scholarly journals Baculoviruses as Vectors for Gene Therapy against Human Prostate Cancer

2003 ◽  
Vol 2003 (2) ◽  
pp. 79-91 ◽  
Author(s):  
Lindsay J. Stanbridge ◽  
Vincent Dussupt ◽  
Norman J. Maitland
Keyword(s):  
Prostate Cancer ◽  
Gene Therapy ◽  
Viral Entry ◽  
Mammalian Cells ◽  
Primary Tumour ◽  
Genetic Material ◽  
Cell Types ◽  
Attractive Alternative

Current curative strategies for prostate cancer are restricted to the primary tumour, and the effect of treatments to control metastatic disease is not sustained. Therefore, the application of gene therapy to prostate cancer is an attractive alternative. Baculoviruses are highly restricted insect viruses, which can enter, but not replicate in mammalian cells. Baculoviruses can incorporate large amounts of extra genetic material, and will express transgenes in mammalian cells when under the control of a mammalian or strong viral promoter. Successful gene delivery has been achieved both in vitro and in vivo and into both dividing and nondividing cells, which is important since prostate cancers divide relatively slowly. In addition, the envelope protein gp64 is sufficiently mutable to allow targeted transduction of particular cell types. In this review, the advantages of using baculoviruses for prostate cancer gene therapy are explored, and the mechanisms of viral entry and transgene expression are described.

scholarly journals A Novel Type V CRISPR System with Potential for Genome Editing in the Liver

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 1862-1862
Author(s):  
Gregory J. Cost ◽  
Morayma Temoche-Diaz ◽  
Janet Mei ◽  
Cristina N. Butterfield ◽  
Christopher T. Brown ◽  
...  
Keyword(s):  
Amino Acid ◽  
Genome Editing ◽  
Mammalian Cells ◽  
Conflicts Of Interest ◽  
Attractive Alternative ◽  
Vitro Assay ◽  
Crispr System ◽  
Type V

Abstract RNA guided CRISPR genome editing systems can make specific changes to the genomes of mammalian cells and have the potential to treat a range of diseases including those that can be addressed by editing hepatocytes. Attempts to edit the liver in vivo have relied almost exclusively on the Cas9 nucleases derived from the bacteria S treptococcus pyogenes or Staphylococcus aureus to which humans are commonly exposed. Pre-existing immunity to both these proteins has been reported in humans which raises concerns about their in vivo application. In silico analysis of a large metagenomics database followed by testing in mammalian cells in culture identified MG29-1, a novel CRISPR system which is a member of the Type V family but exhibits only 41 % amino acid identity to Francisella tularensis Cas12a/cpf1. MG29-1 is a 1280 amino acid RNA programmable nuclease that utilizes a single guide RNA comprised of a 22 nucleotide (nt) constant region and a 20 to 25 nt spacer, recognizes the PAM KTTN (predicted frequency 1 in 16 bp) and generates staggered cuts. MG29-1 was derived from a sample taken from a hydrothermal vent and it is therefore unlikely that humans will have developed pre-existing immunity to this protein. A screen for sgRNA targeting serum albumin in the mouse liver cell line Hepa1-6 identified 6 guides that generated more than 80% INDELS. The MG29-1 system was optimized for in vivo delivery by screening chemical modifications to the guide that improve stability in mammalian cell lysates while retaining or improving editing activity. Two lead guide chemistries were evaluated in mice using MG29-1 mRNA and sgRNA packaged in lipid nanoparticles (LNP). Three days after a single IV administration on-target editing was evaluated in the liver by Sanger sequencing. The sgRNA that was the most stable in the in vitro assay generated INDELS that ranged from 20 to 25% while a sgRNA with lower in vitro stability failed to generate detectable INDELs. The short sgRNA and small protein size compared to spCas9 makes MG29-1 an attractive alternative to spCas9 for in vivo editing applications. Evaluation of the potential of MG29-1 to perform gene knockouts and gene additions via non-homologous end joining is ongoing. Disclosures No relevant conflicts of interest to declare.

