Altered thymic selection in Themis-deficient mice leads to expansion of an unusual virtual memory and bystander-competent CD8+ subpopulation bearing Va3.2 TCR

This study aimed to compare the TCRab repertoires from CD8 T cell subsets in a different T cell progression stage in Themis-sufficient and Themis-deficient mice. Analysis of the NGS-derived data revealed an overall reduction of the TCRa repertoire diversity in Themis's absence. In contrast, the CD8 compartment bearing the Va3.2 TCRs in the Themis-deficient model retains higher diversity than the repertoire from the Themis-sufficient counterpart. Furthermore, analysis of CDR3 peptide sequences of Va3.2+ and Va3.2- TCRs disclose the greater contribution of the hydrophobic residues in the former repertoires, indicating enhanced self-reactivity within this CD8+ T cell fraction. Overall design: Examination of the TCRab repertoires from two mice models: Themis+/+ and :Themis-/-. Each genotype and cell subset is represented by the two data sets derived from two individual mouse.