biostudies-literatureHassler TEuropean Research CouncilDeutsche ForschungsgemeinschaftNIAID NIH HHS18537-18543https://www.ebi.ac.uk/biostudies/studies/S-EPMC6744931biostudies-literatureUnknown116(37)Deletion or T_reg cell differentiation are alternative fates of autoreactive MHCII-restricted thymocytes. How these different modes of tolerance determine the size and composition of polyclonal cohorts of autoreactive T cells with shared specificity is poorly understood. We addressed how tolerance to a naturally expressed autoantigen of the central nervous system shapes the CD4 T cell repertoire. Specific cells in the tolerant peripheral repertoire either were Foxp3⁺ or displayed anergy hallmarks and, surprisingly, were at least as frequent as in the nontolerant repertoire. Despite this apparent lack of deletional tolerance, repertoire inventories uncovered that some T cell receptors (TCRs) were lost from the CD4 T cell pool, whereas others mediated T_reg cell differentiation. The antigen responsiveness of these TCRs supported an affinity model of central tolerance. Importantly, the contribution of different diverter TCRs to the nascent thymic T_reg cell population reflected their antigen reactivity rather than their frequency among precursors. This reveals a multilayered TCR hierarchy in CD4 T cell tolerance that separates deleted and diverted TCRs and assures that the T_reg cell compartment is filled with cells of maximal permissive antigen reactivity.Proceedings of the National Academy of Sciences of the United States of AmericaInventories of naive and tolerant mouse CD4 T cell repertoires reveal a hierarchy of deleted and diverted T cell receptors.PMC6744931SFB 1054P01 AI035296742290ERC-2016-ADG 742290Federle CUrmann EDileepan THinterberger MHassler TTeschner SSchober KBusch DHKlein LJenkins MKfalseInventories of naive and tolerant mouse CD4 T cell repertoires reveal a hierarchy of deleted and diverted T cell receptors.Deletion or T_reg cell differentiation are alternative fates of autoreactive MHCII-restricted thymocytes. How these different modes of tolerance determine the size and composition of polyclonal cohorts of autoreactive T cells with shared specificity is poorly understood. We addressed how tolerance to a naturally expressed autoantigen of the central nervous system shapes the CD4 T cell repertoire. Specific cells in the tolerant peripheral repertoire either were Foxp3⁺ or displayed anergy hallmarks and, surprisingly, were at least as frequent as in the nontolerant repertoire. Despite this apparent lack of deletional tolerance, repertoire inventories uncovered that some T cell receptors (TCRs) were lost from the CD4 T cell pool, whereas others mediated T_reg cell differentiation. The antigen responsiveness of these TCRs supported an affinity model of central tolerance. Importantly, the contribution of different diverter TCRs to the nascent thymic T_reg cell population reflected their antigen reactivity rather than their frequency among precursors. This reveals a multilayered TCR hierarchy in CD4 T cell tolerance that separates deleted and diverted TCRs and assures that the T_reg cell compartment is filled with cells of maximal permissive antigen reactivity.2019-01-01T00:00:00Z2019 Sep2024-02-15T17:17:15.177Z2019-10-11T07:05:30ZS-EPMC67449313145163110.1073/pnas.1907615116