scholarly journals AAV ablates neurogenesis in the adult murine hippocampus

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Stephen Johnston ◽  
Sarah Parylak ◽  
Stacy Kim ◽  
Nolan Mac ◽  
Christina Lim ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Cell Death ◽  
Adult Neurogenesis ◽  
Granule Cells ◽  
Viral Vector ◽  
Cell Types ◽  
Early Gene ◽  
Post Injection

Recombinant adeno-associated virus (rAAV) has been widely used as a viral vector across mammalian biology and has been shown to be safe and effective in human gene therapy. We demonstrate that neural progenitor cells (NPCs) and immature dentate granule cells (DGCs) within the adult murine hippocampus are particularly sensitive to rAAV-induced cell death. Cell loss is dose dependent and nearly complete at experimentally relevant viral titers. rAAV-induced cell death is rapid and persistent, with loss of BrdU-labeled cells within 18 hours post-injection and no evidence of recovery of adult neurogenesis at 3 months post-injection. The remaining mature DGCs appear hyperactive 4 weeks post-injection based on immediate early gene expression, consistent with previous studies investigating the effects of attenuating adult neurogenesis. In vitro application of AAV or electroporation of AAV2 inverted terminal repeats (ITRs) is sufficient to induce cell death. Efficient transduction of the dentate gyrus (DG)-without ablating adult neurogenesis-can be achieved by injection of rAAV2-retro serotyped virus into CA3. rAAV2-retro results in efficient retrograde labeling of mature DGCs and permits in vivo 2-photon calcium imaging of dentate activity while leaving adult neurogenesis intact. These findings expand on recent reports implicating rAAV-linked toxicity in stem cells and other cell types and suggest that future work using rAAV as an experimental tool in the DG and as a gene therapy for diseases of the central nervous system (CNS) should be carefully evaluated.

scholarly journals Kinetics and Specificity of HEK293T Extracellular Vesicle Uptake using Imaging Flow Cytometry

2020 ◽  
Author(s):  
Brian Jurgielewicz ◽  
Yao Yao ◽  
Steven L. Stice
Keyword(s):  
Flow Cytometry ◽  
Genetic Material ◽  
Cell Types ◽  
Extracellular Vesicle ◽  
Human Neural Stem Cells ◽  
Imaging Flow Cytometry ◽  
Gene Therapy Vectors ◽  
Time Variables

Abstract Background : Extracellular vesicles (EVs) are nanosized vesicles naturally secreted from cells responsible for intercellular communication and delivery of proteins, lipids, and other genetic material. Ultimately, EVs could provide innate therapeutic contents and loaded therapeutic payloads such as small molecules and gene therapy vectors to recipient cells. However, comparative kinetic measures that can be used to quantify and ultimately optimize delivery and uptake of EV payloads are lacking. We investigated both dose and time effects on EV uptake and evaluated the potential specificity of EV uptake to better understand the kinetics and uptake of human embryonic kidney (HEK293T) derived EVs. Results : Utilizing an imaging flow cytometry platform (IFC), HEK293T EV uptake was analyzed. HEK293T EV uptake was dose and time dependent with a minimum threshold dose of 6,000 EVs per cell at 4 hours of co-culture. HEK293T EV uptake was inhibited when co-cultured with recipient cells at 4°C or with pre-fixed recipient cells. By co-culturing HEK293T EVs with cell lines from various germ layers, HEK293T EVs were taken up at higher quantities by HEK293T cells. Lastly, human neural stem cells (hNSCs) internalized significantly more HEK293T EVs relative to mature neurons. Conclusions : Imaging flow cytometry is a quantitative, high throughput, and versatile platform to quantify the kinetics of EV uptake. Utilizing this platform, dose and time variables have been implicated to affect EV uptake measurements making standardization of in vitro and in vivo assays vital for the translation of EVs into the clinic. In this study, we quantified the selectivity of EV uptake between a variety of cell types in vitro and found that EVs were internalized at higher quantities by cells of the same origin. The characterization of HEK293T EV uptake in vitro, notably specificity, dose response, and kinetic assays should be used to help inform and develop EV based therapeutics.

scholarly journals Identification of Drugs Blocking SARS-CoV-2 Infection using Human Pluripotent Stem Cell-derived Colonic Organoids

