Compositions and methods for detection and modulation of t cell mediated immune responses against viral vectors utilized for gene therapy

Abstract

Compositions and methods are provided for inhibiting T cell mediated destruction of virally transduced, trangene containing cells.

1 . A soluble T cell receptor (sTCR) which is immunospecific for a peptide sequence present in an adenovirus-associated virus (AAV) in the context of a human MHC Class 1 molecule. 
     
     
         2 . The sTCR of  claim 1 , wherein said adenovirus peptide sequence is obtained from a serotype selected from the group consisting of AAV-1, AAV-2, AAV-5, AAV-8 and other naturally occurring serotypes. 
     
     
         3 . The sTCR of  claim 1 , wherein said human MHC Class I molecule is selected from the group consisting of HLA-A1, HLA-A2, HLA-A3, HLA-B7, HLA-B8, HLA-B15, HLA-B44 and HLA-B51. 
     
     
         4 . A method for detecting the presence a T cell mediated immune response against viral capsid antigen before, during or after administration of an adeno-associated viral vector containing a transgene, comprising:
 a) obtaining a biological sample from a patient, said sample comprising T cells;   b) contacting said cells with a pentamer comprising a peptide epitope of said capsid in context with an MHC Class I molecule; and   c) determining whether the contact of step b) stimulates said cells relative to an untreated control cell, cells being stimulated by said contact having specificity for said peptide epitope of said viral capsid, said cells promoting T cell mediated destruction of capsid and transgene containing cells.   
     
     
         5 . The method of  claim 4 , wherein said biological sample comprises cells selected from the group consisting of transgene containing cells, PBMCs, liver cells, epithelial cells, and muscle cells. 
     
     
         6 . The method of  claim 4  further comprising isolating mRNA from said stimulated cells, preparing cDNA and cloning a soluble T cell receptor immunospecific for said viral capsid antigen. 
     
     
         7 . A soluble T cell receptor prepared by the method of  claim 6 . 
     
     
         8 . A method for inhibiting T cell mediated destruction of virally transduced cells, after administration of an adeno-virus associated vector comprising:
 a) providing an effective amount of a sTCR having specificity for an AAV epitope/MHC complex, said sTCR preventing T cell mediated destruction of said transgene containing cells.   
     
     
         9 . A method for avoiding T cell mediated destruction of virally transduced cells comprising:
 d) detecting specificity for a peptide epitope as claimed in  claim 4  and   e) altering said AAV vector to eliminate the peptide epitope identified in step d) and   f) administering a transgene in said altered AAV vector, said alteration abrogating T cell mediated destruction of said virally transduced cells.   
     
     
         10 . The soluble T cell receptor as claimed in  claim 1 , comprising an epitope of an AAV serotype provided in Table 1. 
     
     
         11 . The method of  claim 9 , wherein said AAV vector is altered to eliminate a AAV peptide set forth in Table 1. 
     
     
         12 . An altered AAV vector prepared by the method of  claim 11 . 
     
     
         13 . The soluble T cell receptor of  claim 1  which is immunospecific for SEQ ID NO: 28.