Identification of t cell target antigens

Abstract

The present invention relates to a method of identifying a target antigen of T cells comprising (a) contacting (aa) cells expressing (i) a functional T cell receptor complex comprising predefined matching T cell receptor α and β chains; and (ii) a read-out system for T cell activation; with (ab) antigen-presenting cells carrying (iii) peptide libraries encoded by randomised nucleic acid sequences; and (iv) WIC molecules recognised by the T cell receptor of (i); (b) assessing T cell activation using said read-out system; (c) isolating antigen-presenting cells that are in contact with the cells in which the read-out system indicates T cell activation; (d) identifying the target antigen or the nucleic acid molecule encoding said target antigen.

1 . A peptide library, wherein the peptide library comprises a plurality of vectors comprising nucleic acid sequences encoding peptides, wherein the peptides of the peptide library are encoded by plasmid vectors, wherein the peptides are potential target antigens of T cells and wherein the nucleic acid sequences are randomized nucleic acid sequences. 
     
     
         2 . The peptide library of  claim 1 , wherein the peptides have a length of between 4 to 20 amino acids. 
     
     
         3 . The peptide library of  claim 2 , wherein the peptides have a length of between 8 to 10 amino acids. 
     
     
         4 . The peptide library of  claim 1 , wherein the peptides, as the potential target antigens of T cells bind and are represented by MHC class I molecules. 
     
     
         5 . A method of preparing antigen-presenting cells that express potential target antigens of T cells, comprising transfecting or transforming cells with a peptide library according to  claim 1 . 
     
     
         6 . The method of  claim 5 , wherein the antigen-presenting cells are cells capable of amplifying the peptide libraries. 
     
     
         7 . The method of  claim 6 , wherein the antigen presenting cells are selected from the group consisting of COS-7, HEK, Hela, H9, Jurkat, NIH3T3, C127, COS-1, CV1, QC1-3, mouse L cells, mouse C2C12 cells and Chinese hamster ovary (CHO), Wi-38, MRC-5, insect cells like Sf9, and Hi-5 cells.