2020 ◽  
Author(s):  
Xiaohua Duan ◽  
Yuling Han ◽  
Liuliu Yang ◽  
Benjamin E. Nilsson-Payant ◽  
Pengfei Wang ◽  
...  
Keyword(s):  
Stem Cell ◽  
Viral Entry ◽  
Pluripotent Stem Cell ◽  
Cell Types ◽  
Human Pluripotent Stem Cell ◽  
Humanized Mouse Model ◽  
Multiple Cell ◽  
Approved Drugs

Summary ParagraphThe current COVID-19 pandemic is caused by SARS-coronavirus 2 (SARS-CoV-2). There are currently no therapeutic options for mitigating this disease due to lack of a vaccine and limited knowledge of SARS-CoV-2 biology. As a result, there is an urgent need to create new disease models to study SARS-CoV-2 biology and to screen for therapeutics using human disease-relevant tissues. COVID-19 patients typically present with respiratory symptoms including cough, dyspnea, and respiratory distress, but nearly 25% of patients have gastrointestinal indications including anorexia, diarrhea, vomiting, and abdominal pain. Moreover, these symptoms are associated with worse COVID-19 outcomes1. Here, we report using human pluripotent stem cell-derived colonic organoids (hPSC-COs) to explore the permissiveness of colonic cell types to SARS-CoV-2 infection. Single cell RNA-seq and immunostaining showed that the putative viral entry receptor ACE2 is expressed in multiple hESC-derived colonic cell types, but highly enriched in enterocytes. Multiple cell types in the COs can be infected by a SARS-CoV-2 pseudo-entry virus, which was further validated in vivo using a humanized mouse model. We used hPSC-derived COs in a high throughput platform to screen 1280 FDA-approved drugs against viral infection. Mycophenolic acid and quinacrine dihydrochloride were found to block the infection of SARS-CoV-2 pseudo-entry virus in COs both in vitro and in vivo, and confirmed to block infection of SARS-CoV-2 virus. This study established both in vitro and in vivo organoid models to investigate infection of SARS-CoV-2 disease-relevant human colonic cell types and identified drugs that blocks SARS-CoV-2 infection, suitable for rapid clinical testing.

scholarly journals Infectious clone construction of dengue virus type 2, strain Jamaican 1409, and characterization of a conditional E6 mutation

2006 ◽  
Vol 87 (8) ◽  
pp. 2263-2268 ◽  
Author(s):  
Dennis J. Pierro ◽  
Ma Isabel Salazar ◽  
Barry J. Beaty ◽  
Ken E. Olson
Keyword(s):  
Cell Culture ◽  
Dengue Virus ◽  
Virus Type ◽  
Mammalian Cells ◽  
Infectious Clone ◽  
Cell Types ◽  
Dengue Virus Type 2

A full-length infectious cDNA clone (ic) was constructed from the genome of the dengue virus type 2 (DENV-2) Jamaica83 1409 strain, pBAC1409ic, by using a bacterial artifical chromosome plasmid system. Infectious virus was generated and characterized for growth in cell culture and for infection in Aedes aegypti mosquitoes. During construction, an isoleucine to methionine (Ile→Met) change was found at position 6 in the envelope glycoprotein sequence between low- and high-passage DENV-2 1409 strains. In vitro-transcribed genomic RNA of 1409ic with E6-Ile produced infectious virions following electroporation in mosquito cells, but not mammalian cells, while 1409ic RNA with an E6-Met mutation produced virus in both cell types. Moreover, DENV-2 1409 with the E6-Ile residue produced syncytia in C6/36 cell culture, whereas viruses with E6-Met did not. However, in vitro cell culture-derived growth-curve data and in vivo mosquito-infection rates revealed that none of the analysed DENV-2 strains differed from each other.

scholarly journals A novel physical and functional association between nucleoside diphosphate kinase A and AMP-activated protein kinase α1 in liver and lung

2005 ◽  
Vol 392 (1) ◽  
pp. 201-209 ◽  
Author(s):  
Russell M. Crawford ◽  
Kate J. Treharne ◽  
O. Giles Best ◽  
Richmond Muimo ◽  
Claudia E. Riemen ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Mammalian Cells ◽  
Nucleoside Diphosphate Kinase ◽  
Cell Types ◽  
Acid Synthesis ◽  
Cellular Fatty Acid ◽  
Energy Status ◽  
Amp Activated Protein Kinase

