Isolation and Maintenance.- Isolation and Differentiation of Medaka Embryonic Stem Cells.- Maintenance of Chicken Embryonic Stem Cells In Vitro.- Derivation and Culture of Mouse Trophoblast Stem Cells In Vitro.- Derivation, Maintenance, and Characterization of Rat Embryonic Stem Cells In Vitro.- Derivation, Maintenance, and Induction of the Differentiation In Vitro of Equine Embryonic Stem Cells.- Generation and Characterization of Monkey Embryonic Stem Cells.- Derivation and Propagation of Embryonic Stem Cells in Serum- and Feeder-Free Culture.- Signaling in Embryonic Stem Cell Differentiation.- Internal Standards in Differentiating Embryonic Stem Cells In Vitro.- Matrix Assembly, Cell Polarization, and Cell Survival.- Phosphoinositides, Inositol Phosphates, and Phospholipase C in Embryonic Stem Cells.- Cripto Signaling in Differentiating Embryonic Stem Cells.- The Use of Embryonic Stem Cells to Study Hedgehog Signaling.- Transfection and Promoter Analysis in Embryonic Stem Cells.- SAGE Analysis to Identify Embryonic Stem Cell-Predominant Transcripts.- Utilization of Digital Differential Display to Identify Novel Targets of Oct3/4.- Gene Silencing Using RNA Interference in Embryonic Stem Cells.- Genetic Manipulation of Embryonic Stem Cells.- Efficient Transfer of HSV-1 Amplicon Vectors Into Embryonic Stem Cells and Their Derivatives.- Lentiviral Vector-Mediated Gene Transfer in Embryonic Stem Cells.- Use of the Cytomegalovirus Promoter for Transient and Stable Transgene Expression in Mouse Embryonic Stem Cells.- Use of Simian Immunodeficiency Virus Vectors for Simian Embryonic Stem Cells.- Generation of Green Fluorescent Protein-Expressing Monkey Embryonic Stem Cells.- DNA Damage Response and Mutagenesis in Mouse Embryonic Stem Cells.- Ultraviolet-Induced Apoptosis in Embryonic Stem Cells In Vitro.- Use of Embryonic Stem Cells in Pharmacological and Toxicological Screens.- Use of Differentiating Embryonic Stem Cells in Pharmacological Studies.- Embryonic Stem Cells as a Source of Differentiated Neural Cells for Pharmacological Screens.- Use of Murine Embryonic Stem Cells in Embryotoxicity Assays.- Use of Chemical Mutagenesis in Mouse Embryonic Stem Cells.- Epigenetic Analysis of Embryonic Stem Cells.- Nuclear Reprogramming of Somatic Nucleus Hybridized With Embryonic Stem Cells by Electrofusion.- Methylation in Embryonic Stem Cells In Vitro.- Tumor-Like Properties.- Identification of Genes Involved in Tumor-Like Properties of Embryonic Stem Cells.- In Vivo Tumor Formation From Primate Embryonic Stem Cells.- Animal Models and Therapy.- Directed Differentiation and Characterization of Genetically Modified Embryonic Stem Cells for Therapy.- Use of Differentiating Embryonic Stem Cells in the Parkinsonian Mouse Model.

Isolation and characterization

We have previously shown correction of X-linked severe combined immunodeficiency [SCID-X1, also known as gamma chain (gamma(c)) deficiency] in 9 out of 10 patients by retrovirus-mediated gamma(c) gene transfer into autologous CD34 bone marrow cells. However, almost 3 years after gene therapy, uncontrolled exponential clonal proliferation of mature T cells (with gammadelta+ or alphabeta+ T cell receptors) has occurred in the two youngest patients. Both patients' clones showed retrovirus vector integration in proximity to the LMO2 proto-oncogene promoter, leading to aberrant transcription and expression of LMO2. Thus, retrovirus vector insertion can trigger deregulated premalignant cell proliferation with unexpected frequency, most likely driven by retrovirus enhancer activity on the LMO2 gene promoter.

https://science.sciencemag.org/content/sci/302/5644/415.full.pdf

LMO2-associated clonal T cell proliferation in two patients after gene therapy for SCID-X1.

Authors Jan L. Brozek, MD, PhD – Department of Clinical Epidemiology & Biostatistics and Medicine, McMaster University, Hamilton, Canada Jean Bousquet, MD, PhD – Service des Maladies Respiratoires, Hopital Arnaud de Villeneuve, Montpellier, France, INSERM, CESP U1018, Respiratory and Environmental Epidemiology Team, France, and WHO Collaborating Center for Rhinitis and Asthma Carlos E. Baena-Cagnani, MD – Faculty of Medicine, Catholic University of Cordoba, Cordoba, Argentina Sergio Bonini, MD – Institute of Neurobiology and Molecular Medicine – CNR, Rome, Italy and Department of Medicine, Second University of Naples, Naples, Italy G. Walter Canonica, MD – Allergy & Respiratory Diseases, DIMI, Department of Internal Medicine, University of Genoa, Genoa, Italy Thomas B. Casale, MD – Division of Allergy and Immunology, Department of Medicine, Creighton University, Omaha, Nebraska, USA Roy Gerth van Wijk, MD, PhD – Section of Allergology, Department of Internal Medicine, Erasmus Medical Centre, Rotterdam, the Netherlands Ken Ohta, MD, PhD – Division of Respiratory Medicine and Allergology, Department of Medicine, Teikyo University School of Medicine, Tokyo, Japan Torsten Zuberbier, MD – Department of Dermatology and Allergy, Charite Universitatsmedizin Berlin, Berlin, Germany Holger J. Schunemann, MD, PhD, MSc – Department of Clinical Epidemiology & Biostatistics and Medicine, McMaster University, Hamilton, Canada

