The present invention provides a retroviral or lentiviral vector having a viral envelope which comprises a mitogenic T-cell activating transmembrane protein which comprises: (i) a mitogenic domain which binds a mitogenic tetraspanin, and (ii) a transmembrane domain; wherein the mitogenic T-cell activating transmembrane protein is not part of a viral envelope glycoprotein. When cells such as T-cells or Natural Killer cells are transduced by such a viral vector, they are activated by the mitogenic T-cell activating transmembrane protein.

Methods and compositions are provided for delivery of a polynucleotide encoding a gene of interest, typically an antigen, to a dendritic cell (DC). The virus envelope comprises a DC-SIGN specific targeting molecule. The methods and related compositions can be used to treat patients suffering from a wide range of conditions, including infection, such as HIV/AIDS, and various types of cancers.

The present invention provides a retroviral or lentiviral vector having a viral envelope which comprises a mitogenic T-cell activating transmembrane protein which comprises: (i) a mitogenic domain which binds a mitogenic tetraspanin, and (ii) a transmembrane domain; wherein the mitogenic T-cell activating transmembrane protein is not part of a viral envelope glycoprotein. When cells such as T-cells or Natural Killer cells are transduced by such a viral vector, they are activated by the mitogenic T-cell activating transmembrane protein.

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.

Methods and compositions are provided for delivery of a polynucleotide encoding a gene of interest, typically an antigen, to a dendritic cell (DC). The virus envelope comprises a DC-SIGN specific targeting molecule. The methods and related compositions can be used to treat patients suffering from a wide range of conditions, including infection, such as HIV/AIDS, and various types of cancers.

The present invention provides means and methods for producing improved ex vivo B cell cultures with a short doubling time.

Methods and compositions are provided for delivery of a polynucleotide encoding a gene of interest, typically an antigen, to a dendritic cell (DC). The virus envelope comprises a DC-SIGN specific targeting molecule. The methods and related compositions can be used to treat patients suffering from a wide range of conditions, including infection, such as HIV/AIDS, and various types of cancers.

The present invention provides a retroviral or lentiviral vector having a viral envelope which comprises: (i) a mitogenic T-cell activating transmembrane protein which comprises a mitogenic domain and a transmembrane domain; and/or (ii) a cytokine-based T-cell activating transmembrane protein which comprises a cytokine domain and a transmembrane domain, wherein the mitogenic or cytokine-based T-cell activating transmembrane protein is not part of a viral envelope glycoprotein. When cells such as T-cells of Natural Killer cells are transduced by such a viral vector, they are simultaneously activated by the mitogenic T-cell activating transmembrane protein and/or the cytokine-based T-cell activating transmembrane protein.

The present invention provides means and methods for producing improved ex vivo B cell cultures with a short doubling time.

The present invention relates to an expression vector, an expression cassette or a pseudotyped viral vector particle comprising at least one nucleic acid encoding at least one Koala Retrovirus (KoRV) Envelope glycoprotein (Env), related nucleic acids, pseudotyped viral vector particles, mammalian packaging cell lines, transduced mammalian cells as well as related methods and uses.