The present disclosure relates to retroviral vectors comprising polynucleotides encoding hapten-binding receptors and T cell activating receptors. The retroviral vectors may also comprise transduction enhancers. Also disclosed are adaptor molecules and their use in conjunction with the retroviral vectors and T cells transduced with the retroviral vectors.

Described herein are virus-like particles (VLPs) and minimal human-derived virus-like particles (mhVLPs), comprising a membrane comprising a phospholipid bilayer with one or more human-derived envelope glycoproteins (env) on the external side. Optionally, a biomolecule cargo is disposed in the core of the VLP or mhVLP on the inside of the membrane. Preferably, the mhVLPs do not comprise any exogenous virally derived proteins, e.g., proteins from viral gag, pro, or pol, or other viral proteins that reside inside of enveloped particles (unless the cargo comprises the viral protein(s)). In some embodiments, the mhVLPs do not comprise any human endogenous retroviral (HERV) proteins other than the env (hENV), e.g., do not comprise gag, pol, or pro that was exogenously introduced into producer cells. In some embodiments, the VLPs include a targeting domain, either fused at the N or C terminus or internally into the hENV, or as a separate membrane-anchored targeting domain. Also described are methods of use of the VLPs or mhVLPs for delivery of the biomolecule cargo to cells.

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.

Provided herein are methods of repeated administration of a lipid particle or viral vector, such as for delivery of a payload gene, to a subject.

Anti-CD90 antibodies, binding fragments, and uses thereof are described. The provided antibodies and binding fragments can be used to isolate CD90 cells or to target such cells ex vivo or in vivo for a research, a diagnostic, or a therapeutic purpose. Anti-CD90 antibodies and binding fragments thereof can also be used in engineered formats to create antibody conjugates or within a recombinant protein to pseudotype viral vectors.

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. A pharmaceutical composition thereof and an in vitro method for transduction of targets cells with said vector particle 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.

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. A pharmaceutical composition thereof and an in vitro method for transduction of targets cells with said vector particle are also disclosed.