/pdf/allergic-rhinitis-and-its-impact-on-asthma-20b4c7y0pr.pdf

Allergic Rhinitis and Its Impact on Asthma

THE early region of the small DNA tumour virus, simian virus 40 (SV40), is known to code for at least two polypeptides, the t and T antigens (‘small t’ and ‘large T’) Both these polypeptides are expressed in cells transformed by the virus1–4, and the T antigen has been shown to be essential for both the initiation and maintenance of the transformed state5–9 We therefore need to know how this T protein interacts with components of the host cell in order to understand the mechanism of SV40-induced transformation We report here that the T antigen in a line of SV40-transformed mouse cells forms an oligomeric complex with a specific cell coded protein

T Antigen Is Bound to a Host Protein in Sv40-Transformed Cells

The development over the past decade of methods for delivering genes to mammalian cells has stimulated great interest in the possibility of treating human disease by gene-based therapies. However, despite substantial progress, a number of key technical issues need to be resolved before gene therapy can be safely and effectively applied in the clinic. Future technological developments, particularly in the areas of gene delivery and cell transplantation, will be critical for the successful practice of gene therapy.

https://science.sciencemag.org/content/sci/260/5110/926.full.pdf

The Basic Science of Gene Therapy

The Cowan I strain of the bacterium Staphylococcus aureus has been used as an adsorbent for antibodies complexed with radiolabeled antigens from cell lysates. This application is advanced as a superior alternative to other methods of immune precipitation for the isolation of antigens. It exploits the high adsorption capacity for IgG molecules by protein A molecules on the cell walls of certain strains of staphylococci, along with the advantageous sedimentation properties of the bacteria. The interaction of immune complexes with the adsorbent was defined initially using a model system of bovine serum albumin with a high excess of rabbit anti-bovine serum albumin antibodies (IgG). The uptake of immune complexes under these conditions was extremely rapid, occurring within seconds, whereas maximum binding of free IgG was much slower. In addition, once bound the complexed antigen could not be displaced from the adsorbent either by large amounts of normal IgG or by extra free antibody. Antigen could be eluted almost completely from the inert adsorbent for analytic or preparative purposes with a variety of solvent systems, such as the detergent SDS in combination with urea and high temperature, and neutral salts with strong lyotropic salting in properties. The efficacy of the protein A-antibody adsorption technique was tested in direct comparisons with a conventional double antibody precipitation method for the isolation of mouse lymphocyte IgM. The bacterial adsorbent not only had a distinct advantage in speed of antigen isolation, but analyses by polyacrylamide gel electrophoresis in SDS also revealed consistently higher antigen recoveries, lower levels of background radioactivity, and an absence of other cell components which may nonspecifically bind to and complicate analyses using conventional immune precipitates.

Rapid isolation of antigens from cells with a staphylococcal protein A-antibody adsorbent: parameters of the interaction of antibody-antigen complexes with protein A.

Moloney Murine Leukemia Virus (MoMuLV) causes T cell neoplasms in rodents but is not known to be a pathogen in primates. The core protein and enzyme genes of the MoMuLV genome together with an amphotropic envelope gene are utilized to engineer the cell lines that generate retroviral vectors for use in current human gene therapy applications. We developed a producer clone that generates a very high concentration of retroviral vector particles to optimize conditions for gene insertion into pluripotent hematopoietic stem cells. This producer cell line also generates a much lower concentration of replication-competent virus that arose through recombination. Stem cells from rhesus monkeys were purified by immunoselection with an anti-CD34 antibody, incubated in vitro for 80-86 h in the presence of retroviral vector particles with accompanying replication-competent virus and used to reconstitute recipients whose bone marrow had been ablated by total body irradiation. The retroviral vector genome was detected in circulating cells of five of eight transplant recipients of CD34+ cells and in the circulating cells of two recipients of infected, unfractionated bone marrow mononuclear cells. Three recipients of CD34+ cells had a productive infection with replication-competent virus. Six or seven mo after transplantation, each of these animals developed a rapidly progressive T cell neoplasm involving the thymus, lymph nodes, liver, spleen, and bone marrow. Lymphoma cells contained 10-50 copies of the replication-competent virus, but lacked the retroviral vector genome. We conclude that replication-competent viruses arising from producer cells making retroviral vectors can be pathogenic in primates, which underscores the importance of carefully screening retroviral producer clones used in human trials to exclude contamination with replication-competent virus.

https://rupress.org/jem/article-pdf/176/4/1125/1102932/1125.pdf

Helper virus induced T cell lymphoma in nonhuman primates after retroviral mediated gene transfer.

