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Sample records for retrovir zidovudine azt

  1. Prospective Double-Blind Study of Zidovudine (AZT) in Early Stage HIV infection

    DTIC Science & Technology

    1988-05-01

    FRONT COVER FUNDING NO. 87PP7875 S L. TITLE: Prospective Double-Blind Study of Zidovudine (AZT) in Early Stage HIV Infection PRINCIPAL INVESTIGATOR...Prospective Double-Blind Study of Zidovudine (AZT) in Early State HIV Infection 12. PERSONAL AUTHOR(S) Shannon M. Harrison 13a. TYPE OF REPORT 113b...COSATI CODES 18. SUBJECT TERMS (Continue on reverse if necessary and identify by block number) FIELD GROUP SUBGROUP HIV , Zidovudine, Early, Infection 06

  2. Role of nucleotide excision repair and p53 in zidovudine (AZT)-induced centrosomal deregulation.

    PubMed

    Momot, Dariya; Nostrand, Terri A; John, Kaarthik; Ward, Yvona; Steinberg, Seth M; Liewehr, David J; Poirier, Miriam C; Olivero, Ofelia A

    2014-12-01

    The nucleoside reverse transcriptase inhibitor zidovudine (AZT) induces genotoxic damage that includes centrosomal amplification (CA > 2 centrosomes/cell) and micronucleus (MN) formation. Here we explored these end points in mice deficient in DNA repair and tumor suppressor function to evaluate their effect on AZT-induced DNA damage. We used mesenchymal-derived fibroblasts cultured from C57BL/6J mice that were null and wild type (WT) for Xpa, and WT, haploinsufficient and null for p53 (6 different genotypes). Dose-responses for CA formation, in cells exposed to 0, 10, and 100 μM AZT for 24 hr, were observed in all genotypes except the Xpa((+/+)) p53((+/-)) cells, which had very low levels of CA, and the Xpa((-/-)) p53((-/-)) cells, which had very high levels of CA. For CA there was a significant three-way interaction between Xpa, p53, and AZT concentration, and Xpa((-/-)) cells had significantly higher levels of CA than Xpa((+/+)) cells, only for p53((+/-)) cells. In contrast, the MN and MN + chromosomes (MN + C) data showed a lack of AZT dose response. The Xpa((-/-)) cells, with p53((+/+)) or ((+/-)) genotypes, had levels of MN and MN + C higher than the corresponding Xpa((+/+)) cells. The data show that CA is a major event induced by exposure to AZT in these cells, and that there is a complicated relationship between AZT and CA formation with respect to gene dosage of Xpa and p53. The loss of both genes resulted in high levels of damage, and p53 haploinsufficicency strongly protected Xpa((+/+)) cells from AZT-induced CA damage.

  3. Enhanced transdermal delivery of AZT (Zidovudine) using iontophoresis and penetration enhancer.

    PubMed

    Oh, S Y; Jeong, S Y; Park, T G; Lee, J H

    1998-02-12

    The effect of current, its magnitude and penetration enhancers (propylene glycol/oleic acid) on the transdermal flux of AZT (Zidovudine) across hairless mouse skin was studied and the results were compared. The in vitro iontophoretic flux from AZT solution increased to about 5-40 fold that obtained by passive diffusion, depending on the magnitude of current density. When the donor side was karaya gum matrix, instead of solution, the flux enhancement effect by iontophoresis was much smaller. Incorporation of penetration enhancers into the matrix increased the passive flux 2-50 fold, depending on the amount of penetration enhancers in the matrix. These enhancers worked synergistically with iontophoresis in the transdermal transport: a much larger flux than that expected from a simple additive effect was observed. Electrical resistance data from our previous work is utilized to further discuss this synergistic effect.

  4. Zidovudine

    MedlinePlus

    ... immunodeficiency virus (HIV) infection. Zidovudine is given to HIV-positive pregnant women to reduce the chance of passing the infection to the baby. Zidovudine is in a class of medications called nucleoside reverse ... the amount of HIV in the blood. Although zidovudine does not cure ...

  5. Reversal of brain metabolic abnormalities following treatment of AIDS dementia complex with 3'-azido-2',3'-dideoxythymidine (AZT, zidovudine): a PET-FDG study

    SciTech Connect

    Brunetti, A.; Berg, G.; Di Chiro, G.; Cohen, R.M.; Yarchoan, R.; Pizzo, P.A.; Broder, S.; Eddy, J.; Fulham, M.J.; Finn, R.D.

    1989-05-01

    Brain glucose metabolism was evaluated in four patients with acquired immunodeficiency syndrome (AIDS) dementia complex using (/sup 18/F)fluorodeoxyglucose (FDG) and positron emission tomography (PET) scans at the beginning of therapy with 3'-azido-2',3'-dideoxythymidine (AZT, zidovudine), and later in the course of therapy. In two patients, baseline, large focal cortical abnormalities of glucose utilization were reversed during the course of therapy. In the other two patients, the initial PET study did not reveal pronounced focal alterations, while the post-treatment scans showed markedly increased cortical glucose metabolism. The improved cortical glucose utilization was accompanied in all patients by immunologic and neurologic improvement. PET-FDG studies can detect cortical metabolic abnormalities associated with AIDS dementia complex, and may be used to monitor the metabolic improvement in response to AZT treatment.

  6. High Incidence of Zidovudine Induced Anaemia in HIV Infected Patients in Southern Odisha.

    PubMed

    Dash, Kaibalya Ranjan; Meher, Lalit Kumar; Hui, P K; Behera, S K; Nayak, S N

    2015-06-01

    Zidovudine (AZT), a nucleoside reverse transcriptase inhibitor was the first breakthrough in AIDS therapy in 1990.This study was conducted with an aim to determine prevalence of AZT induced anaemia in HIV infected patients initiated on AZT containing anti retroviral therapy(ART) regimen and also to find out any risk factor for causing AZT induced anaemia. Study was carried out in ART centre, M.K.C.G, MCH, Berhampur between Jan 2009 and Dec 2011. HIV infected patients registered at ART centre were treated according to National AIDS Control Organisation (NACO) guidelines. Patients (n = 1221) with Hb >8 gm/dl were prescribed AZT based ART regimen. Patients having anaemia (<8 gm/dl) were excluded from the study. Correlation of baseline characteristics (age, sex, weight, Hb level, CD4 count, World Health Organization (WHO) clinical stage) with risk of developing anaemia was also calculated. 178 (14.6 %) patients on AZT regimen developed anaemia. Patients with low CD4 count were more prone to develop severe anaemia. Age, sex, weight, WHO clinical stage had no relation with development of anaemia. Incidence of AZT induced anaemia was very high and patients having low CD4 count were more susceptible to develop anaemia.

  7. Intracellular pharmacokinetic study of zidovudine and its phosphorylated metabolites.

    PubMed

    Mu, Lingli; Zhou, Rui; Tang, Fang; Liu, Xingling; Li, Sanwang; Xie, Feifan; Xie, Xiang; Peng, Jie; Yu, Peng

    2016-03-01

    Zidovudine (AZT), the first drug approved by the US Food and Drug Administration for the treatment of human immunodeficiency virus (HIV) infection, is metabolized in the host cells to 5'-AZT triphosphate (AZT-TP) which inhibits HIV reverse transcriptase. As the pharmacokinetics of AZT and its phosphorylated metabolites in human peripheral blood mononuclear cells (hPBMCs) is limited, the aim of this study was to determine the pharmacokinetic parameters of AZT and its phosphorylated metabolites in hPBMCs from 12 healthy Chinese male subjects after a single oral dose of 600 mg of AZT. Blood samples were collected prior to drug administration, then at 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 5, 6, 8 and 10 h after drug administration. Mononuclear cells collected by Ficoll-Hypaque density gradient centrifugation were used for determination of AZT and metabolites [AZT monophosphate (AZT-MP), AZT diphosphate (AZT-DP) and AZT-TP] and the plasma was used to evaluate the pharmacokinetics of AZT. Plasma concentration of AZT peaked within 0.583 h and intracellular concentrations of AZT, AZT-MP, AZT-DP and AZT-TP peaked within 1.083, 1.500, 1.417 and 1.583 h, respectively. AZT in plasma was eliminated rapidly with t 1/2 of 2.022 h, and AZT-MP, AZT-DP and AZT-TP were eliminated with t 1/2 of 13.428, 8.285 and 4.240 h, respectively. The plasma concentration of the phosphorylated metabolites was not quantifiable.

  8. Intracellular pharmacokinetic study of zidovudine and its phosphorylated metabolites

    PubMed Central

    Mu, Lingli; Zhou, Rui; Tang, Fang; Liu, Xingling; Li, Sanwang; Xie, Feifan; Xie, Xiang; Peng, Jie; Yu, Peng

    2015-01-01

    Zidovudine (AZT), the first drug approved by the US Food and Drug Administration for the treatment of human immunodeficiency virus (HIV) infection, is metabolized in the host cells to 5′-AZT triphosphate (AZT-TP) which inhibits HIV reverse transcriptase. As the pharmacokinetics of AZT and its phosphorylated metabolites in human peripheral blood mononuclear cells (hPBMCs) is limited, the aim of this study was to determine the pharmacokinetic parameters of AZT and its phosphorylated metabolites in hPBMCs from 12 healthy Chinese male subjects after a single oral dose of 600 mg of AZT. Blood samples were collected prior to drug administration, then at 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 5, 6, 8 and 10 h after drug administration. Mononuclear cells collected by Ficoll-Hypaque density gradient centrifugation were used for determination of AZT and metabolites [AZT monophosphate (AZT-MP), AZT diphosphate (AZT-DP) and AZT-TP] and the plasma was used to evaluate the pharmacokinetics of AZT. Plasma concentration of AZT peaked within 0.583 h and intracellular concentrations of AZT, AZT-MP, AZT-DP and AZT-TP peaked within 1.083, 1.500, 1.417 and 1.583 h, respectively. AZT in plasma was eliminated rapidly with t1/2 of 2.022 h, and AZT-MP, AZT-DP and AZT-TP were eliminated with t1/2 of 13.428, 8.285 and 4.240 h, respectively. The plasma concentration of the phosphorylated metabolites was not quantifiable. PMID:27006900

  9. Zidovudine and isoniazid induced liver toxicity and oxidative stress: Evaluation of mitigating properties of silibinin.

    PubMed

    Raghu, Ramanathan; Karthikeyan, Sivanesan

    2016-09-01

    HIV/AIDS patients are more prone for opportunistic TB infections and they are administered the combined regimen of anti-retroviral drug zidovudine (AZT) and isoniazid (INH) for therapy. However, AZT+INH treatment has been documented to induce injury and remedial measures to prevent this adversity are not clearly defined. Silibinin (SBN) is a natural hepatoprotective principle isolated from medicinal plant Silybum marianum and is currently used for therapy of various liver diseases. This study investigate the hepatotoxic potentials of AZT alone, INH alone and AZT+INH treatments and the mitigating potentials of SBN against these drugs induced toxic insults of liver in rats. Separate groups of rats (n=6 in each group) were administered AZT alone (50mg/kg b.w.), INH alone (25mg/kg, b.w.), AZT+INH (50mg/kg, b.w. and 25mg/kg, b.w.), SBN alone (100mg/kg, b.w.) and SBN+AZT+INH daily for sub-chronic period of 45days orally. The control rats received saline/propylene glycol. INH alone and AZT+INH-induced parenchymal cell injury and cholestasis of liver was evidenced by highly significant increase in the activities of marker enzymes (aspartate and alanine transaminase, alkaline phosphatase, argino succinic acid lyase), bilirubin, protein, oxidative stress parameters (lipid peroxidation, superoxide dismutase, catalase, reduced glutathione, vitamins C and E) and membrane bound ATPases were evaluated in serum/liver tissue homogenates. Histopathological studies show ballooning degradation, inflammatory lesions, lipid deposition and hydropic changes in the liver tissue. All the above biochemical and pathological changes induced by AZT+INH treatments were mitigated in rats receiving SBN simultaneously with these hepatotoxins, indicating its hepatoprotective and antioxidant potentials against AZT+INH-induced hepatotoxicity. The moderate hepatoprotective and oxidant potentials of SBN could be due to its low bioavailability and this deficiency could be prevented by supplementation of

  10. Mechanisms of zidovudine-induced mitochondrial toxicity and myopathy.

    PubMed

    Scruggs, Erin R; Dirks Naylor, Amie J

    2008-01-01

    Zidovudine (3-azido-3'-deoxythymidine), also referred to as azidothymidine (AZT), has become an integral component in highly active antiretroviral therapy, and has also been used in the treatment of cancer. The clinical effectiveness of AZT is constrained due to its association with increased adverse effects, such as myopathy. There are numerous potential mechanisms that may contribute to AZT-induced myopathy. The first hypothesized mechanism to explain AZT-induced toxicity was mtDNA depletion due to inhibition of DNA polymerase gamma. Although mtDNA depletion is present in patients with myopathy, current data suggests that alternative mechanisms may play a more direct role in the myotoxicity. These mechanisms include AZT-induced oxidative stress, direct inhibition of mitochondrial bioenergetic machinery, and mitochondrial depletion of L-carnitine. Furthermore, we hypothesize that apoptosis may play a role in AZT-induced myopathy.

  11. Structural basis of HIV-1 resistance to AZT by excision

    SciTech Connect

    Tu, Xiongying; Das, Kalyan; Han, Qianwei; Bauman, Joseph D.; Clark, Jr., Arthur D.; Hou, Xiaorong; Frenkel, Yulia V.; Gaffney, Barbara L.; Jones, Roger A.; Boyer, Paul L.; Hughes, Stephen H.; Sarafianos, Stefan G.; Arnold, Eddy

    2011-11-23

    Human immunodeficiency virus (HIV-1) develops resistance to 3'-azido-2',3'-deoxythymidine (AZT, zidovudine) by acquiring mutations in reverse transcriptase that enhance the ATP-mediated excision of AZT monophosphate from the 3' end of the primer. The excision reaction occurs at the dNTP-binding site, uses ATP as a pyrophosphate donor, unblocks the primer terminus and allows reverse transcriptase to continue viral DNA synthesis. The excision product is AZT adenosine dinucleoside tetraphosphate (AZTppppA). We determined five crystal structures: wild-type reverse transcriptase-double-stranded DNA (RT-dsDNA)-AZTppppA; AZT-resistant (AZTr; M41L D67N K70R T215Y K219Q) RT-dsDNA-AZTppppA; AZTr RT-dsDNA terminated with AZT at dNTP- and primer-binding sites; and AZTr apo reverse transcriptase. The AMP part of AZTppppA bound differently to wild-type and AZTr reverse transcriptases, whereas the AZT triphosphate part bound the two enzymes similarly. Thus, the resistance mutations create a high-affinity ATP-binding site. The structure of the site provides an opportunity to design inhibitors of AZT-monophosphate excision.

  12. Zidovudine Injection

    MedlinePlus

    ... and delivery, women may receive a continuous zidovudine infusion until the baby is delivered.Your doctor may ... the ingredients. If you will be giving the infusion, tell your doctor if you or the person ...

  13. Effect of zidovudine on preimplantation murine embryos.

    PubMed Central

    Toltzis, P; Mourton, T; Magnuson, T

    1993-01-01

    It previously has been demonstrated that zidovudine (AZT) is lethal to early murine embryos. The effect of the drug on pre- and postimplantation embryos was examined to delineate the timing of this toxicity and to investigate its possible mechanisms. Embryos exposed in the whole mouse during preblastocyst development were unable to proceed beyond the blastocyst stage. Similarly, when two-cell embryos harvested from unexposed females were exposed to low-concentration (1 microM) AZT in vitro over 24 h, development beyond the blastocyst stage was inhibited. In contrast, drug exposure during in vitro blastocyst and postblastocyst development resulted in little or no morphologic toxicity. Further investigation revealed that preblastocyst AZT exposure resulted in the development of blastocysts with significantly lower cell numbers than control embryos. While embryonic exposure to AZT at the blastocyst and postblastocyst stages also resulted in retarded cell division, the effects were milder than those recorded after preblastocyst exposure. These data demonstrate that the critical period of AZT toxicity toward murine embryos is between ovulation and implantation and indicate that AZT directly suppresses cell division in the preimplantation embryo. PMID:8215271

  14. Human inter-individual variability in metabolism and genotoxic response to zidovudine

    SciTech Connect

    Olivero, Ofelia A. Ming, Jessica M.; Das, Shreyasi; Vazquez, Irma L.; Richardson, Diana L.; Weston, Ainsley; Poirier, Miriam C.

    2008-04-15

    A mainstay of the antiretroviral drugs used for therapy of HIV-1, zidovudine (AZT) is genotoxic and becomes incorporated into DNA. Here we explored host inter-individual variability in AZT-DNA incorporation, by AZT radioimmunoassay (RIA), using 19 different strains of normal human mammary epithelial cells (NHMECs) exposed for 24 h to 200 {mu}M AZT. Twelve of the 19 NHMEC strains showed detectable AZT-DNA incorporation levels (16 to 259 molecules of AZT/10{sup 6} nucleotides), while 7 NHMEC strains did not show detectable AZT-DNA incorporation. In order to explore the basis for this variability, we compared the 2 NHMEC strains that showed the highest levels of AZT-DNA incorporation (H1 and H2) with 2 strains showing no detectable AZT-DNA incorporation (L1 and L2). All 4 strains had similar ({>=} 80%) cell survival, low levels of accumulation of cells in S-phase, and no relevant differences in response to the direct-acting mutagen bleomycin (BLM). Finally, when levels of thymidine kinase 1 (TK1), the first enzyme in the pathway for incorporation of AZT into DNA, were determined by Western blot analysis in all 19 NHMEC strains at 24 h of AZT exposure, higher TK1 protein levels were found in the 12 strains showing AZT-DNA incorporation, compared to the 7 showing no incorporation (p = 0.0005, Mann-Whitney test). Furthermore, strains L1 and L2, which did not show AZT-DNA incorporation at 24 h, did have measurable incorporation by 48 and 72 h. These data suggest that variability in AZT-DNA incorporation may be modulated by inter-individual differences in the rate of induction of TK1 in response to AZT exposure.

  15. Susceptibility of porcine endogenous retrovirus to anti-retroviral inhibitors

    PubMed Central

    Argaw, Takele; Colon-Moran, Winston; Wilson, Carolyn

    2016-01-01

    Background Porcine endogenous retrovirus (PERV) is an endogenous retrovirus that poses a risk of iatrogenic transmission in the context of pig-to-human xenotransplantation. The lack of a means to control PERV infection in the context of pig-to-human xenotransplantation is a major concern in the field. In this study, we set out to evaluate the ability of currently licensed anti-HIV drugs, and other types of anti-retroviral compounds, to inhibit PERV infection in vitro. Methods We used target cells stably expressing one of the known PERV viral receptors, an infectious molecular clone, PERV-A 14/220, and at least one drug from each class of anti-retroviral inhibitors as well as off-label drugs shown to have anti-viral activities. The susceptibility of PERV-A 14/220 LacZ to the anti-retroviral drugs was determined from infected cells by histochemical staining. Results We extend the results of previous studies by showing that, in addition to raltegravir, dolutegravir is found to have a potent inhibitory activity against PERV replication (IC50 8.634 ±0.336 and IC50 3.06 ± 0.844 nm, respectively). The anti-HIV drug zidovudine (AZT) showed considerable anti-PERV activity with IC50 of 1.923 ±0.691 μm as well. Conclusions The study results indicate that some of the licensed antiretroviral drugs may be useful for controlling PERV infection. However, the efficacy at nanomolar concentrations put forward integrase inhibitors as a drug that has the potential to be useful in the event that xenotransplantation recipients have evidence of PERV transmission and replication. PMID:27028725

  16. Nasal chitosan microparticles target a zidovudine prodrug to brain HIV sanctuaries.

    PubMed

    Dalpiaz, Alessandro; Fogagnolo, Marco; Ferraro, Luca; Capuzzo, Antonio; Pavan, Barbara; Rassu, Giovanna; Salis, Andrea; Giunchedi, Paolo; Gavini, Elisabetta

    2015-11-01

    Zidovudine (AZT) is an antiretroviral drug that is a substrate of active efflux transporters (AETs) that extrude the drug from the central nervous system (CNS) and macrophages, which are considered to be sanctuaries of HIV. The conjugation of AZT to ursodeoxycholic acid is known to produce a prodrug (UDCA-AZT) that is able to elude the AET systems, indicating the potential ability of this prodrug to act as a carrier of AZT in the CNS and in macrophages. Here, we demonstrate that UDCA-AZT is able to permeate and remain in murine macrophages with an efficiency twenty times higher than that of AZT. Moreover, we propose the nasal administration of this prodrug in order to induce its uptake into the CNS. Chitosan chloride-based microparticles (CP) were prepared by spray-drying and were characterized with respect to size, morphology, density, water uptake and the dissolution profile of UDCA-AZT. The CP sample was then nasally administered to rats. All in vitro and in vivo measurements were also performed for a CP parent physical mixture. The CP sample was able to increase the dissolution rate of UDCA-AZT and to reduce water uptake with respect to its parent physical mixture, inducing better uptake of UDCA-AZT into the cerebrospinal fluid of rats, where the prodrug can act as an AZT carrier in macrophages.

  17. Abacavir, Lamivudine, and Zidovudine

    MedlinePlus

    Trizivir®(as a combination product containing Abacavir, Lamivudine, and Zidovudine) ... HIV) infection. Abacavir, lamivudine and zidovudine are in a class of medications called nucleoside reverse transcriptase inhibitors ( ...

  18. All pregnant women advised to get HIV test, consider AZT therapy.

    PubMed

    1995-03-10

    The Centers for Disease Control and Prevention (CDC) advises that all physicians counsel pregnant women to get HIV tested to reduce the risk of HIV transmission to the child. The recommendation was prompted by a report that early use of the antiviral drug zidovudine (AZT) (administered during pregnancy, labor, and childbirth) in HIV-postive pregnant women reduced the risk of HIV infection to the newborn by two-thirds. While studies are showing the value of using AZT, government officials reject mandatory testing for fear that it will force pregnant women away from prenatal care. Because the long-term effects of AZT are unknown, it is also felt that doctors should not coerce infected women into taking AZT, rather they should explain the possible benefits of the therapy as well as the unknown risk of potential side effects to her and her child. The costs of AZT are high. Some private prescription-drug insurers, however, are now covering the costs since the Food and Drug Administration (FDA) has relabeled the drug to include use in pregnancy and childbirth. The Pediatric AIDS Foundation states that an HIV test costs $25 to $30 for each of the 4 million pregnant women in the U.S., and that AZT therapy costs $1,000 for each infected woman.

  19. Centrosomal amplification and aneuploidy induced by the antiretroviral drug AZT in hamster and human cells

    PubMed Central

    Borojerdi, Jennifer P.; Ming, Jessica; Cooch, Catherine; Ward, Yvona; Semino-Mora, Cristina; Yu, Mia; Braun, Hannan M.; Taylor, Barbara J.; Poirier, Miriam C.; Olivero, Ofelia A.

    2009-01-01

    The centrosome directs chromosomal migration by a complex process of tubulin-chromatin binding. In this contribution centrosomal abnormalities, including centrosomal amplification, were explored in Chinese Hamster Ovary (CHO) and Normal Human Mammary Epithelial (NHMEC) cells exposed to the antiretroviral drug zidovudine (3’-azido-3’-deoxythymidine, AZT). Centrosomal amplification/fragmentation was observed in both cell types and kinetochore positive micronuclei were found in AZT-exposed CHO cells in correlation with dose. Normal human mammary epithelial cell (NMHEC), strain M99005, previously identified as a strain that incorporates high levels of AZT into DNA (High incorporator, HI), showed greater centrosomal amplification when compared with a second strain, NHMEC M98040, which did not incorporate AZT into DNA (Low incorporator, LI). Additionally, an abnormal tubulin distribution was observed in AZT-exposed HI cells bearing multiple centrosomes. Immunofluorescent staining of human cells with Aurora A, a kinase involved in the maturation of the centrosome, confirmed the induction of centrosomal amplification and revealed multipolar mitotic figures. Flow cytometric studies revealed that cells bearing abnormal numbers of centrosomes and abnormal tubulin distribution had similar S-phase percentages suggesting that cells bearing unbalanced chromosomal segregation could divide. Therefore, AZT induces genomic instability and clastogenicity as well as alterations in proteins involved in centrosomal activation, all of which may contribute to the carcinogenic properties of this compound. PMID:19427513

  20. Ultrasensitive method to quantify intracellular zidovudine mono-, di- and triphosphate concentrations in peripheral blood mononuclear cells by liquid chromatography-tandem mass spectrometry.

    PubMed

    Kinai, Ei; Gatanaga, Hiroyuki; Kikuchi, Yoshimi; Oka, Shinichi; Kato, Shingo

    2015-06-01

    Although zidovudine (AZT) is not the preferred antiretroviral drug for adult HIV-infected patients, it is still widely used in infants for both prevention of mother-to-infant HIV-1 transmission and treatment of HIV-infected children. However, it is difficult to measure intracellular concentrations of AZT metabolites in small blood samples due to their extremely low concentrations in peripheral blood mononuclear cells and interference by endogenous nucleotide triphosphates, residual plasma phosphates and electrolytes. We developed an ultrasensitive assay using liquid chromatography-tandem mass spectrometry (LC-MS/MS) for measurement of intracellular concentrations of zidovudine (AZT)-monophosphate (AZT-MP), -diphosphate (AZT-DP) and -triphosphate (AZT-TP). The high sensitivity was due to the improvement of peripheral blood mononuclear cells extraction for complete removal of plasma and electrolytes, alkalization of LC buffer and use of alkaline-stable high performance liquid chromatography column and tetrabutylammonium hydroxide as the ion pair. Using this method, the lower limits of quantification of AZT, AZT-MP, -DP and -TP were 6, 6, 10 and 10 fmol per sample, respectively. Accuracy ranged 89-115% and precision was lower than 15% in the quantification range of 6-6000 fmol/sample for plasma AZT and intracellular AZT-MP and 10-10 000 fmol/sample for AZT-DP and -TP. The validation parameters met the international requirements. Among nine AZT-treated HIV-infected adult patients, five had low AZT-TP levels (<10 fmol/10(6) cells). Our assay has high sensitivity and is advantageous for evaluation of AZT phosphates in children and infants based on minimum blood sampling requirement.

  1. Role of ABCB1, ABCG2, ABCC2 and ABCC5 transporters in placental passage of zidovudine.

    PubMed

    Neumanova, Zuzana; Cerveny, Lukas; Ceckova, Martina; Staud, Frantisek

    2016-01-01

    Zidovudine (AZT) is one of the most frequently used antiretroviral drugs in prevention of perinatal transmission of HIV. However, safety concerns on AZT use in pregnancy still persist as severe side effects are associated with AZT exposure in children. In our study we aimed to contribute to current knowledge on AZT transplacental transport and to evaluate potential involvement of the main human drug efflux ATP-binding cassette (ABC) transporters, p-glycoprotein (ABCB1), breast cancer resistance protein (ABCG2) and multidrug resistance-associated proteins 2 and 5 (ABCC2 and ABCC5) in the disposition of AZT between mother and fetus. In order to elucidate this issue we investigated the effect of selected ABC transporters on AZT transepithelial transport across MDCKII cell monolayers. In addition we used the in situ method of dually perfused rat term placenta to further study the role of ABC transporters in AZT transplacental transport. In vitro studies revealed significant effect of ABCB1 and ABCG2 on AZT transport which was subsequently confirmed also on organ level. Lamivudine, an antiretroviral agent commonly co-administered with AZT, did not affect ABC transporter-mediated AZT transfer.

  2. AZT, rodent somatic and germ cell mutagenicity and reproductive toxicity tests

    SciTech Connect

    Shelby, M.D.; Russell, L.B.; Generoso, W.

    1995-11-01

    AZT (3`-axido-3`-deoxythymidine, Zidovudine) is the most widely used therapeutic agent in the treatment of Acquired Immune Deficiency Syndrome (AIDS). Use of AZT has not been limited to HIV-seropositive individuals or to those with symptoms of AIDS. It has also been used as a chemoprophylactic agent in people accidentally exposed to HIV-contaminated body fluids, and to HIV-seropositive pregnant women to prevent infection of the fetus. Because of these latter uses, it is particularly important to determine whether long-term health effects might be associated with AZT exposure. Tests have been conducted to determine the in vivo genetic toxicity of AZT in mice. Dominant-lethal and morphological-specific-locus tests were conducted in males using 2 daily initraperitoneal injections of 750 mg/kg. The dominant-lethal test was negative for all germ cell stages from differentiating spermatogonia to mature sperm. Likewise, no evidence of the induction of specific locus mutations was observed in either spermatogonial stem cells or poststem-cell stages. Further, tests for effects on male and female reproduction and in utero development indicate a lack of effects. These results, along with preliminary clinical reports that birth outcomes are normal in newborns exposed to AZT in utero, are encouraging with regard to the risks to offspring of parents exposed to AZT, either prior to or during pregnancy. However, positive results in mouse bone marrow micronucleus tests and one report on the induction of chromosomal aberrations in the lymphocytes of AIDS patients on AZT therapy indicate that further studies are needed on the potential of AZT to adversely affect the long-term health of exposed individuals.

  3. AZT resistance of simian foamy virus reverse transcriptase is based on the excision of AZTMP in the presence of ATP

    PubMed Central

    Hartl, Maximilian J.; Kretzschmar, Benedikt; Frohn, Anne; Nowrouzi, Ali; Rethwilm, Axel; Wöhrl, Birgitta M.

    2008-01-01

    Azidothymidine (AZT, zidovudine) is one of the few nucleoside inhibitors known to inhibit foamy virus replication. We have shown previously that up to four mutations in the reverse transcriptase gene of simian foamy virus from macaque (SFVmac) are necessary to confer high resistance against AZT. To characterize the mechanism of AZT resistance we expressed two recombinant reverse transcriptases of highly AZT-resistant SFVmac in Escherichia coli harboring three (K211I, S345T, E350K) or four mutations (K211I, I224T, S345T, E350K) in the reverse transcriptase gene. Our analyses show that the polymerization activity of these mutants is impaired. In contrast to the AZT-resistant reverse transcriptase of HIV-1, the AZT resistant enzymes of SFVmac reveal differences in their kinetic properties. The SFVmac enzymes exhibit lower specific activities on poly(rA)/oligo(dT) and higher KM-values for polymerization but no change in KD-values for DNA/DNA or RNA/DNA substrates. The AZT resistance of the mutant enzymes is based on the excision of the incorporated inhibitor in the presence of ATP. The additional amino acid change of the quadruple mutant appears to be important for regaining polymerization efficiency. PMID:18096624

  4. Neurobehavioral effects of prenatal exposure to AZT: a preliminary investigation with the D1 receptor agonist SKF 38393 in mice.

    PubMed

    Venerosi, Aldina; Valanzano, Angelina; Puopolo, Maria; Calamandrei, Gemma

    2005-01-01

    Zidovudine (AZT) is the main therapeutic agent against HIV vertical transmission and is routinely administered to seropositive pregnant women and their newborns. Toxicity after chronic administration as well as citogenetic effects following developmental AZT exposure has been reported. Furthermore, recent animal data indicate alterations of several behavioral endpoints during the entire lifespan of mice and rats after developmental AZT exposure. In this study, we investigated specific central nervous system (CNS) effects of AZT administration during pregnancy on the offspring. CD-1 mouse females were administered twice daily from day 10 of pregnancy until delivery with either AZT (160 mg/kg) or saline (0.9% NaCl). On PND, 60 male offsprings received an intraperitoneal injection of the D1 receptor agonist 2,3,4,5-tetra-hydro-7,8-diol-1-phenyl-(1H)-3-benzazepine (SKF 38393) (0, 3, and 10 mg/kg), and spontaneous behavior was assessed in an automated activity chamber for 40 min. At variance from what observed in control mice that displayed excessive grooming when administered the higher dose of the D1 agonist, SKF 38393 failed to increase duration of grooming in AZT-treated mice. These data suggest that the D1 receptorial dopaminergic subsystem might be hyporesponsive in mice prenatally exposed to AZT.

  5. Long-Term Exposure to AZT, but not d4T, Increases Endothelial Cell Oxidative Stress and Mitochondrial Dysfunction

    PubMed Central

    Kline, Erik R.; Bassit, Leda; Hernandez-Santiago, Brenda I.; Detorio, Mervi A.; Liang, Bill; Kleinhenz, Dean J.; Walp, Erik R.; Dikalov, Sergey; Jones, Dean P.; Schinazi, Raymond F.

    2009-01-01

    Nucleoside reverse transcriptase inhibitors (NRTIs), such as zidovudine (AZT) and stavudine (d4T), cause toxicities to numerous tissues, including the liver and vasculature. While much is known about hepatic NRTI toxicity, the mechanism of toxicity in endothelial cells is incompletely understood. Human aortic endothelial and HepG2 liver cells were exposed to 1 μM AZT or d4T for up to 5 weeks. Markers of oxidative stress, mitochondrial function, NRTI phosphorylation, mitochondrial DNA (mtDNA) levels, and cytotoxicity were monitored over time. In endothelial cells, AZT significantly oxidized glutathione redox potential, increased total cellular and mitochondrial-specific superoxide, decreased mitochondrial membrane potential, increased lactate release, and caused cell death from weeks 3 through 5. Toxicity occurred in the absence of di- and tri-phosphorylated AZT and mtDNA depletion. These data show that oxidative stress and mitochondrial dysfunction in endothelial cells occur with a physiologically relevant concentration of AZT, and require long-term exposure to develop. In contrast, d4T did not induce endothelial oxidative stress, mitochondrial dysfunction, or cytotoxicity despite the presence of d4T-triphosphate. Both drugs depleted mtDNA in HepG2 cells without causing cell death. Endothelial cells are more susceptible to AZT-induced toxicity than HepG2 cells, and AZT caused greater endothelial dysfunction than d4T because of its pro-oxidative effects. PMID:19067249

  6. Preparation and Characterization of Chitosan Nanoparticles for Zidovudine Nasal Delivery.

    PubMed

    Barbi, Mariana Da Silva; Carvalho, Flávia Chiva; Kiill, Charlene Priscila; Barud, Hernane Da Silva; Santagneli, Sílvia Helena; Ribeiro, Sidney José Lima; Gremião, Maria Palmira Daflon

    2015-01-01

    Zidovudine (AZT) is the antiretroviral drug most frequently used for the treatment of Acquired Immunodeficiency Syndrome. Its low oral bioavailability demands the development of innovative strategies to overcome the first pass metabolism. The nasal route is an option for enhanced therapeutic efficacy and to reduce the extent of the first-pass effect. In this article, AZT loaded chitosan nanoparticles were prepared by a modified ionotropic gelation method with sodium tripolyphosphate. The increase proportion of CS (NP1 10:01 (w/w)) promoted the formation of smaller nanoparticles (260 nm), while raising the proportion of TPP (NP2 5:1 w/w) increased the nanoparticles size (330 nm). The incorporation of AZT increased the nanoparticles size for both AZT-loaded nanoparticles AZT-loaded NP1 (406 nm) and AZT-loaded NP2 (425 nm). The incorporation of AZT into NP1 did not change the electrophoretic mobility, however, in AZT-loaded NP2 there was a significant increase. The positive surface of the nanoparticles is very important for the mucoadhesive properties due interaction with the sialic groups of the mucin. Nuclear resonance magnetic data showed that the higher concentration of chitosan in the nanoparticles favored the interaction of few phosphate units (pyrophosphate) by ionic interaction Scanning electron microscopy, revealed that the nanoparticles are nearly spherical shape with porous surface. The entrapment efficiency of AZT, was 17.58% ± 1.48 and 11.02% ± 2.05 for NP1 and NP2, respectively. The measurement of the mucoadhesion force using mucin discs and nasal tissue obtained values of NP1 = 2.12 and NP2 = 4.62. In vitro permeation study showed that the nanoparticles promoted an increase in the flux of the drug through the nasal mucosa. In view of these results, chitosan nanoparticles were found to be a promising approach for the incorporation of hydrophilic drugs and these results suggest that the CS-containing nanoparticles have great potential for nasal AZT

  7. Zidovudine-poly(L-lactic acid) solid dispersions with improved intestinal permeability prepared by supercritical antisolvent process.

    PubMed

    Yoshida, Valquíria M H; Balcão, Victor M; Vila, Marta M D C; Oliveira Júnior, José M; Aranha, Norberto; Chaud, Marco V; Gremião, Maria P D

    2015-05-01

    A supercritical antisolvent (SAS) process for obtaining zidovudine-poly(L-lactic acid) (PLLA) solid dispersions (SDs) was used to attain a better intestinal permeation of this drug. A 3(2) factorial design was used, having as independent variables the ratio 3'-azido-2'3'-dideoxythymidine (AZT)-PLLA and temperature/pressure conditions, as dependent variables the process yield and particle macroscopic morphology. AZT-PLLA production batches were carried out by the SAS process, and the resulting products evaluated via scanning electron microscope, X-ray diffraction, differential scanning calorimetry, and Fourier transform infrared analyses. From the nine possible combinations of tests performed experimentally, only one combination did not produced a solid. The L3 batch of SD, produced with 1:2 (AZT-PLLA) ratio, resulted in a 91.54% yield, with 40% AZT content. Intestinal permeability studies using the AZT-PLLA from L3 batch led to an AZT permeability of approximately 9.87%, which was higher than that of pure AZT (∼3.84%). AZT remained in crystalline form, whereas PLLA remained in semicrystalline form. AZT release is controlled by a diffusion mechanism. It has been demonstrated that it is possible to use PLLA carrier and SAS process to obtain SD, in a single step.

  8. Improved Safety, Bioavailability and Pharmacokinetics of Zidovudine through Lactoferrin Nanoparticles during Oral Administration in Rats.

    PubMed

    Kumar, Prashant; Lakshmi, Yeruva Samrajya; C, Bhaskar; Golla, Kishore; Kondapi, Anand K

    2015-01-01

    Zidovudine (AZT) is one of the most referred antiretroviral drug. In spite of its higher bioavailability (50-75%) the most important reason of its cessation are bone marrow suppression, anemia, neutropenia and various organs related toxicities. This study aims at the improvement of oral delivery of AZT through its encapsulation in lactoferrin nanoparticles (AZT-lactonano). The nanoparticles (NPs) are of 50-60 nm in size and exhibit 67% encapsulation of the AZT. They are stable in simulated gastric and intestinal fluids. Anti-HIV-1 activity of AZT remains unaltered in nanoformulation in acute infection. The bioavailability and tissue distribution of AZT is higher in blood followed by liver and kidney. AZT-lactonano causes the improvement of pharmacokinetic profile as compared to soluble AZT; a more than 4 fold increase in AUC and AUMC in male and female rats. The serum Cmax for AZT-lactonano was increased by 30%. Similarly there was nearly 2-fold increase in Tmax and t1/2. Our in vitro study confirms that, the endosomal pH is ideal for drug release from NPs and shows constant release from up to 96h. Bone marrow micronucleus assay show that nanoformulation exhibits approximately 2fold lower toxicity than soluble form. Histopathological and biochemical analysis further confirms that less or no significant organ toxicities when nanoparticles were used. AZT-lactonano has shown its higher efficacy, low organs related toxicities, improved pharmacokinetics parameter while keeping the antiviral activity intact. Thus, the nanoformulation are safe for the target specific drug delivery.

  9. Zidovudine-based lytic-inducing chemotherapy for Epstein-Barr virus-related lymphomas.

    PubMed

    Bayraktar, Ulas Darda; Diaz, Luis A; Ashlock, Brittany; Toomey, Ngoc; Cabral, Lisa; Bayraktar, Soley; Pereira, Denise; Dittmer, Dirk P; Ramos, Juan Carlos

    2014-04-01

    Treatment of Epstein-Barr virus (EBV)-related lymphomas with lytic-inducing agents is an attractive targeted approach for eliminating virus-infected tumor cells. Zidovudine (AZT) is an excellent substrate for EBV-thymidine kinase: it can induce EBV lytic gene expression and apoptosis in primary EBV+ lymphoma cell lines. We hypothesized that the combination of AZT with lytic-inducing chemotherapy agents would be effective in treating EBV+ lymphomas. We report a retrospective analysis of 19 patients with aggressive EBV+ non-Hodgkin lymphoma, including nine cases of acquired immune deficiency syndrome-associated primary central nervous system lymphoma (AIDS-PCNSL) treated with AZT-based chemotherapy. Our results demonstrate that high-dose AZT-methotrexate is efficacious in treating highly aggressive systemic EBV+ lymphomas in the upfront setting. In primary EBV+ lymphoma cell lines, the combination of AZT with hydroxyurea resulted in synergistic EBV lytic induction and cell death. Further, AZT-hydroxyurea treatment resulted in dramatic responses in patients with AIDS-PCNSL. The combination of AZT with chemotherapy, especially lytic-inducing agents, should be explored further in clinical trials for the treatment of EBV-related lymphomas.

  10. Brain uptake of a Zidovudine prodrug after nasal administration of solid lipid microparticles.

    PubMed

    Dalpiaz, Alessandro; Ferraro, Luca; Perrone, Daniela; Leo, Eliana; Iannuccelli, Valentina; Pavan, Barbara; Paganetto, Guglielmo; Beggiato, Sarah; Scalia, Santo

    2014-05-05

    Our previous results demonstrated that a prodrug obtained by the conjugation of the antiretroviral drug zidovudine (AZT) with ursodeoxycholic acid (UDCA) represents a potential carrier for AZT in the central nervous system, thus possibly increasing AZT efficiency as an anti-HIV drug. Based on these results and in order to enhance AZT brain targeting, the present study focuses on solid lipid microparticles (SLMs) as a carrier system for the nasal administration of UDCA-AZT prodrug. SLMs were produced by the hot emulsion technique, using tristearin and stearic acid as lipidic carriers, whose mean diameters were 16 and 7 μm, respectively. SLMs were of spherical shape, and their prodrug loading was 0.57 ± 0.03% (w/w, tristearin based) and 1.84 ± 0.02% (w/w, stearic acid based). The tristearin SLMs were able to control the prodrug release, whereas the stearic acid SLMs induced a significant increase of the dissolution rate of the free prodrug. The free prodrug was rapidly hydrolyzed in rat liver homogenates with a half-life of 2.7 ± 0.14 min (process completed within 30 min). The tristearin SLMs markedly enhanced the stability of the prodrug (75% of the prodrug still present after 30 min), whereas the stabilization effect of the stearic acid SLMs was lower (14% of the prodrug still present after 30 min). No AZT and UDCA-AZT were detected in the rat cerebrospinal fluid (CSF) after an intravenous prodrug administration (200 μg). Conversely, the nasal administration of stearic acid based SLMs induced the uptake of the prodrug in the CSF, demonstrating the existence of a direct nose-CNS pathway. In the presence of chitosan, the CSF prodrug uptake increased six times, up to 1.5 μg/mL within 150 min after nasal administration. The loaded SLMs appear therefore as a promising nasal formulation for selective zidovudine brain uptake.

  11. Acrolein enhances epigenetic modifications, FasL expression and hepatocyte toxicity induced by anti-HIV drug Zidovudine.

    PubMed

    Ghare, Smita S; Donde, Hridgandh; Chen, Wei-Yang; Barker, David F; Gobejishvilli, Leila; McClain, Craig J; Barve, Shirish S; Joshi-Barve, Swati

    2016-09-01

    Zidovudine (AZT) remains the mainstay of antiretroviral therapy against HIV in resource-poor countries; however, its use is frequently associated with hepatotoxicity. Not all HIV patients on AZT develop hepatotoxicity, and the determining factors are unclear. Alcohol consumption and cigarette smoking are known risk factors for HIV hepatotoxicity, and both are significant sources of acrolein, a highly reactive and toxic aldehyde. This study examines the potential hepatotoxic interactions between acrolein and AZT. Our data demonstrate that acrolein markedly enhanced AZT-induced transcriptionally permissive histone modifications (H3K9Ac and H3K9Me3) allowing the recruitment of transcription factor NF-kB and RNA polymerase II at the FasL gene promoter, resulting in FasL upregulation and apoptosis in hepatocytes. Notably, the acrolein scavenger, hydralazine prevented these promoter-associated epigenetic changes and inhibited FasL upregulation and apoptosis induced by the combination of AZT and acrolein, as well as AZT alone. Our data strongly suggest that acrolein enhancement of promoter histone modifications and FasL upregulation are major pathogenic mechanisms driving AZT-induced hepatotoxicity. Moreover, these data also indicate the therapeutic potential of hydralazine in mitigating AZT hepatotoxicity.

  12. Enhancement of zidovudine transfer to molt-4 cells, a human t-cell model, by dehydroepiandrosterone sulfate.

    PubMed

    Nishimura, Tomohiro; Tanaka, Jun; Tomi, Masatoshi; Seki, Yoshiaki; Kose, Noriko; Sai, Yoshimichi; Nakashima, Emi

    2011-09-01

    A possible approach to improve antiretroviral therapy with nucleoside reverse transcriptase inhibitors is to enhance inhibitor delivery to CD4-positive T cells. We previously showed that dehydroepiandrosterone sulfate (DHEAS) enhances zidovudine (AZT) transfer into syncytiotrophoblast. Here, we investigated whether DHEAS also enhances AZT transfer into a cellular model of human T lymphocytes, and whether AZT is taken up by a specific transport system. The effects of DHEAS and related compounds on the uptake of [(3) H]AZT and other nucleosides by Molt-4 cells (a model of human CD4-positive T cells) were measured. [(3) H]AZT uptake by Molt-4 cells was nitrobenzylthioinosine insensitive and pH dependent, and the uptake was significantly inhibited by 1 mM ethylisopropylamiloride. [(3) H]AZT uptake by Molt-4 cells was increased in the presence of DHEAS, whereas uptake of other nucleosides was reduced. Kinetic study revealed that the maximum uptake velocity (up to 30 min) was increased in the presence of DHEAS. The structural requirements for AZT uptake-enhancing activity were studied using structural analogues of DHEAS. Estrone-3-sulfate and 16α-hydroxy DHEAS also enhanced AZT uptake into Molt-4 cells. The use of uptake enhancers may be a good strategy to improve the efficacy of antiretroviral therapy.

  13. Enhancement of zidovudine uptake by dehydroepiandrosterone sulfate in rat syncytiotrophoblast cell line TR-TBT 18d-1.

    PubMed

    Nishimura, Tomohiro; Seki, Yoshiaki; Sato, Kazuko; Chishu, Takuya; Kose, Noriko; Terasaki, Tetsuya; Kang, Young-Sook; Sai, Yoshimichi; Nakashima, Emi

    2008-10-01

    AZT (3'-azido-3'-deoxythymidine; zidovudine), which is used for the prevention of mother-to-child transmission of HIV-1, is transplacentally transferred to the fetus across the blood-placenta barrier, which is composed of syncytiotrophoblasts. We recently showed that apical uptake of AZT by syncytiotrophoblasts is mediated by saturable transport system(s) in the TR-TBT 18d-1 cell line, and the cellular accumulation of AZT was increased in the presence of dehydroepiandrosterone sulfate (DHEAS). Here, we aimed to clarify the mechanism of this effect of DHEAS. Inhibitors of efflux transporters, including breast cancer resistance protein, P-glycoprotein, and multidrug resistance proteins, had little effect on the cellular accumulation of AZT in TR-TBT 18d-1. Kinetic study revealed that the rate constant for AZT uptake was greatly increased in the presence of 1 mM DHEAS. These results suggested that the effect of DHEAS was because of enhancement of the uptake process(es), rather than inhibition of efflux. When AZT uptake was analyzed according to the Michaelis-Menten equation, the estimated Michaelis constant, Km, for AZT uptake in the presence of 1 mM DHEAS was lower than that in its absence, whereas maximum uptake velocity, Vmax, and nonsaturable uptake clearance, kns, were similar in the presence and absence of DHEAS, indicating that DHEAS may change the recognition characteristics of the transporter for AZT in TR-TBT 18d-1. Thus, the increase of AZT uptake in TR-TBT 18d-1 cells in the presence of DHEAS was concluded to be because of a DHEAS-induced change in the affinity of AZT uptake system, although the transporter responsible for AZT uptake has not been identified.

  14. Zidovudine induces downregulation of mitochondrial deoxynucleoside kinases: implications for mitochondrial toxicity of antiviral nucleoside analogs.

    PubMed

    Sun, Ren; Eriksson, Staffan; Wang, Liya

    2014-11-01

    Mitochondrial thymidine kinase 2 (TK2) and deoxyguanosine kinase (dGK) catalyze the initial phosphorylation of deoxynucleosides in the synthesis of the DNA precursors required for mitochondrial DNA (mtDNA) replication and are essential for mitochondrial function. Antiviral nucleosides are known to cause toxic mitochondrial side effects. Here, we examined the effects of 3'-azido-2',3'-dideoxythymidine (AZT) (zidovudine) on mitochondrial TK2 and dGK levels and found that AZT treatment led to downregulation of mitochondrial TK2 and dGK in U2OS cells, whereas cytosolic deoxycytidine kinase (dCK) and thymidine kinase 1 (TK1) levels were not affected. The AZT effects on mitochondrial TK2 and dGK were similar to those of oxidants (e.g., hydrogen peroxide); therefore, we examined the oxidative effects of AZT. We found a modest increase in cellular reactive oxygen species (ROS) levels in the AZT-treated cells. The addition of uridine to AZT-treated cells reduced ROS levels and protein oxidation and prevented the degradation of mitochondrial TK2 and dGK. In organello studies indicated that the degradation of mitochondrial TK2 and dGK is a mitochondrial event. These results suggest that downregulation of mitochondrial TK2 and dGK may lead to decreased mitochondrial DNA precursor pools and eventually mtDNA depletion, which has significant implications for the regulation of mitochondrial nucleotide biosynthesis and for antiviral therapy using nucleoside analogs.

  15. Antiretroviral Drugs Used in the Treatment of HIV Infection

    MedlinePlus

    ... 6 months Retrovir zidovudine, azidothymidine, AZT, ZDV 19-Mar-87 3.5 months Trizivir abacavir, zidovudine, and ... months Viramune XR (Extended Release) nevirapine, NVP 25-Mar-11 9.9 months Protease Inhibitors (PIs) Brand ...

  16. Differential gene expression in human hepatocyte cell lines exposed to the antiretroviral agent zidovudine.

    PubMed

    Fang, Jia-Long; Han, Tao; Wu, Qiangen; Beland, Frederick A; Chang, Ching-Wei; Guo, Lei; Fuscoe, James C

    2014-03-01

    Zidovudine (3'-azido-3'-deoxythymidine; AZT) is the most widely used nucleoside reverse transcriptase inhibitor for the treatment of AIDS patients and prevention of mother-to-child transmission of HIV-1. Previously, we demonstrated that AZT had significantly greater growth inhibitory effects upon the human liver carcinoma cell line HepG2 as compared to the immortalized human liver cell line THLE2. We have now used gene expression profiling to determine the molecular pathways associated with toxicity in both cell lines. HepG2 cells were incubated with 0, 2, 20, or 100 μM AZT for 2 weeks; THLE2 cells were treated with 0, 50, 500, or 2,500 μM AZT, concentrations that were equi-toxic to those used in the HepG2 cells. After the treatment, total RNA was isolated and subjected to microarray analysis. Global analysis of gene expression, with a false discovery rate ≤0.01 and a fold change ≥1.5, indicated that 6- to 70-fold more genes were differentially expressed in a significant concentration-dependent manner in HepG2 cells when compared to THLE2 cells. Comparative analysis indicated that 7 % of these genes were common to both cell lines. Among the common differentially expressed genes, 70 % changed in the same direction, most of which were associated with cell death and survival, cell cycle, cell growth and proliferation, and DNA replication, recombination, and repair. As determined by the uptake of [methyl-(3)H]AZT, the intracellular levels of total AZT were approximately twofold higher in THLE2 cells than in HepG2 cells. The expression of thymidine kinase 1 (TK1) and UDP-glucuronosyltransferase 2B7 (UGT2B7) genes that regulate the metabolic activation and deactivation of AZT, respectively, was increased in HepG2 cells but decreased in THLE2 cells after treatment with AZT. This differential response in AZT metabolism was confirmed by real-time PCR, western blotting, and/or enzymatic assays. These data indicate that molecular pathways involved with cell death and

  17. Selective protection of zidovudine-induced DNA-damage by the antioxidants WR-1065 and tempol.

    PubMed

    Olivero, Ofelia A; Ongele, Michael O; Braun, Hannan M; Marrogi, Ariadna; Divi, Kathyiani; Mitchell, James B; Poirier, Miriam C

    2014-08-01

    The cytokinesis-block micronucleus cytome (CBMN) assay, introduced by Fenech, was used to demonstrate different types of DNA damage in MOLT-3 human lymphoblastoid cells exposed to 10 μM zidovudine (AZT). In addition, we explored the cytoprotective potential of two antioxidants, WR-1065 and Tempol, to decrease AZT-induced genotoxicity. Binucleated cells, arrested by Cytochalasin B (Cyt B), were evaluated for micronuclei (MN), caused by DNA damage or chromosomal loss, and chromatin nucleoplasmic bridges (NPBs), caused by telomere attrition. Additionally, nuclear buds (NBUDs), caused by amplified DNA, and apoptotic and necrotic (A/N) cells were scored. We hypothesized that AZT exposure would increase the frequency of genotoxic end points, and that the antioxidants Tempol and WR-1065 would protect against AZT-induced genotoxicity. MOLT-3 cells were exposed to 0 or 10 µM AZT for a total of 76 hr. After the first 24 hr, 0 or 5 µM WR-1065 and/or 0 or 200 µM Tempol were added for the remainder of the experiment. For the last 28 hr (of 76 hr), Cyt B was added to arrest replication after one cell division, leaving a predominance of binucleated cells. The nuclear division index (NDI) was similar for all treatment groups, indicating that the exposures did not alter cell viability. MOLT-3 cells exposed to AZT alone had significant (P < 0.05) increases in MN and NBs, compared to unexposed cells. Both Tempol and WR-1065 protected against AZT-induced MN formation (P < 0.003 for both), and WR-1065, but not Tempol, reduced the levels of A/N (P = 0.041). In cells exposed to AZT/Tempol there were significantly reduced levels of NBUDs, compared to cells exposed to AZT alone (P = 0.015). Cells exposed to AZT/WR-1065 showed reduced levels of NPBs, compared to cells exposed to AZT alone (P = 0.037). Thus WR-1065 and Tempol protected MOLT-3 cells against specific types of AZT-induced DNA damage.

  18. Zidovudine-based lytic-inducing chemotherapy for Epstein–Barr virus-related lymphomas

    PubMed Central

    Bayraktar, Ulas Darda; Diaz, Luis A.; Ashlock, Brittany; Toomey, Ngoc; Cabral, Lisa; Bayraktar, Soley; Pereira, Denise; Dittmer, Dirk P.; Ramos, Juan Carlos

    2014-01-01

    Treatment of Epstein–Barr virus (EBV)-related lymphomas with lytic-inducing agents is an attractive targeted approach for eliminating virus-infected tumor cells. Zidovudine (AZT) is an excellent substrate for EBV-thymidine kinase: it can induce EBV lytic gene expression and apoptosis in primary EBV+ lymphoma cell lines. We hypothesized that the combination of AZT with lytic-inducing chemotherapy agents would be effective in treating EBV+ lymphomas. We report a retrospective analysis of 19 patients with aggressive EBV+ non-Hodgkin lymphoma, including nine cases of acquired immune deficiency syndrome-associated primary central nervous system lymphoma (AIDSPCNSL) treated with AZT-based chemotherapy. Our results demonstrate that high-dose AZT–methotrexate is efficacious in treating highly aggressive systemic EBV+ lymphomas in the upfront setting. In primary EBV+ lymphoma cell lines, the combination of AZT with hydroxyurea resulted in synergistic EBV lytic induction and cell death. Further, AZT–hydroxyurea treatment resulted in dramatic responses in patients with AIDSPCNSL. The combination of AZT with chemotherapy, especially lytic-inducing agents, should be explored further in clinical trials for the treatment of EBV-related lymphomas. PMID:23837493

  19. Simultaneous determination of zidovudine and lamivudine in human serum using HPLC with tandem mass spectrometry.

    PubMed

    Kenney, K B; Wring, S A; Carr, R M; Wells, G N; Dunn, J A

    2000-07-01

    A method employing high performance liquid chromatography (HPLC) with tandem mass spectrometry (MS) has been developed and validated for the simultaneous determination of clinically relevant levels of zidovudine (AZT) and lamivudine (3TC) in human serum. The method incorporates a fully automated ultrafiltration sample preparation step that replaces the solid-phase extraction step typically used for HPLC with UV detection. The calibration range of the dual-analyte LC-MS/MS method is 2.5-2,500 and 2.5-5,000 ng ml-1 for AZT and 3TC, respectively, using 0.25 ml of human serum. The lower limit of quantification was 2.5 ng ml-1 for each analyte, with a chromatographic run time of approximately 6 min. Overall accuracy, expressed as bias, and inter- and intra-assay precision are < +/- 7 and < 10% for AZT, and < +/- 5 and < 12.1% for 3TC over the full concentration ranges. A cross-validation study demonstrated that the LC-MS/MS method afforded equivalent results to established methods consisting of a radioimmuno-assay for AZT and an HPLC-UV method for 3TC. Moreover, the LC-MS/MS was more sensitive, allowed markedly higher-throughput, and required smaller sample volumes (for 3TC only). The validated method has been used to support post-marketing clinical studies for Combivir a combination tablet containing AZT and 3TC.

  20. XPC is essential for nucleotide excision repair of zidovudine-induced DNA damage in human hepatoma cells

    SciTech Connect

    Wu Qiangen; Beland, Frederick A.; Chang, Ching-Wei; Fang Jialong

    2011-03-01

    Zidovudine (3'-azido-3'-dexoythymidine, AZT), a nucleoside reverse transcriptase inhibitor, can be incorporated into DNA and cause DNA damage. The mechanisms underlying the repair of AZT-induced DNA damage are unknown. To investigate the pathways involved in the recognition and repair of AZT-induced DNA damage, human hepatoma HepG2 cells were incubated with AZT for 2 weeks and the expression of DNA damage signaling pathways was determined using a pathway-based real-time PCR array. Compared to control cultures, damaged DNA binding and nucleotide excision repair (NER) pathways showed significantly increased gene expression. Further analysis indicated that AZT treatment increased the expression of genes associated with NER, including XPC, XPA, RPA1, GTF2H1, and ERCC1. Western blot analysis demonstrated that the protein levels of XPC and GTF2H1 were also significantly up-regulated. To explore further the function of XPC in the repair of AZT-induced DNA damage, XPC expression was stably knocked down by 71% using short hairpin RNA interference. In the XPC knocked-down cells, 100 {mu}M AZT treatment significantly increased [{sup 3}H]AZT incorporation into DNA, decreased the total number of viable cells, increased the release of lactate dehydrogenase, induced apoptosis, and caused a more extensive G2/M cell cycle arrest when compared to non-transfected HepG2 cells or HepG2 cells transfected with a scrambled short hairpin RNA sequence. Overall, these data indicate that XPC plays an essential role in the NER repair of AZT-induced DNA damage.

  1. Biological comparison of wild-type and zidovudine-resistant isolates of human immunodeficiency virus type 1 from the same subjects: susceptibility and resistance to other drugs.

    PubMed Central

    Rooke, R; Parniak, M A; Tremblay, M; Soudeyns, H; Li, X G; Gao, Q; Yao, X J; Wainberg, M A

    1991-01-01

    We used a viral endpoint dilution assay to show changes in the proportion of zidovudine (azidothymidine; AZT)-resistant viruses within a heterogeneous mixture of human immunodeficiency virus type 1 (HIV-1) quasispecies isolated from patients on long-term AZT therapy. Several HIV-1 isolates, which could replicate in 10 microM AZT, were susceptible to both 2',3'-dideoxycytidine and a novel cytosine analog BCH-189, in which a sulfur atom replaces the 3' carbon of the pentose ring. In certain instances, cross-resistance was seen with 3'-didehydro-2',3'-dideoxythymidine. Although most strains of AZT-resistant HIV-1 displayed reduced susceptibility to 3'-azido-2',3'-dideoxyuridine, two strains were identified for which this was not the case. PMID:1649576

  2. Naringin improves zidovudine- and stavudine-induced skeletal muscle complications in rats.

    PubMed

    Adebiyi, O O; Adebiyi, O A; Owira, Pmo

    2016-03-22

    Chronic use of nucleoside reverse transcriptase inhibitors (NRTIs) in managing human immunodeficiency virus (HIV) infection has been associated with several complications. Available management options for these complications have yielded controversial results, thus the need to urgently find newer alternatives. Naringin, a plant-derived flavonoid, has been shown to possess antioxidant and antiapoptotic properties which can be exploited in managing NRTI-induced complications. This study therefore investigated the effects of naringin on some NRTI-induced complications. Forty-nine rats (200-250 g) were divided into seven groups and were orally treated with stavudine (d4T)-only, d4T + naringin, d4T + vitamin E, zidovudine (AZT)-only, AZT + naringin, AZT + vitamin E, and distilled water, respectively. Drugs were administered once daily for 56 days, and oral glucose tolerance tests conducted on day 54 of the experiments and rats were thereafter sacrificed on day 56 by halothane overdose. Plasma samples and the left gastrocnemius muscles were stored at -80°C for further analysis. There was significant glucose intolerance, insulin resistance, oxidative stress, and apoptosis in the skeletal muscles of AZT- or d4T-only-treated rats. Naringin, however, significantly reduced fasting blood glucose and fasting plasma insulin concentrations, mitigated glucose intolerance, and insulin resistance in addition to reducing malondialdehyde and carbonyl protein concentrations when coadministered with either NRTIs. Furthermore, naringin improved antioxidant enzyme activities, reduced skeletal muscle BCL-2-associated X protein expression, and improved B-cell lymphoma-2 protein expression compared to AZT- or d4T-only-treated rats. Naringin ameliorated AZT- and d4T-induced complications and therefore should be further investigated as a possible nutritional supplement in managing HIV infection.

  3. Silibinin mitigates zidovudine-induced hepatocellular degenerative changes, oxidative stress and hyperlipidaemia in rats.

    PubMed

    Raghu, R; Jesudas, B; Bhavani, G; Ezhilarasan, D; Karthikeyan, S

    2015-11-01

    Prolonged zidovudine (AZT) treatment in HIV-infected and AIDS patients is shown to induce liver toxicity leading to complications. Therapeutic regimen that could encounter this adverse effect is unavailable and management of toxicity is often symptomatic or is limited to withdrawal of therapy. In the present investigation, we evaluated the alleviating properties of silibinin (SBN), a flavanolignan obtained from Silybum marianum against subacute AZT-induced hepatotoxicity and oxidative stress in rats. AZT treatment (50 mg/kg body weight (b.w.) periorally (p.o.), daily for 45 days) caused highly significant increases in alanine transaminase, alkaline phosphatase, argininosuccinic acid lyase and bilirubin in serum. Oxidative stress is shown by a highly significant increase in lipid peroxidase and total carbonyl content and decrease in catalase and protein thiols in the liver tissue. Hyperlipidaemia is indicated by highly significant increase in total lipids and free fatty acid in serum. Evaluation of liver by haematoxylin and eosin staining shows parenchymal cell enlargement, inflammatory changes and increase in sinusoidal spaces. Simultaneous treatment of SBN (100 mg/kg b.w. p.o., daily for 45 days) significantly protected the liver against hepatotoxicity, oxidative stress and hyperlipidaemia induced by AZT, and this alleviating property is attributed to hepatoprotective, membrane-stabilizing, antioxidant and free radical scavenging properties of SBN.

  4. Mucoadhesive Nanostructured Polyelectrolyte Complexes as Potential Carrier to Improve Zidovudine Permeability.

    PubMed

    Pedreiro, Liliane Neves; Stringhetti, Beatriz; Cury, Ferreira; Gremião, Maria Palmira Daflon

    2016-02-01

    Mucoadhesive drug delivery systems have been widely investigated as a strategic to allow the raising of intestinal residence time of drugs and the intimate contact with the intestinal mucosa, both factors that increase the local concentration gradient. Zidovudine (AZT) mucoadhesive nanostructured polyelectrolyte complexes were obtained by chitosan (CS)-hypromellose phthalate (HP) interactions in order to favor the permeability through biological membranes and the AZT absorption. Particle size and morphology analyses showed the obtaining of nanoparticulate delivery systems, with AZT loaded about of 65%. The characterization by DSC, X-ray diffraction and FTIR showed a new crystalline structure formed in which the drug remained molecularly dispersed, without changing this structure. The reduced release rates in the simulated gastric medium and the control of release rates in simulated intestinal medium of AZT were demonstrated by in vitro release studies. The nanoparticles liquid uptake ability associated to the mucoadhesiveness by electronic interaction between the particles and mucus revealed that the drug delivery system developed in this work is a promising approach to improve the permeation of this drug throughout the intestinal mucosa.

  5. Fourier transform infrared spectra and normal mode analysis of drug molecules: Zidovudine

    NASA Astrophysics Data System (ADS)

    Jain, Nivedita; Prabhakar, Santosh; Singh, R. A.

    2013-03-01

    The FTIR spectra of zidovudine molecule have been recorded in the range 4000-400 cm-1. The title compound is used as a drug against AIDS or HIV. The molecular structure, fundamental vibrational frequencies and intensities of vibrational bands are evaluated using density functional theory (DFT) using BLYP, B3LYP, B3PW91 and MPW1PW91 methods with 6-31+G(d,p) standard basis set. Comparison of simulated spectra with the experimental spectrum provides important informations and the ability of the computational method to describe the vibrational modes. These calculations have allowed finding most stable conformational structure of AZT. Calculated results of the title compound indicate that the drug molecule has syn orientation. The glycosidic bond in AZT and a minimum-energy structure in which the glycosy torsion angle χ and torsion angle γ values are consistent with those in the conformation of AZT in the AZT5-triphosphate bound to HIV RT is determined.

  6. Simultaneous determination of abacavir and zidovudine from rat tissues using HPLC with ultraviolet detection.

    PubMed

    Lewis, Summer R; White, Catherine A; Bartlett, Michael G

    2007-05-01

    A simple high-performance liquid chromatography (HPLC) method has been developed and validated for the simultaneous determination of abacavir and zidovudine (AZT) in rat plasma, amniotic fluid, fetal, and placental tissues. Extraction of abacavir, AZT, and the internal standard, azidouridine (AZDU) in amniotic fluid was carried out by protein precipitation. Extraction from plasma, fetal and placental homogenates was achieved by using a salting out technique. Chromatographic separation was performed using a C8 column (150 mm x 4.6 mm, 5 microm). The mobile phase consisted of 12% acetonitrile in 25 mM sodium phosphate buffer (adjusted to pH 7 with sodium hydroxide) for the fetus, placenta, plasma and amniotic fluid samples at a flow rate of 0.8 mL/min. The method was validated over the range from 0.05 to 50 microg/mL for both abacavir and AZT in the four biological matrices. The absolute recovery of abacavir ranged from 79 to 94%, while AZT recoveries ranged from 79 to 90% in the different biological matrices. The internal standard recovery ranged from 90 to 92%. Acceptable intra- and inter-day assay precision (<10% R.S.D.) and accuracy (<10% error) were observed over 0.05-50 microg/mL for all four matrices.

  7. Quantitative determination and sampling of lamivudine and zidovudine residues for cleaning validation in a production area.

    PubMed

    Santoro, Maria Inês Rocha Miritello; Fazio, Tatiana Tatit; Singh, Anil Kumar; Kedor-Hackmann, Erica Rosa Maria

    2007-01-01

    Lamivudine (3TC) and zidovudine (AZT) are systemic antiviral substances extensively used in human immunodeficiency virus (HIV) infected patients. Nowadays, 3TC, AZT, and several other pharmacologically potent pharmaceuticals are manufactured in the same production area. To assure quality of drug products and patient safety, properly validated cleaning methodology is necessary. A carefully designed cleaning validation and its evaluation can ensure that residues of 3TC and AZT will not carry over and cross contaminate the subsequent product. The aim of this study was to validate a simple analytical method for verification of residual 3TC and AZT in equipment used in the production area and to confirm the efficiency of the cleaning procedure. The liquid chromatography method was validated using a Nova-Pak C18 column (3.9 x 150 mm, 4 microm particle size) and methanol-water (20 + 80, v/v) as the mobile phase at a flow rate of 1.0 mL/min. Ultraviolet detection was made at 266 nm. The calibration curve was linear over a concentration range of 2.0-22.0 microg/mL with a correlation coefficient of 0.9998. The detection and quantitation limits were 0.36 and 1.21 microg/mL, respectively. The intra-day and interday precision expressed as relative standard deviation were below 2.0%. The mean recovery of the method was 99.19%. The mean extraction recovery from manufacturing equipment was 83.5%.

  8. Effects of Zidovudine Treatment on Heart mRNA Expression and Mitochondrial DNA Copy Number Associated with Alterations in Deoxynucleoside Triphosphate Composition in a Neonatal Rat Model.

    PubMed

    Snowdin, Jacob W; Hsiung, Chia-Heng; Kesterson, Daniel G; Kamath, Vasudeva G; McKee, Edward E

    2015-10-01

    The prevention of mother-to-child transmission (MTCT) of HIV is a crucial component in HIV therapy. Nucleoside reverse transcriptase inhibitors (NRTIs), primarily 3'-azido-3'-thymidine (AZT [zidovudine]), have been used to treat both mothers and neonates. While AZT is being replaced with less toxic drugs in treating mothers in MTCT prevention, it is still commonly used to treat neonates. Problems related to mitochondrial toxicity and potential mutagenesis associated with AZT treatment have been reported in treated cohorts. Yet little is known concerning the metabolism and potential toxicity of AZT on embryonic and neonatal tissues, especially considering that the enzymes of nucleoside metabolism change dramatically as many tissues convert from hyperplastic to hypertrophic growth during this period. AZT is known to inhibit thymidine phosphorylation and potentially alter deoxynucleoside triphosphate (dNTP) pools in adults. This study examines the effects of AZT on dNTP pools, mRNA expression of deoxynucleoside/deoxynucleotide metabolic enzymes, and mitochondrial DNA levels in a neonatal rat model. Results show that AZT treatment dramatically altered dNTP pools in the first 7 days of life after birth, which normalized to age-matched controls in the second and third weeks. Additionally, AZT treatment dramatically increased the mRNA levels of many enzymes involved in deoxynucleotide synthesis and mitochondrial biogenesis during the first week of life, which normalized to age-matched controls by the third week. These results were correlated with depletion of mitochondrial DNA noted in the second week. Taken together, results demonstrated that AZT treatment has a powerful effect on the deoxynucleotide synthesis pathways that may be associated with toxicity and mutagenesis.

  9. Asteroid observations with NCSFCT's AZT-8 telescope

    NASA Astrophysics Data System (ADS)

    Kozhukhov, O. M.; Maigurova, N. V.

    2017-02-01

    The asteroid observations of the small Solar System bodies were carried out with the AZT-8 telescope (D = 0.7 m, f/4) of the National Center of Space Facilities Control and Testing (NCSFCT) during 2010-2013. The telescope is located near Yevpatoria, the observatory code according IAU is B17. The observational program included perturbed main belt asteroids and NEO's for the GAIA FUN-SSO Company. The MPC database contains more than 4500 asteroids positions and magnitudes obtained during this period at AZT-8 telescope. The article presents analysis of the positional accuracy of B17 observations obtained from the comparison with the JPL HORIZONS ephemeris, and data from AstD-yS-2 and NEODyS-2 web services.

  10. Evaluation of Microemulsion and Lamellar Liquid Crystalline Systems for Transdermal Zidovudine Delivery.

    PubMed

    Carvalho, André Luis Menezes; Silva, José Alexsandro da; Lira, Ana Amélia Moreira; Conceição, Tamara Matos Freire; Nunes, Rogéria de Souza; de Albuquerque Junior, Ricardo Luiz Cavalcanti; Sarmento, Victor Hugo Vitorino; Leal, Leila Bastos; de Santana, Davi Pereira

    2016-07-01

    This study proposed to investigate and to compare colloidal carrier systems containing Zidovudine (3'-azido-3'-deoxythymidine) (AZT) for transdermal administration and optimization of antiretroviral therapy. Microemulsion (ME) and lamellar phase (LP) liquid crystal were obtained and selected from pseudoternary diagrams previously developed. Small-angle X-ray scattering and rheology analysis confirmed the presence of typical ME and liquid crystalline structures with lamellar arrangement, respectively. Both colloidal carrier systems, ME, and LP remained stable, homogeneous, and isotropic after AZT addition. In vitro permeation study (using pig ear skin) showed that the amount of permeated drug was higher for ME compared to the control and LP, obtaining a permeation enhancing effect on the order of approximately 2-fold (p < 0.05). Microscopic examination after in vivo skin irritation studies using mice suggested few histological changes in the skin of animals treated with the ME compared to the control group (hydrogel). Thus, ME proved to be adequate and have promising effects, being able to promote the drug permeation without causing apparent skin irritation. On the order hand, LP functioned as a drug reservoir reducing AZT partitioning into the skin.

  11. Neurotoxic effects of AZT on developing and adult neurogenesis

    PubMed Central

    Demir, Meryem; Laywell, Eric D.

    2015-01-01

    Azidothymidine (AZT) is a synthetic, chain-terminating nucleoside analog used to treat HIV-1 infection. While AZT is not actively transported across the blood brain barrier, it does accumulate at high levels in cerebrospinal fluid, and subsequently diffuses into the overlying parenchyma. Due to the close anatomical proximity of the neurogenic niches to the ventricular system, we hypothesize that diffusion from CSF exposes neural stem/progenitor cells and their progeny to biologically relevant levels of AZT sufficient to perturb normal cell functions. We employed in vitro and in vivo models of mouse neurogenesis in order to assess the effects of AZT on developing and adult neurogenesis. Using in vitro assays we show that AZT reduces the population expansion potential of neural stem/progenitor cells by inducing senescence. Additionally, in a model of in vitro neurogenesis AZT severely attenuates neuroblast production. These effects are mirrored in vivo by clinically-relevant animal models. We show that in utero AZT exposure perturbs both population expansion and neurogenesis among neural stem/progenitor cells. Additionally, a short-term AZT regimen in adult mice suppresses subependymal zone neurogenesis. These data reveal novel negative effects of AZT on neural stem cell biology. Given that the sequelae of HIV infection often include neurologic deficits—subsumed under AIDS Dementia Complex (Brew, 1999)—it is important to determine to what extent AZT negatively affects neurological function in ways that contribute to, or exacerbate, ADC in order to avoid attributing iatrogenic drug effects to the underlying disease process, and thereby skewing the risk/benefit analysis of AZT therapy. PMID:25852464

  12. [Rapid development of anemia in a HIV-positive patient with alpha-thalassemia after zidovudine therapy].

    PubMed

    Altinbaş, Akif; Ozkaya, Gülşen; Büyükaşik, Yahya; Unal, Serhat

    2007-07-01

    Anemia, which may develop due to direct effect of the virus or indirect effect of zidovudine a widely used antiviral agent for the treatment, is not an uncommon complication in human immundeficiency virus (HIV) infections. In this report, a 26 years old male HIV positive patient who developed rapid anemia in the HAART (Highly active anti-retroviral therapy) protocol including zidovudine, was presented. The patient has been followed since May 2003 without anti-retroviral therapy. He was diagnosed as alpha-thalassemia trait, because of the low mean red blood cell volume (MCV), high red blood cell count and living in an Mediterranian country. However, no treatment for thalassemia had been given in this period, since the other laboratory findings [hemoglobin, hematocrit, red cell distribution width index (RDWI), iron and iron binding capacity, transferrin saturation and ferritin levels] were normal. During the follow-up of patient, HAART protocol with zidovudine, lamivudine and indinavir, was started depending on the findings of low CD4+ T-cell count (443/mm3) and high HIV serum load (1,330,000 copies/ml). In the second month of the therapy the hemoglobin level decreased to 12.9 gr/dL, and then to 9.9 gr/dL in the fourth month, while it was 14.5 gr/dL before anti-retroviral therapy. Although the patient had no hemolysis findings, and his serum folic acid level was normal, folbiol treatment was initiated with the possibility of the presence of folic acid deficiency at cellular level. Anemia resolved with folic acid replacement without discontinuation of zidovudine or a reduction in dosage. It was thought that the presence of alpha-thalassemia co-morbidity has facilitated the development of anti-retroviral-induced anemia in this patient. As a result, it is concluded that thalassemia should be considered in the differential diagnosis of anemia in HIV positive patients, especially for the ones from Mediterranian countries.

  13. Metabolism and pharmacokinetics of the combination Zidovudine plus Lamivudine in the adult Erythrocebus patas monkey determined by liquid chromatography-tandem mass spectrometric analysis

    SciTech Connect

    Divi, Rao L.; Doerge, Daniel R.; Twaddle, Nathan C.; Shockley, Marie E.; St Claire, Marisa C.; Harbaugh, Jeffrey W.; Harbaugh, Steven W.; Poirier, Miriam C.

    2008-01-15

    Because of their similarity to humans, non-human primates constitute useful preclinical models in which to examine potential human drug toxicities. Antiretroviral nucleoside reverse transcriptase inhibitor (NRTI) toxicity is currently under investigation in Erythrocebus patas monkeys, and whereas NRTI pharmacokinetics have been studied in other monkey species, pharmacokinetics for Zidovudine plus Lamivudine (AZT/3TC) dosing have not been reported in the patas. Here we present 24 h serum pharmacokinetic parameters after a single oral exposure to the combination of AZT (40 mg) and 3TC (24 mg), doses equivalent to a human daily dose of Combivir (registered) . The patas (n = 3) AZT/3TC pharmacokinetic profiles were similar to those seen in other primate species. Average maximum serum concentrations (C{sub max}) for AZT and 3TC were 2.35 and 2.65 {mu}g/ml, respectively, and were observed at 0.83 h (T{sub max}). C{sub max} was 13.34 {mu}g/ml for the AZT-glucuronide (AZT-G) and was 0.023 {mu}g/ml for the potentially toxic minor metabolite 3'-amino-3'-deoxythymidine (AMT), both occurring at about 1 h after dosing. Similar elimination half-times, 0.70 and 0.68 h{sup -1}, were found for AZT and AZT-G, respectively, while 3TC was eliminated about half as fast (0.33 h{sup -1}) resulting in AUC{sub (0-{infinity})} values of 6.97 {mu}g/ml h for 3TC, 2.99 {mu}g/ml h for AZT, 20.5 {mu}g/ml h for AZT-G and 0.002 for AMT 6.97 {mu}g/ml h. This study shows similar metabolism and pharmacokinetics for oral administration of AZT/3TC in the adult patas monkey, other primate species and humans. The data validate the use of the patas monkey for studies of NRTI toxicity.

  14. Warfarin is an effective modifier of multiple UDP-glucuronosyltransferase enzymes: evaluation of its potential to alter the pharmacokinetics of zidovudine.

    PubMed

    Sun, Hua; Zhang, Tianpeng; Wu, Zhufeng; Wu, Baojian

    2015-01-01

    In this study, we aimed to determine the modulatory effects of warfarin (an extensively used anticoagulant drug) and its metabolites on UDP-glucuronosyltransferase (UGT) activity and to assess the potential of warfarin to alter the pharmacokinetics of zidovudine (AZT). The effects of warfarin and its metabolites on glucuronidation were determined using human and rat liver microsomes (HLM and RLM) as well as expressed UGTs. The mechanisms of warfarin-UGT interactions were explored through kinetic characterization and modeling. Pharmacokinetic studies with rats were performed to evaluate the potential of warfarin to alter the pharmacokinetics of AZT. We found that warfarin was an effective modifier of a panel of UGT enzymes. The effects of warfarin on glucuronidation were inhibitory for UGT1A1, 2B7, and 2B17, but activating for UGT1A3. Mixed effects were observed for UGT1A7 and 1A9. Consistent with its inhibitory effects on UGT2B7 activity, warfarin inhibited AZT glucuronidation in HLM (Ki = 74.9-96.3 μM) and RLM (Ki = 190-230 μM). Inhibition of AZT glucuronidation by UGT2B7, HLM, and RLM was also observed with several hydroxylated metabolites of warfarin. Moreover, the systemic exposure (AUC) of AZT in rats was increased by a 1.5- to 2.1-fold upon warfarin coadministration. The elevated AUC was associated with suppressed glucuronidation that was probably attained through a combined action of warfarin and its hydroxylated metabolites. In conclusion, the activities of multiple UGT enzymes can be modulated by warfarin and the nature of modulation was isoform dependent. Also, pharmacokinetic interactions of zidovudine with warfarin were highly possible through inhibition of UGT metabolism.

  15. Short-course AZT reduces HIV transmission to infants; Glaxo cuts AZT price for developing countries.

    PubMed

    Baker, R

    1998-04-01

    A four-week AZT treatment recently tested by the Centers for Disease Control and Prevention (CDC) and health officials in Thailand revealed reductions in mother-to-infant transmission by 50 percent. The treatment offers hope to HIV-positive pregnant women in developing countries who do not have access to the full-course treatment common in the United States. Critics have charged that the study was unethical because some women were given placebos. The manufacturer, Glaxo Wellcome, is dropping AZT prices by 75 percent. The drug treatment and testing will cost about $100, instead of the $800 to $1,000 that the full treatment costs. Even with the price break, many feel that developed countries will need to heavily subsidize the programs to reduce the number of infant infections, now estimated at 550,000 per year.

  16. Human Serum Albumin Complexed with Myristate and AZT

    SciTech Connect

    Zhu, Lili; Yang, Feng; Chen, Liqing; Meehan, Edward J.; Huang, Mingdong

    2008-06-16

    3'-Azido-3'-deoxythymidine (AZT) is the first clinically effective drug for the treatment of human immunodeficiency virus infection. The drug interaction with human serum albumin (HSA) has been an important component in understanding its mechanism of action, especially in drug distribution and in drug-drug interaction on HSA in the case of multi-drug therapy. We present here crystal structures of a ternary HSA-Myr-AZT complex and a quaternary HSA-Myr-AZT-SAL complex (Myr, myristate; SAL, salicylic acid). From this study, a new drug binding subsite on HSA Sudlow site 1 was identified. The presence of fatty acid is needed for the creation of this subsite due to fatty acid induced conformational changes of HSA. Thus, the Sudlow site 1 of HSA can be divided into three non-overlapped subsites: a SAL subsite, an indomethacin subsite and an AZT subsite. Binding of a drug to HSA often influences simultaneous binding of other drugs. From the HSA-Myr-AZT-SAL complex structure, we observed the coexistence of two drugs (AZT and SAL) in Sudlow site 1 and the competition between these two drugs in subdomain IB. These results provide new structural information on HSA-drug interaction and drug-drug interaction on HSA.

  17. Analysis of the Zidovudine Resistance Mutations T215Y, M41L, and L210W in HIV-1 Reverse Transcriptase.

    PubMed

    Boyer, Paul L; Das, Kalyan; Arnold, Eddy; Hughes, Stephen H

    2015-12-01

    Although anti-human immunodeficiency virus type 1 (HIV-1) therapies have become more sophisticated and more effective, drug resistance continues to be a major problem. Zidovudine (azidothymidine; AZT) was the first nucleoside reverse transcriptase (RT) inhibitor (NRTI) approved for the treatment of HIV-1 infections and is still being used, particularly in the developing world. This drug targets the conversion of single-stranded RNA to double-stranded DNA by HIV-1 RT. However, resistance to the drug quickly appeared both in viruses replicating in cells in culture and in patients undergoing AZT monotherapy. The primary resistance pathway selects for mutations of T215 that change the threonine to either a tyrosine or a phenylalanine (T215Y/F); this resistance pathway involves an ATP-dependent excision mechanism. The pseudo-sugar ring of AZT lacks a 3' OH; RT incorporates AZT monophosphate (AZTMP), which blocks the end of the viral DNA primer. AZT-resistant forms of HIV-1 RT use ATP in an excision reaction to unblock the 3' end of the primer strand, allowing its extension by RT. The T215Y AZT resistance mutation is often accompanied by two other mutations, M41L and L210W. In this study, the roles of these mutations, in combination with T215Y, were examined to determine whether they affect polymerization and excision by HIV-1 RT. The M41L mutation appears to help restore the DNA polymerization activity of RT containing the T215Y mutation and also enhances AZTMP excision. The L210W mutation plays a similar role, but it enhances excision by RTs that carry the T215Y mutation when ATP is present at a low concentration.

  18. Influence of 3-aminobenzamide, an inhibitor of poly(ADP-ribose)polymerase, in the evaluation of the genotoxicity of doxorubicin, cyclophosphamide and zidovudine in female mice.

    PubMed

    Yadav, L; Khan, S; Shekh, K; Jena, G B

    2014-08-01

    Testing new chemical entities for genotoxicity is an integral part of the preclinical drug-development process. Lowering the detection limit and enhancing the sensitivity of genotoxicity assays is required, as the standard test-battery fails to detect some carcinogens (non-genotoxic) and weak genotoxins. One of the mechanisms that affect the detection of weak genotoxins is related with the DNA-repair efficiency of the cell system used. In the present study, 3-aminobenzamide (3-AB, 30 mg/kg body-weight), a poly(ADP-ribose)polymerase inhibitor, was used to evaluate the DNA-damaging potential of zidovudine (AZT, 400 mg/kg bw), doxorubicin (DOX, 5 mg/kg bw) and cyclophosphamide (CP, 50 mg/kg bw, as a positive control) and sucrose (SUC, 3 g/kg bw, as a negative control) in Swiss female mice. The endpoints considered included micronucleus formation, DNA breakage (in peripheral blood lymphocytes, bone marrow and liver; comet assay) and chromosome aberrations, as well as immunohistochemistry of PARP-1 and phosphorylated histone H2AX (γ-H2AX). The results clearly indicate that the genotoxicity of zidovudine (AZT), doxorubicin (DOX) and cyclophosphamide (CP) was significantly increased in the combination treatments (3-AB+AZT, 3-AB+DOX, 3-AB+CP) as compared with the respective controls (treatment with AZT, DOX and CP alone). There was no increase in the genotoxicity per se after treatment with SUC, 3-AB or 3-AB+SUC, compared with the control (saline). Correlation analysis suggests that all genotoxicity parameters are well correlated with each other. The results clearly show that the genotoxicity of weak genotoxins can be enhanced and detected in the presence of 3-AB in mice. Thus, this approach can be used in the pre-clinical genotoxicity screening of weak genotoxins.

  19. Retroviral DNA Integration

    PubMed Central

    2016-01-01

    The integration of a DNA copy of the viral RNA genome into host chromatin is the defining step of retroviral replication. This enzymatic process is catalyzed by the virus-encoded integrase protein, which is conserved among retroviruses and LTR-retrotransposons. Retroviral integration proceeds via two integrase activities: 3′-processing of the viral DNA ends, followed by the strand transfer of the processed ends into host cell chromosomal DNA. Herein we review the molecular mechanism of retroviral DNA integration, with an emphasis on reaction chemistries and architectures of the nucleoprotein complexes involved. We additionally discuss the latest advances on anti-integrase drug development for the treatment of AIDS and the utility of integrating retroviral vectors in gene therapy applications. PMID:27198982

  20. Reverse transcriptase sequence of paired isolates of cerebrospinal fluid and blood from patients infected with human immunodeficiency virus type 1 during zidovudine treatment.

