Novel lentivirus packaging systems engineered with a synthetic gene network having a positive feedback loop to amplify the expression of virus genes are provided. When co-transfected into a host cell with a transfer plasmid and envelope vector, extremely high viral titers are achieved when compared to transfection of a host cell with conventional third generation packaging systems. Methods for enhancing production of lentivirus, compositions comprising high titer lentivirus, and therapeutic methods based on delivery of lentiviral nucleic acid to target cells are also provided.

The present invention describes the development of a modified envelope glycoproteins to pseudo-type viruses of the retroviridae family. These are derived from Murine leukaemia virus amphotropic, Gibbon Ape leukaemia virus and feline endogenous virus envelopes.

The improved envelope glycoproteins contain, among other modifications, newly introduced alternative cleavable sequences.

The viral vectors pseudo-typed with these modified envelopes may be suitably employed for cargo delivery such as in gene and cell therapy applications, for the ex vivo and in vivo delivery of gene(s), protein(s), or molecule(s) of interest to a variety of target cells.

The present invention relates to retroviral particle comprising a protein derived from the Gag polyprotein, an envelope protein, optionally an integrase and at least two encapsidated non-viral RNAs, the encapsidated non-viral RNAs each comprising an RNA sequence of interest bound to an encapsidation sequence, each encapsidation sequence being recognized by a binding domain introduced into the protein derived from the Gag polyprotein and/or into the integrase, and at least one of said sequences of interest of the encapsidated non-viral RNAs comprises a part coding at least one epitope and/or at least one molecular structure specifically recognizing an epitope.

Viral vectors, lentiviral particles, and modified cells are disclosed. They encode or express a small RNA capable of targeting the KIF11 gene. In embodiments, the viral vectors and lenti viral particles further comprise and a KIF11 gene whose non-coding region has been modified such that it is resistant to activity by the small RNA.

The invention discloses a method for constructing functional exosomes capable of efficiently loading specific miRNA. In order to enable the exosome to carry miRNA with specific regulation function more efficiently so as to play a role in targeted regulation more accurately and efficiently, MS2 phage capsid protein is utilized to edit and construct a capture element of a specific miRNA molecule, and placenta mesenchymal stem cells are reprogrammed to enable the secreted exosome to efficiently load a target miRNA molecule, so that the target miRNA molecule is delivered to tissue cells to play a role in effective regulation, and therefore a new strategy is provided for realizing specific precise treatment in the future.

Novel lentivirus packaging systems engineered with a synthetic gene network having a positive feedback loop to amplify the expression of virus genes are provided. When co-transfected into a host cell with a transfer plasmid and envelope vector, extremely high viral titers are achieved when compared to transfection of a host cell with conventional third generation packaging systems. Methods for enhancing production of lentivirus, compositions comprising high titer lentivirus, and therapeutic methods based on delivery of lentiviral nucleic acid to target cells are also provided.

The present disclosure provides compositions and methods for producing stable viral vector producer cell lines that enable industrial scale production of viral vectors. Novel vector constructs carrying a gene of interest and novel vector constructs carrying viral accessory proteins for the production of viral vectors in mammalian cells are also disclosed.

The present disclosure provides methods for genetically modifying lymphocytes and methods for performing adoptive cellular therapy that include transducing T cells and/or NK cells. The methods can include inhibitory RNA molecule(s) and/or engineered signaling polypeptides that can include a lymphoproliferative element, and/or a chimeric antigen receptor (CAR), for example a microenvironment restricted biologic CAR (MRB-CAR). Additional elements of such engineered signaling polypeptides are provided herein, such as those that drive proliferation and regulatory elements therefor, as well as replication incompetent recombinant retroviral particles and packaging cell lines and methods of making the same. Numerous elements and methods for regulating transduced and/or genetically modified T cells and/or NK cells are provided, such as, for example, those including riboswitches, MRB-CARs, recognition domains, and/or pH-modulating agents.

The present disclosure provides methods and compositions for genetically modifying lymphocytes, for example T cells and/or NK cells, in shorter times than previously and/or in whole blood or a component thereof. In some embodiments a lymphodepletion filter assembly is used before or after forming a reaction mixture where lymphocytes are contacted with recombinant retroviral particles in a closed system, to genetically modify the lymphocytes.

The present disclosure provides an automated method of producing viral vectors, utilizing engineered viral vector-producing cell lines within a fully-enclosed cell engineering system. Exemplary viral vectors that can be produced include lentivirus vectors, adeno-associated virus vectors, baculovirus vectors and retrovirus vectors.