T cell receptors

Abstract

The present invention relates to T cell receptors (TCRs) which bind the HLA-A*0201 restricted peptide GVYDGEEHSV (SEQ ID NO: 1) derived from the MAGE-B2 protein. The TCRs of the invention demonstrate excellent specificity profiles for this MAGE epitope. Also provided are nucleic acids encoding the TCRs, cells engineered to present the TCRs, cells harbouring expression vectors encoding the TCRs and pharmaceutical compositions comprising the TCRs, nucleic acids or cells of the invention.

1 . A T cell receptor (TCR) having the property of binding to GVYDGEEHSV (SEQ ID No: 1) in complex with HLA-A*0201 with a dissociation constant of from about 0.05 μM to about 20.0 μM when measured with surface plasmon resonance at 25° C. and at a pH between 7.1 and 7.5 using a soluble form of the TCR, and has at least a ten-fold selectivity of binding to SEQ ID No:1 in complex with HLA-A*0201 over binding to GVYDGREHTV (SEQ ID No 2) in complex with HLA-A*0201 wherein the TCR comprises a TCR alpha chain variable domain and a TCR beta chain variable domain, and wherein the TCR variable domains form contacts with at least residues V2, Y3 and D4 of GVYDGEEHSV (SEQ ID No: 1). 
     
     
         2 . A TCR according to  claim 1 , which is an alpha-beta heterodimer, having an alpha chain TRAV10+TRAC constant domain sequence and a beta chain TRBV24-1+TRBC-2 constant domain sequence. 
     
     
         3 . A TCR as claimed in  claim 1 , which is in single chain format of the type Vα-L-Vβ, Vβ-L-Vα, Vα-Cα-L-Vβ, or Vα-L-Vβ-Cβ, wherein Vα and Vβ are TCR α and β variable regions respectively, Cα and Cβ are TCR α and β constant regions respectively, and L is a linker sequence. 
     
     
         4 . A TCR as claimed in  claim 1 , which is associated with a detectable label, a therapeutic agent or a PK modifying moiety. 
     
     
         5 . A TCR as claimed in  claim 1 , wherein the alpha chain variable domain comprises an amino acid sequence that has at least 80% identity to the sequence of amino acid residues 1-105 of SEQ ID No: 3 and has the following mutation: 
       
         
           
                 
                 
                 
               
                     
                     
                 
                     
                   CDR2 I3 
                   R 
                 
                     
                     
                 
             
                
               
               
                
                
               
            
           
         
         with reference to the numbering shown in SEQ ID No: 3, and/or the beta chain variable domain comprises an amino acid sequence that has at least 80% identity to the sequence of amino acid residues 1-123 of SEQ ID No: 4 and has at least one of the following mutations: 
       
       
         
           
                 
                 
                 
               
                     
                     
                 
                     
                   CDR1 H3 
                   R 
                 
                     
                   CDR3 N10 
                   E 
                 
                     
                   CDR3 N10 
                   R 
                 
                     
                     
                 
             
                
               
               
                
                
                
                
               
            
           
         
         with reference to the numbering shown in SEQ ID No: 4. 
       
     
     
         6 . A TCR as claimed in  claim 1 , wherein the alpha chain variable domain comprises the amino acid sequence of amino acid residues 1-105 of SEQ ID No: 3 or 5 or 7 or
 an amino acid sequence in which amino acid residues 1-27, 34-47, and 54-90 thereof have at least 90% or 95% identity to the sequence of amino acid residues 1-27, 34-47, and 54-90 respectively of SEQ ID No: 3 or 5 or 7 and in which amino acid residues 28-34, 48-53 and 91-105 have at least 90% or 95% identity to the sequence of amino acid residues 28-33, 48-53 and 91-105 respectively of SEQ ID No 3 or 5 or 7.   
     
     
         7 . A TCR as claimed in  claim 1 , wherein the alpha chain variable domain comprises the amino acid sequence of amino acid residues 1-105 of SEQ ID No: 3 or 7 or an amino acid sequence in which amino acid residues 1-27, 34-47 and 55-89 thereof have at least 90% or 95% identity to the sequence of amino acid residues 1-27, 34-47, and 55-89 respectively of SEQ ID No: 3 or 7 and in which amino acid residues 28-33, 48-53 and 91-105 have at least 90% or 95% identity to the sequence of amino acid residues 28-33, 48-53 and 91-105 respectively of SEQ ID No: 3 or 7. 
     
