The development of peptide-MHC class II multimers has provided a novel approach in studying antigen-specific CD4+ T-cells and extended the knowledge of these T cells in various disease settings, including infectious diseases, autoimmune diseases, cancer, and allergies. This chapter discusses the various applications of the peptide-MHC class II multimer technologies, specifically their uses in the evaluation of antigen-specific CD4+ T-cells ex vivo, and their uses in epitope identification.
Keywords: Epitopes; Peptide–MHC class II multimers; Peptide–MHC class II tetramers; T-cell receptor; T-cells.