    PubMed Central

    Di Stefano, M; Sabri, F; Leitner, T; Svennerholm, B; Hagberg, L; Norkrans, G; Chiodi, F

    1995-01-01

    Human immunodeficiency virus type 1 (HIV-1) isolates obtained from the blood of patients undergoing treatment with 3'-azido-3'-deoxythymidine (zidovudine [AZT]) show a decreased sensitivity to the drug in vitro. The aim of the present study was to determine if HIV-1 variants resistant to AZT are present also in the brain compartment. We selected sequential HIV-1 isolates from the blood and the cerebrospinal fluid (CSF) of six patients with HIV-1 infection undergoing AZT therapy for a time varying between 1 and 3 years. The isolates were used to infect peripheral blood mononuclear cell cultures which were used to prepare viral DNA. The viral DNA was amplified by PCR and then directly sequenced. Analysis of the reverse transcriptase (RT) sequence of the isolates from the CSF during therapy demonstrated that CSF-resistant isolates are characterized by the same mutations documented in resistant isolates from the blood compartment. Isolates obtained from one patient (patient 3) showed the same two mutations (codons 70 and 215) in blood and CSF, whereas isolates obtained from an additional four patients presented a different pattern of mutations in the two compartments. We also analyzed the degree of amino acid homology between RT sequences from blood and CSF isolates in patients before and during AZT treatment. The percentages of amino acid variations were approximately equal when isolates from the same or different compartments were considered. Excluding the codons involved in AZT resistance, the time point of sampling did not affect RT variations during therapy significantly.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7536214

  1. Studies on transdermal delivery enhancement of zidovudine.

    PubMed

    Takmaz, Evrim Atilay; Inal, Ozge; Baykara, Tamer

    2009-01-01

    The purpose of this study was to investigate physicochemical characteristics and in vitro release of zidovudine from monolithic film of Eudragit RL 100 and ethyl cellulose. Films included 2.5% or 5% (w/w) zidovudine of the dry polymer weight were prepared in various ratios of polymers by solvent evaporation method from methanol/acetone solvent mixture. The release studies were carried out by vertical Franz cells (2.2 cm(2) area, 20 ml receptor fluid). Ex vivo studies were done on Wistar rat skin within the films F6 (Eudragit RL100) and F7 (Eudragit RL100/Ethylcellulose, 1:1) consisting 5% (w/w) zidovudine in comparison with the same amount of free drug. Either iontophoresis (0.1 and 0.5 mA/cm(2) direct currents, Ag/AgCl electrodes) or dimethyl sulfoxide (pretreatment of 1% and 5%, w/w, solutions) were used as enhancers. Films consisting of ethyl cellulose under the ratio of 50% (w/w) gave similar release profiles, and the highest in vitro cumulative released amount was achieved with F6 film which gave the closest results with the free drug. This result could be due to the high swelling capacity and re-crystallization inhibition effect of RL 100 polymer which also influenced the film homogenization. All the films were fitted to Higuchi release kinetics. It was also observed that both 0.5-mA/cm(2) current and 5% (w/w) dimethyl sulfoxide applications significantly increased the cumulative permeated amount of zidovudine after 8 h; however, the flux enhancement ratio was higher for 0.5-mA/cm(2) current application, especially within F6 film. Thus, it was concluded that Eudragit RL100 film (F6) could be further evaluated for the transdermal application of zidovudine.

  2. Development and validation of a RP-HPLC method for the determination of zidovudine and its related substances in sustained-release tablets.

    PubMed

    dos Santos, Jucimary V; de Carvalho, Luís A E Batista; Pina, M Eugénia

    2011-01-01

    A reversed-phase high-performance liquid chromatography (RP-HPLC) method for the rapid and accurate quantification of zidovudine (AZT) in sustained release tablets during stability testing was developed. A Waters RP-18 XTerra™(®) column, using a water:methanol (80:20, v/v%) mobile phase at a flow rate of 1.0 ml min(-1), and UV detection at 266 nm, was employed. The method of validation parameters indicate a linear range of between 40.0 to 220.0 µg ml(-1) with an LOQ of 1.985 µg ml(-1) and an LOD of 0.655 µg ml(-1) for the analyte. The degradation products of AZT were isolated and characterized for the first time. There was a very little decline of antiviral by heat, and AZT did not completely degrade either by acid or alkaline hydrolysis. On the other hand, oxidation caused a higher degradation stress in the drug. Finally, the degradation products resulting from stress studies were not found to interfere with the detection of antiviral, which is an advantage of the presently proposed method.

  3. Zidovudine as modern day salvage therapy for HIV infection.

    PubMed

    Kupiec, Katherine E; Johnson, James W; Barroso, Luis F; Wrenn, Rebekah H; Williamson, John C

    2014-11-01

    Resistance to the first-line NRTIs, tenofovir and emtricitabine, does not generally confer resistance to zidovudine. The objective of this study was to describe the efficacy of zidovudine as modern day salvage antiretroviral therapy. This was a single-center, retrospective, observational, cohort study. Adult HIV-positive patients prescribed a zidovudine-containing regimen between 2005 and 2010 were identified from a computer database. All patients had failed at least one prior antiretroviral regimen before zidovudine. The primary outcome measure was virologic success at 24 weeks. Other efficacy and safety outcomes were determined, including virologic success at 48 and 96 weeks, CD4 count change from baseline, and incidence of adverse effects. Sixty-nine subjects were enrolled. The mean age was 43 years, 70% were male, and 85.5% were black. Most patients were highly antiretroviral experienced. At 24 weeks, 63.8% and 72.5% of patients achieved HIV RNA less than 50 and 400 c/mL, respectively. The median change in CD4 count from baseline to week 24 was +70 cells/mm(3). The percent of patients who discontinued zidovudine due to adverse effects was 10%. In this highly treatment-experienced population, zidovudine as part of a salvage regimen appeared effective. Gastrointestinal adverse effects were reported, but zidovudine-associated metabolic effects were uncommon, suggesting zidovudine was generally well tolerated.

  4. Kinetic modeling of the interactions between 4-methylumbelliferone, 1-naphthol, and zidovudine glucuronidation by udp-glucuronosyltransferase 2B7 (UGT2B7) provides evidence for multiple substrate binding and effector sites.

    PubMed

    Uchaipichat, Verawan; Galetin, Aleksandra; Houston, J Brian; Mackenzie, Peter I; Williams, J Andrew; Miners, John O

    2008-10-01

    Interactions between the UGT2B7-catalyzed glucuronidation of zidovudine (AZT), 4-methylumbelliferone (4MU), and 1-naphthol (1NP) were analyzed using multisite and empirical kinetic models to explore the existence of multiple substrate and effector binding sites within this important drug metabolizing enzyme. 4MU and 1NP glucuronidation by UGT2B7 exhibit sigmoidal kinetics characteristic of homotropic cooperativity (autoactivation), which may be modeled assuming the existence of two equivalent, interacting substrate binding sites. In contrast, UGT2B7-catalyzed AZT glucuronidation follows hyperbolic (Michaelis-Menten) kinetics. Although 4MU and 1NP decreased the binding affinity of AZT, the kinetics of AZT glucuronidation changed from hyperbolic to sigmoidal in the presence of both modifiers. Data were well described by a generic two-substrate binding site model in which there is no interaction between the sites in the absence of 4MU or 1NP, but heterotropic cooperativity results from the binding of modifier. Inhibition of 4MU and 1NP glucuronidation by AZT and interactions between 4MU and 1NP required more complex three-site models, where the modifier acts via a distinct effector site to alter either substrate binding affinity or Vmax without affecting the homotropic cooperativity characteristic of 4MU and 1NP glucuronidation. It is noteworthy that 1NP inhibited 4MU glucuronidation, whereas 4MU activated 1NP glucuronidation. The results are consistent with the existence of two "catalytic" sites for each substrate within the UGT2B7 active site, along with multiple effector sites. The multiplicity of binding and effector sites results in complex kinetic interactions between UGT2B7 substrates, which potentially complicates inhibition screening studies.

  5. Glaxo's AZT announcement welcomed, but detail is yet to follow. mother-to-child transmission.

    PubMed

    Worthington, H

    1998-04-01

    Following recently completed trials of AZT in Thailand among pregnant women which showed that a short course of AZT can significantly reduce the mother-to-child transmission of HIV, Glaxo Wellcome recently announced that it will supply the antiretroviral drug AZT at a preferential price for pregnant women infected with HIV in developing countries. Since the size of the HIV/AIDS epidemic and the quantity of AZT needed cannot be predicted, Glaxo Wellcome has stated that it is unfeasible to implement a mass donation program of the drug. The preferential public sector pricing was instead arrived at after 3 years of discussions and collaboration with UNAIDS, governments, and nongovernmental organizations (NGOs). Glaxo and UNAIDS both agree that the pricing will be a price reduction and not a subsidy, but additional details remain unclear. Eligible countries will be defined according to World Health Organization guidelines, with UNICEF likely to play a key role in the AZT's distribution.

  6. Retroviral integration: Site matters

    PubMed Central

    Demeulemeester, Jonas; De Rijck, Jan

    2015-01-01

    Here, we review genomic target site selection during retroviral integration as a multistep process in which specific biases are introduced at each level. The first asymmetries are introduced when the virus takes a specific route into the nucleus. Next, by co‐opting distinct host cofactors, the integration machinery is guided to particular chromatin contexts. As the viral integrase captures a local target nucleosome, specific contacts introduce fine‐grained biases in the integration site distribution. In vivo, the established population of proviruses is subject to both positive and negative selection, thereby continuously reshaping the integration site distribution. By affecting stochastic proviral expression as well as the mutagenic potential of the virus, integration site choice may be an inherent part of the evolutionary strategies used by different retroviruses to maximise reproductive success. PMID:26293289

  7. AZT trials pose difficult breast-feeding dilemma.

    PubMed

    1998-02-01

    International AIDS experts and HIV infected women in Africa may soon face an impossible dilemma if short-term AZT treatment prevents perinatal transmission. HIV-infected mothers may not be able to afford infant formula or may not have access to safe water to mix with the formula, and may expose the child to HIV again through breast feeding. Few studies have addressed the breast feeding issue, although a controversial placebo-controlled study is underway in Nairobi. Pediatricians have promoted breast feeding as the preferred means to feed infants, and in many cases, mothers do not have other viable choices. Women who cannot afford formula may be forced to expose their children to HIV.

  8. Biphotonic reactions of a dihydropyridine derivative of AZT related to AIDS dementia

    NASA Astrophysics Data System (ADS)

    Lindqvist, L.; Czochralska, B.; Kawczynski, W.

    1993-06-01

    It was shown that exposure of the AZT derivative 5'-(1,4-dihydro-1-methyl-3- pyridinyl-carbonyl)-3'-azido-2', 3'-dideoxythymidine) (H2PyrAZT) in aqueous solution to pulsed laser emission ((lambda) equals 355 nm, pulse length 2 ns) gives rise to photoelectron ejection by stepwise two-photon absorption. Absorption spectra of the semioxidized radicals obtained in this reaction were determined. It was shown that the photolysis did not affect the azido group.

  9. Targeting retroviral and lentiviral vectors.

    PubMed

    Sandrin, V; Russell, S J; Cosset, F L

    2003-01-01

    Retroviral vectors capable of efficient in vivo gene delivery to specific target cell types or to specific locations of disease pathology would greatly facilitate many gene therapy applications. The surface glycoproteins of membrane-enveloped viruses stand among the choice candidates to control the target cell receptor recognition and host range of retroviral vectors onto which they are incorporated. This can be achieved in many ways, such as the exchange of glycoprotein by pseudotyping, their biochemical modifications, their conjugation with virus-cell bridging agents or their structural modifications. Understanding the fundamental properties of the viral glycoproteins and the molecular mechanism of virus entry into cells has been instrumental in the functional alteration of their tropism. Here we briefly review the current state of our understanding of the structure and function of viral envelope glycoproteins and we discuss the emerging targeting strategies based on retroviral and lentiviral vector systems.

  10. Retroviral superinfection resistance

    PubMed Central

    Nethe, Micha; Berkhout, Ben; van der Kuyl, Antoinette C

    2005-01-01

    The retroviral phenomenon of superinfection resistance (SIR) defines an interference mechanism that is established after primary infection, preventing the infected cell from being superinfected by a similar type of virus. This review describes our present understanding of the underlying mechanisms of SIR established by three characteristic retroviruses: Murine Leukaemia Virus (MuLV), Foamy Virus (FV), and Human Immunodeficiency Virus (HIV). In addition, SIR is discussed with respect to HIV superinfection of humans. MuLV resistant mice exhibit two genetic resistance traits related to SIR. The cellular Fv4 gene expresses an Env related protein that establishes resistance against MuLV infection. Another mouse gene (Fv1) mediates MuLV resistance by expression of a sequence that is distantly related to Gag and that blocks the viral infection after the reverse transcription step. FVs induce two distinct mechanisms of superinfection resistance. First, expression of the Env protein results in SIR, probably by occupancy of the cellular receptors for FV entry. Second, an increase in the concentration of the viral Bet (Between-env-and-LTR-1-and-2) protein reduces proviral FV gene expression by inhibition of the transcriptional activator protein Tas (Transactivator of spumaviruses). In contrast to SIR in FV and MuLV infection, the underlying mechanism of SIR in HIV-infected cells is poorly understood. CD4 receptor down-modulation, a major characteristic of HIV-infected cells, has been proposed to be the main mechanism of SIR against HIV, but data have been contradictory. Several recent studies report the occurrence of HIV superinfection in humans; an event associated with the generation of recombinant HIV strains and possibly with increased disease progression. The role of SIR in protecting patients from HIV superinfection has not been studied so far. The phenomenon of SIR may also be important in the protection of primates that are vaccinated with live attenuated simian

  11. Determination of liposome permeability of ionizable carbamates of zidovudine by steady state fluorescence spectroscopy.

    PubMed

    Raviolo, Mónica A; Sanchez, Julieta M; Briñón, Margarita C; Perillo, María A

    2008-02-15

    In the present paper the relative permeabilities of AZT-Pyp and AZT-Ethy across a phospholipid bilayer were estimated by the means of fluorescence spectroscopy. The center of spectral mass of both non-encapsulated AZT-derivatives (AZT-der) emission spectra increased as a function of the illumination time inside the spectrofluorimeter cell. This phenomenon was even more evident when drugs were incubated under an UV mercury lamp, suggesting its photolytic origin. AZT-der were protected from photolysis inside liposomes and decomposed upon irradiation when they were free in the aqueous phase. The time-dependent decrease in the fluorescence intensity at a constant wavelength was fitted to a two-exponential equation and the values of rate constants for permeability and photolysis were calculated. It was concluded that AZT-Pyp but not AZT-Ethy diffused across the bilayer. This behavior correlated with the molecular volumes of AZT-Pyp (379.6A(3)) and AZT-Ethy (450.5A(3)), determined from the minimum energy conformations but not with previously reported logP values. These results reinforce the concept that not only lipophilicity but also membrane structure and AZT-der molecular size had a critical influence in passive diffusion across bilayers and may help in future refinements of other AZT-der molecular design.

  12. Retroviral infections of small animals.

    PubMed

    Dunham, Stephen P; Graham, Elizabeth

    2008-07-01

    Retroviral infections are particularly important in cats, which are commonly infected with feline leukemia virus and feline immunodeficiency virus. This article describes the biology of these viruses and explores current issues regarding vaccination and diagnosis. The seeming lack of a recognized retrovirus infection in dogs is speculated on, and current and potential future therapies are discussed.

  13. RETROVIRAL INTEGRASE: THEN AND NOW

    PubMed Central

    Andrake, Mark D.; Skalka, Anna Marie

    2016-01-01

    The retroviral integrases are virally encoded, specialized recombinases that catalyze the insertion of viral DNA into the host cell’s DNA, a process that is essential for virus propagation. We have learned a great deal since the existence of an integrated form of retroviral DNA (the provirus) was first proposed by Howard Temin in 1964. Initial studies focused on the genetics and biochemistry of avian and murine virus DNA integration, but the pace of discovery increased substantially with advances in technology, and an influx of investigators focused on the human immunodeficiency virus (HIV). We begin with a brief account of the scientific landscape in which some of the earliest discoveries were made, and summarize research that led to our current understanding of the biochemistry of integration. A more detailed account of recent analyses of integrase structure follows, as they have provided valuable insights into enzyme function and raised important new questions. PMID:26958915

  14. The selective in vitro cytotoxicity of carcinoma cells by AZT is enhanced by concurrent treatment with delocalized lipophilic cations.

    PubMed

    Modica-Napolitano, Josephine S; Nalbandian, Raffi; Kidd, Marianne E; Nalbandian, Angele; Nguyen, Chilinh C

    2003-07-30

    This study assessed the selective growth inhibitory effect on cultured carcinoma cells by 3'-azido-3'-deoxythymidine (AZT), as a single agent, and in combination with delocalized lipophilic cations (DLCs) that are known to inhibit mitochondrial function. In cytotoxicity assays, treatment of cells with varying concentrations of AZT induced a dose-dependent inhibition of cell growth of the human carcinoma lines DU-145 (prostate; IC50 at 24 microM), MCF-7 (breast; IC50 at 22 microM), and CX-1 (colon; IC50 at 23 microM), yet caused no significant effect on the growth of the control epithelial cell line CV-1 (monkey kidney) at a concentration as high as 50 microM AZT. Combination treatment employing a constant concentration (1.25 microM) of the DLC dequalinium chloride (DECA) plus varying concentrations of AZT (0-50 microM) enhanced the AZT-induced cytotoxicity of carcinoma cells at least fourfold for MCF-7 and CX-1 cells (IC50 at 5 microM AZT), and twofold for DU-145 cells (IC50 at 11 microM AZT). Similar results were obtained in DU-145 cells using a constant concentration of the DLC MKT-077 (1.0 microM) and varying concentrations of AZT (IC50 at 12.5 microM). As expected, the drug combination of constant DLC and varying AZT had no significant effect on the growth of CV-1 cells. Clonogenic assays demonstrated up to 20-fold enhancement of selective carcinoma cell killing by combination vs. single agent treatment, depending on the specific drug combination and concentrations used. It is hypothesized that the efficacy of the AZT/DLC drug combination in carcinoma cell killing may be based on a dual selectivity involving inhibition of mitochondrial energy metabolism and inhibition of DNA synthesis due to limited deoxythymidine monophosphate availability.

  15. Protective cellular retroviral immunity requires both CD4+ and CD8+ immune T cells.

    PubMed Central

    Hom, R C; Finberg, R W; Mullaney, S; Ruprecht, R M

    1991-01-01

    We have found previously that postexposure chemoprophylaxis with 3'-azido-3'-deoxythymidine (also known as zidovudine or AZT) in combination with recombinant human alpha A/D interferon fully protected mice exposed to a lethal dose of Rauscher murine leukemia virus (RLV) against viremia and disease. After cessation of therapy, over 90% of these mice were able to resist rechallenge with live RLV, thus demonstrating an acquired immunity. Adoptive cell transfer of 4 x 10(7) cells from immunized mice fully protected naive recipients from viremia and splenomegaly after RLV challenge. However, when these immune T cells were fractionated into CD4+ and CD8+ subpopulations, only partial protection was found when 4 x 10(7) T cells of either subset were given. Full protection against RLV challenge was seen again when the T-cell subsets from immunized mice were recombined and transferred at the same number into naive mice. We conclude that cellular immunity alone is protective and that both CD4+ and CD8+ cell types are required for conferring full protection against live virus challenge. Images PMID:1898666

  16. A model for the immune system response to HIV: AZT treatment studies

    SciTech Connect

    Kirschner, D.E. . Dept. of Mathematics); Perelson, A.S. )

    1993-01-01

    We use mathematical models to describe the interaction of the immune system with the human immunodeficiency virus (HIV). Our model includes T-lymphocytes and macrophages, cells which can be infected with the virus. Using our model we compare the efficacy of AZT treatments given at different stages of disease progression in order to predict when treatment should be initiated.

  17. A model for the immune system response to HIV: AZT treatment studies

    SciTech Connect

    Kirschner, D.E.; Perelson, A.S.

    1993-05-01

    We use mathematical models to describe the interaction of the immune system with the human immunodeficiency virus (HIV). Our model includes T-lymphocytes and macrophages, cells which can be infected with the virus. Using our model we compare the efficacy of AZT treatments given at different stages of disease progression in order to predict when treatment should be initiated.

  18. Efficient syntheses of [¹¹C]zidovudine and its analogs by convenient one-pot palladium(0)-copper(I) co-mediated rapid C-[¹¹C]methylation.

    PubMed

    Zhang, Zhouen; Doi, Hisashi; Koyama, Hiroko; Watanabe, Yasuyoshi; Suzuki, Masaaki

    2014-06-30

    The nucleosides zidovudine (AZT), stavudine (d4T), and telbivudine (LdT) are approved for use in the treatment of human immunodeficiency virus (HIV) and hepatitis B virus (HBV) infections. To promote positron emission tomography (PET) imaging studies on their pharmacokinetics, pharmacodynamics, and applications in cancer diagnosis, a convenient one-pot method for Pd(0)-Cu(I) co-mediated rapid C-C coupling of [(11)C]methyl iodide with stannyl precursor was successfully established and applied to synthesize the PET tracers [(11)C]zidovudine, [(11)C]stavudine, and [(11)C]telbivudine. After HPLC purification and radiopharmaceutical formulation, the desired PET tracers were obtained with high radioactivity (6.4-7.0 GBq) and specific radioactivity (74-147 GBq/µmol) and with high chemical (>99%) and radiochemical (>99.5%) purities. This one-pot Pd(0)-Cu(I) co-mediated rapid C-[(11)C]methylation also worked well for syntheses of [methyl-(11)C]thymidine and [methyl-(11)C]4'-thiothymidine, resulting twice the radioactivity of those prepared by a previous two-pot method. The mechanism of one-pot Pd(0)-Cu(I) co-mediated rapid C-[(11)C]methylation was also discussed.

  19. Retroviral Oncogenes: A Historical Primer

    PubMed Central

    Vogt, Peter K.

    2012-01-01

    Retroviruses are the original source of oncogenes. The discovery and characterization of these genes were made possible by the introduction of quantitative cell biological and molecular techniques for the study of tumor viruses. Key features of all retroviral oncogenes were first identified in src, the oncogene of Rous sarcoma virus. These include non-involvement in viral replication, coding for a single protein, and cellular origin. The myc, ras and erbB oncogenes quickly followed src, and these together with pi3k are now recognized as critical driving forces in human cancer. PMID:22898541

  20. Pharmacokinetics of saquinavir, zidovudine, and zalcitabine in combination therapy.

    PubMed Central

    Vanhove, G F; Kastrissios, H; Gries, J M; Verotta, D; Park, K; Collier, A C; Squires, K; Sheiner, L B; Blaschke, T F

    1997-01-01

    We investigated the pharmacokinetics of zidovudine, zalcitabine, and saquinavir in AIDS Clinical Trial Group protocol 229. Patients received either saquinavir, zalcitabine, or a combination of both, together with zidovudine three times a day. Approximately 100 patients were enrolled in each treatment arm, and intensive pharmacokinetic studies were performed on about 25 patients per arm at weeks 1 and 12. We estimated the pharmacokinetic parameters of all three drugs by using parametric and nonparametric methods. The mean values of the pharmacokinetic parameters of zidovudine (clearance [CL]/bioavailability [F], 168 liters/h; volume of distribution [V]/F, 185 liters; half-life, 0.76 h) and zalcitabine (CL/F, 25 liters/h; V/F, 92.2 liters; half-life, 2.7 h) were similar to those reported previously. For saquinavir, the mean pharmacokinetic parameter estimates using parametric methods were as follows: maximum concentration of drug in serum [Cmax], 70.8 ng/ml; time to Cmax, 3.11 h; area under the curve, 809 ng x h/ml; CL/F, 989 liters/h; V/F, 1,503 liters; half-life, 1.38 h. For all three drugs, clearance decreased with age. Weight did not influence the clearance of zidovudine, but the clearance of zalcitabine and saquinavir increased with weight. There were no differences in pharmacokinetic parameters between study weeks and arms, suggesting that there is no change in kinetics with chronic administration and that there are no significant pharmacokinetic interactions among these three drugs. PMID:9371345

  1. Risk of HIV dementia and opportunistic brain disease in AIDS and zidovudine therapy

    PubMed Central

    Baldeweg, T.; Catalan, J.; Gazzard, B.

    1998-01-01

    OBJECTIVE—To determine the incidence of HIV dementia and opportunistic brain disease in AIDS relative to the use of licensed antiretoviral medication (zidovudine, zalcitabine, didanosine, and stavudine).
METHOD—Medical records were evaluated retrospectively in a longitudinal cohort of 1109 patients with AIDS during the period 1991-4. Treatment groups were defined by start and duration of zidovudine treatment, the drugs used most often during this period were: (a) no zidovudine, (b) zidovudine before AIDS, (c) zidovudine before and after AIDS, and (d) zidovudine used in AIDS. Main outcome measures were cumulative incidence and survival from AIDS to onset of HIV dementia, progressive multifocal leukoencephalopathy (PML), cerebral toxoplasmosis, and primary CNS lymphoma.
RESULTS—Risk of brain disease including HIV dementia and opportunistic brain disease was reduced in patients who started zidovudine before AIDS and continued in AIDS (relative risk (RR) 0.55, 95% confidence interval (95% CI) 0.36-0.84) as well as zidovudine initiated in AIDS (RR 0.27, 95% CI 0.17-0.45) compared with untreated subjects. Treatment effects were not constant over time, decreasing by 14%-32% for each six months of follow up. This was supported by unadjusted incidences across groups stratified by duration of zidovudine use, indicating reduced risk with treatment for up to 18 months but not with longer duration of use of zidovudine. Other antiretroviral drugs had no significant effect, although these were used by only 14% of patients in this cohort.
CONCLUSION—The time limited but effective neuroprotection offered by zidovudine monotherapy for <18 months suggests that non-specific mechanisms of cerebral immunological defence may benefit from antiretroviral treatment. Due to the limitations of a retrospective study these findings require confirmation and further investigation in the context of current combination drug treatments.

 PMID:9667558

  2. Biowaiver monographs for immediate-release solid oral dosage forms: Zidovudine (azidothymidine).

    PubMed

    Soares, Kelen C C; Rediguieri, Camila F; Souza, Jacqueline; Serra, Cristina Helena R; Abrahamsson, Bertil; Groot, D W; Kopp, Sabine; Langguth, Peter; Polli, James E; Shah, Vinod P; Dressman, Jennifer

    2013-08-01

    Literature data on the properties of zidovudine relevant to waiver of in vivo bioequivalence (BE) testing requirements for the approval of immediate-release (IR) solid oral dosage forms containing zidovudine alone or in combination with other active pharmaceutical ingredients (APIs) are reviewed. Solubility, dissolution, and permeability data for zidovudine, along with its dosing schedule, therapeutic index and pharmacokinetic properties, and reports related to BE/bioavailability were all taken into consideration. Data for solubility and permeability suggest that zidovudine belongs to Class I according to the Biopharmaceutics Classification System. Also, zidovudine is not a narrow therapeutic index drug. Although five out of 13 formulations tested in vivo (mostly of unreported composition) failed to show BE, it appears that in vitro studies performed according to biowaiver methods could predict in vivo behavior. Nevertheless, it is highly recommended that if a biowaiver is to be applied, excipient choices be limited to those found in IR drug products approved in International Conference on Harmonisation (ICH) or associated countries in the same dosage form (Table 2 of this monograph), in their usual amounts. These conclusions apply to products containing zidovudine as the only API and also to fixed combination products containing zidovudine with respect to the zidovudine component of the formulation.

  3. N348I in HIV-1 reverse transcriptase counteracts the synergy between zidovudine and nevirapine.

    PubMed

    Yap, Soo Huey; Herman, Brian D; Radzio, Jessica; Sluis-Cremer, Nicolas; Tachedjian, Gilda

    2012-10-01

    The efficacy of regimens that include both zidovudine and nevirapine can be explained by the synergistic interactions between these drugs. N348I in HIV-1 reverse transcriptase confers decreased susceptibility to zidovudine and nevirapine. Here, we demonstrate that N348I reverses the synergistic inhibition of HIV-1 by zidovudine and nevirapine. Also, the efficiency of zidovudine-monophosphate excision in the presence of nevirapine is greater for N348I HIV-1 reverse transcriptase compared with the wild-type enzyme. These data help explain the frequent selection of N348I in regimens that contain zidovudine and nevirapine, and suggest that the selection of N348I should be monitored in resource-limited settings where these drugs are routinely used.

  4. Self-assemblies of 5'-cholesteryl-ethyl-phosphoryl zidovudine.

    PubMed

    Du, Lina; Jia, Junwei; Ge, Pingju; Jin, Yiguang

    2016-12-01

    Anti-HIV prodrugs are recently focused on due to their ability of self-assembly, macrophage targeting, and enhanced antiviral effects. Here, an amphiphilic prodrug of zidovudine, an anti-HIV nucleoside analogue, 5'-cholesteryl-ethyl-phosphoryl zidovudine (CEPZ) was synthesized. CEPZ showed some unique physicochemical properties. The solubility of CEPZ in the noncompetitive solvents chloroform and tetrahydrofuran (THF) was very high based on the hydrogen bonds between zidovudine groups, though CEPZ was sparing soluble in alcohols and almost insoluble in water. The typical amphiphilic property of CEPZ was demonstrated according to the Langmuir monolayers at the air/water interface. The LogP of CEPZ was high to 13.78, indicating the high hydrophobicity of amphiphilic CEPZ similar to phospholipids. Homogenous and stable self-assemblies were formed with the mean size of 128.7nm and the zeta potential of -35.4mV after injecting the CEPZ-in-THF solution into water. Hydrophobic interaction between the cholesteryl moieties of CEPZ could drive molecular self-assembly and lead to the formation of spherical vesicles. CEPZ self-assemblies showed strong stability even under high temperature and gravity probably due to the high surface charge. CEPZ was very slowly degraded in neutral solutions (e.g., pH 7.4), but fast in acid solutions (e.g., pH 5.0) and some tissue homogenates. CEPZ was quickly eliminated from the circulation and distributed into the mononuclear phagocyte system (MPS) including the liver, spleen and lung after bolus intravenous administration of CEPZ self-assemblies to mice. The MPS targeting effect of CEPZ self-assemblies makes them become a promising self-assembled drug delivery system to eradicate the HIV hidden in the macrophages.

  5. Helminthic Infections Rates and Malaria in HIV-Infected Pregnant Women on Anti-Retroviral Therapy in Rwanda

    PubMed Central

    Ivan, Emil; Crowther, Nigel J.; Mutimura, Eugene; Osuwat, Lawrence Obado; Janssen, Saskia; Grobusch, Martin P.

    2013-01-01

    Background Within sub-Saharan Africa, helminth and malaria infections cause considerable morbidity in HIV-positive pregnant women and their offspring. Helminth infections are also associated with a higher risk of mother-to-child HIV transmission. The aim of this study was to determine the prevalence of, and the protective and risk factors for helminth and malaria infections in pregnant HIV-positive Rwandan women receiving anti-retroviral therapy (ART). Methodology and principle findings Pregnant females (n = 980) were recruited from health centres in rural and peri-urban locations in the central and eastern provinces of Rwanda. Helminth infection was diagnosed using the Kato Katz method whilst the presence of Plasmodium falciparum was identified from blood smears. The prevalence of helminth infections was 34.3%; of malaria 13.3%, and of co-infections 6.6%. Helminth infections were more common in rural (43.1%) than peri-urban (18.0%; p<0.0005) sites. A CD4 count ≤350 cells/mm3 was associated with a higher risk of helminth infections (odds ratio, 3.39; 95% CIs, 2.16–5.33; p<0.0005) and malaria (3.37 [2.11–5.38]; p<0.0005) whilst helminth infection was a risk factor for malaria infection and vice versa. Education and employment reduced the risk of all types of infection whilst hand washing protected against helminth infection (0.29 [0.19–0.46]; p<0.0005);). The TDF-3TC-NVP (3.47 [2.21–5.45]; p<0.0005), D4T-3TC-NVP (2.47 [1.27–4.80]; p<0.05) and AZT-NVP (2.60 [1.33–5.08]; p<0.05) regimens each yielded higher helminth infection rates than the AZT-3TC-NVP regimen. Anti-retroviral therapy had no effect on the risk of malaria. Conclusion/significance HIV-positive pregnant women would benefit from the scaling up of de-worming programs alongside health education and hygiene interventions. The differential effect of certain ART combinations (as observed here most strongly with AZT-3TC-NVP) possibly protecting against helminth infection warrants further

  6. Progress cargo spacecraft observed with the AZT-33IK optical telescope

    NASA Astrophysics Data System (ADS)

    Klunko, Evgeniy; Eselevich, Maksim; Tergoev, Vladimir

    2016-09-01

    In this paper, we describe a telescope and measuring equipment used for optical observations of Progress cargo spacecraft (PCS), which were made during Radar-Progress space experiment sessions. We also describe object tracking and measurement techniques. The observations were made with the optical telescope AZT-33IK at Sayan Solar Observatory of ISTP SB RAS. During many of the sessions, we registered optical phenomena that occurred in regions of space surrounding PCS and appeared due to the work of PCS onboard engines. The data we obtained can be used to independently control the geometry of the experiment and to analyze physical conditions in outer space.

  7. Synthesis and antiviral activity of boranophosphonate isosteres of AZT and d4T monophosphates.

    PubMed

    Barral, Karine; Priet, Stéphane; De Michelis, Céline; Sire, Joséphine; Neyts, Johan; Balzarini, Jan; Canard, Bruno; Alvarez, Karine

    2010-02-01

    We report synthesis, in vitro antiviral activity, and stability studies in biological media of original boranophosphonate isosteres of AZT and d4T monophophates. A convenient route for the synthesis of 3'-Azido-3'-deoxythymidine-5'-boranophosphonate 8 and 2',3'-Didehydro-3'-dideoxythymidine-5'-boranophosphonate 12 is described. H-phosphinates 7 and 11, and alpha-boranophosphonates 8 and 12 exhibited no significant in vitro activity against HIV-infected cells, neither against a broad panel of viruses, up to 200 microM. The absence of activity of target compounds 8 and 12 can be partially explained by their short half-life in culture medium.

  8. Bats and Rodents Shape Mammalian Retroviral Phylogeny.

    PubMed

    Cui, Jie; Tachedjian, Gilda; Wang, Lin-Fa

    2015-11-09

    Endogenous retroviruses (ERVs) represent past retroviral infections and accordingly can provide an ideal framework to infer virus-host interaction over their evolutionary history. In this study, we target high quality Pol sequences from 7,994 Class I and 8,119 Class II ERVs from 69 mammalian genomes and surprisingly find that retroviruses harbored by bats and rodents combined occupy the major phylogenetic diversity of both classes. By analyzing transmission patterns of 30 well-defined ERV clades, we corroborate the previously published observation that rodents are more competent as originators of mammalian retroviruses and reveal that bats are more capable of receiving retroviruses from non-bat mammalian origins. The powerful retroviral hosting ability of bats is further supported by a detailed analysis revealing that the novel bat gammaretrovirus, Rhinolophus ferrumequinum retrovirus, likely originated from tree shrews. Taken together, this study advances our understanding of host-shaped mammalian retroviral evolution in general.

  9. Bats and Rodents Shape Mammalian Retroviral Phylogeny

    PubMed Central

    Cui, Jie; Tachedjian, Gilda; Wang, Lin-Fa

    2015-01-01

    Endogenous retroviruses (ERVs) represent past retroviral infections and accordingly can provide an ideal framework to infer virus-host interaction over their evolutionary history. In this study, we target high quality Pol sequences from 7,994 Class I and 8,119 Class II ERVs from 69 mammalian genomes and surprisingly find that retroviruses harbored by bats and rodents combined occupy the major phylogenetic diversity of both classes. By analyzing transmission patterns of 30 well-defined ERV clades, we corroborate the previously published observation that rodents are more competent as originators of mammalian retroviruses and reveal that bats are more capable of receiving retroviruses from non-bat mammalian origins. The powerful retroviral hosting ability of bats is further supported by a detailed analysis revealing that the novel bat gammaretrovirus, Rhinolophus ferrumequinum retrovirus, likely originated from tree shrews. Taken together, this study advances our understanding of host-shaped mammalian retroviral evolution in general. PMID:26548564

  10. ADAM low- and medium-resolution spectrograph for 1.6-m AZT-33IK telescope

    NASA Astrophysics Data System (ADS)

    Afanasiev, V. L.; Dodonov, S. N.; Amirkhanyan, V. R.; Moiseev, A. V.

    2016-10-01

    We describe the design of a suspended low- and medium-resolution spectrograph ( R ≈ 300-1300) designed and made at the Special Astrophysical Observatory of the Russian Academy of Sciences for the 1.6-m AZT-33IK telescope of Sayan Observatory of the Institute of Solar-Terrestrial Physics of the Siberian Branch of the Russian Academy of Sciences. We report the results of laboratory measurements of the parameters of the instrument and tests performed on the 1-m Zeiss-1000 telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences. We measured the total quantum efficiency of the "spectrograph + telescope + detector" system on AZT-33IK telescope, which at its maximum reaches 56%. Such a hight transparency of the spectrograph allows it to be used with the 1.6-m telescope to determine the types and redshifts of objects with integrated magnitudes m AB ≈ 20-21, and this result was confirmed by actual observations.

  11. Role of inosine triphosphate pyrophosphatase gene variant on fever incidence during zidovudine antiretroviral therapy.

    PubMed

    Coelho, A V C; Silva, S P S; Zandonà, L; Stocco, G; Decorti, G; Crovella, S

    2017-01-23

    Zidovudine, the antiretroviral drug used to treat HIV infection, commonly causes adverse effects, such as systemic fever and gastrointestinal alterations. In the present study, the potential role of inosine triphosphate pyrophosphatase (ITPA) gene variant on the incidence of adverse events during antiretroviral therapy (ART) of HIV with zidovudine was discussed. Individuals from Northeastern Brazil (N = 204) receiving treatment for HIV-1 infection were recruited. Zidovudine-related adverse effects developed during the treatment were registered. The rs1127354 polymorphism in the ITPA gene was genotyped using real-time PCR to assess whether this single nucleotide polymorphism was associated with the occurrence of zidovudine-related adverse effects. We observed a significant association between the ITPA variant genotype and the reported systemic fever (odds ratio = 7.17, 95% confidence interval = 1.19-43.15; P = 0.032). Zidovudine use could indirectly lead to an increase in the levels of inosine monophosphate in an antimetabolite-like manner, which is converted to inosine triphosphate (ITP). The rs1127354 variant caused a decrease in ITPA activity, thereby leading to ITP accumulation. This in turn resulted in cytotoxicity, which was manifested by neutropenia and fever. Therefore, we hypothesized a pharmacogenetic model involving the ITPA variant genotype in multifactorial components that act together to determine the onset of zidovudine-related adverse effects.

  12. [Development of HIV 1 antigenemia during treatment with azidothymidine (AZT): follow-up of 90 patients for a year].

    PubMed

    Berlie, H C; Berlioux, J; Daguet, G L

    1989-06-01

    VIH 1 antigenaemia has a significant value in the follow-up of patients treated with AZT. This study of 90 patients (55 ARC - 35 AIDS), each receiving AZT for more than a year, 200 mg every 4 hours, demonstrates the prognosis value of antigenaemia at Day 0, as well as its therapeutic indication value. However, at term and under this treatment, the significance of this virological data has to be reconsidered. Various kinetic patterns are described according to the clinical status and the CD4+ cells count.

  13. Exposure of Allium cepa root cells to zidovudine or nevirapine induces cytogenotoxic changes.

    PubMed

    Onwuamah, Chika K; Ekama, Sabdat O; Audu, Rosemary A; Ezechi, Oliver C; Poirier, Miriam C; Odeigah, Peter G C

    2014-01-01

    Antiretroviral drugs have proved useful in the clinical management of HIV-infected persons, though there are concerns about the effects of exposure to these DNA-reactive drugs. We investigated the potential of the plant model Allium cepa root tip assay to demonstrate the cytogenotoxicity of zidovudine and nevirapine and as a replace-reduce-refine programme amenable to resource-poor research settings. Cells mitotic index were determined in squashed root cells from Allium cepa bulbs exposed to zidovudine or nevirapine for 48 hr. The concentration of zidovudine and nevirapine inhibiting 50% root growth after 96 hr exposure was 65.0 µM and 92.5 µM respectively. Root length of all antiretroviral-exposed roots after 96 hr exposure was significantly shorter than the unexposed roots while additional root growth during a subsequent 48 hr recovery period in the absence of drug was not significantly different. By ANOVA, there was a significant association between percentage of cells in mitosis and zidovudine dose (p=0.004), but not nevirapine dose (p=0.68). Chromosomal aberrations such as sticky chromosomes, chromatin bridges, multipolar mitoses and binucleated cells were observed in root cells exposed to zidovudine and nevirapine for 48 hr. The most notable chromosomal aberration was drug-related increases in sticky chromosomes. Overall, the study showed inhibition in root length growth, changes in the mitotic index, and the induction of chromosomal aberrations in Allium bulbs treated for 96 hr or 48 hr with zidovudine and nevirapine. The study reveals generalized cytogenotoxic damage induced by exposure to zidovudine and nevirapine, and further show that the two compounds differ in their effects on mitosis and the types of chromosomal aberrations induced.

  14. Exposure of Allium cepa Root Cells to Zidovudine or Nevirapine Induces Cytogenotoxic Changes

    PubMed Central

    Onwuamah, Chika K.; Ekama, Sabdat O.; Audu, Rosemary A.; Ezechi, Oliver C.; Poirier, Miriam C.; Odeigah, Peter G C.

    2014-01-01

    Antiretroviral drugs have proved useful in the clinical management of HIV-infected persons, though there are concerns about the effects of exposure to these DNA-reactive drugs. We investigated the potential of the plant model Allium cepa root tip assay to demonstrate the cytogenotoxicity of zidovudine and nevirapine and as a replace-reduce-refine programme amenable to resource–poor research settings. Cells mitotic index were determined in squashed root cells from Allium cepa bulbs exposed to zidovudine or nevirapine for 48 hr. The concentration of zidovudine and nevirapine inhibiting 50% root growth after 96 hr exposure was 65.0 µM and 92.5 µM respectively. Root length of all antiretroviral-exposed roots after 96 hr exposure was significantly shorter than the unexposed roots while additional root growth during a subsequent 48 hr recovery period in the absence of drug was not significantly different. By ANOVA, there was a significant association between percentage of cells in mitosis and zidovudine dose (p = 0.004), but not nevirapine dose (p = 0.68). Chromosomal aberrations such as sticky chromosomes, chromatin bridges, multipolar mitoses and binucleated cells were observed in root cells exposed to zidovudine and nevirapine for 48 hr. The most notable chromosomal aberration was drug-related increases in sticky chromosomes. Overall, the study showed inhibition in root length growth, changes in the mitotic index, and the induction of chromosomal aberrations in Allium bulbs treated for 96 hr or 48 hr with zidovudine and nevirapine. The study reveals generalized cytogenotoxic damage induced by exposure to zidovudine and nevirapine, and further show that the two compounds differ in their effects on mitosis and the types of chromosomal aberrations induced. PMID:24599327

  15. Fluorescence derivatization method for sensitive chromatographic determination of zidovudine based on the Huisgen reaction.

    PubMed

    Maeda, Yuki; Kishikawa, Naoya; Ohyama, Kaname; Wada, Mitsuhiro; Ikeda, Rie; Kuroda, Naotaka

    2014-08-15

    A novel pre-column fluorescence derivatization method for chromatographic analysis of azide compounds was developed based on the Huisgen reaction, which is a specific cycloaddition reaction between an alkyne and an azide. We designed and synthesized a fluorescent alkyne, 2-(4-ethynylphenyl)-4,5-diphenyl-1H-imidazole (DIB-ET) as a reagent. DIB-ET has a lophine skeleton carrying an alkyne acting as fluorophore and reactive center, respectively. In order to evaluate the practicality of DIB-ET, a high-performance liquid chromatography with fluorescence detection method was developed for the determination of zidovudine as a model of azide compound. Zidovudine could be reacted with DIB-ET in the presence of copper(II) sulfate and L-ascorbic acid as catalysts, and the formed derivative was detected fluorometrically. The proposed method allows sensitive and selective determination of zidovudine in plasma samples with the detection limit of 0.28ngmL(-1) at a S/N=3. Finally, the proposed method could be applied to determine the zidovudine concentration in rat plasma after administration of zidovudine without interference from biological components.

  16. Retroviral DNA Transposition: Themes and Variations

    PubMed Central

    Skalka, Anna Marie

    2015-01-01

    SUMMARY Retroviruses and LTR retrotransposons are transposable elements that encapsidate the RNAs that are intermediates in the transposition of DNA copies of their genomes (proviruses), from one cell (or one locus) to another. Mechanistic similarities in DNA transposase enzymes and retroviral/retrotransposon integrases underscore the close evolutionary relationship among these elements. The retroviruses are very ancient infectious agents, presumed to have evolved from Ty3/Gypsy LTR retrotransposons (1), and DNA copies of their sequences can be found embedded in the genomes of most, if not all, members of the tree of life. All retroviruses share a specific gene arrangement and similar replication strategies. However, given their ancestries and occupation of diverse evolutionary niches, it should not be surprising that unique sequences have been acquired in some retroviral genomes and that the details of the mechanism by which their transposition is accomplished can vary. While every step in the retrovirus lifecycle is, in some sense, relevant to transposition, this Chapter focuses mainly on the early phase of retroviral replication, during which viral DNA is synthesized and integrated into its host genome. Some of the initial studies that set the stage for current understanding are highlighted, as well as more recent findings obtained through use of an ever-expanding technological toolbox including genomics, proteomics, and siRNA screening. Persistence in the area of structural biology has provided new insight into conserved mechanisms as well as variations in detail among retroviruses, which can also be instructive. PMID:25844274

  17. Molecular mechanisms of retroviral integration site selection

    PubMed Central

    Kvaratskhelia, Mamuka; Sharma, Amit; Larue, Ross C.; Serrao, Erik; Engelman, Alan

    2014-01-01

    Retroviral replication proceeds through an obligate integrated DNA provirus, making retroviral vectors attractive vehicles for human gene-therapy. Though most of the host cell genome is available for integration, the process of integration site selection is not random. Retroviruses differ in their choice of chromatin-associated features and also prefer particular nucleotide sequences at the point of insertion. Lentiviruses including HIV-1 preferentially integrate within the bodies of active genes, whereas the prototypical gammaretrovirus Moloney murine leukemia virus (MoMLV) favors strong enhancers and active gene promoter regions. Integration is catalyzed by the viral integrase protein, and recent research has demonstrated that HIV-1 and MoMLV targeting preferences are in large part guided by integrase-interacting host factors (LEDGF/p75 for HIV-1 and BET proteins for MoMLV) that tether viral intasomes to chromatin. In each case, the selectivity of epigenetic marks on histones recognized by the protein tether helps to determine the integration distribution. In contrast, nucleotide preferences at integration sites seem to be governed by the ability for the integrase protein to locally bend the DNA duplex for pairwise insertion of the viral DNA ends. We discuss approaches to alter integration site selection that could potentially improve the safety of retroviral vectors in the clinic. PMID:25147212

  18. Sustained high proportion of zidovudine-resistant HIV variants despite prolonged substitution of zidovudine by other nucleoside reverse transcriptase inhibitors.

    PubMed

    Bélec, Laurent; Legoff, Jérôme; Si-Mohamed, Ali; Andréoletti, Laurent; Mbopi-Kéou, François-Xavier; Kolberg, Janice; Matta, Mathieu; Detmer, Jill; Piketty, Christophe; Kazatchkine, Michel D

    2002-09-01

    The consequences of zidovudine (ZDV) replacement by other nucleoside reverse transcriptase inhibitors on the expression of resistance mutations at codons 215 and 41 of the reverse transcriptase (RT) gene was investigated prospectively in 66 patients harboring mutant genotypes who were changed to an effective two- or three-drug combination antiretroviral regimen. Quantitation of mutant (MUT) viral populations at codon 215 by means of RT-PCR with differential hybridization of amplicons specific for MUT and wild (WT) variants revealed no difference in the proportion of 215 MUT variants prior to (93.5 +/- 2.4%) and 12 to 20 months after (96.9 +/- 1.9%) ZDV replacement, independently of a therapeutic change for stavudine. The fitness of the variants harboring the ZDV-resistant MUT 215 genotype following drug withdrawal was calculated to be 96 to 99% of that of the variants harboring the WT 215 genotype. The apparent stability of ZDV-resistant variants in the study population may have two main complementary explanations: persistent selective pressure secondary to partial cross-resistance due to the new regimens given after the therapeutic alteration and suppression of viral replication after the therapeutic alteration that could have hampered the replacement of less fit variants by fitter variants. These findings indicate that, at least within 15 months following discontinuation of ZDV, an effective antiretroviral therapy is insufficient to allow for ZDV-resistant strains to disappear, and thus to allow for the safe re-introduction of the drug.

  19. Transplacental Exposure to AZT Induces Adverse Neurochemical and Behavioral Effects in a Mouse Model: Protection by L-Acetylcarnitine

    PubMed Central

    Venerosi Pesciolini, Aldina; Tramutola, Antonella; Ajmone-Cat, Maria Antonietta; Cinque, Carlo; Alemà, Giovanni Sebastiano; Giovine, Angela; Peluso, Gianfranco; Minghetti, Luisa; Nicolai, Raffaella; Calamandrei, Gemma; Casolini, Paola

    2013-01-01

    Maternal-fetal HIV-1 transmission can be prevented by administration of AZT, alone or in combination with other antiretroviral drugs to pregnant HIV-1-infected women and their newborns. In spite of the benefits deriving from this life-saving prophylactic therapy, there is still considerable uncertainty on the potential long-term adverse effects of antiretroviral drugs on exposed children. Clinical and experimental studies have consistently shown the occurrence of mitochondrial dysfunction and increased oxidative stress following prenatal treatment with antiretroviral drugs, and clinical evidence suggests that the developing brain is one of the targets of the toxic action of these compounds possibly resulting in behavioral problems. We intended to verify the effects on brain and behavior of mice exposed during gestation to AZT, the backbone of antiretroviral therapy during human pregnancy. We hypothesized that glutamate, a neurotransmitter involved in excitotoxicity and behavioral plasticity, could be one of the major actors in AZT-induced neurochemical and behavioral alterations. We also assessed the antioxidant and neuroprotective effect of L-acetylcarnitine, a compound that improves mitochondrial function and is successfully used to treat antiretroviral-induced polyneuropathy in HIV-1 patients. We found that transplacental exposure to AZT given per os to pregnant mice from day 10 of pregnancy to delivery impaired in the adult offspring spatial learning and memory, enhanced corticosterone release in response to acute stress, increased brain oxidative stress also at birth and markedly reduced expression of mGluR1 and mGluR5 subtypes and GluR1 subunit of AMPA receptors in the hippocampus. Notably, administration during the entire pregnancy of L-acetylcarnitine was effective in preventing/ameliorating the neurochemical, neuroendocrine and behavioral adverse effects induced by AZT in the offspring. The present preclinical findings provide a mechanistic hypothesis for

  20. Immobilization of Zidovudine Derivatives on the SBA-15 Mesoporous Silica and Evaluation of Their Cytotoxic Activity.

    PubMed

    Lewandowski, Dawid; Lewandowska, Marta; Ruszkowski, Piotr; Pińska, Anita; Schroeder, Grzegorz

    2015-01-01

    Novel zidovudine derivatives, able to be covalently conjugated to silica surface, have been obtained and grafted to SBA-15 mesoporous silica. Cytotoxic activity of the hybrid organic-inorganic (zidovudine derivatives-silica) systems against HeLa and KB cell lines has been analyzed. Addition of folic acid had a positive influence on the cytotoxicity. Up to 69% of HeLa and 65% of KB tumor cells growth inhibition has been achieved at low silica concentration used (10 μg/mL).

  1. Structure and conformational analysis of the anti-HIV AZT 5‧-aminocarbonylphosphonate prodrug using DFT methods

    NASA Astrophysics Data System (ADS)

    Tamara Molina, A.; Alcolea Palafox, M.

    2011-08-01

    A comprehensive theoretical conformational analysis of the anti-HIV AZT 5'-aminocarbonylphosphonate prodrug was carried out, due to this prodrug has noticeable advantage over approved drugs AZT and Nikavir. The whole conformational parameters ( χ, γ, β, α, δ, ɛ, τ, P, νmax) were analysed as well as the NBO Natural atomic charges. The calculations were carried out by means of B3LYP/6-31G ∗∗ and B3LYP/6-311++G(3df,pd) DFT levels of theory with full relaxation of all geometrical parameters. The search located at least 86 stable structures, 6 of which are within a 1 kcal/mol electronic energy range of the global minimum and 11 conformers are within a 1 kcal/mol Gibbs energy range. The global minimum with the 6-311++G(3df,pd) basis set corresponds to the calculated values of the exocyclic torsional angles χ = -121.6°, β = 153.0°, γ = -152.0° and α = -74.1°. The results obtained are in accordance to those found in related anti-HIV nucleoside Analogs. Comparisons of the conformers with those determined in the common anti-HIV drug AZT were carried out. Several correlations and general conclusions were emphasized.

  2. Impact of HIV Infection and Zidovudine Therapy on RBC Parameters and Urine Methylmalonic Acid Levels.

    PubMed

    Adediran, Adewumi; Osunkalu, Vincent; Wakama, Tamunomieibi; John-Olabode, Sarah; Akinbami, Akinsegun; Uche, Ebele; Akanmu, Sulaimon

    2016-01-01

    Background. Anaemia is a common complication of human immunodeficiency virus (HIV) infection. The aim of this study was to investigate the impact of HIV infection and zidovudine on red blood cells (RBC) parameters and urine methylmalonic acid (UMMA) levels in patients with HIV infection. Material and Methods. A cross-sectional study involving 114 subjects, 94 of which are HIV-infected nonanaemic and 20 HIV negative subjects (Cg) as control. Full blood count parameters and urine methylmalonic acid (UMMA) level of each subject were determined. Associations were determined by Chi-square test and logistic regression statistics where appropriate. Results. Subjects on zidovudine-based ART had mean MCV (93 fL) higher than that of control group (82.9 fL) and ART-naïve (85.9 fL) subjects and the highest mean RDW. Mean UMMA level, which reflects vitamin B12 level status, was high in all HIV-infected groups but was significantly higher in ART-naïve subjects than in ART-experienced subjects. Conclusion. Although non-zidovudine therapy may be associated with macrocytosis (MCV > 95 fL), zidovudine therapy and ART naivety may not. Suboptimal level of vitamin B12 as measured by high UMMA though highest in ART-naïve subjects was common in all HIV-infected subjects.

  3. Retroviral Integrase Structure and DNA Recombination Mechanism

    PubMed Central

    Engelman, Alan; Cherepanov, Peter

    2015-01-01

    SUMMARY Due to the importance of human immunodeficiency virus type 1 (HIV-1) integrase as a drug target, the biochemistry and structural aspects of retroviral DNA integration have been the focus of intensive research during the past three decades. The retroviral integrase enzyme acts on the linear double-stranded viral DNA product of reverse transcription. Integrase cleaves specific phosphodiester bonds near the viral DNA ends during the 3′ processing reaction. The enzyme then uses the resulting viral DNA 3′-OH groups during strand transfer to cut chromosomal target DNA, which simultaneously joins both viral DNA ends to target DNA 5′-phosphates. Both reactions proceed via direct transesterification of scissile phosphodiester bonds by attacking nucleophiles: a water molecule for 3′ processing, and the viral DNA 3′-OH for strand transfer. X-ray crystal structures of prototype foamy virus integrase-DNA complexes revealed the architectures of the key nucleoprotein complexes that form sequentially during the integration process and explained the roles of active site metal ions in catalysis. X-ray crystallography furthermore elucidated the mechanism of action of HIV-1 integrase strand transfer inhibitors, which are currently used to treat AIDS patients, and provided valuable insights into the mechanisms of viral drug resistance. PMID:25705574

  4. Evaluation of the Activity of Lamivudine and Zidovudine against Ebola Virus.

    PubMed

    Cong, Yu; Dyall, Julie; Hart, Brit J; DeWald, Lisa Evans; Johnson, Joshua C; Postnikova, Elena; Zhou, Huanying; Gross, Robin; Rojas, Oscar; Alexander, Isis; Josleyn, Nicole; Zhang, Tengfei; Michelotti, Julia; Janosko, Krisztina; Glass, Pamela J; Flint, Mike; McMullan, Laura K; Spiropoulou, Christina F; Mierzwa, Tim; Guha, Rajarshi; Shinn, Paul; Michael, Sam; Klumpp-Thomas, Carleen; McKnight, Crystal; Thomas, Craig; Eakin, Ann E; O'Loughlin, Kathleen G; Green, Carol E; Catz, Paul; Mirsalis, Jon C; Honko, Anna N; Olinger, Gene G; Bennett, Richard S; Holbrook, Michael R; Hensley, Lisa E; Jahrling, Peter B

    2016-01-01

    In the fall of 2014, an international news agency reported that patients suffering from Ebola virus disease (EVD) in Liberia were treated successfully with lamivudine, an antiviral drug used to treat human immunodeficiency virus-1 and hepatitis B virus infections. According to the report, 13 out of 15 patients treated with lamivudine survived and were declared free from Ebola virus disease. In this study, the anti-Ebola virus (EBOV) activity of lamivudine and another antiretroviral, zidovudine, were evaluated in a diverse set of cell lines against two variants of wild-type EBOV. Variable assay parameters were assessed to include different multiplicities of infection, lengths of inoculation times, and durations of dosing. At a multiplicity of infection of 1, lamivudine and zidovudine had no effect on EBOV propagation in Vero E6, Hep G2, or HeLa cells, or in primary human monocyte-derived macrophages. At a multiplicity of infection of 0.1, zidovudine demonstrated limited anti-EBOV activity in Huh 7 cells. Under certain conditions, lamivudine had low anti-EBOV activity at the maximum concentration tested (320 μM). However, lamivudine never achieved greater than 30% viral inhibition, and the activity was not consistently reproducible. Combination of lamivudine and zidovudine showed no synergistic antiviral activity. Independently, a set of in vitro experiments testing lamivudine and zidovudine for antiviral activity against an Ebola-enhanced green fluorescent protein reporter virus was performed at the Centers for Disease Control and Prevention. No antiviral activity was observed for either compound. A study evaluating the efficacy of lamivudine in a guinea pig model of EVD found no survival benefit. This lack of benefit was observed despite plasma lamivudine concentrations in guinea pig of about 4 μg/ml obtained in a separately conducted pharmacokinetics study. These studies found no evidence to support the therapeutic use of lamivudine for the treatment of EVD.

  5. Evaluation of the Activity of Lamivudine and Zidovudine against Ebola Virus

    PubMed Central

    Hart, Brit J.; DeWald, Lisa Evans; Johnson, Joshua C.; Postnikova, Elena; Zhou, Huanying; Gross, Robin; Rojas, Oscar; Alexander, Isis; Josleyn, Nicole; Zhang, Tengfei; Michelotti, Julia; Janosko, Krisztina; Glass, Pamela J.; Flint, Mike; McMullan, Laura K.; Spiropoulou, Christina F.; Mierzwa, Tim; Guha, Rajarshi; Shinn, Paul; Michael, Sam; Klumpp-Thomas, Carleen; McKnight, Crystal; Thomas, Craig; Eakin, Ann E.; O’Loughlin, Kathleen G.; Green, Carol E.; Catz, Paul; Mirsalis, Jon C.; Honko, Anna N.; Olinger, Gene G.; Bennett, Richard S.; Holbrook, Michael R.; Hensley, Lisa E.; Jahrling, Peter B.

    2016-01-01

    In the fall of 2014, an international news agency reported that patients suffering from Ebola virus disease (EVD) in Liberia were treated successfully with lamivudine, an antiviral drug used to treat human immunodeficiency virus-1 and hepatitis B virus infections. According to the report, 13 out of 15 patients treated with lamivudine survived and were declared free from Ebola virus disease. In this study, the anti-Ebola virus (EBOV) activity of lamivudine and another antiretroviral, zidovudine, were evaluated in a diverse set of cell lines against two variants of wild-type EBOV. Variable assay parameters were assessed to include different multiplicities of infection, lengths of inoculation times, and durations of dosing. At a multiplicity of infection of 1, lamivudine and zidovudine had no effect on EBOV propagation in Vero E6, Hep G2, or HeLa cells, or in primary human monocyte-derived macrophages. At a multiplicity of infection of 0.1, zidovudine demonstrated limited anti-EBOV activity in Huh 7 cells. Under certain conditions, lamivudine had low anti-EBOV activity at the maximum concentration tested (320 μM). However, lamivudine never achieved greater than 30% viral inhibition, and the activity was not consistently reproducible. Combination of lamivudine and zidovudine showed no synergistic antiviral activity. Independently, a set of in vitro experiments testing lamivudine and zidovudine for antiviral activity against an Ebola-enhanced green fluorescent protein reporter virus was performed at the Centers for Disease Control and Prevention. No antiviral activity was observed for either compound. A study evaluating the efficacy of lamivudine in a guinea pig model of EVD found no survival benefit. This lack of benefit was observed despite plasma lamivudine concentrations in guinea pig of about 4 μg/ml obtained in a separately conducted pharmacokinetics study. These studies found no evidence to support the therapeutic use of lamivudine for the treatment of EVD

  6. Pharmacokinetics of zidovudine dosed twice daily according to World Health Organization weight bands in Ugandan HIV-infected children.

    PubMed

    Fillekes, Quirine; Kendall, Lindsay; Kitaka, Sabrina; Mugyenyi, Peter; Musoke, Philippa; Ndigendawani, Milly; Bwakura-Dangarembizi, Mutsa; Gibb, Diana M; Burger, David; Walker, Ann Sarah

    2014-05-01

    Data on zidovudine pharmacokinetics in children dosed using World Health Organization weight bands are limited. About 45 HIV-infected, Ugandan children, 3.4 (2.6-6.2) years, had intensive pharmacokinetic sampling. Geometric mean zidovudine AUC0-12h was 3.0 h.mg/L, which is higher than previously observed in adults, and was independently higher in those receiving higher doses, younger and underweight children. Higher exposure was also marginally associated with lower hemoglobin.

  7. Biochemical Characterization of Novel Retroviral Integrase Proteins

    PubMed Central

    Ballandras-Colas, Allison; Naraharisetty, Hema; Li, Xiang; Serrao, Erik; Engelman, Alan

    2013-01-01

    Integrase is an essential retroviral enzyme, catalyzing the stable integration of reverse transcribed DNA into cellular DNA. Several aspects of the integration mechanism, including the length of host DNA sequence duplication flanking the integrated provirus, which can be from 4 to 6 bp, and the nucleotide preferences at the site of integration, are thought to cluster among the different retroviral genera. To date only the spumavirus prototype foamy virus integrase has provided diffractable crystals of integrase-DNA complexes, revealing unprecedented details on the molecular mechanisms of DNA integration. Here, we characterize five previously unstudied integrase proteins, including those derived from the alpharetrovirus lymphoproliferative disease virus (LPDV), betaretroviruses Jaagsiekte sheep retrovirus (JSRV), and mouse mammary tumor virus (MMTV), epsilonretrovirus walleye dermal sarcoma virus (WDSV), and gammaretrovirus reticuloendotheliosis virus strain A (Rev-A) to identify potential novel structural biology candidates. Integrase expressed in bacterial cells was analyzed for solubility, stability during purification, and, once purified, 3′ processing and DNA strand transfer activities in vitro. We show that while we were unable to extract or purify accountable amounts of WDSV, JRSV, or LPDV integrase, purified MMTV and Rev-A integrase each preferentially support the concerted integration of two viral DNA ends into target DNA. The sequencing of concerted Rev-A integration products indicates high fidelity cleavage of target DNA strands separated by 5 bp during integration, which contrasts with the 4 bp duplication generated by a separate gammaretrovirus, the Moloney murine leukemia virus (MLV). By comparing Rev-A in vitro integration sites to those generated by MLV in cells, we concordantly conclude that the spacing of target DNA cleavage is more evolutionarily flexible than are the target DNA base contacts made by integrase during integration. Given their

  8. Ethical dilemmas in continuing a zidovudine trial after early termination of similar trials.

    PubMed

    Simberkoff, M S; Hartigan, P M; Hamilton, J D; Deykin, D; Gail, M; Bartlett, J G; Feorino, P; Redfield, R; Roberts, R; Collins, D

    1993-02-01

    Ethical dilemmas caused by external events and an interim subset analysis raised concerns about continuing a long-term VA clinical trial comparing early with later zidovudine therapy for symptomatic human immunodeficiency virus (HIV) infection. The first external event was the early termination of other, apparently similar, trials conducted by the AIDS Clinical Trials Group (ACTG) and the announced clear benefits for the zidovudine-treated patients. Interim analysis of the VA trial at this time did not show similar benefits. Subset analyses were performed to explore factors that might explain the different results. These suggested a difference in response to zidovudine in white and minority groups. The Data Monitoring Board and a special advisory panel reviewed these data and concluded that, since the VA results were neutral overall and the subset analyses based on small numbers, the trial should continue. By conference call, the study cochairmen and biostatistician discussed this decision with study personnel without revealing interim results, and study personnel passed the information on to patients at the participating centers. The second event was in March 1990, when the Food and Drug Administration (FDA) approved earlier use of zidovudine, which applied to patients still in the VA trial. Patients were asked to reaffirm their participation by signing a new informed consent that explained the findings reported by the ACTG, the FDA-approved revised recommendations, and the rationale for continuation of the VA trial. The consent form emphasized that continued masked therapy was optional and that unmasked treatment and follow-up would be provided to patients requesting it. Seventy-four percent of the participants chose to continue masked therapy. We conclude that when new external data are announced, informed participation in a long-term clinical trial may require a revised consent form and that it is ethical and practical to present this without disclosure of

  9. Identifying Cancer Driver Genes Using Replication-Incompetent Retroviral Vectors.

    PubMed

    Bii, Victor M; Trobridge, Grant D

    2016-10-25

    Identifying novel genes that drive tumor metastasis and drug resistance has significant potential to improve patient outcomes. High-throughput sequencing approaches have identified cancer genes, but distinguishing driver genes from passengers remains challenging. Insertional mutagenesis screens using replication-incompetent retroviral vectors have emerged as a powerful tool to identify cancer genes. Unlike replicating retroviruses and transposons, replication-incompetent retroviral vectors lack additional mutagenesis events that can complicate the identification of driver mutations from passenger mutations. They can also be used for almost any human cancer due to the broad tropism of the vectors. Replication-incompetent retroviral vectors have the ability to dysregulate nearby cancer genes via several mechanisms including enhancer-mediated activation of gene promoters. The integrated provirus acts as a unique molecular tag for nearby candidate driver genes which can be rapidly identified using well established methods that utilize next generation sequencing and bioinformatics programs. Recently, retroviral vector screens have been used to efficiently identify candidate driver genes in prostate, breast, liver and pancreatic cancers. Validated driver genes can be potential therapeutic targets and biomarkers. In this review, we describe the emergence of retroviral insertional mutagenesis screens using replication-incompetent retroviral vectors as a novel tool to identify cancer driver genes in different cancer types.

  10. Identifying Cancer Driver Genes Using Replication-Incompetent Retroviral Vectors

    PubMed Central

    Bii, Victor M.; Trobridge, Grant D.

    2016-01-01

    Identifying novel genes that drive tumor metastasis and drug resistance has significant potential to improve patient outcomes. High-throughput sequencing approaches have identified cancer genes, but distinguishing driver genes from passengers remains challenging. Insertional mutagenesis screens using replication-incompetent retroviral vectors have emerged as a powerful tool to identify cancer genes. Unlike replicating retroviruses and transposons, replication-incompetent retroviral vectors lack additional mutagenesis events that can complicate the identification of driver mutations from passenger mutations. They can also be used for almost any human cancer due to the broad tropism of the vectors. Replication-incompetent retroviral vectors have the ability to dysregulate nearby cancer genes via several mechanisms including enhancer-mediated activation of gene promoters. The integrated provirus acts as a unique molecular tag for nearby candidate driver genes which can be rapidly identified using well established methods that utilize next generation sequencing and bioinformatics programs. Recently, retroviral vector screens have been used to efficiently identify candidate driver genes in prostate, breast, liver and pancreatic cancers. Validated driver genes can be potential therapeutic targets and biomarkers. In this review, we describe the emergence of retroviral insertional mutagenesis screens using replication-incompetent retroviral vectors as a novel tool to identify cancer driver genes in different cancer types. PMID:27792127

  11. Zidovudine, abacavir and lamivudine increase the radiosensitivity of human esophageal squamous cancer cell lines.

    PubMed

    Chen, Xuan; Wang, Cong; Guan, Shanghui; Liu, Yuan; Han, Lihui; Cheng, Yufeng

    2016-07-01

    Telomerase is a type of reverse transcriptase that is overexpressed in almost all human tumor cells, but not in normal tissues, which provides an opportunity for radiosensitization targeting telomerase. Zidovudine, abacavir and lamivudine are reverse transcriptase inhibitors that have been applied in clinical practice for several years. We sought to explore the radiosensitization effect of these three drugs on human esophageal cancer cell lines. Eca109 and Eca9706 cells were treated with zidovudine, abacavir and lamivudine for 48 h before irradiation was administered. Samples were collected 1 h after irradiation. Clonal efficiency assay was used to evaluate the effect of the combination of these drugs with radiation doses of 2, 4, 6 and 8 Gy. DNA damage was measured by comet assay. Telomerase activity (TA) and relative telomere length (TL) were detected and evaluated by real-time PCR. Apoptosis rates were assessed by flow cytometric analysis. The results showed that all the drugs tested sensitized the esophageal squamous cell carcinoma (ESCC) cell lines to radiation through an increase in radiation-induced DNA damage and cell apoptosis, deregulation of TA and decreasing the shortened TL caused by radiation. Each of the drugs investigated (zidovudine, abacavir and lamivudine) could be used for sensitizing human esophageal cancer cell lines to radiation. Consequently, the present study supports the potential of these three drugs as therapeutic agents for the radiosensitization of esophageal squamous cell cancer.

  12. Photolysis of three antiviral drugs acyclovir, zidovudine and lamivudine in surface freshwater and seawater.

    PubMed

    Zhou, Chengzhi; Chen, Jingwen; Xie, Qing; Wei, Xiaoxuan; Zhang, Ya-nan; Fu, Zhiqiang

    2015-11-01

    Photodegradation is an important elimination process for many pharmaceuticals in surface waters. In this study, photodegradation of three antiviral drugs, acyclovir, zidovudine, and lamivudine, was investigated in pure water, freshwater, and seawater under the irradiation of simulated sunlight. Results showed that zidovudine was easily transformed via direct photolysis, while acyclovir and lamivudine were mainly transformed via indirect photolysis. We found that in freshwater, nitrate enhanced the photodegradation of the three antiviral drugs, bicarbonate promoted the photodegradation of acyclovir, and dissolved organic matter (DOM) accelerated the photolysis of acyclovir and lamivudine. In seawater, the photolysis of acyclovir was not susceptible to Cl(-), Br(-) and ionic strength; however, the photolysis of zidovudine was inhibited by Cl(-) and Br(-), and the photolysis of lamivudine was enhanced by Cl(-), Br(-) and ionic strength. Second-order reaction rate constants for the three antiviral drugs with (1)O2 (k1O2) and OH (kOH) were also measured. These results are important for fate and ecological risk assessment of the antiviral drugs in natural waters.

  13. Effect of maraviroc on the pharmacokinetics of midazolam, lamivudine/ zidovudine, and ethinyloestradiol/ levonorgestrel in healthy volunteers

    PubMed Central

    Abel, Samantha; Russell, Deborah; Whitlock, Lyndsey A; Ridgway, Caroline E; Muirhead, Gary J

    2008-01-01

    Aims To assess the effect of maraviroc on the pharmacokinetics of midazolam, a sensitive probe CYP3A4 substrate; lamivudine/zidovudine, a combination of nucleoside reverse transcriptase inhibitors (NRTIs); and ethinyloestradiol/levonorgestrel, a combination oral contraceptive. Methods Three randomized, double-blind, placebo-controlled studies were conducted in healthy subjects to assess the effect of maraviroc on pharmacokinetics of other drugs. Two, two-period crossover studies were conducted to assess (i) the effect of steady-state maraviroc (300 mg b.i.d.) on pharmacokinetics of midazolam; and (ii) the effect of steady-state maraviroc (300 mg b.i.d.) on the pharmacokinetics of lamivudine/zidovudine. A third two-way crossover study was conducted to evaluate the effect of steady-state maraviroc (100 mg b.i.d.) on the pharmacokinetics of 30 μg ethinyloestradiol/150 μg levonorgestrel (Microgynon®). Results The geometric mean ratios for Cmax and AUC for each of the compounds tested in the presence and absence of maraviroc were between 92% and 121%. There were no notable differences in Tmax, t1/2 or CLR (where measured) for any of the compounds. Conclusions Maraviroc had no clinically relevant effects on the pharmacokinetics of the CYP3A4 substrate midazolam, the NRTIs zidovudine/lamivudine, or the oral contraceptive steroids ethinyloestradiol and levonorgestrel. PMID:18333862

  14. Structural basis for retroviral integration into nucleosomes.

    PubMed

    Maskell, Daniel P; Renault, Ludovic; Serrao, Erik; Lesbats, Paul; Matadeen, Rishi; Hare, Stephen; Lindemann, Dirk; Engelman, Alan N; Costa, Alessandro; Cherepanov, Peter

    2015-07-16

    Retroviral integration is catalysed by a tetramer of integrase (IN) assembled on viral DNA ends in a stable complex, known as the intasome. How the intasome interfaces with chromosomal DNA, which exists in the form of nucleosomal arrays, is currently unknown. Here we show that the prototype foamy virus (PFV) intasome is proficient at stable capture of nucleosomes as targets for integration. Single-particle cryo-electron microscopy reveals a multivalent intasome-nucleosome interface involving both gyres of nucleosomal DNA and one H2A-H2B heterodimer. While the histone octamer remains intact, the DNA is lifted from the surface of the H2A-H2B heterodimer to allow integration at strongly preferred superhelix location ±3.5 positions. Amino acid substitutions disrupting these contacts impinge on the ability of the intasome to engage nucleosomes in vitro and redistribute viral integration sites on the genomic scale. Our findings elucidate the molecular basis for nucleosome capture by the viral DNA recombination machinery and the underlying nucleosome plasticity that allows integration.

  15. Haemoglobin recovery among HIV-1 infected patients on zidovudine-based antiretroviral therapy and other regimens in north-central Nigeria.

    PubMed

    Parrish, Deidra D; Blevins, Meridith; Megazzini, Karen M; Shepherd, Bryan E; Mohammed, Mukhtar Y; Wester, C William; Vermund, Sten H; Aliyu, Muktar H

    2014-04-01

    We conducted a study to assess trends in haemoglobin recovery among HIV-infected patients initiated on zidovudine-based combination antiretroviral therapy (cART) stratified by baseline haemoglobin level. Haemoglobin data from non-pregnant adult patients initiating cART in rural north-central Nigeria between June 2009 and May 2011 were analysed using a linear mixed effects model to assess the interaction between time, zidovudine-containing regimen and baseline haemoglobin level on the outcome of subsequent haemoglobin level. Best-fit curves were created for baseline haemoglobin in the 10th, 25th, 75th and 90th percentiles. We included 313 patients with 736 measures of haemoglobin in the analysis (239 on zidovudine and 74 on non-zidovudine-containing regimens). Median haemoglobin increased over time in both groups, with differences in haemoglobin response over time related to baseline haemoglobin levels and zidovudine use (p = 0.003). The groups of patients on zidovudine at the 10th and 90th percentiles had downward sloping curves while all other groups had upward trending haemoglobin levels. Although haemoglobin levels increased overall for patients on zidovudine-containing regimens, for those in the 10th and 90th percentiles haemoglobin levels trended downward over time. These results have implications for decisions regarding when to initiate, switch from or avoid the use of zidovudine.

  16. Integrated strategy for the production of therapeutic retroviral vectors.

    PubMed

    Carrondo, Manuel; Panet, Amos; Wirth, Dagmar; Coroadinha, Ana Sofia; Cruz, Pedro; Falk, Haya; Schucht, Roland; Dupont, Francis; Geny-Fiamma, Cécile; Merten, Otto-Wilhelm; Hauser, Hansjörg

    2011-03-01

    The broad application of retroviral vectors for gene delivery is still hampered by the difficulty to reproducibly establish high vector producer cell lines generating sufficient amounts of highly concentrated virus vector preparations of high quality. To enhance the process for producing clinically relevant retroviral vector preparations for therapeutic applications, we have integrated novel and state-of-the-art technologies in a process that allows rapid access to high-efficiency vector-producing cells and consistent production, purification, and storage of retroviral vectors. The process has been designed for various types of retroviral vectors for clinical application and to support a high-throughput process. New modular helper cell lines that permit rapid insertion of DNA encoding the therapeutic vector of interest at predetermined, optimal chromosomal loci were developed to facilitate stable and high vector production levels. Packaging cell lines, cultivation methods, and improved medium composition were coupled with vector purification and storage process strategies that yield maximal vector infectivity and stability. To facilitate GMP-grade vector production, standard of operation protocols were established. These processes were validated by production of retroviral vector lots that drive the expression of type VII collagen (Col7) for the treatment of a skin genetic disease, dystrophic epidermolysis bullosa. The potential efficacy of the Col7-expressing vectors was finally proven with newly developed systems, in particular in target primary keratinocyte cultures and three-dimensional skin tissues in organ culture.

  17. A method for quantitating the intracellular metabolism of AZT amino acid phosphoramidate pronucleotides by capillary high-performance liquid chromatography-electrospray ionization mass spectrometry.

    PubMed

    Kim, Jisook; Park, Soobong; Tretyakova, Natalia Y; Wagner, Carston R

    2005-01-01

    A methodology has been developed for the analysis of the intracellular metabolism of 3'-azido-3'-deoxythymidine (AZT) amino acid phosphoramidates utilizing reverse-phase high-performance liquid chromatography interfaced with negative ion electrospray ionization mass spectrometry (LC/ESI(-) -MS). The presented work demonstrates the potential of capillary LC/MS and LC/MS/MS to identify and quantitate the cellular uptake and metabolism of nucleoside phosphoramidate. Significant intracellular amounts of D- and L-phenylalanine methyl ester or D- and L-tryptophan methyl ester AZT phosphoramidates were observed for human T-lymphoblastoid leukemia (CEM) cells incubated for 2 and 4 h with the prodrugs. AZT-MP was the primary metabolite observed for human T-lymphoblastoid leukemia (CEM) cells. In this paper, the details of using LC/MS to analyze AZT amino acid phosphoramidates in biological samples are discussed. LC/MS is an efficient method for analyzing multiple samples containing several analytes in a short period of time. The method also provides high selectivity and sensitivity, and requires minimal sample preparation. This approach should be broadly applicable for the analysis of the intracellular metabolism of nucleoside prodrugs and pronucleotides.

  18. Parameters of optical signals registered with the AZT-33IK telescope in active Radar-Progress space experiment

    NASA Astrophysics Data System (ADS)

    Eselevich, Maksim; Khakhinov, Vitaliy; Klunko, Evgeniy

    2016-09-01

    Images of Progress cargo spacecraft (PCS) and areas around them were captured by the AZT-33IK optical telescope (Sayan Observatory of ISTP SB RAS) during sessions of the active Radar-Progress space experiment. We took images of exhaust and fuel jets when propulsion systems worked and after they were cut off, during fuel system purging. In different sessions of the experiment, PCS had different orientations relative to the telescope, thus allowing us to find some parameters of the observed phenomena. These parameters make it possible to determine instants of engine ignitions, to estimate velocities of the jets, and, if necessary, to control the geometry of the space experiment. The paper reports common features of optical signals from jets measured in these experiments.

  19. Retroviral env glycoprotein trafficking and incorporation into virions.

    PubMed

    Murakami, Tsutomu

    2012-01-01

    Together with the Gag protein, the Env glycoprotein is a major retroviral structural protein and is essential for forming infectious virus particles. Env is synthesized, processed, and transported to certain microdomains at the plasma membrane and takes advantage of the same host machinery for its trafficking as that used by cellular glycoproteins. Incorporation of Env into progeny virions is probably mediated by the interaction between Env and Gag, in some cases with the additional involvement of certain host factors. Although several general models have been proposed to explain the incorporation of retroviral Env glycoproteins into virions, the actual mechanism for this process is still unclear, partly because structural data on the Env protein cytoplasmic tail is lacking. This paper presents the current understanding of the synthesis, trafficking, and virion incorporation of retroviral Env proteins.

  20. Retroviral Restriction Factors and Infectious Risk in Xenotransplantation

    PubMed Central

    Meije, Yolanda; Tönjes, Ralf R.; Fishman, Jay A.

    2010-01-01

    The clinical application of xenotransplantation poses immunologic, ethical, and microbiologic challenges. Significant progress has been made in the investigation of each of these areas. Among concerns regarding infectious risks for human xenograft recipients is the identification in swine of infectious agents including porcine endogenous retroviruses (PERV) that are capable of replication in some human cell lines. PERV replication has, however, been difficult to demonstrate in primate-derived cell lines and in preclinical studies of non-human primates receiving porcine xenografts. Endogenous “retroviral restriction factors” are intracellular proteins and components of the innate immune system that act at various steps in retroviral replication. Recent studies suggest that some of these factors may have applications in the management of endogenous retroviruses in xenotransplantation. The risks of PERV infection and the potential role of retroviral restriction factors in xenotransplantation are reviewed in detail. PMID:20642677

  1. Use of human MAR elements to improve retroviral vector production.

    PubMed

    Buceta, M; Galbete, J L; Kostic, C; Arsenijevic, Y; Mermod, N

    2011-01-01

    Retroviral vectors have many favorable properties for gene therapies, but their use remains limited by safety concerns and/or by relatively lower titers for some of the safer self-inactivating (SIN) derivatives. In this study, we evaluated whether increased production of SIN retroviral vectors can be achieved from the use of matrix attachment region (MAR) epigenetic regulators. Two MAR elements of human origin were found to increase and to stabilize the expression of the green fluorescent protein transgene in stably transfected HEK-293 packaging cells. Introduction of one of these MAR elements in retroviral vector-producing plasmids yielded higher expression of the viral vector RNA. Consistently, viral titers obtained from transient transfection of MAR-containing plasmids were increased up to sixfold as compared with the parental construct, when evaluated in different packaging cell systems and transfection conditions. Thus, use of MAR elements opens new perspectives for the efficient generation of gene therapy vectors.

  2. Retroviral integration: Site matters: Mechanisms and consequences of retroviral integration site selection.

    PubMed

    Demeulemeester, Jonas; De Rijck, Jan; Gijsbers, Rik; Debyser, Zeger

    2015-11-01

    Here, we review genomic target site selection during retroviral integration as a multistep process in which specific biases are introduced at each level. The first asymmetries are introduced when the virus takes a specific route into the nucleus. Next, by co-opting distinct host cofactors, the integration machinery is guided to particular chromatin contexts. As the viral integrase captures a local target nucleosome, specific contacts introduce fine-grained biases in the integration site distribution. In vivo, the established population of proviruses is subject to both positive and negative selection, thereby continuously reshaping the integration site distribution. By affecting stochastic proviral expression as well as the mutagenic potential of the virus, integration site choice may be an inherent part of the evolutionary strategies used by different retroviruses to maximise reproductive success.

  3. Neutralizing antibody and anti-retroviral drug sensitivities of HIV-1 isolates resistant to small molecule CCR5 inhibitors

    SciTech Connect

    Pugach, Pavel; Ketas, Thomas J.; Michael, Elizabeth; Moore, John P.

    2008-08-01

    The small molecule CCR5 inhibitors are a new class of drugs for treating infection by human immunodeficiency virus type 1 (HIV-1). They act by binding to the CCR5 co-receptor and preventing its use during HIV-1-cell fusion. Escape mutants can be raised against CCR5 inhibitors in vitro and will arise when these drugs are used clinically. Here, we have assessed the responses of CCR5 inhibitor-resistant viruses to other anti-retroviral drugs that act by different mechanisms, and their sensitivities to neutralizing antibodies (NAbs). The rationale for the latter study is that the resistance pathway for CCR5 inhibitors involves changes in the HIV-1 envelope glycoproteins (Env), which are also targets for NAbs. The escape mutants CC101.19 and D1/85.16 were selected for resistance to AD101 and vicriviroc (VVC), respectively, from the primary R5 HIV-1 isolate CC1/85. Each escape mutant was cross-resistant to other small molecule CCR5 inhibitors (aplaviroc, maraviroc, VVC, AD101 and CMPD 167), but sensitive to protein ligands of CCR5: the modified chemokine PSC-RANTES and the humanized MAb PRO-140. The resistant viruses also retained wild-type sensitivity to the nucleoside reverse transcriptase inhibitor (RTI) zidovudine, the non-nucleoside RTI nevirapine, the protease inhibitor atazanavir and other attachment and fusion inhibitors that act independently of CCR5 (BMS-806, PRO-542 and enfuvirtide). Of note is that the escape mutants were more sensitive than the parental CC1/85 isolate to a subset of neutralizing monoclonal antibodies and to some sera from HIV-1-infected people, implying that sequence changes in Env that confer resistance to CCR5 inhibitors can increase the accessibility of some NAb epitopes. The need to preserve NAb resistance may therefore be a constraint upon how escape from CCR5 inhibitors occurs in vivo.

  4. Neutralizing antibody and anti-retroviral drug sensitivities of HIV-1 isolates resistant to small molecule CCR5 inhibitors

    PubMed Central

    Pugach, Pavel; Ketas, Thomas J.; Michael, Elizabeth; Moore, John P.

