood was sampled weekly and a glucose tolerance test performed (68-day postnatal age). Hepatic DNA/RNA was extracted at necropsy (83-day postnatal age) to examine methylation status of eight somatotropic axis genes. IGF1 mRNA and protein expression were measured by RT-PCR and radioimmunoassay, respectively. All pregnancies remained viable following Ad.VEGF-A165 treatment. Fetal abdominal circumference and renal volume were greater in the Ad.VEGF-A165 group compared with the saline group at 21/28 days (P ≤ 0.04) postinjection. At delivery, gestation length (P = 0.07), lamb birthweight (P = 0.08), umbilical girth (P = 0.06), and plasma glucose (P = 0.09) tended to be greater in Ad.VEGF-A165-treated lambs. Levels of neonatal intervention required to ensure survival was equivalent between groups. Absolute postnatal growth rate (P = 0.02), insulin area under the curve (P = 0.04) and carcass weight at necropsy (P = 0.04) were increased by Ad.VEGF-A165 treatment. There was no impact on markers of insulin sensitivity or methylation/expression of key genes involved in somatic growth. Ad.VEGF-A165 gene therapy increased fetal growth in a sheep FGR model, and lambs continued to thrive during the neonatal and early postnatal period. PMID:27103444

  12. Intrastriatal Gene Transfer of Vascular Endothelial Growth Factor Rescues Dopaminergic Neurons in a Rat Parkinson's Disease Model

    2006-01-01

    To examine the ability of intrastriatal gene transfer of vascular endothelial growth factor 165 mediated by adenoviral vector to rescue dopaminergic neurons in a rat model of Parkinson's disease (PD), we constructed recombinant replication-deficent adenoviral vectors carrying the gene of VEGF165 (Ad-VEGF), and injected Ad-VEGF (or Ad-LacZ and PBS as controls) into the striatum of rats 7 days after the lesion by 6-hydroxydopamine. The rat rotational behavior analysis and tyrosine hydroxylase (TH) immunohistochemistry were performed to assess the change of dopaminergic neurons. Our results showed that the rats receiving Ad-VEGF injection displayed a significant improvement in apomorphine-induced rotational behavior and a significant preservation of TH-positive neurons and fibers compared with control animals. It is concluded that intrastriatal gene transfer by Ad-VEGF may rescue the dopaminergic neurons from degeneration in a rat model of PD.

  13. Biological activity and safety of adenoviral vector-expressed wild-type p53 after intratumoral injection in melanoma and breast cancer patients with p53-overexpressing tumors

    Dummer, R; Bergh, J; Karlsson, Y; Horovitz, JA; Mulder, NH; Huinin, DT; Burg, G; Hofbauer, G; Osanto, S

    2000-01-01

    p53 mutations are common genetic alterations in human cancer. Gene transfer of a wild-type (wt) p53 gene reverses the loss of normal p53 function in vitro and in vivo. A phase I dose escalation study of single intratumoral (i.t.) injection of a replication-defective adenoviral expression vector cont

  14. Horizontal gene transfer in fungi

    Fitzpatrick, David A.

    2011-01-01

    Horizontal gene transfer (HGT) is frequently observed in prokaryotes and until recently was assumed to be of limited importance to eukaryotes. However, there is an increasing body of evidence to suggest that HGT is an important mechanism in eukaryotic genome evolution, particularly in unicellular organisms. The transfer of individual genes, gene clusters or entire chromosomes can have significant impacts on niche specification, disease emergence or shift in metabolic capabil...

  15. Adenoviral gene delivery of elafin and secretory leukocyte protease inhibitor attenuates NF-kappa B-dependent inflammatory responses of human endothelial cells and macrophages to atherogenic stimuli.

    Henriksen, Peter A; Hitt, Mary; Xing, Zhou; Wang, Jun; Haslett, Chris; Riemersma, Rudolph A; Webb, David J; Kotelevtsev, Yuri V; Sallenave, Jean-Michel

    2004-04-01

    Atherosclerosis is a chronic inflammatory disease affecting arterial vessels. Strategies to reduce the inflammatory responses of endothelial cells and macrophages may slow lesion development and prevent complications such as plaque rupture. The human protease human neutrophil elastase (HNE), oxidized low density lipoprotein, LPS, and TNF-alpha were chosen as model stimuli of arterial wall inflammation and led to production of the chemokine IL-8 in endothelial cells. To counteract the activity of HNE, we have examined the effects of adenoviral gene delivery of the anti-elastases elafin, previously demonstrated within human atheroma, and murine secretory leukocyte protease inhibitor (SLPI), a related molecule, on the inflammatory responses of human endothelial cells and macrophages to atherogenic stimuli. We developed a technique of precomplexing adenovirus with cationic lipid to augment adenoviral infection efficiency in endothelial cells and to facilitate infection in macrophages. Elafin overexpression protected endothelial cells from HNE-induced IL-8 production and cytotoxicity. Elafin and murine SLPI also reduced endothelial IL-8 release in response to oxidized low density lipoprotein, LPS, and TNF-alpha and macrophage TNF-alpha production in response to LPS. This effect was associated with reduced activation of the inflammatory transcription factor NF-kappaB, through up-regulation of IkappaBalpha, in both cell types. Our work suggests a novel and extended anti-inflammatory role for these HNE inhibitors working as effectors of innate immunity to protect tissues against maladaptive inflammatory responses. Our findings indicate that elafin and SLPI may be gene therapy targets for the treatment of atheroma. PMID:15034071

  16. INGN 201: Ad-p53, Ad5CMV-p53, adenoviral p53, p53 gene therapy--introgen, RPR/INGN 201.

    2007-01-01

    Introgen and its wholly owned European subsidiary Gendux AB are developing an adenoviral p53 gene therapy as a treatment for cancer in the US and Europe, respectively. Phase III trials in patients with head and neck cancer are ongoing, and a number of clinical trials in other cancer indications have been completed. INGN 201 is being reviewed by the EMEA for approval in Li-Fraumeni syndrome (LFS) under the provisions of exceptional circumstance; the therapy is available on a compassionate use basis to eligible LFS cancer patients under a protocol authorised by the US FDA. The p53 tumour suppressor gene is deleted or mutated in many tumour cells and is one of the most frequently mutated genes in human tumours. The p53 protein is one of the most intricate elements in the apoptotic signalling cascade, and a mutation in the gene encoding it is believed to result in a decreased ability of a cell to apoptose. Thus replacing this gene via adenovirally-mediated p53 gene therapy is hoped to result in increased apoptosis where it is administered.INGN 201 is available for licensing, although Introgen favours retaining partial or full rights to the therapy in the US. Introgen entered into a license agreement with The University of Texas System and MD Anderson Cancer Center in 1994. The technologies licenced include p53 and fus1 (INGN 401). The collaboration has yielded exclusive patent and licensing rights to numerous technologies. Introgen entered into a collaboration with Rhône-Poulenc Rorer Pharmaceuticals (now sanofi-aventis) to develop therapeutics based on p53 inhibition in October 1994. However, in June 2001 this relationship was restructured and Introgen assumed responsibility for the worldwide development of all p53 products including INGN 201, and acquired all marketing and commercialisation rights with respect to those products. Introgen initiated two phase III trials in head and neck cancer (in June 2000 and May 2001) at about 80 sites in the US, Canada and Europe

  17. Does Gene Translocation Accelerate the Evolution of Laterally Transferred Genes?

    Hao, Weilong; Golding, G. Brian

    2009-01-01

    Lateral gene transfer (LGT) and gene rearrangement are essential for shaping bacterial genomes during evolution. Separate attention has been focused on understanding the process of lateral gene transfer and the process of gene translocation. However, little is known about how gene translocation affects laterally transferred genes. Here we have examined gene translocations and lateral gene transfers in closely related genome pairs. The results reveal that translocated genes undergo elevated ra...

  18. Phase I trial of recombinant adenovirus gene transfer in lung cancer. Longitudinal study of the immune responses to transgene and viral products.

    Gahéry-Ségard, H; Molinier-Frenkel, V.; Le Boulaire, C; Saulnier, P.; Opolon, P; Lengagne, R.; Gautier, E; Le Cesne, A; Zitvogel, L; Venet, A.; Schatz, C; Courtney, M; Le Chevalier, T.; Tursz, T; Guillet, J G

    1997-01-01

    Animal studies indicate that the use of replication-deficient adenovirus for human gene therapy is limited by host antivector immune responses that result in transient recombinant protein expression and blocking of gene transfer when rechallenged. Therefore, we have examined immune responses to an adenoviral vector and to the beta-galactosidase protein in four patients with lung cancer given a single intratumor injection of 10(9) plaque-forming units of recombinant adenovirus. The beta-galact...

  19. Recombinant adenovirus-mediated gene transfer suppresses experimental arthritis

    E. Quattrocchi

    2011-09-01

    Full Text Available Collagen Induced Arthritis (CIA is a widely studied animal model to develop and test novel therapeutic approaches for treating Rheumatoid Arthritis (RA in humans. Soluble Cytotoxic T-Lymphocyte Antigen 4 (CTLA4-Ig, which binds B7 molecule on antigen presenting cells and blocks CD28 mediated T-lymphocyte activation, has been shown to ameliorate experimental autoimmune diseases such as lupus, diabetes and CIA. Objective of our research was to investigate in vivo the effectiveness of blocking the B7/CD28 T-lymphocyte co-stimulatory pathway, utilizing a gene transfer technology, as a therapeutic strategy against CIA. Replication-deficient adenoviruses encoding a chimeric CTLA4-Ig fusion protein, or β-galactosidase as control, have been injected intravenously once at arthritis onset. Disease activity has been monitored by the assessment of clinical score, paw thickness and type II collagen (CII specific cellular and humoral immune responses for 21 days. The adenovirally delivered CTLA4-Ig fusion protein at a dose of 2×108 pfu suppressed established CIA, whereas the control β-galactosidase did not significantly affect the disease course. CII-specific lymphocyte proliferation, IFNg production and anti-CII antibodies were significantly reduced by CTLA4-Ig treatment. Our results demonstrate that blockade of the B7/CD28 co-stimulatory pathway by adenovirus-mediated CTLA4-Ig gene transfer is effective in treating established CIA suggesting its potential in treating RA.

  20. Radiation improves gene transfer into human ovarian carcinoma cells

    Purpose/Objective: Poor gene transfer is the major stumbling block to successful gene therapy today. We hypothesized that ionizing radiation might activate cellular recombination, and so improve stable gene transfer. During studies to quantitate radiation activated recombination, we also found that both plasmid and adenoviral vector transduction could be increased by irradiation. The studies presented here describe the effects of irradiation on gene transduction efficiency (both transient and stable transduction) in several human ovarian carcinoma lines, as a prelude to in vivo animal studies. Materials and Methods: The effect of irradiation on stable gene transfer efficiency was determined in human ovarian carcinoma cell lines (SKOV3, CAOV3 and PA1). Either irradiated or unirradiated cells were transfected with pRSVZ plasmid (containing a LacZ expression cassette) in either the supercoiled and linearized (XmnI) forms and β-galactosidase expression followed with time. Transfection efficiency was measured by flow cytometry following FDG staining at 0, 48, and 96 hours after irradiation. FDG is converted to a fluorescent metabolite by LacZ, and thus reflects the transfection efficiency of the LacZ containing vector. Vector quantitation was also performed by southern hybridization. Stable transduction efficiency was measured 14 -35 days after irradiation. Optimization of the time of irradiation with respect to transfection was performed. Since cells demonstrated increased stable recombination for as long as 96 hours after irradiation, continuous low dose rate and multiple radiation fractions were also tested. These experiments were repeated using the Ad5CMVlacZ. Dividing cells were exposed to Ad5CMVlacZ at an MOI of 0.1,1,5,10 and 100 to determine optimum transfection concentration. Transduction efficiency was again measured at various intervals to determine the radiation dose and interval post transfection which provides the maximum increase in transfection

  1. Adenovirus-mediated transfer of RA538 gene and its antitumor effect

    程金科; 林晨; 隗玥; 张雪艳; 邢嵘; 牟巨伟; 王秀琴; 吴旻

    1999-01-01

    The RA538 cDNA was transferred into human ovarian cancer cell line SK-OV-3 and human melanoma cell line WM-983A by its recombinant adenoviral vector constructed through homologous recombination. It was demonstrated that the recombinant adenovirus could transfer RA538 gene with high efficiency, and could obviously inhibit tumor growth, with the inhibiting rates of 85% and 73% respectively, at the same time greatly repress the colony forming ability of the cells. The therapeutic experiments on transplanted subcutaneous tumor model in nude mice demonstrated that RA538 could significantly inhibit tumor growth. Flow cytometry and DNA fragmentation analysis indicated that RA538 could induce the cell cycle G1 arrest/apoptosis of the tumor cells. The expression of cmyc gene was found pronouncedly reduced by Western blot analysis. These results suggest that the RA538 recombinant adenovirus could be a promising drug in cancer gene therapy.

  2. An adenoviral vector regulated by hypoxia for the treatment of ischaemic disease and cancer.

    Binley, K; Iqball, S; Kingsman, A; Kingsman, S; Naylor, S

    1999-10-01

    Recombinant adenoviral vectors have a number of advantages for gene therapy, including transduction of a range of dividing and non-dividing cell types. However, this broad range may be a disadvantage if non-target cells are transduced and are adversely affected by expression of the transferred gene. Here we describe a novel adenoviral vector in which transcription of the transgene is restricted to the patho-physiological condition of low oxygen tension (hypoxia). Hypoxia activates the expression of a number of genes, principally via the stabilisation of members of the bHLH/PAS family of transcription factors that bind to a con- sensus DNA sequence, the hypoxia response element (HRE). We have configured an optimised HRE expression cassette into an adenoviral vector, AdOBHRE. A range of cell types, including primary human skeletal muscle, when transduced with AdOBHRE display a low basal level of transgene expression that is highly induced in hypoxia to levels equivalent to that obtained from the CMV promoter. The AdOBHRE vector could be exploited for transcriptionally targeted gene therapy for the treatment of diseases such as cancer, peripheral arterial disease, arthritis and anaemia where tissue hypoxia is a cardinal feature. PMID:10516721

  3. Horizontal gene transfer in plants.

    Gao, Caihua; Ren, Xiaodong; Mason, Annaliese S; Liu, Honglei; Xiao, Meili; Li, Jiana; Fu, Donghui

    2014-03-01

    Horizontal gene transfer (HGT) describes the transmission of genetic material across species boundaries. HGT often occurs in microbic and eukaryotic genomes. However, the pathways by which HGTs occur in multicellular eukaryotes, especially in plants, are not well understood. We systematically summarized more than ten possible pathways for HGT. The intimate contact which frequently occurs in parasitism, symbiosis, pathogen, epiphyte, entophyte, and grafting interactions could promote HGTs between two species. Besides these direct transfer methods, genes can be exchanged with a vector as a bridge: possible vectors include pollen, fungi, bacteria, viruses, viroids, plasmids, transposons, and insects. HGT, especially when involving horizontal transfer of transposable elements, is recognized as a significant force propelling genomic variation and biological innovation, playing an important functional and evolutionary role in both eukaryotic and prokaryotic genomes. We proposed possible mechanisms by which HGTs can occur, which is useful in understanding the genetic information exchange among distant species or distant cellular components. PMID:24132513

  4. [Viral transfer of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) in gene therapy].

    Wędrowska, Ewelina; Wandtke, Tomasz; Dyczek, Andrzej; Woźniak, Joanna

    2015-01-01

    Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) selectively induces carcinoma cell death through the extrinsic pathway of apoptosis. Preclinical trials of gene therapy have been conducted using viral transfer of the TRAIL transgene into prostate, bladder, breast, kidney, liver, non-small cell lung cancer and also glioblastoma cells. Experiments in vitro demonstrated the extensive apoptosis of target cells as well as frequent disease regression or remission. TRAIL transfer did not show any side effects, opposite to chemotherapy. Encouraging results of TRAIL-related gene therapy were observed in rheumatoid arthritis and type 1 diabetes. Adenoviral vectors (AdV) encoding TRAIL are the most promising tool in anti-tumor therapy. They have undergone numerous modifications by increasing transfection efficiency and transgene expression in target cells. However, only one clinical phase I trial has been performed. AdV encoding the TRAIL transgene caused local inflammation and apoptosis in patients with prostate cancer. PMID:27259213

  5. Horizontal gene transfer in chromalveolates

    Bhattacharya Debashish

    2007-09-01

    Full Text Available Abstract Background Horizontal gene transfer (HGT, the non-genealogical transfer of genetic material between different organisms, is considered a potentially important mechanism of genome evolution in eukaryotes. Using phylogenomic analyses of expressed sequence tag (EST data generated from a clonal cell line of a free living dinoflagellate alga Karenia brevis, we investigated the impact of HGT on genome evolution in unicellular chromalveolate protists. Results We identified 16 proteins that have originated in chromalveolates through ancient HGTs before the divergence of the genera Karenia and Karlodinium and one protein that was derived through a more recent HGT. Detailed analysis of the phylogeny and distribution of identified proteins demonstrates that eight have resulted from independent HGTs in several eukaryotic lineages. Conclusion Recurring intra- and interdomain gene exchange provides an important source of genetic novelty not only in parasitic taxa as previously demonstrated but as we show here, also in free-living protists. Investigating the tempo and mode of evolution of horizontally transferred genes in protists will therefore advance our understanding of mechanisms of adaptation in eukaryotes.

  6. Expression of Mouse SCP2 Gene Adenoviral Vector Carrying Albumin Promoter in Hepa1-6 Cells%固醇携带蛋白2腺病毒载体的构建与鉴定

    贾岩峰; 崔云峰; 崔乃强; 彭雁飞; 宁召臣; 张琚

    2012-01-01

    Objectives To construct the replication defective adenoviral vector of SCP2 gene carrying murine albumin promoter, and study the relations between SCP2 gene and the formation of cholesterol calculus. Methods The cDNA of SCP2 gene was cloned by using RT-PCR technique. The albumin promoter was linked to SCP2 gene's upstream, and the EGFP gene lied in its downstream. The plasmid pDC312-ALB-SCP2-IRES2 -EGFP was constructed by the gene recombination technique. The Admax Adenoviral Vector System was used to generate the replication defective adenoviral vectors, which were purified by CsCl method. The processes of TCID50 were applied to detect the titers of the adenoviral vectors. The RNA and protein were respectively extracted from the infected Hepal-6 cells by the adenoviral vector. The real-time quantitative PCR was employed to detect the mRNA expression levels, and the Western blotting analysis was used to measure the SCP2 protein levels. Result We constructed successfully the replication defective adenoviral vector of SCP2 gene carrying murine albumin promoter. When the mRNA levels of SCP2 gene were overexpressed, CYP7al mRNA levels were down-regulated (t=3.97,p<0.05); and the mRNA levels of HMGCR were up-regulated (t=3.23,p<0.05). Conclusions The SCP2 gene overexpression may affect cholesterol and bile acid metabolism, which could promote the formation of cholesterol calculus.%目的:构建携带白蛋白启动子SCP2 基因腺病毒载体,研究其与胆固醇结石形成的关系.方法:(1)利用RT-PCR技术克隆小鼠SCP2基因,在其上游接入白蛋白(ALB)启动子,下游连接绿色荧光报告基因(EGFP),构建穿梭质粒pDC312-ALB-SCP2-IRES2-EGFP;(2)采用Ad Max TM Adenoviru5 Vector系统包装病毒,CsCl法纯化病毒、TCID50法测定滴度;(3)重组腺病毒感染小鼠hepa-1-6细胞,实时定量PCR检测mRNA的表达;Western印迹检测SCP2蛋白表达情况;结果:成功构建携带白蛋白启动子SCP2基因腺病毒载体;当SCP2

  7. Efficient Gene Transfer in Bacterial Cell Chains

    Babic, Ana; Berkmen, Melanie B.; Lee, Catherine A.; Grossman, Alan D.

    2011-01-01

    Horizontal gene transfer contributes to evolution and the acquisition of new traits. In bacteria, horizontal gene transfer is often mediated by conjugative genetic elements that transfer directly from cell to cell. Integrative and conjugative elements (ICEs; also known as conjugative transposons) are mobile genetic elements that reside within a host genome but can excise to form a circle and transfer by conjugation to recipient cells. ICEs contribute to the spread of genes involved in pathoge...

  8. Anti-viral state segregates two molecular phenotypes of pancreatic adenocarcinoma: potential relevance for adenoviral gene therapy

    Chiorini Jay A

    2010-01-01

    Full Text Available Abstract Background Pancreatic ductal adenocarcinoma (PDAC remains a leading cause of cancer mortality for which novel gene therapy approaches relying on tumor-tropic adenoviruses are being tested. Methods We obtained the global transcriptional profiling of primary PDAC using RNA from eight xenografted primary PDAC, three primary PDAC bulk tissues, three chronic pancreatitis and three normal pancreatic tissues. The Affymetrix GeneChip HG-U133A was used. The results of the expression profiles were validated applying immunohistochemical and western blot analysis on a set of 34 primary PDAC and 10 established PDAC cell lines. Permissivity to viral vectors used for gene therapy, Adenovirus 5 and Adeno-Associated Viruses 5 and 6, was assessed on PDAC cell lines. Results The analysis of the expression profiles allowed the identification of two clearly distinguishable phenotypes according to the expression of interferon-stimulated genes. The two phenotypes could be readily recognized by immunohistochemical detection of the Myxovirus-resistance A protein, whose expression reflects the activation of interferon dependent pathways. The two molecular phenotypes discovered in primary carcinomas were also observed among established pancreatic adenocarcinoma cell lines, suggesting that these phenotypes are an intrinsic characteristic of cancer cells independent of their interaction with the host's microenvironment. The two pancreatic cancer phenotypes are characterized by different permissivity to viral vectors used for gene therapy, as cell lines expressing interferon stimulated genes resisted to Adenovirus 5 mediated lysis in vitro. Similar results were observed when cells were transduced with Adeno-Associated Viruses 5 and 6. Conclusion Our study identified two molecular phenotypes of pancreatic cancer, characterized by a differential expression of interferon-stimulated genes and easily recognized by the expression of the Myxovirus-resistance A protein. We

  9. Hematopoiesis stimulation test by interleukin 1α gene transfer in the Cynomolgus macaque: application to secondary medullary aplasia from an accidental irradiation

    After a description of the context of medullary aplasia (haematological radiobiology, radiation acute syndrome, therapeutic care), and an overview of knowledge about the interleukin-1 and medullary stroma cells, this research thesis aims at investigating therapeutic alternatives for radio-accidental aplasia. More precisely, it aims at defining means to get cytokines which are efficient for haematopoiesis. Interleukin-1 is chosen for its properties and tests are performed on a macaque with two approaches for gene transfer: an ex vivo transfer by retroviral vector enabling an integration in the target cell genome, and an in situ transfer by adeno-viral vector directly applied in the animal osseous medulla

  10. Transferring alien genes to wheat

    In broad terms an alien gene can be considered to be any gene transferred to wheat from a related species. As described above by Maan (section 7D) the genus Triticum contains a broad range of species, some of which cross readily with the cultivated tetraploid (T. Turgidum L.) or hexaploid (T. aestivum L.) wheats, and others only with great difficulty. In addition, wheat will also cross with species in a number of other genera including Agropyron, Elymus, Elytrigia (=Agropyron), Haynaldia, Hordeum, and Secale (Riley and Kimber, 1966; Knobloch, 1968; Feldman and Sears, 1981). In discussing the Triticum and Aegilops spp., the classification by Kimber and Sears, section SA-I, above, will be followed. For the Agropyron and related species the classification described by Dewey (1983) will be used. To avoid confusion, in referring to the literature the designations used by the authors will be given, followed by the new designation. The wild relatives of wheat are adapted to a broad range of environments and carry a large reservoir of useful genes (Zohary et al., 1969; Kerber and Dyck, 1973; Brezhnev, 1977; Feldman and Sears, 1981; Limin and Fowler, 1981; Sharma et aI., 1981; McGuire and Dvorak, 1981). Initially they were considered to be primarily sources of disease resistance, but more recently they have been recognized as potential sources of genes for high protein, cold tolerance, salt tolerance, drought tolerance, lodging resistance, early maturity, and even yield. Extensive screening of the wild relatives of wheat needs to be done before their useful genes can be fully utilized

  11. Evaluation of the immune response to recombinant DNA vaccine and adenoviral vaccine co-expressing the M1 and HA genes of H5N1 influenza virus in mice.

    Guo, Jianqiang; Yao, Lihong; Chen, Aijun; Liu, Xiaoyu; Fu, Jinqi; Xu, Pengwei; Zhang, Zhiqing

    2011-06-01

    In order to evaluate the response to vector-expressed M1 and HA genes of influenza virus in mice, we prepared recombinant plasmid pStar-M1/HA and recombinant adenovirus Ad-M1/HA containing both the full-length matrix protein 1(M1) and hemagglutinin (HA) genes of human H5N1 influenza virus strain A/Anhui/1/2005. We then combined the DNA vaccine and adenoviral vaccine in immunization of BALB/c mice with a prime-boost regime. We immunized the mice with DNA vaccine at day 0 and 28 and with recombinant adenoviral vaccines at day 14 and 42. We took blood samples before each injection and 14 days after the final injection for detection of humoral immune responses. At day 56, we sacrificed the mice and collected splenocytes for detection of cellular immune responses. ELISA and hemagglutination inhibition (HI) assay showed that specific IgG Abs against H5N1 influenza virus was induced in serum of the immunized mice. ELISPOT results confirmed that the specific cellular immune responses were successfully induced against the M1 and HA proteins of H5N1 influenza virus. This study provides new strategy for development of novel influenza vaccines. PMID:22034816

  12. Viral vectors for vascular gene therapy

    Fischer, Lukas; Preis, Meir; Weisz, Anat; Koren, Belly; Lewis, Basil S; Flugelman, Moshe Y

    2002-01-01

    Vascular gene therapy is the focus of multiple experimental and clinical research efforts. While several genes with therapeutic potential have been identified, the best method of gene delivery is unknown. Viral vectors have the capacity to transfer genes at high efficiency rates. Several viral-based vectors have been used in experimental vascular gene therapy for in vivo and ex vivo gene transfer. Adenoviral-based vectors are being used for the induction of angiogenesis in phase 1 and 2 clini...

  13. Translating Gene Transfer: A Stalled Effort

    Greenberg, Alexandra J.; McCormick, Jennifer; Tapia, Carmen J.; Windebank, Anthony J.

    2011-01-01

    The journey of gene transfer from laboratory to clinic has been slow and fraught with many challenges and barriers. Despite the development of the initial technology in the early 1970s, a standard clinical treatment involving “gene therapy” remains to be seen. Furthermore, much was written about the technology in the early 1990s, but since then, not much has been written about the journey of gene transfer. The translational path of gene transfer thus far, both pitfalls and successes, can serv...

  14. Targeting Radiotherapy to Cancer by Gene Transfer

    R. J. Mairs; Boyd, M.

    2003-01-01

    Targeted radionuclide therapy is an alternative method of radiation treatment which uses a tumor-seeking agent carrying a radioactive atom to deposits of tumor, wherever in the body they may be located. Recent experimental data signifies promise for the amalgamation of gene transfer with radionuclide targeting. This review encompasses aspects of the integration of gene manipulation and targeted radiotherapy, highlighting the possibilities of gene transfer to assist the targeting of cancer ...

  15. Induction of specific humoral and cellular immune responses in a mouse model following gene fusion of HSP70C and Hantaan virus Gn and S0.7 in an adenoviral vector.

    Linfeng Cheng

    Full Text Available Heat shock proteins (HSPs display adjuvant functions when given as fusion proteins to enhance vaccination efficiency. To evaluate enhanced potency of Hantaan virus (HTNV glycoprotein (GP and nucleocapsid protein (NP immunogenicity by heat shock protein 70 (HSP70, a recombinant adenovirus rAd-GnS0.7-pCAG-HSP70C expression vector was developed by genetically linking the HSP70 C-terminal gene (HSP70 359-610 aa, HSP70C to the Gn and 0.7 kb fragment of the NP (aa1-274-S0.7. C57BL/6 mice were immunized with these recombinant adenoviral vectors. A series of immunological assays determined the immunogenicity of the recombinant adenoviral vectors. The results showed that rAd-GnS0.7-pCAG-HSP70C induced a stronger humoral and cellular immune response than other recombinant adenoviruses (rAd-GnS0.7-pCAG and rAd-GnS0.7 and the HFRS vaccine control. Animal protection experiments showed that rAd-GnS0.7-pCAG-HSP70C was effective at protecting C57BL/6 mice from HTNV infection. The results of the immunological experiments showed that HSP70C lead to enhanced vaccine potency, and suggested significant potential in the development of genetically engineered vaccines against HTNV.

  16. Horizontal gene transfer between bacteria and animals

    Dunning Hotopp, Julie C.

    2011-01-01

    Horizontal gene transfer is increasingly described between bacteria and animals. Such transfers that are vertically inherited have the potential to influence the evolution of animals. One classic example is the transfer of DNA from mitochondria and chloroplasts to the nucleus after the acquisition of these organelles by eukaryotes. Even today, many of the described instances of bacteria to animal transfer occur as part of intimate relationships like those of endosymbionts and their invertebra...

  17. Horizontal gene transfer between bacteria and animals.

    Dunning Hotopp, Julie C

    2011-04-01

    Horizontal gene transfer is increasingly described between bacteria and animals. Such transfers that are vertically inherited have the potential to influence the evolution of animals. One classic example is the transfer of DNA from mitochondria and chloroplasts to the nucleus after the acquisition of these organelles by eukaryotes. Even today, many of the described instances of bacteria-to-animal transfer occur as part of intimate relationships such as those of endosymbionts and their invertebrate hosts, particularly insects and nematodes, while numerous transfers are also found in asexual animals. Both of these observations are consistent with modern evolutionary theory, in particular the serial endosymbiotic theory and Muller's ratchet. Although it is tempting to suggest that these particular lifestyles promote horizontal gene transfer, it is difficult to ascertain given the nonrandom sampling of animal genome sequencing projects and the lack of a systematic analysis of animal genomes for such transfers. PMID:21334091

  18. Constructing recombinant replication-defective adenoviral vectors that express glucose transporter-1 through in vitro ligation

    Fangcheng Li; Junliang Li; Ranyi Liu; Xinke Xu; Kaichang Yuan; Zhonghua Wu

    2008-01-01

    BACKGROUND: We constructed a homologous recombination bacterial method based on the pAdEasy system, a widely used system, for generating recombinant adenoviral vectors that express glucose transporter-1 (GLUT1) in rats.OBJECTIVE: This study was designed to investigate the feasibility of generating recombinant replication-defective adenoviral vectors that express GLUT1 in rats by in vitro ligation based on the Adeno-XTM system. DESIGN: An in vitro cell-based experiment. SETTING: This study was performed at the Linbaixin Medical Research Center of the Second Hospital Affiliated to Sun Yat-sen University and Central Laboratory for Prevention and Treatment of Tumor, Sun Yat-sen University between January and August 2004. MATERIALS: Male, adult, Sprague Dawley rats were used to extract total RNA from brain tissue. E. coli DH5?and human embryonic kidney 293 cells (HEK293 cells) used in the present study were cryo-preserved by the Second Hospital Affiliated to Sun Yat-sen University. Rabbit anti-rat GLUT1 polyclonal antibody (Chemicon, U.S.A.) and primers (Shanghai Boya Bioengineering Co., Ltd) were also used. METHODS: E1/E3-deleted replication-defective adenoviral vectors were used. Using in vitro ligation, the target gene was first sub-cloned into a shuttle vector plasmid to obtain the fragment containing target gene expression cassettes by enzyme digestion. Subsequently, the fragment was co-transformed with linearized adenoviral backbone vector into the E. coli strain. The recombinant adenoviral plasmid was transfected into HEK293 cells to assembly recombinant adenoviral vectors with replication capabilities. The procedure was repeated several times for recombinant adenoviral vectors amplification. MAIN OUTCOME MEASURES: Efficiency of recombinant adenoviral vectors to express the target gene was measured by gene and protein expression through polymerase chain reaction and Western Blot assays, respectively.RESULTS: Results demonstrated that recombinant adenoviral

  19. The ethics of human gene transfer.

    Kimmelman, Jonathan

    2008-03-01

    Almost 20 years since the first gene-transfer trial was carried out in humans, the field has made significant advances towards clinical application. Nevertheless, it continues to face numerous unresolved ethical challenges--among them are the question of when to initiate human testing, the acceptability of germline modification and whether the technique should be applied to the enhancement of traits. Although such issues have precedents in other medical contexts, they take on a different character in gene transfer, in part because of the scientific uncertainty and the social context of innovation. PMID:18278058

  20. Gene transfer in the GI tract and oral cavity

    Mullany, Peter

    2000-01-01

    Gene transfer is important in spreading antibiotic resistance and other traits such as virulence factors. In this review the molecular mechanisms of gene transfer are outlined and the biological consequences of bacterial gene transfer in the GI tract and the oral cavity (GIOC) are discussed. Finally areas of possible future research aimed at attaining a deeper understanding of the process of gene transfer and the potential for stopping or slowing unwanted transfer are discussed.Keywords: gene...

  1. Viral Vectors for in Vivo Gene Transfer

    Thévenot, E.; Dufour, N.; Déglon, N.

    The transfer of DNA into the nucleus of a eukaryotic cell (gene transfer) is a central theme of modern biology. The transfer is said to be somatic when it refers to non-germline organs of a developed individual, and germline when it concerns gametes or the fertilised egg of an animal, with the aim of transmitting the relevant genetic modification to its descendents [1]. The efficient introduction of genetic material into a somatic or germline cell and the control of its expression over time have led to major advances in understanding how genes work in vivo, i.e., in living organisms (functional genomics), but also to the development of innovative therapeutic methods (gene therapy). The efficiency of gene transfer is conditioned by the vehicle used, called the vector. Desirable features for a vector are as follows: Easy to produce high titer stocks of the vector in a reproducible way. Absence of toxicity related to transduction (transfer of genetic material into the target cell, and its expression there) and no immune reaction of the organism against the vector and/or therapeutic protein. Stability in the expression of the relevant gene over time, and the possibility of regulation, e.g., to control expression of the therapeutic protein on the physiological level, or to end expression at the end of treatment. Transduction of quiescent cells should be as efficient as transduction of dividing cells. Vectors currently used fall into two categories: non-viral and viral vectors. In non-viral vectors, the DNA is complexed with polymers, lipids, or cationic detergents (described in Chap. 3). These vectors have a low risk of toxicity and immune reaction. However, they are less efficient in vivo than viral vectors when it comes to the number of cells transduced and long-term transgene expression. (Naked DNA transfer or electroporation is rather inefficient in the organism. This type of gene transfer will not be discussed here, and the interested reader is referred to the

  2. Hematopoiesis stimulation test by interleukin 1{alpha} gene transfer in the Cynomolgus macaque: application to secondary medullary aplasia from an accidental irradiation; Essais de stimulation de l'hematopoiese par le transfert de gene de l'interleukine-1{alpha} chez le macaque cynomolgus: application a l'aplasie medullaire secondaire a une irradiation accidentelle

    De Revel, Th.

    2002-12-15

    After a description of the context of medullary aplasia (haematological radiobiology, radiation acute syndrome, therapeutic care), and an overview of knowledge about the interleukin-1 and medullary stroma cells, this research thesis aims at investigating therapeutic alternatives for radio-accidental aplasia. More precisely, it aims at defining means to get cytokines which are efficient for haematopoiesis. Interleukin-1 is chosen for its properties and tests are performed on a macaque with two approaches for gene transfer: an ex vivo transfer by retroviral vector enabling an integration in the target cell genome, and an in situ transfer by adeno-viral vector directly applied in the animal osseous medulla

  3. Adenoviral delivery of pan-caspase inhibitor p35 enhances bystander killing by P450 gene-directed enzyme prodrug therapy using cyclophosphamide+

    Cytochrome P450-based suicide gene therapy for cancer using prodrugs such as cyclophosphamide (CPA) increases anti-tumor activity, both directly and via a bystander killing mechanism. Bystander cell killing is essential for the clinical success of this treatment strategy, given the difficulty of achieving 100% efficient gene delivery in vivo using current technologies. Previous studies have shown that the pan-caspase inhibitor p35 significantly increases CPA-induced bystander killing by tumor cells that stably express P450 enzyme CYP2B6 (Schwartz et al, (2002) Cancer Res. 62: 6928-37). To further develop this approach, we constructed and characterized a replication-defective adenovirus, Adeno-2B6/p35, which expresses p35 in combination with CYP2B6 and its electron transfer partner, P450 reductase. The expression of p35 in Adeno-2B6/p35-infected tumor cells inhibited caspase activation, delaying the death of the CYP2B6 'factory' cells that produce active CPA metabolites, and increased bystander tumor cell killing compared to that achieved in the absence of p35. Tumor cells infected with Adeno-2B6/p35 were readily killed by cisplatin and doxorubicin, indicating that p35 expression is not associated with acquisition of general drug resistance. Finally, p35 did not inhibit viral release when the replication-competent adenovirus ONYX-017 was used as a helper virus to facilitate co-replication and spread of Adeno-2B6/p35 and further increase CPA-induced bystander cell killing. The introduction of p35 into gene therapeutic regimens constitutes an effective approach to increase bystander killing by cytochrome P450 gene therapy. This strategy may also be used to enhance other bystander cytotoxic therapies, including those involving the production of tumor cell toxic protein products

  4. Rates of Lateral Gene Transfer in Prokaryotes

    Vos, Michiel; Hesselman, M.C.; Beek, te T.A.; Passel, van M.W.J.; Eyre-Walker, Adam

    2015-01-01

    Lateral gene transfer is of fundamental importance to the evolution of prokaryote genomes and has important practical consequences, as evidenced by the rapid dissemination of antibiotic resistance and virulence determinants. Relatively little effort has so far been devoted to explicitly quantifyi

  5. Adenoviral-mediated placental gene transfer of IGF-1 corrects placental insufficiency via enhanced placental glucose transport mechanisms.

    Helen N Jones

    Full Text Available Previous work in our laboratory demonstrated that over-expression of human insulin-like growth factor -1 (hIGF-1 in the placenta corrects fetal weight deficits in mouse, rat, and rabbit models of intrauterine growth restriction without changes in placental weight. The underlying mechanisms of this effect have not been elucidated. To investigate the effect of intra-placental IGF-1 over-expression on placental function we examined glucose transporter expression and localization in both a mouse model of IUGR and a model of human trophoblast, the BeWo Choriocarcinoma cell line.At gestational day 18, animals were divided into four groups; sham-operated controls, uterine artery branch ligation (UABL, UABL+Ad-hIGF-1 (10(8 PFU, UABL+Ad-LacZ (10(8 PFU. At gestational day 20, pups and placentas were harvested by C-section. For human studies, BeWo choriocarcinoma cells were grown in F12 complete medium +10%FBS. Cells were incubated in serum-free control media ± Ad-IGF-1 or Ad-LacZ for 48 hours. MOIs of 10∶1 and 100∶1 were utilized. The RNA, protein expression and localization of glucose transporters GLUT1, 3, 8, and 9 were analyzed by RT-PCR, Western blot and immunohistochemistry.In both the mouse placenta and BeWo, GLUT1 regulation was linked to altered protein localization. GLUT3, localized to the mouse fetal endothelial cells, was reduced in placental insufficiency but maintained with Ad-I GF-1 treatment. Interestingly, GLUT8 expression was reduced in the UABL placenta but up-regulated following Ad-IGF-1 in both mouse and human systems. GLUT9 expression in the mouse was increased by Ad-IGF-1 but this was not reflected in the BeWo, where Ad-IGF-1 caused moderate membrane relocalization.Enhanced GLUT isoform transporter expression and relocalization to the membrane may be an important mechanism in Ad-hIGF-1mediated correction of placental insufficiency.

  6. Sensitization of prostate cancer cell lines to 5-fluorocytosine induced by a replication incompetent adenoviral vector carrying a cytosine deaminase transcription unit

    2001-01-01

    AIM: To investigate the efficiency of cytosine deaminase adenoviral/5-fluorocytosine system on prostate cancer cell lines. METHODS: Cell culture, infectivity test and sensitivity test, observing the bystander effect and animal model experiment were carried out. RESULTS: All the established prostate cancer cell lines were eventually infectable, but ratio of vector/cell and time of exposed at which infection occurs was dependent on the cell lines. The expression of transfered cytosine deaminase gene peaked at different days, but persisted beyond 11 days. The prostate cell lines were sensitized to the 5-fluorocytosine by infection with the cytosine deaminase gene adenoviral vector, and only 5% of the LNCap and 10% of the RM-1 cells infected were required for 100% cell death. In the animal model, there was significant eradiation of tumor growth at the ratio of 400 vector particles/cell and with the systematic treatment of 5-fluorocytosine. CONCLUSION: The adenoviral vector carrying a cytosine deaminase transcription unit can sensitize the prostate cancer cell lines to 5-fluorocytosine, and the system can significantly inhibit the growth of prostatic tumor in mice.

  7. Horizontal gene transfer and bacterial diversity

    Chitra Dutta; Archana Pan

    2002-02-01

    Bacterial genomes are extremely dynamic and mosaic in nature. A substantial amount of genetic information is inserted into or deleted from such genomes through the process of horizontal transfer. Through the introduction of novel physiological traits from distantly related organisms, horizontal gene transfer often causes drastic changes in the ecological and pathogenic character of bacterial species and thereby promotes microbial diversification and speciation. This review discusses how the recent influx of complete chromosomal sequences of various microorganisms has allowed for a quantitative assessment of the scope, rate and impact of horizontally transmitted information on microbial evolution.

  8. The use of alien gene transfers

    The present status of the gene transfers from alien species belonging to the sub-tribe Triticanae into wheat is reviewed, and the advantages and disadvantages of the different methods available for such transfers are examined. In general, the alien genes provide a high degree of resistance against a notably wide range of physiological races of wheat rusts, powdery mildew and other diseases. The alien resistance, like other sources of resistance, is known to break down for certain new races. This may happen more often when alien genes of resistance are widely incorporated in commercial cultivars and grown over large areas. So far, few of the available induced translocation stocks have contributed to the development of agronomically superior commercial cultivars, mainly due to the associated undesirable effects of the translocations on agronomic characters of the recipient variety. The deleterious effects appear in some genetic backgrounds and not in others. Extensive hybridization of translocation stocks with different genotypes has been emphasized by most investigators. Such programmes have led to the release of three commercial cultivars - 2 in Australia and 1 in the USA. On the other hand, spontaneous wheat-rye translocations carrying gene(s) for disease resistance have been unconsciously incorporated into several wheat cultivars, some of them are widely cultivated and were top in ranking based on grain yield. (author)

  9. Gene Transfer with Poly-Melittin Peptides

    Chen, Chang-Po; Kim, Ji-Seon; Steenblock, Erin; Liu, Dijie; Rice, Kevin G.

    2006-01-01

    The 26 amino acid hemolytic melittin peptide was converted into a gene transfer peptide that binds to DNA and polymerized through disulfide bond formation. Melittin analogues were synthesized by addition of one to four Lys repeats at either the C or N-subterminal end along with terminal Cys residues. Melittin analogues were able to bind and polymerize on plasmids resulting in the formation of DNA condensates. In the absence of DNA, melittin analogues retained their red blood cell hemolytic po...

  10. Effects of AdCMV-p53 gene transfer induced by irradiation on cycle of human colorectal adenocarcinoma cells

    The work is to investigate effect of AdCMV-p53 gene transfer induced by 60Co γ-rays on cell cycles of human colorectal adenocarcinoma cells. HT-29 cells exposed to 0.5, 1.0 and 2.0 Gy were infected with AdCMV-GFP, a replication deficient recombinant adenoviral vector containing a CMV promoter and green fluorescent protein, or AdCMV-p53, a replication deficient recombinant adenoviral vector containing a CMV promoter and carrying human wild-type p53 gene. Survival rate of the cells was determined by clonogenic assay. Cell cycle and cell apoptosis were determined by flow cytometry. The results showed that, 0.5-1.0 Gy irradiation significantly enhanced the inhibition of AdCMV-p53 infection on HT-29. Compared with the control, 1 day after the infection, the cells in G0/G1 phase decreased by 5%-15%, the cells in S phase increased by 2%-19%. The 0.5 and 1.0 Gy irradiation made the cells in the in G2/M phase increase by 12%, infected with 80 MOI AdCMV-p5. There days later, the proportion of cells in G2/M phase in groups of 0.5 and 1.0 Gy irradiation +40 MOI AdCMV-p53 infection increased by 10%-13%. There was a relation between cell apoptosis and irradiation dose, or AdCMV-p53 dose. Therefore, the irradiation-induction could quicken the progression from G0/G1 phase to S phase, and promote S and G2/M phase arrest. (authors)

  11. Construction and characterization of calreticulin-HBsAg fusion gene recombinant adenovirus expression vector

    2010-01-01

    AIM: To generate recombinant adenoviral vector con-taining calreticulin (CRT)-hepatitis B surface antigen (HBsAg) fusion gene for developing a safe, effective and HBsAg-specific therapeutic vaccine.METHODS: CRT and HBsAg gene were fused using polymerase chain reaction (PCR), endonuclease diges-tion and ligation methods. The fusion gene was cloned into pENTR/D-TOPO transfer vector after the base pairs of DNA (CACC) sequence was added to the 5′ end. Adenoviral expression vector containing CRT-HBsAg fusion gen...

  12. Gene transfer system for Rhodopseudomonas viridis.

    Lang, F S; Oesterhelt, D

    1989-01-01

    A gene transfer system for Rhodopseudomonas viridis was established which uses conjugation with Escherichia coli S17-I as the donor and mobilizable plasmids as vectors. Initially, plasmids of the incompatibility group P1 (pRK290 and pRK404) were used. The more effective shuttle vectors between E. coli and R. viridis, pKV1 and pKVS1, were derived from plasmid pBR322 and showed the highest conjugation frequency (10(-2] thus far demonstrated in purple bacteria. It was also demonstrated that Rhiz...

  13. Evidences of lateral gene transfer between archaea and pathogenic bacteria

    Bokhari, Habib; Anwar, Maryam; Mirza, Hasan Bilal; Gillevet, Patrick Martin

    2011-01-01

    Acquisition of new genetic material through horizontal gene transfer has been shown to be an important feature in the evolution of many pathogenic bacteria. Changes in the genetic repertoire, occurring through gene acquisition and deletion, are the major events underlying the emergence and evolution of bacterial pathogens. However, horizontal gene transfer across the domains i.e. archaea and bacteria is not so common. In this context, we explore events of horizontal gene transfer between arch...

  14. DNA-mediated gene transfer without carrier DNA

    1981-01-01

    DNA-mediated gene transfer is a procedure which uses purified DNA to introduce new genetic elements into cells in culture. The standard DNA- mediated gene transfer procedure involves the use of whole cell DNA as carrier DNA for the transfer. We have modified the standard DNA- mediated gene transfer procedure to transfer the Herpes simplex virus type 1 thymidine kinase gene (TK) into TK- murine recipient cells in the absence of whole cell carrier DNA. The majority (8/10) of carrier- free trans...

  15. The Evolution of Adenoviral Vectors through Genetic and Chemical Surface Modifications

    Cristian Capasso

    2014-02-01

    Full Text Available A long time has passed since the first clinical trial with adenoviral (Ad vectors. Despite being very promising, Ad vectors soon revealed their limitations in human clinical trials. The pre-existing immunity, the marked liver tropism and the high toxicity of first generation Ad (FG-Ad vectors have been the main challenges for the development of new approaches. Significant effort toward the development of genetically and chemically modified adenoviral vectors has enabled researchers to create more sophisticated vectors for gene therapy, with an improved safety profile and a higher transduction ability of different tissues. In this review, we will describe the latest findings in the high-speed, evolving field of genetic and chemical modifications of adenoviral vectors, a field in which different disciplines, such as biomaterial research, virology and immunology, co-operate synergistically to create better gene therapy tools for modern challenges.

  16. The evolution of adenoviral vectors through genetic and chemical surface modifications.

    Capasso, Cristian; Garofalo, Mariangela; Hirvinen, Mari; Cerullo, Vincenzo

    2014-02-01

    A long time has passed since the first clinical trial with adenoviral (Ad) vectors. Despite being very promising, Ad vectors soon revealed their limitations in human clinical trials. The pre-existing immunity, the marked liver tropism and the high toxicity of first generation Ad (FG-Ad) vectors have been the main challenges for the development of new approaches. Significant effort toward the development of genetically and chemically modified adenoviral vectors has enabled researchers to create more sophisticated vectors for gene therapy, with an improved safety profile and a higher transduction ability of different tissues. In this review, we will describe the latest findings in the high-speed, evolving field of genetic and chemical modifications of adenoviral vectors, a field in which different disciplines, such as biomaterial research, virology and immunology, co-operate synergistically to create better gene therapy tools for modern challenges. PMID:24549268

  17. Enhanced Differentiation of Three-Gene-Reprogrammed Induced Pluripotent Stem Cells into Adipocytes via Adenoviral-Mediated PGC-1α Overexpression

    Yi-Jen Chen

    2011-11-01

    Full Text Available Induced pluripotent stem cells formed by the introduction of only three factors, Oct4/Sox2/Klf4 (3-gene iPSCs, may provide a safer option for stem cell-based therapy than iPSCs conventionally introduced with four-gene iPSCs. Peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α plays an important role during brown fat development. However, the potential roles of PGC-1α in regulating mitochondrial biogenesis and the differentiation of iPSCs are still unclear. Here, we investigated the effects of adenovirus-mediated PGC-1α overexpression in 3-gene iPSCs. PGC-1α overexpression resulted in increased mitochondrial mass, reactive oxygen species production, and oxygen consumption. Microarray-based bioinformatics showed that the gene expression pattern of PGC-1α-overexpressing 3-gene iPSCs resembled the expression pattern observed in adipocytes. Furthermore, PGC-1α overexpression enhanced adipogenic differentiation and the expression of several brown fat markers, including uncoupling protein-1, cytochrome C, and nuclear respiratory factor-1, whereas it inhibited the expression of the white fat marker uncoupling protein-2. Furthermore, PGC-1α overexpression significantly suppressed osteogenic differentiation. These data demonstrate that PGC-1α directs the differentiation of 3-gene iPSCs into adipocyte-like cells with features of brown fat cells. This may provide a therapeutic strategy for the treatment of mitochondrial disorders and obesity.

  18. Capsid modification strategies for detargeting adenoviral vectors.

    Parker, Alan L; Bradshaw, Angela C; Alba, Raul; Nicklin, Stuart A; Baker, Andrew H

    2014-01-01

    Adenoviral vectors hold immense potential for a wide variety of gene therapy based applications; however, their efficacy and toxicity is dictated by "off target" interactions that preclude cell specific targeting to sites of disease. A number of "off target" interactions have been described in the literature that occur between the three major capsid proteins (hexon, penton, and fiber) and components of the circulatory system, including cells such as erythrocytes, white blood cells, and platelets, as well as circulatory proteins including complement proteins, coagulation factors, von Willebrand Factor, p-selectin as well as neutralizing antibodies. Thus, to improve efficacious targeting to sites of disease and limit nonspecific uptake of virus to non-target tissues, specifically the liver and the spleen, it is necessary to develop suitable strategies for genetically modifying the capsid proteins to preclude these interactions. To this end we have developed versatile systems based on homologous recombination for modification of each of the major capsid proteins, which are described herein. PMID:24132476

  19. Progress in gene transfer by germ cells in mammals

    2008-01-01

    Use of germ cells as vectors for transgenesis in mammals has been well developed and offers exciting prospects for experimental and applied biology, agricultural and medical sciences.Such approach is referred to as either male germ cell mediated gene transfer (MGCMGT)or female germ cell mediated gene transfer(FGCMGT)technique.Sperm-mediated gene transfer (SMGT),including its alternative method,testis-mediated gene transfer(TMGT),becomes an established and reliable method for transgenesis.They have been extensively used for producing transgenic animals.The newly developed approach of FGCMGT,ovary-mediated gene transfer(OMGT) is also a novel and useful tool for efficient transgenesis.This review highlights an overview of the recent progress in germ cell mediated gene transfer techniques,methods developed and mechanisms of nucleic acid uptake by germ cells.

  20. Fibrin-mediated lentivirus gene transfer: implications for lentivirus microarrays

    Raut, Shruti; Lei, Pedro; Padmashali, Roshan; Andreadis, Stelios T.

    2010-01-01

    We employed fibrin hydrogel as bioactive matrix for lentivirus mediated gene transfer. Fibrin-mediated gene transfer was highly efficient and exhibited strong dependence on fibrinogen concentration. Efficient gene transfer was achieved with fibrinogen concentration between 3.75 – 7.5 mg/mL. Lower fibrinogen concentrations resulted in diffusion of virus out of the gel while higher concentrations led to ineffective fibrin degradation by target cells. Addition of fibrinolytic inhibitors decrease...

  1. Gene Transfer between Salmonella enterica Serovar Typhimurium inside Epithelial Cells

    Ferguson, Gayle C.; Heinemann, Jack A.; Kennedy, Martin A

    2002-01-01

    Virulence and antibiotic resistance genes transfer between bacteria by bacterial conjugation. Conjugation also mediates gene transfer from bacteria to eukaryotic organisms, including yeast and human cells. Predicting when and where genes transfer by conjugation could enhance our understanding of the risks involved in the release of genetically modified organisms, including those being developed for use as vaccines. We report here that Salmonella enterica serovar Typhimurium conjugated inside ...

  2. Measurement of feline cytokines interleukin-12 and interferon- g produced by heat inducible gene therapy adenoviral vector using real time PCR

    Biologic tumor therapy using Interleukin-12 (IL-12) has shown promise as an adjuvant to radiation therapy. The goals for cancer gene immunotherapy include effective eradication of established tumors and generation of a lasting systemic immune response. Among the cytokines, IL-12 has been found to be most effective gene in eradicating experimental tumors, preventing the development of metastases, and eliciting long-term antitumor immunity. Depending on the tumor model, IL-12 can exert antitumor activities via T cells, NK cells or NKT cells. It induces the production of IFN-g and IFN-inducible protein-10. It is also postulated to have antiangiogenic effects, thus inhibiting tumor formation and metastases. However, its use in clinical trials has been restricted largely owing to its systemic hematologic and hepatotoxicity. We tested the efficacy of adenovirus mediated expression of feline IL-12 gene placed under the control of an inducible promoter, the heat shock proteins (hsp70B). This places gene expression under the control of an external physical agent (hyperthermia), thus offering an 'on-off' switch and potentially reducing systemic toxicity by restricting its expression locally to the tumor. Crandell Feline Kidney (CrFK) cells were infected using the construct and the supernatant was then used to stimulate production of interferon g (IFN-g) in feline peripheral blood mononuclear cells (PBMC). As there is no commercially available ELISA kit currently available to detect or measure feline cytokines, we used real time-PCR to measure cytokine mRNA. These results will be used to initiate a clinical trial in cats with soft tissue sarcomas examining hyperthermia Induced gene therapy in conjunction with radiation therapy. The real time- PCR techniques developed here will be used to quantitatively measure cytokine mRNA levels in the punch biopsy samples obtained from the cats during the clinical trial. Support for this study was in part by NCI grant CA72745

  3. Radiopharmaceuticals to monitor the expression of transferred genes in gene transfer therapy

    Wiebe, L. I. [University of Alberta, Edmonton (Canada). Noujaim Institute for Pharmaceutical Oncology Research

    1997-10-01

    The development and application of radiopharmaceuticals has, in many instances, been based on the pharmacological properties of therapeutic agents. The molecular biology-biotechnology revolution has had an important impact on treatment of diseases, in part through the reduced toxicity of `biologicals`, in part because of their specificity for interaction at unique molecular sites and in part because of their selective delivery to the target site. Immunotherapeutic approaches include the use of monoclonal antibodies (MABs), MAB-fragments and chemotactic peptides. Such agents currently form the basis of both diagnostic and immunotherapeutic radiopharmaceuticals. More recently, gene transfer techniques have been advanced to the point that a new molecular approach, gene therapy, has become a reality. Gene therapy offers an opportunity to attack disease at its most fundamental level. The therapeutic mechanism is based on the expression of a specific gene or genes, the product of which will invoke immunological, receptor-based or enzyme-based therapeutic modalities. Several approaches to gene therapy of cancer have been envisioned, the most clinically-advanced concepts involving the introduction of genes that will encode for molecular targets nor normally found in healthy mammalian cells. A number of gene therapy clinical trials are based on the introduction of the Herpes simplex virus type-1 (HSV-1) gene that encodes for viral thymidine kinase (tk+). Once HSV-1 tk+ is expressed in the target (cancer) cell, therapy can be effected by the administration of a highly molecularly-targeted and systemically non-toxic antiviral drug such as ganciclovir. The development of radiodiagnostic imaging in gene therapy will be reviewed, using HSV-1 tk+ and radioiodinated IVFRU as a basis for development of the theme. Molecular targets that could be exploited in gene therapy, other than tk+, will be identified

  4. Radiopharmaceuticals to monitor the expression of transferred genes in gene transfer therapy

    The development and application of radiopharmaceuticals has, in many instances, been based on the pharmacological properties of therapeutic agents. The molecular biology-biotechnology revolution has had an important impact on treatment of diseases, in part through the reduced toxicity of 'biologicals', in part because of their specificity for interaction at unique molecular sites and in part because of their selective delivery to the target site. Immunotherapeutic approaches include the use of monoclonal antibodies (MABs), MAB-fragments and chemotactic peptides. Such agents currently form the basis of both diagnostic and immunotherapeutic radiopharmaceuticals. More recently, gene transfer techniques have been advanced to the point that a new molecular approach, gene therapy, has become a reality. Gene therapy offers an opportunity to attack disease at its most fundamental level. The therapeutic mechanism is based on the expression of a specific gene or genes, the product of which will invoke immunological, receptor-based or enzyme-based therapeutic modalities. Several approaches to gene therapy of cancer have been envisioned, the most clinically-advanced concepts involving the introduction of genes that will encode for molecular targets nor normally found in healthy mammalian cells. A number of gene therapy clinical trials are based on the introduction of the Herpes simplex virus type-1 (HSV-1) gene that encodes for viral thymidine kinase (tk+). Once HSV-1 tk+ is expressed in the target (cancer) cell, therapy can be effected by the administration of a highly molecularly-targeted and systemically non-toxic antiviral drug such as ganciclovir. The development of radiodiagnostic imaging in gene therapy will be reviewed, using HSV-1 tk+ and radioiodinated IVFRU as a basis for development of the theme. Molecular targets that could be exploited in gene therapy, other than tk+, will be identified

  5. Lentiviral vector gene transfer to porcine airways.

    Sinn, Patrick L; Cooney, Ashley L; Oakland, Mayumi; Dylla, Douglas E; Wallen, Tanner J; Pezzulo, Alejandro A; Chang, Eugene H; McCray, Paul B

    2012-01-01

    In this study, we investigated lentiviral vector development and transduction efficiencies in well-differentiated primary cultures of pig airway epithelia (PAE) and wild-type pigs in vivo. We noted gene transfer efficiencies similar to that observed for human airway epithelia (HAE). Interestingly, feline immunodeficiency virus (FIV)-based vectors transduced immortalized pig cells as well as pig primary cells more efficiently than HIV-1-based vectors. PAE express TRIM5α, a well-characterized species-specific lentiviral restriction factor. We contrasted the restrictive properties of porcine TRIM5α against FIV- and HIV-based vectors using gain and loss of function approaches. We observed no effect on HIV-1 or FIV conferred transgene expression in response to porcine TRIM5α overexpression or knockdown. To evaluate the ability of GP64-FIV to transduce porcine airways in vivo, we delivered vector expressing mCherry to the tracheal lobe of the lung and the ethmoid sinus of 4-week-old pigs. One week later, epithelial cells expressing mCherry were readily detected. Our findings indicate that pseudotyped FIV vectors confer similar tropisms in porcine epithelia as observed in human HAE and provide further support for the selection of GP64 as an appropriate envelope pseudotype for future preclinical gene therapy studies in the porcine model of cystic fibrosis (CF).Molecular Therapy - Nucleic Acids (2012) 1, e56; doi:10.1038/mtna.2012.47; published online 27 November 2012. PMID:23187455

  6. Optical gene transfer by femtosecond laser pulses

    Konig, Karsten; Riemann, Iris; Tirlapur, Uday K.

    2003-07-01

    Targeted transfection of cells is an important technique for gene therapy and related biomedical applications. We delineate how high-intensity (1012 W/cm2) near-infrared (NIR) 80 MHz nanojoule femtosecond laser pulses can create highly localised membrane perforations within a minute focal volume, enabling non-invasive direct transfection of mammalian cells with DNA. We suspended Chinese hamster ovarian (CHO), rat kangaroo kidney epithelial (PtK2) and rat fibroblast cells in 0.5 ml culture medium in a sterile miniaturized cell chamber (JenLab GmbH, Jena, Germany) containing 0.2 μg plasmid DNA vector pEGFP-N1 (4.7 kb), which codes for green fluorescent protein (GFP). The NIR laser beam was introduced into a femtosecond laser scanning microscope (JenLab GmbH, Jena, Germany; focussed on the edge of the cell membrane of a target cell for 16 ms. The integration and expression efficiency of EGFP were assessed in situ by two-photon fluorescence-lifetime imaging using time-correlated single photon counting. The unique capability to transfer foreign DNA safely and efficiently into specific cell types (including stem cells), circumventing mechanical, electrical or chemical means, will have many applications, such as targeted gene therapy and DNA vaccination.

  7. Gene Transfer & Hybridization Studies in Hyperthermophilic Species

    Nelson, Karen E.

    2005-10-14

    A. ABSTRACT The importance of lateral gene transfer (LGT) in the evolution of microbial species has become increasingly evident with each completed microbial genome sequence. Most significantly, the genome of Thermotoga maritima MSB8, a hyperthermophilic bacterium isolated by Karl Stetter and workers from Vulcano Italy in 1986, and sequenced at The Institute for Genomic Research (TIGR) in Rockville Maryland in 1999, revealed extensive LGT between % . this bacterium and members of the archaeal domain (in particular Archaeoglobus fulgidus, and Pyracoccus frcriosus species). Based on whole genome comparisons, it was estimated that 24% of the genetic information in this organism was acquired by genetic exchange with archaeal species, Independent analyses including periodicity analysis of the T. maritimu genomic DNA sequence, phylogenetic reconstruction based on genes that appear archaeal-like, and codon and amino acid usage, have provided additional evidence for LGT between T. maritima and the archaea. More recently, DiRuggiero and workers have identified a very recent LGT event between two genera of hyperthermophilic archaea, where a nearly identical DNA fragment of 16 kb in length flanked by insertion sequence (IS) elements, exists. Undoubtedly, additional examples of LGT will be identified as more microbial genomes are completed. For the present moment however, the genome sequence of T. maritima and other hyperthermophiles including P. furiosus, Pyrococcus horikoshii, Pyrococcus abyssi, A. fulgidus, and Aquifex aeolicus, have significantly increased out awareness of evolution being a web of life rather than a tree of life, as suggested by single gene phylogenies. In this proposal, we will aim to determine the extent of LGT across the hyperthemophiles, employing iY maritima as the model organism. A variety of biochemical techniques and phylogenetic reconstructions will allow for a detailed and thorough characterization of the extent of LGT in this species. The

  8. Factors involved in the maturation of murine dendritic cells transduced with adenoviral vector variants

    Adenoviral vector (Ad)-mediated gene transfer is an attractive method for manipulating the immunostimulatory properties of dendritic cells (DCs) for cancer immunotherapy. DCs treated with Ad have phenotype alterations (maturation) that facilitate T cell sensitization. We investigated the mechanisms of DC maturation with Ad transduction. Expression levels of a maturation marker (CD40) on DCs treated with conventional Ad, fiber-modified Ads (AdRGD, AdF35, AdF35ΔRGD), or a different serotype Ad (Ad35) were correlated with their transduction efficacy. The αv-integrin directional Ad, AdRGD, exhibited the most potent ability to enhance both foreign gene expression and CD40 expression, and induced secretion of interleukin-12, tumor necrosis factor-α, and interferon-α in DCs. The presence of a foreign gene expression cassette in AdRGD was not necessary for DC maturation. Maturation of DCs treated with AdRGD was suppressed by destruction of the Ad genome, inhibition of endocytosis, or endosome acidification, whereas proteasome inhibition increased CD40 expression levels on DCs. Moreover, inhibition of αv-integrin signal transduction and blockade of cytokine secretion affected the maturation of DCs treated with AdRGD only slightly or not at all, respectively. Thus, our data provide evidence that Ad-induced DC maturation is due to Ad invasion of the DCs, followed by nuclear transport of the Ad genome, and not to the expression of foreign genes

  9. Intracellular gene transfer: Reduced hydrophobicity facilitates gene transfer for subunit 2 of cytochrome c oxidase

    Daley, Daniel O; Clifton, Rachel; Whelan, James

    2002-01-01

    Subunit 2 of cytochrome c oxidase (Cox2) in legumes offers a rare opportunity to investigate factors necessary for successful gene transfer of a hydrophobic protein that is usually mitochondrial-encoded. We found that changes in local hydrophobicity were necessary to allow import of this nuclear-encoded protein into mitochondria. All legume species containing both a mitochondrial and nuclear encoded Cox2 displayed a similar pattern, with a large decrease in hydrophobicity evident in the first...

