MHC MULTIMER EXPRESSION CONSTRUCTS AND USES THEREOF

MHC multimer expression constructs are provided that contiguously encode an MHC-binding peptide, MHC molecule chains and a multimerization domain in the construct such that expression in a host cell results in production of peptide-loaded MHC (pMHC) multimers by the host cell. The multimers can further comprise oligonucleotide barcodes. Peptide exchange can be performed with a plurality of pMHC multimers to create pMHC multimer libraries. Methods of making and using the pMHC multimers and libraries are also provided. Peptide-loaded MHC Class I and MHC Class II multimers, and libraries thereof, are provided.