    2008-01-01

    The small molecule CCR5 inhibitors are a new class of drugs for treating infection by human immunodeficiency virus type 1 (HIV-1). They act by binding to the CCR5 co-receptor and preventing its use during HIV-1-cell fusion. Escape mutants can be raised against CCR5 inhibitors in vitro and will arise when these drugs are used clinically. Here, we have assessed the responses of CCR5 inhibitor-resistant viruses to other anti-retroviral drugs that act by different mechanisms, and their sensitivities to neutralizing antibodies (NAbs). The rationale for the latter study is that the resistance pathway for CCR5 inhibitors involves changes in the HIV-1 envelope glycoproteins (Env), which are also targets for NAbs. The escape mutants CC101.19 and D1/85.16 were selected for resistance to AD101 and vicriviroc (VVC), respectively, from the primary R5 HIV-1 isolate CC1/85. Each escape mutant was cross resistant to other small molecule CCR5 inhibitors (aplaviroc, maraviroc, VVC, AD101 and CMPD 167), but sensitive to protein ligands of CCR5: the modified chemokine PSC-RANTES and the humanized MAb PRO 140. The resistant viruses also retained wild-type sensitivity to the nucleoside reverse transcriptase inhibitor (RTI) zidovudine, the non-nucleoside RTI nevirapine, the protease inhibitor atazanavir and other attachment and fusion inhibitors that act independently of CCR5 (BMS-806, PRO-542 and enfuvirtide). Of note is that the escape mutants were more sensitive than the parental CC1/85 isolate to a subset of neutralizing monoclonal antibodies and to some sera from HIV-1-infected people, implying that sequence changes in Env that confer resistance to CCR5 inhibitors can increase the accessibility of some NAb epitopes. The need to preserve NAb resistance may therefore be a constraint upon how escape from CCR5 inhibitors occurs in vivo. PMID:18519143

  5. Direct demonstration of retroviral recombination in a rhesus monkey.

    PubMed Central

    Wooley, D P; Smith, R A; Czajak, S; Desrosiers, R C

    1997-01-01

    Recombination may be an important mechanism for increasing variation in retroviral populations. Retroviral recombination has been demonstrated in tissue culture systems by artificially creating doubly infected cells. Evidence for retroviral recombination in vivo is indirect and is based principally on the identification of apparently mosaic human immunodeficiency virus type 1 genomes from phylogenetic analyses of viral sequences. We infected a rhesus monkey with two different molecularly cloned strains of simian immunodeficiency virus. One strain of virus had a deletion in vpx and vpr, and the other strain had a deletion in nef. Each strain on its own induced low virus loads and was nonpathogenic in rhesus monkeys. When injected simultaneously into separate legs of the same monkey, persistent high virus loads and declines in CD4+ lymphocyte concentrations were observed. Analysis of proviral DNA isolated directly from peripheral blood mononuclear cells showed that full-length, nondeleted SIVmac239 predominated by 2 weeks after infection. These results provide direct experimental evidence for genetic recombination between two different retroviral strains in an infected host. The results illustrate the ease and rapidity with which recombination can occur in an infected animal and the selection that can occur for variants generated by genetic recombination. PMID:9371629

  6. The changes in bone organic and inorganic matrix in newborn rats after maternal application of antiretroviral agents: Indinavir and zidovudine.

    PubMed

    Maciejewska, Karina; Drzazga, Zofia; Kaszuba, Michal

    2015-05-06

    This work presents results concerning influence of indinavir (protease inhibitor, PI(1)) and zidovudine (nucleoside and nucleotide inhibitor of reverse transcriptase, NRTI) administered to pregnant Wistar rat females on organic and mineral constituents of bones and teeth (mandibles, skulls, tibiae, femurs, and incisors) of their offspring at the age of: 7, 14, and 28 days studied by means of induced laser and X-ray fluorescence spectroscopy supported by digital radiography. Influence of indinavir administered to pregnant female rats on bone of their offspring revealed mainly in changes of mineral concentration: lowered Ca concentration and disturbances of trace elements. Zidovudine influenced organic matter more than inorganic matrix which was seen in enhancement of LIF fluorescence. However, there was also an unexpected increase of bone density for rats from zidovudine group, unlike indinavir group, observed. Our studies suggest that studied antiretroviral agents given to pregnant women, may have different destructive impact on bone state of their offspring in the first period of life. Maternal administration of zidovudine may delay development of organic matrix, while indinavir may have adverse effects on inorganic structure.

  7. The engineered thymidylate kinase (TMPK)/AZT enzyme-prodrug axis offers efficient bystander cell killing for suicide gene therapy of cancer.

    PubMed

    Sato, Takeya; Neschadim, Anton; Lavie, Arnon; Yanagisawa, Teruyuki; Medin, Jeffrey A

    2013-01-01

    We previously described a novel suicide (or 'cell fate control') gene therapy enzyme/prodrug system based on an engineered variant of human thymidylate kinase (TMPK) that potentiates azidothymidine (AZT) activation. Delivery of a suicide gene sequence into tumors by lentiviral transduction embodies a cancer gene therapy that could employ bystander cell killing as a mechanism driving significant tumor regression in vivo. Here we present evidence of a significant bystander cell killing in vitro and in vivo mediated by the TMPK/AZT suicide gene axis that is reliant on the formation of functional gap-junctional intercellular communications (GJICs). Potentiation of AZT activation by the engineered TMPK expressed in the human prostate cancer cell line, PC-3, resulted in effective bystander killing of PC-3 cells lacking TMPK expression--an effect that could be blocked by the GJIC inhibitor, carbenoxolone. Although GJICs are mainly formed by connexins, a new family of GJIC molecules designated pannexins has been recently identified. PC-3 cells expressed both connexin43 (Cx43) and Pannexin1 (Panx1), but Panx1 expression predominated at the plasma membrane, whereas Cx43 expression was primarily localized to the cytosol. The contribution of bystander effects to the reduction of solid tumor xenografts established by the PC-3 cell line was evaluated in an animal model. We demonstrate the contribution of bystander cell killing to tumor regression in a xenograft model relying on the delivery of expression of the TMPK suicide gene into tumors via direct intratumoral injection of recombinant therapeutic lentivirus. Taken together, our data underscore that the TMPK/AZT enzyme-prodrug axis can be effectively utilized in suicide gene therapy of solid tumors, wherein significant tumor regression can be achieved via bystander effects mediated by GJICs.

  8. 'Click' chemistry synthesis and capillary electrophoresis study of 1,4-linked 1,2,3-triazole AZT-systemin conjugate.

    PubMed

    Dobkowski, Michał; Szychowska, Aleksandra; Pieszko, Małgorzata; Miszka, Anna; Wojciechowska, Monika; Alenowicz, Magdalena; Ruczyński, Jarosław; Rekowski, Piotr; Celewicz, Lech; Barciszewski, Jan; Mucha, Piotr

    2014-09-01

    The Cu(I) catalyzed Huisgen 1,3-dipolar azide-alkyne cycloaddition (CuAAC) was applied for a nucleoside-peptide bioconjugation. Systemin (Sys), an 18-aa plant signaling peptide naturally produced in response to wounding or pathogen attack, was chemically synthesized as its N-propynoic acid functionalized analog (Prp-Sys) using the SPPS. Next, CuAAC was applied to conjugate Prp-Sys with 3'-azido-2',3'-dideoxythymidine (AZT), a model cargo molecule. 1,4-Linked 1,2,3-triazole AZT-Sys conjugate was designed to characterize the spreading properties and ability to translocate of cargo molecules of systemin. CuAAC allowed the synthesis of the conjugate in a chemoselective and regioselective manner, with high purity and yield. The presence of Cu(I) ions generated in situ drove the CuAAC reaction to completion within a few minutes without any by-products. Under typical separation conditions of phosphate 'buffer' at low pH and uncoated fused bare-silica capillary, an increasing peak intensity assigned to triazole-linked AZT-Sys conjugate was observed using capillary electrophoresis (CE) during CuAAC. CE analysis showed that systemin peptides are stable in tomato leaf extract for up to a few hours. CE-ESI-MS revealed that the native Sys and its conjugate with AZT are translocated through the tomato stem and can be directly detected in stem exudates. The results show potential application of systemin as a transporter of low molecular weight cargo molecules in tomato plant and of CE method to characterize a behavior of plant peptides and its analogs.

  9. Retroviral restriction and dependency factors in primates and carnivores.

    PubMed

    Fadel, Hind J; Poeschla, Eric M

    2011-10-15

    Recent studies have extended the rapidly developing retroviral restriction factor field to cells of carnivore species. Carnivoran genomes, and the domestic cat genome in particular, are revealing intriguing properties vis-à-vis the primate and feline lentiviruses, not only with respect to their repertoires of virus-blocking restriction factors but also replication-enabling dependency factors. Therapeutic application of restriction factors is envisioned for human immunodeficiency virus (HIV) disease and the feline immunodeficiency virus (FIV) model has promise for testing important hypotheses at the basic and translational level. Feline cell-tropic HIV-1 clones have also been generated by a strategy of restriction factor evasion. We review progress in this area in the context of what is known about retroviral restriction factors such as TRIM5α, TRIMCyp, APOBEC3 proteins and BST-2/Tetherin.

  10. Convergent capture of retroviral superantigens by mammalian herpesviruses

    PubMed Central

    Aswad, Amr; Katzourakis, Aris

    2015-01-01

    Horizontal gene transfer from retroviruses to mammals is well documented and extensive, but is rare between unrelated viruses with distinct genome types. Three herpesviruses encode a gene with similarity to a retroviral superantigen gene (sag) of the unrelated mouse mammary tumour virus (MMTV). We uncover ancient retroviral sags in over 20 mammals to reconstruct their shared history with herpesviral sags, revealing that the acquisition is a convergent evolutionary event. A retrovirus circulating in South American primates over 10 million years ago was the source of sag in two monkey herpesviruses, and a different retrovirus was the source of sag in a Peruvian rodent herpesvirus. We further show through a timescaled phylogenetic analysis that a cross-species transmission of monkey herpesviruses occurred after the acquisition of sag. These results reveal that a diverse range of ancient sag-containing retroviruses independently donated sag twice from two separate lineages that are distinct from MMTV. PMID:26400439

  11. Retroviral vector production under serum deprivation: The role of lipids.

    PubMed

    Rodrigues, A F; Carmo, M; Alves, P M; Coroadinha, A S

    2009-12-15

    The use of retroviral vectors for gene therapy applications demands high titer preparations and stringent quality standards. However, the manufacturing of these vectors still represents a highly challenging task due to the low productivity of the cell lines and reduced stability of the vector infectivity, particularly under serum-free conditions. With the objective of understanding the major limitations of retroviral vector production under serum deprivation, a thorough study of viral production kinetics, vector characterization and cell growth and metabolic behavior was conducted, for 293 FLEX 18 and Te Fly Ga 18 producer cell lines using different serum concentrations. The reduction of serum supplementation in the culture medium resulted in pronounced decreases in cell productivity of infectious vector, up to ninefold in 293 FLEX 18 cells and sevenfold in Te Fly Ga 18 cells. Total particles productivity was maintained, as assessed by measuring viral RNA; therefore, the decrease in infectious vector production could be attributed to higher defective particles output. The absence of the serum lipid fraction was found to be the major cause for this decrease in cell viral productivity. The use of delipidated serum confirmed the requirement of serum lipids, particularly cholesterol, as its supplementation not only allowed the total recovery of viral titers as well as additional production increments in both cell lines when comparing with the standard 10% (v/v) FBS supplementation. This work identified lower production ratios of infectious particles/total particles as the main restraint of retroviral vector production under serum deprivation; this is of the utmost importance concerning the clinical efficacy of the viral preparations. Lipids were confirmed as the key serum component correlated with the production of infective retroviral vectors and this knowledge can be used to efficiently design medium supplementation strategies for serum-free production. Biotechnol

  12. Deciphering the Code for Retroviral Integration Target Site Selection

    PubMed Central

    Santoni, Federico Andrea; Hartley, Oliver; Luban, Jeremy

    2010-01-01

    Upon cell invasion, retroviruses generate a DNA copy of their RNA genome and integrate retroviral cDNA within host chromosomal DNA. Integration occurs throughout the host cell genome, but target site selection is not random. Each subgroup of retrovirus is distinguished from the others by attraction to particular features on chromosomes. Despite extensive efforts to identify host factors that interact with retrovirion components or chromosome features predictive of integration, little is known about how integration sites are selected. We attempted to identify markers predictive of retroviral integration by exploiting Precision-Recall methods for extracting information from highly skewed datasets to derive robust and discriminating measures of association. ChIPSeq datasets for more than 60 factors were compared with 14 retroviral integration datasets. When compared with MLV, PERV or XMRV integration sites, strong association was observed with STAT1, acetylation of H3 and H4 at several positions, and methylation of H2AZ, H3K4, and K9. By combining peaks from ChIPSeq datasets, a supermarker was identified that localized within 2 kB of 75% of MLV proviruses and detected differences in integration preferences among different cell types. The supermarker predicted the likelihood of integration within specific chromosomal regions in a cell-type specific manner, yielding probabilities for integration into proto-oncogene LMO2 identical to experimentally determined values. The supermarker thus identifies chromosomal features highly favored for retroviral integration, provides clues to the mechanism by which retrovirus integration sites are selected, and offers a tool for predicting cell-type specific proto-oncogene activation by retroviruses. PMID:21124862

  13. Retroviral Infections in Peruvian Men Who Have Sex With Men

    PubMed Central

    La Rosa, Alberto M.; Zunt, Joseph R.; Peinado, Jesus; Lama, Javier R.; Ton, Thanh G.N.; Suarez, Luis; Pun, Monica; Cabezas, Cesar; Sanchez, Jorge

    2009-01-01

    We tested 2,655 Peruvian MSM for retroviral infection: HTLV-1 was detected in 48 (1.8%), HTLV-2 in 28 (1.1%), and HTLV-1 and -2 in 5 (0.2%); HIV infection was detected in 329 (12.4 %); 24 (7.3%) were coinfected with HTLV. Risk factors for HTLV-1 and -2 varied with sexual role. PMID:19480577

  14. Retroviral integrase protein and intasome nucleoprotein complex structures

    PubMed Central

    Grawenhoff, Julia; Engelman, Alan N

    2017-01-01

    Retroviral replication proceeds through the integration of a DNA copy of the viral RNA genome into the host cellular genome, a process that is mediated by the viral integrase (IN) protein. IN catalyzes two distinct chemical reactions: 3’-processing, whereby the viral DNA is recessed by a di- or trinucleotide at its 3’-ends, and strand transfer, in which the processed viral DNA ends are inserted into host chromosomal DNA. Although IN has been studied as a recombinant protein since the 1980s, detailed structural understanding of its catalytic functions awaited high resolution structures of functional IN-DNA complexes or intasomes, initially obtained in 2010 for the spumavirus prototype foamy virus (PFV). Since then, two additional retroviral intasome structures, from the α-retrovirus Rous sarcoma virus (RSV) and β-retrovirus mouse mammary tumor virus (MMTV), have emerged. Here, we briefly review the history of IN structural biology prior to the intasome era, and then compare the intasome structures of PFV, MMTV and RSV in detail. Whereas the PFV intasome is characterized by a tetrameric assembly of IN around the viral DNA ends, the newer structures harbor octameric IN assemblies. Although the higher order architectures of MMTV and RSV intasomes differ from that of the PFV intasome, they possess remarkably similar intasomal core structures. Thus, retroviral integration machineries have adapted evolutionarily to utilize disparate IN elements to construct convergent intasome core structures for catalytic function. PMID:28289517

  15. Proteochemometrics mapping of the interaction space for retroviral proteases and their substrates.

    PubMed

    Kontijevskis, Aleksejs; Petrovska, Ramona; Yahorava, Sviatlana; Komorowski, Jan; Wikberg, Jarl E S

    2009-07-15

    Understanding the complex interactions of retroviral proteases with their ligands is an important scientific challenge in efforts to achieve control of retroviral infections. Development of drug resistance because of high mutation rates and extensive polymorphisms causes major problems in treating the deadly diseases these viruses cause, and prompts efforts to identify new strategies. Here we report a comprehensive analysis of the interaction of 63 retroviral proteases from nine different viral species with their substrates and inhibitors based on publicly available data from the past 17years of retroviral research. By correlating physico-chemical descriptions of retroviral proteases and substrates to their biological activities we constructed a highly statistically valid 'proteochemometric' model for the interactome of retroviral proteases. Analysis of the model indicated amino acid positions in retroviral proteases with the highest influence on ligand activity and revealed general physicochemical properties essential for tight binding of substrates across multiple retroviral proteases. Hexapeptide inhibitors developed based on the discovered general properties effectively inhibited HIV-1 proteases in vitro, and some exhibited uniformly high inhibitory activity against all HIV-1 proteases mutants evaluated. A generalized proteochemometric model for retroviral proteases interactome has been created and analysed in this study. Our results demonstrate the feasibility of using the developed general strategy in the design of inhibitory peptides that can potentially serve as templates for drug resistance-improved HIV retardants.

  16. Microbead-assisted retroviral transduction for clinical application.

    PubMed

    Heemskerk, Bianca; Jorritsma, Annelies; Gomez-Eerland, Raquel; Toebes, Mireille; Haanen, John B A G; Schumacher, Ton N M

    2010-10-01

    Retroviral transduction is the most commonly used strategy to obtain long-term expression of therapeutic genes. To efficiently transduce mammalian cells, a recombinant fibronectin molecule, RetroNectin, is generally used to juxtapose viral particles and cells, and thereby enhance viral uptake. Although this strategy has become widely adopted, in particular for the genetic modification of hematopoietic cells, several limitations apply. For example, it requires the use of culture systems that allow protein coating, something that is not possible for many of the closed cell culture systems that are used in clinical trials. Furthermore, efficient transduction is obtained only when culture systems can be exposed to centrifugation, an approach termed spin transduction. Here, we describe a novel and more potent strategy for the transduction of T cells that can be applied on a clinical scale. We show that RetroNectin can efficiently be coated onto epoxy-modified paramagnetic beads. After a blocking step, these beads can subsequently bind retroviral particles from viral supernatants, rendering such supernatants largely devoid of functional viral particles. Addition of these virus-loaded beads to activated T cells results in efficient retroviral infection. Importantly, transduction does not require the use of culture systems that are compatible with protein coating, nor is it dependent on centrifugation of either the viral supernatant or the cells. Finally, cell growth, phenotype, and function of spin-transduced versus bead-transduced cells are comparable. Viral coating of microbeads should facilitate the production of genetically modified cells, in particular for use in clinical trials.

  17. Retroviral infection in Peruvian men who have sex with men.

    PubMed

    La Rosa, Alberto M; Zunt, Joseph R; Peinado, Jesus; Lama, Javier R; Ton, Thanh G N; Suarez, Luis; Pun, Monica; Cabezas, Cesar; Sanchez, Jorge

    2009-07-01

    We tested 2655 Peruvian men who have sex with men for the presence of retroviral infection. Human T cell lymphotropic virus type 1 (HTLV-1) was detected in 48 (1.8%) of the patients, HTLV-2 was detected in 28 (1.1%), and HTLV-1 and HTLV-2 were both detected in 5 (0.2%). Human immunodeficiency virus infection was detected in 329 (12.4%) of the patients; 24 (7.3%) had HTLV coinfection. Risk factors for HTLV-1 and HTLV-2 infection varied with sexual role.

  18. Release testing of retroviral vectors and gene-modified cells.

    PubMed

    Nordling, Diana; Kaiser, Anne; Reeves, Lilith

    2009-01-01

    This chapter will review the design and execution of release testing requirements for retroviral vectors and gene-modified cells consistent with ensuring the success of the clinical trial on the basis of current US regulatory requirements. It is the ethical and legal responsibility of the clinical trial sponsor(s) to ensure safety of the patients through proper evaluation of the drug products prior to use. Any clinical trial drug product used in human subjects must be produced and evaluated for safety, quality, purity, and effectiveness according to Current Good Manufacturing Practices appropriate for the stage of clinical development.

  19. Exposure to zidovudine adversely affects mitochondrial turnover in primary T cells.

    PubMed

    Wallace, Zoë R; Sanderson, Sharon; Simon, Anna Katarina; Dorrell, Lucy

    2016-09-01

    Zidovudine (ZDV) is a widely used component of antiretroviral therapy (ART) in resource-limited settings, despite its known adverse effects, which include mitochondrial toxicity in muscle, liver and adipose tissue. It has also been associated with impaired immunological recovery. We hypothesised that ZDV might impair mitochondrial health and survival of primary T cells. We performed a cross-sectional analysis of mitochondrial function, mitophagy and susceptibility to apoptosis in healthy donor primary T cells after exposure to ZDV in vitro, together with T cells from patients who were virologically suppressed on ZDV-containing ART regimens for ≥1 year and age-matched subjects receiving non-ZDV ART regimens. The proportion of T cells expressing mitochondrial reactive oxygen species (mtROS) was significantly higher after in vitro (CD4(+) T cells and CD8(+) T cells) and in vivo (CD4(+) T cells) exposure to ZDV than other antiretroviral agents. We did not detect any effect of ZDV on mitophagy, as indicated by change in autophagic flux. However, spontaneous apoptosis, indicated by upregulation of caspase-3 was greater in ZDV-exposed T cells. In conclusion, ZDV exposure was associated with impaired mitochondrial turnover and increased susceptibility to apoptosis in T cells. These mechanisms could contribute to sub-optimal immune reconstitution.

  20. Biphasic Elimination of Tenofovir Diphosphate and Nonlinear Pharmacokinetics of Zidovudine Triphosphate in a Microdosing Study

    PubMed Central

    Chen, Jianmeng; Flexner, Charles; Liberman, Rosa G.; Skipper, Paul L.; Louissaint, Nicolette; Tannenbaum, Steven R.; Hendrix, Craig; Fuchs, Edward

    2012-01-01

    Objective Phase 0 studies can provide initial pharmacokinetics (PK) data in humans and help to facilitate early drug development, but their predictive value for standard dosing is controversial. To evaluate the prediction of microdosing for active intracellular drug metabolites, we compared the PK profile of two antiretroviral drugs, zidovudine (ZDV) and tenofovir (TFV), in microdose and standard dosing regimens. Study Design We administered a microdose (100 μg) of 14C-labeled drug (ZDV or tenofovir disoproxil fumarate (TDF)) with or without a standard unlabelled dose (300 mg) to healthy volunteers. Both the parent drug in plasma and the active metabolite, ZDV-triphosphate (ZDV-TP) or TFV-diphosphate (TFV-DP) in PBMCs and CD4+ cells were measured by AMS. Results The intracellular ZDV-TP concentration increased less than proportionally over the dose range studied (100 μg to 300 mg), while the intracellular TFV-DP PK were linear over the same dose range. ZDV-TP concentrations were lower in CD4+ cells versus total peripheral blood mononuclear cells (PBMCs), while TFV-DP concentrations were not different in CD4+ cells and PBMCs. Conclusion Our data were consistent with a rate-limiting step in the intracellular phosphorylation of ZDV but not TFV. AMS shows promise for predicting the PK of active intracellular metabolites of nucleosides, but nonlinearity of PK may be seen with some drugs. PMID:23187888

  1. Composite alginate hydrogel microparticulate delivery system of zidovudine hydrochloride based on counter ion induced aggregation

    PubMed Central

    Roy, Harekrishna; Rao, P. Venkateswar; Panda, Sanjay Kumar; Biswal, Asim Kumar; Parida, Kirti Ranjan; Dash, Jharana

    2014-01-01

    Aim: The present study deals with preparation of zidovudine loaded microparticle by counter ion induced aggregation method. During this study effect of polyacrylates and hypromellose polymers on release study were investigated. Materials and Methods: The ion induced aggregated alginate based microparticles were characterized for surface morphology, particle size analysis, drug entrapment study, in-vitro study, Fourier-transform infrared (FTIR) spectroscopy, and differential scanning calorimetry (DSC) study. Results and Discussion: The result showed Eudragit RL-100 (ERL) based formulations had smoother surface as well as their mean particle sizes were found greater compared with Eudragit RS-100 (ERS) microparticles. Furthermore, drug entrapments were found to be more in ERL formulae as compared with ERS. RL3 released 101.05% drug over a period of 8th h and followed Higuchi profile and Fickian diffusion. Moreover, data obtained illustrated that, higher amount of quaternary ammonium group, alkali value, and glass transition temperature may be possible reason for improving permeability of ERL based formulations. It was also noticed, hyroxypropyl methylcellulose (HPMC) K4M premium grade polymer sustained drug release more than HPMC K15M. In addition, drug-excipient interaction study was carried out by FTIR and DSC study. PMID:25298940

  2. A new generation of retroviral producer cells: predictable and stable virus production by Flp-mediated site-specific integration of retroviral vectors.

    PubMed

    Schucht, R; Coroadinha, A S; Zanta-Boussif, M A; Verhoeyen, E; Carrondo, M J T; Hauser, H; Wirth, Dagmar

    2006-08-01

    We developed a new strategy that provides well-defined high-titer producer cells for recombinant retroviruses in a minimum amount of time. The strategy involves the targeted integration of the retroviral vector into a chromosomal locus with favorable properties. For proof of concept we established a novel HEK293-based retroviral producer cell line, called Flp293A, with a single-copy retroviral vector integrated at a selected chromosomal locus. The vector was flanked by noninteracting Flp-recombinase recognition sites and was exchanged for different retroviral vectors via Flp-mediated cassette exchange. All analyzed cell clones showed correct integration and identical titers for each of the vectors, confirming that the expression characteristics from the parental cell were preserved. Titers up to 2.5 x 10(7) infectious particles/10(6) cells were obtained. Also, high-titer producer cells for a therapeutic vector that encodes the 8.9-kb collagen VII cDNA in a marker-free cassette were obtained within 3 weeks without screening. Thus, we provide evidence that the precise integration of viral vectors into a favorable chromosomal locus leads to high and predictable virus production. This method is compatible with other retroviral vectors, including self-inactivating vectors and marker-free vectors. Further, it provides a tool for evaluation of different retroviral vector designs.

  3. Retroviral transcriptional regulation and embryonic stem cells: war and peace.

    PubMed

    Schlesinger, Sharon; Goff, Stephen P

    2015-03-01

    Retroviruses have evolved complex transcriptional enhancers and promoters that allow their replication in a wide range of tissue and cell types. Embryonic stem (ES) cells, however, characteristically suppress transcription of proviruses formed after infection by exogenous retroviruses and also of most members of the vast array of endogenous retroviruses in the genome. These cells have unusual profiles of transcribed genes and are poised to make rapid changes in those profiles upon induction of differentiation. Many of the transcription factors in ES cells control both host and retroviral genes coordinately, such that retroviral expression patterns can serve as markers of ES cell pluripotency. This overlap is not coincidental; retrovirus-derived regulatory sequences are often used to control cellular genes important for pluripotency. These sequences specify the temporal control and perhaps "noisy" control of cellular genes that direct proper cell gene expression in primitive cells and their differentiating progeny. The evidence suggests that the viral elements have been domesticated for host needs, reflecting the wide-ranging exploitation of any and all available DNA sequences in assembling regulatory networks.

  4. The Early Years of Retroviral Protease Crystal Structures

    PubMed Central

    Miller, Maria

    2010-01-01

    Soon after its discovery, the attempts to develop anti-AIDS therapeutics focused on the retroviral protease (PR) — an enzyme used by lentiviruses to process the precursor polypeptide into mature viral proteins. An urgent need for the three-dimensional structure of PR to guide rational drug design prompted efforts to produce milligram quantities of this enzyme. However, only minute amounts of PR were present in the HIV-1 and HIV-2 viruses, and initial attempts to express this protein in bacteria were not successful. This review describes X-ray crystallographic studies of the retroviral proteases carried out at NCI-Frederick in the late 1980s and early 1990s and puts into perspective the crucial role that the total protein chemical synthesis played in unraveling the structure, mechanism of action, and inhibition of HIV-1 PR. Notably, the first fully correct structure of HIV-1 PR and the first cocrystal structure of its complex with an inhibitor (a substrate-derived, reduced isostere hexapeptide MVT-101) were determined using chemically synthesized protein. Most importantly, these sets of coordinates were made freely available to the research community and were used worldwide to solve X-ray structures of HIV-1 PR complexes with an array of inhibitors and set in motion a variety of theoretical studies. Publication of the structure of chemically synthesized HIV-1 PR complexed with MVT-101 preceded only by six years the approval of the first PR inhibitor as an anti-AIDS drug. PMID:20593466

  5. Changing T cell specificity by retroviral T cell receptor display

    PubMed Central

    Kessels, Helmut W. H. G.; van den Boom, Marly D.; Spits, Hergen; Hooijberg, Erik; Schumacher, Ton N. M.

    2000-01-01

    The diversity of the T cell receptor (TCR) repertoire is limited, because of the processes of positive and negative T cell selection. To obtain T cells with specificities beyond the immune system's capacity, we have developed a strategy for retroviral TCR display. In this approach, a library of T cell variants is generated in vitro and introduced into a TCR-negative murine T cell line by retroviral transfer. We document the value of TCR display by the creation of a library of an influenza A-specific TCR and the subsequent in vitro selection of TCRs that either recognize the parental influenza epitope or that have acquired a specificity for a different influenza A strain. The resulting in vitro selected TCRs induce efficient T cell activation after ligand recognition and are of equal or higher potency than the in vivo generated parent receptor. TCR display should prove a useful strategy for the generation of high-affinity tumor-specific TCRs for gene transfer purposes. PMID:11121060

  6. Retroviral Transcriptional Regulation and Embryonic Stem Cells: War and Peace

    PubMed Central

    Schlesinger, Sharon

    2014-01-01

    Retroviruses have evolved complex transcriptional enhancers and promoters that allow their replication in a wide range of tissue and cell types. Embryonic stem (ES) cells, however, characteristically suppress transcription of proviruses formed after infection by exogenous retroviruses and also of most members of the vast array of endogenous retroviruses in the genome. These cells have unusual profiles of transcribed genes and are poised to make rapid changes in those profiles upon induction of differentiation. Many of the transcription factors in ES cells control both host and retroviral genes coordinately, such that retroviral expression patterns can serve as markers of ES cell pluripotency. This overlap is not coincidental; retrovirus-derived regulatory sequences are often used to control cellular genes important for pluripotency. These sequences specify the temporal control and perhaps “noisy” control of cellular genes that direct proper cell gene expression in primitive cells and their differentiating progeny. The evidence suggests that the viral elements have been domesticated for host needs, reflecting the wide-ranging exploitation of any and all available DNA sequences in assembling regulatory networks. PMID:25547290

  7. Evaluation of Bystander Cell Killing Effects in Suicide Gene Therapy of Cancer: Engineered Thymidylate Kinase (TMPK)/AZT Enzyme-Prodrug Axis.

    PubMed

    Sato, Takeya; Neschadim, Anton; Nakagawa, Ryo; Yanagisawa, Teruyuki; Medin, Jeffrey A

    2015-01-01

    Suicide gene therapy of cancer (SGTC) entails the introduction of a cDNA sequence into tumor cells whose polypeptide product is capable of either directly activating apoptotic pathways itself or facilitating the activation of pharmacologic agents that do so. The latter class of SGTC approaches is of the greater utility in cancer therapy owing to the ability of some small, activated cytotoxic compounds to diffuse from their site of activation into neighboring malignant cells, where they can also mediate destruction. This phenomenon, termed "bystander killing", can be highly advantageous in driving significant tumor regression in vivo without the requirement of transduction of each and every tumor cell with the suicide gene. We have developed a robust suicide gene therapy enzyme/prodrug system based on an engineered variant of the human thymidylate kinase (TMPK), which has been endowed with the ability to drive azidothymidine (AZT) activation. Delivery of this suicide gene sequence into tumors by means of recombinant lentivirus-mediated transduction embodies an SGTC strategy that successfully employs bystander cell killing as a mechanism to achieve significant ablation of solid tumors in vivo. Thus, this engineered TMPK/AZT suicide gene therapy axis holds great promise for clinical application in the treatment of inoperable solid tumors in the neoadjuvant setting. Here we present detailed procedures for the preparation of recombinant TMPK-based lentivirus, transduction of target cells, and various approaches for the evaluation of bystander cell killing effects in SGCT in both in vitro and in vivo models.

  8. AIDS Issues (Part 1). Hearings before the Subcommittee on Health and the Environment of the Committee on Energy and Commerce. House of Representatives, One Hundredth Congress, First Session (March 10 1987--Cost and Availability of AZT; April 27, 1987--AIDS and Minorities; September 22, 1987--AIDS Research and Education).

    ERIC Educational Resources Information Center

    Congress of the U.S., Washington, DC. House Committee on Energy and Commerce.

    The texts of three hearings on issues connected with AIDS (Acquired Immune Deficiency Syndrome) are recorded in this document. The first hearing concerned the availability and cost of the drug azidothymidine (AZT) for victims of the disease and considered such questions as what a fair price for AZT is, who will pay for people currently being…

  9. Zidovudine, an anti-viral drug, resensitizes gemcitabine-resistant pancreatic cancer cells to gemcitabine by inhibition of the Akt-GSK3β-Snail pathway.

    PubMed

    Namba, T; Kodama, R; Moritomo, S; Hoshino, T; Mizushima, T

    2015-06-25

    Pancreatic cancer is one of the most difficult malignancies to treat owing to the rapid acquisition of resistance to chemotherapy. Gemcitabine, a first-line treatment for pancreatic cancer, prolongs patient survival by several months, and combination treatment with gemcitabine and other anti-cancer drugs in the clinic do not show any significant effects on overall survival. Thus, identification of a drug that resensitizes gemcitabine-resistant pancreatic cancer to gemcitabine and a better understanding of the molecular mechanisms of gemcitabine resistance are critical to develop new therapeutic options for pancreatic cancer. Here, we report that zidovudine resensitizes gemcitabine-resistant pancreatic cancer to gemcitabine as shown by screening a compound library, including clinical medicine, using gemcitabine-resistant cells. In analyzing the molecular mechanisms of zidovudine effects, we found that the epithelial-to-mesenchymal transition (EMT)-like phenotype and downregulation of human equilibrative nucleoside transporter 1 (hENT1) are essential for the acquisition of gemcitabine resistance, and zidovudine restored these changes. The chemical biology investigations also revealed that activation of the Akt-GSK3β-Snail1 pathway in resistant cells is a key signaling event for gemcitabine resistance, and zidovudine resensitized resistant cells to gemcitabine by inhibiting this activated pathway. Moreover, our in vivo study demonstrated that co-administration of zidovudine and gemcitabine strongly suppressed the formation of tumors by gemcitabine-resistant pancreatic cancer and prevented gemcitabine-sensitive pancreatic tumors from acquiring gemcitabine-resistant properties, inducing an EMT-like phenotype and downregulating hENT1 expression. These results suggested that co-treatment with zidovudine and gemcitabine may become a novel therapeutic strategy for pancreatic cancer by inhibiting chemoresistance-specific signaling.

  10. Zidovudine, an anti-viral drug, resensitizes gemcitabine-resistant pancreatic cancer cells to gemcitabine by inhibition of the Akt-GSK3β-Snail pathway

    PubMed Central

    Namba, T; Kodama, R; Moritomo, S; Hoshino, T; Mizushima, T

    2015-01-01

    Pancreatic cancer is one of the most difficult malignancies to treat owing to the rapid acquisition of resistance to chemotherapy. Gemcitabine, a first-line treatment for pancreatic cancer, prolongs patient survival by several months, and combination treatment with gemcitabine and other anti-cancer drugs in the clinic do not show any significant effects on overall survival. Thus, identification of a drug that resensitizes gemcitabine-resistant pancreatic cancer to gemcitabine and a better understanding of the molecular mechanisms of gemcitabine resistance are critical to develop new therapeutic options for pancreatic cancer. Here, we report that zidovudine resensitizes gemcitabine-resistant pancreatic cancer to gemcitabine as shown by screening a compound library, including clinical medicine, using gemcitabine-resistant cells. In analyzing the molecular mechanisms of zidovudine effects, we found that the epithelial-to-mesenchymal transition (EMT)-like phenotype and downregulation of human equilibrative nucleoside transporter 1 (hENT1) are essential for the acquisition of gemcitabine resistance, and zidovudine restored these changes. The chemical biology investigations also revealed that activation of the Akt-GSK3β-Snail1 pathway in resistant cells is a key signaling event for gemcitabine resistance, and zidovudine resensitized resistant cells to gemcitabine by inhibiting this activated pathway. Moreover, our in vivo study demonstrated that co-administration of zidovudine and gemcitabine strongly suppressed the formation of tumors by gemcitabine-resistant pancreatic cancer and prevented gemcitabine-sensitive pancreatic tumors from acquiring gemcitabine-resistant properties, inducing an EMT-like phenotype and downregulating hENT1 expression. These results suggested that co-treatment with zidovudine and gemcitabine may become a novel therapeutic strategy for pancreatic cancer by inhibiting chemoresistance-specific signaling. PMID:26111057

  11. Retroviral vectors for homologous recombination provide efficient cloning and expression in mammalian cells.

    PubMed

    Kobayashi, Eiji; Kishi, Hiroyuki; Ozawa, Tatsuhiko; Horii, Masae; Hamana, Hiroshi; Nagai, Terumi; Muraguchi, Atsushi

    2014-02-14

    Homologous recombination technologies enable high-throughput cloning and the seamless insertion of any DNA fragment into expression vectors. Additionally, retroviral vectors offer a fast and efficient method for transducing and expressing genes in mammalian cells, including lymphocytes. However, homologous recombination cannot be used to insert DNA fragments into retroviral vectors; retroviral vectors contain two homologous regions, the 5'- and 3'-long terminal repeats, between which homologous recombination occurs preferentially. In this study, we have modified a retroviral vector to enable the cloning of DNA fragments through homologous recombination. To this end, we inserted a bacterial selection marker in a region adjacent to the gene insertion site. We used the modified retroviral vector and homologous recombination to clone T-cell receptors (TCRs) from single Epstein Barr virus-specific human T cells in a high-throughput and comprehensive manner and to efficiently evaluate their function by transducing the TCRs into a murine T-cell line through retroviral infection. In conclusion, the modified retroviral vectors, in combination with the homologous recombination method, are powerful tools for the high-throughput cloning of cDNAs and their efficient functional analysis.

  12. Resistance detected by pyrosequencing following zidovudine monotherapy for prevention of HIV-1 mother-to-child-transmission.

    PubMed

    Olson, Scott C; Ngo-Giang-Huong, Nicole; Beck, Ingrid; Deng, Wenjie; Britto, Paula; Shapiro, David E; Bumgarner, Roger E; Mullins, James I; Van Dyke, Russell B; Jourdain, Gonzague; Frenkel, Lisa M

    2015-07-31

    To prevent mother-to-child-transmission of HIV-1, the 2010 WHO guidelines recommended prenatal zidovudine (ZDV) monotherapy (option A). To determine if ZDV monotherapy selects for HIV resistance in antiretroviral-naive women during pregnancy, specimens from 50 individuals were examined using pyrosequencing. ZDV-resistance mutations were detected at delivery in seven women (14%, 95% confidence interval 6.6-26.5%). These data raise the question whether women administered ZDV monotherapy for prevention of mother-to-child-transmission could have higher risk of virologic failure when later started on combination antiretroviral therapy, as has been demonstrated following single-dose nevirapine prophylaxis.

  13. New insight into transcription of human endogenous retroviral elements.

    PubMed

    Pačes, Jan; Huang, Yao-Ting; Pačes, Václav; Rídl, Jakub; Chang, Chung-Ming

    2013-03-25

    It is generally assumed that human endogenous retroviral elements (HERVs) belong to the class of genomic repetitive nucleotide sequences often called 'junk DNA'. These elements were categorized to families, and members of some of these families (e.g. HERV-H, HERV-W and HERV-K) were shown to be transcribed. These transcriptions were associated with several severe diseases such as mental disorders, AIDS, autoimmune diseases and cancer. In this review we discuss several bioinformatics strategies for genome-wide scan of HERVs transcription using high-throughput RNA sequencing on several platforms. We show that many more HERVs than previously described are transcribed to various levels and we discuss possible implications of these transcriptions.

  14. Retroviral display in gene therapy, protein engineering, and vaccine development.

    PubMed

    Urban, Johannes H; Merten, Christoph A

    2011-01-21

    The display and analysis of proteins expressed on biological surfaces has become an attractive tool for the study of molecular interactions in enzymology, protein engineering, and high-throughput screening. Among the growing number of established display systems, retroviruses offer a unique and fully mammalian platform for the expression of correctly folded and post-translationally modified proteins in the context of cell plasma membrane-derived particles. This is of special interest for therapeutic applications such as gene therapy and vaccine development and also offers advantages for the engineering of mammalian proteins toward customized binding affinities and catalytic activities. This review critically summarizes the basic concepts and applications of retroviral display and analyses its benefits in comparison to other display techniques.

  15. Retroviral Integrase Proteins and HIV-1 DNA Integration*

    PubMed Central

    Krishnan, Lavanya; Engelman, Alan

    2012-01-01

    Retroviral integrases catalyze two reactions, 3′-processing of viral DNA ends, followed by integration of the processed ends into chromosomal DNA. X-ray crystal structures of integrase-DNA complexes from prototype foamy virus, a member of the Spumavirus genus of Retroviridae, have revealed the structural basis of integration and how clinically relevant integrase strand transfer inhibitors work. Underscoring the translational potential of targeting virus-host interactions, small molecules that bind at the host factor lens epithelium-derived growth factor/p75-binding site on HIV-1 integrase promote dimerization and inhibit integrase-viral DNA assembly and catalysis. Here, we review recent advances in our knowledge of HIV-1 DNA integration, as well as future research directions. PMID:23043109

  16. The NRTIs Lamivudine, Stavudine and Zidovudine Have Reduced HIV-1 Inhibitory Activity in Astrocytes

    PubMed Central

    Gray, Lachlan R.; Tachedjian, Gilda; Ellett, Anne M.; Roche, Michael J.; Cheng, Wan-Jung; Guillemin, Gilles J.; Brew, Bruce J.; Turville, Stuart G.; Wesselingh, Steve L.; Gorry, Paul R.; Churchill, Melissa J.

    2013-01-01

    HIV-1 establishes infection in astrocytes and macroage-lineage cells of the central nervous system (CNS). Certain antiretroviral drugs (ARVs) can penetrate the CNS, and are therefore often used in neurologically active combined antiretroviral therapy (Neuro-cART) regimens, but their relative activity in the different susceptible CNS cell populations is unknown. Here, we determined the HIV-1 inhibitory activity of CNS-penetrating ARVs in astrocytes and macrophage-lineage cells. Primary human fetal astrocytes (PFA) and the SVG human astrocyte cell line were used as in vitro models for astrocyte infection, and monocyte-derived macrophages (MDM) were used as an in vitro model for infection of macrophage-lineage cells. The CNS-penetrating ARVs tested were the nucleoside reverse transcriptase inhibitors (NRTIs) abacavir (ABC), lamivudine (3TC), stavudine (d4T) and zidovudine (ZDV), the non-NRTIs efavirenz (EFV), etravirine (ETR) and nevirapine (NVP), and the integrase inhibitor raltegravir (RAL). Drug inhibition assays were performed using single-round HIV-1 entry assays with luciferase viruses pseudotyped with HIV-1 YU-2 envelope or vesicular stomatitis virus G protein (VSV-G). All the ARVs tested could effectively inhibit HIV-1 infection in macrophages, with EC90s below concentrations known to be achievable in the cerebral spinal fluid (CSF). Most of the ARVs had similar potency in astrocytes, however the NRTIs 3TC, d4T and ZDV had insufficient HIV-1 inhibitory activity in astrocytes, with EC90s 12-, 187- and 110-fold greater than achievable CSF concentrations, respectively. Our data suggest that 3TC, d4T and ZDV may not adequately target astrocyte infection in vivo, which has potential implications for their inclusion in Neuro-cART regimens. PMID:23614033

  17. Alteration of Blood–Brain Barrier Integrity by Retroviral Infection

    PubMed Central

    Afonso, Philippe V.; Ozden, Simona; Cumont, Marie-Christine; Seilhean, Danielle; Cartier, Luis; Rezaie, Payam; Mason, Sarah; Lambert, Sophie; Huerre, Michel; Gessain, Antoine; Couraud, Pierre-Olivier; Pique, Claudine

    2008-01-01

    The blood–brain barrier (BBB), which forms the interface between the blood and the cerebral parenchyma, has been shown to be disrupted during retroviral-associated neuromyelopathies. Human T Lymphotropic Virus (HTLV-1) Associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP) is a slowly progressive neurodegenerative disease associated with BBB breakdown. The BBB is composed of three cell types: endothelial cells, pericytes and astrocytes. Although astrocytes have been shown to be infected by HTLV-1, until now, little was known about the susceptibility of BBB endothelial cells to HTLV-1 infection and the impact of such an infection on BBB function. We first demonstrated that human cerebral endothelial cells express the receptors for HTLV-1 (GLUT-1, Neuropilin-1 and heparan sulfate proteoglycans), both in vitro, in a human cerebral endothelial cell line, and ex vivo, on spinal cord autopsy sections from HAM/TSP and non-infected control cases. In situ hybridization revealed HTLV-1 transcripts associated with the vasculature in HAM/TSP. We were able to confirm that the endothelial cells could be productively infected in vitro by HTLV-1 and that blocking of either HSPGs, Neuropilin 1 or Glut1 inhibits this process. The expression of the tight-junction proteins within the HTLV-1 infected endothelial cells was altered. These cells were no longer able to form a functional barrier, since BBB permeability and lymphocyte passage through the monolayer of endothelial cells were increased. This work constitutes the first report of susceptibility of human cerebral endothelial cells to HTLV-1 infection, with implications for HTLV-1 passage through the BBB and subsequent deregulation of the central nervous system homeostasis. We propose that the susceptibility of cerebral endothelial cells to retroviral infection and subsequent BBB dysfunction is an important aspect of HAM/TSP pathogenesis and should be considered in the design of future therapeutics strategies. PMID:19008946

  18. Endogenous non-retroviral RNA virus elements in mammalian genomes.

    PubMed

    Horie, Masayuki; Honda, Tomoyuki; Suzuki, Yoshiyuki; Kobayashi, Yuki; Daito, Takuji; Oshida, Tatsuo; Ikuta, Kazuyoshi; Jern, Patric; Gojobori, Takashi; Coffin, John M; Tomonaga, Keizo

    2010-01-07

    Retroviruses are the only group of viruses known to have left a fossil record, in the form of endogenous proviruses, and approximately 8% of the human genome is made up of these elements. Although many other viruses, including non-retroviral RNA viruses, are known to generate DNA forms of their own genomes during replication, none has been found as DNA in the germline of animals. Bornaviruses, a genus of non-segmented, negative-sense RNA virus, are unique among RNA viruses in that they establish persistent infection in the cell nucleus. Here we show that elements homologous to the nucleoprotein (N) gene of bornavirus exist in the genomes of several mammalian species, including humans, non-human primates, rodents and elephants. These sequences have been designated endogenous Borna-like N (EBLN) elements. Some of the primate EBLNs contain an intact open reading frame (ORF) and are expressed as mRNA. Phylogenetic analyses showed that EBLNs seem to have been generated by different insertional events in each specific animal family. Furthermore, the EBLN of a ground squirrel was formed by a recent integration event, whereas those in primates must have been formed more than 40 million years ago. We also show that the N mRNA of a current mammalian bornavirus, Borna disease virus (BDV), can form EBLN-like elements in the genomes of persistently infected cultured cells. Our results provide the first evidence for endogenization of non-retroviral virus-derived elements in mammalian genomes and give novel insights not only into generation of endogenous elements, but also into a role of bornavirus as a source of genetic novelty in its host.

  19. Detection of a human intracisternal A-type retroviral particle antigenically related to HIV

    NASA Technical Reports Server (NTRS)

    Garry, R. F.; Fermin, C. D.; Hart, D. J.; Alexander, S. S.; Donehower, L. A.; Luo-Zhang, H.

    1990-01-01

    Sjogren's syndrome is an autoimmune disease that is characterized by dryness of the mouth and eyes. The loss of salivary and lacrimal gland function is accompanied by lymphocytic infiltration. Because similar symptoms and glandular pathology are observed in certain persons infected with human immunodeficiency virus (HIV), a search was initiated for a possible retroviral etiology in this syndrome. A human intracisternal A-type retroviral particle that is antigenically related to HIV was detected in lymphoblastoid cells exposed to homogenates of salivary tissue from patients with Sjogren's syndrome. Comparison of this retroviral particle to HIV indicates that they are distinguishable by several ultrastructural, physical, and enzymatic criteria.

  20. Efficacy of zidovudine and human immunodeficiency virus (HIV) hyperimmune immunoglobulin for reducing perinatal HIV transmission from HIV-infected women with advanced disease: results of Pediatric AIDS Clinical Trials Group protocol 185.

    PubMed

    Stiehm, E R; Lambert, J S; Mofenson, L M; Bethel, J; Whitehouse, J; Nugent, R; Moye, J; Glenn Fowler, M; Mathieson, B J; Reichelderfer, P; Nemo, G J; Korelitz, J; Meyer, W A; Sapan, C V; Jimenez, E; Gandia, J; Scott, G; O'Sullivan, M J; Kovacs, A; Stek, A; Shearer, W T; Hammill, H

    1999-03-01

    Pediatric AIDS Clinical Trials Group protocol 185 evaluated whether zidovudine combined with human immunodeficiency virus (HIV) hyperimmune immunoglobulin (HIVIG) infusions administered monthly during pregnancy and to the neonate at birth would significantly lower perinatal HIV transmission compared with treatment with zidovudine and intravenous immunoglobulin (IVIG) without HIV antibody. Subjects had baseline CD4 cell counts zidovudine for maternal health (24% received zidovudine before pregnancy). Transmission was associated with lower maternal baseline CD4 cell count (odds ratio, 1.58 per 100-cell decrement; P=.005; 10.0% vs. 3.6% transmission for count <200 vs. >/=200/microL) but not with time of zidovudine initiation (5.6% vs. 4.8% if started before vs. during pregnancy; P=. 75). The Kaplan-Meier transmission rate for HIVIG recipients was 4. 1% (95% confidence interval, 1.5%-6.7%) and for IVIG recipients was 6.0% (2.8%-9.1%) (P=.36). The unexpectedly low transmission confirmed that zidovudine prophylaxis is highly effective, even for women with advanced HIV disease and prior zidovudine therapy, although it limited the study's ability to address whether passive immunization diminishes perinatal transmission.

  1. A prospective study of haematological changes after switching from stavudine to zidovudine-based antiretroviral treatment in HIV-infected children.

    PubMed

    Singh, Archana; Hemal, Alok; Agarwal, Sheetal; Dubey, N K; Buxi, Gurdeep

    2016-11-01

    Long-term use of stavudine is associated with a high incidence of lipodystrophy, warranting its substitution with zidovudine in first-line antiretroviral therapy (ART) regimens. In a prospective observational study, we determined the spectrum and severity of haematological changes after switching from stavudine- to zidovudine-based ART in Indian children aged 2-18 years who had received a stavudine-based ART regimen for at least 48 weeks. They were followed for 48 weeks for changes in haematological parameters and CD4 cell counts after switching to zidovudine. Of the 60 children analysed, 45 (75%) showed a significant fall in Hb (>1 g/dl). A majority developed grade 1 anaemia (14 [31%]) while only three (6%) developed grade 4 anaemia. The lowest Hb was recorded between 12 and 16 weeks with spontaneous improvement noticed after 28 weeks. A significant drop in absolute neutrophil count (5067 cells/mm(3) to 3625 cells/mm(3); p = 0.004) was also observed but none developed severe neutropenia. No significant changes were observed in platelet and CD4 cell counts. Since the incidence of severe drug toxicity was low with zidovudine and the majority of children recovered without intervention, drug toxicity should not preclude its routine use in poor countries.

  2. Oligonucleotide Ligation Assay for Detecting Mutations in the Human Immunodeficiency Virus Type 1 pol Gene That Are Associated with Resistance to Zidovudine, Didanosine, and Lamivudine

    PubMed Central

    Edelstein, Reva E.; Nickerson, Deborah A.; Tobe, Vincent O.; Manns-Arcuino, Laura A.; Frenkel, Lisa M.

    1998-01-01

    This report describes the detection of mutations in the pol gene of human immunodeficiency virus type 1 associated with resistance to zidovudine, didanosine, and lamivudine by genotyping by an oligonucleotide ligation assay specific codons in the pol gene amplified by PCR. Our studies demonstrate the sensitivity, simplicity, and specificity of this genotyping system. PMID:9466779

  3. Abacavir, zidovudine, or stavudine as paediatric tablets for African HIV-infected children (CHAPAS-3): an open-label, parallel-group, randomised controlled trial

    PubMed Central

    Mulenga, Veronica; Musiime, Victor; Kekitiinwa, Adeodata; Cook, Adrian D; Abongomera, George; Kenny, Julia; Chabala, Chisala; Mirembe, Grace; Asiimwe, Alice; Owen-Powell, Ellen; Burger, David; McIlleron, Helen; Klein, Nigel; Chintu, Chifumbe; Thomason, Margaret J; Kityo, Cissy; Walker, A Sarah; Gibb, Diana M

    2016-01-01

    Summary Background WHO 2013 guidelines recommend universal treatment for HIV-infected children younger than 5 years. No paediatric trials have compared nucleoside reverse-transcriptase inhibitors (NRTIs) in first-line antiretroviral therapy (ART) in Africa, where most HIV-infected children live. We aimed to compare stavudine, zidovudine, or abacavir as dual or triple fixed-dose-combination paediatric tablets with lamivudine and nevirapine or efavirenz. Methods In this open-label, parallel-group, randomised trial (CHAPAS-3), we enrolled children from one centre in Zambia and three in Uganda who were previously untreated (ART naive) or on stavudine for more than 2 years with viral load less than 50 copies per mL (ART experienced). Computer-generated randomisation tables were incorporated securely within the database. The primary endpoint was grade 2–4 clinical or grade 3/4 laboratory adverse events. Analysis was intention to treat. This trial is registered with the ISRCTN Registry number, 69078957. Findings Between Nov 8, 2010, and Dec 28, 2011, 480 children were randomised: 156 to stavudine, 159 to zidovudine, and 165 to abacavir. After two were excluded due to randomisation error, 156 children were analysed in the stavudine group, 158 in the zidovudine group, and 164 in the abacavir group, and followed for median 2·3 years (5% lost to follow-up). 365 (76%) were ART naive (median age 2·6 years vs 6·2 years in ART experienced). 917 grade 2–4 clinical or grade 3/4 laboratory adverse events (835 clinical [634 grade 2]; 40 laboratory) occurred in 104 (67%) children on stavudine, 103 (65%) on zidovudine, and 105 (64%), on abacavir (p=0·63; zidovudine vs stavudine: hazard ratio [HR] 0·99 [95% CI 0·75–1·29]; abacavir vs stavudine: HR 0·88 [0·67–1·15]). At 48 weeks, 98 (85%), 81 (80%) and 95 (81%) ART-naive children in the stavudine, zidovudine, and abacavir groups, respectively, had viral load less than 400 copies per mL (p=0·58); most ART

  4. The Effect of Life History on Retroviral Genome Invasions

    PubMed Central

    Kanda, Ravinder K.; Coulson, Tim

    2015-01-01

    Endogenous retroviruses (ERV), or the remnants of past retroviral infections that are no longer active, are found in the genomes of most vertebrates, typically constituting approximately 10% of the genome. In some vertebrates, particularly in shorter-lived species like rodents, it is not unusual to find active endogenous retroviruses. In longer-lived species, including humans where substantial effort has been invested in searching for active ERVs, it is unusual to find them; to date none have been found in humans. Presumably the chance of detecting an active ERV infection is a function of the length of an ERV epidemic. Intuitively, given that ERVs or signatures of past ERV infections are passed from parents to offspring, we might expect to detect more active ERVs in species with longer generation times, as it should take more years for an infection to run its course in longer than in shorter lived species. This means the observation of more active ERV infections in shorter compared to longer-lived species is paradoxical. We explore this paradox using a modeling approach to investigate factors that influence ERV epidemic length. Our simple epidemiological model may explain why we find evidence of active ERV infections in shorter rather than longer-lived species. PMID:25692467

  5. Epigenetics, drugs of abuse, and the retroviral promoter

    PubMed Central

    Shirazi, Jasmine; Shah, Sonia; Sagar, Divya; Nonnemacher, Michael R.; Wigdahl, Brian; Khan, Zafar K.; Jain, Pooja

    2013-01-01

    Drug abuse alone has been shown to cause epigenetic changes in brain tissue that have been shown to play roles in addictive behaviors. In conjunction with HIV-1 infection, it can cause epigenetic changes at the viral promoter that can result in altered gene expression, and exacerbate disease progression overall. This review entails an in-depth look at research conducted on the epigenetic effects of three of the most widely abused drugs (cannabinoids, opioids, and cocaine), with a particular focus on the mechanisms through which these drugs interact with HIV-1 infection at the viral promoter. Here we discuss the impact of this interplay on disease progression from the point of view of the nature of gene regulation at the level of chromatin accessibility, chromatin remodeling, and nucleosome repositioning. Given the importance of chromatin remodeling and DNA methylation in controlling the retroviral promoter, and the high susceptibility of the drug abusing population of individuals to HIV infection, it would be beneficial to understand the way in which the host genome is modified and regulated by drugs of abuse. PMID:24218017

  6. Retroviral DNA Integration Directed by HIV Integration Protein in Vitro

    NASA Astrophysics Data System (ADS)

    Bushman, Frederic D.; Fujiwara, Tamio; Craigie, Robert

    1990-09-01

    Efficient retroviral growth requires integration of a DNA copy of the viral RNA genome into a chromosome of the host. As a first step in analyzing the mechanism of integration of human immunodeficiency virus (HIV) DNA, a cell-free system was established that models the integration reaction. The in vitro system depends on the HIV integration (IN) protein, which was partially purified from insect cells engineered to express IN protein in large quantities. Integration was detected in a biological assay that scores the insertion of a linear DNA containing HIV terminal sequences into a λ DNA target. Some integration products generated in this assay contained five-base pair duplications of the target DNA at the recombination junctions, a characteristic of HIV integration in vivo; the remaining products contained aberrant junctional sequences that may have been produced in a variation of the normal reaction. These results indicate that HIV IN protein is the only viral protein required to insert model HIV DNA sequences into a target DNA in vitro.

  7. Neural stem cells as tools for understanding retroviral neuropathogenesis.

    PubMed

    Lynch, W P; Portis, J L

    2000-06-05

    The discovery within the past decade that neural stem cells (NSCs) from the developing and adult mammalian brain can be propagated, cloned, and genetically manipulated ex vivo for ultimate transfer back into the CNS has opened the door to a novel means for modifying the CNS environment for experimental and therapeutic purposes. While a great deal of interest has been focused on the properties and promise of this new technology, especially in regard to cellular replacement and gene therapy, this minireview will focus on the recent use of NSCs to study the neuropathogenesis of the murine oncornaviruses. In brief, the use of this NSC-based approach has provided a means for selective reconstitution within the brain, of specific retroviral life cycle events, in order to consider their contribution to the induction of neurodegeneration. Furthermore, by virtue of their ability to disseminate virus within the brain, NSCs have provided a reliable means for assessing the true neurovirulence potential of murine oncornaviruses by directly circumventing a restriction to virus entry into the CNS. Importantly, these experiments have demonstrated that the neurovirulence of oncornaviruses requires late virus life cycle events occurring specifically within microglia, the resident macrophages of the brain. This initial application of NSC biology to the analysis of oncornavirus-CNS interactions may serve as an example for how other questions in viral neuropathogenesis might be addressed in the future.

  8. Retroviral particles in neoplasms of Burmese pythons (Python molurus bivittatus).

    PubMed

    Chandra, A M; Jacobson, E R; Munn, R J

    2001-09-01

    Neoplastic diseases associated with retroviruses were diagnosed in four Burmese pythons (Python molurus bivattatus) from a single collection. Snake No. 1 was a 7-year-old female with recurrent undifferentiated mesenchymal round cell tumor (lymphosarcoma) of the oral cavity. At necropsy, similar neoplastic masses were evident in the uterus and ovary, and there was diffuse involvement of the spleen. Snake No. 2 was a 4.5-year-old female that was euthanatized because of complications following resection of a segmental colonic adenocarcinoma. Snake No. 3 was a 5-year-old female that was euthanatized because of a large transitional cell carcinoma of the right kidney. Snake No. 4 was a 19-year-old female that was euthanatized following recurrence of an intermandibular fibrosarcoma. Ultrastructural examination revealed few to numerous extracellular and intracellular (intravacuolar) type C-like retroviral particles in all tumors. Tumors were about 90-95 nm in diameter, with an electron-dense core and bilaminar external membrane. The relationship of the intraneoplastic viral particles to the etiology of the tumors is uncertain.

  9. Comparative Application of PLS and PCR Methods to Simultaneous Quantitative Estimation and Simultaneous Dissolution Test of Zidovudine - Lamivudine Tablets.

    PubMed

    Üstündağ, Özgür; Dinç, Erdal; Özdemir, Nurten; Tilkan, M Günseli

    2015-01-01

    In the development strategies of new drug products and generic drug products, the simultaneous in-vitro dissolution behavior of oral dosage formulations is the most important indication for the quantitative estimation of efficiency and biopharmaceutical characteristics of drug substances. This is to force the related field's scientists to improve very powerful analytical methods to get more reliable, precise and accurate results in the quantitative analysis and dissolution testing of drug formulations. In this context, two new chemometric tools, partial least squares (PLS) and principal component regression (PCR) were improved for the simultaneous quantitative estimation and dissolution testing of zidovudine (ZID) and lamivudine (LAM) in a tablet dosage form. The results obtained in this study strongly encourage us to use them for the quality control, the routine analysis and the dissolution test of the marketing tablets containing ZID and LAM drugs.

  10. Pure red cell aplasia induced by lamivudine without the influence of zidovudine in a patient infected with human immunodeficiency virus.

    PubMed

    Nakamura, Kiwamu; Tateyama, Masao; Tasato, Daisuke; Haranaga, Shusaku; Tamayose, Maki; Yara, Satomi; Higa, Futoshi; Fujita, Jiro

    2014-01-01

    We herein report the case of a patient with human immunodeficiency virus infection and acquired immune deficiency syndrome who was diagnosed with drug-induced pure red cell aplasia consequent to lamivudine treatment. The patient was admitted to our hospital for treatment of increasing shortness of breath following physical effort. Upon admission, routine blood tests revealed a hemoglobin level of 7.6 g/dL and a hematocrit proportion of 21.2%, with normal leukocyte and platelet counts. After stopping the lamivudine treatment, the patient's hemoglobin concentration and hematocrit level returned to normal. A bone marrow examination showed an exclusive reduction in erythrocyte formation. This case indicates that lamivudine can induce severe anemia without the influence of zidovudine.

  11. Pharmacokinetic Modeling of Lamivudine and Zidovudine Triphosphates Predicts Differential Pharmacokinetics in Seminal Mononuclear Cells and Peripheral Blood Mononuclear Cells.

    PubMed

    Dumond, Julie B; Yang, Kuo H; Kendrick, Racheal; Reddy, Y Sunila; Kashuba, Angela D M; Troiani, Luigi; Bridges, Arlene S; Fiscus, Susan A; Forrest, Alan; Cohen, Myron S

    2015-10-01

    The male genital tract is a potential site of viral persistence. Therefore, adequate concentrations of antiretrovirals are required to eliminate HIV replication in the genital tract. Despite higher zidovudine (ZDV) and lamivudine (3TC) concentrations in seminal plasma (SP) than in blood plasma (BP) (SP/BP drug concentration ratios of 2.3 and 6.7, respectively), we have previously reported lower relative intracellular concentrations of their active metabolites, zidovudine triphosphate (ZDV-TP) and lamivudine triphosphate (3TC-TP), in seminal mononuclear cells (SMCs) than in peripheral blood mononuclear cells (PBMCs) (SMC/PBMC drug concentration ratios of 0.36 and 1.0, respectively). Here, we use population pharmacokinetic (PK) modeling-based methods to simultaneously describe parent and intracellular metabolite PK in blood, semen, and PBMCs and SMCs. From this model, the time to steady state in each matrix was estimated, and the results indicate that the PK of 3TC-TP and ZDV-TP in PBMCs are different from the PK of the two in SMCs and different for the two triphosphates. We found that steady-state conditions in PBMCs were achieved within 2 days for ZDV-TP and 3 days for 3TC-TP. However, steady-state conditions in SMCs were achieved within 2 days for ZDV-TP and 2 weeks for 3TC-TP. Despite this, or perhaps because of it, ZDV-TP in SMCs does not achieve the surrogate 50% inhibitory concentration (IC50) (as established for PBMCs, assuming SMC IC50 = PBMC IC50) at the standard 300-mg twice-daily dosing. Mechanistic studies are needed to understand these differences and to explore intracellular metabolite behavior in SMCs for other nucleoside analogues used in HIV prevention, treatment, and cure.

  12. Investigating the dissolution profiles of amoxicillin, metronidazole, and zidovudine formulations used in Trinidad and Tobago, West Indies.

    PubMed

    Stuart, Arlene Villarroel; Zuo, Jieyu; Löbenberg, Raimar

    2014-10-01

    Trinidad and Tobago is a twin-island Republic in the Caribbean and like many developing countries, it has included generic drugs on the national drug formulary to decrease the financial burden of pharmaceutical medications. However, to ensure that medications received by patients are beneficial, generic drugs need to be interchangeable with the innovator which has demonstrated safety, efficacy, and quality. The objective of the study was to compare the dissolution profiles and weight variations for different formulations of amoxicillin, metronidazole, and zidovudine that are on the national drug formulary and marketed in Trinidad and Tobago. All the products investigated are categorized as class 1 drugs according to the Biopharmaceutics Classification System (BCS) and the dissolution profiles were assessed according to the World Health Organization (WHO) criteria for interchangeability between products. The similarity factor, f 2, was used to determine sameness between the products. No generic formulation was found to be similar to Amoxil® 500-mg capsules. The two generic products for metronidazole 200-mg tablets demonstrated more than 85% drug release within 15 min in all three of the buffers; however, their 400-mg counterparts did not fulfill this requirement. The zidovudine 300-mg tablet complied with the requirements in buffer pH 4.5 and simulated gastric fluid (SGF) but not for simulated intestinal fluid (SIF). Some Class 1 pharmaceutical formulations may possess the same active ingredient and amount of drug but may show significant differences to in vitro equivalence requirements. Nevertheless, the dissolution process is suitable to detect these variations.

  13. Larger Mammalian Body Size Leads to Lower Retroviral Activity

    PubMed Central

    Katzourakis, Aris; Magiorkinis, Gkikas; Lim, Aaron G.; Gupta, Sunetra; Belshaw, Robert; Gifford, Robert

    2014-01-01

    Retroviruses have been infecting mammals for at least 100 million years, leaving descendants in host genomes known as endogenous retroviruses (ERVs). The abundance of ERVs is partly determined by their mode of replication, but it has also been suggested that host life history traits could enhance or suppress their activity. We show that larger bodied species have lower levels of ERV activity by reconstructing the rate of ERV integration across 38 mammalian species. Body size explains 37% of the variance in ERV integration rate over the last 10 million years, controlling for the effect of confounding due to other life history traits. Furthermore, 68% of the variance in the mean age of ERVs per genome can also be explained by body size. These results indicate that body size limits the number of recently replicating ERVs due to their detrimental effects on their host. To comprehend the possible mechanistic links between body size and ERV integration we built a mathematical model, which shows that ERV abundance is favored by lower body size and higher horizontal transmission rates. We argue that because retroviral integration is tumorigenic, the negative correlation between body size and ERV numbers results from the necessity to reduce the risk of cancer, under the assumption that this risk scales positively with body size. Our model also fits the empirical observation that the lifetime risk of cancer is relatively invariant among mammals regardless of their body size, known as Peto's paradox, and indicates that larger bodied mammals may have evolved mechanisms to limit ERV activity. PMID:25033295

  14. Retroviral nucleocapsid proteins possess potent nucleic acid strand renaturation activity.

    PubMed Central

    Dib-Hajj, F.; Khan, R.; Giedroc, D. P.

    1993-01-01

    The nucleocapsid protein (NC) is the major genomic RNA binding protein that plays integral roles in the structure and replication of all animal retroviruses. In this report, select biochemical properties of recombinant Mason-Pfizer monkey virus (MPMV) and HIV-1 NCs are compared. Evidence is presented that two types of saturated Zn2 NC-polynucleotide complexes can be formed under conditions of low [NaCl] that differ in apparent site-size (n = 8 vs. n = 14). The formation of one or the other complex appears dependent on the molar ratio of NC to RNA nucleotide with the putative low site-size mode apparently predominating under conditions of protein excess. Both MPMV and HIV-1 NCs kinetically facilitate the renaturation of two complementary DNA strands, suggesting that this is a general property of retroviral NCs. NC proteins increase the second-order rate constant for renaturation of a 149-bp DNA fragment by more than four orders of magnitude over that obtained in the absence of protein at 37 degrees C. The protein-assisted rate is 100-200-fold faster than that obtained at 68 degrees C, 1 M NaCl, solution conditions considered to be optimal for strand renaturation. Provided that sufficient NC is present to coat all strands, the presence of 400-1,000-fold excess nonhomologous DNA does not greatly affect the reaction rate. The HIV-1 NC-mediated renaturation reaction functions stoichiometrically, requiring a saturated strand of DNA nucleotide:NC ratio of about 7-8, rather than 14. Under conditions of less protein, the rate acceleration is not realized. The finding of significant nucleic acid strand renaturation activity may have important implications for various events of reverse transcription particularly in initiation and cDNA strand transfer. PMID:8443601

  15. An Intact Retroviral Gene Conserved in Spiny-Rayed Fishes for over 100 My.

    PubMed

    Henzy, Jamie E; Gifford, Robert J; Kenaley, Christopher P; Johnson, Welkin E

    2016-12-30

    We have identified a retroviral envelope gene with a complete, intact open reading frame (ORF) in 20 species of spiny-rayed fishes (Acanthomorpha). The taxonomic distribution of the gene, "percomORF", indicates insertion into the ancestral lineage >110 Ma, making it the oldest known conserved gene of viral origin in a vertebrate genome. Underscoring its ancient provenence, percomORF exists as an isolated ORF within the intron of a widely conserved host gene, with no discernible proviral sequence nearby. Despite its remarkable age, percomORF retains canonical features of a retroviral glycoprotein, and tests for selection strongly suggest cooption for a host function. Retroviral envelope genes have been coopted for a role in placentogenesis by numerous lineages of mammals, including eutherians and marsupials, representing a variety of placental structures. Therefore percomORF's presence within the group Percomorpha-unique among spiny-finned fishes in having evolved placentation and live birth-is especially intriguing.

  16. An XMRV Derived Retroviral Vector as a Tool for Gene Transfer

    PubMed Central

    2011-01-01

    Background Retroviral vectors are widely used tools for gene delivery and gene therapy. They are useful for gene expression studies and genetic manipulation in vitro and in vivo. Many retroviral vectors are derived from the mouse gammaretrovirus, murine leukemia virus (MLV). These vectors have been widely used in gene therapy clinical trials. XMRV, initially found in prostate cancer tissue, was the first human gammaretrovirus described. Findings We developed a new retroviral vector based on XMRV called pXC. It was developed for gene transfer to human cells and is produced by transient cotransfection of LNCaP cells with pXC and XMRV-packaging plasmids. Conclusions We demonstrated that pXC mediates expression of inserted transgenes in cell lines. This new vector will be a useful tool for gene transfer in human and non-human cell lines, including gene therapy studies. PMID:21651801

  17. Purification of retroviral vectors for clinical application: biological implications and technological challenges.

    PubMed

    Rodrigues, Teresa; Carrondo, Manuel J T; Alves, Paula M; Cruz, Pedro E

    2007-01-10

    For centuries mankind led a difficult battle against viruses, the smallest infectious agents at the surface of the earth. Nowadays it is possible to use viruses for our benefit, both at a prophylactic level in the production of vaccines and at a therapeutic level in the promising field of gene therapy. Retroviruses were discovered at the end of the 19th century and constitute one of the most effective entities for gene transfer and insertion into the genome of mammalian cells. This attractive feature has intensified research in retroviral vectors development and production over the past years, mainly due to the expectations raised by the concept of gene therapy. The demand for high quality retroviral vectors that meet standard requisites from the regulatory agencies (FDA and EMEA) is therefore increasing, as the technology has moved into clinical trials. The development of safer producer cell lines that can be used in large-scale production will result in the production of large quantities of retroviral stocks. Cost-efficient and scalable purification processes are essential for production of injectable-grade preparations to achieve final implementation of these vectors as therapeutics. Several preparative purification steps already established for proteins can certainly be applied to retroviral vectors, in particular membrane filtration and chromatographic methods. Nevertheless, the special properties of these complex products require technological improvement of the existing purification steps and/or development of particular purification steps to increase productivity and throughput, while maintaining biological activity of the final product. This review focuses on downstream process development in relation to the retroviral vectors characteristics and quality assessment of retroviral stocks for intended use in gene therapy.

  18. Optimization of a retroviral vector for transduction of human CD34 positive cells.

    PubMed

    Szyda, Anna; Paprocka, Maria; Krawczenko, Agnieszka; Lenart, Katarzyna; Heimrath, Jerzy; Grabarczyk, Piotr; Mackiewicz, Andrzej; Duś, Danuta

    2006-01-01

    Human stem and progenitor cells have recently become objects of intensive studies as an important target for gene therapy and regenerative medicine. Retroviral vectors are among the most effective tools for genetic modification of these cells. However, their transduction efficiency strongly depends on the choice of the ex vivo transduction system. The aim of this study was to elaborate a system for retroviral vector transduction of human CD34 positive cells isolated from cord blood. The retroviral vector pMINV EGFP was chosen for transduction of two human erythroblastoid cell lines: KG-1a (CD34 positive) and K562 (CD34 negative). For vector construction, three promoters and two retroviral vector packaging cell lines were used. To optimize the physicochemical conditions of the transduction process, different temperatures of supernatant harvesting, the influence of centrifugation and the presence of transduction enhancing agents were tested. The conditions elaborated with KG-1a cells were further applied for transduction of CD34 positive cells isolated from cord blood. The optimal efficiency of transduction of CD34 positive cells with pMINV EGFP retroviral vector (26% of EGFP positive cells), was obtained using infective vector with LTR retroviral promoter, produced by TE FLY GA MINV EGFP packaging cell line. The transduction was performed in the presence of serum, at 37 degrees C, with co-centrifugation of cells with viral supernatants and the use of transduction enhancing agents. This study confirmed that for gene transfer into CD34 positive cells, the detailed optimization of each element of the transduction process is of great importance.

  19. Nevirapine-Resistant HIV-1 DNA in Breast Milk After Single-Dose Nevirapine With or Without Zidovudine for Prevention of Mother-to-Child Transmission

    PubMed Central

    Gantt, Soren; Payant, Rachel; Carlsson, Jacquelyn; Micek, Mark A.; Blanco, Ana Judith; Beck, Ingrid A.; Matunha, Laurinda; Montoya, Pablo; Matediana, Eduardo; Gloyd, Stephen; Frenkel, Lisa M.

    2012-01-01

    Among 30 human immunodeficiency virus type 1 (HIV-1)–infected women who received single-dose nevirapine (NVP), 17 (57%) had NVP-resistant HIV-1 detected in breast milk. NVP resistance in breast milk persisted for at least 8 months postpartum and was apparently transmitted to at least 1 infant. NVP resistance was detected less often in women who also received zidovudine. PMID:23687579

  20. Disclosing the parameters leading to high productivity of retroviral producer cells lines: evaluating random vs. targeted integration.

    PubMed

    Bandeira, Vanessa Sofia; Tomás, Hélio A; Alici, Evren; Carrondo, Manuel J C T; Coroadinha, Ana Sofia

    2017-03-16

    Gammaretrovirus and lentivirus are the preferred viral vectors to genetically modify T- and NK- cells to be used in immune-cell therapies. The transduction efficiency of hematopoietic and T cells is more efficient using Gibbon ape leukemia virus (GaLV) pseudotyping. In this context gammaretroviral vector producer cells offer competitive higher titers than transient lentiviral vectors productions. The main aim of this work was to identify the key parameters governing GalV pseudotyped gammaretroviral vector productivity in stable producer cells using a retroviral vector expression cassette enabling positive (facilitating cell enrichment) and negative cell selection (allowing cell elimination). The retroviral vector contains a thymidine kinase suicide gene fused with an Ouabain-resistant Na+K+-ATPase gene, a potential safer and faster marker. The establishment of retroviral vector producer cells is traditionally performed by randomly integrating the retroviral vector expression cassette codifying the transgene. More recently recombinase mediated cassette exchange methodologies have been introduced to achieve targeted integration. Herein we compared random and targeted integration of the retroviral vector transgene construct. Two retroviral producer cell lines, 293 OuaS and 293 FlexOuaS, were generated using random and targeted integration, respectively, producing high titers (in the order of 107 IP.mL-1). Results showed that the retroviral vector transgene cassette is the key retroviral vector component determining the viral titers notwithstanding, single copy integration is sufficient to provide high titers. The expression levels of the three retroviral constructs (gag-pol, GaLV env and retroviral vector transgene) were analyzed. Although gag-pol and GaLV env gene expression levels should surpass a minimal threshold, we found that relatively modest expression levels of these two expression cassettes are required. Their levels of expression should not be maximized. We

  1. Statistical analysis of sparse infection data and its implications for retroviral treatment trials in primates.

    PubMed Central

    Spouge, J L

    1992-01-01

    Reports on retroviral primate trials rarely publish any statistical analysis. Present statistical methodology lacks appropriate tests for these trials and effectively discourages quantitative assessment. This paper describes the theory behind VACMAN, a user-friendly computer program that calculates statistics for in vitro and in vivo infectivity data. VACMAN's analysis applies to many retroviral trials using i.v. challenges and is valid whenever the viral dose-response curve has a particular shape. Statistics from actual i.v. retroviral trials illustrate some unappreciated principles of effective animal use: dilutions other than 1:10 can improve titration accuracy; infecting titration animals at the lowest doses possible can lower challenge doses; and finally, challenging test animals in small trials with more virus than controls safeguards against false successes, "reuses" animals, and strengthens experimental conclusions. The theory presented also explains the important concept of viral saturation, a phenomenon that may cause in vitro and in vivo titrations to agree for some retroviral strains and disagree for others. PMID:1323844

  2. Retroviral vectors elevate coexpressed protein levels in trans through cap-dependent translation.

    PubMed

    Gou, Yongqiang; Byun, Hyewon; Zook, Adam E; Singh, Gurvani B; Nash, Andrea K; Lozano, Mary M; Dudley, Jaquelin P

    2015-03-17

    Retroviruses cause immunodeficiency and cancer but also are used as vectors for the expression of heterologous genes. Nevertheless, optimal translation of introduced genes often is not achieved. Here we show that transfection into mammalian cells of lentiviral or gammaretroviral vectors, including those with specific shRNAs, increased expression of a cotransfected gene relative to standard plasmid vectors. Levels of most endogenous cellular proteins were unchanged. Transfer of lentiviral vector sequences into a standard plasmid conferred the ability to give increased expression of cotransfected genes (superinduction). Superinduction by the retroviral vector was not dependent on the cell type or species, the type of reporter gene, or the method of transfection. No differences were detected in the IFN, unfolded protein, or stress responses in the presence of retroviral vectors. RT-PCRs revealed that RNA levels of cotransfected genes were unchanged during superinduction, yet Western blotting, pulse labeling, and the use of bicistronic vectors showed increased cap-dependent translation of cointroduced genes. Expression of the mammalian target of rapamycin (mTOR) kinase target 4E-BP1, but not the mTOR inhibitor Torin 1, preferentially inhibited superinduction relative to basal protein expression. Furthermore, transcription of lentiviral vector sequences from a doxycycline-inducible promoter eliminated superinduction, consistent with a DNA-triggered event. Thus, retroviral DNA increased translation of cointroduced genes in trans by an mTOR-independent signaling mechanism. Our experiments have broad applications for the design of retroviral vectors for transfections, DNA vaccines, and gene therapy.

  3. Characterization of retroviral infectivity and superinfection resistance during retrovirus-mediated transduction of mammalian cells.

    PubMed

    Liao, J; Wei, Q; Fan, J; Zou, Y; Song, D; Liu, J; Liu, F; Ma, C; Hu, X; Li, L; Yu, Y; Qu, X; Chen, L; Yu, X; Zhang, Z; Zhao, C; Zeng, Z; Zhang, R; Yan, S; Wu, T; Wu, X; Shu, Y; Lei, J; Li, Y; Zhang, W; Wang, J; Reid, R R; Lee, M J; Huang, W; Wolf, J M; He, T-C; Wang, J

    2017-04-07

    Retroviral vectors including lentiviral vectors are commonly-used tools to stably express transgenes or RNA molecules in mammalian cells. Their utilities are roughly divided into two categories, stable overexpression of transgenes and RNA molecules, which requires maximal transduction efficiency, or functional selection with retrovirus-based libraries, which takes advantage of retroviral superinfection resistance. However, the dynamic features of retrovirus-mediated transduction are not well-characterized. Here, we engineered two MSCV-based retroviral vectors expressing dual fluorescence proteins and antibiotic markers and analyzed virion production efficiency and virion stability, dynamic infectivity and superinfection resistance in different cell types, and strategies to improve transduction efficiency. We found that the highest virion production occurred between 60 and 72 h after transfection. The stability of the harvested virion supernatant decreased by >60% after three days in storage. We found that retrovirus infectivity varied drastically in the tested human cancer lines, while low transduction efficiency was partially overcome with increased virus titer, prolonged infection duration, and/or repeated infections. Furthermore, we demonstrated that retrovirus receptors PIT1 and PIT2 were lowly expressed in the analyzed cells, and that PIT1 and/or PIT2 overexpression significantly improved transduction efficiency in certain cell lines. Thus, our findings provide resourceful information for the optimal conditions of retroviral-mediated gene delivery.Gene Therapy accepted article preview online, 07 April 2017. doi:10.1038/gt.2017.24.

  4. Biochemical characterization of a multi-drug resistant HIV-1 subtype AG reverse transcriptase: antagonism of AZT discrimination and excision pathways and sensitivity to RNase H inhibitors

    PubMed Central

    Schneider, Anna; Corona, Angela; Spöring, Imke; Jordan, Mareike; Buchholz, Bernd; Maccioni, Elias; Di Santo, Roberto; Bodem, Jochen; Tramontano, Enzo; Wöhrl, Birgitta M.

    2016-01-01

    We analyzed a multi-drug resistant (MR) HIV-1 reverse transcriptase (RT), subcloned from a patient-derived subtype CRF02_AG, harboring 45 amino acid exchanges, amongst them four thymidine analog mutations (TAMs) relevant for high-level AZT (azidothymidine) resistance by AZTMP excision (M41L, D67N, T215Y, K219E) as well as four substitutions of the AZTTP discrimination pathway (A62V, V75I, F116Y and Q151M). In addition, K65R, known to antagonize AZTMP excision in HIV-1 subtype B was present. Although MR-RT harbored the most significant amino acid exchanges T215Y and Q151M of each pathway, it exclusively used AZTTP discrimination, indicating that the two mechanisms are mutually exclusive and that the Q151M pathway is obviously preferred since it confers resistance to most nucleoside inhibitors. A derivative was created, additionally harboring the TAM K70R and the reversions M151Q as well as R65K since K65R antagonizes excision. MR-R65K-K70R-M151Q was competent of AZTMP excision, whereas other combinations thereof with only one or two exchanges still promoted discrimination. To tackle the multi-drug resistance problem, we tested if the MR-RTs could still be inhibited by RNase H inhibitors. All MR-RTs exhibited similar sensitivity toward RNase H inhibitors belonging to different inhibitor classes, indicating the importance of developing RNase H inhibitors further as anti-HIV drugs. PMID:26850643

  5. High-resolution structure of a retroviral protease folded as a monomer

    SciTech Connect

    Gilski, Miroslaw; Kazmierczyk, Maciej; Krzywda, Szymon; Zábranská, Helena; Cooper, Seth; Popović, Zoran; Khatib, Firas; DiMaio, Frank; Thompson, James; Baker, David; Pichová, Iva; Jaskolski, Mariusz

    2011-11-01

    The crystal structure of Mason–Pfizer monkey virus protease folded as a monomer has been solved by molecular replacement using a model generated by players of the online game Foldit. The structure shows at high resolution the details of a retroviral protease folded as a monomer which can guide rational design of protease dimerization inhibitors as retroviral drugs. Mason–Pfizer monkey virus (M-PMV), a D-type retrovirus assembling in the cytoplasm, causes simian acquired immunodeficiency syndrome (SAIDS) in rhesus monkeys. Its pepsin-like aspartic protease (retropepsin) is an integral part of the expressed retroviral polyproteins. As in all retroviral life cycles, release and dimerization of the protease (PR) is strictly required for polyprotein processing and virion maturation. Biophysical and NMR studies have indicated that in the absence of substrates or inhibitors M-PMV PR should fold into a stable monomer, but the crystal structure of this protein could not be solved by molecular replacement despite countless attempts. Ultimately, a solution was obtained in mr-rosetta using a model constructed by players of the online protein-folding game Foldit. The structure indeed shows a monomeric protein, with the N- and C-termini completely disordered. On the other hand, the flap loop, which normally gates access to the active site of homodimeric retropepsins, is clearly traceable in the electron density. The flap has an unusual curled shape and a different orientation from both the open and closed states known from dimeric retropepsins. The overall fold of the protein follows the retropepsin canon, but the C{sup α} deviations are large and the active-site ‘DTG’ loop (here NTG) deviates up to 2.7 Å from the standard conformation. This structure of a monomeric retropepsin determined at high resolution (1.6 Å) provides important extra information for the design of dimerization inhibitors that might be developed as drugs for the treatment of retroviral infections

  6. Amperometric sensing of anti-HIV drug zidovudine on Ag nanofilm-multiwalled carbon nanotubes modified glassy carbon electrode.

    PubMed

    Rafati, Amir Abbas; Afraz, Ahmadreza

    2014-06-01

    The zidovudine (ZDV) is the first drug approved for the treatment of HIV virus infection. The detection and determination of this drug are very importance in human serum because of its undesirable effects. A new ZDV sensor was fabricated on the basis of nanocomposite of silver nanofilm (Ag-NF) and multiwalled carbon nanotubes (MWCNTs) immobilized on glassy carbon electrode (GCE). The modified electrodes were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), cyclic voltammetry (CV), and linear sweep voltammetry (LSV) techniques. Results showed that the electrodeposited silver has a nanofilm structure and further electrochemical studies showed that the prepared nanocomposite has high electrocatalytic activity and is appropriate for using in sensors. The amperometric technique under optimal conditions is used for the determination of ZDV ranging from 0.1 to 400ppm (0.37μM-1.5mM) with a low detection limit of 0.04ppm (0.15μM) (S/N=3) and good sensitivity. The prepared sensor possessed accurate and rapid response to ZDV and shows an average recovery of 98.6% in real samples.

  7. Lack of Pharmacokinetic Interaction between Amdoxovir and Reduced- and Standard-Dose Zidovudine in HIV-1-Infected Individuals▿

    PubMed Central

    Hurwitz, Selwyn J.; Asif, Ghazia; Fromentin, Emilie; Tharnish, Phillip M.; Schinazi, Raymond F.

