Retroviral and lentiviral vectors
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.
1. A retroviral or lentiviral vector having a viral envelope which comprises:
(i) a first mitogenic T-cell activating transmembrane protein which comprises a mitogenic domain which binds CD3, and a transmembrane domain; and
(ii) a second mitogenic T cell activating transmembrane protein which comprises a mitogenic domain which binds CD28 and a transmembrane domain
wherein the mitogenic T cell activating transmembrane proteins are not part of a viral envelope glycoprotein.
2. The viral vector according to claim 1 , which comprises a cytokine-based T-cell activating transmembrane protein which comprises a cytokine selected from IL2, IL7 and IL15.
3. The viral vector according to claim 1 , wherein the viral envelope also comprises:
(iii) a tagging protein which comprises:
a binding domain which binds to a capture moiety; and
a transmembrane domain
which tagging protein facilitates purification of the viral vector from cellular supernatant via binding of the tagging protein to the capture moiety.
4. The viral vector according to claim 1 which comprises a nucleic acid sequence encoding a T-cell receptor or a chimeric antigen receptor.
5. The viral vector according to claim 1 which is a virus-like particle (VLP).
6. A host cell which expresses, at the cell surface,
(i) a first mitogenic T-cell activating transmembrane protein which comprises a mitogenic domain which binds CD3 and a transmembrane domain; and
(ii) a second mitogenic T cell activating transmembrane protein which comprises a mitogenic domain which binds CD28 and a transmembrane domain;
and which produces a retroviral or lentiviral vector according to claim 1 .
7. The host cell according to claim 6 , which also expresses, at the cell surface:
(iii) a tagging protein which comprises:
a binding domain which binds to a capture moiety; and
a transmembrane domain;
wherein the viral envelope of the retroviral or lentiviral vector produced by the host cell comprises the tagging protein,
which tagging protein facilitates purification of the retroviral or lentiviral vector from the cellular supernatant via binding of the tagging protein to the capture moiety.
8. A packaging cell which expresses, at the cell surface,
(i) a first mitogenic T-cell activating transmembrane protein which comprises a mitogenic domain which binds CD3 and a transmembrane domain; and
(ii) a second mitogenic T cell activating transmembrane protein which comprises a mitogenic domain which binds CD28 and a transmembrane domain
and comprises one or more of the following genes: gag, pol, env and/or rev.
9. A producer cell which expresses, at the cell surface,
(i) a first mitogenic T-cell activating transmembrane protein which comprises a mitogenic domain which binds CD3 and a transmembrane domain; and/or
(ii) a second mitogenic T cell activating transmembrane protein which comprises a mitogenic domain which binds CD28 and a transmembrane domain
which comprises gag, pol, env and optionally rev genes and also comprises a retroviral or lentiviral genome.
10. A method for making a host cell according to claim 6 , which comprises the step of transducing or transfecting a cell with a nucleic acid encoding a first mitogenic T-cell activating transmembrane protein and a second mitogenic T cell activating transmembrane protein.
11. A method for producing a viral vector according to claim 1 which comprises the step of expressing a retroviral or lentiviral genome in a cell.
12. A method for making an activated transgenic T-cell or natural killer (NK) cell, which comprises the step of transducing a T or NK cell with a viral vector according to claim 1 , such that the T-cell or NK cell is activated by the one or more mitogenic T-cell activating transmembrane protein(s).