Cell

1. A cell which comprises a first chimeric antigen receptor (CAR) and a second CAR, wherein the first and second CARs bind different epitopes on the same ligand, wherein the ligand is a cytokine, a chemokine, a tumor-associated antigen, or a soluble ligand secreted by tumor cells.

2. A cell according to claim 1 , wherein the ligand is a soluble ligand.

3. A cell according to claim 2 , wherein the ligand is a cytokine, chemokine or metabolite.

4. A cell according to claim 1 which comprises a third CAR which binds a cell surface antigen.

5. A cell according to claim 4 , wherein the first and/or second and third CARs each comprise:

(i) an antigen-binding domain;

(ii) a trans-membrane domain; and

(iii) an endodomain

wherein the endodomains of the third CAR and the first and/or second CAR(s) are complementary, such that cell activation occurs when the ligand is bound by the first and second CARs and the cell surface antigen is bound by the third CAR.

6. A cell according to claim 5 , wherein the third CAR comprises a CD3 zeta endodomain, and the first and/or second CAR(s) comprise a CD28 endodomain and a OX40 or 41BB endodomain.

7. A cell according to claim 4 wherein the third CAR binds prostate-specific membrane antigen (PSMA) and the first and second CARs bind prostate-specific antigen (PSA).

8. A nucleic acid construct which comprises a first nucleic acid sequence encoding a first CAR; and a second nucleic acid sequence encoding a second CAR, wherein the first and second CARs bind different epitopes on the same ligand, wherein the ligand is a cytokine, a chemokine, a tumor-associated antigen, or a soluble ligand secreted by tumor cells.

9. A nucleic acid construct according to claim 8 , which has the following structure:

AgB1-spacer1-TM1-endo1-coexpr-AbB2-spacer2-TM2-endo2

in which

AgB1 is a nucleic acid sequence encoding the antigen-binding domain of the first CAR;

spacer 1 is a nucleic acid sequence encoding the spacer of the first CAR;

TM1 is a nucleic acid sequence encoding the transmembrane domain of the first CAR;

endo 1 is a nucleic acid sequence encoding the endodomain of the first CAR;

coexpr is a nucleic acid sequence encoding a cleavage site enabling co-expression of both CARs;

AgB2 is a nucleic acid sequence encoding the antigen-binding domain of the second CAR;

spacer 2 is a nucleic acid sequence encoding the spacer of the second CAR;

TM2 is a nucleic acid sequence encoding the transmembrane domain of the second CAR;

endo 2 is a nucleic acid sequence encoding the endodomain of the second CAR;

which nucleic acid construct, when expressed in a T cell, encodes a polypeptide which is cleaved at the cleavage site such that the first and second CARs are co-expressed at the T cell surface.

10. A nucleic acid construct according to claim 8 , which also comprises a nucleic acid sequence encoding a third CAR which binds a cell surface antigen.

11. A vector comprising a nucleic acid construct according to claim 8 .

12. A retroviral vector or a lentiviral vector or a transposon according to claim 11 .

13. A kit which comprises:

i) a vector comprising a nucleic acid sequence encoding a first; and

ii) a vector comprising a nucleic acid sequence encoding a second CAR, wherein the first and seconded CARs bind different epitopes on the same ligand, wherein the ligand is a cytokine, a chemokine, a tumor-associated antigen, or a soluble ligand secreted by tumor cells.

14. A kit according to claim 13 which also comprises a vector comprising a nucleic acid sequence encoding a third CAR which binds a cell surface antigen.

15. A method for making a cell, which comprises the step of introducing: a nucleic acid construct according to claim 8 , into a cell.

16. A method according to claim 15 , wherein the cell is from a sample isolated from a subject.

17. A pharmaceutical composition comprising a plurality of cells according to claim 1 .

18. A method for treating cancer, which comprises the step of administering a pharmaceutical composition according to claim 17 to a subject.

19. A method according to claim 18 , which comprises the following steps:

(i) isolation of a cell-containing sample from a subject;

(ii) transduction or transfection of the cells with: a nucleic acid construct according to any of claim 8 ; and

(iii) administering the cells from (ii) to a the subject.