  10. Comparison of Human Sodium/Iodide Symporter (hNIS) Gene Expressions between Lentiviral and Adenoviral Vectors in Rat Mesenchymal Stem Cells

    Quantitative comparison of transgene expression within stem cells between lentivirus and adenovirusmediated delivery systems has not been reported. Here, we evaluated the human sodium iodide symporter (hNIS) gene expression in rat mesenchymal stem cell (rMSC) transduced by lentivirus or adenovirus, and compared the hNIS expression quantitatively between the two delivery systems. Lentiviral-mediated hNIS expressing rMSC (lenti-hNIS-rMSC) was constructed by cloning hNIS gene into pLenti6/UbC/V5-DEST (Invitrogen) to obtain pLenti-hNIS, transducing rMSC with the pLenti-hNIS, and selecting with blasticidin for 3 weeks. Recombinant adenovirus expressing hNIS gene (Rad-hNIS) was produced by homologous recombination and transduction efficiency of Rad-hNIS into rMSC evaluated by Rad-GFP was 19.1±4.7%, 54.0±6.4%, 85.7±8.7%, and 98.4±1.3% at MOI 1, 5, 20, and 100, respectively. The hNIS expressions in lenti-hNIS-rMSC or adeno-hNIS-rMSC were assessed by immunocytochemistry, western blot, and I-125 uptake. Immunocytochemistry and western blot analyses revealed that hNIS expressions in lenti-hNIS-rMSC were greater than those in adeno-hNIS-rMSC at MOI 20 but lower than at MOI 50. However in vitro I-125 uptake test demonstrated that iodide uptake in lenti-hNIS-rMSC (29,704±6,659 picomole/106 cells) was greater than that in adeno-hNIS-rMSC at MOI 100 (6,168±2,134 picomole/106 cells). Despite lower amount of expressed protein, hNIS function in rMSC was greater by lentivirus than by adenovirus mediated expression. Stem cell tracking using hNIS as a reporter gene should be conducted in consideration of relative vector efficiency for transgene expression

  11. Comparison of human sodium iodide symporter (hNIS) gene expression between lentiviral and adenoviral vectors in rat mesenchymal stem cell

    Quantitative comparison of transgene expression within stem cells between lentivirus and adenovirus-mediated delivery systems has not been done. Here, we evaluated the human sodium iodide symporter (hNIS) gene expression in rat mesenchymal stem cell (rMSC) transduced by lentivirus or adenovirus, and compared the hNIS expression quantitatively between the two delivery systems. Lentiviral-mediated stably hNIS expressing rMSC (lenti-hNIS-rMSC) was constructed by cloning the hNIS gene into pLenti6/UbC/V5-DEST (Invitrogen) to obtain pLenti-hNIS, transducing rMSC with the pLenti-hNIS, and selecting with blasticidin for 3 weeks. Recombinant adenovirus expressing hNIS gene (Rad-hNIS) was produced by homologous recombination and Rad-hNIS transduced rMSC (adeno-hNIS-rMSC) was evaluated for the hNIS expression 48 hours post infection at MOI 1, 5, 20, 50, and 100. The hNIS expression in lenti-hNIS-rMSC or adeno-hNIS-rMSC was assessed by immunocytochemistry, western blot, and I-125 uptake. Immunocytochemistry using mono-clonal anti-hNIS antibody revealed that intensity of hNIS immunoreactivity in lenti-hNIS-rMSC was greater than that in adeno-hNIS-rMSC at MOl 20 but lower than that at MOl 50. Western blot analysis also showed that lenti-hNIS-rMSC was intermediate between adeno-hNIS-rMSCs at MOl 20 and 50 in hNIS expression. However in vitro I-125 uptake test demonstrated that iodide uptake in lenti-hNIS-rMSC (297046659 picomole/106 cells) was greater than that in adeno-hNIS-rMSC at MOI 100 (61682134 picomole/106 cells). These results suggest that lentivirus mediated hNIS expression is greater in terms of hNIS function but lower in terms of hNIS protein amount than adenovirus mediated hNIS expression 48 hours post infection. Stem cell tracking using hNIS as a reporter gene should be conducted in consideration of relative viral efficiency of transgene expression

  12. Comparison of Human Sodium/Iodide Symporter (hNIS) Gene Expressions between Lentiviral and Adenoviral Vectors in Rat Mesenchymal Stem Cells

    Park, So Yeon; Lee, Won Woo; Kim, Hyun Joo; Chung, June Key; Kim, Sang Eun [Seoul National University College of Medicine, Seoul (Korea, Republic of); Kim, Sung Jin; Lee, Heui Ran [Medical Research Center, Seoul National University, Seoul (Korea, Republic of)

    2008-10-15

    Quantitative comparison of transgene expression within stem cells between lentivirus and adenovirusmediated delivery systems has not been reported. Here, we evaluated the human sodium iodide symporter (hNIS) gene expression in rat mesenchymal stem cell (rMSC) transduced by lentivirus or adenovirus, and compared the hNIS expression quantitatively between the two delivery systems. Lentiviral-mediated hNIS expressing rMSC (lenti-hNIS-rMSC) was constructed by cloning hNIS gene into pLenti6/UbC/V5-DEST (Invitrogen) to obtain pLenti-hNIS, transducing rMSC with the pLenti-hNIS, and selecting with blasticidin for 3 weeks. Recombinant adenovirus expressing hNIS gene (Rad-hNIS) was produced by homologous recombination and transduction efficiency of Rad-hNIS into rMSC evaluated by Rad-GFP was 19.1{+-}4.7%, 54.0{+-}6.4%, 85.7{+-}8.7%, and 98.4{+-}1.3% at MOI 1, 5, 20, and 100, respectively. The hNIS expressions in lenti-hNIS-rMSC or adeno-hNIS-rMSC were assessed by immunocytochemistry, western blot, and I-125 uptake. Immunocytochemistry and western blot analyses revealed that hNIS expressions in lenti-hNIS-rMSC were greater than those in adeno-hNIS-rMSC at MOI 20 but lower than at MOI 50. However in vitro I-125 uptake test demonstrated that iodide uptake in lenti-hNIS-rMSC (29,704{+-}6,659 picomole/10{sup 6} cells) was greater than that in adeno-hNIS-rMSC at MOI 100 (6,168{+-}2,134 picomole/10{sup 6} cells). Despite lower amount of expressed protein, hNIS function in rMSC was greater by lentivirus than by adenovirus mediated expression. Stem cell tracking using hNIS as a reporter gene should be conducted in consideration of relative vector efficiency for transgene expression.

  13. Identification and Categorization of Horizontally Transferred Genes in Prokaryotic Genomes

    Shuo-Yong SHI; Xiao-Hui CAI; Da-fu DING

    2005-01-01

    Horizontal gene transfer (HGT), a process through which genomes acquire genetic materials from distantly related organisms, is believed to be one of the major forces in prokaryotic genome evolution.However, systematic investigation is still scarce to clarify two basic issues about HGT: (1) what types of genes are transferred; and (2) what influence HGT events over the organization and evolution of biological pathways. Genome-scale investigations of these two issues will advance the systematical understanding of HGT in the context of prokaryotic genome evolution. Having investigated 82 genomes, we constructed an HGT database across broad evolutionary timescales. We identified four function categories containing a high proportion of horizontally transferred genes: cell envelope, energy metabolism, regulatory functions, and transport/binding proteins. Such biased function distribution indicates that HGT is not completely random;instead, it is under high selective pressure, required by function restraints in organisms. Furthermore, we mapped the transferred genes onto the connectivity structure map of organism-specific pathways listed in Kyoto Encyclopedia of Genes and Genomes (KEGG). Our results suggest that recruitment of transferred genes into pathways is also selectively constrained because of the tuned interaction between original pathway members. Pathway organization structures still conserve well through evolution even with the recruitment of horizontally transferred genes. Interestingly, in pathways whose organization were significantly affected by HGT events, the operon-like arrangement of transferred genes was found to be prevalent. Such results suggest that operon plays an essential and directional role in the integration of alien genes into pathways.

  14. Transduction of brain dopamine neurons by adenoviral vectors is modulated by CAR expression: rationale for tropism modified vectors in PD gene therapy.

    Travis B Lewis

    Full Text Available BACKGROUND: Gene-based therapy is a new paradigm for the treatment of Parkinson disease (PD and offers considerable promise for precise targeting and flexibility to impact multiple pathobiological processes for which small molecule agents are not available. Some success has been achieved utilizing adeno-associated virus for this approach, but it is likely that the characteristics of this vector system will ultimately create barriers to progress in clinical therapy. Adenovirus (Ad vector overcomes limitations in payload size and targeting. The cellular tropism of Ad serotype 5 (Ad5-based vectors is regulated by the Ad attachment protein binding to its primary cellular receptor, the coxsackie and adenovirus receptor (CAR. Many clinically relevant tissues are refractory to Ad5 infection due to negligible CAR levels but can be targeted by tropism-modified, CAR-independent forms of Ad. Our objective was to evaluate the role of CAR protein in transduction of dopamine (DA neurons in vivo. METHODOLOGY/PRINCIPAL FINDINGS: Ad5 was delivered to the substantia nigra (SN in wild type (wt and CAR transgenic animals. Cellular tropism was assessed by immunohistochemistry (IHC in the SN and striatal terminals. CAR expression was assessed by western blot and IHC. We found in wt animals, Ad5 results in robust transgene expression in astrocytes and other non-neuronal cells but poor infection of DA neurons. In contrast, in transgenic animals, Ad5 infects SNc neurons resulting in expression of transduced protein in their striatal terminals. Western blot showed low CAR expression in the ventral midbrain of wt animals compared to transgenic animals. Interestingly, hCAR protein localizes with markers of post-synaptic structures, suggesting synapses are the point of entry into dopaminergic neurons in transgenic animals. CONCLUSIONS/SIGNIFICANCE: These findings demonstrate that CAR deficiency limits infection of wild type DA neurons by Ad5 and provide a rationale for the

  15. HIGH EFFICIENCY RETROVIRUS-MEDIATED GENE TRANSFER TO LEUKEMIA CELLS

    FU Jian-xin; CHEN Zi-xing; CEN Jian-nong; WANG Wei; RUAN Chang-geng

    1999-01-01

    Objective: To establish an efficient and safe gene transfer system mediated by retrovirus for gene marking and gene therapy of human leukemia. Method: The retroviral vector LXSN, containing the neomycin resistance (NeoR) gene, was transferred into amphotropic packaging cells GP+envAm12 by liposome transfection or by ecotropic retrovirus transduction. Amphotropic retrovirus in supernatants with higher titer was used to infect human leukemic cell lines NB4, U937, and THP-1.The efficiency of gene transfer was assayed on colonies formed by transduced K562 cells. Results: The titer of DOSPER directly transfected GP+envAm12 cells determined on NIH3T3 cells was 8.0×105 CFU/ml, while that of producer infected with retrovirus was 1.6×107CFU/ml. Integration of NeoR gene into all leukemia cells was confirmed by polymerase chain reaction (PCR).Absence of replication-competent virus was proved by both nested PCR for env gene and marker gene rescue assay. Gene transfer with the efficiency as high as 93.3 to 100% in K562 cells was verified by seminested PCR for integrated NeoR gene on colonies after 7 days' culture.Conclusion: The efficiency and safety of retrovirus mediated gene transfer system might provide an optimal system in gene therapy for leukemia or genetic diseases.

  16. Evolution of and Horizontal Gene Transfer in the Endornavirus Genus

    Song, Dami; Cho, Won Kyong; Park, Sang-Ho; Jo, Yeonhwa; Kim, Kook-Hyung

    2013-01-01

    The transfer of genetic information between unrelated species is referred to as horizontal gene transfer. Previous studies have demonstrated that both retroviral and non-retroviral sequences have been integrated into eukaryotic genomes. Recently, we identified many non-retroviral sequences in plant genomes. In this study, we investigated the evolutionary origin and gene transfer of domains present in endornaviruses which are double-stranded RNA viruses. Using the available sequences for endor...

  17. Cytotoxic effect of replication-competent adenoviral vectors carrying L-plastin promoter regulated E1A and cytosine deaminase genes in cancers of the breast, ovary and colon.

    Akbulut, Hakan; Zhang, Lixin; Tang, Yucheng; Deisseroth, Albert

    2003-05-01

    Prodrug activating transcription unit gene therapy is one of several promising approaches to cancer gene therapy. Combining that approach with conditionally replication-competent viral vectors that are truly tumor specific has been an important objective of recent work. In this study, we report the construction of a new conditionally replication-competent bicistronic adenoviral vector in which the cytosine deaminase (CD) gene and the E1a gene are driven by the L-plastin tumor-specific promoter (AdLpCDIRESE1a). A similar vector driven by the CMV promoter has also been constructed (AdCMVCDIRESE1a) as a control. We have carried out in vitro cytotoxicity in carcinomas of the breast, ovary and colon, and in vivo efficacy studies with these vectors in an animal model of colon cancer. While the addition of the AdLpCDIRESE1a vector to established cancer cell lines showed significant cytotoxicity in tumor cells derived from carcinomas of the breast (MCF-7), colon (HTB-38) and ovary (Ovcar 5), no significant toxicity was seen in explant cultures of normal human mammary epithelial cells (HMEC) exposed to this vector. The addition of 5-fluorocytosine (5FC) significantly increased the cytotoxicity in an additive fashion of both the AdLpCDIRESE1a and AdCMVCDIRESE1a vectors as well as that of the AdLpCD replication incompetent vector to established tumor cell lines. However, no significant cytotoxicity was observed with the addition of 5FC to explant cultures of normal human mammary epithelial cells that had been exposed to the L-plastin-driven vectors. Studies with mixtures of infected and uninfected tumor cell lines showed that the established cancer cell lines infected with the AdLpCDIRESE1a vector generated significant toxicity to surrounding uninfected cells (the "bystander effect") even at a ratio of 0.25 of infected cells to infected + uninfected cells in the presence of 5FC. The injection of the AdLpCDIRESE1a vector into subcutaneous deposits of human tumor nodules in the

  18. Gene transfer approaches in cancer immunotherapy.

    Larin, S S; Georgiev, G P; Kiselev, S L

    2004-10-01

    The idea of enhancing or establishing effective immune response against endogenously developed tumor cells is not novel. More than a hundred years ago, bacterial components were used to develop antitumor immune response. Later, when a number of immune system-effecting cytokines had been discovered, they were used for systemic treatment of cancer patients. However, systemic treatment often resulted in even negative outcome. Recent developments of genetic approaches of cell modifications allowed developing of modern techniques of targeted tumor cell elimination. In the present paper, we review modern trends of the antitumor response enhancement based on immunoregulatory gene transfer into different cell types both in vivo and in vitro. Almost all these approaches are based on the activation of the adaptive arm of the immune system in response to tumor cells. However, recent studies indicate that the innate arm of the immune system, as well as adaptive arm, is involved in tumor suppression. The innate immune system uses nonrearranging germline receptors, which could trigger cellular effector responses that are conditional (or instructive) to the subsequent adaptive immune response. Last years' viewpoints on 'self' and 'non-self' recognition and primary induction of the immune response have changed. The key role of lymphocytes is pathogen recognition and, following immune response induction, switched on the central role of dendritic cells in 'non-self' recognition and induction of both innate and adaptive responses. Moreover, innate response is supposed to be an essential starting point in induction of successful and effective acquired response. Most cancer vaccines do not have 'non-self' marks presentation due to their endogenous origin, thus lacking their effectiveness in the induction of the specific long-lasting immune response. Taking this point into consideration, we can conclude that to make cancer vaccine more effective we have to present tumor antigens

  19. Patterns of prokaryotic lateral gene transfers affecting parasitic microbial eukaryotes

    Alsmark, Cecilia; Foster, Peter G; Sicheritz-Pontén, Thomas;

    2013-01-01

    approach to systematically investigate lateral gene transfer affecting the proteomes of thirteen, mainly parasitic, microbial eukaryotes, representing four of the six eukaryotic super-groups. All of the genomes investigated have been significantly affected by prokaryote-to-eukaryote lateral gene transfers......, dramatically affecting the enzymes of core pathways, particularly amino acid and sugar metabolism, but also providing new genes of potential adaptive significance in the life of parasites. A broad range of prokaryotic donors is involved in such transfers, but there is clear and significant enrichment for...... bacterial groups that share the same habitats, including the human microbiota, as the parasites investigated. CONCLUSIONS: Our data show that ecology and lifestyle strongly influence gene origins and opportunities for gene transfer and reveal that, although the outlines of the core eukaryotic metabolism are...

  20. Gene Transfer Strategies to Promote Chondrogenesis and Cartilage Regeneration.

    Im, Gun-Il

    2016-04-01

    Gene transfer has been used experimentally to promote chondrogenesis and cartilage regeneration. While it is controversial to apply gene therapy for nonlethal conditions such as cartilage defect, there is a possibility that the transfer of therapeutic transgenes may dramatically increase the effectiveness of cell therapy and reduce the quantity of cells that are needed to regenerate cartilage. Single or combination of growth factors and transcription factors has been transferred to mesenchymal stem cells or articular chondrocytes using both nonviral and viral approaches. The current challenge for the clinical applications of genetically modified cells is ensuring the safety of gene therapy while guaranteeing effectiveness. Viral gene delivery methods have been mainstays currently with enhanced safety features being recently refined. On the other hand, efficiency has been greatly improved in nonviral delivery. This review summarizes the history and recent update on the gene transfer to enhance chondrogenesis from stem cells or articular chondrocytes. PMID:26414246

  1. Immunocompromised Children with Severe Adenoviral Respiratory Infection

    Joanna C. Tylka

    2016-01-01

    Full Text Available Purpose. To investigate the impact of severe respiratory adenoviral infection on morbidity and case fatality in immunocompromised children. Methods. Combined retrospective-prospective cohort study of patients admitted to the intensive care unit (ICU in four children’s hospitals with severe adenoviral respiratory infection and an immunocompromised state between August 2009 and October 2013. We performed a secondary case control analysis, matching our cohort 1 : 1 by age and severity of illness score with immunocompetent patients also with severe respiratory adenoviral infection. Results. Nineteen immunocompromised patients were included in our analysis. Eleven patients (58% did not survive to hospital discharge. Case fatality was associated with cause of immunocompromised state (p=0.015, multiple organ dysfunction syndrome (p=0.001, requirement of renal replacement therapy (p=0.01, ICU admission severity of illness score (p=0.011, and treatment with cidofovir (p=0.005. Immunocompromised patients were more likely than matched controls to have multiple organ dysfunction syndrome (p=0.01, require renal replacement therapy (p=0.02, and not survive to hospital discharge (p=0.004. One year after infection, 43% of immunocompromised survivors required chronic mechanical ventilator support. Conclusions. There is substantial case fatality as well as short- and long-term morbidity associated with severe adenoviral respiratory infection in immunocompromised children.

  2. Generation of insulin-producing cells from the mouse liver using β cell-related gene transfer including Mafa and Mafb.

    Haruka Nagasaki

    Full Text Available Recent studies on the large Maf transcription factors have shown that Mafb and Mafa have respective and distinctive roles in β-cell development and maturation. However, whether this difference in roles is due to the timing of the gene expression (roughly, expression of Mafb before birth and of Mafa after birth or to the specific function of each gene is unclear. Our aim was to examine the functional differences between these genes that are closely related to β cells by using an in vivo model of β-like cell generation. We monitored insulin gene transcription by measuring bioluminescence emitted from the liver of insulin promoter-luciferase transgenic (MIP-Luc-VU mice. Adenoviral gene transfers of Pdx1/Neurod/Mafa (PDA and Pdx1/Neurod/Mafb (PDB combinations generated intense luminescence from the liver that lasted for more than 1 week and peaked at 3 days after transduction. The peak signal intensities of PDA and PDB were comparable. However, PDA but not PDB transfer resulted in significant bioluminescence on day 10, suggesting that Mafa has a more sustainable role in insulin gene activation than does Mafb. Both PDA and PDB transfers ameliorated the glucose levels in a streptozotocin (STZ-induced diabetic model for up to 21 days and 7 days, respectively. Furthermore, PDA transfer induced several gene expressions necessary for glucose sensing and insulin secretion in the liver on day 9. However, a glucose tolerance test and liver perfusion experiment did not show glucose-stimulated insulin secretion from intrahepatic β-like cells. These results demonstrate that bioluminescence imaging in MIP-Luc-VU mice provides a noninvasive means of detecting β-like cells in the liver. They also show that Mafa has a markedly intense and sustained role in β-like cell production in comparison with Mafb.

  3. The power of phylogenetic approaches to detect horizontally transferred genes

    Gogarten J Peter

    2007-03-01

    Full Text Available Abstract Background Horizontal gene transfer plays an important role in evolution because it sometimes allows recipient lineages to adapt to new ecological niches. High genes transfer frequencies were inferred for prokaryotic and early eukaryotic evolution. Does horizontal gene transfer also impact phylogenetic reconstruction of the evolutionary history of genomes and organisms? The answer to this question depends at least in part on the actual gene transfer frequencies and on the ability to weed out transferred genes from further analyses. Are the detected transfers mainly false positives, or are they the tip of an iceberg of many transfer events most of which go undetected by current methods? Results Phylogenetic detection methods appear to be the method of choice to infer gene transfers, especially for ancient transfers and those followed by orthologous replacement. Here we explore how well some of these methods perform using in silico transfers between the terminal branches of a gamma proteobacterial, genome based phylogeny. For the experiments performed here on average the AU test at a 5% significance level detects 90.3% of the transfers and 91% of the exchanges as significant. Using the Robinson-Foulds distance only 57.7% of the exchanges and 60% of the donations were identified as significant. Analyses using bipartition spectra appeared most successful in our test case. The power of detection was on average 97% using a 70% cut-off and 94.2% with 90% cut-off for identifying conflicting bipartitions, while the rate of false positives was below 4.2% and 2.1% for the two cut-offs, respectively. For all methods the detection rates improved when more intervening branches separated donor and recipient. Conclusion Rates of detected transfers should not be mistaken for the actual transfer rates; most analyses of gene transfers remain anecdotal. The method and significance level to identify potential gene transfer events represent a trade

  4. Endosymbiotic gene transfer from prokaryotic pangenomes: Inherited chimerism in eukaryotes

    Ku, Chuan; Nelson-Sathi, Shijulal; Roettger, Mayo; Garg, Sriram; Hazkani-Covo, Einat; Martin, William F.

    2015-01-01

    Endosymbiotic theory in eukaryotic-cell evolution rests upon a foundation of three cornerstone partners—the plastid (a cyanobacterium), the mitochondrion (a proteobacterium), and its host (an archaeon)—and carries a corollary that, over time, the majority of genes once present in the organelle genomes were relinquished to the chromosomes of the host (endosymbiotic gene transfer). However, notwithstanding eukaryote-specific gene inventions, single-gene phylogenies have never traced eukaryotic ...

  5. Replication-deficient adenovirus vector transfer of gfp reporter gene into supraoptic nucleus and subfornical organ neurons

    Vasquez, E. C.; Johnson, R. F.; Beltz, T. G.; Haskell, R. E.; Davidson, B. L.; Johnson, A. K.

    1998-01-01

    The present studies used defined cells of the subfornical organ (SFO) and supraoptic nuclei (SON) as model systems to demonstrate the efficacy of replication-deficient adenovirus (Ad) encoding green fluorescent protein (GFP) for gene transfer. The studies investigated the effects of both direct transfection of the SON and indirect transfection (i.e., via retrograde transport) of SFO neurons. The SON of rats were injected with Ad (2 x 10(6) pfu) and sacrificed 1-7 days later for cell culture of the SON and of the SFO. In the SON, GFP fluorescence was visualized in both neuronal and nonneuronal cells while only neurons in the SFO expressed GFP. Successful in vitro transfection of cultured cells from the SON and SFO was also achieved with Ad (2 x 10(6) to 2 x 10(8) pfu). The expression of GFP in in vitro transfected cells was higher in nonneuronal (approximately 28% in SON and SFO) than neuronal (approximately 4% in SON and 10% in SFO) cells. The expression of GFP was time and viral concentration related. No apparent alterations in cellular morphology of transfected cells were detected and electrophysiological characterization of transfected cells was similar between GFP-expressing and nonexpressing neurons. We conclude that (1) GFP is an effective marker for gene transfer in living SON and SFO cells, (2) Ad infects both neuronal and nonneuronal cells, (3) Ad is taken up by axonal projections from the SON and retrogradely transported to the SFO where it is expressed at detectable levels, and (4) Ad does not adversely affect neuronal viability. These results demonstrate the feasibility of using adenoviral vectors to deliver genes to the SFO-SON axis. Copyright 1998 Academic Press.

  6. Bone formation in vivo induced by Cbfa1-carrying adenoviral vectors released from a biodegradable porous {beta}-tricalcium phosphate ({beta}-TCP) material

    Uemura, Toshimasa; Kojima, Hiroko, E-mail: t.uemura@aist.go.jp [Nanosystem Research Institute (NRI), National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba Central-4, Tsukuba, Ibaraki 305-8562 (Japan)

    2011-06-15

    Overexpression of Cbfa1 (a transcription factor indispensable for osteoblastic differentiation) is expected to induce the formation of bone directly and indirectly in vivo by accelerating osteoblastic differentiation. Adenoviral vectors carrying the cDNA of Cbfa1/til-1(Adv-Cbf1) were allowed to be adsorbed onto porous blocks of {beta}-tricalcium phosphate ({beta}-TCP), a biodegradable ceramic, which were then implanted subcutaneously and orthotopically into bone defects. The adenoviral vectors were released sustainingly by biodegradation, providing long-term expression of the genes. Results of the subcutaneous implantation of Adv-Cbfa1-adsorbed {beta}-TCP/osteoprogenitor cells suggest that a larger amount of bone formed in the pores of the implant than in the control material. Regarding orthotopic implantation into bone defects, the released Adv-Cbfa1 accelerated regeneration in the cortical bone, whereas it induced bone resorption in the marrow cavity. A safer gene transfer using a smaller amount of the vector was achieved using biodegradable porous {beta}-TCP as a carrier.

  7. Fibrin-mediated lentivirus gene transfer: implications for lentivirus microarrays.

    Raut, Shruti D; Lei, Pedro; Padmashali, Roshan M; Andreadis, Stelios T

    2010-06-01

    We employed fibrin hydrogel as a bioactive matrix for lentivirus mediated gene transfer. Fibrin-mediated gene transfer was highly efficient and exhibited strong dependence on fibrinogen concentration. Efficient gene transfer was achieved with fibrinogen concentration between 3.75 and 7.5mg/ml. Lower fibrinogen concentrations resulted in diffusion of virus out of the gel while higher concentrations led to ineffective fibrin degradation by target cells. Addition of fibrinolytic inhibitors decreased gene transfer in a dose-dependent manner suggesting that fibrin degradation by target cells may be necessary for successful gene delivery. Under these conditions transduction may be limited only to cells interacting with the matrix thereby providing a method for spatially-localized gene delivery. Indeed, when lentivirus-containing fibrin microgels were spotted in an array format gene transfer was confined to virus-containing fibrin spots with minimal cross-contamination between neighboring sites. Collectively, our data suggest that fibrin may provide an effective matrix for spatially-localized gene delivery with potential applications in high-throughput lentiviral microarrays and in regenerative medicine. PMID:20153386

  8. Functional correction of adult mdx mouse muscle using gutted adenoviral vectors expressing full-length dystrophin

    DelloRusso, Christiana; Scott, Jeannine M.; Hartigan-O'Connor, Dennis; Salvatori, Giovanni; Barjot, Catherine; Robinson, Ann S.; Robert W Crawford; Brooks, Susan V; Jeffrey S. Chamberlain

    2002-01-01

    Duchenne muscular dystrophy is a lethal X-linked recessive disorder caused by mutations in the dystrophin gene. Delivery of functionally effective levels of dystrophin to immunocompetent, adult mdx (dystrophin-deficient) mice has been challenging because of the size of the gene, immune responses against viral vectors, and inefficient infection of mature muscle. Here we show that high titer stocks of three different gutted adenoviral vectors carrying full-length, muscle-specific, dystrophin ex...

  9. Electroporation-Mediated Gene Transfer Directly to the Swine Heart

    Hargrave, Barbara; Downey, Harre; Strange, Robert; Murray, Len; Cinnamond, Cade; Lundberg, Cathryn; Israel, Annelise; Chen, Yeong-Jer; Marshall, William; Heller, Richard

    2012-01-01

    In vivo gene transfer to the ischemic heart via electroporation holds promise as a potential therapeutic approach for the treatment of heart disease. In the current study, we investigated the use of in vivo electroporation for gene transfer using 3 different penetrating electrodes and one non-penetrating electrode. The hearts of adult male swine were exposed through a sternotomy. Eight electric pulses synchronized to the rising phase of the R wave of the ECG were administered at varying pulse...

  10. Phase I trial of recombinant adenovirus gene transfer in lung cancer. Longitudinal study of the immune responses to transgene and viral products.

    Gahéry-Ségard, H; Molinier-Frenkel, V; Le Boulaire, C; Saulnier, P; Opolon, P; Lengagne, R; Gautier, E; Le Cesne, A; Zitvogel, L; Venet, A; Schatz, C; Courtney, M; Le Chevalier, T; Tursz, T; Guillet, J G; Farace, F

    1997-01-01

    Animal studies indicate that the use of replication-deficient adenovirus for human gene therapy is limited by host antivector immune responses that result in transient recombinant protein expression and blocking of gene transfer when rechallenged. Therefore, we have examined immune responses to an adenoviral vector and to the beta-galactosidase protein in four patients with lung cancer given a single intratumor injection of 10(9) plaque-forming units of recombinant adenovirus. The beta-galactosidase protein was expressed in day-8 tumor biopsies from all patients at variable levels. Recombinant virus DNA was detected by PCR in day-30 and day-60 tumor biopsies from all patients except patient 1. A high level of neutralizing antiadenovirus antibodies was detected in patient 1 before Ad-beta-gal injection whereas it was low (patient 3) or undetectable in the other two patients. All patients developed potent CD4 type 1 helper T cell (Th1) responses to adenoviral particles which increased gradually over time after injection. Antiadenovirus cytotoxic T lymphocyte responses were consistently boosted in the two patients examined (patients 3 and 4). Sustained production of anti-beta-galactosidase IgG was observed in all patients except patient 1. Consistent with anti-beta-gal antibody production, all patients except patient 1 developed intense, dose-dependent Th1 responses to soluble beta-galactosidase which increased over time. Strong beta-galactosidase-specific cytotoxic T lymphocyte responses were detected in patients 2, 3, and 4. Our results clearly show that despite the intensity of antiadenovirus responses, transgene protein expression was sufficient to induce strong and prolonged immunity in three patients. Recombinant adenovirus injected directly into the tumor is a highly efficient vector for immunizing patients against the transgene protein. PMID:9410899

  11. Gene transfer for cytokine functional studies in the lung: the multifunctional role of GM-CSF in pulmonary inflammation.

    Xing, Z; Braciak, T; Ohkawara, Y; Sallenave, J M; Foley, R; Sime, P J; Jordana, M; Graham, F L; Gauldie, J

    1996-04-01

    Using adenoviral-mediated gene transfer techniques, the murine granulocyte-macrophage colony-stimulating factor (GM-CSF) transgene is efficiently targeted to and highly expressed by the respiratory epithelium of rat lung. This lung tissue-directed expression of GM-CSF induces accumulation of both eosinophils and macrophages at early stages and an irreversible fibrotic reaction at later stages. These tissue responses to GM-CSF appear to be distinct from those induced by other proinflammatory cytokines, interleukin (IL)-5, IL-6, macrophage inflammatory protein-2 (MIP-2), or RANTES overexpressed in the lung. These findings clearly demonstrate that GM-CSF is more than a hematopoietic cytokine in the lung and may play a pivotal role in the multiple pathological processes underlying numerous respiratory illnesses, including asthma. In this overview, the differences in tissue responses induced by GM-CSF and other individual cytokines are highlighted. In addition, the mechanisms by which GM-CSF and other individual cytokines are highlighted. In addition, the mechanisms by which GM-CSF contributes to the development of eosinophilia, macrophage granuloma, and fibrosis are discussed in conjunction with the recent findings from us and others. PMID:8613693

  12. Effect of human hepatocyte growth factor on promoting wound healing and preventing scar formation by adenovirus-mediated gene transfer

    哈小琴; 李元敏; 劳妙芬; 苑宾; 吴祖泽

    2003-01-01

    Objective To evaluate the effects of hepatocyte growth factor (HGF) on the prevention of scar formation and the promotion of wound healing by gene transfer. Methods A total of 12 female New Zealand rabbits were used in this study. Rabbits were anesthetized with an intravenous injection of sodium pentobarbital, and identical wounds were made over the ventral surface of each ear. Five circular wounds, 7 mm in diameter, were created in each ear by excision through the skin to the underlying cartilage using sterile technique. After the surgical procedures, 10 of the rabbits were randomly allocated to five groups, with 2 rabbits in each group: Ad-HGF group 1, Ad-HGF group 2, Ad-HGF group 3, Ad-GFP (a reporter gene) group and the solvent group. Immediately after surgery, 6×107 pfu Ad-HGF, 6×108 pfu Ad-HGF, 6×109 pfu of Ad-HGF, 6×109 pfu of Ad-GFP, or same volume of solvent (PBS, pH 7.2) was applied once to each wound in groups 1 to 5, respectively. One additional rabbit was used to evaluate the transfer efficiency of the adenovirus vector by transferring Ad-GFP (6×109 pfu) into its wounds. Ice slides of wounds from this animal were observed under fluorescence microscopy. Another additional rabbit was used to evaluate the expression of HGF and TGFβ1 after transferring Ad-HGF (6×109 pfu) into each of its wound. Immunohistochemistry was used for detection. Results The effect of HGF on reducing excessive dermal scarring was observed by adenovirus-mediated gene transfer. Transfection of the human HGF cDNA into skin wounds through an adenoviral vector suppressed the over-expression of TGFβ1, which plays an essential role in the progression of dermal fibrogenesis. Application of HGF to the wounds significantly enhanced wound healing and inhibited over scarring.Conclusion HGF gene therapy could be a new approach for preventing excessive dermal scarring in wound healing.

  13. Gentamicin resistance genes in environmental bacteria: prevalence and transfer

    Heuer, H.; Krögerrecklenfort, E.; Wellington, E.M.H.; Egan, S.; Elsas, van J.D.; Overbeek, van L.S.; Collard, J.M.; Guillaume, G.; Karagouni, A.; Nikolakopoulou, D.; Smalla, K.

    2002-01-01

    A comprehensive multiphasic survey of the prevalence and transfer of gentamicin resistance (Gmr) genes in different non-clinical environments has been performed. We were interested to find out whether Gmr genes described from clinical isolates can be detected in different environmental habitats and

  14. Global Analysis of Horizontal Gene Transfer in Fusarium verticillioides

    The co-occurrence of microbes within plants and other specialized niches may facilitate horizontal gene transfer (HGT) affecting host-pathogen interactions. We recently identified fungal-to-fungal HGTs involving metabolic gene clusters. For a global analysis of HGTs in the maize pathogen Fusarium ve...

  15. Can we modify response to radiation therapy with gene transfer?

    Several recent studies suggest that gene transfer can be combined with irradiation to increase anti-tumor efficacy. Among genes of particular interest to be used in this combined approach are those involved in the regulation of radiation-induced lethality (apoptosis, DNA repair). Some additional aspects appear to be relatively specific to these combinations, such as the type of vector to be used (anaerobic bacteria) or the type of promoter (radio-inducible promoters). The first results obtained in mice bearing human xenograft tumors, combining gene transfer and irradiation are encouraging, but no clinical study has been performed so far. Finally it should be pointed out, in this area as well as in cancer gene therapy in general, that progress in gene vectorization is mandatory to optimize gene distribution within the tumor. (authors)

  16. Design of radiopharmaceuticals for monitoring gene transfer therapy

    The development of radiopharmaceuticals for monitoring gene transfer therapy with emission tomography is expected to lead to improved management of cancer by the year 2010. There are now only a few examples and approaches to the design of radiopharmaceuticals for gene transfer therapy. This paper introduces a novel concept for the monitoring of gene therapy. We present the optimisation of the labelling of recombinant human β-NGF ligands for in vitro studies prior to using 123I for SPET and 124I for PET studies. (author)

  17. Horizontal gene transfer between Wolbachia and the mosquito Aedes aegypti

    Walker Thomas

    2009-01-01

    Full Text Available Abstract Background The evolutionary importance of horizontal gene transfer (HGT from Wolbachia endosymbiotic bacteria to their eukaryotic hosts is a topic of considerable interest and debate. Recent transfers of genome fragments from Wolbachia into insect chromosomes have been reported, but it has been argued that these fragments may be on an evolutionary trajectory to degradation and loss. Results We have discovered a case of HGT, involving two adjacent genes, between the genomes of Wolbachia and the currently Wolbachia-uninfected mosquito Aedes aegypti, an important human disease vector. The lower level of sequence identity between Wolbachia and insect, the transcription of all the genes involved, and the fact that we have identified homologs of the two genes in another Aedes species (Ae. mascarensis, suggest that these genes are being expressed after an extended evolutionary period since horizontal transfer, and therefore that the transfer has functional significance. The association of these genes with Wolbachia prophage regions also provides a mechanism for the transfer. Conclusion The data support the argument that HGT between Wolbachia endosymbiotic bacteria and their hosts has produced evolutionary innovation.

  18. Selective homocysteine lowering gene transfer improves infarct healing, attenuates remodelling, and enhances diastolic function after myocardial infarction in mice.

    Ilayaraja Muthuramu

    Full Text Available BACKGROUND AND AIMS: Homocysteine levels predict heart failure incidence in prospective epidemiological studies and correlate with severity of heart failure in cross-sectional surveys. The objective of this study was to evaluate whether a selective homocysteine lowering intervention beneficially affects cardiac remodelling and cardiac function after myocardial infarction (MI in a murine model of combined hypercholesterolemia and hyperhomocysteinemia. METHODOLOGY AND PRINCIPAL FINDINGS: A selective homocysteine lowering gene transfer strategy was evaluated in female C57BL/6 low density lipoprotein receptor (Ldlr⁻/⁻ cystathionine-ß-synthase (Cbs⁺/⁻ deficient mice fed a hyperhomocysteinemic and high saturated fat/high cholesterol diet using an E1E3E4-deleted hepatocyte-specific adenoviral vector expressing Cbs (AdCBS. MI was induced by permanent ligation of the left anterior descending coronary artery 14 days after saline injection or gene transfer. AdCBS gene transfer resulted in a persistent more than 5-fold (p<0.01 decrease of plasma homocysteine levels and significantly improved endothelial progenitor cell function. Selective homocysteine lowering enhanced infarct healing as indicated by a 21% (p<0.01 reduction of infarct length at day 28 after MI and by an increased number of capillaries and increased collagen content in the infarct zone. Adverse remodelling was attenuated in AdCBS MI mice as evidenced by a 29% (p<0.05 reduction of left ventricular cavity area at day 28, by an increased capillary density in the remote myocardium, and by reduced interstitial collagen. The peak rate of isovolumetric relaxation was increased by 19% (p<0.05 and the time constant of left ventricular relaxation was reduced by 21% (p<0.05 in AdCBS MI mice compared to control MI mice, indicating improved diastolic function. CONCLUSION/SIGNIFICANCE: Selective homocysteine lowering gene transfer improves infarct healing, attenuates remodelling, and

  19. Gene transfer strategies for improving radiolabeled peptide imaging and therapy

    Rogers, B.E.; Buchsbaum, D.J. [Birmingham University of Alabama, Birmingham, AL (United States). Dept. of Radiation Oncology; Zinn, K.R. [Birmingham University of Alabama, Birmingham, AL (United States). Radiology

    2000-09-01

    Utilization of molecular biology techniques offers attractive options in nuclear medicine for improving cancer imaging and therapy with radiolabeled peptides. Two of these options include utilization of phage-panning to identify novel tumor specific peptides or single chain antibodies and gene transfer techniques to increase the antibodies and gene transfer techniques to increase the number of antigen/receptor sites expressed on malignant cells. The group has focused on the latter approach for improving radiolabeled peptide imaging and therapy. The most widely used gene transfer vectors in clinical gene therapy trials include retrovirus, cationic lipids and adenovirus. It has been utilized adenovirus vectors for gene transfer because of their ability to accomplish efficient in vivo gene transfer. Adenovirus vectors encoding the genes for a variety of antigens/receptors (carcinoembryonic antigen, gastrin-releasing peptide receptor, somatostatin receptor subtype 2 (SSTr2)) have all shown that their expression is increased on cancer cells both in vitro and in vivo following adenovirus infection. Of particular interest has been the adenovirus encoding for SSTr2 (AdCMVSSTr2). Various radioisotopes have been attached to somatostatin analogues for imaging and therapy of SSTr2-positive tumors both clinically and in animal models. The use of these analogues in combination with AdCMVSSTr2 is a promising approach for improving the detection sensitivity and therapeutic efficacy of these radiolabeled peptides against solid tumors. In addition, it has been proposed the use of SSTr2 as a marker for imaging the expression of another cancer therapeutic trans gene (e.g., cytosine deaminase, thymidine kinase) encoded within the same vector. This would allow for non-invasive monitoring of gene delivery to tumor sites.

  20. GSH depletion enhances adenoviral bax-induced apoptosis in lung cancer cells.

    Honda, Tsuyoshi; Coppola, Simona; Ghibelli, Lina; Cho, Song H; Kagawa, Shunsuke; Spurgers, Kevin B; Brisbay, Shawn M; Roth, Jack A; Meyn, Raymond E; Fang, Bingliang; McDonnell, Timothy J

    2004-04-01

    The utility of dominant acting proapoptotic molecules to induce cell death in cancer cells is being evaluated in preclinical studies and clinical trials. We recently developed a binary adenoviral expression system to enable the efficient gene transfer of Bax and other proapoptotic molecules. Using this system, overexpression of Bax protein in four non-small-cell lung cancer (NSCLC) cell lines, H1299, A549, H226 and H322, was evaluated. The H322 line exhibited significant resistance to Bax-induced cell death compared to the other cell lines. H322 cells had the highest level of glutathione (GSH). GSH levels were significantly decreased following buthionine sulfoximine treatment and this coincided with enhanced apoptosis induction by Ad-Bax in H322 cells. GSH depletion enhanced Bax protein translocation to mitochondrial membranes. These findings suggest that the redox status may be a determinant of Bax-mediated cell death and that manipulation of intracellular thiols may sensitize cells to apoptosis by facilitating Bax insertion into mitochondrial membranes. PMID:15002033

  1. Agrobacterium-mediated gene transfer to Chrysanthemum.

    Wordragen, van M.F.

    1991-01-01

    Genetic manipulation of plants is a technique that enables us to add to the plant genome, in a precise and well controlled manner, one or a few new genes, coding for desirable traits. In contrast to this, the conventional method for the introduction of new properties in plants, by cross breeding, is

  2. Transfection of Primary Hepatocytes with Liver-Enriched Transcription Factors Using Adenoviral Vectors.

    Benet, Marta; Jover, Ramiro; Bort, Roque

    2015-01-01

    Primary cultured hepatocytes are probably the best model to study endogenous metabolic pathways, toxicity, or drug metabolism. Many of these studies require expression of ectopic genes. It would be desirable to use a method of transfection that allows dose-response studies, high efficiency of transfection, and the possibility to express several genes at the same time. Adenoviral vectors fulfill these requirements, becoming a valuable tool for primary hepatocyte transfection. Moreover, they are easy to generate and do not require a high level of biocontainment. In the present chapter, we describe the generation, cloning, amplification, and purification of an adenoviral vector capable of infecting primary cultured hepatocytes. This recombinant adenovirus induces robust expression of the protein of interest in hepatocytes within a wide range of doses. PMID:26272145

  3. DNA-mediated gene transfer into ataxia-telangiectasia cells

    The complete description of the genetic lesion(s) underlying the AT mutation might, therefore, highlight not only a DNA-repair pathwa, but also an important aspect of the physiology of lymphocytes. DNA-mediated gene transfer into eukaryotic cells has proved a powerful tool for the molecular cloning of certain mammalian genes. The possibility to clone a given gene using this technology depends, basically, on the availability of a selectable marker associated with the expression of the transfected gene in the recipient cell. Recently, a human DNA repair gene has been cloned in CHO mutant cells by taking advantage of the increased resistance to ultraviolet radiation of the transformants. As a preliminary step toward the molecular cloning of the AT gene(s), the authors have attempted to confer radioresistance to AT cells by transfection with normal human DNA

  4. Gene transfer strategies for improving radiolabeled peptide imaging and therapy

    Utilization of molecular biology techniques offers attractive options in nuclear medicine for improving cancer imaging and therapy with radiolabeled peptides. Two of these options include utilization of phage-panning to identify novel tumor specific peptides or single chain antibodies and gene transfer techniques to increase the antibodies and gene transfer techniques to increase the number of antigen/receptor sites expressed on malignant cells. The group has focused on the latter approach for improving radiolabeled peptide imaging and therapy. The most widely used gene transfer vectors in clinical gene therapy trials include retrovirus, cationic lipids and adenovirus. It has been utilized adenovirus vectors for gene transfer because of their ability to accomplish efficient in vivo gene transfer. Adenovirus vectors encoding the genes for a variety of antigens/receptors (carcinoembryonic antigen, gastrin-releasing peptide receptor, somatostatin receptor subtype 2 (SSTr2) have all shown that their expression is increased on cancer cells both in vitro and in vivo following adenovirus infection. Of particular interest has been the adenovirus encoding for SSTr2 (AdCMVSSTr2). Various radioisotopes have been attached to somatostatin analogues for imaging and therapy of SSTr2-positive tumors both clinically and in animal models. The use of these analogues in combination with AdCMVSSTr2 is a promising approach for improving the detection sensitivity and therapeutic efficacy of these radiolabeled peptides against solid tumors. In addition, it has been proposed the use of SSTr2 as a marker for imaging the expression of another cancer therapeutic transgene (e.g. cytosine deaminase, thymidine kinase) encoded within the same vector. This would allow for non-invasive monitoring of gene delivery to tumor sites

  5. Expression of a transferred nuclear gene in a mitochondrial genome

    Yichun Qiu

    2014-08-01

    Full Text Available Transfer of mitochondrial genes to the nucleus, and subsequent gain of regulatory elements for expression, is an ongoing evolutionary process in plants. Many examples have been characterized, which in some cases have revealed sources of mitochondrial targeting sequences and cis-regulatory elements. In contrast, there have been no reports of a nuclear gene that has undergone intracellular transfer to the mitochondrial genome and become expressed. Here we show that the orf164 gene in the mitochondrial genome of several Brassicaceae species, including Arabidopsis, is derived from the nuclear ARF17 gene that codes for an auxin responsive protein and is present across flowering plants. Orf164 corresponds to a portion of ARF17, and the nucleotide and amino acid sequences are 79% and 81% identical, respectively. Orf164 is transcribed in several organ types of Arabidopsis thaliana, as detected by RT-PCR. In addition, orf164 is transcribed in five other Brassicaceae within the tribes Camelineae, Erysimeae and Cardamineae, but the gene is not present in Brassica or Raphanus. This study shows that nuclear genes can be transferred to the mitochondrial genome and become expressed, providing a new perspective on the movement of genes between the genomes of subcellular compartments.

  6. Agrobacterium-mediated gene transfer to Chrysanthemum.

    Wordragen, van, M.F.

    1991-01-01

    Genetic manipulation of plants is a technique that enables us to add to the plant genome, in a precise and well controlled manner, one or a few new genes, coding for desirable traits. In contrast to this, the conventional method for the introduction of new properties in plants, by cross breeding, is a random process in which two complete genomes are mixed and the desired phenotype has to be regained by repeated back crossing with the cultivated parent line. Despite these differences, both pro...

  7. Experiments on Gene Transferring to Primary Hematopoietic Cells by Liposome

    2000-01-01

    Liposomes have showed many advantages in mediating exogenous gene into many cell types in vitro and in vivo. But few data are available concerning gene transfer into hematopoietic cells. In this report, we described two-marker genes (Neo R and Lac Z) co-transferred into hematopoietic cells of human and mouse by using liposome in vitro. The efficiency of gene transfer was tested by Xgal staining and observation of colony formation. The X-gal blue staining rate of transduced cells was about (13.33±2. 68) % in human and about (16. 28±2.95) % in mouse without G418 selection. After G418 selection, the blue cell rate was (46. 06±3.47)%in human and (43. 45±4. 1) % in mouse, which were markedly higher than those before selection, suggesting that high-efficiency gene transfer and expression could be attained in primary hematopoietic cells using this easy and harmless transduction protocol. At the same time, this protocol provided experimental data for clinicians to investigate the biology of marrow reconstitution and trace the origin of relapse after autologous bone marrow transplantation for the patients with leukemia.

  8. Influence of heme oxygenase-1 gene transfer on the viability and function of rat islets in in vitro culture

    Xiao-Bo Chen; Yong-Xiang Li; Yang Jiao; Wei-Ping Dong; Ge Li; Jing Chen; Jian-Ming Tan

    2007-01-01

    AIM:To ifivestigate the influence of heme oxygenase-1(HO-1)gene transfer on the viability and function of cultured rat islets in vitro.METHODS:Islets were isolated from the pancreata of Sprague-Dawley rats by intraductal collagenase digestion,and purified by discontinuous Ficoll density gradient centrifugation.Purified rat islets were transfected with adenoviral vectors containing human HO-1 gene(Ad-HO-1)or enhanced green fluorescent protein gene(Ad-EGFP),and then cultured for seven days.Transfection was confirmed by fluorescence microscopy and Western blot.Islet viability was evaluated by acridine orange/propidium iodide fluorescent staining.Glucose-stimulated insulin release was detected using insulin radioimmunoassay kits and was used to assess the function of islets.Stimulation index (SI)was calculated by dividing the insulin release upon high glucose stimulation by the insulin release upon low glucose stimulation.RESULTS:After seven days culture,the viability of cultured rat islets decreased significantly(92% ± 6% vs 52% ± 13%,P < 0.05),and glucose-stimulated insulin release also decreased significantly(6.47 ± 0.55 mIU/L/30IEQ vs 4.57 ± 0.40 mIU/L/30IEQ,14.93 ± 1.17mIU/L/30IEQ vs 9.63 ± 0.71 mIU/L/30IEQ,P < 0.05).Transfection of rat Islets with adenoviral vectors at an MOI of 20 was efficient,and did not impair islet function.At 7 d post-transfection,the viability of Ad-HO-1 transfected islets was higher than that of control islets (71% ± 15% vs 52% ± 13%,P < 0.05).There was no significant difference in insulin release upon low glucose stimulation(2.8 mmol/L)among Ad-HO-1 transfected group,Ad-EGFP transfected group,and control group(P > 0.05),while when stimulated by high glucose(16.7 mmol/L)solution,insulin release in Ad-HO-1 transfected group was significantly higher than that in Ad-EGFP transfected group and control group,respectively(12.50 ± 2.17 mIU/L/30IEQ vs 8.87 ± 0.65 mIU/L/30IEQ;12.50 ± 2.17 mIU/L/30IEQ vs 9.63 ± 0.71 mIU/L/30IEQ

  9. Plastid evolution: gene transfer and the maintenance of 'stolen' organelles

    Archibald John M

    2010-06-01

    Full Text Available Abstract Many heterotrophic organisms sequester plastids from prey algae and temporarily utilize their photosynthetic capacity. A recent article in BMC Genomics reveals that the dinoflagellate Dinophysis acuminata has acquired photosynthesis-related genes by horizontal gene transfer, which might explain its ability to retain 'stolen' plastids for extended periods of time. See research article http://www.biomedcentral.com/1471-2164/11/366

  10. Synthetic Fatty Acids Prevent Plasmid-Mediated Horizontal Gene Transfer

    Getino Redondo, María; Sanabria Ríos, David J.; Fernández López, Raúl; Campos Gómez, Javier; Sánchez López, José M.; Fernández Medarde, Antonio; Carballeira Cabranes, Néstor M.; Cruz Calahorra, Fernando de la

    2015-01-01

    Bacterial conjugation constitutes a major horizontal gene transfer mechanism for the dissemination of antibiotic resistance genes among human pathogens. Antibiotic resistance spread could be halted or diminished by molecules that interfere with the conjugation process. In this work, synthetic 2-alkynoic fatty acids were identified as a novel class of conjugation inhibitors. Their chemical properties were investigated by using the prototype 2-hexadecynoic acid and its derivatives. Essential fe...

  11. Plasmid-mediated horizontal gene transfer is a coevolutionary process

    Harrison, Ellie; Brockhurst, Michael A

    2012-01-01

    Conjugative plasmids are key agents of horizontal gene transfer (HGT) that accelerate bacterial adaptation by vectoring ecologically important traits between strains and species. However, although many conjugative plasmids carry beneficial traits, all plasmids exert physiological costs-of-carriage on bacteria. The existence of conjugative plasmids, therefore, presents a paradox because non-beneficial plasmids should be lost to purifying selection, whereas beneficial genes carried on plasmids ...

  12. Unconventional lateral gene transfer in extreme thermophilic bacteria

    César, Carolina Elvira; Bricio, Carlos; van Heerden, Esta; Littauer, Dereck; Berenguer, José; Álvarez, Laura

    2011-01-01

    Conjugation and natural competence are two major mechanisms that explain the acquisition of foreign genes throughout bacterial evolution. In recent decades, several studies in model organisms have revealed in great detail the steps involved in such processes. The findings support the idea that the major basis of these mechanisms is essentially similar in all bacteria. However, recent work has pinpointed the existence of new, evolutionarily different processes underlying lateral gene transfer....

  13. Adenovirus-mediated interleukin-12 gene therapy for metastatic colon carcinoma.

    M. CARUSO; Pham-Nguyen, K; Kwong, Y. L.; Xu, B; Kosai, K I; Finegold, M; Woo, S L; Chen, S. H.

    1996-01-01

    Recombinant adenoviral mediated delivery of suicide and cytokine genes has been investigated as a treatment for hepatic metastases of colon carcinoma in mice. Liver tumors were established by intrahepatic implantation of a poorly immunogenic colon carcinoma cell line (MCA-26), which is syngeneic in BALB/c mice. Intratumoral transfer of the herpes simplex virus type 1 thymidine kinase (HSV-tk) and the murine interleukin (mIL)-2 genes resulted in substantial hepatic tumor regression, induced an...

  14. Gene transfer of GLT-1, a glial glutamate transporter, into the spinal cord by recombinant adenovirus attenuates inflammatory and neuropathic pain in rats

    Nakagawa Takayuki

    2008-12-01

    Full Text Available Abstract Background The glial glutamate transporter GLT-1 is abundantly expressed in astrocytes and is crucial for glutamate removal from the synaptic cleft. Decreases in glutamate uptake activity and expression of spinal glutamate transporters are reported in animal models of pathological pain. However, the lack of available specific inhibitors and/or activators for GLT-1 makes it difficult to determine the roles of spinal GLT-1 in inflammatory and neuropathic pain. In this study, we examined the effect of gene transfer of GLT-1 into the spinal cord with recombinant adenoviruses on the inflammatory and neuropathic pain in rats. Results Intraspinal infusion of adenoviral vectors expressing the GLT-1 gene increased GLT-1 expression in the spinal cord 2–21 days after the infusion. Transgene expression was primarily localized to astrocytes. The spinal GLT-1 gene transfer had no effect on acute mechanical and thermal nociceptive responses in naive rats, whereas it significantly reduced the inflammatory mechanical hyperalgesia induced by hindlimb intraplantar injection of carrageenan/kaolin. Spinal GLT-1 gene transfer 7 days before partial sciatic nerve ligation recovered the extent of the spinal GLT-1 expression in the membrane fraction that was decreased following the nerve ligation, and prevented the induction of tactile allodynia. However, the partial sciatic nerve ligation-induced allodynia was not reversed when the adenoviruses were infused 7 or 14 days after the nerve ligation. Conclusion These results suggest that overexpression of GLT-1 on astrocytes in the spinal cord by recombinant adenoviruses attenuates the induction, but not maintenance, of inflammatory and neuropathic pain, probably by preventing the induction of central sensitization, without affecting acute pain sensation. Upregulation or functional enhancement of spinal GLT-1 could be a novel strategy for the prevention of pathological pain.

  15. Lifetime correction of genetic deficiency in mice with a single injection of helper-dependent adenoviral vector

    Kim, In-Hoo; Józkowicz, Alicja; Piedra, Pedro A.; Oka, Kazuhiro; Chan, Lawrence

    2001-01-01

    Ideally, somatic gene therapy should result in lifetime reversal of genetic deficiencies. However, to date, phenotypic correction of monogenic hyperlipidemia in mouse models by in vivo gene therapy has been short-lived and associated with substantial toxicity. We have developed a helper-dependent adenoviral vector (HD-Ad) containing the apolipoprotein (apo) E gene. A single i.v. injection of this vector completely and stably corrected the hypercholesterolemia in apoE-deficient mice, an effect...

  16. Myeloprotection by Cytidine Deaminase Gene Transfer in Antileukemic Therapy

    Nico Lachmann

    2013-03-01

    Full Text Available Gene transfer of drug resistance (CTX-R genes can be used to protect the hematopoietic system from the toxicity of anticancer chemotherapy and this concept recently has been proven by overexpression of a mutant O6-methylguaninemethyltransferase in the hematopoietic system of glioblastoma patients treated with temozolomide. Given its protection capacity against such relevant drugs as cytosine arabinoside (ara-C, gemcitabine, decitabine, or azacytidine and the highly hematopoiesis-specific toxicity profile of several of these agents, cytidine deaminase (CDD represents another interesting candidate CTX-R gene and our group recently has established the myeloprotective capacity of CDD gene transfer in a number of murine transplant studies. Clinically, CDD overexpression appears particularly suited to optimize treatment strategies for acute leukemias and myelodysplasias given the efficacy of ara-C (and to a lesser degree decitabine and azacytidine in these disease entities. This article will review the current state of the art with regard to CDD gene transfer and point out potential scenarios for a clinical application of this strategy. In addition, risks and potential side effects associated with this approach as well as strategies to overcome these problems will be highlighted.

  17. Effects of ionizing radiation on DNA-mediated gene transfer

    The process of DNA-mediated gene transfer is a powerful genetic tool that involves the cellular uptake, genomic integration and expression of exogenous DNA sequences. This process can also be used to examine the effects of radiation at the molecular level. There have been a few reported describing the enhancement of the gene transfer process by a number of DNA damaging agents. The agents tested included UV light, x-rays and accelerated argon particles. One hypothesis to explain this phenomenon is that these DNA damaging agents themselves, or subsequent DNA repair processes, introduce strand breaks into the cellular DNA of recipient cells. These DNA breaks then serve as possible sites of integration for the exogenous DNA sequences. The authors are continuing these studies by determining what effect neutrons have on the transfection of DNA. The gene transfer system we plan to employ involves the transfection of the chimeric plasmid pSV2-GPT into recipient hamster cell lines. This plasmid contains the Escherichia coli ecogpt gene, which codes for the enzyme xanthine-guanine phosphoribosyltransferase (XGPRT), along with simian virus 40 (SV40) sequences which allow for expression of the bacterial gene in mammalian cells

  18. Horizontal gene transfer in the evolution of photosynthetic eukaryotes

    Jinling HUANG; Jipei YUE

    2013-01-01

    Horizontal gene transfer (HGT) may not only create genome mosaicism,but also introduce evolutionary novelties to recipient organisms.HGT in plastid genomes,though relatively rare,still exists.HGT-derived genes are particularly common in unicellular photosynthetic eukaryotes and they also occur in multicellular plants.In particular,ancient HGT events occurring during the early evolution of primary photosynthetic eukaryotes were probably frequent.There is clear evidence that anciently acquired genes played an important role in the establishment of primary plastids and in the transition of plants from aquatic to terrestrial environments.Although algal genes have often been used to infer historical plastids in plastid-lacking eukaryotes,reliable approaches are needed to distinguish endosymbionts-derived genes from those independently acquired from preferential feeding or other activities.

  19. Usefulness of intra-arterial embolization method using gelfoam particles in effective gene transduction of adenoviral vector for liver-directed gene therapy: an preliminary animal study in dogs

    Liver-directed gene therapy is being actively pursued and developed as a method of treating various liver diseases. A number of aspects, including gene intervention, an efficient gene delivery system, and stable transgene expression are key to the success of the chosen strategy, and to overcome problems in these areas, several tactics can be used. In this study, we assess the utility of transarterial embolization using gelfoam particles soaked in an adenovirus vector as a gene-delivery method. Using the angiographic approach, three dogs each weighing 9.5-11kg were superselectively catheterized at the left hepatic artery using a 3-F microcatheter and the coaxial method. Two of the dogs were embolized at the left hepatic artery using 3x2x2-mm and 2x1x1-mm gelfoam particles soaked in 2x1011 particles/kg of recombinant adv. CMV.LacZ(LacZ-adv). The left hepatic artery of the remaining animal, used as a control, was infused with the same dose of lacZ-adv in the same way as before but without embolization of the left hepatic artery. Three days after embolization or the infusion of LacZ-adv, the dogs were sacrificed prior to harvest of the entire liver for the evaluation of gene transduction. X-gal staining of the liver tissue obtained was positive for hepatocytes, but the pattern and degree of gene transduction differed according to gelfoam particle size. Where this was 3x2x2 mm, gene transduction along the liver hilum varied, but where 2x1x1-mm particles were used, transduction was more even. No pathologic hepatic tissue injury or inflammation was apparent, and control liver tissue was not stained by X-gal. Serum SGOT and SGPT levels were slightly higher one day after the procedure, but had normalized by day 3. Intrahepatic transarterial embolization using gelfoam particles soaked in LacZ-adv appears to be a good method for effective liver-targed gene therapy

  20. Endosymbiotic gene transfer from prokaryotic pangenomes: Inherited chimerism in eukaryotes.

    Ku, Chuan; Nelson-Sathi, Shijulal; Roettger, Mayo; Garg, Sriram; Hazkani-Covo, Einat; Martin, William F

    2015-08-18

    Endosymbiotic theory in eukaryotic-cell evolution rests upon a foundation of three cornerstone partners--the plastid (a cyanobacterium), the mitochondrion (a proteobacterium), and its host (an archaeon)--and carries a corollary that, over time, the majority of genes once present in the organelle genomes were relinquished to the chromosomes of the host (endosymbiotic gene transfer). However, notwithstanding eukaryote-specific gene inventions, single-gene phylogenies have never traced eukaryotic genes to three single prokaryotic sources, an issue that hinges crucially upon factors influencing phylogenetic inference. In the age of genomes, single-gene trees, once used to test the predictions of endosymbiotic theory, now spawn new theories that stand to eventually replace endosymbiotic theory with descriptive, gene tree-based variants featuring supernumerary symbionts: prokaryotic partners distinct from the cornerstone trio and whose existence is inferred solely from single-gene trees. We reason that the endosymbiotic ancestors of mitochondria and chloroplasts brought into the eukaryotic--and plant and algal--lineage a genome-sized sample of genes from the proteobacterial and cyanobacterial pangenomes of their respective day and that, even if molecular phylogeny were artifact-free, sampling prokaryotic pangenomes through endosymbiotic gene transfer would lead to inherited chimerism. Recombination in prokaryotes (transduction, conjugation, transformation) differs from recombination in eukaryotes (sex). Prokaryotic recombination leads to pangenomes, and eukaryotic recombination leads to vertical inheritance. Viewed from the perspective of endosymbiotic theory, the critical transition at the eukaryote origin that allowed escape from Muller's ratchet--the origin of eukaryotic recombination, or sex--might have required surprisingly little evolutionary innovation. PMID:25733873

  1. Suppression of Akt1 phosphorylation by adenoviral transfer of the PTEN gene inhibits hypoxia-induced proliferation of rat pulmonary arterial smooth muscle cells

    Luo, Chunxia [Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Chongqing 400038 (China); Yi, Bin, E-mail: yibin1974@163.com [Department of Anesthesia, Southwest Hospital, Third Military Medical University, Chongqing 400038 (China); Institute of Respiratory Disease, Xinqiao Hospital, Third Military Medical University, Chongqing 400037 (China); Bai, Li [Institute of Respiratory Disease, Xinqiao Hospital, Third Military Medical University, Chongqing 400037 (China); Xia, Yongzhi [Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Chongqing 400038 (China); Wang, Guansong; Qian, Guisheng [Institute of Respiratory Disease, Xinqiao Hospital, Third Military Medical University, Chongqing 400037 (China); Feng, Hua [Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Chongqing 400038 (China)

    2010-07-02

    Recent findings identify the role of proliferation of pulmonary artery smooth muscle cells (PASMCs) in pulmonary vascular remodeling. Phosphoinositide 3 kinase (PI3K) and serine/threonine kinase (Akt) proteins are expressed in vascular smooth muscle cells. In addition, phosphatase and tensin homolog deleted on chromosome 10 (PTEN) has been identified as a negative regulator of cytokine signaling that inhibits the PI3K-Akt pathway. However, little is known about the role of PTEN/Akt signaling in hypoxia-associated vascular remodeling. In this study, we found that hypoxia-induced the expression of Akt1 mRNA and phosphorylated protein by at least twofold in rat PASMCs. Phospho-PTEN significantly decreased in the nuclei of PASMCs after hypoxic stimulation. After forcing over-expression of PTEN by adenovirus-mediated PTEN (Ad-PTEN) transfection, the expression of phospho-Akt1 was significantly suppressed in PASMCs at all time-points measured. Additionally, we showed here that hypoxia increased proliferation of PASMCs by nearly twofold and over-expression of PTEN significantly inhibited hypoxia-induced PASMCs proliferation. These findings suggest that phospho-PTEN loss in the nuclei of PASMCs under hypoxic conditions may be the major cause of aberrant activation of Akt1 and may, therefore, play an important role in hypoxia-associated pulmonary arterial remodeling. Finally, the fact that transfection with Ad-PTEN inhibits the phosphorylation of Akt1 in PASMCs suggests a potential therapeutic effect on hypoxia-associated pulmonary arterial remodeling.

  2. Suppression of Akt1 phosphorylation by adenoviral transfer of the PTEN gene inhibits hypoxia-induced proliferation of rat pulmonary arterial smooth muscle cells

    Recent findings identify the role of proliferation of pulmonary artery smooth muscle cells (PASMCs) in pulmonary vascular remodeling. Phosphoinositide 3 kinase (PI3K) and serine/threonine kinase (Akt) proteins are expressed in vascular smooth muscle cells. In addition, phosphatase and tensin homolog deleted on chromosome 10 (PTEN) has been identified as a negative regulator of cytokine signaling that inhibits the PI3K-Akt pathway. However, little is known about the role of PTEN/Akt signaling in hypoxia-associated vascular remodeling. In this study, we found that hypoxia-induced the expression of Akt1 mRNA and phosphorylated protein by at least twofold in rat PASMCs. Phospho-PTEN significantly decreased in the nuclei of PASMCs after hypoxic stimulation. After forcing over-expression of PTEN by adenovirus-mediated PTEN (Ad-PTEN) transfection, the expression of phospho-Akt1 was significantly suppressed in PASMCs at all time-points measured. Additionally, we showed here that hypoxia increased proliferation of PASMCs by nearly twofold and over-expression of PTEN significantly inhibited hypoxia-induced PASMCs proliferation. These findings suggest that phospho-PTEN loss in the nuclei of PASMCs under hypoxic conditions may be the major cause of aberrant activation of Akt1 and may, therefore, play an important role in hypoxia-associated pulmonary arterial remodeling. Finally, the fact that transfection with Ad-PTEN inhibits the phosphorylation of Akt1 in PASMCs suggests a potential therapeutic effect on hypoxia-associated pulmonary arterial remodeling.

  3. Regulatory and Ethical Issues for Phase I In Utero Gene Transfer Studies

    Strong, Carson

    2011-01-01

    Clinical gene transfer research has involved adult and child subjects, and it is expected that gene transfer in fetal subjects will occur in the future. Some genetic diseases have serious adverse effects on the fetus before birth, and there is hope that prenatal gene therapy could prevent such disease progression. Research in animal models of prenatal gene transfer is actively being pursued. The prospect of human phase I in utero gene transfer studies raises important regulatory and ethical i...

  4. Human gene transfer: Characterization of human tumor-infiltrating lymphocytes as vehicles for retroviral-mediated gene transfer in man

    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. The authors 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 β- and γ-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 β and γ chains following transduction and selection of TILs in the neomycin analog G418. Human TILs expressed mRNA for tumor necrosis factors (α and β) and interleukin 2 receptor P55. This pattern of cytokine-mRNA expression was not significantly altered following the transduction of TILs. The studies demonstrate the feasibility of TILs as suitable cellular vehicles for the introduction of therapeutic genes into patients receiving autologous TILs

  5. Examining Ancient Inter-domain Horizontal Gene Transfer

    Francisca C. Almeida

    2008-01-01

    Full Text Available Details of the genomic changes that occurred in the ancestors of Eukarya, Archaea and Bacteria are elusive. Ancient interdomain horizontal gene transfer (IDHGT amongst the ancestors of these three domains has been difficult to detect and analyze because of the extreme degree of divergence of genes in these three domains and because most evidence for such events are poorly supported. In addition, many researchers have suggested that the prevalence of IDHGT events early in the evolution of life would most likely obscure the patterns of divergence of major groups of organisms let alone allow the tracking of horizontal transfer at this level. In order to approach this problem, we mined the E. coli genome for genes with distinct paralogs. Using the 1,268 E. coli K-12 genes with 40% or higher similarity level to a paralog elsewhere in the E. coli genome we detected 95 genes found exclusively in Bacteria and Archaea and 86 genes found in Bacteria and Eukarya. These genes form the basis for our analysis of IDHGT. We also applied a newly developed statistical test (the node height test, to examine the robustness of these inferences and to corroborate the phylogenetically identifi ed cases of ancient IDHGT. Our results suggest that ancient inter domain HGT is restricted to special cases, mostly involving symbiosis in eukaryotes and specific adaptations in prokaryotes. Only three genes in the Bacteria + Eukarya class (Deoxyxylulose-5-phosphate synthase (DXPS, fructose 1,6-phosphate aldolase class II protein and glucosamine-6-phosphate deaminase and three genes–in the Bacteria + Archaea class (ABC-type FE3+ -siderophore transport system, ferrous iron transport protein B, and dipeptide transport protein showed evidence of ancient IDHGT. However, we conclude that robust estimates of IDHGT will be very difficult to obtain due to the methodological limitations and the extreme sequence saturation of the genes suspected of being involved in IDHGT.

  6. Inhibition of apoptosis reduces immunogeneic potential of adenoviral-treated syngeneic liver grafts.

    Puellmann, Kerstin; Beham, Alexander; Kienle, Klaus; Vogel, Mandy; Schlitt, Hans Juergen; Jauch, Karl Walter; Rentsch, Markus

    2006-11-27

    Effects of adenoviral therapy and reduced apoptosis on immune response were investigated in a rat liver transplantation model after prolonged ischemia-reperfusion. Liver donors were treated i.v. either with an adenoviral construct, expressing bcl-2, green-fluorescent-protein, or doxycyclin. Intrahepatic apoptosis was assessed by terminal transferase dUTP nick end labeling assay. The intrahepatic presence of CD4, CD8a, CD163, immunoglobulin (Ig)beta, tumor necrosis factor (TNF)-alpha and myeloperoxidase (MPO) was quantified by realtime polymerase chain reaction at 24 hours and seven days after transplantation. Bcl-2 expression abrogated the TNF-alpha elevation and reduced apoptosis of hepatocytes and sinusoidal endothelial cells as compared to advCMV green fluorescent protein. No effects on CD4, CD8a, CD163 and MPO expression were noticed in bcl-2 pretreated livers, whereas Igbeta was slightly enhanced compared to controls. Adenoviral infected liver grafts trigger an immune response but reduced apoptosis resulted in down-regulation of TNF-alpha. Thus, bcl-2 transfer might simultaneously reduce graft ischemia reperfusion injury and immunogenicity. PMID:17130789

  7. Adenovirus-mediated interleukin-12 gene transfer combined with cytosine deaminase followed by 5-fluorocytosine treatment exerts potent antitumor activity in Renca tumor-bearing mice

    Therapeutic gene transfer affords a clinically feasible and safe approach to cancer treatment but a more effective modality is needed to improve clinical outcomes. Combined transfer of therapeutic genes with different modes of actions may be a means to this end. Interleukin-12 (IL-12), a heterodimeric immunoregulatory cytokine composed of covalently linked p35 and p40 subunits, has antitumor activity in animal models. The enzyme/prodrug strategy using cytosine deaminase (CD) and 5-fluorocytosine (5-FC) has been used for cancer gene therapy. We have evaluated the antitumor effect of combining IL-12 with CD gene transfer in mice bearing renal cell carcinoma (Renca) tumors. Adenoviral vectors were constructed encoding one or both subunits of murine IL-12 (Ad.p35, Ad.p40 and Ad.IL-12) or cytosine deaminase (Ad.CD). The functionality of the IL-12 or CD gene products expressed from these vectors was validated by splenic interferon (IFN)-γ production or viability assays in cultured cells. Ad.p35 plus Ad.p40, or Ad.IL-12, with or without Ad.CD, were administered (single-dose) intratumorally to Renca tumor-bearing mice. The animals injected with Ad.CD also received 5-FC intraperitoneally. The antitumor effects were then evaluated by measuring tumor regression, mean animal survival time, splenic natural killer (NK) cell activity and IFN-γ production. The inhibition of tumor growth in mice treated with Ad.p35 plus Ad.p40 and Ad.CD, followed by injection of 5-FC, was significantly greater than that in mice treated with Ad.CD/5-FC, a mixture of Ad.p35 plus Ad.p40, or Ad.GFP (control). The combined gene transfer increased splenic NK cell activity and IFN-γ production by splenocytes. Ad.CD/5-FC treatment significantly increased the antitumor effect of Ad.IL-12 in terms of tumor growth inhibition and mean animal survival time. The results suggest that adenovirus-mediated IL-12 gene transfer combined with Ad.CD followed by 5-FC treatment may be useful for treating cancers

  8. Adenovirus-mediated interleukin-12 gene transfer combined with cytosine deaminase followed by 5-fluorocytosine treatment exerts potent antitumor activity in Renca tumor-bearing mice

    Kim Samyong

    2005-05-01

    Full Text Available Abstract Background Therapeutic gene transfer affords a clinically feasible and safe approach to cancer treatment but a more effective modality is needed to improve clinical outcomes. Combined transfer of therapeutic genes with different modes of actions may be a means to this end. Interleukin-12 (IL-12, a heterodimeric immunoregulatory cytokine composed of covalently linked p35 and p40 subunits, has antitumor activity in animal models. The enzyme/prodrug strategy using cytosine deaminase (CD and 5-fluorocytosine (5-FC has been used for cancer gene therapy. We have evaluated the antitumor effect of combining IL-12 with CD gene transfer in mice bearing renal cell carcinoma (Renca tumors. Methods Adenoviral vectors were constructed encoding one or both subunits of murine IL-12 (Ad.p35, Ad.p40 and Ad.IL-12 or cytosine deaminase (Ad.CD. The functionality of the IL-12 or CD gene products expressed from these vectors was validated by splenic interferon (IFN-γ production or viability assays in cultured cells. Ad.p35 plus Ad.p40, or Ad.IL-12, with or without Ad.CD, were administered (single-dose intratumorally to Renca tumor-bearing mice. The animals injected with Ad.CD also received 5-FC intraperitoneally. The antitumor effects were then evaluated by measuring tumor regression, mean animal survival time, splenic natural killer (NK cell activity and IFN-γ production. Results The inhibition of tumor growth in mice treated with Ad.p35 plus Ad.p40 and Ad.CD, followed by injection of 5-FC, was significantly greater than that in mice treated with Ad.CD/5-FC, a mixture of Ad.p35 plus Ad.p40, or Ad.GFP (control. The combined gene transfer increased splenic NK cell activity and IFN-γ production by splenocytes. Ad.CD/5-FC treatment significantly increased the antitumor effect of Ad.IL-12 in terms of tumor growth inhibition and mean animal survival time. Conclusion The results suggest that adenovirus-mediated IL-12 gene transfer combined with Ad.CD followed by

  9. Can Viruses be Modified to Achieve Sustained Gene Transfer?

    HildegundCJErtl

    2011-07-01

    Full Text Available It is very easy to replace a faulty gene in an immunocompromised mouse. First, one takes a well-characterized virus, such as an adenovirus or an adeno-associated virus, and incorporates the correct version of the faulty gene together with some regulatory sequences into the genome. Then, one transduces the recombinant genome into helper cells, which will add the viral capsid. At last, one injects the resulting viral vector into the sick mouse, and the mouse is cured. It is not that easy in an immunocompetent mouse, let alone in a human, as over the eons the immune system evolved to eliminate viruses regardless if they penetrate as dangerous pathogens or are injected by a well-meaning gene therapist. Here we offer our perspective on the potential of how viral vectors achieve sustained gene transfer in the face of a hostile immune system.

  10. Nano-Sized Sunflower Polycations As Effective Gene Transfer Vehicles.

    Cheng, Yilong; Wei, Hua; Tan, James-Kevin Y; Peeler, David J; Maris, Don O; Sellers, Drew L; Horner, Philip J; Pun, Suzie H

    2016-05-01

    The architecture of polycations plays an important role in both gene transfection efficiency and cytotoxicity. In this work, a new polymer, sunflower poly(2-dimethyl amino)ethyl methacrylate) (pDMAEMA), is prepared by atom transfer radical polymerization and employed as nucleic acid carriers compared to linear pDMAEMA homopolymer and comb pDMAEMA. The sunflower pDMAEMAs show higher IC50 , greater buffering capacity, and stronger binding capacity toward plasmid DNA than their linear and comb counterparts. In vitro transfection studies demonstrate that sunflower pDMAEMAs exhibit high transfection efficiency as well as relatively low cytotoxicity in complete growth medium. In vivo gene delivery by intraventricular injection to the brain shows that sunflower polymer delivers plasmid DNA more effectively than comb polymer. This study provides a new insight into the relationship between polymeric architecture and gene delivery capability, and as well as a useful means to design potent vectors for successful gene delivery. PMID:27061622

  11. Characterization of an ancient lepidopteran lateral gene transfer.

    David Wheeler

    Full Text Available Bacteria to eukaryote lateral gene transfers (LGT are an important potential source of material for the evolution of novel genetic traits. The explosion in the number of newly sequenced genomes provides opportunities to identify and characterize examples of these lateral gene transfer events, and to assess their role in the evolution of new genes. In this paper, we describe an ancient lepidopteran LGT of a glycosyl hydrolase family 31 gene (GH31 from an Enterococcus bacteria. PCR amplification between the LGT and a flanking insect gene confirmed that the GH31 was integrated into the Bombyx mori genome and was not a result of an assembly error. Database searches in combination with degenerate PCR on a panel of 7 lepidopteran families confirmed that the GH31 LGT event occurred deep within the Order approximately 65-145 million years ago. The most basal species in which the LGT was found is Plutella xylostella (superfamily: Yponomeutoidea. Array data from Bombyx mori shows that GH31 is expressed, and low dN/dS ratios indicates the LGT coding sequence is under strong stabilizing selection. These findings provide further support for the proposition that bacterial LGTs are relatively common in insects and likely to be an underappreciated source of adaptive genetic material.

  12. Adenovirus-mediated transfer of the PTEN gene inhibits human colorectal cancer growth in vitro and in vivo.

    Saito, Y; Swanson, X; Mhashilkar, A M; Oida, Y; Schrock, R; Branch, C D; Chada, S; Zumstein, L; Ramesh, R

    2003-11-01

    The tumor-suppressor gene PTEN encodes a multifunctional phosphatase that is mutated in a variety of human cancers. PTEN inhibits the phosphatidylinositol 3-kinase pathway and downstream functions, including activation of Akt/protein kinase B (PKB), cell survival, and cell proliferation in tumor cells carrying mutant- or deletion-type PTEN. In such tumor cells, enforced expression of PTEN decreases cell proliferation through cell-cycle arrest at G1 phase accompanied, in some cases, by induction of apoptosis. More recently, the tumor-suppressive effect of PTEN has been reported in ovarian and thyroid tumors that are wild type for PTEN. In the present study, we examined the tumor-suppressive effect of PTEN in human colorectal cancer cells that are wild type for PTEN. Adenoviral-mediated transfer of PTEN (Ad-PTEN) suppressed cell growth and induced apoptosis significantly in colorectal cancer cells (DLD-1, HT29, and SW480) carrying wtPTEN than in normal colon fibroblast cells (CCD-18Co) carrying wtPTEN. This suppression was induced through downregulation of the Akt/PKB pathway, dephosphorylation of focal adhesion kinase (FAK) and mitogen-activated protein kinase (MAPK) and cell-cycle arrest at the G2/M phase, but not the G1 phase. Furthermore, treatment of human colorectal tumor xenografts (HT-29, and SW480) with Ad-PTEN resulted in significant (P=0.01) suppression of tumor growth. These results indicate that Ad-PTEN exerts its tumor-suppressive effect on colorectal cancer cells through inhibition of cell-cycle progression and induction of cell death. Thus Ad-PTEN may be a potential therapeutic for treatment of colorectal cancers. PMID:14528320

  13. A rice Stowaway MITE for gene transfer in yeast.

    Isam Fattash

    Full Text Available Miniature inverted repeat transposable elements (MITEs lack protein coding capacity and often share very limited sequence similarity with potential autonomous elements. Their capability of efficient transposition and dramatic amplification led to the proposition that MITEs are an untapped rich source of materials for transposable element (TE based genetic tools. To test the concept of using MITE sequence in gene transfer, a rice Stowaway MITE previously shown to excise efficiently in yeast was engineered to carry cargo genes (neo and gfp for delivery into the budding yeast genome. Efficient excision of the cargo gene cassettes was observed even though the excision frequency generally decreases with the increase of the cargo sizes. Excised elements insert into new genomic loci efficiently, with about 65% of the obtained insertion sites located in genes. Elements at the primary insertion sites can be remobilized, frequently resulting in copy number increase of the element. Surprisingly, the orientation of a cargo gene (neo on a construct bearing dual reporter genes (gfp and neo was found to have a dramatic effect on transposition frequency. These results demonstrated the concept that MITE sequences can be useful in engineering genetic tools to deliver cargo genes into eukaryotic genomes.

  14. Gene Transfer To Intact Mesenteric Arteries by Electroporation

    Martin, Jason B.; Young, Jennifer L.; Benoit, Joseph N.; Dean, David A.

    2000-01-01

    The purpose of the present study was to develop a rapid, reproducible method of non-viral gene transfer to the intact vasculature. Male Sprague-Dawley rats were anesthetized, a midline abdominal incision was made and segmental branches of the superior mesenteric artery were dissected free of surrounding mesentery. A specially designed electroporation probe was placed around the neurovascular bundle and the electroporation chamber filled with a solution containing the firefly luciferase expres...

  15. Selective Gene Transfer to the Retina Using Intravitreal Ultrasound Irradiation

    Shozo Sonoda

    2012-01-01

    Full Text Available This paper aims to evaluate the efficacy of intravitreal ultrasound (US irradiation for green fluorescent protein (GFP plasmid transfer into the rabbit retina using a miniature US transducer. Intravitreal US irradiation was performed by a slight modification of the transconjunctival sutureless vitrectomy system utilizing a small probe. After vitrectomy, the US probe was inserted through a scleral incision. A mixture of GFP plasmid (50 μL and bubble liposomes (BLs; 50 μL was injected into the vitreous cavity, and US was generated to the retina using a SonoPore 4000. The control group was not exposed to US. After 72 h, the gene-transfer efficiency was quantified by counting the number of GFP-positive cells. The retinas that received plasmid, BL, and US showed a significant increase in the number (average ± SEM of GFP-positive cells (32±4.9; n=7; P<0.01 . No GFP-positive cells were observed in the control eyes (n=7. Intravitreal retinal US irradiation can transfer the GFP plasmid into the retina without causing any apparent damage. This procedure could be used to transfer genes and drugs directly to the retina and therefore has potential therapeutic value.

  16. Dynamic monitoring of horizontal gene transfer in soil

    Cheng, H. Y.; Masiello, C. A.; Silberg, J. J.; Bennett, G. N.

    2015-12-01

    Soil microbial gene expression underlies microbial behaviors (phenotypes) central to many aspects of C, N, and H2O cycling. However, continuous monitoring of microbial gene expression in soils is challenging because genetically-encoded reporter proteins widely used in the lab are difficult to deploy in soil matrices: for example, green fluorescent protein cannot be easily visualized in soils, even in the lab. To address this problem we have developed a reporter protein that releases small volatile gases. Here, we applied this gas reporter in a proof-of-concept soil experiment, monitoring horizontal gene transfer, a microbial activity that alters microbial genotypes and phenotypes. Horizontal gene transfer is central to bacterial evolution and adaptation and is relevant to problems such as the spread of antibiotic resistance, increasing metal tolerance in superfund sites, and bioremediation capability of bacterial consortia. This process is likely to be impacted by a number of matrix properties not well-represented in the petri dish, such as microscale variations in water, nutrients, and O2, making petri-dish experiments a poor proxy for environmental processes. We built a conjugation system using synthetic biology to demonstrate the use of gas-reporting biosensors in safe, lab-based biogeochemistry experiments, and here we report the use of these sensors to monitor horizontal gene transfer in soils. Our system is based on the F-plasmid conjugation in Escherichia coli. We have found that the gas signal reports on the number of cells that acquire F-plasmids (transconjugants) in a loamy Alfisol collected from Kellogg Biological Station. We will report how a gas signal generated by transconjugants varies with the number of F-plasmid donor and acceptor cells seeded in a soil, soil moisture, and soil O2 levels.

  17. Evidence of horizontal gene transfer between obligate leaf nodule symbionts.

    Pinto-Carbó, Marta; Sieber, Simon; Dessein, Steven; Wicker, Thomas; Verstraete, Brecht; Gademann, Karl; Eberl, Leo; Carlier, Aurelien

    2016-09-01

    Bacteria of the genus Burkholderia establish an obligate symbiosis with plant species of the Rubiaceae and Primulaceae families. The bacteria, housed within the leaves, are transmitted hereditarily and have not yet been cultured. We have sequenced and compared the genomes of eight bacterial leaf nodule symbionts of the Rubiaceae plant family. All of the genomes exhibit features consistent with genome erosion. Genes potentially involved in the biosynthesis of kirkamide, an insecticidal C7N aminocyclitol, are conserved in most Rubiaceae symbionts. However, some have partially lost the kirkamide pathway due to genome erosion and are unable to synthesize the compound. Kirkamide synthesis is therefore not responsible for the obligate nature of the symbiosis. More importantly, we find evidence of intra-clade horizontal gene transfer (HGT) events affecting genes of the secondary metabolism. This indicates that substantial gene flow can occur at the early stages following host restriction in leaf nodule symbioses. We propose that host-switching events and plasmid conjugative transfers could have promoted these HGTs. This genomic analysis of leaf nodule symbionts gives, for the first time, new insights in the genome evolution of obligate symbionts in their early stages of the association with plants. PMID:26978165

  18. Horizontal Gene Transfer Contributes to the Evolution of Arthropod Herbivory.

    Wybouw, Nicky; Pauchet, Yannick; Heckel, David G; Van Leeuwen, Thomas

    2016-01-01

    Within animals, evolutionary transition toward herbivory is severely limited by the hostile characteristics of plants. Arthropods have nonetheless counteracted many nutritional and defensive barriers imposed by plants and are currently considered as the most successful animal herbivores in terrestrial ecosystems. We gather a body of evidence showing that genomes of various plant feeding insects and mites possess genes whose presence can only be explained by horizontal gene transfer (HGT). HGT is the asexual transmission of genetic information between reproductively isolated species. Although HGT is known to have great adaptive significance in prokaryotes, its impact on eukaryotic evolution remains obscure. Here, we show that laterally transferred genes into arthropods underpin many adaptations to phytophagy, including efficient assimilation and detoxification of plant produced metabolites. Horizontally acquired genes and the traits they encode often functionally diversify within arthropod recipients, enabling the colonization of more host plant species and organs. We demonstrate that HGT can drive metazoan evolution by uncovering its prominent role in the adaptations of arthropods to exploit plants. PMID:27307274

  19. Gene Transfer into Mouse Prepancreatic Endoderm by Whole Embryo Electroporation

    Rousseau GG

    2005-03-01

    Full Text Available CONTEXT: Understanding gene function in the developing pancreas is a major issue for pancreatic cell therapy. The in vivo analysis of gene function has essentially been performed by modulating gene expression in transgenesis. A faster and easier method is electroporation of mouse embryos. This technique, coupled with whole embryo culture, enables one to deliver genes and analyze their effects in a spatially and temporally regulated manner. OBJECTIVE: We wanted to adapt the electroporation technique for gene transfer of whole e8.5 mouse embryos into the endoderm to allow expression of transgenes in the pancreas or liver. RESULTS: Using two platinum plate electrodes, low voltage and a precise positioning of the embryo in the electroporation cuvette we could target and express DNA constructs in the prepancreatic or prehepatic territories, identified with cell markers. We also demonstrated that this technique is a valuable tool in the study of transcriptional regulation in the developing endoderm. CONCLUSIONS: Targeted electroporation of whole embryos is a useful method of characterizing the gene network which controls pancreatic development.

  20. Monitoring of gene transfer for cancer therapy with radioactive isotopes

    Gene therapy for cancer has recently been developed, and four approaches are currently being evaluated in experimental and clinical studies: 1) protection of normal tissue, such as bone marrow, which are normally targets for cytotoxic drugs; 2) improvement of the host antitumor response by increasing the antitumor activity of tumor-infiltrating immuno-competent cells or by modifying the tumor cells to enhance their immunogenicity; 3) reversion of the malignant phenotype either by suppression of oncogene expression or by introduction of normal tumor suppressor genes; 4) direct killing of tumor cells by the transfer of cytotoxic or prodrug-activating genes. Monitoring of gene therapy by assessing metabolic effects or the uptake of a specific substance with radioactive isotopes is reviewed. The author's experience is mostly described: uptake measurements with 11 Cthymidine, 18FDG, 3-D-methylglucose, and methionine in the presence of different concentrations of ganciclovir after transfection of a rat hepatoma cell line with a retroviral vector containing the HSVtk gene. Non-suicide reporter gene approaches are also discussed. (K.H.)

  1. PCR-based detection of gene transfer vectors: application to gene doping surveillance.

    Perez, Irene C; Le Guiner, Caroline; Ni, Weiyi; Lyles, Jennifer; Moullier, Philippe; Snyder, Richard O

    2013-12-01

    Athletes who illicitly use drugs to enhance their athletic performance are at risk of being banned from sports competitions. Consequently, some athletes may seek new doping methods that they expect to be capable of circumventing detection. With advances in gene transfer vector design and therapeutic gene transfer, and demonstrations of safety and therapeutic benefit in humans, there is an increased probability of the pursuit of gene doping by athletes. In anticipation of the potential for gene doping, assays have been established to directly detect complementary DNA of genes that are top candidates for use in doping, as well as vector control elements. The development of molecular assays that are capable of exposing gene doping in sports can serve as a deterrent and may also identify athletes who have illicitly used gene transfer for performance enhancement. PCR-based methods to detect foreign DNA with high reliability, sensitivity, and specificity include TaqMan real-time PCR, nested PCR, and internal threshold control PCR. PMID:23912835

  2. Gene ontology based transfer learning for protein subcellular localization

    Zhou Shuigeng

    2011-02-01

    Full Text Available Abstract Background Prediction of protein subcellular localization generally involves many complex factors, and using only one or two aspects of data information may not tell the true story. For this reason, some recent predictive models are deliberately designed to integrate multiple heterogeneous data sources for exploiting multi-aspect protein feature information. Gene ontology, hereinafter referred to as GO, uses a controlled vocabulary to depict biological molecules or gene products in terms of biological process, molecular function and cellular component. With the rapid expansion of annotated protein sequences, gene ontology has become a general protein feature that can be used to construct predictive models in computational biology. Existing models generally either concatenated the GO terms into a flat binary vector or applied majority-vote based ensemble learning for protein subcellular localization, both of which can not estimate the individual discriminative abilities of the three aspects of gene ontology. Results In this paper, we propose a Gene Ontology Based Transfer Learning Model (GO-TLM for large-scale protein subcellular localization. The model transfers the signature-based homologous GO terms to the target proteins, and further constructs a reliable learning system to reduce the adverse affect of the potential false GO terms that are resulted from evolutionary divergence. We derive three GO kernels from the three aspects of gene ontology to measure the GO similarity of two proteins, and derive two other spectrum kernels to measure the similarity of two protein sequences. We use simple non-parametric cross validation to explicitly weigh the discriminative abilities of the five kernels, such that the time & space computational complexities are greatly reduced when compared to the complicated semi-definite programming and semi-indefinite linear programming. The five kernels are then linearly merged into one single kernel for

  3. In vivo Cytokine Gene Transfer by Gene Gun Reduces Tumor Growth in Mice

    Sun, Wenn H.; Burkholder, Joseph K.; Sun, Jian; Culp, Jerilyn; Turner, Joel; Lu, Xing G.; Pugh, Thomas D.; Ershler, William B.; Yang, Ning-Sun

    1995-03-01

    Implantation of tumor cells modified by in vitro cytokine gene transfer has been shown by many investigators to result in potent in vivo antitumor activities in mice. Here we describe an approach to tumor immunotherapy utilizing direct transfection of cytokine genes into tumorbearing animals by particle-mediated gene transfer. In vivo transfection of the human interleukin 6 gene into the tumor site reduced methylcholanthrene-induced fibrosarcoma growth, and a combination of murine tumor necrosis factor α and interferon γ genes inhibited growth of a renal carcinoma tumor model (Renca). In addition, treatment with murine interleukin 2 and interferon γ genes prolonged the survival of Renca tumor-bearing mice and resulted in tumor eradication in 25% of the test animals. Transgene expression was demonstrated in treated tissues by ELISA and immunohistochemical analysis. Significant serum levels of interleukin 6 and interferon γ were detected, demonstrating effective secretion of transgenic proteins from treated skin into the bloodstream. This in vivo cytokine gene therapy approach provides a system for evaluating the antitumor properties of various cytokines in different tumor models and has potential utility for human cancer gene therapy.

  4. Expression of the Thy-1 glycoprotein gene by DNA-mediated gene transfer.

    Evans, G A; Ingraham, H A; Lewis, K; Cunningham, K; Seki, T.; Moriuchi, T; Chang, H. C.; Silver, J; Hyman, R

    1984-01-01

    We isolated a gene encoding the Thy-1.2 glycoprotein from a recombinant library constructed from BALB/c mouse DNA. To evaluate the expression of this cloned gene in different genomic environments, we introduced it into cell lines derived from fibroblast, lymphoid, and neuronal tissues by DNA-mediated gene transfer. When integrated into the genome of mouse L cells, cell-surface Thy-1 can be detected with anti-Thy-1 monoclonal antibodies. These L-cell lines contain between two and four copies o...

  5. Differences in lateral gene transfer in hypersaline versus thermal environments

    House Christopher H

    2011-07-01

    Full Text Available Abstract Background The role of lateral gene transfer (LGT in the evolution of microorganisms is only beginning to be understood. While most LGT events occur between closely related individuals, inter-phylum and inter-domain LGT events are not uncommon. These distant transfer events offer potentially greater fitness advantages and it is for this reason that these "long distance" LGT events may have significantly impacted the evolution of microbes. One mechanism driving distant LGT events is microbial transformation. Theoretically, transformative events can occur between any two species provided that the DNA of one enters the habitat of the other. Two categories of microorganisms that are well-known for LGT are the thermophiles and halophiles. Results We identified potential inter-class LGT events into both a thermophilic class of Archaea (Thermoprotei and a halophilic class of Archaea (Halobacteria. We then categorized these LGT genes as originating in thermophiles and halophiles respectively. While more than 68% of transfer events into Thermoprotei taxa originated in other thermophiles, less than 11% of transfer events into Halobacteria taxa originated in other halophiles. Conclusions Our results suggest that there is a fundamental difference between LGT in thermophiles and halophiles. We theorize that the difference lies in the different natures of the environments. While DNA degrades rapidly in thermal environments due to temperature-driven denaturization, hypersaline environments are adept at preserving DNA. Furthermore, most hypersaline environments, as topographical minima, are natural collectors of cellular debris. Thus halophiles would in theory be exposed to a greater diversity and quantity of extracellular DNA than thermophiles.

  6. Horizontal gene transfer of microbial cellulases into nematode genomes is associated with functional assimilation and gene turnover

    Dieterich Christoph

    2011-01-01

    Full Text Available Abstract Background Natural acquisition of novel genes from other organisms by horizontal or lateral gene transfer is well established for microorganisms. There is now growing evidence that horizontal gene transfer also plays important roles in the evolution of eukaryotes. Genome-sequencing and EST projects of plant and animal associated nematodes such as Brugia, Meloidogyne, Bursaphelenchus and Pristionchus indicate horizontal gene transfer as a key adaptation towards parasitism and pathogenicity. However, little is known about the functional activity and evolutionary longevity of genes acquired by horizontal gene transfer and the mechanisms favoring such processes. Results We examine the transfer of cellulase genes to the free-living and beetle-associated nematode Pristionchus pacificus, for which detailed phylogenetic knowledge is available, to address predictions by evolutionary theory for successful gene transfer. We used transcriptomics in seven Pristionchus species and three other related diplogastrid nematodes with a well-defined phylogenetic framework to study the evolution of ancestral cellulase genes acquired by horizontal gene transfer. We performed intra-species, inter-species and inter-genic analysis by comparing the transcriptomes of these ten species and tested for cellulase activity in each species. Species with cellulase genes in their transcriptome always exhibited cellulase activity indicating functional integration into the host's genome and biology. The phylogenetic profile of cellulase genes was congruent with the species phylogeny demonstrating gene longevity. Cellulase genes show notable turnover with elevated birth and death rates. Comparison by sequencing of three selected cellulase genes in 24 natural isolates of Pristionchus pacificus suggests these high evolutionary dynamics to be associated with copy number variations and positive selection. Conclusion We could demonstrate functional integration of acquired

  7. 放射诱导调控腺病毒介导gfp报告基因在肿瘤细胞内的表达%The Expression of Adenoviral Mediated gfp Reporter Gene in Tumor Cells Induced and Regulated by Irradiation

    魏道严; 戴冰冰; 陈诗书; 王中和

    2001-01-01

    为建立放射诱导基因表达调控系统并用于肿瘤的基因治疗, 利用PCR技术克隆出放射诱导基因Egr-1基因启动子, 经测序证实后与报告基因gfp连接, 并利用新型、高效的细菌内同源重组腺病毒载体制备方法制备出重组腺病毒AdEgr-GFP。 感染腺病毒的肿瘤细胞给予不同剂量的γ射线照射, 体外采用FACS方法检测GFP的表达发现, 照射可明显提高GFP表达, 并呈剂量依赖性, Western印迹检测也显示类似的结果。 为进行体内实验, 瘤内注射AdEgr-GFP腺病毒后48 h, 肿瘤局部接受不同剂量的γ射线照射, 8 h后制备肿瘤组织标本用于分析GFP的表达。 肿瘤组织图像分析结果显示, γ射线照射可显著提高肿瘤组织中GFP的表达, 并呈剂量依赖性。 结果说明, 放射经Egr-1启动子可有效调控腺病毒介导gfp基因的肿瘤细胞内表达。%In order to establish a radiation inducible gene expression system for cancer gene therapy, the promoter sequence of radiation-inducible Egr-1 gene was amplified from genomic DNA of BALB/c mouse with PCR method, and linked to gfp reporter gene. Then the pEgr-gfp expression cassette was subcloned into an adenoviral shuttle plasmid to generate recombinant adenovirus of AdEgr-GFP by using a novel, high efficient method of homologous recombination in bacteria. After infection with AdEgr-GFP, MM45T.Li tumor cells were exposed to different doses of γ-irradiation from 0 Gy to 15 Gy in vitro. The percentage of GFP expression positive cells increased greatly in a dose-dependent manner as detected by FACS and Western blot analysis. For in vivo study, AdEgr-GFP were injected intratumorally, and tumor site received different doses of local γ-irradiation 48 h after injection, and after 8 h the tumor samples were biopsed for investigating the GFP expression. Tumor tissue image analysis revealed that γ-irradiation could markedly increase GFP expression in a dose-dependent manner as

  8. Foreign gene transfer into Chinese shrimps (Penaeus chinensis) with gene gun

    2001-01-01

    Plasmids pG DNA-RZ1 with a GFP (green fluorescent protein) reporter gene and a ribozyme gene incising penaeid white spot baculovirus (WSBV) were first introduced into the fertilized eggs of Chinese shrimps by gene gun. The treated and control samples of different development stages were observed with a fluorescent microscope. The transient expression of GFP gene was high in nauplius and zoea larvae. Results from RT-PCR and PCR for adults showed that the foreign genes had been transferred into the shrimps and had expressed the corresponding proteins. This work has established a transgenic method for penaeid shrimps, which will set base for the application of genetic engineering breeding into industry.

  9. Study on magnetic gene transfer using HTS bulk magnet

    Highlights: •DNA–magnetite complexes were prepared as ferromagnetic DNA carrier. •The condition of magnetic field to suppress the diffusion was found by calculation. •The result of model experiment showed the validity of the calculated value. •The results of in vivo experiments showed that the amount of gene expression was significantly increased by magnetic field. -- Abstract: This study aimed to realize local and high-efficient gene expression by suppressing the diffusion of ferromagnetic DNA carriers in a strong magnetic field generated by HTS bulk magnet. DNA–magnetite complexes were prepared as ferromagnetic DNA carrier and the magnetic gene transfer using the DNA carriers was examined. From the results of the simulation and the model experiment, it was shown that the particle diffusion was suppressed within 10 mm in diameter by the magnetic field at 20 mm above the HTS bulk magnet. The results of in vivo experiments showed that the amount of gene expression was significantly increased by magnetic field

  10. Gene Transfer Enhancement by Alkylcarboxylation of Poly(propylenimine

    Maryam Hashemi

    2013-01-01

    Full Text Available Abstract Among synthetic carriers, dendrimers with the more flexible structure have attracted a great deal of researchers’ attention in the field of gene delivery. Followed by the promising results upon hydrophobic modification on polymeric structures in our laboratory, alkylcarboxylated poly (propylenimine-based carriers were synthesized by nucleophilic substitution of amines with alkyl moieties and were further characterized for their physicochemical and biological characteristics for plasmid DNA delivery. Although not noticeably effective gene transfer activity for hexanoate- and hexadecanoate-modified series was observed, but alkylation by decanoic acid significantly improved the transfection efficiency of the final constructs up to 60 fold in comparison with unmodified poly(propylenimine (PPI. PPI modified by 10-bromodecanoic acid at 50% grafting, showed significantly higher gene expression at c/p ratio of 2 compared to Superfect as positive control.  Overall, modification of PPI with 50% primary amines grafting with 10-bromodecanoic acid could increase the transfection efficiency which is occurred at lower c/p ratio when compared to Superfect, i.e. less amount of modified vector is required to exhibit the same efficiency as Superfect. Therefore, the obtained constructs seem to be safer carriers for long-term gene therapy applications.

  11. Association between translation efficiency and horizontal gene transfer within microbial communities

    Tuller, Tamir; Girshovich, Yana; Sella, Yael; Kreimer, Avi; Freilich, Shiri; Kupiec, Martin; Gophna, Uri; Ruppin, Eytan

    2011-01-01

    Horizontal gene transfer (HGT) is a major force in microbial evolution. Previous studies have suggested that a variety of factors, including restricted recombination and toxicity of foreign gene products, may act as barriers to the successful integration of horizontally transferred genes. This study identifies an additional central barrier to HGT—the lack of co-adaptation between the codon usage of the transferred gene and the tRNA pool of the recipient organism. Analyzing the genomic sequenc...

  12. Potential of Helper-Dependent Adenoviral Vectors in Modulating Airway Innate Immunity

    Rahul Kushwah; Huibi Cao; Jim Hu

    2007-01-01

    Innate immune responses form the first line of defense against foreign insults and recently significant advances have been made in our understanding of the initiation of innate immune response along with its ability to modulate inflammation. In airway diseases such as asthma, COPD and cystic fibrosis, over reacting of the airway innate immune responses leads to cytokine imbalance and airway remodeling or damage. Helper-dependent adenoviral vectors have the potential to deliver genes to modulate airway innate immune responses and have many advantages over its predecessors. However, there still are a few limitations that need to be addressed prior to their use in clinical applications.

  13. GENE TRANSFER IN TOBACCO MITOCHONDRIA IN VITRO AND IN VIVO

    Katyshev A.I.

    2012-08-01

    Full Text Available Earlier, we had showed that isolated mitochondria from different organisms can import DNA. Exploiting this mechanism, we assessed the possibility of genes transfer in tobacco mitochondria in vitro and in vivo. Whereas homologous recombination is a rare occasion in higher plant nuclei, recombination between the large direct repeats in plant mitochondrial genome generates its multipartite structure. Following transfection of isolated organelles with constructs composed of a partial gfp gene flanked by mitochondrial DNA fragments, we showed the homologous recombination of imported DNA with the resident DNA and the integration of the reporter gene. The recombination yielded an insertion of a continuous exogenous DNA fragment including the gfp sequence and at least the 0.5 kb of the flanking sequence on each side. Using of transfection constructs carrying multiple sequences homologous to mitochondrial DNA could be suitable for insertion of a target gene into any region of the mitochondrial genome, which turns this approach to be of a general and methodical importance. Usually mitochondrial reactive oxygen species (ROS level is under strict control of the antioxidant system including the Mn-containing superoxide dismutase (MnSOD. MnSOD is presented in multiple forms encoded by several genes in plants. Possibly, this enzyme, beside its catalytic function, fulfills as well some unknown biochemical functions. Thus, one of maize SOD enzymes (SOD3.4 could bind with mitochondrial DNA. Another SOD form (SOD3.1 is located in close proximity to mitochondrial respiratory complexes, where ROS are generated. To study possible physiological functions of this enzyme, we cloned the maize SOD3.1 gene. Compared to the SOD3.4, this enzyme didn't demonstrate DNA-binding activity. At the same time, SOD3.1 didn't show non-specific DNA-hydrolyzing activity as Cu/ZnSOD does. It means that this enzyme might have some DNA protective function. We made NtPcob-sod3.1-IGR

  14. Immunization Against the Transgene but not the TetON Switch Reduces Expression From Gutless Adenoviral Vectors in the Brain

    Xiong, Weidong; Candolfi, Marianela; Kroeger, Kurt M.; Puntel, Mariana; Mondkar, Sonali; Larocque, Daniel; Liu, Chunyan; Curtin, James F.; Palmer, Donna; Ng, Philip; Lowenstein, Pedro R; Castro, Maria G.

    2008-01-01

    Immune responses against vectors or encoded transgenes can impose limitations on gene therapy. We demonstrated that tetracycline-regulated high-capacity adenoviral vectors (HC-Ads) sustain regulated transgene expression in the brain even in the presence of systemic pre-existing immune responses against adenoviruses. In this study we assessed whether systemic pre-existing immune responses against the transgene products, i.e., β-Gal or the tetracycline-dependent (TetON) regulatory transcription...

  15. Amoebozoa possess lineage-specific globin gene repertoires gained by individual horizontal gene transfers.

    Dröge, Jasmin; Buczek, Dorota; Suzuki, Yutaka; Makałowski, Wojciech

    2014-01-01

    The Amoebozoa represent a clade of unicellular amoeboid organisms that display a wide variety of lifestyles, including free-living and parasitic species. For example, the social amoeba Dictyostelium discoideum has the ability to aggregate into a multicellular fruiting body upon starvation, while the pathogenic amoeba Entamoeba histolytica is a parasite of humans. Globins are small heme proteins that are present in almost all extant organisms. Although several genomes of amoebozoan species have been sequenced, little is known about the phyletic distribution of globin genes within this phylum. Only two flavohemoglobins (FHbs) of D. discoideum have been reported and characterized previously while the genomes of Entamoeba species are apparently devoid of globin genes. We investigated eleven amoebozoan species for the presence of globin genes by genomic and phylogenetic in silico analyses. Additional FHb genes were identified in the genomes of four social amoebas and the true slime mold Physarum polycephalum. Moreover, a single-domain globin (SDFgb) of Hartmannella vermiformis, as well as two truncated hemoglobins (trHbs) of Acanthamoeba castellanii were identified. Phylogenetic evidence suggests that these globin genes were independently acquired via horizontal gene transfer from some ancestral bacteria. Furthermore, the phylogenetic tree of amoebozoan FHbs indicates that they do not share a common ancestry and that a transfer of FHbs from bacteria to amoeba occurred multiple times. PMID:25013378

  16. Genome-wide experimental determination of barriers to horizontal gene transfer

    Rubin, Edward; Sorek, Rotem; Zhu, Yiwen; Creevey, Christopher J.; Francino, M. Pilar; Bork, Peer; Rubin, Edward M.

    2007-09-24

    Horizontal gene transfer, in which genetic material is transferred from the genome of one organism to another, has been investigated in microbial species mainly through computational sequence analyses. To address the lack of experimental data, we studied the attempted movement of 246,045 genes from 79 prokaryotic genomes into E. coli and identified genes that consistently fail to transfer. We studied the mechanisms underlying transfer inhibition by placing coding regions from different species under the control of inducible promoters. Their toxicity to the host inhibited transfer regardless of the species of origin and our data suggest that increased gene dosage and associated increased expression is a predominant cause for transfer failure. While these experimental studies examined transfer solely into E. coli, a computational analysis of gene transfer rates across available bacterial and archaeal genomes indicates that the barriers observed in our study are general across the tree of life.

  17. Gene transfer into older chicken embryos by ex ovo electroporation.

    Luo, Jiankai; Yan, Xin; Lin, Juntang; Rolfs, Arndt

    2012-01-01

    The chicken embryo provides an excellent model system for studying gene function and regulation during embryonic development. In ovo electroporation is a powerful method to over-express exogenous genes or down-regulate endogenous genes in vivo in chicken embryos(1). Different structures such as DNA plasmids encoding genes(2-4), small interfering RNA (siRNA) plasmids(5), small synthetic RNA oligos(6), and morpholino antisense oligonucleotides(7) can be easily transfected into chicken embryos by electroporation. However, the application of in ovo electroporation is limited to embryos at early incubation stages (younger than stage HH20--according to Hamburg and Hamilton)(8) and there are some disadvantages for its application in embryos at later stages (older than stage HH22--approximately 3.5 days of development). For example, the vitelline membrane at later stages is usually stuck to the shall membrane and opening a window in the shell causes rupture of the vessels, resulting in death of the embryos; older embryos are covered by vitelline and allantoic vessels, where it is difficult to access and manipulate the embryos; older embryos move vigorously and is difficult to control the orientation through a relatively small window in the shell. In this protocol we demonstrate an ex ovo electroporation method for gene transfer into chicken embryos at late stages (older than stage HH22). For ex ovo electroporation, embryos are cultured in Petri dishes(9) and the vitelline and allantoic vessels are widely spread. Under these conditions, the older chicken embryos are easily accessed and manipulated. Therefore, this method overcomes the disadvantages of in ovo electroporation applied to the older chicken embryos. Using this method, plasmids can be easily transfected into different parts of the older chicken embryos(10-12). PMID:22872055

  18. Repeated, recent and diverse transfers of a mitochondrial gene to the nucleus in flowering plants.

    Adams, K L; Daley, D O; Qiu, Y L; Whelan, J; Palmer, J D

    2000-11-16

    A central component of the endosymbiotic theory for the bacterial origin of the mitochondrion is that many of its genes were transferred to the nucleus. Most of this transfer occurred early in mitochondrial evolution; functional transfer of mitochondrial genes has ceased in animals. Although mitochondrial gene transfer continues to occur in plants, no comprehensive study of the frequency and timing of transfers during plant evolution has been conducted. Here we report frequent loss (26 times) and transfer to the nucleus of the mitochondrial gene rps10 among 277 diverse angiosperms. Characterization of nuclear rps10 genes from 16 out of 26 loss lineages implies that many independent, RNA-mediated rps10 transfers occurred during recent angiosperm evolution; each of the genes may represent a separate functional gene transfer. Thus, rps10 has been transferred to the nucleus at a surprisingly high rate during angiosperm evolution. The structures of several nuclear rps10 genes reveal diverse mechanisms by which transferred genes become activated, including parasitism of pre-existing nuclear genes for mitochondrial or cytoplasmic proteins, and activation without gain of a mitochondrial targeting sequence. PMID:11099041

  19. Genetic modification of cereal crops by direct gene transfer

    On the basis of efficient in vitro culture and regeneration systems, reproducible transformation methods for different cereal crops were developed. Scutellar tissue of the immature embryos of hexaploid wheat and maize were used as targets for microprojectile mediated gene transfer. Bombardment of haploid microspores resulted in homozygous, transgenic and fertile barley plants. Each target was the subject of individual optimization processes of bombardment conditions by analysing the transient β-glucuronidase activity. Furthermore, phosphinothricin resistance conferred by the bar gene turned out to be a suitable selectable marker for regenerating transgenic crop plants. Summarizing the results of independent transformation experiments for wheat and maize led to a transformation efficiency of one transgenic plant per 83 and 230 bombardment immature embryos, respectively. For barley, the average of all the experiments was one transgenic plant per 2.8 x 1016 bombarded microspores. Primary transformants and progeny were analyzed for the enzyme activity of the two marker enzymes introduced and integration of the corresponding genes by Southern blot experiments. Stable integration of the foreign DNA and its inheritance by progeny were demonstrated. All the transformed plants showed normal morphology and their development and flowering were comparable with those of seed derived plants. (author). 28 refs, 2 tabs

  20. Chromosomal nif Genes Transfer by Conjugation in Nitrogen Fixing Azotobacter chroococcum to Lactobacillus plantarium

    Adel Kamal Khider; Aras Muhammad Khidher

    2011-01-01

    To determine the possibility of transferring chromosomal nitrogen fixation genes (nif genes) from Azotobacter chroococcum to Lactobacillus planetarium, a total of 72 Azotobacter chroococcum isolated from Erbil governorate, Iraq were culturally, morphologically and biochemically characterized. Genes for atmospheric nitrogen fixation, located on the chromosome of Azotobacter chroococcum isolates were transferred by conjugation process to a recipient Lactobacillus plantarium isolated from Erbil ...

  1. Adenovirus-p53 gene therapy in human nasopharyngeal carcinoma xenografts

    Background: One major challenge to human cancer gene therapy, is efficient delivery of the gene-vector complex. Methods and results: Using two distinct human nasopharyngeal carcinoma (NPC) models, we demonstrate that intra-tumoural (IT) administration of adenoviral-mediated wild-type p53 gene therapy (Ad-p53) caused no greater inhibition of tumour growth as compared to ionizing radiation (XRT) alone. Detailed histologic examination of tumour sections demonstrated that <15% of tumour cells were transduced by IT adv-β-gal. Conclusions: This report underscores the importance of developing gene transfer vectors, which can provide therapeutic levels of transgene expression efficiently in solid tumours

  2. Neuronal expression and regulation of CGRP promoter activity following viral gene transfer into cultured trigeminal ganglia neurons

    Durham, Paul L; Dong, Penny X; Belasco, Kevin T;

    2004-01-01

    -expression with endogenous CGRP. In contrast, an adenoviral vector containing a CMV-lacZ reporter was predominantly expressed in non-neuronal cells, with only 29% co-expression with CGRP. We then asked whether the CGRP promoter in the viral vector could be regulated by serotonin receptor type 1 (5-HT(1)) agonists......We have examined the regulation of calcitonin gene-related peptide (CGRP) promoter activity in primary cultures of rat trigeminal ganglia neurons. A viral vector was used to circumvent the potential complication of examining only a small subpopulation of cells in the heterogeneous cultures....... Infection with high titers of recombinant adenovirus containing 1.25 kb of the rat CGRP promoter linked to the beta-galactosidase reporter gene (AdCGRP-lacZ) yielded expression in about 50% of the CGRP-expressing neurons. The CGRP-lacZ reporter gene was preferentially expressed in neurons, with 91% co...

  3. Multiple inter-kingdom horizontal gene transfers in the evolution of the phosphoenolpyruvate carboxylase gene family.

    Peng, Yingmei; Cai, Jing; Wang, Wen; Su, Bing

    2012-01-01

    Pepcase is a gene encoding phosphoenolpyruvate carboxylase that exists in bacteria, archaea and plants,playing an important role in plant metabolism and development. Most plants have two or more pepcase genes belonging to two gene sub-families, while only one gene exists in other organisms. Previous research categorized one plant pepcase gene as plant-type pepcase (PTPC) while the other as bacteria-type pepcase (BTPC) because of its similarity with the pepcase gene found in bacteria. Phylogenetic reconstruction showed that PTPC is the ancestral lineage of plant pepcase, and that all bacteria, protistpepcase and BTPC in plants are derived from a lineage of pepcase closely related with PTPC in algae. However, their phylogeny contradicts the species tree and traditional chronology of organism evolution. Because the diversification of bacteria occurred much earlier than the origin of plants, presumably all bacterialpepcase derived from the ancestral PTPC of algal plants after divergingfrom the ancestor of vascular plant PTPC. To solve this contradiction, we reconstructed the phylogeny of pepcase gene family. Our result showed that both PTPC and BTPC are derived from an ancestral lineage of gamma-proteobacteriapepcases, possibly via an ancient inter-kingdom horizontal gene transfer (HGT) from bacteria to the eukaryotic common ancestor of plants, protists and cellular slime mold. Our phylogenetic analysis also found 48other pepcase genes originated from inter-kingdom HGTs. These results imply that inter-kingdom HGTs played important roles in the evolution of the pepcase gene family and furthermore that HGTsare a more frequent evolutionary event than previouslythought. PMID:23251445

  4. Multiple inter-kingdom horizontal gene transfers in the evolution of the phosphoenolpyruvate carboxylase gene family.

    Yingmei Peng

    Full Text Available Pepcase is a gene encoding phosphoenolpyruvate carboxylase that exists in bacteria, archaea and plants,playing an important role in plant metabolism and development. Most plants have two or more pepcase genes belonging to two gene sub-families, while only one gene exists in other organisms. Previous research categorized one plant pepcase gene as plant-type pepcase (PTPC while the other as bacteria-type pepcase (BTPC because of its similarity with the pepcase gene found in bacteria. Phylogenetic reconstruction showed that PTPC is the ancestral lineage of plant pepcase, and that all bacteria, protistpepcase and BTPC in plants are derived from a lineage of pepcase closely related with PTPC in algae. However, their phylogeny contradicts the species tree and traditional chronology of organism evolution. Because the diversification of bacteria occurred much earlier than the origin of plants, presumably all bacterialpepcase derived from the ancestral PTPC of algal plants after divergingfrom the ancestor of vascular plant PTPC. To solve this contradiction, we reconstructed the phylogeny of pepcase gene family. Our result showed that both PTPC and BTPC are derived from an ancestral lineage of gamma-proteobacteriapepcases, possibly via an ancient inter-kingdom horizontal gene transfer (HGT from bacteria to the eukaryotic common ancestor of plants, protists and cellular slime mold. Our phylogenetic analysis also found 48other pepcase genes originated from inter-kingdom HGTs. These results imply that inter-kingdom HGTs played important roles in the evolution of the pepcase gene family and furthermore that HGTsare a more frequent evolutionary event than previouslythought.

  5. Improved gene transfer with histidine-functionalized mesoporous silica nanoparticles.

    Brevet, David; Hocine, Ouahiba; Delalande, Anthony; Raehm, Laurence; Charnay, Clarence; Midoux, Patrick; Durand, Jean-Olivier; Pichon, Chantal

    2014-08-25

    Mesoporous silica nanoparticles (MSN) were functionalized with aminopropyltriethoxysilane (MSN-NH2) then L-histidine (MSN-His) for pDNA delivery in cells and in vivo. The complexation of pDNA with MSN-NH2 and MSN-His was first studied with gel shift assay. pDNA complexed with MSN-His was better protected from DNase degradation than with MSN-NH2. An improvement of the transfection efficiency in cells was observed with MSN-His/pDNA compared to MSN-NH2/pDNA, which could be explained by a better internalization of MSN-His. The improvement of the transfection efficiency with MSN-His was also observed for gene transfer in Achilles tendons in vivo. PMID:24853464

  6. Detecting rare gene transfer events in bacterial populations

    Kaare Magne Nielsen

    2014-01-01

    Full Text Available Horizontal gene transfer (HGT enables bacteria to access, share, and recombine genetic variation, resulting in genetic diversity that cannot be obtained through mutational processes alone. In most cases, the observation of evolutionary successful HGT events relies on the outcome of initially rare events that lead to novel functions in the new host, and that exhibit a positive effect on host fitness. Conversely, the large majority of HGT events occurring in bacterial populations will go undetected due to lack of replication success of transformants. Moreover, other HGT events that would be highly beneficial to new hosts can fail to ensue due to lack of physical proximity to the donor organism, lack of a suitable gene transfer mechanism, genetic compatibility, and stochasticity in tempo-spatial occurrence. Experimental attempts to detect HGT events in bacterial populations have typically focused on the transformed cells or their immediate offspring. However, rare HGT events occurring in large and structured populations are unlikely to reach relative population sizes that will allow their immediate identification; the exception being the unusually strong positive selection conferred by antibiotics. Most HGT events are not expected to alter the likelihood of host survival to such an extreme extent, and will confer only minor changes in host fitness. Due to the large population sizes of bacteria and the time scales involved, the process and outcome of HGT are often not amenable to experimental investigation. Population genetic modeling of the growth dynamics of bacteria with differing HGT rates and resulting fitness changes is therefore necessary to guide sampling design and predict realistic time frames for detection of HGT, as it occurs in laboratory or natural settings. Here we review the key population genetic parameters, consider their complexity and highlight knowledge gaps for further research.

  7. Pathogen-origin horizontally transferred genes contribute to the evolution of Lepidopteran insects

    Li Zi-Wen; Shen Yi-Hong; Xiang Zhong-Huai; Zhang Ze

    2011-01-01

    Abstract Background Horizontal gene transfer (HGT), a source of genetic variation, is generally considered to facilitate hosts' adaptability to environments. However, convincing evidence supporting the significant contribution of the transferred genes to the evolution of metazoan recipients is rare. Results In this study, based on sequence data accumulated to date, we used a unified method consisting of similarity search and phylogenetic analysis to detect horizontally transferred genes (HTGs...

  8. A novel Cre recombinase reporter mouse strain facilitates selective and efficient infection of primary immune cells with adenoviral vectors.

    Heger, Klaus; Kober, Maike; Rieß, David; Drees, Christoph; de Vries, Ingrid; Bertossi, Arianna; Roers, Axel; Sixt, Michael; Schmidt-Supprian, Marc

    2015-06-01

    Replication-deficient recombinant adenoviruses are potent vectors for the efficient transient expression of exogenous genes in resting immune cells. However, most leukocytes are refractory to efficient adenoviral transduction as they lack expression of the coxsackie/adenovirus receptor (CAR). To circumvent this obstacle, we generated the R26/CAG-CARΔ1(StopF) (where R26 is ROSA26 and CAG is CMV early enhancer/chicken β actin promoter) knock-in mouse line. This strain allows monitoring of in situ Cre recombinase activity through expression of CARΔ1. Simultaneously, CARΔ1 expression permits selective and highly efficient adenoviral transduction of immune cell populations, such as mast cells or T cells, directly ex vivo in bulk cultures without prior cell purification or activation. Furthermore, we show that CARΔ1 expression dramatically improves adenoviral infection of in vitro differentiated conventional and plasmacytoid dendritic cells (DCs), basophils, mast cells, as well as Hoxb8-immortalized hematopoietic progenitor cells. This novel dual function mouse strain will hence be a valuable tool to rapidly dissect the function of specific genes in leukocyte physiology. PMID:25787118

  9. Passive Immunization against HIV/AIDS by Antibody Gene Transfer

    Lili Yang

    2014-01-01

    Full Text Available Despite tremendous efforts over the course of many years, the quest for an effective HIV vaccine by the classical method of active immunization remains largely elusive. However, two recent studies in mice and macaques have now demonstrated a new strategy designated as Vectored ImmunoProphylaxis (VIP, which involves passive immunization by viral vector-mediated delivery of genes encoding broadly neutralizing antibodies (bnAbs for in vivo expression. Robust protection against virus infection was observed in preclinical settings when animals were given VIP to express monoclonal neutralizing antibodies. This unorthodox approach raises new promise for combating the ongoing global HIV pandemic. In this article, we survey the status of antibody gene transfer, review the revolutionary progress on isolation of extremely bnAbs, detail VIP experiments against HIV and its related virus conduced in humanized mice and macaque monkeys, and discuss the pros and cons of VIP and its opportunities and challenges towards clinical applications to control HIV/AIDS endemics.

  10. Genome-scale phylogenetic analysis finds extensive gene transfer among fungi

    Szöllősi, Gergely J.; Davín, Adrián Arellano; Tannier, Eric; Daubin, Vincent; Boussau, Bastien

    2015-01-01

    Although the role of lateral gene transfer is well recognized in the evolution of bacteria, it is generally assumed that it has had less influence among eukaryotes. To explore this hypothesis, we compare the dynamics of genome evolution in two groups of organisms: cyanobacteria and fungi. Ancestral genomes are inferred in both clades using two types of methods: first, Count, a gene tree unaware method that models gene duplications, gains and losses to explain the observed numbers of genes present in a genome; second, ALE, a more recent gene tree-aware method that reconciles gene trees with a species tree using a model of gene duplication, loss and transfer. We compare their merits and their ability to quantify the role of transfers, and assess the impact of taxonomic sampling on their inferences. We present what we believe is compelling evidence that gene transfer plays a significant role in the evolution of fungi. PMID:26323765

  11. Evaluation of biolistic gene transfer methods in vivo using non-invasive bioluminescent imaging techniques

    Daniell Henry

    2011-06-01

    Full Text Available Abstract Background Gene therapy continues to hold great potential for treating many different types of disease and dysfunction. Safe and efficient techniques for gene transfer and expression in vivo are needed to enable gene therapeutic strategies to be effective in patients. Currently, the most commonly used methods employ replication-defective viral vectors for gene transfer, while physical gene transfer methods such as biolistic-mediated ("gene-gun" delivery to target tissues have not been as extensively explored. In the present study, we evaluated the efficacy of biolistic gene transfer techniques in vivo using non-invasive bioluminescent imaging (BLI methods. Results Plasmid DNA carrying the firefly luciferase (LUC reporter gene under the control of the human Cytomegalovirus (CMV promoter/enhancer was transfected into mouse skin and liver using biolistic methods. The plasmids were coupled to gold microspheres (1 μm diameter using different DNA Loading Ratios (DLRs, and "shot" into target tissues using a helium-driven gene gun. The optimal DLR was found to be in the range of 4-10. Bioluminescence was measured using an In Vivo Imaging System (IVIS-50 at various time-points following transfer. Biolistic gene transfer to mouse skin produced peak reporter gene expression one day after transfer. Expression remained detectable through four days, but declined to undetectable levels by six days following gene transfer. Maximum depth of tissue penetration following biolistic transfer to abdominal skin was 200-300 μm. Similarly, biolistic gene transfer to mouse liver in vivo also produced peak early expression followed by a decline over time. In contrast to skin, however, liver expression of the reporter gene was relatively stable 4-8 days post-biolistic gene transfer, and remained detectable for nearly two weeks. Conclusions The use of bioluminescence imaging techniques enabled efficient evaluation of reporter gene expression in vivo. Our results

  12. Improved efficiency of the walnut somatic embryo gene transfer system.

    McGranahan, G H; Leslie, C A; Uratsu, S L; Dandekar, A M

    1990-01-01

    AnAgrobacterium-mediated gene transfer system which relies on repetitive embryogenesis to regenerate transgenic walnut plants has been made more efficient by using a more virulent strain ofAgrobacterium and vectors containing genes for both kanamycin resistance and beta-glucuronidase (GUS) activity to facilitate early screening and selection. Two plasmids (pCGN7001 and pCGN7314) introduced individually into the disarmedAgrobacterium host strain EHA101 were used as inoculum. Embryos maintained on medium containing 100 mg/l kanamycin after co-cultivation produced more transformed secondary embryos than embryos maintained on kanamycin-free medium. Of the 186 GUS-positive secondary embryo lines identified, 70% were regenerated from 3 out of 16 primary embryos inoculated with EHA101/pCGN7314 and grown on kanamycin- containing medium, 28% from 4 out of 17 primary embryos inoculated with EHA101/ pCGN7001 and grown on kanamycin medium, and 2% from one out of 13 primary embryos inoculated with EHA101/pCGN7001 but not exposed to kanamycin. Because kanamycin inhibits but does not completely block new embryo formation in controls, identification of transformants formerly required repetitive selection on kanamycin for several months. Introduction of the GUS marker gene allowed positive identification of transformant secondary embryos as early as 5-6 weeks after inoculation. DNA analysis of a representative subset of lines (n=13) derived from secondary embryos confirmed transformation and provided evidence for multiple insertion events in single inoculated primary embryos. PMID:24226275

  13. Evolutionary advantage conferred by an eukaryote-to-eukaryote gene transfer event in wine yeasts

    Marsit, Souhir; Mena, Adriana; Bigey, Frederic; Sauvage, Francois Xavier; Couloux, Arnaud; Guy, Julie; Legras, Jean Luc; Barrio, Eladio; Dequin, Sylvie

    2015-01-01

    Although an increasing number of horizontal gene transfers have been reported in eukaryotes, experimental evidence for their adaptive value is lacking. Here, we report the recent transfer of a 158-kb genomic region between Torulaspora microellipsoides and Saccharomyces cerevisiae wine yeasts or closely related strains. This genomic region has undergone several rearrangements in S. cerevisiae strains, including gene loss and gene conversion between two tandemly duplicated FOT genes encoding ol...

  14. The Use of Viral Vectors in Gene Transfer Therapy

    Dziaková, A.; Valenčáková, A.; Hatalová, E.; J. Kalinová

    2016-01-01

    Gene therapy is strategy based on using genes as pharmaceuticals. Gene therapy is a treatment that involves altering the genes inside body's cells to stop disease. Genes contain DNA- the code controlling body form and function. Genes that do not work properly can cause disease. Gene therapy replaces a faulty gene or adds a new gene in an attempt to cure disease or improve the ability of the body to fight disease. Gene therapy holds promise for treating a wide range of diseases, including canc...

  15. Quality of the transgene-specific CD8+ T cell response induced by adenoviral vector immunization is critically influenced by virus dose and route of vaccination

    Holst, Peter Johannes; Ørskov, Cathrine; Thomsen, Allan Randrup;

    2010-01-01

    Adenoviral vectors have been widely used for experimental gene therapy and vaccination, yet there is a surprising lack of knowledge connecting the route and dose of adenovirus administration to the induced transgene-specific immune response. We have recently demonstrated polyfunctional CD8(+) T c...... effector functions, accumulated in the spleen. These findings indicate that the localization of the adenoviral inoculum and not the total Ag load determines the quality of the CD8(+) T cell response induced with adenoviral vaccines.......Adenoviral vectors have been widely used for experimental gene therapy and vaccination, yet there is a surprising lack of knowledge connecting the route and dose of adenovirus administration to the induced transgene-specific immune response. We have recently demonstrated polyfunctional CD8(+) T...... correlated positively with dissemination, whereas the functional capacity of the generated T cells correlated inversely with vector dissemination. A comparison of the immune response to s.c. or i.v. administration at moderate doses revealed that inoculation by both routes induced a transient peak of IFN...

  16. Transduction-like gene transfer in the methanogen Methanococcus voltae

    Bertani, G.

    1999-01-01

    Strain PS of Methanococcus voltae (a methanogenic, anaerobic archaebacterium) was shown to generate spontaneously 4.4-kbp chromosomal DNA fragments that are fully protected from DNase and that, upon contact with a cell, transform it genetically. This activity, here called VTA (voltae transfer agent), affects all markers tested: three different auxotrophies (histidine, purine, and cobalamin) and resistance to BES (2-bromoethanesulfonate, an inhibitor of methanogenesis). VTA was most effectively prepared by culture filtration. This process disrupted a fraction of the M. voltae cells (which have only an S-layer covering their cytoplasmic membrane). VTA was rapidly inactivated upon storage. VTA particles were present in cultures at concentrations of approximately two per cell. Gene transfer activity varied from a minimum of 2 x 10(-5) (BES resistance) to a maximum of 10(-3) (histidine independence) per donor cell. Very little VTA was found free in culture supernatants. The phenomenon is functionally similar to generalized transduction, but there is no evidence, for the time being, of intrinsically viral (i.e., containing a complete viral genome) particles. Consideration of VTA DNA size makes the existence of such viral particles unlikely. If they exist, they must be relatively few in number;perhaps they differ from VTA particles in size and other properties and thus escaped detection. Digestion of VTA DNA with the AluI restriction enzyme suggests that it is a random sample of the bacterial DNA, except for a 0.9-kbp sequence which is amplified relative to the rest of the bacterial chromosome. A VTA-sized DNA fraction was demonstrated in a few other isolates of M. voltae.

  17. The effect of adenovirus-mediated gene expression of FHIT in small cell lung cancer cells

    Zandi, Roza; Xu, Kai; Poulsen, Hans S;

    2011-01-01

    The candidate tumor suppressor fragile histidine traid (FHIT) is frequently inactivated in small cell lung cancer (SCLC). Mutations in the p53 gene also occur in the majority of SCLC leading to the accumulation of the mutant protein. Here we evaluated the effect of FHIT gene therapy alone or in...... combination with the mutant p53-reactivating molecule, PRIMA-1(Met)/APR-246, in SCLC. Overexpression of FHIT by recombinant adenoviral vector (Ad-FHIT)-mediated gene transfer in SCLC cells inhibited their growth by inducing apoptosis and when combined with PRIMA-1(Met)/APR-246, a synergistic cell growth...

  18. Heparin Inhibits Retrovirus Binding to Fibronectin as Well as Retrovirus Gene Transfer on Fibronectin Fragments

    Carstanjen, D.; Dutt, P; Moritz, T.

    2001-01-01

    Fibronectin fragments have been shown to improve retrovirus gene transfer efficiency by binding retrovirus and target cells. Using a novel virus adhesion assay, we confirmed binding of type C oncoretrovirus vectors to the heparin II domain of fibronectin and demonstrated inhibition of viral binding and gene transfer by heparin.

  19. Codon optimization of the adenoviral fiber negatively impacts structural protein expression and viral fitness

    Villanueva, Eneko; Martí-Solano, Maria; Fillat, Cristina

    2016-06-01

    Codon usage adaptation of lytic viruses to their hosts is determinant for viral fitness. In this work, we analyzed the codon usage of adenoviral proteins by principal component analysis and assessed their codon adaptation to the host. We observed a general clustering of adenoviral proteins according to their function. However, there was a significant variation in the codon preference between the host-interacting fiber protein and the rest of structural late phase proteins, with a non-optimal codon usage of the fiber. To understand the impact of codon bias in the fiber, we optimized the Adenovirus-5 fiber to the codon usage of the hexon structural protein. The optimized fiber displayed increased expression in a non-viral context. However, infection with adenoviruses containing the optimized fiber resulted in decreased expression of the fiber and of wild-type structural proteins. Consequently, this led to a drastic reduction in viral release. The insertion of an exogenous optimized protein as a late gene in the adenovirus with the optimized fiber further interfered with viral fitness. These results highlight the importance of balancing codon usage in viral proteins to adequately exploit cellular resources for efficient infection and open new opportunities to regulate viral fitness for virotherapy and vaccine development.

