Direct measurement of T cell receptor affinity and sequence from naïve antiviral T cells

Abstract

T cells recognize and kill a myriad of pathogen-infected or cancer cells using a diverse set of T cell receptors (TCR). The affinity of TCR to cognate antigen is of high interest in adoptive T cell transfer immunotherapy and antigen-specific T cell repertoire immune profiling because it is widely known to correlate with downstream T cell responses. Here, we introduce the in situ TCR affinity and sequence test (iTAST) for simultaneous measurement of TCR affinity and sequence from single primary CD8+ T cells in human blood. We demonstrate that the repertoire of primary antigen-specific T cells from pathogen inexperienced individuals has a surprisingly broad affinity range of 1000-fold composed of diverse TCR sequences. Within this range, samples from older individuals contained a reduced frequency of high affinity T cells compared to young individuals, demonstrating an age-related effect of T cell attrition that could cause holes in the repertoire. iTAST should enable the rapid selection of high affinity TCRs ex vivo for adoptive immunotherapy and measurement of T cell response for immune monitoring applications.

Low-affinity CD4+ T cells are major responders in the primary immune response

“…3b). TCR affinity ranges of 10-fold or less are characteristic of clonal T-cell populations12283040, while polyclonal populations can possess a 1,000-fold range in affinity941. Of note, mouse number 1 displayed a wider range of TCR affinity that appeared as distinct higher-affinity and lower-affinity populations, suggesting the presence of two clones.…”

The Principles of Engineering Immune Cells to Treat Cancer

“…The TCR is an unusual receptor in that the antigen receptor recognizes peptide and self MHC molecules (Figure 2). An advantage of the TCR is that a vast array of distinct peptides can be recognized (Zhang et al, 2016), including tumor-specific mutations (Schumacher and Schreiber, 2015). Thus, the intracellular proteome of cancer cells may represent the largest set of currently untapped targets for new cancer therapies.…”

TCR-ligand dissociation rate is a robust and stable biomarker of CD8+ T cell potency

“…In that regard, Nauerth and colleagues (67) proposed that small polyclonal virus-specific CD8 + T cell populations could be analyzed directly ex vivo without the need of previous TCR cloning or T cell sorting. The recent implementation of an ex vivo platform allowing for the single-cell serial determination of 2D TCR-pMHC affinity (based on micropipette adhesion frequency) and TCR clonotyping is also highly promising (68). In conclusion, recent technological breakthroughs now enable the rapid development of TCR-pMHC binding kinetics-based simple assays as sensitive and reliable biomarkers of CD8 + T cell activity and clinical efficacy.…”