Simultaneous detection of many T-cell specificities using combinatorial tetramer staining.

The direct detection of antigen-specific T cells using tetramers of soluble peptide-major histocompatibilty complex (pMHC) molecules is widely used in both basic and clinical immunology. However, the number of specificities that can be assessed simultaneously has been a major limitation. Here we describe and validate a method using combinations of fluorescent pMHC tetramers to simultaneously detect large numbers (≥ 15) of T cell specificities in a single human blood sample.