    2010-01-01

    Amdoxovir (AMDX) inhibits HIV-1 containing the M184V/I mutation and is rapidly absorbed and deaminated to its active metabolite, β-d-dioxolane guanosine (DXG). DXG is synergistic with zidovudine (ZDV) in HIV-1-infected primary human lymphocytes. A recent in silico pharmacokinetic (PK)/enzyme kinetic study suggested that ZDV at 200 mg twice a day (b.i.d.) may reduce toxicity without compromising efficacy relative to the standard 300-mg b.i.d. dose. Therefore, an intense PK clinical study was conducted using AMDX/placebo, with or without ZDV, in 24 subjects randomized to receive oral AMDX at 500 mg b.i.d., AMDX at 500 mg plus ZDV at 200 or 300 mg b.i.d., or ZDV at 200 or 300 mg b.i.d. for 10 days. Full plasma PK profiles were collected on days 1 and 10, and complete urine sampling was performed on day 9. Plasma and urine concentrations of AMDX, DXG, ZDV, and ZDV-5′-O-glucuronide (GZDV) were measured using a validated liquid chromatography-tandem mass spectrometry method. Data were analyzed using noncompartmental methods, and multiple comparisons were performed on the log-transformed parameters, at steady state. Coadministration of AMDX with ZDV did not significantly change either of the plasma PK parameters or percent recovery in the urine of AMDX, DXG, or ZDV/GZDV. Larger studies with AMDX/ZDV, with a longer duration, are warranted. PMID:20038617

  8. Factors associated with zidovudine receipt and prenatal care among HIV-infected pregnant women in New Jersey.

    PubMed

    Abatemarco, Diane J; Catov, Janet M; Cross, Helene; Delnevo, Cristine; Hausman, Alice

    2008-08-01

    Despite reductions in perinatal HIV transmission, cases continue to occur. To determine factors associated with zidovudine (ZDV) receipt among HIV-infected pregnant women we merged three data sets for women in New Jersey in 1995-1997, identifying 395 HIV-infected pregnant women. Half received two arms of ZDV prophylaxis. Attendance at five or more prenatal visits was the strongest independent factor related to ZDV receipt (OR 6.37, 95% CI 3.84, 10.57). Half (49.0%) had limited prenatal care. AIDS diagnosis, race/ethnicity, and drug use were also independently related to ZDV receipt. Post hoc analysis revealed that being unmarried, Black, multiparous, having no insurance, and illegal drug use were associated with limited prenatal care. Although the U.S. has seen reductions in HIV perinatal transmission, our research showed that HIV-infected women who did not get prenatal care were less likely to receive two arms of ZDV prophylaxis. A wide public health net that brings all women into care is necessary to reduce perinatal transmission further.

  9. Use of accelerator mass spectrometry to measure the pharmacokinetics and peripheral blood mononuclear cell concentrations of zidovudine.

    PubMed

    Vuong, Le T; Ruckle, Jon L; Blood, Arlin B; Reid, Michael J; Wasnich, Richard D; Synal, Hans-Arno; Dueker, Stephen R

    2008-07-01

    The remarkable sensitivity of accelerator mass spectrometry (AMS) is finding many new applications in pharmacology. In this study AMS was used to measure [(14)C]-Zidovudine (ZDV) concentrations at the drug's site of action (peripheral blood mononuclear cells, PBMCs) following a dose of 520 ng (less than one-millionth of the standard daily dose) to a healthy volunteer. In addition, the pharmacokinetics of this microdose were determined and compared to previously published parameters for therapeutic doses. Microdose ZDV pharmacokinetic parameters fell within reported 95% confidence intervals or standard deviations of most previously published values for therapeutic doses. Blood, urine, stool, saliva, and isolated PBMCs were collected periodically through 96 h postdose and analyzed for ZDV and metabolite concentrations. The results showed that ZDV is rapidly absorbed and eliminated, has one major metabolite, and is sequestered in PBMCs. (14)C mass balance assessments indicated a significant portion of ZDV remained after 96 h with a much prolonged elimination half-life. Results of this study demonstrate the usefulness of microdosing and AMS as a tool for studying the pharmacokinetic characteristics, including PBMC concentrations, of ZDV and underscore the value of AMS as a tool with which to perform pharmacokinetic and mass balance studies using trace amounts of radiolabeled compound.

  10. Mean Corpuscular Volume as a Marker for Adherence to Zidovudine-Containing Therapy in HIV-Infected Adults

    PubMed Central

    Mugisha, Joseph O; Donegan, Katherine; Fidler, Sarah; Ramjee, Gita; Hodson, Andrew; Dunn, David T; Porter, Kholoud; Kaleebu, Pontiano

    2012-01-01

    Objectives: To assess whether mean corpuscular volume (MCV) is useful in detecting non-adherence to AZTcontaining therapy. Design: Observational study within randomised controlled trial. Methods: We combined data from two treatment arms in SPARTAC, an RCT of short-course cART in primary HIV infection, classifying participants as responders (HIV-RNA decrease ≥1 log10 or reaching <400copies/ml) or nonresponders following cART initiation. We assessed the sensitivity and specificity of using different percentage increases in MCV for accurately differentiating between responders and non-responders. We further examined changes in MCV levels up to 24 weeks after protocol-indicated cART cessation. Results: Of 119 participants included in this analysis, 73 (61%) were women, 71 of whom were randomised in Africa. Ninety-eight (88%) and 84 (85%) were classified as responders at 4 and 12 weeks respectively following cART initiation. MCV increased by a mean 3% and 1% at week 4, and 14% and <1% at 12 weeks for responders and non-responders. A 2% MCV increase at 4 weeks had 62% sensitivity and specificity for identifying virological response. At 12 weeks, an 8% increase had 89% sensitivity and specificity. In responders, MCV remained lower for individuals in African compared to non-African sites throughout and rose from 85 vs 90 fL at cART start to 96 vs 103 fL at 12 weeks post-initiation then fell to 88 vs 93 fL and 86 vs 89 fL at 12 and 48 weeks post-cessation. Conclusion: In low-income countries, where HIV RNA may be unavailable, 12-weekly MCV measurements may be useful in monitoring adherence to AZT-containing regimens. PMID:22715353

  11. Expression of human. alpha. sub 1 -antitrypsin in dogs after autologous transplantation of retroviral transduced hepatocytes

    SciTech Connect

    Kay, M.A.; Baley, P.; Rothenberg, S.; Leland, F; Fleming, L.; Ponder, K.P.; Liu, Tajen; Finegold, M.; Darlington, G.; Pokorny, W.; Woo, S.L.C. )

    1992-01-01

    The liver represents an excellent organ for gene therapy since many genetic disorders result from the deficiency of liver-specific gene products. The authors have previously demonstrated that transgenic mouse hepatocytes can be heterologously transplanted into congenic recipients where they survived indefinitely and continued to function as hepatocytes. Here they demonstrate the autologous transplantation of retrovirally transduced canine hepatocytes. In two animals they have transplanted hepatocytes transduced with a retroviral vector containing the human {alpha}{sub 1}-antitrypsin cDNA under transcriptional control of the cytomegalovirus promotor. Both animals had significant human {alpha}{sub 1}-antitrypsin in the serum for 1 month. The results suggest that gene therapy of hepatic deficiencies may be achieved by hepatocellular transplantation after genetic reconstruction with the use of promoters of cellular genes that are active in the normal liver.

  12. Hypoxia- and radiation-inducible, breast cell-specific targeting of retroviral vectors

    SciTech Connect

    Lipnik, Karoline; Greco, Olga; Scott, Simon; Knapp, Elzbieta; Mayrhofer, Elisabeth; Rosenfellner, Doris; Guenzburg, Walter H.; Salmons, Brian; Hohenadl, Christine . E-mail: christine.hohenadl@vu-wien.ac.at

    2006-05-25

    To facilitate a more efficient radiation and chemotherapy of mammary tumours, synthetic enhancer elements responsive to hypoxia and ionizing radiation were coupled to the mammary-specific minimal promoter of the murine whey acidic protein (WAP) encoding gene. The modified WAP promoter was introduced into a retroviral promoter conversion (ProCon) vector. Expression of a transduced reporter gene in response to hypoxia and radiation was analysed in stably infected mammary cancer cell lines and an up to 9-fold increase in gene expression demonstrated in comparison to the respective basic vector. Expression analyses in vitro, moreover, demonstrated a widely preserved mammary cell-specific promoter activity. For in vivo analyses, xenograft tumours consisting of infected human mammary adenocarcinoma cells were established in SCID/beige mice. Immunohistochemical analyses demonstrated a hypoxia-specific, markedly increased WAP promoter-driven expression in these tumours. Thus, this retroviral vector will facilitate a targeted gene therapeutic approach exploiting the unique environmental condition in solid tumours.

  13. Dichotomy between T Cell and B Cell Tolerance to Neonatal Retroviral Infection Permits T Cell Therapy

    PubMed Central

    Mavrommatis, Bettina; Baudino, Lucie; Levy, Prisca; Merkenschlager, Julia; Eksmond, Urszula; Donnarumma, Tiziano; Young, George; Stoye, Jonathan

    2016-01-01

    Elucidation of the immune requirements for control or elimination of retroviral infection remains an important aim. We studied the induction of adaptive immunity to neonatal infection with a murine retrovirus, under conditions leading to immunological tolerance. We found that the absence of either maternal or offspring adaptive immunity permitted efficient vertical transmission of the retrovirus. Maternal immunodeficiency allowed the retrovirus to induce central Th cell tolerance in the infected offspring. In turn, this compromised the offspring’s ability to mount a protective Th cell–dependent B cell response. However, in contrast to T cells, offspring B cells were not centrally tolerized and retained their ability to respond to the infection when provided with T cell help. Thus, escape of retrovirus-specific B cells from deletional tolerance offers the opportunity to induce protective retroviral immunity by restoration of retrovirus-specific T cell help, suggesting similar T cell immunotherapies for persistent viral infections. PMID:27647833

  14. Adeno-associated virus Rep-mediated targeting of integrase-defective retroviral vector DNA circles into human chromosome 19

    SciTech Connect

    Huang, Shuohao; Kawabe, Yoshinori; Ito, Akira; Kamihira, Masamichi

    2012-01-06

    Highlights: Black-Right-Pointing-Pointer Adeno-associated virus (AAV) is capable of targeted integration in human cells. Black-Right-Pointing-Pointer Integrase-defective retroviral vector (IDRV) enables a circular DNA delivery. Black-Right-Pointing-Pointer A targeted integration system of IDRV DNA using the AAV integration mechanism. Black-Right-Pointing-Pointer Targeted IDRV integration ameliorates the safety concerns for retroviral vectors. -- Abstract: Retroviral vectors have been employed in clinical trials for gene therapy owing to their relative large packaging capacity, alterable cell tropism, and chromosomal integration for stable transgene expression. However, uncontrollable integrations of transgenes are likely to cause safety issues, such as insertional mutagenesis. A targeted transgene integration system for retroviral vectors, therefore, is a straightforward way to address the insertional mutagenesis issue. Adeno-associated virus (AAV) is the only known virus capable of targeted integration in human cells. In the presence of AAV Rep proteins, plasmids possessing the p5 integration efficiency element (p5IEE) can be integrated into the AAV integration site (AAVS1) in the human genome. In this report, we describe a system that can target the circular DNA derived from non-integrating retroviral vectors to the AAVS1 site by utilizing the Rep/p5IEE integration mechanism. Our results showed that after G418 selection 30% of collected clones had retroviral DNA targeted at the AAVS1 site.

  15. Zidovudine-induced nail hyper-pigmentation in 45-year-old women prescribed for HIV/tuberculosis co-infection.

    PubMed

    Tandon, Vishal R; Sadiq, Shamiya; Khajuria, Vijay; Mahajan, Annil; Sharma, Sudhaa; Gillani, Zahid

    2016-01-01

    Zidovudine is an important component of first-line antiretroviral treatment regimens used to manage HIV and tuberculosis (TB) co-infection. Nail pigmentation is documented both in adult as well as pediatric HIV patients, but to the best of our knowledge, it has not been reported in 45-year-old women of HIV/TB co-infection. Such an adverse drugs reactions (ADR), although is harmless and reversible, psychological aspects of such ADR may be immense to the extent that it can negatively affect the compliance and result in therapeutic failure. Thus, it is worth reporting.

  16. Foscarnet, zidovudine and dolutegravir combination efficacy and tolerability for late stage HIV salvage therapy: A case-series experience.

    PubMed

    Delory, Tristan; Papot, Emmanuelle; Rioux, Christophe; Charpentier, Charlotte; Auge-Courtoi, Claire; Michard, Florence; Peytavin, Gilles; Descamps, Diane; Matheron, Sophie; Yazdanpanah, Yazdan

    2016-07-01

    Salvage therapy including foscarnet (PFA), zidovudine (ZDV) and an optimized background ART (OBT) has been shown to be effective in patients with advanced HIV infection, and no therapeutic options. Dolutegravir (DTG) may offer a more active combination. Objective was to describe efficacy and tolerability of PFA-ZDV-DTG containing regimen. In our cohort, we identified patients who: (i) had plasma HIV-1 RNA load (pVL) >50 c/ml (>100 for HIV-2) on combination ART (cART); (ii) had at least 1 PI/r, 1 NRTI, 1 NNRTI (for HIV-1), and at least 1 raltegravir resistance mutations; (iii) were naive to DTG; and (iv) initiated on a PFA-ZDV-DTG containing-regimen with 48 weeks (W48) of follow-up. Out of 5 patients, 2 were infected with HIV-2. At PFA-ZDV-DTG initiation, CD4 cell count was (/mm(3) ) of 64, 40, 10, in HIV-1, and 37, 199, in HIV-2 infected patients; and pVL (log10 c/ml) of 4.8, 5.1, 4.4, in HIV-1, and 3.6, 4.2, in HIV-2 infected patients, respectively. Median OBT genotypic sensitivity score was 1.5 [1-2]. PFA was discontinued in one patient, due to an acute renal failure. At W48, one HIV-1 infected patient had a pVL <50 c/ml and two <200 c/ml; the two HIV-2 infected patients had pVL >100 c/ml. No lack of treatment adherence was observed. In treatment experienced HIV-infected patients, failing cART and without other therapeutic options, a PFA-ZDV-DTG combination therapy could be effective. Renal adverse events should be monitored.

  17. Nanoassemblies containing a fluorouracil/zidovudine glyceryl prodrug with phospholipase A2-triggered drug release for cancer treatment.

    PubMed

    Jin, Yiguang; Yang, Fang; Du, Lina

    2013-12-01

    Secretory phospholipase A2 (sPLA2), which is overexpressed in many tumors, cleaves ester bonds at the sn-2 position of phospholipids. A PLA2-sensitive amphiphilic prodrug, 1-O-octadecyl-2-(5-fluorouracil)-N-acetyl-3-zidovudine-phosphorylglycerol (OFZG), was synthesized and used to prepare nanoassemblies through the injection of a mixture of OFZG/cholesterol/Tween 80 (2:1:0.1, mol:mol:mol) into water. Cholesterol and Tween 80 was incorporated into the OFZG monolayers at the air/water interface to yield nanoassemblies. The resulting nanoassemblies exhibited a narrow size distribution with a mean size of 77.8nm and were stable due to their high surface charges. The in vitro experiments showed that PLA2 degraded OFZG. The nanoassemblies exhibited higher anticancer activity than the parent drug 5-fluorouracil (5-FU) in COLO205, HT-28, and HCT-116 cells. The intravenous (i.v.) administration of the nanoassemblies into mice resulted in the rapid elimination of OFZG from the circulation and its distribution mainly in the liver, lung, spleen, and kidney. After their injection into tumor-bearing mice, the nanoassemblies exhibited anticancer efficiency comparable to that of 5-FU, even though the nanoassemblies contained concentrations of only 1/10 of the molar amount of 5-FU. The lessons learned from the study and methods for the design of PLA2-sensitive amphiphilic prodrugs are also discussed. Enzyme-sensitive amphiphilic combinatorial prodrugs and prodrug-loaded nanoassemblies may represent a new strategy for anticancer drug design.

  18. Retroviral envelope gene captures and syncytin exaptation for placentation in marsupials

    PubMed Central

    Cornelis, Guillaume; Vernochet, Cécile; Carradec, Quentin; Souquere, Sylvie; Mulot, Baptiste; Catzeflis, François; Nilsson, Maria A.; Menzies, Brandon R.; Renfree, Marilyn B.; Pierron, Gérard; Zeller, Ulrich; Heidmann, Odile; Dupressoir, Anne; Heidmann, Thierry

    2015-01-01

    Syncytins are genes of retroviral origin captured by eutherian mammals, with a role in placentation. Here we show that some marsupials—which are the closest living relatives to eutherian mammals, although they diverged from the latter ∼190 Mya—also possess a syncytin gene. The gene identified in the South American marsupial opossum and dubbed syncytin-Opo1 has all of the characteristic features of a bona fide syncytin gene: It is fusogenic in an ex vivo cell–cell fusion assay; it is specifically expressed in the short-lived placenta at the level of the syncytial feto–maternal interface; and it is conserved in a functional state in a series of Monodelphis species. We further identify a nonfusogenic retroviral envelope gene that has been conserved for >80 My of evolution among all marsupials (including the opossum and the Australian tammar wallaby), with evidence for purifying selection and conservation of a canonical immunosuppressive domain, but with only limited expression in the placenta. This unusual captured gene, together with a third class of envelope genes from recently endogenized retroviruses—displaying strong expression in the uterine glands where retroviral particles can be detected—plausibly correspond to the different evolutionary statuses of a captured retroviral envelope gene, with only syncytin-Opo1 being the present-day bona fide syncytin active in the opossum and related species. This study would accordingly recapitulate the natural history of syncytin exaptation and evolution in a single species, and definitely extends the presence of such genes to all major placental mammalian clades. PMID:25605903

  19. Gene transfer in ovarian cancer cells: a comparison between retroviral and lentiviral vectors.

    PubMed

    Indraccolo, Stefano; Habeler, Walter; Tisato, Veronica; Stievano, Laura; Piovan, Erich; Tosello, Valeria; Esposito, Giovanni; Wagner, Ralf; Uberla, Klaus; Chieco-Bianchi, Luigi; Amadori, Alberto

    2002-11-01

    Local gene therapy could be a therapeutic option for ovarian carcinoma, a life-threatening malignancy, because of disease containment within the peritoneal cavity in most patients. Lentiviral vectors, which are potentially capable of stable transgene expression, may be useful to vehicle therapeutic molecules requiring long-term production in these tumors. To investigate this concept, we used lentiviral vectors to deliver the enhanced green fluorescent protein (EGFP) gene to ovarian cancer cells. Their efficiency of gene transfer was compared with that of a retroviral vector carrying the same envelope. In vitro, both vectors infected ovarian cancer cells with comparable efficiency under standard culture conditions; however, the lentiviral vector was much more efficient in transducing growth-arrested cells when compared with the retroviral vector. Gene transfer was fully neutralized by an anti-VSV-G antibody, and in vitro stability was similar. In vivo, the lentiviral vector delivered the transgene 10-fold more efficiently to ovarian cancer cells growing i.p. in SCID mice, as evaluated by real-time PCR analysis of the tumors. Confocal microscopy analysis of tumor sections showed a dramatic difference at the level of transgene expression, because abundant EGFP(+) cells were detected only in mice receiving the lentiviral vector. Quantitative analysis by flow cytometry confirmed this and indicated 0.05 and 5.6% EGFP(+) tumor cells after administration of the retroviral and lentiviral vector, respectively. Injection of ex vivo transduced tumor cells, sorted for EGFP expression, indicated that the lentiviral vector was considerably more resistant to in vivo silencing in comparison with the retroviral vector. Finally, multiple administrations of a murine IFN-alpha(1)-lentiviral vector to ovarian carcinoma-bearing mice significantly prolonged the animals' survival, indicating the therapeutic efficacy of this approach. These findings indicate that lentiviral vectors deserve

  20. Increased immunoglobulin G, but not M, binding to endogenous retroviral antigens in HIV-1 infected persons.

    PubMed

    Lawoko, A; Johansson, B; Rabinayaran, D; Pipkorn, R; Blomberg, J

    2000-12-01

    The modes of interaction between products of human endogenous retroviral (HERV) sequences and the immune system are largely unknown. In HIV infected persons, an exogenous retrovirus adds further complexity to the situation. Therefore, 14 synthetic peptides with sequences derived from conserved regions of various endogenous retroviruses (ERVs) and from related exogenous retroviruses were used to search for IgG and IgM antibodies that bind to such antigens in 15 HIV-1 seropositive and 17 seronegative immunosuppressed patients. IgG binding to three peptides, namely, the C-terminal half of murine leukemia virus (MLV) capsid protein, the conserved portion of HERV-H transmembrane protein, and the Pol region of human mouse mammary tumor virus (MMTV)-like (HML3) sequence, was observed in both groups. Binding was, however, more frequent and more firm in HIV-1 positive samples (P<0.0001, Wilcoxon rank sum test). IgM binding to the same peptides showed no significant differentiation between the two groups of patients. Binding to both immunoglobulin isotypes was sometimes variable over time in both groups. No correlation of either IgG or IgM peptide binding with progression to AIDS in HIV-1 infected individuals was observed. Inhibition studies using analogous endogenous and exogenous retroviral peptides, including HIV-1, demonstrated specificity of the IgG antibodies for a narrow range of MLV- and MMTV-like retroviral antigens, and excluded cross-reactivity of antibodies to HIV-1 as a cause of these observations. Thus, unlike IgG, IgM binding to retroviral antigens was ubiquitous. It is suggested that anti-HERV IgM belong to a class of natural antibodies and might serve as primers in the mediation of humoral immune responses to more or less related exogenous retroviruses. Increased IgG binding in HIV-1 infected individuals could result from such priming, or reflect higher HERV antigen expression.

  1. Evaluation of antioxidant defense systems in H4IIE cells infected with a retroviral vector.

    PubMed

    Oh, Soo Jin; Chae, Jooyoung; Zhu, Hongmei; Hien, Tran Thi; Lee, Kiho; Kim, Hwan Mook; Kang, Keon Wook; Song, Gyu Yong; Kang, Jong Seong; Kim, Bong-Hee; Kwon, Kwang-il; Kim, Sang Kyum

    2010-06-01

    Retroviral gene transfer technology is frequently used to establish stable transgenic cell lines. However, no studies to date have evaluated antioxidant defense systems in cells infected with retroviral particles. In the present study, we examined the effects of retroviral infection on antioxidant defense systems using H4IIE cells infected with a retrovirus that overexpresses green fluorescent protein (retro-H4IIE cells). Total oxyradical scavenging capacity and glutathione (GSH), malondialdehyde, and peroxide levels were not significantly altered in retro-H4IIE cells; however, retro-H4IIE cells showed a higher resistance against cytotoxicity, GSH depletion, and malondialdehyde elevation under H(2)O(2)-induced oxidative stress conditions. Immunoblot analysis showed that alpha-class GSH S-transferase (GST) was increased 2.5-fold in retro-H4IIE cells as compared with H4IIE cells; however, catalase, GSH peroxidase-1, peroxiredoxin-1, and thioredoxin-1 remained unaltered or slightly decreased. l-Buthionine-(S,R)-sulfoximine, a GSH synthesis inhibitor, and 1-chloro-2,4-dinitrobenzene, a GST substrate and competitive inhibitor, decreased the difference in H(2)O(2) responses between the two cell types. These results support the hypothesis that the resistance of retro-H4IIE cells to H(2)O(2) can be attributed to an increase in alpha-class GST expression, as levels of GSH and GSH peroxidase-1 were not altered. The present study suggests that antioxidant enzyme expression may change during the establishment of stable transformed cell lines using retroviral techniques.

  2. Murine leukemias with retroviral insertions at Lmo2 are predictive of the leukemias induced in SCID-X1 patients following retroviral gene therapy.

    PubMed

    Davé, Utpal P; Akagi, Keiko; Tripathi, Rati; Cleveland, Susan M; Thompson, Mary A; Yi, Ming; Stephens, Robert; Downing, James R; Jenkins, Nancy A; Copeland, Neal G

    2009-05-01

    Five X-linked severe combined immunodeficiency patients (SCID-X1) successfully treated with autologous bone marrow stem cells infected ex vivo with an IL2RG-containing retrovirus subsequently developed T-cell leukemia and four contained insertional mutations at LMO2. Genetic evidence also suggests a role for IL2RG in tumor formation, although this remains controversial. Here, we show that the genes and signaling pathways deregulated in murine leukemias with retroviral insertions at Lmo2 are similar to those deregulated in human leukemias with high LMO2 expression and are highly predictive of the leukemias induced in SCID-X1 patients. We also provide additional evidence supporting the notion that IL2RG and LMO2 cooperate in leukemia induction but are not sufficient and require additional cooperating mutations. The highly concordant nature of the genetic events giving rise to mouse and human leukemias with mutations at Lmo2 are an encouraging sign to those wanting to use mice to model human cancer and may help in designing safer methods for retroviral gene therapy.

  3. Cross- and Co-Packaging of Retroviral RNAs and Their Consequences

    PubMed Central

    Ali, Lizna M.; Rizvi, Tahir A.; Mustafa, Farah

    2016-01-01

    Retroviruses belong to the family Retroviridae and are ribonucleoprotein (RNP) particles that contain a dimeric RNA genome. Retroviral particle assembly is a complex process, and how the virus is able to recognize and specifically capture the genomic RNA (gRNA) among millions of other cellular and spliced retroviral RNAs has been the subject of extensive investigation over the last two decades. The specificity towards RNA packaging requires higher order interactions of the retroviral gRNA with the structural Gag proteins. Moreover, several retroviruses have been shown to have the ability to cross-/co-package gRNA from other retroviruses, despite little sequence homology. This review will compare the determinants of gRNA encapsidation among different retroviruses, followed by an examination of our current understanding of the interaction between diverse viral genomes and heterologous proteins, leading to their cross-/co-packaging. Retroviruses are well-known serious animal and human pathogens, and such a cross-/co-packaging phenomenon could result in the generation of novel viral variants with unknown pathogenic potential. At the same time, however, an enhanced understanding of the molecular mechanisms involved in these specific interactions makes retroviruses an attractive target for anti-viral drugs, vaccines, and vectors for human gene therapy. PMID:27727192

  4. Suppression of retroviral propagation and disease by suramin in murine systems.

    PubMed Central

    Ruprecht, R M; Rossoni, L D; Haseltine, W A; Broder, S

    1985-01-01

    Retroviral propagation crucially depends on reverse transcriptase (RT). We have developed murine models to test the biological effectiveness of the RT inhibitor suramin. The drug was active in our assay system, which includes (i) inhibition of RT activity in the murine T-cell tropic virus SL3-3 and Rauscher murine leukemia virus (MuLV), (ii) inhibition of plaque formation in the XC plaque assay, (iii) inhibition of viral infection of cultured murine T cells, and (iv) inhibition of splenomegaly induced by Rauscher MuLV in BALB/c mice. Suramin decreases viral titers significantly, even if started 36 hr after infection. Viral titers and number of infected cells increased to control levels after removal of the drug. BALB/c mice treated i.v. with 40 mg of suramin per kg twice per week following infection with Rauscher MuLV showed a 35% decrease in splenomegaly. Suramin is an active antiretroviral agent whose effect on retroviral propagation is reversible. We conclude that it acts as a virustatic drug and that long-term administration of suramin will be necessary if it is used for experimental treatment of human retroviral illnesses such as the acquired immune deficiency syndrome. PMID:2415971

  5. Cryo-EM reveals a novel octameric integrase structure for β-retroviral intasome function

    PubMed Central

    Ballandras-Colas, Allison; Brown, Monica; Cook, Nicola J.; Dewdney, Tamaria G.; Demeler, Borries; Cherepanov, Peter; Lyumkis, Dmitry; Engelman, Alan N.

    2016-01-01

    Retroviral integrase (IN) catalyzes the integration of viral DNA (vDNA) into host target (tDNA), which is an essential step in the lifecycle of all retroviruses1. Prior structural characterization of IN-vDNA complexes, or intasomes, from the spumavirus prototype foamy virus (PFV) revealed a functional IN tetramer2–5, and it is generally believed that intasomes derived from other retroviral genera will employ tetrameric IN6–9. However, the intasomes of orthoretroviruses, which include all known pathogenic species, have not been characterized structurally. Using single-particle cryo-electron microscopy (cryo-EM) and X-ray crystallography, we determine here an unexpected octameric IN architecture for the β-retrovirus mouse mammary tumor virus (MMTV) intasome. The structure is composed of two core IN dimers, which interact with the vDNA ends and structurally mimic the PFV IN tetramer, and two flanking IN dimers that engage the core structure via their IN C-terminal domains (CTDs). Contrary to the belief that tetrameric IN components are sufficient to catalyze integration, the flanking IN dimers were necessary for MMTV IN activity. The IN octamer solves a conundrum for the β- as well as α-retroviruses by providing critical CTDs to the intasome core that cannot be provided in cis due to evolutionarily restrictive catalytic core domain (CCD)-CTD linker regions. The octameric architecture of the MMTV intasome provides a new paradigm for the structural basis of retroviral DNA integration. PMID:26887496

  6. Comparing the landcapes of common retroviral insertion sites across tumor models

    NASA Astrophysics Data System (ADS)

    Weishaupt, Holger; Čančer, Matko; Engström, Cristopher; Silvestrov, Sergei; Swartling, Fredrik J.

    2017-01-01

    Retroviral tagging represents an important technique, which allows researchers to screen for candidate cancer genes. The technique is based on the integration of retroviral sequences into the genome of a host organism, which might then lead to the artificial inhibition or expression of proximal genetic elements. The identification of potential cancer genes in this framework involves the detection of genomic regions (common insertion sites; CIS) which contain a number of such viral integration sites that is greater than expected by chance. During the last two decades, a number of different methods have been discussed for the identification of such loci and the respective techniques have been applied to a variety of different retroviruses and/or tumor models. We have previously established a retrovirus driven brain tumor model and reported the CISs which were found based on a Monte Carlo statistics derived detection paradigm. In this study, we consider a recently proposed alternative graph theory based method for identifying CISs and compare the resulting CIS landscape in our brain tumor dataset to those obtained when using the Monte Carlo approach. Finally, we also employ the graph-based method to compare the CIS landscape in our brain tumor model with those of other published retroviral tumor models.

  7. Using RT-prone recombination to promote re-building of complete retroviral vectors from two defective precursors: low efficiency and sequence specificities.

    PubMed

    Bru, Thierry; Galetto, Román; Piver, Eric; Collin, Christine; Negroni, Matteo; Pagès, Jean-Christophe

    2007-06-01

    Retroviral recombination has been suggested as a useful way to modify retroviral vectors. The possibility to combine two multiply deleted retroviral vectors into a novel vector was evaluated. To investigate this possibility we have constructed two defective vectors containing a shared internal ribosome entry site (IRES). The IRES was selected for its complex secondary structure, a feature described to favour retroviral recombination. The IRES was expected to promote a recombination event leading to the formation of a unique, functional retroviral vector. By supporting expression of two transgenes from a single promoter, this sequence was also expected to allow straightforward detection of the recombination event. The present data confirms the achievement of recombination-dependent rescue, albeit at low efficiency. Unexpectedly, a preferential use of the packaging signal (Psi) for recombination was observed, as compared to the IRES. Together these observations mitigate the idea of using this technique for the design of retroviral vectors.

  8. TRIM5 Retroviral Restriction Activity Correlates with the Ability To Induce Innate Immune Signaling

    PubMed Central

    Lascano, Josefina; Uchil, Pradeep D.; Mothes, Walther

    2015-01-01

    ABSTRACT Host restriction factor TRIM5 inhibits retroviral transduction in a species-specific manner by binding to and destabilizing the retroviral capsid lattice before reverse transcription is completed. However, the restriction mechanism may not be that simple since TRIM5 E3 ubiquitin ligase activity, the proteasome, autophagy, and TAK1-dependent AP-1 signaling have been suggested to contribute to restriction. Here, we show that, among a panel of seven primate and Carnivora TRIM5 orthologues, each of which has potential for potent retroviral restriction activity, all activated AP-1 signaling. In contrast, TRIM family paralogues most closely related to TRIM5 did not. While each primate species has a single TRIM5 gene, mice have at least seven TRIM5 homologues that cluster into two groups, Trim12a, -b, and -c and Trim30a, -b, -c, and -d. The three Trim12 proteins activated innate immune signaling, while the Trim30 proteins did not, though none of the murine Trim5 homologues restricted any of a panel of cloned retroviruses. To determine if any mouse TRIM5 homologues had potential for restriction activity, each was fused to the human immunodeficiency virus type 1 (HIV-1) CA binding protein cyclophilin A (CypA). The three Trim12-CypA fusions all activated AP-1 and restricted HIV-1 transduction, whereas the Trim30-CypA fusions did neither. AP-1 activation and HIV-1 restriction by the Trim12-CypA fusions were inhibited by disruption of TAK1. Overall then, these experiments demonstrate that there is a strong correlation between TRIM5 retroviral restriction activity and the ability to activate TAK1-dependent innate immune signaling. IMPORTANCE The importance of retroviruses for the evolution of susceptible host organisms cannot be overestimated. Eight percent of the human genome is retrovirus sequence, fixed in the germ line during past infection. Understanding how metazoa protect their genomes from mutagenic retrovirus infection is therefore of fundamental importance to

  9. Formulation and optimization of coated PLGA - Zidovudine nanoparticles using factorial design and in vitro in vivo evaluations to determine brain targeting efficiency.

    PubMed

    Peter Christoper, G V; Vijaya Raghavan, C; Siddharth, K; Siva Selva Kumar, M; Hari Prasad, R

    2014-04-01

    In the current study zidovudine loaded PLGA nanoparticles were prepared, coated and further investigated for its effectiveness in brain targeting. IR and DSC studies were performed to determine the interaction between excipients used and to find out the nature of drug in the formulation. Formulations were prepared by adopting 2(3) factorial designs to evaluate the effects of process and formulation variables. The prepared formulations were subjected for in vitro and in vivo evaluations. In vitro evaluations showed particle size below 100 nm, entrapment efficiency of formulations ranges of 28-57%, process yield of 60-76% was achieved and drug release for the formulations were in the range of 50-85%. The drug release from the formulations was found to follow Higuchi release pattern, n-value obtained after Korsemeyer plot was in the range of 0.56-0.78. In vivo evaluations were performed in mice after intraperitoneal administration of zidovudine drug solution, uncoated and coated formulation. Formulation when coated with Tween 80 achieved a higher concentration in the brain than that of the drug in solution and of the uncoated formulation. Stability studies indicated that there was no degradation of the drug in the formulation after 90 days of preparation when stored in refrigerated condition.

  10. [Clinical experience with zidovudine in patients with acquired immunodeficiency syndrome. Analysis of 117 cases. Grupo Andaluz para el Estudio de las Enfermedades Infecciosas].

    PubMed

    Biedma, D; Bascuñana, A; Viciana, P; Causse, M; Torres Tortosa, M; Lozano de León, F; Pujol, E; Pachón, J

    1992-09-01

    In order to assess the efficacy and the toxicity of zidovudine in AIDS patients, we have studied, prospectively, 117 patients that were treated with this drug, in several andalusian hospitals between January 1988 and June 1990. Initial dose of the drug was 200 mg every 4 hours. Mean survival was 100% at 6 months and 66.5% at 23 months. Survival at 19 months was higher in ADVP (77%) than in non-ADVP (48%). A positive influence on weight. Karnofsky index and number of opportunistic infections during the six first months of treatment was recorded, benefit that was lost progressively from that moment onwards. Main adverse effects were hematological, 10.1% of the patients requiring transfusions due to hemoglobin lower than 6.5 gr%. The more frequent cause to stop therapy was severe neutropenia (less than 500 neutrophils per mm). We consider that the beneficial effect of zidovudine is only transient, diminishing gradually when the treatment is prolonged. At present doses adverse effects are moderate not being present in most of the patients.

  11. Formulation and optimization of coated PLGA – Zidovudine nanoparticles using factorial design and in vitro in vivo evaluations to determine brain targeting efficiency

    PubMed Central

    Peter Christoper, G.V.; Vijaya Raghavan, C.; Siddharth, K.; Siva Selva Kumar, M.; Hari Prasad, R.

    2013-01-01

    In the current study zidovudine loaded PLGA nanoparticles were prepared, coated and further investigated for its effectiveness in brain targeting. IR and DSC studies were performed to determine the interaction between excipients used and to find out the nature of drug in the formulation. Formulations were prepared by adopting 23 factorial designs to evaluate the effects of process and formulation variables. The prepared formulations were subjected for in vitro and in vivo evaluations. In vitro evaluations showed particle size below 100 nm, entrapment efficiency of formulations ranges of 28–57%, process yield of 60–76% was achieved and drug release for the formulations were in the range of 50–85%. The drug release from the formulations was found to follow Higuchi release pattern, n–value obtained after Korsemeyer plot was in the range of 0.56–0.78. In vivo evaluations were performed in mice after intraperitoneal administration of zidovudine drug solution, uncoated and coated formulation. Formulation when coated with Tween 80 achieved a higher concentration in the brain than that of the drug in solution and of the uncoated formulation. Stability studies indicated that there was no degradation of the drug in the formulation after 90 days of preparation when stored in refrigerated condition. PMID:24648825

  12. The nucleoside reverse transcriptase inhibitors didanosine, lamivudine, stavudine and zidovudine show little effect on the virulence of Candida albicans in vitro.

    PubMed

    Ahmadou Ahidjo, Bintou; Veale, Rob; Dusé, Adriano G; Becker, Piet; Marais, Else

    2008-08-01

    Nucleoside reverse transcriptase inhibitors (NRTIs) are used in the treatment of human immunodeficiency virus (HIV). Since the analogue 5-fluorouracil increases Candida albicans virulence in vitro, and zidovudine therapy is associated with enhanced C. albicans adherence and biofilm formation, we investigated the effects of commonly used NRTIs on the virulence of C. albicans isolated from 21 antiretroviral-naïve HIV/AIDS patients. The isolates were exposed to didanosine, lamivudine, stavudine and zidovudine at their expected patient serum peak levels and at one-half and two times these levels for 24h and 72 h. Assays assessing changes in adherence, proliferation, biofilm formation and antifungal susceptibility were performed. No differences in these virulence characteristics of isolates exposed to NRTIs were noted in most cases. However, at 24h and 72 h a significant increase in the rate of proliferation was observed in response to two-fold the peak concentration of lamivudine. The results suggest a limited effect of NRTIs on C. albicans virulence.

  13. High-dose zidovudine plus valganciclovir for Kaposi sarcoma herpesvirus-associated multicentric Castleman disease: a pilot study of virus-activated cytotoxic therapy

    PubMed Central

    Uldrick, Thomas S.; Polizzotto, Mark N.; Aleman, Karen; O'Mahony, Deirdre; Wyvill, Kathleen M.; Wang, Victoria; Marshall, Vickie; Pittaluga, Stefania; Steinberg, Seth M.; Tosato, Giovanna; Whitby, Denise; Little, Richard F.

    2011-01-01

    Kaposi sarcoma herpesvirus (KSHV)–associated multicentric Castleman disease (MCD) is a lymphoproliferative disorder most commonly observed in HIV-infected patients. It is characterized by KSHV-infected plasmablasts that frequently express lytic genes. Patients manifest inflammatory symptoms attributed to overproduction of KSHV viral IL-6, human IL-6, and human IL-6. There is no standard therapy and no established response criteria. We investigated an approach targeting 2 KSHV lytic genes, ORF36 and ORF21, the protein of which, respectively, phosphorylate ganciclovir and zidovudine to toxic moieties. In a pilot study, 14 HIV-infected patients with symptomatic KSHV-MCD received high-dose zidovudine (600 mg orally every 6 hours) and the oral prodrug, valganciclovir (900 mg orally every 12 hours). Responses were evaluated using new response criteria. A total of 86% of patients attained major clinical responses and 50% attained major biochemical responses. Median progression-free survival was 6 months. With 43 months of median follow-up, overall survival was 86% at 12 months and beyond. At the time of best response, the patients showed significant improvements in C-reactive protein, albumin, platelets, human IL-6, IL-10, and KSHV viral load. The most common toxicities were hematologic. These observations provide evidence that therapy designed to target cells with lytic KSHV replication has activity in KSHV-MCD. This trial was registered at www.clinicaltrials.gov as #NCT00099073. PMID:21487108

  14. Intravenous and oral zidovudine pharmacokinetics and coagulation effects in asymptomatic human immunodeficiency virus-infected hemophilia patients.

    PubMed Central

    Morse, G D; Portmore, A C; Marder, V; Plank, C; Olson, J; Taylor, C; Bonnez, W; Reichman, R C

    1992-01-01

    Pharmacokinetic and coagulation studies were carried out over a 12-week period with 11 asymptomatic hemophilia patients with human immunodeficiency virus infection receiving zidovudine (ZDV). The patients received 300 mg every 4 h while awake (the accepted dose at the time of this study); consecutive 24-h intravenous (i.v.) and 12-h oral pharmacokinetic studies were conducted at weeks 1, 6, and 12. Coagulation studies were conducted at weeks 0, 4, 8, and 12. The numbers of units of factors VIII and IX and cryoprecipitate transfused during the 12-week periods before, during, and after ZDV treatment were recorded. Following i.v. and oral ZDV administration, the concentration in plasma declined rapidly over the first 4 h, and in some patients, ZDV was still detectable at 4 to 10 h. The i.v. total clearances (means +/- standard deviations) were 14.9 +/- 7.3, 11.2 +/- 3.7, and 15.1 +/- 4.7 ml/min/kg of body weight. The i.v. distribution volumes were 1.08 +/- 0.5, 1.0 +/- 0.4, and 1.65 +/- 1.4 liters/kg. The bioavailabilities were 0.54 +/- 0.22, 0.46 +/- 0.19, and 0.59 +/- 0.13 at weeks 1, 6, and 12, respectively. The pattern of ZDV-glucuronide (GZDV) disposition was similar to that of ZDV, and the peak plasma GZDV-to-ZDV ratio was higher after oral dosing, consistent with first-pass metabolism. In some individuals, up to 33% of an i.v. dose was excreted unchanged. At weeks 6 and 12, greater than 300 mg of total ZDV (GZDV plus ZDV) was recovered in the urine of some patients, suggesting tissue redistribution. Concentration in plasma after oral ZDV administration were variable, both within and between patients. The von Willebrand antigen level consistently decreased throughout the study but was not accompanied by a parallel change in ristocetin cofactor A activity, and no clinical adverse effects on coagulation were noted. This study demonstrates that ZDV can be used in hemophilia patients without worsening of their bleeding tendencies. The clinical significance of

  15. Large-scale Clinical-grade Retroviral Vector Production in a Fixed-Bed Bioreactor

    PubMed Central

    Wang, Xiuyan; Olszewska, Malgorzata; Qu, Jinrong; Wasielewska, Teresa; Bartido, Shirley; Hermetet, Gregory; Sadelain, Michel

    2015-01-01

    The successful genetic engineering of patient T cells with γ-retroviral vectors expressing chimeric antigen receptors or T-cell receptors for phase II clinical trials and beyond requires the large-scale manufacture of high-titer vector stocks. The production of retroviral vectors from stable packaging cell lines using roller bottles or 10- to 40-layer cell factories is limited by a narrow harvest window, labor intensity, open-system operations, and the requirement for significant incubator space. To circumvent these shortcomings, we optimized the production of vector stocks in a disposable fixed-bed bioreactor using good manufacturing practice–grade packaging cell lines. High-titer vector stocks were harvested over 10 days, representing a much broader harvest window than the 3-day harvest afforded by cell factories. For PG13 and 293Vec packaging cells, the average vector titer and the vector stocks’ yield in the bioreactor were higher by 3.2- to 7.3-fold, and 5.6- to 13.1-fold, respectively, than those obtained in cell factories. The vector production was 10.4 and 18.6 times more efficient than in cell factories for PG13 and 293Vec cells, respectively. Furthermore, the vectors produced from the fixed-bed bioreactors passed the release test assays for clinical applications. Therefore, a single vector lot derived from 293Vec is suitable to transduce up to 500 patients cell doses in the context of large clinical trials using chimeric antigen receptors or T-cell receptors. These findings demonstrate for the first time that a robust fixed-bed bioreactor process can be used to produce γ-retroviral vector stocks scalable up to the commercialization phase. PMID:25751502

  16. Green fluorescent protein retroviral vectors: low titer and high recombination frequency suggest a selective disadvantage.

    PubMed

    Hanazono, Y; Yu, J M; Dunbar, C E; Emmons, R V

    1997-07-20

    Green fluorescent protein (GFP) has been used as a reporter molecule for gene expression because it fluoresces green after blue-light excitation. Inclusion of this gene in a vector could allow rapid, nontoxic selection of successfully transduced cells. However, many attempts by our laboratory to isolate stable retroviral producer cell clones secreting biologically active vectors containing either the highly fluorescent S65T-GFP mutant or humanized GFP have failed. Vector plasmids containing various forms of GFP and the neomycin resistance gene were transfected into three different packaging cell lines and fluorescence was observed for several days, but stable clones selected with G418 no longer fluoresced. Using confocal microscopy, the brightest cells were observed to contract and die within a matter of days. RNA slot-blot analysis of retroviral producer supernatants showed no viral production from the GFP plasmid-transfected clones, although all clones derived after transfection with an identical retroviral construct not containing GFP produced virus. Genomic Southern analysis of the GFP-transduced clones showed a much higher probability of rearrangement of the priviral sequences than in the control non-GFP clones. Overall, 18/34 S65T-GFP clones and 17/33 humanized-GFP clones had rearrangements, whereas 2/15 control non-GFP clones had rearrangements. Hence, producer cells expressing high levels of these GFP genes seem to be selected against, with stable clones undergoing major rearrangements or other mutations that both abrogate GFP expression and prevent vector production. These observations indicate that GFP may not be an appropriate reporter gene for gene transfer applications in our vector/packaging system.

  17. Large-scale clinical-grade retroviral vector production in a fixed-bed bioreactor.

    PubMed

    Wang, Xiuyan; Olszewska, Malgorzata; Qu, Jinrong; Wasielewska, Teresa; Bartido, Shirley; Hermetet, Gregory; Sadelain, Michel; Rivière, Isabelle

    2015-04-01

    The successful genetic engineering of patient T cells with γ-retroviral vectors expressing chimeric antigen receptors or T-cell receptors for phase II clinical trials and beyond requires the large-scale manufacture of high-titer vector stocks. The production of retroviral vectors from stable packaging cell lines using roller bottles or 10- to 40-layer cell factories is limited by a narrow harvest window, labor intensity, open-system operations, and the requirement for significant incubator space. To circumvent these shortcomings, we optimized the production of vector stocks in a disposable fixed-bed bioreactor using good manufacturing practice-grade packaging cell lines. High-titer vector stocks were harvested over 10 days, representing a much broader harvest window than the 3-day harvest afforded by cell factories. For PG13 and 293Vec packaging cells, the average vector titer and the vector stocks' yield in the bioreactor were higher by 3.2- to 7.3-fold, and 5.6- to 13.1-fold, respectively, than those obtained in cell factories. The vector production was 10.4 and 18.6 times more efficient than in cell factories for PG13 and 293Vec cells, respectively. Furthermore, the vectors produced from the fixed-bed bioreactors passed the release test assays for clinical applications. Therefore, a single vector lot derived from 293Vec is suitable to transduce up to 500 patients cell doses in the context of large clinical trials using chimeric antigen receptors or T-cell receptors. These findings demonstrate for the first time that a robust fixed-bed bioreactor process can be used to produce γ-retroviral vector stocks scalable up to the commercialization phase.

  18. Homo- and hetero-dimerization of human UDP-glucuronosyltransferase 2B7 (UGT2B7) wild type and its allelic variants affect zidovudine glucuronidation activity.

    PubMed

    Yuan, Lingmin; Qian, Sainan; Xiao, Yongsheng; Sun, Hongying; Zeng, Su

    2015-05-01

    Most human UDP-glucuronosyltransferase (UGT; EC 2.4.1.17) genes contain non-synonymous single nucleotide polymorphisms (nsSNPs) which cause amino acid substitutions. Allelic variants caused by nsSNPs may exhibit absent or reduced enzyme activity. UGT2B7 is one of the most important UGTs that glucuronidates abundant endobiotics and xenobiotics, such as estriol, morphine, and anticancer drugs. Three nsSNPs, UGT2B7*71S (211G>T), UGT2B7*2 (802C>T) and UGT2B7*5 (1192G>A) are observed in the UGT2B7 gene, and they code for allozymes UGT2B7*71S (A71S), UGT2B7*2 (H268Y), and UGT2B7*5 (D398N). UGT2B7 has been observed to form oligomers that affect its enzymatic activity and in this study, we investigated protein-protein interactions among UGT2B7 allozymes wild type (WT), A71S, H268Y and D398N, by performing a systematic quantitative fluorescence resonance energy transfer (FRET) analysis in combination with co-immunoprecipitation assay. Quantitative FRET analysis revealed that UGT2B7 allozymes formed homo- and hetero-dimers and showed distinct features in donor-acceptor distances. Both codon 71 and codon 268 in the N-terminal domain were involved in the dimeric interaction. Co-immunoprecipitation experiments also proved that UGT2B7 allozymes formed stable dimers. The glucuronidation activities of homo- and hetero-dimers were further tested with zidovudine as the substrate. An increase in activity was observed when WT hetero-dimerized with A71S compared with homo-dimers, while both H268Y and D398N impaired the activity of WT and A71S by forming hetero-dimers. In addition, zidovudine glucuronidation activity is associated with FRET distance. These findings provide insights into the consequences of amino acid substitution in UGT2B7 on zidovudine glucuronidation and the association between protein-protein interaction and glucuronidation activity.

  19. Inducible expression of p21WAF-1/CIP-1/SDI-1 from a promoter conversion retroviral vector.

    PubMed

    Mrochen, S; Klein, D; Nikol, S; Smith, J R; Salmons, B; Günzburg, W H

    1997-01-01

    Constitutive, high-level expression of the potentially therapeutic WAF-1/CIP-1/SDI-1 gene is incompatible with cell growth. A promoter conversion retroviral vector carrying the WAF-1/CIP-1/SDI-1 gene under the transcriptional control of the glucocorticoid inducible promoter of mouse mammary tumor virus was used to infect human bladder carcinoma or feline kidney cells. Reduced cell growth due to a greater proportion of cells being in the G0/G1 phase of the cell cycle was observed when WAF-1/CIP-1/SDI-1 expression was activated by addition of glucocorticoid hormone. This system demonstrates the potential long-term therapeutic use of WAF-1/CIP-1/SDI-1 delivered by retroviral vectors for inhibiting the growth of rapidly proliferating cells. Moreover, the conditional expression of genes such as WAF-1/CIP-1/SDI-1 from such retroviral vectors may facilitate analysis of their function.

  20. Truncation of TRIM5 in the Feliformia explains the absence of retroviral restriction in cells of the domestic cat.

    PubMed

    McEwan, William A; Schaller, Torsten; Ylinen, Laura M; Hosie, Margaret J; Towers, Greg J; Willett, Brian J

    2009-08-01

    TRIM5alpha mediates a potent retroviral restriction phenotype in diverse mammalian species. Here, we identify a TRIM5 transcript in cat cells with a truncated B30.2 capsid binding domain and ablated restrictive function which, remarkably, is conserved across the Feliformia. Cat TRIM5 displayed no restriction activity, but ectopic expression conferred a dominant negative effect against human TRIM5alpha. Our findings explain the absence of retroviral restriction in cat cells and suggest that disruption of the TRIM5 locus has arisen independently at least twice in the Carnivora, with implications concerning the evolution of the host and pathogen in this taxon.

  1. Effects of Short-Course Zidovudine on the Selection of Nevirapine-Resistant HIV-1 in Women Taking Single-Dose Nevirapine

    PubMed Central

    Micek, Mark A.; Blanco, Ana Judith; Carlsson, Jacquelyn; Beck, Ingrid A.; Dross, Sandra; Matunha, Laurinda; Seidel, Kristy; Montoya, Pablo; Gantt, Soren; Matediana, Eduardo; Jamisse, Lilia; Gloyd, Stephen; Frenkel, Lisa M.

    2012-01-01

    Single-dose nevirapine (sdNVP) given to prevent mother-to-child-transmission of HIV-1 selects NVP-resistance. Short-course zidovudine (ZDV) was hypothesized to lower rates of NVP-resistance. HIV-1 infected pregnant women administered sdNVP with or without short-course ZDV were assessed for HIV-1 mutations (K103N, Y181C, G190A, and V106M) prior to delivery and postpartum. Postpartum NVP-resistance was lower among 31 taking ZDV+sdNVP compared to 33 taking only sdNVP (35.5% vs 72.7%; χ2 P = .003). NVP mutants decayed to <2% in 24/35 (68.6%) at a median 6 months postpartum, with no differences based on ZDV use (logrank P = .99). Short-course ZDV was associated with reduced NVP-resistance mutations among women taking sdNVP. PMID:22492850

  2. Biologically active mutants with deletions in the v-mos oncogene assayed with retroviral vectors.

    PubMed Central

    Bold, R J; Donoghue, D J

    1985-01-01

    We have constructed retroviral expression vectors by manipulation of the Moloney murine leukemia virus genome such that an exogenous DNA sequence may be inserted and subsequently expressed when introduced into mammalian cells. A series of N-terminal deletions of the v-mos oncogene was constructed and assayed for biological activity with these retroviral expression vectors. The results of the deletion analysis demonstrate that the region of p37mos coding region upstream of the third methionine codon is dispensable with respect to transformation. However, deletion mutants of v-mos which allow initiation of translation at the fourth methionine codon have lost the biological activity of the parental v-mos gene. Furthermore, experiments were also carried out to define the C-terminal limit of the active region of p37mos by the construction of premature termination mutants by the insertion of a termination oligonucleotide. Insertion of the oligonucleotide just 69 base pairs upstream from the wild-type termination site abolished the focus-forming ability of v-mos. Thus, we have shown the N-terminal limit of the active region of p37mos to be between the third and fourth methionines, while the C-terminal limit is within the last 23 amino acids of the protein. PMID:3018503

  3. Mechanism of Nucleic Acid Chaperone Function of Retroviral Nuceleocapsid (NC) Proteins

    NASA Astrophysics Data System (ADS)

    Rouzina, Ioulia; Vo, My-Nuong; Stewart, Kristen; Musier-Forsyth, Karin; Cruceanu, Margareta; Williams, Mark

    2006-03-01

    Recent studies have highlighted two main activities of HIV-1 NC protein contributing to its function as a universal nucleic acid chaperone. Firstly, it is the ability of NC to weakly destabilize all nucleic acid,(NA), secondary structures, thus resolving the kinetic traps for NA refolding, while leaving the annealed state stable. Secondly, it is the ability of NC to aggregate NA, facilitating the nucleation step of bi-molecular annealing by increasing the local NA concentration. In this work we use single molecule DNA stretching and gel-based annealing assays to characterize these two chaperone activities of NC by using various HIV-1 NC mutants and several other retroviral NC proteins. Our results suggest that two NC functions are associated with its zinc fingers and cationic residues, respectively. NC proteins from other retroviruses have similar activities, although expressed to a different degree. Thus, NA aggregating ability improves, and NA duplex destabilizing activity decreases in the sequence: MLV NC, HIV NC, RSV NC. In contrast, HTLV NC protein works very differently from other NC proteins, and similarly to typical single stranded NA binding proteins. These features of retroviral NCs co-evolved with the structure of their genomes.

  4. Detection of sequences homologous to human retroviral DNA in multiple sclerosis by gene amplification

    SciTech Connect

    Greenberg, S.J.; Ehrlich, G.D.; Abbott, M.A.; Hurwitz, B.J.; Waldmann, T.A.; Poiesz, B.J. )

    1989-04-01

    Twenty-one patients with multiple sclerosis, chronic progressive type, were examined for DNA sequences homologous to a human retrovirus. Genomic DNA from peripheral blood mononuclear cells was analyzed for the presence of homologous sequences to the human T-cell leukemia/lymphoma virus type I (HTLV-I) long terminal repeat, 3{prime} gag, pol, and env domains by the enzymatic in vitro gene amplification technique, polymerase chain reaction. Positive identification of homologous pol sequences was made in the amplified DNA from six of these patients (29%). Three of these six patients (14%) also tested positive for the env region, but not for the other regions tested. In contrast, none of the samples from 35 normal individuals studied was positive when amplified and tested with the same primers and probes. Comparison of patterns obtained from controls and from patients with adult T-cell leukemia or tropical spastic paraparesis suggests that the DNA sequences identified are exogenous to the human genome and may correspond to a human retroviral species. The data support the detection of a human retroviral agent in some patients with multiple sclerosis.

  5. Improved self-inactivating retroviral vectors derived from spleen necrosis virus.

    PubMed Central

    Olson, P; Nelson, S; Dornburg, R

    1994-01-01

    Self-inactivating (SIN) retroviral vectors contain a deletion spanning most of the right long terminal repeat's (LTR's) U3 region. Reverse transcription copies this deletion to both LTRs. As a result, there is no transcription from the 5' LTR, preventing further replication. Many previously developed SIN vectors, however, had reduced titers or were genetically unstable. Earlier, we reported that certain SIN vectors derived from spleen necrosis virus (SNV) experienced reconstitution of the U3-deleted LTR at high frequencies. This reconstitution occurred on the DNA level and appeared to be dependent on defined vector sequences. To study this phenomenon in more detail, we developed an almost completely U3-free retroviral vector. The promoter and enhancer of the left LTR were replaced with those of the cytomegalovirus immediate-early genes. This promoter swap did not impair the level of transcription or alter its start site. Our data indicate that SNV contains a strong initiator which resembles that of human immunodeficiency virus. We show that the vectors replicate with efficiencies similar to those of vectors possessing two wild-type LTRs. U3-deleted vectors carrying the hygromycin B phosphotransferase gene did not observably undergo LTR reconstitution, even when replicated in helper cells containing SNV-LTR sequences. However, vectors carrying the neomycin resistance gene did undergo LTR reconstitution with the use of homologous helper cell LTR sequences as template. This supports our earlier finding that sequences within the neomycin resistance gene can trigger recombination. Images PMID:7933088

  6. Epigenetic regulation of transcription and splicing of syncytins, fusogenic glycoproteins of retroviral origin

    PubMed Central

    Trejbalová, Kateřina; Blažková, Jana; Matoušková, Magda; Kučerová, Dana; Pecnová, Lubomíra; Vernerová, Zdenka; Heráček, Jiří; Hirsch, Ivan; Hejnar, Jiří

    2011-01-01

    Syncytin-1 and -2, human fusogenic glycoproteins encoded by the env genes of the endogenous retroviral loci ERVWE1 and ERVFRDE1, respectively, contribute to the differentiation of multinucleated syncytiotrophoblast in chorionic villi. In non-trophoblastic cells, however, the expression of syncytins has to be suppressed to avoid potential pathogenic effects. We studied the epigenetic suppression of ERVWE1 and ERVFRDE1 5′-long terminal repeats by DNA methylation and chromatin modifications. Immunoprecipitation of the provirus-associated chromatin revealed the H3K9 trimethylation at transcriptionally inactivated syncytins in HeLa cells. qRT-PCR analysis of non-spliced ERVWE1 and ERVFRDE1 mRNAs and respective env mRNAs detected efficient splicing of endogenously expressed RNAs in trophoblastic but not in non-placental cells. Pointing to the pathogenic potential of aberrantly expressed syncytin-1, we have found deregulation of transcription and splicing of the ERVWE1 in biopsies of testicular seminomas. Finally, ectopic expression experiments suggest the importance of proper chromatin context for the ERVWE1 splicing. Our results thus demonstrate that cell-specific retroviral splicing represents an additional epigenetic level controling the expression of endogenous retroviruses. PMID:21771862

  7. Moesin regulates stable microtubule formation and limits retroviral infection in cultured cells.

    PubMed

    Naghavi, Mojgan H; Valente, Susana; Hatziioannou, Theodora; de Los Santos, Kenia; Wen, Ying; Mott, Christina; Gundersen, Gregg G; Goff, Stephen P

    2007-01-10

    In a functional screen of mammalian complementary DNA libraries, we identified moesin as a novel gene whose overexpression blocks infection by murine leukemia viruses and human immunodeficiency virus type 1 in human and rodent lines, before the initiation of reverse transcription. Knockdown of moesin by RNA interference resulted in enhanced infection, suggesting that even the endogenous basal levels of moesin in rat fibroblasts are sufficient to limit virus infection. Moesin acts as a crosslinker between plasma membrane and actin filaments, as well as a signal transducer in responses involving cytoskeletal remodeling. Moesin overexpression was found to downregulate the formation of stable microtubules, whereas knockdown of moesin increased stable microtubule formation. A virus-resistant mutant cell line also displayed decreased stable microtubule levels, and virus-sensitive revertants recovered from the mutant line showed restoration of the stable microtubules, suggesting that these cytoskeletal networks play an important role in early post-entry events in the retroviral lifecycle. Together, these results suggest that moesin negatively regulates stable microtubule networks and is a natural determinant of cellular sensitivity to retroviral infection.

  8. Retroviral-mediated transfer of the human glucocerebrosidase gene into cultured Gaucher bone marrow.

    PubMed Central

    Nolta, J A; Yu, X J; Bahner, I; Kohn, D B

    1992-01-01

    Gaucher disease, a lysosomal glycolipid storage disorder, results from the genetic deficiency of an acidic glucosidase, glucocerebrosidase (GC). The beneficial effects of allogeneic bone marrow transplantation (BMT) for Gaucher disease suggest that GC gene transduction and the transplantation of autologous hematopoietic stem cells (gene therapy) may similarly alleviate symptoms. We have constructed a retroviral vector, L-GC, produced by a clone of the amphotropic packaging cell line PA317, which transduces the normal human GC cDNA with high efficiency. Whole-marrow mononuclear cells and CD34-enriched cells from a 4-yr-old female with type 3 Gaucher disease were transduced by the L-GC vector and studied in long-term bone marrow culture (LTBMC). Prestimulation of marrow with IL-3 and IL-6, followed by co-cultivation with vector-producing fibroblasts, produced gene transfer into 40-45% of the hematopoietic progenitor cells. The levels of GC expression in progeny cells (primarily mature myelomonocytic) produced by the LTBMC were quantitatively analyzed by Northern blot, Western blot, and glucocerebrosidase enzyme assay. Normal levels of GC RNA, immunoreactive protein, and enzymatic activity were detected throughout the duration of culture. These studies demonstrate that retroviral vectors can efficiently transfer the GC gene into long-lived hematopoietic progenitor cells from the bone marrow of patients with Gaucher disease and express physiologically relevant levels of GC enzyme activity. Images PMID:1379609

  9. Long terminal repeat of murine retroviral DNAs: sequence analysis, host-proviral junctions, and preintegration site.

    PubMed Central

    Van Beveren, C; Rands, E; Chattopadhyay, S K; Lowy, D R; Verma, I M

    1982-01-01

    The nucleotide sequence of the long terminal repeat (LTR) of three murine retroviral DNAs has been determined. The data indicate that the U5 region (sequences originating from the 5' end of the genome) of various LTRs is more conserved than the U3 region (sequences from the 3' end of the genome). The location and sequence of the control elements such as the 5' cap, "TATA-like" sequences, "CCAAT-box," and presumptive polyadenylic acid addition signal AATAAA in the various LTRs are nearly identical. Some murine retroviral DNAs contain a duplication of sequences within the LTR ranging in size from 58 to 100 base pairs. A variant of molecularly cloned Moloney murine sarcoma virus DNA in which one of the two LTRs integrated into the viral DNA was also analyzed. A 4-base-pair duplication was generated at the site of integration of LTR in the viral DNA. The host-viral junction of two molecularly cloned AKR-murine leukemia virus DNAs (clones 623 and 614) was determined. In the case of AKR-623 DNA, a 3- or 4-base-pair direct repeat of cellular sequences flanking the viral DNA was observed. However, AKR-614 DNA contained a 5-base-pair repeat of cellular sequences. The nucleotide sequence of the preintegration site of AKR-623 DNA revealed that the cellular sequences duplicated during integration are present only once. Finally, a striking homology between the sequences flanking the preintegration site and viral LTRs was observed. Images PMID:6281466

  10. Viral and Cellular Requirements for the Nuclear Entry of Retroviral Preintegration Nucleoprotein Complexes

    PubMed Central

    Matreyek, Kenneth A.; Engelman, Alan

    2013-01-01

    Retroviruses integrate their reverse transcribed genomes into host cell chromosomes as an obligate step in virus replication. The nuclear envelope separates the chromosomes from the cell cytoplasm during interphase, and different retroviral groups deal with this physical barrier in different ways. Gammaretroviruses are dependent on the passage of target cells through mitosis, where they are believed to access chromosomes when the nuclear envelope dissolves for cell division. Contrastingly, lentiviruses such as HIV-1 infect non-dividing cells, and are believed to enter the nucleus by passing through the nuclear pore complex. While numerous virally encoded elements have been proposed to be involved in HIV-1 nuclear import, recent evidence has highlighted the importance of HIV-1 capsid. Furthermore, capsid was found to be responsible for the viral requirement of various nuclear transport proteins, including transportin 3 and nucleoporins NUP153 and NUP358, during infection. In this review, we describe our current understanding of retroviral nuclear import, with emphasis on recent developments on the role of the HIV-1 capsid protein. PMID:24103892

  11. DNA minicircles clarify the specific role of DNA structure on retroviral integration.

    PubMed

    Pasi, Marco; Mornico, Damien; Volant, Stevenn; Juchet, Anna; Batisse, Julien; Bouchier, Christiane; Parissi, Vincent; Ruff, Marc; Lavery, Richard; Lavigne, Marc

    2016-09-19

    Chromatin regulates the selectivity of retroviral integration into the genome of infected cells. At the nucleosome level, both histones and DNA structure are involved in this regulation. We propose a strategy that allows to specifically study a single factor: the DNA distortion induced by the nucleosome. This strategy relies on mimicking this distortion using DNA minicircles (MCs) having a fixed rotational orientation of DNA curvature, coupled with atomic-resolution modeling. Contrasting MCs with linear DNA fragments having identical sequences enabled us to analyze the impact of DNA distortion on the efficiency and selectivity of integration. We observed a global enhancement of HIV-1 integration in MCs and an enrichment of integration sites in the outward-facing DNA major grooves. Both of these changes are favored by LEDGF/p75, revealing a new, histone-independent role of this integration cofactor. PFV integration is also enhanced in MCs, but is not associated with a periodic redistribution of integration sites, thus highlighting its distinct catalytic properties. MCs help to separate the roles of target DNA structure, histone modifications and integrase (IN) cofactors during retroviral integration and to reveal IN-specific regulation mechanisms.

  12. The impact of maternal anti-retroviral therapy on cytokine profile in the uninfected neonates.

    PubMed

    Kasahara, Taissa M; Hygino, Joana; Blanco, Bernardo; Xavier, Luciana; Araújo-Lima, Carlos Fernando; Guillermo, Landi V C; Bittencourt, Vera Carolina B; Guimarães, Vander; Andrade, Arnaldo F B; Bento, Cleonice A M

    2013-09-01

    The number of HIV-infected young women has been increasing since the beginning of the AIDS epidemic. The objective of the present study was to investigate the impact of anti-retroviral treatment (ART) of HIV-1-infected pregnant women (PW) on cytokine profile of uninfected neonates. Our results demonstrated that higher levels of IL-1β and TNF-α associated with lower IL-10 production were detected in the plasma obtained from neonates born from ART-treated PW. Furthermore, the production of TNF- α and IFN-γ was also significantly higher in polyclonally-activated T cells from those neonates. This elevated pro-inflammatory pattern detected by these activated-T cells was not associated to HIV-1 antigens sensitization. Finally, ART-exposed neonates showed to be born with lower weight, and it was inversely correlated with maternal peripheral TNF-a level. In summary, the data presented here suggest a significant disturbance in cytokine network of HIV-1-uninfected neonates exposed to potent anti-retroviral schemes during pregnancy.

  13. High Expression of Endogenous Retroviral Envelope Gene in the Equine Fetal Part of the Placenta

    PubMed Central

    Stefanetti, Valentina; Marenzoni, Maria Luisa; Passamonti, Fabrizio; Cappelli, Katia; Garcia-Etxebarria, Koldo; Coletti, Mauro; Capomaccio, Stefano

    2016-01-01

    Endogenous retroviruses (ERVs) are proviral phases of exogenous retroviruses that have co-evolved with vertebrate genomes for millions of years. Previous studies have identified the envelope (env) protein genes of retroviral origin preferentially expressed in the placenta which suggests a role in placentation based on their membrane fusogenic capacity and therefore they have been named syncytins. Until now, all the characterized syncytins have been associated with three invasive placentation types: the endotheliochorial (Carnivora), the synepitheliochorial (Ruminantia), and the hemochorial placentation (human, mouse) where they play a role in the syncytiotrophoblast formation. The purpose of the present study was to evaluate whether EqERV env RNA is expressed in horse tissues as well and investigate if the horse, possessing an epitheliochorial placenta, has “captured” a common retroviral env gene with syncytin-like properties in placental tissues. Interestingly, although in the equine placenta there is no syncytiotrophoblast layer at the maternal-fetal interface, our results showed that EqERV env RNA is highly expressed at that level, as expected for a candidate syncytin-like gene but with reduced abundance in the other somatic tissues (nearly 30-fold lower) thus suggesting a possible role in the placental tissue. Although the horse is one of the few domestic animals with a sequenced genome, few studies have been conducted about the EqERV and their expression in placental tissue has never been investigated. PMID:27176223

  14. Retroviral intasomes search for a target DNA by 1D diffusion which rarely results in integration

    PubMed Central

    Jones, Nathan D.; Lopez Jr, Miguel A.; Hanne, Jeungphill; Peake, Mitchell B.; Lee, Jong-Bong; Fishel, Richard; Yoder, Kristine E.

    2016-01-01

    Retroviruses must integrate their linear viral cDNA into the host genome for a productive infection. Integration is catalysed by the retrovirus-encoded integrase (IN), which forms a tetramer or octamer complex with the viral cDNA long terminal repeat (LTR) ends termed an intasome. IN removes two 3′-nucleotides from both LTR ends and catalyses strand transfer of the recessed 3′-hydroxyls into the target DNA separated by 4–6 bp. Host DNA repair restores the resulting 5′-Flap and single-stranded DNA (ssDNA) gap. Here we have used multiple single molecule imaging tools to determine that the prototype foamy virus (PFV) retroviral intasome searches for an integration site by one-dimensional (1D) rotation-coupled diffusion along DNA. Once a target site is identified, the time between PFV strand transfer events is 470 ms. The majority of PFV intasome search events were non-productive. These observations identify new dynamic IN functions and suggest that target site-selection limits retroviral integration. PMID:27108531

  15. Lamivudine and Zidovudine

    MedlinePlus

    ... Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website (http://goo.gl/c4Rm4p) for ...

  16. Recombinant adeno-associated virus-mediated high-efficiency, transient expression of the murine cationic amino acid transporter (ecotropic retroviral receptor) permits stable transduction of human HeLa cells by ecotropic retroviral vectors.

    PubMed Central

    Bertran, J; Miller, J L; Yang, Y; Fenimore-Justman, A; Rueda, F; Vanin, E F; Nienhuis, A W

    1996-01-01

    Adeno-associated virus has a broad host range, is nonpathogenic, and integrates into a preferred location on chromosome 19, features that have fostered development of recombinant adeno-associated viruses (rAAV) as gene transfer vectors for therapeutic applications. We have used an rAAV to transfer and express the murine cationic amino acid transporter which functions as the ecotropic retroviral receptor, thereby rendering human cells conditionally susceptible to infection by an ecotropic retroviral vector. The proportion of human HeLa cells expressing the receptor at 60 h varied as a function of the multiplicity of infection (MOI) with the rAAV. Cells expressing the ecotropic receptor were efficiently transduced with an ecotropic retroviral vector encoding a nucleus-localized form of beta-galactosidase. Cells coexpressing the ecotropic receptor and nucleus-localized beta-galactosidase were isolated by fluorescence-activated cell sorting, and cell lines were recovered by cloning at limiting dilution. After growth in culture, all clones contained the retroviral vector genome, but fewer than 10% (3 of 47) contained the rAAV genome and continued to express the ecotropic receptor. The ecotropic receptor coding sequences in the rAAV genome were under the control of a tetracycline-modulated promoter. In the presence of tetracycline, receptor expression was low and the proportion of cells transduced by the ecotropic retroviral vector was decreased. Modulation of receptor expression was achieved with both an episomal and an integrated form of the rAAV genome. These data establish that functional gene expression from an rAAV genome can occur transiently without genome integration. PMID:8794313

  17. High-definition mapping of retroviral integration sites defines the fate of allogeneic T cells after donor lymphocyte infusion.

    PubMed

    Cattoglio, Claudia; Maruggi, Giulietta; Bartholomae, Cynthia; Malani, Nirav; Pellin, Danilo; Cocchiarella, Fabienne; Magnani, Zulma; Ciceri, Fabio; Ambrosi, Alessandro; von Kalle, Christof; Bushman, Frederic D; Bonini, Chiara; Schmidt, Manfred; Mavilio, Fulvio; Recchia, Alessandra

    2010-12-22

    The infusion of donor lymphocytes transduced with a retroviral vector expressing the HSV-TK suicide gene in patients undergoing hematopoietic stem cell transplantation for leukemia/lymphoma promotes immune reconstitution and prevents infections and graft-versus-host disease. Analysis of the clonal dynamics of genetically modified lymphocytes in vivo is of crucial importance to understand the potential genotoxic risk of this therapeutic approach. We used linear amplification-mediated PCR and pyrosequencing to build a genome-wide, high-definition map of retroviral integration sites in the genome of peripheral blood T cells from two different donors and used gene expression profiling and bioinformatics to associate integration clusters to transcriptional activity and to genetic and epigenetic features of the T cell genome. Comparison with matched random controls and with integrations obtained from CD34(+) hematopoietic stem/progenitor cells showed that integration clusters occur within chromatin regions bearing epigenetic marks associated with active promoters and regulatory elements in a cell-specific fashion. Analysis of integration sites in T cells obtained ex vivo two months after infusion showed no evidence of integration-related clonal expansion or dominance, but rather loss of cells harboring integration events interfering with RNA post-transcriptional processing. The study shows that high-definition maps of retroviral integration sites are a powerful tool to analyze the fate of genetically modified T cells in patients and the biological consequences of retroviral transduction.

  18. Association of murine lupus and thymic full-length endogenous retroviral expression maps to a bone marrow stem cell

    SciTech Connect

    Krieg, A.M.; Gourley, M.F.; Steinberg, A.D. )

    1991-05-01

    Recent studies of thymic gene expression in murine lupus have demonstrated 8.4-kb (full-length size) modified polytropic (Mpmv) endogenous retroviral RNA. In contrast, normal control mouse strains do not produce detectable amounts of such RNA in their thymuses. Prior studies have attributed a defect in experimental tolerance in murine lupus to a bone marrow stem cell rather than to the thymic epithelium; in contrast, infectious retroviral expression has been associated with the thymic epithelium, rather than with the bone marrow stem cell. The present study was designed to determine whether the abnormal Mpmv expression associated with murine lupus mapped to thymic epithelium or to a marrow precursor. Lethally irradiated control and lupus-prone mice were reconstituted with T cell depleted bone marrow; one month later their thymuses were studied for endogenous retroviral RNA and protein expression. Recipients of bone marrow from nonautoimmune donors expressed neither 8.4-kb Mpmv RNA nor surface MCF gp70 in their thymuses. In contrast, recipients of bone marrow from autoimmune NZB or BXSB donors expressed thymic 8.4-kb Mpmv RNA and mink cell focus-forming gp70. These studies demonstrate that lupus-associated 8.4-kb Mpmv endogenous retroviral expression is determined by bone marrow stem cells.

  19. Characterization of rodent models of HIV-gp120 and anti-retroviral-associated neuropathic pain

    PubMed Central

    Wallace, Victoria C. J.; Blackbeard, Julie; Segerdahl, Andrew R.; Hasnie, Fauzia; Pheby, Timothy; McMahon, Stephen B.; Rice, Andrew S. C.

    2009-01-01

    A distal symmetrical sensory peripheral neuropathy is frequently observed in people living with Human Immunodeficiency Virus Type 1 (HIV-1). This neuropathy can be associated with viral infection alone, probably involving a role for the envelope glycoprotein gp120; or a drug-induced toxic neuropathy associated with the use of nucleoside analogue reverse transcriptase inhibitors as a component of highly active anti-retroviral therapy. In order to elucidate the mechanisms underlying drug-induced neuropathy in the context of HIV infection, we have characterized pathological events in the peripheral and central nervous system following systemic treatment with the anti-retroviral agent, ddC (Zalcitabine) with or without the concomitant delivery of HIV-gp120 to the rat sciatic nerve (gp120+ddC). Systemic ddC treatment alone is associated with a persistent mechanical hypersensitivity (33% decrease in limb withdrawal threshold) that when combined with perineural HIV-gp120 is exacerbated (48% decrease in threshold) and both treatments result in thigmotactic (anxiety-like) behaviour. Immunohistochemical studies revealed little ddC-associated alteration in DRG phenotype, as compared with known changes following perineural HIV-gp120. However, the chemokine CCL2 is significantly expressed in the DRG of rats treated with perineural HIV-gp120 and/or ddC and there is a reduction in intraepidermal nerve fibre density, comparable to that seen in herpes zoster infection. Moreover, a spinal gliosis is apparent at times of peak behavioural sensitivity that is exacerbated in gp120+ddC as compared to either treatment alone. Treatment with the microglial inhibitor, minocycline, is associated with delayed onset of hypersensitivity to mechanical stimuli in the gp120+ddC model and reversal of some measures of thigmotaxis. Finally, the hypersensitivity to mechanical stimuli was sensitive to systemic treatment with gabapentin, morphine and the cannabinoid WIN 55,212-2, but not with

  20. Characterization of rodent models of HIV-gp120 and anti-retroviral-associated neuropathic pain.

    PubMed

    Wallace, Victoria C J; Blackbeard, Julie; Segerdahl, Andrew R; Hasnie, Fauzia; Pheby, Timothy; McMahon, Stephen B; Rice, Andrew S C

    2007-10-01

    A distal symmetrical sensory peripheral neuropathy is frequently observed in people living with Human Immunodeficiency Virus Type 1 (HIV-1). This neuropathy can be associated with viral infection alone, probably involving a role for the envelope glycoprotein gp120; or a drug-induced toxic neuropathy associated with the use of nucleoside analogue reverse transcriptase inhibitors as a component of highly active anti-retroviral therapy. In order to elucidate the mechanisms underlying drug-induced neuropathy in the context of HIV infection, we have characterized pathological events in the peripheral and central nervous system following systemic treatment with the anti-retroviral agent, ddC (Zalcitabine) with or without the concomitant delivery of HIV-gp120 to the rat sciatic nerve (gp120+ddC). Systemic ddC treatment alone is associated with a persistent mechanical hypersensitivity (33% decrease in limb withdrawal threshold) that when combined with perineural HIV-gp120 is exacerbated (48% decrease in threshold) and both treatments result in thigmotactic (anxiety-like) behaviour. Immunohistochemical studies revealed little ddC-associated alteration in DRG phenotype, as compared with known changes following perineural HIV-gp120. However, the chemokine CCL2 is significantly expressed in the DRG of rats treated with perineural HIV-gp120 and/or ddC and there is a reduction in intraepidermal nerve fibre density, comparable to that seen in herpes zoster infection. Moreover, a spinal gliosis is apparent at times of peak behavioural sensitivity that is exacerbated in gp120+ddC as compared to either treatment alone. Treatment with the microglial inhibitor, minocycline, is associated with delayed onset of hypersensitivity to mechanical stimuli in the gp120+ddC model and reversal of some measures of thigmotaxis. Finally, the hypersensitivity to mechanical stimuli was sensitive to systemic treatment with gabapentin, morphine and the cannabinoid WIN 55,212-2, but not with

  1. Synthesis, Assembly, and Processing of the Env ERVWE1/Syncytin Human Endogenous Retroviral Envelope

    PubMed Central

    Cheynet, V.; Ruggieri, A.; Oriol, G.; Blond, J.-L.; Boson, B.; Vachot, L.; Verrier, B.; Cosset, F.-L.; Mallet, F.

    2005-01-01

    Syncytin is a fusogenic protein involved in the formation of the placental syncytiotrophoblast layer. This protein is encoded by the envelope gene of the ERVWE1 proviral locus belonging to the human endogenous retrovirus W (HERV-W) family. The HERV-W infectious ancestor entered the primate lineage 25 to 40 million years ago. Although the syncytin fusion property has been clearly demonstrated, little is known about this cellular protein maturation process with respect to classical infectious retrovirus envelope proteins. Here we show that the cellular syncytin protein is synthesized as a glycosylated gPr73 precursor cleaved into two mature proteins, a gp50 surface subunit (SU) and a gp24 transmembrane subunit (TM). These SU and TM subunits are found associated as homotrimers. The intracytoplasmic tail is critical to the fusogenic phenotype, although its cleavage requirements seem to have diverged from those of classical retroviral maturation. PMID:15827173

  2. Synthesis, assembly, and processing of the Env ERVWE1/syncytin human endogenous retroviral envelope.

    PubMed

    Cheynet, V; Ruggieri, A; Oriol, G; Blond, J-L; Boson, B; Vachot, L; Verrier, B; Cosset, F-L; Mallet, F

    2005-05-01

    Syncytin is a fusogenic protein involved in the formation of the placental syncytiotrophoblast layer. This protein is encoded by the envelope gene of the ERVWE1 proviral locus belonging to the human endogenous retrovirus W (HERV-W) family. The HERV-W infectious ancestor entered the primate lineage 25 to 40 million years ago. Although the syncytin fusion property has been clearly demonstrated, little is known about this cellular protein maturation process with respect to classical infectious retrovirus envelope proteins. Here we show that the cellular syncytin protein is synthesized as a glycosylated gPr73 precursor cleaved into two mature proteins, a gp50 surface subunit (SU) and a gp24 transmembrane subunit (TM). These SU and TM subunits are found associated as homotrimers. The intracytoplasmic tail is critical to the fusogenic phenotype, although its cleavage requirements seem to have diverged from those of classical retroviral maturation.

  3. Home-based caregivers' knowledge regarding anti-retroviral therapy in Namibia.

    PubMed

    Niikondo, H N; Hoque, M E; Ntuli-Ngcobo, B

    2011-03-01

    Lack of practical knowledge among home-based caregivers (HBCs) on HIV/AIDS, anti-retroviral treatment (ART) and poor individual adherence to treatment are among the root causes of ineffective ART service delivery in Namibia. The purpose of the study was to investigate the knowledge of HBCs in Namibia regarding ART. The study was a descriptive, cross-sectional study in which 89 participants completed self-administered questionnaires to assess their knowledge regarding ART. Knowledge of HBCs on ART was above average in some aspects, there was still lack of knowledge on necessity of post-test counseling. Training organizations should put emphasis on the necessity of post-test counseling, consequence of poor adherence and type of facilities that issue ART.

  4. Multiple sulfatase deficiency: catalytically inactive sulfatases are expressed from retrovirally introduced sulfatase cDNAs.

    PubMed Central

    Rommerskirch, W; von Figura, K

    1992-01-01

    Multiple sulfatase deficiency (MSD) is an inherited lysosomal storage disease characterized by the deficiency of at least seven sulfatases. The basic defect in MSD is thought to be in a post-translational modification common to all sulfatases. In accordance with this concept, RNAs of normal size and amount were detected in MSD fibroblasts for three sulfatases tested. cDNAs encoding arylsulfatase A, arylsulfatase B, or steroid sulfatase were introduced into MSD fibroblasts and fibroblasts with a single sulfatase deficiency by retroviral gene transfer. Infected fibroblasts overexpressed the respective sulfatase polypeptides. While in single-sulfatase-deficiency fibroblasts a concomitant increase of sulfatase activities was observed, MSD fibroblasts expressed sulfatase polypeptides with a severely diminished catalytic activity. From these results we conclude that the mutation in MSD severely decreases the capacity of a co- or post-translational process that renders sulfatases enzymatically active or prevents their premature inactivation. Images PMID:1348358

  5. Multiple sulfatase deficiency: catalytically inactive sulfatases are expressed from retrovirally introduced sulfatase cDNAs.

    PubMed

    Rommerskirch, W; von Figura, K

    1992-04-01

    Multiple sulfatase deficiency (MSD) is an inherited lysosomal storage disease characterized by the deficiency of at least seven sulfatases. The basic defect in MSD is thought to be in a post-translational modification common to all sulfatases. In accordance with this concept, RNAs of normal size and amount were detected in MSD fibroblasts for three sulfatases tested. cDNAs encoding arylsulfatase A, arylsulfatase B, or steroid sulfatase were introduced into MSD fibroblasts and fibroblasts with a single sulfatase deficiency by retroviral gene transfer. Infected fibroblasts overexpressed the respective sulfatase polypeptides. While in single-sulfatase-deficiency fibroblasts a concomitant increase of sulfatase activities was observed, MSD fibroblasts expressed sulfatase polypeptides with a severely diminished catalytic activity. From these results we conclude that the mutation in MSD severely decreases the capacity of a co- or post-translational process that renders sulfatases enzymatically active or prevents their premature inactivation.

  6. Feline mediastinal lymphoma: a retrospective study of signalment, retroviral status, response to chemotherapy and prognostic indicators.

    PubMed

    Fabrizio, Francesca; Calam, Amy E; Dobson, Jane M; Middleton, Stephanie A; Murphy, Sue; Taylor, Samantha S; Schwartz, Anita; Stell, Anneliese J

    2014-08-01

    Historically, feline mediastinal lymphoma has been associated with young age, positive feline leukaemia virus (FeLV) status, Siamese breed and short survival times. Recent studies following widespread FeLV vaccination in the UK are lacking. The aim of this retrospective multi-institutional study was to re-evaluate the signalment, retroviral status, response to chemotherapy, survival and prognostic indicators in feline mediastinal lymphoma cases in the post-vaccination era. Records of cats with clinical signs associated with a mediastinal mass and cytologically/histologically confirmed lymphoma were reviewed from five UK referral centres (1998-2010). Treatment response, survival and prognostic indicators were assessed in treated cats with follow-up data. Fifty-five cases were reviewed. The median age was 3 years (range, 0.5-12 years); 12 cats (21.8%) were Siamese; and the male to female ratio was 3.2:1.0. Five cats were FeLV-positive and two were feline immunodeficiency-positive. Chemotherapy response and survival was evaluated in 38 cats. Overall response was 94.7%; complete (CR) and partial response (PR) rates did not differ significantly between protocols: COP (cyclophosphamide, vincristine, prednisone) (n = 26, CR 61.5%, PR 34.0%); Madison-Wisconsin (MW) (n = 12, CR 66.7%, PR 25.0%). Overall median survival was 373 days (range, 20-2015 days) (COP 484 days [range, 20-980 days]; MW 211 days [range, 24-2015 days] [P = 0.892]). Cats achieving CR survived longer (980 days vs 42 days for PR; P = 0.032). Age, breed, sex, location (mediastinal vs mediastinal plus other sites), retroviral status and glucocorticoid pretreatment did not affect response or survival. Feline mediastinal lymphoma cases frequently responded to chemotherapy with durable survival times, particularly in cats achieving CR. The prevalence of FeLV-antigenaemic cats was low; males and young Siamese cats appeared to be over-represented.