  20. Codon optimization of the adenoviral fiber negatively impacts structural protein expression and viral fitness.

    Villanueva, Eneko; Martí-Solano, Maria; Fillat, Cristina

    2016-01-01

    Codon usage adaptation of lytic viruses to their hosts is determinant for viral fitness. In this work, we analyzed the codon usage of adenoviral proteins by principal component analysis and assessed their codon adaptation to the host. We observed a general clustering of adenoviral proteins according to their function. However, there was a significant variation in the codon preference between the host-interacting fiber protein and the rest of structural late phase proteins, with a non-optimal codon usage of the fiber. To understand the impact of codon bias in the fiber, we optimized the Adenovirus-5 fiber to the codon usage of the hexon structural protein. The optimized fiber displayed increased expression in a non-viral context. However, infection with adenoviruses containing the optimized fiber resulted in decreased expression of the fiber and of wild-type structural proteins. Consequently, this led to a drastic reduction in viral release. The insertion of an exogenous optimized protein as a late gene in the adenovirus with the optimized fiber further interfered with viral fitness. These results highlight the importance of balancing codon usage in viral proteins to adequately exploit cellular resources for efficient infection and open new opportunities to regulate viral fitness for virotherapy and vaccine development. PMID:27278133

  1. Horizontal Gene Transfer and Its Part in the Reorganisation of Genetics during the LUCA Epoch

    Jheeta, Sohan

    2013-01-01

    Currently there are five known mechanisms of horizontal gene transfer (HGT): transduction, conjugation, transformation, gene transfer agents and membrane vesicle transfer. The question here is: what part did HGT play in the reorganisation of genetics during the last universal common ancestor (LUCA) epoch? LUCA is a construct to explain the origin of the three domains of life; namely Archaea, Bacteria and Eukarya. This editorial offers a general introduction to the relevance and ultimate signi...

  2. Differential gene transfers and gene duplications in primary and secondary endosymbioses

    McFadden Geoffrey I

    2006-04-01

    Full Text Available Abstract Background Most genes introduced into phototrophic eukaryotes during the process of endosymbiosis are either lost or relocated into the host nuclear genome. In contrast, groEL homologues are found in different genome compartments among phototrophic eukaryotes. Comparative sequence analyses of recently available genome data, have allowed us to reconstruct the evolutionary history of these genes and propose a hypothesis that explains the unusual genome distribution of groEL homologues. Results Our analyses indicate that while two distinct groEL genes were introduced into eukaryotes by a progenitor of plastids, these particular homologues have not been maintained in all evolutionary lineages. This is of significant interest, because two chaperone proteins always co-occur in oxygenic photosynthetic organisms. We infer strikingly different lineage specific processes of evolution involving deletion, duplication and targeting of groEL proteins. Conclusion The requirement of two groEL homologues for chaperon function in phototrophs has provided a constraint that has shaped convergent evolutionary scenarios in divergent evolutionary lineages. GroEL provides a general evolutionary model for studying gene transfers and convergent evolutionary processes among eukaryotic lineages.

  3. Asialoglycoprotein receptor and liposome synergistically mediate the gene transfer into primary rat hepatocytes

    李崇辉; 温守明; 翟海峰; 孙曼霁

    1999-01-01

    Gene transfer into primary rat hepatocytes was performed by employing cationic liposome as DNA carrier and the specific ligand of hepatic asialoglycoprotein receptor (ASGPR), asialofetuin, as liver-targeting ligand. The resuits showed that asialofetuin, when added to the gene transfer complexes, could significantly increase the hepatocyte transfeetion efficiency, and alleviate the cellular toxicity of Lipofectin. Several synthetic ligands of ASGPR (galactosyl albumin) could also increase the transfection efficiency of hepatocyte like asialofetuin. It was proved that ASGPR and cationic liposome could synergistically mediate the gene transfer into primary rat hepatoeytes. This novel gene delivery system provided a safer, more simple and efficient gene transfer method for primary hepatocytes, and showed prospecting application in hepatic gene therapy.

  4. Proteasome Inhibitors Enhance Bacteriophage Lambda (λ) Mediated Gene Transfer in Mammalian Cells

    Volcy, Ketna; Dewhurst, Stephen

    2008-01-01

    Bacteriophage lambda vectors can transfer their genomes into mammalian cells, resulting in expression of phage-encoded genes. However, this process is inefficient. Experiments were therefore conducted to delineate the rate limiting step(s) involved, using a phage vector that contains a mammalian luciferase reporter gene cassette. The efficiency of phage-mediated gene transfer in mammalian cells was quantitated, in the presence or absence of pharmacologic inhibitors of cell uptake and degradat...

  5. On the need for widespread horizontal gene transfers under genome size constraint

    Stein Richard R

    2009-08-01

    Full Text Available Abstract Background While eukaryotes primarily evolve by duplication-divergence expansion (and reduction of their own gene repertoire with only rare horizontal gene transfers, prokaryotes appear to evolve under both gene duplications and widespread horizontal gene transfers over long evolutionary time scales. But, the evolutionary origin of this striking difference in the importance of horizontal gene transfers remains by and large a mystery. Hypothesis We propose that the abundance of horizontal gene transfers in free-living prokaryotes is a simple but necessary consequence of two opposite effects: i their apparent genome size constraint compared to typical eukaryote genomes and ii their underlying genome expansion dynamics through gene duplication-divergence evolution, as demonstrated by the presence of many tandem and block repeated genes. In principle, this combination of genome size constraint and underlying duplication expansion should lead to a coalescent-like process with extensive turnover of functional genes. This would, however, imply the unlikely, systematic reinvention of functions from discarded genes within independent phylogenetic lineages. Instead, we propose that the long-term evolutionary adaptation of free-living prokaryotes must have resulted in the emergence of efficient non-phylogenetic pathways to circumvent gene loss. Implications This need for widespread horizontal gene transfers due to genome size constraint implies, in particular, that prokaryotes must remain under strong selection pressure in order to maintain the long-term evolutionary adaptation of their "mutualized" gene pool, beyond the inevitable turnover of individual prokaryote species. By contrast, the absence of genome size constraint for typical eukaryotes has presumably relaxed their need for widespread horizontal gene transfers and strong selection pressure. Yet, the resulting loss of genetic functions, due to weak selection pressure and inefficient gene

  6. The Use of Viral Vectors in Gene Transfer Therapy

    A. Dziaková

    2016-05-01

    Full Text Available Gene therapy is strategy based on using genes as pharmaceuticals. Gene therapy is a treatment that involves altering the genes inside body's cells to stop disease. Genes contain DNA- the code controlling body form and function. Genes that do not work properly can cause disease. Gene therapy replaces a faulty gene or adds a new gene in an attempt to cure disease or improve the ability of the body to fight disease. Gene therapy holds promise for treating a wide range of diseases, including cancer, cystic fibrosis, heart disease, diabetes, hemophilia and AIDS. Various types of genetic material are used in gene therapy; double-stranded DNA (dsDNA, single-stranded DNA (ssDNA, plasmid DNA and antisense oligodeoxynucleotides (ASON. The success of gene therapy depends on assuring the entrance of the therapeutic gene to targeted cells without any form of biodegradation. Commonly used vectors in gene therapy are: adenoviruses (400 clinical studies; 23.8%, retroviruses (344 clinical studies; 20.5%, unenveloped/plasmid DNA (304 clinical studies, 17.7%, adeno-associated viruses (75 clinical studies; 4.5% and others. In this paper, we have reviewed the major gene delivery vectors and recent improvements made in their design meant to overcome the issues that commonly arise with the use of gene therapy vectors.

  7. Estimating the extent of horizontal gene transfer in metagenomic sequences

    Moya Andrés

    2008-03-01

    Full Text Available Abstract Background Although the extent of horizontal gene transfer (HGT in complete genomes has been widely studied, its influence in the evolution of natural communities of prokaryotes remains unknown. The availability of metagenomic sequences allows us to address the study of global patterns of prokaryotic evolution in samples from natural communities. However, the methods that have been commonly used for the study of HGT are not suitable for metagenomic samples. Therefore it is important to develop new methods or to adapt existing ones to be used with metagenomic sequences. Results We have created two different methods that are suitable for the study of HGT in metagenomic samples. The methods are based on phylogenetic and DNA compositional approaches, and have allowed us to assess the extent of possible HGT events in metagenomes for the first time. The methods are shown to be compatible and quite precise, although they probably underestimate the number of possible events. Our results show that the phylogenetic method detects HGT in between 0.8% and 1.5% of the sequences, while DNA compositional methods identify putative HGT in between 2% and 8% of the sequences. These ranges are very similar to these found in complete genomes by related approaches. Both methods act with a different sensitivity since they probably target HGT events of different ages: the compositional method mostly identifies recent transfers, while the phylogenetic is more suitable for the detections of older events. Nevertheless, the study of the number of HGT events in metagenomic sequences from different communities shows a consistent trend for both methods: the lower amount is found for the sequences of the Sargasso Sea metagenome, while the higher quantity is found in the whale fall metagenome from the bottom of the ocean. The significance of these observations is discussed. Conclusion The computational approaches that are used to find possible HGT events in complete

  8. Assessment and Improvement of Gene Transfer into Human Hematopoietic Stem Cells

    D.A. Breems (Dimitri)

    1997-01-01

    textabstractThe application of somatic gene transfer as a potential treatment in human disease has progressed from speculation to reality in a short time [4,20,21,84,85,87,105,117,174]. In May 1989 the first clinical marker gene protocol took place [145], followed by the first gene therapy protocol

  9. Gene transfer from wild Helianthus to sunflower: topicalities and limits

    Breton Catherine

    2010-03-01

    Full Text Available Sunflower (2n=17 belongs to the Helianthus genus (Asteraceae. Wild Helianthus species display morphological variation for branching and stem number, for architecture and seed size, and for resistance to abiotic and biotic stresses due to which they thrive in different environments in North America. The genus is divided into botanical sections, two for annual as sunflower, and two for perennial species as Jerusalem artichoke that produces rhizomes (tubers. We explain the difficulties and successes obtained by crossing sunflower with these species to improve the agronomic traits of the sunflower crop. It is easier to cross the annual species than the perennials’ with sunflower. Several traits such as Cytoplasmic male sterility and restorer Rf-PET1 genes, Downy mildew resistance, Phomopsis resistance, Sclerotinia resistance, Rust resistance, and Orobanche resistance have already been introduced from annual species into sunflower crop, but the complex genomic organization of these species compared to sunflower limits their important potential. Perennial species are much more diverse, and their genomes display 2n, 4n, or 6n chromosomes for n 17. The realities of inter-specific hybridization are relatively disappointing due to the introgression lines that have low oil and low seed yield. We report here several attempts to introgress agronomic traits from these species to sunflower, and we present as a case study, an introgressed progenies from H. mollis, a diploid species with sessile small leaves. We constructed a preliminary genetic map with AFLP markers in 21 BC1 plants, and we then showed that some progenies display 6 to 44% of introgression from H. mollis. Although this study is promising due to the novel compact architecture of the progenies, we cannot estimate the transferability from H. mollis to other perennial Helianthus to improve sunflower.

  10. Nuclear transfer of goat somatic cells transgenic for human lactoferrin gene

    Lan LI; Wei SHEN; Lingjiang MIN; Qingyu PAN; Yujiang SUN; Jixian DENG; Qingjie PAN

    2008-01-01

    Transgenic animal mammary gland bioreactors are used to produce recombinant proteins with appropri-ate post-translational modifications.The nuclear transfer of transgenic somatic cells is a powerful method to pro-duce mammary gland bioreactors.We established an effi-cient gene transfer and nuclear transfer approach in goat somatic cells.Gene targeting vector pGBC2LF was con-structed by cloning human lactoferrin (LF) gene cDNA into exon 2 of the milk goat beta-casein gene and the endogenous start codon was replaced by that of human LF gene.Goat fetal fibroblasts were transfected with lin-earized pGBC2LF and 14 cell lines were positive accord-ing to PCR and Southern blot.The transgenic cells were used as donor cells of nuclear transfer and some of recon-structed embryos could develop into blastocyst in vitro.

  11. Leu452His mutation in lipoprotein lipase gene transfer associated with hypertriglyceridemia in mice in vivo.

    Kaiyue Sun

    Full Text Available Mutated mouse lipoprotein lipase (LPL containing a leucine (L to histidine (H substitution at position 452 was transferred into mouse liver by hydrodynamics-based gene delivery (HD. Mutated-LPL (MLPL gene transfer significantly increased the concentrations of plasma MLPL and triglyceride (TG but significantly decreased the activity of plasma LPL. Moreover, the gene transfer caused adiposis hepatica and significantly increased TG content in mouse liver. To understand the effects of MLPL gene transfer on energy metabolism, we investigated the expression of key functional genes related to energy metabolism in the liver, epididymal fat, and leg muscles. The mRNA contents of hormone-sensitive lipase (HSL, adipose triglyceride lipase (ATGL, fatty acid-binding protein (FABP, and uncoupling protein (UCP were found to be significantly reduced. Furthermore, we investigated the mechanism by which MLPL gene transfer affected fat deposition in the liver, fat tissue, and muscle. The gene expression and protein levels of forkhead Box O3 (FOXO3, AMP-activated protein kinase (AMPK, and peroxisome proliferator-activated receptor-gamma coactivator 1 alpha (PGC-1α were found to be remarkably decreased in the liver, fat and muscle. These results suggest that the Leu452His mutation caused LPL dysfunction and gene transfer of MLPL in vivo produced resistance to the AMPK/PGC-1α signaling pathway in mice.

  12. Horizontal gene transfer and the evolution of transcriptionalregulation in Escherichia coli

    Price, Morgan N.; Dehal, Paramvir S.; Arkin, Adam P.

    2007-12-20

    Background: Most bacterial genes were acquired by horizontalgene transfer from other bacteria instead of being inherited bycontinuous vertical descent from an ancient ancestor}. To understand howthe regulation of these {acquired} genes evolved, we examined theevolutionary histories of transcription factors and of regulatoryinteractions from the model bacterium Escherichia coli K12. Results:Although most transcription factors have paralogs, these usually arose byhorizontal gene transfer rather than by duplication within the E. colilineage, as previously believed. In general, most neighbor regulators --regulators that are adjacent to genes that they regulate -- were acquiredby horizontal gene transfer, while most global regulators evolvedvertically within the gamma-Proteobacteria. Neighbor regulators wereoften acquired together with the adjacent operon that they regulate, sothe proximity might be maintained by repeated transfers (like "selfishoperons"). Many of the as-yet-uncharacterized (putative) regulators havealso been acquired together with adjacent genes, so we predict that theseare neighbor regulators as well. When we analyzed the histories ofregulatory interactions, we found that the evolution of regulation byduplication was rare, and surprisingly, many of the regulatoryinteractions that are shared between paralogs result from convergentevolution. Another surprise was that horizontally transferred genes aremore likely than other genes to be regulated by multiple regulators, andmost of this complex regulation probably evolved after the transfer.Conclusions: Our results highlight the rapid evolution of niche-specificgene regulation in bacteria.

  13. Can we modify response to radiation therapy with gene transfer?; Transfert de gene pour modifier la reponse a la radiotherapie

    Marangoni, E.; Bourhis, J. [Institut Gustave Roussy, Dept. de Radiotherapie, 94 - Villejuif (France); Bay, J.O.; Verrelle, P. [Centre Jean-Perrin, Lab. d' Oncologie Moleculaire, INSERM CRI 9502 EA 2145, 63 - Clermont-Ferrand (France)

    2000-06-01

    Several recent studies suggest that gene transfer can be combined with irradiation to increase anti-tumor efficacy. Among genes of particular interest to be used in this combined approach are those involved in the regulation of radiation-induced lethality (apoptosis, DNA repair). Some additional aspects appear to be relatively specific to these combinations, such as the type of vector to be used (anaerobic bacteria) or the type of promoter (radio-inducible promoters). The first results obtained in mice bearing human xenograft tumors, combining gene transfer and irradiation are encouraging, but no clinical study has been performed so far. Finally it should be pointed out, in this area as well as in cancer gene therapy in general, that progress in gene vectorization is mandatory to optimize gene distribution within the tumor. (authors)

  14. Rate of Gene Transfer From Mitochondria to Nucleus: Effects of Cytoplasmic Inheritance System and Intensity of Intracellular Competition

    Yamauchi, Atsushi

    2005-01-01

    Endosymbiotic theory states that mitochondria originated as bacterial intracellular symbionts, the size of the mitochondrial genome gradually reducing over a long period owing to, among other things, gene transfer from the mitochondria to the nucleus. Such gene transfer was observed in more genes in animals than in plants, implying a higher transfer rate of animals. The evolution of gene transfer may have been affected by an intensity of intracellular competition among organelle strains and t...

  15. Gene Transfer into Older Chicken Embryos by ex ovo Electroporation

    Luo, Jiankai; Yan, Xin; Lin, Juntang; Rolfs, Arndt

    2012-01-01

    The chicken embryo provides an excellent model system for studying gene function and regulation during embryonic development. In ovo electroporation is a powerful method to over-express exogenous genes or down-regulate endogenous genes in vivo in chicken embryos1. Different structures such as DNA plasmids encoding genes2-4, small interfering RNA (siRNA) plasmids5, small synthetic RNA oligos6, and morpholino antisense oligonucleotides7 can be easily transfected into chicken embryos by electrop...

  16. Transfer of engineered genes from crop to wild plants

    Bagger Jørgensen, Rikke; Hauser, T.P.; Mikkelsen, T.R.; Østergård, Hanne

    1996-01-01

    The escape of engineered genes - genes inserted using recombinant DNA techniques - from cultivated plants to wild or weedy relatives has raised concern about possible risks to the environment or to health. The media have added considerably to public concern by suggesting that such gene escape is a...

  17. Transfer of engineered genes from crop to wild plants

    Bagger Jørgensen, Rikke; Hauser, T.P.; Mikkelsen, T.R.; Østergård, Hanne

    1996-01-01

    The escape of engineered genes - genes inserted using recombinant DNA techniques - from cultivated plants to wild or weedy relatives has raised concern about possible risks to the environment or to health. The media have added considerably to public concern by suggesting that such gene escape is a...... sexual reproduction has been the basis for breeding almost all crops....

  18. Horizontal gene transfer of an entire metabolic pathway between a eukaryotic alga and its DNA virus.

    Monier, Adam; Pagarete, António; de Vargas, Colomban; Allen, Michael J; Read, Betsy; Claverie, Jean-Michel; Ogata, Hiroyuki

    2009-08-01

    Interactions between viruses and phytoplankton, the main primary producers in the oceans, affect global biogeochemical cycles and climate. Recent studies are increasingly revealing possible cases of gene transfers between cyanobacteria and phages, which might have played significant roles in the evolution of cyanobacteria/phage systems. However, little has been documented about the occurrence of horizontal gene transfer in eukaryotic phytoplankton/virus systems. Here we report phylogenetic evidence for the transfer of seven genes involved in the sphingolipid biosynthesis pathway between the cosmopolitan eukaryotic microalga Emiliania huxleyi and its large DNA virus EhV. PCR assays indicate that these genes are prevalent in E. huxleyi and EhV strains isolated from different geographic locations. Patterns of protein and gene sequence conservation support that these genes are functional in both E. huxleyi and EhV. This is the first clear case of horizontal gene transfer of multiple functionally linked enzymes in a eukaryotic phytoplankton-virus system. We examine arguments for the possible direction of the gene transfer. The virus-to-host direction suggests the existence of ancient viruses that controlled the complex metabolic pathway in order to infect primitive eukaryotic cells. In contrast, the host-to-virus direction suggests that the serial acquisition of genes involved in the same metabolic pathway might have been a strategy for the ancestor of EhVs to stay ahead of their closest relatives in the great evolutionary race for survival. PMID:19451591

  19. In utero recombinant adeno-associated virus gene transfer in mice, rats, and primates

    Marrero Luis

    2003-09-01

    Full Text Available Abstract Background Gene transfer into the amniotic fluid using recombinant adenovirus vectors was shown previously to result in high efficiency transfer of transgenes into the lungs and intestines. Adenovirus mediated in utero gene therapy, however, resulted in expression of the transgene for less than 30 days. Recombinant adenovirus associated viruses (rAAV have the advantage of maintaining the viral genome in daughter cells thus providing for long-term expression of transgenes. Methods Recombinant AAV2 carrying green fluorescent protein (GFP was introduced into the amniotic sac of fetal rodents and nonhuman primates. Transgene maintenance and expression was monitor. Results Gene transfer resulted in rapid uptake and long-term gene expression in mice, rats, and non-human primates. Expression and secretion of the reporter gene, GFP, was readily demonstrated within 72 hours post-therapy. In long-term studies in rats and nonhuman primates, maintenance of GFP DNA, protein expression, and reporter gene secretion was documented for over one year. Conclusions Because only multipotential stem cells are present at the time of therapy, these data demonstrated that in utero gene transfer with AAV2 into stem cells resulted in long-term systemic expression of active transgene roducts. Thus, in utero gene transfer via the amniotic fluid may be useful in treatment of gene disorders.

  20. Gene gun transferring-bone morphogenetic protein 2 (BMP-2) gene enhanced bone fracture healing in rabbits

    Li, Wenju; Wei, Haifeng; Xia, Chunmei; Zhu, Xiaomeng; Hou, Guozhu; Xu, Feng; Xinghua SONG; Zhan, Yulin

    2015-01-01

    Purpose: Transferring the bone morphogenetic protein 2 (BMP-2) genes into the tissues or cells can improve the bone healing of the fracture has been widely accepted. We evaluated the efficiency of using gene gun to transfer the BMP-2 gene thereby affected the healing of a fractured bone. Methods: The vector coding for BMP-2 was constructed by a non-replicating encephalo-myocarditis virus (ECMV)-based vector. The segmental bone defect (1.5 cm) model was created by a wire-saw at the middle part...

  1. Ultrasound -Assisted Gene Transfer to Adipose Tissue-Derived Stem/Progenitor Cells (ASCs)

    Miyamoto, Yoshitaka; Ueno, Hitomi; Hokari, Rei; Yuan, Wenji; Kuno, Shuichi; Kakimoto, Takashi; Enosawa, Shin; Negishi, Yoichi; Yoshinaka, Kiyoshi; Matsumoto, Yoichiro; Chiba, Toshio; Hayashi, Shuji

    2011-09-01

    In recent years, multilineage adipose tissue-derived stem cells (ASCs) have become increasingly attractive as a promising source for cell transplantation and regenerative medicine. Particular interest has been expressed in the potential to make tissue stem cells, such as ASCs and marrow stromal cells (MSCs), differentiate by gene transfection. Gene transfection using highly efficient viral vectors such as adeno- and sendai viruses have been developed for this purpose. Sonoporation, or ultrasound (US)-assisted gene transfer, is an alternative gene manipulation technique which employs the creation of a jet stream by ultrasonic microbubble cavitation. Sonoporation using non-viral vectors is expected to be a much safer, although less efficient, tool for prospective clinical gene therapy. In this report, we assessed the efficacy of the sonoporation technique for gene transfer to ASCs. We isolated and cultured adipocyets from mouse adipose tissue. ASCs that have the potential to differentiate with transformation into adipocytes or osteoblasts were obtained. Using the US-assisted system, plasmid DNA containing beta-galactosidase (beta-Gal) and green fluorescent protein (GFP) genes were transferred to the ASCs. For this purpose, a Sonopore 4000 (NEPAGENE Co.) and a Sonazoid (Daiichi Sankyo Co.) instrument were used in combination. ASCs were subjected to US (3.1 MHz, 50% duty cycle, burst rate 2.0 Hz, intensity 1.2 W/cm2, exposure time 30 sec). We observed that the gene was more efficiently transferred with increased concentrations of plasmid DNA (5-150 μg/mL). However, further optimization of the US parameters is required, as the gene transfer efficiency was still relatively low. In conclusion, we herein demonstrate that a gene can be transferred to ASCs using our US-assisted system. In regenerative medicine, this system might resolve the current issues surrounding the use of viral vectors for gene transfer.

  2. Conjugal gene transfer between bacteria in soil and rhizosphere.

    Smit, E.

    1994-01-01

    The extent of possible conjugal transfer of recombinant DNA present in genetically engineered microorganisms (GEMs) was studied. Occurrence of transfer of recombinant DNA is only one of the concerns regarding the use of GEMs (Chapter 2). Other potential hazards preventing the application of GEMs for

  3. Inter-genomic displacement via lateral gene transfer of bacterial trp operons in an overall context of vertical genealogy

    Keyhani Nemat O; Song Jian; Bonner Carol A; Xie Gary; Jensen Roy A

    2004-01-01

    Abstract Background The growing conviction that lateral gene transfer plays a significant role in prokaryote genealogy opens up a need for comprehensive evaluations of gene-enzyme systems on a case-by-case basis. Genes of tryptophan biosynthesis are frequently organized as whole-pathway operons, an attribute that is expected to facilitate multi-gene transfer in a single step. We have asked whether events of lateral gene transfer are sufficient to have obscured our ability to track the vertica...

  4. Antitumor Activity and Prolonged Expression from a TRAIL-Expressing Adenoviral Vector

    Jeongwu Lee

    2002-01-01

    Full Text Available Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL induces apoptosis in a variety of transformed cell lines, but generally spares most normal cells. Transduction by an adenoviral vector expressing human TRAIL cDNA (Ad.TRAIL-GFP resulted in both direct tumor cell killing as well as a potent bystander effect through presentation of TRAIL by transduced normal cells. Administration of Ad.TRAIL-GFP significantly prolonged survival of mice harboring either intracerebral glioblastomas or breast carcinoma-induced peritoneal carcinomatosis. Additionally, TRAIL induced prolonged transgene expression in normal tissue, presumably as a result of diminished immunemediated destruction of vector-transduced cells. Taken together, these data suggest that vector-mediated transduction of TRAIL may represent an effective strategy for cancer gene therapy.

  5. Alterations in radioresistance of eucaryotic cells after the transfer of genomic wildtype DNA and metallothionein genes

    The presented paper describes experiments concerning the alteration of radiosensitivity of eucaryotic cells after gene transfer. Ionizing radiation (γ- or X-ray) induces DNA single- or double strand breaks, which are religated by an unknown repair system. Repair deficient cells are highly sensitive to ionizing radiation. In the experiments described, cells from a patient with the heritable disease Ataxia telangiectasia were used as well as two X-ray sensitive CHO mutant cell lines. After gene transfer of an intact human DNA repair gene or a metallothionein gene the cells should regain radioresistance. (orig.)

  6. Regulated expression of foreign genes in vivo after germline transfer.

    Passman, R S; Fishman, G I

    1994-01-01

    Tight transcriptional control of foreign genes introduced into the germline of transgenic mice would be of great experimental value in studies of gene function. To develop a system in which the spatial and temporal expression of candidate genes implicated in cardiac development or function could be tightly controlled in vivo, we have generated transgenic mice expressing a tetracycline-controlled transactivator (tTA) under the control of a rat alpha myosin heavy chain promoter (MHC alpha-tTA m...

  7. Gene transfer system for the phytopathogenic fungus Ustilago maydis.

    Wang, J.; Holden, D. W.; Leong, S A

    1988-01-01

    A selectable marker for transformation was constructed by transcriptional fusion of a Ustilago maydis heat shock gene promoter with the hygromycin B phosphotransferase gene of Escherichia coli. U. maydis was transformed to hygromycin B resistance by polyethylene glycol-induced fusion of spheroplasts following exposure to plasmid DNA that carried the marker gene. Transformation frequencies of 50 and 1000 transformants per microgram of DNA per 2 x 10(7) spheroplasts were obtained for circular a...

  8. Isolation, culture and adenoviral transduction of parietal cells from mouse gastric mucosa

    Here we describe a method for the isolation of intact gastric glands from mice and primary culture and transfection of mouse gastric epithelial cells. Collagenase digestion of PBS-perfused mouse stomachs released large intact gastric glands that were plated on a basement membrane matrix. The heterogeneous gland cell cultures typically contain ∼60% parietal cells. Isolated mouse parietal cells remain viable in culture for up to 5 days and react strongly with an antibody specific to the gastric H+/K+ ATPase. Isolated intact mouse gastric glands and primary cultures of mouse parietal cells respond to the secretagogue, histamine. Typical morphological changes from a resting to an acid-secreting active parietal cell were observed. In resting cultures of mouse parietal cells, the H+/K+ ATPase displayed a cytoplasmic punctate staining pattern consistent with tubulovesicle element structures. Following histamine stimulation, an expansion of internal apical vacuole structures was observed together with a pronounced redistribution of the H+/K+ ATPase from the cytoplasm to the apical vacuoles. A reproducible procedure to express genes of interest exogenously in these cultures of mouse parietal cells was also established. This method combines recombinant adenoviral transduction with magnetic field-assisted transfection resulting in ∼30% transduced parietal cells. Adenoviral-transduced parietal cells maintain their ability to undergo agonist-induced activation. This protocol will be useful for the isolation, culture and expression of genes in parietal cells from genetically modified mice and as such will be an invaluable tool for studying the complex exocytic and endocytic trafficking events of the H+/K+ ATPase which underpin the regulation of acid secretion

  9. Evolutionary change and phylogenetic relationships in light of horizontal gene transfer

    Luis Boto

    2015-06-01

    Horizontal gene transfer has, over the past 25 years, become a part of evolutionary thinking. In the present paper I discuss horizontal gene transfer (HGT) in relation to contingency, natural selection, evolutionary change speed and the Tree-of-Life endeavour, with the aim of contributing to the understanding of the role of HGT in evolutionary processes. In addition, the challenges that HGT imposes on the current view of evolution are emphasized.

  10. Feline Immunodeficiency Virus as a Gene Transfer Vector in the Rat Nucleus Tractus Solitarii

    Lin, L. H.; Langasek, J. E.; Talman, L. S.; Taktakishvili, O. M.; Talman, W. T.

    2009-01-01

    Gene transfer has been used to examine the role of putative neurotransmitters in the nucleus tractus solitarii (NTS). Most such studies used adenovirus vector-mediated gene transfer although adenovirus vector transfects both neuronal and non-neuronal cells. Successful transfection in the NTS has also been reported with lentivirus as the vector. Feline immunodeficiency virus (FIV), a lentivirus, may preferentially transfect neurons and could be a powerful tool to delineate physiological effect...

  11. Effect of Caenorhabditis elegans age and genotype on horizontal gene transfer in intestinal bacteria

    Portal-Celhay, Cynthia; Nehrke, Keith; Martin J. Blaser

    2013-01-01

    Horizontal gene transfer (HGT) between bacteria occurs in the intestinal tract of their animal hosts and facilitates both virulence and antibiotic resistance. A model in which both the pathogen and the host are genetically tractable facilitates developing insight into mechanistic processes enabling or restricting the transfer of antibiotic resistance genes. Here we develop an in vivo experimental system to study HGT in bacteria using Caenorhabditis elegans as a model host. Using a thermosensi...

  12. Plasmids as mediators of gene transfer in the genetic manipulation of gram-positive bacteria

    O'Hara, Seamus

    1989-01-01

    Lack of suitable gene transfer techniques hampers genetic improvement and analysis of several industrially and clinically important gram-positive bacteria. Techniques already developed are often difficult to reproduce and limited in application. This study examines the feasibility of expanding the techniques available through the use of conjugation as a broad host range gene transfer mechanism. Such systems have been developed for gram-negative bacteria. Theoretical and practical aspec...

  13. Retrovirus-Associated Heparan Sulfate Mediates Immobilization and Gene Transfer on Recombinant Fibronectin

    Lei, Pedro; Bajaj, Bharat; Andreadis, Stelios T.

    2002-01-01

    Recombinant retroviruses have been shown to bind to fibronectin (FN) and increase the efficiency of gene transfer to a variety of cell types. Despite recent work to optimize gene transfer on recombinant FN, the mechanism of retrovirus binding to FN and the interactions of target cells with the bound virus remain elusive. We investigated the roles of virus surface glycoprotein (gp70), cell-conditioned medium, and proteoglycans in mediating retrovirus binding to FN. We also examined the role of...

  14. Effective generation of transgenic pigs and mice by linker based sperm-mediated gene transfer.

    Shih Ping Yao; Ho Pei-Yu; Huang Hsiao-I; Bolen James; Brown Lucy; Hsiao Chin-Ton; Lo Hsin-Lung; Lai Chao-Kuen; Chen Chi-Dar; Wu Ming-Che; Liu Yi-Hsin; Jiang MeiSheng; Qian Jin; Chang Keejong; Yao Chen-Wen

    2002-01-01

    Abstract Background Transgenic animals have become valuable tools for both research and applied purposes. The current method of gene transfer, microinjection, which is widely used in transgenic mouse production, has only had limited success in producing transgenic animals of larger or higher species. Here, we report a linker based sperm-mediated gene transfer method (LB-SMGT) that greatly improves the production efficiency of large transgenic animals. Results The linker protein, a monoclonal ...

  15. The impact of non-electrical factors on electrical gene transfer

    Hu, Jiemiao; CUTRERA, JEFFRY; LI, SHULIN

    2014-01-01

    Electrical pulses directly and effectively boost both in vitro and in vivo gene transfer, but this process is greatly affected by non-electrical factors that exist during electroporation. These factors include, but are not limited to, the types of cells or tissues used, the property of DNA, DNA formulation, and the expressed protein. In this mini-review, we only describe and discuss a summary of DNA properties and selected DNA formulations on gene transfer via electroporation. The properties ...

  16. Induction of fibroblasts to neurons through adenoviral gene delivery

    Fengxi Meng; Siye Chen; Qinglong Miao; Kechun Zhou; Qicheng Lao; Xiaohui Zhang; Wenyi Guo; Jianwei Jiao

    2012-01-01

    Dear Editor,The direct conversion of mouse fibroblasts to neurons [1] was developed while many scientists were interested in neuronal differentiation using induced pluripotent stem cells (iPSCs) [2].This direct reprogramming skips a pluripotent state,making patient- and/or disease-specific cell therapy much faster and more feasible.Recent reports have indicated that mouse or human fibroblasts could be directly converted to a number of different cell types,such as cardiomyocytes,blood progenitor cells,hepatocyte-like cells,neural progenitors and specific dopaminergic neurons [3-9].However,all of the studies in this field have employed the retroviral or lentiviral vector delivery system.

  17. Exploration of horizontal gene transfer between transplastomic tobacco and plant-associated bacteria.

    Demanèche, Sandrine; Monier, Jean-Michel; Dugat-Bony, Eric; Simonet, Pascal

    2011-10-01

    The likelihood of gene transfer from transgenic plants to bacteria is dependent on the transgene copy number and on the presence of homologous sequences for recombination. The large number of chloroplast genomes in a plant cell as well as the prokaryotic origin of the transgene may thus significantly increase the likelihood of gene transfer from transplastomic plants to bacteria. In order to assess the probability of such a transfer, bacterial isolates, screened for their ability to colonize decaying tobacco plant tissue and possessing DNA sequence similarity to the chloroplastic genes accD and rbcL flanking the transgene (aadA), were tested for their ability to take up extracellular DNA (broad host-range pBBR1MCS-3-derived plasmid, transplastomic plant DNA and PCR products containing the genes accD-aadA-rbcL) by natural or electrotransformation. The results showed that among the 16 bacterial isolates tested, six were able to accept foreign DNA and acquire the spectinomycin resistance conferred by the aadA gene on plasmid, but none of them managed to integrate transgenic DNA in their chromosome. Our results provide no indication that the theoretical gene transfer-enhancing properties of transplastomic plants cause horizontal gene transfer at rates above those found in other studies with nuclear transgenes. PMID:21564143

  18. Field Supervisory Test of DREB-Transgenic Populus: Salt Tolerance, Long-Term Gene Stability and Horizontal Gene Transfer

    Nan Lu

    2014-05-01

    Full Text Available Improving saline resistance may be useful for reducing environmental susceptibility and improving yields in poplar plantations. However, the instability of genetically engineered traits and gene transfer reduce their usefulness and commercial value. To investigate whether the foreign gene is still present in the genome of receptor plants after seven years (i.e., long-term foreign gene stability and gene transfer, we randomly analyzed ten field-grown transgenic hybrid Populus ((Populus tomentosa × Populus bolleana × P. tomentosa carrying the DREB1 gene from Atriplex hortensis. The results of PCR and tissue culture experiments showed that AhDREB1 was present in the transgenic trees and was still expressed. However, the transcriptional expression level had decreased compared with that four years earlier. The PCR results also indicated no foreign gene in the genomic DNA of microorganisms in the soil near the transgenic poplars, indicating that no significant gene transfer had occurred from the transgenic poplars to the microorganisms at seven years after planting.

  19. ENHANCED ANTITUMOR EFFECTS OF SUICIDE GENE THERAPY BY SIMULTANEOUS TRANSFER OF GMCSF GENE IN LEUKEMIA-BEARING MICE

    Ju Dianwen; Cao Xuetao; Yu Yizhi; Tao Qun; Wang Baomei; Wan Tao

    1998-01-01

    In the present report, antitumor effect of combined transfer of suicide gene and cytokine gene was studied.Adenovirus engineered to express E. Coli. Cytosine deaminase (AdCD) and/or adenovirus engineered toexpress murine granulocyte-macrophage colonystimulating factor (AdGMCSF) were used for the treatment of leukemia-bearing mice. The mice were inoculated s.c. With FBL-3 erythroleukemia cells and 3days later received intratumoral injection of AdCD in the presence or absence of AdGMCSF followed by intraperitoneal 5-fluorocytosine (5FC) treatment. The results demonstrated that mice received combined therapy of AdCD/5FC and AdGMCSF developed tumors most slowly and survived much longer when compared with mice treated with AdCD/5FC alone, AdGMCSF alone, AdlacZ/5FC or PBS. Combined transfer of CD gene and GM-CSF gene achieved higher specific CTL activity than control therapies. Pathological examination illustrated that the tumor mass showed obvious necrosis and inflammatory cell infiltration in mice after combined therapy. The results demonstrated that combined transfer of suicide gene and cytokine gene could synergistically inhibit the growth of leukemia in mice and induce antitumor immunity of the host. The combination therapy might be a potential approach for cancer gene therapy.

  20. Lentiviral vector-mediated gene transfer and RNA silencing technology in neuronal dysfunctions.

    Dreyer, Jean-Luc

    2011-02-01

    Lentiviral-mediated gene transfer in vivo or in cultured mammalian neurons can be used to address a wide variety of biological questions, to design animals models for specific neurodegenerative pathologies, or to test potential therapeutic approaches in a variety of brain disorders. Lentiviruses can infect non-dividing cells, thereby allowing stable gene transfer in post-mitotic cells such as mature neurons. An important contribution has been the use of inducible vectors: the same animal can thus be used repeatedly in the doxycycline-on or -off state, providing a powerful mean for assessing the function of a gene candidate in a disorder within a specific neuronal circuit. Furthermore, lentivirus vectors provide a unique tool to integrate siRNA expression constructs with the aim to locally knockdown expression of a specific gene, enabling to assess the function of a gene in a very specific neuronal pathway. Lentiviral vector-mediated delivery of short hairpin RNA results in persistent knockdown of gene expression in the brain. Therefore, the use of lentiviruses for stable expression of siRNA in brain is a powerful aid to probe gene functions in vivo and for gene therapy of diseases of the central nervous system. In this chapter I review the applications of lentivirus-mediated gene transfer in the investigation of specific gene candidates involved in major brain disorders and neurodegenerative processes. Major applications have been in polyglutamine disorders, such as synucleinopathies and Parkinson's disease, or in investigating gene function in Huntington's disease, dystonia, or muscular dystrophy. Recently, lentivirus gene transfer has been an invaluable tool for evaluation of gene function in behavioral disorders such as drug addiction and attention-deficit hyperactivity disorder or in learning and cognition. PMID:20862616

  1. Expression of transferred thymidine kinase genes is controlled by methylation.

    Christy, B.; Scangos, G

    1982-01-01

    Plasmid pTKx-1, containing the herpes simplex virus gene for thymidine kinase (TK) inserted into the BamHI site of plasmid pBR322, was introduced into Ltk- cells by calcium phosphate precipitation in the absence of carrier DNA. Line 101 is a TK+ derivative of Ltk- that contains multiple copies of pTKx-1 in a multimeric structure. A derivative of 101 that retained but no longer expressed the herpes simplex TK genes (termed 101BU1) and derivatives of line 101BU1 that reexpressed the genes (term...

  2. The experimental study of reporter probe 131I-FIAU in neonatal cardiac myocytes after transfer of herpes simplex virus type 1 thymidine kinase reporter gene by different vectors

    Objective: Reporter gene imaging is a promising approach for noninvasive monitoring of cardiac gene therapy. In the present study, the recombinant plasmid and adenoviral vector carrying reporter gene. herpes simplex virus type 1 thymidine kinase (HSV1-tk), were constructed and transferred into nee-natal cardiac myocytes, and a series of in vitro studies were carried out on the cells transferred to evaluate the uptake of radiolabeled reporter probe and to compare both vectors for cardiac reporter gene imaging. Methods: Neonatal cardiac myocytes were obtained from rat heart by single collagenase digestion. HSVI-tk. chosen as the reporter gene.was inserted into adenovirus vector (Ad5-tk) and plasmid (pDC316-tk), thus it could be transferred into neonatal cardiac myocytes. Recombinant adenovirus containing enhanced green fluorescent protein (Ad5-EGFP) was used as control. Recombinant plasmid was coated with lipofectamine TM 2000 (pDC316-tk/lipoplex). The specific reporter probe of HSV1-tk, 2'-fluoro-2'-deoxy-l-β-D-arabinofuranosyl-uracil (FAU), was labeled with 131I by solid phase oxidation with lodogen. Product wag purified on a reverse. phase Sep-Pak C18 column and the radiochemical purity wag then assessed. The accumulation of it in the transferred cardiac myocytes wag detected as uptake rate. Furthermore, mRNA expression of HSV1-tk was detected by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR), while its protein expression wag located by immunocytochemistry. Results: FAU could be labeled with 131I and the labeling efficiency was (53.82 ±2.05)%. The radiochemical purity was (94.85 ± 1.76)% after purification, and it kept stable in vitro for at least 24h. Time-dependent increase of the ac- cumulation of 131I-FIAU was observed in both Ad5-tk group and pDC316-tk/lipoplex group. and the highest uptake rate occurred at 5h, with peak values of (12.55 ± 0.37)% and (2.09 ± 0.34)% respectively. However, it also indicated that greater

  3. Evolutionary transfer of the chloroplast tufA gene to the nucleus.

    Baldauf, S L; Palmer, J D

    1990-03-15

    Evolutionary gene transfer is a basic corollary of the now widely accepted endosymbiotic theory, which proposes that mitochondria and chloroplasts originated from once free-living eubacteria. The small organellar chromosomes are remnants of larger bacterial genomes, with most endosymbiont genes having been either transferred to the nucleus soon after endosymbiosis or lost entirely, with some being functionally replaced by pre-existing nuclear genes. Several lines of evidence indicate that relocation of some organelle genes could have been more recent. These include the abundance of non-functional organelle sequences of recent origin in nuclear DNA, successful artificial transfer of functional organelle genes to the nucleus, and several examples of recently lost organelle genes, although none of these is known to have been replaced by a nuclear homologue that is clearly of organellar ancestry. We present gene sequence and molecular phylogenetic evidence for the transfer of the chloroplast tufA gene to the nucleus in the green algal ancestor of land plants. PMID:2314461

  4. Apical Gene Transfer into Quiescent Human and Canine Polarized Intestinal Epithelial Cells by Lentivirus Vectors

    Seppen, Jurgen; Barry, Simon C.; Klinkspoor, J. Henriette; Katen, Louis J.; Lee, Sum P; Garcia, J. Victor; Osborne, William R. A.

    2000-01-01

    Intestinal epithelial cells secrete a protective luminal mucus barrier inhibiting viral gene transfer. Quiescent, polarized monolayers of primary epithelial cells from dog gallbladder and human colon are efficiently transduced through the apical mucus side by lentivirus vectors, suggesting their application to intestinal gene therapy.

  5. The interconnection between biofilm formation and horizontal gene transfer

    Madsen, Jonas Stenløkke; Burmølle, Mette; Hansen, Lars H.;

    2012-01-01

    . Biofilms, furthermore, promote plasmid stability and may enhance the host range of mobile genetic elements that are transferred horizontally. Plasmids, on the other hand, are very well suited to promote the evolution of social traits such as biofilm formation. This, essentially, transpires because plasmids...... believed importance in the understanding of the adaptation and subsequent evolution of social traits in bacteria. Here, we discuss current evidence for such interconnectedness centred on plasmids. Horizontal transfer rates are typically higher in biofilm communities compared with those in planktonic states...

  6. Efficient retrovirus-mediated transfer of cell-cycle control genes to transformed cells

    B.E. Strauss

    1999-07-01

    Full Text Available The use of gene therapy continues to be a promising, yet elusive, alternative for the treatment of cancer. The origins of cancer must be well understood so that the therapeutic gene can be chosen with the highest chance of successful tumor regression. The gene delivery system must be tailored for optimum transfer of the therapeutic gene to the target tissue. In order to accomplish this, we study models of G1 cell-cycle control in both normal and transformed cells in order to understand the reasons for uncontrolled cellular proliferation. We then use this information to choose the gene to be delivered to the cells. We have chosen to study p16, p21, p53 and pRb gene transfer using the pCL-retrovirus. Described here are some general concepts and specific results of our work that indicate continued hope for the development of genetically based cancer treatments.

  7. Horizontal Gene Transfers from Bacteria to Entamoeba Complex: A Strategy for Dating Events along Species Divergence.

    Romero, Miguel; Cerritos, R; Ximenez, Cecilia

    2016-01-01

    Horizontal gene transfer has proved to be relevant in eukaryotic evolution, as it has been found more often than expected and related to adaptation to certain niches. A relatively large list of laterally transferred genes has been proposed and evaluated for the parasite Entamoeba histolytica. The goals of this work were to elucidate the importance of lateral gene transfer along the evolutionary history of some members of the genus Entamoeba, through identifying donor groups and estimating the divergence time of some of these events. In order to estimate the divergence time of some of the horizontal gene transfer events, the dating of some Entamoeba species was necessary, following an indirect dating strategy based on the fossil record of plausible hosts. The divergence between E. histolytica and E. nuttallii probably occurred 5.93 million years ago (Mya); this lineage diverged from E. dispar 9.97 Mya, while the ancestor of the latter separated from E. invadens 68.18 Mya. We estimated times for 22 transferences; the most recent occurred 31.45 Mya and the oldest 253.59 Mya. Indeed, the acquisition of genes through lateral transfer may have triggered a period of adaptive radiation, thus playing a major role in the evolution of the Entamoeba genus. PMID:27239333

  8. Direct gene transfer with DNA-liposome complexes in melanoma: expression, biologic activity, and lack of toxicity in humans.

    Nabel, G J; Nabel, E. G.; Z.Y. Yang; Fox, B A; Plautz, G E; Gao, X.; Huang, L.; Shu, S.; Gordon, D.; Chang, A.E. (Alfred E.)

    1993-01-01

    Direct gene transfer offers the potential to introduce DNA encoding therapeutic proteins to treat human disease. Previously, gene transfer in humans has been achieved by a cell-mediated ex vivo approach in which cells from the blood or tissue of patients are genetically modified in the laboratory and subsequently returned to the patient. To determine the feasibility and safety of directly transferring genes into humans, a clinical study was performed. The gene encoding a foreign major histoco...

  9. Gene loss and horizontal gene transfer contributed to the genome evolution of the extreme acidophile Ferrovum

    Sophie Roxana Ullrich

    2016-05-01

    Full Text Available Acid mine drainage (AMD, associated with active and abandoned mining sites, is a habitat for acidophilic microorganisms that gain energy from the oxidation of reduced sulfur compounds and ferrous iron and that thrive at pH below 4. Members of the recently proposed genus Ferrovum are the first acidophilic iron oxidizers to be described within the Betaproteobacteria. Although they have been detected as typical community members in AMD habitats worldwide, knowledge of their phylogenetic and metabolic diversity is scarce. Genomics approaches appear to be most promising in addressing this lacuna since isolation and cultivation of Ferrovum has proven to be extremely difficult and has so far only been successful for the designated type strain Ferrovum myxofaciens P3G. In this study, the genomes of two novel strains of Ferrovum (PN-J185 and Z-31 derived from water samples of a mine water treatment plant were sequenced. These genomes were compared with those of Ferrovum sp. JA12 that also originated from the mine water treatment plant, and of the type strain (P3G. Phylogenomic scrutiny suggests that the four strains represent three Ferrovum species that cluster in two groups (1 and 2. Comprehensive analysis of their predicted metabolic pathways revealed that these groups harbor characteristic metabolic profiles, notably with respect to motility, chemotaxis, nitrogen metabolism, biofilm formation and their potential strategies to cope with the acidic environment. For example, while the F. myxofaciens strains (group 1 appear to be motile and diazotrophic, the non-motile group 2 strains have the predicted potential to use a greater variety of fixed nitrogen sources. Furthermore, analysis of their genome synteny provides first insights into their genome evolution, suggesting that horizontal gene transfer and genome reduction in the group 2 strains by loss of genes encoding complete metabolic pathways or physiological features contributed to the observed

  10. Kinetics of conjugative gene transfer on surfaces in granular porous media

    Massoudieh, A.; Crain, C.; Lambertini, E.; Nelson, K. E.; Barkouki, T.; L'Amoreaux, P.; Loge, F. J.; Ginn, T. R.

    2010-03-01

    The transfer of genetic material among bacteria in the environment can occur both in the planktonic and attached state. Given the propensity of organisms to exist in sessile microbial communities in oligotrophic subsurface conditions, and that such conditions typify the subsurface, this study focuses on exploratory modeling of horizontal gene transfer among surface-associated Escherichiacoli in the subsurface. The mathematics so far used to describe the kinetics of conjugation in biofilms are developed largely from experimental observations of planktonic gene transfer, and are absent of lags or plasmid stability that appear experimentally. We develop a model and experimental system to quantify bacterial filtration and gene transfer in the attached state, on granular porous media. We include attachment kinetics described in Nelson et al. (2007) using the filtration theory approach of Nelson and Ginn (2001, 2005) with motility of E. coli described according to Biondi et al. (1998).

  11. Horizontal gene transfer facilitated the evolution of plant parasitic mechanisms in the oomycetes

    Richards, Thomas A; Soanes, Darren M.; Jones, Meredith D.M.; Vasieva, Olga; Leonard, Guy; Paszkiewicz, Konrad; Foster, Peter G.; Hall, Neil; Talbot, Nicholas J.

    2011-01-01

    Horizontal gene transfer (HGT) can radically alter the genomes of microorganisms, providing the capacity to adapt to new lifestyles, environments, and hosts. However, the extent of HGT between eukaryotes is unclear. Using whole-genome, gene-by-gene phylogenetic analysis we demonstrate an extensive pattern of cross-kingdom HGT between fungi and oomycetes. Comparative genomics, including the de novo genome sequence of Hyphochytrium catenoides, a free-living sister of the oomycetes, shows that t...

  12. Synthetic gene transfer vectors II: back to the future.

    Behr, Jean-Paul

    2012-07-17

    The discovery of RNA interference has given a new lease on life to both the chemistry of oligonucleotides and chemical approaches for the intracellular delivery of nucleic acids. In particular, delivery of siRNA, whether in vitro for screening and target validation purposes or in humans as a new class of drugs, may revolutionize our approach to therapy. Their impact could equal that of the bioproduction and various uses of monoclonal antibodies today. Unfortunately, global pharmaceutical companies again seem to be waiting to buy the next Genentech or Genzyme of gene silencing rather than investing research and development into this promising area of research. Gene silencing encounters barriers similar to gene addition and hence may benefit from the extra decade of experience brought by gene therapy. "Chemical" transfection of cells in culture has become routine, and this Account discusses some of the reasons this success has not extended to nonviral gene therapy trials, most of which do not progress beyond the phase 2 stage. The author also discusses a (much debated) mechanism of nucleic acid cell entry and subsequent release of the polycationic particles into the cytoplasm. Both topics should be useful to those interested in delivery of siRNA. The move from gene therapy toward siRNA as an oligonucleotide-based therapy strategy provides a much wider range of druggable targets. Even though these molecules are a hundredfold smaller than a gene, they are delivered via similar cellular mechanisms. Their complexes with cationic polymers are less stable than those with a higher number of phosphate groups, which may be compensated by siRNA concatemerization or by chemical conjugation with the cationic carrier. Thus chemistry is again desperately needed. PMID:22311735

  13. Cellular automata-based artificial life system of horizontal gene transfer

    Ji-xin Liu

    2016-02-01

    Full Text Available Mutation and natural selection is the core of Darwin's idea about evolution. Many algorithms and models are based on this idea. However, in the evolution of prokaryotes, more and more researches have indicated that horizontal gene transfer (HGT would be much more important and universal than the authors had imagined. Owing to this mechanism, the prokaryotes not only become adaptable in nearly any environment on Earth, but also form a global genetic bank and a super communication network with all the genes of the prokaryotic world. Under this background, they present a novel cellular automata model general gene transfer to simulate and study the vertical gene transfer and HGT in the prokaryotes. At the same time, they use Schrodinger's life theory to formulate some evaluation indices and to discuss the intelligence and cognition of prokaryotes which is derived from HGT.

  14. The Agricultural Antibiotic Carbadox Induces Phage-mediated Gene Transfer in Salmonella

    Bradley L. Bearson

    2014-02-01

    Full Text Available Antibiotics are used for disease therapeutic or preventative effects in humans and animals, as well as for enhanced feed conversion efficiency in livestock. Antibiotics can also cause undesirable effects in microbial populations, including selection for antibiotic resistance, enhanced pathogen invasion, and stimulation of horizontal gene transfer. Carbadox is a veterinary antibiotic used in the U.S. during the starter phase of swine production for improved feed efficiency and control of swine dysentery and bacterial swine enteritis. Carbadox has been shown in vitro to induce phage-encoded Shiga toxin in Shiga toxin-producing Escherichia coli and a phage-like element transferring antibiotic resistance genes in Brachyspira hyodysenteriae, but the effect of carbadox on prophages in other bacteria is unknown. This study examined carbadox exposure on prophage induction and genetic transfer in Salmonella enterica serovar Typhimurium, a human foodborne pathogen that frequently colonizes swine without causing disease. S. Typhimurium LT2 exposed to carbadox induced prophage production, resulting in bacterial cell lysis and release of virions that were visible by electron microscopy. Carbadox induction of phage-mediated gene transfer was confirmed by monitoring the transduction of a sodCIII::neo cassette in the Fels-1 prophage from LT2 to a recipient Salmonella strain. Furthermore, carbadox frequently induced generalized transducing phages in multidrug-resistant phage type DT104 and DT120 isolates, resulting in the transfer of chromosomal and plasmid DNA that included antibiotic resistance genes. Our research indicates that exposure of Salmonella to carbadox induces prophages that can transfer virulence and antibiotic resistance genes to susceptible bacterial hosts. Carbadox-induced, phage-mediated gene transfer could serve as a contributing factor in bacterial evolution during animal production, with prophages being a reservoir for bacterial fitness

  15. Number and size of human X chromosome fragments transferred to mouse cells by chromosome-mediated gene transfer.

    Olsen, A S; McBride, O W; Moore, D. E.

    1981-01-01

    Labeled probes of unique-sequence human X chromosomal deoxyribonucleic acid, prepared by two different procedures, were used to measure the amount of human X chromosomal deoxyribonucleic acid in 12 mouse cell lines expressing human hypoxanthine phosphoribosyltransferase after chromosome-mediated gene transfer. The amount of X chromosomal deoxyribonucleic acid detected by this procedure ranged from undetectable levels in the three stable transformants and some unstable transformants examined t...

  16. Prokaryotic genes in eukaryotic genome sequences: when to infer horizontal gene transfer and when to suspect an actual microbe.

    Artamonova, Irena I; Lappi, Tanya; Zudina, Liudmila; Mushegian, Arcady R

    2015-07-01

    Assessment of phylogenetic positions of predicted gene and protein sequences is a routine step in any genome project, useful for validating the species' taxonomic position and for evaluating hypotheses about genome evolution and function. Several recent eukaryotic genome projects have reported multiple gene sequences that were much more similar to homologues in bacteria than to any eukaryotic sequence. In the spirit of the times, horizontal gene transfer from bacteria to eukaryotes has been invoked in some of these cases. Here, we show, using comparative sequence analysis, that some of those bacteria-like genes indeed appear likely to have been horizontally transferred from bacteria to eukaryotes. In other cases, however, the evidence strongly indicates that the eukaryotic DNA sequenced in the genome project contains a sample of non-integrated DNA from the actual bacteria, possibly providing a window into the host microbiome. Recent literature suggests also that common reagents, kits and laboratory equipment may be systematically contaminated with bacterial DNA, which appears to be sampled by metagenome projects non-specifically. We review several bioinformatic criteria that help to distinguish putative horizontal gene transfers from the admixture of genes from autonomously replicating bacteria in their hosts' genome databases or from the reagent contamination. PMID:25919787

  17. Two Horizontally Transferred Xenobiotic Resistance Gene Clusters Associated with Detoxification of Benzoxazolinones by Fusarium Species.

    Anthony E Glenn

    Full Text Available Microbes encounter a broad spectrum of antimicrobial compounds in their environments and often possess metabolic strategies to detoxify such xenobiotics. We have previously shown that Fusarium verticillioides, a fungal pathogen of maize known for its production of fumonisin mycotoxins, possesses two unlinked loci, FDB1 and FDB2, necessary for detoxification of antimicrobial compounds produced by maize, including the γ-lactam 2-benzoxazolinone (BOA. In support of these earlier studies, microarray analysis of F. verticillioides exposed to BOA identified the induction of multiple genes at FDB1 and FDB2, indicating the loci consist of gene clusters. One of the FDB1 cluster genes encoded a protein having domain homology to the metallo-β-lactamase (MBL superfamily. Deletion of this gene (MBL1 rendered F. verticillioides incapable of metabolizing BOA and thus unable to grow on BOA-amended media. Deletion of other FDB1 cluster genes, in particular AMD1 and DLH1, did not affect BOA degradation. Phylogenetic analyses and topology testing of the FDB1 and FDB2 cluster genes suggested two horizontal transfer events among fungi, one being transfer of FDB1 from Fusarium to Colletotrichum, and the second being transfer of the FDB2 cluster from Fusarium to Aspergillus. Together, the results suggest that plant-derived xenobiotics have exerted evolutionary pressure on these fungi, leading to horizontal transfer of genes that enhance fitness or virulence.

  18. Two Horizontally Transferred Xenobiotic Resistance Gene Clusters Associated with Detoxification of Benzoxazolinones by Fusarium Species.

    Glenn, Anthony E; Davis, C Britton; Gao, Minglu; Gold, Scott E; Mitchell, Trevor R; Proctor, Robert H; Stewart, Jane E; Snook, Maurice E

    2016-01-01

    Microbes encounter a broad spectrum of antimicrobial compounds in their environments and often possess metabolic strategies to detoxify such xenobiotics. We have previously shown that Fusarium verticillioides, a fungal pathogen of maize known for its production of fumonisin mycotoxins, possesses two unlinked loci, FDB1 and FDB2, necessary for detoxification of antimicrobial compounds produced by maize, including the γ-lactam 2-benzoxazolinone (BOA). In support of these earlier studies, microarray analysis of F. verticillioides exposed to BOA identified the induction of multiple genes at FDB1 and FDB2, indicating the loci consist of gene clusters. One of the FDB1 cluster genes encoded a protein having domain homology to the metallo-β-lactamase (MBL) superfamily. Deletion of this gene (MBL1) rendered F. verticillioides incapable of metabolizing BOA and thus unable to grow on BOA-amended media. Deletion of other FDB1 cluster genes, in particular AMD1 and DLH1, did not affect BOA degradation. Phylogenetic analyses and topology testing of the FDB1 and FDB2 cluster genes suggested two horizontal transfer events among fungi, one being transfer of FDB1 from Fusarium to Colletotrichum, and the second being transfer of the FDB2 cluster from Fusarium to Aspergillus. Together, the results suggest that plant-derived xenobiotics have exerted evolutionary pressure on these fungi, leading to horizontal transfer of genes that enhance fitness or virulence. PMID:26808652

  19. CD133-targeted gene transfer into long-term repopulating hematopoietic stem cells.

    Brendel, Christian; Goebel, Benjamin; Daniela, Abriss; Brugman, Martijn; Kneissl, Sabrina; Schwäble, Joachim; Kaufmann, Kerstin B; Müller-Kuller, Uta; Kunkel, Hana; Chen-Wichmann, Linping; Abel, Tobias; Serve, Hubert; Bystrykh, Leonid; Buchholz, Christian J; Grez, Manuel

    2015-01-01

    Gene therapy for hematological disorders relies on the genetic modification of CD34(+) cells, a heterogeneous cell population containing about 0.01% long-term repopulating cells. Here, we show that the lentiviral vector CD133-LV, which uses a surface marker on human primitive hematopoietic stem cells (HSCs) as entry receptor, transfers genes preferentially into cells with high engraftment capability. Transduction of unstimulated CD34(+) cells with CD133-LV resulted in gene marking of cells with competitive proliferative advantage in vitro and in immunodeficient mice. The CD133-LV-transduced population contained significantly more cells with repopulating capacity than cells transduced with vesicular stomatitis virus (VSV)-LV, a lentiviral vector pseudotyped with the vesicular stomatitis virus G protein. Upon transfer of a barcode library, CD133-LV-transduced cells sustained gene marking in vivo for a prolonged period of time with a 6.7-fold higher recovery of barcodes compared to transduced control cells. Moreover, CD133-LV-transduced cells were capable of repopulating secondary recipients. Lastly, we show that this targeting strategy can be used for transfer of a therapeutic gene into CD34(+) cells obtained from patients suffering of X-linked chronic granulomatous disease. In conclusion, direct gene transfer into CD133(+) cells allows for sustained long-term engraftment of gene corrected cells. PMID:25189742

  20. Ex ovo electroporation for gene transfer into older chicken embryos.

    Luo, Jiankai; Redies, Christoph

    2005-08-01

    In ovo electroporation is an excellent method to ectopically induce or inhibit gene expression in chicken embryos and to study the in vivo function of genes during embryonic development. However, the application of electroporation in ovo to date is limited to an early stage of incubation ( stage 22), the vitelline and allantoic vessels have developed extensively and the in ovo manipulation of the embryo becomes exceedingly difficult. Therefore, in this study, we validate an ex ovo electroporation system, by which the time for performing electroporation can be extended up to at least day 7 of incubation. The application of this method will help to study gene function and regulation at later stages of development in the living chicken embryo. PMID:15965981

  1. Smelt was the likely beneficiary of an antifreeze gene laterally transferred between fishes

    Graham Laurie A

    2012-09-01

    Full Text Available Abstract Background Type II antifreeze protein (AFP from the rainbow smelt, Osmerus mordax, is a calcium-dependent C-type lectin homolog, similar to the AFPs from herring and sea raven. While C-type lectins are ubiquitous, type II AFPs are only found in a few species in three widely separated branches of teleost fishes. Furthermore, several other non-homologous AFPs are found in intervening species. We have previously postulated that this sporadic distribution has resulted from lateral gene transfer. The alternative hypothesis, that the AFP evolved from a lectin present in a shared ancestor and that this gene was lost in most species, is not favored because both the exon and intron sequences are highly conserved. Results Here we have sequenced and annotated a 160 kb smelt BAC clone containing a centrally-located AFP gene along with 14 other genes. Quantitative PCR indicates that there is but a single copy of this gene within the smelt genome, which is atypical for fish AFP genes. The corresponding syntenic region has been identified and searched in a number of other species and found to be devoid of lectin or AFP sequences. Unlike the introns of the AFP gene, the intronic sequences of the flanking genes are not conserved between species. As well, the rate and pattern of mutation in the AFP gene are radically different from those seen in other smelt and herring genes. Conclusions These results provide stand-alone support for an example of lateral gene transfer between vertebrate species. They should further inform the debate about genetically modified organisms by showing that gene transfer between ‘higher’ eukaryotes can occur naturally. Analysis of the syntenic regions from several fishes strongly suggests that the smelt acquired the AFP gene from the herring.

  2. Gene transfer-applied cancer boron neutron capture therapy

    Mishima, Yutaka [ed.] [Mishima Institute for Dermatological Research, Kobe (Japan)

    1999-02-01

    On the basis of research progress made in basic investigations to clinical treatment in melanoma BNCT, we have advanced the present project through the application of the latest in melanogenesis research as well as cancer gene therapy. The multiple findings obtained during the fiscal years of 1997 and 1998 and contained in this current volume. (J.P.N.)

  3. Gene transfer-applied cancer boron neutron capture therapy

    On the basis of research progress made in basic investigations to clinical treatment in melanoma BNCT, we have advanced the present project through the application of the latest in melanogenesis research as well as cancer gene therapy. The multiple findings obtained during the fiscal years of 1997 and 1998 and contained in this current volume. (J.P.N.)

  4. Follistatin allows efficient retroviral-mediated gene transfer into rat liver

    Retroviral vectors are widely used tools for gene therapy. However, in vivo gene transfer is only effective in dividing cells, which, in liver, requires a regenerative stimulus. Follistatin is effective in promoting liver regeneration after 90% and 70% hepatectomy in rats. We studied its efficacy on liver regeneration and retroviral-mediated gene delivery in 50% hepatectomized rats. When human recombinant follistatin was infused into the portal vein immediately after 50% hepatectomy, hepatocyte proliferation was significantly higher than in control 50% hepatectomized rats. A single injection of virus particles administered 23 h after follistatin infusion resulted in more than 20% gene transduction efficiency in hepatocytes compared to 3% in control rats. It is concluded that a single injection of follistatin induces onset of proliferation in 50% hepatectomized rats and allows efficient retroviral-mediated gene transfer to the liver

  5. Mucus altering agents as adjuncts for nonviral gene transfer to airway epithelium.

    Ferrari, S; Kitson, C; Farley, R; Steel, R; Marriott, C; Parkins, D A; Scarpa, M; Wainwright, B; Evans, M J; Colledge, W H; Geddes, D M; Alton, E W

    2001-09-01

    Nonviral vectors have been shown to be a safe and valid alternative to recombinant viruses for gene therapy of cystic fibrosis (CF). Nevertheless, gene transfer efficiency needs to be increased before clinical efficacy is likely in man. One barrier to increased efficacy is normal airway mucus. Using an ex vivo model of sheep tracheal epithelium, we show that this barrier can, in part, be overcome by treatment with the mucolytic agents, Nacystelyn or N-acetylcysteine using either a cationic lipid or a cationic polymer as the gene transfer agent. Further, in vivo application of either Nacystelyn or the anticholinergic glycopyrrolate, both clinically used agents, resulted in increased reporter gene expression in the mouse lung, but no significant correction of the bioelectric defect in CF null mice. These results, whilst unlikely to be sufficient in themselves to achieve clinically relevant gene therapy, may be a further useful step in the attainment of this goal. PMID:11571577

  6. Induction of a Protective Heterosubtypic Immune Response Against the Influenza Virus by using Recombinant Adenoviral Vectors Expressing Hemagglutinin of the Influenza H5 Virus.