Nucleoside diphosphate kinase (NDPK, NM23/awd) belongs to a multifunctional family of highly conserved proteins (∼16–20 kDa) containing two well-characterized isoforms (NM23-H1 and -H2; also known as NDPK A and B). NDPK catalyses the conversion of nucleoside diphosphates into nucleoside triphosphates, regulates a diverse array of cellular events and can act as a protein histidine kinase. AMPK (AMP-activated protein kinase) is a heterotrimeric protein complex that responds to cellular energy status by switching off ATP-consuming pathways and switching on ATP-generating pathways when ATP is limiting. AMPK was first discovered as an activity that inhibited preparations of ACC1 (acetyl-CoA carboxylase), a regulator of cellular fatty acid synthesis. We report that NM23-H1/NDPK A and AMPK α1 are associated in cytosol from two different tissue sources: rat liver and a human lung cell line (Calu-3). Co-immunoprecipitation and binding assay data from both cell types show that the H1/A (but not H2/B) isoform of NDPK is associated with AMPK complexes containing the α1 (but not α2) catalytic subunit. Manipulation of NM23-H1/NDPK A nucleotide transphosphorylation activity to generate ATP (but not GTP) enhances the activity of AMPK towards its specific peptide substrate in vitro and also regulates the phosphorylation of ACC1, an in vivo target for AMPK. Thus novel NM23-H1/NDPK A-dependent regulation of AMPK α1-mediated phosphorylation is present in mammalian cells.

scholarly journals High Throughput Screening Method for Identification of New Lipofection Reagents

2001 ◽  
Vol 6 (4) ◽  
pp. 245-254 ◽  
Author(s):  
Anne E. Regelin ◽  
Erhard Fernholz ◽  
Harald F. Krug ◽  
Ulrich Massing
Keyword(s):  
High Throughput Screening ◽  
Screening Method ◽  
Genetic Material ◽  
Cell Types ◽  
Cationic Lipids ◽  
Adherent Cell ◽  
Gene Assay

Lipofection, the transfer of genetic material into cells by means of cationic lipids, is of growing interest for in vitro and in vivo approaches. In order to identify ideal lipofection reagents in a HTS, we have developed an automated lipofection method for the transfer of reporter genes into cells and for determination of the lipofection results. The method has specifically been designed and optimized for 96-well microtiter plates and can successfully be carried out by a pipetting robot with accessory equipment. It consists of two separate parts: (1) pretransfection (preparation of liposomes, formation of lipoplexes, and lipoplex transfer to the cells) and (2) posttransfection (determination of the reporter enzyme activity and the protein content of the transfected cells). Individual steps of the lipofection method were specifically optimized—for example, lipoplex formation and incubation time as well as cell lysis, cell cultivating, and the reporter gene assay. The HTS method facilitates characterization of the transfection properties (efficiency and cytotoxicity) of large numbers of (cationic) lipids in various adherent cell types.

scholarly journals Homemade Bread: Repurposing an Ancient Technology for Low Cost in vitro Tissue Engineering

2020 ◽  
Author(s):  
Jessica T. Holmes ◽  
Ziba Jaberansari ◽  
William Collins ◽  
Maxime Leblanc Latour ◽  
Daniel J. Modulevsky ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Mammalian Cells ◽  
Mechanical Stability ◽  
Low Cost ◽  
Cell Types ◽  
Meat Industry ◽  
High Porosity ◽  
3D Microenvironment

ABSTRACTCellular function is well known to be influenced by the physical cues and architecture of their three dimensional (3D) microenvironment. As such, numerous synthetic and naturally-occurring biomaterials have been developed to provide such architectures to support the proliferation of mammalian cells in vitro and in vivo. In recent years, our group, and others, have shown that scaffolds derived from plants can be utilized for tissue engineering applications in biomedicine and in the burgeoning cultured meat industry. Such scaffolds are straightforward to prepare, allowing researchers to take advantage of their intrinsic 3D microarchitectures. During the 2020 SARS-CoV-2 pandemic many people around the world began to rediscover the joy of preparing bread at home and as a research group, our members participated in this trend. Having observed the high porosity of the crumb (the internal portion of the bread) we were inspired to investigate whether it might support the proliferation of mammalian cells in vitro. Here, we develop and validate a yeast-free “soda bread” that maintains its mechanical stability over two weeks in culture conditions. The scaffolding is highly porous, allowing the 3D proliferation of multiple cell types relevant to both biomedical tissue engineering and the development of novel future foods. Bread derived scaffolds are highly scalable and represent a surprising new alternative to synthetic or animal-derived scaffolds for addressing a diverse variety of tissue engineering challenges.

