The present invention discloses a process for engineering a host cell comprising the steps of; a) integrating a first polynucleotide cassette including a first selection marker flanked by a first pair of recombination sites; b) removing the first selection marker by the action of a recombinase which recognises the first pair of recombination sites; c) integrating a second polynucleotide cassette including a second selection marker flanked by a second pair of recombination sites; and d) removing the second selection marker by the action of a recombinase which recognises the second pair of recombination sites. Also disclosed is a host cell genome polynucleotide comprising a first recombinantly engineered region and a second recombinantly engineered region, wherein a first single recombination site is adjacent to the first recombinantly engineered region, and a second single recombination site is adjacent to the second recombinantly engineered region.

Provided herein, are compositions based on retroviruses (e.g., lentiviruses) comprising one or more nucleic acid molecules encoding retroviral Pol polyprotein components and a nucleic acid molecule comprising one or more transgene sequences flanked by long terminal repeat sequences, for delivery of the one or more transgenes to a target cell ex vivo or in vivo. The compositions are useful for delivering to a target cell (e.g., hematopoietic stem cells (HSCs), liver cells, ocular cells, muscle cells, epithelial cells, T cells, etc.) and/or stably expressing any transgene (e.g., beta-globin, Factor VIII, RP GTPase regulator (RPGR), dystrophin, cystic fibrosis transmembrane conductance regulator (CFTR), a chimeric antigen receptor, etc.) with a biological effect to treat and/or ameliorate the symptoms associated with any disorder related to gene expression (e.g., sickle cell disease, beta-thalassemia, haemophilia B, retinitis pigmentosa, Duchenne muscular dystrophy, cystic fibrosis, cancer, etc.).

The invention relates to an adenoviral-based biological delivery and expression system for use in the treatment or prevention of osteoathritis in human or mammalian joints by long-term inducible gene expression of human or mammalian interleukin-1 receptor antagonist (II-1 Ra) in synovial cells, comprising a helper-dependent adenoviral vector containing a nucleic acid sequence encoding for human or mammalian interleukin-1 receptor antagonist (II-1 Ra), left and right inverted terminal repeats (L ITR and R ITR), the adenoviral packaging signal and non-viral, non-coding stuffer nucleic acid sequences, wherein the expression of the human or mammalian interleukin-1 receptor antagonist (II-1 Ra) gene within synovial cells is regulated by an inflammation-inducible promoter.

Methods are disclosed for reprogramming a somatic cell, including an adherent cell and a cell in suspension, into an induced pluripotent stem comprising expressing exogenous Sox-2, exogenous Klf-4, exogenous Oct3/4 from DNA that has not integrated into the genome of the somatic cell, suppressing p53 activity within the somatic cell, and exposing the somatic cell to reprogramming-assistance factors comprising an exogenous Alk-5 inhibitor, an exogenous histone deacetylase inhibitor, and an exogenous activator of glycolysis. Compositions and kits for use in such methods are also disclosed as are cells made by such a method.

A vector production system is provided. The system comprises recombinant cells designed to encode at least a first recombinase under the control of an inducible promoter and the cells include an expression vector encoding a nucleic acid of interest within the regulatory elements of the expression vector which are flanked on either side by a target sequence for at least the first recombinase. The vector production system provides an efficient one-step process for producing linear or circular covalently closed vectors that incorporate a nucleic acid sequence of interest.

Methods and compositions are provided for editing the genome of a cell without the use of an exogenously supplied nuclease. Aspects of the methods include contacting a cell with a targeting vector comprising nucleic acid sequence to be integrated into the target locus, where the cell is not also contacted with a nuclease. In addition, reagents, devices and kits thereof that find use in practicing the subject methods are provided.

The present invention relates to the production and use of covalently closed circular (ccc) recombinant DNA molecules such as plasmids, cosmids, bacterial artificial chromosomes (BACs), bacteriophages, viral vectors and hybrids thereof, and more particularly to vector modifications that improve expression of said DNA molecules.

The present invention discloses an engineered bacteriophage capable of binding to a commensal bacterium and inserting its genome polynucleotide into the commensal bacterium, but incapable of producing progeny, incapable of carrying out a lysogenic cycle and incapable of carrying out a lytic cycle within the commensal bacterium, wherein the engineered bacteriophage comprises a genome polynucleotide including at least one gene encoding at least one heterologous antigen(s) under the control of a promoter.

A eukaryotic replicative pUC-free minicircle expression vector is provided. The eukaryotic replicative pUC-free minicircle expression vector includes a pUC-free eukaryotic region sequence encoding a transgene of interest and comprising 5′ and 3′ ends and a ii) pUC-free spacer region of less than 500 basepairs in length linking the 5′ and 3′ ends of the eukaryotic region sequences and comprising a bacterial R6K replication origin having at least 95% sequence identity to SEQ ID NO: 11 and SEQ ID NO: 12 and a RNA selectable marker, the RNA selectable marker being an RNA-IN regulating RNA-OUT functional variant having at least 95% sequence identity to SEQ ID NO: 20 or SEQ ID NO: 22.

The present disclosure provides a non-naturally occurring CRISPR-Cas system comprising: a Cas9 effector protein capable of generating cohesive ends (stiCas9), and a guide polynucleotide that forms a complex with the stiCas9 and comprising a guide sequence, wherein the guide sequence hybridizes with a target sequence in a eukaryotic cell but does not hybridize to a sequence in a bacterial cell, and wherein the complex does not occur in nature. The present disclosure also provides a method of introducing a sequence of interest into a chromosome of a cell. Finally, the present disclosure provides for a method of modifying one or more nucleotides using seamless mutagenesis.