Abstract: This disclosure provides a composition comprising i) a pseudotyped retroviral vector particle or virus-like particle thereof comprising a) one envelope protein with antigen-binding activity, wherein said envelope protein is a recombinant protein that does not interact with at least one of its native receptor(s) and is fused at its ectodomain to a polypeptide comprising an antigen binding domain specific for a tag of a tagged polypeptide, and wherein said envelope protein is protein G, HN or H derived from the Paramyxoviridae family, and b) one envelope protein with fusion activity derived from the Paramyxoviridae family, and ii) said tagged polypeptide, wherein said tagged polypeptide binds specifically to an antigen expressed on the surface of a target cell, thereby transducing the target cell with said retroviral vector particle or thereby inducing uptake of the virus-like particle into the target cell.

Abstract: The present invention provides a composition comprising i) a pseudotyped retroviral vector particle or virus-like particle thereof comprising a) one envelope protein with antigen-binding activity, wherein said envelope protein is a recombinant protein that does not interact with at least one of its native receptor(s) and is fused at its ectodomain to a polypeptide comprising an antigen binding domain specific for a tag of a tagged polypeptide, and wherein said envelope protein is protein G, HN or H derived from the Paramyxoviridae family, and b) one envelope protein with fusion activity derived from the Paramyxoviridae family, and ii) said tagged polypeptide, wherein said tagged polypeptide binds specifically to an antigen expressed on the surface of a target cell, thereby transducing the target cell with said retroviral vector particle or thereby inducing uptake of the virus-like particle into the target cell.

Abstract: The present invention provides the use of a packaging cell line for the production of VSV-G pseudotyped retroviral vector particles or virus like particles thereof, wherein said packaging cell line is negative for Low-Density Lipoprotein Receptor (LDLR), optionally said packaging cell line stably expresses VSV-G. A method for producing said VSV-G pseudotyped retroviral vector particles or virus like particles thereof is disclosed as well as said particles obtained by said method.

Abstract: The present invention provides a composition comprising i) a pseudotyped retroviral vector particle comprising a) one envelope protein with antigen-binding activity, wherein said envelope protein is a recombinant protein that does not interact with at least one of its original receptors and is fused at its ectodomain to a polypeptide comprising an antigen binding domain specific for CD62L, and wherein said envelope protein is protein G, HN or H derived from the Paramyxoviridae family, b) one envelope protein with fusion activity derived from the Paramyxoviridae family, and T cells expressing CD62L. Alternatively, when said polypeptide comprising an antigen binding domain is specific for a tag of a tagged polypeptide instead of the antigen binding domain specific for CD62L, wherein said tagged polypeptide binds specifically to CD62L, then the composition comprises further said tagged polypeptide.

Abstract: The present invention provides a composition comprising A) immune cells such as T cells comprising a) an inducible gene expression system comprising I) a first nucleic acid comprising a drug-inducible promoter operably linked to a second nucleic acid, and II) said second nucleic acid encoding a polypeptide or a non-coding RNA (ncRNA) which decreases cell surface expression level of major histocompatibility complex (MHC) class I relative to cell surface expression level of MHC class I of an immune cell that does not express said polypeptide or ncRNA; and b) a third nucleic acid encoding a chimeric antigen receptor (CAR) or T cell receptor (TCR); and B) a drug that induces said drug-inducible promoter. Preferentially, said polypeptide may be a viral protein which decreases cell surface expression level of major histocompatibility complex (MHC) class I relative to cell surface expression level of MHC class I of an immune cell that does not express the viral protein.

Abstract: The present invention provides an in-vitro method of reducing the efficiency of transducing malignant cells of the blood system of a subject that are not derived from T cells with lentiviral vector particles without reducing the efficiency of transducing T cells in a sample comprising T cells and said malignant cells. A combination of compositions comprising a first composition and a second composition is also disclosed, wherein said first composition comprises i) transduced T cells of a subject, wherein said transduced T cells express a CAR comprising an antigen binding domain, wherein the antigen binding domain of said CAR binds specifically to a tag of a tagged polypeptide, and ii) non-transduced malignant cells of the blood system of said subject, and wherein said second composition comprises said tagged polypeptide, wherein said tagged polypeptide binds specifically to an antigen expressed on the surface of said malignant cells.

Abstract: The present invention provides a method for the generation of genetically modified T cells comprising the steps a) a sample provided comprising T cells, b) preparation of said sample by centrifugation, c) enrichment of the T cells, d) activation of the T cells using modulatory agents, e) genetic modification of the T cells by transduction with lentiviral vector particles, f) removal of said modulatory agents, thereby generating a sample of genetically modified T cells, wherein said method is performed in equal or less than 144 hours, less than 120 hours, less than 96 hours, less than 72 hours, less than 48 hours, or less than 24 hours. In one embodiment of the invention said enrichment of T cells is performed by magnetic cell separation using magnetic particles that are directly or indirectly coupled to antibodies or antigen binding fragments thereof specific for CD4 and/or CD8 wherein said magnetic particles can be removed from the cells after separation.

Abstract: The present invention provides a composition comprising i) a pseudotyped retroviral vector particle comprising a) one envelope protein with antigen-binding activity, wherein said envelope protein is a recombinant protein that does not interact with at least one of its original receptors and is fused at its ectodomain to a polypeptide comprising an antigen binding domain specific for CD62L, and wherein said envelope protein is protein G, HN or H derived from the Paramyxoviridae family, b) one envelope protein with fusion activity derived from the Paramyxoviridae family, and T cells expressing CD62L. Alternatively, when said polypeptide comprising an antigen binding domain is specific for a tag of a tagged polypeptide instead of the antigen binding domain specific for CD62L, wherein said tagged polypeptide binds specifically to CD62L, then the composition comprises further said tagged polypeptide.

Abstract: The present invention provides the use of a packaging cell line for the production of VSV-G pseudotyped retroviral vector particles or virus like particles thereof, wherein said packaging cell line is negative for Low-Density Lipoprotein Receptor (LDLR), optionally said packaging cell line stably expresses VSV-G. A method for producing said VSV-G pseudotyped retroviral vector particles or virus like particles thereof is disclosed as well as said particles obtained by said method.

Abstract: The present invention provides a composition comprising i) a pseudotyped retroviral vector particle or virus-like particle thereof comprising a) one envelope protein with antigen-binding activity, wherein said envelope protein is a recombinant protein that does not interact with at least one of its native receptor(s) and is fused at its ectodomain to a polypeptide comprising an antigen binding domain specific for a tag of a tagged polypeptide, and wherein said envelope protein is protein G, HN or H derived from the Paramyxoviridae family, and b) one envelope protein with fusion activity derived from the Paramyxoviridae family, and ii) said tagged polypeptide, wherein said tagged polypeptide binds specifically to an antigen expressed on the surface of a target cell, thereby transducing the target cell with said retroviral vector particle or thereby inducing uptake of the virus-like particle into the target cell.