  7. Size distribution of retrovirally marked lineages matches prediction from population measurements of cell cycle behavior

    NASA Technical Reports Server (NTRS)

    Cai, Li; Hayes, Nancy L.; Takahashi, Takao; Caviness, Verne S Jr; Nowakowski, Richard S.

    2002-01-01

    Mechanisms that regulate neuron production in the developing mouse neocortex were examined by using a retroviral lineage marking method to determine the sizes of the lineages remaining in the proliferating population of the ventricular zone during the period of neuron production. The distribution of clade sizes obtained experimentally in four different injection-survival paradigms (E11-E13, E11-E14, E11-E15, and E12-E15) from a total of over 500 labeled lineages was compared with that obtained from three models in which the average behavior of the proliferating population [i.e., the proportion of cells remaining in the proliferative population (P) vs. that exiting the proliferative population (Q)] was quantitatively related to lineage size distribution. In model 1, different proportions of asymmetric, symmetric terminal, and symmetric nonterminal cell divisions coexisted during the entire developmental period. In model 2, the developmental period was divided into two epochs: During the first, asymmetric and symmetric nonterminal cell divisions occurred, but, during the second, asymmetric and symmetric terminal cell divisions occurred. In model 3, the shifts in P and Q are accounted for by changes in the proportions of the two types of symmetric cell divisions without the inclusion of any asymmetric cell divisions. The results obtained from the retroviral experiments were well accounted for by model 1 but not by model 2 or 3. These findings demonstrate that: 1) asymmetric and both types of symmetric cell divisions coexist during the entire period of neurogenesis in the mouse, 2) neuron production is regulated in the proliferative population by the independent decisions of the two daughter cells to reenter S phase, and 3) neurons are produced by both asymmetric and symmetric terminal cell divisions. In addition, the findings mean that cell death and/or tangential movements of cells in the proliferative population occur at only a low rate and that there are no

  8. Tumor-specific suicide gene therapy for hepatocellular carcinoma by transcriptionally targeted retroviral replicating vectors.

    PubMed

    Lai, Y-H; Lin, C-C; Chen, S-H; Tai, C-K

    2015-02-01

    Replicating virus vectors are attractive tools for anticancer gene therapy, but the potential for adverse events due to uncontrolled spread of the vectors has been a major concern. To design a tumor-specific retroviral replicating vector (RRV), we replaced the U3 region of the RRV ACE-GFP with a regulatory sequence consisting of the hepatitis B virus enhancer II (EII) and human α-fetoprotein (AFP) core promoter to produce ACE-GFP-EIIAFP, a hepatocellular carcinoma (HCC)-targeting RRV. Similar to ACE-GFP, ACE-GFP-EIIAFP exhibited robust green fluorescent protein (GFP) expression in HCC cells and, most importantly, it exhibited HCC-specific replication and did not replicate in non-HCC tumor cells or normal liver cells. We sequenced the promoter region of ACE-GFP-EIIAFP collected from serial infection cycles to examine the genomic stability of the vector during its replicative spread, and found that the vector could retain the hybrid promoter in the genome for at least six infection cycles. In vitro studies revealed that ACE-CD-EIIAFP and ACE-PNP-EIIAFP, which express the yeast cytosine deaminase and Escherichia coli purine nucleoside phosphorylase, respectively, exert a highly potent cytotoxic effect on HCC cells in the presence of their respective prodrugs. In vivo, ACE-CD-EIIAFP-mediated suicide gene therapy efficiently suppressed HCC tumor growth and no detectable RRV signal was observed in extratumoral tissues. These results suggest that the tumor-specific, suicide-gene-encoding RRV may fulfill the promise of retroviral gene therapy for cancer.

  9. An amphotropic retroviral vector expressing a mutant gsp oncogene: effects on human thyroid cells in vitro.

    PubMed

    Ivan, M; Ludgate, M; Gire, V; Bond, J A; Wynford-Thomas, D

    1997-08-01

    Point mutations of the gsp protooncogene (encoding the alpha-subunit of the Gs protein) that constitutively activate the cAMP signaling pathway are a common feature of and a plausible causative mechanism for thyroid hyperfunctioning adenomas (hot nodules). To investigate the extent to which mutant gsp acting alone can induce proliferation of thyroid follicular cells, we generated an amphotropic retroviral vector (based on the pBABE-neo plasmid and psi-CRIP packaging line) to permit stable introduction of a hemagglutinin-tagged Gln227-->Leu mutant gsp gene into normal human thyrocytes in vitro. The biological activity of the vector was confirmed by detection of HA-tagged Gsp protein expression and induction of cAMP synthesis in selected target cells. Normal human thyroid follicular cells in primary monolayer culture were infected with the gsp retroviral vector or with corresponding vectors expressing mutant H-ras or neo only as positive and negative controls, respectively. Although, as before, mutant ras generated 10-20 well differentiated epithelial colonies/dish of 10(5) infected cells, with an average lifespan of 15-20 population doublings, only small groups of no more than 15-50 differentiated thyrocytes were observed with the gsp vector. In addition to standard conditions (10% FCS), infections were performed in reduced serum (1% FCS, TSH, and insulin), in the presence of isobutylylmethylxanthine, or in the presence of agents capable of closing gap junctions, with no significant difference in outcome. Although little or no proliferative response was observed regardless of the conditions, there was clear evidence of morphological response (rearrangement of the actin cytoskeleton and increased cell size). The results suggest that gsp mutation may not be a sufficient proliferogenic stimulus by itself to account for hot nodule formation.

  10. Sites of Retroviral DNA Integration: From Basic Research to Clinical Applications

    PubMed Central

    Serrao, Erik; Engelman, Alan N.

    2016-01-01

    One of the most crucial steps in the life cycle of a retrovirus is the integration of the viral DNA (vDNA) copy of the RNA genome into the genome of an infected host cell. Integration provides for efficient viral gene expression as well as for the segregation of the viral genomes to daughter cells upon cell division. Some integrated viruses are not well expressed, and cells latently infected with HIV-1 can resist the action of potent antiretroviral drugs and remain dormant for decades. Intensive research has been dedicated to understanding the catalytic mechanism of integration, as well as the viral and cellular determinants that influence integration site distribution throughout the host genome. In this review we summarize the evolution of techniques that have been used to recover and map retroviral integration sites, from the early days that first indicated that integration could occur in multiple cellular DNA locations, to current technologies that map upwards of millions of unique integration sites from single in vitro integration reactions or cell culture infections. We further review important insights gained from the use of such mapping techniques, including the monitoring of cell clonal expansion in patients treated with retrovirus-based gene therapy vectors, or AIDS patients on suppressive antiretroviral therapy (ART). These insights span from integrase (IN) enzyme sequence preferences within target DNA (tDNA) at the sites of integration, to the roles of host cellular proteins in mediating global integration distribution, to the potential relationship between genomic location of vDNA integration site and retroviral latency. PMID:26508664

  11. Sites of retroviral DNA integration: From basic research to clinical applications.

    PubMed

    Serrao, Erik; Engelman, Alan N

    2016-01-01

    One of the most crucial steps in the life cycle of a retrovirus is the integration of the viral DNA (vDNA) copy of the RNA genome into the genome of an infected host cell. Integration provides for efficient viral gene expression as well as for the segregation of viral genomes to daughter cells upon cell division. Some integrated viruses are not well expressed, and cells latently infected with human immunodeficiency virus type 1 (HIV-1) can resist the action of potent antiretroviral drugs and remain dormant for decades. Intensive research has been dedicated to understanding the catalytic mechanism of integration, as well as the viral and cellular determinants that influence integration site distribution throughout the host genome. In this review, we summarize the evolution of techniques that have been used to recover and map retroviral integration sites, from the early days that first indicated that integration could occur in multiple cellular DNA locations, to current technologies that map upwards of millions of unique integration sites from single in vitro integration reactions or cell culture infections. We further review important insights gained from the use of such mapping techniques, including the monitoring of cell clonal expansion in patients treated with retrovirus-based gene therapy vectors, or patients with acquired immune deficiency syndrome (AIDS) on suppressive antiretroviral therapy (ART). These insights span from integrase (IN) enzyme sequence preferences within target DNA (tDNA) at the sites of integration, to the roles of host cellular proteins in mediating global integration distribution, to the potential relationship between genomic location of vDNA integration site and retroviral latency.

  12. The utilization of humanized mouse models for the study of human retroviral infections

    PubMed Central

    Van Duyne, Rachel; Pedati, Caitlin; Guendel, Irene; Carpio, Lawrence; Kehn-Hall, Kylene; Saifuddin, Mohammed; Kashanchi, Fatah

    2009-01-01

    The development of novel techniques and systems to study human infectious diseases in both an in vitro and in vivo settings is always in high demand. Ideally, small animal models are the most efficient method of studying human afflictions. This is especially evident in the study of the human retroviruses, HIV-1 and HTLV-1, in that current simian animal models, though robust, are often expensive and difficult to maintain. Over the past two decades, the construction of humanized animal models through the transplantation and engraftment of human tissues or progenitor cells into immunocompromised mouse strains has allowed for the development of a reconstituted human tissue scaffold in a small animal system. The utilization of small animal models for retroviral studies required expansion of the early CB-17 scid/scid mouse resulting in animals demonstrating improved engraftment efficiency and infectivity. The implantation of uneducated human immune cells and associated tissue provided the basis for the SCID-hu Thy/Liv and hu-PBL-SCID models. Engraftment efficiency of these tissues was further improved through the integration of the non-obese diabetic (NOD) mutation leading to the creation of NODSCID, NOD/Shi-scid IL2rγ-/-, and NOD/SCID β2-microglobulinnull animals. Further efforts at minimizing the response of the innate murine immune system produced the Rag2-/-γc-/- model which marked an important advancement in the use of human CD34+ hematopoietic stem cells. Together, these animal models have revolutionized the investigation of retroviral infections in vivo. PMID:19674458

  13. Interleukin-encoding adenoviral vectors as genetic adjuvant for vaccination against retroviral infection.

    PubMed

    Ohs, Inga; Windmann, Sonja; Wildner, Oliver; Dittmer, Ulf; Bayer, Wibke

    2013-01-01

    Interleukins (IL) are cytokines with stimulatory and modulatory functions in the immune system. In this study, we have chosen interleukins which are involved in the enhancement of TH2 responses and B cell functions to analyze their potential to improve a prophylactic adenovirus-based anti-retroviral vaccine with regard to antibody and virus-specific CD4(+) T cell responses. Mice were vaccinated with an adenoviral vector which encodes and displays the Friend Virus (FV) surface envelope protein gp70 (Ad.pIXgp70) in combination with adenoviral vectors encoding the interleukins IL4, IL5, IL6, IL7 or IL23. Co-application of Ad.pIXgp70 with Ad.IL5, Ad.IL6 or Ad.IL23 resulted in improved protection with high control over FV-induced splenomegaly and reduced viral loads. Mice co-immunized with adenoviral vectors encoding IL5 or IL23 showed increased neutralizing antibody responses while mice co-immunized with Ad.IL6 or Ad.IL23 showed improved FV-specific CD4(+) T cell responses compared to mice immunized with Ad.pIXgp70 alone. We show that the co-application of adenoviral vectors encoding specific interleukins is suitable to improve the vaccination efficacy of an anti-retroviral vaccine. Improved protection correlated with improved CD4(+) T cell responses and especially with higher neutralizing antibody titers. The co-application of selected interleukin-encoding adenoviral vectors is a valuable tool for vaccination with regard to enhancement of antibody mediated immunity.

  14. Spectra resolution for simultaneous spectrophotometric determination of lamivudine and zidovudine components in pharmaceutical formulation of human immunodeficiency virus drug based on using continuous wavelet transform and derivative transform techniques.

    PubMed

    Sohrabi, Mahmoud Reza; Tayefeh Zarkesh, Mahshid

    2014-05-01

    In the present paper, two spectrophotometric methods based on signal processing are proposed for the simultaneous determination of two components of an anti-HIV drug called lamivudine (LMV) and zidovudine (ZDV). The proposed methods are applied to synthetic binary mixtures and commercial pharmaceutical tablets without the need for any chemical separation procedures. The developed methods are based on the application of Continuous Wavelet Transform (CWT) and Derivative Spectrophotometry (DS) combined with the zero cross point technique. The Daubechies (db5) wavelet family (242 nm) and Dmey wavelet family (236 nm) were found to give the best results under optimum conditions for simultaneous analysis of lamivudine and zidovudine, respectively. In addition, the first derivative absorption spectra were selected for the determination of lamivudine and zidovudine at 266 nm and 248 nm, respectively. Assaying various synthetic mixtures of the components validated the presented methods. Mean recovery values were found to be between 100.31% and 100.2% for CWT and 99.42% and 97.37% for DS, respectively for determination of LMV and ZDV. The results obtained from analyzing the real samples by the proposed methods were compared to the HPLC reference method. One-way ANOVA test at 95% confidence level was applied to the results. The statistical data from comparing the proposed methods with the reference method showed no significant differences.

  15. L-chicoric acid, an inhibitor of human immunodeficiency virus type 1 (HIV-1) integrase, improves on the in vitro anti-HIV-1 effect of Zidovudine plus a protease inhibitor (AG1350).

    PubMed

    Robinson, W E

    1998-08-01

    Combinations of anti-human immunodeficiency virus (HIV) drugs, including reverse transcriptase inhibitors and protease inhibitors, have proven immensely potent in the therapy of acquired immune deficiency syndrome (AIDS). To determine whether HIV integrase is a suitable target for combination therapy, the ability of an HIV integrase inhibitor, L-chicoric acid, to work in combination with a protease inhibitor and Zidovudine was tested in vitro. The addition of L-chicoric acid to either Zidovudine or protease inhibitor improved upon the observed anti-HIV activity of either compound alone. When all three drugs were combined, the anti-HIV activity was substantially better than either of the three compounds alone or any combination of two inhibitors. Doses of both Zidovudine and protease inhibitor could be reduced by more than 33% for an equivalent anti-HIV effect if L-chicoric acid was added. The improved anti-HIV activity was observed with a tissue culture adapted strain of HIV (HIV(LAI)) and with limited passage clinical isolates of HIV (HIV(R19) and HIV(R45)). These data demonstrate that a first generation HIV integrase inhibitor, L-chicoric acid, is at least additive in combination with existing multi-drug regimens and suggest that HIV integrase will be an excellent target for combination therapy of HIV infection.

  16. Clinical Outcomes of Tenofovir Versus Zidovudine-based Regimens Among People Living with HIV/AIDS: a Two Years Retrospective Cohort Study

    PubMed Central

    Ayele, Teshale; Jarso, Habtemu; Mamo, Girma

    2017-01-01

    Background: Tenofovir (TDF) based regimen is one of the first line agents that has been utilized routinely since 2013 in Ethiopia. Unfortunately, there is limited information regarding the Clinical outcomes and associated risk factors in this setting, where patients generally present late, have high rates of TB and other infectious conditions. Methods: A two year retrospective cohort study was conducted from February 10/2015 to March 10/2015 at Jimma University Specialized Hospital. A total of 280 records were reviewed by including data from September 3, 2012 to July 31, 2014. Records were selected using a simple random sampling technique. Data was collected on socio-demographic, clinical and drug related variables. Data was analyzed using STATA 13.1. Kaplan-Meier and Cox regression were used to compare survival experience and identify independent predictors. Propensity score matching analysis was conducted to elucidate the average treatment effects of each regimen over opportunistic infections. Results: Of 280 patients, 183(65.36%) were females and 93(33.32%) of females belong to Tenofovir group. Through 24 months analysis, TDF based regimen had a protective effect against death and opportunistic infections (OIs), (AHR=0.79, 95% CI [0.24, 2.62]) and (AHR=0.78, 95%CI [0.43, 1.4] respectively. The average treatment effect of TDF/3TC/EFV was (-71/1000, p=0.026), while it was (+114/1000, p=0.049) for AZT/3TC/EFV. However, TDF/3TC/NVP was associated with statistically insignificant morbidity reduction (-74/1000, p=0.377). Those with body mass-index (BMI) <18.5kg/m2 (AHR=3.21, 95%CI [0.93, 11.97]) had higher hazard of death. Absence of baseline prophylaxis (AHR=8.22, 95% CI [1.7, 39.77]), Cotrimoxazole prophylaxis alone (AHR=6.15, 95% CI [1.47, 26.67]) and BMI<18.5kg/m2 (AHR=2.06, 95% CI [1.14, 3.73]) had higher hazards of OIs. Conclusion: The survival benefit of TDF based regimen was similar to AZT based regimen and therefore can be used as an alternative for HIV

  17. Anti-Retroviral Lectins Have Modest Effects on Adherence of Trichomonas vaginalis to Epithelial Cells In Vitro and on Recovery of Tritrichomonas foetus in a Mouse Vaginal Model.

    PubMed

    Chatterjee, Aparajita; Ratner, Daniel M; Ryan, Christopher M; Johnson, Patricia J; O'Keefe, Barry R; Secor, W Evan; Anderson, Deborah J; Robbins, Phillips W; Samuelson, John

    2015-01-01

    Trichomonas vaginalis causes vaginitis and increases the risk of HIV transmission by heterosexual sex, while Tritrichomonas foetus causes premature abortion in cattle. Our goals were to determine the effects, if any, of anti-retroviral lectins, which are designed to prevent heterosexual transmission of HIV, on adherence of Trichomonas to ectocervical cells and on Tritrichomonas infections in a mouse model. We show that Trichomonas Asn-linked glycans (N-glycans), like those of HIV, bind the mannose-binding lectin (MBL) that is part of the innate immune system. N-glycans of Trichomonas and Tritrichomonas bind anti-retroviral lectins (cyanovirin-N and griffithsin) and the 2G12 monoclonal antibody, each of which binds HIV N-glycans. Binding of cyanovirin-N appears to be independent of susceptibility to metronidazole, the major drug used to treat Trichomonas. Anti-retroviral lectins, MBL, and galectin-1 cause Trichomonas to self-aggregate and precipitate. The anti-retroviral lectins also increase adherence of ricin-resistant mutants, which are less adherent than parent cells, to ectocervical cell monolayers and to organotypic EpiVaginal tissue cells. Topical application of either anti-retroviral lectins or yeast N-glycans decreases by 40 to 70% the recovery of Tritrichomonas from the mouse vagina. These results, which are explained by a few simple models, suggest that the anti-retroviral lectins have a modest potential for preventing or treating human infections with Trichomonas.

  18. Anti-Retroviral Lectins Have Modest Effects on Adherence of Trichomonas vaginalis to Epithelial Cells In Vitro and on Recovery of Tritrichomonas foetus in a Mouse Vaginal Model

    PubMed Central

    Chatterjee, Aparajita; Ratner, Daniel M.; Ryan, Christopher M.; Johnson, Patricia J.; O’Keefe, Barry R.; Secor, W. Evan; Anderson, Deborah J.; Robbins, Phillips W.; Samuelson, John

    2015-01-01

    Trichomonas vaginalis causes vaginitis and increases the risk of HIV transmission by heterosexual sex, while Tritrichomonas foetus causes premature abortion in cattle. Our goals were to determine the effects, if any, of anti-retroviral lectins, which are designed to prevent heterosexual transmission of HIV, on adherence of Trichomonas to ectocervical cells and on Tritrichomonas infections in a mouse model. We show that Trichomonas Asn-linked glycans (N-glycans), like those of HIV, bind the mannose-binding lectin (MBL) that is part of the innate immune system. N-glycans of Trichomonas and Tritrichomonas bind anti-retroviral lectins (cyanovirin-N and griffithsin) and the 2G12 monoclonal antibody, each of which binds HIV N-glycans. Binding of cyanovirin-N appears to be independent of susceptibility to metronidazole, the major drug used to treat Trichomonas. Anti-retroviral lectins, MBL, and galectin-1 cause Trichomonas to self-aggregate and precipitate. The anti-retroviral lectins also increase adherence of ricin-resistant mutants, which are less adherent than parent cells, to ectocervical cell monolayers and to organotypic EpiVaginal tissue cells. Topical application of either anti-retroviral lectins or yeast N-glycans decreases by 40 to 70% the recovery of Tritrichomonas from the mouse vagina. These results, which are explained by a few simple models, suggest that the anti-retroviral lectins have a modest potential for preventing or treating human infections with Trichomonas. PMID:26252012

  19. Use of the piggyBac transposon to create stable packaging cell lines for the production of clinical-grade self-inactivating γ-retroviral vectors.

    PubMed

    Feldman, Steven A; Xu, Hui; Black, Mary A; Park, Tristen S; Robbins, Paul F; Kochenderfer, James N; Morgan, Richard A; Rosenberg, Steven A

    2014-08-01

    Efforts to improve the biosafety of γ-retroviral-mediated gene therapy have resulted in a shift toward the use of self-inactivating (SIN) γ-retroviral vectors. However, scale-up and manufacturing of such vectors requires significant optimization of transient transfection-based processes or development of novel platforms for the generation of stable producer cell clones. To that end, we describe the use of the piggybac transposon to generate stable producer cell clones for the production of SIN γ-retroviral vectors. The piggybac transposon is a universal tool allowing for the stable integration of SIN γ-retroviral constructs into murine (PG13) and human 293-based Phoenix (GALV and RD114, respectively) packaging cell lines without reverse transcription. Following transposition, a high-titer clone is selected for manufacture of a master cell bank and subsequent γ-retroviral vector supernatant production. Packaging cell clones created using the piggybac transposon have comparable titers to non-SIN vectors generated via conventional methods. We describe herein the use of the piggybac transposon for the production of stable packaging cell clones for the manufacture of clinical-grade SIN γ-retroviral vectors for ex vivo gene therapy clinical trials.

  20. Low Third-Trimester Serum Levels of Lamivudine/Zidovudine and Lopinavir/Ritonavir in an HIV-Infected Pregnant Woman with Gastric Bypass.

    PubMed

    Michalik, David E; Jackson-Alvarez, Janielle T; Flores, Roxana; Tolentino-Baldridge, Christina; Batra, Jagmohan S

    2015-01-01

    Pharmacokinetics of lamivudine (3TC)/zidovudine (ZDV) and lopinavir/ritonavir (LPV/r) are described in a gravid 27-year-old HIV-infected woman with gastric bypass. Blood levels were obtained for these medications at time points 0 (predose) and 1, 2, 4, 6, 8, and 12 hours postdose. For these times, the levels (µg/mL) of 3TC were 0.0801, 0.69, 0.339, 0.237, 0.202, 0.108, and 0.0461; the levels of ZDV were 0.0153, 0.433, 0.0717, 0.0481, 0.0107, 0.0214, and 0.00864; the levels of lopinavir (LPV) were 2.45, 2.64, 1.95, 2.78, 3.83, 3.20, and 1.92; and the levels of ritonavir (RTV) were 0.09, 0.10, 0.07, 0.11, 0.15, 0.15, and 0.06. These data suggest that gastric bypass affected these antiretroviral drug levels. A functional, intact small bowel is responsible for absorption of these medications.

  1. Evaluation of in-vitro cytotoxicity and cellular uptake efficiency of zidovudine-loaded solid lipid nanoparticles modified with Aloe Vera in glioma cells.

    PubMed

    K S, Joshy; Sharma, Chandra P; Kalarikkal, Nandakumar; Sandeep, K; Thomas, Sabu; Pothen, Laly A

    2016-09-01

    Zidovudine loaded solid lipid nanoparticles of stearic acid modified with Aloe Vera (AV) have been prepared via simple emulsion solvent evaporation method which showed excellent stability at room temperature and refrigerated condition. The nanoparticles were examined by Fourier transform infrared spectroscopy (FT-IR), which revealed the overlap of the AV absorption peak with the absorption peak of modified stearic acid nanoparticles. The inclusion of AV to stearic acid decreased the crystallinity and improved the hydrophilicity of lipid nanoparticles and thereby improved the drug loading efficacy of lipid nanoparticles. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) imaging revealed that, the average particle size of unmodified (bare) nanoparticles was 45.66±12.22nm and modified solid lipid nanoparticles showed an average size of 265.61±80.44nm. Solid lipid nanoparticles with well-defined morphology were tested in vitro for their possible application in drug delivery. Cell culture studies using C6 glioma cells on the nanoparticles showed enhanced growth and proliferation of cells without exhibiting any toxicity. In addition, normal cell morphology and improved uptake were observed by fluorescence microscopy images of rhodamine labeled modified solid lipid nanoparticles compared with unmodified nanoparticles. The cellular uptake study suggested that these nanoparticles could be a promising drug delivery system to enhance the uptake of antiviral drug by brain cells and it could be a suitable drug carrier system for the treatment of HIV.

  2. A simple and efficient procedure for generating stable expression libraries by cDNA cloning in a retroviral vector.

    PubMed Central

    Rayner, J R; Gonda, T J

    1994-01-01

    cDNA expression cloning is a powerful method for the rescue and identification of genes that are able to confer a readily identifiable phenotype on specific cell types. Retroviral vectors provide several advantages over DNA-mediated gene transfer for the introduction of expression libraries into eukaryotic cells since they can be used to express genes in a wide range of cell types, including those that form important experimental systems such as the hemopoietic system. We describe here a straightforward and efficient method for generating expression libraries by using a murine retroviral vector. Essentially, the method involves the directional cloning of cDNA into the retroviral vector and the generation of pools of stable ecotropic virus producing cells from this DNA. The cells so derived constitute the library, and the virus they yield is used to infect appropriate target cells for subsequent functional screening. We have demonstrated the feasibility of this procedure by constructing several large retroviral libraries (10(5) to 10(6) individual clones) and then using one of these libraries to isolate cDNAs for interleukin-3 and granulocyte-macrophage colony-stimulating factor on the basis of the ability of these factors to confer autonomous growth on the factor-dependent hemopoietic cell line FDC-P1. Moreover, the frequency at which these factor-independent clones were isolated approximated the frequency at which they were represented in the original plasmid library. These results suggest that expression cloning with retroviruses is a practical and efficient procedure and should be a valuable method for the isolation of important regulatory genes. Images PMID:8289827

  3. Structural and functional studies of murine Mbo I repeat LTR (MRL) retroviral genes on the Y chromosome

    SciTech Connect

    Ch'ang, L.Y.; Hoyt, P.R.; Wang, T.H.; Kanagala, R.; Henley, D.C.; Yang, D.M.; Yang, W.K. )

    1991-03-15

    The mouse genome harbors approximately 200 copies of MRL retroviral elements (or MuRRs) that are preferentially expressed in the reproductive system. The MRL retroviral gene family is wildly distributed in the genus Mus. About 10% of the elements are located on the Y chromosome and the abundance is probably due to gene amplification. Multiple copies of Y chromosome-specific MRL retroviral sequences are present only in the genome of M spretus and M. musculus. Structural and sequence analyses revealed a truncation of the male-specific MRL elements isolated from a BALB/c mouse DNA library. Consequently, two-thirds of an intact LTR was retained at the 5{prime} end and the 3{prime} structure was disrupted immediately downstream of the pol gene with a concomitant loss of the 3{prime} LTR. Southern analysis of male and female mouse DNA confirmed that sequences adjacent to the 3{prime} breakpoint were Y chromosome specific. These sequences are length polymorphic in nature and appear to be co-amplified with MRL retroviral genes on the Y chromosome. A collinear cDNA of 9.5 kb containing fused MRL and Y chromosome sequences was also isolated from a testis library. The LTR of male-specific MRL elements was unable to drive the expression of the bacterial CAT gene in cultured mouse NIH/3T3 and mink CCL64 cells. However, when its enhancer domain was linked to an SV40 promoter, the CAT gene was expressed at a significant level. Differential binding activities to male-specific MRL were found in nuclear extracts of the liver, kidney, and testis.

  4. Activities of wildtype and mutant p53 in suppression of homologous recombination as measured by a retroviral vector system.

    PubMed

    Lu, Xiongbin; Lozano, Guillermina; Donehower, Lawrence A

    2003-01-28

    DNA repair of double strand breaks, interstrand DNA cross-links, and other types of DNA damage utilizes the processes of homologous recombination and non-homologous end joining to repair the damage. Aberrant homologous recombination is likely to be responsible for a significant fraction of chromosomal deletions, duplications, and translocations that are observed in cancer cells. To facilitate measurement of homologous recombination frequencies in normal cells, mutant cells, and cancer cells, we have developed a high titer retroviral vector containing tandem repeats of mutant versions of a GFP-Zeocin resistance fusion gene and an intact neomycin resistance marker. Recombination between the tandem repeats regenerates a functional GFP-Zeo(R) marker that can be easily scored. This retroviral vector was used to assess homologous recombination frequencies in human cancer cells and rodent fibroblasts with differing dosages of wild type or mutant p53. Absence of wild type p53 stimulated spontaneous and ionizing radiation-induced homologous recombination, confirming previous studies. Moreover, p53(+/-) mouse fibroblasts show elevated levels of homologous recombination compared to their p53(+/+) counterparts following retroviral vector infection, indicating that p53 is haploinsufficient for suppression of homologous recombination. Transfection of vector-containing p53 null Saos-2 cells with various human cancer-associated p53 mutants revealed that these altered p53 proteins retain some recombination suppression function despite being totally inactive for transcriptional transactivation. The retroviral vector utilized in these studies may be useful in performing recombination assays on a wide array of cell types, including those not readily transfected by normal vectors.

  5. HTLV-associated diseases: human retroviral infection and cutaneous T-cell lymphomas.

    PubMed

    Fujihara, K; Goldman, B; Oseroff, A R; Glenister, N; Jaffe, E S; Bisaccia, E; Pincus, S; Greenberg, S J

    1997-01-01

    An array of neurologic, oncologic, and autoimmune disorders are associated with infection with the human pathogenic retroviruses human T-cell leukemia virus types I and II (HTLV-I, II), as well as the human immunodeficiency viruses (HIV). The cutaneous T-cell lymphomas, mycosis fungoides (MF) and its hematogenous variant Sezary Syndrome (SS), share similar clinical and pathological features to HTLV-I-associated adult T-cell leukemia (ATL) and speculation of a retroviral link to MF and SS, especially in areas non-endemic for ATL, has lead to an intensified search for HTLV- and HIV-like agents in these diseases. To further explore a potential role for human retroviruses in MF and SS, skin biopsy-derived or peripheral blood mononuclear cell-derived DNA from 17 patients (MF, n = 7; erythrodermic MF (EMF), n = 5; SS, n = 5) from the North Eastern United States were screened using gene amplification by PCR and a liquid hybridization detection assay. Previously published primers and probes for HTLV-I (LTR, gag, pol, env, and pX), and our own primers and probes for HTLV-I (gag, pol, and env), HTLV-II (pol and env) and HIV-I (gag and pol) were employed. Serum antibodies to HTLV-I were negative in all but one EMF patient. The single HTLV-I seropositive patient carrying a diagnosis of EMF generated positive amplified signals for all of the eight HTLV-I regions tested. Ultimately, this individual evolved to exhibit clinical manifestations indistinguishable from ATL. The other 16 patients were negative for all 12 HTLV and HIV retroviral regions. Our findings suggest that none of the known prototypic human retroviruses are associated with seronegative MF and SS. The uniformly positive results for HTLV-I in the seropositive patient suggests that this patient initially presented with a smoldering form of ATL and illustrates the difficulty that sometimes may be encountered in the differential diagnosis of MF, SS, and ATL based solely on clinical and histopathological criteria.

  6. Effects of Membrane Charge and Order on Membrane Binding of the Retroviral Structural Protein Gag

    PubMed Central

    Wen, Yi; Dick, Robert A.

    2016-01-01

    ABSTRACT The retroviral structural protein Gag binds to the inner leaflet of the plasma membrane (PM), and many cellular proteins do so as well. We used Rous sarcoma virus (RSV) Gag together with membrane sensors to study the principles governing peripheral protein membrane binding, including electrostatics, specific recognition of phospholipid headgroups, sensitivity to phospholipid acyl chain compositions, preference for membrane order, and protein multimerization. We used an in vitro liposome-pelleting assay to test protein membrane binding properties of Gag, the well-characterized MARCKS peptide, a series of fluorescent electrostatic sensor proteins (mNG-KRn), and the specific phosphatidylserine (PS) binding protein Evectin2. RSV Gag and mNG-KRn bound well to membranes with saturated and unsaturated acyl chains, whereas the MARCKS peptide and Evectin2 preferentially bound to membranes with unsaturated acyl chains. To further discriminate whether the primary driving force for Gag membrane binding is electrostatic interactions or preference for membrane order, we measured protein binding to giant unilamellar vesicles (GUVs) containing the same PS concentration in both disordered (Ld) and ordered (Lo) phases. RSV Gag and mNG-KRn membrane association followed membrane charge, independent of membrane order. Consistent with pelleting data, the MARCKS peptide showed preference for the Ld domain. Surprisingly, the PS sensor Evectin2 bound to the PS-rich Ld domain with 10-fold greater affinity than to the PS-rich Lo domain. In summary, we found that RSV Gag shows no preference for membrane order, while proteins with reported membrane-penetrating domains show preference for disordered membranes. IMPORTANCE Retroviral particles assemble on the PM and bud from infected cells. Our understanding of how Gag interacts with the PM and how different membrane properties contribute to overall Gag assembly is incomplete. This study examined how membrane charge and membrane order

  7. Induction of methotrexate resistance by retroviral-mediated transfer of a mutant dihydrofolate reductase gene

    SciTech Connect

    Ricciardone, M.D.

    1986-01-01

    Methotrexate (MTX), a folate analog which inhibits the enzyme dihydrofolate reductase (DHFR), is an effective antineoplastic drug. However, MTX-induced myelosuppression limits the effectiveness of this agent. Selective induction of MTX resistance in bone marrow stem cells, prior to treatment with MTX, might prevent this toxicity and improve the therapeutic index of the drug. In these studies drug resistance was transferred to mouse and human bone marrow stem cells by retroviral expression vectors containing coding sequences of a mutant DHFR with a decreased affinity for MTX. Three retroviral expression vectors were analyzed. The CIS DR vector contained the mutant DHFR gene inserted into the replication-defective amphotropic 4070 virus, Cistor. The other vectors contained the mutant DHFR inserted into either the env region (SDHT1) or gag-pol region (SDHT2) of a replication-defective spleen focus-forming virus. All three constructs induced approximately a 200-fold resistance to MTX when transfected into NIH3T3 cells. Amphotropic infectious retroviruses were obtained by transfecting the mutant DHFR vectors into a packaging cell line, which supplied the gag, pol, and env proteins for virus production. Virus titers of 4.5 x 10/sup 3/ colony-forming units (CFU)/ml (CIS DR), 1.5 x 10/sup 4/ CFU/ml (SDHT2), and 5 x 10/sup 5/ CFU/ml (SDHT1) were measured by the transfer of MTX resistance to NIH3T3 cells. The amphotropic SDHT1 virus efficiently induced MTX resistance in cells of several species, including mouse NIH3T3 cells (5 x 10/sup 5/ CFU/ml), monkey CV1 cells (4 x 10/sup 3/ CFU/ml), and human MCF-7 cells (6 x 10/sup 4/ CFU/ml). When cocultured with SDHT1 virus-producing cells, both mouse and human bone marrow cells could be infected and rendered resistant to MTX. Mouse cytotoxic T lymphocytes and mouse helper T lymphocytes can also be made resistant to MTX.

  8. Quantitative analysis of recombination between YFP and CFP genes of FRET biosensors introduced by lentiviral or retroviral gene transfer

    PubMed Central

    Komatsubara, Akira T.; Matsuda, Michiyuki; Aoki, Kazuhiro

    2015-01-01

    Biosensors based on the principle of Förster (or fluorescence) resonance energy transfer (FRET) have been developed to visualize spatio-temporal dynamics of signalling molecules in living cells. Many of them adopt a backbone of intramolecular FRET biosensor with a cyan fluorescent protein (CFP) and yellow fluorescent protein (YFP) as donor and acceptor, respectively. However, there remains the difficulty of establishing cells stably expressing FRET biosensors with a YFP and CFP pair by lentiviral or retroviral gene transfer, due to the high incidence of recombination between YFP and CFP genes. To address this, we examined the effects of codon-diversification of YFP on the recombination of FRET biosensors introduced by lentivirus or retrovirus. The YFP gene that was fully codon-optimized to E.coli evaded the recombination in lentiviral or retroviral gene transfer, but the partially codon-diversified YFP did not. Further, the length of spacer between YFP and CFP genes clearly affected recombination efficiency, suggesting that the intramolecular template switching occurred in the reverse-transcription process. The simple mathematical model reproduced the experimental data sufficiently, yielding a recombination rate of 0.002–0.005 per base. Together, these results show that the codon-diversified YFP is a useful tool for expressing FRET biosensors by lentiviral or retroviral gene transfer. PMID:26290434

  9. Quantitative analysis of recombination between YFP and CFP genes of FRET biosensors introduced by lentiviral or retroviral gene transfer.

    PubMed

    Komatsubara, Akira T; Matsuda, Michiyuki; Aoki, Kazuhiro

    2015-08-20

    Biosensors based on the principle of Förster (or fluorescence) resonance energy transfer (FRET) have been developed to visualize spatio-temporal dynamics of signalling molecules in living cells. Many of them adopt a backbone of intramolecular FRET biosensor with a cyan fluorescent protein (CFP) and yellow fluorescent protein (YFP) as donor and acceptor, respectively. However, there remains the difficulty of establishing cells stably expressing FRET biosensors with a YFP and CFP pair by lentiviral or retroviral gene transfer, due to the high incidence of recombination between YFP and CFP genes. To address this, we examined the effects of codon-diversification of YFP on the recombination of FRET biosensors introduced by lentivirus or retrovirus. The YFP gene that was fully codon-optimized to E.coli evaded the recombination in lentiviral or retroviral gene transfer, but the partially codon-diversified YFP did not. Further, the length of spacer between YFP and CFP genes clearly affected recombination efficiency, suggesting that the intramolecular template switching occurred in the reverse-transcription process. The simple mathematical model reproduced the experimental data sufficiently, yielding a recombination rate of 0.002-0.005 per base. Together, these results show that the codon-diversified YFP is a useful tool for expressing FRET biosensors by lentiviral or retroviral gene transfer.

  10. Adaptation of Chimeric Retroviruses In Vitro and In Vivo: Isolation of Avian Retroviral Vectors with Extended Host Range

    PubMed Central

    Barsov, Eugene V.; Payne, William S.; Hughes, Stephen H.

    2001-01-01

    We have designed and characterized two new replication-competent avian sarcoma/leukosis virus-based retroviral vectors with amphotropic and ecotropic host ranges. The amphotropic vector RCASBP-M2C(797-8), was obtained by passaging the chimeric retroviral vector RCASBP-M2C(4070A) (6) in chicken embryos. The ecotropic vector, RCASBP(Eco), was created by replacing the env-coding region in the retroviral vector RCASBP(A) with the env region from an ecotropic murine leukemia virus. It replicates efficiently in avian DFJ8 cells that express murine ecotropic receptor. For both vectors, permanent cell lines that produce viral stocks with titers of about 5 × 106 CFU/ml on mammalian cells can be easily established by passaging transfected avian cells. Some chimeric viruses, for example, RCASBP(Eco), replicate efficiently without modifications. For those chimeric viruses that do require modification, adaptation by passage in vitro or in vivo is a general strategy. This strategy has been used to prepare vectors with altered host range and could potentially be used to develop vectors that would be useful for targeted gene delivery. PMID:11333876

  11. Adaptation of chimeric retroviruses in vitro and in vivo: isolation of avian retroviral vectors with extended host range.

    PubMed

    Barsov, E V; Payne, W S; Hughes, S H

    2001-06-01

    We have designed and characterized two new replication-competent avian sarcoma/leukosis virus-based retroviral vectors with amphotropic and ecotropic host ranges. The amphotropic vector RCASBP-M2C(797-8), was obtained by passaging the chimeric retroviral vector RCASBP-M2C(4070A) (6) in chicken embryos. The ecotropic vector, RCASBP(Eco), was created by replacing the env-coding region in the retroviral vector RCASBP(A) with the env region from an ecotropic murine leukemia virus. It replicates efficiently in avian DFJ8 cells that express murine ecotropic receptor. For both vectors, permanent cell lines that produce viral stocks with titers of about 5 x 10(6) CFU/ml on mammalian cells can be easily established by passaging transfected avian cells. Some chimeric viruses, for example, RCASBP(Eco), replicate efficiently without modifications. For those chimeric viruses that do require modification, adaptation by passage in vitro or in vivo is a general strategy. This strategy has been used to prepare vectors with altered host range and could potentially be used to develop vectors that would be useful for targeted gene delivery.

  12. Non-integrating gamma-retroviral vectors as a versatile tool for transient zinc-finger nuclease delivery.

    PubMed

    Bobis-Wozowicz, Sylwia; Galla, Melanie; Alzubi, Jamal; Kuehle, Johannes; Baum, Christopher; Schambach, Axel; Cathomen, Toni

    2014-04-11

    Designer nucleases, like zinc-finger nucleases (ZFNs), represent valuable tools for targeted genome editing. Here, we took advantage of the gamma-retroviral life cycle and produced vectors to transfer ZFNs in the form of protein, mRNA and episomal DNA. Transfer efficacy and ZFN activity were assessed in quantitative proof-of-concept experiments in a human cell line and in mouse embryonic stem cells. We demonstrate that retrovirus-mediated protein transfer (RPT), retrovirus-mediated mRNA transfer (RMT), and retrovirus-mediated episome transfer (RET) represent powerful methodologies for transient protein delivery or protein expression. Furthermore, we describe complementary strategies to augment ZFN activity after gamma-retroviral transduction, including serial transduction, proteasome inhibition, and hypothermia. Depending on vector dose and target cell type, gene disruption frequencies of up to 15% were achieved with RPT and RMT, and >50% gene knockout after RET. In summary, non-integrating gamma-retroviral vectors represent a versatile tool to transiently deliver ZFNs to human and mouse cells.

  13. Evaluating a Ligation-Mediated PCR and Pyrosequencing Method for the Detection of Clonal Contribution in Polyclonal Retrovirally Transduced Samples

    PubMed Central

    Brugman, Martijn H.; Suerth, Julia D.; Rothe, Michael; Suerbaum, Sebastian; Schambach, Axel; Modlich, Ute; Kustikova, Olga

    2013-01-01

    Abstract Retroviral gene transfer has proven therapeutic potential in clinical gene therapy trials but may also cause abnormal cell growth via perturbation of gene expression in the locus surrounding the insertion site. By establishing clonal marks, retroviral insertions are also used to describe the regenerative potential of individual cells. Deep sequencing approaches have become the method of choice to study insertion profiles in preclinical models and clinical trials. We used a protocol combining ligation-mediated polymerase chain reaction (LM-PCR) and pyrosequencing for insertion profiling and quantification in cells of various tissues transduced with various retroviral vectors. The presented method allows simultaneous analysis of a multitude of DNA-barcoded samples per pyrosequencing run, thereby allowing cost-effective insertion screening in studies with multiple samples. In addition, we investigated whether the number of pyrosequencing reads can be used to quantify clonal abundance. By comparing pyrosequencing reads against site-specific quantitative PCR and by performing spike-in experiments, we show that considerable variation exists in the quantification of insertion sites even when present in the same clone. Our results suggest that the protocol used here and similar approaches might misinterpret abundance clones defined by insertion sites, unless careful calibration measures are taken. The crucial variables causing this variation need to be defined and methodological improvements are required to establish pyrosequencing reads as a quantification measure in polyclonal situations. PMID:23384086

  14. Membrane immunoglobulin expressed by retroviral vector gene transfer mimics partial function of the B-cell receptor in vivo.

    PubMed

    Lu, Jing; Chen, Feng; Xu, Zhen; Zhang, Lingling; Xu, Peng; Liu, Depei; Liang, Chihchuan

    2016-01-01

    Activation of B-cells is initiated by the ligation of B-cell receptors by its cognate antigen, inducing a series of signal cascades. Understanding the molecular mechanisms of these important events is a crucial goal for immunologists. Chimeric B cell receptors provide a powerful tool for analysis of B-cell signal function. However, this method can only be used in tool cells, but cannot be used for in vivo study. Here, we constructed a retroviral vector to encode both heavy chains and light chains of a membrane immunoglobulin, and expressed them in primary B-cells using retroviral gene transfer. Our results demonstrate that the membrane immunoglobulin expressed by retroviral vectors transfer can initiate B-cell receptor-mediated signaling, resulting in the phosphorylation of Syk and Erk1/2 proteins. The results showed that B-cells expressing membrane immunoglobulin can make proliferative responses to cognate antigen both in vitro and in vivo. Therefore, we provide a methodology for rapidly analyzing the downstream signals of B-cell receptors both in vitro and in vivo, which could expedite the identification of proteins involved in B-cell function.

  15. Single molecule DNA interaction kinetics of retroviral nucleic acid chaperone proteins

    NASA Astrophysics Data System (ADS)

    Williams, Mark

    2010-03-01

    Retroviral nucleocapsid (NC) proteins are essential for several viral replication processes including specific genomic RNA packaging and reverse transcription. The nucleic acid chaperone activity of NC facilitates the latter process. In this study, we use single molecule biophysical methods to quantify the DNA interactions of wild type and mutant human immunodeficiency virus type 1 (HIV-1) NC and Gag and human T-cell leukemia virus type 1 (HTLV-1) NC. We find that the nucleic acid interaction properties of these proteins differ significantly, with HIV-1 NC showing rapid protein binding kinetics, significant duplex destabilization, and strong DNA aggregation, all properties that are critical components of nucleic acid chaperone activity. In contrast, HTLV-1 NC exhibits significant destabilization activity but extremely slow DNA interaction kinetics and poor aggregating capability, which explains why HTLV-1 NC is a poor nucleic acid chaperone. To understand these results, we developed a new single molecule method for quantifying protein dissociation kinetics, and applied this method to probe the DNA interactions of wild type and mutant HIV-1 and HTLV-1 NC. We find that mutations to aromatic and charged residues strongly alter the proteins' nucleic acid interaction kinetics. Finally, in contrast to HIV-1 NC, HIV-1 Gag, the nucleic acid packaging protein that contains NC as a domain, exhibits relatively slow binding kinetics, which may negatively impact its ability to act as a nucleic acid chaperone.

  16. Production of human glucocerebrosidase in mice after retroviral gene transfer into multipotential hematopoietic progenitor cells

    SciTech Connect

    Correll, P.H.; Fink, J.K.; Brady, R.O.; Perry, L.K.; Karlsson, S. )

    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.

  17. Neonatal Gene Therapy With a Gamma Retroviral Vector in Mucopolysaccharidosis VI Cats

    PubMed Central

    Ponder, Katherine P; O'Malley, Thomas M; Wang, Ping; O'Donnell, Patricia A; Traas, Anne M; Knox, Van W; Aguirre, Gustavo A; Ellinwood, N Matthew; Metcalf, Jason A; Wang, Bin; Parkinson-Lawrence, Emma J; Sleeper, Meg M; Brooks, Doug A; Hopwood, John J; Haskins, Mark E

    2012-01-01

    Mucopolysaccharidosis (MPS) VI is due to a deficiency in the activity of N-acetylgalactosamine 4-sulfatase (4S), also known as arylsulfatase B. Previously, retroviral vector (RV)-mediated neonatal gene therapy reduced the clinical manifestations of MPS I and MPS VII in mice and dogs. However, sulfatases require post-translational modification by sulfatase-modifying factors. MPS VI cats were injected intravenously (i.v.) with a gamma RV-expressing feline 4S, resulting in 5 ± 3 copies of RV per 100 cells in liver. Liver and serum 4S activity were 1,450 ± 1,720 U/mg (26-fold normal) and 107 ± 60 U/ml (13-fold normal), respectively, and were directly proportional to the liver 4S protein levels for individual cats. This study suggests that sulfatase-modifying factor (SUMF) activity in liver was sufficient to result in active enzyme despite overexpression of 4S. RV-treated MPS VI cats achieved higher body weights and longer appendicular skeleton lengths, had reduced articular cartilage erosion, and reduced aortic valve thickening and aortic dilatation compared with untreated MPS VI cats, although cervical vertebral bone lengths were not improved. This demonstrates that therapeutic expression of a functional sulfatase protein can be achieved with neonatal gene therapy using a gamma RV, but some aspects of bone disease remain difficult to treat. PMID:22395531

  18. Retroviral-mediated gene transfer and expression of human phenylalanine hydroxylase in primary mouse hepatocytes.

    PubMed Central

    Peng, H; Armentano, D; MacKenzie-Graham, L; Shen, R F; Darlington, G; Ledley, F D; Woo, S L

    1988-01-01

    Genetic therapy for phenylketonuria (severe phenylalanine hydroxylase deficiency) may require introduction of a normal phenylalanine hydroxylase gene into hepatic cells of patients. We 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 alpha 1-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 form the retroviral and internal promoters. These results demonstrate that the transcriptional regulatory elements of the alpha 1-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. Images PMID:3186716

  19. Inhibition Profiling of Retroviral Protease Inhibitors Using an HIV-2 Modular System

    PubMed Central

    Mahdi, Mohamed; Szojka, Zsófia; Mótyán, János András; Tőzsér, József

    2015-01-01

    Retroviral protease inhibitors (PIs) are fundamental pillars in the treatment of HIV infection and acquired immunodeficiency syndrome (AIDS). Currently used PIs are designed against HIV-1, and their effect on HIV-2 is understudied. Using a modular HIV-2 protease cassette system, inhibition profiling assays were carried out for protease inhibitors both in enzymatic and cell culture assays. Moreover, the treatment-associated resistance mutations (I54M, L90M) were introduced into the modular system, and comparative inhibition assays were performed to determine their effect on the susceptibility of the protease. Our results indicate that darunavir, saquinavir, indinavir and lopinavir were very effective HIV-2 protease inhibitors, while tipranavir, nelfinavir and amprenavir showed a decreased efficacy. I54M, L90M double mutation resulted in a significant reduction in the susceptibility to most of the inhibitors with the exception of tipranavir. To our knowledge, this modular system constitutes a novel approach in the field of HIV-2 protease characterization and susceptibility testing. PMID:26633459

  20. A retroviral RNA secondary structure required for efficient initiation of reverse transcription.

    PubMed Central

    Cobrinik, D; Soskey, L; Leis, J

    1988-01-01

    Genetic evidence is presented which suggests the existence of an important structural element in the 5' noncoding region of avian retrovirus RNA. The proposed structure, which we term the U5-leader stem, is composed of sequences in the middle of U5 and in the leader, flanking the primer-binding site. U5 and leader mutations which would disrupt this structure caused a partial replication defect. However, nucleotide substitutions in the leader, which would structurally compensate for a U5 deletion mutation, restored normal replication. Analysis of replication intermediates of viruses with the above mutations suggests that the U5-leader stem is required for efficient DNA synthesis in vivo and for initiation of DNA synthesis from the tRNA(Trp) primer in melittin-activated virions. However, this structure does not appear to be required for binding of the tRNA(Trp) primer to viral RNA. These results support a role for the U5-leader stem structure, independent of its primary sequence, in the initiation of retroviral replication. Images PMID:2458484

  1. Foxp3-dependent Transformation of Human Primary CD4+ T Lymphocytes by the Retroviral Protein Tax

    PubMed Central

    Chen, Li; Liu, Dan; Zhang, Yang; Zhang, Huan; Cheng, Hua

    2015-01-01

    The retroviral Tax proteins of human T cell leukemia virus type 1 and 2 (HTLV-1 and -2) are highly homologous viral transactivators. Both viral proteins can immortalize human primary CD4+ memory T cells, but when expressed alone they rarely transform T cells. In the present study, we found that the Tax proteins displayed a differential ability to immortalize human CD4+Foxp3+ T cells with characteristic expression of CTLA-4 and GITR. Because epidermal growth factor receptor (EGFR) was reportedly expressed and activated in a subset of CD4+Foxp3+ T cells, we introduced an activated EGFR into Tax-immortalized CD4+Foxp3+ T cells. We observed that these modified cells were grown independently of exogenous IL-2, correlating with a T cell transformation phenotype. In Tax-immortalized CD4+Foxp3- T cells, ectopic expression of Foxp3 was a prerequisite for Tax transformation of T cells. Accordingly, treatment of the transformed T cells with erlotinib, a selective inhibitor of EGFR, induced degradation of EGFR in lysosome, consequently causing T cell growth inhibition. Further, we identified autophagy as a crucial cellular survival pathway for the transformed T cells. Silencing key autophagy molecules including Beclin1, Atg5 and PI3 kinase class III (PI3KC3) resulted in drastic impairment of T cell growth. Our data, therefore, unveiled a previously unidentified role of Foxp3 in T cell transformation, providing a molecular basis for HTLV-1 transformation of CD4+Foxp3+ T cells. PMID:26381169

  2. Structural and functional comparisons of retroviral envelope protein C-terminal domains: still much to learn.

    PubMed

    Steckbeck, Jonathan D; Kuhlmann, Anne-Sophie; Montelaro, Ronald C

    2014-01-16

    Retroviruses are a family of viruses that cause a broad range of pathologies in animals and humans, from the apparently harmless, long-term genomic insertion of endogenous retroviruses, to tumors induced by the oncogenic retroviruses and acquired immunodeficiency syndrome (AIDS) resulting from human immunodeficiency virus infection. Disease can be the result of diverse mechanisms, including tumorigenesis induced by viral oncogenes or immune destruction, leading to the gradual loss of CD4 T-cells. Of the virally encoded proteins common to all retroviruses, the envelope (Env) displays perhaps the most diverse functionality. Env is primarily responsible for binding the cellular receptor and for effecting the fusion process, with these functions mediated by protein domains localized to the exterior of the virus. The remaining C-terminal domain may have the most variable functionality of all retroviral proteins. The C-terminal domains from three prototypical retroviruses are discussed, focusing on the different structures and functions, which include fusion activation, tumorigenesis and viral assembly and lifecycle influences. Despite these genetic and functional differences, however, the C-terminal domains of these viruses share a common feature in the modulation of Env ectodomain conformation. Despite their differences, perhaps each system still has information to share with the others.

  3. The RUNX Genes as Conditional Oncogenes: Insights from Retroviral Targeting and Mouse Models.

    PubMed

    Neil, James C; Gilroy, Kathryn; Borland, Gillian; Hay, Jodie; Terry, Anne; Kilbey, Anna

    2017-01-01

    The observation that the Runx genes act as targets for transcriptional activation by retroviral insertion identified a new family of dominant oncogenes. However, it is now clear that Runx genes are 'conditional' oncogenes whose over-expression is growth inhibitory unless accompanied by another event such as concomitant over-expression of MYC or loss of p53 function. Remarkably, while the oncogenic activities of either MYC or RUNX over-expression are suppressed while p53 is intact, the combination of both neutralises p53 tumour suppression in vivo by as yet unknown mechanisms. Moreover, there is emerging evidence that endogenous, basal RUNX activity is important to maintain the viability and proliferation of MYC-driven lymphoma cells. There is also growing evidence that the human RUNX genes play a similar conditional oncogenic role and are selected for over-expression in end-stage cancers of multiple types. Paradoxically, reduced RUNX activity can also predispose to cell immortalisation and transformation, particularly by mutant Ras. These apparently conflicting observations may be reconciled in a stage-specific model of RUNX involvement in cancer. A question that has yet to be fully addressed is the extent to which the three Runx genes are functionally redundant in cancer promotion and suppression.

  4. AAV gene transfer to the retina does not protect retrovirally transduced hepatocytes from the immune response.

    PubMed

    Bellodi-Privato, Marta; Le Meur, Guylène; Aubert, Dominique; Mendes-Madera, Alexandra; Pichard, Virginie; Rolling, Fabienne; Ferry, Nicolas

    2004-06-01

    Gene therapy of inherited hepatic disease relies on sustained expression of the therapeutic transgene. In many instances, such expression will require immune tolerization to the non-self therapeutic transgene product. We previously demonstrated that a cytotoxic immune response eliminated hepatocytes after in vivo transduction using recombinant retroviral vectors. In the present study we investigated whether prior gene transfer to the retina, which is suspected to induce immune tolerance, could alleviate the immune response occurring after retrovirus mediated gene transfer to the liver. Retinal cells were transduced using adeno-associated viral vectors harbouring a beta-galactosidase transgene. Sixty days later, regenerating hepatocytes were transduced after partial hepatectomy using a recombinant retrovirus carrying the transgene. Three weeks later, anti beta-galactosidase antibodies were present in all animals. Elimination of the transduced hepatocytes eventually occurred in all animals by 2 months after liver gene transfer, although sustained beta-galactosidase expression was still present in the retina in 66% of the animals. We conclude that although the retina behaves as an immunoprivileged site, gene expression in the subretinal space is not sufficient to induce immune tolerance to a transgene product expressed in the liver.

  5. Foxp3-dependent transformation of human primary CD4+ T lymphocytes by the retroviral protein tax.

    PubMed

    Chen, Li; Liu, Dan; Zhang, Yang; Zhang, Huan; Cheng, Hua

    2015-10-23

    The retroviral Tax proteins of human T cell leukemia virus type 1 and 2 (HTLV-1 and -2) are highly homologous viral transactivators. Both viral proteins can immortalize human primary CD4+ memory T cells, but when expressed alone they rarely transform T cells. In the present study, we found that the Tax proteins displayed a differential ability to immortalize human CD4+Foxp3+ T cells with characteristic expression of CTLA-4 and GITR. Because epidermal growth factor receptor (EGFR) was reportedly expressed and activated in a subset of CD4+Foxp3+ T cells, we introduced an activated EGFR into Tax-immortalized CD4+Foxp3+ T cells. We observed that these modified cells were grown independently of exogenous IL-2, correlating with a T cell transformation phenotype. In Tax-immortalized CD4+Foxp3- T cells, ectopic expression of Foxp3 was a prerequisite for Tax transformation of T cells. Accordingly, treatment of the transformed T cells with erlotinib, a selective inhibitor of EGFR, induced degradation of EGFR in lysosome, consequently causing T cell growth inhibition. Further, we identified autophagy as a crucial cellular survival pathway for the transformed T cells. Silencing key autophagy molecules including Beclin1, Atg5 and PI3 kinase class III (PI3KC3) resulted in drastic impairment of T cell growth. Our data, therefore, unveiled a previously unidentified role of Foxp3 in T cell transformation, providing a molecular basis for HTLV-1 transformation of CD4+Foxp3+ T cells.

  6. Effects of retroviral envelope-protein cleavage upon trafficking, incorporation, and membrane fusion

    SciTech Connect

    Apte, Swapna; Sanders, David Avram

    2010-09-15

    Retroviral envelope glycoproteins undergo proteolytic processing by cellular subtilisin-like proprotein convertases at a polybasic amino-acid site in order to produce the two functional subunits, SU and TM. Most previous studies have indicated that envelope-protein cleavage is required for rendering the protein competent for promoting membrane fusion and for virus infectivity. We have investigated the role of proteolytic processing of the Moloney murine leukemia virus envelope-protein through site-directed mutagenesis of the residues near the SU-TM cleavage site and have established that uncleaved glycoprotein is unable either to be incorporated into virus particles efficiently or to induce membrane fusion. Additionally, the results suggest that cleavage of the envelope protein plays an important role in intracellular trafficking of protein via the cellular secretory pathway. Based on our results it was concluded that a positively charged residue located at either P2 or P4 along with the arginine at P1 is essential for cleavage.

  7. Definition of a high-affinity Gag recognition structure mediating packaging of a retroviral RNA genome

    PubMed Central

    Gherghe, Cristina; Lombo, Tania; Leonard, Christopher W.; Datta, Siddhartha A. K.; Bess, Julian W.; Gorelick, Robert J.; Rein, Alan; Weeks, Kevin M.

    2010-01-01

    All retroviral genomic RNAs contain a cis-acting packaging signal by which dimeric genomes are selectively packaged into nascent virions. However, it is not understood how Gag (the viral structural protein) interacts with these signals to package the genome with high selectivity. We probed the structure of murine leukemia virus RNA inside virus particles using SHAPE, a high-throughput RNA structure analysis technology. These experiments showed that NC (the nucleic acid binding domain derived from Gag) binds within the virus to the sequence UCUG-UR-UCUG. Recombinant Gag and NC proteins bound to this same RNA sequence in dimeric RNA in vitro; in all cases, interactions were strongest with the first U and final G in each UCUG element. The RNA structural context is critical: High-affinity binding requires base-paired regions flanking this motif, and two UCUG-UR-UCUG motifs are specifically exposed in the viral RNA dimer. Mutating the guanosine residues in these two motifs—only four nucleotides per genomic RNA—reduced packaging 100-fold, comparable to the level of nonspecific packaging. These results thus explain the selective packaging of dimeric RNA. This paradigm has implications for RNA recognition in general, illustrating how local context and RNA structure can create information-rich recognition signals from simple single-stranded sequence elements in large RNAs. PMID:20974908

  8. Probing Retroviral and Retrotransposon Genome Structures: The “SHAPE” of Things to Come

    PubMed Central

    Sztuba-Solinska, Joanna; Le Grice, Stuart F. J.

    2012-01-01

    Understanding the nuances of RNA structure as they pertain to biological function remains a formidable challenge for retrovirus research and development of RNA-based therapeutics, an area of particular importance with respect to combating HIV infection. Although a variety of chemical and enzymatic RNA probing techniques have been successfully employed for more than 30 years, they primarily interrogate small (100–500 nt) RNAs that have been removed from their biological context, potentially eliminating long-range tertiary interactions (such as kissing loops and pseudoknots) that may play a critical regulatory role. Selective 2′ hydroxyl acylation analyzed by primer extension (SHAPE), pioneered recently by Merino and colleagues, represents a facile, user-friendly technology capable of interrogating RNA structure with a single reagent and, combined with automated capillary electrophoresis, can analyze an entire 10,000-nucleotide RNA genome in a matter of weeks. Despite these obvious advantages, SHAPE essentially provides a nucleotide “connectivity map,” conversion of which into a 3-D structure requires a variety of complementary approaches. This paper summarizes contributions from SHAPE towards our understanding of the structure of retroviral genomes, modifications to which technology that have been developed to address some of its limitations, and future challenges. PMID:22685659

  9. Serial bone marrow transplantation reveals in vivo expression of the pCLPG retroviral vector

    PubMed Central

    2010-01-01

    Background Gene therapy in the hematopoietic system remains promising, though certain aspects of vector design, such as transcriptional control elements, continue to be studied. Our group has developed a retroviral vector where transgene expression is controlled by p53 with the intention of harnessing the dynamic and inducible nature of this tumor suppressor and transcription factor. We present here a test of in vivo expression provided by the p53-responsive vector, pCLPG. For this, we used a model of serial transplantation of transduced bone marrow cells. Results We observed, by flow cytometry, that the eGFP transgene was expressed at higher levels when the pCLPG vector was used as compared to the parental pCL retrovirus, where expression is directed by the native MoMLV LTR. Expression from the pCLPG vector was longer lasting, but did decay along with each sequential transplant. The detection of eGFP-positive cells containing either vector was successful only in the bone marrow compartment and was not observed in peripheral blood, spleen or thymus. Conclusions These findings indicate that the p53-responsive pCLPG retrovirus did offer expression in vivo and at a level that surpassed the non-modified, parental pCL vector. Our results indicate that the pCLPG platform may provide some advantages when applied in the hematopoietic system. PMID:20096105

  10. Host factors in retroviral integration and the selection of integration target sites

    PubMed Central

    Craigie, Robert; Bushman, Frederic D.

    2015-01-01

    In order to replicate, a retrovirus must integrate a DNA copy of the viral RNA genome into a chromosome of the host cell. The study of retroviral integration has advanced considerably in the last few years. Here we focus on host factor interactions and the linked area of integration targeting. Genome-wide screens for cellular factors affecting HIV replication have identified a series of host cell proteins that may mediate subcellular trafficking of integration complexes, nuclear import, and integration target site selection. The cell transcriptional co-activator protein LEDGF/p75 has been identified as a tethering factor important for HIV integration, and recently, BET proteins (Brd2, 4, and 4) have been identified as tethering factors for the gammaretroviruses. A new class of HIV inhibitors has been developed targeting the HIV-1 IN-LEDGF binding site, though surprisingly these inhibitors appear to block assembly late during replication and do not act at the integration step. Going forward, genome-wide studies of HIV-host interactions offer many new starting points to investigate HIV replication and identify potential new inhibitor targets. PMID:26104434

  11. Economic evaluation of task-shifting approaches to the dispensing of anti-retroviral therapy

    PubMed Central

    2012-01-01

    Background A scarcity of human resources for health has been identified as one of the primary constraints to the scale-up of the provision of Anti-Retroviral Treatment (ART). In South Africa there is a particularly severe lack of pharmacists. The study aims to compare two task-shifting approaches to the dispensing of ART: Indirectly Supervised Pharmacist’s Assistants (ISPA) and Nurse-based pharmaceutical care models against the standard of care which involves a pharmacist dispensing ART. Methods A cross-sectional mixed methods study design was used. Patient exit interviews, time and motion studies, expert interviews and staff costs were used to conduct a costing from the societal perspective. Six facilities were sampled in the Western Cape province of South Africa, and 230 patient interviews conducted. Results The ISPA model was found to be the least costly task-shifting pharmaceutical model. However, patients preferred receiving medication from the nurse. This related to a fear of stigma and being identified by virtue of receiving ART at the pharmacy. Conclusions While these models are not mutually exclusive, and a variety of pharmaceutical care models will be necessary for scale up, it is useful to consider the impact of implementing these models on the provider, patient access to treatment and difficulties in implementation. PMID:22974373

  12. In vitro dissolution of generic immediate-release solid oral dosage forms containing BCS class I drugs: comparative assessment of metronidazole, zidovudine, and amoxicillin versus relevant comparator pharmaceutical products in South Africa and India.

    PubMed

    Reddy, Nallagundla H S; Patnala, Srinivas; Löbenberg, Raimar; Kanfer, Isadore

    2014-10-01

    Biowaivers are recommended for immediate-release solid oral dosage forms using dissolution testing as a surrogate for in vivo bioequivalence studies. Several guidance are currently available (the World Health Organization (WHO), the US FDA, and the EMEA) where the conditions are described. In this study, definitions, criteria, and methodologies according to the WHO have been applied. The dissolution performances of immediate-release metronidazole, zidovudine, and amoxicillin products purchased in South African and Indian markets were compared to the relevant comparator pharmaceutical product (CPP)/reference product. The dissolution performances were studied using US Pharmacopeia (USP) apparatus 2 (paddle) set at 75 rpm in each of three dissolution media (pH1.2, 4.5, and 6.8). Concentrations of metronidazole, zidovudine, and amoxicillin in each dissolution media were determined by HPLC. Of the 11 metronidazole products tested, only 8 could be considered as very rapidly dissolving products as defined by the WHO, whereas 2 of those products could be considered as rapidly dissolving products but did not comply with the f 2 acceptance criteria in pH 6.8. All 11 zidovudine products were very rapidly dissolving, whereas in the case of the 14 amoxicillin products tested, none of those products met any of the WHO criteria. This study indicates that not all generic products containing the same biopharmaceutics classification system (BCS) I drug and in similar strength and dosage form are necessarily in vitro equivalent. Hence, there is a need for ongoing market surveillance to determine whether marketed generic products containing BCS I drugs meet the release requirements to confirm their in vitro bioequivalence to the respective reference product.

  13. Non-hominid TP63 lacks retroviral LTRs but contains a novel conserved upstream exon.

    PubMed

    Beyer, Ulrike; Dobbelstein, Matthias

    2011-06-15

    We have recently identified novel isoforms of human p63, with specific expression in testicular germ cells. The synthesis of these p63 mRNA species is driven by the long terminal repeat (LTR) of the endogenous retrovirus ERV9. This LTR was inserted upstream of the previously known TP63 exons roughly 15 million years ago, leading to the expression of novel exons and the synthesis of germline-specific transactivating p63 (GTAp63) isoforms in humans and great apes (Beyer et al. Proc Natl Acad Sci USA 2011; 108:3624-9). However, this study did not reveal whether similar upstream exons can also be found in the TP63 genes of non-hominid animals. Here we performed rapid amplification of cDNA ends (RACE) to identify a novel upstream exon of murine TP63, located in the 5' position from the previously described start of transcription. This exon, termed "exon U3" in our previous publication, is conserved within a broad range of mammalian species, including hominids. However, in contrast to the human TP63 gene structure, the murine exon U3 represented the most upstream transcribed sequence of TP63. Murine exon U3 is then alternatively spliced to acceptor sites within exon 1 or upstream of exon 2, resulting in two different available translational start sites. p63 mRNAs comprising exon U3 are detectable in various tissues, with no particular preference for testicular cells. Thus, whereas the retroviral LTR in hominid species results in strictly germline-associated p63 isoforms, the upstream exon in non-hominids fails to confer this tissue specificity. This notion strongly supports the concept that the synthesis of a testis-specific p63 isoform is a recently acquired, unique feature of humans and great apes.

  14. Inhibition of retroviral replication by members of the TRIM protein family.

    PubMed

    Fletcher, Adam J; Towers, Greg J

    2013-01-01

    The TRIM protein family is emerging as a central component of mammalian antiviral innate immunity. Beginning with the identification of TRIM5α as a mammalian post-entry restriction factor against retroviruses, to the repeated observation that many TRIMs ubiquitinate and regulate signaling pathways, the past decade has witnessed an intense research effort to understand how TRIM proteins influence immunity. The list of viral families targeted directly or indirectly by TRIM proteins has grown to include adenoviruses, hepadnaviruses, picornaviruses, flaviviruses, orthomyxoviruses, paramyxoviruses, herpesviruses, rhabdoviruses and arenaviruses. We have come to appreciate how, through intense bouts of positive selection, some TRIM genes have been honed into species-specific restriction factors. Similarly, in the case of TRIMCyp, we are beginning to understand how viruses too have mutated to evade restriction, suggesting that TRIM and viruses have coevolved for millions of years of primate evolution. Recently, TRIM5α returned to the limelight when it was shown to trigger the expression of antiviral genes upon recognition of an incoming virus, a paradigm shift that demonstrated that restriction factors make excellent pathogen sensors. However, it remains unclear how many of ~100 human TRIM genes are antiviral, despite the expression of many of these genes being upregulated by interferon and upon viral infection. TRIM proteins do not conform to one type of antiviral mechanism, reflecting the diversity of viruses they target. Moreover, the cofactors of restriction remain largely enigmatic. The control of retroviral replication remains an important medical subject and provides a useful backdrop for reviewing how TRIM proteins act to repress viral replication.

  15. Unhealthy Alcohol Use is Associated with Monocyte Activation Prior to Starting Anti-Retroviral Therapy

    PubMed Central

    Carrico, Adam W.; Hunt, Peter W.; Emenyonu, Nneka I.; Muyindike, Winnie; Ngabirano, Christine; Cheng, Debbie M.; Winter, Michael R.; Samet, Jeffrey H.; Hahn, Judith A.

    2015-01-01

    Background Alcohol use may accelerate HIV disease progression, but the plausible biological mechanisms have not been clearly elucidated. Methods HIV-positive persons who were not on anti-retroviral therapy (ART) completed the baseline assessment for a longitudinal study examining the association of alcohol use with HIV disease markers. Oversampling drinkers, baseline samples were tested for markers of monocyte activation (sCD14), inflammation (IL-6), and coagulation (D-dimer). We defined “unhealthy alcohol use” as testing positive using the Alcohol Use Disorders Identification Test – Consumption (AUDIT-C; ≥ 3 for women and ≥ 4 for men) in the past 3 months or testing positive using a biomarker of heavy drinking, phophatidylethanol (PEth; ≥ 50 ng/ml). Multiple linear regression was used to examine the associations of unhealthy alcohol use with sCD14, Log10 IL-6, and D-dimer. Results Compared to those who were abstinent from alcohol, unhealthy drinkers had significantly higher sCD14 levels (mean = 1,676 vs. 1,387 ng/ml; mean difference (95% CI) = 289 (83, 495), p < 0.01). In analyses adjusted for demographic factors, current cigarette smoking, and HIV disease markers, unhealthy drinkers continued to display significantly higher sCD14 levels compared to those who were abstinent from alcohol (adjusted mean = 1,670 vs. 1,406 ng/ml; adjusted mean difference (95% CI) = 264 (47, 480), p = 0.02). Unhealthy alcohol use was not significantly associated with IL-6 or D-dimer levels. Conclusions unhealthy alcohol use was independently associated with a marker of monocyte activation (i.e., higher sCD14) that predicts mortality in treated HIV infection. Longitudinal research should examine if unhealthy alcohol use predicts changes in sCD14 prior to and following ART initiation. PMID:26509359

  16. Cloning of the rat ecotropic retroviral receptor and studies of its expression in intestinal tissues

    SciTech Connect

    Puppi, M.; Henning, S.J.

    1995-05-01

    A long-term goal of our laboratory is to establish a rat model to study the feasibility of using the intestinal tract as a site for somatic gene therapy. As a step toward that goal, the current study reports the cloning of the rat ecotropic retroviral receptor (EcoR) cDNA and the study of various aspects of its expression in the intestinal cDNA library with mouse EcoR cDNA. A clone of approximately 7 kb, designated MP10, was obtained. Partial sequencing of MP10 from the 5{prime} end revealed a level of similarity of 92% compared with mouse EcoR. The presence of a 5{prime} untranslated region and a 3{prime} poly(A)tract, together with the overall size of the cDNA, suggest that is very close to being a full-length cDNA for this large transcript. Northern blots with MP10 showed an RNA of approximately 7.9 kb present along the entire length of the small intestine and somewhat less abundant in the colon. Developmental studies showed high levels of EcoR in fetal rat intestine, a decline in the early postnatal period, then a gradual rise to adulthood. Caco-2 cells were used to assess the expression of EcoR in proliferating compared with differentiated intestinal epithelial cells. EcoR mRNA was found to be very much more abundant in nondifferentiated cells and declined to low levels as the cells underwent spontaneous differentiation. These patterns of EcoR expression indicate that ecotropic retroviruses should be suitable vectors with which to attempt gene transfer into the intestinal epithelium. In addition, since the endogenous role of EcoR is as the y{sup +} cationic amino acid transporter, these data have significance for understanding patterns of amino acid transport in the intestinal epithelium. 37 refs., 4 figs.

  17. Retrovirally transduced murine T lymphocytes expressing FasL mediate effective killing of prostate cancer cells

    PubMed Central

    Symes, JC; Siatskas, C; Fowler, DH; Medin, JA

    2010-01-01

    Adoptively transferred T cells possess anticancer activities partially mediated by T-cell FasL engagement of Fas tumor targets. However, antigen-induced T-cell activation and clonal expansion, which stimulates FasL activity, is often inefficient in tumors. As a gene therapy approach to overcome this obstacle, we have created oncoretroviral vectors to overexpress FasL or non-cleavable FasL (ncFasL) on murine T cells of a diverse T-cell receptor repertoire. Expression of c-FLIP was also engineered to prevent apoptosis of transduced cells. Retroviral transduction of murine T lymphocytes has historically been problematic, and we describe optimized T-cell transduction protocols involving CD3/CD28 co-stimulation of T cells, transduction on ice using concentrated oncoretrovirus, and culture with IL-15. Genetically modified T cells home to established prostate cancer tumors in vivo. Co-stimulated T cells expressing FasL, ncFasL and ncFasL/c-FLIP each mediated cytotoxicity in vitro against RM-1 and LNCaP prostate cancer cells. To evaluate the compatibility of this approach with current prostate cancer therapies, we exposed RM-1, LNCaP, and TRAMP-C1 cells to radiation, mitoxantrone, or docetaxel. Fas and H-2b expression were upregulated by these methods. We have developed a novel FasL-based immuno-gene therapy for prostate cancer that warrants further investigation given the apparent constitutive and inducible Fas pathway expression in this malignancy. PMID:19096446

  18. Cytotoxic immune response after retroviral-mediated hepatic gene transfer in rat does not preclude expression from adeno-associated virus 1 transduced muscles.

    PubMed

    Aubert, Dominique; Pichard, Virginie; Durand, Sophie; Moullier, Philippe; Ferry, Nicolas

    2003-03-20

    Intravenous delivery of nls-lacZ retroviral vectors to the regenerating liver triggers a cytotoxic immune response directed against transduced hepatocytes. We sought to determine whether prior immunization with retroviral vectors impacted on adeno-associated virus (AAV)-mediated muscular expression of the same transgene. The first group of rats first received nls-lacZ retroviral vectors intravenously after a partial hepatectomy. Thirty days later they received AAV vectors intramuscularly in both legs. In the second group, animals received the same vectors in the opposite sequence (i.e., AAV first and retroviruses 20 days later). In the first group, immune response occurred after retrovirus delivery with appearance of anti-beta-galactosidase antibodies and elimination of transduced hepatocytes. However, the immune response did not prevent sustained (9-month) beta-galactosidase expression in AAV-injected muscles. In the second group, AAV injections did not induce immune response and resulted in beta-galactosidase expression in myofibers. In this group, subsequent delivery of retroviral vectors triggered appearance of immune response and elimination of transduced hepatocytes. However, the immune response did not modify beta-galactosidase expression in AAV-transduced myofibers for up to 9 months. These results demonstrate a differential susceptibility between retrovirally transduced liver and AAV-transduced muscles to immune response against the transgene product.

  19. Retroviral insertions 90 kilobases proximal to the Evi-1 myeloid transforming gene activate transcription from the normal promoter.

    PubMed Central

    Bartholomew, C; Ihle, J N

    1991-01-01

    The inappropriate production of the Evi-1 zinc finger protein occurs in retrovirus-induced murine myeloid leukemias and human acute myelogenous leukemias. In murine leukemias, expression of the Evi-1 gene is associated with retroviral insertions either in the Evi-1 locus, which is immediately 5' of the coding region of the gene, or in the genetically linked Cb-1/fim-3 locus. In these studies, we demonstrate by chromosomal walking and pulse field electrophoresis that the Cb-1/fim-3 locus is located 90 kb 5' of the Evi-1 locus. Primary structure analysis of Evi-1 cDNA clones from a Cb-1/fim-3 rearranged cell line (DA-3) demonstrates that transcription initiates 5' of the Evi-1 locus and that the first noncoding exon of the gene is 681 bp larger than previously defined. S1 nuclease protection studies reveal multiple transcription initiation sites within this region. Comparable transcriptional initiation sites were identified in RNA from kidney and ovary, in which the gene is normally expressed, suggesting that retroviral insertions in the Cb-1/fim-3 locus activate transcription from the normal promoter. In one myeloid cell line (DA-3), a single long terminal repeat (LTR) is present in the Cb-1/fim-3 locus. No stable transcripts were detectable from this LTR. In cells with retroviral insertions in the Cb-1/fim-3 locus, one allele of the Evi-1 locus becomes hypermethylated in the 5' region of the gene. Together, these results are most consistent with an LTR-mediated, long-range cis activation of Evi-1 gene expression. Images PMID:1848663

  20. Gamma-retroviral vector design for the co-expression of artificial microRNAs and therapeutic proteins.

    PubMed

    Park, Tristen S; Abate-Daga, Daniel; Zhang, Ling; Zheng, Zhili; Morgan, Richard A

    2014-10-01

    To generate γ-retroviral vectors for stable conjoint expression of artificial microRNAs (amiR) and therapeutic genes in primary human lymphocytes, and to identify the design parameters that are key for successful vector generation. Gamma-retroviral vectors were designed to co-express both amiRs and a linked reporter gene, truncated CD34 (tCD34). Artificial miRs based on microRNAs miR-16, miR-142, miR-146b, miR-150, miR155, and miR-223 were inserted into sites within the intron of the vector and tested for tCD34 expression by flow cytometry (FACS). Different constructs were assembled with amiRs targeted to knockdown expression of suppressor of cytokine signaling 1 (SOCS1) or programmed cell death 1 (PDCD1, PD-1). Three of the six amiRs maintained tCD34 expression. Expansion of primary human T cells transduced with these amiR vectors, as well as transgene expression, were equivalent to control engineered T cells over a 40-day period. Knockdown of SOCS1 RNA and PD-1 expression by FACS was shown to vary between constructs, dependent on either the specific short interfering RNA sequence used in the amiR, or the microRNA backbone and location in the vector intron. Gamma-retroviral vectors that both efficiently knockdown endogenous gene expression and maintain linked transgene production can be produced, but empirical vector evaluations were best suited for optimal construct analysis.

  1. Evaluation of γ-retroviral vectors that mediate the inducible expression of IL-12 for clinical application.

    PubMed

    Zhang, Ling; Feldman, Steven A; Zheng, Zhili; Chinnasamy, Nachimuthu; Xu, Hui; Nahvi, Azam V; Dudley, Mark E; Rosenberg, Steven A; Morgan, Richard A

    2012-06-01

    The clinical application of interleukin-12 (IL-12) has been hindered by the toxicity associated with its systemic administration. To potentially overcome this problem, we developed a promoter designed to direct IL-12 expression within the tumor environment using an inducible composite promoter containing binding motifs for the nuclear factor of activated T cells (NFAT) linked to a minimal IL-2 promoter. In this study, the NFAT promoter was coupled to a single-chain human IL-12 gene and inserted into 2 γ-retroviral self-inactivating vectors (SERS.NFAT.hIL12 and SERS.NFAT.hIL12.PA2) and 1 γ-retroviral vector (MSGV1.NFAT.hIL.12 PA2). Peripheral blood lymphocytes (PBLs) were double transduced with an antigen-specific T-cell receptor and the 3 NFAT.hIL12 vectors. Evaluation of inducible IL-12 expression, transduction efficiency, and vector production considerations led to the choice of the MSGV1.NFAT.hIL12.PA2 vector for clinical application. MSGV1.NFAT.hIL12.PA2 PG13 retroviral vector producer cell clones were screened by transduction of tumor antigen-specific PBLs. On the basis of expression studies in PBL, clone D3 was chosen to produce clinical-grade viral vector supernatant and was demonstrated to efficiently transduce young tumor-infiltrating lymphocytes (TIL). The vector-transduced young TIL with known tumor recognition demonstrated specific inducible IL-12 production after coculture with HLA-matched tumor targets and had augmented effector function as demonstrated by increased IFN-γ secretion. These results support the clinical application of adoptive transfer of young TIL engineered with the NFAT.hIL12 vector as a new approach for cancer immunotherapy.

  2. Role of Murine Leukemia Virus Reverse Transcriptase Deoxyribonucleoside Triphosphate-Binding Site in Retroviral Replication and In Vivo Fidelity

    PubMed Central

    Halvas, Elias K.; Svarovskaia, Evguenia S.; Pathak, Vinay K.

    2000-01-01

    Retroviral populations exhibit a high evolutionary potential, giving rise to extensive genetic variation. Error-prone DNA synthesis catalyzed by reverse transcriptase (RT) generates variation in retroviral populations. Structural features within RTs are likely to contribute to the high rate of errors that occur during reverse transcription. We sought to determine whether amino acids within murine leukemia virus (MLV) RT that contact the deoxyribonucleoside triphosphate (dNTP) substrate are important for in vivo fidelity of reverse transcription. We utilized the previously described ANGIE P encapsidating cell line, which expresses the amphotropic MLV envelope and a retroviral vector (pGA-1). pGA-1 expresses the bacterial β-galactosidase gene (lacZ), which serves as a reporter of mutations. Extensive mutagenesis was performed on residues likely to interact with the dNTP substrate, and the effects of these mutations on the fidelity of reverse transcription were determined. As expected, most substitution mutations of amino acids that directly interact with the dNTP substrate significantly reduced viral titers (>10,000-fold), indicating that these residues played a critical role in catalysis and viral replication. However, the D153A and A154S substitutions, which are predicted to affect the interactions with the triphosphate, resulted in statistically significant increases in the mutation rate. In addition, the conservative substitution F155W, which may affect interactions with the base and the ribose, increased the mutation rate 2.8-fold. Substitutions of residues in the vicinity of the dNTP-binding site also resulted in statistically significant decreases in fidelity (1.3- to 2.4-fold). These results suggest that mutations of residues that contact the substrate dNTP can affect viral replication as well as alter the fidelity of reverse transcription. PMID:11044079

  3. Virologic failure in first-line human immunodeficiency virus therapy with a CCR5 entry inhibitor, aplaviroc, plus a fixed-dose combination of lamivudine-zidovudine: nucleoside reverse transcriptase inhibitor resistance regardless of envelope tropism.

    PubMed

    Demarest, James F; Amrine-Madsen, Heather; Irlbeck, David M; Kitrinos, Kathryn M

    2009-03-01

    The CCR102881 (ASCENT) study evaluated the antiviral activity of the novel CCR5 entry inhibitor aplaviroc plus a fixed-dose combination of lamivudine-zidovudine (Combivir) in drug-naïve human immunodeficiency virus type 1-infected subjects with only CCR5-tropic virus detected in plasma. Although the trial was stopped prematurely due to idiosyncratic hepatotoxicity, eight subjects met protocol-defined virologic failure criteria. Clonal analyses of the viral envelope tropism, aplaviroc susceptibility, and env sequencing were performed on plasma at baseline and at the time of virologic failure. Molecular evolutionary analyses were also performed. The majority of the subjects with virologic failure (six of eight) acquired the lamivudine resistance-associated mutation M184V, and none had evidence of reduced susceptibility to aplaviroc at the time of virologic failure, even at the clonal level. Six subjects with virologic failure maintained CCR5 tropism, while two exhibited a change in population tropism readout to dual/mixed-tropic with R5X4-tropic clones detected prior to therapy. Two evolutionary patterns were observed: five subjects had no evidence of population turnover, while three subjects had multiple lines of evidence for env population turnover. The acquisition of the M184V mutation is the primary characteristic of virologic failure in first-line therapy with aplaviroc plus lamivudine-zidovudine, regardless of the envelope tropism.

  4. Cloning of the rat ecotropic retroviral receptor and studies of its expression in intestinal tissues.

    PubMed

    Puppi, M; Henning, S J

    1995-05-01

    A long-term goal of our laboratory is to establish a rat model to study the feasibility of using the intestinal tract as a site for somatic gene therapy. As a step toward that goal, the current study reports the cloning of the rat ecotropic retroviral receptor (EcoR) cDNA and the study of various aspects of its expression in the intestinal tissues. The cDNA for rat EcoR was cloned by screening a size-selected rat intestinal cDNA library with mouse EcoR cDNA. A clone of approximately 7 kb, designated MP10, was obtained. Partial sequencing of MP10 from the 5' end revealed a level of similarity of 92% compared with mouse EcoR. The presence of a 5' untranslated region and a 3' poly(A) tract, together with the overall size of the cDNA, suggest that is very close to being a full-length cDNA for this large transcript. Northern blots with MP10 showed an RNA of approximately 7.9 kb present along the entire length of the small intestine and somewhat less abundant in the colon. Developmental studies showed high levels of EcoR in fetal rat intestine, a decline in the early postnatal period, then a gradual rise to adulthood. Caco-2 cells were used to assess the expression of EcoR in proliferating compared with differentiated intestinal epithelial cells. EcoR mRNA was found to be very much more abundant in nondifferentiated cells and declined to low levels as the cells underwent spontaneous differentiation. These patterns of EcoR expression indicate that ecotropic retroviruses should be suitable vectors with which to attempt gene transfer into the intestinal epithelium. In addition, since the endogenous role of EcoR is as the y+ cationic amino acid transporter, these data have significance for understanding patterns of amino acid transport in the intestinal epithelium.

  5. Lack of evidence for retroviral infections formerly related to chronic fatigue in Spanish Fibromyalgia patients

    PubMed Central

    2013-01-01

    present evidence of any of the two types of retroviral infection formerly associated to chronic fatigue does not rule out the possibility that other viruses are involved in inciting or maintaining fibromyalgia and/or chronic fatigue conditions. PMID:24216038

  6. Retroviral Gene Therapy for X-linked Chronic Granulomatous Disease: Results From Phase I/II Trial

    PubMed Central

    Kang, Hyoung Jin; Bartholomae, Cynthia C; Paruzynski, Anna; Arens, Anne; Kim, Sujeong; Yu, Seung Shin; Hong, Youngtae; Joo, Chang-Wan; Yoon, Nam-Kyung; Rhim, Jung-Woo; Kim, Joong Gon; Von Kalle, Christof; Schmidt, Manfred; Kim, Sunyoung; Ahn, Hyo Seop

    2011-01-01

    X-linked chronic granulomatous disease (CGD) is an inherited immunodeficiency caused by a defect in the gp91phox gene. In an effort to treat X-CGD, we investigated the safety and efficacy of gene therapy using a retroviral vector, MT-gp91. Two X-CGD patients received autologous CD34+ cells transduced with MT-gp91 after a conditioning regimen consisting of fludarabine and busulfan. The level of gene-marked cells was highest at day 21 (8.3 and 11.7% in peripheral blood cells) but decreased to 0.08 and 0.5%, respectively, 3 years after gene transfer. The level of functionally corrected cells, as determined by nicotinamide adenine dinucleotide phosphate (NADPH) oxidase assay, reached a peak at day 17 (6.5% patient 1 (P1) and 14.3% patient 2 (P2) of total granulocytes) and declined to 0.05% (P1) and 0.21% (P2), 3 years later. Some retroviral vectors were found to have integrated within or close to the proto-oncogenes MDS1-EVI1, PRDM16, and CCND2; however, no abnormal cell expansion or related hematological malignancy was observed. Overall, the gene transfer procedure did not produce any serious adverse effects and was able to convert a significant fraction of blood cells to biologically functional cells, albeit for a short period of time. PMID:21878903

  7. Expression of the human. beta. -globin gene following retroviral-mediated transfer into multipotential hematopoietic progenitors of mice

    SciTech Connect

    Karlsson, S.; Bodine, D.M.; Perry, L.; Papayannopoulou, T.; Nienhuis, A.W. )

    1988-08-01

    Efficient transfer of the {beta}-globin gene into primitive hematopoietic progenitors was achieved with consistent and significant expression in the progeny of those cells. Retroviral vectors containing the intact genomic human {beta}-globin gene and the neomycin (G418)-resistance (neo{sup R}) gene were constructed. These gave titers of 10{sup 6} or more neo{sup R} colony-forming units/ml when packaged in {psi}2 cells. Mouse bone marrow cells were infected by coculture with producer cells and injected into lethally irradiated animals. Several parameters were varied to enhance infection frequency of colony-forming units, spleen (CFU-S); overall 41% of 116 foci studied contained an intact proviral genome. The human {beta}-globin gene was expressed in 31 of 35 CFU-S-derived spleen colonies that contained the intact vector genome at levels ranging from 1% to 5% of that of the mouse {beta}-globin genes. Infected bone marrow cells were also injected into genetically anemic W/W{sup v} recipients without prior irradiation. Human {beta}-globin chains were detected in circulating erythrocytes by immunofluorescent staining with a specific monoclonal antibody. All animals injected with donor cells that had been cultured in G418 (1 mg/ml) for 48 hr after retroviral infection had circulating erythrocytes containing human {beta}-globin chains between 3 and 8 weeks after transplantation.

  8. Detection of clinical interactions between methadone and anti-retroviral compounds using an enantioselective capillary electrophoresis for methadone analysis.

    PubMed

    Esteban, Javier; de la Cruz Pellín, María; Gimeno, Carmen; Barril, José; Mora, Eva; Giménez, Jesús; Vilanova, Eugenio

    2004-06-15

    A capillary electrophoresis method was developed to detect interactions between methadone and anti-retroviral compounds. Eight subjects, who underwent methadone maintenance treatment in the Province of Alicante (Spain), consented to participate in the present study. Of those, one subject was followed up for 123 days to detect drug-drug interactions. The enantiomers of methadone and those of its main metabolite were conveniently resolved within 4 min using a chiral electrophoresis buffer mixture which consisted of phosphate buffer, pH 5, plus 0.2% highly sulphated-(beta)-cyclodextrin. The effective mobility of the analytes was in the 0.061-0.140 cm(2)/(kV s) range at pH 5. The R-methadone plasma concentration range for seven patients was 91-318 ng/mL, it decreased from 186 to 46 ng/mL in a patient followed-up on commencement of the anti-retroviral therapy, returning to the previous higher levels after progressive dose increases. We conclude that monitoring R-methadone plasma levels can be a useful tool for the dose adjustment of methadone.

  9. Retroviral envelope syncytin capture in an ancestrally diverged mammalian clade for placentation in the primitive Afrotherian tenrecs

    PubMed Central

    Cornelis, Guillaume; Vernochet, Cécile; Malicorne, Sébastien; Souquere, Sylvie; Tzika, Athanasia C.; Goodman, Steven M.; Catzeflis, François; Robinson, Terence J.; Milinkovitch, Michel C.; Pierron, Gérard; Heidmann, Odile; Dupressoir, Anne; Heidmann, Thierry

    2014-01-01

    Syncytins are fusogenic envelope (env) genes of retroviral origin that have been captured for a function in placentation. Syncytins have been identified in Euarchontoglires (primates, rodents, Leporidae) and Laurasiatheria (Carnivora, ruminants) placental mammals. Here, we searched for similar genes in species that retained characteristic features of primitive mammals, namely the Malagasy and mainland African Tenrecidae. They belong to the superorder Afrotheria, an early lineage that diverged from Euarchotonglires and Laurasiatheria 100 Mya, during the Cretaceous terrestrial revolution. An in silico search for env genes with full coding capacity within a Tenrecidae genome identified several candidates, with one displaying placenta-specific expression as revealed by RT-PCR analysis of a large panel of Setifer setosus tissues. Cloning of this endogenous retroviral env gene demonstrated fusogenicity in an ex vivo cell–cell fusion assay on a panel of mammalian cells. Refined analysis of placental architecture and ultrastructure combined with in situ hybridization demonstrated specific expression of the gene in multinucleate cellular masses and layers at the materno–fetal interface, consistent with a role in syncytium formation. This gene, which we named “syncytin-Ten1,” is conserved among Tenrecidae, with evidence of purifying selection and conservation of fusogenic activity. To our knowledge, it is the first syncytin identified to date within the ancestrally diverged Afrotheria superorder. PMID:25267646

  10. Production of high-titer helper virus-free retroviral vectors by cocultivation of packaging cells with different host ranges.

    PubMed Central

    Lynch, C M; Miller, A D

    1991-01-01

    The titer of retroviral vectors can be increased by cocultivation of retrovirus packaging cells that produce a vector with packaging cells having a different host range. Multiple rounds of infection occur in such cultures, producing an amplification of vector copy number and titer. Production of a vector with a very high titer of over 10(10) CFU per ml of conditioned medium has been reported, although replication-competent helper virus was also present. Since helper-free virus is a requirement for many applications of retroviral vectors, we repeated this procedure with a modified vector and achieved a 2- to 10-fold amplification of vector titer in the absence of helper virus, up to 2 x 10(7) CFU/ml. We have also repeated these experiments with the same vector and methods described previously or have assayed virus from the high-titer vector-producing cell line reported previously and observed maximum titers of 10(8) CFU/ml, invariably accompanied by helper virus. Thus, while amplification of vector titer in the absence of helper virus is possible, some unexplained difference in the assays for virus titer must account for our inability to obtain the exceptionally high vector titers that were reported previously. PMID:2041097

  11. Comprehensive profiling of retroviral integration sites using target enrichment methods from historical koala samples without an assembled reference genome.

    PubMed

    Cui, Pin; Löber, Ulrike; Alquezar-Planas, David E; Ishida, Yasuko; Courtiol, Alexandre; Timms, Peter; Johnson, Rebecca N; Lenz, Dorina; Helgen, Kristofer M; Roca, Alfred L; Hartman, Stefanie; Greenwood, Alex D

    2016-01-01

    Background. Retroviral integration into the host germline results in permanent viral colonization of vertebrate genomes. The koala retrovirus (KoRV) is currently invading the germline of the koala (Phascolarctos cinereus) and provides a unique opportunity for studying retroviral endogenization. Previous analysis of KoRV integration patterns in modern koalas demonstrate that they share integration sites primarily if they are related, indicating that the process is currently driven by vertical transmission rather than infection. However, due to methodological challenges, KoRV integrations have not been comprehensively characterized. Results. To overcome these challenges, we applied and compared three target enrichment techniques coupled with next generation sequencing (NGS) and a newly customized sequence-clustering based computational pipeline to determine the integration sites for 10 museum Queensland and New South Wales (NSW) koala samples collected between the 1870s and late 1980s. A secondary aim of this study sought to identify common integration sites across modern and historical specimens by comparing our dataset to previously published studies. Several million sequences were processed, and the KoRV integration sites in each koala were characterized. Conclusions. Although the three enrichment methods each exhibited bias in integration site retrieval, a combination of two methods, Primer Extension Capture and hybridization capture is recommended for future studies on historical samples. Moreover, identification of integration sites shows that the proportion of integration sites shared between any two koalas is quite small.

  12. Comprehensive profiling of retroviral integration sites using target enrichment methods from historical koala samples without an assembled reference genome

    PubMed Central

    Alquezar-Planas, David E.; Ishida, Yasuko; Courtiol, Alexandre; Timms, Peter; Johnson, Rebecca N.; Lenz, Dorina; Helgen, Kristofer M.; Roca, Alfred L.; Hartman, Stefanie

    2016-01-01

    Background. Retroviral integration into the host germline results in permanent viral colonization of vertebrate genomes. The koala retrovirus (KoRV) is currently invading the germline of the koala (Phascolarctos cinereus) and provides a unique opportunity for studying retroviral endogenization. Previous analysis of KoRV integration patterns in modern koalas demonstrate that they share integration sites primarily if they are related, indicating that the process is currently driven by vertical transmission rather than infection. However, due to methodological challenges, KoRV integrations have not been comprehensively characterized. Results. To overcome these challenges, we applied and compared three target enrichment techniques coupled with next generation sequencing (NGS) and a newly customized sequence-clustering based computational pipeline to determine the integration sites for 10 museum Queensland and New South Wales (NSW) koala samples collected between the 1870s and late 1980s. A secondary aim of this study sought to identify common integration sites across modern and historical specimens by comparing our dataset to previously published studies. Several million sequences were processed, and the KoRV integration sites in each koala were characterized. Conclusions. Although the three enrichment methods each exhibited bias in integration site retrieval, a combination of two methods, Primer Extension Capture and hybridization capture is recommended for future studies on historical samples. Moreover, identification of integration sites shows that the proportion of integration sites shared between any two koalas is quite small. PMID:27069793

  13. Clonotypic Composition of the CD4+ T Cell Response to a Vectored Retroviral Antigen Is Determined by Its Speed

    PubMed Central

    Thorborn, Georgina; Ploquin, Mickaël J.; Eksmond, Urszula; Pike, Rebecca; Bayer, Wibke; Dittmer, Ulf; Hasenkrug, Kim J.; Pepper, Marion

    2014-01-01

    The mechanisms whereby different vaccines may expand distinct Ag-specific T cell clonotypes or induce disparate degrees of protection are incompletely understood. We found that several delivery modes of a model retroviral Ag, including natural infection, preferentially expanded initially rare high-avidity CD4+ T cell clonotypes, known to mediate protection. In contrast, the same Ag vectored by human adenovirus serotype 5 induced clonotypic expansion irrespective of avidity, eliciting a predominantly low-avidity response. Nonselective clonotypic expansion was caused by relatively weak adenovirus serotype 5–vectored Ag presentation and was reproduced by replication-attenuated retroviral vaccines. Mechanistically, the potency of Ag presentation determined the speed and, consequently, completion of the CD4+ T cell response. Whereas faster completion retained the initial advantage of high-avidity clonotypes, slower completion permitted uninhibited accumulation of low-avidity clonotypes. These results highlighted the importance of Ag presentation patterns in determining the clonotypic composition of vaccine-induced T cell responses and ultimately the efficacy of vaccination. PMID:25000983

  14. WHI-05, a novel bromo-methoxy substituted phenyl phosphate derivative of zidovudine, is a dual-action spermicide with potent anti-HIV activity.

    PubMed

    D'Cruz, O J; Zhu, Z; Yiv, S H; Chen, C L; Waurzyniak, B; Uckun, F M

    1999-05-01

    Heterosexual transmission of HIV to women is the fastest-growing mode of transmission. In a systematic effort to develop a microbicide capable of preventing HIV transmission as well as providing fertility control, novel phenyl phosphate derivatives of 3'-azido-3'-deoxythymidine (zidovudine, ZDV) have been identified that exhibit potent anti-HIV and spermicidal activities. This study reports the synthesis, characterization, and preclinical formulation of compound WHI-05, 5-bromo-6-methoxy-5,6-dihydro-3'-azidothymidine-5'-(p-methoxyphenyl) methoxyalaninyl phosphate. The anti-HIV activities of WHI-05 and ZDV were compared by measuring p24 antigen production and reverse transcriptase activity as markers of viral replication using human peripheral blood mononuclear cells (PBMC) infected with both ZDV-sensitive and ZDV-resistant strains of HIV. The sperm immobilizing activity (SIA) of WHI-05 was compared with that of ZDV and nonoxynol-9 (N-9) by computer-assisted sperm analysis (CASA). The effect of WHI-05 on sperm membrane integrity was examined by high resolution, low voltage scanning electron microscopy (HR-LVSEM). The in vitro cytotoxicity profile of WHI-05 versus N-9 were compared using normal human vaginal, ectocervical, and endocervical epithelial cells. The in vivo vaginal tolerance, absorption, and toxicity of a 2% WHI-05 gel-microemulsion was tested in the rabbit. Whereas ZDV displayed potent anti-HIV activity but lacked SIA, WHI-05 elicited both potent anti-HIV activity and SIA. WHI-05 inhibited the replication of ZDV-sensitive as well as ZDV-resistant strains of HIV in PBMC. CASA combined with HR-LVSEM demonstrated that WHI-05-induced SIA was not associated with membrane damage. Unlike, N-9, the spermicidal activity of WHI-05 was not associated with cytotoxicity to reproductive tract epithelial cells. Repetitive intravaginal application of a 2% WHI-05 gel-microemulsion did not damage the vaginal epithelium or cause local inflammation in the rabbit model. As a

  15. Protease Inhibitor Resistance Analysis in the MONARK Trial Comparing First-Line Lopinavir-Ritonavir Monotherapy to Lopinavir-Ritonavir plus Zidovudine and Lamivudine Triple Therapy▿

    PubMed Central

    Delaugerre, Constance; Flandre, Philippe; Chaix, Marie Laure; Ghosn, Jade; Raffi, François; Dellamonica, Pierre; Jaeger, H.; Shürmann, D.; Cohen-Codar, Isabelle; Ngo Van, Philippe; Norton, Michael; Taburet, Anne-Marie; Delfraissy, Jean-François; Rouzioux, Christine

    2009-01-01

    The MONARK study was a pilot randomized trial comparing the safety and efficacy of lopinavir-ritonavir (LPV/r) monotherapy to those of LPV/r-zidovudine-lamivudine triple therapy for antiretroviral-naïve human immunodeficiency virus type 1 (HIV-1)-infected patients. Resistance testing was performed at the time of initial screening and at the time of virological failure (defined to include low-level viremia with >50 and <400 HIV-1 virus RNA copies/ml of plasma). Changes from the baseline sequences, including mutations noted on the 2008 International AIDS Society—USA list of resistance-associated protease mutations, were considered. Drug resistance testing was performed for 38 patients (5 of 53 on triple therapy and 33 of 83 on monotherapy). By week 96 (W96), virus samples from 18 of 33 patients in the monotherapy arm showed changes from baseline sequences, and 5 of these patients had viruses with major protease inhibitor (PI) resistance-associated mutations (M46I at W40, L76V at W48, M46I and L76V at W48, L10F and V82A at W72, and L76V at W84). Data on virus phenotypes detected at the time of initial screening and the time of virological failure were available for four patients in whom major PI resistance mutations developed, and these data revealed a mean increase of 2.2-fold (range, 0.75- to 4.6-fold) in the LPV 50% inhibitory concentration. All three patients in whom the L76V PI resistance mutation developed were infected with HIV-1 subtype CRF02_AG. In the triple-therapy group, no major PI resistance mutation was selected among the three patients with protease changes by W48. No association between the baseline CD4 cell count and the viral load, the W4 and final viral loads, or the final LPV trough concentration and the emergence of a major PI resistance mutation was found. Major PI resistance-associated mutations were detected in 5 (6%) of 83 patients treated with LPV/r monotherapy, suggesting that LPV/r monotherapy is an inappropriate first option. The

  16. Pharmacokinetics and Safety of Nelfinavir When Used in Combination with Zidovudine and Lamivudine in HIV-Infected Pregnant Women: Pediatric AIDS Clinical Trials Group (PACTG) Protocol 353

    PubMed Central

    Bryson, Y.J.; Mirochnick, M.; Stek, A.; Mofenson, L.M.; Connor, J.; Capparelli, E.; Watts, D.H.; Huang, S.; Hughes, M.D.; Kaiser, K.; Purdue, L.; Asfaw, Y.; Keller, M.; Smith, E.

    2014-01-01

    Background Combination antiretroviral regimens including nelfinavir (NFV) are commonly used in pregnancy. We studied the safety, antiviral effect, and pharmacokinetics of NFV and its M8 metabolite with two dosing regimens in combination with zidovudine (ZDV) and lamivudine (3TC) in HIV-infected pregnant women. Method HIV-infected pregnant women between 14 and 34 weeks gestation received NFV (Cohort 1: 750 mg tid, n = 10; Cohort 2: 1250 mg bid, n = 23) with ZDV and 3TC. Serial blood sampling for NFV concentrations was performed antepartum (AP) and 6 weeks postpartum (PP). Maternal and cord blood samples were also obtained at delivery. NFV and M8 levels were determined by high-performance liquid chromatography. The pharmacokinetic (PK) target was an extrapolated NFV AUC0–24 > 30 μg · h/mL. Mothers were followed frequently for potential clinical and laboratory toxicity. Results Overall, NFV in combination with ZDV and 3TC was well tolerated. The PK target was met in 3/8 AP and 5/7 PP in Cohort 1 and 17/21 AP and 16/17 PP in Cohort 2. When Cohort 2 NFV PK parameters AP and PP were compared, median Cmax (3.90 μg/mL vs. 5.01 μg/mL, p < .05) and AUC0–24 (56.6 vs. 86.8 μg · h/mL, p < .05) were increased PP and oral clearance (Cl/F; 44.2 vs. 28.8 L/h, p < .05) was decreased PP. The average M8/NFV ratio was increased PP compared to AP (0.085 vs. 0.29, p < .001). Placental transfer of NFV was low with a median cord blood:maternal plasma ratio at delivery of 0.05. Maternal mean CD4+ T cell counts increased significantly and plasma HIV-1 RNA levels decreased from entry to delivery and 6 to 12 weeks postpartum. Conclusion NFV used in combination with ZDV and 3TC was well tolerated in pregnant HIV-infected women and produced a significant improvement in HIV disease parameters. NFV drug exposure is inadequate in most pregnant women receiving 750 mg tid but is much improved with 1250 mg bid. NFV crosses the placenta poorly. The AP increase in NFV oral clearance and

  17. Early upper digestive tract side effects of zidovudine with tenofovir plus emtricitabine in West African adults with high CD4 counts

    PubMed Central

    Ouattara, Eric; Danel, Christine; Moh, Raoul; Gabillard, Delphine; Peytavin, Gilles; Konan, Romuald; Carrou, Jérome Le; Bohoussou, Franck; Eholie, Serge P; Anglaret, Xavier

    2013-01-01

    Introduction Tenofovir (TDF) with emtricitabine (FTC) and zidovudine (ZDV) is a recognized alternate first-line antiretroviral (ART) regimen for patients who cannot start treatment with non-nucleoside reverse transcriptase inhibitors (NNRTIs). Clinical studies comparing TDF+FTC+ZDV to other regimens are lacking. Methods Participants in a trial of early ART in Côte d'Ivoire (Temprano ANRS 12136) started treatment with TDF/FTC plus either efavirenz (EFV) or ZDV (HIV-1+2 dually infected patients and women refusing contraception or previously treated with nevirapine). We compared rates of upper digestive serious adverse events (sAEs) between TDF/FTC+EFV and TDF/FTC+ZDV patients during the first six months of treatment. sAEs were defined as either grade 3–4 AEs or persistent grade 1–2 AEs leading to drug discontinuation. Results A total of 197 patients (76% women, median CD4 count 395/mm3) started therapy with TDF/FTC, 126 with EFV and 71 with ZDV. During the first six months of ART, 94 patients had digestive AEs (nausea/vomiting) of any grade (EFV 36/126, 29%; ZDV 58/71, 82%, p<0.0001), including 20 sAEs (EFV 3/126, 5%; ZDV 17/71, 24%, p<0.0001). In-patients on TDF/FTC+ZDV with digestive AEs, the median time to the first symptom was two days (IQR: 1–4). Plasma ZDV (Cmax) distributions and pill ZDV dosages were normal. Patients with digestive AEs had higher haemoglobin levels and tended to have higher body mass indices and more frequent past histories of cotrimoxazole (CTX) prophylaxis. Conclusions We observed an unexpectedly high rate of digestive sAEs in West African adults, mostly women, who started a 3-nuc ART with TDF/FTC+ZDV in Côte d'Ivoire. These adults were participating in a trial of early ART and had much higher CD4 counts than those who currently routinely start ART in sub-Saharan Africa. They all received CTX concomitantly with ZDV. We suggest that further early prescriptions of TDF+XTC+ZDV should be carefully monitored and that whenever possible

  18. Anaemia and zidovudine-containing antiretroviral therapy in paediatric antiretroviral programmes in the IeDEA Paediatric West African Database to evaluate AIDS

    PubMed Central

    Renner, Lorna A; Dicko, Fatoumata; Kouéta, Fla; Malateste, Karen; Gueye, Ramatoulaye D; Aka, Edmond; Eboua, Tanoh K; Azondékon, Alain; Okomo, Uduok; Touré, Pety; Ekouévi, Didier; Leroy, Valeriane

    2013-01-01

    Introduction There is a risk of anaemia among HIV-infected children on antiretroviral therapy (ART) containing zidovudine (ZDV) recommended in first-line regimens in the WHO guidelines. We estimated the risk of severe anaemia after initiation of a ZDV-containing regimen in HIV-infected children included in the IeDEA West African database. Methods Standardized collection of data from HIV-infected children (positive PCR<18 months or positive serology ≥18 months) followed up in HIV programmes was included in the regional IeDEA West Africa collaboration. Ten clinical centres from seven countries contributed (Benin, Burkina Faso, Côte d'Ivoire, Gambia, Ghana, Mali and Senegal) to this collection. Inclusion criteria were age <16 years and starting ART. We explored the data quality of haemoglobin documentation over time and the incidence and predictors of severe anaemia (Hb<7g/dL) per 100 child-years of follow-up over the duration of first-line antiretroviral therapy. Results As of December 2009, among the 2933 children included in the collaboration, 45% were girls, median age was five years; median CD4 cell percentage was 13%; median weight-for-age z-score was −2.7; and 1772 (60.4%) had a first-line ZDV-containing regimen. At baseline, 70% of the children with a first-line ZDV-containing regimen had a haemoglobin measure available versus 76% in those not on ZDV (p≤0.01): the prevalence of severe anaemia was 3.0% (n=38) in the ZDV group versus 10.2% (n=89) in those without (p<0. 01). Over the first-line follow-up, 58.9% of the children had ≥1 measure of haemoglobin available in those exposed to ZDV versus 60.4% of those not (p=0.45). Severe anaemia occurred in 92 children with an incidence of 2.47 per 100 child-years of follow-up in those on a ZDV-containing regimen versus 4.25 in those not (p≤0.01). Adjusted for age at ART initiation and first-line regimen, a weight-for-age z-score ≤−3 was a strong predictor associated with a 5.59 times risk of severe

  19. Altered Oligodendrocyte Maturation and Myelin Maintenance: The Role of Anti-Retrovirals in HIV-Associated Neurocognitive Disorders

    PubMed Central

    Jensen, Brigid K.; Monnerie, Hubert; Mannell, Maggie V.; Gannon, Patrick J.; Espinoza, Cagla Akay; Erickson, Michelle A.; Bruce-Keller, Annadora J.; Gelman, Benjamin B.; Briand, Lisa A.; Pierce, R. Christopher; Jordan-Sciutto, Kelly L.; Grinspan, Judith B.

    2015-01-01

    Despite effective viral suppression through combined antiretroviral therapy (cART), approximately half of HIV-positive individuals suffer from HIV-Associated Neurocognitive Disorders (HAND). Studies of antiretroviral treated patients have revealed persistent white matter pathologies including diffuse myelin pallor, diminished white matter tracts, and decreased myelin protein mRNAs. Loss of myelin can contribute to neurocognitive dysfunction as the myelin membrane generated by oligodendrocytes is essential for rapid signal transduction and axonal maintenance. We hypothesized that myelin changes in HAND are partly due to effects of antiretroviral drugs on oligodendrocyte survival and/or maturation. We showed that primary mouse oligodendrocyte precursor cell cultures treated with therapeutic concentrations of HIV protease inhibitors Ritonavir or Lopinavir displayed dose-dependent decreases in oligodendrocyte maturation; however, this effect was rapidly reversed following drug removal. Conversely, nucleoside reverse transcriptase inhibitor Zidovudine had no effect. Furthermore, in vivo Ritonavir administration to adult mice reduced frontal cortex myelin protein levels. Finally, prefrontal cortex tissue from HIV-positive individuals with HAND on cART showed a significant decrease in myelin basic protein compared with untreated HIV-positive individuals with HAND or HIV-negative controls. These findings demonstrate that antiretrovirals can impact myelin integrity, and have implications for myelination in juvenile HIV patients, and myelin maintenance in adults on lifelong therapy. PMID:26469251

  20. Metabolic properties of phosphonate esters.

    PubMed

    Somogyi, G; Buchwald, P; Bodor, N

    2004-05-01

    The object of the present work was to investigate the difference in the metabolism of the phosphonate derivatives of primary or secondary hydroxyl groups. To study the phosphorolytic cleavage of such P-O bonds, zidovudine (AZT) hexanoyloxymethyl-methylphosphonate (HOM-AZT-P), an ester of a primary OH functionality, and methyl-pivaloyloxymethyl-testosterylphosphonate (POM-T-P), an ester of a secondary OH functionality, were prepared. The actions of pure enzymes such as alkaline phosphatase and phosphodiesterase on the corresponding phosphonate compounds (AZT-P and T-P) were investigated at various pH values. The phosphonate derivative of the secondary hydroxyl group of testosterone proved completely resistant to such phosphorolytic attacks, and release of free testosterone could not be detected. The phosphonate derivative of the primary hydroxyl group of zidovudine proved resistant to phosphodiesterase, but not to alkaline phosphatase, and in this second case, release of free zidovudine could be detected.

  1. The retroviral hypermutation specificity of APOBEC3F and APOBEC3G is governed by the C-terminal DNA cytosine deaminase domain.

    PubMed

    Haché, Guylaine; Liddament, Mark T; Harris, Reuben S

    2005-03-25

    The human proteins APOBEC3F and APOBEC3G restrict retroviral infection by deaminating cytosine residues in the first cDNA strand of a replicating virus. These proteins have two putative deaminase domains, and it is unclear whether one or both catalyze deamination, unlike their homologs, AID and APOBEC1, which are well characterized single domain deaminases. Here, we show that only the C-terminal cytosine deaminase domain of APOBEC3F and -3G governs retroviral hypermutation. A chimeric protein with the N-terminal cytosine deaminase domain from APOBEC3G and the C-terminal cytosine deaminase domain from APOBEC3F elicited a dinucleotide hypermutation preference nearly indistinguishable from that of APOBEC3F. This 5'-TC-->TT mutational specificity was confirmed in a heterologous Escherichia coli-based mutation assay, in which the 5'-CC-->CT dinucleotide hypermutation preference of APOBEC3G also mapped to the C-terminal deaminase domain. An N-terminal APOBEC3G deletion mutant displayed a preference indistinguishable from that of the full-length protein, and replacing the C-terminal deaminase domain of APOBEC3F with AID resulted in an AID-like mutational signature. Together, these data indicate that only the C-terminal domain of APOBEC3F and -3G dictates the retroviral minus strand 5'-TC and 5'-CC dinucleotide hypermutation preferences, respectively, leaving the N-terminal domain to perform other aspects of retroviral restriction.

  2. Cognitive and Behavioural Correlates of Non-Adherence to HIV Anti-Retroviral Therapy: Theoretical and Practical Insight for Clinical Psychology and Health Psychology

    ERIC Educational Resources Information Center

    Begley, Kim; McLaws, Mary-Louise; Ross, Michael W.; Gold, Julian

    2008-01-01

    This cross-sectional study identified variables associated with protease inhibitor (PI) non-adherence in 179 patients taking anti-retroviral therapy. Univariate analyses identified 11 variables associated with PI non-adherence. Multiple logistic regression modelling identified three predictors of PI non-adherence: low adherence self-efficacy and…

  3. Inhibition of histone deacetylation in 293GPG packaging cell line improves the production of self-inactivating MLV-derived retroviral vectors

    PubMed Central

    Jaalouk, Diana E; Crosato, Milena; Brodt, Pnina; Galipeau, Jacques

    2006-01-01

    Background Self-inactivating retroviral vectors (SIN) are often associated with very low titers. Promoter elements embedded within SIN designs may suppress transcription of packageable retroviral RNA which in turn results in titer reduction. We tested whether this dominant-negative effect involves histone acetylation state. We designed an MLV-derived SIN vector using the cytomegalovirus immediate early enhancer-promoter (CMVIE) as an embedded internal promoter (SINCMV) and transfected the pantropic 293GPG packaging cell line. Results The SINCMV retroviral producer had uniformly very low titers (~10,000 infectious retroparticles per ml). Northern blot showed low levels of expression of retroviral mRNA in producer cells in particular that of packageable RNA transcript. Treatment of the producers with the histone deacetylase (HDAC) inhibitors sodium butyrate and trichostatin A reversed transcriptional suppression and resulted in an average 106.3 ± 4.6 – fold (P = 0.002) and 15.5 ± 1.3 – fold increase in titer (P = 0.008), respectively. A histone gel assay confirmed increased histone acetylation in treated producer cells. Conclusion These results show that SIN retrovectors incorporating strong internal promoters such as CMVIE, are susceptible to transcriptional silencing and that treatment of the producer cells with HDAC inhibitors can overcome this blockade suggesting that histone deacetylation is implicated in the mechanism of transcriptional suppression. PMID:16603064

  4. An Efficient Large-Scale Retroviral Transduction Method Involving Preloading the Vector into a RetroNectin-Coated Bag with Low-Temperature Shaking

    PubMed Central

    Dodo, Katsuyuki; Chono, Hideto; Saito, Naoki; Tanaka, Yoshinori; Tahara, Kenichi; Nukaya, Ikuei; Mineno, Junichi

    2014-01-01

    In retroviral vector-mediated gene transfer, transduction efficiency can be hampered by inhibitory molecules derived from the culture fluid of virus producer cell lines. To remove these inhibitory molecules to enable better gene transduction, we had previously developed a transduction method using a fibronectin fragment-coated vessel (i.e., the RetroNectin-bound virus transduction method). In the present study, we developed a method that combined RetroNectin-bound virus transduction with low-temperature shaking and applied this method in manufacturing autologous retroviral-engineered T cells for adoptive transfer gene therapy in a large-scale closed system. Retroviral vector was preloaded into a RetroNectin-coated bag and incubated at 4°C for 16 h on a reciprocating shaker at 50 rounds per minute. After the supernatant was removed, activated T cells were added to the bag. The bag transduction method has the advantage of increasing transduction efficiency, as simply flipping over the bag during gene transduction facilitates more efficient utilization of the retroviral vector adsorbed on the top and bottom surfaces of the bag. Finally, we performed validation runs of endoribonuclease MazF-modified CD4+ T cell manufacturing for HIV-1 gene therapy and T cell receptor-modified T cell manufacturing for MAGE-A4 antigen-expressing cancer gene therapy and achieved over 200-fold (≥1010) and 100-fold (≥5×109) expansion, respectively. In conclusion, we demonstrated that the large-scale closed transduction system is highly efficient for retroviral vector-based T cell manufacturing for adoptive transfer gene therapy, and this technology is expected to be amenable to automation and improve current clinical gene therapy protocols. PMID:24454964

  5. Synthesis, molecular structure and physicochemical properties of bis(3‧-azido-3‧-deoxythymidin-5‧-yl) carbonate

    NASA Astrophysics Data System (ADS)

    Raviolo, Mónica A.; Williams, Patricia A. M.; Etcheverry, Susana B.; Piro, Oscar E.; Castellano, Eduardo E.; Gualdesi, Maria S.; Briñón, Margarita C.

    2010-04-01

    3'-Azido-3'-deoxythymidine (zidovudine, AZT), a synthetic analog of natural nucleoside thymidine, has been used extensively in AIDS treatments. We report here the synthesis, X-ray crystal and molecular structure, NMR, IR and Raman spectra and the thermal behavior of a novel carbonate of AZT [(AZT-O) 2C dbnd O], prepared by the reaction of zidovudine with carbonyldiimidazole. The carbonate compound, C 21H 24N 10O 9, crystallizes in the tetragonal space group P4 12 12 with a = b = 15.284(1), c = 21.695(1) Å, and Z = 8 molecules per unit cell. It consists of two AZT moieties of closely related conformations which are bridged by a carbonyl group to adopt a folded Z-like shape.

  6. Structure-function Studies of Nucleocytoplasmic Transport of Retroviral Genomic RNA by mRNA Export Factor TAP

    SciTech Connect

    M Teplova; L Wohlbold; N Khin; E Izaurralde; D Patel

    2011-12-31

    mRNA export is mediated by the TAP-p15 heterodimer, which belongs to the family of NTF2-like export receptors. TAP-p15 heterodimers also bind to the constitutive transport element (CTE) present in simian type D retroviral RNAs, and they mediate the export of viral unspliced RNAs to the host cytoplasm. We have solved the crystal structure of the RNA recognition and leucine-rich repeat motifs of TAP bound to one symmetrical half of the CTE RNA. L-shaped conformations of protein and RNA are involved in a mutual molecular embrace on complex formation. We have monitored the impact of structure-guided mutations on binding affinities in vitro and transport assays in vivo. Our studies define the principles by which CTE RNA subverts the mRNA export receptor TAP, thereby facilitating the nuclear export of viral genomic RNAs, and, more generally, provide insights on cargo RNA recognition by mRNA export receptors.

  7. Restoration of normal lysosomal function in mucopolysaccharidosis type VII cells by retroviral vector-mediated gene transfer.

    PubMed Central

    Wolfe, J H; Schuchman, E H; Stramm, L E; Concaugh, E A; Haskins, M E; Aguirre, G D; Patterson, D F; Desnick, R J; Gilboa, E

    1990-01-01

    Retroviral vectors were constructed containing a rat beta-glucuronidase cDNA driven by heterologous promoters. Vector-mediated gene transfer into human and canine beta-glucuronidase-deficient mucopolysaccharidosis type VII fibroblasts completely corrected the deficiency in beta-glucuronidase enzymatic activity. In primary cultures of canine mucopolysaccharidosis type VII retinal pigment epithelial cells, which contain large amounts of undegraded glycosaminoglycan substrates, vector correction restored normal processing of specific glycosaminoglycans in the lysosomal compartment. In canine mucopolysaccharidosis type VII bone marrow cells, beta-glucuronidase was expressed at high levels in transduced cells. Thus, the vector-encoded beta-glucuronidase was expressed at therapeutic levels in the appropriate organelle and corrected the metabolic defect in cells exhibiting the characteristic pathology of this lysosomal storage disorder. Images PMID:2158095

  8. Identification of a novel retroviral gene unique to human immunodeficiency virus type 2 and simian immunodeficiency virus SIVMAC.

    PubMed Central

    Kappes, J C; Morrow, C D; Lee, S W; Jameson, B A; Kent, S B; Hood, L E; Shaw, G M; Hahn, B H

    1988-01-01

    Human and simian immunodeficiency-associated retroviruses are extraordinarily complex, containing at least five genes, tat, art, sor, R, and 3' orf, in addition to the structural genes gag, pol, and env. Recently, nucleotide sequence analysis of human immunodeficiency virus type 2 (HIV-2) and simian immunodeficiency virus SIVMAC revealed the existence of still another open reading frame, termed X, which is highly conserved between these two viruses but absent from HIV-1. In this report, we demonstrate for the first time that the X open reading frame represents a functional retroviral gene in both HIV-2 and SIVMAC and that it encodes a virion-associated protein of 14 and 12 kilodaltons, respectively. We also describe the production of recombinant TrpE/X fusion proteins in Escherichia coli and show that sera from some HIV-2-infected individuals specifically recognize these proteins. Images PMID:3136256

  9. A retroviral-derived peptide phosphorylates protein kinase D/protein kinase Cmu involving phospholipase C and protein kinase C.

    PubMed

    Luangwedchakarn, Voravich; Day, Noorbibi K; Hitchcock, Remi; Brown, Pam G; Lerner, Danica L; Rucker, Rajivi P; Cianciolo, George J; Good, Robert A; Haraguchi, Soichi

    2003-05-01

    CKS-17, a synthetic peptide representing a unique amino acid motif which is highly conserved in retroviral transmembrane proteins and other immunoregulatory proteins, induces selective immunomodulatory functions, both in vitro and in vivo, and activates intracellular signaling molecules such as cAMP and extracellular signal-regulated kinases. In the present study, using Jurkat T-cells, we report that CKS-17 phosphorylates protein kinase D (PKD)/protein kinase C (PKC) mu. Total cell extracts from CKS-17-stimulated Jurkat cells were immunoblotted with an anti-phospho-PKCmu antibody. The results show that CKS-17 significantly phosphorylates PKD/PKCmu in a dose- and time-dependent manner. Treatment of cells with the PKC inhibitors GF 109203X and Ro 31-8220, which do not act directly on PKD/PKCmu, attenuates CKS-17-induced phosphorylation of PKD/PKCmu. In contrast, the selective protein kinase A inhibitor H-89 does not reverse the action of CKS-17. Furthermore, a phospholipase C (PLC) selective inhibitor, U-73122, completely blocks the phosphorylation of PKD/PKCmu by CKS-17 while a negative control U-73343 does not. In addition, substitution of lysine for arginine residues in the CKS-17 sequence completely abrogates the ability of CKS-17 to phosphorylate PKD/PKCmu. These results clearly indicate that CKS-17 phosphorylates PKD/PKCmu through a PLC- and PKC-dependent mechanism and that arginine residues play an essential role in this activity of CKS-17, presenting a novel modality of the retroviral peptide CKS-17 and molecular interaction of this compound with target cells.

  10. Reduction of client waiting time using task shifting in an anti-retroviral clinic at Specialist Hospital Bauchi, Nigeria

    PubMed Central

    Umar, Nisser Ali; Hajara, Moses John; Khalifa, Mohammed

    2010-01-01

    Aiming to assess the impact of the intervention in reducing the patients' waiting time in the clinic, two surveys were conducted before and after task shifting intervention in an anti-retroviral (ARV) clinic at the Specialist Hospital, Bauchi, Nigeria in November 2008 and April 2009, respectively. Before the task shifting, six nurses from the clinic were trained on integrated management of adolescent and adult illness, as well as on the principle and guidelines for the anti-retroviral therapy, after which their schedule in the clinic was broadened to include seeing HIV patients presenting for routine refill and follow-up visits. In this study, fifty-six and sixty patients, respectively out of 186 and 202 who attended the clinic on the days of the pre- and post-intervention surveys, were randomly sampled. Data on patients' sex, age and marital status, whether patient a first timer or follow up visitor and the time spent in the clinic on that day as well as the number and composition of staff and equipment in the clinic was collected. The difference in waiting time spent between the first group before task shifting and second group after task shifting was statistically analyzed and significance tested using unpaired t-test. There was a reduction in the average waiting time for patients attending the clinic from 6.48 h before task shifting to 4.35 h after task shifting. The difference of mean was -2.13 h, with 95% CI: -2.44:-1.82 hours and the test of significance by unpaired t-test P<0.0001. PMID:28299042

  11. Reduction of client waiting time using task shifting in an anti-retroviral clinic at Specialist Hospital Bauchi, Nigeria

    PubMed Central

    Umar, Nisser Ali; Hajara, Moses John; Khalifa, Mohammed

    2011-01-01

    Aiming to assess the impact of the intervention in reducing the patients' waiting time in the clinic, two surveys were conducted before and after task shifting intervention in an anti-retroviral (ARV) clinic at the Specialist Hospital, Bauchi, Nigeria in November 2008 and April 2009, respectively. Before the task shifting, six nurses from the clinic were trained on integrated management of adolescent and adult illness, as well as on the principle and guidelines for the anti-retroviral therapy, after which their schedule in the clinic was broadened to include seeing HIV patients presenting for routine refill and follow-up visits. In this study, fifty-six and sixty patients, respectively out of 186 and 202 who attended the clinic on the days of the pre- and post-intervention surveys, were randomly sampled. Data on patients' sex, age and marital status, whether patient a first timer or follow up visitor and the time spent in the clinic on that day as well as the number and composition of staff and equipment in the clinic was collected. The difference in waiting time spent between the first group before task shifting and second group after task shifting was statistically analyzed and significance tested using unpaired t-test. There was a reduction in the average waiting time for patients attending the clinic from 6.48 h before task shifting to 4.35 h after task shifting. The difference of mean was −2.13 h, with 95% CI: −2.44:−1.82 hours and the test of significance by unpaired t-test P<0.0001. PMID:28299044

  12. Ping-pong amplification of a retroviral vector achieves high-level gene expression: human growth hormone production.

    PubMed Central

    Kozak, S L; Kabat, D

    1990-01-01

    Retroviral vectors offer major advantages for gene transfer studies but have not been useful for producing proteins in large quantities. This deficiency has resulted in part from interference to superinfection, which limits the numbers of active proviruses in cells. Recently, we found that these vectors amplify when they are added as calcium phosphate precipitates to cocultures of cells that package retroviruses into ecotropic and amphotropic host range envelopes. Helper-free virions from either cell type can infect the other without interference, resulting in theoretically limitless back-and-forth (ping-pong) vector replication. In initial studies, however, amplifications of a vector that contained the human growth hormone gene ceased when the hormone produced was 0.3% or less of cellular protein synthesis. This limit was caused by two factors. First, recombinant shutoff viruses that are replication defective and encode envelope glycoproteins form at a low probability during any round of the vector replication cycle and these spread in cocultures, thereby establishing interference. Single cells in shutoff cocultures therefore synthesize both ecotropic and amphotropic envelope glycoproteins, and they release promiscuous (presumably hybrid) virions. The probability of forming shutoff viruses before the vector had amplified to a high multiplicity was reduced by using small cocultures. Second, cells with large numbers of proviruses are unhealthy and their proviral expression can be unstable. Stable expresser cell clones were obtained by selection. Thereby, cell lines were readily obtained that stably produce human growth hormone as 4 to 6% of the total protein synthesis. A ping-pong retroviral vector can be used for high-level protein production in vertebrate cells. Images PMID:2352330

  13. Endothelial progenitor and mesenchymal stem cell-derived cells persist in tissue-engineered patch in vivo: application of green and red fluorescent protein-expressing retroviral vector.

    PubMed

    Sales, Virna L; Mettler, Bret A; Lopez-Ilasaca, Marco; Johnson, John A; Mayer, John E

    2007-03-01

    An unresolved question regarding tissue-engineered (TE) cardiac valves and vessels is the fate of the transplanted cells in vivo. We have developed a strategy to track the anatomic location of seeded cells within TE constructs and neighboring tissues using a retroviral vector system encoding green and red fluorescent proteins (GFPs and RFPs, respectively) in ovine circulating endothelial progenitor cells (EPCs) and bone marrow-derived mesenchymal stem cells (BMSCs). We demonstrate that stable transduction ex vivo with high-titer Moloney murine leukemia virus-based retroviral vector yields transduction efficiency of greater than 97% GFP(+) EPC- and RFP(+) mesenchymal stem cell (MSC)-derived cells. Cellular phenotype and transgene expression were also maintained through 25 subsequent passages. Using a retroviral vector system to distinguish our pre-seeded cells from tissue-resident progenitor cells and circulating endothelial and marrow-derived precursors, we simultaneously co-seeded 2 x 10(6) GFP(+) EPCs and 2 x 10(5) RFP(+) MSCs onto the TE patches. In a series of ovine pulmonary artery patch augmentation studies, transplanted GFP(+) EPC- and RFP(+) MSC-derived cells persisted within the TE patch 7 to 14 days after implantation, as identified using immunofluorescence. Analysis showed 81% luminal coverage of the TE patches before implantation with transduced cells, increasing to 96% at day 7 and decreasing to 67% at day 14 post-implantation. This suggests a temporal association between retroviral expression of progenitor cells and mediating effects of these cells on the physiological remodeling and maturation of the TE constructs. To our knowledge, this is the first cardiovascular tissue-engineering in vivo study using a double-labeling method to demonstrate a direct evidence of the source, persistence, and incorporation into a TE vascular patch of co-cultured and simultaneously pre-seeded adult progenitor cells.

  14. Accelerated generation of human induced pluripotent stem cells with retroviral transduction and chemical inhibitors under physiological hypoxia

    SciTech Connect

    Shimada, Hidenori; Hashimoto, Yoshiya; Nakada, Akira; Shigeno, Keiji; Nakamura, Tatsuo

    2012-01-13

    Highlights: Black-Right-Pointing-Pointer Very rapid generation of human iPS cells under optimized conditions. Black-Right-Pointing-Pointer Five chemical inhibitors under hypoxia boosted reprogramming. Black-Right-Pointing-Pointer We performed genome-wide DNA methylation analysis. -- Abstract: Induced pluripotent stem (iPS) cells are generated from somatic cells by the forced expression of a defined set of pluripotency-associated transcription factors. Human iPS cells can be propagated indefinitely, while maintaining the capacity to differentiate into all cell types in the body except for extra-embryonic tissues. This technology not only represents a new way to use individual-specific stem cells for regenerative medicine but also constitutes a novel method to obtain large amounts of disease-specific cells for biomedical research. Despite their great potential, the long reprogramming process (up to 1 month) remains one of the most significant challenges facing standard virus-mediated methodology. In this study, we report the accelerated generation of human iPS cells from adipose-derived stem (ADS) cells, using a new combination of chemical inhibitors under a setting of physiological hypoxia in conjunction with retroviral transduction of Oct4, Sox2, Klf4, and L-Myc. Under optimized conditions, we observed human embryonic stem (ES)-like cells as early as 6 days after the initial retroviral transduction. This was followed by the emergence of fully reprogrammed cells bearing Tra-1-81-positive and DsRed transgene-silencing properties on day 10. The resulting cell lines resembled human ES cells in many respects including proliferation rate, morphology, pluripotency-associated markers, global gene expression patterns, genome-wide DNA methylation states, and the ability to differentiate into all three of the germ layers, both in vitro and in vivo. Our method, when combined with chemical inhibitors under conditions of physiological hypoxia, offers a powerful tool for rapidly

  15. Overexpression of connexin 43 using a retroviral vector improves electrical coupling of skeletal myoblasts with cardiac myocytes in vitro

    PubMed Central

    Tolmachov, Oleg; Ma, Yu-Ling; Themis, Michael; Patel, Pravina; Spohr, Hilmar; MacLeod, Kenneth T; Ullrich, Nina D; Kienast, Yvonne; Coutelle, Charles; Peters, Nicholas S

    2006-01-01

    Background Organ transplantation is presently often the only available option to repair a damaged heart. As heart donors are scarce, engineering of cardiac grafts from autologous skeletal myoblasts is a promising novel therapeutic strategy. The functionality of skeletal muscle cells in the heart milieu is, however, limited because of their inability to integrate electrically and mechanically into the myocardium. Therefore, in pursuit of improved cardiac integration of skeletal muscle grafts we sought to modify primary skeletal myoblasts by overexpression of the main gap-junctional protein connexin 43 and to study electrical coupling of connexin 43 overexpressing myoblasts to cardiac myocytes in vitro. Methods To create an efficient means for overexpression of connexin 43 in skeletal myoblasts we constructed a bicistronic retroviral vector MLV-CX43-EGFP expressing the human connexin 43 cDNA and the marker EGFP gene. This vector was employed to transduce primary rat skeletal myoblasts in optimised conditions involving a concomitant use of the retrovirus immobilising protein RetroNectin® and the polycation transduction enhancer Transfectam®. The EGFP-positive transduced cells were then enriched by flow cytometry. Results More than four-fold overexpression of connexin 43 in the transduced skeletal myoblasts, compared with non-transduced cells, was shown by Western blotting. Functionality of the overexpressed connexin 43 was demonstrated by microinjection of a fluorescent dye showing enhanced gap-junctional intercellular transfer in connexin 43 transduced myoblasts compared with transfer in non-transduced myoblasts. Rat cardiac myocytes were cultured in multielectrode array culture dishes together with connexin 43/EGFP transduced skeletal myoblasts, control non-transduced skeletal myoblasts or alone. Extracellular field action potential activation rates in the co-cultures of connexin 43 transduced skeletal myoblasts with cardiac myocytes were significantly higher than

  16. Endogenous IL-2 production by natural killer cells maintains cytotoxic and proliferative capacity following retroviral-mediated gene transfer.

    PubMed

    Miller, J S; Tessmer-Tuck, J; Blake, N; Lund, J; Scott, A; Blazar, B R; Orchard, P J

    1997-10-01

    Interleukin (IL)-2 therapy given at tolerable doses is insufficient to induce maximum activation of natural killer (NK) cells. We recently demonstrated that NK cells expanded in vivo can be maximally activated by short-term ex vivo incubation with 1000 U/mL IL-2. However, IL-2 withdrawal, which would occur with reinfusion, may lead to a rapid loss of cell viability and function. We hypothesized that retroviral transduction could provide an endogenous source of IL-2 to maintain NK function as measured by proliferation and cytotoxicity. Enriched NK cells were transduced with supernatants containing an MFG-based retrovirus designed to express murine IL-2 cDNA. Several supernatant transduction strategies were evaluated. NK cells were initially cultured in 1000 U/mL of huIL2 for 7-8 days, harvested, and replated prior to transduction (4 hours at 37degrees C); this proved insufficient to sustain NK proliferation or maintain cytotoxicity after exogenous human IL-2 (huIL-2) withdrawal. An alternative transduction procedure using phosphate-depleted medium, centrifugation, and transduction for 16 hours at 32degrees C was then evaluated. NK cells transduced under these conditions maintained significant NK proliferation in the absence of exogenous IL-2 compared with sham-transduced controls. Two consecutive daily transductions resulted in less proliferation, suggesting that several exposures to retroviral supernatant may inhibit subsequent NK proliferation. Cytotoxicity of the transduced NK cells against K562 and Raji was maintained under these conditions without exogenous IL-2. Sham-transduced NK cells produced 8.3+/-2.6 U/mL of murine IL-2 (muIL-2) by ELISA (background) after 7 days without exogenous IL-2. In contrast, 109+/-23 U/mL muIL-2 was produced by NK cells transduced with supernatant from the MFG/muIL-2 producer line. These experiments demonstrate that NK cells can be successfully transduced with retroviruses and induced to express sufficient IL-2 to maintain their

  17. Ex Vivo γ-Retroviral Gene Therapy of Dogs with X-linked Severe Combined Immunodeficiency and the Development of a Thymic T Cell Lymphoma

    PubMed Central

    Kennedy, Douglas R.; Hartnett, Brian J.; Kennedy, Jeffrey S.; Vernau, William; Moore, Peter F.; O’Malley, Thomas; Burkly, Linda C.; Henthorn, Paula S.; Felsburg, Peter J.

    2011-01-01

    We have previously shown that in vivo γ-retroviral gene therapy of dogs with X-linked severe combined immunodeficiency (XSCID) results in sustained T cell reconstitution and sustained marking in myeloid and B cells for up to 4 years with no evidence of any serious adverse effects. The purpose of this study was to determine whether ex vivo γ-retroviral gene therapy of XSCID dogs results in a similar outcome. Eight of 12 XSCID dogs treated with an average of dose of 5.8 × 106 transduced CD34+ cells/kg successfully engrafted producing normal numbers of gene-corrected CD45RA+ (naïve) T cells. However, this was followed by a steady decrease in CD45RA+ T cells, T cell diversity, and thymic output as measured by T cell receptor excision circles (TRECs) resulting in a T cell lymphopenia. None of the dogs survived past 11 months post treatment. At necropsy, few gene-corrected thymocytes were observed correlating with the TREC levels and one of the dogs was diagnosed with a thymic T cell lymphoma that was attributed to the gene therapy. This study highlights the outcome differences between the ex vivo and in vivo approach to γ-retroviral gene therapy and is the first to document a serious adverse event following gene therapy in a canine model of a human genetic disease. PMID:21536334

  18. Complementation of a primer binding site-impaired murine leukemia virus-derived retroviral vector by a genetically engineered tRNA-like primer.

    PubMed Central

    Lund, A H; Duch, M; Lovmand, J; Jørgensen, P; Pedersen, F S

    1997-01-01

    Reverse transcription of retroviral genomes is primed by a tRNA annealed to an 18-nucleotide primer binding site. Here, we present a primer complementation system to study molecular interaction of the replication machinery with the primer and primer binding site in vivo. Introduction of eight base substitutions into the primer binding site of a murine leukemia virus-based vector allowed efficient RNA encapsidation but resulted in severely reduced vector replication capacity. Replication was restored upon complementation with a synthetic gene designed to encode a complementary tRNA-like primer, but not with a noncomplementary tRNA-like molecule. The engineered primer was shown to be involved in both the initiation of first-strand synthesis and second-strand transfer. These results provide an in vivo demonstration that the retroviral replication machinery may recognize sequence complementarity rather than actual primer binding site and 3' primer sequences. Use of mutated primer binding site vectors replicating via engineered primers may add additional control features to retroviral gene transfer technology. PMID:8995641

  19. Retroviral insertional activation in a herpesvirus: transcriptional activation of US genes by an integrated long terminal repeat in a Marek's disease virus clone.

    PubMed Central

    Jones, D; Brunovskis, P; Witter, R; Kung, H J

    1996-01-01

    Insertional activation of host proto-oncogenes has been recognized as a basic mechanism by which nonacute retroviruses induce cancer. Our previous work has demonstrated that retroviruses can efficiently integrate into DNA virus genomes. Specifically, coinfection of cultured fibroblasts with a chicken herpesvirus, Marek's disease virus (MDV), and a chicken retrovirus results in frequent stable retroviral insertions into the herpesvirus genome. Such insertions could alter the expression of herpesvirus genes, possibly resulting in novel phenotypic properties. In this article, we report the characterization of a replication-competent clone of MDV with integrated retroviral sequences. This virus was isolated from a chicken following injection of fibroblasts coinfected with MDV and the retrovirus, reticuloendotheliosis virus. Transcripts originating from the reticuloendotheliosis virus long terminal repeat promoters were found to encode the adjoining MDV genes, SORF2, US1, and US10. This virus replicates well in culture but has an unusual phenotype in chickens, characterized by an attenuated virulence which produces no nerve lesions but, rather, severe thymic atrophy. While the causal relationship between the insertion and the observed phenotypes remains to be established, our data provide the first evidence of retroviral insertional activation of herpesvirus genes. PMID:8642673

  20. Effects of T592 phosphomimetic mutations on tetramer stability and dNTPase activity of SAMHD1 can not explain the retroviral restriction defect

    PubMed Central

    Bhattacharya, Akash; Wang, Zhonghua; White, Tommy; Buffone, Cindy; Nguyen, Laura A.; Shepard, Caitlin N.; Kim, Baek; Demeler, Borries; Diaz-Griffero, Felipe; Ivanov, Dmitri N.

    2016-01-01

    SAMHD1, a dNTP triphosphohydrolase, contributes to interferon signaling and restriction of retroviral replication. SAMHD1-mediated retroviral restriction is thought to result from the depletion of cellular dNTP pools, but it remains controversial whether the dNTPase activity of SAMHD1 is sufficient for restriction. The restriction ability of SAMHD1 is regulated in cells by phosphorylation on T592. Phosphomimetic mutations of T592 are not restriction competent, but appear intact in their ability to deplete cellular dNTPs. Here we use analytical ultracentrifugation, fluorescence polarization and NMR-based enzymatic assays to investigate the impact of phosphomimetic mutations on SAMHD1 tetramerization and dNTPase activity in vitro. We find that phosphomimetic mutations affect kinetics of tetramer assembly and disassembly, but their effects on tetramerization equilibrium and dNTPase activity are insignificant. In contrast, the Y146S/Y154S dimerization-defective mutant displays a severe dNTPase defect in vitro, but is indistinguishable from WT in its ability to deplete cellular dNTP pools and to restrict HIV replication. Our data suggest that the effect of T592 phosphorylation on SAMHD1 tetramerization is not likely to explain the retroviral restriction defect, and we hypothesize that enzymatic activity of SAMHD1 is subject to additional cellular regulatory mechanisms that have not yet been recapitulated in vitro. PMID:27511536

  1. Imported acquired immunodeficiency syndrome-related histoplasmosis in metropolitan France: a comparison of pre-highly active anti-retroviral therapy and highly active anti-retroviral therapy eras.

    PubMed

    Peigne, Vincent; Dromer, Françoise; Elie, Caroline; Lidove, Olivier; Lortholary, Olivier

    2011-11-01

    Histoplasma capsulatum var. capsulatum infection is rare outside disease-endemic areas. Clinical presentation and outcome of acquired immunodeficiency syndrome-related histoplasmosis are unknown in non-endemic areas with wide access to highly active anti-retroviral therapy (HAART). Retrospective analysis of cases recorded at the French National Reference Center for Mycoses and Antifungals during two decades: pre-HAART (1985-1994) and HAART (1997-2006). Clinical features and outcome of all adults with proven acquired immunodeficiency syndrome-related histoplasmosis were compared between the two periods. One hundred four patients were included (40 during the pre-HAART era and 64 during the HAART era). Diagnosis was established a mean of 62 days after onset of symptoms. One-year overall mortality rates decreased from 53% (pre-HAART era) to 22% (HAART era). Diagnosis during the pre-HAART era and an older age were the only independent factors associated with death. Histoplasmosis is a rare invasive fungal infection outside disease-endemic areas. Its prognosis improved significantly during the HAART era.

  2. Annotation and visualization of endogenous retroviral sequences using the Distributed Annotation System (DAS) and eBioX

    PubMed Central

    Martínez Barrio, Álvaro; Lagercrantz, Erik; Sperber, Göran O; Blomberg, Jonas; Bongcam-Rudloff, Erik

    2009-01-01

    Background The Distributed Annotation System (DAS) is a widely used network protocol for sharing biological information. The distributed aspects of the protocol enable the use of various reference and annotation servers for connecting biological sequence data to pertinent annotations in order to depict an integrated view of the data for the final user. Results An annotation server has been devised to provide information about the endogenous retroviruses detected and annotated by a specialized in silico tool called RetroTector. We describe the procedure to implement the DAS 1.5 protocol commands necessary for constructing the DAS annotation server. We use our server to exemplify those steps. Data distribution is kept separated from visualization which is carried out by eBioX, an easy to use open source program incorporating multiple bioinformatics utilities. Some well characterized endogenous retroviruses are shown in two different DAS clients. A rapid analysis of areas free from retroviral insertions could be facilitated by our annotations. Conclusion The DAS protocol has shown to be advantageous in the distribution of endogenous retrovirus data. The distributed nature of the protocol is also found to aid in combining annotation and visualization along a genome in order to enhance the understanding of ERV contribution to its evolution. Reference and annotation servers are conjointly used by eBioX to provide visualization of ERV annotations as well as other data sources. Our DAS data source can be found in the central public DAS service repository, , or at . PMID:19534743

  3. IMMUNE RECONSTITUTION INFLAMMATORY SYNDROME (IRIS)-ASSOCIATED BURKITT LYMPHOMA FOLLOWING COMBINATION ANTI-RETROVIRAL THERAPY IN HIV-INFECTED PATIENTS

    PubMed Central

    Vishnu, Prakash; Dorer, Russell P.; Aboulafia, David M.

    2015-01-01

    HIV/AIDS-associated immune reconstitution inflammatory syndrome (IRIS) is defined as a paradoxical worsening or unmasking of infections and autoimmune diseases, following initiation of combination anti-retroviral therapy (cART). More recently, the case definition of IRIS has been broadened to include certain malignancies including Kaposi’s sarcoma, and less frequently Hodgkin’s and non-Hodgkin’s lymphoma (NHL). Here in we describe 3 patients infected with HIV who began cART and within a median of 15 weeks each achieved non-detectable HIV viral loads, and yet within 6 months presented for medical attention with fevers, night sweats, weight loss and bulky lymphadenopathy. Laboratory studies included elevated lactate dehydrogenase and β-2 microglobulin levels and well preserved CD4+ lymphocyte counts in excess of 350 cells/µL. In each patient lymph node biopsies were diagnostic of Burkitt lymphoma (BL). Patients were managed with multi-agent chemotherapy in conjunction with cART. We also survey the medical literature of other cases of IRIS-associated BL. Although the pathogenesis of IRIS-associated BL is not well elucidated, chronic antigenic stimulation coupled with immune deterioration, followed by subsequent restoration of the immune response and aberrant cytokine expression may be a pathway to lymphomagenesis. IRIS-associated BL should be suspected in patients with normal or near normal CD4+ lymphocyte counts who develop progressive lymphadenopathy post-initiation of cART. PMID:25458079

  4. [Successful treatment of HIV-associated chronic inflammatory demyelinating polyneuropathy by early initiation of highly active anti-retroviral therapy].

    PubMed

    Kume, Kodai; Ikeda, Kazuyo; Kamada, Masaki; Touge, Tetsuo; Deguchi, Kazushi; Masaki, Tsutomu

    2013-01-01

    A 47-year-old man with HIV infection presented with lower leg dominant dysesthesia, muscle weakness and sensory ataxia of 3 month's duration. Nerve conduction studies (NCS) showed demyelination change in the median and tibial nerves and sensory nerve action potential (SNAP) in the sural nerve was not evoked. Somatosensory evoked potential (SEP) showed the delayed N9 latency. Diagnose of HIV-associated chronic inflammatory demyelinating polyneuropathy (CIDP) was made. Although the CD4 lymphocyte counts were relatively preserved (466/μl), highly active anti-retroviral therapy (HAART) was started according to a new guideline for the use of antiretroviral agents in HIV-1-infected adults and adolescents recommending early initiation of treatment. After six months, HIV1-RNA was not detected and the CD4 lymphocyte counts showed a recovering trend (585/μl). His symptoms had disappeared, except for dysesthesia in the tip of a toe. Repeated NCS demonstrated full recovery from the demyelination and appearance of SNAP in the sural nerve. The improvement of his symptoms and NCS findings has been maintained for two years. Although effectiveness of immunotherapies such as oral prednisone, high-dose immunoglobulins and plasmapheresis have been reported in HIV-associated CIDP, early initiation of HAART may be also important for favorable prognosis in HIV-associated CIDP.

  5. IMMORTALIZATION OF HUMAN AND RHESUS MACAQUE PRIMARY ANTIGEN-SPECIFIC T CELLS BY RETROVIRALLY TRANSDUCED TELOMERASE REVERSE TRANSCRIPTASE

    PubMed Central

    Barsov, Eugene V.

    2011-01-01

    Human and rhesus macaque primary antigen-specific T cells derived from infected or immunized individuals or animals are a valuable material with which to study cellular immune responses against pathogens and tumors. Antigen-specific T cells can be expanded in vitro but have a finite proliferative life span. After a limited period in culture, primary T cells undergo replicative senescence and stop dividing. This restricts their applicability to short term experiments and complicates their use in adoptive immunotherapy. The proliferative life span of primary human and rhesus macaque T cells can be considerably extended by ectopically expressed human telomerase reverse transcriptase (TERT). Antigen-specific T cells transduced with TERT-expressing retroviral vectors can proliferate and expand in culture for long periods of time while maintaining their primary T cell characteristics including antigen-specific responses. Thus, TERT-immortalized T cells are an important and valuable resource for studying T cell immune responses and, potentially, for adoptive immunotherapy. PMID:22048804

  6. Retroviral vector integration in post-transplant hematopoiesis in mice conditioned with either submyeloablative or ablative irradiation.

    PubMed

    Sadat, M A; Dirscherl, S; Sastry, L; Dantzer, J; Pech, N; Griffin, S; Hawkins, T; Zhao, Y; Barese, C N; Cross, S; Orazi, A; An, C; Goebel, W S; Yoder, M C; Li, X; Grez, M; Cornetta, K; Mooney, S D; Dinauer, M C

    2009-12-01

    X-linked chronic granulomatous disease (X-CGD) is an inherited immunodeficiency with absent phagocyte NADPH-oxidase activity caused by defects in the gene-encoding gp91(phox). Here, we evaluated strategies for less intensive conditioning for gene therapy of genetic blood disorders without selective advantage for gene correction, such as might be used in a human X-CGD protocol. We compared submyeloablative with ablative irradiation as conditioning in murine X-CGD, examining engraftment, oxidase activity and vector integration in mice transplanted with marrow transduced with a gamma-retroviral vector for gp91(phox) expression. The frequency of oxidase-positive neutrophils in the donor population was unexpectedly higher in many 300 cGy-conditioned mice compared with lethally irradiated recipients, as was the fraction of vector-marked donor secondary CFU-S12. Vector integration sites in marrow, spleen and secondary CFU-S12 DNA from primary recipients were enriched for cancer-associated genes, including Evi1, and integrations in or near cancer-associated genes were more frequent in marrow and secondary CFU-S12 from 300 cGy-conditioned mice compared with fully ablated mice. These findings support the concept that vector integration can confer a selection bias, and suggest that the intensity of the conditioning regimen may further influence the effects of vector integration on clonal selection in post-transplant engraftment and hematopoiesis.

  7. Scale-up and manufacturing of clinical-grade self-inactivating γ-retroviral vectors by transient transfection.

    PubMed

    van der Loo, J C M; Swaney, W P; Grassman, E; Terwilliger, A; Higashimoto, T; Schambach, A; Baum, C; Thrasher, A J; Williams, D A; Nordling, D L; Reeves, L; Malik, P

    2012-03-01

    The need for γ-retroviral (gRV) vectors with a self-inactivating (SIN) design for clinical application has prompted a shift in methodology of vector manufacturing from the traditional use of stable producer lines to transient transfection-based techniques. Herein, we set out to define and optimize a scalable manufacturing process for the production of gRV vectors using transfection in a closed-system bioreactor in compliance with current good manufacturing practices (cGMP). The process was based on transient transfection of 293T cells on Fibra-Cel disks in the Wave Bioreactor. Cells were harvested from tissue culture flasks and transferred to the bioreactor containing Fibra-Cel in the presence of vector plasmid, packaging plasmids and calcium-phosphate in Dulbecco's modified Eagle's medium and 10% fetal bovine serum. Virus supernatant was harvested at 10-14 h intervals. Using optimized procedures, a total of five ecotropic cGMP-grade gRV vectors were produced (9 liters each) with titers up to 3.6 × 10(7) infectious units per milliliter on 3T3 cells. One GMP preparation of vector-like particles was also produced. These results describe an optimized process for the generation of SIN viral vectors by transfection using a disposable platform that allows for the generation of clinical-grade viral vectors without the need for cleaning validation in a cost-effective manner.

  8. Mesenchymal stromal cells retrovirally transduced with prodrug-converting genes are suitable vehicles for cancer gene therapy.

    PubMed

    Ďuriniková, E; Kučerová, L; Matúšková, M

    2014-01-01

    Mesenchymal stem/stromal cells (MSC) possess a set of several fairly unique properties which make them ideally suitable both for cellular therapies and regenerative medicine. These include: relative ease of isolation, the ability to differentiate along mesenchymal and non-mesenchymal lineages in vitro and the ability to be extensively expanded in culture without a loss of differentiative capacity. MSC are not only hypoimmunogenic, but they mediate immunosuppression upon transplantation, and possess pronounced anti-inflammatory properties. They are able to home to damaged tissues, tumors, and metastases following systemic administration. The ability of homing holds big promise for tumor-targeted delivery of therapeutic agents. Viruses are naturally evolved vehicles efficiently transferring their genes into host cells. This ability made them suitable for engineering vector systems for the delivery of genes of interest. MSC can be retrovirally transduced with genes encoding prodrug-converting genes (suicide genes), which are not toxic per se, but catalyze the formation of highly toxic metabolites following the application of a nontoxic prodrug. The homing ability of MSC holds advantages compared to virus vehicles which display many shortcomings in effective delivery of the therapeutic agents. Gene therapies mediated by viruses are limited by their restricted ability to track cancer cells infiltrating into the surrounding tissue, and by their low migratory capacity towards tumor. Thus combination of cellular therapy and gene delivery is an attractive option - it protects the vector from immune surveillance, and supports targeted delivery of a therapeutic gene/protein to the tumor site.

  9. Retroviral Transduction of Helper T Cells as a Genetic Approach to Study Mechanisms Controlling their Differentiation and Function

    PubMed Central

    Singh, Yogesh; Garden, Oliver A.; Lang, Florian; Cobb, Bradley S.

    2016-01-01

    Helper T cell development and function must be tightly regulated to induce an appropriate immune response that eliminates specific pathogens yet prevents autoimmunity. Many approaches involving different model organisms have been utilized to understand the mechanisms controlling helper T cell development and function. However, studies using mouse models have proven to be highly informative due to the availability of genetic, cellular, and biochemical systems. One genetic approach in mice used by many labs involves retroviral transduction of primary helper T cells. This is a powerful approach due to its relative ease, making it accessible to almost any laboratory with basic skills in molecular biology and immunology. Therefore, multiple genes in wild type or mutant forms can readily be tested for function in helper T cells to understand their importance and mechanisms of action. We have optimized this approach and describe here the protocols for production of high titer retroviruses, isolation of primary murine helper T cells, and their transduction by retroviruses and differentiation toward the different helper subsets. Finally, the use of this approach is described in uncovering mechanisms utilized by microRNAs (miRNAs) to regulate pathways controlling helper T cell development and function. PMID:27842353

  10. Pentecostalism and AIDS treatment in Mozambique: creating new approaches to HIV prevention through anti-retroviral therapy.

    PubMed

    Pfeiffer, James

    2011-01-01

    Pentecostal fervor has rapidly spread throughout central and southern Mozambique since the end of its protracted civil war in the early 1990s. In the peri-urban bairros and septic fringes of Mozambican cities African Independent Churches (AICs) with Pentecostal roots and mainstream Pentecostals can now claim over half the population as adherents. Over this same period another important phenomenon has coincided with this church expansion: the AIDS epidemic. Pentecostalism and HIV have travelled along similar vectors and been propelled by deepening inequality. Recognising this relationship has important implications for HIV/AIDS prevention and treatment strategies. The striking overlap between high HIV prevalence in peri-urban populations and high Pentecostal participation suggests that creative strategies, to include these movements in HIV/AIDS programming, may influence the long-term success of HIV care and the scale-up of anti-retroviral treatment (ART) across the region. The provision of ART has opened up new possibilities for engaging with local communities, especially Pentecostals and AICS, who are witnessing the immediate benefits of ARV therapy. Expanded treatment may be the key to successful prevention as advocates of a comprehensive approach to the epidemic have long argued.

  11. [Successful treatment with hyper-CVAD and highly active anti-retroviral therapy (HAART) for AIDS-related Burkitt lymphoma].

    PubMed

    Suzuki, Kazuhito; Nakazato, Tomonori; Sanada, Yukinari; Mihara, Ai; Tachikawa, Natsuo; Kurai, Hanako; Yoshimura, Yukihiro; Hayashi, Hiroyuki; Yoshida, Sachiko; Kakimoto, Tsunayuki

    2010-03-01

    A 38-year-old man was admitted to our hospital because of continuous fever and right facial palsy. He was diagnosed as HIV positive. Abdominal CT scan showed a large mass in the ascending colon. Gallium scintigraphy demonstrated increased uptake in the ascending colon. Colonoscopy was performed and histological examination of the colon tumor revealed Burkitt's lymphoma (BL). He received highly active anti-retroviral therapy (HAART) and his facial palsy improved. Because CD4 count was significantly low at 31/microl, he was treated with dose-adjusted EPOCH (DA-EPOCH) combined with HAART. Although the tumor was decreased in size by DA-EPOCH, we changed to the combination of hyper-CVAD/MTX-Ara-C alternating therapy with HAART in order to increase dose intensity. Six cycles of hyper-CVAD/MTX-Ara-C were performed and complete remission was obtained. In the HAART era, the survival of patients with AIDS-related diffuse large cell lymphoma (DLCL) improved dramatically, whereas the survival of similarly treated patients with AIDS-related BL remained poor. Our case suggests that intensive chemotherapy with hyper-CVAD/MTX-Ara-C combined with HAART may be well tolerated and effective in AIDS-related BL.

  12. Retroviral Replicating Vectors Deliver Cytosine Deaminase Leading to Targeted 5-Fluorouracil-Mediated Cytotoxicity in Multiple Human Cancer Types

    PubMed Central

    Twitty, Chris G.; Diago, Oscar R.; Hogan, Daniel J.; Burrascano, Cindy; Ibanez, Carlos E.; Jolly, Douglas J.; Ostertag, Derek

    2016-01-01

    Toca 511 is a modified retroviral replicating vector based on Moloney γ-retrovirus with an amphotropic envelope. As an investigational cancer treatment, Toca 511 preferentially infects cancer cells without direct cell lysis and encodes an enhanced yeast cytosine deaminase that converts the antifungal drug 5-fluorocytosine to the anticancer drug, 5-fluorouracil. A panel of established human cancer cell lines, derived from glioblastoma, colon, and breast cancer tissue, was used to evaluate parameters critical for effective anticancer activity. Gene transfer, cytosine deaminase production, conversion of 5-fluorocytosine to 5-fluorouracil, and subsequent cell killing occurred in all lines tested. We observed >50% infection within 25 days in all lines and 5-fluorocytosine LD50 values between 0.02 and 6 μg/ml. Although we did not identify a small number of key criteria, these studies do provide a straightforward approach to rapidly gauge the probability of a Toca 511 and 5-fluorocytosine treatment effect in various cancer indications: a single MTS assay of maximally infected cancer cell lines to determine 5-fluorocytosine LD50. The data suggest that, although there can be variation in susceptibility to Toca 511 and 5-fluorocytosine because of multiple mechanistic factors, this therapy may be applicable to a broad range of cancer types and individuals. PMID:26467507

  13. Restoration of LDL receptor function in cells from patients with autosomal recessive hypercholesterolemia by retroviral expression of ARH1.

    PubMed

    Eden, Emily R; Patel, Dilipkumar D; Sun, Xi-Ming; Burden, Jemima J; Themis, Michael; Edwards, Matthew; Lee, Philip; Neuwirth, Clare; Naoumova, Rossitza P; Soutar, Anne K

    2002-12-01

    Familial hypercholesterolemia is an autosomal dominant disorder with a gene-dosage effect that is usually caused by mutations in the LDL receptor gene that disrupt normal clearance of LDL. In the homozygous form, it results in a distinctive clinical phenotype, characterized by inherited hypercholesterolemia, cholesterol deposition in tendons, and severe premature coronary disease. We described previously two families with autosomal recessive hypercholesterolemia that is not due to mutations in the LDL receptor gene but is characterized by defective LDL receptor-dependent internalization and degradation of LDL by transformed lymphocytes from the patients. We mapped the defective gene to chromosome 1p36 and now show that the disorder in these and a third English family is due to novel mutations in ARH1, a newly identified gene encoding an adaptor-like protein. Cultured skin fibroblasts from affected individuals exhibit normal LDL receptor activity, but their monocyte-derived macrophages are similar to transformed lymphocytes, being unable to internalize and degrade LDL. Retroviral expression of normal human ARH1 restores LDL receptor internalization in transformed lymphocytes from an affected individual, as demonstrated by uptake and degradation of (125)I-labeled LDL and confocal microscopy of cells labeled with anti-LDL-receptor Ab.

  14. Gene therapy for adenosine deaminase-deficient severe combined immune deficiency: clinical comparison of retroviral vectors and treatment plans.

    PubMed

    Candotti, Fabio; Shaw, Kit L; Muul, Linda; Carbonaro, Denise; Sokolic, Robert; Choi, Christopher; Schurman, Shepherd H; Garabedian, Elizabeth; Kesserwan, Chimene; Jagadeesh, G Jayashree; Fu, Pei-Yu; Gschweng, Eric; Cooper, Aaron; Tisdale, John F; Weinberg, Kenneth I; Crooks, Gay M; Kapoor, Neena; Shah, Ami; Abdel-Azim, Hisham; Yu, Xiao-Jin; Smogorzewska, Monika; Wayne, Alan S; Rosenblatt, Howard M; Davis, Carla M; Hanson, Celine; Rishi, Radha G; Wang, Xiaoyan; Gjertson, David; Yang, Otto O; Balamurugan, Arumugam; Bauer, Gerhard; Ireland, Joanna A; Engel, Barbara C; Podsakoff, Gregory M; Hershfield, Michael S; Blaese, R Michael; Parkman, Robertson; Kohn, Donald B

    2012-11-01

    We conducted a gene therapy trial in 10 patients with adenosine deaminase (ADA)-deficient severe combined immunodeficiency using 2 slightly different retroviral vectors for the transduction of patients' bone marrow CD34(+) cells. Four subjects were treated without pretransplantation cytoreduction and remained on ADA enzyme-replacement therapy (ERT) throughout the procedure. Only transient (months), low-level (< 0.01%) gene marking was observed in PBMCs of 2 older subjects (15 and 20 years of age), whereas some gene marking of PBMC has persisted for the past 9 years in 2 younger subjects (4 and 6 years). Six additional subjects were treated using the same gene transfer protocol, but after withdrawal of ERT and administration of low-dose busulfan (65-90 mg/m(2)). Three of these remain well, off ERT (5, 4, and 3 years postprocedure), with gene marking in PBMC of 1%-10%, and ADA enzyme expression in PBMC near or in the normal range. Two subjects were restarted on ERT because of poor gene marking and immune recovery, and one had a subsequent allogeneic hematopoietic stem cell transplantation. These studies directly demonstrate the importance of providing nonmyeloablative pretransplantation conditioning to achieve therapeutic benefits with gene therapy for ADA-deficient severe combined immunodeficiency.

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

    SciTech Connect

    Kasid, A.; Morecki, S.; Aebersold, P.; Cornetta, K.; Culver, K.; Freeman, S.; Director, E.; Lotze, M.T.; Blaese, R.M.; Anderson, W.F.; Rosenberg, S.A. )

    1990-01-01

    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 (Neo{sup R}) using the retroviral vector N2. The transduced TIL populations were stable and polyclonal with respect to the intact Neo{sup R} gene integration and expressed high levels of neomycin phosphotransferase activity. The Neo{sup R} gene insertion did not alter the in vitro growth pattern and interleukin 2 dependence of the transduced TILs. Analyses of T-cell receptor gene rearrangement for {beta}- and {gamma}-chain genes revealed the oligoclonal nature of the TIL populations with no major change in the DNA rearrangement patterns or the levels of mRNA expression of the {beta} and {gamma} chains following transduction and selection of TILs in the neomycin analog G418. Human TILs expressed mRNA for tumor necrosis factors ({alpha} and {beta}) and interleukin 2 receptor P55. 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.

  16. A review of ICT systems for HIV/AIDS and anti-retroviral treatment management in South Africa.

    PubMed

    Sørensen, Tove; Rivett, Ulrike; Fortuin, Jill

    2008-01-01

    Telemedicine and e-health systems have been proposed as a support tool, to monitor and evaluate HIV/AIDS management strategies. The aim of the present study was to provide an overview of telemedicine and e-health systems for HIV/AIDS in South Africa as a basis for developing an e-health toolkit for anti-retroviral treatment (ART). An initial literature review and a subsequent interactive networking approach were chosen to identify telemedicine and e-health systems, projects and services for HIV/AIDS and ART facilities in low-resource settings and under-served areas. The literature review produced little useful information. In contrast, the face-to-face interviews and the focus group discussions provided useful information about projects and systems which had not been published. The meetings involved 1 - 5 people per session, about 30 people in total. The review showed that there were some plans for telemedicine and e-health implementation in South Africa. However, there was no all-inclusive ICT-based system in place for AIDS treatment there. With the exception of the major health information systems and electronic patient record systems, none of the telemedicine and e-health systems identified in the review were ready to be deployed across the country as a whole.

  17. Reported consent processes and demographics: a substudy of the INSIGHT Strategic Timing of AntiRetroviral Treatment trial

    PubMed Central

    Denning, Eileen; Sharma, Shweta; Smolskis, Mary; Touloumi, Giota; Walker, Sarah; Babiker, Abdel; Clewett, Megan; Emanuel, Ezekiel; Florence, Eric; Papadopoulos, Antonios; Sánchez, Adriana; Tavel, Jorge; Grady, Christine

    2014-01-01

    Objectives Efforts are needed to improve informed consent of participants in research. The Strategic Timing of AntiRetroviral Therapy (START) study provides a unique opportunity to study the effect of length and complexity of informed consent documents on understanding and satisfaction among geographically diverse participants. Methods Interested START sites were randomised to use either the standard consent form or the concise consent form for all of the site’s participants. Results A total of 4473 HIV-positive participants at 154 sites worldwide took part in the Informed Consent Substudy, with consent given in 11 primary languages. Most sites sent written information to potential participants in advance of clinic visits, usually including the consent form. At about half the sites, staff reported spending less than an hour per participant in the consent process. The vast majority of sites assessed participant understanding using informal nonspecific questions or clinical judgment. Conclusions These data reflect the interest of START research staff in evaluating the consent process and improving informed consent. The START Informed Consent Substudy is by far the largest study of informed consent intervention ever conducted. Its results have the potential to impact how consent forms are written around the world. PMID:25711320

  18. Retroviral Replicating Vectors Deliver Cytosine Deaminase Leading to Targeted 5-Fluorouracil-Mediated Cytotoxicity in Multiple Human Cancer Types.

    PubMed

    Twitty, Chris G; Diago, Oscar R; Hogan, Daniel J; Burrascano, Cindy; Ibanez, Carlos E; Jolly, Douglas J; Ostertag, Derek

    2016-02-01

    Toca 511 is a modified retroviral replicating vector based on Moloney γ-retrovirus with an amphotropic envelope. As an investigational cancer treatment, Toca 511 preferentially infects cancer cells without direct cell lysis and encodes an enhanced yeast cytosine deaminase that converts the antifungal drug 5-fluorocytosine to the anticancer drug, 5-fluorouracil. A panel of established human cancer cell lines, derived from glioblastoma, colon, and breast cancer tissue, was used to evaluate parameters critical for effective anticancer activity. Gene transfer, cytosine deaminase production, conversion of 5-fluorocytosine to 5-fluorouracil, and subsequent cell killing occurred in all lines tested. We observed >50% infection within 25 days in all lines and 5-fluorocytosine LD50 values between 0.02 and 6 μg/ml. Although we did not identify a small number of key criteria, these studies do provide a straightforward approach to rapidly gauge the probability of a Toca 511 and 5-fluorocytosine treatment effect in various cancer indications: a single MTS assay of maximally infected cancer cell lines to determine 5-fluorocytosine LD50. The data suggest that, although there can be variation in susceptibility to Toca 511 and 5-fluorocytosine because of multiple mechanistic factors, this therapy may be applicable to a broad range of cancer types and individuals.

  19. Reconstitution of T cell receptor signaling in ZAP-70-deficient cells by retroviral transduction of the ZAP-70 gene.

    PubMed

    Taylor, N; Bacon, K B; Smith, S; Jahn, T; Kadlecek, T A; Uribe, L; Kohn, D B; Gelfand, E W; Weiss, A; Weinberg, K

    1996-11-01

    A variant of severe combined immunodeficiency syndrome (SCID) with a selective inability to produce CD8 single positive T cells and a signal transduction defect in peripheral CD4+ cells has recently been shown to be the result of mutations in the ZAP-70 gene. T cell receptor (TCR) signaling requires the association of the ZAP-70 protein tyrosine kinase with the TCR complex. Human T cell leukemia virus type I-transformed CD4+ T cell lines were established from ZAP-70-deficient patients and normal controls. ZAP-70 was expressed and appropriately phosphorylated in normal T cell lines after TCR engagement, but was not detected in T cell lines from ZAP-70-deficient patients. To determine whether signaling could be reconstituted, wild-type ZAP-70 was introduced into deficient cells with a ZAP-70 retroviral vector. High titer producer clones expressing ZAP-70 were generated in the Gibbon ape leukemia virus packaging line PG13. After transduction, ZAP-70 was detected at levels equivalent to those observed in normal cells, and was appropriately phosphorylated on tyrosine after receptor engagement. The kinase activity of ZAP-70 in the reconstituted cells was also appropriately upregulated by receptor aggregation. Moreover, normal and transduced cells, but not ZAP-70-deficient cells, were able to mobilize calcium after receptor ligation, indicating that proximal TCR signaling was reconstituted. These results indicate that this form of SCID may be corrected by gene therapy.

