Rejuvenation of car t cell

Abstract

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: