Compositions and methods for t-cell and cytokine activation

Abstract

Chimeric antigen receptors (CARs) are provided that comprise a CD123-specific antigen recognition domain and IL7Ra transmembrane and intracellular signaling domains (CD123/IL7Ra CARs). In particular embodiments, provided herein are engineered lymphocytes that express and display CD123/IL7Ra CARs, and methods of targeting CD123-positive leukemic cells and treating leukemias, such as acute myeloid leukemia (AML), therewith.

1 . A polypeptide comprising a chimeric antigen receptor (CAR), the CAR comprising an anti-CD123 antigen-recognition domain, an IL7Ra transmembrane domain, and an IL7Ra intracellular signaling domain. 
     
     
         2 . The polypeptide of  claim 1 , wherein the antigen-recognition domain is an antibody fragment. 
     
     
         3 . The polypeptide of  claim 2 , wherein the antigen-recognition domain is a single chain variable fragment (scFv). 
     
     
         4 . The polypeptide of  claim 1 , further comprising a hinge domain between the antigen-recognition domain and transmembrane domain. 
     
     
         5 . The polypeptide of  claim 1 , further comprising one or more linker segments between domains. 
     
     
         6 . An engineered lymphocyte expressing a polypeptide of  claim 1 . 
     
     
         7 . The engineered lymphocyte of  claim 6 , wherein the lymphocyte is a T cell. 
     
     
         8 . The engineered lymphocyte of  claim 6 , wherein the lymphocyte is an NK cell. 
     
     
         9 . The engineered lymphocyte of  claim 6 , wherein the lymphocyte further expresses a bispecific engager molecule comprising:
 (a) an antigen-recognition domain that specifically binds to C-type lectin-like molecule-1 (CLL-1); and   (b) an activation domain that interacts with a portion of T cell receptor (TCR) to induce an immunomodulatory signal.   
     
     
         10 . The engineered lymphocyte of  claim 9 , wherein the antigen-recognition domain of the bispecific engager is an antibody fragment. 
     
     
         11 . The engineered lymphocyte of  claim 10 , wherein the antigen-recognition domain is a single chain variable fragment (scFv). 
     
     
         12 . The engineered lymphocyte of  claim 9 , wherein the activation domain is an antibody fragment. 
     
     
         13 . The engineered lymphocyte of  claim 12 , wherein the activation domain is a single chain variable fragment (scFv). 
     
     
         14 . The engineered lymphocyte of  claim 12 , wherein the activation domain is an anti-CD3 antibody fragment. 
     
     
         15 . The engineered lymphocyte of  claim 9 , wherein the activation domain and antigen-recognition domain are single chain variable fragments tethered to each other by a linker domain. 
     
     
         16 . An engineered lymphocyte comprising:
 (a) a first polynucleotide sequence encoding bispecific engager molecule that comprises a CLL-1 antigen-recognition domain capable of binding a CLL-1 antigen and an activation domain capable of binding a molecule moiety displayed on T cells that activates an immunomodulatory signal upon binding; and   (b) a second polynucleotide sequence encoding a chimeric antigen receptor (CAR) that comprises a CD123 antigen-recognition domain capable of binding a CD123 antigen, a IL7Ra transmembrane domain, and a IL7Ra intracellular signaling domain.   
     
     
         17 . The engineered lymphocyte of  claim 16 , wherein the first polynucleotide sequence and the second polynucleotide sequence are portions of a single nucleic acid or vector. 
     
     
         18 . The engineered lymphocyte of  claim 16 , wherein the first polynucleotide sequence and the second polynucleotide sequence are portions of separate nucleic acids or vectors. 
     
     
         19 . The engineered lymphocyte of  claim 16 , wherein the lymphocyte is a T cell. 
     
     
         20 . The engineered lymphocyte of  claim 16 , wherein the lymphocyte is an NK cell. 
     
     
         21 . A method of treating a disease or condition comprising administering the engineered lymphocyte of one or  claims 6 - 20  to a subject. 
     
     
         22 . The method of  claim 21 , wherein the subject suffers from cancer. 
     
     
         23 . The method of  claim 22 , wherein the subject suffers from leukemia. 
     
     
         24 . The method of  claim 23 , wherein the subject suffers from acute myeloid leukemia (AML). 
     
     
         25 . Use of an engineered lymphocyte of one or  claims 6 - 20  for the treatment of a disease or condition. 
     
     
         26 . The use of  claim 25 , wherein the disease or condition is cancer. 
     
     
         27 . The use of  claim 26 , wherein the disease or condition is leukemia. 
     
     
         28 . The use of  claim 27 , wherein the disease or condition is acute myeloid leukemia (AML).