Methods and Compositions for Reducing Immunosupression by Tumor Cells

Abstract

The present disclosure provides, in part, methods of discovering immunotherapy targets in vivo, therapeutic compositions (e.g., shRNA, immunoresponsive cells expressing shRNA and/or a chimeric antigen receptors (CAR)), and methods of use thereof.

1 . An isolated nucleic acid encoding a chimeric antigen receptor (CAR) and a sequence encoding an shRNA,
 the shRNA comprises 15 contiguous nucleotides complementary a nucleic acid sequence of SEQ ID NO: 612, and   wherein the CAR comprising an antigen binding domain, a transmembrane domain, a stimulatory domain, and a co-stimulatory domain.   
     
     
         2 . The isolated nucleic acid of  claim 1 , wherein the shRNA sequence reduces expression of Cb1b. 
     
     
         3 . The isolated nucleic acid of  claim 1 , wherein the antigen binding domain is an antigen-binding fragment of an antibody. 
     
     
         4 . The isolated nucleic acid of  claim 3 , wherein the antigen-binding fragment is a Fab or scFv. 
     
     
         5 . The isolated nucleic acid of  claim 1 , wherein the antigen-binding domain binds tumor antigen. 
     
     
         6 . The isolated nucleic acid of  claim 5 , wherein the tumor antigen is associated with a melanoma, carcinoma, sarcomas, adenocarcinoma, lymphoma, leukemia, kidney, breast, lung, bladder, colon, ovarian, prostate, pancreas, stomach, brain, head and neck, skin, uterine, testicular, glioma, esophagus, and liver cancer. 
     
     
         7 . The isolated nucleic acid of  claim 5 , wherein the tumor antigen is associated with a solid tumor or lymphoid tumor. 
     
     
         8 . A vector comprising the nucleic acid of  claim 1 . 
     
     
         9 . An immunoresponsive cell comprising the nucleic acid of  claim 1 . 
     
     
         10 . The immunoresponsive cell of  claim 9 , wherein the immunoresponsive cell is tumor specific. 
     
     
         11 . The immunoresponsive cell of  claim 10 , wherein the immunoresponsive cell is selected from the group consisting of a tumorinfiltrating lymphocyte (TIL), a Natural Killer T cell (NKT), a cytotoxic T lymphocyte (CTL), and a CD4 T cell. 
     
     
         12 . The immunoresponsive cell of  claim 9 , wherein the CAR is directed to a tumor antigen comprising prostate-specific membrane antigen (PSMA). 
     
     
         13 . A human T cell harboring the nucleic acid molecule of  claim 1 . 
     
     
         14 . A method for preparing an immunoresponsive cell having tumor specificity and increased resistance to immunosuppression, comprising:
 providing an immunoresponsive cell having tumor specificity; and   introducing into the cell a vector comprising a sequence encoding a shRNA,   wherein the shRNA comprises 15 contiguous nucleotides complementary a nucleic acid sequence of SEQ ID NO: 612.   
     
     
         15 . The method of  claim 14 , wherein the immunoresponsive cell is selected from the group consisting of a tumor-infiltrating lymphocyte (TIL), a Natural Killer T cell (NKT), a cytotoxic T lymphocyte (CTL), and a CD4T cell. 
     
     
         16 . The method of  claim 14 , wherein the immunoresponsive cell expresses a tumor-specific T-cell receptor. 
     
     
         17 . The method of  claim 14 , wherein the immunoresponsive cell comprises a vector encoding a chimeric antigen receptor (CAR), wherein the CAR comprises an antigen binding domain, a transmembrane domain, and a stimulatory domain. 
     
     
         18 . The method of  claim 17 , wherein the CAR is directed to a tumor antigen comprising prostate-specific membrane antigen (PSMA). 
     
     
         19 . The method of  claim 14 , wherein the shRNA sequence reduces expression of Cb1b. 
     
     
         20 . The isolated nucleic acid molecule of  claim 1 , wherein the sequence encoding the shRNA comprises a first sequence comprising 15-25 nucleotides complementary to SEQ ID NO: 612 and a second sequence that is the reverse complement of the first sequence with one or no mismatches, and a third sequence of 5-9 nucleotides positioned between the first and second sequences.