Linking T-cell receptor sequence to functional phenotype at the single-cell level

Although each T lymphocyte expresses a T-cell receptor (TCR) that recognizes cognate antigen and controls T-cell activation, different T cells bearing the same TCR can be functionally distinct. Each TCR is a heterodimer, and both alpha- and beta-chains contribute to determining TCR antigen specificity. Here we present a methodology enabling integration of information about TCR specificity with information about T cell function. This method involves sequencing of TCR alpha and TCR beta genes, and amplifying functional genes characteristic of different T cell subsets, in single T cells. Because this approach retains information about individual TCR alpha-TCRb beta pairs, TCRs of interest can be expressed and used in functional studies, for antigen discovery, or in therapeutic applications. We apply this approach to study the clonal ancestry and differentiation of T lymphocytes infiltrating a human colorectal carcinoma.