    Shmarov, M M; Sedova, E S; Verkhovskaya, L V; Rudneva, I A; Bogacheva, E A; Barykova, Yu A; Shcherbinin, D N; Lysenko, A A; Tutykhina, I L; Logunov, D Y; Smirnov, Yu A; Naroditsky, B S; Gintsburg, A L

    2010-04-01

    Influenza viruses are characterized by a high degree of antigenic variability, which causes the annual emergence of flu epidemics and irregularly timed pandemics caused by viruses with new antigenic and biological traits. Novel approaches to vaccination can help circumvent this problem. One of these new methods incorporates genetic vaccines based on adenoviral vectors. Recombinant adenoviral vectors which contain hemagglutinin-encoding genes from avian H5N1 and H5N2 (Ad-HA5-1 and Ad-HA5-2) influenza viruses were obtained using the AdEasy Adenoviral Vector System (Stratagene). Laboratory mice received a double intranasal vaccination with Ad-HA5-1 and Ad-HA5-2. This study demonstrates that immunization with recombinant adenoviruses bearing the Н 5 influenza virus hemagglutinin gene induces a immune response which protects immunized mice from a lethal dose of the H5 influenza virus. Moreover, it also protects the host from a lethal dose of the H1 virus, which belongs to the same clade as H5, but does not confer protection from the subtype H3 influenza virus, which belongs to a different clade. PMID:22649637

  7. GFP as a marker for transient gene transfer and expression in Mycoplasma hyorhinis.

    Ishag, Hassan Z A; Liu, Maojun; Yang, Ruosong; Xiong, Qiyan; Feng, Zhixin; Shao, Guoqing

    2016-01-01

    Mycoplasma hyorhinis (M. hyorhinis) is an opportunistic pathogen of pigs and has been shown to transform cell cultures, which has increased the interest of researchers. The green florescence proteins (GFP) gene of Aquorea victoria, proved to be a vital marker to identify transformed cells in mixed populations. Use of GFP to observe gene transfer and expression in M. hyorhinis (strain HUB-1) has not been described. We have constructed a pMD18-O/MHRgfp plasmid containing the p97 gene promoter, origin of replication, tetracycline resistance marker and GFP gene controlled by the p97 gene promoter. The plasmid transformed into M. hyorhinis with a frequency of ~4 × 10(-3) cfu/µg plasmid DNA and could be detected by PCR amplification of the GFP gene from the total DNA of the transformant mycoplasmas. Analysis of a single clone grown on KM2-Agar containing tetracycline, showed a green fluorescence color. Conclusively, this report suggests the usefulness of GFP to monitor transient gene transfer and expression in M. hyorhinis, eventually minimizing screening procedures for gene transfer and expression. PMID:27386255

  8. Exploration of new perspectives and limitations in Agrobacterium mediated gene transfer technology. Progress report, [June 1, 1992-- May 31, 1994

    Marton, L.

    1994-12-31

    This report describes progress aimed at constructing gene-transfer technology for Nicotiana plumbaginifolia. Most actual effort as described herein has so far been directed at exploring new perspectives and limitations in Agrobacterium mediated gene transfer. Accomplishments are described using a core homologous gene targeting vector.

  9. Ancient horizontal gene transfer from bacteria enhances biosynthetic capabilities of fungi.

    Imke Schmitt

    Full Text Available BACKGROUND: Polyketides are natural products with a wide range of biological functions and pharmaceutical applications. Discovery and utilization of polyketides can be facilitated by understanding the evolutionary processes that gave rise to the biosynthetic machinery and the natural product potential of extant organisms. Gene duplication and subfunctionalization, as well as horizontal gene transfer are proposed mechanisms in the evolution of biosynthetic gene clusters. To explain the amount of homology in some polyketide synthases in unrelated organisms such as bacteria and fungi, interkingdom horizontal gene transfer has been evoked as the most likely evolutionary scenario. However, the origin of the genes and the direction of the transfer remained elusive. METHODOLOGY/PRINCIPAL FINDINGS: We used comparative phylogenetics to infer the ancestor of a group of polyketide synthase genes involved in antibiotic and mycotoxin production. We aligned keto synthase domain sequences of all available fungal 6-methylsalicylic acid (6-MSA-type PKSs and their closest bacterial relatives. To assess the role of symbiotic fungi in the evolution of this gene we generated 24 6-MSA synthase sequence tags from lichen-forming fungi. Our results support an ancient horizontal gene transfer event from an actinobacterial source into ascomycete fungi, followed by gene duplication. CONCLUSIONS/SIGNIFICANCE: Given that actinobacteria are unrivaled producers of biologically active compounds, such as antibiotics, it appears particularly promising to study biosynthetic genes of actinobacterial origin in fungi. The large number of 6-MSA-type PKS sequences found in lichen-forming fungi leads us hypothesize that the evolution of typical lichen compounds, such as orsellinic acid derivatives, was facilitated by the gain of this bacterial polyketide synthase.

  10. HVJ-E-mediated gene transfer into the intestinal epithelium

    sprotocols

    2015-01-01

    This protocol describes a novel method that enables transfection of plasmids and siRNAs into the mouse intestinal epithelium. The mouse was anesthetized with isoflurane, and the small intestine was pulled out from the peritoneal cavity. The small intestinal lumen was then washed with buffer containing a reducing agent, dithiothreitol, to remove mucus, and injected with transfection solution. To achieve efficient gene delivery, we used a hemagglutinating virus of Japan envelope (HVJ-E)-based t...

  11. Organic farming and gene transfer from genetically modified crops

    Moyes, Catherine L.; Dale, Philip J.

    1999-01-01

    This is the final report of MAFF/Defra project OF0157. Genetically modified (GM) crops cannot be released into the environment and used as food, feed, medicines or industrial processing before they have passed through a rigorous and internationally recognised regulatory process designed to protect human and animal health, and the environment. The UK body that oversees standards in organic farming, the United Kingdom Register of Organic Food Standards (UKROFS), has ruled that gene...

  12. Modulation of lung development by In utero gene transfer

    Santos, Sílvia Gonzaga da Silva

    2009-01-01

    Tese de doutoramento em Ciências da Saúde (ramo de conhecimento em Ciências Biológicas e Biomédicas) Advances in prenatal diagnosis of genetic and congenital disorders with progressively more sensitive techniques may increase opportunities for consideration of prenatal gene therapy. There are a number of genetic and acquired disorders with peri or postnatal pulmonary manifestations. These include monogenetic diseases like cystic fibrosis or surfactant protein B deficiency that wou...

  13. Microbubble-Enhanced Ultrasound Gene Transfer into Fibroblast Cells

    Hirayama, Kota; Kaneko, Yukio; Tei, Yuichi; Matsumoto, Yoichiro

    2007-05-01

    Ultrasound finds many applications in the medical field, including ultrasound imaging, non-invasive treatment of tumors and lithotripsy. Ultrasound also has a potential to deliver some therapeutic materials, such as genes, drugs or proteins into cells. It is known that microbubbles can improve the delivery efficiency. It is believed that therapeutic materials can pass through the cell membrane whose permeability is increased by microbubble destruction or the ultrasound pressure. In this study, we investigated the delivery of GFP plasmid gene into the fibroblast cells. Ultrasound (frequency = 2.1 MHz, duty cycle = 10%) was used to irradiate the cultured cells through a medium that contains microbubbles and GFP plasmid. GFP plasmid transfection could be easily observed by fluorescence microscopy. Ultrasound irradiation under a variety of conditions resulted in successful GFP plasmid delivery. Microbubbles enhanced GFP transfection, and conclusions were drawn as to the relationship between gene transfection and various ultrasound exposure parameters. We also investigated the effect of ultrasound intensity on cell viability.

  14. A first glimpse into the pattern and scale of gene transfer in the Apicomplexa

    Huang, J.L.; Mullapudi, N.; Sicheritz-Pontén, Thomas; Kissinger, J.C.

    2004-01-01

    Reports of plant-like and bacterial-like genes for a number of parasitic organisms, most notably those within the Apicomplexa and Kinetoplastida, have appeared in the literature over the last few years. Among the apicomplexan organisms, following discovery of the apicomplexan plastid (apicoplast...... combined with a phylogenomic approach to detect potential gene transfers in four apicomplexan genomes. We have detected genes of algal nuclear, chloroplast (cyanobacterial) and proteobacterial origin. Plant-like genes were detected in species not currently harbouring a plastid (e.g. Cryptosporidium parvum...

  15. Potential transfer of extended spectrum β-lactamase encoding gene, blashv18 gene, between Klebsiella pneumoniae in raw foods.

    Jung, Yangjin; Matthews, Karl R

    2016-12-01

    This study investigated the transfer frequency of the extended-spectrum β-lactamase-encoding gene (blaSHV18) among Klebsiella pneumoniae in tryptic soy broth (TSB), pasteurized milk, unpasteurized milk, alfalfa sprouts and chopped lettuce at defined temperatures. All transconjugants were characterized phenotypically and genotypically. KP04(ΔKM) and KP08(ΔKM) isolated from seed sprouts and KP342 were used as recipients in mating experiments with K. pneumoniae ATCC 700603 serving as the donor. In mating experiments, no transconjugants were detected at 4 °C in liquid media or chopped lettuce, but detected in all media tested at 15 °C, 24 °C, and 37 °C. At 24 °C, the transfer of blaSHV18 gene occurred more frequently in alfalfa sprouts (5.15E-04 transconjugants per recipient) and chopped lettuce (3.85E-05) than liquid media (1.08E-05). On chopped lettuce, transconjugants were not detected at day 1 post-mating at 15 °C, but observed on day 2 (1.43E-05). Transconjugants carried the blaSHV18 gene transferred from the donor and the virulence gene harbored by recipient. More importantly, a class 1 integrase gene and resistance to tetracycline, trimethoprim/sulfamethoxazole were co-transferred during mating. These quantitative results suggest that fresh produce exposed to temperature abuse may serve as a competent vehicle for the spread of gene encoding for antibiotic resistance, having a potential negative impact on human health. PMID:27554144

  16. Herpes simplex virus-mediated human hypoxanthine-guanine phosphoribosyltransferase gene transfer into neuronal cells

    Palella, T.D.; Silverman, L.J.; Schroll, C.T.; Homa, F.L.; Levine, M.; Kelley, W.N.

    1988-01-01

    The virtually complete deficiency of the purine salvage enzyme hypoxanthine-guanine phosphoribosyltransferase (HPRT) results in a devastating neurological disease, Lesch-Nyhan syndrome. Transfer of the HPRT gene into fibroblasts and lymphoblasts in vitro and into hematopoietic cells in vivo has been accomplished by other groups with retroviral-derived vectors. It appears to be necessary, however, to transfer the HPRT gene into neuronal cells to correct the neurological dysfunction of this disorder. The neurotropic virus herpes simplex virus type 1 has features that make it suitable for use as a vector to transfer the HPRT gene into neuronal tissue. This report describes the isolation of an HPRT-deficient rat neuroma cell line, designated B103-4C, and the construction of a recombinant herpes simplex virus type 1 that contained human HPRT cDNA. These recombinant viruses were used to infect B103-4C cells. Infected cells expressed HPRT activity which was human in origin.

  17. RETROVIRAL MEDIATED EFFICIENT TRANSFER ANDEXPRESSION OF MULTIPLE DRUG RESISTANCE GENE TO HUMAN LEUKEMIC CELLS

    2000-01-01

    Objective: To investigate retroviral-mediated transfer and expression of human multidrug resistance (MDR) gene MDR1 in leukemic cells. Methods: Human myeloid cells, K562 and NB4, were infected by MDR retrovirus from the producer PA317/HaMDR, and the resistant cells were selected with cytotoxic drug. The transfer and expression of MDR1 gene was analyzed by using polymerase chain reaction (PCR), flow cytometry (FCM) and semisolid colonies cultivation. Results: The resistant cells, K562/MDR and NB4/MDR, in which integration of the exogenous MDR1 gene was confirmed by PCR analysis, displayed a typical MDR phenotype. The expression of MDR1 transgene was detected on truncated as well as full-length transcripts. Moreover, the resistant cells were P-glycoprotein postiive at 78.0% to 98.7% analyzed with FCM. The transduction efficieny in K562 cells was studied on suspension cultures and single-cell colonies. The transduction was more efficient in coculture system (67.9%~ 72.5%) than in supernatant system (33.1%~ 46.8%), while growth factors may improve the efficiency. Conclusion: Retrovirus could allow a functional transfer and expression of MDR1 gene in human leukemia cells, and MDR1 might act as a dominant selectable gene for coexpression with the genes of interest in gene therapy.

  18. Horizontal Transfer of Plasmid-Mediated Cephalosporin Resistance Genes in the Intestine of Houseflies (Musca domestica).

    Fukuda, Akira; Usui, Masaru; Okubo, Torahiko; Tamura, Yutaka

    2016-06-01

    Houseflies are a mechanical vector for various types of bacteria, including antimicrobial-resistant bacteria (ARB). If the intestine of houseflies is a suitable site for the transfer of antimicrobial resistance genes (ARGs), houseflies could also serve as a biological vector for ARB. To clarify whether cephalosporin resistance genes are transferred efficiently in the housefly intestine, we compared with conjugation experiments in vivo (in the intestine) and in vitro by using Escherichia coli with eight combinations of four donor and two recipient strains harboring plasmid-mediated cephalosporin resistance genes and chromosomal-encoded rifampicin resistance genes, respectively. In the in vivo conjugation experiment, houseflies ingested donor strains for 6 hr and then recipient strains for 3 hr, and 24 hr later, the houseflies were surface sterilized and analyzed. In vitro conjugation experiments were conducted using the broth-mating method. In 3/8 combinations, the in vitro transfer frequency (Transconjugants/Donor) was ≥1.3 × 10(-4); the in vivo transfer rates of cephalosporin resistance genes ranged from 2.0 × 10(-4) to 5.7 × 10(-5). Moreover, cephalosporin resistance genes were transferred to other species of enteric bacteria of houseflies such as Achromobacter sp. and Pseudomonas fluorescens. These results suggest that houseflies are not only a mechanical vector for ARB but also a biological vector for the occurrence of new ARB through the horizontal transfer of ARGs in their intestine. PMID:26683492

  19. Use of gene transfer and a novel cosmid rescue strategy to isolate transforming sequences.

    Brady, G.; Funk, A.; Mattern, J.; Schütz, G; Brown, R.

    1985-01-01

    Mouse Lewis Lung tumor DNA was ligated to a cosmid containing a geneticin (G418)/kanamycin resistance gene and transferred into NIH3T3 cells. Recipient cells were first selected for geneticin resistance and subsequently for their ability to grow as a tumour when injected into nude mice. By repeating this transfection procedure with DNA from resultant tumours, geneticin-resistant NIH3T3 cells were obtained which were tumorigenic and contained approximately 1-5 copies of the transferred cosmid....

  20. Induction of Apoptosis in Sonoporation and Ultrasonic Gene Transfer

    Miller, Douglas L.; Dou, Chunyan

    2008-01-01

    The role of apoptosis in sonoporation and ultrasound enhanced gene transfection of cell suspensions was examined in vitro. Suspensions of HL-60 and of CHO-K1 cells were exposed to 2.25 MHz continuous ultrasound for 1 min in a 60 rpm rotating-tube exposure system, with ultrasound contrast media added to ensure nucleation of cavitation. Cell necrosis was measured by trypan blue dye exclusion (using a hemacytometer) and by propidium iodide nuclear staining (using flow cytometry). Apoptosis was d...

  1. Improved retroviral suicide gene transfer in colon cancer cell lines after cell synchronization with methotrexate

    Nordlinger Bernard

    2011-10-01

    Full Text Available Abstract Background Cancer gene therapy by retroviral vectors is mainly limited by the level of transduction. Retroviral gene transfer requires target cell division. Cell synchronization, obtained by drugs inducing a reversible inhibition of DNA synthesis, could therefore be proposed to precondition target cells to retroviral gene transfer. We tested whether drug-mediated cell synchronization could enhance the transfer efficiency of a retroviral-mediated gene encoding herpes simplex virus thymidine kinase (HSV-tk in two colon cancer cell lines, DHDK12 and HT29. Methods Synchronization was induced by methotrexate (MTX, aracytin (ara-C or aphidicolin. Gene transfer efficiency was assessed by the level of HSV-TK expression. Transduced cells were driven by ganciclovir (GCV towards apoptosis that was assessed using annexin V labeling by quantitative flow cytometry. Results DHDK12 and HT29 cells were synchronized in S phase with MTX but not ara-C or aphidicolin. In synchronized DHDK12 and HT29 cells, the HSV-TK transduction rates were 2 and 1.5-fold higher than those obtained in control cells, respectively. Furthermore, the rate of apoptosis was increased two-fold in MTX-treated DHDK12 cells after treatment with GCV. Conclusions Our findings indicate that MTX-mediated synchronization of target cells allowed a significant improvement of retroviral HSV-tk gene transfer, resulting in an increased cell apoptosis in response to GCV. Pharmacological control of cell cycle may thus be a useful strategy to optimize the efficiency of retroviral-mediated cancer gene therapy.

  2. Transferring Gus gene into intact rice cells by low energy ion beam

    Zengliang, Yu; Jianbo, Yang; Yuejin, Wu; Beijiu, Cheng; Jianjun, He; Yuping, Huo

    1993-06-01

    A new technique of transferring genes by low energy ion beam has been reported in this paper. The Gus and CAT (chloramphenicol acetyltransferase) genes, as "foreign" genetic materials, were introduced into the suspension cells and ripe embryos or rice by implantation of 20-30 keV Ar + at doses ranging from 1 × 10 15 to 4 × 10 15 ions/cm 2. The activities of CAT and Gus were detected in the cells and embryos after several weeks. The results indicate that the transfer was a success.

  3. Regulatory and ethical issues for phase I in utero gene transfer studies.

    Strong, Carson

    2011-11-01

    Clinical gene transfer research has involved adult and child subjects, and it is expected that gene transfer in fetal subjects will occur in the future. Some genetic diseases have serious adverse effects on the fetus before birth, and there is hope that prenatal gene therapy could prevent such disease progression. Research in animal models of prenatal gene transfer is actively being pursued. The prospect of human phase I in utero gene transfer studies raises important regulatory and ethical issues. One issue not previously addressed arises in applying U.S. research regulations to such studies. Specifically, current regulations state that research involving greater than minimal risk to the fetus and no prospect of direct benefit to the fetus or pregnant woman is not permitted. Phase I studies will involve interventions such as needle insertions through the uterus, which carry risks to the fetus including spontaneous abortion and preterm birth. It is possible that these risks will be regarded as exceeding minimal. Also, some regard the probability of therapeutic benefit in phase I studies to be so low that these studies do not satisfy the regulatory requirement that they "hold out the prospect of direct benefit" to subjects. On the basis of these considerations, investigators and institutional review boards might reasonably conclude that some phase I in utero studies are not to be permitted. This paper identifies considerations that are relevant to such judgments and explores ethically acceptable ways in which phase I studies can be designed so that they are permitted by the regulations. PMID:21846200

  4. Peptide nanofibrils boost retroviral gene transfer and provide a rapid means for concentrating viruses

    Yolamanova, Maral; Meier, Christoph; Shaytan, Alexey K.; Vas, Virag; Bertoncini, Carlos W.; Arnold, Franziska; Zirafi, Onofrio; Usmani, Shariq M.; Müller, Janis A.; Sauter, Daniel; Goffinet, Christine; Palesch, David; Walther, Paul; Roan, Nadia R.; Geiger, Hartmut; Lunov, Oleg; Simmet, Thomas; Bohne, Jens; Schrezenmeier, Hubert; Schwarz, Klaus; Ständker, Ludger; Forssmann, Wolf-Georg; Salvatella, Xavier; Khalatur, Pavel G.; Khokhlov, Alexei R.; Knowles, Tuomas P. J.; Weil, Tanja; Kirchhoff, Frank; Münch, Jan

    2013-02-01

    Inefficient gene transfer and low virion concentrations are common limitations of retroviral transduction. We and others have previously shown that peptides derived from human semen form amyloid fibrils that boost retroviral gene delivery by promoting virion attachment to the target cells. However, application of these natural fibril-forming peptides is limited by moderate efficiencies, the high costs of peptide synthesis, and variability in fibril size and formation kinetics. Here, we report the development of nanofibrils that self-assemble in aqueous solution from a 12-residue peptide, termed enhancing factor C (EF-C). These artificial nanofibrils enhance retroviral gene transfer substantially more efficiently than semen-derived fibrils or other transduction enhancers. Moreover, EF-C nanofibrils allow the concentration of retroviral vectors by conventional low-speed centrifugation, and are safe and effective, as assessed in an ex vivo gene transfer study. Our results show that EF-C fibrils comprise a highly versatile, convenient and broadly applicable nanomaterial that holds the potential to significantly facilitate retroviral gene transfer in basic research and clinical applications.

  5. Bacteriophage Mediates Efficient Gene Transfer in Combination with Conventional Transfection Reagents

    Amanda Donnelly

    2015-12-01

    Full Text Available The development of commercially available transfection reagents for gene transfer applications has revolutionized the field of molecular biology and scientific research. However, the challenge remains in ensuring that they are efficient, safe, reproducible and cost effective. Bacteriophage (phage-based viral vectors have the potential to be utilized for general gene transfer applications within research and industry. Yet, they require adaptations in order to enable them to efficiently enter cells and overcome mammalian cellular barriers, as they infect bacteria only; furthermore, limited progress has been made at increasing their efficiency. The production of a novel hybrid nanocomplex system consisting of two different nanomaterial systems, phage vectors and conventional transfection reagents, could overcome these limitations. Here we demonstrate that the combination of cationic lipids, cationic polymers or calcium phosphate with M13 bacteriophage-derived vectors, engineered to carry a mammalian transgene cassette, resulted in increased cellular attachment, entry and improved transgene expression in human cells. Moreover, addition of a targeting ligand into the nanocomplex system, through genetic engineering of the phage capsid further increased gene expression and was effective in a stable cell line generation application. Overall, this new hybrid nanocomplex system (i provides enhanced phage-mediated gene transfer; (ii is applicable for laboratory transfection processes and (iii shows promise within industry for large-scale gene transfer applications.

  6. In vivo tyrosinase mini-gene transfer enhances killing effect of BNCT on amelanotic melanoma

    Kondoh, H.; Mishima, Y. [Mishima Institute for Dermatological Research, Kobe, Hyogo (Japan); Hiratsuka, J. [Kawasaki Medical School, Dept. of Radiation Oncology, Kurashiki, Okayama (Japan); Iwakura, M. [Kobe Univ. (Japan). School of Medicine

    2000-10-01

    Using accentuated melanogenesis principally occurring within melanoma cells, we have successfully treated human malignant melanoma (Mm) with {sup 10}B-BPA BNCT. Despite this success, there are still remaining issues for poorly melanogenic Mm and further non-pigment cell tumors. We found the selective accumulation of {sup 10}B-BPA to Mm is primarily due to the complex formation of BPA and melanin-monomers activity synthesized within Mm cells. Then, we succeeded in transferring the tyrosinase gene into amelanotic to substantially produce melanin monomers. These cells has demonstrated increased boron accumulation and enhanced killing effect of BNCT. Further, transfection of TRP-2 (DOPAchrome tautomerase) gene into poorly eumelanotic and slightly phenomelanotic Mm cells in culture cell systems also led to increased BPA accumulation. Thereafter, we studied in vivo gene transfer. We transferred the tyrosinase mini-gene by intra-tumor injection into poorly melanotic Mm proliferating subcutaneously in hamster skin, and performed BNCT. Compared to control tumors, gene-transferred tumors showed increased BPA accumulation leading to enhanced killing effect. (author)

  7. In vivo tyrosinase mini-gene transfer enhances killing effect of BNCT on amelanotic melanoma

    Using accentuated melanogenesis principally occurring within melanoma cells, we have successfully treated human malignant melanoma (Mm) with 10B-BPA BNCT. Despite this success, there are still remaining issues for poorly melanogenic Mm and further non-pigment cell tumors. We found the selective accumulation of 10B-BPA to Mm is primarily due to the complex formation of BPA and melanin-monomers activity synthesized within Mm cells. Then, we succeeded in transferring the tyrosinase gene into amelanotic to substantially produce melanin monomers. These cells has demonstrated increased boron accumulation and enhanced killing effect of BNCT. Further, transfection of TRP-2 (DOPAchrome tautomerase) gene into poorly eumelanotic and slightly phenomelanotic Mm cells in culture cell systems also led to increased BPA accumulation. Thereafter, we studied in vivo gene transfer. We transferred the tyrosinase mini-gene by intra-tumor injection into poorly melanotic Mm proliferating subcutaneously in hamster skin, and performed BNCT. Compared to control tumors, gene-transferred tumors showed increased BPA accumulation leading to enhanced killing effect. (author)

  8. Analysis of bone marrow stromal cell transferred bacterial β-galactosidase gene by PIXE

    PIXE, Particle Induced X-ray Emission, is a powerful, multi-elemental analysis method which has many distinguishing features and has been used in varies research fields. Recently the method of applying baby cyclotrons for nuclear medicine to PIXE has been developed. This enables us to study biomedical phenomena from the physical point of view. Mouse bone marrow stromal cells were transferred bacterial β-galactosidase gene (LacZ gene) by murine retroviral vectors. Analysis of the bone marrow stromal cells with the LacZ gene by PIXE revealed remarkable changes of intracellular trace elements compared with the normal control cells. These results indicate that gene transfer by retroviral vectors may bring about a dynamic change of intracellular circumstances of the target cell. (author)

  9. Collective evolution of cyanobacteria and cyanophages mediated by horizontal gene transfer

    Shih, Hong-Yan; Rogers, Tim; Goldenfeld, Nigel

    We describe a model for how antagonistic predator-prey coevolution can lead to mutualistic adaptation to an environment, as a result of horizontal gene transfer. Our model is a simple description of ecosystems such as marine cyanobacteria and their predator cyanophages, which carry photosynthesis genes. These genes evolve more rapidly in the virosphere than the bacterial pan-genome, and thus the bacterial population could potentially benefit from phage predation. By modeling both the barrier to predation and horizontal gene transfer, we study this balance between individual sacrifice and collective benefits. The outcome is an emergent mutualistic coevolution of improved photosynthesis capability, benefiting both bacteria and phage. This form of multi-level selection can contribute to niche stratification in the cyanobacteria-phage ecosystem. This work is supported in part by a cooperative agreement with NASA, Grant NNA13AA91A/A0018.

  10. Ephrin A2 receptor targeting does not increase adenoviral pancreatic cancer transduction in vivo

    Michael A van Geer; Conny T Bakker; Naoya Koizumi; Hiroyuki Mizuguchi; John G Wesseling; Ronald PJ Oude Elferink; Piter J Bosma

    2009-01-01

    AIM:To generate an adenoviral vector specifically targeting the EphA2 receptor (EphA2R) highly expressed on pancreatic cancer cells in vivo.METHODS:YSA,a small peptide ligand that binds the EphA2R with high affinity,was inserted into the HI loop of the adenovirus serotype 5 fiber knob.To further increase the specificity of this vector,binding sites for native adenoviral receptors,the coxsackie and adenovirus receptor (CAR) and integrin,were ablated from the viral capsid.The ablated retargeted adenoviral vector was produced on 293T cells.Specific targeting of this novel adenoviral vector to pancreatic cancer was investigated on established human pancreatic cancer cell lines.Upon demonstrating specific in vitro targeting,in vivo targeting to subcutaneous growing human pancreatic cancer was tested by intravenous and intraperitoneal administration of the ablated adenoviral vector.RESULTS:Ablation of native cellular binding sites reduced adenoviral transduction at least 100-fold.Insertion of the YSA peptide in the HI loop restored adenoviral transduction of EphA2R-expressing cells but not of cells lacking this receptor.YSA-mediated transduction was inhibited by addition of synthetic YSA peptide.The transduction specificity of the ablated retargeted vector towards human pancreatic cancer cells was enhanced almost 10-fold in vitro.In a subsequent in vivo study in a nude (nu/nu) mouse model however,no increased adenoviral targeting to subcutaneously growing human pancreas cancer nodules was seen upon injection into the tail vein,nor upon injection into the peritoneum.CONCLUSION:Targeting the EphA2 receptor increases specificity of adenoviral transduction of human pancreatic cancer cells in vitro but fails to enhance pancreatic cancer transduction in vivo.

  11. Eukaryote-to-eukaryote gene transfer gives rise to genome mosaicism in euglenids

    Weber Andreas PM

    2011-04-01

    Full Text Available Abstract Background Euglenophytes are a group of photosynthetic flagellates possessing a plastid derived from a green algal endosymbiont, which was incorporated into an ancestral host cell via secondary endosymbiosis. However, the impact of endosymbiosis on the euglenophyte nuclear genome is not fully understood due to its complex nature as a 'hybrid' of a non-photosynthetic host cell and a secondary endosymbiont. Results We analyzed an EST dataset of the model euglenophyte Euglena gracilis using a gene mining program designed to detect laterally transferred genes. We found E. gracilis genes showing affinity not only with green algae, from which the secondary plastid in euglenophytes evolved, but also red algae and/or secondary algae containing red algal-derived plastids. Phylogenetic analyses of these 'red lineage' genes suggest that E. gracilis acquired at least 14 genes via eukaryote-to-eukaryote lateral gene transfer from algal sources other than the green algal endosymbiont that gave rise to its current plastid. We constructed an EST library of the aplastidic euglenid Peranema trichophorum, which is a eukaryovorous relative of euglenophytes, and also identified 'red lineage' genes in its genome. Conclusions Our data show genome mosaicism in E. gracilis and P. trichophorum. One possible explanation for the presence of these genes in these organisms is that some or all of them were independently acquired by lateral gene transfer and contributed to the successful integration and functioning of the green algal endosymbiont as a secondary plastid. Alternative hypotheses include the presence of a phagocytosed alga as the single source of those genes, or a cryptic tertiary endosymbiont harboring secondary plastid of red algal origin, which the eukaryovorous ancestor of euglenophytes had acquired prior to the secondary endosymbiosis of a green alga.

  12. Rate of gene transfer from mitochondria to nucleus: effects of cytoplasmic inheritance system and intensity of intracellular competition.

    Yamauchi, Atsushi

    2005-11-01

    Endosymbiotic theory states that mitochondria originated as bacterial intracellular symbionts, the size of the mitochondrial genome gradually reducing over a long period owing to, among other things, gene transfer from the mitochondria to the nucleus. Such gene transfer was observed in more genes in animals than in plants, implying a higher transfer rate of animals. The evolution of gene transfer may have been affected by an intensity of intracellular competition among organelle strains and the organelle inheritance system of the organism concerned. This article reveals a relationship between those factors and the gene transfer rate from organelle to nuclear genomes, using a mathematical model. Mutant mitochondria that lose a certain gene by deletion are considered to replicate more rapidly than normal ones, resulting in an advantage in intracellular competition. If the competition is intense, heteroplasmic individuals possessing both types of mitochondria change to homoplasmic individuals including mutant mitochondria only, with high probability. According to the mathematical model, it was revealed that the rate of gene transfer from mitochondria to the nucleus can be affected by three factors, the intensity of intracellular competition, the probability of paternal organelle transmission, and the effective population size. The gene transfer rate tends to increase with decreasing intracellular competition, increasing paternal organelle transmission, and decreasing effective population size. Intense intracellular competition tends to suppress gene transfer because it is likely to exclude mutant mitochondria that lose the essential gene due to the production of lethal individuals. PMID:16079242

  13. The influence of gene transfer on the lactic acid bacteria evolution

    Višnja Bačun-Družina; Jasna Mrvčić; Ana Butorac; Krešimir Gjuračić

    2009-01-01

    In the case of preparing various dairy products, the exploitation of lactic acid bacteria has been essential in the course of past millennia in all known nations. Numerous comparative analyses of gene and genome sequences reveal that the exchange of genetic material within and between bacterial species is far more general and frequent than has previously been thought. Consequently, the horizontal gene transfer between distant species or within the same species is an important factor in the La...

  14. Local Gene Transfer of OPG Prevents Joint Damage and Disease Progression in Collagen-Induced Arthritis

    Qingguo Zhang; Weiming Gong; Bin Ning; Lin Nie; Paul H. Wooley; Shang-You Yang

    2013-01-01

    This study examined the influence of osteoprotegerin (OPG) gene transfer on a murine collagen-induced arthritis model. A single periarticular injection of AAV-OPG or AAV-LacZ on the arthritic paw successfully incorporated the exogenous gene to the local tissue and resulted in marked transgene expression in the joint homogenate for at least three weeks. Clinical disease scores were significantly improved in OPG treated mice starting at 28-day post-treatment (P < 0.05). Histological assessment ...

  15. CRISPR Interference Limits Horizontal Gene Transfer in Staphylococci by Targeting DNA

    Marraffini, Luciano A.; Sontheimer, Erik J.

    2008-01-01

    Horizontal gene transfer (HGT) in bacteria and archaea occurs through phage transduction, transformation, or conjugation, and the latter is particularly important for the spread of antibiotic resistance. Clustered, regularly interspaced short palindromic repeats (CRISPR) loci confer sequence-directed immunity against phages. A clinical isolate of Staphylococcus epidermidis harbors a CRISPR spacer that matches the nickase gene present in nearly all staphylococcal conjugative plasmids. Here we ...

  16. Adaptive horizontal transfer of a bacterial gene to an invasive insect pest of coffee

    Acuña, Ricardo; Padilla, Beatriz E.; Flórez-Ramos, Claudia P.; Rubio, José D.; Herrera, Juan C; Benavides, Pablo; Lee, Sang-Jik; Yeats, Trevor H.; Egan, Ashley N.; Doyle, Jeffrey J.; Rose, Jocelyn K. C.

    2012-01-01

    Horizontal gene transfer (HGT) involves the nonsexual transmission of genetic material across species boundaries. Although often detected in prokaryotes, examples of HGT involving animals are relatively rare, and any evolutionary advantage conferred to the recipient is typically obscure. We identified a gene (HhMAN1) from the coffee berry borer beetle, Hypothenemus hampei, a devastating pest of coffee, which shows clear evidence of HGT from bacteria. HhMAN1 encodes a mannanase, representing a...

  17. Extensive horizontal transfer of core genome genes between two Lactobacillus species found in the gastrointestinal tract

    Maguin Emmanuelle

    2007-08-01

    Full Text Available Abstract Background While genes that are conserved between related bacterial species are usually thought to have evolved along with the species, phylogenetic trees reconstructed for individual genes may contradict this picture and indicate horizontal gene transfer. Individual trees are often not resolved with high confidence, however, and in that case alternative trees are generally not considered as contradicting the species tree, although not confirming it either. Here we conduct an in-depth analysis of 401 protein phylogenetic trees inferred with varying levels of confidence for three lactobacilli from the acidophilus complex. At present the relationship between these bacteria, isolated from environments as diverse as the gastrointestinal tract (Lactobacillus acidophilus and Lactobacillus johnsonii and yogurt (Lactobacillus delbrueckii ssp. bulgaricus, is ambiguous due to contradictory phenotypical and 16S rRNA based classifications. Results Among the 401 phylogenetic trees, those that could be reconstructed with high confidence support the 16S-rRNA tree or one alternative topology in an astonishing 3:2 ratio, while the third possible topology is practically absent. Lowering the confidence threshold for trees to be taken into consideration does not significantly affect this ratio, and therefore suggests that gene transfer may have affected as much as 40% of the core genome genes. Gene function bias suggests that the 16S rRNA phylogeny of the acidophilus complex, which indicates that L. acidophilus and L. delbrueckii ssp. bulgaricus are the closest related of these three species, is correct. A novel approach of comparison of interspecies protein divergence data employed in this study allowed to determine that gene transfer most likely took place between the lineages of the two species found in the gastrointestinal tract. Conclusion This case-study reports an unprecedented level of phylogenetic incongruence, presumably resulting from extensive

  18. Operon Formation is Driven by Co-Regulation and Not by Horizontal Gene Transfer

    Price, Morgan N.; Huang, Katherine H.; Arkin, Adam P.; Alm, Eric J.

    2005-04-12

    Although operons are often subject to horizontal gene transfer (HGT), non-HGT genes are particularly likely to be in operons. To resolve this apparent discrepancy and to determine whether HGT is involved in operon formation, we examined the evolutionary history of the genes and operons in Escherichia coli K12. We show that genes that have homologs in distantly related bacteria but not in close relatives of E. coli (indicating HGTi) form new operons at about the same rates as native genes. Furthermore, genes in new operons are no more likely than other genes to have phylogenetic trees that are inconsistent with the species tree. In contrast, essential genes and ubiquitous genes without paralogs (genes believed to undergo HGT rarely) often form new operons. We conclude that HGT is not associated with operon formation, but instead promotes the prevalence of pre-existing operons. To explain operon formation, we propose that new operons reduce the amount of regulatory information required to specify optimal expression patterns. Consistent with this hypothesis, operons have greater amounts of conserved regulatory sequences than do individually transcribed genes.

  19. Detection of horizontal transfer of individual genes by anomalous oligomer frequencies

    Elhai Jeff

    2012-06-01

    Full Text Available Abstract Background Understanding the history of life requires that we understand the transfer of genetic material across phylogenetic boundaries. Detecting genes that were acquired by means other than vertical descent is a basic step in that process. Detection by discordant phylogenies is computationally expensive and not always definitive. Many have used easily computed compositional features as an alternative procedure. However, different compositional methods produce different predictions, and the effectiveness of any method is not well established. Results The ability of octamer frequency comparisons to detect genes artificially seeded in cyanobacterial genomes was markedly increased by using as a training set those genes that are highly conserved over all bacteria. Using a subset of octamer frequencies in such tests also increased effectiveness, but this depended on the specific target genome and the source of the contaminating genes. The presence of high frequency octamers and the GC content of the contaminating genes were important considerations. A method comprising best practices from these tests was devised, the Core Gene Similarity (CGS method, and it performed better than simple octamer frequency analysis, codon bias, or GC contrasts in detecting seeded genes or naturally occurring transposons. From a comparison of predictions with phylogenetic trees, it appears that the effectiveness of the method is confined to horizontal transfer events that have occurred recently in evolutionary time. Conclusions The CGS method may be an improvement over existing surrogate methods to detect genes of foreign origin.

  20. In vivo and in vitro gene transfer to mammalian somatic cells by particle bombardment

    Chimeric chloramphenicol acetyltransferase and β-galactosidase marker genes were coated onto fine gold particles and used to bombard a variety of mammalian tissues and cells. Transient expression of the genes was obtained in liver, skin, and muscle tissues of rat and mouse bombarded in vivo. Similar results were obtained with freshly isolated ductal segments of rat and human mammary glands and primary cultures derived from these explants. Gene transfer and transient expression were also observed in eight human cell culture lines, including cells of epithelial, endothelial, fibroblast, and lymphocyte origin. Using CHO and MCF-7 cell cultures as models, we obtained stable gene transfer at frequencies of 1.7 x 10-3 and 6 x 10-4, respectively. The particle bombardment technology thus provides a useful means to transfer foreign genes into a variety of mammalian somatic cell systems. The method is applicable to tissues in vivo as well as to isolated cells in culture and has proven effective with all cell or tissue types tested thus far. This technology may therefore prove to be applicable in various aspects of gene therapy

  1. Preventing High Fat Diet-induced Obesity and Improving Insulin Sensitivity through Neuregulin 4 Gene Transfer.

    Ma, Yongjie; Gao, Mingming; Liu, Dexi

    2016-01-01

    Neuregulin 4 (NRG4), an epidermal growth factor-like signaling molecule, plays an important role in cell-to-cell communication during tissue development. Its function to regulate energy metabolism has recently been reported. This current study was designed to assess the preventive and therapeutic effects of NRG4 overexpression on high fat diet (HFD)-induced obesity. Using the hydrodynamic gene transfer method, we demonstrate that Nrg4 gene transfer in mice suppressed the development of diet-induced obesity, but did not affect pre-existing adiposity and body weight in obese mice. Nrg4 gene transfer curbed HFD-induced hepatic steatosis by inhibiting lipogenesis and PPARγ-mediated lipid storage. Concurrently, overexpression of NRG4 reduced chronic inflammation in both preventive and treatment studies, evidenced by lower mRNA levels of macrophage marker genes including F4/80, Cd68, Cd11b, Cd11c, and macrophage chemokine Mcp1, resulting in improved insulin sensitivity. Collectively, these results demonstrate that overexpression of the Nrg4 gene by hydrodynamic gene delivery prevents HFD-induced weight gain and fatty liver, alleviates obesity-induced chronic inflammation and insulin resistance, and supports the health benefits of NRG4 in managing obesity and obesity-associated metabolic disorders. PMID:27184920

  2. Gene Transfer and the Reconstruction of Life's Early History from Genomic Data

    Gogarten, J. Peter; Fournier, Gregory; Zhaxybayeva, Olga

    2008-03-01

    The metaphor of the unique and strictly bifurcating tree of life, suggested by Charles Darwin, needs to be replaced (or at least amended) to reflect and include processes that lead to the merging of and communication between independent lines of descent. Gene histories include and reflect processes such as gene transfer, symbioses and lineage fusion. No single molecule can serve as a proxy for the tree of life. Individual gene histories can be reconstructed from the growing molecular databases containing sequence and structural information. With some simplifications these gene histories can be represented by furcating trees; however, merging these gene histories into web-like organismal histories, including the transfer of metabolic pathways and cell biological innovations from now-extinct lineages, has yet to be accomplished. Because of these difficulties in interpreting the record retained in molecular sequences, correlations with biochemical fossils and with the geological record need to be interpreted with caution. Advances to detect and pinpoint transfer events promise to untangle at least a few of the intertwined histories of individual genes within organisms and trace them to the organismal ancestors. Furthermore, analysis of the shape of molecular phylogenetic trees may point towards organismal radiations that might reflect early mass extinction events that occurred on a planetary scale.

  3. Horizontal gene transfer and nucleotide compositional anomaly in large DNA viruses

    Ogata Hiroyuki

    2007-12-01

    Full Text Available Abstract Background DNA viruses have a wide range of genome sizes (5 kb up to 1.2 Mb, compared to 0.16 Mb to 1.5 Mb for obligate parasitic bacteria that do not correlate with their virulence or the taxonomic distribution of their hosts. The reasons for such large variation are unclear. According to the traditional view of viruses as gifted "gene pickpockets", large viral genome sizes could originate from numerous gene acquisitions from their hosts. We investigated this hypothesis by studying 67 large DNA viruses with genome sizes larger than 150 kb, including the recently characterized giant mimivirus. Given that horizontally transferred DNA often have anomalous nucleotide compositions differing from the rest of the genome, we conducted a detailed analysis of the inter- and intra-genome compositional properties of these viruses. We then interpreted their compositional heterogeneity in terms of possible causes, including strand asymmetry, gene function/expression, and horizontal transfer. Results We first show that the global nucleotide composition and nucleotide word usage of viral genomes are species-specific and distinct from those of their hosts. Next, we identified compositionally anomalous (cA genes in viral genomes, using a method based on Bayesian inference. The proportion of cA genes is highly variable across viruses and does not exhibit a significant correlation with genome size. The vast majority of the cA genes were of unknown function, lacking homologs in the databases. For genes with known homologs, we found a substantial enrichment of cA genes in specific functional classes for some of the viruses. No significant association was found between cA genes and compositional strand asymmetry. A possible exogenous origin for a small fraction of the cA genes could be confirmed by phylogenetic reconstruction. Conclusion At odds with the traditional dogma, our results argue against frequent genetic transfers to large DNA viruses from their

  4. Fluoroquinolone induction of phage-mediated gene transfer in multidrug-resistant Salmonella.

    Bearson, Bradley L; Brunelle, Brian W

    2015-08-01

    Fluoroquinolones are broad-spectrum antibiotics that inhibit bacterial DNA gyrase and topoisomerase activity, which can cause DNA damage and result in bacterial cell death. In response to DNA damage, bacteria induce an SOS response to stimulate DNA repair. However, the SOS response may also induce prophage with production of infectious virions. Salmonella strains typically contain multiple prophages, and certain strains including phage types DT120 and DT104 contain prophage that upon induction are capable of generalised transduction. In this study, strains of multidrug-resistant (MDR) Salmonella enterica serovar Typhimurium DT120 and DT104 were exposed to fluoroquinolones important for use in human and veterinary disease therapy to determine whether prophage(s) are induced that could facilitate phage-mediated gene transfer. Cultures of MDR S. Typhimurium DT120 and DT104 containing a kanamycin resistance plasmid were lysed after exposure to fluoroquinolones (ciprofloxacin, enrofloxacin and danofloxacin). Bacterial cell lysates were able to transfer the plasmid to a recipient kanamycin-susceptible Salmonella strain by generalised transduction. In addition, exposure of DT120 to ciprofloxacin induced the recA gene of the bacterial SOS response and genes encoded in a P22-like generalised transducing prophage. This research indicates that fluoroquinolone exposure of MDR Salmonella can facilitate horizontal gene transfer, suggesting that fluoroquinolone usage in human and veterinary medicine may have unintended consequences, including the induction of phage-mediated gene transfer from MDR Salmonella. Stimulation of gene transfer following bacterial exposure to fluoroquinolones should be considered an adverse effect, and clinical decisions regarding antibiotic selection for infectious disease therapy should include this potential risk. PMID:26078016

  5. Noninvasive radiological imaging of pulmonary gene transfer and expression using the human sodium iodide symporter

    Niu, Gang; Krager, Kimberly J.; Domann, Frederick E. [University of Iowa, Free Radical and Radiation Biology Program, Department of Radiation Oncology, Roy J. and Lucille A. Carver College of Medicine, Iowa City (United States); Graham, Michael M.; Hichwa, Richard D. [University of Iowa, Division of Nuclear Medicine, Department of Radiology, Roy J. and Lucille A. Carver College of Medicine, Iowa City, IA (United States)

    2005-04-01

    In this study we investigated the application of the human sodium iodide symporter (hNIS) as a reporter gene to noninvasively image in vivo gene transfer and expression in lung tissue in real time. Human NIS-expressing adenoviruses (Ad-hNIS) or empty adenoviruses (Ad-Bgl II) were instilled into the lungs of Cotton rats via the nostrils. After 3, 10, and 17 days post infection, gamma camera scintigraphy with {sup 99m}TcO{sub 4}{sup -} was performed to observe the distribution and duration of gene transfer. At 20 days after infection, reverse transcription polymerase chain reaction was performed to detect hNISgene expression. Dual expressing vector Ad-hNIS-eGFP was used to detect transgene expression by fluorescence photomicroscopy in infected lung tissue. Positron emission tomography (PET) imaging of gene transfer to the lungs was performed using {sup 124}I{sup -} as tracer. Finally, hNIStransfer to a polarized human airway epithelial cell layer was evaluated by phosphorimaging. Lungs in animals infected with Ad-hNIS were clearly visible on scintigraphy and PET scans, while those infected with Ad-Bgl II were undetectable. Lungs in Ad-hNIS infected animals could still be visualized at 17 days but were no longer detectable at 20 days. Fluorescence microscopy showed that lung tissue infected with Ad-hNIS-eGFP had significantly higher GFP signal intensity than that infected with Ad-Bgl II. It is feasible to use the hNISgene as a reporter gene to monitor the location, magnitude, and timing of expression of genes delivered during pulmonary gene therapy. The ability to noninvasively visualize gene expression tomographically in real time has significant translational implications in human gene therapy. (orig.)

  6. Identification of a Divided Genome for VSH-1, the Prophage-Like Gene Transfer Agent of Brachyspira hyodysenteriae

    The Brachyspira hyodysenteriae B204 genome sequence revealed three VSH-1 tail genes hvp31, hvp60, and hvp37, in a 3.6 kb cluster. The location and transcription direction of these genes relative to the previously described VSH-1 16.3 kb gene operon indicate that the gene transfer agent VSH-1 has a ...

  7. Chimeric smooth muscle-specific enhancer/promoters: valuable tools for adenovirus-mediated cardiovascular gene therapy.

    Ribault, S; Neuville, P; Méchine-Neuville, A; Augé, F; Parlakian, A; Gabbiani, G; Paulin, D; Calenda, V

    2001-03-16

    Gene transfer with adenoviral vectors is an attractive approach for the treatment of atherosclerosis and restenosis. However, because expression of a therapeutic gene in nontarget tissues may have deleterious effects, artery-specific expression is desirable. Although expression vectors containing transcriptional regulatory elements of genes expressed solely in smooth muscle cells (SMCs) have proved efficient to restrict expression of the transgene, their use in the clinical setting can be limited by their reduced strength. In the present study, we show that low levels of transgene expression are obtained with the smooth muscle (SM)-specific SM22alpha promoter compared with the viral cytomegalovirus (CMV) enhancer/promoter. We have generated chimeric transcriptional cassettes containing either a SM (SM-myosin heavy chain) or a skeletal muscle (creatine kinase) enhancer combined with the SM22alpha promoter. With both constructs we observed significantly stronger expression that remains SM-specific. In vivo, reporter gene expression was restricted to arterial SMCs with no detectable signal at remote sites. Moreover, when interferon-gamma expression was driven by one of these two chimeras, SMC growth was inhibited as efficiently as with the CMV promoter. Finally, we demonstrate that neointima formation in the rat carotid balloon injury model was reduced to the same extent by adenoviral gene transfer of interferon-gamma driven either by the SM-myosin heavy chain enhancer/SM22alpha promoter or the CMV promoter. These results indicate that such vectors can be useful for the treatment of hyperproliferative vascular disorders. PMID:11249869

  8. Microbubbles and ultrasound increase intraventricular polyplex gene transfer to the brain.

    Tan, James-Kevin Y; Pham, Binhan; Zong, Yujin; Perez, Camilo; Maris, Don O; Hemphill, Ashton; Miao, Carol H; Matula, Thomas J; Mourad, Pierre D; Wei, Hua; Sellers, Drew L; Horner, Philip J; Pun, Suzie H

    2016-06-10

    Neurons in the brain can be damaged or lost from neurodegenerative disease, stroke, or traumatic injury. Although neurogenesis occurs in mammalian adult brains, the levels of natural neurogenesis are insufficient to restore function in these cases. Gene therapy has been pursued as a promising strategy to induce differentiation of neural progenitor cells into functional neurons. Non-viral vectors are a preferred method of gene transfer due to potential safety and manufacturing benefits but suffer from lower delivery efficiencies compared to viral vectors. Since the neural stem and progenitor cells reside in the subventricular zone of the brain, intraventricular injection has been used as an administration route for gene transfer to these cells. However, the choroid plexus epithelium remains an obstacle to delivery. Recently, transient disruption of the blood-brain barrier by microbubble-enhanced ultrasound has been used to successfully improve drug delivery to the brain after intravenous injection. In this work, we demonstrate that microbubble-enhanced ultrasound can similarly improve gene transfer to the subventricular zone after intraventricular injection. Microbubbles of different surface charges (neutral, slightly cationic, and cationic) were prepared, characterized by acoustic flow cytometry, and evaluated for their ability to increase the permeability of immortalized choroid plexus epithelium monolayers in vitro. Based on these results, slightly cationic microbubbles were evaluated for microbubble and ultrasound-mediated enhancement of non-viral gene transfer in vivo. When coupled with our previously reported gene delivery vehicles, the slightly cationic microbubbles significantly increased ultrasound-mediated transfection of the murine brain when compared to commercially available Definity® microbubbles. Temporary disruption of the choroid plexus by microbubble-enhanced ultrasound is therefore a viable way of enhancing gene delivery to the brain and merits

  9. Pathogen-origin horizontally transferred genes contribute to the evolution of Lepidopteran insects

    Li Zi-Wen

    2011-12-01

    Full Text Available Abstract Background Horizontal gene transfer (HGT, a source of genetic variation, is generally considered to facilitate hosts' adaptability to environments. However, convincing evidence supporting the significant contribution of the transferred genes to the evolution of metazoan recipients is rare. Results In this study, based on sequence data accumulated to date, we used a unified method consisting of similarity search and phylogenetic analysis to detect horizontally transferred genes (HTGs between prokaryotes and five insect species including Drosophila melanogaster, Anopheles gambiae, Bombyx mori, Tribolium castaneum and Apis mellifera. Unexpectedly, the candidate HTGs were not detected in D. melanogaster, An. gambiae and T. castaneum, and 79 genes in Ap. mellifera sieved by the same method were considered as contamination based on other information. Consequently, 14 types of 22 HTGs were detected only in the silkworm. Additionally, 13 types of the detected silkworm HTGs share homologous sequences in species of other Lepidopteran superfamilies, suggesting that the majority of these HTGs were derived from ancient transfer events before the radiation of Ditrysia clade. On the basis of phylogenetic topologies and BLAST search results, donor bacteria of these genes were inferred, respectively. At least half of the predicted donor organisms may be entomopathogenic bacteria. The predicted biochemical functions of these genes include four categories: glycosyl hydrolase family, oxidoreductase family, amino acid metabolism, and others. Conclusions The products of HTGs detected in this study may take part in comprehensive physiological metabolism. These genes potentially contributed to functional innovation and adaptability of Lepidopteran hosts in their ancient lineages associated with the diversification of angiosperms. Importantly, our results imply that pathogens may be advantageous to the subsistence and prosperity of hosts through effective HGT

  10. Reliable transfer of transcriptional gene regulatory networks between taxonomically related organisms

    Tauch Andreas

    2009-01-01

    Full Text Available Abstract Background Transcriptional regulation of gene activity is essential for any living organism. Transcription factors therefore recognize specific binding sites within the DNA to regulate the expression of particular target genes. The genome-scale reconstruction of the emerging regulatory networks is important for biotechnology and human medicine but cost-intensive, time-consuming, and impossible to perform for any species separately. By using bioinformatics methods one can partially transfer networks from well-studied model organisms to closely related species. However, the prediction quality is limited by the low level of evolutionary conservation of the transcription factor binding sites, even within organisms of the same genus. Results Here we present an integrated bioinformatics workflow that assures the reliability of transferred gene regulatory networks. Our approach combines three methods that can be applied on a large-scale: re-assessment of annotated binding sites, subsequent binding site prediction, and homology detection. A gene regulatory interaction is considered to be conserved if (1 the transcription factor, (2 the adjusted binding site, and (3 the target gene are conserved. The power of the approach is demonstrated by transferring gene regulations from the model organism Corynebacterium glutamicum to the human pathogens C. diphtheriae, C. jeikeium, and the biotechnologically relevant C. efficiens. For these three organisms we identified reliable transcriptional regulations for ~40% of the common transcription factors, compared to ~5% for which knowledge was available before. Conclusion Our results suggest that trustworthy genome-scale transfer of gene regulatory networks between organisms is feasible in general but still limited by the level of evolutionary conservation.

  11. The standard lateral gene transfer model is statistically consistent for pectinate four-taxon trees

    Sand, Andreas; Steel, Mike

    2013-01-01

    species trees from gene trees under such conditions is to combine three-taxon analyses for several genes using a majority vote approach. For incomplete lineage sorting this method is known to be statistically consistent; however, for lateral gene transfers it was recently shown that a zone of...... inconsistency exists for a specific four-taxon tree topology, and it was posed as an open question whether inconsistencies could exist for other four-taxon tree topologies? In this letter we analyze all remaining four-taxon topologies and show that no other inconsistencies exist....

  12. Editing T cell specificity towards leukemia by zinc-finger nucleases and lentiviral gene transfer

    Lombardo, Angelo; Magnani, Zulma; Liu, Pei-Qi; Reik, Andreas; Chu, Victoria; Paschon, David E.; Zhang, Lei; Kuball, Jurgen; Camisa, Barbara; Bondanza, Attilio; Casorati, Giulia; Ponzoni, Maurilio; Ciceri, Fabio; Bordignon, Claudio; Greenberg, Philip D.; Holmes, Michael C.; Gregory, Philip D.; Naldini, Luigi; Bonini, Chiara

    2016-01-01

    The transfer of high-avidity T-cell receptor (TCR) genes isolated from rare tumor-specific lymphocytes into polyclonal T cells is an attractive cancer immunotherapy strategy. However, TCR gene transfer results in competition for surface expression and inappropriate pairing between the exogenous and endogenous TCR chains, resulting in suboptimal activity and potentially harmful unpredicted specificities. We designed zinc-finger nucleases (ZFNs) promoting the disruption of endogenous TCR β and α chain genes. ZFN-treated lymphocytes lacked CD3/TCR surface expression and expanded with IL-7 and IL-15. Upon lentiviral transfer of a TCR for the WT1 tumor antigen, these TCR-edited cells expressed the new TCR at high levels, were easily expanded to near-purity, and proved superior in specific antigen recognition to matched TCR-transferred cells. In contrast to TCR-transferred cells, TCR edited lymphocytes did not mediate off-target reactivity while maintaining anti-tumor activity in vivo, thus demonstrating that complete editing of T-cell specificity generate tumor-specific lymphocytes with improved biosafety profile. PMID:22466705

  13. Direct transfer of A20 gene into pancreas protected mice from streptozotocin-induced diabetes

    Lu-yang YU; Bo LIN; Zhen-lin ZHANG; Li-he GUO

    2004-01-01

    AIM: To investigate the efficiency of transfer of A20 gene into pancreas against STZ-induced diabetes. METHODS:PVP-plasmid mixture was directly transferred into the pancreatic parenchyma 2 d before STZ injection. The uptake of plasmid pcDNA3-LacZ or pcDNA3-A20 was detected by PCR and the expression of LacZ was confirmed by histological analysis with X-gal. A20 expression in the pancreas of pcDNA3-A20 transgenic mice was measured by RT-PCR and Westem blots. Urine amylase, NO generation, and histological examination were examined. RESULTS:Injection of PVP-plasmid mixture directly into the pancreatic parenchyma increased urine amylase concentration 16 h after operation and reversed it to nearly normal 36 h later. On d 33 LacZ expression could be found in spleen,duodenum, and islets. The development of diabetes was prevented by direct A20 gene transferring into the pancreas and A20-mediated protection was correlated with suppression of NO production. The insulitis was ameliorated in A20-treated mice. CONCLUSION: Injection of PVP-plasmid mixture directly into the pancreatic parenchyma led to target gene expression in islets. Direct transfer of A20 gene into the pancreas protected mice from STZ-induced diabetes.

  14. Assessing the effects of a sequestered germline on interdomain lateral gene transfer in Metazoa.

    Jensen, Lindy; Grant, Jessica R; Laughinghouse, Haywood Dail; Katz, Laura A

    2016-06-01

    A sequestered germline in Metazoa has been argued to be an obstacle to lateral gene transfer (LGT), though few studies have specifically assessed this claim. Here, we test the hypothesis that the origin of a sequestered germline reduced LGT events in Bilateria (i.e., triploblast lineages) as compared to early-diverging Metazoa (i.e., Ctenophora, Cnidaria, Porifera, and Placozoa). We analyze single-gene phylogenies generated with over 900 species sampled from among Bacteria, Archaea, and Eukaryota to identify well-supported interdomain LGTs. We focus on ancient interdomain LGT (i.e., those between prokaryotes and multiple lineages of Metazoa) as systematic errors in single-gene tree reconstruction create uncertainties for interpreting eukaryote-to-eukaryote transfer. The breadth of the sampled Metazoa enables us to estimate the timing of LGTs, and to examine the pattern before versus after the evolution of a sequestered germline. We identified 58 LGTs found only in Metazoa and prokaryotes (i.e., bacteria and/or archaea), and seven genes transferred from prokaryotes into Metazoa plus one other eukaryotic clade. Our analyses indicate that more interdomain transfers occurred before the development of a sequestered germline, consistent with the hypothesis that this feature is an obstacle to LGT. PMID:27139503

  15. Bacteriophage-like Particles Associated with the Gene Transfer Agent of Methanococcus Voltale PS

    Bertani, G.; Eiserling, F.; Pushkin, A.; Gingery, M.

    1999-01-01

    The methanogenic archaebacterium Methanococus voltae (strain PS) is known to produce a filterable, DNase resistant agent (called VTA, for voltae transfer agent), which carries very small fragments (4,400 base pairs) of bacterial DNA and is able to transduce bacterial genes between derivatives of the strain.

  16. Structural analysis of DNA sequence: evidence for lateral gene transfer in Thermotoga maritima

    Worning, Peder; Jensen, Lars Juhl; Nelson, K. E.;

    2000-01-01

    The recently published complete DNA sequence of the bacterium Thermotoga maritima provides evidence, based on protein sequence conservation, for lateral gene transfer between Archaea and Bacteria. We introduce a new method of periodicity analysis of DNA sequences, based on structural parameters, ...

  17. Current status of gene transfer into haemopoietic progenitor cells: application to Langerhans cell histiocytosis.

    M. Brenner

    1994-01-01

    A number of recent studies have shown that it is possible to obtain significant levels of gene transfer and expression in marrow progenitor cells and their progeny by using retroviral vectors. The data obtained from these studies and the possible applications to Langerhans cell histiocytosis (LCH) are reviewed.

  18. Horizontal Gene Transfer among Bacteria and Its Role in Biological Evolution

    Werner Arber

    2014-01-01

    This is a contribution to the history of scientific advance in the past 70 years concerning the identification of genetic information, its molecular structure, the identification of its functions and the molecular mechanisms of its evolution. Particular attention is thereby given to horizontal gene transfer among microorganisms, as well as to biosafety considerations with regard to beneficial applications of acquired scientific knowledge.

  19. Evolution of Acetoclastic Methanogenesis in Methanosarcina via Horizontal Gene Transfer from Cellulolytic Clostridia▿ †

    Fournier, Gregory P.; Gogarten, J. Peter

    2007-01-01

    Phylogenetic analysis confirmed that two genes required for acetoclastic methanogenesis, ackA and pta, were horizontally transferred to the ancestor of Methanosarcina from a derived cellulolytic organism in the class Clostridia. This event likely occurred within the last 475 million years, causing profound changes in planetary methane biogeochemistry.

  20. The evolution of land plants: a perspective from horizontal gene transfer

    Qia Wang; Hang Sun; Jinling Huang

    2014-01-01

    Recent studies suggest that horizontal gene transfer (HGT) played a significant role in the evolution of eukaryotic lineages. We here review the mechanisms of HGT in plants and the importance of HGT in land plant evolution. In particular, we discuss the role of HGT in plant colonization of land, phototropic response, C4 photosynthesis, and mitochondrial genome evolution.

  1. Molecular Evidence for the Evolution of Metal Homeostasis Genes by Lateral Gene Transfer in Bacteria from the Deep Terrestrial Subsurface

    Coombs, J. M.; Barkay, T.

    2004-01-01

    Lateral gene transfer (LGT) plays a vital role in increasing the genetic diversity of microorganisms and promoting the spread of fitness-enhancing phenotypes throughout microbial communities. To date, LGT has been investigated in surface soils, natural waters, and biofilm communities but not in the deep terrestrial subsurface. Here we used a combination of molecular analyses to investigate the role of LGT in the evolution of metal homeostasis in lead-resistant subsurface bacteria. A nested PC...

  2. Diversity, evolution, and horizontal gene transfer (HGT) in soda lakes

    Pinkart, Holly C.; Storrie-Lombardi, Michael C.

    2007-09-01

    Soap Lake is a hypersaline, alkaline lake in Central Washington State (USA). For the past five years the lake has been the site of an NSF Microbial Observatory project devoted to identifying critical geochemical and microbial characteristics of the monimolimnion sediment and water column, and has demonstrated rich multispecies communities occupy all areas of the lake. Soap Lake and similar soda lakes are subject to repeated transient periods of extreme evaporation characterized by significant repetitive alterations in salinity, pH, and total water volume, yet maintain high genetic and metabolic diversity. It has been argued that this repetitive cycle for salinity, alkalinity, and sulfur concentration has been a major driver for prokaryote evolution and diversity. The rapidity of wet-dry cycling places special demands on genome evolution, requirements that are beyond the relatively conservative eukaryotic evolutionary strategy of serial alteration of existing gene sequences in a relatively stable genome. Although HGT is most likely responsible for adding a significant amount of noise to the genetic record, analysis of HGT activity can also provide us with a much-needed probe for exploration of prokaryotic genome evolution and the origin of diversity. Packaging of genetic information within the protective protein capsid of a bacteriophage would seem preferable to exposing naked DNA to the highly alkaline conditions in the lake. In this study, we present preliminary data demonstrating the presence of a diverse group of phage integrases in Soap Lake. Integrase is the viral enzyme responsible for the insertion of phage DNA into the bacterial host's chromosome. The presence of the integrase sequence in bacterial chromosomes is evidence of lysogeny, and the diversity of integrase sequences reported here suggests a wide variety of temperate phage exist in this system, and are especially active in transition zones.

  3. Plasmid encoded antibiotic resistance: acquisition and transfer of antibiotic resistance genes in bacteria.

    Bennett, P M

    2008-03-01

    Bacteria have existed on Earth for three billion years or so and have become adept at protecting themselves against toxic chemicals. Antibiotics have been in clinical use for a little more than 6 decades. That antibiotic resistance is now a major clinical problem all over the world attests to the success and speed of bacterial adaptation. Mechanisms of antibiotic resistance in bacteria are varied and include target protection, target substitution, antibiotic detoxification and block of intracellular antibiotic accumulation. Acquisition of genes needed to elaborate the various mechanisms is greatly aided by a variety of promiscuous gene transfer systems, such as bacterial conjugative plasmids, transposable elements and integron systems, that move genes from one DNA system to another and from one bacterial cell to another, not necessarily one related to the gene donor. Bacterial plasmids serve as the scaffold on which are assembled arrays of antibiotic resistance genes, by transposition (transposable elements and ISCR mediated transposition) and site-specific recombination mechanisms (integron gene cassettes).The evidence suggests that antibiotic resistance genes in human bacterial pathogens originate from a multitude of bacterial sources, indicating that the genomes of all bacteria can be considered as a single global gene pool into which most, if not all, bacteria can dip for genes necessary for survival. In terms of antibiotic resistance, plasmids serve a central role, as the vehicles for resistance gene capture and their subsequent dissemination. These various aspects of bacterial resistance to antibiotics will be explored in this presentation. PMID:18193080

  4. Phylogenetic evidence for lateral gene transfer in the intestine of marine iguanas.

    David M Nelson

    Full Text Available BACKGROUND: Lateral gene transfer (LGT appears to promote genotypic and phenotypic variation in microbial communities in a range of environments, including the mammalian intestine. However, the extent and mechanisms of LGT in intestinal microbial communities of non-mammalian hosts remains poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: We sequenced two fosmid inserts obtained from a genomic DNA library derived from an agar-degrading enrichment culture of marine iguana fecal material. The inserts harbored 16S rRNA genes that place the organism from which they originated within Clostridium cluster IV, a well documented group that habitats the mammalian intestinal tract. However, sequence analysis indicates that 52% of the protein-coding genes on the fosmids have top BLASTX hits to bacterial species that are not members of Clostridium cluster IV, and phylogenetic analysis suggests that at least 10 of 44 coding genes on the fosmids may have been transferred from Clostridium cluster XIVa to cluster IV. The fosmids encoded four transposase-encoding genes and an integrase-encoding gene, suggesting their involvement in LGT. In addition, several coding genes likely involved in sugar transport were probably acquired through LGT. CONCLUSION: Our phylogenetic evidence suggests that LGT may be common among phylogenetically distinct members of the phylum Firmicutes inhabiting the intestinal tract of marine iguanas.

