Enhanced affinity t cell receptors and methods for making the same

A method for generating an enhanced affinity T cell receptor (TCR), comprising:

• a. contacting hematopoietic progenitor cells with stromal cells and a peptide antigen, under conditions and for a time sufficient to induce differentiation of hematopoietic progenitor cells into DN TCRαβ+ thymocytes, b. isolating nucleic acid sequences encoding the various TCRβ chains from the DN TCRαβ+ thymocytes and introducing the nucleic acid sequences encoding the TCRβ chains into cells that are capable of expressing a TCR on the cell surface and comprise the nucleic acid sequence encoding the TCRα chain from step (a);
• and
• c. identifying enhanced affinity TCR,
• wherein the hematopoietic progenitor cells comprise a non-endogenous nucleic acid sequence encoding a TCRα chain from a parent TCR specific for the peptide antigen, and
• wherein the stromal cells comprise a non-endogenous nucleic acid sequence encoding Delta-like-1 or Delta-like-4 and a nucleic acid sequence encoding an MHC molecule;