  20. Gene therapy for adenosine deaminase–deficient severe combined immune deficiency: clinical comparison of retroviral vectors and treatment plans

    PubMed Central

    Candotti, Fabio; Shaw, Kit L.; Muul, Linda; Carbonaro, Denise; Sokolic, Robert; Choi, Christopher; Schurman, Shepherd H.; Garabedian, Elizabeth; Kesserwan, Chimene; Jagadeesh, G. Jayashree; Fu, Pei-Yu; Gschweng, Eric; Cooper, Aaron; Tisdale, John F.; Weinberg, Kenneth I.; Crooks, Gay M.; Kapoor, Neena; Shah, Ami; Abdel-Azim, Hisham; Yu, Xiao-Jin; Smogorzewska, Monika; Wayne, Alan S.; Rosenblatt, Howard M.; Davis, Carla M.; Hanson, Celine; Rishi, Radha G.; Wang, Xiaoyan; Gjertson, David; Yang, Otto O.; Balamurugan, Arumugam; Bauer, Gerhard; Ireland, Joanna A.; Engel, Barbara C.; Podsakoff, Gregory M.; Hershfield, Michael S.; Blaese, R. Michael; Parkman, Robertson

    2012-01-01

    We conducted a gene therapy trial in 10 patients with adenosine deaminase (ADA)–deficient severe combined immunodeficiency using 2 slightly different retroviral vectors for the transduction of patients' bone marrow CD34+ cells. Four subjects were treated without pretransplantation cytoreduction and remained on ADA enzyme-replacement therapy (ERT) throughout the procedure. Only transient (months), low-level (< 0.01%) gene marking was observed in PBMCs of 2 older subjects (15 and 20 years of age), whereas some gene marking of PBMC has persisted for the past 9 years in 2 younger subjects (4 and 6 years). Six additional subjects were treated using the same gene transfer protocol, but after withdrawal of ERT and administration of low-dose busulfan (65-90 mg/m2). Three of these remain well, off ERT (5, 4, and 3 years postprocedure), with gene marking in PBMC of 1%-10%, and ADA enzyme expression in PBMC near or in the normal range. Two subjects were restarted on ERT because of poor gene marking and immune recovery, and one had a subsequent allogeneic hematopoietic stem cell transplantation. These studies directly demonstrate the importance of providing nonmyeloablative pretransplantation conditioning to achieve therapeutic benefits with gene therapy for ADA-deficient severe combined immunodeficiency. PMID:22968453

  1. Quality of life assessment among HIV-positive persons entering the INSIGHT Strategic Timing of AntiRetroviral Treatment trial

    PubMed Central

    Lifson, Alan R.; Grandits, Greg; Gardner, Edward M.; Wolff, Marcelo; Pulik, Piotr; Williams, Ian; Burman, William J.

    2014-01-01

    Objectives With HIV treatment prolonging survival and HIV managed as a chronic illness, quality of life (QOL) is important to evaluate in persons living with HIV (PLWH). We assessed QOL at study entry in the Strategic Timing of AntiRetroviral Treatment clinical trial of antiretroviral-naive PLWH with >500 CD4 cells/μL. Methods QOL was assessed with: 1) visual analogue scale (VAS) for self-assessment of overall current health; 2) SF-12V2 Health Survey®, summarised into eight individual QOL domains plus component summary scores for physical health (PCS) and mental health (MCS). The VAS and eight domain scores were scaled 0–100. Mean QOL measures were calculated overall and by demographic, clinical and behavioural factors. Results 4631 participants completed the VAS and 4119 the SF-12. Mean VAS score was 80.9 ±15.7. Mean SF-12 domain scores were lowest for vitality (66.3 ±26.4) and mental health (68.6 ±21.4), and highest for physical functioning (89.3 ±23.0) and bodily pain (88.0 ±21.4). Using multiple linear regression, PCS scores were lower (p<0.001) for Asians, North Americans, females, older age, less education, longer duration of known HIV, alcoholism/substance dependence, and body mass index ≥30 kg/m2. MCS scores were highest (p<0.001) for Africans, South Americans, and older age and lowest for females, current smokers, and alcoholism/ substance dependence. Conclusions In this primarily healthy population, QOL was mostly favorable, emphasising importance that HIV treatments do not negatively impact QOL. Self-assessed physical health was higher than mental health. Factors such as older age and geographic region have different influences on perceived physical and mental health. PMID:25711327

  2. Demographic and HIV-specific characteristics of participants enrolled in the INSIGHT Strategic Timing of AntiRetroviral Treatment trial

    PubMed Central

    Sharma, S; Babiker, AG; Emery, S; Gordin, FM; Lundgren, JD; Neaton, JN; Bakowska, E; Schechter, M; Wiselka, MJ; Wolff, MJ

    2014-01-01

    Objectives The risks and benefits of initiating antiretroviral treatment (ART) at high CD4 cell counts have not been reliably quantified. The Strategic Timing of AntiRetroviral Treatment (START) study is a randomised international clinical trial that compares immediate with deferred initiation of ART for HIV-positive individuals with CD4 cell counts above 500 cells/μL. We describe the demographics, HIV-specific characteristics and medical history of this cohort. Methods Data collected at baseline include demographics, HIV-specific laboratory values, prior medical diagnoses and concomitant medications. Baseline characteristics were compared by geographical region, gender, and age. Results START enrolled 4685 HIV-positive participants from 215 sites in 35 countries. The median age is 36 years (IQR: 29-44), 27% are female, 45% self-identify as white, 30% black, 14% Latino/Hispanic, 8% Asian and 3% other. HIV acquisition is reported as 55% men who have sex with men, 38% heterosexual sex, 1% injecting drug use, and 5% other/unknown. Median time since HIV diagnosis is 1.0 year (IQR: 0.4-3.0) and the median CD4 and HIV RNA values at study entry are 651 cells/μL (584-765) and 12,754 copies/mL (IQR: 3,014-43,607), respectively. Conclusion START has enrolled a diverse group of ART-naïve individuals with high CD4 cell counts who are comparable to the HIV-positive population from the regions they were enrolled. The information collected with this robust study design will provide a database to evaluate the risks and benefits of early ART use for many important outcomes. PMID:25711321

  3. Acute retroviral syndrome and high baseline viral load are predictors of rapid HIV progression among untreated Argentinean seroconverters

    PubMed Central

    2011-01-01

    Background Diagnosis of primary HIV infection (PHI) has important clinical and public health implications. HAART initiation at this stage remains controversial. Methods Our objective was to identify predictors of disease progression among Argentinean seroconverters during the first year of infection, within a multicentre registry of PHI-patients diagnosed between 1997 and 2008. Cox regression was used to analyze predictors of progression (LT-CD4 < 350 cells/mm3, B, C events or death) at 12 months among untreated patients. Results Among 134 subjects, 74% presented with acute retroviral syndrome (ARS). Seven opportunistic infections (one death), nine B events, and 10 non-AIDS defining serious events were observed. Among the 92 untreated patients, 24 (26%) progressed at 12 months versus three (7%) in the treated group (p = 0.01). The 12-month progression rate among untreated patients with ARS was 34% (95% CI 22.5-46.3) versus 13% (95% CI 1.1-24.7) in asymptomatic patients (p = 0.04). In univariate analysis, ARS, baseline LT-CD4 < 350 cells/mm3, and baseline and six-month viral load (VL) > 100,000 copies/mL were associated with progression. In multivariate analysis, only ARS and baseline VL > 100,000 copies/mL remained independently associated; HR: 8.44 (95% CI 0.97-73.42) and 9.44 (95% CI 1.38-64.68), respectively. Conclusions In Argentina, PHI is associated with significant morbidity. HAART should be considered in PHI patients with ARS and high baseline VL to prevent disease progression. PMID:21831310

  4. A retroviral promoter and a cellular enhancer define a bipartite element which controls env ERVWE1 placental expression.

    PubMed

    Prudhomme, Sarah; Oriol, Guy; Mallet, François

    2004-11-01

    The HERV-W family contains hundreds of loci diversely expressed in several physiological and pathological contexts. A unique locus termed ERVWE1 encodes an envelope glycoprotein (syncytin) involved in hominoid placental physiology. Here we show that syncytin expression is regulated by a bipartite element consisting of a cyclic AMP (cAMP)-inducible long terminal repeat (LTR) retroviral promoter adjacent to a cellular enhancer conferring a high level of expression and placental tropism. Deletion mutant analysis showed that the ERVWE1 5' LTR contains binding sites essential for basal placental activity in the region from positions +1 to +125. The region from positions +125 to +310 represents a cAMP-responsive core HERV-W promoter active in all cell types. Site-directed mutagenesis analysis highlighted the complexity of U3 regulation. ERVWE1 placenta-specific positive (e.g., T240) and negative (e.g., G71) regulatory sites were identified, as were essential sites required for basic activity (e.g., A247). The flanking sequences of the ERVWE1 provirus contain several putative regulatory elements. The upstream HERV-H and HERV-P LTRs were found to be inactive. Conversely, the 436-bp region located between the HERV-P LTR and ERVWE1 was shown to be an upstream regulatory element (URE) which is significantly active in placenta cells. This URE acts as a tissue-specific enhancer. Genetic and functional analyses of hominoid UREs revealed large differences between UREs of members of the Hominidae and the Hylobatidae. These data allowed the identification of a positive regulatory region from positions -436 to -128, a mammalian apparent LTR retrotransposon negative regulatory region from positions -128 to -67, and a trophoblast-specific enhancer (TSE) from positions -67 to -35. Putative AP-2, Sp-1, and GCMa binding sites are essential constituents of the 33-bp TSE.

  5. A novel, Q-PCR based approach to measuring endogenous retroviral clearance by capture protein A chromatography.

    PubMed

    Zhang, Min; Lute, Scott; Norling, Lenore; Hong, Connie; Safta, Aurelia; O'Connor, Deborah; Bernstein, Lisa J; Wang, Hua; Blank, Greg; Brorson, Kurt; Chen, Qi

    2009-04-01

    Quantification of virus removal by the purification process during production is required for clinical use of biopharmaceuticals. The current validation approach for virus removal by chromatography steps typically involves time-consuming spiking experiments with expensive model viruses at bench scale. Here we propose a novel, alternative approach that can be applied in at least one instance: evaluating retroviral clearance by protein A chromatography. Our strategy uses a quantitative PCR (Q-PCR) assay that quantifies the endogenous type C retrovirus-like particle genomes directly in production Chinese Hamster Ovary (CHO) cell culture harvests and protein A pools. This eliminates the need to perform spiking with model viruses, and measures the real virus from the process. Using this new approach, clearance values were obtained that was comparable to those from the old model-virus spike/removal approach. We tested the concept of design space for CHO retrovirus removal using samples from a protein A characterization study, where a wide range of chromatographic operating conditions were challenged, including load density, flow rate, wash, pooling, temperature, and resin life cycles. Little impact of these variables on CHO retrovirus clearance was found, arguing for implementation of the design space approach for viral clearance to support operational ranges and manufacturing excursions. The viral clearance results from Q-PCR were confirmed by an orthogonal quantitative product-enhanced reverse transcriptase (Q-PERT) assay that quantifies CHO retrovirus by their reverse transcriptase (RT) enzyme activity. Overall, our results demonstrate that protein A chromatography is a robust retrovirus removal step and CHO retrovirus removal can be directly measured at large scale using Q-PCR assays.

  6. Update on the safety and efficacy of retroviral gene therapy for immunodeficiency due to adenosine deaminase deficiency

    PubMed Central

    Cicalese, Maria Pia; Ferrua, Francesca; Castagnaro, Laura; Pajno, Roberta; Barzaghi, Federica; Giannelli, Stefania; Dionisio, Francesca; Brigida, Immacolata; Bonopane, Marco; Casiraghi, Miriam; Tabucchi, Antonella; Carlucci, Filippo; Grunebaum, Eyal; Adeli, Mehdi; Bredius, Robbert G.; Puck, Jennifer M.; Stepensky, Polina; Tezcan, Ilhan; Rolfe, Katie; De Boever, Erika; Reinhardt, Rickey R.; Appleby, Jonathan; Ciceri, Fabio; Roncarolo, Maria Grazia

    2016-01-01

    Adenosine deaminase (ADA) deficiency is a rare, autosomal-recessive systemic metabolic disease characterized by severe combined immunodeficiency (SCID). The treatment of choice for ADA-deficient SCID (ADA-SCID) is hematopoietic stem cell transplant from an HLA-matched sibling donor, although <25% of patients have such a donor available. Enzyme replacement therapy (ERT) partially and temporarily relieves immunodeficiency. We investigated the medium-term outcome of gene therapy (GT) in 18 patients with ADA-SCID for whom an HLA-identical family donor was not available; most were not responding well to ERT. Patients were treated with an autologous CD34+-enriched cell fraction that contained CD34+ cells transduced with a retroviral vector encoding the human ADA complementary DNA sequence (GSK2696273) as part of single-arm, open-label studies or compassionate use programs. Overall survival was 100% over 2.3 to 13.4 years (median, 6.9 years). Gene-modified cells were stably present in multiple lineages throughout follow up. GT resulted in a sustained reduction in the severe infection rate from 1.17 events per person-year to 0.17 events per person-year (n = 17, patient 1 data not available). Immune reconstitution was demonstrated by normalization of T-cell subsets (CD3+, CD4+, and CD8+), evidence of thymopoiesis, and sustained T-cell proliferative capacity. B-cell function was evidenced by immunoglobulin production, decreased intravenous immunoglobulin use, and antibody response after vaccination. All 18 patients reported infections as adverse events; infections of respiratory and gastrointestinal tracts were reported most frequently. No events indicative of leukemic transformation were reported. Trial details were registered at www.clinicaltrials.gov as #NCT00598481. PMID:27129325

  7. Deciphering the impact of parameters influencing transgene expression kinetics after repeated cell transduction with integration-deficient retroviral vectors.

    PubMed

    Schott, Juliane W; Jaeschke, Nico M; Hoffmann, Dirk; Maetzig, Tobias; Ballmaier, Matthias; Godinho, Tamaryin; Cathomen, Toni; Schambach, Axel

    2015-05-01

    Lentiviral and gammaretroviral vectors are state-of-the-art tools for transgene expression within target cells. The integration of these vectors can be deliberately suppressed to derive a transient gene expression system based on extrachromosomal circular episomes with intact coding regions. These episomes can be used to deliver DNA templates and to express RNA or protein. Importantly, transient gene transfer avoids the genotoxic side effects of integrating vectors. Restricting their applicability, episomes are rapidly lost upon dilution in dividing target cells. Addressing this limitation, we could establish comparably stable percentages of transgene-positive cells over prolonged time periods in proliferating cells by repeated transductions. Flow cytometry was applied for kinetic analyses to decipher the impact of individual parameters on the kinetics of fluoroprotein expression after episomal retransduction and to visualize sequential and simultaneous transfer of heterologous fluoroproteins. Expression windows could be exactly timed by the number of transduction steps. The kinetics of signal loss was affected by the cell proliferation rate. The transfer of genes encoding fluoroproteins with different half-lives revealed a major impact of protein stability on temporal signal distribution and accumulation, determining optimal retransduction intervals. In addition, sequential transductions proved broad applicability in different cell types and using different envelope pseudotypes without receptor overload. Stable percentages of cells coexpressing multiple transgenes could be generated upon repeated coadministration of different episomal vectors. Alternatively, defined patterns of transgene expression could be recapitulated by sequential transductions. Altogether, we established a methodology to control and adjust a temporally defined window of transgene expression using retroviral episomal vectors. Combined with the highly efficient cell entry of these vectors while

  8. Update on the safety and efficacy of retroviral gene therapy for immunodeficiency due to adenosine deaminase deficiency.

    PubMed

    Cicalese, Maria Pia; Ferrua, Francesca; Castagnaro, Laura; Pajno, Roberta; Barzaghi, Federica; Giannelli, Stefania; Dionisio, Francesca; Brigida, Immacolata; Bonopane, Marco; Casiraghi, Miriam; Tabucchi, Antonella; Carlucci, Filippo; Grunebaum, Eyal; Adeli, Mehdi; Bredius, Robbert G; Puck, Jennifer M; Stepensky, Polina; Tezcan, Ilhan; Rolfe, Katie; De Boever, Erika; Reinhardt, Rickey R; Appleby, Jonathan; Ciceri, Fabio; Roncarolo, Maria Grazia; Aiuti, Alessandro

    2016-07-07

    Adenosine deaminase (ADA) deficiency is a rare, autosomal-recessive systemic metabolic disease characterized by severe combined immunodeficiency (SCID). The treatment of choice for ADA-deficient SCID (ADA-SCID) is hematopoietic stem cell transplant from an HLA-matched sibling donor, although <25% of patients have such a donor available. Enzyme replacement therapy (ERT) partially and temporarily relieves immunodeficiency. We investigated the medium-term outcome of gene therapy (GT) in 18 patients with ADA-SCID for whom an HLA-identical family donor was not available; most were not responding well to ERT. Patients were treated with an autologous CD34(+)-enriched cell fraction that contained CD34(+) cells transduced with a retroviral vector encoding the human ADA complementary DNA sequence (GSK2696273) as part of single-arm, open-label studies or compassionate use programs. Overall survival was 100% over 2.3 to 13.4 years (median, 6.9 years). Gene-modified cells were stably present in multiple lineages throughout follow up. GT resulted in a sustained reduction in the severe infection rate from 1.17 events per person-year to 0.17 events per person-year (n = 17, patient 1 data not available). Immune reconstitution was demonstrated by normalization of T-cell subsets (CD3(+), CD4(+), and CD8(+)), evidence of thymopoiesis, and sustained T-cell proliferative capacity. B-cell function was evidenced by immunoglobulin production, decreased intravenous immunoglobulin use, and antibody response after vaccination. All 18 patients reported infections as adverse events; infections of respiratory and gastrointestinal tracts were reported most frequently. No events indicative of leukemic transformation were reported. Trial details were registered at www.clinicaltrials.gov as #NCT00598481.

  9. Challenges, successes and patterns of enrolment in the INSIGHT Strategic Timing of AntiRetroviral Treatment (START) trial

    PubMed Central

    Rappoport, C; Engen, NW; Carey, C; Hudson, F; Denning, E; Sharma, S; Florence, E; Vjecha, MJ

    2015-01-01

    Objectives The aim of this report is to describe the challenges, successes and patterns of enrolment in the Strategic Timing of AntiRetroviral Treatment (START) study. Methods START is a collaboration of many partners with central coordination provided by the protocol team, the statistical and data management centre (SDMC), the International Network for Strategic Initiatives in Global HIV Trials (INSIGHT) network leadership, international coordinating centres and site coordinating centres. The SDMC prepared reports on study accrual, baseline characteristics and site performance that allowed monitoring of enrolment and data quality and helped to ensure the successful enrolment of this large international trial. We describe the pattern of enrolment and challenges faced during the enrolment period of the trial. Results An initial pilot phase began in April 2009 and established feasibility of accrual at 101 sites. In August 2010, funding approval for an expanded definitive phase led to the successful accrual of 4688 participants from 215 sites in 35 countries by December 2013. Challenges to accrual included regulatory delays (e.g. national/local ethics approval and drug importation approval) and logistical obstacles (e.g. execution of contracts with pharmaceutical companies, setting up of a central drug repository and translation of participant materials). The personal engagement of investigators, strong central study coordination, and frequent and transparent communication with site investigators, community members and participants were key contributing factors to this success. Conclusions Accrual into START was completed in a timely fashion despite multiple challenges. This success was attributable to the efforts of site investigators committed to maintaining study equipoise, transparent and responsive study coordination, and community involvement in problem‐solving. PMID:25711319

  10. Inhibition of Electrical Activity by Retroviral Infection with Kir2.1 Transgenes Disrupts Electrical Differentiation of Motoneurons

    PubMed Central

    Yoon, Yone Jung; Kominami, Hisashi; Trimarchi, Thomas; Martin-Caraballo, Miguel

    2008-01-01

    Network-driven spontaneous electrical activity in the chicken spinal cord regulates a variety of developmental processes including neuronal differentiation and formation of neuromuscular structures. In this study we have examined the effect of chronic inhibition of spinal cord activity on motoneuron survival and differentiation. Early spinal cord activity in chick embryos was blocked using an avian replication-competent retroviral vector RCASBP (B) carrying the inward rectifier potassium channel Kir2.1. Chicken embryos were infected with one of the following constructs: RCASBP(B), RCASBP(B)-Kir2.1, or RCASBP(B)-GFP. Infection of chicken embryos at E2 resulted in widespread expression of the viral protein marker p27 gag throughout the spinal cord. Electrophysiological recordings revealed the presence of functional Kir2.1 channels in RCASBP(B)-Kir2.1 but not in RCASBP(B)-infected embryos. Kir2.1 expression significantly reduced the generation of spontaneous motor movements in chicken embryos developing in ovo. Suppression of spontaneous electrical activity was not due to a reduction in the number of surviving motoneurons or the number of synapses in hindlimb muscle tissue. Disruption of the normal pattern of activity in chicken embryos resulted in a significant downregulation in the functional expression of large-conductance Ca2+-dependent K+ channels. Reduction of spinal cord activity also generates a significant acceleration in the inactivation rate of A-type K+ currents without any significant change in current density. Kir2.1 expression did not affect the expression of voltage-gated Na+ channels or cell capacitance. These experiments demonstrate that chronic inhibition of chicken spinal cord activity causes a significant change in the electrical properties of developing motoneurons. PMID:18698433

  11. Native structure of a retroviral envelope protein and its conformational change upon interaction with the target cell.

    PubMed

    Riedel, Christiane; Vasishtan, Daven; Siebert, C Alistair; Whittle, Cathy; Lehmann, Maik J; Mothes, Walther; Grünewald, Kay

    2017-02-01

    Enveloped viruses enter their host cells by membrane fusion. The process of attachment and fusion in retroviruses is mediated by a single viral envelope glycoprotein (Env). Conformational changes of Env in the course of fusion are a focus of intense studies. Here we provide further insight into the changes occurring in retroviral Env during its initial interaction with the cell, employing murine leukemia virus (MLV) as model system. We first determined the structure of both natively membrane anchored MLV Env and MLV Env tagged with YFP in the proline rich region (PRR) by electron cryo tomography (cET) and sub-volume averaging. At a resolution of ∼20Å, native MLV Env presents as a hollow trimer (height ∼85Å, diameter ∼120Å) composed of step-shaped protomers. The major difference to the YFP-tagged protein was in regions outside of the central trimer. Next, we focused on elucidating the changes in MLV Env upon interaction with a host cell. Virus interaction with the plasma membrane occurred over a large surface and Env clustering on the binding site was observed. Sub-volume averaging did yield a low-resolution structure of Env interacting with the cell, which had lost its threefold symmetry and was elongated by ∼35Å in comparison to the unbound protein. This indicates a major rearrangement of Env upon host cell binding. At the site of virus interaction, the otherwise clearly defined bilayer structure of the host cell plasma membrane was much less evident, indicative of integral membrane protein accumulation and/or a change in membrane lipid composition.

  12. Cytokine-independent growth and clonal expansion of a primary human CD8+ T-cell clone following retroviral transduction with the IL-15 gene

    PubMed Central

    Hsu, Cary; Jones, Stephanie A.; Cohen, Cyrille J.; Zheng, Zhili; Kerstann, Keith; Zhou, Juhua; Robbins, Paul F.; Peng, Peter D.; Shen, Xinglei; Gomes, Theotonius J.; Dunbar, Cynthia E.; Munroe, David J.; Stewart, Claudia; Cornetta, Kenneth; Wangsa, Danny; Ried, Thomas; Rosenberg, Steven A.

    2007-01-01

    Malignancies arising from retrovirally transduced hematopoietic stem cells have been reported in animal models and human gene therapy trials. Whether mature lymphocytes are susceptible to insertional mutagenesis is unknown. We have characterized a primary human CD8+ T-cell clone, which exhibited logarithmic ex vivo growth in the absence of exogenous cytokine support for more than 1 year after transduction with a murine leukemia virus–based vector encoding the T-cell growth factor IL-15. Phenotypically, the clone was CD28−, CD45RA−, CD45RO+, and CD62L−, a profile consistent with effector memory T lymphocytes. After gene transfer with tumor-antigen–specific T-cell receptors, the clone secreted IFN-γ upon encountering tumor targets, providing further evidence that they derived from mature lymphocytes. Gene-expression analyses revealed no evidence of insertional activation of genes flanking the retroviral insertion sites. The clone exhibited constitutive telomerase activity, and the presence of autocrine loop was suggested by impaired cell proliferation following knockdown of IL-15Rα expression. The generation of this cell line suggests that nonphysiologic expression of IL-15 can result in the long-term in vitro growth of mature human T lymphocytes. The cytokine-independent growth of this line was a rare event that has not been observed in other IL-15 vector transduction experiments or with any other integrating vector system. It does not appear that the retroviral vector integration sites played a role in the continuous growth of this cell clone, but this remains under investigation. PMID:17353346

  13. Cytokine-independent growth and clonal expansion of a primary human CD8+ T-cell clone following retroviral transduction with the IL-15 gene.

    PubMed

    Hsu, Cary; Jones, Stephanie A; Cohen, Cyrille J; Zheng, Zhili; Kerstann, Keith; Zhou, Juhua; Robbins, Paul F; Peng, Peter D; Shen, Xinglei; Gomes, Theotonius J; Dunbar, Cynthia E; Munroe, David J; Stewart, Claudia; Cornetta, Kenneth; Wangsa, Danny; Ried, Thomas; Rosenberg, Steven A; Morgan, Richard A

    2007-06-15

    Malignancies arising from retrovirally transduced hematopoietic stem cells have been reported in animal models and human gene therapy trials. Whether mature lymphocytes are susceptible to insertional mutagenesis is unknown. We have characterized a primary human CD8(+) T-cell clone, which exhibited logarithmic ex vivo growth in the absence of exogenous cytokine support for more than 1 year after transduction with a murine leukemia virus-based vector encoding the T-cell growth factor IL-15. Phenotypically, the clone was CD28(-), CD45RA(-), CD45RO(+), and CD62L(-), a profile consistent with effector memory T lymphocytes. After gene transfer with tumor-antigen-specific T-cell receptors, the clone secreted IFN-gamma upon encountering tumor targets, providing further evidence that they derived from mature lymphocytes. Gene-expression analyses revealed no evidence of insertional activation of genes flanking the retroviral insertion sites. The clone exhibited constitutive telomerase activity, and the presence of autocrine loop was suggested by impaired cell proliferation following knockdown of IL-15R alpha expression. The generation of this cell line suggests that nonphysiologic expression of IL-15 can result in the long-term in vitro growth of mature human T lymphocytes. The cytokine-independent growth of this line was a rare event that has not been observed in other IL-15 vector transduction experiments or with any other integrating vector system. It does not appear that the retroviral vector integration sites played a role in the continuous growth of this cell clone, but this remains under investigation.

  14. Capture of syncytin-Mar1, a Fusogenic Endogenous Retroviral Envelope Gene Involved in Placentation in the Rodentia Squirrel-Related Clade

    PubMed Central

    Redelsperger, François; Cornelis, Guillaume; Vernochet, Cécile; Tennant, Bud C.; Catzeflis, François; Mulot, Baptiste; Heidmann, Odile; Dupressoir, Anne

    2014-01-01

    ABSTRACT Syncytin genes are fusogenic envelope protein (env) genes of retroviral origin that have been captured for a function in placentation. Within rodents, two such genes have previously been identified in the mouse-related clade, allowing a demonstration of their essential role via knockout mice. Here, we searched for similar genes in a second major clade of the Rodentia order, the squirrel-related clade, taking advantage of the complete sequencing of the ground squirrel Ictidomys tridecemlineatus genome. In silico search for env genes with full coding capacity identified several candidate genes with one displaying placenta-specific expression, as revealed by quantitative reverse transcription-PCR analysis of a large panel of tissues. This gene belongs to a degenerate endogenous retroviral element, with recognizable hallmarks of an integrated provirus. Cloning of the gene in an expression vector for ex vivo cell-cell fusion and pseudotype assays demonstrated fusogenicity on a large panel of mammalian cells. In situ hybridization on placenta sections showed specific expression in domains where trophoblast cells fuse into a syncytiotrophoblast at the fetomaternal interface, consistent with a role in syncytium formation. Finally, we show that the gene is conserved among the tribe Marmotini, thus dating its capture back to about at least 25 million years ago, with evidence for purifying selection and conservation of fusogenic activity. This gene that we named syncytin-Mar1 is distinct from all seven Syncytin genes identified to date in eutherian mammals and is likely to be a major effector of placentation in its related clade. IMPORTANCE Syncytin genes are fusogenic envelope genes of retroviral origin, ancestrally captured for a function in placentation. Within rodents, two such genes had been previously identified in the mouse-related clade. Here, in the squirrel-related rodent clade, we identified the envelope gene of an endogenous retrovirus with all the

  15. Capture of syncytin-Mar1, a fusogenic endogenous retroviral envelope gene involved in placentation in the Rodentia squirrel-related clade.

    PubMed

    Redelsperger, François; Cornelis, Guillaume; Vernochet, Cécile; Tennant, Bud C; Catzeflis, François; Mulot, Baptiste; Heidmann, Odile; Heidmann, Thierry; Dupressoir, Anne

    2014-07-01

    Syncytin genes are fusogenic envelope protein (env) genes of retroviral origin that have been captured for a function in placentation. Within rodents, two such genes have previously been identified in the mouse-related clade, allowing a demonstration of their essential role via knockout mice. Here, we searched for similar genes in a second major clade of the Rodentia order, the squirrel-related clade, taking advantage of the complete sequencing of the ground squirrel Ictidomys tridecemlineatus genome. In silico search for env genes with full coding capacity identified several candidate genes with one displaying placenta-specific expression, as revealed by quantitative reverse transcription-PCR analysis of a large panel of tissues. This gene belongs to a degenerate endogenous retroviral element, with recognizable hallmarks of an integrated provirus. Cloning of the gene in an expression vector for ex vivo cell-cell fusion and pseudotype assays demonstrated fusogenicity on a large panel of mammalian cells. In situ hybridization on placenta sections showed specific expression in domains where trophoblast cells fuse into a syncytiotrophoblast at the fetomaternal interface, consistent with a role in syncytium formation. Finally, we show that the gene is conserved among the tribe Marmotini, thus dating its capture back to about at least 25 million years ago, with evidence for purifying selection and conservation of fusogenic activity. This gene that we named syncytin-Mar1 is distinct from all seven Syncytin genes identified to date in eutherian mammals and is likely to be a major effector of placentation in its related clade. Importance: Syncytin genes are fusogenic envelope genes of retroviral origin, ancestrally captured for a function in placentation. Within rodents, two such genes had been previously identified in the mouse-related clade. Here, in the squirrel-related rodent clade, we identified the envelope gene of an endogenous retrovirus with all the features of a

  16. Sustainability of a community-based anti-retroviral care delivery model – a qualitative research study in Tete, Mozambique

    PubMed Central

    Rasschaert, Freya; Decroo, Tom; Remartinez, Daniel; Telfer, Barbara; Lessitala, Faustino; Biot, Marc; Candrinho, Baltazar; Van Damme, Wim

    2014-01-01

    Introduction To overcome patients’ reported barriers to accessing anti-retroviral therapy (ART), a community-based delivery model was piloted in Tete, Mozambique. Community ART Groups (CAGs) of maximum six patients stable on ART offered cost- and time-saving benefits and mutual psychosocial support, which resulted in better adherence and retention outcomes. To date, Médecins Sans Frontières has coordinated and supported these community-driven activities. Methods To better understand the sustainability of the CAG model, we developed a conceptual framework on sustainability of community-based programmes. This was used to explore the data retrieved from 16 focus group discussions and 24 in-depth interviews with different stakeholder groups involved in the CAG model and to identify factors influencing the sustainability of the CAG model. Results We report the findings according to the framework's five components. (1) The CAG model was designed to overcome patients’ barriers to ART and was built on a concept of self-management and patient empowerment to reach effective results. (2) Despite the progressive Ministry of Health (MoH) involvement, the daily management of the model is still strongly dependent on external resources, especially the need for a regulatory cadre to form and monitor the groups. These additional resources are in contrast to the limited MoH resources available. (3) The model is strongly embedded in the community, with patients taking a more active role in their own healthcare and that of their peers. They are considered as partners in healthcare, which implies a new healthcare approach. (4) There is a growing enabling environment with political will and general acceptance to support the CAG model. (5) However, contextual factors, such as poverty, illiteracy and the weak health system, influence the community-based model and need to be addressed. Conclusions The community embeddedness of the model, together with patient empowerment, high

  17. Down-regulation of CD81 tetraspanin in human cells producing retroviral-based particles: tailoring vector composition.

    PubMed

    Rodrigues, A F; Guerreiro, M R; Santiago, V M; Dalba, C; Klatzmann, D; Alves, P M; Carrondo, M J T; Coroadinha, A S

    2011-11-01

    Retroviral-derived biopharmaceuticals (RV) target numerous therapeutic applications, from gene therapy to virus-like particle (rVLP)-based vaccines. During particle formation, beside the pseudotyped envelope proteins, RV can incorporate proteins derived from the virus producer cells (VPC). This may be detrimental by reducing the amounts of the pseudotyped envelope and/or by incorporating protein capable of inducing immune responses when non-human VPC are used. Manipulating the repertoire of VPC proteins integrated onto the vector structure is an underexplored territory and should provide valuable insights on potential targets to improve vector pharmacokinetic and pharmacodynamic properties. In this work, human HEK 293 cells producing retrovirus-like particles (rVLPs) and infectious RV vectors were used to prove the concept of customizing RV composition by manipulating cellular protein content. The tetraspanin CD81 was chosen since it is significantly incorporated in the RV membrane, conferring to the vector significant immunogenicity when used in mice. RNA interference-mediated by shRNA lentiviral vector transduction was efficiently used to silence CD81 expression (up to 99%) and the rVLPs produced by knocked-down cells lack CD81. Silenced clones were analyzed for cell proliferation, morphological changes, susceptibility to oxidative stress conditions, and rVLP productivities. The results showed that the down-regulation of VPC proteins requires close monitoring for possible side effects on cellular production performance. Yet, they confirm that it is possible to change the composition of host-derived immunogens in RV by altering cellular protein content with no detriment for vector productivity and titers. This constitutes an important manipulation tool in vaccinology--by exploiting the potential adjuvant effect of VPC proteins or using them as fusion agents to other proteins of interest to be exposed on the vector membrane--and in gene therapy, by reducing the

  18. Structure of the Brd4 ET domain bound to a C-terminal motif from γ-retroviral integrases reveals a conserved mechanism of interaction.

    PubMed

    Crowe, Brandon L; Larue, Ross C; Yuan, Chunhua; Hess, Sonja; Kvaratskhelia, Mamuka; Foster, Mark P

    2016-02-23

    The bromodomain and extraterminal domain (BET) protein family are promising therapeutic targets for a range of diseases linked to transcriptional activation, cancer, viral latency, and viral integration. Tandem bromodomains selectively tether BET proteins to chromatin by engaging cognate acetylated histone marks, and the extraterminal (ET) domain is the focal point for recruiting a range of cellular and viral proteins. BET proteins guide γ-retroviral integration to transcription start sites and enhancers through bimodal interaction with chromatin and the γ-retroviral integrase (IN). We report the NMR-derived solution structure of the Brd4 ET domain bound to a conserved peptide sequence from the C terminus of murine leukemia virus (MLV) IN. The complex reveals a protein-protein interaction governed by the binding-coupled folding of disordered regions in both interacting partners to form a well-structured intermolecular three-stranded β sheet. In addition, we show that a peptide comprising the ET binding motif (EBM) of MLV IN can disrupt the cognate interaction of Brd4 with NSD3, and that substitutions of Brd4 ET residues essential for binding MLV IN also impair interaction of Brd4 with a number of cellular partners involved in transcriptional regulation and chromatin remodeling. This suggests that γ-retroviruses have evolved the EBM to mimic a cognate interaction motif to achieve effective integration in host chromatin. Collectively, our findings identify key structural features of the ET domain of Brd4 that allow for interactions with both cellular and viral proteins.

  19. Improvement of retroviral retargeting by using amino acid spacers between an additional binding domain and the N terminus of Moloney murine leukemia virus SU.

    PubMed Central

    Valsesia-Wittmann, S; Morling, F J; Nilson, B H; Takeuchi, Y; Russell, S J; Cosset, F L

    1996-01-01

    We previously reported a strategy to redirect the retroviral host range by expressing single-chain antibodies (S. J. Russell, R. E. Hawkins, and G. Winter, Nucleic Acids Res. 21:1081-1085, 1993) or ligands (F.-L. Cosset, F. J Morling, Y. Takeuchi, R. A. Weiss, M. K. L. Collins, and S. J. Russell, J. Virol. 69:6314-6322, 1995) at the N terminus of Moloney murine leukemia virus (MoMLV) surface proteins (SU). Although such chimeric envelopes were able to bind the new receptors, the transduction efficiency of retargeted viruses was generally low. We hypothesized that conformational rearrangements of envelope glycoproteins were not optimally triggered following binding, and to overcome these postbinding blocks, we have generated here a set of chimeric MoMLV-derived envelopes targeted to the Ram-1 phosphate transporter in which we have varied the spacing between the Ram-1-binding domain and the MoMLV SU. All of the recombinant envelopes were correctly expressed on virions, and all bound efficiently to Ram-1. However, the interdomain spacing greatly affected the efficiency of gene transfer by retroviral vectors that had bound to Ram-1 via their chimeric envelopes. Optimal interdomain spacing allowed a 100-fold-increased viral transduction via Ram-1 compared to our previous results. PMID:8627737

  20. Characterization of Leukemia-Inducing Genes Using a Proto-Oncogene/Homeobox Gene Retroviral Human cDNA Library in a Mouse In Vivo Model.

    PubMed

    Jang, Su Hwa; Lee, Sohyun; Chung, Hee Yong

    2015-01-01

    The purpose of this research is to develop a method to screen a large number of potential driver mutations of acute myeloid leukemia (AML) using a retroviral cDNA library and murine bone marrow transduction-transplantation system. As a proof-of-concept, murine bone marrow (BM) cells were transduced with a retroviral cDNA library encoding well-characterized oncogenes and homeobox genes, and the virus-transduced cells were transplanted into lethally irradiated mice. The proto-oncogenes responsible for leukemia initiation were identified by PCR amplification of cDNA inserts from genomic DNA isolated from leukemic cells. In an initial screen of ten leukemic mice, the MYC proto-oncogene was detected in all the leukemic mice. Of ten leukemic mice, 3 (30%) had MYC as the only transgene, and seven mice (70%) had additional proto-oncogene inserts. We repeated the same experiment after removing MYC-related genes from the library to characterize additional leukemia-inducing gene combinations. Our second screen using the MYC-deleted proto-oncogene library confirmed MEIS1and the HOX family as cooperating oncogenes in leukemia pathogenesis. The model system we introduced in this study will be valuable in functionally screening novel combinations of genes for leukemogenic potential in vivo, and the system will help in the discovery of new targets for leukemia therapy.

  1. SIN retroviral vectors expressing COL7A1 under human promoters for ex vivo gene therapy of recessive dystrophic epidermolysis bullosa.

    PubMed

    Titeux, Matthias; Pendaries, Valérie; Zanta-Boussif, Maria A; Décha, Audrey; Pironon, Nathalie; Tonasso, Laure; Mejia, José E; Brice, Agnes; Danos, Olivier; Hovnanian, Alain

    2010-08-01

    Recessive dystrophic epidermolysis bullosa (RDEB) is caused by loss-of-function mutations in COL7A1 encoding type VII collagen which forms key structures (anchoring fibrils) for dermal-epidermal adherence. Patients suffer since birth from skin blistering, and develop severe local and systemic complications resulting in poor prognosis. We lack a specific treatment for RDEB, but ex vivo gene transfer to epidermal stem cells shows a therapeutic potential. To minimize the risk of oncogenic events, we have developed new minimal self-inactivating (SIN) retroviral vectors in which the COL7A1 complementary DNA (cDNA) is under the control of the human elongation factor 1alpha (EF1alpha) or COL7A1 promoters. We show efficient ex vivo genetic correction of primary RDEB keratinocytes and fibroblasts without antibiotic selection, and use either of these genetically corrected cells to generate human skin equivalents (SEs) which were grafted onto immunodeficient mice. We achieved long-term expression of recombinant type VII collagen with restored dermal-epidermal adherence and anchoring fibril formation, demonstrating in vivo functional correction. In few cases, rearranged proviruses were detected, which were probably generated during the retrotranscription process. Despite this observation which should be taken under consideration for clinical application, this preclinical study paves the way for a therapy based on grafting the most severely affected skin areas of patients with fully autologous SEs genetically corrected using a SIN COL7A1 retroviral vector.

  2. SIN Retroviral Vectors Expressing COL7A1 Under Human Promoters for Ex Vivo Gene Therapy of Recessive Dystrophic Epidermolysis Bullosa

    PubMed Central

    Titeux, Matthias; Pendaries, Valérie; Zanta-Boussif, Maria A; Décha, Audrey; Pironon, Nathalie; Tonasso, Laure; Mejia, José E; Brice, Agnes; Danos, Olivier; Hovnanian, Alain

    2010-01-01

    Recessive dystrophic epidermolysis bullosa (RDEB) is caused by loss-of-function mutations in COL7A1 encoding type VII collagen which forms key structures (anchoring fibrils) for dermal–epidermal adherence. Patients suffer since birth from skin blistering, and develop severe local and systemic complications resulting in poor prognosis. We lack a specific treatment for RDEB, but ex vivo gene transfer to epidermal stem cells shows a therapeutic potential. To minimize the risk of oncogenic events, we have developed new minimal self-inactivating (SIN) retroviral vectors in which the COL7A1 complementary DNA (cDNA) is under the control of the human elongation factor 1α (EF1α) or COL7A1 promoters. We show efficient ex vivo genetic correction of primary RDEB keratinocytes and fibroblasts without antibiotic selection, and use either of these genetically corrected cells to generate human skin equivalents (SEs) which were grafted onto immunodeficient mice. We achieved long-term expression of recombinant type VII collagen with restored dermal–epidermal adherence and anchoring fibril formation, demonstrating in vivo functional correction. In few cases, rearranged proviruses were detected, which were probably generated during the retrotranscription process. Despite this observation which should be taken under consideration for clinical application, this preclinical study paves the way for a therapy based on grafting the most severely affected skin areas of patients with fully autologous SEs genetically corrected using a SIN COL7A1 retroviral vector. PMID:20485266

  3. In vivo cell lineage analysis during chemical hepatocarcinogenesis in rats using retroviral-mediated gene transfer: evidence for dedifferentiation of mature hepatocytes.

    PubMed

    Gournay, Jérôme; Auvigne, Isabelle; Pichard, Virginie; Ligeza, Catherine; Bralet, Marie-Pierre; Ferry, Nicolas

    2002-06-01

    Feeding adult rats with a diet containing 2-acetylaminofluorene (2-AAF) results in suppression of hepatocyte proliferation and stimulation of oval cell proliferation. Although oval cells may be facultative liver stem cells, the actual relationship between oval cells and liver cancer has not been clearly established in vivo. Our goal was to label hepatic cells in vivo using retroviral vectors and follow their fate during the early steps of chemically induced hepatocarcinogenesis. Oval cell proliferation was induced by continuous feeding with a carcinogenic diet containing 2-AAF. We used two different strategies to genetically label hepatic cells: (a) labeling of proliferating cells in rats fed 2-AAF by injecting recombinant retroviral vectors containing the beta-galactosidase gene either in a peripheral vein or in the common bile duct at the peak of oval cell proliferation and (b) prelabeling of hepatocytes by intravenously injecting recombinant vectors 1 day after partial hepatectomy and 1 week before subsequent administration of 2-AAF. Using the first strategy, transgene expression occurred in both oval cells and hepatocytes. Using the second strategy, we could selectively label, and hence study the fate of, differentiated hepatocytes. In the latter case, we observed clusters of beta-galactosidase-positive hepatocytes, some of them also expressing preneoplastic markers such as gamma-glutamyl transpeptidase as well as the placental form of glutathione-S-transferase. These results demonstrate that preneoplastic foci can originate from mature hepatocytes and are consistent with the hypothesis that dedifferentiation of mature hepatocytes may occur during the course of carcinogenic regimen.

  4. SEROPREVALENCE OF Toxoplasma gondii (Nicole & Manceaux, 1909) AND RETROVIRAL STATUS OF CLIENT-OWNED PET CATS (Felis catus, Linnaeus, 1758) IN RIO DE JANEIRO, BRAZIL

    PubMed Central

    Bastos, Bethânia Ferreira; Brener, Beatriz; Gershony, Liza; Willi, Liliane; Labarthe, Norma; Pereira, Cássia; Mendes-De-Almeida, Flavya

    2014-01-01

    Cats, as definitive host, play an important role in the transmission of Toxoplasma gondii. This study aimed to establish the seroprevalence of anti-T. gondii immunoglobulins G and M, and determine the frequency of oocysts in the feces of the domestic cat population in Rio de Janeiro, Brazil. We also aimed to study the association between T. gondii infection and age, sex, breed, lifestyle, diet and retroviral infection. A total of 108 cats were included in the study and fecal samples of 54 of those cats were obtained. Only 5.6% of the cats were seropositive for anti-T. gondii immunoglobulins using the indirect hemagglutination test. None of the 54 cats presented oocysts in their fecal samples. Although not statistically significant, males, mixed-breed, free-roaming and cats aged two years and older were found to be more exposed. Age, lifestyle and the use of litter boxes were found to play an important role as risk factors. Anemia and retroviral infections were independent of T. gondii infection. No antibodies were detected in the majority of cats (94.4%), indicating that those cats had never been exposed to the parasite and, therefore, once infected, they could present the risk of shedding large numbers of oocysts into the environment. PMID:24878997

  5. The cytochrome b5 tail anchors and stabilizes subdomains of human DNA topoisomerase II alpha in the cytoplasm of retrovirally infected mammalian cells.

    PubMed

    Soltermann, A; Ernst, A; Leroy, D; Stahel, R A; Gasser, S M

    1999-06-15

    DNA topoisomerase II (topo II) is the target of many anticancer drugs and is often altered in drug-resistant cell lines. In some tumor cell lines truncated isoforms of topo IIalpha are localized to the cytoplasm. To study the localization and function of individual enzyme domains, we have epitope-tagged several fragments of human topo IIalpha and expressed them by retroviral infection of rodent and human cells. We find that fusion of the topo II fragments to the hydrophobic tail of human liver cytochrome b5 anchors the fusion protein to the outer face of cytoplasmic membranes, as determined by colocalization with calnexin and selective detergent permeabilization. Moreover, whereas the minimal ATPase domain (aa 1-266) is weakly and diffusely expressed, addition of the cytb5 anchor (1-266-b5) increases its steady-state level 16-fold with no apparent toxicity. Similar results are obtained with the complete ATPase domain (aa 1-426). A C-terminal domain (aa 1030-1504) of human topo IIalpha containing an intact dimerization motif is stably expressed and accumulates in the nucleus. Fusion to the cytb5 anchor counteracts the nuclear localization signal and relocalizes the protein to cytoplasmic membranes. In conclusion, we describe a technique that stabilizes and targets retrovirally expressed proteins such that they are exposed on the cytoplasmic surface of cellular membranes. This approach may be of general use for regulating the nuclear accumulation of drugs or proteins in living cells.

  6. Correction of interleukin-2 receptor function in X-SCID lymphoblastoid cells by retrovirally mediated transfer of the gamma-c gene.

    PubMed

    Taylor, N; Uribe, L; Smith, S; Jahn, T; Kohn, D B; Weinberg, K

    1996-04-15

    X-SCID, the most common form of human SCID, is due to mutations in the common gamma chain gene (gamma-c) that encodes an essential component of the cytokine receptors for interleukin-2 (IL-2), IL-4, IL-7, IL-9, and IL-15. Activation of the Janus family tyrosine kinases Jak1 and Jak3 is necessary for appropriate signalling through the IL-2 receptor (IL-2R). Neither Jak1 nor Jak3 was phosphorylated after IL-2 stimulation of an Epstein-Barr virus-transformed cell line (LCL) from an X-SCID patient with a gamma-c null mutation. However, we now show that appropriate IL-2R function can be restored in an X-SCID LCL by transduction of a wild-type gamma-c gene. A retroviral vector, G1gamma-cSvNa, was constructed and produced in the PG13 packaging line. Transduced X-SCID LCL expressed the G1gamma-cSvNa transcript. IL-2 stimulation of the transduced cell line resulted in appropriate tyrosine phosphorylation of both Jak1 and Jak3. Thus, retroviral-mediated transduction of normal gamma-c can reconstitute downstream signalling through the IL-2R in X-SCID cell lines, suggesting that gene therapy may be a treatment for this disease.

  7. The multimerization state of retroviral RNA is modulated by ammonium ions and affects HIV-1 full-length cDNA synthesis in vitro.

    PubMed Central

    Weiss, S; Häusl, G; Famulok, M; König, B

    1993-01-01

    Genomic human immunodeficiency virus type 1 (HIV-1) RNA fragments containing the dimer linkage structure (DLS) can be dimerized and multimerized in the presence of NH4+ and in the absence of any other cation and any viral or cellular protein. This effect strongly supports the notion that dimerization and multimerization of genomic RNA occurs via purine-quartet formation in quadruple helical RNA structures. The efficiency of RNA dimerization and multimerization in the presence of ammonium ions is about 400 fold increased as compared to alkali metal ions such as potassium. Dimerized retroviral RNA representing a pseudodiploid genome could account for genetic recombination within the virion and during reverse transcription. Application of a novel South-Northern-Blotting procedure with biotinylated RNA and digoxigenin-labelled cDNA in vitro reveals that efficient human- and bovine tRNA(Lys3) primed full-length cDNA-synthesis only takes place with a predominantly monomerized RNA template. Dimerization and multimerization of the RNA significantly reduces full-length cDNA-synthesis. This suggests that monomerization of the dimerized RNA, effected by deionization in vitro, is essential for efficient retroviral reverse transcription in vivo. Images PMID:8177734

  8. A Multicenter, Open Labeled, Randomized, Phase III Study Comparing Lopinavir/Ritonavir Plus Atazanavir to Lopinavir/Ritonavir Plus Zidovudine and Lamivudine in Naive HIV-1-Infected Patients: 48-Week Analysis of the LORAN Trial

    PubMed Central

    Ulbricht, K.U; Behrens, G.M; Stoll, M; Salzberger, B; Jessen, H; Jessen, A.B; Kuhlmann, B; Heiken, H; Trein, A; Schmidt, R.E

    2011-01-01

    Objective: The primary aim of the study was to compare the metabolic side effects of a nucleoside analogue-containing regimen with a nucleoside analogue-sparing double protease inhibitor regimen. A secondary goal was to test for efficacy of a double-PI regimen. Design: Multicenter, randomized, open-label, phase III clinical trial. Subjects: Adult HIV-1-infected individuals naïve to antiretroviral therapy with viral load above 400 HIV-RNA copies/ml were randomized (1:1) to either 400 mg lopinavir /100 mg ritonavir (LPV/r) BID plus 150 mg lamivudine/300 mg zidovudine (CBV) BID versus LPV/r BID plus 300 mg atazanavir (ATV) QD. Main outcome measure was the virologic failure in both groups, defined as viral load ≥50 copies/ml at week 48. Results: In the CBV/LPV/r-arm, 29 out of 35 patients [(83%; 95% confidence interval (CI) 66.9-92.2%] and 18 out of 40 patients (45%; 95% CI 29.7-61.5%) in the ATV/LPV/r-arm had a HIV-RNA level <50 copies/ml at week 48. The intent-to-treat analysis revealed inferior virologic response in the ATV/LPV/r arm (Chi-Q and Fisher´s Exact Test p<0.001) and resulted in premature termination of the trial. Eleven patients in the ATV/LPV/r-arm discontinued therapy because of virological failure. These failures mostly presented with low level replication (<1,000 copies/ml). Increases in CD4 cell counts was significantly more rapid in the ATV/LPV/r arm (p=0.02), but comparable at week 48. Conclusions: ATV/LPV/r had less virologic efficacy than the conventional RTI-based regimen and resulted in a high virological failure rate with low level replication. PMID:21643422

  9. Considerations in the rationale, design and methods of the Strategic Timing of AntiRetroviral Treatment (START) study

    PubMed Central

    Babiker, Abdel G; Emery, Sean; Fätkenheuer, Gerd; Gordin, Fred M; Grund, Birgit; Lundgren, Jens D; Neaton, James D; Pett, Sarah L; Phillips, Andrew; Touloumi, Giota; Vjecha, Michael J

    2012-01-01

    Background Untreated human immunodeficiency virus (HIV) infection is characterized by progressive depletion of CD4+ T lymphocyte (CD4) count leading to the development of opportunistic diseases (acquired immunodeficiency syndrome (AIDS)), and more recent data suggest that HIV is also associated with an increased risk of serious non-AIDS (SNA) diseases including cardiovascular, renal, and liver diseases and non-AIDS-defining cancers. Although combination antiretroviral treatment (ART) has resulted in a substantial decrease in morbidity and mortality in persons with HIV infection, viral eradication is not feasible with currently available drugs. The optimal time to start ART for asymptomatic HIV infection is controversial and remains one of the key unanswered questions in the clinical management of HIV-infected individuals. Purpose In this article, we outline the rationale and methods of the Strategic Timing of AntiRetroviral Treatment (START) study, an ongoing multicenter international trial designed to assess the risks and benefits of initiating ART earlier than is currently practiced. We also describe some of the challenges encountered in the design and implementation of the study and how these challenges were addressed. Methods A total of 4000 study participants who are HIV type 1 (HIV-1) infected, ART naïve with CD4 count > 500 cells/μL are to be randomly allocated in a 1:1 ratio to start ART immediately (early ART) or defer treatment until CD4 count is <350 cells/ μL (deferred ART) and followed for a minimum of 3 years. The primary outcome is time to AIDS, SNA, or death. The study had a pilot phase to establish feasibility of accrual, which was set as the enrollment of at least 900 participants in the first year. Results Challenges encountered in the design and implementation of the study included the limited amount of data on the risk of a major component of the primary endpoint (SNA) in the study population, changes in treatment guidelines when the pilot

  10. Adeno-associated virus type 2-mediated transfer of ecotropic retrovirus receptor cDNA allows ecotropic retroviral transduction of established and primary human cells.

    PubMed

    Qing, K; Bachelot, T; Mukherjee, P; Wang, X S; Peng, L; Yoder, M C; Leboulch, P; Srivastava, A

    1997-07-01

    The cellular receptors that mediate binding and internalization of retroviruses have recently been identified. The concentration and accessibility of these receptors are critical determinants in accomplishing successful gene transfer with retrovirus-based vectors. Murine retroviruses containing ecotropic glycoproteins do not infect human cells since human cells do not express the receptor that binds the ecotropic glycoproteins. To enable human cells to become permissive for ecotropic retrovirus-mediated gene transfer, we have developed a recombinant adeno-associated virus type 2 (AAV) vector containing ecotropic retroviral receptor (ecoR) cDNA under the control of the Rous sarcoma virus (RSV) long terminal repeat (LTR) promoter (vRSVp-ecoR). Established human cell lines, such as HeLa and KB, known to be nonpermissive for murine ecotropic retroviruses, became permissive for infection by a retroviral vector containing a bacterial gene for resistance to neomycin (RV-Neo(r)), with a transduction efficiency of up to 47%, following transduction with vRSVp-ecoR, as determined by the development of colonies that were resistant to the drug G418, a neomycin analog. No G418-resistant colonies were present in cultures infected with either vRSVp-ecoR or RV-Neo(r) alone. Southern and Northern blot analyses revealed stable integration and long-term expression, respectively, of the transduced murine ecoR gene in clonal isolates of HeLa and KB cells. Similarly, ecotropic retrovirus-mediated Neo(r) transduction of primary human CD34+ hematopoietic progenitor cells from normal bone marrow was also documented, but only following infection with vRSVp-ecoR. The retroviral transduction efficiency was approximately 7% without prestimulation and approximately 14% with prestimulation of CD34+ cells with cytokines, as determined by hematopoietic clonogenic assays. No G418-resistant progenitor cell colonies were present in cultures infected with either vRSVp-ecoR or RV-Neo(r) alone. These

  11. Elevated rate of fixation of endogenous retroviral elements in Haplorhini TRIM5 and TRIM22 genomic sequences: impact on transcriptional regulation.

    PubMed

    Diehl, William E; Johnson, Welkin E; Hunter, Eric

    2013-01-01

    All genes in the TRIM6/TRIM34/TRIM5/TRIM22 locus are type I interferon inducible, with TRIM5 and TRIM22 possessing antiviral properties. Evolutionary studies involving the TRIM6/34/5/22 locus have predominantly focused on the coding sequence of the genes, finding that TRIM5 and TRIM22 have undergone high rates of both non-synonymous nucleotide replacements and in-frame insertions and deletions. We sought to understand if divergent evolutionary pressures on TRIM6/34/5/22 coding regions have selected for modifications in the non-coding regions of these genes and explore whether such non-coding changes may influence the biological function of these genes. The transcribed genomic regions, including the introns, of TRIM6, TRIM34, TRIM5, and TRIM22 from ten Haplorhini primates and one prosimian species were analyzed for transposable element content. In Haplorhini species, TRIM5 displayed an exaggerated interspecies variability, predominantly resulting from changes in the composition of transposable elements in the large first and fourth introns. Multiple lineage-specific endogenous retroviral long terminal repeats (LTRs) were identified in the first intron of TRIM5 and TRIM22. In the prosimian genome, we identified a duplication of TRIM5 with a concomitant loss of TRIM22. The transposable element content of the prosimian TRIM5 genes appears to largely represent the shared Haplorhini/prosimian ancestral state for this gene. Furthermore, we demonstrated that one such differentially fixed LTR provides for species-specific transcriptional regulation of TRIM22 in response to p53 activation. Our results identify a previously unrecognized source of species-specific variation in the antiviral TRIM genes, which can lead to alterations in their transcriptional regulation. These observations suggest that there has existed long-term pressure for exaptation of retroviral LTRs in the non-coding regions of these genes. This likely resulted from serial viral challenges and provided a

  12. Crofelemer for the symptomatic relief of non-infectious diarrhea in adult patients with HIV/AIDS on anti-retroviral therapy.

    PubMed

    Castro, Jose G; Chin-Beckford, Nafeesa

    2015-01-01

    Chronic diarrhea remains a common condition that affects people infected with human immunodeficiency virus (HIV) despite the widespread use of potent antiretroviral therapy. It is important that providers control this condition, as the persistence of diarrhea affects the quality of life of patients and may contribute to decreased adherence to antiretroviral therapy. Strategies to control diarrhea in patients with HIV infection include switching to a new antiretroviral regimen and/or the use of specific medications to control the diarrhea. This review aims to provide a concise evaluation of a newly approved medication (crofelemer) that has a novel mechanism of action and has received approval for the symptomatic relief of non-infectious diarrhea in adult patients with HIV on anti-retroviral therapy.

  13. Effect of maternal aging on transgene heritability in transgenic founder mice derived from zygotes microinjected with retroviral long terminal repeat-containing recombinant deoxyribonucleic acid.

    PubMed

    Wang, T H; Yang, W K; Hoyt, P R; Ch'ang, L Y; Savin, T J

    1993-05-01

    To determine the stability of artificially introduced recombinant DNA in the mouse germline throughout the reproductive life, founder mice derived from fertilized eggs injected with retroviral long-terminal-repeat-containing recombinant DNAs were mated with congenic FVB/N mice. Tail DNA of all progeny were screened and restriction fragment patterns of the transgenes were examined. Litter size and percentage of transgene transmission at various reproductive age periods were analyzed. Microinjection of 1737 eggs with four different recombinant DNAs resulted in 12 female and 11 male transgenic mice; 2 males were sterile and the remaining 21 mice served as founders to produce 1087 F1 progeny. With increasing parental age, litter size decreased generally. The percentage of progeny inheriting the transgenes declined markedly with increasing aging of 4 female founders; this aging effect was not observed in male founders (p < 0.005). No apparent change in transgenes was detected in progeny from late reproductive stages.

  14. Cloning of the canine beta-glucuronidase cDNA, mutation identification in canine MPS VII, and retroviral vector-mediated correction of MPS VII cells.

    PubMed

    Ray, J; Bouvet, A; DeSanto, C; Fyfe, J C; Xu, D; Wolfe, J H; Aguirre, G D; Patterson, D F; Haskins, M E; Henthorn, P S

    1998-03-01

    Mucopolysaccharidosis type VII (MPS VII) is an inherited disease resulting from deficient activity of the lysosomal acid hydrolase beta-glucuronidase (GUSB) and has been reported in humans, mice, cats, and dogs. To characterize canine MPS VII, we have isolated and sequenced the canine GUSB cDNA from normal and affected animals. A single nucleotide substitution was detected in the GUSB cDNA derived from MPS VII dogs. This guanosine to adenine base change at nucleotide position 559 in the canine cDNA sequence causes an arginine to histidine substitution at amino acid position 166. Introduction of the G to A substitution at position 559 in a mammalian expression vector containing the normal canine GUSB cDNA nearly eliminated the GUSB enzymatic activity, demonstrating that this mutation is the cause of canine MPS VII. A retroviral vector expressing the full-length canine beta-glucuronidase cDNA corrected the deficiency in MPS VII cells.

  15. Efficient and persistent expression of beta-glucuronidase gene in CD34+ cells from human umbilical cord blood by retroviral vector.

    PubMed

    Ohashi, T; Iizuka, S; Sly, W S; Machiki, K; Eto, Y

    1998-10-01

    We succeeded in efficiently transferring the beta-glucuronidase gene in a retroviral vector to human hematopoietic progenitor cells using a centrifugation enhancement protocol. The transduction efficiency in CFU-GM was highly variable (23-100%) with an average of 66.8%. In the case of BFU-E, efficiency was 83% and 76% in 2 separate experiments. In LTCIC (long-term culture-initiating cell), transduction efficiency were 20% and 50% in 2 experiments. The enzymatic activity of beta-glucuronidase in transduced cells were increased above the control level up to 5 wk. Considering that correction of the enzyme deficiency in a small number of hematopoietic cells can be therapeutic for the Sly disease mouse, our data provide encouragement that human trials of gene therapy based on transferring beta-glucuronidase gene to hematopoietic cells may be efficacious.

  16. Anti-retroviral therapy's miracle in the treatment of Bowen's disease in a human immunodeficiency virus-positive patient: A rare case report

    PubMed Central

    Gopalan, Kannan; Vellaisamy, Seethalakshmi Ganga; Manickam, Navakumar; Ahamed, Razil

    2016-01-01

    Bowen's disease (BD) is a form of squamous cell carcinoma in situ often associated with human papillomavirus. Co-infection with human immunodeficiency virus (HIV) is associated with a greater risk of malignancy. We describe a case of BD in a 52-year-old unmarried HIV-positive male who presented with extensive skin lesions of 1-year duration. Histopathology was suggestive of BD. He had been tried with topical imiquimod cream and cryo-therapy for 6 months. We observed no response for these above therapies. He was started on with anti-retroviral therapy (ART) as his CD4 count was 253 cells/mm3. The entire cutaneous lesions completely disappeared within 6 months of ART, which was an interesting incidence. PMID:27890959

  17. HIV reverse transcriptase gene mutations in anti-retroviral treatment naïve rural people living with HIV/AIDS.

    PubMed

    Mohanakrishnan, K; Kasthuri, A; Amsavathani, S K; Sumathi, G

    2015-01-01

    This study is designed to find out the mutational variations of reverse transcriptase (RT) gene of HIV, after the traditional drug usage among anti-retroviral therapy naïve rural people living with HIV/AIDS. HIV Reactive patients, who were exposed for indigenous medicines such as Siddha, Ayurveda etc., for a minimum period of 6 months were taken for this study. Among 40 patients, two samples (5.55%) demonstrated high-level mutational resistance variations for nucleoside RT inhibitor (NRTI) and non-NRTI. The predominant polymorphisms detected were K122E (91.7%), V60I (91.7%), V35T (89%), Q207E (89%), D177E (89%), T200A (86.1%), S48T (83.33%), K173A (80.6%).

  18. Stochastic modelling of the eradication of the HIV-1 infection by stimulation of latently infected cells in patients under highly active anti-retroviral therapy.

    PubMed

    Sánchez-Taltavull, Daniel; Vieiro, Arturo; Alarcón, Tomás

    2016-10-01

    HIV-1 infected patients are effectively treated with highly active anti-retroviral therapy (HAART). Whilst HAART is successful in keeping the disease at bay with average levels of viral load well below the detection threshold of standard clinical assays, it fails to completely eradicate the infection, which persists due to the emergence of a latent reservoir with a half-life time of years and is immune to HAART. This implies that life-long administration of HAART is, at the moment, necessary for HIV-1-infected patients, which is prone to drug resistance and cumulative side effects as well as imposing a considerable financial burden on developing countries, those more afflicted by HIV, and public health systems. The development of therapies which specifically aim at the removal of this latent reservoir has become a focus of much research. A proposal for such therapy consists of elevating the rate of activation of the latently infected cells: by transferring cells from the latently infected reservoir to the active infected compartment, more cells are exposed to the anti-retroviral drugs thus increasing their effectiveness. In this paper, we present a stochastic model of the dynamics of the HIV-1 infection and study the effect of the rate of latently infected cell activation on the average extinction time of the infection. By analysing the model by means of an asymptotic approximation using the semi-classical quasi steady state approximation (QSS), we ascertain that this therapy reduces the average life-time of the infection by many orders of magnitudes. We test the accuracy of our asymptotic results by means of direct simulation of the stochastic process using a hybrid multi-scale Monte Carlo scheme.

  19. Production of glycosylated physiologically "normal" human alpha 1-antitrypsin by mouse fibroblasts modified by insertion of a human alpha 1-antitrypsin cDNA using a retroviral vector.

    PubMed Central

    Garver, R I; Chytil, A; Karlsson, S; Fells, G A; Brantly, M L; Courtney, M; Kantoff, P W; Nienhuis, A W; Anderson, W F; Crystal, R G

    1987-01-01

    Alpha 1-Antitrypsin (alpha 1AT) deficiency is a hereditary disorder characterized by reduced serum levels of alpha 1AT, resulting in destruction of the lower respiratory tract by neutrophil elastase. As an approach to augment alpha 1AT levels in this disorder with physiologically normal human alpha 1AT, we have integrated a full-length normal human alpha 1AT cDNA into the genome of mouse fibroblasts. To accomplish this, the retroviral vector N2 was modified by inserting the simian virus 40 early promoter followed by the alpha 1AT cDNA. Southern analysis demonstrated that the intact cDNA was present in the genome of selected clones of the transfected murine fibroblasts psi 2 and infected NIH 3T3. The clones produced three mRNA transcripts (5.8, 4.8, and 2.4 kilobases) containing human alpha 1AT sequences, secreted an alpha 1AT molecule recognized by an anti-human alpha 1AT antibody, with the same molecular mass (52 kDa) as normal human alpha 1AT and that complexed with and inhibited human neutrophil elastase. The psi 2 produced alpha 1AT was glycosylated, and when infused intravenously into mice, it had a serum half-life similar to normal alpha 1AT purified from human plasma and markedly longer than that of nonglycosylated human alpha 1AT cDNA-directed yeast-produced alpha 1AT. These studies demonstrate the feasibility of using a retroviral vector to insert the normal human alpha 1AT cDNA into non-alpha 1AT-producing cells, resulting in the synthesis and secretion of physiologically "normal" human alpha 1AT. Images PMID:3029759

  20. Brain tumor eradication and prolonged survival from intratumoral conversion of 5-fluorocytosine to 5-fluorouracil using a nonlytic retroviral replicating vector.

    PubMed

    Ostertag, Derek; Amundson, Karin K; Lopez Espinoza, Fernando; Martin, Bryan; Buckley, Taylor; Galvão da Silva, Ana Paula; Lin, Amy H; Valenta, David T; Perez, Omar D; Ibañez, Carlos E; Chen, Ching-I; Pettersson, Pär L; Burnett, Ryan; Daublebsky, Veronika; Hlavaty, Juraj; Gunzburg, Walter; Kasahara, Noriyuki; Gruber, Harry E; Jolly, Douglas J; Robbins, Joan M

    2012-02-01

    Patients with the most common and aggressive form of high-grade glioma, glioblastoma multiforme, have poor prognosis and few treatment options. In 2 immunocompetent mouse brain tumor models (CT26-BALB/c and Tu-2449-B6C3F1), we showed that a nonlytic retroviral replicating vector (Toca 511) stably delivers an optimized cytosine deaminase prodrug activating gene to the tumor lesion and leads to long-term survival after treatment with 5-fluorocytosine (5-FC). Survival benefit is dose dependent for both vector and 5-FC, and as few as 4 cycles of 5-FC dosing after Toca 511 therapy provides significant survival advantage. In the virally permissive CT26-BALB/c model, spread of Toca 511 to other tissues, particularly lymphoid tissues, is detectable by polymerase chain reaction (PCR) over a wide range of levels. In the Tu-2449-B6C3F1 model, Toca 511 PCR signal in nontumor tissues is much lower, spread is not always observed, and when observed, is mainly detected in lymphoid tissues at low levels. The difference in vector genome spread correlates with a more effective antiviral restriction element, APOBEC3, present in the B6C3F1 mice. Despite these differences, neither strain showed signs of treatment-related toxicity. These data support the concept that, in immunocompetent animals, a replicating retroviral vector carrying a prodrug activating gene (Toca 511) can spread through a tumor mass, leading to selective elimination of the tumor after prodrug administration, without local or systemic pathology. This concept is under investigation in an ongoing phase I/II clinical trial of Toca 511 in combination with 5-FC in patients with recurrent high-grade glioma (www.clinicaltrials.gov NCT01156584).

  1. Identification of a cis-acting element in the class I major histocompatibility complex gene promoter responsive to activation by retroviral sequences.

    PubMed Central

    Choi, S Y; van de Mark, K; Faller, D V

    1997-01-01

    The infection of cells with Moloney murine leukemia virus (M-MuLV) causes an increase in specific cellular gene products, including the major histocompatibility complex (MHC) class I antigens. This upregulation occurs through a transactivation process mediated by the long terminal repeat (LTR) of M-MuLV, and we show here that the gene activation response to the LTR requires at least one specific cis element within the MHC proximal promoter region. Nested deletions of MHC class I H-2Kb gene promoter sequence were subcloned into a chloramphenicol acetyltransferase (CAT) reporter vector and then transiently introduced into BALB/c-3T3 cells expressing M-MuLV or cotransfected into BALB/c-3T3 cells with a vector containing subgenomic portions of the virus, including the LTR. CAT activity assays demonstrated that a minimal H-2Kb gene promoter (-64 to +12) contained elements sufficient for this transactivation. DNase I footprinting assays located a protein-binding site in the region of -64 to -34 bp from the transcriptional start site, and point mutation analysis confirmed the location of this cis-acting element, designated the let response element (LRE), and defined a binding motif. This LRE is distinct from binding sites for currently known transcription factors in the class I MHC gene promoter and is conserved in the promoters of human and murine MHC class I genes. Mutation of the LRE resulted in dramatic reduction in both DNA-protein binding activity in electrophoretic mobility shift assay and in the ability of the mutated promoter to respond to retroviral transactivation. Addition of the LRE to a heterologous promoter conferred the ability to respond to retroviral transactivation. PMID:8995614

  2. Interactions of the Cytoplasmic Domains of Human and Simian Retroviral Transmembrane Proteins with Components of the Clathrin Adaptor Complexes Modulate Intracellular and Cell Surface Expression of Envelope Glycoproteins

    PubMed Central

    Berlioz-Torrent, Clarisse; Shacklett, Barbara L.; Erdtmann, Lars; Delamarre, Lelia; Bouchaert, Isabelle; Sonigo, Pierre; Dokhelar, Marie Christine; Benarous, Richard

    1999-01-01

    The cytoplasmic domains of the transmembrane (TM) envelope proteins (TM-CDs) of most retroviruses have a Tyr-based motif, YXXØ, in their membrane-proximal regions. This signal is involved in the trafficking and endocytosis of membrane receptors via clathrin-associated AP-1 and AP-2 adaptor complexes. We have used CD8-TM-CD chimeras to investigate the role of the Tyr-based motif of human immunodeficiency virus type 1 (HIV-1), simian immunodeficiency virus (SIV), and human T-leukemia virus type 1 (HTLV-1) TM-CDs in the cell surface expression of the envelope glycoprotein. Flow cytometry and confocal microscopy studies showed that this motif is a major determinant of the cell surface expression of the CD8-HTLV chimera. The YXXØ motif also plays a key role in subcellular distribution of the envelope of lentiviruses HIV-1 and SIV. However, these viruses, which encode TM proteins with a long cytoplasmic domain, have additional determinants distal to the YXXØ motif that participate in regulating cell surface expression. We have also used the yeast two-hybrid system and in vitro binding assays to demonstrate that all three retroviral YXXØ motifs interact with the μ1 and μ2 subunits of AP complexes and that the C-terminal regions of HIV-1 and SIV TM proteins interact with the β2 adaptin subunit. The TM-CDs of HTLV-1, HIV-1, and SIV also interact with the whole AP complexes. These results clearly demonstrate that the cell surface expression of retroviral envelope glycoproteins is governed by interactions with adaptor complexes. The YXXØ-based signal is the major determinant of this interaction for the HTLV-1 TM, which contains a short cytoplasmic domain, whereas the lentiviruses HIV-1 and SIV have additional determinants distal to this signal that are also involved. PMID:9882340

  3. Gene transfer to pre-hematopoietic and committed hematopoietic precursors in the early mouse Yolk Sac: a comparative study between in situ electroporation and retroviral transduction

    PubMed Central

    Giroux, Sébastien JD; Alves-Leiva, Celmar; Lécluse, Yann; Martin, Patrick; Albagli, Olivier; Godin, Isabelle

    2007-01-01

    Background Hematopoietic development in vertebrate embryos results from the sequential contribution of two pools of precursors independently generated. While intra-embryonic precursors harbour the features of hematopoietic stem cells (HSC), precursors formed earlier in the yolk sac (YS) display limited differentiation and self-renewal potentials. The mechanisms leading to the generation of the precursors in both sites are still largely unknown, as are the molecular basis underlying their different potential. A possible approach to assess the role of candidate genes is to transfer or modulate their expression/activity in both sites. We thus designed and compared transduction protocols to target either native extra-embryonic precursors, or hematopoietic precursors. Results One transduction protocol involves transient modification of gene expression through in situ electroporation of the prospective blood islands, which allows the evolution of transfected mesodermal cells in their "normal" environment, upon organ culture. Following in situ electroporation of a GFP reporter construct into the YS cavity of embryos at post-streak (mesodermal/pre-hematopoietic precursors) or early somite (hematopoietic precursors) stages, high GFP expression levels as well as a good preservation of cell viability is observed in YS explants. Moreover, the erythro-myeloid progeny typical of the YS arises from GFP+ mesodermal cells or hematopoietic precursors, even if the number of targeted precursors is low. The second approach, based on retroviral transduction allows a very efficient transduction of large precursor numbers, but may only be used to target 8 dpc YS hematopoietic precursors. Again, transduced cells generate a progeny quantitatively and qualitatively similar to that of control YS. Conclusion We thus provide two protocols whose combination may allow a thorough study of both early and late events of hematopoietic development in the murine YS. In situ electroporation constitutes

  4. Congenital erythropoietic porphyria: prolonged high-level expression and correction of the heme biosynthetic defect by retroviral-mediated gene transfer into porphyric and erythroid cells.

    PubMed

    Kauppinen, R; Glass, I A; Aizencang, G; Astrin, K H; Atweh, G F; Desnick, R J

    1998-09-01

    Congenital erythropoietic porphyria (CEP) is an autosomal recessive disorder resulting from the deficient activity of the heme biosynthetic enzyme uroporphyrinogen III synthase (UROS). Severely affected patients are transfusion dependent and have mutilating cutaneous manifestations. Successful bone marrow transplantation has proven curative, providing the rationale for stem cell gene therapy. Toward this goal, two retroviral MFG vectors containing the UROS cDNA were constructed, one with the wild-type sequence (MFG-UROS-wt) and a second with an optimized Kozak consensus sequence (MFG-UROS-K). Following transduction of CEP fibroblasts, the MFG-UROS-wt and MFG-UROS-K vectors increased the endogenous activity without selection to levels that were 18- and 5-fold greater, respectively, than the mean activity in normal fibroblasts. Notably, the MFG-UROS-wt vector expressed UROS activity in CEP fibroblasts at these high levels for over 6 months without cell toxicity. Addition of either delta-aminolevulinic acid (ALA) or ferric chloride did not affect expression of the transduced UROS gene nor did the increased concentrations of uroporphyrin isomers or porphyrin intermediates affect cell viability. Similarly, transduction of CEP lymphoblasts with the MFG-UROS-wt vector without G418 selection increased the endogenous UROS activity by 7-fold or almost 2-fold greater than that in normal lymphoblasts. Transduction of K562 erythroleukemia cells by cocultivation with the MFG-UROS-wt producer cells increased their high endogenous UROS activity by 1.6-fold without selection. Clonally isolated K562 cells expressed UROS for over 4 months at mean levels 4.7-fold greater than the endogenous activity without cell toxicity. Thus, the prolonged, high-level expression of UROS in transduced CEP fibroblasts and lymphoblasts, as well as in transduced K562 erythroid cells, demonstrated that the enzymatic defect in CEP cells could be corrected by retroviral-mediated gene therapy without

  5. South Africa: defiance campaign continues.

    PubMed

    2002-03-01

    The Treatment Action Campaign (TAC) has continued its "defiance campaign against patent abuse and AIDS profiteering." In partnership with Médecins Sans Frontières (Doctors Without Borders), and with the support of Oxfam and the Council of South African Trade Unions (COSATU), on 28 January 2002 three TAC members returned to South Africa from Brazil carrying generic versions of the antiretroviral drugs zidovudine (AZT), lamivudine (3TC), and nevirapine (NVP). Some of the imported capsules contain a combination of AZT and 3TC.

  6. Microfinance and HIV mitigation among people living with HIV in the era of anti-retroviral therapy: emerging lessons from Cote d'Ivoire.

    PubMed

    Holmes, Kathleen; Winskell, Kate; Hennink, Monique; Chidiac, Sybil

    2011-01-01

    The effects of HIV/AIDS have been far-reaching in Africa. Beyond adverse health outcomes and the tremendous toll on life, AIDS has serious economic impacts on households, increasing livelihood insecurity while simultaneously depleting socio-economic resources. Although microfinance is believed to have the potential to mitigate the economic impacts of HIV by helping affected households and communities better prepare for and cope with HIV-related economic shocks, little empirical research exists on this subject. This qualitative study examines the socio-economic impacts of economic strengthening activities on people living with HIV (PLHIV) in the era of increased access to anti-retroviral therapy to determine if savings-led, community-managed microfinance is a justified activity for HIV programmes. Findings from a village savings and loan programme, implemented by CARE International in Cote d'Ivoire, revealed that when appropriate medical treatment is available PLHIV are capable of participating in and benefit from microfinance activities, which increased HIV-positive clients' access to money and economic self-sufficiency. By bringing individuals with similar experiences together, savings and loan groups also acted as self-support groups providing psychosocial support while reducing stigmatisation and increasing members' sense of dignity and self-worth.

  7. Mechanism of B-box 2 domain-mediated higher-order assembly of the retroviral restriction factor TRIM5α

    PubMed Central

    Wagner, Jonathan M; Roganowicz, Marcin D; Skorupka, Katarzyna; Alam, Steven L; Christensen, Devin; Doss, Ginna; Wan, Yueping; Frank, Gabriel A; Ganser-Pornillos, Barbie K; Sundquist, Wesley I; Pornillos, Owen

    2016-01-01

    Restriction factors and pattern recognition receptors are important components of intrinsic cellular defenses against viral infection. Mammalian TRIM5α proteins are restriction factors and receptors that target the capsid cores of retroviruses and activate ubiquitin-dependent antiviral responses upon capsid recognition. Here, we report crystallographic and functional studies of the TRIM5α B-box 2 domain, which mediates higher-order assembly of TRIM5 proteins. The B-box can form both dimers and trimers, and the trimers can link multiple TRIM5α proteins into a hexagonal net that matches the lattice arrangement of capsid subunits and enables avid capsid binding. Two modes of conformational flexibility allow TRIM5α to accommodate the variable curvature of retroviral capsids. B-box mediated interactions also modulate TRIM5α’s E3 ubiquitin ligase activity, by stereochemically restricting how the N-terminal RING domain can dimerize. Overall, these studies define important molecular details of cellular recognition of retroviruses, and how recognition links to downstream processes to disable the virus. DOI: http://dx.doi.org/10.7554/eLife.16309.001 PMID:27253059

  8. Integration profile of retroviral vector in gene therapy treated patients is cell-specific according to gene expression and chromatin conformation of target cell.

    PubMed

    Biasco, Luca; Ambrosi, Alessandro; Pellin, Danilo; Bartholomae, Cynthia; Brigida, Immacolata; Roncarolo, Maria Grazia; Di Serio, Clelia; von Kalle, Christof; Schmidt, Manfred; Aiuti, Alessandro

    2011-02-01

    The analysis of genomic distribution of retroviral vectors is a powerful tool to monitor 'vector-on-host' effects in gene therapy (GT) trials but also provides crucial information about 'host-on-vector' influences based on the target cell genetic and epigenetic state. We had the unique occasion to compare the insertional profile of the same therapeutic moloney murine leukemia virus (MLV) vector in the context of the adenosine deaminase-severe combined immunodeficiency (ADA-SCID) genetic background in two GT trials based on infusions of transduced mature lymphocytes (peripheral blood lymphocytes, PBL) or a single infusion of haematopoietic stem/progenitor cells (HSC). We found that vector insertions are cell-specific according to the differential expression profile of target cells, favouring, in PBL-GT, genes involved in immune system and T-cell functions/pathways as well as T-cell DNase hypersensitive sites, differently from HSC-GT. Chromatin conformations and histone modifications influenced integration preferences but we discovered that only H3K27me3 was cell-specifically disfavoured, thus representing a key epigenetic determinant of cell-type dependent insertion distribution. Our study shows that MLV vector insertional profile is cell-specific according to the genetic/chromatin state of the target cell both in vitro and in vivo in patients several years after GT.

  9. Clonality analysis after retroviral-mediated gene transfer to CD34+ cells from the cord blood of ADA-deficient SCID neonates.

    PubMed

    Schmidt, Manfred; Carbonaro, Denise A; Speckmann, Carsten; Wissler, Manuela; Bohnsack, John; Elder, Melissa; Aronow, Bruce J; Nolta, Jan A; Kohn, Donald B; von Kalle, Christof

    2003-04-01

    A clinical trial of retroviral-mediated transfer of the adenosine deaminase (ADA) gene into umbilical cord blood CD34(+) cells was started in 1993. ADA-containing peripheral blood mononuclear cells (PBMCs) have persisted in patients from this trial, with T lymphocytes showing the highest prevalence of gene marking. To gain a greater understanding of the nature and number of the transduced cells that were engrafted, we used linear amplification-mediated PCR (LAM-PCR) to identify clonal vector proviral integrants. In one patient, a single vector integrant was predominant in T lymphocytes at a stable level over most of the eight-year time span analyzed and was also detected in some myeloid samples. T-cell clones with the predominant integrant, isolated after eight years, showed multiple patterns of T-cell receptor (TCR) gene rearrangement, indicating that a single pre-thymic stem or progenitor cell served as the source of the majority of the gene-marked cells over an extended period of time. It is important to distinguish the stable pattern of monoclonal gene marking that we observed here from the progressive increase of a T-cell clone with monoclonal gene marking that results from leukemic transformation, as observed in two subjects in a clinical trial of gene therapy for X-linked severe combined immunodeficiency (SCID).

  10. Inhibition of clinical human immunodeficiency virus (HIV) type 1 isolates in primary CD4+ T lymphocytes by retroviral vectors expressing anti-HIV genes.

    PubMed Central

    Vandendriessche, T; Chuah, M K; Chiang, L; Chang, H K; Ensoli, B; Morgan, R A

    1995-01-01

    Gene therapy may be of benefit in human immunodeficiency virus type 1 (HIV-1)-infected individuals by virtue of its ability to inhibit virus replication and prevent viral gene expression. It is not known whether anti-HIV-1 gene therapy strategies based on antisense or transdominant HIV-1 mutant proteins can inhibit the replication and expression of clinical HIV-1 isolates in primary CD4+ T lymphocytes. We therefore transduced CD4+ T lymphocytes from uninfected individuals with retroviral vectors expressing either HIV-1-specific antisense-TAR or antisense-Tat/Rev RNA, transdominant HIV-1 Rev protein, and a combination of antisense-TAR and transdominant Rev. The engineered CD4+ T lymphocytes were then infected with four different clinical HIV-1 isolates. We found that replication of all HIV-1 isolates was inhibited by all the anti-HIV vectors tested. Greater inhibition of HIV-1 was observed with transdominant Rev than with antisense RNA. We hereby demonstrated effective protection by antisense RNA or transdominant mutant proteins against HIV-1 infection in primary CD4+ T lymphocytes using clinical HIV-1 isolates, and this represents an essential step toward clinical anti-HIV-1 gene therapy. PMID:7769662

  11. Obstacles in provision of anti-retroviral treatment to drug users in Central and Eastern Europe and Central Asia: a regional overview.

    PubMed

    Bobrova, Natalia; Sarang, Anya; Stuikyte, Raminta; Lezhentsev, Konstantin

    2007-08-01

    Central and Eastern Europe and Central Asia is currently the region with the fastest growing HIV epidemic, mainly among injecting drug users (IDUs). This study explored access to anti-retroviral (ARV) treatment among IDUs and evaluated obstacles to gaining access to treatment. Semi-structured questionnaires were collected from 21 countries from agencies which deliver services to IDUs (N=55), including AIDS centres, drug treatment institutions and Non-governmental Organisations. Results showed that there was poor access to ARV treatment for IDUs. The major obstacles reported were: limited range of institutions for the provision of ARVs, lack of treatment due to high cost of ARVs, lack of clear policies and regulations in providing treatment for IDUs, lack of infrastructure and trained staff to provide treatment, and in some countries, absence of mechanisms such as methadone substitution programmes to support IDUs receiving ARV. There is a need for human and capital resources to bring ARV treatment to IDU populations in the region. Regulations and treatment protocols need to be developed to address this particular group of HIV positive clients to insure better adherence and monitoring of clients with HCV co-infection. Integration of provision of ARV treatment with drug treatment and low-threshold services is advised. Substitution therapy should be advocated for in countries where it is not available or where access is limited. Finally, more research needs to be conducted to understand what will work best in each country, region or setting.