  5. The effect of interleukin-6 gene transfer on human cord blood megakaryopoiesis

    Yang Xingsheng; Hitoshi Kurata; Kazuyuki Fujita; Kenichi Tanaka

    2004-01-01

    Objective:To investigate the effect of IL-6 gene transfer into human cord blood hematopoietic stem cells on the production of megakaryocytic progenitors. Methods: IL-6 gene was transfected into human cord blood CD34 + cells using a retrovirus vector with the aid of recombinant fibronectin fragments in the presence of a cocktail of cytokines (SCF, IL-6, sIL-6R, FL, and TPO). Colony-forming units-megakaryocyte (CFU-MK) assays were perfonned as IL-6 gene transduced CD34 + cells were incubated alone or in combination with IL-3 or sIL-6R, controlled with neoR gene transduced CD34 + cells. Results: IL-6 alone or sIL-6R alone stimulated few CFU-MK colonies, the addition of sIL-6R to IL-6 gene transduced CD34 + cells significantly enhanced the production of CFU-MK colonies. IL-6 gene transduced CD34 + cells showed a modest synergistic effect with IL-3. Conclusion: These results suggest that IL-6 gene transfer may protect patients from chemotherapy-induced thrombocytopenia.

  6. Lentivirus-mediated gene transfer to the central nervous system: therapeutic and research applications.

    Wong, Liang-Fong; Goodhead, Lucy; Prat, Christine; Mitrophanous, Kyriacos A; Kingsman, Susan M; Mazarakis, Nicholas D

    2006-01-01

    The management of disorders of the nervous system remains a medical challenge. The key goals are to understand disease mechanisms, to validate therapeutic targets, and to develop new therapeutic strategies. Viral vector-mediated gene transfer can meet these goals and vectors based on lentiviruses have particularly useful features. Lentiviral vectors can deliver 8 kb of sequence, they mediate gene transfer into any neuronal cell type, expression and therapy are sustained, and normal cellular functions in vitro and in vivo are not compromised. After delivery into the nervous system they induce no significant immune responses, there are no unwanted side effects of the vectors per se to date, and manufacturing and safety testing for clinical applications are well advanced. There are now numerous examples of effective long-term treatment of animal models of neurological disorders, such as Parkinson's disease, Alzheimer's disease, Huntington's disease, motor neuron diseases, lysosomal storage diseases, and spinal injury, using a range of therapeutic genes expressed in lentiviral vectors. Significant issues remain in some areas of neural gene therapy including defining the optimum therapeutic gene(s), increasing the specificity of delivery, regulating expression of potentially toxic genes, and designing clinically relevant strategies. We discuss the applications of lentiviral vectors in therapy and research and highlight the essential features that will ensure their translation to the clinic in the near future. PMID:16409120

  7. Optimization of the uidA Gene Transfer of Rosa hybrida via Agrobacterium tumefaciens:an Assessment of Factors Influencing the Efficiency of Gene Transfer

    Gao Liping; Bao Manzhu

    2004-01-01

    To develop a transformation protocol of Rosa hybrida 'Samantha' via Agrobacterium tumefaciens, the authors examined the effect of different factors on T-DNA transfer by measuring transient expression levels of an intron-containing β-glucuronidase gene. The results indicate that explant, light condition, salt concentration and acetosyringone (AS) concentration in co-culture medium are the most important factors, and factors like co-culture temperature, co-culture period and bacteria density have a strong effect on the growth of bacteria and then T-DNA transfer. Optimized co-cultivation was performed by inoculation of embryogenic callus with bacteria at a density of OD600= 0.5-0.8 for 20 min and co-culture in darkness under 23 °C on medium with 1/2 MS salts and 300 μmol·L-1 AS for 3 d.

  8. Chromosomal nif Genes Transfer by Conjugation in Nitrogen Fixing Azotobacter chroococcum to Lactobacillus plantarium

    Adel Kamal Khider

    2011-03-01

    Full Text Available To determine the possibility of transferring chromosomal nitrogen fixation genes (nif genes from Azotobacter chroococcum to Lactobacillus planetarium, a total of 72 Azotobacter chroococcum isolated from Erbil governorate, Iraq were culturally, morphologically and biochemically characterized. Genes for atmospheric nitrogen fixation, located on the chromosome of Azotobacter chroococcum isolates were transferred by conjugation process to a recipient Lactobacillus plantarium isolated from Erbil city soils. The chromosomal genes transferred were verified by analysis of the genomes of donor, recipient and putative transconjugants, by polymorphism of DNA bands obtained through amplification of nifH1, nifH2, nifH3, nifU and nifV genes by PCR technique. The transconjugant cells promote an efficient fixation of nitrogen in liquid cultures fixed 0.2% nitrogen, and in the soil as inoculums of wheat plants, fixed 0.31% nitrogen and solublized 11.71 ppm phosphorus, beside all advantages of Lactic acid bacteria, and probably to be used as inoculums for both nitrogen fixation and solublizing insoluble phosphorus components, and used as biofertilizers

  9. Adenoviral-mediated correction of methylmalonyl-CoA mutase deficiency in murine fibroblasts and human hepatocytes

    Korson Mark

    2007-04-01

    Full Text Available Abstract Background Methylmalonic acidemia (MMA, a common organic aciduria, is caused by deficiency of the mitochondrial localized, 5'deoxyadenosylcobalamin dependent enzyme, methylmalonyl-CoA mutase (MUT. Liver transplantation in the absence of gross hepatic dysfunction provides supportive therapy and metabolic stability in severely affected patients, which invites the concept of using cell and gene delivery as future treatments for this condition. Methods To assess the effectiveness of gene delivery to restore the defective metabolism in this disorder, adenoviral correction experiments were performed using murine Mut embryonic fibroblasts and primary human methylmalonyl-CoA mutase deficient hepatocytes derived from a patient who harbored two early truncating mutations, E224X and R228X, in the MUT gene. Enzymatic and expression studies were used to assess the extent of functional correction. Results Primary hepatocytes, isolated from the native liver after removal subsequent to a combined liver-kidney transplantation procedure, or Mut murine fibroblasts were infected with a second generation recombinant adenoviral vector that expressed the murine methylmalonyl-CoA mutase as well as eGFP from distinct promoters. After transduction, [1-14C] propionate macromolecular incorporation studies and Western analysis demonstrated complete correction of the enzymatic defect in both cell types. Viral reconstitution of enzymatic expression in the human methylmalonyl-CoA mutase deficient hepatocytes exceeded that seen in fibroblasts or control hepatocytes. Conclusion These experiments provide proof of principle for viral correction in methylmalonic acidemia and suggest that hepatocyte-directed gene delivery will be an effective therapeutic treatment strategy in both murine models and in human patients. Primary hepatocytes from a liver that was unsuitable for transplantation provided an important resource for these studies.

  10. Gene transfer and genome-wide insertional mutagenesis by retroviral transduction in fish stem cells.

    Qizhi Liu

    Full Text Available Retrovirus (RV is efficient for gene transfer and integration in dividing cells of diverse organisms. RV provides a powerful tool for insertional mutagenesis (IM to identify and functionally analyze genes essential for normal and pathological processes. Here we report RV-mediated gene transfer and genome-wide IM in fish stem cells from medaka and zebrafish. Three RVs were produced for fish cell transduction: rvLegfp and rvLcherry produce green fluorescent protein (GFP and mCherry fluorescent protein respectively under control of human cytomegalovirus immediate early promoter upon any chromosomal integration, whereas rvGTgfp contains a splicing acceptor and expresses GFP only upon gene trapping (GT via intronic in-frame integration and spliced to endogenous active genes. We show that rvLegfp and rvLcherry produce a transduction efficiency of 11~23% in medaka and zebrafish stem cell lines, which is as 30~67% efficient as the positive control in NIH/3T3. Upon co-infection with rvGTgfp and rvLcherry, GFP-positive cells were much fewer than Cherry-positive cells, consistent with rareness of productive gene trapping events versus random integration. Importantly, rvGTgfp infection in the medaka haploid embryonic stem (ES cell line HX1 generated GTgfp insertion on all 24 chromosomes of the haploid genome. Similar to the mammalian haploid cells, these insertion events were presented predominantly in intergenic regions and introns but rarely in exons. RV-transduced HX1 retained the ES cell properties such as stable growth, embryoid body formation and pluripotency gene expression. Therefore, RV is proficient for gene transfer and IM in fish stem cells. Our results open new avenue for genome-wide IM in medaka haploid ES cells in culture.

  11. Using the nucleotide substitution rate matrix to detect horizontal gene transfer

    Betterton M D

    2006-10-01

    Full Text Available Abstract Background Horizontal gene transfer (HGT has allowed bacteria to evolve many new capabilities. Because transferred genes perform many medically important functions, such as conferring antibiotic resistance, improved detection of horizontally transferred genes from sequence data would be an important advance. Existing sequence-based methods for detecting HGT focus on changes in nucleotide composition or on differences between gene and genome phylogenies; these methods have high error rates. Results First, we introduce a new class of methods for detecting HGT based on the changes in nucleotide substitution rates that occur when a gene is transferred to a new organism. Our new methods discriminate simulated HGT events with an error rate up to 10 times lower than does GC content. Use of models that are not time-reversible is crucial for detecting HGT. Second, we show that using combinations of multiple predictors of HGT offers substantial improvements over using any single predictor, yielding as much as a factor of 18 improvement in performance (a maximum reduction in error rate from 38% to about 3%. Multiple predictors were combined by using the random forests machine learning algorithm to identify optimal classifiers that separate HGT from non-HGT trees. Conclusion The new class of HGT-detection methods introduced here combines advantages of phylogenetic and compositional HGT-detection techniques. These new techniques offer order-of-magnitude improvements over compositional methods because they are better able to discriminate HGT from non-HGT trees under a wide range of simulated conditions. We also found that combining multiple measures of HGT is essential for detecting a wide range of HGT events. These novel indicators of horizontal transfer will be widely useful in detecting HGT events linked to the evolution of important bacterial traits, such as antibiotic resistance and pathogenicity.

  12. Source-sink plasmid transfer dynamics maintain gene mobility in soil bacterial communities.

    Hall, James P J; Wood, A Jamie; Harrison, Ellie; Brockhurst, Michael A

    2016-07-19

    Horizontal gene transfer is a fundamental process in bacterial evolution that can accelerate adaptation via the sharing of genes between lineages. Conjugative plasmids are the principal genetic elements mediating the horizontal transfer of genes, both within and between bacterial species. In some species, plasmids are unstable and likely to be lost through purifying selection, but when alternative hosts are available, interspecific plasmid transfer could counteract this and maintain access to plasmid-borne genes. To investigate the evolutionary importance of alternative hosts to plasmid population dynamics in an ecologically relevant environment, we established simple soil microcosm communities comprising two species of common soil bacteria, Pseudomonas fluorescens and Pseudomonas putida, and a mercury resistance (Hg(R)) plasmid, pQBR57, both with and without positive selection [i.e., addition of Hg(II)]. In single-species populations, plasmid stability varied between species: although pQBR57 survived both with and without positive selection in P. fluorescens, it was lost or replaced by nontransferable Hg(R) captured to the chromosome in P. putida A simple mathematical model suggests these differences were likely due to pQBR57's lower intraspecific conjugation rate in P. putida By contrast, in two-species communities, both models and experiments show that interspecific conjugation from P. fluorescens allowed pQBR57 to persist in P. putida via source-sink transfer dynamics. Moreover, the replacement of pQBR57 by nontransferable chromosomal Hg(R) in P. putida was slowed in coculture. Interspecific transfer allows plasmid survival in host species unable to sustain the plasmid in monoculture, promoting community-wide access to the plasmid-borne accessory gene pool and thus potentiating future evolvability. PMID:27385827

  13. Source–sink plasmid transfer dynamics maintain gene mobility in soil bacterial communities

    Wood, A. Jamie

    2016-01-01

    Horizontal gene transfer is a fundamental process in bacterial evolution that can accelerate adaptation via the sharing of genes between lineages. Conjugative plasmids are the principal genetic elements mediating the horizontal transfer of genes, both within and between bacterial species. In some species, plasmids are unstable and likely to be lost through purifying selection, but when alternative hosts are available, interspecific plasmid transfer could counteract this and maintain access to plasmid-borne genes. To investigate the evolutionary importance of alternative hosts to plasmid population dynamics in an ecologically relevant environment, we established simple soil microcosm communities comprising two species of common soil bacteria, Pseudomonas fluorescens and Pseudomonas putida, and a mercury resistance (HgR) plasmid, pQBR57, both with and without positive selection [i.e., addition of Hg(II)]. In single-species populations, plasmid stability varied between species: although pQBR57 survived both with and without positive selection in P. fluorescens, it was lost or replaced by nontransferable HgR captured to the chromosome in P. putida. A simple mathematical model suggests these differences were likely due to pQBR57’s lower intraspecific conjugation rate in P. putida. By contrast, in two-species communities, both models and experiments show that interspecific conjugation from P. fluorescens allowed pQBR57 to persist in P. putida via source–sink transfer dynamics. Moreover, the replacement of pQBR57 by nontransferable chromosomal HgR in P. putida was slowed in coculture. Interspecific transfer allows plasmid survival in host species unable to sustain the plasmid in monoculture, promoting community-wide access to the plasmid-borne accessory gene pool and thus potentiating future evolvability. PMID:27385827

  14. Growth enhancement of shrimp (Litopenaeus schmitti) after transfer of tilapia growth hormone gene.

    Arenal, Amilcar; Pimentel, Rafael; Pimentel, Eulogio; Martín, Leonardo; Santiesteban, Dayamí; Franco, Ramón; Aleström, Peter

    2008-05-01

    Electroporation of Litopenaeus schmitti embryos was used to transfer the pE300tiGH15 plasmid that contains the tilapia growth hormone gene (tiGH) complexed with a nuclear localization signal peptide into the zygotes. The gene construct was detected in 35 (36%) of the 98 larvae screened by PCR and Southern blot analyses. Western blot analyses revealed that 34% of the screened larvae expressed a single tiGH-specific band with the expected molecular mass (23.1 kDa). The development index and larval length indicated a significant growth enhancement from day 3 on after electroporation, with an average of 32% of the growth enhancement. To our knowledge, this is the first report on gene transfer enhanced growth in crustaceans. PMID:18204820

  15. The influence of gene transfer on the lactic acid bacteria evolution

    Višnja Bačun-Družina

    2009-09-01

    Full Text Available In the case of preparing various dairy products, the exploitation of lactic acid bacteria has been essential in the course of past millennia in all known nations. Numerous comparative analyses of gene and genome sequences reveal that the exchange of genetic material within and between bacterial species is far more general and frequent than has previously been thought. Consequently, the horizontal gene transfer between distant species or within the same species is an important factor in the Lactobacillales evolution. Knowledge about the exchange of lactobacillus genetic information through horizontal gene transfer, mobile genetic elements, and its evolution is very important due to characterizations and stability maintenance of autochthonous as well as industrial lactic acid bacteria strains in dairy products that benefit human health.

  16. Parallel Evolution and Horizontal Gene Transfer of the pst Operon in Firmicutes from Oligotrophic Environments

    Alejandra Moreno-Letelier

    2011-01-01

    Full Text Available The high affinity phosphate transport system (pst is crucial for phosphate uptake in oligotrophic environments. Cuatro Cienegas Basin (CCB has extremely low P levels and its endemic Bacillus are closely related to oligotrophic marine Firmicutes. Thus, we expected the pst operon of CCB to share the same evolutionary history and protein similarity to marine Firmicutes. Orthologs of the pst operon were searched in 55 genomes of Firmicutes and 13 outgroups. Phylogenetic reconstructions were performed for the pst operon and 14 concatenated housekeeping genes using maximum likelihood methods. Conserved domains and 3D structures of the phosphate-binding protein (PstS were also analyzed. The pst operon of Firmicutes shows two highly divergent clades with no correlation to the type of habitat nor a phylogenetic congruence, suggesting horizontal gene transfer. Despite sequence divergence, the PstS protein had a similar 3D structure, which could be due to parallel evolution after horizontal gene transfer events.

  17. Homologous recombination mediates functional recovery of dysferlin deficiency following AAV5 gene transfer.

    William E Grose

    Full Text Available The dysferlinopathies comprise a group of untreatable muscle disorders including limb girdle muscular dystrophy type 2B, Miyoshi myopathy, distal anterior compartment syndrome, and rigid spine syndrome. As with other forms of muscular dystrophy, adeno-associated virus (AAV gene transfer is a particularly auspicious treatment strategy, however the size of the DYSF cDNA (6.5 kb negates packaging into traditional AAV serotypes known to express well in muscle (i.e. rAAV1, 2, 6, 8, 9. Potential advantages of a full cDNA versus a mini-gene include: maintaining structural-functional protein domains, evading protein misfolding, and avoiding novel epitopes that could be immunogenic. AAV5 has demonstrated unique plasticity with regards to packaging capacity and recombination of virions containing homologous regions of cDNA inserts has been implicated in the generation of full-length transcripts. Herein we show for the first time in vivo that homologous recombination following AAV5.DYSF gene transfer leads to the production of full length transcript and protein. Moreover, gene transfer of full-length dysferlin protein in dysferlin deficient mice resulted in expression levels sufficient to correct functional deficits in the diaphragm and importantly in skeletal muscle membrane repair. Intravascular regional gene transfer through the femoral artery produced high levels of transduction and enabled targeting of specific muscle groups affected by the dysferlinopathies setting the stage for potential translation to clinical trials. We provide proof of principle that AAV5 mediated delivery of dysferlin is a highly promising strategy for treatment of dysferlinopathies and has far-reaching implications for the therapeutic delivery of other large genes.

  18. Cumulus-specific genes are transcriptionally silent following somatic cell nuclear transfer in a mouse model

    2007-01-01

    This study investigated whether four cumulus-specific genes: follicular stimulating hormone receptor (FSHr), hyaluronan synthase 2 (Has2), prostaglandin synthase 2 (Ptgs2) and steroidogenic acute regulator protein (Star), were correctly reprogrammed to be transcriptionally silent following somatic cell nuclear transfer (SCNT) in a murine model. Cumulus cells of C57×CBA F1 female mouse were injected into enucleated oocytes, followed by activation in 10 μmol/L strontium chloride for 5 h and subsequent in vitro culture up to the blastocyst stage. Expression of cumulus-specific genes in SCNT-derived embryos at 2-cell, 4-cell and day 4.5 blastocyst stages was compared with corresponding in vivo fertilized embryos by real-time PCR. It was demonstrated that immediately after the first cell cycle, SCNT-derived 2-cell stage embryos did not express all four cumulus-specific genes, which continually remained silent at the 4-cell and blastocyst stages. It is therefore concluded that all four cumulus-specific genes were correctly reprogrammed to be silent following nuclear transfer with cumulus donor cells in the mouse model. This would imply that the poor preimplantation developmental competence of SCNT embryos derived from cumulus cells is due to incomplete reprogramming of other embryonic genes, rather than cumulus-specific genes.

  19. Targeted disruption of Ataxia-telangiectasia mutated gene in miniature pigs by somatic cell nuclear transfer

    Kim, Young June; Ahn, Kwang Sung; Kim, Minjeong; Kim, Min Ju; Park, Sang-Min; Ryu, Junghyun; Ahn, Jin Seop; Heo, Soon Young; Kang, Jee Hyun; Choi, You Jung [Department of Nanobiomedical Science and BK21 PLUS NBM Global Research Center for Regenerative Medicine, Dankook University, Cheonan (Korea, Republic of); Choi, Seong-Jun [Institute of Tissue Regeneration Engineering, Dankook University, Cheonan (Korea, Republic of); Shim, Hosup, E-mail: shim@dku.edu [Department of Nanobiomedical Science and BK21 PLUS NBM Global Research Center for Regenerative Medicine, Dankook University, Cheonan (Korea, Republic of); Institute of Tissue Regeneration Engineering, Dankook University, Cheonan (Korea, Republic of); Department of Physiology, Dankook University School of Medicine, Cheonan (Korea, Republic of)

    2014-10-03

    Highlights: • ATM gene-targeted pigs were produced by somatic cell nuclear transfer. • A novel large animal model for ataxia telangiectasia was developed. • The new model may provide an alternative to the mouse model. - Abstract: Ataxia telangiectasia (A-T) is a recessive autosomal disorder associated with pleiotropic phenotypes, including progressive cerebellar degeneration, gonad atrophy, and growth retardation. Even though A-T is known to be caused by the mutations in the Ataxia telangiectasia mutated (ATM) gene, the correlation between abnormal cellular physiology caused by ATM mutations and the multiple symptoms of A-T disease has not been clearly determined. None of the existing ATM mouse models properly reflects the extent to which neurological degeneration occurs in human. In an attempt to provide a large animal model for A-T, we produced gene-targeted pigs with mutations in the ATM gene by somatic cell nuclear transfer. The disrupted allele in the ATM gene of cloned piglets was confirmed via PCR and Southern blot analysis. The ATM gene-targeted pigs generated in the present study may provide an alternative to the current mouse model for the study of mechanisms underlying A-T disorder and for the development of new therapies.

  20. Growth factor enhanced retroviral gene transfer to the adult central nervous system.

    King, L A; Mitrophanous, K A; Clark, L A; Kim, V N; Rohll, J B; Kingsman, A J; Colello, R J

    2000-07-01

    The use of viral vectors for gene delivery into mammalian cells provides a new approach in the treatment of many human diseases. The first viral vector approved for human clinical trials was murine leukemia virus (MLV), which remains the most commonly used vector in clinical trials to date. However, the application of MLV vectors is limited since MLV requires cells to be actively dividing in order for transduction and therefore gene delivery to occur. This limitation precludes the use of MLV for delivering genes to the adult CNS, where very little cell division is occurring. However, we speculated that this inherent limitation of ML V may be overcome by utilizing the known mitogenic effect of growth factors on cells of the CNS. Specifically, an in vivo application of growth factor to the adult brain, if able to induce cell division, could enhance MLV-based gene transfer to the adult brain. We now show that an exogenous application of basic fibroblast growth factor induces cell division in vivo. Under these conditions, where cells of the adult brain are stimulated to divide, MLV-based gene transfer is significantly enhanced. This novel approach precludes any vector modifications and provides a simple and effective way of delivering genes to cells of the adult brain utilizing MLV-based retroviral vectors. PMID:10918476

  1. Targeted disruption of Ataxia-telangiectasia mutated gene in miniature pigs by somatic cell nuclear transfer

    Highlights: • ATM gene-targeted pigs were produced by somatic cell nuclear transfer. • A novel large animal model for ataxia telangiectasia was developed. • The new model may provide an alternative to the mouse model. - Abstract: Ataxia telangiectasia (A-T) is a recessive autosomal disorder associated with pleiotropic phenotypes, including progressive cerebellar degeneration, gonad atrophy, and growth retardation. Even though A-T is known to be caused by the mutations in the Ataxia telangiectasia mutated (ATM) gene, the correlation between abnormal cellular physiology caused by ATM mutations and the multiple symptoms of A-T disease has not been clearly determined. None of the existing ATM mouse models properly reflects the extent to which neurological degeneration occurs in human. In an attempt to provide a large animal model for A-T, we produced gene-targeted pigs with mutations in the ATM gene by somatic cell nuclear transfer. The disrupted allele in the ATM gene of cloned piglets was confirmed via PCR and Southern blot analysis. The ATM gene-targeted pigs generated in the present study may provide an alternative to the current mouse model for the study of mechanisms underlying A-T disorder and for the development of new therapies

  2. Highly efficient adenoviral transduction of pancreatic islets using a microfluidic device.

    Silva, Pamuditha N; Atto, Zaid; Regeenes, Romario; Tufa, Uilki; Chen, Yih Yang; Chan, Warren C W; Volchuk, Allen; Kilkenny, Dawn M; Rocheleau, Jonathan V

    2016-08-01

    Tissues are challenging to genetically manipulate due to limited penetration of viral particles resulting in low transduction efficiency. We are particularly interested in expressing genetically-encoded sensors in ex vivo pancreatic islets to measure glucose-stimulated metabolism, however poor viral penetration biases these measurements to only a subset of cells at the periphery. To increase mass transfer of viral particles, we designed a microfluidic device that holds islets in parallel hydrodynamic traps connected by an expanding by-pass channel. We modeled viral particle flow into the tissue using fluorescently-labelled gold nanoparticles of varying sizes and showed a penetration threshold of only ∼5 nm. To increase this threshold, we used EDTA to transiently reduce cell-cell adhesion and expand intercellular space. Ultimately, a combination of media flow and ETDA treatment significantly increased adenoviral transduction to the core of the islet. As proof-of-principle, we used this protocol to transduce an ER-targeted redox sensitive sensor (eroGFP), and revealed significantly greater ER redox capacity at core islet cells. Overall, these data demonstrate a robust method to enhance transduction efficiency of islets, and potentially other tissues, by using a combination of microfluidic flow and transient tissue expansion. PMID:27378588

  3. Ionizing and ultraviolet radiation enhances the efficiency of DNA mediated gene transfer in vitro

    The enhancement effects of ionizing and non-ionizing radiation on the efficiency of DNA mediated gene transfer were studied. Confluent Rat-2 cells were transfected with purified SV40 viral DNA, irradiated with either X-rays or ultraviolet, trypsinized, plated, and assayed for the formation of foci on Rat-2 monolayers. Both ionizing and ultraviolet radiation enhanced the frequency of A-gene transformants/survivor compared to unirradiated transfected cells. These enhancements were non-linear and dose dependent. A recombinant plasmid, pOT-TK5, was constructed that contained the SV40 virus A-gene and the Herpes Simplex virus (HSV) thymidine kinase (TK) gene. Confluent Rat-2 cells transfected with pOT-TK5 DNA and then immediately irradiated with either X-rays or 330 MeV/amu argon particles at the Berkeley Bevalac showed a higher frequency of HAT+ colonies/survivor than unirradiated transfected cells. Rat-2 cells transfected with the plasmid, pTK2, containing only the HSV TK-gene were enhanced for TK-transformation by both X-rays and ultraviolet radiation. The results demonstrate that radiation enhancement of the efficiency of DNA mediated gene transfer is not explained by increased nuclear uptake of the transfected DNA. Radiation increases the competence of the transfected cell population for genetic transformation. Three models for this increased competence are presented. The targeted integration model, the inducible recombination model, the partition model, and the utilization of DNA mediated gene transfer for DNA repair studies are discussed. 465 references

  4. Ionizing and ultraviolet radiation enhances the efficiency of DNA mediated gene transfer in vitro

    Perez, C.F.

    1984-08-01

    The enhancement effects of ionizing and non-ionizing radiation on the efficiency of DNA mediated gene transfer were studied. Confluent Rat-2 cells were transfected with purified SV40 viral DNA, irradiated with either X-rays or ultraviolet, trypsinized, plated, and assayed for the formation of foci on Rat-2 monolayers. Both ionizing and ultraviolet radiation enhanced the frequency of A-gene transformants/survivor compared to unirradiated transfected cells. These enhancements were non-linear and dose dependent. A recombinant plasmid, pOT-TK5, was constructed that contained the SV40 virus A-gene and the Herpes Simplex virus (HSV) thymidine kinase (TK) gene. Confluent Rat-2 cells transfected with pOT-TK5 DNA and then immediately irradiated with either X-rays or 330 MeV/amu argon particles at the Berkeley Bevalac showed a higher frequency of HAT/sup +/ colonies/survivor than unirradiated transfected cells. Rat-2 cells transfected with the plasmid, pTK2, containing only the HSV TK-gene were enhanced for TK-transformation by both X-rays and ultraviolet radiation. The results demonstrate that radiation enhancement of the efficiency of DNA mediated gene transfer is not explained by increased nuclear uptake of the transfected DNA. Radiation increases the competence of the transfected cell population for genetic transformation. Three models for this increased competence are presented. The targeted integration model, the inducible recombination model, the partition model, and the utilization of DNA mediated gene transfer for DNA repair studies are discussed. 465 references.

  5. Horizontal gene transfers and cell fusions in microbiology, immunology and oncology (Review).

    Sinkovics, Joseph G

    2009-09-01

    Evolving young genomes of archaea, prokaryota and unicellular eukaryota were wide open for the acceptance of alien genomic sequences, which they often preserved and vertically transferred to their descendants throughout three billion years of evolution. Established complex large genomes, although seeded with ancestral retroelements, have come to regulate strictly their integrity. However, intruding retroelements, especially the descendents of Ty3/Gypsy, the chromoviruses, continue to find their ways into even the most established genomes. The simian and hominoid-Homo genomes preserved and accommodated a large number of endogenous retroviral genomic segments. These retroelements may mature into exogenous retroviruses, or into functional new genes. Phages and viruses have been instrumental in incorporating and transferring host cell genes. These events profoundly influenced and altered the course of evolution. Horizontal (lateral) gene transfers (HGT) overwhelmed the genomes of the ancient protocells and the evolving unicellular microorganisms, actually leading to their Cambrian explosion. While the rigidly organized genomes of multicellular organisms increasingly resist H/LGT, de-differentiated cells assuming the metabolism of their onto- or phylogenetic ancestors, open up widely to the practice of H/LGT by direct transfer, or to transfers mediated by viruses, or by cell fusions. This activity is intensified in malignantly transformed cells, thus rendering these subjects receptive to therapy with oncolytic viruses and with viral vectors of tumor-suppressive or immunogenic genetic materials. Naturally formed hybrids of dendritic and tumor cells are often tolerogenic, whereas laboratory products of these unisons may be immunogenic in the hosts of origin. As human breast cancer stem cells are induced by a treacherous class of CD8+ T cells to undergo epithelial to mesenchymal (ETM) transition and to yield to malignant transformation by the omnipresent proto

  6. Sequence diversities of serine-aspartate repeat genes among Staphylococcus aureus isolates from different hosts presumably by horizontal gene transfer.

    Huping Xue

    Full Text Available BACKGROUND: Horizontal gene transfer (HGT is recognized as one of the major forces for bacterial genome evolution. Many clinically important bacteria may acquire virulence factors and antibiotic resistance through HGT. The comparative genomic analysis has become an important tool for identifying HGT in emerging pathogens. In this study, the Serine-Aspartate Repeat (Sdr family has been compared among different sources of Staphylococcus aureus (S. aureus to discover sequence diversities within their genomes. METHODOLOGY/PRINCIPAL FINDINGS: Four sdr genes were analyzed for 21 different S. aureus strains and 218 mastitis-associated S. aureus isolates from Canada. Comparative genomic analyses revealed that S. aureus strains from bovine mastitis (RF122 and mastitis isolates in this study, ovine mastitis (ED133, pig (ST398, chicken (ED98, and human methicillin-resistant S. aureus (MRSA (TCH130, MRSA252, Mu3, Mu50, N315, 04-02981, JH1 and JH9 were highly associated with one another, presumably due to HGT. In addition, several types of insertion and deletion were found in sdr genes of many isolates. A new insertion sequence was found in mastitis isolates, which was presumably responsible for the HGT of sdrC gene among different strains. Moreover, the sdr genes could be used to type S. aureus. Regional difference of sdr genes distribution was also indicated among the tested S. aureus isolates. Finally, certain associations were found between sdr genes and subclinical or clinical mastitis isolates. CONCLUSIONS: Certain sdr gene sequences were shared in S. aureus strains and isolates from different species presumably due to HGT. Our results also suggest that the distributional assay of virulence factors should detect the full sequences or full functional regions of these factors. The traditional assay using short conserved regions may not be accurate or credible. These findings have important implications with regard to animal husbandry practices that may

  7. Plant-Agrobacterium interaction mediated by ethylene and super-Agrobacterium conferring efficient gene transfer ability

    Satoko eNonaka

    2014-12-01

    Full Text Available Agrobacterium tumefaciens has a unique ability to transfer genes into plant genomes. This ability has been utilized for plant genetic engineering. However, the efficiency is not sufficient for all plant species. Several studies have shown that ethylene decreased the Agrobacterium-mediated transformation frequency. Thus, A. tumefaciens with an ability to suppress ethylene evolution would increase the efficiency of Agrobacterium-mediated transformation. Some studies showed that plant growth-promoting rhizobacteria (PGPR can reduce ethylene levels in plants through 1-aminocyclopropane-1-carboxylic acid (ACC deaminase, which cleaves the ethylene precursor ACC into α-ketobutyrate and ammonia, resulting in reduced ethylene production. The whole genome sequence data showed that A. tumefaciens does not possess an ACC deaminase gene in its genome. Therefore, providing ACC deaminase activity to the bacteria would improve gene transfer. As expected, A. tumefaciens with ACC deaminase activity, designated as super-Agrobacterium, could suppress ethylene evolution and increase the gene transfer efficiency in several plant species. In this review, we summarize plant–Agrobacterium interactions and their applications for improving Agrobacterium-mediated genetic engineering techniques via super-Agrobacterium.

  8. Evidence of recent interkingdom horizontal gene transfer between bacteria and Candida parapsilosis

    Butler Geraldine

    2008-06-01

    Full Text Available Abstract Background To date very few incidences of interdomain gene transfer into fungi have been identified. Here, we used the emerging genome sequences of Candida albicans WO-1, Candida tropicalis, Candida parapsilosis, Clavispora lusitaniae, Pichia guilliermondii, and Lodderomyces elongisporus to identify recent interdomain HGT events. We refer to these as CTG species because they translate the CTG codon as serine rather than leucine, and share a recent common ancestor. Results Phylogenetic and syntenic information infer that two C. parapsilosis genes originate from bacterial sources. One encodes a putative proline racemase (PR. Phylogenetic analysis also infers that there were independent transfers of bacterial PR enzymes into members of the Pezizomycotina, and protists. The second HGT gene in C. parapsilosis belongs to the phenazine F (PhzF superfamily. Most CTG species also contain a fungal PhzF homolog. Our phylogeny suggests that the CTG homolog originated from an ancient HGT event, from a member of the proteobacteria. An analysis of synteny suggests that C. parapsilosis has lost the endogenous fungal form of PhzF, and subsequently reacquired it from a proteobacterial source. There is evidence that Schizosaccharomyces pombe and Basidiomycotina also obtained a PhzF homolog through HGT. Conclusion Our search revealed two instances of well-supported HGT from bacteria into the CTG clade, both specific to C. parapsilosis. Therefore, while recent interkingdom gene transfer has taken place in the CTG lineage, its occurrence is rare. However, our analysis will not detect ancient gene transfers, and we may have underestimated the global extent of HGT into CTG species.

  9. Fc receptor-mediated, antibody-dependent enhancement of bacteriophage lambda-mediated gene transfer in mammalian cells

    Sapinoro, Ramil; Volcy, Ketna; Shanaka, W.W.; Rodrigo, I.; Schlesinger, Jacob J.; Dewhurst, Stephen

    2008-01-01

    Lambda phage vectors mediate gene transfer in cultured mammalian cells and in live mice, and in vivo phage-mediated gene expression is increased when mice are pre-immunized with bacteriophage lambda. We now show that, like eukaryotic viruses, bacteriophage vectors are subject to Fc receptor-mediated, antibody-dependent enhancement of infection in mammalian cells. Antibody-dependent enhancement of phage gene transfer required FcγRI, but not its associated γ chain, and was not supported by othe...

  10. Retroviral-mediated transfer of genomic globin genes leads to regulated production of RNA and protein

    A high-titer amphotropic retroviral vector containing the neomycin resistance gene and a hybrid γ-β genomic human globin gene has been constructed. Mouse erythroleukemia cells infected with this virus were found to contain the full transcriptional unit of the transferred human globin gene by Southern blot analysis. These cells contain normally initiated, spliced, and terminated human globin mRNA. The human globin mRNA level increased 5- to 10-fold upon induction of the mouse erythroleukemia cells. Human globin chains were produced but only in a fraction of the cells as detected by immunofluorescent staining. A similar retrovirus containing a human β-globin gene was used to transduce mouse erythroleukemia cells resulting in much higher levels of human globin synthesis than detected in mouse erythroleukemia cells transduced with the γ-β globin virus

  11. Phylogeographic reconstruction of a bacterial species with high levels of lateral gene transfer

    Kaul Rajinder

    2009-11-01

    Full Text Available Abstract Background Phylogeographic reconstruction of some bacterial populations is hindered by low diversity coupled with high levels of lateral gene transfer. A comparison of recombination levels and diversity at seven housekeeping genes for eleven bacterial species, most of which are commonly cited as having high levels of lateral gene transfer shows that the relative contributions of homologous recombination versus mutation for Burkholderia pseudomallei is over two times higher than for Streptococcus pneumoniae and is thus the highest value yet reported in bacteria. Despite the potential for homologous recombination to increase diversity, B. pseudomallei exhibits a relative lack of diversity at these loci. In these situations, whole genome genotyping of orthologous shared single nucleotide polymorphism loci, discovered using next generation sequencing technologies, can provide very large data sets capable of estimating core phylogenetic relationships. We compared and searched 43 whole genome sequences of B. pseudomallei and its closest relatives for single nucleotide polymorphisms in orthologous shared regions to use in phylogenetic reconstruction. Results Bayesian phylogenetic analyses of >14,000 single nucleotide polymorphisms yielded completely resolved trees for these 43 strains with high levels of statistical support. These results enable a better understanding of a separate analysis of population differentiation among >1,700 B. pseudomallei isolates as defined by sequence data from seven housekeeping genes. We analyzed this larger data set for population structure and allele sharing that can be attributed to lateral gene transfer. Our results suggest that despite an almost panmictic population, we can detect two distinct populations of B. pseudomallei that conform to biogeographic patterns found in many plant and animal species. That is, separation along Wallace's Line, a biogeographic boundary between Southeast Asia and Australia

  12. Functional biogeography as evidence of gene transfer in hypersaline microbial communities.

    J Jacob Parnell

    Full Text Available BACKGROUND: Horizontal gene transfer (HGT plays a major role in speciation and evolution of bacteria and archaea by controlling gene distribution within an environment. However, information that links HGT to a natural community using relevant population-genetics parameters and spatial considerations is scarce. The Great Salt Lake (Utah, USA provides an excellent model for studying HGT in the context of biogeography because it is a contiguous system with dispersal limitations due to a strong selective salinity gradient. We hypothesize that in spite of the barrier to phylogenetic dispersal, functional characteristics--in the form of HGT--expand beyond phylogenetic limitations due to selective pressure. METHODOLOGY AND RESULTS: To assay the functional genes and microorganisms throughout the GSL, we used a 16S rRNA oligonucleotide microarray (Phylochip and a functional gene array (GeoChip to measure biogeographic patterns of nine microbial communities. We found a significant difference in biogeography based on microarray analyses when comparing Sørensen similarity values for presence/absence of function and phylogeny (Student's t-test; p = 0.005. CONCLUSION AND SIGNIFICANCE: Biogeographic patterns exhibit behavior associated with horizontal gene transfer in that informational genes (16S rRNA have a lower similarity than functional genes, and functional similarity is positively correlated with lake-wide selective pressure. Specifically, high concentrations of chromium throughout GSL correspond to an average similarity of chromium resistance genes that is 22% higher than taxonomic similarity. This suggests active HGT may be measured at the population level in microbial communities and these biogeographic patterns may serve as a model to study bacteria adaptation and speciation.

  13. Gene Transfer by Guanidinium-Cholesterol Cationic Lipids into Airway Epithelial Cells in vitro and in vivo

    Oudrhiri, Noufissa; Vigneron, Jean-Pierre; Peuchmaur, Michel; Leclerc, Tony; Lehn, Jean-Marie; Lehn, Pierre

    1997-03-01

    Synthetic vectors represent an attractive alternative approach to viral vectors for gene transfer, in particular into airway epithelial cells for lung-directed gene therapy for cystic fibrosis. Having recently found that guanidinium-cholesterol cationic lipids are efficient reagents for gene transfer into mammalian cell lines in vitro, we have investigated their use for gene delivery into primary airway epithelial cells in vitro and in vivo. The results obtained indicate that the lipid bis (guanidinium)-tren-cholesterol (BGTC) can be used to transfer a reporter gene into primary human airway epithelial cells in culture. Furthermore, liposomes composed of BGTC and dioleoyl phosphatidylethanolamine (DOPE) are efficient for gene delivery to the mouse airway epithelium in vivo. Transfected cells were detected both in the surface epithelium and in submucosal glands. In addition, the transfection efficiency of BGTC/DOPE liposomes in vivo was quantitatively assessed by using the luciferase reporter gene system.

  14. Sleeping Beauty-Mediated Drug Resistance Gene Transfer in Human Hematopoietic Progenitor Cells.

    Hyland, Kendra A; Olson, Erik R; McIvor, R Scott

    2015-10-01

    The Sleeping Beauty (SB) transposon system can insert sequences into mammalian chromosomes, supporting long-term expression of both reporter and therapeutic genes. Hematopoietic progenitor cells (HPCs) are an ideal therapeutic gene transfer target as they are used in therapy for a variety of hematologic and metabolic conditions. As successful SB-mediated gene transfer into human CD34(+) HPCs has been reported by several laboratories, we sought to extend these studies to the introduction of a therapeutic gene conferring resistance to methotrexate (MTX), potentially providing a chemoprotective effect after engraftment. SB-mediated transposition of hematopoietic progenitors, using a transposon encoding an L22Y variant dihydrofolate reductase fused to green fluorescent protein, conferred resistance to methotrexate and dipyridamole, a nucleoside transport inhibitor that tightens MTX selection conditions, as assessed by in vitro hematopoietic colony formation. Transposition of individual transgenes was confirmed by sequence analysis of transposon-chromosome junctions recovered by linear amplification-mediated PCR. These studies demonstrate the potential of SB-mediated transposition of HPCs for expression of drug resistance genes for selective and chemoprotective applications. PMID:26176276

  15. Retroviral-mediated gene transfer and expression of human phenylalanine hydroxylase in primary mouse hepatocytes

    Genetic therapy for phenylketonuria (severe phenylalanine hydroxylase deficiency) may require introduction of a normal phenylalanine hydroxylase gene into hepatic cells of patients. The authors report development of a recombinant retrovirus based on the N2 vector for gene transfer and expression of human phenylalanine hydroxylase cDNA in primary mouse hepatocytes. This construct contains an internal promoter of the human α1-antitrypsin gene driving transcription of the phenylalanine hydroxylase cDNA. Primary mouse hepatocytes were isolated from newborn mice, infected with the recombinant virus, and selected for expression of the neomycin-resistance gene. Hepatocytes transformed with the recombinant virus contained high levels of human phenylalanine hydroxylase mRNA transcripts originating from the retroviral and internal promoters. These results demonstrate that the transcriptional regulatory elements of the α1 antitrypsin gene retain their tissue-specific function in the recombinant provirus and establish a method for efficient transfer and high-level expression of human phenylalanine hydroxylase in primary hepatocytes

  16. Baculovirus vector-mediated transfer of NIS gene into colon tumor cells for radionuclide therapy

    2010-01-01

    AIM:To investigate the feasibility of radionuclide therapy of colon tumor cells by baculovirus vector-mediated transfer of the sodium/iodide symporter(NIS) gene.METHODS:A recombinant baculovirus plasmid carrying the NIS gene was constructed,and the viruses(BacNIS) were prepared using the Bac-to-Bac system.The infection efficiency in the colon cancer cell line SW1116 of a green fluorescent protein(GFP) expressing baculovirus(Bac-GFP) at different multiplicities of infection(MOI) with various concentrations o...

  17. Horizontal gene transfer of acetyltransferases, invertases and chorismate mutases from different bacteria to diverse recipients

    Noon, Jason B.; Baum, Thomas J.

    2016-01-01

    Background Hoplolaimina plant-parasitic nematodes (PPN) are a lineage of animals with many documented cases of horizontal gene transfer (HGT). In a recent study, we reported on three likely HGT candidate genes in the soybean cyst nematode Heterodera glycines, all of which encode secreted candidate effectors with putative functions in the host plant. Hg-GLAND1 is a putative GCN5-related N-acetyltransferase (GNAT), Hg-GLAND13 is a putative invertase (INV), and Hg-GLAND16 is a putative chorismat...

  18. Enhanced horizontal transfer of antibiotic resistance genes in freshwater microcosms induced by an ionic liquid.

    Qing Wang

    Full Text Available The spread and propagation of antibiotic resistance genes (ARGs is a worldwide public health concern. Ionic liquids (ILs, considered as "environmentally friendly" replacements for industrial organic solvents, have been widely applied in modern industry. However, few data have been collected regarding the potential ecological and environmental risks of ILs, which are important for preparing for their potential discharge into the environment. In this paper, the IL 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIm][PF6] (0.001-5.0 g/L was tested for its effects on facilitating ARGs horizontal transfer mediated by plasmid RP4 in freshwater microcosms. In the horizontal transfer microcosms, the transfer frequency of plasmid RP4 was significantly enhanced (60-fold higher than untreated groups by the IL [BMIm][PF6] (1.0 g/L. Meanwhile, two strains of opportunistic pathogen Acinetobacter spp. and Salmonella spp. were isolated among the transconjugants, illustrating plasmid RP4 mediated horizontal transfer of ARGs occurred in pathogen. This could increase the risk of ARGs dissemination to human pathogens and pose great threat to public health. The cause that [BMIm[PF6] enhanced the transfer frequency of plasmid RP4 was proposed by suppressed cell membrane barrier and enhanced cell membrane permeability, which was evidenced by flow cytometry (FCM. This is the first report that some ILs facilitate horizontal transfer of plasmid RP4 which is widely distributed in the environment and thus add the adverse effects of the environmental risk of ILs.

  19. Lysophosphatidylcholine as an adjuvant for lentiviral vector mediated gene transfer to airway epithelium: effect of acyl chain length

    Anson Don S

    2010-06-01

    Full Text Available Abstract Background Poor gene transfer efficiency has been a major problem in developing an effective gene therapy for cystic fibrosis (CF airway disease. Lysophosphatidylcholine (LPC, a natural airway surfactant, can enhance viral gene transfer in animal models. We examined the electrophysiological and physical effect of airway pre-treatment with variants of LPC on lentiviral (LV vector gene transfer efficiency in murine nasal airways in vivo. Methods Gene transfer was assessed after 1 week following nasal instillations of a VSV-G pseudotype LV vector pre-treated with a low and high dose of LPC variants. The electrophysiological effects of a range of LPC variants were assessed by nasal transepithelial potential difference measurements (TPD to determine tight junction permeability. Any physical changes to the epithelium from administration of the LPC variants were noted by histological methods in airway tissue harvested after 1 hour. Results Gene transduction was significantly greater compared to control (PBS for our standard LPC (palmitoyl/stearoyl mixture treatment and for the majority of the other LPC variants with longer acyl chain lengths. The LPC variant heptadecanoyl also produced significantly greater LV gene transfer compared to our standard LPC mixture. LV gene transfer and the transepithelial depolarization produced by the 0.1% LPC variants at 1 hour were strongly correlated (r2 = 0.94, but at the 1% concentration the correlation was less strong (r2 = 0.59. LPC variants that displayed minor to moderate levels of disruption to the airway epithelium were clearly associated with higher LV gene transfer. Conclusions These findings show the LPC variants effect on airway barrier function and their correlation to the effectiveness of gene expression. The enhanced expression produced by a number of LPC variants should provide new options for preclinical development of efficient airway gene transfer techniques.

  20. Emergence of collective territorial defense in bacterial communities: horizontal gene transfer can stabilize microbiomes.

    Juhász, János; Kertész-Farkas, Attila; Szabó, Dóra; Pongor, Sándor

    2014-01-01

    Multispecies bacterial communities such as the microbiota of the gastrointestinal tract can be remarkably stable and resilient even though they consist of cells and species that compete for resources and also produce a large number of antimicrobial agents. Computational modeling suggests that horizontal transfer of resistance genes may greatly contribute to the formation of stable and diverse communities capable of protecting themselves with a battery of antimicrobial agents while preserving a varied metabolic repertoire of the constituent species. In other words horizontal transfer of resistance genes makes a community compatible in terms of exoproducts and capable to maintain a varied and mature metagenome. The same property may allow microbiota to protect a host organism, or if used as a microbial therapy, to purge pathogens and restore a protective environment. PMID:24755769

  1. Bidirectional transfer of RNAi between honey bee and Varroa destructor: Varroa gene silencing reduces Varroa population.

    Yael Garbian

    2012-12-01

    Full Text Available The mite Varroa destructor is an obligatory ectoparasite of the honey bee (Apis mellifera and is one of the major threats to apiculture worldwide. We previously reported that honey bees fed on double-stranded RNA (dsRNA with a sequence homologous to that of the Israeli acute paralysis virus are protected from the viral disease. Here we show that dsRNA ingested by bees is transferred to the Varroa mite and from mite on to a parasitized bee. This cross-species, reciprocal exchange of dsRNA between bee and Varroa engendered targeted gene silencing in the latter, and resulted in an over 60% decrease in the mite population. Thus, transfer of gene-silencing-triggering molecules between this invertebrate host and its ectoparasite could lead to a conceptually novel approach to Varroa control.

  2. Effects of laser parameters on propagation characteristics of laser-induced stress wave for gene transfer

    Ando, Takahiro; Sato, Shunichi; Terakawa, Mitsuhiro; Ashida, Hiroshi; Obara, Minoru

    2010-02-01

    Laser-based gene delivery is attractive as a new method for topical gene therapy because of the high spatial controllability of laser energy. Previously, we demonstrated that an exogenous gene can be transferred to cells both in vitro and in vivo by applying nanosecond pulsed laser-induced stress waves (LISWs) or photomechanical waves (PMWs). In this study, we investigated effects of laser parameters on the propagation characteristics of LISWs in soft tissue phantoms and depth-dependent properties of gene transfection. Temporal pressure profiles of LISWs were measured with a hydrophone, showing that with a larger laser spot diameter, LISWs can be propagated more efficiently in phantoms with keeping flat wavefront. Phantoms with various thicknesses were placed on the rat dorsal skin that had been injected with plasmid DNA coding for reporter gene, and LISWs were applied from the top of the phantom. Efficient gene expression was observed in the rat skin that had interacted with LISWs propagating through a 15-mm-thick phantom. These results would be useful to determine appropriate laser parameters for gene delivery to deep-located tissue by transcutaneous application of LISWs.

  3. Cumulus-specific genes are transcriptionally silent following somatic cell nuclear transfer in a mouse model*

    Tong, Guo-qing; Heng, Boon-chin; Ng, Soon-chye

    2007-01-01

    This study investigated whether four cumulus-specific genes: follicular stimulating hormone receptor (FSHr), hyaluronan synthase 2 (Has2), prostaglandin synthase 2 (Ptgs2) and steroidogenic acute regulator protein (Star), were correctly reprogrammed to be transcriptionally silent following somatic cell nuclear transfer (SCNT) in a murine model. Cumulus cells of C57×CBA F1 female mouse were injected into enucleated oocytes, followed by activation in 10 µmol/L strontium chloride for 5 h and sub...

  4. Gene Transfer Efficiency in Gonococcal Biofilms: Role of Biofilm Age, Architecture, and Pilin Antigenic Variation

    Kouzel, Nadzeya; Oldewurtel, Enno R.; Maier, Berenike

    2015-01-01

    Extracellular DNA is an important structural component of many bacterial biofilms. It is unknown, however, to which extent external DNA is used to transfer genes by means of transformation. Here, we quantified the acquisition of multidrug resistance and visualized its spread under selective and nonselective conditions in biofilms formed by Neisseria gonorrhoeae. The density and architecture of the biofilms were controlled by microstructuring the substratum for bacterial adhesion. Horizontal t...

  5. Transcriptional reprogramming of gene expression in bovine somatic cell chromatin transfer embryos

    Page Grier P

    2009-04-01

    Full Text Available Abstract Background Successful reprogramming of a somatic genome to produce a healthy clone by somatic cells nuclear transfer (SCNT is a rare event and the mechanisms involved in this process are poorly defined. When serial or successive rounds of cloning are performed, blastocyst and full term development rates decline even further with the increasing rounds of cloning. Identifying the "cumulative errors" could reveal the epigenetic reprogramming blocks in animal cloning. Results Bovine clones from up to four generations of successive cloning were produced by chromatin transfer (CT. Using Affymetrix bovine microarrays we determined that the transcriptomes of blastocysts derived from the first and the fourth rounds of cloning (CT1 and CT4 respectively have undergone an extensive reprogramming and were more similar to blastocysts derived from in vitro fertilization (IVF than to the donor cells used for the first and the fourth rounds of chromatin transfer (DC1 and DC4 respectively. However a set of transcripts in the cloned embryos showed a misregulated pattern when compared to IVF embryos. Among the genes consistently upregulated in both CT groups compared to the IVF embryos were genes involved in regulation of cytoskeleton and cell shape. Among the genes consistently upregulated in IVF embryos compared to both CT groups were genes involved in chromatin remodelling and stress coping. Conclusion The present study provides a data set that could contribute in our understanding of epigenetic errors in somatic cell chromatin transfer. Identifying "cumulative errors" after serial cloning could reveal some of the epigenetic reprogramming blocks shedding light on the reprogramming process, important for both basic and applied research.

  6. Production of human glucocerebrosidase in mice after retroviral gene transfer into multipotential hematopoietic progenitor cells.

    Correll, P H; Fink, J K; Brady, R O; Perry, L K; S. Karlsson

    1989-01-01

    The human glucocerebrosidase (GC) gene has been transferred efficiently into spleen colony-forming unit (CFU-S) multipotential hematopoietic progenitor cells, and production of human GC RNA and protein has been achieved in transduced CFU-S colonies. High-titer retroviral vectors containing the human GC cDNA were constructed. Mouse bone marrow cells were stimulated with hematopoietic growth factors, infected by coculture with producer cells, and injected into lethally irradiated animals. Four ...

  7. Emergence of Collective Territorial Defense in Bacterial Communities: Horizontal Gene Transfer Can Stabilize Microbiomes

    János Juhász; Attila Kertész-Farkas; Dóra Szabó; Sándor Pongor

    2014-01-01

    Multispecies bacterial communities such as the microbiota of the gastrointestinal tract can be remarkably stable and resilient even though they consist of cells and species that compete for resources and also produce a large number of antimicrobial agents. Computational modeling suggests that horizontal transfer of resistance genes may greatly contribute to the formation of stable and diverse communities capable of protecting themselves with a battery of antimicrobial agents while preserving ...

  8. Plant–Agrobacterium interaction mediated by ethylene and super-Agrobacterium conferring efficient gene transfer

    Nonaka, Satoko; Ezura, Hiroshi

    2014-01-01

    Agrobacterium tumefaciens has a unique ability to transfer genes into plant genomes. This ability has been utilized for plant genetic engineering. However, the efficiency is not sufficient for all plant species. Several studies have shown that ethylene decreased the Agrobacterium-mediated transformation frequency. Thus, A. tumefaciens with an ability to suppress ethylene evolution would increase the efficiency of Agrobacterium-mediated transformation. Some studies showed that plant growth-pro...

  9. Eukaryote to gut bacteria transfer of a glycoside hydrolase gene essential for starch breakdown in plants

    Arias, Maria Cecilia; Danchin, Étienne G.J.; Coutinho, Pedro; Henrissat, Bernard; Ball, Steven

    2012-01-01

    Lateral gene transfer (LGT) between bacteria constitutes a strong force in prokaryote evolution, transforming the hierarchical tree of life into a network of relationships between species. In contrast, only a few cases of LGT from eukaryotes to prokaryotes have been reported so far. The distal animal intestine is predominantly a bacterial ecosystem, supplying the host with energy from dietary polysaccharides through carbohydrate-active enzymes absent from its genome. It has been suggested tha...

  10. Interkingdom Gene Transfer May Contribute to the Evolution of Phytopathogenicity in Botrytis Cinerea

    Bo Zhu; Qing Zhou; Guanlin Xie; Guoqing Zhang; Xiaowei Zhang; Yanli Wang; Gunchang Sun; Bin Li; Gulei Jin

    2012-01-01

    The ascomycete Botrytis cinerea is a phytopathogenic fungus infecting and causing significant yield losses in a number of crops. The genome of B. cinerea has been fully sequenced while the importance of horizontal gene transfer (HGT) to extend the host range in plant pathogenic fungi has been recently appreciated. However, recent data confirm that the B. cinerea fungus shares conserved virulence factors with other fungal plant pathogens with narrow host range. Therefore, interkingdom HGT may ...

  11. Transcriptional regulation of pWW0 transfer genes in Pseudomonas putida KT2440

    Lambertsen, L.M.; Molin, Søren; Kroer, N.; Thomas, C.M.

    2004-01-01

    IncP-9 transfer genes are transcribed from at least three promoter regions. The promoters for traA and traD act divergently from the region found to encode the origin of transfer, oriT. These promoters regulate expression of traA, B, and perhaps traC in one direction and traD in the other, all of...... are, as in pWWO, transcribed divergently from an operon for replication and/or stable inheritance functions, MpfR is not related to the known regulatory proteins of these other transfer systems outside those of the IncP-9 family and indeed the regulators tend to be specific for each plasmid family...

  12. Transfer of alien genes by means of induced translocation in oats and other crop species

    Some of the best sources of resistance to mildew, which is the most important disease of the oat crop in the United Kingdom, occur in related weed species. The mildew resistance found in a genotype of the tetraploid species Avena barbata has been transferred into the germ plasm of the cultivated hexaploid species A. sativa by means of an induced translocation. The procedures adopted to isolate the desirable translocation and to determine its breeding behaviour are described. A number of alien genes have been transferred into wheat by means of induced translocations and genetic induction, but their successful introduction into commercial varieties has been limited. In this paper, the use and limitations of alien transfers as breeding material are discussed. (author)

  13. Phage-mediated transfer of a dextranase gene in Lactobacillus sanfranciscensis and characterization of the enzyme.

    Picozzi, Claudia; Meissner, Daniel; Chierici, Margherita; Ehrmann, Matthias A; Vigentini, Ileana; Foschino, Roberto; Vogel, Rudi F

    2015-06-01

    While phages of lactobacilli are extensively studied with respect to their structure and role in the dairy environment, knowledge about phages in bacteria residing in sourdough fermentation is limited. Based on the previous finding that the Lactobacillus sanfranciscensis phage EV3 carries a putative dextranase gene (dex), we have investigated the distribution of similar dex(+) phages in L. sanfranciscensis, the chance of gene transfer and the properties of the dextranase encoded by phage EV3. L. sanfranciscensis H2A (dex(-)), originally isolated from a wheat sourdough, expressed a Dex(+) phenotype upon infection with EV3. The dextranase gene was isolated from the transductant and heterologously expressed in Escherichia coli. The gene encoded a protein of 801 amino acids with a calculated molecular weight (Mw) of 89.09 kDa and a calculated pI of 5.62. Upon purification aided by a 6-His tag, enzyme kinetic parameters were determined. The Km value was 370 mM, and the Vmax was calculated in about 16 μmol of glucose released from dextran by 1 mg of enzyme in 1 min in a buffer solution at pH 5.0. The optimum conditions were 60 °C and pH 4.5. The enzyme retained its activity for >3h at 60 °C and exhibited only 40% activity at 30 °C; the highest homology of 72% was found to a dextranase gene from Lactobacillus fermentum phage φPYB5. Within 25 L. sanfransiscensis isolates tested, the strain 4B5 carried a similar prophage encoding a dextranase gene. Our data suggest a phage-mediated transfer of dextranase genes in the sourdough environment resulting in superinfection-resistant L. sanfranciscensis Dex(+) strains with a possible ecological advantage in dextran-containing sourdoughs. PMID:25771219

  14. Transferability of microsatellite markers located in candidate genes for wood properties between Eucalyptus species

    Cintia V. Acuña

    2014-12-01

    Full Text Available Aim of study:  To analyze the feasibility of extrapolating conclusions on wood quality genetic control between different Eucalyptus species, particularly from species with better genomic information, to those less characterized. For this purpose, the first step is to analyze the conservation and cross-transferability of microsatellites markers (SSRs located in candidate genes.Area of study: Eucalyptus species implanted in Argentina coming from different Australian origins.Materials and methods: Twelve validated and polymorphic SSRs in candidate genes (SSR-CGs for wood quality in E. globulus were selected for cross species amplification in six species: E. grandis, E. saligna, E. dunnii, E. viminalis, E. camaldulensis and E. tereticornis.Main results: High cross-species transferability (92% to 100% was found for the 12 polymorphic SSRs detected in E. globulus. These markers revealed allelic diversity in nine important candidate genes: cinnamoyl CoA reductase (CCR, cellulose synthase 3 (CesA3, the transcription factor LIM1, homocysteine S-methyltransferase (HMT, shikimate kinase (SK, xyloglucan endotransglycosylase 2 (XTH2, glutathione S-transferase (GST, glutamate decarboxylase (GAD and peroxidase (PER.Research highlights: The markers described are potentially suitable for comparative QTL mapping, molecular marker assisted breeding (MAB and for population genetic studies across different species within the subgenus Symphyomyrtus.Keywords: validation; cross-transferability; SSR; functional markers; eucalypts; Symphyomyrtus.

  15. THE RISK OF GENE TRANSFERRING IN THE INSURANCE PROTECTION OF AGRICULTERE

    M. Malik

    2016-05-01

    Full Text Available The paper justified essence of genetic engineering as the object of insurance services. Defines the concept of risk gene transferring. The character features of this specific risk. The influence and consequences for agricultural producers. The description of the possible creation of the concept of insurance services that cover risk of gene transferring. The study reveals of the use of GMOs in agriculture, due to issues of economic security of a particular region or country as a whole. To determined the impact of risks and control for developing and developed countries that are important aspects of farming. Changes in weather, climate, productivity, price values, public policy, the situation on global markets can cause large fluctuations in agricultural production, and consequently affecting the income of agricultural producers. Risk management includes a range of strategies that reduce the social and financial implications of possible changes affecting the production and income of farmers. There is a need for an in-depth study of the theoretical and practical aspects of the impact of the risk of gene transferring in the context of insurance protection.

  16. Production of human glucocerebrosidase in mice after retroviral gene transfer into multipotential hematopoietic progenitor cells

    The human glucocerebrosidase (GC) gene has been transferred efficiently into spleen colony-forming unit (CFU-S) multipotential hematopoietic progenitor cells, and production of human GC RNA and protein has been achieved in transduced CFU-S colonies. High-titer retroviral vectors containing the human GC cDNA were constructed. Four vectors were compared with respect to gene-transfer efficiency into CFU-S progenitors. One vector (G vector) required high concentrations of interleukins 3 and 6 during stimulation and coculture for efficient transduction of CFU-S progenitors. The remaining three vectors (NTG, GTN, and GI vectors) transduced these progenitors at infection frequencies approaching 100% using low concentrations of hematopoietic growth factors to simulate cell division prior to and during the infection. Vectors using the viral long terminal repeat enhancer/promoter to drive the human GC cDNA produced high levels of human GC RNA in the progeny of CFU-S progenitors after gene transfer. All three vectors producing human GC RNA in CFU-S colonies can generate human GC as detected by immunochemical analysis of CFU-S colonies. The capacity of the viral long terminal repeat and the internal thymidine kinase promoter to direct synthesis of RNA in transduced bone marrow and spleen cells 5 months after bone marrow transplantation reflected the performance of these promoters in NTG-transduced CFU-S colonies

  17. Production of human glucocerebrosidase in mice after retroviral gene transfer into multipotential hematopoietic progenitor cells

    Correll, P.H.; Fink, J.K.; Brady, R.O.; Perry, L.K.; Karlsson, S. (National Institutes of Health, Bethesda, MD (USA))

    1989-11-01

    The human glucocerebrosidase (GC) gene has been transferred efficiently into spleen colony-forming unit (CFU-S) multipotential hematopoietic progenitor cells, and production of human GC RNA and protein has been achieved in transduced CFU-S colonies. High-titer retroviral vectors containing the human GC cDNA were constructed. Four vectors were compared with respect to gene-transfer efficiency into CFU-S progenitors. One vector (G vector) required high concentrations of interleukins 3 and 6 during stimulation and coculture for efficient transduction of CFU-S progenitors. The remaining three vectors (NTG, GTN, and GI vectors) transduced these progenitors at infection frequencies approaching 100% using low concentrations of hematopoietic growth factors to simulate cell division prior to and during the infection. Vectors using the viral long terminal repeat enhancer/promoter to drive the human GC cDNA produced high levels of human GC RNA in the progeny of CFU-S progenitors after gene transfer. All three vectors producing human GC RNA in CFU-S colonies can generate human GC as detected by immunochemical analysis of CFU-S colonies. The capacity of the viral long terminal repeat and the internal thymidine kinase promoter to direct synthesis of RNA in transduced bone marrow and spleen cells 5 months after bone marrow transplantation reflected the performance of these promoters in NTG-transduced CFU-S colonies.

  18. Novel recA-Independent Horizontal Gene Transfer in Escherichia coli K-12.

    Anthony W Kingston

    Full Text Available In bacteria, mechanisms that incorporate DNA into a genome without strand-transfer proteins such as RecA play a major role in generating novelty by horizontal gene transfer. We describe a new illegitimate recombination event in Escherichia coli K-12: RecA-independent homologous replacements, with very large (megabase-length donor patches replacing recipient DNA. A previously uncharacterized gene (yjiP increases the frequency of RecA-independent replacement recombination. To show this, we used conjugal DNA transfer, combining a classical conjugation donor, HfrH, with modern genome engineering methods and whole genome sequencing analysis to enable interrogation of genetic dependence of integration mechanisms and characterization of recombination products. As in classical experiments, genomic DNA transfer begins at a unique position in the donor, entering the recipient via conjugation; antibiotic resistance markers are then used to select recombinant progeny. Different configurations of this system were used to compare known mechanisms for stable DNA incorporation, including homologous recombination, F'-plasmid formation, and genome duplication. A genome island of interest known as the immigration control region was specifically replaced in a minority of recombinants, at a frequency of 3 X 10(-12 CFU/recipient per hour.

  19. Efficient Gene Transfer Mediated by HIV-1-based Defective Lentivector and Inhibition of HIV-1 Replication

    2007-01-01

    Lentiviral vectors have drawn considerable attention recently and show great promise to become important delivery vehicles for future gene transfer manipulation. In the present study we have optimized a protocol for preparation of human immunodeficiency virus type-1 (HIV-1)-based defective lentiviral vectors (DLV) and characterized these vectors in terms of their transduction of different cells. Transient co-transfection of 293T packaging cells with DNA plasmids encoding lentiviral vector constituents resulted in production of high-titer DLV (0.5-1.2 × 107IU/mL), which can be further concentrated over 100-fold through a single step ultracentrifugation. These vectors were capable of transducing a variety of cells from both primate and non-primate sources and high transduction efficiency was achieved using concentrated vectors. Assessment of potential generation of RCV revealed no detection of infection by infectious particles in DLV-transduced CEM, SupT-1 and MT-2 cells. Long-term culture of transduced cells showed a stable expression of transgenes without apparent alteration in cellular morphology and growth kinetics. Vector mobilization to untransduced cells mediated by wild-type HIV-1 infection was confirmed in this test. Challenge of transduced human T-lymphocytes with wild-type HIV-1 showed these cells are totally resistant to the viral infection. Considering the effective gene transfer and stable gene expression, safety and anti-HIV activity, these DLV vectors warrant further exploration for their potential use as a gene transfer vehicle in the development of gene therapy protocols.