THE PROSPECTS FOR APPLICATION OF LACTOFERRIN AND ITS DERIVATIVES IN THE TREATMENT OF CANCER

2019 ◽  
Vol 65 (6) ◽  
pp. 785-790
Author(s):  
Veronika Zorina
Keyword(s):  
Gene Therapy ◽  
Synthetic Peptides ◽  
Cell Types ◽  
In Vitro Models ◽  
The World ◽  
Specific Receptors ◽  
Methods Of Treatment ◽  
Universal Protein

Annually more than 250 thousand deaths from malignant diseases are registered in Russia and 8 million - in the world. The effectiveness of traditional methods of treatment, as well as of monoclonal antibodies and gene therapy is limited in the case of resistant forms of cancer and hard to reach tumors. Lactoferrin (LF) is a universal protein with anticancer activity and cross-species biocompatibility, which modulates the immune response and the redox/antioxidant system. Due to the ability to interact not only with specific receptors, but also with signaling and endocytosis receptors, TLR on various cell types, LF can overcome tissue barriers. The therapeutic efficacy of lactoferrin, its cleavage products, and synthetic peptides against various types of malignant proliferation was demonstrated with in vivo and in vitro models. The prospects of using LF as an adjuvant before chemotherapy and radiotherapy and as a carrier for gene therapy of cancer were experimentally demonstrated. However, the results of clinical studies are few and require further study.

scholarly journals Murine pneumotropic virus VP1 virus-like particles (VLPs) bind to several cell types independent of sialic acid residues and do not serologically cross react with murine polyomavirus VP1 VLPs

2003 ◽  
Vol 84 (12) ◽  
pp. 3443-3452 ◽  
Author(s):  
K. Tegerstedt ◽  
K. Andreasson ◽  
A. Vlastos ◽  
K. O. Hedlund ◽  
T. Dalianis ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Sialic Acid ◽  
Recombinant Baculovirus ◽  
Antigen Expression ◽  
Cell Types ◽  
Cell Receptor ◽  
Virus Like Particles ◽  
Murine Polyomavirus

The ability of murine pneumotropic virus (MPtV) major capsid protein VP1 to form virus-like particles (VLPs) was examined. MPtV-VLPs obtained were used to estimate the potential of MPtV to attach to different cells and to assess some characteristics of the MPtV cell receptor. Furthermore, to evaluate if MPtV-VLPs could potentially complement murine polyomavirus (MPyV) VP1 VLPs (MPyV-VLPs) as vectors for prime–boost gene therapy, the capability of MPtV-VLPs to serologically cross react with MPyV-VLPs and to transduce DNA into cells was examined. MPtV VP1 obtained in a recombinant baculovirus system formed MPtV-VLPs readily. MPtV-VLPs were shown by FACS analysis to bind to different cells, independent of MHC class I antigen expression. In addition, MPtV-VLPs did not cause haemagglutination of red blood cells and MPtV-VLP binding to cells was neuraminidase resistant but mostly trypsin and papain sensitive, indicating that the MPtV receptor lacks sialic acid components. When tested by ELISA and in vivo neutralization assays, MPtV-VLPs did not serologically cross react with MPyV-VLPs, suggesting that MPtV-VLPs and MPyV-VLPs could potentially be interchanged as carriers of DNA in repeated gene therapy. Finally, MPtV-VLPs were shown to transduce foreign DNA in vitro and in vivo. In conclusion, the data suggest that MPtV-VLPs, and possibly also MPtV, bind to several different cell types, that binding is neuraminidase resistant and that MPtV-VLPs should potentially be able to complement MPyV-VLPs for prime–boost gene transfer in vivo.

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