REJUVENATION OF CAR T CELL
A payload of drug conjugated to a targeting ligand specifically designed to deliver to exhausted CART cells to rejuvenate these CAR T cells is provided herein. The targeted CAR T cells are modified with a fusion receptor which can bind to the targeting ligand and internalize the conjugated payload of drug to execute its regulatory function to exhausted CAR T cell.
1 . A system to rejuvenate an exhausted classical CAR T cell, comprising at least two components: a first component is a conjugate comprising a targeting ligand covalently linked to a payload drug; and a second component is a targeting ligand binding module linked to a membrane-anchoring module, wherein the targeting ligand binding module of the second component recognizes the targeting ligand in the first component with high affinity to form a complex, the payload drug either blocks the inhibitory signaling of the exhausted classical CAR T, or re-activates said CAR T through an antigen independent pathway, and wherein the membrane-anchoring module mediates internalization of the two component complex into the exhausted CAR T cell.
2 . The system according to claim 1 , wherein the targeting ligand of the first component is folate, FITC or FK506.
3 . The system according to claim 1 , wherein the targeting ligand binding module of the second component comprises an anti-FITC antibody fragment or FKBP or folate receptor.
4 . The system according to claim 1 , wherein the membrane anchoring module is a folate receptor.
5 . The system according to claim 1 , wherein the first component comprises a releasable linker between the targeting ligand and the payload drug.
6 . The system according to claim 1 , wherein the first component comprises a non-releasable linker between the targeting ligand and the payload drug.
7 . The system according to claim 1 , wherein the binding affinity between the targeting ligand and the ligand-binding module is in sub-nanomolar range.
8 . The system according to claim 1 , wherein the payload of drug is a Toll Like Receptor 7 (TLR7) agonist or Simulator of interferon genes (STING) agonist.
9 . The system according to claim 1 , wherein the payload of drug is an inhibitor to following proteins: SHP1/2, TC-PTP or DGKα, TGFβ.
10 . The system according to claim 8 , wherein the TLR7 agonist has the structure of
11 . The system according to claim 1 , wherein the first component is a Fluorescein-TLR7 agonist having the structure of
12 . The system according to claim 1 , wherein the first component is a FK506-TLR7 agonist having the structure of
13 . The system according to claim 1 , wherein the first component is one of the following:
14 . The system according to claim 1 , wherein the first component comprising the payload drug selected from the group consisting of following TC-PTP phosphatase inhibitors:
15 . The system according to claim 14 , wherein the phosphatase inhibitor is connected to the fluorescein or FK506 (tacrolimus) to form the following structures:
16 . The system according to claim 1 , wherein the payload drug in the first component comprises a STING agonist of one of the following structures.
17 . The system according to claim 1 , wherein the first component comprises a spacer between the targeting ligand and the payload drug selected from the group consisting of the following structures:
18 . A method to rejuvenate an exhausted CAR T cell, comprising:
a. providing said exhausted CAR T cell a first component comprising a conjugate, wherein the conjugate comprises a targeting ligand covalently linked to a payload of drug through a releasable or non-releasable linker;
b. providing said exhausted CAR T cell a second component comprising a fusion receptor linked to the exhausted CAR construct, wherein the fusion receptor comprises a targeting ligand binding module and a membrane bound receptor module;
c. letting the targeting ligand binding module of the second component bind to the targeting ligand in the first component to form a complex,
d. letting the membrane bound CAR module mediate internalization of the complex into the exhausted CAR T cell;
e. letting the payload drug either block the inhibitory signaling of the exhausted CAR T, or re-activate said CAR T through an antigen independent pathway.
19 . The method according to claim 18 , wherein the payload drug executes its function within the endosome of the exhausted CAR T, and the targeting ligand and the payload drug are linked by a nonreleasable linker.
20 . The method according to claim 18 , wherein the payload drug executes its function as a free drug in the cytosol of the exhausted CAR T, and the targeting ligand and the payload drug are linked by a releasable linker.
21 . The method according to claim 18 , wherein the targeting ligand of the first component is folate, FITC or FK506.
22 . The method according to claim 18 , wherein the targeting ligand binding module of the second component anti-FITC, folate receptor, or FKBP.
23 . The method according to claim 18 , wherein the ligand binding module is Folate Receptor alpha (FRa).
24 . The method according to claim 18 , wherein the payload of drug is a Toll Like Receptor 7 (TLR7) agonist or Simulator of interferon genes (STING) agonist.
25 . The method according to claim 18 , wherein the payload of drug is an inhibitor to following proteins: SHP1/2, TC-PTP or DGKα, TGFβ.
26 . The method according to claim 18 , wherein the TLR7 agonist has the structure of
27 . The method according to claim 18 , wherein the first component is a Fluorescein-TLR7 agonist having the structure of
28 . The method according to claim 18 , wherein the first component is a FK506-TLR7 agonist having the structure of
29 . The method according to claim 18 , wherein the first component is one of the following
30 . The method according to claim 18 , wherein the first component comprising the payload drug selected from the group consisting of following TC-PTP phosphatase inhibitors:
31 . The method according to claim 30 , wherein the Phosphatase inhibitor is connected to the fluorescein or FK506 (tacrolimus) to form the following structures:
32 . The method according to claim 18 , wherein the payload drug in the first component comprising a STING agonist of the following structures.
33 . The method according to claim 18 , wherein the first component comprising a spacer between the targeting ligand and the payload drug selected from the group consisting of the following structures: