Inhibitory chimeric antigen receptors

1. A chimeric antigen receptor (CAR) comprising an extracellular domain comprising an antigen binding domain, a transmembrane domain, and an intracellular domain, wherein:

(a) the intracellular domain comprises an Immunoreceptor Tyrosine-based Switch Motif (ITSM), wherein said ITSM is a sequence of amino acids TX 1 YX 2 X 3 X 4 (SEQ ID NO: 2049), wherein

X 1 is E;

X 2 is A or S;

X 3 is S or E; and

X 4 is V or I; and

(b) the intracellular domain has at least 95% amino acid sequence identity with SEQ ID NO: 2016.

2. The CAR according to claim 1 , wherein said ITSM is selected from the group consisting of TEYASI (SEQ ID NO: 936), TEYSEI (SEQ ID NO: 940), and TEYSEV (SEQ ID NO: 941).

3. The CAR according to claim 1 , wherein the antigen binding domain is a single chain variable fragment (scFv).

4. The CAR according to claim 1 , wherein the intracellular domain is selected from the group consisting of SEQ ID NO: 2014, SEQ ID NO: 2015, and SEQ ID NO: 2016.

5. The CAR according to claim 1 , wherein the antigen binding domain binds to PSMA, ITGAX, CD1E, CD34, CD1C, CD123, CD141, ZP2, GABRA6, CRTAM, GRM4, MDGA1, ZP2, GABRA6, CRTAM, GRM4, MDGA1, SFTPC, ROS1, SLC6A4, AGTR2, LRRC26, HTR3A, TMEM211, MRGPRX3, MEP1B, TMIGD1, CEACAM20, ALPI, TMPRSS11B, CYP17A1, ATP4B, GP2, MUC21, CLCA4 or SLC27A6.

6. The CAR according to claim 1 , wherein the transmembrane domain comprises the transmembrane region(s) of the alpha, beta or zeta chain of the T-cell receptor, PD-1, 4-1BB, OX40, ICOS, CTLA-4, LAG3, 2B4, BTLA4, TIM-3, TIGIT, SIRPA, CD28, CD3 epsilon, CD45, CD4, CD5, CD8, CD9, CD16, CD22, CD33, CD37, CD64, CD80, CD86, CD134, CD137 or CD154.

7. The CAR according to claim 1 , wherein the transmembrane domain comprises the transmembrane region of PD-1 or CD8 alpha.

8. The CAR according to claim 1 , wherein the transmembrane domain is attached to the extracellular domain of the CAR via a hinge.

9. The CAR according to claim 8 , wherein the hinge is an IgG4 hinge, a CD8 alpha hinge or a PD-1 hinge.

10. The CAR according to claim 1 , wherein said ITSM is TEYASI (SEQ ID NO: 936).

11. The CAR according to claim 1 , wherein said ITSM is TEYSEI (SEQ ID NO: 940).

12. The CAR according to claim 1 , wherein said ITSM is TEYSEV (SEQ ID NO: 941).

13. The CAR according to claim 10 , wherein the intracellular domain is PD1 (ITSM mut3) (SEQ ID NO: 2016).

14. The CAR according to claim 11 , wherein the intracellular domain is PD1 (ITSM mut1) (SEQ ID NO: 2014).

15. The CAR according to claim 12 , wherein the intracellular domain is PD1 (ITSM mut2) (SEQ ID NO: 2015).

16. An isolated immune cell, comprising:

a first CAR comprising an extracellular domain comprising an antigen binding domain, a transmembrane domain, and an intracellular domain; and

a second CAR, wherein the second CAR is a CAR according to claim 1 .

17. The immune cell according to claim 16 , wherein:

the antigen to which the antigen binding domain of the first CAR binds is CD33 and the antigen to which the antigen binding domain of the second CAR binds is ITGAX, CD1E, CD34, CD1C, CD123, or CD141, or,

the antigen to which the antigen binding domain of the first CAR binds is FLT3 and the antigen to which the antigen binding domain of the second CAR binds is ZP2, GABRA6, CRTAM, GRM4 or MDGA1, or,

the antigen to which the antigen binding domain of the first CAR binds is MSLN and the antigen to which the antigen binding domain of the second CAR binds is SFTPC, ROS1, SLC6A4 or AGTR2, or,

the antigen to which the antigen binding domain of the first CAR binds is MUC16 and the antigen to which the antigen binding domain of the second CAR binds is LRRC26, HTR3A, TMEM211 or MRGPRX3, or,

the antigen to which the antigen binding domain of the first CAR binds is MUC17 and the antigen to which the antigen binding domain of the second CAR binds is MEP1B, TMIGD1, CEACAM20 or ALPI, or,

the antigen to which the antigen binding domain of the first CAR binds is present in tumor cells of pancreatic ductal adenocarcinoma and the antigen to which the antigen binding domain of the second CAR binds is TMPRSS11B, CYP17A1 or ATP4B,

the antigen to which the antigen binding domain of the first CAR binds is present in tumor cells of kidney clear cell carcinoma and the antigen to which the antigen binding domain of the second CAR binds is GP2, MUC21, CLCA4 and SLC27A6.

18. The immune cell according to claim 16 , wherein the immune cell is a human T-cell.

19. A method of engineering an immune cell according to claim 16 comprising: (a) providing an immune cell; and (b) expressing the second CAR and the first CAR at the surface of said cells.

20. A polynucleotide comprising a nucleic acid sequence encoding a CAR according to claim 1 .

21. A vector comprising a polynucleotide according to claim 20 .