Human cytomegalovirus plasmid-based amplicon vector system for gene therapy

We have constructed and evaluated the utility of a helper-dependent virus vector system that is derived from Human Cytomegalovirus (HCMV). This vector is based on the herpes simplex virus (HSV) amplicon system and contains the HCMV orthologs of the two cis-acting functions required for replication and packaging of HSV genomes, the complex HCMV viral DNA replication origin (oriLyt), and the cleavage packaging signal (the a sequence). The HCMV amplicon vector replicated independently and was packaged into infectious virions in the presence of helper virus. This vector is capable of delivering and expressing foreign genes in infected cells including progenitor cells such as human CD34+ cells. Packaged defective viral genomes were passaged serially in fibroblasts and could be detected at passage 3; however, the copy number appeared to diminish upon serial passage. The HCMV amplicon offers an alternative vector strategy useful for gene(s) delivery to cells of the hematopoietic lineage

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Not AvailableThis second volume provides new and updated methods detailing advancements in CRISPR-Cas technical protocols. Chapters guide readers through protocols on prime editing, base editing, multiplex editing, editing in cell-free extract, in silico analysis of gRNA secondary structure and CRISPR-diagnosis. Authoritative and cutting-edge, CRISPR-Cas Methods, Volume 2 aims to serves as a laboratory manual providing scientists with a holistic view of CRISPR-Cas methodologies and its practical application for the editing of crop plants, cell lines, nematode and microorganism. The chapter “CRISPR/Cas9-mediated gene editing in human induced pluripotent stem cells” is available open access under a Creative Commons Attribution 4.0 International License via link.springer.com.”Not Availabl

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Not AvailableThe discovery and subsequent repurposing of the CRISPR (clustered regularly interspaced short palindromic repeats) and Cas proteins (CRISPR-associated proteins) has revolutionized our ability to manipulate DNA and RNA sequences in vitro, ex vivo, and in vivo. In this introductory chapter, we present a brief overview of basics of CRISPR-Cas-mediated genome editing and different orthologues and engineered versions of Cas protein with altered specificity and expanded targetability. More importantly, we comprehensively portray the advances made by developing diverse CRISPR-Cas-based genome modification tools and their application in basic biology, agriculture, and medicine.Not Availabl

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Includes cutting-edge methods and protocols Provides step-by-step detail essential for reproducible results Contains key notes and implementation advice from the expertsThis volume details the fundamentals of the CRISPR-Cas system, and its protocols illustrate advances in CRISPR-Cas techniques for efficient genome editing. Introductory chapters provide a wide horizon of CRISPR/Cas-based methods and applications. Additional chapters guide readers through HDR-mediated editing, sgRNA design, the step-by-step procedure of multiplex adenine base editing experiments in rice, generating mutants for rice, wheat, Brachypodium, Barley, Flax, and Phytophthora, visual screening of mutants, gene deletion (knock-out), tagging (knock-in) in mammalian cells, the cloning-free (DNA-free) technique, cell-penetrating peptides, generating a genome-edited banana, and nuclear genome editing of Chlamydomonas employing CRISPR-Cpf1 combined with a single-stranded DNA (ssODN) repair template. Authoritative and cutting-edge, CRISPR-Cas Methods aims to assist researchers who are new to the field and are aiming to learn how best to adopt this technology for a particular organism.Not Availabl

Multiple Gene Segments Control the Temperature Sensitivity and Attenuation Phenotypes of ca B/Ann Arbor/1/66

Cold-adapted (ca) B/Ann Arbor/1/66 is the influenza B virus strain master donor virus for FluMist, a live, attenuated, influenza virus vaccine licensed in 2003 in the United States. Each FluMist vaccine strain contains six gene segments of the master donor virus; these master donor gene segments control the vaccine's replication and attenuation. These gene segments also express characteristic biological traits in model systems. Unlike most virulent wild-type (wt) influenza B viruses, ca B/Ann Arbor/1/66 is temperature sensitive (ts) at 37°C and attenuated (att) in the ferret model. In order to define the minimal genetic components of these phenotypes, the amino acid sequences of the internal genes of ca B/Ann Arbor/1/66 were aligned to those of other influenza B viruses. These analyses revealed eight unique amino acids in three proteins: two in the polymerase subunit PA, two in the M1 matrix protein, and four in the nucleoprotein (NP). Using reverse genetics, these eight wt amino acids were engineered into a plasmid-derived recombinant of ca B/Ann Arbor/1/66, and these changes reverted both the ts and the att phenotypes. A detailed mutational analysis revealed that a combination of two sites in NP (A114 and H410) and one in PA (M431) controlled expression of ts, whereas these same changes plus two additional residues in M1 (Q159 and V183) controlled the att phenotype. Transferring this genetic signature to the divergent wt B/Yamanashi/166/98 strain conferred both the ts and the att phenotypes on the recombinant, demonstrating that this small, complex, genetic signature encoded the essential elements for these traits

Eradication of Pre-Established Lymphoma Using Herpes Simplex Virus Amplicon Vectors

Abstract Herpes simplex virus amplicon vectors expressing RANTES (HSVrantes) and the T-cell costimulatory ligand B7.1 (HSVB7.1) were studied for their ability to elicit a tumor-specific T-cell response in a murine lymphoma model. HSVB7.1- and HSVrantes-transduced EL4 cells expressed high levels of B7.1 and RANTES as analyzed by flow cytometry and enzyme-linked immunosorbent assay, respectively. Inoculation of ex vivo HSVB7.1 transduced cells in syngeneic mice resulted in regression of both transduced cells and nontransduced cells inoculated contralaterally. Direct intratumoral injection of HSVB7.1 and/or HSVrantes alone or in combination into established EL4 tumors led to complete tumor regression in injected tumors as well as in nontransduced contralaterally implanted tumor, whereas control tumors or tumors injected with HSVlac expressing β-galactosidase did not regress. Maximal protection was achieved with combined injection of HSVB7.1 and HSVrantes; mice showing tumor regression were resistant to rechallenge with parental EL4 cells, and tumor cell-specific cytolytic T-cell activity was observed in mice demonstrating regression. HSV amplicon-mediated delivery of immune effector molecules may represent a useful strategy for immunotherapy in the setting of pre-existing tumor