Procedures are detailed for the rapid isolation of representative cell membrane antigens with protein A-bearing staphylococci as an adsorbent for IgG antibodies complexed with the antigens. Cell surface membrane proteins were radioiodinated and solubilized in nonionic detergent. Specific antisera were subsequently added and the immune complexes precipitated by addition of the staphylococcal adsorbent and low speed centrifugation. The antigens isolated included surface immunoglobulins from mouse and human lymphocytes, human beta-microglobulin and HL-A alloantigens, mouse H-2 alloantigens, and the murine leukemia virus glycoprotein gp 70. Rabbit, sheep, goat, and mouse antisera were all effective for the specific phase of the precipitation reaction. The surface membrane immunoglobulins of mouse splenic lymphocytes and human peripheral blood lymphocytes differed with respect to class composition and protein A reactivity. Mouse lymphocyte surface immunoglobulins were nonreactive with protein A, whereas a high proportion of human lymphocyte surface immunoglobulins of different classes bound directly to the staphylococci. In sequential immunoprecipitation studies the prior isolation of one antigen had no appreciable effect on the subsequent recovery of another antigen. Adsorption of antigen-antibody complexes is quantitative when protein A sites are provided in excess over antiserum IgG sites, and this obviates the need for equivalence point titrations for optimal precipitation necessary with alternative double antibody techniques.

Cell membrane antigen isolation with the staphylococcal protein A-antibody adsorbent.

Myeloid progenitor cells were highly purified from normal human bone marrow by positive immunoselection with high-affinity monoclonal antibodies linked to magnetic beads and were successfully infected in vitro with the human immunodeficiency virus type 1 (HIV-1). From 99 to 100 percent pure bone marrow cells expressing the CD34 phenotypic marker were obtained. These cells were devoid of mature myeloid or T cell surface and intracellular markers as analyzed by immunohistochemical staining and flow cytometry. HIV-1 particles were detected by supernatant reverse transcriptase activity and transmission electron microscopy 40 to 60 days after infection. Viral particles were predominantly observed assembling and accumulating from within intracellular membranes, while phenotypically the cells were observed to have differentiated into CD4+ monocytes. These studies have important implications in understanding the pathogenesis of HIV-1 as well as the possible cause of certain of the observed hematologic abnormalities in HIV-1 infection. They also indicate that the bone marrow may serve as a potentially important reservoir of HIV-1 in the body.

https://science.sciencemag.org/content/sci/242/4880/919.full.pdf

Infection and replication of HIV-1 in purified progenitor cells of normal human bone marrow

It has been established that murine mast cells are derived from a pluripotent bone marrow stem cell In humans, the corresponding pluripotent cell is included in the CD34+ bone marrow population To determine whether human mast cells arise from CD34+ human progenitor cells, enriched CD34+ cells were cultured over agarose surfaces (interphase cultures) or cocultured with mouse 3T3 fibroblasts in the presence of recombinant human (rh) IL-3 The presence of both mast cells and basophils was determined using a variety of histochemical and immunohistologic techniques, including immunogold labeling for IgE receptors and mast cell tryptase Mast cells and basophils continued to appear in cultures when T cell, B cell, macrophage, and eosinophil committed progenitor cells were removed, but were not seen in cultures from which CD34+ cells were removed CD34+ cells layered over agarose in the presence of rhIL-3 were shown to give rise to cultures that contained mast cells (1 to 5%) and basophils (25 to 40%) Cultures supplemented with rhIL-4 showed no additional increase in mast cells or basophils CD34+ cells cocultured with 3T3 fibroblasts in the presence of rhIL-3 gave rise to mast cells within the fibroblast monolayer, which by 6 wk comprised up to 46% of the monolayer CD34-cells on 3T3 fibroblasts gave rise to few mast cells (2% of the monolayer) Mast cell granules from interphase cultures contained homogeneous electron-dense material In contrast, mast cells within 3T3 monolayers at 6 wk contained a variety of granule morphologies, including scroll, mixed, reticular, dense core, or homogeneous patterns We conclude that both human mast cells and basophils arise from CD34+ human progenitor cells

Steven W. Kessler

Papers

Rapid isolation of antigens from cells with a staphylococcal protein A-antibody adsorbent: parameters of the interaction of antibody-antigen complexes with protein A.

Helper virus induced T cell lymphoma in nonhuman primates after retroviral mediated gene transfer.

Cell membrane antigen isolation with the staphylococcal protein A-antibody adsorbent.

Infection and replication of HIV-1 in purified progenitor cells of normal human bone marrow

Demonstration of the Origin of Human Mast Cells from CD34+ Bone Marrow Progenitor Cells