  12. Syncytin-A and syncytin-B, two fusogenic placenta-specific murine envelope genes of retroviral origin conserved in Muridae

    PubMed Central

    Dupressoir, Anne; Marceau, Geoffroy; Vernochet, Cécile; Bénit, Laurence; Kanellopoulos, Colette; Sapin, Vincent; Heidmann, Thierry

    2005-01-01

    Recently, we and others have identified two human endogenous retroviruses that entered the primate lineage 25–40 million years ago and that encode highly fusogenic retroviral envelope proteins (syncytin-1 and -2), possibly involved in the formation of the placenta syncytiotrophoblast layer generated by trophoblast cell fusion at the materno–fetal interface. A systematic in silico search throughout mouse genome databases presently identifies two fully coding envelope genes, present as unique copies and unrelated to any known murine endogenous retrovirus, that we named syncytin-A and -B. Quantitative RT-PCR demonstrates placenta-specific expression for both genes, with increasing transcript levels in this organ from 9.5 to 14.5 days postcoitum. In situ hybridization of placenta cryosections further localizes these transcripts in the syncytiotrophoblast-containing labyrinthine zona. Consistently, we show that both genes can trigger cell–cell fusion in ex vivo transfection assays, with distinct cell type specificities suggesting different receptor usage. Genes orthologous to syncytin-A and -B and disclosing a striking conservation of their coding status are found in all Muridae tested (mouse, rat, gerbil, vole, and hamster), dating their entry into the rodent lineage ≈20 million years ago. Together, these data strongly argue for a critical role of syncytin-A and -B in murine syncytiotrophoblast formation, thus unraveling a rather unique situation where two pairs of endogenous retroviruses, independently acquired by the primate and rodent lineages, would have been positively selected for a convergent physiological role. PMID:15644441

  13. T cell anergy and activation are associated with suboptimal humoral responses to measles revaccination in HIV-infected children on anti-retroviral therapy in Nairobi, Kenya.

    PubMed

    Buechler, M B; Newman, L P; Chohan, B H; Njoroge, A; Wamalwa, D; Farquhar, C

    2015-09-01

    HIV-infected children are less capable of mounting and maintaining protective humoral responses to vaccination against measles compared to HIV-uninfected children. This poses a public health challenge in countries with high HIV burdens. Administration of anti-retroviral therapy (ART) and revaccinating children against measles is one approach to increase measles immunity in HIV-infected children, yet it is not effective in all cases. Immune anergy and activation during HIV infection are factors that could influence responses to measles revaccination. We utilized a flow cytometry-based approach to examine whether T cell anergy and activation were associated with the maintenance of measles-specific immunoglobulin (Ig)G antibodies generated in response to measles revaccination in a cohort of HIV-infected children on ART in Nairobi, Kenya. Children who sustained measles-specific IgG for at least 1 year after revaccination displayed significantly lower programmed cell death 1 (PD-1) surface expression on CD8(+) T cells on a per-cell basis and exhibited less activated CD4(+) T cells compared to those unable to maintain detectable measles-specific antibodies. Children in both groups were similar in age and sex, CD4(+) T cell frequency, duration of ART treatment and HIV viral load at enrolment. These data suggest that aberrant T cell anergy and activation are associated with the impaired ability to sustain an antibody response to measles revaccination in HIV-infected children on ART.

  14. Plasmacytoid Dendritic Cells in the Duodenum of Individuals Diagnosed with Myalgic Encephalomyelitis Are Uniquely Immunoreactive to Antibodies to Human Endogenous Retroviral Proteins

    PubMed Central

    De Meirleir, Kenny L.; Khaiboullina, Svetlana F.; Frémont, Marc; Hulstaert, Jan; Rizvanov, Albert A.; Palotás, András; Lombardi, Vincent C.

    2013-01-01

    Myalgic encephalomyelitis (ME) is a debilitating illness of unknown etiology characterized by neurocognitive dysfunction, inflammation, immune abnormalities and gastrointestinal distress. An increasing body of evidence suggests that disruptions in the gut may contribute to the induction of neuroinflammation. Therefore, reports of human endogenous retroviral (HERV) expression in association with neuroinflammatory diseases prompted us to investigate the gut of individuals with ME for the presence of HERV proteins. In eight out of 12 individuals with ME, immunoreactivity to HERV proteins was observed in duodenal biopsies. In contrast, no immunoreactivity was detected in any of the eight controls. Immunoreactivity to HERV Gag and Env proteins was uniquely co-localized in hematopoietic cells expressing the C-type lectin receptor CLEC4C (CD303/BDCA2), the co-stimulatory marker CD86 and the class II major histocompatibility complex HLA-DR, consistent with plasmacytoid dendritic cells (pDCs). Although the significance of HERVs present in the pDCs of individuals with ME has yet to be determined, these data raise the possibility of an involvment of pDCs and HERVs in ME pathology. To our knowledge, this report describes the first direct association between pDCs and HERVs in human disease. PMID:23422476

  15. Anxiety-like behaviour is attenuated by gabapentin, morphine and diazepam in a rodent model of HIV anti-retroviral-associated neuropathic pain

    PubMed Central

    Wallace, Victoria C.J.; Segerdahl, Andrew R.; Blackbeard, Julie; Pheby, Timothy; Rice, Andrew S.C.

    2008-01-01

    Neuropathic pain is commonly associated with affective disorders such as anxiety and depression. We have previously characterised a rodent model of HIV, anti-retroviral-associated neuropathy in which rats develop hypersensitivity to a punctate mechanical stimulus and display anxiety-like behaviour in the open field paradigm. To assess the potential of this behavioural paradigm for the assessment of pain related co-morbidities in rodent models of pain, here we test the sensitivity of this anxiety-like behaviour to the analgesic agents gabapentin and morphine in comparison to the known anxiolytic drug diazepam. We found that gabapentin (30 mg/kg, i.p.) and morphine (2.5 mg/kg, i.p.), which reduce mechanical hypersensitivity in these rats, significantly reduces measures of thigmotaxis in the open field. The effect of gabapentin and morphine did not differ significantly from diazepam (1 mg/kg, i.p.). This study highlights the potential use of this rodent model and behavioural paradigm in the validation of the affective component of novel analgesic pharmacological targets and elucidation of underlying pathophysiological mechanisms. PMID:18926876

  16. Anxiety-like behaviour is attenuated by gabapentin, morphine and diazepam in a rodent model of HIV anti-retroviral-associated neuropathic pain.

    PubMed

    Wallace, Victoria C J; Segerdahl, Andrew R; Blackbeard, Julie; Pheby, Timothy; Rice, Andrew S C

    2008-12-19

    Neuropathic pain is commonly associated with affective disorders such as anxiety and depression. We have previously characterised a rodent model of HIV, anti-retroviral-associated neuropathy in which rats develop hypersensitivity to a punctate mechanical stimulus and display anxiety-like behaviour in the open field paradigm. To assess the potential of this behavioural paradigm for the assessment of pain related co-morbidities in rodent models of pain, here we test the sensitivity of this anxiety-like behaviour to the analgesic agents gabapentin and morphine in comparison to the known anxiolytic drug diazepam. We found that gabapentin (30 mg/kg, i.p.) and morphine (2.5 mg/kg, i.p.), which reduce mechanical hypersensitivity in these rats, significantly reduces measures of thigmotaxis in the open field. The effect of gabapentin and morphine did not differ significantly from diazepam (1 mg/kg, i.p.). This study highlights the potential use of this rodent model and behavioural paradigm in the validation of the affective component of novel analgesic pharmacological targets and elucidation of underlying pathophysiological mechanisms.

  17. Retroviral Replicating Vector Delivery of miR-PDL1 Inhibits Immune Checkpoint PDL1 and Enhances Immune Responses In Vitro.

    PubMed

    Lin, Amy H; Twitty, Christopher G; Burnett, Ryan; Hofacre, Andrew; Mitchell, Leah A; Espinoza, Fernando Lopez; Gruber, Harry E; Jolly, Douglas J

    2017-03-17

    Tumor cells express a number of immunosuppressive molecules that can suppress anti-tumor immune responses. Efficient delivery of small interfering RNAs to treat a wide range of diseases including cancers remains a challenge. Retroviral replicating vectors (RRV) can be used to stably and selectively introduce genetic material into cancer cells. Here, we designed RRV to express shRNA (RRV-shPDL1) or microRNA30-derived shRNA (RRV-miRPDL1) using Pol II or Pol III promoters to downregulate PDL1 in human cancer cells. We also designed RRV expressing cytosine deaminase (yCD2) and miRPDL1 for potential combinatorial therapy. Among various configurations tested, we showed that RRV-miRPDL1 vectors with Pol II or Pol III promoter replicated efficiently and exhibited sustained downregulation of PDL1 protein expression by more than 75% in human cancer cell lines with high expression of PDL1. Immunologic effects of RRV-miRPDL1 were assessed by a trans-suppression lymphocyte assay. In vitro data showed downregulation of PDL1(+) tumor cells restored activation of CD8(+) T cells and bio-equivalency compared to anti-PDL1 antibody treatment. These results suggest RRV-miRPDL1 may be an alternative therapeutic approach to enhance anti-tumor immunity by overcoming PDL1-induced immune suppression from within cancer cells and this approach may also be applicable to other cancer targets.

  18. An Evaluation of Alternative Markers to Guide Initiation of Anti-retroviral Therapy in HIV-Infected Children in Settings where CD4 Assays are not Available

    PubMed Central

    Moons, Peter; Maseko, Nelson; Gushu, Montfort B.; Wit, Ferdinand W.; Graham, Steve M.; van Hensbroek, Michael Boele; Calis, Job C.

    2016-01-01

    Objectives: In settings where CD4 testing is not available, alternative markers to start paediatric anti-retroviral therapy (ART) could be used. A comprehensive evaluation of these markers has not been performed. Methods: Prospective cross-sectional study of HIV-infected Malawian children not eligible for ART based on clinical criteria. Associations between CD4 and alternative markers [haemoglobin, total lymphocyte count (TLC), serum albumin, thrombocytes and growth parameters] were analysed, and accuracy of existing and new cut-offs were evaluated. Results: In all, 417 children were enrolled. Of 261 children aged ≥5 years, 155 (59%) qualified to start ART using CD4. In this group, only TLC was associated with CD4 (p < 0.001). Sensitivity for TLC was 21% (95% CI: 15–29%), using World Health Organization cut-offs. Improved cut-offs increased sensitivity to 73% (95% CI: 65–80%), specificity 62% (95% CI: 52–72%). Conclusion: Clinical staging alone is an unreliable strategy to start ART in children. TLC is the only alternative marker for CD4, cut-offs need to be revised though. PMID:26491058

  19. A retroviral expression system based on tetracycline-regulated tricistronic transactivator/repressor vectors for functional analyses of antiproliferative and toxic genes.

    PubMed

    Ausserlechner, Michael J; Obexer, Petra; Deutschmann, Andrea; Geiger, Kathrin; Kofler, Reinhard

    2006-08-01

    Establishment of stably transfected mammalian cells with conditional expression of antiproliferative or proapoptotic proteins is often hampered by varying expression within bulk-selected cells and high background in the absence of the inducing drug. To overcome such limitations, we designed a gene expression system that transcribes the tetracycline-dependent rtTA2-M2-activator, TRSID-silencer, and selection marker as a tricistronic mRNA from a single retroviral vector. More than 92% of bulk-selected cells expressed enhanced green fluorescent protein or luciferase over more than three orders of magnitude in an almost linear, dose-dependent manner. To functionally test this system, we studied how dose-dependent expression of p27(Kip1) affects proliferation and viability of SH-EP neuroblastoma cells. Low to moderate p27(Kip1) expression caused transient G(0)-G(1) accumulation without reduced viability, whereas high p27(Kip1) levels induced significant apoptosis after 72 hours. This proves that this expression system allows concentration-dependent analysis of gene function and implicates p27(Kip1) as a critical regulator of both proliferation and apoptosis in SH-EP neuroblastoma cells.

  20. NIH oversight of human gene transfer research involving retroviral, lentiviral, and adeno-associated virus vectors and the role of the NIH recombinant DNA advisory committee.

    PubMed

    O'Reilly, Marina; Shipp, Allan; Rosenthal, Eugene; Jambou, Robert; Shih, Tom; Montgomery, Maureen; Gargiulo, Linda; Patterson, Amy; Corrigan-Curay, Jacqueline

    2012-01-01

    In response to public and scientific concerns regarding human gene transfer research, the National Institutes of Health (NIH) developed a transparent oversight system that extends to human gene transfer protocols that are either conducted with NIH funding or conducted at institutions that receive NIH funding for recombinant DNA research. The NIH Recombinant DNA Advisory Committee (RAC) has been the primary advisory body to NIH regarding the conduct of this research. Human gene transfer research proposals that are subject to the NIH Guidelines for Research Involving Recombinant DNA Molecules (NIH Guidelines) must be submitted to the NIH Office of Biotechnology Activities (OBA), and protocols that raise novel scientific, safety, medical, ethical, or social issues are publicly discussed at the RAC's quarterly public meetings. OBA also convenes gene transfer safety symposia and policy conferences to provide a public forum for scientific experts to discuss emerging issues in the field. This transparent system of review promotes the rapid exchange of important scientific information and dissemination of data. The goal is to optimize the conduct of individual research protocols and to advance gene transfer research generally. This process has fostered the development of retroviral, lentiviral, and adeno-associated viral vector mediated gene delivery.

  1. A retroviral mutagenesis screen reveals strong cooperation between Bcl11a overexpression and loss of the Nf1 tumor suppressor gene

    PubMed Central

    Yin, Bin; Delwel, Ruud; Valk, Peter J.; Wallace, Margaret R.; Loh, Mignon L.; Shannon, Kevin M.

    2009-01-01

    NF1 inactivation occurs in specific human cancers, including juvenile myelomonocytic leukemia, an aggressive myeloproliferative disorder of childhood. However, evidence suggests that Nf1 loss alone does not cause leukemia. We therefore hypothesized that inactivation of the Nf1 tumor suppressor gene requires cooperating mutations to cause acute leukemia. To search for candidate genes that cooperate with Nf1 deficiency in leukemogenesis, we performed a forward genetic screen using retroviral insertion mutagenesis in Nf1 mutant mice. We identified 43 common proviral insertion sites that contain candidate genes involved in leukemogenesis. One of these genes, Bcl11a, confers a growth advantage in cultured Nf1 mutant hematopoietic cells and causes early onset of leukemia of either myeloid or lymphoid lineage in mice when expressed in Nf1-deficient bone marrow. Bcl11a-expressing cells display compromised p21Cip1 induction, suggesting that Bcl11a's oncogenic effects are mediated, in part, through suppression of p21Cip1. Importantly, Bcl11a is expressed in human chronic myelomonocytic leukemia and juvenile myelomonocytic leukemia samples. A subset of AML patients, who had poor outcomes, of 16 clusters, displayed high levels of BCL11A in leukemic cells. These findings suggest that deregulated Bcl11a cooperates with Nf1 in leukemogenesis, and a therapeutic strategy targeting the BCL11A pathway may prove beneficial in the treatment of leukemia. PMID:18948576

  2. Critical Variables affecting clinical-grade production of the self-inactivating gamma-retroviral vector for the treatment of X-linked severe combined immunodeficiency

    PubMed Central

    van der Loo, JCM; Swaney, WP; Grassman, E; Terwilliger, A; Higashimoto, T; Schambach, A; Hacein-Bey-Abina, S; Nordling, DL; Cavazzana-Calvo, M; Thrasher, AJ; Williams, DA; Reeves, L; Malik, P

    2014-01-01

    Patients with X-linked severe combined immunodeficiency (SCID-X1) were successfully cured following gene therapy with a gamma-retroviral vector (gRV) expressing the common gamma chain of the interleukin-2 receptor (IL2RG). However, 5 of 20 patients developed leukemia from activation of cellular proto-oncogenes by viral enhancers in the long-terminal repeats (LTR) of the integrated vector. These events prompted the design of a gRV vector with self-inactivating (SIN) LTRs to enhance vector safety. Herein we report on the production of a clinical-grade SIN IL2RG gRV pseudotyped with the Gibbon Ape Leukemia Virus envelope for a new gene therapy trial for SCID-X1, and highlight variables that were found to be critical for transfection-based large-scale SIN gRV production. Successful clinical production required careful selection of culture medium without pre-added glutamine, reduced exposure of packaging cells to cell-dissociation enzyme, and presence of cations in wash buffer. The clinical vector was high titer; transduced 68–70% normal human CD34 + cells, as determined by colony-forming unit assays and by xenotransplantation in immunodeficient NOD.CB17-Prkdcscid/J (nonobese diabetic/severe combined immunodeficiency (NOD/SCID)) and NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ (NOD/SCID gamma (NSG))) mice; and resulted in the production of T cells in vitro from human SCID-X1 CD34 + cells. The vector was certified and released for the treatment of SCID-X1 in a multi-center international phase I/II trial. PMID:22551777

  3. MicroRNA 142-3p Attenuates Spread of Replicating Retroviral Vector in Hematopoietic Lineage-Derived Cells While Maintaining an Antiviral Immune Response

    PubMed Central

    Lin, Amy H.; Timberlake, Nina; Logg, Christopher R.; Liu, Yanzheng; Kamijima, Shuichi; Diago, Oscar; Wong, Kenneth; Gammon, Dawn K.; Ostertag, Derek; Hacke, Katrin; Yang, Emily C.; Gruber, Harry; Kasahara, Noriyuki

    2014-01-01

    Abstract We are developing a retroviral replicating vector (RRV) encoding cytosine deaminase as an anticancer agent for gliomas. Despite its demonstrated natural selectivity for tumors, and other safety features, such a virus could potentially cause off-target effects by productively infecting healthy tissues. Here, we investigated whether incorporation of a hematopoietic lineage-specific microRNA target sequence in RRV further restricts replication in hematopoietic lineage-derived human cells in vitro and in murine lymphoid tissues in vivo. One or four copies of a sequence perfectly complementary to the guide strand of microRNA 142-3p were inserted into the 3′ untranslated region of the RRV genome expressing the transgene encoding green fluorescent protein (GFP). Viral spread and GFP expression of these vectors in hematopoietic lineage cells in vitro and in vivo were measured by qPCR, qRT-PCR, and flow cytometry. In hematopoietic lineage-derived human cell lines and primary human stimulated peripheral blood mononuclear cells, vectors carrying the 142-3pT sequence showed a remarkable decrease in GFP expression relative to the parental vector, and viral spread was not observed over time. In a syngeneic subcutaneous mouse tumor model, RRVs with and without the 142-3pT sequences spread equally well in tumor cells; were strongly repressed in blood, bone marrow, and spleen; and generated antiviral immune responses. In an immune-deficient mouse model, RRVs with 142-3pT sequences were strongly repressed in blood, bone marrow, and spleen compared with unmodified RRV. Tissue-specific microRNA-based selective attenuation of RRV replication can maintain antiviral immunity, and if needed, provide an additional safeguard to this delivery platform for gene therapy applications. PMID:24825189

  4. The effect of neonatal gene therapy with a gamma retroviral vector on cardiac valve disease in mucopolysaccharidosis VII dogs after a decade.

    PubMed

    Bigg, Paul W; Sleeper, Meg M; O'Donnell, Patricia A; Liu, Yuli; Wu, Susan; Casal, Margret L; Haskins, Mark E; Ponder, Katherine P

    2013-11-01

    Mucopolysaccharidosis VII (MPS VII) is due to deficient activity of the lysosomal enzyme β-glucuronidase (GUSB) and results in the accumulation of glycosaminoglycans (GAGs). This study determined the long-term effect of neonatal intravenous injection of a gamma retroviral vector (RV) on cardiac valve disease in MPS VII dogs. Transduced hepatocytes secreted GUSB into the blood for up to 11 years at levels similar to or greater than those achieved with enzyme replacement therapy (ERT). Valve regurgitation and thickening were scored from 0 (normal) to +4 (severely abnormal). At 1 year, untreated MPS VII dogs had mitral regurgitation, mitral valve thickening, aortic regurgitation, and aortic valve thickening scores of 2.3 ± 0.7, 2.3 ± 0.6, 1.8 ± 0.5, and 1.6 ± 0.7, respectively, which were higher than the values of 0.6 ± 0.1, 0.1 ± 0.4, 0.3 ± 0.8, and 0.1 ± 0.4, respectively, in treated MPS VII dogs. Treated MPS VII dogs maintained low aortic regurgitation and aortic valve thickening scores in their lifetime. Although mitral regurgitation and mitral valve thickening scores increased to 2.0 at ≥ 8 years of age in the treated MPS VII dogs, older normal dogs from the colony had similar scores, making it difficult to assess mitral valve disease. Older treated dogs had calcification within the mitral and the aortic valve annulus, while GUSB staining demonstrated enzyme activity within the mitral valve. We conclude that neonatal RV-mediated gene therapy reduced cardiac valve disease in MPS VII dogs for up to 11 years, and propose that neonatal initiation of ERT should have a similar effect.

  5. Mutations of a residue within the polyproline-rich region of Env alter the replication rate and level of cytopathic effects in chimeric avian retroviral vectors.

    PubMed

    Chang, Kevin W; Barsov, Eugene V; Ferris, Andrea L; Hughes, Stephen H

    2005-08-01

    Previous attempts to extend the host range of the avian sarcoma/leukosis virus (ASLV)-based RCASBP vectors produced two viral vectors, RCASBP M2C (4070A) and RCASBP M2C (797-8), which replicate using the amphotropic murine leukemia virus 4070A Env protein (2). Both viruses were adapted to replicate efficiently in the avian cell line DF-1, but RCASBP M2C (4070A) caused extensive cytopathic effects (CPE) in DF-1 cells whereas RCASBP M2C (797-8) induced low levels of CPE. The two viruses differed only at amino acid 242 of the polyproline-rich region in the surface (SU) subunit of the Env protein. In RCASBP M2C (4070A), an isoleucine replaced the wild-type proline residue, whereas a threonine residue was found in RCASBP M2C (797-8). In the present study, we show that other amino acid substitutions at position 242 strongly influence the CPE and replication rate of the chimeric viruses. There was a correlation between the amount of unintegrated linear retroviral DNA present in infected DF-1 cells and the level of CPE. This suggests that there may be a role for superinfection in the CPE. The treatment of RCASBP M2C (4070A)-infected cells with dantrolene, which inhibits the release of calcium from the endoplasmic reticulum (ER), reduced the amount of CPE seen during infection with the highly cytotoxic virus. Dantrolene treatment did not appear to affect virus production, suggesting that Ca2+ release from the ER had a role in the CPE caused by these viruses.

  6. Integration of retroviral vectors induces minor changes in the transcriptional activity of T cells from ADA-SCID patients treated with gene therapy.

    PubMed

    Cassani, Barbara; Montini, Eugenio; Maruggi, Giulietta; Ambrosi, Alessandro; Mirolo, Massimiliano; Selleri, Silvia; Biral, Erika; Frugnoli, Ilaria; Hernandez-Trujillo, Vivian; Di Serio, Clelia; Roncarolo, Maria Grazia; Naldini, Luigi; Mavilio, Fulvio; Aiuti, Alessandro

    2009-10-22

    Gene transfer into hematopoietic stem cells by gamma-retroviral vectors (RVs) is an effective treatment for inherited blood disorders, although potentially limited by the risk of insertional mutagenesis. We evaluated the genomic impact of RV integration in T lymphocytes from adenosine deaminase-deficient severe combined immunodeficiency (ADA-SCID) patients 10 to 30 months after infusion of autologous, genetically corrected CD34(+) cells. Expression profiling on ex vivo T-cell bulk population revealed no difference with respect to healthy controls. To assess the effect of vector integration on gene expression at the single-cell level, primary T-cell clones were isolated from 2 patients. T-cell clones harbored either 1 (89.8%) or 2 (10.2%) vector copies per cell and displayed partial to full correction of ADA expression, purine metabolism, and T-cell receptor-driven functions. Analysis of RV integration sites indicated a high diversity in T-cell origin, consistently with the polyclonal T-cell receptor-Vbeta repertoire. Quantitative transcript analysis of 120 genes within a 200-kb window around RV integration sites showed modest (2.8- to 5.2-fold) dysregulation of 5.8% genes in 18.6% of the T-cell clones compared with controls. Nonetheless, affected clones maintained a stable phenotype and normal in vitro functions. These results confirm that RV-mediated gene transfer for ADA-SCID is safe, and provide crucial information for the development of future gene therapy protocols. The trials described herein have been registered at http://www.clinicaltrials.gov as #NCT00598481 and #NCT00599781.

  7. High efficiency retroviral mediated gene transduction into single isolated immature and replatable CD34(3+) hematopoietic stem/progenitor cells from human umbilical cord blood

    PubMed Central

    1993-01-01

    Umbilical cord blood is rich in hematopoietic stem and progenitor cells and has recently been used successfully in the clinic as an alternative source of engrafting and marrow repopulating cells. With the likelihood that cord blood stem/progenitor cells will be used for gene therapy to correct genetic disorders, we evaluated if a TK-neo gene could be directly transduced in a stable manner into single isolated subsets of purified immature hematopoietic cells that demonstrate self-renewed ability as estimated by colony replating capacity. Sorted CD34(3+) cells from cord blood were prestimulated with erythropoietin (Epo), steel factor (SLF), interleukin (IL)-3, and granulocyte-macrophage colony stimulating factor (GM-CSF) and transduced with the gene in two ways. CD34(3+) cells were incubated with retroviral-containing supernatant from TK-neo vector-producing cells, washed, and plated directly or resorted as CD34(3+) cells into single wells containing a single cell or 10 cells. Alternatively, CD34(3+) cells were sorted as a single cell/well and then incubated with viral supernatant. These cells were cultured with Epo, SLF, IL-3, and GM-CSF +/- G418. The TK-neo gene was introduced at very high efficiency into low numbers of or isolated single purified CD34(3+) immature hematopoietic cells without stromal cells as a source of virus or accessory cells. Proviral integration was detected in primary G418-resistant(R) colonies derived from single immature hematopoietic cells, and in cells from replated colonies derived from G418R-colony forming unit-granulocyte erythroid macrophage megakaryocyte (CFU-GEMM) and -high proliferative potential colony forming cells (HPP-CFC). This demonstrates stable expression of the transduced gene into single purified stem/progenitor cells with replating capacity, results that should be applicable for future clinical studies that may utilize selected subsets of stem/progenitor cells for gene therapy. PMID:7504056

  8. Nuclear Magnetic Resonance Based Profiling of Biofluids Reveals Metabolic Dysregulation in HIV-Infected Persons and Those on Anti-Retroviral Therapy

    PubMed Central

    Munshi, Saif Ullah; Rewari, Bharat Bhushan; Bhavesh, Neel Sarovar; Jameel, Shahid

    2013-01-01

    Background Although HIV causes immune deficiency by infection and depletion of immunocytes, metabolic alterations with clinical manifestations are also reported in HIV/AIDS patients. Here we aimed to profile metabolite changes in the plasma, urine, and saliva of HIV/AIDS patients, including those on anti-retroviral therapy (ART). Methods Metabolic profiling of biofluids collected from treatment naïve HIV/AIDS patients and those receiving ART was done with solution-state nuclear magnetic resonance (NMR) spectroscopy followed by statistical analysis and annotation. Results In Principal Component Analysis (PCA) of the NMR spectra, Principal Component 1 (PC1) alone accounted for 99.3%, 87.2% and 78.8% variations in plasma, urine, and saliva, respectively. Partial least squares discriminant analysis (PLS-DA) was applied to generate three-component models, which showed plasma and urine to be better than saliva in discriminating between patients and healthy controls, and between ART-naïve patients and those receiving therapy. Twenty-six metabolites were differentially altered in any or two types of samples. Our results suggest that urinary Neopterin, and plasma Choline and Sarcosine could be used as metabolic biomarkers of HIV/AIDS infection. Pathway analysis revealed significant alternations in 12 metabolic pathways. Conclusions This study catalogs differentially regulated metabolites in biofluids, which helped classify subjects as healthy controls, HIV/AIDS patients, and those on ART. It also underscores the importance of further studying the consequences of HIV infection on host metabolism and its implications for pathogenesis. PMID:23696880

  9. Effects of UVA1 Phototherapy on Expression of Human Endogenous Retroviral Sequence (HERV)-K10 gag in Morphea: A Preliminary Study

    PubMed Central

    Kowalczyk, Michał Jacek; Teresiak-Mikołajczak, Ewa; Dańczak-Pazdrowska, Aleksandra; Żaba, Ryszard; Adamski, Zygmunt; Osmola-Mańkowska, Agnieszka

    2017-01-01

    Background Morphea, also known as localized scleroderma, is a rare autoimmune connective tissue disease characterized by skin fibrosis. UVA1 phototherapy is an important asset in the reduction of clinical manifestations in morphea. There are studies claiming that UV light modulates the expression of some human endogenous retroviral sequences. The aim of this study was to determine if the expression of HERV-K10 gag element is lowered by UVA1 phototherapy in morphea, a disease in which such irradiation has a soothing effect. Material/Methods The expression levels of the HERV-K10 gag were assessed by real-time PCR (polymerase chain reaction) in peripheral blood mononuclear cells (PBMC) and skin-punch biopsies of healthy volunteers and 9 morphea patients before and after phototherapy. Additionally, correlations between the HERV-K10 gag expression and age, disease duration, the Localized Scleroderma Skin Severity Index (LoSSI), and antinuclear antibody (ANA) titers were assessed. Results In PBMC, HERV-K10 gag mRNA was significantly elevated after UVA1 phototherapy compared to healthy controls. Most of the patients responded with an increased expression level of this sequence. However, we found no statistical evidence at this point that phototherapy indeed has an effect on the HERV-K10 gag expression (there were no statistical differences in PBMC of morphea patients before and after phototherapy). Similarly, there was no statistically relevant effect of the UVA1 on the expression of HERV-K10 gag in skin. Conclusions At this point, the effect of UVA1 phototherapy on the expression of HERV-K10 gag cannot be statistically confirmed. PMID:28130554

  10. Lineage Analysis of the Late Otocyst Stage Mouse Inner Ear by Transuterine Microinjection of A Retroviral Vector Encoding Alkaline Phosphatase and an Oligonucleotide Library

    PubMed Central

    Jiang, Han; Wang, Lingyan; Beier, Kevin T.; Cepko, Constance L.; Fekete, Donna M.; Brigande, John V.

    2013-01-01

    The mammalian inner ear subserves the special senses of hearing and balance. The auditory and vestibular sensory epithelia consist of mechanically sensitive hair cells and associated supporting cells. Hearing loss and balance dysfunction are most frequently caused by compromise of hair cells and/or their innervating neurons. The development of gene- and cell-based therapeutics will benefit from a thorough understanding of the molecular basis of patterning and cell fate specification in the mammalian inner ear. This includes analyses of cell lineages and cell dispersals across anatomical boundaries (such as sensory versus nonsensory territories). The goal of this study was to conduct retroviral lineage analysis of the embryonic day 11.5(E11.5) mouse otic vesicle. A replication-defective retrovirus encoding human placental alkaline phosphatase (PLAP) and a variable 24-bp oligonucleotide tag was microinjected into the E11.5 mouse otocyst. PLAP-positive cells were microdissected from cryostat sections of the postnatal inner ear and subjected to nested PCR. PLAP-positive cells sharing the same sequence tag were assumed to have arisen from a common progenitor and are clonally related. Thirty five multicellular clones consisting of an average of 3.4 cells per clone were identified in the auditory and vestibular sensory epithelia, ganglia, spiral limbus, and stria vascularis. Vestibular hair cells in the posterior crista were related to one another, their supporting cells, and nonsensory epithelial cells lining the ampulla. In the organ of Corti, outer hair cells were related to a supporting cell type and were tightly clustered. By contrast, spiral ganglion neurons, interdental cells, and Claudius' cells were related to cells of the same type and could be dispersed over hundreds of microns. These data contribute new information about the developmental potential of mammalian otic precursors in vivo. PMID:23935981

  11. Extensive Replication of a Retroviral Replicating Vector Can Expand the A Bulge in the Encephalomyocarditis Virus Internal Ribosome Entry Site and Change Translation Efficiency of the Downstream Transgene.

    PubMed

    Lin, Amy H; Liu, Yanzheng; Burrascano, Cynthia; Cunanan, Kathrina; Logg, Christopher R; Robbins, Joan M; Kasahara, Noriyuki; Gruber, Harry; Ibañez, Carlos; Jolly, Douglas J

    2016-04-01

    We have developed retroviral replicating vectors (RRV) derived from Moloney murine gammaretrovirus with an amphotropic envelope and an encephalomyocarditis virus (EMCV) internal ribosome entry site (IRES)-transgene cassette downstream of the env gene. During long-term (180 days) replication of the vector in animals, a bulge of 7 adenosine residues (A's) in the J-K bifurcation domain sometimes serially added A's. Therefore, vectors with 4-12 A's in the A bulge in the J-K bifurcation domain were generated, and the impact of the variants on transgene protein expression, vector stability, and IRES sequence upon multiple infection cycles was assessed in RRV encoding yeast-derived cytosine deaminase and green fluorescent protein in vitro. For transgene protein expression, after multiple infection cycles, RRV-IRES with 5-7 A's gave roughly comparable levels, 4 and 8 A's were within about 4-5-fold of the 6 A's, whereas 10 and 12 A's were marked lower. In terms of stability, after 10 infection cycles, expansion of A's appeared to be a more frequent event affecting transgene protein expression than viral genome deletions or rearrangement: 4 and 5 A's appeared completely stable; 6, 7, and particularly 8 A's showed some level of expansion in the A bulge; 10 and 12 A's underwent both expansion and transgene deletion. The strong relative translational activity of the 5 A's in the EMCV IRES has not been reported previously. The 5A RRV-IRES may have utility for preclinical and clinical applications where extended replication is required.

  12. Prevalence of renal disease in Nigerian children infected with the human immunodeficiency virus and on highly active anti-retroviral therapy.

    PubMed

    Iduoriyekemwen, Nosakhare J; Sadoh, Wilson E; Sadoh, Ayebo E

    2013-01-01

    Access to highly active anti-retroviral therapy (HAART) has improved the prognosis of Nigerian children infected with the human immunodeficiency virus (HIV); thus, more children are surviving. Long-term exposure to HAART is potentially nephrotoxic. We therefore aimed at assessing the prevalence of renal disease in Nigerian children infected with HIV, who are on HAART. In this cross-sectional study, we studied children, aged ten months to 17 years, infected with HIV, attending the pediatric HIV clinics of the University of Benin Teaching Hospital. Demographic and clinical data were obtained by parental interview as well as from the medical records. Each child's urine was tested for albumin and microalbuminuria using multi test strips and mitral test strips, respectively. The serum creatinine level of each child was also estimated and used in calculating the glomerular filtration rate (GFR). Renal disease was defined as the presence of significant proteinuria of 1+ and above on dipstick or the presence of microalbuminuria of ≥20 mg and/or GFR <60 mL/min/1.73 m 2 . Of the 99 children recruited, 60 were males and 39 were females. The mean age of the children was 6.6 ± 3.5 years. All the children were on HAART and 85% had acquired the HIV infection by vertical transmission. The overall prevalence of renal disease was 16.2%. Microalbuminuria was seen in 11 children with renal disease (11.1%); 3 of them had significant proteinuria. GFR of less than 60 mL/min/1.73 m 2 was seen in five children (5.1%) with renal disease, but none had end-stage renal disease (GFR less than 15 mL/min/1.73 m 2 ). Renal disease was found to be significantly associated with advanced stage of HIV infection (P < 0.049). Our study showed that t he prevalence of renal disease in HAART-treated Nigerian children is high and majority of them are asymptomatic of renal disease, but in the advanced stages of HIV infection.

  13. Genome-Wide Screening of Retroviral Envelope Genes in the Nine-Banded Armadillo (Dasypus novemcinctus, Xenarthra) Reveals an Unfixed Chimeric Endogenous Betaretrovirus Using the ASCT2 Receptor

    PubMed Central

    Malicorne, Sébastien; Vernochet, Cécile; Cornelis, Guillaume; Mulot, Baptiste; Delsuc, Frédéric; Heidmann, Odile

    2016-01-01

    ABSTRACT Retroviruses enter host cells through the interaction of their envelope (Env) protein with a cell surface receptor, which triggers the fusion of viral and cellular membranes. The sodium-dependent neutral amino acid transporter ASCT2 is the common receptor of the large RD114 retrovirus interference group, whose members display frequent env recombination events. Germ line retrovirus infections have led to numerous inherited endogenous retroviruses (ERVs) in vertebrate genomes, which provide useful insights into the coevolutionary history of retroviruses and their hosts. Rare ERV-derived genes display conserved viral functions, as illustrated by the fusogenic syncytin env genes involved in placentation. Here, we searched for functional env genes in the nine-banded armadillo (Dasypus novemcinctus) genome and identified dasy-env1.1, which clusters with RD114 interference group env genes and with two syncytin genes sharing ASCT2 receptor usage. Using ex vivo pseudotyping and cell-cell fusion assays, we demonstrated that the Dasy-Env1.1 protein is fusogenic and can use both human and armadillo ASCT2s as receptors. This gammaretroviral env gene belongs to a provirus with betaretrovirus-like features, suggesting acquisition through recombination. Provirus insertion was found in several Dasypus species, where it has not reached fixation, whereas related family members integrated before diversification of the genus Dasypus >12 million years ago (Mya). This newly described ERV lineage is potentially useful as a population genetic marker. Our results extend the usage of ASCT2 as a retrovirus receptor to the mammalian clade Xenarthra and suggest that the acquisition of an ASCT2-interacting env gene is a major selective force driving the emergence of numerous chimeric viruses in vertebrates. IMPORTANCE Retroviral infection is initiated by the binding of the viral envelope glycoprotein to a host cell receptor(s), triggering membrane fusion. Ancient germ line infections

  14. Refractory anemia in human immunodeficiency virus: Expect the unexpected.

    PubMed

    Mirgh, Sumeet Prakash; Mishra, Vikas A; Shah, Virti D; Sorabjee, Jehangir Soli

    2016-01-01

    Pure red cell aplasia (PRCA) is an uncommon hematological disorder affecting selectively the erythroid cell lines. PRCA is defined as anemia with normal leukocyte and platelet counts, a corrected reticulocyte count <1%, <5% erythroid precursors in the bone marrow and an absence of hemolysis. We describe a case of Zidovudine (AZT) induced PRCA causing severe anemia in a patient taking antiretroviral therapy (ART) after 4 months of starting therapy and in whom all other causes were excluded. The hematological abnormalities resolved after AZT was replaced with tenofovir and the patient remained transfusion independent thereafter. A slowly progressive normocytic-normochromic anemia and reticulocytopenia, without leukopenia and thrombocytopenia in a patient, should raise the suspicion of PRCA. Search for underlying diseases, infections and drugs may help in the diagnosis and etiology of acquired PRCA. Elimination of potentially causative factors may induce complete recovery. AZT is a well-known cause of anemia and thus should be used with caution in the initiation of ART.

  15. Optimization of gene transfer into primitive human hematopoietic cells of granulocyte-colony stimulating factor-mobilized peripheral blood using low-dose cytokines and comparison of a gibbon ape leukemia virus versus an RD114-pseudotyped retroviral vector.

    PubMed

    van der Loo, Johannes C M; Liu, B L; Goldman, A I; Buckley, S M; Chrudimsky, K S

    2002-07-20

    Primitive human hematopoietic cells in granulocyte-colony stimulating factor (G-CSF)-mobilized peripheral blood (MPB) are more difficult to transduce compared to cells from umbilical cord blood. Based on the hypothesis that MPB cells may require different stimulation for efficient retroviral infection, we compared several culture conditions known to induce cycling of primitive hematopoietic cells. MPB-derived CD34(+) cells were stimulated in the presence or absence of the murine fetal liver cell line AFT024 in trans-wells with G-CSF, stem cell factor (SCF), and thrombopoietin (TPO) (G/S/T; 100 ng/ml) or Flt3-L, SCF, interleukin (IL)-7, and TPO (F/S/7/T; 10-20 ng/ml), and transduced using a GaLV-pseudotyped retroviral vector expressing the enhanced green fluorescence protein (eGFP). Compared to cultures without stroma, the presence of AFT024 increased the number of transduced colony-forming cells (CFC) by 3.5-fold (with G/S/T), long-term culture-initiating cells (LTC-IC) by 4.6-fold (with F/S/7/T), and nonobese diabetic/severe immunodeficiency disease (NOD/SCID)-repopulating cells (SRC) by 6.8-fold (with F/S/7/T). Similar numbers of long-term culture-initiating cells (LTC-IC) and SRC could be transduced using AFT024-conditioned medium (AFT-CM) or a defined medium that had been supplemented with factors identified in AFT-CM. Finally, using our best condition based on transduction with the gibbon ape leukemia virus (GaLV)-pseudotyped vector, we demonstrate a 33-fold higher level of gene transfer (p < 0.001) in SRC using an RD114-pseudotyped vector. In summary, using an optimized protocol with low doses of cytokines, and transduction with an RD114 compared to a GaLV-pseudotyped retroviral vector, the overall number of transduced cells in NOD/SCID mice could be improved 144-fold, with a gene-transfer efficiency in SRC of 16.3% (13.3-19.9; n = 6).

  16. HIV-1 and HIV-2 LTR nucleotide sequences: assessment of the alignment by N-block presentation, "retroviral signatures" of overrepeated oligonucleotides, and a probable important role of scrambled stepwise duplications/deletions in molecular evolution.

    PubMed

    Laprevotte, I; Pupin, M; Coward, E; Didier, G; Terzian, C; Devauchelle, C; Hénaut, A

    2001-07-01

    Previous analyses of retroviral nucleotide sequences, suggest a so-called "scrambled duplicative stepwise molecular evolution" (many sectors with successive duplications/deletions of short and longer motifs) that could have stemmed from one or several starter tandemly repeated short sequence(s). In the present report, we tested this hypothesis by focusing on the long terminal repeats (LTRs) (and flanking sequences) of 24 human and 3 simian immunodeficiency viruses. By using a calculation strategy applicable to short sequences, we found consensus overrepresented motifs (often containing CTG or CAG) that were congruent with the previously defined "retroviral signature." We also show many local repetition patterns that are significant when compared with simply shuffled sequences. First- and second-order Markov chain analyses demonstrate that a major portion of the overrepresented oligonucleotides can be predicted from the dinucleotide compositions of the sequences, but by no means can biological mechanisms be deduced from these results: some of the listed local repetitions remain significant against dinucleotide-conserving shuffled sequences; together with previous results, this suggests that interspersed and/or local mononucleotide and oligonucleotide repetitions could have biased the dinucleotide compositions of the sequences. We searched for suggestive evolutionary patterns by scrutinizing a reliable multiple alignment of the 27 sequences. A manually constructed alignment based on homology blocks was in good agreement with the polypeptide alignment in the coding sectors and has been exhaustively assessed by using a multiplied alphabet obtained by the promising mathematical strategy called the N-block presentation (taking into account the environment of each nucleotide in a sequence). Sector by sector, we hypothesize many successive duplication/deletion scenarios that fit our previous evolutionary hypotheses. This suggests an important duplication/deletion role for

  17. Poly(ethylene glycol) enclatherated pectin-mucin submicron matrices for intravaginal anti-HIV-1 drug delivery.

    PubMed

    Mashingaidze, Felix; Choonara, Yahya E; Kumar, Pradeep; du Toit, Lisa C; Maharaj, Vinesh; Buchmann, Eckhart; Pillay, Viness

    2016-04-30

    This paper explores the potential of polyethylene glycol enclatherated pectin-mucin (PEG-encl-PEC:MUC) submicron matrices (SMMs) as an intravaginal drug delivery system capable of delivering an anti-HIV-1 agent (zidovudine; AZT) over a prolonged duration. A three factor and three level (3(3)) Box-Behnken statistical design was employed to optimize the SMMs. Optimized PEG-encl-PEC:MUC SMMs prepared as a stable W/O emulsion (determined by the degree of reversible colloidal phenomena) were spherical with a mean particle size of 270.6 ± 5.533 nm and mean zeta potential of -34.4 ± 0.539 mV. The microencapsulation of AZT and the hydrogen bonding mediated shielding of AZT by SMMs was confirmed by Fourier Transform Infrared (FTIR) analysis. The thermochemical (differential scanning calorimetry and thermogravimetric analysis) data proposed that Ca(2+)-based macromolecular ionic crosslinking as well as the intermolecular interactions may be responsible for the thermal stability of the delivery system. The partially amorphous nature of drug-loaded SMMs, as confirmed by X-ray diffraction patterns, further strengthened the matricization of AZT into the pectin-mucin matrix. In vitro drug release studies from the SMMs showed approximately 91% zidovudine release in simulated vaginal fluid (SVF) and 94% in phosphate buffered saline (PBS) in 24h. The mean dissolution time (MDT) of zidovudine from the SMMs was 5.974 h. The attainment of required dimensional structure and drug release profiles from SMMs highlights the potential of their inclusion into a secondary carrier system for extended and controlled intravaginal stay.

  18. Synthesis and evaluation of sulfonylethyl-containing phosphotriesters of 3'-azido-3'-deoxythymidine as anticancer prodrugs.

    PubMed

    Wang, Jiang; Wang, Yi-Jun; Chen, Zhe-Sheng; Kwon, Chul-Hoon

    2014-11-01

    A series of bis(sulfonylethyl) and mono(sulfonylethyl) phenyl phosphotriesters of zidovudine (3'-azido-3'-deoxythymidine, AZT) were synthesized as potential anticancer prodrugs that liberate AZT monophosphate via nonenzymatic β-elimination mechanism. Stability studies demonstrated that all the synthesized prodrugs spontaneously liberate AZT monophosphate with half-lives in the range of 0.07-278.8h under model physiological conditions in 0.1M phosphate buffer at pH 7.4 and 37 °C. Analogous to aldophosphamide, the elimination rates were accelerated in the presence of reconstituted human plasma under the same conditions. Among the compounds, 3, 4, 8, and 10 were comparable or superior to AZT against five established human cancerous cell lines in vitro. Moreover, the selected compounds were equally sensitive to both the wild-type osteosarcoma 143 B and the thymidine kinase-deficient 143 B/TK(-) cell lines. The findings are consistent with that these compounds deliver AZT monophosphate intracellularly.

  19. Economic evaluation of 3-drug antiretroviral regimens for the prevention of mother-to-child HIV transmission in Thailand.

    PubMed

    Werayingyong, Pitsaphun; Phanuphak, Nittaya; Chokephaibulkit, Kulkunya; Tantivess, Sripen; Kullert, Nareeluk; Tosanguan, Kakanang; Butchon, Rukmanee; Voramongkol, Nipunporn; Boonsuk, Sarawut; Pilasant, Songyot; Kulpeng, Wantanee; Teerawattananon, Yot

    2015-03-01

    The current program for prevention of mother-to-child HIV transmission in Thailand recommends a 2-drugs regimen for HIV-infected pregnant women with a CD4 count >200 cells/mm(3). This study assesses the value for money of 3 antiretroviral drugs compared with zidovudine (AZT)+single-dose nevirapine (sd-NVP). A decision tree was constructed to predict costs and outcomes using the governmental perspective for assessing cost-effectiveness of 3-drug regimens: (1) AZT, lamivudine, and efavirenz and (2) AZT, 3TC, and lopinavir/ritonavir, in comparison with the current protocol, AZT+sd-NVP. The 3-drug antiretroviral regimens yield lower costs and better health outcomes compared with AZT+sd-NVP. Although these 3-drug regimens offer higher program costs and health care costs for premature birth, they save money significantly in regard to pediatric HIV treatment and treatment costs for drug resistance in mothers. The 3-drug regimens are cost-saving interventions. The findings from this study were used to support a policy change in the national recommendation.

  20. Mitochondrial and metabolic effects of nucleoside reverse transcriptase inhibitors (NRTIs) in mice receiving one of five single- and three dual-NRTI treatments.

    PubMed

    Note, Reine; Maisonneuve, Caroline; Lettéron, Philippe; Peytavin, Gilles; Djouadi, Fatima; Igoudjil, Anissa; Guimont, Marie-Christine; Biour, Michel; Pessayre, Dominique; Fromenty, Bernard

    2003-11-01

    Although treatments with nucleoside reverse transcriptase inhibitors (NRTIs) can modify fat metabolism and fat distribution in humans, the mechanisms of these modifications and the roles of diverse NRTIs are unknown. We studied the mitochondrial and metabolic effects of stavudine (d4T), zidovudine (AZT), didanosine (ddI), lamivudine (3TC), zalcitabine (ddC), and three combinations (AZT-3TC, d4T-3TC, and d4T-ddI) in mice treated for 2 weeks with daily doses equivalent to the human dose per body area. Concentrations of AZT and d4T in plasma were lower when these drugs were administered with 3TC or ddI. Whatever the treatment, mitochondrial DNA was not significantly decreased in muscle, heart, brain, or white adipose tissue but was moderately decreased in liver tissue after the administration of AZT, 3TC, or d4T alone. Blood lactate was unchanged, even when NRTIs were administered at supratherapeutic doses. In contrast, the level of plasma ketone bodies increased with the administration of AZT or high doses of d4T but not with ddC, 3TC, or ddI, suggesting that the thymine moiety could be involved. Indeed, the levels of plasma ketone bodies increased in mice treated with beta-aminoisobutyric acid, a thymine catabolite. Treatment with AZT, d4T, or beta-aminoisobutyric acid increased hepatic carnitine palmitoyltransferase I (CPT-I) mRNA expression and the mitochondrial generation of ketone bodies from palmitate. In conclusion, therapeutic doses of NRTIs have no or moderate effects on mitochondrial DNA and no effects on plasma lactate in mice. However, AZT and high doses of d4T increase the levels of hepatic CPT-I, mitochondrial fatty acid beta-oxidation, and ketone bodies, and these catabolic effects are reproduced by beta-aminoisobutyric acid, a thymine metabolite.

  1. The development of antiretroviral therapy and its impact on the HIV-1/AIDS pandemic

    PubMed Central

    Broder, Samuel

    2010-01-01

    In the last 25 years, HIV-1, the retrovirus responsible for the Acquired Immunodeficiency Syndrome (AIDS), has gone from being an “inherently untreatable” infectious agent to one eminently susceptible to a range of approved therapies. During a five-year period, starting in the mid-1980s, my group at the National Cancer Institute played a role in the discovery and development of the first generation of antiretroviral agents, starting in 1985 with Retrovir® (zidovudine, AZT) in a collaboration with scientists at the Burroughs-Wellcome Company (now GlaxoSmithKline). We focused on AZT and related congeners in the dideoxynucleoside family of nucleoside reverse transcriptase inhibitors (NRTIs), taking them from the laboratory to the clinic in response to the pandemic of AIDS, then a terrifying and lethal disease. These drugs proved, above all else, that HIV-1 infection is treatable, and such proof provided momentum for new therapies from many sources, directed at a range of viral targets, at a pace that has rarely if ever been matched in modern drug development. Antiretroviral therapy has brought about a substantial decrease in the death rate due to HIV-1 infection, changing it from a rapidly lethal disease into a chronic manageable condition, compatible with very long survival. This has special implications within the classic boundaries of public health around the world, but at the same time in certain regions may also affect a cycle of economic and civil instability in which HIV-1/AIDS is both cause and consequence. Many challenges remain, including 1.) the life-long duration of therapy; 2.) the ultimate role of pre-exposure prophylaxis (PrEP); 3.) the cardiometabolic side effects or other toxicities of long-term therapy; 4.) the emergence of drug-resistance and viral genetic diversity (non-B subtypes); 5.) the specter of new cross-species transmissions from established retroviral reservoirs in apes and Old World monkeys; and 6.) the continued pace of new HIV-1

  2. Development of a hamster kidney cell line expressing stably T7 RNA polymerase using retroviral gene transfer technology for efficient rescue of infectious foot-and-mouth disease virus.

    PubMed

    Zheng, Haixue; Tian, Hong; Jin, Ye; Wu, Jinyan; Shang, Youjun; Yin, Shuanghui; Liu, Xiangtao; Xie, Qingge

    2009-03-01

    Reverse genetics systems, with the ability to manipulate viral genomes at the DNA molecular level, are an important platform for study of the assembly and function of viruses. Genome manipulation, such as gene recombination, mosaicism, and mutation may interfere with replication, assembly and release of viruses. An efficient, convenient and economical method of virus rescue is undoubtedly required for increasing the efficiency of rescuing recombinant viruses. To develop an efficient, helper virus-free viral recovery system (reverse genetics), a retroviral gene transfer technology was used to establish a stable BHK-21 cell line (designated as BHKT7) which expressed constitutively bacteriophage T7 RNA polymerase (T7 RNAP). An improved method for rescue of infectious foot-and-mouth disease virus (FMDV) was then developed. FMDV full-length cDNA under control of a T7 promotor, was transfected into BHKT7 of differing passages. FMDV virus was rescued efficiently from the BHKT7 cells, the passage number not having an effect on the efficiency of recovery. As a result, the cell line was stable even after multiple passages, expressing sufficient T7 RNAP to support ex vivo transcription and efficient rescue. The reverse genetics system described below is efficient, stable, and convenient. The system could provide not only the basis of gene function research into FMDV, but could also be used for reverse genetics research into other positive-strand RNA viruses, without the need for helper viruses.

  3. EMdeCODE: a novel algorithm capable of reading words of epigenetic code to predict enhancers and retroviral integration sites and to identify H3R2me1 as a distinctive mark of coding versus non-coding genes

    PubMed Central

    Santoni, Federico Andrea

    2013-01-01

    Existence of some extra-genetic (epigenetic) codes has been postulated since the discovery of the primary genetic code. Evident effects of histone post-translational modifications or DNA methylation over the efficiency and the regulation of DNA processes are supporting this postulation. EMdeCODE is an original algorithm that approximate the genomic distribution of given DNA features (e.g. promoter, enhancer, viral integration) by identifying relevant ChIPSeq profiles of post-translational histone marks or DNA binding proteins and combining them in a supermark. EMdeCODE kernel is essentially a two-step procedure: (i) an expectation-maximization process calculates the mixture of epigenetic factors that maximize the Sensitivity (recall) of the association with the feature under study; (ii) the approximated density is then recursively trimmed with respect to a control dataset to increase the precision by reducing the number of false positives. EMdeCODE densities improve significantly the prediction of enhancer loci and retroviral integration sites with respect to previous methods. Importantly, it can also be used to extract distinctive factors between two arbitrary conditions. Indeed EMdeCODE identifies unexpected epigenetic profiles specific for coding versus non-coding RNA, pointing towards a new role for H3R2me1 in coding regions. PMID:23234700

  4. Pulmonary function in an international sample of HIV-positive, treatment-naïve adults with CD4 counts >500 cells/μL: a substudy of the INSIGHT Strategic Timing of AntiRetroviral Treatment trial

    PubMed Central

    KUNISAKI, Ken M.; NIEWOEHNER, Dennis E.; COLLINS, Gary; NIXON, Daniel E.; TEDALDI, Ellen; AKOLO, Christopher; KITYO, Cissy; KLINKER, Hartwig; LA ROSA, Alberto; CONNETT, John E.

    2014-01-01

    Objectives To describe the prevalence and correlates of chronic obstructive pulmonary disease (COPD) in a multicentre international cohort of persons living with HIV (PLWH). Methods We performed a cross-sectional analysis of adult PLWH, naïve to HIV treatment, with baseline CD4 cell count >500 cells/μL enrolled in the Pulmonary Substudy of the Strategic Timing of AntiRetroviral Treatment trial. We collected standardised, quality-controlled spirometry. COPD was defined as forced expiratory volume in one second/forced vital capacity (FEV1/FVC) ratio less than the lower limit of normal. Results Among 1026 participants from 80 sites and 20 countries, median (IQR) age was 36 (30, 44) years, 29% were female, and time since HIV diagnosis was 1.2 (0.4, 3.5) years. Baseline CD4 cell count was 648 (583, 767) cells/μL, viral load was 4.2 (3.5, 4.7) log10 copies/mL, and 10% had viral load ≤400 copies/mL despite lack of HIV treatment. Current/former/never smokers comprised 28%/11%/61% of the cohort, respectively. COPD was present in 6.8% of participants, and varied by age, smoking status, and region. 48% of those with COPD reported lifelong nonsmoking. In multivariable regression, age and pack-years of smoking had the strongest associations with FEV1/FVC ratio (p<0.0001). There were significant differences between the effect of region on FEV1/FVC ratio (p=0.010). Conclusions Our data suggest that among PLWH, naïve to HIV treatment and with CD4 cell count >500 cells/μL, smoking and age are important factors related to COPD. Smoking cessation should remain a high global priority for clinical care and research in PLWH. PMID:25711330

  5. An Inducible Retroviral Expression System for Tandem Affinity Purification Mass-Spectrometry-Based Proteomics Identifies Mixed Lineage Kinase Domain-like Protein (MLKL) as an Heat Shock Protein 90 (HSP90) Client.

    PubMed

    Bigenzahn, Johannes W; Fauster, Astrid; Rebsamen, Manuele; Kandasamy, Richard K; Scorzoni, Stefania; Vladimer, Gregory I; Müller, André C; Gstaiger, Matthias; Zuber, Johannes; Bennett, Keiryn L; Superti-Furga, Giulio

    2016-03-01

    Tandem affinity purification-mass spectrometry (TAP-MS) is a popular strategy for the identification of protein-protein interactions, characterization of protein complexes, and entire networks. Its employment in cellular settings best fitting the relevant physiology is limited by convenient expression vector systems. We developed an easy-to-handle, inducible, dually selectable retroviral expression vector allowing dose- and time-dependent control of bait proteins bearing the efficient streptavidin-hemagglutinin (SH)-tag at their N- or C termini. Concomitant expression of a reporter fluorophore allows to monitor bait-expressing cells by flow cytometry or microscopy and enables high-throughput phenotypic assays. We used the system to successfully characterize the interactome of the neuroblastoma RAS viral oncogene homolog (NRAS) Gly12Asp (G12D) mutant and exploited the advantage of reporter fluorophore expression by tracking cytokine-independent cell growth using flow cytometry. Moreover, we tested the feasibility of studying cytotoxicity-mediating proteins with the vector system on the cell death-inducing mixed lineage kinase domain-like protein (MLKL) Ser358Asp (S358D) mutant. Interaction proteomics analysis of MLKL Ser358Asp (S358D) identified heat shock protein 90 (HSP90) as a high-confidence interacting protein. Further phenotypic characterization established MLKL as a novel HSP90 client. In summary, this novel inducible expression system enables SH-tag-based interaction studies in the cell line proficient for the respective phenotypic or signaling context and constitutes a valuable tool for experimental approaches requiring inducible or traceable protein expression.

  6. An Inducible Retroviral Expression System for Tandem Affinity Purification Mass-Spectrometry-Based Proteomics Identifies Mixed Lineage Kinase Domain-like Protein (MLKL) as an Heat Shock Protein 90 (HSP90) Client*

    PubMed Central

    Bigenzahn, Johannes W.; Fauster, Astrid; Rebsamen, Manuele; Kandasamy, Richard K.; Scorzoni, Stefania; Vladimer, Gregory I.; Müller, André C.; Gstaiger, Matthias; Zuber, Johannes; Bennett, Keiryn L.; Superti-Furga, Giulio

    2016-01-01

    Tandem affinity purification–mass spectrometry (TAP-MS) is a popular strategy for the identification of protein–protein interactions, characterization of protein complexes, and entire networks. Its employment in cellular settings best fitting the relevant physiology is limited by convenient expression vector systems. We developed an easy-to-handle, inducible, dually selectable retroviral expression vector allowing dose- and time-dependent control of bait proteins bearing the efficient streptavidin-hemagglutinin (SH)-tag at their N- or C termini. Concomitant expression of a reporter fluorophore allows to monitor bait-expressing cells by flow cytometry or microscopy and enables high-throughput phenotypic assays. We used the system to successfully characterize the interactome of the neuroblastoma RAS viral oncogene homolog (NRAS) Gly12Asp (G12D) mutant and exploited the advantage of reporter fluorophore expression by tracking cytokine-independent cell growth using flow cytometry. Moreover, we tested the feasibility of studying cytotoxicity-mediating proteins with the vector system on the cell death-inducing mixed lineage kinase domain-like protein (MLKL) Ser358Asp (S358D) mutant. Interaction proteomics analysis of MLKL Ser358Asp (S358D) identified heat shock protein 90 (HSP90) as a high-confidence interacting protein. Further phenotypic characterization established MLKL as a novel HSP90 client. In summary, this novel inducible expression system enables SH-tag-based interaction studies in the cell line proficient for the respective phenotypic or signaling context and constitutes a valuable tool for experimental approaches requiring inducible or traceable protein expression. PMID:26933192

  7. Theoretical and experimental studies of the stability of drug-drug interact

    NASA Astrophysics Data System (ADS)

    Soares, Monica F. R.; Alves, Lariza D. S.; Nadvorny, Daniela; Soares-Sobrinho, José L.; Rolim-Neto, Pedro J.

    2016-11-01

    Several factors can intervene in the molecular properties and consequently in the stability of drugs. The molecular complexes formation often occur due to favor the formation of hydrogen bonds, leading the system to configuration more energy stable. This work we aim to investigate through theoretical and experimental methods the relation between stability and properties of molecular complexes the molecular complex formed between the drugs, efavirenz (EFV), lamivudine (3TC) and zidovudine (AZT). With this study was possible determining the most stable complex formed between the compounds evaluated. In addition the energy and structural properties of the complex formed in relation to its individual components allowed us to evaluate the stability of the same.

  8. Anti-retroviral Therapy Based HIV Prevention Among a Sample of Men Who Have Sex with Men in Cape Town, South Africa: Use of Post-exposure Prophylaxis and Knowledge on Pre-exposure Prophylaxis.

    PubMed

    Hugo, J M; Stall, R D; Rebe, K; Egan, J E; De Swardt, G; Struthers, H; McIntyre, J A

    2016-12-01

    Men who have Sex with Men (MSM) have been affected disproportionately by the global HIV pandemic. Rates of consistent condom-use are low and there is a need for further biomedical prevention interventions to prevent new HIV infections. Post exposure prophylaxis (PEP) can reduce the risk of HIV, but uptake among MSM is low. Pre-exposure prophylaxis (PrEP), an innovative anti-retroviral-based HIV prevention tool might be an appropriate intervention for MSM who have recently accessed PEP that involves HIV negative individuals taking daily tenofovir+emtricitabine for HIV prevention. 44 MSM, attending a primary health-care level MSM-focused sexual health clinic in Cape Town, South Africa, who had initiated PEP were enrolled in this study. Participants were followed up after 2, 4 and 12 weeks. Self-administered electronic surveys were completed at the initial, 4 and 12 week visit. Barriers and facilitators to accessing PEP and remaining adherent were examined, as was knowledge about PrEP. Thirty-two participants (80 %) were <40 years of age (range 20-65 years). 35 % of the participants reported their reason for requiring PEP as condomless receptive anal intercourse. A further 20 % required PEP following condomless penetrative anal intercourse; 27.5 % required PEP due to a broken condom during receptive anal sex and 2 participants during insertive anal sex. Three participants did not complete 28 days of PEP or were lost to follow up. Over half (58.5 %) of the participants reported being completely adherent to their regime; under a third (31.7 %) reported missing one PEP dose; and 9.8 % reported missing more than one dose. 36/40 (90 %) had heard of PrEP and 30/40 (75 %) indicated that they would use PrEP if it were accessible to them. That we enrolled 44 MSM who accessed PEP from a Department of Health affiliated clinic over 12 months, speaks to the low uptake by MSM of PEP services in South Africa. Adherence was high and demonstrates that adherence

  9. The test of the layout of polarimeter "UFP" on the telescope AZT-2

    NASA Astrophysics Data System (ADS)

    Levchenko, T. A.; Nevodovskyi, P. V.; Vidmachenko, A. P.; Morozhenko, O. V.; Saryboha, H. V.; Zbrutsky, O. V.; Ivakhiv, O. V.

    2016-05-01

    Main Astronomical Observatory of NAS of Ukraine in cooperation with the National Technical University of Ukraine "KPI" and National University "Lviv Polytechnic" for a long time working on the design of an optical polarimeter to study of the stratospheric layer of the Earth using of orbital satellite. During this time, was accumulated a large experience of such work, and was established a layout of compact ultraviolet polarimeter (UFP) on board of satellite

  10. New Jersey's Emergency Retrovir Reimbursement Program (ERRP).

    ERIC Educational Resources Information Center

    Conviser, Richard; And Others

    In 1987 Congress made available a one-time, 1-year emergency appropriation to pay for Food and Drug Administration (FDA)-approved life-sustaining drugs for people with Acquired Immune Deficiency Syndrome (AIDS). New Jersey received $1.5 million from this program for antiviral drugs for low-income people with AIDS and AIDS Related Complex lacking…

  11. Heterogeneity in Retroviral Nucleocapsid Protein Function

    NASA Astrophysics Data System (ADS)

    Landes, Christy

    2009-03-01

    Time-resolved single-molecule fluorescence spectroscopy was used to study the human T-cell lymphotropic virus type 1 (HTLV-1) nucleocapsid protein (NC) chaperone activity as compared to that of the HIV-1 NC protein. HTLV-1 NC contains two zinc fingers with each having a CCHC binding motif similar to HIV-1 NC. HIV-1 NC is required for recognition and packaging of the viral RNA and is also a nucleic acid chaperone protein that facilitates nucleic acid restructuring during reverse transcription. Because of similarities in structures between the two retroviruses, we have used single-molecule fluorescence energy transfer to investigate the chaperoning activity of HTLV-1 NC protein. The results indicate that HTLV-1 NC protein induces structural changes by opening the transactivation response (TAR)-DNA hairpin to an even greater extent than HIV-1 NC. However, unlike HIV-1 NC, HTLV-1 NC does not chaperone the strand-transfer reaction involving TAR-DNA. These results suggest that despite its effective destabilization capability, HTLV-1 NC is not as effective at overall chaperone function as is its HIV-1 counterpart.

  12. Genetic diversity of koala retroviral envelopes.

    PubMed

    Xu, Wenqin; Gorman, Kristen; Santiago, Jan Clement; Kluska, Kristen; Eiden, Maribeth V

    2015-03-17

    Genetic diversity, attributable to the low fidelity of reverse transcription, recombination and mutation, is an important feature of infectious retroviruses. Under selective pressure, such as that imposed by superinfection interference, gammaretroviruses commonly adapt their envelope proteins to use alternative receptors to overcome this entry block. The first characterized koala retroviruses KoRV subgroup A (KoRV-A) were remarkable in their absence of envelope genetic variability. Once it was determined that KoRV-A was present in all koalas in US zoos, regardless of their disease status, we sought to isolate a KoRV variant whose presence correlated with neoplastic malignancies. More than a decade after the identification of KoRV-A, we isolated a second subgroup of KoRV, KoRV-B from koalas with lymphomas. The envelope proteins of KoRV-A and KoRV-B are sufficiently divergent to confer the ability to bind and employ distinct receptors for infection. We have now obtained a number of additional KoRV envelope variants. In the present studies we report these variants, and show that they differ from KoRV-A and KoRV-B envelopes in their host range and superinfection interference properties. Thus, there appears to be considerable variation among KoRVs envelope genes suggesting genetic diversity is a factor following the KoRV-A infection process.

  13. Reaction-diffusion basis of retroviral infectivity

    NASA Astrophysics Data System (ADS)

    Sadiq, S. Kashif

    2016-11-01

    Retrovirus particle (virion) infectivity requires diffusion and clustering of multiple transmembrane envelope proteins (Env3) on the virion exterior, yet is triggered by protease-dependent degradation of a partially occluding, membrane-bound Gag polyprotein lattice on the virion interior. The physical mechanism underlying such coupling is unclear and only indirectly accessible via experiment. Modelling stands to provide insight but the required spatio-temporal range far exceeds current accessibility by all-atom or even coarse-grained molecular dynamics simulations. Nor do such approaches account for chemical reactions, while conversely, reaction kinetics approaches handle neither diffusion nor clustering. Here, a recently developed multiscale approach is considered that applies an ultra-coarse-graining scheme to treat entire proteins at near-single particle resolution, but which also couples chemical reactions with diffusion and interactions. A model is developed of Env3 molecules embedded in a truncated Gag lattice composed of membrane-bound matrix proteins linked to capsid subunits, with freely diffusing protease molecules. Simulations suggest that in the presence of Gag but in the absence of lateral lattice-forming interactions, Env3 diffuses comparably to Gag-absent Env3. Initial immobility of Env3 is conferred through lateral caging by matrix trimers vertically coupled to the underlying hexameric capsid layer. Gag cleavage by protease vertically decouples the matrix and capsid layers, induces both matrix and Env3 diffusion, and permits Env3 clustering. Spreading across the entire membrane surface reduces crowding, in turn, enhancing the effect and promoting infectivity. This article is part of the themed issue 'Multiscale modelling at the physics-chemistry-biology interface'.

  14. Formulation, In Vitro and In Vivo Pharmacokinetics of Anti-HIV Vaginal Bioadhesive Gel

    PubMed Central

    Chatterjee, A; Bhowmik, B B; Thakur, Y S

    2011-01-01

    Inexpensive and female-controlled pre-exposure prophylaxis strategies to prevent mucosal transmission of the virus, is urgently needed with the rising prevalence of human immunodeficiency virus (HIV-1 and HIV2) infections in women. Zidovudine-loaded bioadhesive vaginal gel may become one of the very useful strategies, as it can be used not only for controlled release but also for enhancing bioavailability. Drug delivery through vaginal gel is a promising area for continued research with the aim of achieving controlled release with enhanced bioavailability over longer periods of time. The aim of the study was to develop a newer prolong releasing Zidovudine (AZT) bioadhesive vaginal gel to treat HIV infections with increased patient convenience. AZT-loaded bioadhesive vaginal gel was prepared successfully by using cold mechanical method. F3 formulation containing carbopol–HPMC (1:3) was selected and evaluated in order to achieve objectives of this study. In vitro drug release study of F3 showed in 24 h drug released following case I Fickian (n ≤ 0.5) transport mechanism, and in vivo drug release was found much better (Tmax), (Cmax), and bioavailability (F) comparison with oral pour drug solution. It was also showed good extrudability, spreadability, and bioadhesive strength. A generalized protocol, for the further research, in this area will surely expected to yield significant outcome with improved drug delivery system. PMID:21731351

  15. The antiretrovirus drug 3'-azido-3'-deoxythymidine increases the retrovirus mutation rate.

    PubMed Central

    Julias, J G; Kim, T; Arnold, G; Pathak, V K

    1997-01-01

    It was previously observed that the nucleoside analog 5-azacytidine increased the spleen necrosis virus (SNV) mutation rate 13-fold in one cycle of retrovirus replication (V. K. Pathak and H. M. Temin, J. Virol. 66:3093-3100, 1992). Based on this observation, we hypothesized that nucleoside analogs used as antiviral drugs may also increase retrovirus mutation rates. We sought to determine if 3'-azido-3'-deoxythymidine (AZT), the primary treatment for human immunodeficiency virus type 1 (HIV-1) infection, increases the retrovirus mutation rate. Two assays were used to determine the effects of AZT on retrovirus mutation rates. The strategy of the first assay involved measuring the in vivo rate of inactivation of the lacZ gene in one replication cycle of SNV- and murine leukemia virus-based retroviral vectors. We observed 7- and 10-fold increases in the SNV mutant frequency following treatment of target cells with 0.1 and 0.5 microM AZT, respectively. The murine leukemia virus mutant frequency increased two- and threefold following treatment of target cells with 0.5 and 1.0 microM AZT, respectively. The second assay used an SNV-based shuttle vector containing the lacZ alpha gene. Proviruses were recovered as plasmids in Escherichia coli, and the rate of inactivation of lacZ alpha was measured. The results indicated that treatment of target cells increased the overall mutation rate two- to threefold. DNA sequence analysis of mutant proviruses indicated that AZT increased both the deletion and substitution rates. These results suggest that AZT treatment of HIV-1 infection may increase the degree of viral variation and alter virus evolution or pathogenesis. PMID:9151812

  16. Nevirapine resistance mutations of human immunodeficiency virus type 1 selected during therapy.

    PubMed Central

    Richman, D D; Havlir, D; Corbeil, J; Looney, D; Ignacio, C; Spector, S A; Sullivan, J; Cheeseman, S; Barringer, K; Pauletti, D

    1994-01-01

    Drug susceptibility and mutations in the reverse transcriptase (RT) gene were analyzed with 167 virus isolates from 38 patients treated with nevirapine, a potent nonnucleoside inhibitor of human immunodeficiency virus type 1 (HIV-1) RT. Resistant isolates emerged quickly and uniformly in all patients administered nevirapine either as monotherapy or in combination with zidovudine (AZT). Resistance developed as early as 1 week, indicating rapid turnover of the virus population. The development of resistance was associated with the loss of antiviral drug activity as measured by CD4 lymphocyte counts and levels of HIV p24 antigen and RNA in serum. In addition to mutations at amino acid residues 103, 106, and 181 that had been identified by selection in cell culture, mutations at residues 108, 188, and 190 were also found in the patient isolates. Sequences from patient clones documented cocirculating mixtures of populations of different mutants. The most common mutation with monotherapy, tyrosine to cysteine at residue 181, was prevented from emerging by coadministration of AZT, which resulted in the selection of alternative mutations. The observations documented that, under selective drug pressure, the circulating virus population can change rapidly, and many alternative mutants can emerge, often in complex mixtures. The addition of a second RT inhibitor, AZT, significantly altered the pattern of mutations in the circulating population of HIV. PMID:7509000

  17. Compartmentalized accumulation of cAMP near complexes of multidrug resistance protein 4 (MRP4) and cystic fibrosis transmembrane conductance regulator (CFTR) contributes to drug-induced diarrhea.

    PubMed

    Moon, Changsuk; Zhang, Weiqiang; Ren, Aixia; Arora, Kavisha; Sinha, Chandrima; Yarlagadda, Sunitha; Woodrooffe, Koryse; Schuetz, John D; Valasani, Koteswara Rao; de Jonge, Hugo R; Shanmukhappa, Shiva Kumar; Shata, Mohamed Tarek M; Buddington, Randal K; Parthasarathi, Kaushik; Naren, Anjaparavanda P

    2015-05-01

    Diarrhea is one of the most common adverse side effects observed in ∼7% of individuals consuming Food and Drug Administration (FDA)-approved drugs. The mechanism of how these drugs alter fluid secretion in the gut and induce diarrhea is not clearly understood. Several drugs are either substrates or inhibitors of multidrug resistance protein 4 (MRP4), such as the anti-colon cancer drug irinotecan and an anti-retroviral used to treat HIV infection, 3'-azido-3'-deoxythymidine (AZT). These drugs activate cystic fibrosis transmembrane conductance regulator (CFTR)-mediated fluid secretion by inhibiting MRP4-mediated cAMP efflux. Binding of drugs to MRP4 augments the formation of MRP4-CFTR-containing macromolecular complexes that is mediated via scaffolding protein PDZK1. Importantly, HIV patients on AZT treatment demonstrate augmented MRP4-CFTR complex formation in the colon, which defines a novel paradigm of drug-induced diarrhea.

  18. Comparison of cardiovascular disease risk markers in HIV-infected patients receiving abacavir and tenofovir: the nucleoside inflammation, coagulation and endothelial function (NICE) study

    PubMed Central

    Wohl, David A; Arnoczy, Gretchen; Fichtenbaum, Carl J; Campbell, Thomas; Taiwo, Babafemi; Hicks, Charles; McComsey, Grace A; Koletar, Susan; Sax, Paul; Tebas, Pablo; Ha, Belinda; Massengale, Kelly; Walsh, Kendall; Stein, James H

    2015-01-01

    Background The association between abacavir (ABC) and cardiovascular disease (CVD) risk in HIV-infected individuals is unclear. Putative mechanisms for an effect of ABC on CVD risk including endothelial dysfunction have been proposed; however, a biological mechanism has not been established. Methods This was a cross-sectional study of HIV-infected subjects with HIV RNA levels <400 copies/ml, who were randomly assigned to ABC or tenofovir (TDF) as initial therapy during a prior clinical trial. A small cohort of subjects on zidovudine (AZT; not randomly assigned) were studied to explore long-term exposure to this agent. All underwent brachial artery ultrasound for flow-mediated dilation (FMD), and D-dimer, high-sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6) and fasting lipids were measured. Between-arm differences were evaluated by multivariable linear or logistic regression modelling. Results There were 148 subjects (46 on ABC, 72 on TDF and 30 on AZT). Demographic characteristics were balanced across the groups except, as expected, AZT-treated participants were older, had higher CD4+ T-cell counts, and longer antiretroviral therapy duration. After adjusting for age, brachial artery diameter, and treatment duration, FMD was similar in those on ABC (3.9%) and TDF (5.4%; P=0.181). FMD was higher in those on AZT (6.1%; P<0.005). Levels of IL-6, hsCRP and detectable D-dimer were similar between groups. Conclusions Among individuals assigned to ABC or TDF in randomized clinical trials there were no significant differences in FMD or markers of inflammation and coagulation. Whether ABC contributes to risk of CVD remains unclear, but our results suggest that endothelial dysfunction, heightened inflammation, and altered coagulation are unlikely to be mechanisms by which the drug could increase CVD risk above that seen with TDF. PMID:23985706

  19. [Guidelines for the management of patients with HIV infection. II. Pregnant women and children. Liege Working Group on HIV Infection].

    PubMed

    Schmitz, V; Nkoghe, D; Hoyoux, C; Dresse, M F

    2000-05-01

    The management of the HIV infected child is nearly identical to the adult. Nevertheless, there are many clinical, immunological and virological details. Difficulties evoked for the adult have an even bigger importance, in view of the foreseeable longevity of these children under treatment. The reduction of the mother to child transmission, thanks to the AZT-caesarean association, must be continued. The use of anti-retroviral drugs during pregnancy requires a sustained attention because of the potential risks and benefits for the foetus and mother. The long-term impact of these drugs, in children exposed during pregnancy, remains unknown. The follow-up of these children therefore remains important.

  20. Magnitude and correlates of moderate to severe anemia among adult HIV patients receiving first line HAART in Northwestern Tanzania: a cross sectional clinic based study

    PubMed Central

    Gunda, Daniel Wilfred; Kilonzo, Semvua Bukheti; Mpondo, Bonaventura Cornel

    2016-01-01

    Introduction Moderate to severe anemia is an important clinical problem in HIV patients on Highly Active Antiretroviral Therapy. The rate of progression and mortality in this sub group of patients is high compared to non anemic patients. In sub Saharan Africa with scale up of Anti retroviral therapy, the magnitude of this problem is not known especially in Tanzania. This study aimed at determining the magnitude and correlates of moderate to severe anemia in HIV patients receiving first line ART in northwestern Tanzania. Methods This was a cross sectional clinic based study, involving adult HIV patients on first line Highly Active Antiretroviral Therapy at Bugando Medical Centre Care and Treatment Center. The patients’ data were analyzed using STATA version 11 to determine the prevalence of moderate to severe anemia and risk factors that could predict occurrence of anemia. Results In this study 346 patients on Highly Active Anti-Retroviral Therapy were enrolled, of whom 100(40.46%) had moderate to severe anemia. The odds of being anemic were strongly predicted by Zidovudine based regime, low baseline CD4 count (< 200 cells/μl) and HIV stage 3&4 at enrollment. Most of the anemic patients had mean corpuscular volume of >100fl. Conclusion The prevalence of moderate to severe anemia is significantly high in this cohort of HIV-infected patients on first line Anti Retroviral Therapy and it is strongly predicted by Zidovudine based regime, low baseline CD4 and HIV stage 3 and 4. On clinical grounds this suggests that patients who are initiated on Zidovudine based regimen and those in advanced HIV at enrollment should have regular haemoglobin follow up to identify anemia at its earliest stage to improve the clinical outcome of these patients. PMID:27200131

  1. Disclosure of HIV status and its impact on the loss in the follow-up of HIV-infected patients on potent anti-retroviral therapy programs in a (post-) conflict setting: A retrospective cohort study from Goma, Democratic Republic of Congo

    PubMed Central

    Akilimali, Pierre Zalagile; Musumari, Patou Masika; Kashala-Abotnes, Espérance; Kayembe, Patrick Kalambayi; Lepira, François B.; Mutombo, Paulin Beya; Tylleskar, Thorkild; Ali, Mapatano Mala

    2017-01-01

    Background The study aimed to identify the impact of non-disclosure of HIV status on the loss to follow-up (LTFU) of patients receiving anti-retroviral therapy. Methodology A historic cohort of HIV patients from 2 major hospitals in Goma, Democratic Republic of Congo was followed from 2004 to 2012. LTFU was defined as not taking an ART refill for a period of 3 months or longer since the last attendance, and had not yet been classified as ‘dead’ or ‘transferred-out’. Kaplan-Meier plots were used to determine the probability of LTFU as a function of time as inclusive of the cohort. The log-rank test was used to compare survival curves based on determinants. Cox proportional hazard modeling was used to measure predictors of LTFU from the time of treatment induction until December 15th, 2012 (the end-point). Results The median follow-up time was 3.99 years (IQR = 2.33 to 5.59). Seventy percent of patients had shared their HIV status with others (95% CI: 66.3–73.1). The proportion of LTFU was 12% (95%CI: 9.6–14.4). Patients who did not share their HIV status (Adjusted HR 2.28, 95% CI 1.46–2.29), patients who did not live in the city of Goma (Adjusted HR 1.97, 95% CI 1.02–3.77), and those who attained secondary or higher education level (Adjusted HR 1.60, 95% CI 1.02–2.53) had a higher hazard of being LTFU. Conclusion This study shows the relationship between the non–disclosure HIV status and LTFU. Healthcare workers in similar settings should pay more attention to clients who have not disclosed their HIV status, and to those living far from health settings where they receive medication. PMID:28170410

  2. New directions in research: report from the 10th International Conference on AIDS.

    PubMed Central

    Berger, P B

    1995-01-01

    Research findings presented at the 10th International Conference on AIDS, held in Yokohama, Japan, in August 1994, indicate that few advances have been made in standard antiretroviral therapy for HIV infection. The perinatal administration of AZT (zidovudine) was reported to reduce transmission of HIV from mother to child, and its use in combination with acyclovir appears to improve survival among patients with advanced disease. Other research has focused on asymptomatic patients with long-standing HIV infection. Their survival may be related to the activity of cell antiviral factor, a cytokine produced by CD8+ cells. In gene therapy research, one approach involved the genetic alteration of target cells to enable them to render the virus harmless. A second approach consisted of enhancing the function of CD8+ cells to allow them to compensate for dysfunctional CD4+ cells. The author believes that gene therapy may offer the greatest hope of an effective treatment for HIV infection. PMID:7780908

  3. Synthesis and biological evaluation of CHX-DAPYs as HIV-1 non-nucleoside reverse transcriptase inhibitors.

    PubMed

    Yan, Zi-Hong; Wu, Hai-Qiu; Chen, Wen-Xue; Wu, Yan; Piao, Hu-Ri; He, Qiu-Qin; Chen, Fen-Er; De Clercq, Erik; Pannecouque, Christophe

    2014-06-15

    A series of new diarylpyrimidines (DAPYs) characterized by a halogen atom on the methylene linker between wing I and the central pyrimidine ring was synthesized and evaluated for their anti-HIV activity in MT-4 cell cultures. The two most promising compounds 7f and 7g showed excellent activity against wild-type HIV-1 with low nanomolar EC50 values of 0.005 and 0.009 μM, respectively, which were comparable to or more potent than all the reference drugs zidovudine (AZT), lamivudine (3TC), nevirapine (NEV), efavirenz (EFV), delaviridine (DLV) and etravirine (ETV). In particular, 7g also displayed strong activity against the double mutant strain 103N + 181C with an EC50 value of 8.2 μM. The preliminary structure-activity relationship (SAR) and molecular docking analysis of this new series of CHX-DAPYs were also investigated.

  4. Nickel-induced heritable alterations in retroviral transforming gene expression.

    PubMed Central

    Biggart, N W; Gallick, G E; Murphy, E C

    1987-01-01

    Determination of the mutagenic effects of carcinogenic nickel compounds has been difficult because, like many metals, nickel is poorly or nonmutagenic in procaryotic mutagenicity assays. We attempted to characterize nickel-induced genetic lesions by assessing the effect of nickel chloride on the conditionally defective expression of the v-mos transforming gene in normal rat kidney cells infected with the Murine sarcoma virus mutant ts110 (MuSVts110) retrovirus. MuSVts110 contains an out-of-frame gag gene-mos gene junction that prevents the expression of the v-mos gene at the nonpermissive temperature (39 degrees C). In MuSVts110-infected cells (6m2 cells) grown at 33 degrees C, however, this defect can be suppressed by a splicing event that restores the mos reading frame, allowing the expression of a gag-mos fusion protein which induces the transformed phenotype. The capacity to splice the viral transcript at 33 degrees C, but not at 39 degrees C, is an intrinsic property of the viral RNA. This property allowed us to target the MuSVts110 genome using a positive selection scheme whereby nickel was used to induce genetic changes which resulted in expression of the transformed phenotype at 39 degrees C. We treated 6m2 cells with NiCl2 and isolated foci consisting of cells which had reverted to the transformed phenotype at 39 degrees C. We found that brief nickel treatment increased the reversion frequency of 6m2 cells grown at 39 degrees C sevenfold over the spontaneous reversion frequency. The nickel-induced revertants displayed the following heritable characteristics: They stably maintained the transformed phenotype at 39 degrees C; unlike the MuSVts110 RNA in 6m2 cells, the nickel-induced revertant viral RNA could be spliced efficiently at 39 degrees C; as a consequence of the enhanced accumulation of spliced viral RNA, the nickel-induced revertants produced substantial amounts of the transforming v-mos protein P85gag-mos at 39 degrees C; the nickel-induced revertant P85gag-mos serine kinase, like the parental 6m2 P85gag-mos kinase, was found to be rapidly inactivated at 39 degrees C; however, in the nickel-induced revertants, overproduction of P85gag-mos allowed the transformed state to be maintained; and even though viral RNA processing was much changed, no rearrangements of the viral DNA in the nickel-induced revertant cells were detected by partial restriction analysis. Images PMID:3037102

  5. Monitoring Retroviral RNA Dimerization In Vivo via Hammerhead Ribozyme Cleavage

    PubMed Central

    Pal, Bijay K.; Scherer, Lisa; Zelby, Laurie; Bertrand, Edouard; Rossi, John J.

    1998-01-01

    We have used a strategy for colocalization of Psi (Ψ)-tethered ribozymes and targets to demonstrate that Ψ sequences are capable of specific interaction in the cytoplasm of both packaging and nonpackaging cells. These results indicate that current in vitro dimerization models may have in vivo counterparts. The methodology used may be applied to further genetic analyses on Ψ domain interactions in vivo. PMID:9733882

  6. Cellular and viral determinants of retroviral nuclear entry.

    PubMed

    Bin Hamid, Faysal; Kim, Jinsun; Shin, Cha-Gyun

    2016-01-01

    Retroviruses must integrate their cDNA into the host genome to generate proviruses. Viral DNA-protein complexes interact with cellular proteins and produce pre-integration complexes, which carry the viral genome and cross the nuclear pore channel to enter the nucleus and integrate viral DNA into host chromosomal DNA. If the reverse transcripts fail to integrate, linear or circular DNA species such as 1- and 2-long terminal repeats are generated. Such complexes encounter numerous cellular proteins in the cytoplasm, which restrict viral infection and protect the nucleus. To overcome host cell defenses, the pathogens have evolved several evasion strategies. Viral proteins often contain nuclear localization signals, allowing entry into the nucleus. Among more than 1000 proteins identified as required for HIV infection by RNA interference screening, karyopherins, cleavage and polyadenylation specific factor 6, and nucleoporins have been predominantly studied. This review di