     
         8 . A TCR as claimed in  claim 1 , wherein in the alpha chain variable domain the sequence of
 (i) amino acid residues 1-27 thereof has (a) at least 90% identity to the sequence of amino acid residues 1-26 of SEQ ID No: 3 or (b) has one, two or three amino acid residues inserted or deleted relative to the sequence of (a);   (ii) amino acid residues 28-33 is VSPFSN;   (iii) amino acid residues 34-47 thereof has (a) at least 90% identity to the sequence of amino acid residues 34-47 of SEQ ID NO: 3 or (b) has one, two or three amino acid residues inserted or deleted relative to the sequence of (a);   (iv) amino acid residues 48-53 is LTIMTF or LTRMTF   (v) amino acid residues 54-90 thereof has at least 90% identity to the sequence of amino acid residues 55-89 of SEQ ID No: 3 or has one, two or three insertions, deletions or substitutions relative thereto;   (vi) amino acids 91-105 is CVVSGGTDSWGKLQF.   
     
     
         9 . A TCR as claimed in  claim 1 , wherein the beta chain variable domain comprises the amino acid sequence of SEQ ID No: 4 or 8-10 or an amino acid sequence in which amino acid residues 1-45, 51-67, and 74-109 thereof have at least 90% or 95% identity to the sequence of amino acid residues 1-45, 51-67, and 74-109 respectively of SEQ ID No: 4 or 8-10 and in which amino acid residues 46-50, 68-73 and 109-123 have at least 90% or 95% identity to the sequence of amino acid residues 46-50, 68-73 and 109-123 respectively of SEQ ID No: 4 or 8-10. 
     
     
         10 . A TCR according to  claim 1 , wherein in the beta chain variable domain the sequence of
 (i) amino acid residues 1-45 thereof has (a) at least 90% identity to the amino acid sequence of residues 1-26 of SEQ ID No: 4 or (b) has one, two or three amino acid residues inserted or deleted relative to the sequence of (a);   (ii) amino acid residues 46-50 is KGHDR or KGRDR   (iii) amino acid residues 51-67 thereof has (a) at least 90% identity to the sequence of amino acid residues 51-67 of SEQ ID NO: 4 or (b) has one, two or three amino acid residues inserted or deleted relative to the sequence of (a);   (iv) amino acid residues 68-73 is SFDVK;   (v) amino acid residues 54-90 thereof has (a) at least 90% identity to the sequence of amino acid residues 54-90 of SEQ ID NO: 4 or (b) has one, two or three amino acid residues inserted or deleted relative to the sequence of (a);   (vi) amino acids 109-123 is CATSGQGAYNEQFF or CATSGQGAYREQFF or CATSGQGAYKEQFF.   
     
     
         11 . A nucleic acid encoding a TCR as claimed in  claim 1 . 
     
     
         12 . An isolated or non-naturally occurring cell, especially a T-cell, presenting a TCR as claimed in  claim 1 . 
     
     
         13 . A cell harboring
 (a) a TCR expression vector which comprises nucleic acid as claimed in  claim 11  in a single open reading frame, or two distinct open reading frames encoding the alpha chain and the beta chain respectively; or   (b) a first expression vector which comprises nucleic acid encoding the alpha chain of a TCR as claimed in  claim 1 , and a second expression vector which comprises nucleic acid encoding the beta chain of a TCR as claimed in  claim 1 .   
     
     
         14 . A pharmaceutical composition comprising the TCR as claimed in  claim 1 , together with one or more pharmaceutically acceptable carriers or excipients. 
     
     
         15 . A method of treating cancer comprising administering the TCR of  claim 1 . 
     
     
         16 . A pharmaceutical composition comprising the nucleic acid as claimed in  claim 11 , together with one or more pharmaceutically acceptable carriers or excipients. 
     
     
         17 . A pharmaceutical composition comprising the cell as claimed in  claim 13 , together with one or more pharmaceutically acceptable carriers or excipients. 
     
     
         18 . A method of treating cancer comprising administering the nucleic acid of  claim 11 . 
     
     
         19 . A method of treating cancer comprising administering the cell of  claim 13 .