T-Cell Repertoire Characterization

T-cell repertoire characterization is a methodology that enables the identification of T-cell receptor (TCR) gene sequences in a T-cell population. TCR genes are composed of modular gene segments V (D) J that undergo somatic recombination, resulting in unique and unpredictable sequences that can be utilized to identify each T-cell clone. The analysis of the TCR composition in a T-cell population can give information on the biological phenomenon such as antigen-driven expansion and heterogeneity of T-cell responses. Bulk TCR analysis can give useful information on the clonality and can help track a specific clonotype over time or in different compartments, although the information about pairing cannot be provided. Single-cell TCR sequencing, on the other hand, can provide pairing information that are necessary to reconstruct the TCR and confirm antigen specificity.Here we describe common methods to characterize T-cell repertoires based on both bulk and single-cell next-generation sequencing.