  20. Airway gene transfer in a non-human primate: lentiviral gene expression in marmoset lungs.

    Farrow, N; Miller, D; Cmielewski, P; Donnelley, M; Bright, R; Parsons, D W

    2013-01-01

    Genetic therapies for cystic fibrosis (CF) must be assessed for safety and efficacy, so testing in a non-human primate (NHP) model is invaluable. In this pilot study we determined if the conducting airways of marmosets (n = 2) could be transduced using an airway pre-treatment followed by an intratracheal bolus dose of a VSV-G pseudotyped HIV-1 based lentiviral (LV) vector (LacZ reporter). LacZ gene expression (X-gal) was assessed after 7 days and found primarily in conducting airway epithelia as well as in alveolar regions. The LacZ gene was not detected in liver or spleen via qPCR. Vector p24 protein bio-distribution into blood was transient. Dosing was well tolerated. This preliminary study confirmed the transducibility of CF-relevant airway cell types. The marmoset is a promising NHP model for testing and translating genetic treatments for CF airway disease towards clinical trials. PMID:23412644

  1. Changes in glucose metabolism and gene expression after transfer of anti-angiogenic genes in rat hepatoma

    Human troponin I (TROP), the soluble receptor for vascular endothelial growth factor (sFLT) and angiostatin (ASTAT) are potent inhibitors of endothelial cell proliferation, angiogenesis and tumour growth in vivo. Transfer of these genes into tumours may induce changes not only in perfusion, but also more general ones such as changes in metabolism. The aim of this study was to assess these reactions using FDG-PET and high-throughput methods such as gene profiling. We established Morris hepatoma (MH3924A) cell lines expressing TROP, sFLT or ASTAT and quantified 18F-fluorodeoxyglucose (18FDG) uptake by dynamic positron emission tomography (PET) after tumour inoculation in ACI rats. Furthermore, expression of glucose transporter-1 and -3 (GLUT-1 and GLUT-3) as well as hexokinase-1 and -2 were investigated by RT-PCR and immunohistomorphometry. In addition, gene array analyses were performed. 18FDG uptake, vascular fraction and distribution volume were significantly higher in all genetically modified tumours. Immunohistomorphometry showed an increased percentage of hexokinase-1 and -2 as well as GLUT-1 and -3 immunoreactive (ir) cells. Using gene arrays and comparing all three groups of genetically modified tumours, we found upregulated expression of 36 genes related to apoptosis, signal transduction, stress or metabolism. TROP-, sFLT- or ASTAT-expressing MH3924A tumours show enhanced influx of 18FDG, which seems to be caused by several factors: enhanced exchange of nutrients between blood and tumour, increased amounts of glucose transporters and hexokinases, and increased expression of genes related to apoptosis, matrix and stress, which induce an increased demand for glucose. (orig.)

  2. Horizontal gene transfer events reshape the global landscape of arm race between viruses and homo sapiens.

    Chen, Dong-Sheng; Wu, Yi-Quan; Zhang, Wei; Jiang, San-Jie; Chen, Shan-Ze

    2016-01-01

    Horizontal gene transfer (HGT) drives the evolution of recipient organism particularly if it provides a novel function which enhances the fitness or its adaption to the environment. Virus-host co-evolution is attractive for studying co-evolutionary processes, since viruses strictly replicate inside of the host cells and thus their evolution is inexorably tangled with host biology. HGT, as a mechanism of co-evolution between human and viruses, has been widely documented, however, the roles HGT play during the interaction between human and viruses are still in their infancy. In this study, we performed a comprehensive analysis on the genes horizontally transferred between viruses and their corresponding human hosts. Our study suggests that the HGT genes in human are predominantly enriched in immune related GO terms while viral HGT genes are tend to be encoded by viruses which promote the invasion of immune system of hosts. Based on our results, it gives us a hint about the evolution trajectory of HGT events. Overall, our study suggests that the HGT between human and viruses are highly relevant to immune interaction and probably reshaped the arm race between hosts and viruses. PMID:27270140

  3. Histidine-rich stabilized polyplexes for cMet-directed tumor-targeted gene transfer

    Kos, Petra; Lächelt, Ulrich; Herrmann, Annika; Mickler, Frauke Martina; Döblinger, Markus; He, Dongsheng; Krhač Levačić, Ana; Morys, Stephan; Bräuchle, Christoph; Wagner, Ernst

    2015-03-01

    Overexpression of the hepatocyte growth factor receptor/c-Met proto oncogene on the surface of a variety of tumor cells gives an opportunity to specifically target cancerous tissues. Herein, we report the first use of c-Met as receptor for non-viral tumor-targeted gene delivery. Sequence-defined oligomers comprising the c-Met binding peptide ligand cMBP2 for targeting, a monodisperse polyethylene glycol (PEG) for polyplex surface shielding, and various cationic (oligoethanamino) amide cores containing terminal cysteines for redox-sensitive polyplex stabilization, were assembled by solid-phase supported syntheses. The resulting oligomers exhibited a greatly enhanced cellular uptake and gene transfer over non-targeted control sequences, confirming the efficacy and target-specificity of the formed polyplexes. Implementation of endosomal escape-promoting histidines in the cationic core was required for gene expression without additional endosomolytic agent. The histidine-enriched polyplexes demonstrated stability in serum as well as receptor-specific gene transfer in vivo upon intratumoral injection. The co-formulation with an analogous PEG-free cationic oligomer led to a further compaction of pDNA polyplexes with an obvious change of shape as demonstrated by transmission electron microscopy. Such compaction was critically required for efficient intravenous gene delivery which resulted in greatly enhanced, cMBP2 ligand-dependent gene expression in the distant tumor.Overexpression of the hepatocyte growth factor receptor/c-Met proto oncogene on the surface of a variety of tumor cells gives an opportunity to specifically target cancerous tissues. Herein, we report the first use of c-Met as receptor for non-viral tumor-targeted gene delivery. Sequence-defined oligomers comprising the c-Met binding peptide ligand cMBP2 for targeting, a monodisperse polyethylene glycol (PEG) for polyplex surface shielding, and various cationic (oligoethanamino) amide cores containing

  4. Evaluation of tetrafunctional block copolymers as synthetic vectors for lung gene transfer.

    Richard-Fiardo, Peggy; Hervouet, Catherine; Marsault, Robert; Franken, Philippe R; Cambien, Béatrice; Guglielmi, Julien; Warnez-Soulie, Julie; Darcourt, Jacques; Pourcher, Thierry; Colombani, Thibault; Haudebourg, Thomas; Peuziat, Pauline; Pitard, Bruno; Vassaux, Georges

    2015-03-01

    In the present study, we evaluated, in mice, the efficacy of the tetrafunctional block copolymer 704 as a nonviral gene delivery vector to the lungs. SPECT/CT molecular imaging of gene expression, biochemical assays, and immunohistochemistry were used. Our dataset shows that the formulation 704 resulted in higher levels of reporter gene expression than the GL67A formulation currently being used in a clinical trial in cystic fibrosis patients. The inflammatory response associated with this gene transfer was lower than that induced by the GL67A formulation, and the 704 formulation was amenable to repeated administrations. The cell types transfected by the 704 formulation were type I and type II pneumocytes, and transgene expression could not be detected in macrophages. These results emphasize the relevance of the 704 formulation as a nonviral gene delivery vector for lung gene therapy. Further studies will be required to validate this vector in larger animals, in which the lungs are more similar to human lungs. PMID:25662490

  5. Evolution of Type II Antifreeze Protein Genes in Teleost Fish: A Complex Scenario Involving Lateral Gene Transfers and Episodic Directional Selection

    Ulf Sorhannus

    2012-01-01

    I examined hypotheses about lateral transfer of type II antifreeze protein (AFP) genes among “distantly” related teleost fish. The effects of episodic directional selection on amino acid evolution were also investigated. The strict consensus results showed that the type II AFP and type II antifreeze-like protein genes were transferred from Osmerus mordax to Clupea harengus, from the ancestral lineage of the Brachyopsis rostratus—Hemitripterus americanus clade to the ancestor of the Hypomesus ...

  6. Fishing for biodiversity: Novel methanopterin-linked C1 transfer genes deduced from the Sargasso Sea metagenome

    Kalyuzhnaya, Marina G.; Nercessian, Olivier; Lapidus, Alla; Chistoserdova, Ludmila

    2004-01-01

    The recently generated database of microbial genes from an oligotrophic environment populated by a calculated 1,800 of major phylotypes (the Sargasso Sea metagenome) presents a great source for expanding local databases of genes indicative of a specific function. In this paper we analyze the Sargasso Sea metagenome in terms of the presence of methanopterin-linked C1 transfer genes that are signature for methylotrophy. We conclude that more than 10 phylotypes possessing genes of interest ...

  7. Correction of glucocerebrosidase deficiency after retroviral-mediated gene transfer into hematopoietic progenitor cells from patients with Gaucher disease.

    Fink, J K; Correll, P H; Perry, L K; Brady, R O; S. Karlsson

    1990-01-01

    Retroviral gene transfer has been used successfully to correct the glucocerebrosidase (GCase) deficiency in primary hematopoietic cells from patients with Gaucher disease. For this model of somatic gene therapy, we developed a high-titer, amphotropic retroviral vector designated NTG in which the human GCase gene was driven by the mutant polyoma virus enhancer/herpesvirus thymidine kinase gene (tk) promoter (Py+/Htk). NTG normalized GCase activity in transduced Gaucher fibroblasts and efficien...

  8. Mapping of metastasis suppressor genes for prostate cancer by microcell-mediated chromosome transfer

    TomohikoICHIKAWA; ShigeruHOSOKI; HiroyoshiSUZUKI; KoichiroAKAKURA; TatsuoIGARASHI; YuzoFURUYA; MitsuoOSHIMURA; CarrieW.RINKER-SCHAEFFER; NaokiNIHEI; JohnT.ISAACS; HaruoITO

    2000-01-01

    Aim: To identify the metastasis suppressor genes for prostate cancer. Methods: A copy of human chromosomes was introduced into the highly metastatic Dunning R-3327 rat prostate cancer cells by the use of microcell-mediated chromosome transfer. Relationships between the size of human chromosomes introduced into microcell hybrid clones and the number of lung metastases produced by the clones were analyzed to determine which part of human chromosomes contained the metastasis suppressor gene (s) for prostate cancer. To determine portions of human chromosomes introduced, G-banding chromosomal analysis, fluorescence in situ hybridization analysis, and polymerase chain reaction analysis were performed. Results: Each of microcell hybrid clones containing human chromosomes 7, 8, 10, 11, 12, or 17 showed decreased ability to metastasize to the lung without any loss of ttmaorigenicity. This demonstrates that these human chromosomes contain metastasis suppressor genes for prostate cancer. Spontaneous deletion of portions of human chromosomes was observed in the human chromosome 7, 10, 11, 12, and 17 studies. In the human chromosome 8 study, irradiated microcell-mediated chromosome transfer was performed to enrich chromosomal ann deletions of human chromosome 8. Molecular and cytogenetic analyses of microcell hybrid clones demonstrated that metastasis suppressor genes on human chromosomes were located on 7q21-22, 7q31.2-32, 8p21-12, 10q11-22, 11p13-11.2, 12p11-q13, 12q24-ter, and 17pter-q23. KAI1 and MKK4/SEKI were identified as metastasis suppressor genes from 11p11.2 and 17p12, respectively. Conclusion: This assay system is useful to identify metastasis suppressor gene (s) for prostate cancer.

  9. Challenges and Prospects for Alpha-1 Antitrypsin Deficiency Gene Therapy.

    Wozniak, Joanna; Wandtke, Tomasz; Kopinski, Piotr; Chorostowska-Wynimko, Joanna

    2015-11-01

    Alpha-1 antitrypsin (AAT) is a protease inhibitor belonging to the serpin family. A number of identified mutations in the SERPINA1 gene encoding this protein result in alpha-1 antitrypsin deficiency (AATD). A decrease in AAT serum concentration or reduced biological activity causes considerable risk of chronic respiratory and liver disorders. As a monogenic disease, AATD appears to be an attractive target for gene therapy, particularly for patients with pulmonary dysfunction, where augmentation of functional AAT levels in plasma might slow down respiratory disease development. The short AAT coding sequence and its activity in the extracellular matrix would enable an increase in systemic serum AAT production by cellular secretion. In vitro and in vivo experimental AAT gene transfer with gamma-retroviral, lentiviral, adenoviral, and adeno-associated viral (AAV) vectors has resulted in enhanced AAT serum levels and a promising safety profile. Human clinical trials using intramuscular viral transfer with AAV1 and AAV2 vectors of the AAT gene demonstrated its safety, but did not achieve a protective level of AAT >11 μM in serum. This review provides an in-depth critical analysis of current progress in AATD gene therapy based on viral gene transfer. The factors affecting transgene expression levels, such as site of administration, dose and type of vector, and activity of the immune system, are discussed further as crucial variables for optimizing the clinical effectiveness of gene therapy in AATD subjects. PMID:26413996

  10. Retrovirus-Mediated Gene Transfer in Immortalization of Progenitor Hair Cell Lines in Newborn Rat

    ZHANG Yuan; ZHAI Suo-qiang; SONG Wei; GUO Wei; ZHENG Gui-liang; HU Yin-yan

    2008-01-01

    Objective To present an experimental method that allows isolation of greater epithelial ridge (GER) and lesser epithelial ridge(LER) cells from postnatal rat cochleae using a combinatorial approach of enzymatic digestion and mechanical separation and to investigate a retrovirus-mediated gene transfer technique for its possibl utility in immortalization of the GER and LER cell lines, in an effort to establish an in vitro model system of hair cell differentiation. Methods GER and LER cells were dissected from postnatal rat cochleae and immortalized by transferring the SV40 large T antigen using a retrovirus. The established cell lines were confirmed through morphology observation, immunnocytochemical staining and RT-PCR analysis. The Hathl gene was transferred into the cell lines using adenovirus-mediated techniques to explore their potential to differentiate into hair cells. Results The established cell lines were stably maintained for more than 20 passages and displayed many features similar to primary GER and LER cells. They grew in patches and assumed a polygonal morphology. Immunostaining showed labeling by SV40 large T antigen and Islet1 (a specific marker for GER and LER). All passages of the cell lines expressed SV40 large T antigen on RT-PCR analysis. The cells also showed the capability to differenti-ate into hair cell-like cells when forced to express Hathl. Conclusion Retrovirus-mediated gene transfer can be used in establishing immortalized progenitor hair cell lines in newborn rat, which may provide an invaluable system for studying hair cell differentiation and regeneration for new treatment of sensory hearing loss caused by hair cell loss.

  11. Mutation and gene transfer of neutral amino acid transport System L genes in mammalian cells

    The authors are attempting to clone the genes coding for amino acid transport System L. Chinese hamster ovary (CHO) cell mutants that are temperature sensitive in their leucyl-tRNA synthetase show temperature-dependent regulation of System L. Temperature resistant mutants isolated from these cells have constitutively derepressed System L activity. Somatic cell fusion studies using these mutants have suggested that a trans-acting element controls regulation of System L. Mutants with reduced transport activity were isolated by a 3H-suicide selection. The growth of these mutant cells is limited by the transport defect. CHO mutants were transformed with a human cosmid library, followed by selection at high temperatures and low leucine concentrations. Some transformants have increased levels of System L activity, suggesting that human genes coding for leucine transport have been incorporated into the CHO genome. Human sequences were rescued by a lambda in vitro packaging system. These sequences hybridize to vector and total human DNA. Experiments are being done to confirm that these sequences indeed code for transport System L. They are also attempting to label membrane components of amino acid transporters by group-specific modifying reagents

  12. Adenoviral protein V promotes a process of viral assembly through nucleophosmin 1

    Ugai, Hideyo; Dobbins, George C.; Wang, Minghui [Division of Human Gene Therapy, Departments of Medicine, Obstetrics and Gynecology, Pathology, and Surgery, University of Alabama at Birmingham, Birmingham, AL 35294 (United States); Le, Long P. [Massachusetts General Hospital, Pathology Service, 55 Fruit St.-GRJ 249, Boston, MA 02114 (United States); Matthews, David A. [School of Cellular and Molecular Medicine, Medical Sciences Building, University of Bristol, Bristol BS8 1TD (United Kingdom); Curiel, David T., E-mail: dcuriel@radonc.wustl.edu [Division of Human Gene Therapy, Departments of Medicine, Obstetrics and Gynecology, Pathology, and Surgery, University of Alabama at Birmingham, Birmingham, AL 35294 (United States); The Gene Therapy Center, University of Alabama at Birmingham, Birmingham, AL 35294 (United States)

    2012-10-25

    Adenoviral infection induces nucleoplasmic redistribution of a nucleolar nucleophosmin 1/NPM1/B23.1. NPM1 is preferentially localized in the nucleoli of normal cells, whereas it is also present at the nuclear matrix in cancer cells. However, the biological roles of NPM1 during infection are unknown. Here, by analyzing a pV-deletion mutant, Ad5-dV/TSB, we demonstrate that pV promotes the NPM1 translocation from the nucleoli to the nucleoplasm in normal cells, and the NPM1 translocation is correlated with adenoviral replication. Lack of pV causes a dramatic reduction of adenoviral replication in normal cells, but not cancer cells, and Ad5-dV/TSB was defective in viral assembly in normal cells. NPM1 knockdown inhibits adenoviral replication, suggesting an involvement of NPM1 in adenoviral biology. Further, we show that NPM1 interacts with empty adenovirus particles which are an intermediate during virion maturation by immunoelectron microscopy. Collectively, these data implicate that pV participates in a process of viral assembly through NPM1.

  13. Gene expression system in green sulfur bacteria by conjugative plasmid transfer.

    Chihiro Azai

    Full Text Available Gene transfer and expression systems in green sulfur bacteria were established by bacterial conjugation with Escherichia coli. Conjugative plasmid transfer from E. coli S17-1 to a thermophilic green sulfur bacterium, Chlorobaculum tepidum (formerly Chlorobium tepidum WT2321, was executed with RSF1010-derivative broad-host-range plasmids, named pDSK5191 and pDSK5192, that confer erythromycin and streptomycin/spectinomycin resistance, respectively. The transconjugants harboring these plasmids were reproducibly obtained at a frequency of approximately 10(-5 by selection with erythromycin and a combination of streptomycin and spectinomycin, respectively. These plasmids were stably maintained in C. tepidum cells in the presence of these antibiotics. The plasmid transfer to another mesophilic green sulfur bacterium, C. limnaeum (formerly Chlorobium phaeobacteroides RK-j-1, was also achieved with pDSK5192. The expression plasmid based on pDSK5191 was constructed by incorporating the upstream and downstream regions of the pscAB gene cluster on the C. tepidum genome, since these regions were considered to include a constitutive promoter and a ρ-independent terminator, respectively. Growth defections of the ∆cycA and ∆soxB mutants were completely rescued after introduction of pDSK5191-cycA and -soxB that were designed to express their complementary genes. On the other hand, pDSK5191-6xhis-pscAB, which incorporated the gene cluster of 6xhis-pscA and pscB, produced approximately four times more of the photosynthetic reaction center complex with His-tagged PscA as compared with that expressed in the genome by the conventional natural transformation method. This expression system, based on conjugative plasmid, would be applicable to general molecular biological studies of green sulfur bacteria.

  14. Horizontal gene transfer of zinc and non-zinc forms of bacterial ribosomal protein S4

    Luthey-Schulten Zaida

    2009-07-01

    Full Text Available Abstract Background The universal ribosomal protein S4 is essential for the initiation of small subunit ribosomal assembly and translational accuracy. Being part of the information processing machinery of the cell, the gene for S4 is generally thought of as being inherited vertically and has been used in concatenated gene phylogenies. Here we report the evolution of ribosomal protein S4 in relation to a broad sharing of zinc/non-zinc forms of the gene and study the scope of horizontal gene transfer (HGT of S4 during bacterial evolution. Results In this study we present the complex evolutionary history of ribosomal protein S4 using 660 bacterial genomes from 16 major bacterial phyla. According to conserved characteristics in the sequences, S4 can be classified into C+ (zinc-binding and C- (zinc-free variants, with 26 genomes (mainly from the class Clostridia containing genes for both. A maximum likelihood phylogenetic tree of the S4 sequences was incongruent with the standard bacterial phylogeny, indicating a departure from strict vertical inheritance. Further analysis using the genome content near the S4 genes, which are usually located in a conserved gene cluster, showed not only that HGT of the C- gene had occurred at various stages of bacterial evolution, but also that both the C- and C+ genes were present before the individual phyla diverged. To explain the latter, we theorize that a gene pool existed early in bacterial evolution from which bacteria could sample S4 gene variants, according to environmental conditions. The distribution of the C+/- variants for seven other zinc-binding ribosomal proteins in these 660 bacterial genomes is consistent with that seen for S4 and may shed light on the evolutionary pressures involved. Conclusion The complex history presented for "core" protein S4 suggests the existence of a gene pool before the emergence of bacterial lineages and reflects the pervasive nature of HGT in subsequent bacterial evolution

  15. Microsporidia: Eukaryotic Intracellular Parasites Shaped by Gene Loss and Horizontal Gene Transfers.

    Corradi, Nicolas

    2015-01-01

    Microsporidia are eukaryotic parasites of many animals that appear to have adapted to an obligate intracellular lifestyle by modifying the morphology and content of their cells. Living inside other cells, they have lost many, or all, metabolic functions, resulting in genomes that are always gene poor and often very small. The minute content of microsporidian genomes led many to assume that these parasites are biochemically static and uninteresting. However, recent studies have demonstrated that these organisms can be surprisingly complex and dynamic. In this review I detail the most significant recent advances in microsporidian genomics and discuss how these have affected our understanding of many biological aspects of these peculiar eukaryotic intracellular pathogens. PMID:26195306

  16. Survival of Antibiotic Resistant Bacteria and Horizontal Gene Transfer Control Antibiotic Resistance Gene Content in Anaerobic Digesters

    Miller, Jennifer H.; Novak, John T.; Knocke, William R.; Pruden, Amy

    2016-01-01

    Understanding fate of antibiotic resistant bacteria (ARB) vs. their antibiotic resistance genes (ARGs) during wastewater sludge treatment is critical in order to reduce the spread of antibiotic resistance through process optimization. Here, we spiked high concentrations of tetracycline-resistant bacteria, isolated from mesophilic (Iso M1-1—a Pseudomonas sp.) and thermophilic (Iso T10—a Bacillus sp.) anaerobic digested sludge, into batch digesters and monitored their fate by plate counts and quantitative polymerase chain reaction (QPCR) of their corresponding tetracycline ARGs. In batch studies, spiked ARB plate counts returned to baseline (thermophilic) or 1-log above baseline (mesophilic) while levels of the ARG present in the spiked isolate [tet(G)] remained high in mesophilic batch reactors. To compare results under semi-continuous flow conditions with natural influent variation, tet(O), tet(W), and sul1 ARGs, along with the intI1 integrase gene, were monitored over a 9-month period in the raw feed sludge and effluent sludge of lab-scale thermophilic and mesophilic anaerobic digesters. sul1 and intI1 in mesophilic and thermophilic digesters correlated positively (Spearman rho = 0.457–0.829, P < 0.05) with the raw feed sludge. There was no correlation in tet(O) or tet(W) ratios in raw sludge and mesophilic digested sludge or thermophilic digested sludge (Spearman rho = 0.130–0.486, P = 0.075–0.612). However, in the thermophilic digester, the tet(O) and tet(W) ratios remained consistently low over the entire monitoring period. We conclude that the influent sludge microbial composition can influence the ARG content of a digester, apparently as a result of differential survival or death of ARBs or horizontal gene transfer of genes between raw sludge ARBs and the digester microbial community. Notably, mesophilic digestion was more susceptible to ARG intrusion than thermophilic digestion, which may be attributed to a higher rate of ARB survival and

  17. Survival of Antibiotic Resistant Bacteria and Horizontal Gene Transfer Control Antibiotic Resistance Gene Content in Anaerobic Digesters.

    Miller, Jennifer H; Novak, John T; Knocke, William R; Pruden, Amy

    2016-01-01

    Understanding fate of antibiotic resistant bacteria (ARB) vs. their antibiotic resistance genes (ARGs) during wastewater sludge treatment is critical in order to reduce the spread of antibiotic resistance through process optimization. Here, we spiked high concentrations of tetracycline-resistant bacteria, isolated from mesophilic (Iso M1-1-a Pseudomonas sp.) and thermophilic (Iso T10-a Bacillus sp.) anaerobic digested sludge, into batch digesters and monitored their fate by plate counts and quantitative polymerase chain reaction (QPCR) of their corresponding tetracycline ARGs. In batch studies, spiked ARB plate counts returned to baseline (thermophilic) or 1-log above baseline (mesophilic) while levels of the ARG present in the spiked isolate [tet(G)] remained high in mesophilic batch reactors. To compare results under semi-continuous flow conditions with natural influent variation, tet(O), tet(W), and sul1 ARGs, along with the intI1 integrase gene, were monitored over a 9-month period in the raw feed sludge and effluent sludge of lab-scale thermophilic and mesophilic anaerobic digesters. sul1 and intI1 in mesophilic and thermophilic digesters correlated positively (Spearman rho = 0.457-0.829, P < 0.05) with the raw feed sludge. There was no correlation in tet(O) or tet(W) ratios in raw sludge and mesophilic digested sludge or thermophilic digested sludge (Spearman rho = 0.130-0.486, P = 0.075-0.612). However, in the thermophilic digester, the tet(O) and tet(W) ratios remained consistently low over the entire monitoring period. We conclude that the influent sludge microbial composition can influence the ARG content of a digester, apparently as a result of differential survival or death of ARBs or horizontal gene transfer of genes between raw sludge ARBs and the digester microbial community. Notably, mesophilic digestion was more susceptible to ARG intrusion than thermophilic digestion, which may be attributed to a higher rate of ARB survival and/or horizontal gene

  18. Effective generation of transgenic pigs and mice by linker based sperm-mediated gene transfer.

    Shih Ping Yao

    2002-04-01

    Full Text Available Abstract Background Transgenic animals have become valuable tools for both research and applied purposes. The current method of gene transfer, microinjection, which is widely used in transgenic mouse production, has only had limited success in producing transgenic animals of larger or higher species. Here, we report a linker based sperm-mediated gene transfer method (LB-SMGT that greatly improves the production efficiency of large transgenic animals. Results The linker protein, a monoclonal antibody (mAb C, is reactive to a surface antigen on sperm of all tested species including pig, mouse, chicken, cow, goat, sheep, and human. mAb C is a basic protein that binds to DNA through ionic interaction allowing exogenous DNA to be linked specifically to sperm. After fertilization of the egg, the DNA is shown to be successfully integrated into the genome of viable pig and mouse offspring with germ-line transfer to the F1 generation at a highly efficient rate: 37.5% of pigs and 33% of mice. The integration is demonstrated again by FISH analysis and F2 transmission in pigs. Furthermore, expression of the transgene is demonstrated in 61% (35/57 of transgenic pigs (F0 generation. Conclusions Our data suggests that LB-SMGT could be used to generate transgenic animals efficiently in many different species.

  19. Different fates of the chloroplast tufA gene following its transfer to the nucleus in green algae.

    Baldauf, S L; Manhart, J R; J.D. Palmer

    1990-01-01

    Previous work suggested that the tufA gene, encoding protein synthesis elongation factor Tu, was transferred from the chloroplast to the nucleus within the green algal lineage giving rise to land plants. In this report we investigate the timing and mode of transfer by examining chloroplast and nuclear DNA from the three major classes of green algae, with emphasis on the class Charophyceae, the proposed sister group to land plants. Filter hybridizations reveal a chloroplast tufA gene in all Ul...

  20. Viral Vectors for In Vivo Gene Transfer in Parkinson’s disease: Properties and Clinical Grade Production

    Mandel, Ronald J.; Burger, Corinna; Snyder, Richard O.

    2007-01-01

    Because Parkinson’s disease is a progressive degenerative disorder that is mainly confined to the basal ganglia, gene transfer to deliver therapeutic molecules is an attractive treatment avenue. The present review focuses on direct in vivo gene transfer vectors that have been developed to a degree that they have been successfully used in animal model of Parkinson’s disease. Accordingly, the properties of recombinant adenovirus, recombinant adeno-associated virus, herpes simplex virus, and len...

  1. Gene Electro Transfer of Plasmid Encoding Vascular Endothelial Growth Factor for Enhanced Expression and Perfusion in the Ischemic Swine Heart

    Hargrave, Barbara; Strange, Robert; Navare, Sagar; Stratton, Michael; Burcus, Nina; Murray, Len; Lundberg, Cathryn; Bulysheva, Anna; Li, Fanying; Heller, Richard

    2014-01-01

    Myocardial ischemia can damage heart muscle and reduce the heart's pumping efficiency. This study used an ischemic swine heart model to investigate the potential for gene electro transfer of a plasmid encoding vascular endothelial growth factor for improving perfusion and, thus, for reducing cardiomyopathy following acute coronary syndrome. Plasmid expression was significantly greater in gene electro transfer treated tissue compared to injection of plasmid encoding vascular endothelial growth...

  2. Prostate-specific expression of Bax delivered by an adenoviral vector induces apoptosis in LNCaP prostate cancer cells.

    Lowe, S L; Rubinchik, S; Honda, T; McDonnell, T J; Dong, J Y; Norris, J S

    2001-09-01

    In prostate carcinoma, overexpression of the anti-apoptotic gene Bcl-2 has been found to be associated with resistance to therapies including radiation and androgen ablation. Restoring the balance of Bcl-2 family members may result in the induction of apoptosis in prostate cancer cells previously resistant to treatment. To accomplish this, a strategy involving overexpression of the pro-apoptotic gene Bax was executed. The use of cytotoxic genes such as Bax require selective expression of the gene. In this study, we examined the ability of selective expression of Bax protein directed by a prostate-specific promoter to induce apoptosis in human prostate carcinoma. A second-generation adenoviral vector was constructed with the modified prostate-specific probasin promoter, ARR2PB, directing expression of an HA-tagged Bax gene and a green fluorescent protein reporter translated from an internal ribosome entry site (ARR2PB.Bax.GFP). ARR2PB promoter activity is tightly regulated and highly prostate specific and is responsive to androgens and glucocorticoids. The prostate-specific promoter-Bax-GFP transgene cassette was inserted into a cloning site near the right inverted terminal repeat of the adenoviral vector to retain specificity of the promoter. LNCaP cells infected with Ad/ARR(2)PB.Bax.GFP showed high levels of Bax expression 48 h after infection resulting in an 85% reduction in cell viability. Importantly, LNCaP cells stably transfected to overexpress Bcl-2 showed similar patterns of cell death when infected with Ad/ARR(2)PB.Bax.GFP, an 82% reduction in cell viability seen 48 h after infection. Apoptosis was confirmed by measuring caspase activation and using the TUNEL assay. Tissue specificity was evaluated using A549 cells (lung adenocarcinoma), SK-Hep-1 (liver cancer) cells, and Hela (cervical cancer) cells which did not show detectable expression of virally delivered Bax protein or any increase in cell death. Systemic administration of Ad/ARR2PB. Bax.GFP in nude

  3. Investigation of transfection efficacy with transcatheter arterial transporting transferring to enhance p53 gene

    Objective: To investigate the function of transferrin-DNA complex, transported by transferrin(Tf) and trans-arterial injection via interventional approach be the duel-target-orientated delivery and the transferring into malignant cells to get more effective therapy. Methods: p53-LipofectAMINE ligand with different concentrations of Tf (0, 10, 25, 50, 100 μg)transfected the 4 strains including LM6,Hep3B,YY and L02 in vitro to evaluate the gene transfection efficiency through western blot. Then, after setting up the VX2 hepatocarcinoma models, we delivered the Tf-p53-LipofectAMlNE complex into the hepatic arteries via interventional techniques to analyse the transfection efficiency in vivo. Results: Tf, within the range of l0 100 μg, could increase gene transfection efficiency mediated by liposome, and the efficiency increases with the raise of Tf concentration. Combination with interventional technique to inject Tf-DNA complex into tumor arteries, gene transfection efficiency was enhanced in rabbit models. Conclusion: Tf can enhance gene-liposome transfection efficiency, furthermore with combination of interventional catheter technique, there would be a potential duel-target-orientated gene therapy method. (authors)

  4. No evidence for extensive horizontal gene transfer in the genome of the tardigrade Hypsibius dujardini.

    Koutsovoulos, Georgios; Kumar, Sujai; Laetsch, Dominik R; Stevens, Lewis; Daub, Jennifer; Conlon, Claire; Maroon, Habib; Thomas, Fran; Aboobaker, Aziz A; Blaxter, Mark

    2016-05-01

    Tardigrades are meiofaunal ecdysozoans that are key to understanding the origins of Arthropoda. Many species of Tardigrada can survive extreme conditions through cryptobiosis. In a recent paper [Boothby TC, et al. (2015) Proc Natl Acad Sci USA 112(52):15976-15981], the authors concluded that the tardigrade Hypsibius dujardini had an unprecedented proportion (17%) of genes originating through functional horizontal gene transfer (fHGT) and speculated that fHGT was likely formative in the evolution of cryptobiosis. We independently sequenced the genome of H. dujardini As expected from whole-organism DNA sampling, our raw data contained reads from nontarget genomes. Filtering using metagenomics approaches generated a draft H. dujardini genome assembly of 135 Mb with superior assembly metrics to the previously published assembly. Additional microbial contamination likely remains. We found no support for extensive fHGT. Among 23,021 gene predictions we identified 0.2% strong candidates for fHGT from bacteria and 0.2% strong candidates for fHGT from nonmetazoan eukaryotes. Cross-comparison of assemblies showed that the overwhelming majority of HGT candidates in the Boothby et al. genome derived from contaminants. We conclude that fHGT into H. dujardini accounts for at most 1-2% of genes and that the proposal that one-sixth of tardigrade genes originate from functional HGT events is an artifact of undetected contamination. PMID:27035985

  5. IMPROVEMENT OF HUMAN ISLET FUNCTION BY ADENOVIRUS MEDIATED HO-1 GENE TRANSFER

    2007-01-01

    Objective To investigate in vitro heme oxygenase-1 gene (HO-1) delivery to human pancreatic islets by adenovirus vectors. Methods Recombinant adenovirus containing HO-1 or enhanced green fluorescent protein gene(EGFP) was generated by using the AdEasy System. The purified human pancreatic islets were infected with recombinant adenovirus vectors at various multiplicity of infection (MOI). Transduction was confirmed by fluorescence photographs and Western blot. Glucose-stimulated insulin secretion was detected by using Human insulin radioimmunoassay kits and was used to assess the function of human islets infected by recombinant adenovirus.Results Viral titers of Ad-hHO-1 and Ad-EGFP were 1.96×109 and 1.99×109 pfu/mL, respectively. Human pancreatic islets were efficiently infected by recombinant adenovirus vectors in vitro. Transfection of human islets at an MOI of 20 did not inhibit islet function. Recombinant adenovirus mediated HO-1gene transfer significantly improved the islet function of insulin release when simulated by high level glucose. Conclusion Recombinant adenovirus is efficient to deliver exogenous gene into human pancreatic islets in vitro. HO-1 gene transfection can improve human islet function.

  6. Gene Transfer into the Lung by Nanoparticle Dextran-Spermine/Plasmid DNA Complexes

    Syahril Abdullah

    2010-01-01

    Full Text Available A novel cationic polymer, dextran-spermine (D-SPM, has been found to mediate gene expression in a wide variety of cell lines and in vivo through systemic delivery. Here, we extended the observations by determining the optimal conditions for gene expression of D-SPM/plasmid DNA (D-SPM/pDNA in cell lines and in the lungs of BALB/c mice via instillation delivery. In vitro studies showed that D-SPM could partially protect pDNA from degradation by nuclease and exhibited optimal gene transfer efficiency at D-SPM to pDNA weight-mixing ratio of 12. In the lungs of mice, the levels of gene expression generated by D-SPM/pDNA are highly dependent on the weight-mixing ratio of D-SPM to pDNA, amount of pDNA in the complex, and the assay time postdelivery. Readministration of the complex at day 1 following the first dosing showed no significant effect on the retention and duration of gene expression. The study also showed that there was a clear trend of increasing size of the complexes as the amount of pDNA was increased, where the sizes of the D-SPM/pDNA complexes were within the nanometer range.

  7. Algal endosymbionts as vectors of horizontal gene transfer in photosynthetic eukaryotes

    Huan eQiu

    2013-09-01

    Full Text Available Photosynthesis in eukaryotes occurs in the plastid, an organelle that is derived from a single cyanobacterial primary endosymbiosis in the common ancestor of the supergroup Plantae (or Archaeplastida that includes green, red, and glaucophyte algae and plants. However a variety of other phytoplankton such as the chlorophyll c-containing diatoms, dinoflagellates, and haptophytes contain a red alga-derived plastid that traces its origin to secondary or tertiary (eukaryote engulfs eukaryote endosymbiosis. The hypothesis of Plantae monophyly has only recently been substantiated, however the extent and role of endosymbiotic and horizontal gene transfer (EGT and HGT in algal genome evolution still remain to be fully understood. What is becoming clear from analysis of complete genome data is that algal gene complements can no longer be considered essentially eukaryotic in provenance; i.e., with the expected addition of several hundred cyanobacterial genes derived from EGT and a similar number derived from the mitochondrial ancestor. For example, we now know that foreign cells such as Chlamydiae and other prokaryotes have made significant contributions to plastid functions in Plantae. Perhaps more surprising is the recent finding of extensive bacterium-derived HGT in the nuclear genome of the unicellular red alga Porphyridium purpureum that does not relate to plastid functions. These non-endosymbiont gene transfers not only shaped the evolutionary history of Plantae but also were propagated via secondary endosymbiosis to a multitude of other phytoplankton. Here we discuss the idea that Plantae (in particular red algae are one of the major players in eukaryote genome evolution by virtue of their ability to act as sinks and sources of foreign genes through HGT and endosymbiosis, respectively. This hypothesis recognizes the often under-appreciated Rhodophyta as major sources of genetic novelty among photosynthetic eukaryotes.

  8. Transfer of genes for stem rust resistance from Agropyron elongatum and imperial rye to durum wheat

    The Agropyron elongatum gene for stem rust resistance on chromosome 6A of Knott's Thatcher translocation line was transferred to a susceptible local durum wheat variety, Jaya, through a series of back-crosses. Plants heterozygous for the Agropyron translocation always show at least one open bivalent. Homozygotes have not been obtained, probably because of the absence of male transmission in durum background. Monotelosomic addition of the short arm of Imperial rye chromosome 3R (formerly ''G'' of Sears), which carries a gene(s) for resistance to wheat stem rust, was obtained in the local durum variety. Rust-resistant plants from parents having the added rye telocentric were irradiated with gamma rays just before meiosis, and the pollen obtained from the irradiated spikes was used to pollinate euploid plants. In addition, seeds harvested from 2n+1 resistant plants were irradiated with thermal neutrons and the resistant M1 plants were selfed to raise M2 families. Two durum-rye translocation lines were obtained following irradiation. DRT-1 was transmitted normally through the female gametes but showed no male transmission. As a result of this, homozygotes have not been obtained. Gametic transmission rates of DRT-2 are being tested. Alien translocations, which show normal gametic and zygotic transmissions in the hexaploid wheat, may behave differently in a tetraploid background. The results indicate that alien genetic transfers may be more difficult to obtain in durum wheat, probably owing to the reduced buffering effect of the tetraploid genome. (author)

  9. AAV9-mediated gene transfer of desmin ameliorates cardiomyopathy in desmin-deficient mice.

    Heckmann, M B; Bauer, R; Jungmann, A; Winter, L; Rapti, K; Strucksberg, K-H; Clemen, C S; Li, Z; Schröder, R; Katus, H A; Müller, O J

    2016-08-01

    Mutations of the human desmin (DES) gene cause autosomal dominant and recessive myopathies affecting skeletal and cardiac muscle tissue. Desmin knockout mice (DES-KO), which develop progressive myopathy and cardiomyopathy, mirror rare human recessive desminopathies in which mutations on both DES alleles lead to a complete ablation of desmin protein expression. Here, we investigated whether an adeno-associated virus-mediated gene transfer of wild-type desmin cDNA (AAV-DES) attenuates cardiomyopathy in these mice. Our approach leads to a partial reconstitution of desmin protein expression and the de novo formation of the extrasarcomeric desmin-syncoilin network in cardiomyocytes of treated animals. This finding was accompanied by reduced fibrosis and heart weights and improved systolic left-ventricular function when compared with control vector-treated DES-KO mice. Since the re-expression of desmin protein in cardiomyocytes of DES-KO mice restores the extrasarcomeric desmin-syncoilin cytoskeleton, attenuates the degree of cardiac hypertrophy and fibrosis, and improves contractile function, AAV-mediated desmin gene transfer may be a novel and promising therapeutic approach for patients with cardiomyopathy due to the complete lack of desmin protein expression. PMID:27101257

  10. A Versatile Vector for Gene and Oligonucleotide Transfer into Cells in Culture and in vivo: Polyethylenimine

    Boussif, Otmane; Lezoualc'h, Frank; Zanta, Maria Antonietta; Djavaheri Mergny, Mojgan; Scherman, Daniel; Demeneix, Barbara; Behr, Jean-Paul

    1995-08-01

    Several polycations possessing substantial buffering capacity below physiological pH, such as lipopolyamines and polyamidoamine polymers, are efficient transfection agents per se-i.e., without the addition of cell targeting or membrane-disruption agents. This observation led us to test the cationic polymer polyethylenimine (PEI) for its genedelivery potential. Indeed, every third atom of PEI is a protonable amino nitrogen atom, which makes the polymeric network an effective "proton sponge" at virtually any pH. Luciferase reporter gene transfer with this polycation into a variety of cell lines and primary cells gave results comparable to, or even better than, lipopolyamines. Cytotoxicity was low and seen only at concentrations well above those required for optimal transfection. Delivery of oligonucleotides into embryonic neurons was followed by using a fluorescent probe. Virtually all neurons showed nuclear labeling, with no toxic effects. The optimal PEI cation/anion balance for in vitro transfection is only slightly on the cationic side, which is advantageous for in vivo delivery. Indeed, intracerebral luciferase gene transfer into newborn mice gave results comparable (for a given amount of DNA) to the in vitro transfection of primary rat brain endothelial cells or chicken embryonic neurons. Together, these properties make PEI a promising vector for gene therapy and an outstanding core for the design of more sophisticated devices. Our hypothesis is that its efficiency relies on extensive lysosome buffering that protects DNA from nuclease degradation, and consequent lysosomal swelling and rupture that provide an escape mechanism for the PEI/DNA particles.

  11. Image of HSV1-TK gene expression with 123IVDU

    The liver is an important target organ for gene transfer due to its capacity for synthesizing serum protein and its involvement in numerous genetic diseases. So livertargeted gene transfer is significant tool for expanding the treatment options and gene function studies. Gene transfer methods commonly use recombinant viral vector. However, viral vectors also have various disadvantages for example immune recognition after adenoviral vector delivery and potential viralassociated toxicity including helper virus replication and insertional mutagenesis. In contrast, nonviral vectors such as naked plasmid DNA(pDNA) and cationic liposomal systems exhibit low immunogenicity and repeated administration is possible(Ledley et al.,1992; Nabel et al.,1993). These are attractive vectors for in vivo gene transfer because of their suitable characteristics such as biodegradability, minimal toxicity, nonimmunogenicity, and simplicity of use. But non-viral gene delivery, has problems associated with limited efficiency at gene expression. hydrodynamic-based produce has very high level efficiency of gene extraction in liver or soild tumor. In mice, hydrodynamic-based produce was reported that a high level of transgene expression could be obtained in the liver by intravenous injection of large volume( 8∼10% of body weight) and high-speed ( Kobayashi N et al., 2004 ). HSV1-TK is one of the most widely use effect gene systems sued for imaging gene expression, in association with its use as a suicide gene, or as a reporter gene In non-invasive imaging of the HSV1-TK system, many nucleoside derivatives have developed as prodrug for tumor proliferation imaging or as anti-viral drugs. Several 5-substituted uracil nucleoside derivatives have been identified to have high sensitivity and selective accumulation in HSV1-TK expression cell. This producer has been used hydrodynamic-based produce, we investigated to image of herpes simplex virus type 1 thymidine kinase (HSV1-tk) gene with (E)- 5

  12. Intranasal vaccination with a helper-dependent adenoviral vector enhances transgene-specific immune responses in BALB/c mice.

    Fu, Yuan-hui; He, Jin-sheng; Zheng, Xian-xian; Wang, Xiao-bo; Xie, Can; Shi, Chang-xin; Zhang, Mei; Tang, Qian; Wei, Wei; Qu, Jian-guo; Hong, Tao

    2010-01-01

    Helper-dependent adenoviral (HDAd) vectors were developed primarily for genetic disease therapy by deleting all coding regions for attenuating the host cellular immune response to adenovirus (Ad) and long-lasting gene expression. Recently Harui et al. reported that HDAd vaccine could stimulate superior transgene-specific cytotoxic T lymphocyte (CTL) and antibody responses via the intraperitoneal route, compared to first-generation adenoviral (FGAd) vaccine. This prompted us to explore the potential of HDAd as a vaccine vector administrated intranasally. In this study, we prepared HDAd and FGAd vectors expressing enhanced green fluorescent protein (EGFP), respectively, and compared their efficacy in mice. Mice were immunized intranasally with 5x10(9) vp HDAd or FGAd vector particles. Despite stimulating similar anti-Ad antibody responses with FGAd vaccine in the prime/boost strategy, HDAd vector expressing EGFP displayed superior transgene-specific serum IgG, mucosal IgA and cellular immune response, with the characterization of balanced or mixed Th1/Th2 CD4+ T-cell responses. Meanwhile, a single dose of intranasal (i.n.) vaccine of HDAd-EGFP induced a serum IgG response with more efficacy than FGAd-EGFP. In addition, i.n. boost immunization enhanced transgene-specific humoral and cellular responses, compared to single i.n. HDAd-EGFP immunization. Our results suggest that HDAd has potential for a mucosal vaccine vector via i.n. route, which will be useful for the development of vaccines against respiratory viruses, such as respiratory syncytial virus and influenza virus. PMID:19945423

  13. Evolution of substrate specificity in a recipient's enzyme following horizontal gene transfer.

    Noda-García, Lianet; Camacho-Zarco, Aldo R; Medina-Ruíz, Sofía; Gaytán, Paul; Carrillo-Tripp, Mauricio; Fülöp, Vilmos; Barona-Gómez, Francisco

    2013-09-01

    Despite the prominent role of horizontal gene transfer (HGT) in shaping bacterial metabolism, little is known about the impact of HGT on the evolution of enzyme function. Specifically, what is the influence of a recently acquired gene on the function of an existing gene? For example, certain members of the genus Corynebacterium have horizontally acquired a whole l-tryptophan biosynthetic operon, whereas in certain closely related actinobacteria, for example, Mycobacterium, the trpF gene is missing. In Mycobacterium, the function of the trpF gene is performed by a dual-substrate (βα)8 phosphoribosyl isomerase (priA gene) also involved in l-histidine (hisA gene) biosynthesis. We investigated the effect of a HGT-acquired TrpF enzyme upon PriA's substrate specificity in Corynebacterium through comparative genomics and phylogenetic reconstructions. After comprehensive in vivo and enzyme kinetic analyses of selected PriA homologs, a novel (βα)8 isomerase subfamily with a specialized function in l-histidine biosynthesis, termed subHisA, was confirmed. X-ray crystallography was used to reveal active-site mutations in subHisA important for narrowing of substrate specificity, which when mutated to the naturally occurring amino acid in PriA led to gain of function. Moreover, in silico molecular dynamic analyses demonstrated that the narrowing of substrate specificity of subHisA is concomitant with loss of ancestral protein conformational states. Our results show the importance of HGT in shaping enzyme evolution and metabolism. PMID:23800623

  14. The onset of foreign gene transcription in nuclear-transferred embryos of fish

    2000-01-01

    The transcriptional onset of hGH-transgene in fish was studied in the following three cases: the first is in MThGH-transgenic F4 common carp (Cyprinus carpio) embryos, the second is in nuclear-transferred embryos supported by the transgenic F4 embryonic nuclei, and the third is in nuclear-transferred embryos supported by the transgenic F4 tail-fin nuclei. RT-PCR results show that the hGH-transgene initiates its transcriptional activity from early-gastrula stage, the early blas-tula stage and even 16-cell stage in the first, second and third cases, respectively. It looks like that fish egg cytoplasm could just offer a very restricted reprogramming on transcriptional activity of specific gene in differentiated cell nuclei by nuclear transplantation.

  15. The onset of foreign gene transcription in nuclear-transferred embryos of fish

    孙永华; 陈尚萍; 汪亚平; 朱作言

    2000-01-01

    The transcriptional onset ot hGH-transgene in fish was studied in the following three cases: the first is in MThGH-transgenic F4 common carp (Cyprinus carpio) embryos, the second is in nuclear-transferred embryos supported by the transgenic F4 embryonic nuclei, and the third is in nuclear-transferred embryos supported by the transgenic F4 tail-fin nuclei. RT-PCR results show that the hGH-transgene initiates its transcriptional activity from early-gastrula stage, the early blastula stage and even 16-cell stage in the first, second and third cases, respectively. It looks like that fish egg cytoplasm could just offer a very restricted reprogramming on transcriptional activity of specific gene in differentiated cell nuclei by nuclear transplantation.

  16. Ultrasound-mediated gene transfer (sonoporation) in fibrin-based matrices: potential for use in tissue regeneration.

    Nomikou, Nikolitsa; Feichtinger, Georg A; Redl, Heinz; McHale, Anthony P

    2016-01-01

    It has been suggested that gene transfer into donor cells is an efficient and practical means of locally supplying requisite growth factors for applications in tissue regeneration. Here we describe, for the first time, an ultrasound-mediated system that can non-invasively facilitate gene transfer into cells entrapped within fibrin-based matrices. Since ultrasound-mediated gene transfer is enhanced using microbubbles, we compared the efficacy of neutral and cationic forms of these reagents on the ultrasound-stimulated gene transfer process in gel matrices. In doing so we demonstrated the beneficial effects associated with the use of cationic microbubble preparations that interact directly with cells and nucleic acid within matrices. In some cases, gene expression was increased two-fold in gel matrices when cationic microbubbles were compared with neutral microbubbles. In addition, incorporating collagen into fibrin gels yielded a 25-fold increase in gene expression after application of ultrasound to microbubble-containing matrices. We suggest that this novel system may facilitate non-invasive temporal and spatial control of gene transfer in gel-based matrices for the purposes of tissue regeneration. PMID:23596105

  17. The Reacquisition of Biotin Prototrophy in Saccharomyces cerevisiae Involved Horizontal Gene Transfer, Gene Duplication and Gene Clustering

    Hall, Charles; Dietrich, Fred S

    2007-01-01

    The synthesis of biotin, a vitamin required for many carboxylation reactions, is a variable trait in Saccharomyces cerevisiae. Many S. cerevisiae strains, including common laboratory strains, contain only a partial biotin synthesis pathway. We here report the identification of the first step necessary for the biotin synthesis pathway in S. cerevisiae. The biotin auxotroph strain S288c was able to grow on media lacking biotin when BIO1 and the known biotin synthesis gene BIO6 were introduced t...

  18. An exceptional horizontal gene transfer in plastids: gene replacement by a distant bacterial paralog and evidence that haptophyte and cryptophyte plastids are sisters

    Palmer Jeffrey D; Rice Danny W

    2006-01-01

    Abstract Background Horizontal gene transfer (HGT) to the plant mitochondrial genome has recently been shown to occur at a surprisingly high rate; however, little evidence has been found for HGT to the plastid genome, despite extensive sequencing. In this study, we analyzed all genes from sequenced plastid genomes to unearth any neglected cases of HGT and to obtain a measure of the overall extent of HGT to the plastid. Results Although several genes gave strongly supported conflicting trees u...

  19. A unique horizontal gene transfer event has provided the octocoral mitochondrial genome with an active mismatch repair gene that has potential for an unusual self-contained function

    Bilewitch Jaret P; Degnan Sandie M

    2011-01-01

    Abstract Background The mitochondrial genome of the Octocorallia has several characteristics atypical for metazoans, including a novel gene suggested to function in DNA repair. This mtMutS gene is favored for octocoral molecular systematics, due to its high information content. Several hypotheses concerning the origins of mtMutS have been proposed, and remain equivocal, although current weight of support is for a horizontal gene transfer from either an epsilonproteobacterium or a large DNA vi...

  20. 腺病毒载体介导胞嘧啶脱氨酶基因转染的前列腺癌细胞株对5-氟胞嘧啶作用敏感性的研究%Sensitization of prostate cancer cell lines to 5-fluorocytosine induced by adenoviral vector carrying a CD transcription unit

    殷莲华; 王新红

    2001-01-01

    目的研究胞嘧啶脱氨酶/5-氟胞嘧啶系统对前列腺癌细胞株的作用.方法细胞培养,细胞转染,药物敏感性实验,观察旁观者效应,动物实验.结果腺病毒载体可以转染所有已建立的前列腺癌细胞株,但是每种细胞株转染所要求的载体浓度以及暴露时间不同.转染的胞嘧啶脱氨酶基因在细胞内的表达高峰出现在不同的时间,但一直持续到11天以后.腺病毒载体介导的胞嘧啶脱氨酶基因转染可以使前列腺癌细胞株提高对5-氟胞嘧啶的敏感性.在LNCap和RM-1细胞株中,只有5%的细胞转染了胞嘧啶脱氨酶基因就可以引起100%的细胞杀伤效应.在动物实验中,用400MOI转染过的肿瘤细胞建立小鼠皮下肿瘤并同时腹腔注射5-氟胞嘧啶,可以有效的抑制肿瘤生长.结论腺病毒载体介导的胞嘧啶脱氨酶基因转染可以提高前列腺癌细胞株对5-氟胞嘧啶的敏感性,胞嘧啶脱氨酶/5-氟胞嘧啶的联合应用能显著抑制小鼠肿瘤生长.%Objective To investigate the efficiency of the cytosine deaminase adenoviral/5-fluorocytosine system on prostate cancer cell lines. Methods We used cell culture, infectivity and sensitivity tests, to observe bystander effect by animal tests. Results Established prostate cancer cell lines are eventually infectible by adenoviral vector. The ratio of vector/cell at which infection occurs depends on the specific cell line. The peak of expression of the transferred cytosine deaminase gene occurred in cells at different time, but persisted beyond 11 days. These prostate cell lines are sensitized to 5-fluorocytosine by infection with adenoviral vector carrying the cytosine deaminase gene. Only 5% of the LNCap and 10% of the RM-1 cells were infected and produced 100% cell death. In the animal test, there was significant inhibition of tumor growth at a ratio of 400 vector particles/cell with the systematic treatment of 5-fluorocytosine. Conclusions Adenoviral

  1. Combination recombinant simian or chimpanzee adenoviral vectors for vaccine development.

    Cheng, Cheng; Wang, Lingshu; Ko, Sung-Youl; Kong, Wing-Pui; Schmidt, Stephen D; Gall, Jason G D; Colloca, Stefano; Seder, Robert A; Mascola, John R; Nabel, Gary J

    2015-12-16

    Recombinant adenoviral vector (rAd)-based vaccines are currently being developed for several infectious diseases and cancer therapy, but pre-existing seroprevalence to such vectors may prevent their use in broad human populations. In this study, we investigated the potential of low seroprevalence non-human primate rAd vectors to stimulate cellular and humoral responses using HIV/SIV Env glycoprotein (gp) as the representative antigen. Mice were immunized with novel simian or chimpanzee rAd (rSAV or rChAd) vectors encoding HIV gp or SIV gp by single immunization or in heterologous prime/boost combinations (DNA/rAd; rAd/rAd; rAd/NYVAC or rAd/rLCM), and adaptive immunity was assessed. Among the rSAV and rChAd tested, rSAV16 or rChAd3 vector alone generated the most potent immune responses. The DNA/rSAV regimen also generated immune responses similar to the DNA/rAd5 regimen. rChAd63/rChAd3 and rChAd3 /NYVAC induced similar or even higher levels of CD4+ and CD8+ T-cell and IgG responses as compared to rAd28/rAd5, one of the most potent combinations of human rAds. The optimized vaccine regimen stimulated improved cellular immune responses and neutralizing antibodies against HIV compared to the DNA/rAd5 regimen. Based on these results, this type of novel rAd vector and its prime/boost combination regimens represent promising candidates for vaccine development. PMID:26514419

  2. The Extent and Regulation of Lateral Gene Transfer in Natural Microbial Ecosystems

    Aminov, Rustam I.

    The importance of horizontal gene transfer (HGT) in bacterial evolution is evident from the retrospective analyses of bacterial genomes, which suggest that a substantial part of bacterial genomes is of foreign origin. Another line of evidence that supports the possibility of rapid adaptation of...... allowed monitoring HGT events in situ. In this chapter, a brief overview of the milestones of mobile genetic elements (MGEs) research is given, followed by discussion of the conceptual framework development. Then the occurrence and diversity of MGEs as well as the frequencies of HGT in terrestrial...

  3. Microbiota aeróbia conjuntival nas conjuntivites adenovirais Ocular flora in adenoviral conjunctivitis

    Eliane Mayumi Nakano; Denise de Freitas; Maria Cecília Zorat Yu; Lênio Souza Alvarenga; Ana Luisa Hofling- Lima

    2002-01-01

    Objetivos: Estudar a microbiota aeróbica conjuntival em pacientes com quadro clínico de conjuntivite viral aguda. Método: Trinta pacientes entre 18 e 40 anos portadores de conjuntivite adenoviral e 30 pacientes sem a doença foram submetidos à colheita de material da conjuntiva para cultura. Os portadores de conjuntivite adenoviral foram submetidos ao exame até 3 dias após o início dos sintomas. As culturas foram realizadas utilizando-se os meios de ágar-sangue e ágar-chocolate. Pacientes em u...

  4. VERTICAL HEREDITY VS. HORIZONTAL GENE TRANSFER: A CHALLENGE TO BACTERIAL CLASSIFICATION

    HAO Bailin; QI Ji

    2003-01-01

    The diversity and classification of microbes has been a long-standing issue. Molecular phylogeny of the prokaryotes based on comparison of the 16S rRNA sequences of the small ribosomal subunit has led to a reasonable tree of life in the late 1970s. However, the availability of more and more complete bacterial genomes has brought about complications instead of refinement of the tree. In particular, it turns out that different choice of genes may tell different history. This might be caused by possible horizontal gene transfer (HGT) among species. There is an urgent need to develop phylogenetic methods that make use of whole genome data. We describe a new approach in molecular phylogeny, namely, tree construction based on K-tuple frequency analysis of the genomic sequences. Putting aside the technicalities, we emphasize the transition from randomness to determinism when the string length K increases and try to comment on the challenge mentioned in the title.

  5. Localized gene transfer into organotypic hippocampal slice cultures and acute hippocampal slices

    Casaccia-Bonnefil, P; Benedikz, Eirikur; Shen, H;

    1993-01-01

    Viral vectors derived from herpes simplex virus, type-1 (HSV), can transfer and express genes into fully differentiated, post-mitotic neurons. These vectors also transduce cells effectively in organotypic hippocampal slice cultures. Nanoliter quantities of a virus stock of HSVlac, an HSV vector...... effective and rapid. The titer of the HSVlac stocks was determined on NIH3T3 cells. Eighty-three percent of the beta-gal forming units successfully transduced beta-gal after microapplication to slice cultures. beta-Gal expression was detected as rapidly as 4 h after transduction into cultures of fibroblasts...... or hippocampal slices. The rapid expression of beta-gal by HSVlac allowed efficient transduction of acute hippocampal slices. Many genes have been transduced and expressed using HSV vectors; therefore, this microapplication method can be applied to many neurobiological questions....

  6. Transfer and expression of the gene for human growth hormone in Oryza sativa and Phleum pratense L

    Two derived pB322 plasmids harboring bla (for Beta-lactamase genes) and Human growth Hormone (hGH) genes, were transferred to a cereal plant (Rice) and to a gramine ous fodder (Timothy) in which they are expressed, whereas those constructions are not expressed in Escherichia coli.

  7. Multiple Antibiotic Resistance Gene Transfer from Animal to Human Enterococci in the Digestive Tract of Gnotobiotic Mice

    Moubareck, C.; Bourgeois, N.; Courvalin, P; Doucet-Populaire, F.

    2003-01-01

    It has been proposed that food animals represent the source of glycopeptide resistance genes present in enterococci from humans. We demonstrated the transfer of vanA and of other resistance genes from porcine to human Enterococcus faecium at high frequency in the digestive tract of gnotobiotic mice. Tylosin in the drinking water favored colonization by transconjugants.

  8. A single intravenous AAV9 injection mediates bilateral gene transfer to the adult mouse retina.

    Alexis-Pierre Bemelmans

    Full Text Available Widespread gene delivery to the retina is an important challenge for the treatment of retinal diseases, such as retinal dystrophies. We and others have recently shown that the intravenous injection of a self-complementary (sc AAV9 vector can direct efficient cell transduction in the central nervous system, in both neonatal and adult animals. We show here that the intravenous injection of scAAV9 encoding green fluorescent protein (GFP resulted in gene transfer to all layers of the retina in adult mice, despite the presence of a mature blood-eye barrier. Cell morphology studies and double-labeling with retinal cell-specific markers showed that GFP was expressed in retinal pigment epithelium cells, photoreceptors, bipolar cells, Müller cells and retinal ganglion cells. The cells on the inner side of the retina, including retinal ganglion cells in particular, were transduced with the highest efficiency. Quantification of the cell population co-expressing GFP and Brn-3a showed that 45% of the retinal ganglion cells were efficiently transduced after intravenous scAAV9-GFP injection in adult mice. This study provides the first demonstration that a single intravenous scAAV9 injection can deliver transgenes to the retinas of both eyes in adult mice, suggesting that this vector serotype is able to cross mature blood-eye barriers. This intravascular gene transfer approach, by eliminating the potential invasiveness of ocular surgery, could constitute an alternative when fragility of the retina precludes subretinal or intravitreal injections of viral vectors, opening up new possibilities for gene therapy for retinal diseases.

  9. Iodide uptake in human anaplastic thyroid carcinoma cells after transfer of the human thyroid peroxidase gene

    Human thyroperoxidase (hTPO) is critical for the accumulation of iodide in thyroid tissues. Poorly differentiated and anaplastic thyroid tumours which lack thyroid-specific gene expression fail to accumulate iodide and, therefore, do not respond to iodine-131 therapy. We consequently investigated whether transfer of the hTPO gene is sufficient to restore the iodide-trapping capacity in undifferentiated thyroid and non-thyroid tumour cells. The human anaplastic thyroid carcinoma cell lines C643 and SW1736, the rat Morris hepatoma cell line MH3924A and the rat papillary thyroid carcinoma cell line L2 were used as in vitro model systems. Employing a bicistronic retroviral vector based on the myeloproliferative sarcoma virus for the transfer of the hTPO and the neomycin resistance gene, the C643 cells and SW1736 cells were transfected while the L2 cells and MH3924A cells were infected with retroviral particles. Seven recombinant C643 and seven SW1736 cell lines as well as four recombinant L2 and four MH3924A cell lines were established by neomycin selection. They were studied for hTPO expression using an antibody-based luminescence kit, followed by determination of the enzyme activity in the guaiacol assay and of the iodide uptake capacity in the presence of Na125I. Genetically modified cell lines expressed up to 1,800 times more hTPO as compared to wild type tumour cells. The level of hTPO expression varied significantly between individual neomycin-resistant cell lines, suggesting that the recombinant retroviral DNA was integrated at different sites of the cellular genome. The accumulation of iodide, however, was not significantly enhanced in individual recombinant cell lines, irrespective of low or high hTPO expression. Moreover, there was no correlation between hTPO expression and enzyme activity in individual cell lines. The transduction of the hTPO gene per se is not sufficient to restore iodide trapping in non-iodide-concentrating tumour cells. Future studies

  10. Adenoviral overexpression of Lhx2 attenuates cell viability but does not preserve the stem cell like phenotype of hepatic stellate cells

    Genz, Berit [Institute for Experimental Surgery, Rostock University Medical Center, Rostock (Germany); Thomas, Maria [Dr. Margarete Fischer-Bosch Institute of Clinical Pharmacology, Stuttgart (Germany); Pützer, Brigitte M. [Institute of Experimental Gene Therapy and Cancer Research, Rostock University Medical Center, Rostock (Germany); Siatkowski, Marcin; Fuellen, Georg [Institute for Biostatistics and Informatics in Medicine and Ageing Research, Rostock University Medical Center, Rostock (Germany); Vollmar, Brigitte [Institute for Experimental Surgery, Rostock University Medical Center, Rostock (Germany); Abshagen, Kerstin, E-mail: kerstin.abshagen@uni-rostock.de [Institute for Experimental Surgery, Rostock University Medical Center, Rostock (Germany)

    2014-11-01

    Hepatic stellate cells (HSC) are well known initiators of hepatic fibrosis. After liver cell damage, HSC transdifferentiate into proliferative myofibroblasts, representing the major source of extracellular matrix in the fibrotic organ. Recent studies also demonstrate a role of HSC as progenitor or stem cell like cells in liver regeneration. Lhx2 is described as stem cell maintaining factor in different organs and as an inhibitory transcription factor in HSC activation. Here we examined whether a continuous expression of Lhx2 in HSC could attenuate their activation and whether Lhx2 could serve as a potential target for antifibrotic gene therapy. Therefore, we evaluated an adenoviral mediated overexpression of Lhx2 in primary HSC and investigated mRNA expression patterns by qRT-PCR as well as the activation status by different in vitro assays. HSC revealed a marked increase in activation markers like smooth muscle actin alpha (αSMA) and collagen 1α independent from adenoviral transduction. Lhx2 overexpression resulted in attenuated cell viability as shown by a slightly hampered migratory and contractile phenotype of HSC. Expression of stem cell factors or signaling components was also unaffected by Lhx2. Summarizing these results, we found no antifibrotic or stem cell maintaining effect of Lhx2 overexpression in primary HSC. - Highlights: • We performed adenoviral overexpression of Lhx2 in primary hepatic stellate cells. • Hepatic stellate cells expressed stem cell markers during cultivation. • Cell migration and contractility was slightly hampered upon Lhx2 overexpression. • Lhx2 overexpression did not affect stem cell character of hepatic stellate cells.

