Lentiviral packaging cells and methods for producing the same are provided herein. Specifically, lentiviral packaging cells capable of producing lentiviral vector suitable for use in clinical trials are provided. Methods for producing lentiviral packaging cells capable of producing lentiviral vector suitable for use in clinical trials are described.

The present invention relates to a retroviral system for the transfer of non-viral RNA into target cells and more particularly a retroviral particle capable of delivering multiple RNAs. More particularly, it relates to retroviral particles 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 linked to an encapsidation sequence, each encapsidation sequence being recognised by a binding domain introduced into the protein derived from the Gag polyprotein and/or into the integrase.

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 invention provides a vaccine for feline leukemia virus and methods of making and using the vaccine alone, or in combinations with other protective agents.

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 and related methods that include genetically modifying T cells and/or NK cells. The methods use replication incompetent recombinant retroviral particles that comprise a pseudotyping element on their surface and optionally a membrane-bound T cell activation element, such as an anti-CD3, and encode one or more engineered signaling polypeptides that can include a lymphoproliferative element, and/or a chimeric antigen receptor (CAR). The methods can include contacting PBMCs with replication incompetent recombinant retroviral particles for various exemplary time periods, such as less than 24 hours or in some illustrative embodiments less than 15 minutes. In some aspects, the present disclosure provides methods and compositions for genetically modifying lymphocytes, for example T cells and/or NK cells, 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.