  11. Adenoviral overexpression of Lhx2 attenuates cell viability but does not preserve the stem cell like phenotype of hepatic stellate cells

    Hepatic stellate cells (HSC) are well known initiators of hepatic fibrosis. After liver cell damage, HSC transdifferentiate into proliferative myofibroblasts, representing the major source of extracellular matrix in the fibrotic organ. Recent studies also demonstrate a role of HSC as progenitor or stem cell like cells in liver regeneration. Lhx2 is described as stem cell maintaining factor in different organs and as an inhibitory transcription factor in HSC activation. Here we examined whether a continuous expression of Lhx2 in HSC could attenuate their activation and whether Lhx2 could serve as a potential target for antifibrotic gene therapy. Therefore, we evaluated an adenoviral mediated overexpression of Lhx2 in primary HSC and investigated mRNA expression patterns by qRT-PCR as well as the activation status by different in vitro assays. HSC revealed a marked increase in activation markers like smooth muscle actin alpha (αSMA) and collagen 1α independent from adenoviral transduction. Lhx2 overexpression resulted in attenuated cell viability as shown by a slightly hampered migratory and contractile phenotype of HSC. Expression of stem cell factors or signaling components was also unaffected by Lhx2. Summarizing these results, we found no antifibrotic or stem cell maintaining effect of Lhx2 overexpression in primary HSC. - Highlights: • We performed adenoviral overexpression of Lhx2 in primary hepatic stellate cells. • Hepatic stellate cells expressed stem cell markers during cultivation. • Cell migration and contractility was slightly hampered upon Lhx2 overexpression. • Lhx2 overexpression did not affect stem cell character of hepatic stellate cells

  12. Design and bioinformatics analysis of novel biomimetic peptides as nanocarriers for gene transfer

    Asia Majidi

    2015-01-01

    Full Text Available Objective(s: The introduction of nucleic acids into cells for therapeutic objectives is significantly hindered by the size and charge of these molecules and therefore requires efficient vectors that assist cellular uptake. For several years great efforts have been devoted to the study of development of recombinant vectors based on biological domains with potential applications in gene therapy. Such vectors have been synthesized in genetically engineered approach, resulting in biomacromolecules with new properties that are not present in nature. Materials and Methods: In this study, we have designed new peptides using homology modeling with the purpose of overcoming the cell barriers for successful gene delivery through Bioinformatics tools. Three different carriers were designed and one of those with better score through Bioinformatics tools was cloned, expressed and its affinity for pDNA was monitored. Results: The resultszz demonstrated that the vector can effectively condense pDNAinto nanoparticles with the average sizes about 100 nm. Conclusion: We hope these peptides can overcome the biological barriers associated with gene transfer, and mediate efficient gene delivery.

  13. An Approach for Treating the Hepatobiliary Disease of Cystic Fibrosis by Somatic Gene Transfer

    Yang, Yiping; Raper, Steven E.; Cohn, Jonathan A.; Engelhardt, John F.; Wilson, James M.

    1993-05-01

    Cystic fibrosis (CF) is an inherited disease of epithelial cell ion transport that is associated with pathology in multiple organ systems, including lung, pancreas, and liver. As treatment of the pulmonary manifestations of CF has improved, management of CF liver disease has become increasingly important in adult patients. This report describes an approach for treating CF liver disease by somatic gene transfer. In situ hybridization and immunocytochemistry analysis of rat liver sections indicated that the endogenous CFTR (cystic fibrosis transmembrane conductance regulator) gene is primarily expressed in the intrahepatic biliary epithelial cells. To specifically target recombinant genes to the biliary epithelium in vivo, recombinant adenoviruses expressing lacZ or human CFTR were infused retrograde into the biliary tract through the common bile duct. Conditions were established for achieving recombinant gene expression in virtually all cells of the intrahepatic bile ducts in vivo. Expression persisted in the smaller bile ducts for the duration of the experiment, which was 21 days. These studies suggest that it may be feasible to prevent CF liver disease by genetically reconstituting CFTR expression in the biliary tract, using an approach that is clinically feasible.

  14. A novel roseobacter phage possesses features of podoviruses, siphoviruses, prophages and gene transfer agents

    Zhan, Yuanchao; Huang, Sijun; Voget, Sonja; Simon, Meinhard; Chen, Feng

    2016-07-01

    Bacteria in the Roseobacter lineage have been studied extensively due to their significant biogeochemical roles in the marine ecosystem. However, our knowledge on bacteriophage which infects the Roseobacter clade is still very limited. Here, we report a new bacteriophage, phage DSS3Φ8, which infects marine roseobacter Ruegeria pomeroyi DSS-3. DSS3Φ8 is a lytic siphovirus. Genomic analysis showed that DSS3Φ8 is most closely related to a group of siphoviruses, CbK-like phages, which infect freshwater bacterium Caulobacter crescentus. DSS3Φ8 contains a smaller capsid and has a reduced genome size (146 kb) compared to the CbK-like phages (205–279 kb). DSS3Φ8 contains the DNA polymerase gene which is closely related to T7-like podoviruses. DSS3Φ8 also contains the integrase and repressor genes, indicating its potential to involve in lysogenic cycle. In addition, four GTA (gene transfer agent) genes were identified in the DSS3Φ8 genome. Genomic analysis suggests that DSS3Φ8 is a highly mosaic phage that inherits the genetic features from siphoviruses, podoviruses, prophages and GTAs. This is the first report of CbK-like phages infecting marine bacteria. We believe phage isolation is still a powerful tool that can lead to discovery of new phages and help interpret the overwhelming unknown sequences in the viral metagenomics.

  15. A novel roseobacter phage possesses features of podoviruses, siphoviruses, prophages and gene transfer agents.

    Zhan, Yuanchao; Huang, Sijun; Voget, Sonja; Simon, Meinhard; Chen, Feng

    2016-01-01

    Bacteria in the Roseobacter lineage have been studied extensively due to their significant biogeochemical roles in the marine ecosystem. However, our knowledge on bacteriophage which infects the Roseobacter clade is still very limited. Here, we report a new bacteriophage, phage DSS3Φ8, which infects marine roseobacter Ruegeria pomeroyi DSS-3. DSS3Φ8 is a lytic siphovirus. Genomic analysis showed that DSS3Φ8 is most closely related to a group of siphoviruses, CbK-like phages, which infect freshwater bacterium Caulobacter crescentus. DSS3Φ8 contains a smaller capsid and has a reduced genome size (146 kb) compared to the CbK-like phages (205-279 kb). DSS3Φ8 contains the DNA polymerase gene which is closely related to T7-like podoviruses. DSS3Φ8 also contains the integrase and repressor genes, indicating its potential to involve in lysogenic cycle. In addition, four GTA (gene transfer agent) genes were identified in the DSS3Φ8 genome. Genomic analysis suggests that DSS3Φ8 is a highly mosaic phage that inherits the genetic features from siphoviruses, podoviruses, prophages and GTAs. This is the first report of CbK-like phages infecting marine bacteria. We believe phage isolation is still a powerful tool that can lead to discovery of new phages and help interpret the overwhelming unknown sequences in the viral metagenomics. PMID:27460944

  16. Genetic diversity of bacterial communities and gene transfer agents in northern South China Sea.

    Fu-Lin Sun

    Full Text Available Pyrosequencing of the 16S ribosomal RNA gene (rDNA amplicons was performed to investigate the unique distribution of bacterial communities in northern South China Sea (nSCS and evaluate community structure and spatial differences of bacterial diversity. Cyanobacteria, Proteobacteria, Actinobacteria, and Bacteroidetes constitute the majority of bacteria. The taxonomic description of bacterial communities revealed that more Chroococcales, SAR11 clade, Acidimicrobiales, Rhodobacterales, and Flavobacteriales are present in the nSCS waters than other bacterial groups. Rhodobacterales were less abundant in tropical water (nSCS than in temperate and cold waters. Furthermore, the diversity of Rhodobacterales based on the gene transfer agent (GTA major capsid gene (g5 was investigated. Four g5 gene clone libraries were constructed from samples representing different regions and yielded diverse sequences. Fourteen g5 clusters could be identified among 197 nSCS clones. These clusters were also related to known g5 sequences derived from genome-sequenced Rhodobacterales. The composition of g5 sequences in surface water varied with the g5 sequences in the sampling sites; this result indicated that the Rhodobacterales population could be highly diverse in nSCS. Phylogenetic tree analysis result indicated distinguishable diversity patterns among tropical (nSCS, temperate, and cold waters, thereby supporting the niche adaptation of specific Rhodobacterales members in unique environments.

  17. Comparative genomics of mitochondria in chlorarachniophyte algae: endosymbiotic gene transfer and organellar genome dynamics

    Tanifuji, Goro; Archibald, John M.; Hashimoto, Tetsuo

    2016-02-01

    Chlorarachniophyte algae possess four DNA-containing compartments per cell, the nucleus, mitochondrion, plastid and nucleomorph, the latter being a relic nucleus derived from a secondary endosymbiont. While the evolutionary dynamics of plastid and nucleomorph genomes have been investigated, a comparative investigation of mitochondrial genomes (mtDNAs) has not been carried out. We have sequenced the complete mtDNA of Lotharella oceanica and compared it to that of another chlorarachniophyte, Bigelowiella natans. The linear mtDNA of L. oceanica is 36.7 kbp in size and contains 35 protein genes, three rRNAs and 24 tRNAs. The codons GUG and UUG appear to be capable of acting as initiation codons in the chlorarachniophyte mtDNAs, in addition to AUG. Rpl16, rps4 and atp8 genes are missing in L.oceanica mtDNA, despite being present in B. natans mtDNA. We searched for, and found, mitochondrial rpl16 and rps4 genes with spliceosomal introns in the L. oceanica nuclear genome, indicating that mitochondrion-to-host-nucleus gene transfer occurred after the divergence of these two genera. Despite being of similar size and coding capacity, the level of synteny between L. oceanica and B. natans mtDNA is low, suggesting frequent rearrangements. Overall, our results suggest that chlorarachniophyte mtDNAs are more evolutionarily dynamic than their plastid counterparts.

  18. CFTR gene transfer to lung epithelium--on the trail of a target cell.

    O'Dea, S; Harrison, D J

    2002-05-01

    Cystic fibrosis (CF) is a lethal inherited disease that afflicts up to 1 in 2,500 people in the western world. Since 1989, when mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene were identified as responsible for the disease, intense effort has been applied to the development of replacement gene therapy strategies to cure CF. Problems with basic gene delivery techniques along with limited knowledge of the pathogenesis of CF have hindered progress so far. However, recent insights into the expression patterns and functions of CFTR in developing and adult lungs are now advancing our understanding of this disease. It is becoming apparent that progress in gene delivery to cure CF may be best served by identification of a target cell(s) around which gene transfer strategies can be specifically tailored to most closely reproduce the effects of normal CFTR expression. In fact, accurate restoration of endogenous expression patterns may be crucial, not only for disease reversal, but also to avoid potentially deleterious effects of inappropriate expression. This approach is in turn confounded however, by ill-defined stem and progenitor cell pathways within the lung epithelium. Nonetheless, studies to date suggest that these pathways are relatively plastic and may respond differently during homeostasis compared with repair following injury. It may therefore be feasible to target the lung epithelium in a non-cell specific manner and allow endogenous differentiation pathways to subsequently establish correct CFTR distribution patterns. In this review, emerging information on CFTR expression and function in developing and adult lungs is discussed in the context of putative stem cell populations and their potential for current gene delivery approaches. PMID:12109214

  19. Lateral Gene Transfer in a Heavy Metal-Contaminated-Groundwater Microbial Community

    Hemme, Christopher L.; Green, Stefan J.; Rishishwar, Lavanya; Prakash, Om; Pettenato, Angelica; Chakraborty, Romy; Deutschbauer, Adam M.; Van Nostrand, Joy D.; Wu, Liyou; He, Zhili; Jordan, I. King; Arkin, Adam P.; Kostka, Joel E.

    2016-01-01

    ABSTRACT Unraveling the drivers controlling the response and adaptation of biological communities to environmental change, especially anthropogenic activities, is a central but poorly understood issue in ecology and evolution. Comparative genomics studies suggest that lateral gene transfer (LGT) is a major force driving microbial genome evolution, but its role in the evolution of microbial communities remains elusive. To delineate the importance of LGT in mediating the response of a groundwater microbial community to heavy metal contamination, representative Rhodanobacter reference genomes were sequenced and compared to shotgun metagenome sequences. 16S rRNA gene-based amplicon sequence analysis indicated that Rhodanobacter populations were highly abundant in contaminated wells with low pHs and high levels of nitrate and heavy metals but remained rare in the uncontaminated wells. Sequence comparisons revealed that multiple geochemically important genes, including genes encoding Fe2+/Pb2+ permeases, most denitrification enzymes, and cytochrome c553, were native to Rhodanobacter and not subjected to LGT. In contrast, the Rhodanobacter pangenome contained a recombinational hot spot in which numerous metal resistance genes were subjected to LGT and/or duplication. In particular, Co2+/Zn2+/Cd2+ efflux and mercuric resistance operon genes appeared to be highly mobile within Rhodanobacter populations. Evidence of multiple duplications of a mercuric resistance operon common to most Rhodanobacter strains was also observed. Collectively, our analyses indicated the importance of LGT during the evolution of groundwater microbial communities in response to heavy metal contamination, and a conceptual model was developed to display such adaptive evolutionary processes for explaining the extreme dominance of Rhodanobacter populations in the contaminated groundwater microbiome. PMID:27048805

  20. Gene transfer of the Na+,K+-ATPase β1 subunit using electroporation increases lung liquid clearance in rats

    Machado-Aranda, David; Adir, Yochai; Young, Jennifer L.; Briva, A.; Budinger, G.R. Scott; Yeldandi, Anjana V.; Sznajder, Jacob I.; Dean, David A.

    2004-01-01

    The development of non-viral methods for efficient gene transfer to the lung is highly desired for the treatment of a number of pulmonary diseases. We have developed a non-invasive procedure using electroporation to transfer genes to the lungs of rats. Purified plasmid (100 to 600 μg) was delivered to the lungs of anesthetized rats through an endotracheal tube and a series of square wave pulses were delivered via electrodes placed on the chest. Relatively uniform gene expression was observed ...

  1. Gain and loss of multiple functionally related, horizontally transferred genes in the reduced genomes of two microsporidian parasites

    Pombert, Jean-François; Selman, Mohammed; Burki, Fabien; Bardell, Floyd T.; Farinelli, Laurent; Solter, Leellen F.; Whitman, Douglas W.; Weiss, Louis M.; Corradi, Nicolas; Patrick J Keeling

    2012-01-01

    Microsporidia of the genus Encephalitozoon are widespread pathogens of animals that harbor the smallest known nuclear genomes. Complete sequences from Encephalitozoon intestinalis (2.3 Mbp) and Encephalitozoon cuniculi (2.9 Mbp) revealed massive gene losses and reduction of intergenic regions as factors leading to their drastically reduced genome size. However, microsporidian genomes also have gained genes through horizontal gene transfers (HGT), a process that could allow the parasites to ex...

  2. Transfers

    Xavier Sala-i-Martin

    1992-01-01

    In this paper I develop a positive theory of intergenerational transfers. I argue that transfers are a means to induce retirement. that is, to buy the elderly out of the labor force. The reason why societies choose to do such a thing is that aggregate output is higher if the elderly do not work. I model this idea through positive externalities in the average stock of human capital: because skills depreciate with age. one implication of these externalities is that the elderly have a negative e...

  3. DNA-mediated gene transfer into human diploid fibroblasts derived from normal and ataxia-telangiectasia donors: parameters for DNA transfer and properties of DNA transformants

    An investigation was made of the feasibility of DNA-mediated gene transfer into human diploid fibroblasts derived from patients with the radiation sensitive syndrome ataxia-telangiectasia (A-T) and from a normal donor. Although they are markedly different in their growth characteristics, both normal and A-T strains give similar frequencies for DNA transfer in a model system using the recombinant plasmid pSV2-gpt. pSV2-gpt DNA transformants arise with a frequency between 10-5 and 10-4 per viable cell. Analysis of such transformants, although possible, is severely handicapped by the limited clonal life span of diploid human cells. Despite these problems it may be concluded that diploid human fibroblasts are competent recipients for DNA-mediated gene transfer and the putative repair deficiency of A-T does not markedly effect the efficiency of this process. (author)

  4. Progress in identifying a human ionizing-radiation repair gene using DNA-mediated gene transfer techniques

    The authors employing DNA-mediated gene transfer techniques in introducing human DNA into a DNA double-strand break (DSB) repair deficient Chinese hamster (CHO) cell mutant (xrs-6), which is hypersensitive to both X-rays (D0 = 0.39 Gy) and the antibiotic bleomycin (D0 = 0.01 μg/ml). High molecular weight DNA isolated from cultured human skin fibroblasts was partially digested with restriction enzyme Sau 3A to average sizes of 20 or 40 Kb, ligated with plasmid pSV2-gpt DNA, and transfected into xrs-6 cells. Colonies which developed under a bleomycin and MAX (mycophenolic acid/adenine/xanthine) double-selection procedure were isolated and further tested for X-ray sensitivity and DSB rejoining capacity. To date a total of six X-ray or bleomycin resistant transformants have been isolated. All express rejoining capacity for X-ray-induced DSB, similar to the rate observed for DSB repair in CHO wild type cells. DNA isolated from these primary transformants contain various copy numbers of pSV2-gpt DNA and also contain human DNA sequences as determined by Southern blot hybridization. Recently, a secondary transformant has been isolated using DNA from one of the primary transformants. Cellular and molecular characterization of this transformant is in progress. DNA from a genuine secondary transformant will be used in the construction of a DNA library to isolate human genomic DNA encoding this radiation repair gene

  5. Suppression of tumorigenicity of breast cancer cells by transfer of human chromosome 17 does not require transferred BRCA1 and p53 genes.

    Theile, M; Hartmann, S; Scherthan, H; Arnold, W; Deppert, W; Frege, R; Glaab, F; Haensch, W; Scherneck, S

    1995-02-01

    A number of candidate tumor suppressor genes located on the human chromosome 17 are thought to have a role to play in the development of breast cancer. In addition to the p53 gene on 17p13.1 and the BRCA1 gene mapped to 17q12-21, other chromosomal regions for tumor suppressor genes have been suggested to exist on 17p13.3 and both the central and the distal parts of 17q, although definitive functional proof of their involvement in breast cancer tumorigenesis is still lacking. In this report we show that microcell transfer of a human chromosome 17 into wild-type p53 breast cancer cells CAL51 results in loss of tumorigenicity and anchorage-independent growth, changes in cell morphology and a reduction of cell growth rates of the neo-selected microcell hybrids. In the hybrid cells, which express the p53 wild-type protein, only the p- and the distal parts of the q arm of donor chromosome 17 are transferred. Thus, our results provide functional evidence for the presence of one or more tumor suppressor gene(s) on chromosome 17, which are distinct from the p53 and the BRCA1 genes. PMID:7845668

  6. Microbial co-habitation and lateral gene transfer: what transposases can tell us

    Hooper, Sean D.; Mavromatis, Konstantinos; Kyrpides, Nikos C.

    2009-03-01

    Determining the habitat range for various microbes is not a simple, straightforward matter, as habitats interlace, microbes move between habitats, and microbial communities change over time. In this study, we explore an approach using the history of lateral gene transfer recorded in microbial genomes to begin to answer two key questions: where have you been and who have you been with? All currently sequenced microbial genomes were surveyed to identify pairs of taxa that share a transposase that is likely to have been acquired through lateral gene transfer. A microbial interaction network including almost 800 organisms was then derived from these connections. Although the majority of the connections are between closely related organisms with the same or overlapping habitat assignments, numerous examples were found of cross-habitat and cross-phylum connections. We present a large-scale study of the distributions of transposases across phylogeny and habitat, and find a significant correlation between habitat and transposase connections. We observed cases where phylogenetic boundaries are traversed, especially when organisms share habitats; this suggests that the potential exists for genetic material to move laterally between diverse groups via bridging connections. The results presented here also suggest that the complex dynamics of microbial ecology may be traceable in the microbial genomes.

  7. Comparison of lentiviral and sleeping beauty mediated αβ T cell receptor gene transfer.

    Anne-Christine Field

    Full Text Available Transfer of tumour antigen-specific receptors to T cells requires efficient delivery and integration of transgenes, and currently most clinical studies are using gamma retroviral or lentiviral systems. Whilst important proof-of-principle data has been generated for both chimeric antigen receptors and αβ T cell receptors, the current platforms are costly, time-consuming and relatively inflexible. Alternative, more cost-effective, Sleeping Beauty transposon-based plasmid systems could offer a pathway to accelerated clinical testing of a more diverse repertoire of recombinant high affinity T cell receptors. Nucleofection of hyperactive SB100X transposase-mediated stable transposition of an optimised murine-human chimeric T cell receptor specific for Wilm's tumour antigen from a Sleeping Beauty transposon plasmid. Whilst transfer efficiency was lower than that mediated by lentiviral transduction, cells could be readily enriched and expanded, and mediated effective target cells lysis in vitro and in vivo. Integration sites of transposed TCR genes in primary T cells were almost randomly distributed, contrasting the predilection of lentiviral vectors for transcriptionally active sites. The results support exploitation of the Sleeping Beauty plasmid based system as a flexible and adaptable platform for accelerated, early-phase assessment of T cell receptor gene therapies.

  8. Heat-transfer-based detection of SNPs in the PAH gene of PKU patients.

    Vanden Bon, Natalie; van Grinsven, Bart; Murib, Mohammed Sharif; Yeap, Weng Siang; Haenen, Ken; De Ceuninck, Ward; Wagner, Patrick; Ameloot, Marcel; Vermeeren, Veronique; Michiels, Luc

    2014-01-01

    Conventional neonatal diagnosis of phenylketonuria is based on the presence of abnormal levels of phenylalanine in the blood. However, for carrier detection and prenatal diagnosis, direct detection of disease-correlated mutations is needed. To speed up and simplify mutation screening in genes, new technologies are developed. In this study, a heat-transfer method is evaluated as a mutation-detection technology in entire exons of the phenylalanine hydroxylase (PAH) gene. This method is based on the change in heat-transfer resistance (R(th)) upon thermal denaturation of dsDNA (double-stranded DNA) on nanocrystalline diamond. First, ssDNA (single-stranded DNA) fragments that span the size range of the PAH exons were successfully immobilized on nanocrystalline diamond. Next, it was studied whether an R(th) change could be observed during the thermal denaturation of these DNA fragments after hybridization to their complementary counterpart. A clear R(th) shift during the denaturation of exon 5, exon 9, and exon 12 dsDNA was observed, corresponding to lengths of up to 123 bp. Finally, R(th) was shown to detect prevalent single-nucleotide polymorphisms, c.473G>A (R158Q), c.932T>C (p.L311P), and c.1222C>T (R408W), correlated with phenylketonuria, displaying an effect related to the different melting temperatures of homoduplexes and heteroduplexes. PMID:24741310

  9. Cre-dependent selection yields AAV variants for widespread gene transfer to the adult brain.

    Deverman, Benjamin E; Pravdo, Piers L; Simpson, Bryan P; Kumar, Sripriya Ravindra; Chan, Ken Y; Banerjee, Abhik; Wu, Wei-Li; Yang, Bin; Huber, Nina; Pasca, Sergiu P; Gradinaru, Viviana

    2016-02-01

    Recombinant adeno-associated viruses (rAAVs) are commonly used vehicles for in vivo gene transfer. However, the tropism repertoire of naturally occurring AAVs is limited, prompting a search for novel AAV capsids with desired characteristics. Here we describe a capsid selection method, called Cre recombination-based AAV targeted evolution (CREATE), that enables the development of AAV capsids that more efficiently transduce defined Cre-expressing cell populations in vivo. We use CREATE to generate AAV variants that efficiently and widely transduce the adult mouse central nervous system (CNS) after intravenous injection. One variant, AAV-PHP.B, transfers genes throughout the CNS with an efficiency that is at least 40-fold greater than that of the current standard, AAV9 (refs. 14,15,16,17), and transduces the majority of astrocytes and neurons across multiple CNS regions. In vitro, it transduces human neurons and astrocytes more efficiently than does AAV9, demonstrating the potential of CREATE to produce customized AAV vectors for biomedical applications. PMID:26829320

  10. Dual effects of adenovirus-mediated thrombopoietin gene transfer on hepatic oval cell proliferation and platelet counts

    Thrombopoietin (TPO) is the growth factor for megakaryocytes and platelets, however, it also acts as a potent regulator of stem cell proliferation. To examine the significance of TPO expression in proliferation of hepatic oval cells, the effect of adenovirus-mediated TPO gene transfer into livers of the Solt-Farber model, which mimics the condition where liver regeneration is impaired, was examined. Hepatic TPO mRNA peaked its expression at 2 days after gene transduction and then gradually decreased. The peripheral platelet number began to increase at 4 days (P < 0.05) and reached its plateau at 9 days (P < 0.01). Oval cells expressed c-Mpl, a receptor for TPO as well as immature hematopoietic and hepatocytic surface markers such as CD34 and AFP. The proliferating cell nuclear antigen-positive oval cells in rats into which adenovirus-TPO gene was transferred at 7 and 9 days were significantly greater than those in adenovirus-LacZ gene transferred (P < 0.05, each), and the total numbers of oval cells in the adenovirus-TPO gene transferred at 9 and 13 days were also significantly greater than those in adenovirus-LacZ gene transferred (P < 0.05, each). Expression of SCF protein was increased at 4, 7, and 9 days by TPO gene administration and that of c-Kit was increased at 4 and 7 days. These data suggest that adenovirus-mediated TPO gene transfer stimulated oval cell proliferation in liver as well as increasing peripheral platelet counts, emphasizing the significance of the TPO/c-Mpl system in proliferation of hepatic oval cells

  11. High-frequency conjugative transfer of antibiotic resistance genes to Yersinia pestis in the flea midgut.

    Hinnebusch, B Joseph; Rosso, Marie-Laure; Schwan, Tom G; Carniel, Elisabeth

    2002-10-01

    The acquisition of foreign DNA by horizontal transfer from unrelated organisms is a major source of variation leading to new strains of bacterial pathogens. The extent to which this occurs varies widely, due in part to lifestyle factors that determine exposure to potential donors. Yersinia pestis, the plague bacillus, infects normally sterile sites in its mammalian host, but forms dense aggregates in the non-sterile digestive tract of its flea vector to produce a transmissible infection. Here we show that unrelated co-infecting bacteria in the flea midgut are readily incorporated into these aggregates, and that this close physical contact leads to high-frequency conjugative genetic exchange. Transfer of an antibiotic resistance plasmid from an Escherichia coli donor to Y. pestis occurred in the flea midgut at a frequency of 10-3 after only 3 days of co-infection, and after 4 weeks 95% of co-infected fleas contained an average of 103 antibiotic-resistant Y. pestis transconjugants. Thus, transit in its arthropod vector exposes Y. pestis to favourable conditions for efficient genetic exchange with microbial flora of the flea gut. Horizontal gene transfer in the flea may be the source of antibiotic-resistant Y. pestis strains recently isolated from plague patients in Madagascar. PMID:12406213

  12. Adenovirus-mediated p53 gene transfer increases radiosensitivity of human gastric carcinoma cells

    Objective: To evaluate the effect of adenovirus-mediated p53 gene (Adp53) on apoptosis and radiosensitivity of human gastric carcinoma cell lines. Methods: Recombinant adenovirus carrying wild-type p53 gene was transferred into four human gastric carcinoma cell lines with different p53 genetic status. P53 protein expression was detected by immunohistochemistry and Western blot assay. Cell survival was assessed using a clonogenic assay. TUNEL assay was used in determination of apoptosis. The four human gastric carcinoma cell line infected with Adp53 were irradiated with 4 Gy, and cell cycle distribution and apoptotic rate were assayed by flow cytometry. Nude mice xenograft models of W and M cell were intratumorally injected with Adp53 and 48 h later were irradiated with 6 Gy. Relative volume in growth curve of tumor was used to observe tumor regression. Results: G2/M arrest, apoptosis and inhibition of tumor cell proliferation were induced by infection with Adp53 at 100 MOI, which caused high transfer rate of wild-type p53 and strong expression of P53 protein in the four human gastric carcinoma cell line cells. When evaluating radio-biologic efficacy by apoptotic rate, the apoptotic enhancement ratio of Adp53 at 4 Gy was 3.0 for W cell, 3.6 for M cell, 2.2 for neo cell and 2.5 for 823 cell respectively, in vitro. The antitumor enhancement ratio of Adp53 at 6 Gy was 1.41 for cell-implanted tumor and 1.91 for M cell-implanted tumor in vivo. Conclusion: This study demonstrated that Adp53 transfer increased cellular apoptosis and radiosensitivity of human gastric carcinoma

  13. Heat-transfer-based detection of SNPs in the PAH gene of PKU patients

    Vanden Bon N

    2014-03-01

    Full Text Available Natalie Vanden Bon,1 Bart van Grinsven,2 Mohammed Sharif Murib,2 Weng Siang Yeap,2 Ken Haenen,2,3 Ward De Ceuninck,2,3 Patrick Wagner,2,3 Marcel Ameloot,1 Veronique Vermeeren,1 Luc Michiels11Biomedical Research Institute, Hasselt University, Diepenbeek, Belgium; 2Institute for Materials Research, Hasselt University, Diepenbeek, Belgium; 3IMOMEC, Diepenbeek, BelgiumAbstract: Conventional neonatal diagnosis of phenylketonuria is based on the presence of abnormal levels of phenylalanine in the blood. However, for carrier detection and prenatal diagnosis, direct detection of disease-correlated mutations is needed. To speed up and simplify mutation screening in genes, new technologies are developed. In this study, a heat-transfer method is evaluated as a mutation-detection technology in entire exons of the phenylalanine hydroxylase (PAH gene. This method is based on the change in heat-transfer resistance (Rth upon thermal denaturation of dsDNA (double-stranded DNA on nanocrystalline diamond. First, ssDNA (single-stranded DNA fragments that span the size range of the PAH exons were successfully immobilized on nanocrystalline diamond. Next, it was studied whether an Rth change could be observed during the thermal denaturation of these DNA fragments after hybridization to their complementary counterpart. A clear Rth shift during the denaturation of exon 5, exon 9, and exon 12 dsDNA was observed, corresponding to lengths of up to 123 bp. Finally, Rth was shown to detect prevalent single-nucleotide polymorphisms, c.473G>A (R158Q, c.932T>C (p.L311P, and c.1222C>T (R408W, correlated with phenylketonuria, displaying an effect related to the different melting temperatures of homoduplexes and heteroduplexes.Keywords: mutation detection, heat-transfer resistance, melting temperature, nanocrystalline diamond, persistence length

  14. Extensive recombination events and horizontal gene transfer shaped the Legionella pneumophila genomes

    Rouy Zoé

    2011-11-01

    Full Text Available Abstract Background Legionella pneumophila is an intracellular pathogen of environmental protozoa. When humans inhale contaminated aerosols this bacterium may cause a severe pneumonia called Legionnaires' disease. Despite the abundance of dozens of Legionella species in aquatic reservoirs, the vast majority of human disease is caused by a single serogroup (Sg of a single species, namely L. pneumophila Sg1. To get further insights into genome dynamics and evolution of Sg1 strains, we sequenced strains Lorraine and HL 0604 1035 (Sg1 and compared them to the available sequences of Sg1 strains Paris, Lens, Corby and Philadelphia, resulting in a comprehensive multigenome analysis. Results We show that L. pneumophila Sg1 has a highly conserved and syntenic core genome that comprises the many eukaryotic like proteins and a conserved repertoire of over 200 Dot/Icm type IV secreted substrates. However, recombination events and horizontal gene transfer are frequent. In particular the analyses of the distribution of nucleotide polymorphisms suggests that large chromosomal fragments of over 200 kbs are exchanged between L. pneumophila strains and contribute to the genome dynamics in the natural population. The many secretion systems present might be implicated in exchange of these fragments by conjugal transfer. Plasmids also play a role in genome diversification and are exchanged among strains and circulate between different Legionella species. Conclusion Horizontal gene transfer among bacteria and from eukaryotes to L. pneumophila as well as recombination between strains allows different clones to evolve into predominant disease clones and others to replace them subsequently within relatively short periods of time.

  15. Retroviral-mediated transfer and expression of human β-globin genes in cultured murine and human erythroid cells

    The authors cloned human β-globin DNA sequences from a genomic library prepared from DNA isolated from the human leukemia cell line K562 and have used the retroviral vector pZip-NeoSV(X)1 to introduce a 3.0-kilobase segment encompassing the globin gene into mouse erythroleukemia cells. Whereas the endogenous K562 β-globin gene is repressed in K562 cells, when introduced into mouse erythroleukemia cells by retroviral-mediated gene transfer, the β-globin gene from K562 cells was transcribed and induced 5-20-fold after treatment of the cells with dimethyl sulfoxide. The transcripts were correctly initiated, and expression and regulation of the K562 gene were identical to the expression of a normal human β-globin gene transferred into mouse erythroleukemia cells in the same way. They have also introduced the normal human β-globin gene into K562 cells using the same retrovirus vector. SP6 analysis of the RNA isolated from the transduced cells showed that the normal β-globin gene was transcribed at a moderately high level, before or after treatment with hemin. Based on these data, they suggest that the lack of expression of the endogenous β-globin gene in K562 cells does not result from an alteration in the gene itself and may not result from a lack of factor(s) necessary for β-lobin gene transcription. Retroviral-mediated transfer of the human β-globin gene may, however, uniquely influence expression of the gene K562 cells

  16. Putative cross-kingdom horizontal gene transfer in sponge (Porifera) mitochondria

    Rot, Chagai; Goldfarb, Itay; Ilan, Micha; Huchon, Dorothée

    2006-01-01

    Background The mitochondrial genome of Metazoa is usually a compact molecule without introns. Exceptions to this rule have been reported only in corals and sea anemones (Cnidaria), in which group I introns have been discovered in the cox1 and nad5 genes. Here we show several lines of evidence demonstrating that introns can also be found in the mitochondria of sponges (Porifera). Results A 2,349 bp fragment of the mitochondrial cox1 gene was sequenced from the sponge Tetilla sp. (Spirophorida). This fragment suggests the presence of a 1143 bp intron. Similar to all the cnidarian mitochondrial introns, the putative intron has group I intron characteristics. The intron is present in the cox1 gene and encodes a putative homing endonuclease. In order to establish the distribution of this intron in sponges, the cox1 gene was sequenced from several representatives of the demosponge diversity. The intron was found only in the sponge order Spirophorida. A phylogenetic analysis of the COI protein sequence and of the intron open reading frame suggests that the intron may have been transmitted horizontally from a fungus donor. Conclusion Little is known about sponge-associated fungi, although in the last few years the latter have been frequently isolated from sponges. We suggest that the horizontal gene transfer of a mitochondrial intron was facilitated by a symbiotic relationship between fungus and sponge. Ecological relationships are known to have implications at the genomic level. Here, an ecological relationship between sponge and fungus is suggested based on the genomic analysis. PMID:16972986

  17. Putative cross-kingdom horizontal gene transfer in sponge (Porifera mitochondria

    Ilan Micha

    2006-09-01

    Full Text Available Abstract Background The mitochondrial genome of Metazoa is usually a compact molecule without introns. Exceptions to this rule have been reported only in corals and sea anemones (Cnidaria, in which group I introns have been discovered in the cox1 and nad5 genes. Here we show several lines of evidence demonstrating that introns can also be found in the mitochondria of sponges (Porifera. Results A 2,349 bp fragment of the mitochondrial cox1 gene was sequenced from the sponge Tetilla sp. (Spirophorida. This fragment suggests the presence of a 1143 bp intron. Similar to all the cnidarian mitochondrial introns, the putative intron has group I intron characteristics. The intron is present in the cox1 gene and encodes a putative homing endonuclease. In order to establish the distribution of this intron in sponges, the cox1 gene was sequenced from several representatives of the demosponge diversity. The intron was found only in the sponge order Spirophorida. A phylogenetic analysis of the COI protein sequence and of the intron open reading frame suggests that the intron may have been transmitted horizontally from a fungus donor. Conclusion Little is known about sponge-associated fungi, although in the last few years the latter have been frequently isolated from sponges. We suggest that the horizontal gene transfer of a mitochondrial intron was facilitated by a symbiotic relationship between fungus and sponge. Ecological relationships are known to have implications at the genomic level. Here, an ecological relationship between sponge and fungus is suggested based on the genomic analysis.

  18. Multiple Origins of Eukaryotic cox15 Suggest Horizontal Gene Transfer from Bacteria to Jakobid Mitochondrial DNA.

    He, Ding; Fu, Cheng-Jie; Baldauf, Sandra L

    2016-01-01

    The most gene-rich and bacterial-like mitochondrial genomes known are those of Jakobida (Excavata). Of these, the most extreme example to date is the Andalucia godoyi mitochondrial DNA (mtDNA), including a cox15 gene encoding the respiratory enzyme heme A synthase (HAS), which is nuclear-encoded in nearly all other mitochondriate eukaryotes. Thus cox15 in eukaryotes appears to be a classic example of mitochondrion-to-nucleus (endosymbiotic) gene transfer, with A. godoyi uniquely retaining the ancestral state. However, our analyses reveal two highly distinct HAS types (encoded by cox15-1 and cox15-2 genes) and identify A. godoyi mitochondrial cox15-encoded HAS as type-1 and all other eukaryotic cox15-encoded HAS as type-2. Molecular phylogeny places the two HAS types in widely separated clades with eukaryotic type-2 HAS clustering with the bulk of α-proteobacteria (>670 sequences), whereas A. godoyi type-1 HAS clusters with an eclectic set of bacteria and archaea including two α-proteobacteria missing from the type-2 clade. This wide phylogenetic separation of the two HAS types is reinforced by unique features of their predicted protein structures. Meanwhile, RNA-sequencing and genomic analyses fail to detect either cox15 type in the nuclear genome of any jakobid including A. godoyi. This suggests that not only is cox15-1 a relatively recent acquisition unique to the Andalucia lineage but also the jakobid last common ancestor probably lacked both cox15 types. These results indicate that uptake of foreign genes by mtDNA is more taxonomically widespread than previously thought. They also caution against the assumption that all α-proteobacterial-like features of eukaryotes are ancient remnants of endosymbiosis. PMID:26412445

  19. Multiple interkingdom horizontal gene transfers in Pyrenophora and closely related species and their contributions to phytopathogenic lifestyles.

    Bao-Fa Sun

    Full Text Available Many studies have reported horizontal gene transfer (HGT events from eukaryotes, especially fungi. However, only a few investigations summarized multiple interkingdom HGTs involving important phytopathogenic species of Pyrenophora and few have investigated the genetic contributions of HGTs to fungi. We investigated HGT events in P. teres and P. tritici-repentis and discovered that both species harbored 14 HGT genes derived from bacteria and plants, including 12 HGT genes that occurred in both species. One gene coding a leucine-rich repeat protein was present in both species of Pyrenophora and it may have been transferred from a host plant. The transfer of genes from a host plant to pathogenic fungi has been reported rarely and we discovered the first evidence for this transfer in phytopathogenic Pyrenophora. Two HGTs in Pyrenophora underwent subsequent duplications. Some HGT genes had homologs in a few other fungi, indicating relatively ancient transfer events. Functional analyses indicated that half of the HGT genes encoded extracellular proteins and these may have facilitated the infection of plants by Pyrenophora via interference with plant defense-response and the degradation of plant cell walls. Some other HGT genes appeared to participate in carbohydrate metabolism. Together, these functions implied that HGTs may have led to highly efficient mechanisms of infection as well as the utilization of host carbohydrates. Evolutionary analyses indicated that HGT genes experienced amelioration, purifying selection, and accelerated evolution. These appeared to constitute adaptations to the background genome of the recipient. The discovery of multiple interkingdom HGTs in Pyrenophora, their significance to infection, and their adaptive evolution, provided valuable insights into the evolutionary significance of interkingdom HGTs from multiple donors.

  20. Improving access to intestinal stem cells as a step toward intestinal gene transfer.

    Sandberg, J W; Lau, C; Jacomino, M; Finegold, M; Henning, S J

    1994-03-01

    In previous studies exploring the intestinal epithelium as a potential site for somatic gene therapy, we concluded that the mucus lining the intestine constitutes a significant barrier to any attempts at gene transfer via the lumenal route. The mucus problem is aggravated by the fact that the epithelial stem cells, which are the logical target for gene transfer, are located deep in the intestinal crypts. The goals of the current study were to develop procedures that would improve accessibility to the intestinal stem cells and which would effect in vivo mucus removal without damaging the underlying epithelium. Initial experiments involved evaluation of the use of distension to improve accessibility to the intestinal crypts and the use of the mucolytic agents dithiothreitol (DTT) and N-acetyl-cysteine (NAC) versus a control solution of phosphate-buffered saline (PBS) for mucus removal. Catheters were inserted in each end of 3-cm terminal ileal segments in anesthetized rats. Two milliliters of agent was instilled into the clamped segment for 2 min, removed, and repeated. Lumenal distension resulted in shortened villi with wider intervillus spacing, thereby improving crypt access. Both NAC and DTT washes removed significant mucus between the villi but failed to reach the crypt lumen. To enhance mucus release from the crypt lumen, pilocarpine was selected due to its cholinergic properties and preferential binding to muscarinic receptors on crypt goblet cells. Pilocarpine given intraperitoneally 30 min prior to the mucolytic or PBS wash resulted in significant eradication of mucus down into the crypt lumen. This effect was still evident 3-4 hr later provided the intestine remained undisturbed. PMID:8018747

  1. The prevalence of adenoviral conjunctivitis at the Clinical Hospital of the State University of Campinas, Brazil

    Roberto Damian Pacheco Pinto

    2015-11-01

    Full Text Available OBJECTIVES: Viral conjunctivitis is a common, highly contagious disease that is often caused by an adenovirus. The aim of this study was to evaluate the prevalence of adenoviral conjunctivitis by analyzing data from a prospective clinical study of 122 consecutively enrolled patients who were treated at the Clinical Hospital of the State University of Campinas (UNICAMP after a clinical diagnosis of infectious conjunctivitis between November 2011 and June 2012. METHODS: Polymerase chain reaction was used to evaluate all cases of clinically diagnosed infectious conjunctivitis and based on the laboratory findings, the prevalence of adenoviral infections was determined. The incidence of subepithelial corneal infiltrates was also investigated. RESULTS: Of the 122 patients with acute infectious conjunctivitis included, 72 had positive polymerase chain reaction results for adenoviruses and 17 patients developed subepithelial corneal infiltrates (13.93%. CONCLUSIONS: The polymerase chain reaction revealed that the prevalence of adenoviral conjunctivitis was 59% in all patients who presented with a clinical diagnosis of infectious conjunctivitis from November 2011 to June 2012. The prevalence of adenoviral conjunctivitis in the study population was similar to its prevalence in other regions of the world.

  2. Amplification of inflammation in emphysema and its association with latent adenoviral infection.

    Retamales, I; Elliott, W M; Meshi, B; Coxson, H O; Pare, P D; Sciurba, F C; Rogers, R M; Hayashi, S; Hogg, J C

    2001-08-01

    This study examines the hypothesis that the cigarette smoke-induced inflammatory process is amplified in severe emphysema and explores the association of this response with latent adenoviral infection. Lung tissue from patients with similar smoking histories and either no (n = 7), mild (n = 7), or severe emphysema (n = 7) was obtained by lung resection. Numbers of polymorphonuclear cells (PMN), macrophages, B cells, CD4, CD8 lymphocytes, and eosinophils present in tissue and airspaces and of epithelial cells expressing adenoviral E1A protein were determined using quantitative techniques. Severe emphysema was associated with an absolute increase in the total number of inflammatory cells in the lung tissue and airspaces. The computed tomography (CT) determined extent of lung destruction was related to the number of cells/m(2) surface area by R(2) values that ranged from 0.858 (CD8 cells) to 0.483 (B cells) in the tissue and 0.630 (CD4 cells) to 0.198 (B cells) in the airspaces. These changes were associated with a 5- to 40-fold increase in the number of alveolar epithelial cells expressing adenoviral E1A protein in mild and severe disease, respectively. We conclude that cigarette smoke-induced lung inflammation is amplified in severe emphysema and that latent expression of the adenoviral E1A protein expressed by alveolar epithelial cells influenced this amplification process. PMID:11500352

  3. Effect of 6-azacytidine on the course of experimental adenoviral infection in newborn Syrian hamsters.

    Zarubalev, V V; Slita, A V; Sukhinin, V P; Nosach, L N; Dyachenko, N S; Povnitsa, O Y; Zhovnovataya, V L; Alexeeva, I V; Palchikovskaya, L I

    2007-02-01

    Adenoviral infection is a serious human pathology leading to respiratory, gastrointestinal and ocular disorders and epidemic outbreaks, especially in children's groups. Here we present the results from an investigation of anti- adenoviral effect of 6-azacytidine (6-AC) both in vitro and in vivo. The selectivity index of 6-AC for adenovirus type 5 in HEp-2 cells was 374, the 50% effective concentration was 0.5 mg/ml. For in vivo investigations we developed a model of disseminated adenoviral infection in newborn Syrian hamsters. The infectious virus was recovered from the liver, kidney, lungs and heart. Application of 6-AC led to a reduced period of the virus presence (7 days in the liver and 4 days in the kidney and heart) and lowered virus titers on day 3 post-inoculation (p.i.) (liver - 2.7 and 4.1, heart - 0 and 3.2, kidney - 0 and 2.4 log(10 )CPD(50)/mg tissue weight, in the presence and absence of 6-AC, respectively). Application of 6-AC to newborn Syrian hamsters led to partial destruction of their splenocytes. The results obtained suggest that 6-AC or 6-ACbased drugs with lower toxicity or applied topically may be suitable for therapy and prevention of adenoviral infection in humans. PMID:17309850

  4. Expression of VEGF protein of lung and liver in GM-CSF gene transferred mice after neutron acute injury

    Objective: To study lung and liver vascular endothelial growth factor (VEGF) protein expression changes in granulocyte-macrophage colony-stimulating factor(GM-CSF) transgene mice after neutron exposure. Methods: Male BALB/C mice were irradiated with neutron, in dose of 0.6Gy, the mice were divided into the non-transfer group and the gene transfer group. In the gene transfer group, hGM-CSF gene was transfered by electroporation in vivo 24 h prior to exposure. Animals in the two groups were sacrificed at the 1st, 14th, 28th day, using pathologic test, immunohistochemica test and Western blot to study VEGF protein expression in lung and liver. Results: From 14 d to 28 d after exposure, the levels of VEGF protein expression in the mice in the genetransfer group was significantly higher than that in the non-transfer group. Conclusion: GM-CSF in vivo gene transfer in mice significantly promote angiogenesis and restoration in the climax and recovery phase acute injury caused by neutron. (authors)

  5. Stimulating recovery of hemopoietic and immunological functions by co-transferring IL-6 and SCF genes in irradiated mice

    Objective: To explore the hemopoietic and immunological functions of retroviral-mediated IL-6 and SCF genes co-transferred into bone marrow stromal cells in irradiated mice. Methods: IL-6 and SCF cDNA were recombined with retroviral vector pLXSN by gene recombination technology. Number of peripheral blood and bone marrow cells, CFU-GM of bone marrow cells, LTT and CD4/CD8 ratio of spleen were also assayed in vivo. Results: The bone marrow stromal cells transferred with IL-6 and SCF genes could stimulate the recovery of hemopoietic and immunological functions in irradiated mice in vivo. Conclusion: IL-6 and SCF genes are simultaneously expressed in bone marrow stromal cells, which provide a basis for studies on hematopoietic regulation by gene-transfected bone marrow stromal cells

  6. Improvement of Drought Tolerance in Transgenic Tobacco Plants by a Dehydrin-Like Gene Transfer

    SHEN Ye; JIA Wei-long; ZHANG Yan-qin; HU Yuan-lei; WU Qi; LIN Zhong-ping

    2004-01-01

    A full-length cDNA of dehydrin BcDh2 from Boea crassifolia and its antisense nucleotide sequence have been transferred into tobacco (Nicotiana tabacum) NC89 under the control of a caulifower mosaic virus 35S promoter. Under a progressive water stress, photosynthetic rate, transpiration rate and stomatal conductance of the sense and antisense plants reduced, and those of the control reduced much more. Photosynthetic rate, transpiration rate and stomatal conductance of all plants tested increased significantly 24 hours later after recoveried water supply, and those of the sense and antisense plants were higher than control. These indicated that overexpression of a dehydrin gene in tobacco may improve tolerance to water stress for plants, however, antisense BcDh2 gene in transgenic plant did not influence physiological conditions. The results of germination experiment of the transgenic seeds showed that on MS medium with different concentration PEG (8000), sense seed could more endure drought than control, while antisense seed was sensitive to drought. The results suggested that the overexpression of a dehydrin gene in tobacco might improve the tolerance to water stress for plants.

  7. Improvement of Drought Tolerance in Transgenic Tobacco Plants by aDehydrin-Like Gene Transfer

    SHENYe; JIAWei-long; ZHANGYan-qin; HUYuan-lei; WUQi; LINZhongping

    2004-01-01

    A full-length cDNA of dehydrin BcDh2 from Boea crassifolia and its antisense nucleotide sequence have been transferred into tobacco (Nicotiana tabacum) NC89 under the control of a caulifower mosaic virus 35S promoter. Under a progressive water stress, photosynthetic rate, transpiration rate and stomatal conductance of the sense and antisense plants reduced, and those of the control reduced much more. Photosynthetic rate, transpiration rate and stomatal conductance of all plants tested increased significantly 24 hours later after recoveried water supply, and those of the sense and antisense plants were higher than control. These indicated that overexpression of a dehydrin gene in tobacco may improve tolerance to water stress for plants, however, antisense BcDh2 gene in transgenic plant did not influence physiological conditions. The results of germination experiment of the transgenic seeds showed that on MS medium with different concentration PEG (8000), sense seed could more endure drought than control, while antisense seed was sensitive to drought. The results suggested that the overexpression of a dehydrin gene in tobacco might improve the tolerance to water stress for plants.

  8. Polygalacturonase from Sitophilus oryzae: Possible horizontal transfer of a pectinase gene from fungi to weevils

    Zhicheng Shen

    2003-08-01

    Full Text Available Endo-polygalacturonase, one of the group of enzymes known collectively as pectinases, is widely distributed in bacteria, plants and fungi. The enzyme has also been found in several weevil species and a few other insects, such as aphids, but not in Drosophila melanogaster, Anopheles gambiae, or Caenorhabditis elegans or, as far as is known, in any more primitive animal species. What, then, is the genetic origin of the polygalacturonases in weevils? Since some weevil species harbor symbiotic microorganisms, it has been suggested, reasonably, that the symbionts' genomes of both aphids and weevils, rather than the insects' genomes, could encode polygalacturonase. We report here the cloning of a cDNA that encodes endo-polygalacturonase in the rice weevil, Sitophilus oryzae (L., and investigations based on the cloned cDNA. Our results, which include analysis of genes in antibiotic-treated rice weevils, indicate that the enzyme is, in fact, encoded by the insect genome. Given the apparent absence of the gene in much of the rest of the animal kingdom, it is therefore likely that the rice weevil polygalacturonase gene was incorporated into the weevil's genome by horizontal transfer, possibly from a fungus.

  9. Parkinson-related parkin reduces α-Synuclein phosphorylation in a gene transfer model

    Rebeck GW

    2010-11-01

    Full Text Available Abstract Background α-Synuclein aggregates in Lewy bodies and plays a central role in the pathogenesis of a group of neurodegenerative disorders, known as "Synucleinopathies", including Parkinson's disease. Parkin mutations result in loss of parkin E3-ubiquitin ligase activity and cause autosomal recessive early onset parkinsonism. Results We tested how these two genes interact by examining the effects of parkin on post-translational modification of α-Synuclein in gene transfer animal models, using a lentiviral gene delivery system into the striatum of 2-month old male Sprague Dawley rats. Viral expression of wild type α-Synuclein caused accumulation of α-Synuclein and was associated with increased cell death and inflammation. α-Synuclein increased PLK2 levels and GSK-3β activity and increased the levels of phosphorylated α-Synuclein and Tau. Parkin co-expression reduced the levels of phosphorylated α-Synuclein and attenuated cell death and inflammation. Parkin reduced PLK2 levels and increased PP2A activation. Conclusions These data suggest that parkin reduces α-Synuclein levels and alters the balance between phosphatase and kinase activities that affect the levels of phosphorylated α-Synuclein. These results indicate novel mechanisms for parkin protection against α-Synuclein-induced toxicity in PD.

  10. Adaptive horizontal transfer of a bacterial gene to an invasive insect pest of coffee.

    Acuña, Ricardo; Padilla, Beatriz E; Flórez-Ramos, Claudia P; Rubio, José D; Herrera, Juan C; Benavides, Pablo; Lee, Sang-Jik; Yeats, Trevor H; Egan, Ashley N; Doyle, Jeffrey J; Rose, Jocelyn K C

    2012-03-13

    Horizontal gene transfer (HGT) involves the nonsexual transmission of genetic material across species boundaries. Although often detected in prokaryotes, examples of HGT involving animals are relatively rare, and any evolutionary advantage conferred to the recipient is typically obscure. We identified a gene (HhMAN1) from the coffee berry borer beetle, Hypothenemus hampei, a devastating pest of coffee, which shows clear evidence of HGT from bacteria. HhMAN1 encodes a mannanase, representing a class of glycosyl hydrolases that has not previously been reported in insects. Recombinant HhMAN1 protein hydrolyzes coffee berry galactomannan, the major storage polysaccharide in this species and the presumed food of H. hampei. HhMAN1 was found to be widespread in a broad biogeographic survey of H. hampei accessions, indicating that the HGT event occurred before radiation of the insect from West Africa to Asia and South America. However, the gene was not detected in the closely related species H. obscurus (the tropical nut borer or "false berry borer"), which does not colonize coffee beans. Thus, HGT of HhMAN1 from bacteria represents a likely adaptation to a specific ecological niche and may have been promoted by intensive agricultural practices. PMID:22371593

  11. Genome analysis and gene nblA identification of Microcystis aeruginosa myovirus (MaMV-DC) reveal the evidence for horizontal gene transfer events between cyanomyovirus and host.

    Ou, Tong; Gao, Xiao-Chan; Li, San-Hua; Zhang, Qi-Ya

    2015-12-01

    The genome sequence, genetic characterization and nblA gene function of Microcystis aeruginosa myovirus isolated from Lake Dianchi in China (MaMV-DC) have been analysed. The genome DNA is 169 223 bp long, with 170 predicted protein-coding genes (001L–170L) and a tRNA gene. About one-sixth of these genes have homologues in the host cyanobacteria M. aeruginosa. The genome carries a gene homologous to host nblA, which encodes a protein involved in the degradation of cyanobacterial phycobilisome. Its expression during MaMV-DC infection was confirmed by reverse transcriptase PCR and Western blot detection and abundant expression was companied by the significant decline of phycocyanin content and massive release of progeny MaMV-DC. In addition, expressing MaMV-DC nblA reduced the phycocyanin peak and the phycocyanin to chlorophyll ratio in model cyanobacteria. These results confirm that horizontal gene transfer events have occurred between cyanobacterial host and cyanomyovirus and suggest that MaMV-DC carrying host-derived genes (such as 005L, that codes for NblA) is responsible for more efficient expression of cyanophage genes and release of progeny cyanophage. This study provides novel insight into the horizontal gene transfer in cyanophage and the interactions between cyanophage and their host. PMID:26399243

  12. Orexin gene transfer into the amygdala suppresses both spontaneous and emotion-induced cataplexy in orexin-knockout mice.

    Liu, Meng; Blanco-Centurion, Carlos; Konadhode, Roda Rani; Luan, Liju; Shiromani, Priyattam J

    2016-03-01

    Narcolepsy is a chronic sleep disorder linked to the loss of orexin-producing neurons in the hypothalamus. Cataplexy, a sudden loss of muscle tone during waking, is an important distinguishing symptom of narcolepsy and it is often triggered by strong emotions. The neural circuit underlying cataplexy attacks is not known, but is likely to involve the amygdala, a region implicated in regulating emotions. In mice models of narcolepsy, transfer of the orexin gene into surrogate neurons has been successful in ameliorating narcoleptic symptoms. However, it is not known whether this method also blocks cataplexy triggered by strong emotions. To examine this possibility, the gene encoding mouse prepro-orexin was transferred into amygdala neurons of orexin-knockout (KO) mice (rAAV-orexin; n = 8). Orexin-KO mice that did not receive gene transfer (no-rAAV; n = 7) or received only the reporter gene (rAAV-GFP; n = 7) served as controls. Three weeks later, the animal's sleep and behaviour were recorded at night (no-odour control night), followed by another recording at night in the presence of predator odour (odour night). Orexin-KO mice given the orexin gene transfer into surrogate amygdala neurons had significantly less spontaneous bouts of cataplexy, and predator odour did not induce cataplexy compared with control mice. Moreover, the mice with orexin gene transfer were awake more during the odour night. These results demonstrate that orexin gene transfer into amygdala neurons can suppress both spontaneous and emotion-induced cataplexy attacks in narcoleptic mice. It suggests that manipulating amygdala pathways is a potential strategy for treating cataplexy in narcolepsy. PMID:26741960

  13. New Markov Model Approaches to Deciphering Microbial Genome Function and Evolution: Comparative Genomics of Laterally Transferred Genes

    Borodovsky, M.

    2013-04-11

    Algorithmic methods for gene prediction have been developed and successfully applied to many different prokaryotic genome sequences. As the set of genes in a particular genome is not homogeneous with respect to DNA sequence composition features, the GeneMark.hmm program utilizes two Markov models representing distinct classes of protein coding genes denoted "typical" and "atypical". Atypical genes are those whose DNA features deviate significantly from those classified as typical and they represent approximately 10% of any given genome. In addition to the inherent interest of more accurately predicting genes, the atypical status of these genes may also reflect their separate evolutionary ancestry from other genes in that genome. We hypothesize that atypical genes are largely comprised of those genes that have been relatively recently acquired through lateral gene transfer (LGT). If so, what fraction of atypical genes are such bona fide LGTs? We have made atypical gene predictions for all fully completed prokaryotic genomes; we have been able to compare these results to other "surrogate" methods of LGT prediction.

  14. Modeling horizontal gene transfer (HGT in the gut of the Chagas disease vector Rhodnius prolixus

    Durvasula Ravi V

    2011-05-01

    Full Text Available Abstract Background Paratransgenesis is an approach to reducing arthropod vector competence using genetically modified symbionts. When applied to control of Chagas disease, the symbiont bacterium Rhodococcus rhodnii, resident in the gut lumen of the triatomine vector Rhodnius prolixus (Hemiptera: Reduviidae, is transformed to export cecropin A, an insect immune peptide. Cecropin A is active against Trypanosoma cruzi, the causative agent of Chagas disease. While proof of concept has been achieved in laboratory studies, a rigorous and comprehensive risk assessment is required prior to consideration of field release. An important part of this assessment involves estimating probability of transgene horizontal transfer to environmental organisms (HGT. This article presents a two-part risk assessment methodology: a theoretical model predicting HGT in the gut of R. prolixus from the genetically transformed symbiont R. rhodnii to a closely related non-target bacterium, Gordona rubropertinctus, in the absence of selection pressure, and a series of laboratory trials designed to test the model. Results The model predicted an HGT frequency of less than 1.14 × 10-16 per 100,000 generations at the 99% certainty level. The model was iterated twenty times, with the mean of the ten highest outputs evaluated at the 99% certainty level. Laboratory trials indicated no horizontal gene transfer, supporting the conclusions of the model. Conclusions The model treats HGT as a composite event, the probability of which is determined by the joint probability of three independent events: gene transfer through the modalities of transformation, transduction, and conjugation. Genes are represented in matrices and Monte Carlo method and Markov chain analysis are used to simulate and evaluate environmental conditions. The model is intended as a risk assessment instrument and predicts HGT frequency of less than 1.14 × 10-16 per 100,000 generations. With laboratory studies that

  15. Noninvasive Assessment of Gene Transfer and Expression by In Vivo Functional and Morphologic Imaging in a Rabbit Tumor Model

    Ravoori, Murali K.; Han, Lin; Singh, Sheela P.; Dixon, Katherine; Duggal, Jyoti; Liu, Ping; Uthamanthil, Rajesh; Gupta, Sanjay; Wright, Kenneth C; Kundra, Vikas

    2013-01-01

    Purpose To evaluate the importance of morphology in quantifying expression after in vivo gene transfer and to compare gene expression after intra-arterial (IA) and intra-tumoral (IT) delivery of adenovirus expressing a SSTR2-based reporter gene in a large animal tumor model. Materials and Methods Tumor directed IA or IT delivery of adenovirus containing a human somatostatin receptor type 2A (Ad-CMV-HA-SSTR2A) gene chimera or control adenovirus (Ad-CMV-GFP) was performed in VX2 tumors growing ...

  16. The Dynamics of Lateral Gene Transfer in Genus Leishmania - A Route for Adaptation and Species Diversification.

    Elisabet Vikeved

    2016-01-01

    Full Text Available The genome of Leishmania major harbours a comparably high proportion of genes of prokaryote origin, acquired by lateral gene transfer (LGT. Some of these are present in closely related trypanosomatids, while some are detected in Leishmania only. We have evaluated the impact and destiny of LGT in genus Leishmania.To study the dynamics and fate of LGTs we have performed phylogenetic, as well as nucleotide and amino acid composition analyses within orthologous groups of LGTs detected in Leishmania. A set of universal trypanosomatid LGTs was added as a reference group. Both groups of LGTs have, to some extent, ameliorated to resemble the recipient genomes. However, while virtually all of the universal trypanosomatid LGTs are distributed and conserved in the entire genus Leishmania, the LGTs uniquely present in genus Leishmania are more prone to gene loss and display faster rates of evolution. Furthermore, a PCR based approach has been employed to ascertain the presence of a set of twenty LGTs uniquely present in genus Leishmania, and three universal trypanosomatid LGTs, in ten additional strains of Leishmania. Evolutionary rates and predicted expression levels of these LGTs have also been estimated. Ten of the twenty LGTs are distributed and conserved in all species investigated, while the remainder have been subjected to modifications, or undergone pseudogenization, degradation or loss in one or more species.LGTs unique to the genus Leishmania have been acquired after the divergence of Leishmania from the other trypanosomatids, and are evolving faster than their recipient genomes. This implies that LGT in genus Leishmania is a continuous and dynamic process contributing to species differentiation and speciation. This study also highlights the importance of carefully evaluating these dynamic genes, e.g. as LGTs have been suggested as potential drug targets.

  17. Horizontal gene transfer confers fermentative metabolism in the respiratory-deficient plant trypanosomatid Phytomonas serpens.

    Ienne, Susan; Pappas, Georgios; Benabdellah, Karim; González, Antonio; Zingales, Bianca

    2012-04-01

    Among trypanosomatids, the genus Phytomonas is the only one specifically adapted to infect plants. These hosts provide a particular habitat with a plentiful supply of carbohydrates. Phytomonas sp. lacks a cytochrome-mediated respiratory chain and Krebs cycle, and ATP production relies predominantly on glycolysis. We have characterised the complete gene encoding a putative pyruvate/indolepyruvate decarboxylase (PDC/IPDC) (548 amino acids) of P. serpens, that displays high amino acid sequence similarity with phytobacteria and Leishmania enzymes. No orthologous PDC/IPDC genes were found in Trypanosoma cruzi or T. brucei. Conservation of the PDC/IPDC gene sequence was verified in 14 Phytomonas isolates. A phylogenetic analysis shows that Phytomonas protein is robustly monophyletic with Leishmania spp. and C. fasciculata enzymes. In the trees this clade appears as a sister group of indolepyruvate decarboxylases of γ-proteobacteria. This supports the proposition that a horizontal gene transfer event from a donor phytobacteria to a recipient ancestral trypanosome has occurred prior to the separation between Phytomonas, Leishmania and Crithidia. We have measured the PDC activity in P. serpens cell extracts. The enzyme has a Km value for pyruvate of 1.4mM. The acquisition of a PDC, a key enzyme in alcoholic fermentation, explains earlier observations that ethanol is one of the major end-products of glucose catabolism under aerobic and anaerobic conditions. This represents an alternative and necessary route to reoxidise part of the NADH produced in the highly demanding glycolytic pathway and highlights the importance of this type of event in metabolic adaptation. PMID:22293462

  18. In vivo evaluation of adeno-associated virus gene transfer in airways of mice with acute or chronic respiratory infection.

    Myint, Melissa; Limberis, Maria P; Bell, Peter; Somanathan, Suryanarayan; Haczku, Angela; Wilson, James M; Diamond, Scott L

    2014-11-01

    Patients with cystic fibrosis (CF) often suffer chronic lung infection with concomitant inflammation, a setting that may reduce the efficacy of gene transfer. While gene therapy development for CF often involves viral-based vectors, little is known about gene transfer in the context of an infected airway. In this study, three mouse models were established to evaluate adeno-associated virus (AAV) gene transfer in such an environment. Bordetella bronchiseptica RB50 was used in a chronic, nonlethal respiratory infection in C57BL/6 mice. An inoculum of ∼10(5) CFU allowed B. bronchiseptica RB50 to persist in the upper and lower respiratory tracts for at least 21 days. In this infection model, administration of an AAV vector on day 2 resulted in 2.8-fold reduction of reporter gene expression compared with that observed in uninfected controls. Postponement of AAV administration to day 14 resulted in an even greater (eightfold) reduction of reporter gene expression, when compared with uninfected controls. In another infection model, Pseudomonas aeruginosa PAO1 was used to infect surfactant protein D (SP-D) or surfactant protein A (SP-A) knockout (KO) mice. With an inoculum of ∼10(5) CFU, infection persisted for 2 days in the nasal cavity of either mouse model. Reporter gene expression was approximately ∼2.5-fold lower compared with uninfected mice. In the SP-D KO model, postponement of AAV administration to day 9 postinfection resulted in only a two fold reduction in reporter gene expression, when compared with expression seen in uninfected controls. These results confirm that respiratory infections, both ongoing and recently resolved, decrease the efficacy of AAV-mediated gene transfer. PMID:25144316

  19. IR-FEL-induced green fluorescence protein (GFP) gene transfer into plant cell

    A Free Electron Laser (FEL) holds potential for various biotechnological applications due to its characteristics such as flexible wavelength tunability, short pulse and high peak power. We could successfully introduce the Green Fluorescent Protein (GFP) gene into tobacco BY2 cells by IR-FEL laser irradiation. The irradiated area of the solution containing BY2 cells and plasmid was about 0.1 mm2. FEL irradiation at a wavelength of 5.75 and 6.1 μm, targeting absorption by the ester bond of the lipid and the amide I bond of the protein, respectively, was shown to cause the introduction of the fluorescent dye into the cell. On the other hand, transient expression of the GFP fluorescence was only observed after irradiation at 5.75 μm. The maximum transfer efficiency was about 0.5%

  20. Transferring gfp gene with ion implantation and transient expression of gfp in liliaceous pollen cells

    YUAN Shibin; CHEN Qizhong; WANG Yugang; ZHAO Weijiang; XU An; YANG Gen; WANG Wenxian; WU Lijun

    2004-01-01

    Liliaceous pollen cells were implanted by 4.0 MeV C2+ ion beam or by 25.0 keV N+ ion beam. Laser confocal scanning microscopy (LCSM) of the implanted intact samples showed that parts of the implanted pollen cells could be stained by propidium iodide (PI). This indicated that energetic ion beam could directly act on cells beneath the pollen coats and made channels for entry of the molecules from outside of the cells. LCSM analysis of green fluorescent protein (GFP) showed that energetic ion beam could mediate transient expression of gfp in treated pollen cells. Compared with 25.0 keV N+ ion beam, implantation of 4.0 MeV C2+ ion beam greatly improved gene transfer efficiency in pollen cells.